A system and method for providing secure communications between remote computing devices and servers. A network device sends characteristics of a client computing device over the network. A network device receives characteristics of a client computing device over the network. A plurality of credentials are generated where at least one of the plurality of credentials based on both the received characteristics of the client computing device and a unique client key, and at least one of the plurality of credentials based on both the received characteristics of the client computing device and a generic key. A network device sends the plurality of credentials over the network. A network device receives the plurality of credentials via the network.

I. Field
The present invention generally relates to secure communications between remote computing devices and servers. More particularly, the invention relates to the creation, maintenance, revocation and renewal of secure client credentials used in providing strong authentication between remote computing devices and servers.
II. Background
Advances in technology have resulted in smaller and more powerful personal computing devices. For example, there currently exist a variety of portable personal computing devices, including wireless computing devices, such as portable wireless telephones, personal digital assistants (PDAs), and paging devices that are each small, lightweight, and can be easily carried by users. More specifically, the portable wireless telephones, for example, further include cellular telephones that communicate voice and data packets over wireless networks. Further, many such cellular telephones are being manufactured with relatively large increases in computing capabilities, and as such, are becoming tantamount to small personal computers and hand-held PDAs. Typically, these smaller and more powerful personal computing devices are severely resource constrained. For example, the screen size, amount of available memory and file system space, amount of input and output capabilities and processing capability may be each limited by the small size of the device. Because of such severe resource constraints, it is often typically desirable, for example, to maintain a limited size and quantity of software applications and other information residing on such personal computing devices (client computing devices).
Some of these personal computing devices utilize application programming interfaces ("APIs"), sometimes referred to as runtime environments and software platforms, that are installed onto their local computer platform and which are used, for example, to simplify operation of such devices, such as by providing generalized calls for device specific resources. Further, some such APIs are also known to provide software developers the ability to create software applications that are fully executable on such devices. In addition, often such APIs are known to be operationally located between the computing device system software and the software applications such that the computing device computing functionality is made available to the software applications without requiring the software developer to have the specific computing device system source code. Further, some like APIs are known to provide mechanisms for secure communications between such personal devices (i.e., clients) and remote devices (i.e., servers) using secure cryptographic key information.
Examples of such an APIs, some of which are discussed in more detail below, include those currently publicly available versions of the Binary Runtime Environment for Wireless® (BREW®) developed by Qualcomm, Inc., of San Diego, Calif. BREW® is sometimes described as a thin veneer existing over a computing device's (typically a wireless cellular phone) operating system, which, among other features, provides interfaces to hardware features particularly found on personal computing devices. BREW® is further characterized by, at least, the one advantage of being able to be provided on such personal computing devices at a relatively low cost with respect to demands on such device resources and with respect to the price paid by consumers for devices containing the BREW® API. Other features known to be associated with BREW® include its end-to-end software distribution platform that provides a variety of benefits for wireless service operators, software developers and computing device consumers. At least one such currently available end-to-end software distribution platform includes logic distributed over a server-client architecture, where the server performs, for example, billing, security and application distribution functionality, and the client performs, for example, application execution, security and user interface functionality.
Regarding providing strong authentication between client computing devices and servers, currently, some systems provide such secure communications by incorporating corresponding cryptographic (encryption) algorithms or programs on the corresponding client computing devices and servers. This is done in order to allow servers to authenticate client devices. Here, such systems typically provide similar cryptographic algorithms on the server to decipher whether a credential received from the apparent corresponding client is from a trusted, authenticated source. Such systems are characterized by the generation of credential-type information based on information all of which is available on, for example, each client computing device. Such systems are known to contain certain vulnerabilities such as the possibility of the loss of secure communications because of unauthorized access to any one of the copies of the cryptographic algorithm as it exists on any one of the corresponding client computing devices. This vulnerability exists, for example, because generally such cryptographic algorithms generate credential information based on available information often maintained on the corresponding client computing devices and/or servers. Therefore, when both the cryptographic algorithm and the data used by such algorithms are freely available, any entity that is successful in deciphering how credentials are generated in any such device, is now also all but in possession of the information that would allow such entity to selectively breach the secure communications otherwise present in such systems and masquerade as an authenticated and valid client computing device.
Other systems that provide secure communications between client computing devices and servers are known to do so by, at least in part, having a secure credential installed on the client computing devices at the time of manufacture. In one example, a service provider provides secure credentials to computing device manufacturers such that the manufacturers can install the individual secure credentials on separate client computing devices during the manufacturing process. Although such systems do not generally suffer from some of the vulnerabilities of those systems described above, e.g., those that maintain cryptographic algorithms on each of the handsets, such credential installation systems do have their own unique problems and vulnerabilities. For example, such credential installation systems are often difficult to implement because of the general requirement of having to add a dynamic step to what otherwise is typically a series of static steps that make up the manufacturing process. More specifically, unlike the typical static step that represents an identical operation performed on each and every computing device, the new dynamic step, in contrast, represents a new step where a different operation is performed (the adding of a unique credential) on each separate client computing device. This is highly unlike the typical static step of, for example, installing an identical display in an identical manner on each and every separate client computing device. In addition, at least one vulnerability of such systems include the potential occurrence of unauthorized access to the list of secure credentials that might allow unauthorized entities to spoof the identity of an otherwise authorized device.
In other systems, secure communication is provided, in part, by the installation or programming of phones by an authorized agent. Typically such programming occurs after the client computing devices have been manufactured and shipped. In one example, a secure credential is installed on the client computing device at the time and place of sale of the device. Here, in at least one example, an authorized agent inputs a code, from a list of unique secure codes, into the client computing device. In other instances, automated readers are used to transfer individual secure codes to each client computing device. Although, this process avoids some of the difficulties associated with programming such client computing devices at the time of manufacture, such as adding a dynamic manufacturing step to a typically static step process, this process still contains its own difficulties and vulnerabilities. For example, one vulnerability is the problem of potential unauthorized access to the list of secure credentials that would allow unauthorized entities to spoof the identity of an otherwise authorized device.
Also generally typical of currently available secure communication systems is the hard-wired or hard-coded aspect of the use of credentials on corresponding client devices. This hard-wired/hard-coded aspect of such systems requires that client devices be physically serviced by a service technician whenever a situation, such as a security breach, has occurred where, for example, any one or more credentials, need to be replaced, added to, and/or otherwise updated. Such a requirement to be physically serviced by a service technician is extremely costly, particularly when large numbers of client devices are compromised.
Accordingly it would be advantageous to provide a client-server system that includes many of the secure communication advantages inherent in general secure communications techniques, such as those associated with the use of secure credentials, while also avoiding other less advantageous aspects of such existing systems, such as the problems associated with storing cryptographic algorithms on client computing devices, requiring the installation of secure credentials at the time of manufacture or the programming of secure credentials at point of sale locations and the ability to update or replace these credentials in the event of a security breach.

System and method for providing a multi-credential authentication protocol


A predicted corrosion amount of a painted or unpainted atmospheric corrosion resistant steel is calculated by using extrinsic corrosion information including weather observation data, an amount of airborne salt, and an amount of sulfur oxide in a planned location for use where the atmospheric corrosion resistant steel is to be used, and intrinsic corrosion information on components of the atmospheric corrosion resistant steel. The weather observation data on this occasion preferably includes the annual wetness time, annual mean wind speed, and annual mean temperature. Moreover, it is preferable to calculate a corrosivity index, estimate a first-year corrosion amount of the atmospheric corrosion resistant steel and a rust stabilization index from the corrosivity index, and calculate a corrosion amount accumulated over time.

