A satellite communications system (10) includes a hub (14), a satellite (32), and any number of remote terminals (16). Each remote terminal (16) includes a remote receiver (38), a monitor (40), and a network access controller (42). Each remote receiver (38) is configured to receive and down convert the system's entire spectrum of interest from which channels are accessed by the remote terminals (16). The monitors (40) independently perform FFT processes over this entire spectrum, but at a low frequency resolution which is no higher than needed to distinguish channels. Based on these spectral analyses, uplink/inbound channels are independently selected by the network access controllers (42) at each remote terminal (16). Remote terminals (16) immediately transmit data to the hub (14) as soon as they select an uplink/inbound channel.

Communication using satellite transmission links has become common in recent history. Television, voice traffic, data transfer and a wide variety of other communication types are now routinely sent via satellite. As satellite networks are utilized to provide a medium for more recently developed communications types, satellite network providers and administrators face ongoing challenges in fulfilling this demand. In particular, with the explosion of the Internet as a communications vehicle, the transmission of Internet protocol (IP) traffic via satellite has presented a unique set of challenges. IP, along with electronic mail (e-mail), closed network communications, and the like, reflect the variety of such communication types.
Two of the largest costs for operating a satellite communications network are the use of the satellite's transponder bandwidth, or space segment, and the capital expenditure in both hardware and software associated with the establishment of the network. For many years the use of Single Channel per Carrier (SCPC) satellite links provided an effective communication means for point-to-point connectivity. In SCPC, a satellite channel is reserved for a particular use. Although SCPC provided excellent access, the satellite transponder bandwidth used by a channel resulted in high space segment cost even in low utilization scenarios. In order to reduce space segment costs, there has been a major effort in the satellite communications industry to develop bandwidth management solutions resulting in lower operating costs. This effort has been ongoing over the past several decades. Previously, any reasonable cost could be supported in terrestrial hardware and software, and would be compensated by reduced space segment cost. In today's market however, the falling price of space segment has dictated that terrestrial segment costs must be lowered substantially as well, in order to address a broader market.
One approach to managing satellite bandwidth that has been in use over this time frame is Time Division Multiple Access (TDMA). TDMA divides the satellite bandwidth into time slots that are dedicated to each remote site in a satellite communications network, the network comprising one or more hub sites and multiple remote user sites. The hub sites and the remote sites may be linked via the satellite in a wide variety of architectures well known in the art, including mesh and star architectures, to name two. By time-allocating access to a satellite channel among multiple remote sites, TDMA networks such as the Skystar Advantage® satellite systems provided by Gilat Spacenet of McLean, Va., and the X. Star satellite systems provided by STM Wireless, Inc, of Irvine, Calif. have more efficiently used the space segment and reduced operating costs. In the present terminology, Very Small Aperture Terminal (VSAT) networks typically refer to networks that use some variation of TDMA. Many variations of TDMA have been developed and include Slotted ALOHA, Multiple Frequency TDMA (MF-TDMA) and Selective TDMA (STDMA), to name a few.
Conventional TDMA based networks require an excessively complex and expensive Network Management System (NMS) at the hub. The NMS utilizes centralized network management software to control access to the network by the remote sites, thereby supervising the traffic over the network. The core code for this software is complex and expensive to change resulting in the use of network management logic, which was developed over a decade ago and is not adaptable to changes in network traffic characteristics. Additionally, the capital costs of the hub station electronic equipment are significant. If the network comprises many hundreds of sites, the hub cost becomes a less significant factor as it is amortized over the large number of remote sites. However, for small-to-medium networks of fewer than 1000 sites, the hub capital costs can be prohibitive.
Another disadvantage of TDMA is the limited throughput of the remote sites, particularly during network peak usage periods. TDMA systems utilize equipment that operates in the burst mode to time allocate the space segment. As will be known by one of ordinary skill in the art, because TDMA divides bandwidth into time slots, the aggregate throughput of any satellite channel is limited to the bandwidth of the shared channel, and as the number of remote sites increases, each site's time slot is reduced and the total throughput for each site decreases. As a result, the network average throughput decreases due to the overhead associated with each burst. Some TDMA systems such as MF-TDMA have tried to mitigate this decrease in throughput by jumping (Frequency Hopping) between multiple TDMA channel frequencies. This scheme, however, adds cost and time delay to the system. There are also a number of complex timing considerations with MFTDMA systems that affect network elements interdependently. These factors are, among others, differences in range to the satellite from the earth station, buffer hold time, and frequency uncertainty.
Another commonly used bandwidth management scheme in VSAT networks is Demand Assigned Multiple Access (DAMA). DAMA allows a pool of satellite channels to be shared among multiple user sites on an on-demand basis and is an efficient and logical network topology for satellite systems. DAMA reduces space segment operating costs for networks with remote sites that require full mesh connectivity, but do not require full time communication circuits. Bandwidth-on-demand and rural telephony are examples of popular DAMA applications.
In DAMA, idle satellite transponder bandwidth is available for any remote user site in the network when requested as long as it is not currently in use. The bandwidth becomes available for a requesting user at a remote site upon the completion of its use by another user at a remote site. By sharing the available bandwidth among multiple users, DAMA systems such as the FaraWay™ satellite telephony systems provided by Gilat Spacenet, and the rural telephony systems provided by STM Wireless, Inc., deliver cost-effective use of the satellite space segment.
One disadvantage of DAMA systems is that they are hardware intensive resulting in high capital costs when compared to similarly configured star SCPC networks. In addition to a complex and costly NMS, DAMA systems require one or more network control channels with associated hardware for network management. The control channel manages traffic by passing requests for bandwidth channel use among remote sites and the network manager at the hub site. They require a control channel modem (or modems, depending on the size of the network) at each remote site and at the hub site, and a network management computer and complex network management software at the hub.
Another disadvantage of DAMA is slow communication link set up times. In a DAMA network, when a remote site sends a request to establish a communication link, the request is sent over the control channel to the NMS. The NMS sends an acknowledgement message to the remote and determines bandwidth availability on the satellite transponder. When the determination is made that a channel is available, the NMS allocates bandwidth to the remote by sending a command over the control channel, which tunes a remote traffic modem to the center frequency of the available channel and turns the transmitter on. This process is time consuming due to the satellite round trip times of the remote requests and acknowledgements and the commands from the hub. With several trips up to and back from the satellite, which are a minimum of 240 milliseconds in propagation delay for each direction of the trip, the time to set up a circuit can easily grow to several seconds.
The differences in bandwidth usage by DAMA and TDMA lend each to be more effective in certain applications. Typically, DAMA has been used for rural voice networks and circuit restoral systems, and TDMA has been used for Point of Sale systems, other transactional data networks, and, more recently, IP networks.
With the explosion of the Internet and the rapid adoption of IP as a transport protocol for telecommunications networking, the disadvantages of capital cost intensive VSAT networks with slow response times resulting from long set-up or reduced throughput during high usage scenarios has created a need for a satellite access scheme that that is cost effective and works efficiently in an IP environment. Many companies in the satellite networks business have attempted to adapt TDMA and DAMA for IP transport over satellite, but have had limited success.
A simple application for DAMA in an IP environment is to use it in a manner similar to a dial-up Internet connection. This, however, is an inefficient use of satellite bandwidth resulting in high operating costs. It is akin to dialing into an Internet Service Provider (ISP) via an expensive long distance telephone line and staying connected for periods of time; and, the cost gets very large very quickly. Additionally, IP networks have difficulty functioning properly due to the slow circuit set-up. Routers functioning in a DAMA network start sending route broadcasts to let the destination site know that the route is available. The DAMA system, therefore, establishes a circuit every time the router updates its tables. This may be as frequently as several times a second, but normally is every 2 to 5 seconds. The destination router then acknowledges the receipt of the route updates and recognizes the availability to interchange data.
Subsequent to the adaptation of TDMA and DAMA systems for IP use, a technique was developed for one-way transport of IP data via satellite. This technique uses a standard protocol known as Digital Video Broadcast (DVB) developed for broadcast digital video transport and commonly referred to as an MPEG2 Transport Stream. These systems statistically multiplex an IP stream and encapsulate the IP onto DVB frames using an IP encapsulator. The encapsulator output is fed to a DVB modulator and multicast to multiple receive-only sites via satellite. This technique is commonly referred to as DVB-IP. The DVB-IP equipment manufacturers have adopted a standard within DVB-IP called Multiple Protocol Emulation (MPE). This standard allows any MPE compliant receiver to interoperate with any other manufacturer's IP encapsulator. The receive equipment at the remotes are called Integrated Receiver Decoders (IRD) and are standardized and readily available from a large number of vendors. DVB-IP equipment is produced using large volume manufacturing techniques and shares components with Direct to Home (DTH) television receivers, resulting in very inexpensive equipment.
DVB-IP has proved to be an effective technique for point to multipoint distribution of IP data via satellite. One example is delivering IP backbone connection to far-flung ISPs. Using DVB-IP for delivering downstream data to ISPs is cost effective due to the asymmetrical nature of ISP circuits. The limitation of the DVB-IP system architecture is the upstream (return) path. To date, most networks using DVB-IP are strictly one-way, or use terrestrial links such as dial-up leased lines for the upstream return path. The throughput requirement for the return channel very much depends on the application. If the purpose of the circuit is basic web surfing, the upstream throughput requirement is relatively small. Typically, the downstream to upstream data ratio for ISP backbone access is between 8/1 and 15/1. In many cases, however, the reason for using VSAT systems is the lack of other communications infrastructure. If the station is in a remote area, there may be no dial-up connection for the return path.
An effective solution to the problems associated with the lack of infrastructure is to use SCPC links for the return path. This is what overseas ISP's such as Reach Global Services, Ltd. of Hong Kong use for their Internet backbone connection. An ISP can serve thousands of subscribers with a Committed Bit Rate (CBR) of 2 Mb/s and an SCPC return channel of 128 or 256 Kb/s. Many major satellite operators are currently offering these types of services to ISPs worldwide. Such services include SPOTbytes, the Internet service delivered by PanAmSat Corporation of Wilton, Conn.
SCPC return channels, however, necessitate a separate carrier for each return link. These channels are dedicated full-time to a single link, are usually not fully utilized, and require guard bands between the channels. This spectral inefficiency is very costly, particularly for medium or large networks. Additionally, if the network application is corporate communications, including voice and fax calls, file transfers, e-mail and other services, the demands on the upstream channel are much greater.
Some VSAT equipment vendors have adapted TDMA systems to be used as return channel solutions for DVB-IP systems since IP traffic is very bursty and TDMA lends itself well to burst traffic. Also, the periodic router updates previously mentioned herein function more effectively if they have a constant connection as provided by TDMA rather than the "on request" connection as provided by DAMA. These TDMA based DVB-IP systems, however, suffer from the cost and performance limitations outlined above. That is, the hub equipment is very expensive and throughput is limited when network loads are heavy.
Standardization for TDMA and DAMA based satellite systems has been slow to develop mainly due to the large number of variations required to accommodate the applications and architectures, which they serve. The adaptation of these systems for different applications requires considerable modification. A standard for Internet service over satellite recently promoted by the DVB community is return channel satellite DVB (DVB-RCS) that is based on traditional TDMA technologies. There is also a DVB (DVB-RCT) standard for terrestrial applications and cable systems (DVB-RCC). DVB-RCS is a TDMA based return channel solution designed to serve networks of thousands of sites, and is more targeted at the consumer/SOHO/small enterprise market. This standard was developed in an effort to emulate the success enjoyed by the DVB/MPEG-2 video standard specification. Since the MPEG-2 specification was intended to allow digitally compressed video to be transmitted to a variety of manufacturers' equipment, the MPEG-2 equipment for the hub-to-remote circuit is completely standardized. Many vendors manufacture equipment for this market and it is readily available at very low cost.
The effort to standardize DVB-RCS has foundered, however, due at least in part to the very high complexity and cost of the hub systems. These systems have not performed as effectively as expected. Furthermore, the standard does not address the medium-to-large enterprise network market.
In view of the above discussion, there exists a need for a system and method that provide for the control of multiple remote terminals and their access to satellite communications systems.