Atmospheric corrosion resistant steels have been applied to many actual structures including bridges because of its unique property of preventing rust by rust. There are many cases where a reduction in maintenance management costs is attained by using this steel material with its functions utilized to the full. On the other hand, a problem sometimes arises when the atmospheric corrosion resistant steel is carelessly used in coastal regions and the like where there is a lot of airborne salt. In recent years, in inland regions as well, local formation of abnormal rust due to the spraying of thawing salt is sometimes found.
As is represented by the minimum maintenance bridge concept proposed by the Ministry of Land, Infrastructure and Transport of Japan, future structures including bridges are requested to employ atmospheric corrosion resistant steels, surface treatment technology, structural design methods, and the like which can be actually used reliably for a very long period while achieving a further reduction in maintenance and management costs. Therefore, as a form of 21st century type infrastructure which maintains and develops cost-competitiveness with Asian countries as our country as a whole, rust science study and application technology development related to the atmospheric corrosion resistant steel capable of realizing Life Cycle Cost ("LCC") minimum are greatly expected.
Against this background, in the Japan Society of Corrosion Engineering, the Rust Science Workshop which supports 21st century infrastructure was organized for four years from 1997. Many specialists enthusiastically discussed the concept of "stable rust" heretofore very confused as basic understanding to use atmospheric corrosion resistant steels more securely and safely.
As a result, the following suggestion has been issued as the opinion of the Society in the 132nd Corrosion Engineering Symposium sponsored by the Japan Society of Corrosion Engineering held on Jun. 25, 2001 (Japan Society of Corrosion Engineering, Rust Science Workshop: Reference materials for the 132nd Corrosion Engineering Symposium "New Development of Rust Science to Realize Minimum Maintenance Bridge Concept", p 3, Jun. 25, 2001).
"Rust stabilization" of the atmospheric corrosion resistant steel means a state in which the corrosion rate has reduced to the extent that the secular deterioration of the load carrying capacity of a structure is insignificant from an engineering viewpoint (0.01 mm/year or less as a standard).
As provisional interpretation: the stable rust is rust formed when rust on the atmospheric corrosion resistant steel is "stabilized". However, although the aforementioned state is defined as "rust stabilization", since the term of stable rust has a strong physical image, it is desirable to withhold the scientific use of this term. As an alternative material term, the term of protective rust is used for rust having a high protective function.
Rust when "stabilized" is characterized in that although a sufficient period (e.g., five years or more) has elapsed, the rust does not grow thick (except a case where traces of exfoliated rust are left).
One of the important messages in this suggestion is the definition of "rust stabilazation" of the atmospheric corrosion resistant steel. Namely, when the industrial material called an atmospheric corrosion resistant steel is used for a structure, the realization of "a rust stabilization state" in which the load carrying capacity of the structure using this material can exist stably over a long period is recognized anew as a higher objective concept than other various arguments about what the matter called stable rust is. Moreover, the development of the technology of predicting the accumulated amount of corrosion of the atmospheric corrosion resistant steel over a long period of time is suggested as one of the most important items in material selection, structural design, and maintenance/management.
Conventionally, among methods for predicting an accumulated corrosion amount of an atmospheric corrosion resistant steel over a long period of time which are generally performed, there is a method of performing an exposure test over a period of approximately ten years in a construction site or under atmospheric environmental conditions similar to those of the construction site, finding a value A and a value B by fitting a secular change of a corrosion loss obtained in this period to a relational expression of (amount of corrosion)=A×(exposure period)B, and calculating a corrosion loss over any given long period of time with these values (see, for example, Public Works Research Institute of the Ministry of Construction, the Kozai Club, Japan Association of Steel Bridge Construction: Collaborative Research Report on Application of Atmospheric corrosion resistant steel to Bridges (XII), p 20, March, 1992).
However, in this predicting method, the exposure test in actual atmospheric environment over a period of approximately ten years is necessary to obtain constant terms, the value A and the value B, and funds, labor, and time are needed before a judgment is made. Hence, a problem that the market competitiveness of a technical business method adopted at present of the atmospheric corrosion resistant steel is weaker than that of concrete structures and the like which compete with the atmospheric corrosion resistant steel is indicated.
As for a flow concerning judgment on the applicability of the atmospheric corrosion resistant steel, flows such as shown in FIG. 1 to FIG. 4 are disclosed in Japanese Patent Laid-open No. 2000-1816 and so on. However, in each flow, only factors which contribute to the amount of corrosion in the usage environment are substantially arranged, and no quantitative criterion for judging the propriety of use of a steel type to be applied based on a predicted corrosion amount in an adaptive environment is proposed or disclosed. Namely, these flows are not effective solutions for a demand for a more quantitative judgment method based on the predicted corrosion amount. Moreover, these flows have a problem that the amount of sulfur oxide and the annual wetness time which are important parameters for the prediction of the corrosion amount are not considered at all.
In the conventional method for predicting long-term corrosion/wear of the atmospheric corrosion resistant steel, exposure test data in the construction site or exposure test data in an atmospheric environment similar to the construction site are indispensable, and to obtain the data, high expenses of test/analysis are needed. Further, regions where unpainted atmospheric corrosion resistant steels are used for road bridges in our country are limited to regions where the amount of airborne salt is 0.05 mdd or less (mdd is a brevity code of mg/dm2day), but in some cases, abnormality does not occur to the atmospheric corrosion resistant steel even under the environmental condition of an airborne salt amount of 0.05 mdd or more. Therefore, there are some cases where an opportunity to reduce the maintenance cost is missed because the applicability is judged only with a single index. Furthermore, when the atmospheric corrosion resistant steel is used beyond the limit of application without sufficient prediction of corrosion/wear behavior, partial abnormal corrosion occurs, which causes unexpected repairing expenses.
As described above, no solution which associates corrosivity of environmental condition with rust stabilization performance of the atmospheric corrosion resistant steel exists, and hence it is said that the application of the atmospheric corrosion resistant steel entails high risks and high returns.

Method for predicting degree of corrosion of weather-resistant steel


An epoxy resin molding material for sealing which comprises an epoxy resin, an epoxy resin curing agent, and a pitch, as well as an electronic component comprising an element that is sealed with the molding material. This molding material exhibits favorable coloring properties, and even when used in packages with narrow distances between pads or wires, shorting defects caused by conductive materials can be prevented, as the molding material contains no conductive carbon black.

Conventionally, in the field of element sealing for electronic components such as transistors and ICs, resin sealing is commonly used for reasons of productivity and cost and the like, and epoxy resin molding materials are widely used. The reason for this widespread use is that epoxy resins are able to offer a favorable balance across many characteristics, including the electrical properties, moisture resistance, heat resistance, mechanical properties, and adhesion to inserts.
In recent years, as the packaging of electronic components on printed wiring boards has increased in density, the most common configuration for these electronic components is changing from conventional pin insertion-type packages to surface mounted packages. In order to increase the packaging density and lower the mounting height, surface mounted ICs and LSIs and the like have become thinner and smaller, the occupied volume of the elements relative to the package has increased, and the thickness of the package has become extremely small.
In order to cope with a shift towards even smaller and lighter packages, the package configuration is also changing from packages known as QFP (Quad Flat Package) and SOP (Small Outline Package) to area-mounted packages such as BGA (Ball Grid Array) that include CSP (Chip Size Package) which are more readily able to cope with increased numbers of pins, and enable even higher density packaging. Recently, in order to realize increased speed and multi-functionality, packages with new structures are being developed, including face down packages, stacked packages, flip-chip packages, and wafer level packages. Many of these packages have a single side sealing-type package structure, wherein only the surface on the side to which the elements are mounted is sealed with a sealing material such as an epoxy resin molding material, and solder balls are then formed on the rear surface to join the package to a circuit board.
As these types of packages are reduced in size and the number of pins is increased, the pitch distances between inner leads, pads, and wires and the like are narrowing at a rapid rate. As a result, the fact that carbon black, which has conventionally been used as a colorant, has an inherent conductivity has led to a problem in that aggregates of carbon black can become lodged between inner leads, pads, and wires, causing electrical defects.
Accordingly, methods in which organic dyes, organic pigments, and inorganic pigments are used instead of carbon black have been investigated (see Japanese Patent Laid-Open No. Sho 60-119760, Japanese Patent Laid-Open No. Sho 63-179921, Japanese Patent Laid-Open No. Hei 11-60904, and Japanese Patent Laid-Open No. 2003-160713).
However, these methods suffer various problems, including a deterioration in the coloring properties, a deterioration in curability, and increased costs, and have been unable to achieve a satisfactory level of performance.

Epoxy resin molding material for sealing and electronic component


The present invention provides a crystalline form of HPPH (2-((1′-n-hexyloxy)ethyl)-2-divinyl-pyropheophorbide-a):

2-((1′-n-hexyloxy)ethyl)-2-divinyl-pyropheophorbide-a (HPPH) is a derivative of pyropheophorbide-n-hexylether, which has been developed by the Roswell Park Cancer Institute. HPPH has strong absorption at 650 nm. In addition, it has a high singlet oxygen quantum yield. As a result, it is considered that the photosensitizer which has the highest efficiency and the brightest future of development. Its structural formula is as follows:

In the photodynamic therapy experiment carried out in 5 esophageal cancer patients, at a very low dose, HPPH has exhibited a very good photodynamic therapeutic efficacy. In addition, no photosensitive side effect of skin has been observed clinically.
The research group of Dr. Pandey who was working at the Roswell Park Cancer Institute reported a method for synthesizing HPPH (U.S. Pat. No. 5,198,460; US20040044198A1; Photochemistry and Photobiology, 1991, 53 (1), 65 to 72; Organic Process Research & Development, 2004, 8, 287 to 290). Up to date, in all of the reports about HPPH, there has been no mention of its crystalline form. However, crystalline form may significantly affect a drug's stability, solubility and bioavailability. In this regard, our research group has studied the preparation method of the crystalline form of HPPH. Moreover, we have obtained a crystalline form of HPPH.

Crystalline form of 2-((1′-n-hexyloxy) ethyl)-2-divinyl-pyropheophorbide-a and method for preparing thereof

Abstract: The crystalline form can be characterized by an X-ray powder diffraction (XRD) pattern and differential scanning calorimeter (DSC) pattern. The present invention also provides a method for preparing the crystalline form of HPPH.


The present disclosure discloses a word vector retrofitting method. The method includes obtaining, by a computing device, a first model and a second model that are generated when original word vectors are trained, the first model being configured to predict a context according to an inputted word, and the second model being configured to predict a target word according to a context; inputting a corpus unit from a target corpus into the first model, inputting an output of the first model into the second model, and determining losses generated by the first model and the second model when the second model outputs the corpus unit; and retrofitting the first model and the second model according to the losses.

With continuous development of computer application technologies, natural language processing is increasingly widely used. The requirements of various applications, such as applications using machine translation, speech recognition, and information retrieval, pose increasingly high demands on natural language processing capabilities of computers.
At present, when a natural language task is processed, a distributed representation is a commonly used text representation method. In this method, all words in natural language are mapped into fixed-length vectors through training, and all the vectors are placed together to form a word vector space. Each vector is a point in the space, and then the word vector is directly used to replace the word to represent text, thereby transforming the understanding of natural language into a mathematical problem of machine learning.
To obtain word vectors that can be used for subsequent machine processing based on natural language training, a variety of training models that focus on different processing scenarios have been provided in the related art, such as a context-to-word Continuous Bag-of-words, (CB) model that is more suitable for text classification, and a word-to-context skip-gram (SG) model that is more suitable for sequence labeling. However, none of the models supports incremental training. Once the word vectors obtained through training need to be adjusted, it is often necessary to reconstruct a large-scale corpus and train the word vectors from scratch, resulting in additional computational burden.
In addition to training of word vectors, retrofitting of word vectors is also a key technology to effectively improve the performance of word vectors. A common word vector retrofitting process is usually directed to given word vectors that are pre-trained, where the word vectors are adjusted under the guide of manually labeled or automatically extracted word-to-word relationships, thereby upgrading original low-quality word vectors to high-quality word vectors. However, such a retrofitting method is only suitable for a small quantity of words, and is useless for words without labeled data.
The existing word vector training models and retrofitting methods cannot improve quality of word vectors by directly using any external information, nor resolve the domain migration problem of adjusting old word vectors for use in a new usage environment.