System and method for multiple access control in satellite communications system


The present invention is directed to optical structures and methods detecting the fluorescence of a molecule using metal-enhanced fluorescence. In particular, the invention describes the use of surface plasmon excitation for excitation of fluorophores near the metal surface and the efficient collection of the emission by coupling into the plasmon resonance and directing towards the detector. More particularly, the present invention makes use of the unique directionality of the plasmon induced fluorescence signal. The present invention is directed to optical structures using metal enhanced fluorescence including: an optical fiber having a conductive external coating; a light emitting diode (LED) having a conical shaped depression with curved sides on a front end surface, the curved sides having a conducting coating on the outer surface with respect to the LED.

1. Field of the Invention
The present invention is directed to apparatus and methods for increasing and detecting the fluorescence emitted by a molecule using metal-enhanced fluorescence. In particular, the invention describes the use of surface plasmon excitation for excitation of fluorophores near the metal surface and the efficient collection of the emission by coupling into the plasmon resonance and directing towards the detector. More particularly, the present invention makes use of the unique directionality of the plasmon induced fluorescence signal.
2. Background of the Related Art
Many experiments have been done demonstrating that metal particles can enhance fluorescence. Results in the literature show that fluorescence can be excited via the surface plasmon excitation. See Lakowicz, J. R., Radiative decay engineering: biophysical and biomedical applications. Anal Biochem, 2001. 298(1): p. 1–24; Lakowicz, J. R., et al., Radiative decay engineering: 2. Effects of Silver Island films on fluorescence intensity, lifetimes, and resonance energy transfer. Anal Biochem, 2002. 301(2): p. 261–77. Results in other publications have shown that emission can couple back into the plasmon at discrete angles.
FIG. 1 shows the well-known total internal reflection in fibers, where the refractive index n2>n1. Light approaching the refractive index boundary from the medium of higher refractive index is reflected away from the normal. For small angles of incidence, there is both a reflected ray and a refracted ray. However at some critical angle of incidence, θc, the refracted ray emerges parallel to the surface. For any angle of incidence greater than θc the light is totally internally reflected back into the medium of higher refractive index.
Fluorescent effects can be excited using various light sources. One light source is Xenon arc lamp. However, the spectral characteristics of the lamp vary over time and cannot provide a stable output. Light-Emitting-Diodes (LED) sources are also used. The LED sources can provide a stable output and offer opportunities for miniaturization and tunability of the output wavelength.

Optical structures for metal-enhanced sensing


The present invention is to provide a real time clock charging circuit mounted on a circuit board, which comprising an booting power input terminal adapted to receive a booting power passed through a first control module to a power storage unit and a second control module; the power storage unit adapted to store the booting power and to output a spare power prohibited from flowing into the first control module and the spare power only flows into the second control module as receiving no input power; a standby power input terminal adapted to receive a standby power to the second control module enabling to output those power to the real time clock and avoiding them to transmit outside.

In the cyber era, the information transmission speed and communication mode which has been greatly improved subject to the development of sophisticated wireless communication devices, electronic device and network transmission technology. Nowadays, a variety of portable electronic apparatus are intensively used in our daily life as important means for wireless communication and network services. An electronic apparatus generally has a RTC (real time clock) installed in the circuit board thereof for recording system time. A real time clock is one of the requisite hardware devices of an electronic apparatus. The real time clock of an electronic apparatus uses a battery to provide the necessary working voltage for normal functioning when input power is off, eliminating the problem of resetting the time frequently.
FIG. 1 shows a real time clock charging circuit according to the prior art. According to this design, the real time clock charging circuit 1 is mounted on a circuit board, comprising a booting power input terminal 11, a standby power input terminal 12, a charging battery 13, a resistor 14, and a chip 15. The booting power input terminal 11 is adapted to receive a booting power. The standby power input terminal 12 is adapted to receive a standby power. The charging battery 13 is adapted to store electricity and to output it. The resistor 14 has one end electrically connected to the chip 15 and the other end electrically connected to the charging battery 13. The chip 15 is electrically connected to the real time clock. The chip 15 controls the flowing direction of the booting power, the standby power and the charging power.
Referring to FIG. 1 again, the chip 15 has a first input pin 151, a second input pin 152, a third input pin 153, and a power output pin 154. The first input pin 151 is electrically connected to the booting power input terminal 11. The second input pin 152 is electrically connected to the standby power input terminal 12. The third input pin 153 is electrically connected to one end of the resistor 14. The power output pin 154 is electrically connected to the real time clock to provide the real time clock with the necessary working power. During input of the booting power, the first input pin 151 receives the booting power. During input of the standby power, the second input pin 152 receives the standby power. The booting power and the standby power can be outputted to the real time clock through the power output pin 154, and transmitted through the third input pin 153 and the resistor 14 to the charging battery 13 for storage. When the booting power and the standby power are off, the charging battery 13 outputs the charging power through the third input pin 153 and the power output pin 154 to the real time clock. Thus, the necessary working power is constantly provided to the real time clock, keeping the real time clock to work continuously.
According to the aforesaid prior art real time clock charging circuit 1, the chip 15 is an important component that controls the flowing direction of power inputted from different power sources into the real time clock charging circuit 1. However, the complicated structure of the power input pins 151,152,153 and power output pin 154 of the chip 15 greatly increases the cost to install the chip 15 in the circuit board. Under the market trend to increase the density of component parts and chip sets in a circuit board, it is difficult to arrange the chip 15 in the limited space of the circuit board. The high cost of the chip 15 greatly complicates the design of the real time clock charging circuit and increases its manufacturing cost. Therefore, it is desirable to provide an inexpensive real time clock charging circuit that can easily be arranged on a circuit board.


A thermally-tuned rotary labyrinth seal for a gas turbine engine includes an inner annular seal member having axially spaced, radially projecting annular seal teeth, and an outer annular seal member having a stepped honeycomb structure which face the annular seal teeth of the inner seal member and define therewith axially spaced regions bounded by the seal teeth and honeycomb structure. The seal teeth and stepped honeycomb structure cooperate to inhibit gas flow from one region to the next. Also, the seal has inlet and outlet vent holes defined through the honeycomb structure at respective upstream and downstream ends thereof which communicate with correspondingly located ones of the regions. The inlet and outlet vent holes are aligned along respective planes extending radially relative to a longitudinal axis of the engine and the holes are disposed at angles extending in tangential directions along the radial planes. Further, the seal includes an annular housing attached on an outer side of the honeycomb structure which defines a single axially elongated annular cavity spanning the honeycomb structure. The cavity interconnects in flow communication the inlet and outlet vent holes for providing gas flow in heat transfer relationship along the outer side of the honeycomb structure from the inlet vent holes to the outlet vent holes to provide active seal clearance control.

The present invention relates generally to gas turbine engines and, more particularly, is concerned with a thermally-tuned rotary labyrinth seal for a gas turbine engine.
2. Description of the Prior Art
Gas turbine engines generally include a gas generator which comprises a compressor for compressing air flowing aft through the engine, a combustor in which fuel is mixed with the compressed air and ignited to form a high energy gas stream, and a turbine driven by the gas stream and connected for driving a rotor which, in turn, drives the compressor. Many engines further include a second turbine, known as a power turbine, located aft of the gas generator and which extracts energy from the gas flow to drive a rotating load with variable pitch blades such as found in the propulsor of helicopters, ducted turbofan engines, and turboprop engines.
A recent improvement over the turbofan and turboprop engines is an unducted fan engine such as disclosed in the first U.S. patent application cross-referenced above. In the unducted fan engine, the power turbine includes counterrotating rotors with turbine blades defining counterrotating airfoil stages which drive in corresponding fashion unducted fan blades radially located with respect to the power turbine. The fan blades of the unducted fan engine are variable pitched blades to achieve optimum performance. During operation, fuel efficiency of the engine can be increased by varying the pitch of the blade to correspond to specific operating conditions.
In order to minimize engine performance losses due to leakage of pressure to outside the flowpath from between a stationary casing and the rotary outer rotor at a relatively high pressure upstream region of the flowpath through the power turbine, a single labyrinth seal has been used between the casing and rotor to deter passage of air. One typical prior art labyrinth seal is composed of a plurality of seal teeth axially spaced, circumferentially extending and outwardly projecting on an annular shaped rim attached to the rotary rotor and a stepped honeycomb structure attached to the stationary casing which sealably interface with the teeth.
However, the seal is located in a thermal environment where the temperature of the teeth is influenced by the higher temperature rotor in contact with the hot gas flow, whereas the temperature of the honeycomb structure is influenced by the lower temperature casing in contact with outside air. This produces a temperature differential between the seal parts which creates a problem. The inner teeth-bearing rim undergoes faster thermal growth than the outer honeycomb structure. This results in increased rubbing of the teeth against the honeycomb structure which makes seal clearance control more difficult.
One approach to solving this problem is presented in U.S. Pat. No. 4,513,975 to Hauser et al, assigned to the same assignee as the present invention. In the Hauser et al patent, a series of axially spaced conduits are provided which join upstream with downstream regions defined by the steps of the stationary honeycomb structure and the teeth on the rotary rotor. The conduits conduct a portion of hot gas from the upstream regions to the downstream regions. Each conduit includes an annular cavity with pluralities of inlet and outlet passages offset circumferentially from one another. Each inlet passage is aligned along a radius of the engine, whereas each outlet passage is aligned within an axial plane and extends at an acute angle relative to the engine axis.
As the temperature of the gas increases, the gas portion passing through each conduit f rom the upstream region assists the downstream region to heat more rapidly. The objective is to increase the rate of heat transfer between seal members and decrease the time it takes to reach thermal equilibrium.
The approach of the above-cited patent is a step in the right direction toward reducing the problem of differential thermal growth between the seal members and its deleterious effects. However, it is perceived that further improvements are needed in this approach in order to devise a practical solution to the problem.