Word vector retrofitting method and apparatus

TENCENT TECHNOLOGY (SHENZHEN) COMPANY LIMITED


A system, in a programmable active reflector (AR) device associated with a first radio frequency (RF) device and a second RF device, receives a request and associated metadata from the second RF device via a first antenna array. Based on the received request and associated metadata, one or more antenna control signals are received from the first RF device. The programmable AR device is dynamically selected and controlled by the first RF device based on a set of criteria. A controlled plurality of RF signals is transmitted, via a second antenna array, to the second RF device within a transmission range of the programmable AR device based on the associated metadata. The controlled plurality of RF signals are cancelled at the second RF device based on the associated metadata.

Typically, in an RF device network, radio transmitter devices (for example, mobile base stations and television/radio broadcast stations) broadcast RF energy in form of beams of RF signals to a variety of RF receiver devices. Such beams of RF signals may reach the receiving antenna via multiple paths. As a result, such beams of RF signals may constructively or destructively interfere with each other at the receiving antenna. Constructive interference occurs when the beams of RF signals are in phase, and destructive interference occurs when the beams of RF signals are half a cycle out of phase. For the latter case, there is required a robust and advanced system in an RF device network by which the beams of RF signals are intelligently controlled for signal cancellation in such RF device network.
Further limitations and disadvantages of conventional and traditional approaches will become apparent to one of skill in the art, through comparison of such systems with some aspects of the present disclosure as set forth in the remainder of the present application with reference to the drawings.

Signal cancellation in radio frequency (RF) device network


A decoder includes a first bank and a second bank. The first bank is supplied with dynamic control from a microcomputer via a data bus, and the second bank is supplied with static control data from the data bus via the data bus. The dynamic control data or the static control data is read from an address in the bank designated by an address signal. The dynamic control data read from the first bank and second bank is transferred to one of a plurality of registers designated by the address signal.

Various types of image display devices, such as television receivers or monitoring devices, are commonly used. In the image display device, the contrast, luminance, and the like of an image are initialized when the power is applied thereto. Further, the contrast, luminance, and the like of the image can be set by a user's operation.
In recent years, image display devices which automatically control the contrast, luminance and the like of the image displayed on the screen based on a changing video signal have been developed (refer to, for example, JP 5-127608 A).
In the image display device, the contrast, luminance, and the like are set or controlled by the transfer of control data to a control device for carrying out control operations.
However, the enhancement of the image display performance of the image display device results in an increased amount of control data to be transferred to the control device. The control data is transferred to various signal process means via a storage device; but, increased control data have been conventionally stored in a disorder manner, resulting in a wasteful amount of time for the input/output of control data. This develops a delay in response for operations of controlling the contrast, luminance, and the like unless the control data is efficiently transferred.

Display controller, image display and method for transferring control data

Matsushita Electric Industrial Co., Ltd.


A cost-effective conditioning circuit for extracting a weak, floating, wide-band signal with a low common-mode voltage from noisy environments is proposed that includes a high gain single ended operational amplifier to increase the amplitude of the signal. A simple, cost-effective approximately unity gain differential amplifier stage is used to level-shift the signal down to the desired reference potential. A typical application is a motor drive system, where the signals to be measured are bi-directional motor currents.

Feedback control is an important technique for obtaining high quality servo responses. To monitor system operation, sensors are used to observe the desired signals, which could be temperature, torque, speed, current, voltage, etc. An ideal sensor, accompanied with a related signal conditioning circuit, should have the following characteristics:
(a) cost-effective; PA1 (b) compact size and flexible packaging capability; PA1 (c) accuracy over a temperature range from -40.degree. to +125.degree. C. with high bandwidth; PA1 (d) high common-mode rejection capability; PA1 (e) a ground referenced output for the controller stage; PA1 (f) minimum offset error; and PA1 (e) minimum power consumption. PA1 2. Reduce G.sub.ideal. However, this parameter is dictated by how small the input signal is and how big an output amplitude is desired. PA1 3. Reduce the common-mode voltage. However, this is mainly decided by the structure and operation of the system. PA1 4. Select precision amplifier to reduce V.sub.OS and I.sub.OS. However, this will normally increases the cost significantly.
Unfortunately, most sensors cannot satisfy all of these requirements, and most sensors (e.g., thermal couples) inherently output very low amplitude signals. In addition, due to the existence of wideband, common-mode noise in the harsh automotive environment, the sensor signals are distorted. To deal with these situations, sensors with inherent electrical isolation (e.g., hall effect sensors for electric current measurement) or extra isolation amplifier stages are inserted to reject common-mode noise. However, high cost and wide operating temperature range, cause these techniques to often be unacceptable for automotive applications.
To measure a floating signal with wide bandwidth, a few well-known techniques have been used in the past. For example, if the common-mode voltage is within a few volts and the desired signal is large, a high quality differential amplifier stage, such as shown in FIG. 1 has been used that includes a high performance operational amplifier 10 and a networks of matched resistor 12-22. The ideal output of this circuit can be expressed by the following equation: EQU Assume R.sub.12 =R.sub.14, R.sub.16 =R.sub.18, and R.sub.20 =R.sub.22,
then EQU (V.sub.out).sub.ideal =G.sub.ideal V.sub.sig ( 1)
where ##EQU1## In FIG. 1, V.sub.bias is an optional bias source to shift the amplifier input voltages to desired ranges, and R.sub.20, R.sub.22 form an optional resistor network for attenuating the common-mode input voltage. For example, if the common-mode voltage V.sub.cm is hundreds of Volts, attenuation is necessary to reduce the amplifier terminal voltages to the typical .+-.10 Volts range.
If the resistors and the operational amplifier are not perfect, the actual output voltage in the worst case can be approximated by: ##EQU2## where ERROR=4 (%R) (G.sub.ideal V.sub.cm +G.sub.2 V.sub.bias)+G.sub.3 (V.sub.OS +I.sub.OS R.sub.eq);
(%R) is the tolerance of resistors;
V.sub.OS is the offset voltage of the operational amplifier;
I.sub.OS is the offset current of the operational amplifier;
R.sub.eq =R.sub.12 //R.sub.14 //R.sub.20 =equivalent parallel resistance of these three resistors,
and ##EQU3## This equation also shows how the output error may be reduced: 1. Use precision, matched resistors (or resistor networks). However, resistors with tolerance better than 1% are expensive. An alternative way is to sort out 1% resistors to get matched resistor pairs to approach 0.2% or even o.1% accuracy. Better accuracy beyond this is difficult without excessive cost penalty.
The following typical numbers will provide a better understanding of which parameter(s) dominate(s) the output error:
(%R)=0.1% (0.001)
V.sub.OS =2 mV
I.sub.OS =100 nA
R.sub.eq =10 K.OMEGA.
and assume
V.sub.cm =10 V, V.sub.bias =0 V
and
G.sub.ideal =10, G.sub.2 =0, G.sub.3 =11
then, the error output voltage is:
______________________________________ ERROR = 4 (%R) (G.sub.ideal V.sub.com + G.sub.2 V.sub.bias) + G.sub.3 (V.sub.os +I.sub.ox R.sub.eq) = 0.004 (10*10V + 0) + 11 (2mV + 100nA*10K), = 0.004*100V + 11 * 3mV = 0.43V ______________________________________
This result shows that the common mode voltage and the tolerance of resistors are the major error contributors. If the common-mode voltage cannot be reduced, the only choice is to increase the accuracy of resistors. Unfortunately, this becomes impractical when the common-mode voltage is too high or the error tolerance is too tight. Under this situation, isolation amplifiers are normally chosen to achieve good performance, and various schemes are currently available for this purpose in the market. They are transformer-coupled isolation amplifiers, Sigma-delta modulation opto iso-amps and capacitively coupled iso-amps.
Transformer-coupled isolation amplifiers provide very good galvanic isolation, very high signal gain and reasonable offset, but the frequency bandwidth is limited to a few Khz, and the cost is high compared to other products.
One of the main limitations of the opto isoamps is the operating temperature range. The other limitation is the output common-mode voltage range which will be further amplified if the output requires amplification to meet the controller requirements. This would require calibration of every unit and would be expensive. Also, this approach requires 5 V power supplies and regulators since the automotive battery voltage is typically 12 volts. All of these requirements increase cost. Opto iso-amps also have built in propagation delays that may present a problem for very high frequency operation.
One of the limitations of the capacitively coupled isolation amplifiers is the ripple voltage at the carrier frequency that is amplified by the post amplifier circuits. Also, capacitively coupled systems do not have high input to output common mode transient rejection.
Some sensors are inherently isolated, but have limitations that prevent high performance or operation in harsh applications. For example, both current transformers (CTs) and hall-effect current sensors have no conductive connection to the measured circuit. However, the CTs cannot measure dc currents, and the hall sensors are normally bulky, cannot work in the extended automotive temperature range, and are not very effective in small current measurement. Also, both sensors introduce additional stray inductance to the measured circuits.

Signal conditioning circuit for low amplitude, high common mode voltage input signals


A method and apparatus for controlling the brightness of an image processing device to improve a brightness characteristic of an image signal, by reducing a pedestal voltage range and correspondingly expanding a brightness control voltage range in a highlight mode. The brightness control method includes the operations of determining whether a highlight mode is enabled; and if the highlight mode is enabled, reducing a pedestal voltage range by a first predetermined value and expanding a brightness control voltage range by a second predetermined value. The pedestal driving voltage and the brightness control voltage can be reciprocally controlled without modifications to a circuit having limited amplification, and the brightness can be improved without saturating an image in a highlight mode.

1. Field of the Invention
The present invention relates to a method and apparatus that processes image signals, and more particularly, to a method and apparatus that controls brightness of an image processing device to improve brightness characteristics of image signals in a highlight mode.
2. Description of the Related Art
Generally, a device that processes image signals, such as a display device, enhances the brightness of an image by processing an input image signal via a highlight circuit. An image signal passed through the highlight circuit is amplified by pre-amplifier and main amplifier circuits and applied to, e.g., a cathode ray tube that produces light beams corresponding to the image signals. The brightness of the image displayed on a screen of the display device is determined on the basis of amplitude of the image signals. However, since amplification of the image signals is limited to a certain extent due to characteristics of circuit elements of the pre-amplifier and main amplifier circuits, it is occasionally impossible to display an image as brightly as a user wishes. Particularly, in a highlight mode enhancing the brightness of an image, image signals are likely to be saturated if the pre-amplifier and main amplifier circuits are not capable of sufficiently amplifying the image signals. If the image signals are saturated, the quality of the image is deteriorated.

Method and apparatus for controlling brightness of image processing device


The present invention relates to antagonists of neuropilin receptor fuction and use thereof in the treatment of cancer, particularly metastatic cancer, and angiogenic diseases.

Cancer, its development and treatment is a major health concern. The standard treatments available are few and directed to specific types of cancer, and provide no absolute guarantee of success. Most treatments rely on an approach that involves killing off rapidly growing cells in the hope that rapidly growing cancerous cells will succumb, either to the treatment, or at least be sufficiently reduced in numbers to allow the body's system to eliminate the remainder. However most, of these treatments are non-specific to cancer cells and adversely effect non-malignant cells. Many cancers although having some phenotype relationship are quite diverse. Yet, what treatment works most effectively for one cancer may not be the best means for treating another cancer. Consequently, an appreciation of the severity of the condition must be made before beginning many therapies. In order to most effective, these treatments require not only an early detection of the malignancy, but an appreciation of the severity of the malignancy. Currently, it can be difficult to distinguish cells at a molecular level as it relates to effect on treatment. Thus, methods of being able to screen malignant cells and better understand their disease state are desirable.
While different forms of cancer have different properties, one factor which many cancers share is that they can metastasize. Until such time as metastasis occurs, a tumor, although it may be malignant, is confined to one area of the body. This may cause discomfort and/or pain, or even lead to more serious problems including death, but if it can be located, it may be surgically removed and, if done with adequate care, be treatable. However, once metastasis sets in, cancerous cells have invaded the body and while surgical resection may remove the parent tumor, this does not address other tumors. Only chemotherapy, or some particular form of targeting therapy, then stands any chance of success.
The process of tumor metastasis is a multistage event involving local invasion and destruction of intercellular matrix, intravasation into blood vessels, lymphatics or other channels of transport, survival in the circulation, extravasation out of the vessels in the secondary site and growth in the new location (Fidler, et al., Adv. Cancer Res. 28, 149-250 (1978), Liotta, et al., Cancer Treatment Res. 40, 223-238 (1988), Nicolson, Biochim. Biophy. Acta 948, 175-224 (1988) and Zetter, N. Eng. J Med. 322, 605-612 (1990)). Success in establishing metastatic deposits requires tumor cells to be able to accomplish these steps sequentially. Common to many steps of the metastatic process is a requirement for motility. The enhanced movement of malignant tumor cells is a major contributor to the progression of the disease toward metastasis. Increased cell motility has been associated with enhanced metastatic potential in animal as well as human tumors (Hosaka, et al., Gann 69, 273-276 (1978) and Haemmerlin, et al., Int. J Cancer 27, 603-610 (1981)).
Identifying factors that are associated with onset of tumor metastasis is extremely important. In addition, to using such factors for diagnosis and prognosis, those factors are an important site for identifying new compounds that can be used for treatment and as a target for treatment identifying new modes of treatment such as inhibition of metastasis is highly desirable.
Tumor angiogenesis is essential for both primary tumor expansion and metastatic tumor spread, and angiogenesis itself requires ECM degradation (Blood et al., Biochim. Biophys. Acta 1032:89-118 (1990)). Thus, malignancy is a systemic disease in which interactions between the neoplastic cells and their environment play a crucial role during evolution of the pathological process (Fidler, I. J, Cancer Metastasis Rev. 5:29-49 (1986)).
There is mounting evidence that VEGF may be a major regulator of angiogenesis (reviewed in Ferrara, et al., Endocr. Rev., 13, 18-32 (1992); Klagsbrun, et al., Curr. Biol., 3, 699-702 (1993); Ferrara, et al., Biochem. Biophjs. Res. Commun., 161, 851-858 (1989) ). VEGF was initially purified from the conditioned media of folliculostellate cells (Ferrara, et al., Biochem. Biophjs. Res. Commun., 161, 851-858 (1989)) and from a variety of tumor cell lines (Myoken, et al., Proc. Natl. Acad. Sci. USA, 88:5819-5823 (1991); Plouet, et al., EMBO. J., 8:3801-3806 (1991)). VEGF was found to be identical to vascular permeability factor, a regulator of blood vessel permeability that was purified from the conditioned medium of U937 cells at the same time (Keck, et al., Science, 246:1309-1312 (1989)). VEGF is a specific mitogen for endothelial cells (EC) in vitro and a potent angiogenic factor in vivo. The expression of VEGF is up-regulated in tissue undergoing vascularization during embryogenesis and the female reproductive cycle (Brier, et al., Development, 114:521-532 (1992); Shweiki, et al., J. Clin. Invest., 91:2235-2243 (1993)). High levels of VEGF are expressed in various types of tumors, but not in normal tissue, in response to tumor-induced hypoxia (Shweiki, et al., Nature 359:843-846 (1992); Dvorak et al., J. Exp. Med., 174:1275-1278 (1991); Plate, et al., Cancer Res., 53:5822-5827; Ikea, et al., J Biol. Chem., 270:19761-19766 (1986)). Treatment of tumors with monoclonal antibodies directed against VEGF resulted in a dramatic reduction in tumor mass due to the suppression of tumor angiogeneis (Kim, et al., Nature, 382:841-844 (1993)). VEGF appears to play a principle role in many pathological states and processes related to neovascularization. Regulation of VEGF expression in affected tissues could therefore be key in treatment or prevention of VEGF induced neovascularization/angiogenesis.
VEGF exists in a number of different isoforms that are produced by alternative splicing from a single gene containing eight exons (Ferrara, et al., Endocr. Rev., 13:18-32 (1992); Tischer, et al., J. Biol. Chem., 806:11947-11954 (1991); Ferrara, et al., Trends Cardio Med., 3:244-250 (1993); Polterak, et al., J. Biol. Chem., 272:7151-7158 (1997)). Human VEGF isoforms consists of monomers of 121, 145, 165, 189, and 206 amino acids, each capable of making an active homodimer (Polterak et at., J Biol. Chem, 272:7151-7158 (1997); Houck, et al., Mol Endocrinol., 8:1806-1814 (1991)). The VEGF121 and VEGF165 isoforms are the most abundant. VEGF121 is the only VEGF isoforms that does not bind to heparin and is totally secreted into the culture medium. VEGF165 is functionally different than VEGF121 in that it binds to heparin and cell surface heparin sulfate proteoglycans (HSPGs) and is only partially released into the culture medium (Houck, et al., J Biol. Chem., 247:28031-28037 (1992); Park, et al., Mol. Biol. Chem., 4:1317-1326 (1993)). The remaining isoforms are entirely associated with cell surface and extracellular matrix HSPGs (Houck, et al., J Biol. Chem., 247:28031-28037 (1992); Park, et al., Mol. Biol. Chem., 4:1317-1326 (1993)).
VEGF receptor tyrosine kinases, KDR/Flk-1 and/or Flt-1, are mostly expressed by EC (Terman, et al., Biochem. Biophys. Res. Commun., 187:1579-1586 (1992); Shibuya, et al., Oncogene, 5:519-524 (1990); De Vries, et al., Science, 265:989-991 (1992); Gitay-Goran, et al., J Biol. Chem., 287:6003-6096 (1992); Jakeman, et al., J Clin. Invest., 89:244-253 (1992)). It appears that VEGF activities such as mitogenicity, chemotaxis, and induction of morphological changes are mediated by KDR/Flk-1 but not Flt-1, even though both receptors undergo phosphorylation upon binding of VEGF (Millauer, et al., Cell, 72:835-846 (1993); Waltenberger, et al., J Biol. Chem., 269:26988-26995 (1994); Seetharam, et al., Oncogene, 10:135-147 (1995); Yoshida, et al., Growth Factors, 7:131-138 (1996)). Recently, Soker et al., identified a new VEGF receptor which is expressed on EC and various tumor-derived cell lines such as breast cancer-derived MDA-MB-231 (231) cells (Soker, et al., J. Biol Chem., 271:5761-5767 (1996)). This receptor requires the VEGF isoform to contain the portion encoded by exon 7. For example, although both VEGF121 and VEGF165R bind to KDR/Flk-1 and Flt-1, only VEGF165 binds to the new receptor. Thus, this is an isoform-specific receptor and has been named the VEGF165 receptor (VEGF165R). It will also bind the 189 and 206 isoforms. VEGF165R has a molecular mass of approximately 130 kDa, and it binds VEGF165 with a Kd of about 2×10−10M, compared with approximately 5×10−12M for KDR/Flk-1. In structure-function analysis, it was shown directly that VEGF165 binds to VEGF165R via its exon 7-encoded domain which is absent in VEGF121 (Soker, et al., J Biol. Chem., 271:5761-5767 (1996)). However, the function of the receptor was unclear.
Identifying the alterations in gene expression which are associated with malignant tumors, including those involved in tumor progression and angiogenesis, is clearly a prerequisite not only for a full understanding of cancer, but also to develop new rational therapies against cancer.
A further problem arises, in that the genes characteristic of cancerous cells are very often host genes being abnormally expressed. It is quite often the case that a particular protein marker for a given cancer while expressed in high levels in connection with that cancer is also expressed elsewhere throughout the body, albeit at reduced levels.
The current treatment of angiogenic diseases is inadequate. Agents which prevent continued angiogenesis, e.g, drugs (TNP-470), monoclonal antibodies, antisense nucleic acids and proteins (angiostatin and endostatin) are currently being tested. See, Battegay, J Mol. Med., 73, 333-346 (1995); Hanahan et al., Cell, 86, 353-364 (1996); Folkman, N. Engl. J Med., 333, 1757-1763 (1995). Although preliminary results with the antiangiogenic proteins are promising, there is still a need for identifying genes encoding ligands and receptors involved in angiogenesis for the development of new antiangiogenic therapies.