Thermally-tuned rotary labyrinth seal with active seal clearance control


In an X-ray image intensifier tube, a casing for the protection from x-radiation from the X-ray image intensifier tube. The casing according to the present invention comprises a jacket of a thermoplastic material charged with a powder of a material that absorbs the x-radiation and a shielding from outside magnetic fields. The shielding is in contact with the jacket. The screen that absorbs the x radiation thus is at least partially formed of the jacket.

1. Field of the Invention
The present invention relates to the casings for x-ray image intensifier tubes and, more particularly, to the means used in these casings to achieve protection from X-radiation.
2. Discussion of the Background
X-ray image intensifier tubes (in abbreviated form "XII tube" hereafter) are vacuum tubes comprising an input screen toward the front of the tube, an electron optical system, and a screen located at the back of the tube for observing a visible image.
FIG. 1 diagrammatically shows such an XII tube. The tube comprises a glass vacuum enclosure 2 having one end at the front of the tube which is closed by a input window 3 exposed to x-photon radiation.
The second end of enclosure 2 forming the back of the tube is closed by an output window 4 that is transparent to light.
Generated x-rays are converted into light rays by a scintillator screen 5. The light rays excite a photocathode 6 which in response emits electrons. These electrons are accelerated toward output window 4 using different electrodes 7 placed along a longitudinal axis 9 of the tube, and which form the electron optical system. In the example shown, output window 4 carries a cathodoluminescent screen 10, made of luminophores for example. The impact of the electrons on cathodoluminescent screen 10 makes it possible to restore an image formed at the beginning on photocathode 6.
The XII tube is contained in a protective enclosure casing 15, which in particular assures the following functions:
1) protection of electron optical system 7 and of the tube from spurious outside magnetic fields;
2) protection of persons from x-radiation, both direct x-radiation that is not absorbed by scintillator 5, and scattered x-radiation produced by the tube itself;
3) mechanical protection of vacuum enclosure 2 from the outside environment; and
4) to form the fastening interface with radiological equipment (not shown) on which the tube must be mounted, and with accessories for using this equipment, which may comprise, for example, threaded holes for the fastening at faces or planes of reference.
For this purpose, the wall of a standard casing 15 for an XII tube generally comprises several superposed layers 16, 17, 18.
The most outside layer 16 forms a jacket 16 which is the mechanical framework of casing 15. This jacket can be, for example: a cast of metal alloy; or else worked or stamped; or further, mechanical-welded, made from metal foils. Outside layer or jacket 16 assures the mechanical protection of the vacuum enclosure, and particularly in its back part 13, located toward output window 4 of the tube, it performs the fastening interface role. The image produced by cathodoluminescent screen 10 is visible outside the casing thanks to an opening 14 made in back part 13.
An inside layer 17, placed between outside layer 16 and enclosure 2 of the XII tube, constitutes a shielding that assures the protection of the electron optical system from outside magnetic fields. This inside or shielding layer 17 is made of a material exhibiting a high magnetic permeability, such as, for example, soft iron, or an iron-based alloy such as, for example, "permalloy" (iron-nickel alloy), or mu-metal, etc.
It should be noted that inside layer 17 that forms a shielding from the magnetic fields is made from foils of these materials having a high magnetic permeability.
A second inside layer 18, placed between enclosure 2 of the XII tube and the first inside layer 17, constitutes a screen whose function is to absorb the x-radiation. The object of this screen 18 is to attenuate the x-radiation which leaves casing 15.
The materials that are used to make this second inside layer 18 are also generally available in the form of foils, so that the making of this second layer or screen 18 (but also of first inside layer 17) relies on the techniques of boiler making: partial stamping, working, rolling, mechanical welding. These techniques result in long and costly operations which further result in high geometric tolerances.
To produce the second inside layer or screen 18, it is common to use materials having a high atomic number, and more particularly lead which exhibits the advantage of having a cost that is not very high and the ability for greatly absorbing the x-radiation.
However, lead is a material that is difficult to use because of its great malleability or ductility. Moreover, working with lea is regulated and the personnel who perform this work are subjected to constraints of medical observation.
Another point that poses a problem in the production of XII tube casings comes from the difficulty that there is in bonding the various layers 16, 17, 18 to one another.
These layers are often bonded by gluing, which constitutes an operation that is not very compatible with industrial requirements and which results, in particular, in high tolerances on the wall thicknesses.
The absorption of the x-radiation has as its goal to attenuate the x-radiation leaving the casing, up to a value compatible with determined regulations. Since the intensities of this incident x-radiation are not equal at all points of casing 15, the absorption of the radiation must not necessarily be equal at all these points, and it is enough to impart to the wall of the casing at these various points the appropriate coefficient of absorption to obtain the desired attenuation.
As shown in FIG. 2, it is possible to define in an XII tube casing several main zones a, b, c, d, e, which extend from the front 21 of the casing on the side of input window 3 up to the back 13 of the casing on the side of output window 4. Each of these zones can require an attenuation of the x-radiation that is different from that of an adjacent zone. For example, zone b where the tube is at its largest diameter requires overall to attenuate the x-radiation less than zone c where this diameter steadily decreases.
In each of zones a to e, the thickness of screen or layer 18 that absorbs the x-rays is calculated to reduce to the determined regulation value the highest level of incident x-rays existing in each zone.
But in the same zone, there can be considerable differences in the level of x-radiation, and the thickness of layer o screen 18 is selected for the attenuation of the x-radiation having the highest intensity.
Consequently, the quantity of material constituting screen 18 is superabundant in many of its points, which results in increases in weight and cost.
Thus, for example, it is common to impart to the various zones a, b, c, d, e of screen 18, if it consists of lead foils, thicknesses respectively of about 1.7 mm, 1.2 mm, 2.3 mm, 1.2 mm and 2.7 mm, whereas for zone b, for example, the greater part of this zone could have a thickness of only 0.6 mm.