This patent is subject to a terminal disclaimer.

Antagonists of neuropilin receptor function and use thereof


A stack type semiconductor apparatus package includes: (i) a first circuit substrate, (ii) a semiconductor apparatus package mounted on the first circuit substrate, (iii) a semiconductor apparatus, and (iv) a sealing resin for covering them. The first circuit substrate has a surface on which first connecting pads and second connecting pads are provided. The first connecting pads are connected to first external input/output terminals of the semiconductor apparatus package, and the second connecting pads are connected to electrodes of the first semiconductor apparatus, respectively. On a rear surface of the first circuit substrate, there are provided second external input/output terminals connected to the first connecting pads and the second connecting pads. The semiconductor apparatus package includes: a second circuit substrate, and a second semiconductor apparatus mounted on the second circuit substrate. On a surface of the second circuit substrate, there are provided third connecting pads connected to electrodes of the second semiconductor apparatus, respectively. The first external input/output terminals are provided on a rear surface of the second circuit substrate. This makes it possible to provide a stack type semiconductor apparatus package that can be easily manufactured with inexpensive cost.

Conventionally used is a semiconductor apparatus package containing a semiconductor apparatus (semiconductor chip).
Downsizing and weight saving of a mobile information device requires high density packaging of semiconductor apparatuses. Proposed in recent years in response to such a demand is a stack type semiconductor apparatus package (stack type multi-chip package) obtained by stacking a plurality of semiconductor apparatuses (semiconductor chips) in a single package. See patent documents 1 and 2.
The following fully explains a conventional stack type semiconductor apparatus package described in the patent document 1. FIG. 34 is a cross sectional view illustrating a structure of the conventional stack type semiconductor apparatus package described in the patent document 1.
As shown in FIG. 34, the conventional semiconductor apparatus package is arranged as follows. That is, electrodes of a first semiconductor apparatus 201 are electrically connected, via connecting metal members 205, to first connecting pads 206 formed in a first face of a circuit substrate 219, respectively. The electric connecting is carried out in accordance with the flip method. There is provided an interface sealing resin 209 in a void between (i) an element face of the first semiconductor apparatus 201 and (ii) the first face of the circuit substrate 219. Further, a second semiconductor apparatus 202 is provided on a rear face of the first semiconductor apparatus 201 such that a rear face of the second semiconductor apparatus 201 faces and is aligned with the rear face of the first semiconductor apparatus 201. The second semiconductor apparatus 202 has electrodes 204 which are electrically connected, via thin metal wires 208, to second connecting pads 207 provided outside the first connecting pads 206 provided on the circuit substrate 219, respectively. Each first connecting pad 206 and each second connecting pad 207, both of which are provided on the first face of the circuit substrate 219, are electrically connected to each other via external input/output terminals 230 and 226 provided on a second face of the circuit substrate 219.
[Patent Document 1]
U.S. Pat. No. 6,157,080 (corresponding to Japanese Unexamined Patent Publication Tokukaihei 11-219984/1999 (published on Aug. 10, 1999)
[Patent Document 2]
Japanese Unexamined Patent Publication Tokukai 2003-234451 (published on Aug. 22, 2003)
Generally, electrode positions (positions of electrodes) are different among various types of semiconductor apparatus, so that the following inconvenience occurs when manufacturing a plurality of such stack type semiconductor apparatus packages having different types of first semiconductor apparatus. That is, such a difference in the electrode positions makes it impossible that a circuit substrate prepared for a stack type semiconductor apparatus package is used for manufacture of another stack type semiconductor apparatus package having a different type of first semiconductor apparatus (semiconductor apparatus mounted on the circuit substrate in accordance with the flip chip mounting technology), so that another circuit substrate needs to be prepared so as to accommodate to the electrode positions of the semiconductor apparatus having the different type of first semiconductor apparatus. In other words, a plurality of types of first circuit substrate need to be prepared for the manufacture of a plurality of stack type semiconductor apparatus packages having different types of first semiconductor apparatus. This requires relatively much work and cost.
Each of such stack type semiconductor apparatus packages having different types of first semiconductor apparatus is manufactured in cases where, e.g., the first semiconductor apparatus serves as a memory semiconductor apparatus and the second semiconductor apparatus serves as a logic semiconductor apparatus, and where a plurality of types of memory semiconductor apparatus are used for the first semiconductor apparatus. This is because designs (chip size, the number of pads, pad position, etc.) of the semiconductor apparatuses generally differ among semiconductor apparatus manufacturers.
Moreover, each of such stack type semiconductor apparatus packages having different types of first semiconductor apparatus is manufactured also in the following case. That is, the stack type semiconductor apparatus package is manufactured such that the first semiconductor apparatus serves as a memory semiconductor apparatus and the second semiconductor apparatus serves as a logic semiconductor apparatus, and where the memory semiconductor apparatus is replaced, after the manufacturing, with a memory semiconductor apparatus having a larger memory capacity.
Further, the following case is also presumable. That is, the stack type semiconductor package is manufactured such that the first semiconductor apparatus serves as a memory semiconductor apparatus and the second semiconductor apparatus serves as a logic semiconductor apparatus; however, for increase of the memory capacity of the memory semiconductor apparatus, the first semiconductor apparatus and the second semiconductor apparatus are replaced with each other after the manufacturing such that the first semiconductor apparatus serves as the logic semiconductor apparatus and the second semiconductor apparatus serves as the memory semiconductor apparatus. However, only wire bonding cannot deal with such a case where the number of the pads and the positions of the pads are different between the memory semiconductor apparatuses. Accordingly, another circuit substrate needs to be manufactured.
Further, the first semiconductor apparatus of the conventional stack type semiconductor apparatus package shown in FIG. 34 is possibly not a KGD (Known Good Die; a semiconductor whose quality is guaranteed). In the case where the first semiconductor apparatus is not a KGD, a defect of the first semiconductor apparatus possibly causes the stack type semiconductor apparatus package to be entirely defective. With this, a repair process is possibly required.

Stack type semiconductor apparatus package and manufacturing method thereof


A manually pull-type carrier includes a mobile carriage and a towing handle assembly slidably mounted to the carriage for changing the overall length of the carrier. The mobile carriage includes a pair of longitudinal rails rigidly interconnected and spaced laterally apart by a plurality of fore-and-aft spaced transverse bars, and a pair of wheels or skis with axle assemblies movably supporting the rails and being adjustable for changing the height of the rails above the ground. The towing handle assembly includes a pair of angle side braces and a front U-shaped handle telescopic with the angle side braces for adjusting the height of the handle to fit hunters of differing heights who tow the carriage.

1. Field of the Invention
The present invention generally relates to a and, more particularly, is concerned with a manual pull-type carrier for transporting a large game carcass.
2. Description of the Prior Art
Hunters often hunt in remote locations that are not accessible by motorized vehicles, such as trucks and automobiles. As a consequence, the hunters must transport their hunting equipment and large game carcasses, such as deer, without the aid of their motorized vehicles.
Various kinds of devices are employed by hunters for transporting the large game carcasses from the location where they were killed back to camps and for transporting the carcasses and hunting equipment between the camps and motorized vehicles or other locations. Representative examples of these prior art devices are the ones disclosed in U.S. Pat. Nos. to Giovannoni (2,613,953), Schrecengost (3,580,592), Fails (4,045,040) and Eagleson (5,064,020). However, these prior art devices suffer from a common drawback, which is the failure of users to be able to adjust their components to accommodate differing conditions of terrain, size of the load, and size of the user.
Consequently, a need exists for a manual pull-type carrier which will overcome this common drawback of the prior art devices without introducing a new drawback in its place.

Manual pull-type carrier for transporting a large game carcass


A semiconductor device comprises a semiconductor substrate having a major surface, a semiconductor region defined between at least two trenches formed in the major surface, a first insulating layer formed on at least side walls of each of the trenches, and a second insulating layer formed in a predetermined area of the surface of the semiconductor region to contact the first insulating layer. The thickness of the first insulating layer at the top of the side walls is set larger than the thickness of the second insulating layer.

1. Field of the Invention
The invention relates to a semiconductor device which is provided with a MIS (Metal Insulator Semiconductor) type of FET (Field Effect Transistor) in a trench-isolated region and a method of manufacturing the same.
2. Description of the Related Art
In recent years, to increase the packing density of semiconductor integrated circuits, the conventional LOCOS (Local Oxidation of Silicon) isolation has been replaced with the trench isolation which provides a high electrical isolation capability with insulating layers of narrower width. With the usual trench isolation structure, a single device isolation insulating layer is merely embedded in given locations in a semiconductor substrate. The use of this trench isolation structure for formation of a MISFET will result in such problems as described below.
Reference will be made to FIGS. 1A, 1B and 1C to describe the problems with a conventional flat type of MISFET using the trench isolation. FIG. 1A is a plan view of a MISFET, and FIGS. 1B and 1C are sectional views of the MISFET taken along the line 1B--1B and the line 1C-1C, respectively, of FIG. 1A. In these figures, reference numeral 1 denotes a semiconductor substrate, 3 a buried device isolation insulating layer, 8 a gate electrode, 9 a source/drain region, and 12 a gate insulating layer.
Conventionally, the gate insulating layer 12 is formed after the formation of the device isolation insulating layer 3 and the gate electrode 8 is subsequently formed over the gate insulating layer. In order to expose the surface of the semiconductor substrate 1 after the device isolation insulating layer 3 has been embedded, it is required to etch back the insulating layer. In this case, the insulating layer 3 is apt to be overetched, which will result in the surface of the insulating layer becoming lower than the exposed surface of the semiconductor substrate 1 as shown in FIG. 1B. Consequently, in a portion indicated at b, the edge of the semiconductor substrate 1 is exposed. A gate electric field will concentrate in this exposed portion when a transistor is formed and operated. Thus, the threshold voltage in the portion b becomes lower than in the flat portion a, resulting in a parasitic transistor being formed.
The ratio in conductance of the parasitic transistor to the transistor in the flat portion becomes large as the gate width decreases and each of these transistors will have a different threshold voltage. For this reason, with an integrated circuit in which there are formed a large number of transistors which are different in gate width, the generation of parasitic transistors will result in serious problems in circuit design.
In general, the shape of the semiconductor region and the device isolation region varies in the neighborhood of the parasitic transistor, depending on the amount of etching involved in preprocessing for the formation of the gate insulating layer and the trench shape. For this reason, the electrical characteristics of transistors vary, deteriorating the reproducibility of transistor characteristics.
As described above, the problem with the conventional trench isolation structure in which the device isolation insulating layer is made of a single layer is that parasitic transistors having their threshold voltages lowered are formed because preprocessing for the formation of the gate insulating layer in MISFETs overetches the device isolation insulating layer with the result that the insulating layer becomes lower than the semiconductor region and the edges of the semiconductor region are exposed.

Semiconductor device and method of manufacture of the same


The invention includes a system and method for changing a playback speed of a selected video segment containing field pictures which has been recorded onto a portion of a storage medium. A selected video segment can be modified for a changed playback speed and the modified video segment can be recorded exclusively on the portion of the storage medium. A plurality of non-video packs in the selected video segment can be deleted to reduce the amount of data contained in the modified video segment. The video segment can be modified by adding at least one field picture. Alternatively, the video segment can be modified by removing at least one field picture contained in the video segment. In either arrangement, the video segment can be reencoded to produce a smoother trick mode and playback performance.

1. Technical Field
The inventive arrangements relate generally to methods and apparatus providing advanced operating features for programs recorded on disc media, for example recordable digital video discs, hard drives and magneto optical discs.
2. Description of the Related Art
While trick modes enable a user to view recorded video at different speeds, the video is not permanently altered by the process. If the video is displayed at a later time, then the user must initiate another trick mode to view the video at a different speed. Significantly, however, many users may wish to permanently change the playback speed of a particular portion of video by modifying the video once the video has been recorded onto a disc. Such a process can permit speed variations during playback without the user invoking a trick mode command. Unfortunately, several significant obstacles exist that make editing recorded video in such a fashion impracticable. Specifically, the space occupied by the original video is not large enough to store the pictures that must be repeated in order to produce slow motion playback. In addition to spatial limitations, repeating pictures on the disc can interfere with the conventional picture structure of the video, which can degrade the display quality of the video during playback.
Modifying recorded video to produce fast-forward playback, however, is not affected by the spatial limitations that impede slow-motion editing. This is because fast-forward editing merely deletes pictures from the recorded video. Nevertheless, creating fast-forward video, similar to slow-motion modification, also negatively impacts the conventional picture to structure of the video. Thus, what is needed is a device that can change the playback speed of video recorded under a field structure format yet can overcome the spatial and structural limitations associated with such recorded video.

Changing a playback speed for video presentation recorded in a field structure format


According to the present invention, not only still images but also moving images can be compressed with high quality. In an image coding apparatus, a wavelet transform unit low-pass filters and high-pass filters an input image signal in the vertical and horizontal directions to hierarchically transform a low frequency component repetitively. In the case of an interlaced image, the wavelet transform unit further decomposes a subband including, for example, a horizontal low frequency component and a vertical high frequency component in consideration of the characteristics of the image signal. A code-block generation unit divides quantized coefficients into code-blocks each having a predetermined size. The code-block serves as a unit subjected to entropy coding. In the case of the interlaced image, each code-block is set to, for example, 32×32 so as to be smaller than each code-block of a progressive image.

1. Field of the Invention
The present invention relates to an image coding apparatus and method for compressing an image using wavelet transform and entropy coding according to, for example, JPEG-2000, an image decoding apparatus and method for decoding the compressed image, and a recording medium in which a program to allow a computer to execute an image coding process or an image decoding process is recorded.
2. Description of the Related Art
Conventional typical image compression systems include JPEG (Joint Photographic Experts Group) standardized by the ISO (International Standards Organization). JPEG uses discrete cosine transform (DCT). As is generally known, according to the DCT, favorable coded images and decoded images are provided when a bit-rate is relatively high. However, when the number of bits to be coded is less than a predetermined value, block distortion inherent in the DCT becomes noticeable. Thus, a subjective loss of image quality may be noticeably found.
On the other hand, there is a system in which an image is divided into a plurality of frequency bands using a filter called a filter bank composed of a high-pass filter and a low-pass filter and each frequency band component is then coded. In recent years, researches and studies of this system are increasing. Among them, wavelet transform coding is regarded as the most effective new technique that substitutes for the DCT because the wavelet transform coding does not have a disadvantage in that block distortion is noticeable due to high compression in the same case as in the DCT.
JPEG-2000 has completed as international standards in January 2001. JPEG-2000 uses a system accomplished by combining the wavelet transform with high-efficient entropy coding (bit modeling and arithmetic coding for each bit-plane), thus realizing remarkably improved coding efficiency higher than that of JPEG.
In these international standards, only standards for a decoder are defined. Standards for an encoder can be freely designed. On the other hand, there is no standard regarding means for reducing large loads on processes of the entropy coding and means for effectively controlling a bit-rate in order to realize target compressibility. Therefore, it is important to establish the know-how to reduce the loads and to control a bit-rate. Particularly, in JPEG, it is difficult to control a bit-rate. In many cases, coding has to be performed many times until a target bit-rate is achieved. However, it results in long processing time. In JPEG-2000, it is desired to obtain a target bit-rate by one implementation of coding.
JPEG-2000 is developed specifically for still images. Accordingly, in JPEG-2000, support for interlaced images which often exist in moving images is not studied enough. Therefore, if techniques for still images are applied to moving images, the image quality is noticeably degraded.

Image coding apparatus and method, image decoding apparatus and method, and recording medium


Disclosed are representative embodiments of methods, apparatus, and systems for voltage-related analysis of layout design data. According to embodiments of the disclosed technology, voltage association data objects are generated for drawn layers in a net of a layout design and voltage values or ranges of voltage values associated with the net are collected. The voltage values or ranges of voltage values are then associated with the voltage association data objects. A voltage-related analysis may be performed by searching the voltage association data objects according to a predetermined criterion.