The present invention provides a highly reliable network of interconnected voice processing modules. The voice processing modules are interconnected by a high speed FDDI (Fiber Distributed Data Interface) network so that information can be transferred between the modules at high speed. All of the incoming lines for all the interconnected modules are connected in a single hunt group. Each user's profile is stored in two modules and each module includes a directory that shows were each user's profile is stored. When a call arrives at a particular module, the directory is first checked to insure that the desired user does have a mailbox somewhere on the network and to determine where the particular user's profile is located. The user's profile is obtained via the FDDI network from one of the modules where it is located. The profile will show where the associated greeting is stored. The greeting is obtained via the FDDI bus (if it is not on the system which received the call) and the greeting is played. If the caller leaves a message, it is stored on the system which received the call. The user's profile is updated to show that a message was stored and to show where the message is stored. The updated user's profile is then returned to the two systems where it was originally stored.

Voice processing systems, sometimes called voice mail systems, are in widespread use. Many of the early voice processing systems were small, relatively simple systems designed for a limited number of users and having a limited number of functions. The technology has advanced to the point where today large voice processing systems which can served thousands of user are available from a variety of vendors. The large voice processing systems that are available today provide a rich menu of functions and they can service many thousands of users.
As systems have grown in size and complexity, two needs have become evident, namely, very high reliability and modularity. Very high reliability is needed so that users can come to depend upon voice processing systems without fear that information will be lost. Modularity is needed so that a module which serves a relatively small number of users can be installed and then as the number of users grows, additional modules can be easily installed, increasing the capacity of the system without the need to discard what has already been installed. Designing systems which satisfy both of these requirements presents significant challenges.
The prior art includes voice processing systems that increase reliability by providing redundant hardware. However, in the prior art systems, each user is assigned to a particular module or sub-system. The module or sub-system to which each user is assigned is generally termed the user's "home" system. Backup is sometimes provided by having each user assigned both to a home module or sub-system and to a backup module or sub-system. The backup module or sub-system only becomes operable if the primary hardware experiences a problem. For example, Digital Equipment Corporation markets a system called DECVoice which can accommodate redundant backup hardware. The cost of providing reliability by merely providing redundant backup hardware is relatively high since such hardware is only used when the primary hardware experiences a problem.
The present invention provides redundancy in a manner that utilizes the backup hardware for normal operations until one of the modules in the system has a problem. When a module has a problem, the work previously done by that module is shifted to the other modules in the system. The typical user would in most instances not even recognize that there was a problem. Stated differently, with the present invention the system includes a number of modules which share the work load. If one of the modules experiences a problem the workload is merely shared by the other modules in the system.
The second requirement discussed above, that is the need to allow for modular growth is also recognized in the prior art. An example of a system which includes a plurality of interconnected voice processing modules is shown in U.S. Pat. No. 5,029,199 (Jones et al.) issued Jul. 2, 1991. U.S. Pat. No. 5,029,199 describes a system which has a distributed architecture including a plurality of message processing modules. The system shown in U.S. Pat. No. 5,029,199 includes a master control unit that directs each incoming call to a particular one of the voice processing modules depending upon a variety of factors. The voice processing modules are interconnected by a local bus. Each subscriber is assigned to a home system; however, messages can be stored remotely and the home processing system can access the remotely stored messages over the local network. The master control unit stores subscriber related information including the identification of the home unit for each subscriber. A key aspect of the system shown in this reference is the fact that the incoming lines are switched between the various voice processing modules by the master control unit.
The present invention provides a modular system without utilizing a master control unit to direct incoming calls. With the present invention the incoming lines are connected as a single hunt group and any module in the system can handle any incoming call.

Voice processing systems connected in a cluster


To eliminate misfit dislocation occurring in a hetero-interface and to provide a bipolar transistor capable of a high speed operation, the bipolar transistor is configured such that the energy band gap is progressively narrowing from part of an emitter layer towards part of a collector layer through a base layer.

The present invention relates to a bipolar transistor and, more particularly, to a heterojunction bipolar transistor and a fabrication method thereof.
When the delay time of a basic gate is compared in terms of a trend in a highly integrated memory of each generation, performance of a bipolar transistor must be improved in the same way as an MOS transistor in order to maintain a superiority of a BiCMOS gate over a CMOS gate in future. When the switching time is compared between the MOS transistor and the bipolar transistor that are used in the BiCMOS gate circuit, the switching speed of the bipolar transistor tends to decrease in the silicon system of the prior art although a high speed switching time can be accomplished in the MOS transistor with the scale-down of the transistor size and its lowering voltage.
One of the high speed bipolar transistors is a heterojunction bipolar transistor which has a difference of the band gap between its base region and emitter region. The characterizing feature of the heterojunction bipolar transistor is that a high current gain can be obtained by preventing the injection of majority carriers from the base region to the emitter region by utilizing the barrier height of the step of the band gap on the hetero-interface of the emitter-base junction. Consequently, since the base concentration can be set to a relatively higher concentration than in the conventional bipolar transistors, the base resistance can be reduced and higher speed performance of the bipolar transistor can be accomplished.
The structure of the conventional heterojunction bipolar transistor uses a silicon-germanium alloy (Si.sub.1-x Ge.sub.x) for its base region, and FIG. 19 shows its sectional view. Reference numeral 2 in the drawing represents an n.sup.+ -Si collector region, 3 is a p-Si.sub.1-x Ge.sub.x base region, 4 is n.sup.+ -Si emitter region, 5 is an emitter electrode, 6 is a base electrode and 7 is a collector electrode. Among them, the X value of Si.sub.1-x Ge.sub.x in the base region is increased from the emitter region side towards the collector region side and the energy band gap becomes narrower from the emitter region side towards the collector region side. Therefore, a drift field is generated in the base region, so that the base transit time of the minority carriers can be shortened and high speed performance of the bipolar transistor can thus be accomplished.
A heterojunction bipolar transistor using the silicon-germanium alloy (Si.sub.1-x Ge.sub.x) for the base is described, for example, in JP-A-1-231371.
According to the prior art described above, since the band gap of the emitter and base regions sharply changes at the emitter-base junction, misfit dislocations resulting from the lattice mismatch between silicon and germanium occur in the active regions of the bipolar transistor and problems such as a drop of high speed performance voltage breakdown of the bipolar transistor and an increase of the leakage current result.
Generally, in hetero-epitaxy of lattice mismatched materials such as silicon and germanium, a growth layer coherently grows without generating misfit dislocations and the lattice mismatch is mitigated by a strain in the lattice when a film thickness is below a thickness approximate to a super-lattice, but when the growth layer grows into a thickness about the film thickness necessary for constituting the bipolar transistor, the lattice mismatch invites the strain in the lattice and the misfit dislocations. The occurrence of the misfit dislocations which exerts adverse influences on the electrical characteristics is a critical problem which is unavoidable when a hetero-material of the silicon-germanium alloy (Si.sub.1-x Ge.sub.x) is injected into the Si system bipolar transistor.