Many microdevices, such as integrated circuits, have become so complex that these devices cannot be manually designed. For example, even a simple microprocessor may have millions and millions of transistors that cooperate to form the components of the microprocessor. As a result, electronic design automation tools have been created to assist circuit designers in analyzing a circuit design before it is manufactured. These electronic design automation tools typically will execute one or more electronic design automation (EDA) processes to verify that the circuit design complies with specified requirements, identify problems in the design, modify the circuit design to improve its manufacturability, or some combination thereof. For example, some electronic design automation tools may provide one or more processes for simulating the operation of a circuit manufactured from a circuit design to verify that the design will provides the desired functionality. Still other electronic design automation tools may alternately or additionally provide one or more processes for confirming that a circuit design matches the intended circuit schematic, for identifying portions of a circuit design that do not comply with preferred design conventions, for identifying flaws or other weaknesses the design, or for modifying the circuit design to address any of these issues. Examples of electronic design automation tools include the Calibre family of software tools available from Mentor Graphics Corporation of Wilsonville, Oreg.
As electronic design automation tools continue to develop, greater sophistication is being demanded from these tools. For example, in addition to detecting obvious design flaws, many electronic design automation tools are now expected to identify those design objects in a design that have a significant likelihood of being improperly formed during the manufacturing process, determine the resultant impact on manufacturing yield that these design objects will create, and/or identify design changes that will allow the design objects to be more reliably manufactured during the manufacturing process (e.g., "design-for-manufacture" (DFM)). In order to meet these expectations, a process executed by an electronic design automation tool may need to perform more calculations than with previous generations of electronic design automation tools. For example, a design rule check process may confirm that the polygons used in a physical layout design to form individual wiring lines are separated by a minimum specified distance. In addition, however, the design rule check process also may determine the likelihood that the polygons may nonetheless form the wiring lines with an erroneous bridging fault. This determination may require, for example, calculating the distance between the polygons, the length for which the polygons run adjacent to each other, and the thickness of the polygons at their adjacent portions.
As process nodes are becoming smaller, foundries are requiring or performing more voltage-related checks for layout design data. For example, a foundry may determine that a given spacing between geometric elements is acceptable when the geometric elements are associated with a relatively small voltage drop. If, however, the geometric elements are associated with a relatively large voltage difference, then the foundry may deem that the same spacing between the geometric elements is too small, and must be changed.
To facilitate this type of voltage-related analysis, a designer will typically add voltage markers to layout design data. These markers associate a specific geometric element in the layout design data with a particular voltage. With some automated design tools, such as the Calibre® family of physical verification tools available from Mentor Graphics Corporation of Wilsonville, Oreg., a voltage marker can be implemented by a geometric element positioned to overlap (and thus be associated with) the geometric element for which the voltage is being specified. The specified voltage value can then attached to the marker as a "property" value, as described in detail in U.S. patent application Ser. No. 11/869,731 entitled "Properties In Electronic Design Automation," filed on Oct. 9, 2007, and naming Fedor Pikus as inventor, which application is incorporated entirely herein by reference as well. In this manner, the specified voltage value is associated with a circuit geometric element through the marker geometric element.
When an electronic design automation tool initiates a check (such as a design rule check) to be performed on geometric elements associated with a specific voltage value or range of voltage values, the tool can identify relevant geometric elements by examining the voltage markers. For example, the tool can determine whether geometric elements in a net are associated with a voltage value or range of voltage values by examining all of the voltage markers for all of the geometric elements in the net. While this arrangement is helpful, it is also very time consuming and computationally expensive, since the tool must examine all of the voltage markers for all of the geometric elements in the net. Because even a single process executed by an electronic design automation tool may require millions of calculations, improvements in the speed and efficiency of electronic design automation tools are continuously being sought.

Voltage-related analysis of layout design data


A remote device includes a device unit having a communications network interface. A management module is in communication with the device unit, and the management module is connectable to a powered copper network. The management module operates a management communications channel over the powered copper network and receives power from the powered copper network.

Conventional copper telecommunications infrastructures exist in most countries to provide public telephony services. In addition to communications services provided by the copper infrastructure, a small power source is provided over the copper network to telephony equipment.
Additional networks may be deployed over more recently developed media types such as fiber optics, wireless networks, and satellite communications. These new media networks typically terminate at or near the end user's location. The media service provider can use a demarcation device that signifies the edge of the service provider's management domain. The demarcation device may be a simple device, but it can also be an important networking tool because it is often the last device that can be controlled or monitored by the service provider.
Remote management and/or device failures usually result in the dispatchment of a technician to manually service a remote device. These repair procedures can be costly and time consuming. Demarcation devices may be the most numerous element in a communications network system, and reliable management and monitoring of the devices may decrease the cost to the service provider and increase the reliability of service to the end user.
Currently, demarcation devices may be managed and monitored through the same communications channels as the communications services that are being provided. That is, the management and monitoring data is communicated to remote monitoring stations via the same physical link as the communication services. As a result, the management and monitoring abilities may be limited by the reliability of the communications services and the network through which the services are provided. In addition, the management of a remote device may be intricately tied to a local power source at the remote device, and the device typically cannot be monitored or diagnosed if local power to the device is interrupted. Furthermore, the service provider may not be able to differentiate transient power source failures from a network failure or from a device failure because in each case, the remote device is likely to be unreachable. However, the action required to repair each type of failure may be different, and the service provider may not be able to easily determine the most likely cause of the failure.
For example, referring to FIG. 1, a typical prior art communications network includes remote devices 13 that are connected to the communications infrastructure 15 by connections 19. The remote devices 13 can be demarcation devices at or near an end user and are powered by a local power supply such as a battery. The communications infrastructure 15 can be an infrastructure for various media types such as fiber optics, wireless networks, and satellite communications. Management stations 11 monitor the remote devices 13, and can be physically removed from the remote devices 13.
The communications infrastructure 15 may overlap with a powered copper network 17 if the communications infrastructure 15 includes copper communications. The powered copper network 17 can be a plain old telephone system (POTS).
Communications services are provided by the communications infrastructure 15 via the connections 19 to the remote devices 13. Management and monitoring data also flow through the same communications infrastructure 15 via connections 19 to the remote devices 13. As discussed above, the monitoring functions of the management stations 11 are only as reliable as the communications infrastructure 15 and connections 19.

Methods and systems for remote management of networked devices


A method of practicing a golf swing and a kit for use with the method is provided, whereby the golfer applies a colorant to the sole of a golf club with a marking instrument and hits golf balls off of a resilient flexible mat, so that the colorant is transferred to the upper surface of the mat, thereby creating marks that are characteristic of the golfer's swing.

Myriad devices have been invented to assist golfers in improving the mechanics of their swing. One category of device employs a marker attached to the head of a golf club in combination with a sheet or mat to record the marks generated by swinging the club.
Swords—U.S. Pat. No. 3,687,459 discloses a pair of spaced apart scribers (pens) attached to the head of a club. The tracks of the scribers on a sheet indicate the nature of the golfer's swing.
Golden—U.S. Pat. No. 3,992,013 discloses a dust covered mat and a golf club, modified by attaching a device with protruding pegs to the club head. The attachment is capable of dispersing the dust, when the club contacts the mat.
Blaisdell—U.S. Pat. No. 4,932,662 discloses a club lie angle evaluator having a club whose lower surface has received an abradable coating. When the golf club comes into contact with the surface supporting the golf ball, the coating is abraded, indicating whether the lie angle of the club is appropriate for the particular golfer.
Cerami—U.S. Pat. No. 5,120,064 discloses a spring loaded marker attached to the head of a golf club. The marker traces lines on a sheet, indicating the path of the golf club.
Hsu—U.S. Pat. No. 5,620,376 discloses a marker attached to the shaft of a golf club, adjacent the club head. The marker has a chamber for holding a liquid and an orifice at the bottom. Swinging the club releases the liquid and creates a mark on the ground indicating the path of the golf club.
Another category of devices provide a removable recording medium attached to the face of a golf club. When a golf ball is struck, an impression is created in the medium. Examples of such devices are disclosed in Lee—U.S. Pat. No. 5,142,309 and Butler, Jr. —U.S. Pat. No. 5,609,530.
Yet another category of golf swing analysis aids include mats that indicate the swing path of a golf club.
Goduto—U.S. Pat. No. 3,815,923 discloses mats having fibers that are moved from a first position to a second position after being struck by the head of a golf club. The fibers are bicolored, so that the path of the club head will be readily apparent.
Tiffin—U.S. Pat. No. 6,913,544 B2 discloses a divot practice mat having a mark retaining surface, such as carbon paper or wax. Simulated golf balls are imprinted on the surface of the mat and provide a target for the golfer.
Snopkowski—US 2006/0128493 A1 discloses a synthetic turf practice mat having fibers that change visually in appearance after being struck with the head of a golf club. Alternatively, the mat may employ liquid applied to the fibers, sand, aluminum powder or magnetic powder, to visually identify the path of a club head.
Nusbaum et al. —US 2007/0298895 A1 disclose a golf swing analysis mat that has electronic sensors to detect the point of impact and path of a golf club head. A microcontroller analyzes the data and provides feedback to the golfer.
Mitchell—US 2008/0200277 A1 discloses a golf mat with grass-like blades that "toggle" from a forward face to a rearward face, after being struck by the head of a golf club. When the blades are toggled, they appear a different color.

Method of analyzing a golf swing and practice mat


A system for applying hair extensions to natural hair growing on the scalp of an individual comprises flared cylindrical tubes, a threading hook and a crimping tool. The threading tool is used to feed scalp hair through the flared tube. The hair extension is then inserted into the flared end or the tube and the tube is crushed flat trapping the threaded scalp hair and hair extension within the crushed structure. The removal of the hair extension is facilitated by use of a removal tool designed to open the crimped flared tube.