Bipolar transistor with a particular silicon germanium alloy structure


A fabrication method for a chip size semiconductor package includes the steps of bonding conductive wires on bonding pads formed on an upper surface of a semiconductor chip, putting the semiconductor chip including the bonded conductive wires in an electrolyzer containing an electrolytic solution in such a manner that one end of each of the conductive wires is exposed outside of the electrolytic solution, attaching a plating electrode to an inner wall of the electrolyzer, attaching a conductive plate to serve as a common electrode to the exposed one end of each of the conductive wires; and connecting the conductive plate and the outer wall of the electrolyzer to an electric current source.

1. Field of the Invention
The present invention relates to a fabrication method for a chip size semiconductor package (CSP), and more particularly, to an improved fabrication method for a CSP in which conductive wires are bonded directly on bonding pads formed on a semiconductor chip.
2. Description of the Prior Art
The conventional CSP fabrication method will now be described in detail with reference to FIGS. 1A through 1F.
First, as shown in FIG. 1A, a bonding pad 13 is formed on a semiconductor chip 11 (or a wafer), and a passivation layer 15 is formed on the upper surface of the semiconductor chip 11 except the bonding pad 13. Then, as shown in FIG. 1B, a first conductive layer 17 formed of TiW and a second conductive layer 19 formed of Au are sequentially deposited by a sputtering method on the bonding pad 13 and the passivation layer 15. As shown in FIG. 1C, one end of a conductive wire 21 formed of gold (Au) is bonded on the surface of the second conductive layer 19 above the bonding pad 13, and then the conductive wire 21 is cut to be formed in a straight or curved line of 1 to 2 mm. The conductive layer 19 is used as a common terminal when a post electroplating process is carried out.
As shown in FIG. 1D, a photoresist 23 is formed on the second conductive layer 19 except the portion where the bonding pad 13 is formed. Then, as shown in FIG. 1E, to enhance the strength of the conductive wire 21, a nickel (Ni) plating 25 is performed on the surface of the conductive wire 21. As shown in FIG. 1F, a gold (Au) plating 27 is carried out on the nickel-plated portion of the conductive wire 21. The gold plating improves an electrical solder joint between the conductive wire 21 and a printed circuit board (PCB) when the CSP is mounted on the PCB, and prevents corrosion. An electroplating method can be used for plating nickel and gold. Finally, the photoresist 23 is removed and the first and second conductive layers 17 and 19 are removed except in the region where the bonding pad 13 is formed.
The conventional CSP fabrication method has the following disadvantages. In order to enhance the strength of the conductive wire 21 and the electrical solder joint, and in order to prevent corrosion, very difficult processes with associated high cost, such as sputtering, photoresist deposition and etching are required.

Fabrication method for chip size semiconductor package


This invention relates to the use and composition of materials which, when added to oral fluid samples, make such samples suitable for use with microparticle-based immunoassays. In one embodiment, this invention provides a method of reducing false positives in assays for the detection of an analyte in an oral fluid sample. The method involves providing an oral fluid sample combined with a bile acid or salt where the bile acid or salt is present in a concentration sufficient to reduce the rate of occurrence of false positives in said oral fluid based immunoassays.

Immunoassays utilizing colored microparticles are widely used to provide simple, sensitive field and laboratory tests for analytes of clinical interest such as drugs, antibodies, and antigens. Such tests have been applied to analytes in urine, serum, and whole blood.
In typical immunoassays that use a particulate moiety as a detectable label, colored microparticles such as gelatin, dyed latex, or colloidal gold are labeled with a material (e.g. antibody) which binds the analyte of interest. The most common assay utilizing microparticle indicators is the lateral flow immunochromatography assay (see, e.g., U.S. Pat. No. 5,120,643, British Patent GB 2204398A, and European patent EP 0323605 B1). In most lateral flow immunochromatography assays, microparticles are dried onto a sample application pad (typically glass fiber) which in turn is affixed to one end of a strip of chromatographic medium such as nitrocellulose. Another material binding to the analyte of interest is affixed to the chromatographic medium at or near the end opposite to the end having the application pad.
The liquid sample to be analyzed is placed on the pad, causing the suspension of the microparticles into the liquid and allowing any analyte in the liquid sample to bind to the analyte-binding material attached to the microparticles. The liquid sample leaves the application pad by diffusion and capillary action and begins to migrate along the nitrocellulose strip carrying the microparticles down the strip along with the liquid. When the liquid containing the suspended microparticles arrives at the region of the chromatographic strip bearing the second binding material, the analyte (if present in the original sample) will form a molecular bridge between the analyte-binding material on the microparticles and the analyte-binding material affixed to the strip, resulting in the immobilization of the microparticles at that point on the strip where the analyte-binding material is affixed. This immobilization of the microparticles results in a visible signal (e.g., a colored band or dot) at this point on the strip. If the analyte is not present in the sample, the microparticles will continue past this location on the chromatographic strip and a visible signal will not be produced.
A significant problem in the implementation of microparticle-based immunochromatography assays is prevention of non-specific binding of the microparticles to each other (agglutination), to the sample application pad, and to the nitrocellulose strip. Such non-specific binding (binding that is not mediated by specific recognition of the analyte and analyte-binding materials) results in false-positive test results.
A number of strategies have been used to prevent this non-specific binding. These strategies include "blocking" of the sample application pad and nitrocellulose strip with materials such as casein, gelatin, serum albumin, polyethylene glycol, polyvinyl alcohol, and a number of ionic and non-ionic detergents. In other approaches the microparticles are dried on the sample application pad in the presence of some of these same "blocking" materials and "chromatographic transport facilitating agents".
Although the relevant literature typically states that samples suitable for microparticle-based immunoassays include "physiological fluids, for example blood, saliva, ocular lens fluid, cerebral spinal fluid, sweat, urine, milk, ascites fluid, mucous, synovial fluid, peritoneal fluid amniotic fluid or the like" (see, e.g., Devereaux et al. EP 0 323 605 B1), in practice such assays have only been applied to blood and urine samples. Saliva, and other oral fluid samples, in particular, pose significant problems in these assays because of the low level of some analytes of clinical interest (e.g. antibodies and antigens relevant to infectious disease), and because of the presence of mucopolysaccharides in saliva which amplify and change the character of the nonspecific binding problems of the microparticles. Accordingly, the routine use of the blocking agents cited above has not proven adequate to produce a practical microparticle-based immunoassay which utilizes a sample containing an oral fluid.

Reduction of false positives in oral-fluid based immunoassays


Process for multi-coat lacquering of a substrate with a stoved first electrodeposition layer by applying a second surface coating layer of 10 to 30 .mu.m dry layer thickness consisting of a base lacquering agent containing a first, water-based, polyurethane resin, and wet-on-wet application of a third coating agent with a thinner dry layer thickness of 7 to 15 .mu.m consisting of a second water-based base lacquering agent, further application without prior stoving of a clear lacquer layer and mutual stoving, wherein the first base lacquering agent has a higher concentration of polyurethane resin than the second base lacquering agent.