There are a wide variety of techniques and procedures to provide an individual with a fuller or longer appearing head of hair. In describing the invention and methods of supplementing natural hair growth, the natural hair growing on the head of an individual will be referred to as "scalp hair", also medically designated as capillus or capilli. The simplest approach is to apply a wig or add hair pieces such as pony tails, braids or wefts. A permanent procedure is the use of hair plugs which are surgically implanted. A temporary method suitable for longer periods of time is to sew or weave strands of natural hair or synthetic hair replacements into normal hair growing on the scalp. Alternatively, hair extensions may be adhesively secured to the scalp or hair growing from the scalp. A still further method is to use small clamps or clips for the attachment of strands or bundles of hair, referred to as a hair extensions, to multiplestrands of scalp hair.
U.S. Pat. No. 4,934,387 shows the use of a thermoplastic glue, U.S. Pat. No. 5,072,745 discloses use of a hot melt adhesive, U.S. Pat. No. 5,575,298 uses a contact adhesive, U.S. Pat. No. 5,868,145 uses a liquid latex along with a cyanoacrylate adhesive, U.S. Pat. No. 6,405,736 and U.S. Published Applications 2002/0185146, 2001/0035192 and 2001/0037813 each disclose a self adhesive tape for attaching an extension or multiple extensions to the scalp. U.S. Pat. No. 5,107,867 describes the use of a thermosetting adhesive in combination with a heat shrinkable tubing. These techniques require the use of heat and/or solvents to reverse the attachment process.
U.S. Pat. No. 5,121,761 describes a method of attaching hair extensions which first requires securing anchors to multiple strands of hair attached to the scalp, forming the hair extensions into a single wide hair piece with an upper weave portion an attaching that weave portion to the anchors.
U.S. Pat. No. 5,894,846 describes the attachment of hair extensions to strands of knotted, scalp hair using heat shrinkable tubes. The hair is first knotted to form an enlarged portion that is readily trapped in the tubing after heat is applied to cause shrinking of the tubing.
U.S. Pat. No. 5,752,530 to Taintinger describes a process for attaching hair extensions to scalp hair which comprises using a clamping tool to temporarily clamp loose strands of a hair extension to gathered strands of hair near the scalp, placing the combined hair extension and scalp hair strands through a threading loop and then pulling that combination through a straight cylindrical sleeve. The hair extension and scalp hair are then trapped in the sleeve by crushing the cylindrical sleeve first into a U or V shape, with the bottom of the U or V extending along the length of the cylindrical sleeve (parallel to the hair strands), to loosely grasp the strands, sliding the sleeve along the strands until it is close to the scalp and then further folding the sleeve over on itself (i.e. folding the sleeve in half longitudinally) thus compressing the U or V shape, trapping the hair strands within the crushed, folded sleeve. Special pliers which includes a U or V shaped groove in one face and a matching anvil shaped extension in the other face of the plier jaws are used to form the tube into the desired hollow U or V configuration with the hair within the reshaped hollow cylinder. Another portion of the plier jaws is then used to complete the formation of the folded U or V shaped cylinder. To undo the process (remove the hair extension) the pointed tips of the pliers are used to unfold the folded U or V, releasing the compressive forces on the scalp hair and hair extension.
Each of the techniques disclosed in these referenced documents have problems in use and speed of application which are addressed by the current invention. The use of adhesives and the heat or chemicals described in previous published procedures required to attach or remove the hair extensions can be damaging to the natural hair and scalp. In addition, the adhesive materials also retain dirt and natural skin oils making them difficult to maintain in a clean manner. Heat shrinkable tubes are difficult to remove, particularly when the hair requires knotting and may necessitate cutting the natural hair to remove the extensions. Other tubular attachment means require additional tools for mounting the extensions and may be difficult and very time consuming for an individual to apply and remove.
Therefore, there is a need for a simple, fast and easy application technique for adding hair extensions. The devices and procedure embodying features of the present invention meet these needs.

Methods and devices for applying hair extensions


An anterior instrumentation method of treating spinal deformities involves a combination of a spinal rod anterior system and one or two spinal plates fixed on the cephalad and caudal end vertebrae of the instrumented segment. Deformities are treated by the anterior rod system through compression, distraction and derotation. Two spinal plates are fixed to the cephalad and caudal end vertebrae respectively to prevent the end vertebrae from rotating into kyphosis. A number of cancellous screws are inserted into the cephalad and caudal end vertebrae and their adjacent vertebrae through the spinal plate to provide several points of fixation on the end vertebrae to prevent implant failure and loss of correction.

Dwyer first introduced spinal instrumentation for anterior spinal fusion in 1969. The Dwyer system used screws and a flexible cable. However, this system merely provided limited stability by the compressive effect of the one vertebral body against the other. The flexible cable resisted only tension forces, and the inability of the Dwyer system to provide a rigid connection between vertebrae often led to cable or screw failure with subsequent pseudarthrosis. In 1976 Zielke modified the Dwyer system by substituting a small diameter threaded rod and nuts for the cable and introduced a derotator designed to correct rotation and to prevent kyphosis. Over time, the Zielke instrumentation procedure for management of thoracolumbar and lumbar scoliosis was recognized to have significant advantages over the Dwyer system in terms of effective correctability of the coronal curvature, the ability to correct deformity by instrumenting shorter segments of the spine and also its derotation capability. However, the Zielke instrumentation has been reported to have high incidence of implant breakage, loss of correction, progression of the kyphosis, and pseudarthrosis caused primarily by lack of segmental stiffness in the relatively small diameter rod.
With the introduction of a larger diameter solid rod system by TSRH in 1989, creation of lordosis in the instrumented segment was possible by the appropriate contouring and rotation of a larger diameter rod. The 300% to 400% increased stiffness of the 6.4 mm rod over that of the Dwyer or Zielke longitudinal members was expected to provide stiffness sufficient to increase fusion rates while maintaining correction without external immobilization. However, after review of cases performed with the instrumentation, the incidence of loss of correction in both frontal and sagittal planes remained unacceptable, though improved compared to Dwyer and Zielke.
Some authors documented significantly high strains at the bone-screw interface of the cephalad and caudal end vertebral screws. Loss of correction and kyphosis in the single rod instrumented segment probably resulted from insufficient construct stiffness in the early postoperative period as a consequence of bone-screw interface loosening, especially at the cephalad and caudal interspaces. The single rigid rod may provide sufficient stability for the correction of the deformed spine during the early postoperative period. However, it may not prevent the vertebral rotation about each screw axis at the bone-screw interface during everyday activity. The possible reason is that the single solid rod system lacks two fixation points on each vertebra, particularly in the most cephalad and caudal end vertebrae of the instrumented segment.
In 1996, Kaneda introduced a two-rod anterior system (KASS) with two fixation points on each vertebra for management of thoracolumbar and lumbar scoliosis. The KASS system seemed to address some of the problems associated with prior systems, preventing the end vertebrae from rotating into kyphosis. This technique has been performed with good results in the early follow-up period. However, this system has some limitations; namely, the system has a high prominent profile and is difficult to apply to a severely deformed spine.
To combine the relative ease of implanting a single rigid rod structure with two fixation points on each end vertebra, the rod-plate anterior system of the present invention is an improvement over the single solid rod anterior system (TSRH), and also allows spinal plate fixation at the cephalad and caudal end vertebrae of the instrumentation segment.

Method for the correction of spinal deformities using a rod-plate anterior system


A method for efficient encryption and decryption (100) comprises the steps of encrypting a message (104) at a sending unit which is to be sent to a receiving unit using a message key (106) and appending to the message at the sending unit the message key encrypted (108 and 109) using a receiver's public key (110). Subsequently, a sender's certificate (116) is appended at a first server (302) and extracted at a second server (310). The message key is then decrypted at the receiving unit using a receiver's private key (140) to provide a decrypted message key. Subsequently the message is decrypted using the decrypted message key (142 & 143) and authenticated by comparing a pair of digest (152 and 156).

In a broad sense, efficient paging and security for wireless applications such as paging have opposing constraints. On the one hand, paging uses its non-real time capabilities to pack information efficiently to reduce the inefficient use of the wireless bandwidth. Security measures such as encryption on the other hand typically add to the information being transmitted over the air. The increased number of users and the increase in the average size of messages (including text, facsimile, audio and eventually video information) will only put further constraints on the use of the limited bandwidth provided.
In the normal process for passing a secured message with signature from a sender to a receiver, the steps in method 10 are typically followed as described with reference to FIG. 1. First the user creates a text message at step 12. Then, the user generates a digest of the text message using a one-way function (e.g. a secure hash function) at step 14. The user then attaches his signature at step 18 by first encrypting the digest using his signature or private key at step 20 and running it through an asymmetric engine 16, typically the private key corresponds to a public key found in a traceable certificate 26. The message and digital signature are then appended at step 22. The message with signature 24 is then catenated at step 27 to the traceable certificate 26 to create an authenticatable message 28. The authenticatable message 28 is then encrypted by using a symmetric engine 30 and a session key 32 to provide an encrypted message 40. The session key 32 (normally a random symmetric key) is itself encrypted using a recipient's asymmetric public key 34 and an asymmetric engine 36 to create a digital envelope 38. The encrypted message 40 is then appended at step 42 to the digital envelope 38 to create an encrypted message plus signature plus certificate with envelope 44.
With reference to FIG. 2, the typical decryption process begins by separating (46) the components of the encrypted message plus signature plus certificate with envelope 44 into the encrypted message 56 and a digital envelope 48. Preferably, digital envelope 48 is the same as digital envelope 38 from FIG. 1. The session key 54 (preferably session key 54 is the same as session key 32 of FIG. 1) is recovered (decrypted) by the recipient using their private key 52 (corresponding to the recipient's private key 34) and running the digital envelope 48 through an asymmetric engine 49 using the private key 52. The encrypted message 56 with signature is decrypted using the session key 54. In other words, by using the session key 54 the encrypted message 56 is run through a symmetric engine 58 to obtain an authenticatable message 60 (which should be the same as the authenticatable message 28 of FIG. 1). Thus, the recipient can confirm (to a reasonable degree) the identity of the sender of the message as will be seen in the next few steps. Next, the authenticatable message is separated (62) into a certificate 64 and a separate signed message 68 corresponding respectivley to the certificate 26 and signed message 24 of FIG. 1. The signed message 68 itself will also be separated (70) into a readable text message 80 and a digital signature 72 corresponding respectively to the message 12 and digital signature 18 of FIG. 1. A sender's public key 66 is extracted from the certificate 64 and then used to decrypt the signature into a digest 77. In other words, the digital signature 72 is passed through an asymmetric engine 74 using the sender's public key 66 to provide a digest 77 which should be a copy of the actual digest. The text message 80 is run through the same (hash) function (as in step 14 of FIG. 1) to retrieve the actual digest 79. The actual digest 79 and the digest 77 are compared at step 76 to verify proper signature. Note that in the example above, the certificate is embedded in the encrypted message and significantly increases the size of the encrypted message.

Encryption and decryption method and apparatus