Modern production line car lacquerings mostly consist of a base lacquer/clear lacquer top coat which is applied to an electrophoretically primed car body which has been provided with a filler layer. The base lacquer and clear lacquer are preferably applied wet-on-wet, i.e. the clear lacquer is applied to the base lacquer after an evaporation time, optionally with heating, and the two are stoved together after the clear lacquer has been applied. EP-A-0 238 037 discloses a process which can be used to reduce the stoved layers in which a filler and a water-based metallic base lacquer are applied by the wet-on-wet process. The examples section reveals that the filler layer is applied with a dry film thickness of 35 .mu.m which is conventional for filler lacquers.
EP-A-0 265 363 discloses providing a previously stoved cataphoretically applied primer with a two-layered base lacquer/clear lacquer top coat using a wet-on-wet process. There is no filler layer. However, there is a problem in that damage due to flying stones on vehicles lacquered by this process is particularly conspicuous since the primer layer is revealed when the impact of a stone dislodges the top coat. Although corrosion protection is still guaranteed, the visual impression cannot be tolerated.
For reasons of rationalisation and in order to save materials, there is a desire to reduce the thickness of the layers in vehicle lacquerings when building up the lacquer, but without producing any substantial losses in overall characteristics.

Herberts Gesellschaft mit beschrankter Haftung


The present invention includes a patch. The patch includes a main body with a base portion and a vapor emitting portion. The base portion includes a hydrogel comprising a first surface and an opposing surface. The vapor emitting portion is attached to the first surface of the hydrogel. A vapor emitting material is incorporated in the vapor emitting portion.

The present invention relates to a patch device for emitting vapor and to a method for releasing vapor.
Human beings have been using products that emit scents and aromas since ancient times. These products have been used for purposes such as masking unpleasant odors, attracting a member of the opposite sex, repelling animals and insects, and treating disease symptoms.
In order to extend the time of aroma emission, individuals making and using these products have dissolved or suspended the scents and aromas with other materials. For instance, perfumes are blended with volatiles that control and extend the period of evaporation of a particular scent. The Lindauer U.S. Pat. No. 5,234,689 issuing Aug. 10, 1993, describes a liquid perfume substance. This substance is applied to many areas of the skin. The fragrance is typically in a bottle or flask. Consequently, the user must reapply the substance.
Other formulations capture the aroma or scent material in a solid or a gel matrix. One type of solid matrix is wax in a candle. Scents and aromas within the wax are released when heated. The Nakatsu U.S. Pat. No. 6,086,644 issuing Jul. 11, 2000, describes a scented candle. In order to emit fragrances the candle must be lit. This type of scent emission has only limited use. For instance, the candles are not transportable because of their predisposition to start fires.
Other formulations use polymeric matrices to control release of a scent or aroma. For instance, the Wick U.S. Pat. No. 6,010,715 issuing Jan. 4, 2000, describes a patch for controlled release of a substance. The patch includes a formulation of an active agent and a thermoplastic resin. The formulation releases active agents through the skin. The patch is strategically positioned in order to be effective. Agents released by this patch are limited to substances that are absorbable into the human body.


A method for forming a P-type region in a semiconducting crystalline substrate by ion implantation is disclosed, wherein the implant species is an ionic molecule that contains titanium and boron.

1. Field Of The Invention
This invention relates generally to the field of integrated circuit manufacturing and, more particularly, to ion implantation.
2. Description Of The Related Art
Ion implantation is a well known technique for forming junctions in semiconductors. During ion implantation, a source material is used to produce ions which are ultimately implanted into a silicon wafer. Where the ions become embedded in the silicon, they change the silicon's electrical properties. If an N-type source material is used (e.g., one containing phosphorous), the resulting silicon will become N-type, or rich with electrons. If a P-type source material is used (e.g., one containing boron), the resulting silicon will become P-type, or rich with "holes."
P-type junctions have traditionally been manufactured by the use of a boron-based source gas, usually boron trifluoride, or BF.sub.3. Inside of an ion implantation machine, the source gas is ionized, creating, amongst other species, BF.sub.2.sup.+ ions. In traditional Ultra Large Scale Integration (ULSI) applications requiring P-type junctions, the BF.sub.2.sup.+ species is used as the implant species in the formation of boron-doped, P-type junctions. The BF.sub.2.sup.+ species can be extracted by adjusting the field strength of extractor magnet inside of the ion implanter so as to choose an ion species of the desired charge-to-mass ratio.
However, using the BF.sub.2.sup.+ ion as the implant species has its drawbacks. Most importantly, molybdenum is usually present in ion implantation machine components and acts as a source of contamination. An ionized molybdenum ion, Mo.sup.++, has approximately the same charge-to-mass ratio as the BF.sub.2.sup.+ species. Therefore, if Mo.sup.++ ions are present in the ion plasma, the magnet will be unable to extract the desired BF.sub.2.sup.+ species without also extracting the Mo.sup.++ species. As a result, any ionized molybdenum will be implanted into the silicon along with the BF.sub.2.sup.+ species. Unfortunately, the presence of molybdenum degrades the performance of the P-type junctions formed, because the presence of molybdenum in the junction will increase the junction's reverse bias leakage. In DRAM technologies, for instance, increased reverse bias leakage degrades refresh characteristics. Junction degradation issues become particularly acute in the ULSI era, which demands shallow junctions of high purity.

Contamination free source for shallow low energy junction implants using implanted molecules containing titanium and boron


A suitably dimensioned, hollow, crescent-shaped die with an upstanding handle provides a culinary tool for conveniently and quickly removing all the seeds from a watermelon. Upright side walls on the perimeter of the die engage each of the seed-bearing, crescent-shaped-in-section columns and extract the column as the die is withdrawn at the conclusion of the cutting portion of the cycle. By arranging a portion of the die and side walls in an overlapping relation, the areal extent of the die can be expanded, after withdrawal, to allow the attendant seed-bearing column to drop from the die by gravity. If desired, the overlapping portion can be augmented by slots and a pair of retainer pins to restrict the extent of change of the die area to a predetermined range; and inward shark tooth projections on the side walls can be used to enhance the ability of the side walls to lift the column during die withdrawal. A spring-loaded cross-tong attached to the side walls can serve not only as a handle but also as a die expander to release a seed-bearing column at the conclusion of the seed-removal cycle.

The present invention takes advantage of the fact that watermelon seeds are arranged in six elongated columns symmetrically disposed about the longitudinal axis of the melon. More specifically, each of the columns is crescent-shaped in cross-section, with the seeds dispersed within the flesh of the melon but invariably located within the confines of the crescent-shaped imaginary envelope of the elongated column.


A monitoring system for a satellite is disclosed. The satellite includes a bus, an optical sensor configured to optically detect objects in a first zone extending from the satellite, and a solar assembly comprising a solar panel and a radar device. The radar device can be configured to detect objects in a second zone, different from the first zone, extending from the satellite in a direction transverse to a surface of the solar panel.

Satellites orbiting the planet, such as Earth, can be susceptible to damage caused by nearby objects or debris. Such objects may pose a risk of collision with the satellite, undesired observation of the satellite, interference with the satellite, or other incidental or malicious harm that could disrupt the integrity, orbit, or operation of the satellite.

Deployed radar panel for space situational awareness


A method of analysing a structure of a composition of matter in a sample includes obtaining a data set comprising a plurality of spectra from the composition, from a first method of analysis, dividing each of the spectra into a plurality of bins, determining a control parameter or parameters indicative of synchronised fluctuations in signal intensity across some or all channels, resulting in universal correlation between said bins, and determining a partial covariance of different bins across the plurality of spectra using the control parameter to correct the correlation of intensity fluctuations between said bins.

Laboratory analytical techniques and equipment have advanced to such a degree of power and sensitivity that they are able to produce large quantities of data when analysing even relatively simple samples. The challenge for the analyst is then in reviewing this data to derive useful information about the sample. This is particularly the case when the sample under analysis is a complex mixture of materials and/or represents a sample of biological origin, such as one or more proteins or peptides, nucleic acids or metabolites.
Mass spectrometry (MS) is a popular and effective method for analysing the structure of biomolecules such as proteins, DNA, lipids or metabolites. The major applications of biomolecular MS in clinical biology are in protein studies (proteomics). The primary aim of proteomic MS analysis is to establish the sequence of the biomolecular building blocks, (i.e. amino acids), and the covalent post-translational modifications (PTMs) of particular proteins. To do so, the biomolecules are typically first cut into smaller fragments, e.g. acting on proteins with enzymes to obtain peptides, the peptides are sent to a mass spectrometer via soft ionisation techniques [such as electrospray ionisation (ESI) or matrix assisted laser desorption-ionisation (MALDI)], where in tandem mass spectrometry (MS/MS) they are fragmented even further to obtain peptide structure details (often by collision induced dissociation, CID), and the spectral information is pieced together to deduce the full structure of the original biomolecule.
A reliable data interpretation of complex biomolecular fragment spectra generated during the MS/MS step is one of the biggest challenges of current MS technology. This crucial step of interpreting the data output from the spectrometer has been achieved by (i) matching the measured spectrum to the expected "theoretical" one on the basis of the structure of the known peptides derived from a protein database combined with general peptide fragmentation rules, (ii) matching the measured mass spectrum to a database of experimental spectra, or finally (iii) a first-principles structural reconstruction using the measured spectrum and the peptide fragmentation rules only (so-called de novo algorithms). In each case, the strength of a match between a given peptide structure and the measured mass spectrum is expressed as a peptide score, and those scores exceeding an empirical threshold or sufficiently separated from scores for all other candidate peptide structures are taken to correspond to correct identifications. Low-confidence (low-score) assignment of a given spectrum to correct structure, or best-match to incorrect structure, turns out to be a quite common place.
These methods have low success rates of interpretation, meaning that 50% or more of the measured MS spectra can be wasted. The poor efficiency of assignment, even often of very high quality fragment mass spectra, arises from MS/MS method limitations, strong sequence-dependent character of peptide fragmentations, unexpected protein PTMs, insufficient signal to noise ratio of multiple sequence-informative peaks, genetic mutations, signal overlapping (in particular for longer peptide and protein sequences) and other causes.
To alleviate this ambiguity mass resolution has been increased far beyond integer mass-to-charge (m/z) ratio to identify atoms of MS fragments from their accurate masses, e.g. to tell apart two nitrogen atoms (28.007 Da) from one carbon and one oxygen atom (27.995 Da). Although this high resolution MS reduces considerably the number of prospective hits (e.g. peptide sequence options in the case of proteomics) generated by matching the experimental data to databases or derived directly from the mass spectra (such as in de-novo sequencing), it does not provide by itself any experimental evidence for the assumed origin of the biomolecular fragments that is derived from the observed mass-to-charge ratios. This leads to multiple false positive/negative results in the identification of fragments characterised by highly accurate m/z, limiting significantly the capability and reliability of biomolecular structural analysis using MS.
Fragment mass spectra of peptides and proteins commonly display signals of unusual origin caused by the strong dependence of the fragmentation patterns on amino acid sequence, peptide length, charge state, modifying groups and other factors. A significant proportion of these fragment ions miss identification or do not undergo a correct interpretation, frequently causing the spectrum-to-structure matching failure. Furthermore, low relative peak intensities ("relative abundances") and poor signal to noise ratios of standard fragments of a well-known origin are also very common, which leads to them being missed by the existing MS interpretation algorithms. Indeed, any interpretation of a mass spectrum must employ some threshold on the relative abundance of spectral peaks, below which those peaks within a certain mass-to-charge (m/z) range are not taken into consideration. As a result of the finite signal-to-noise ratio, structure determining algorithms work using a limited number of spectral signals ('good peaks'), which is currently limited to being defined purely on the grounds of relative intensities. If low-intensity MS peaks bearing crucial structural information are not taken into consideration, the algorithm will produce low-confidence structural assignment that eventually leads to lack of successful spectral interpretation and correct sample component analysis. Increasing the mass accuracy and mass resolution of the MS instruments can only partially solve this problem by resolving overlapping signals and reducing a number of candidate fragment ions for relatively intense "unknown" fragments. So, to an extent, can alternative fragmentation techniques by causing different fragmentation patterns. However, a general solution for the poor interpretation efficiency of the tandem mass spectra, independent of the fragment origin complexity or the ion relative abundance, is clearly lacking.

Methods and systems for analysis of mass spectrometry data

IMPERIAL COLLEGE OF SCIENCE, TECHNOLOGY AND MEDICINE


The clipless pedal system for mountain bikes or other bicycles comprises a generally circular pedal body, at least one side of which has a mushroom or T-shaped extension which is created by either forming a larger diameter head over a small diameter neck or by forming grooves or slots in the extension slightly below its top, with the grooves being the equivalent of the neck. The cleat consists of a mounting plate which can be attached to the sole of mountain biking shoe, and has a generally open interior of sufficient dimensions to permit insertion of the head therein. Engaging means extend inwardly at a spacing corresponding to the head of the extension. The engaging means can be inserted into the neck of the extension to catch just below the head of the extension. One or more spring tabs may be used to releasably lock the cleat and pedal extension together once the head is in position with respect to the engaging means.

Mountain bikes have overtaken road bikes in popularity over the past few years, with sales of mountain bikes exceeding those of road bikes 4 to 1. However, advanced equipment to improve speed and pedalling efficiency is still primarily available only for road bikes. With the exception of lightweight composites and high-tech metals to decrease the overall weight of the bicycle, the single most significant improvement in bicycle accessories is the clipless pedal.
Clipless pedals have been available for road bikes, both for racing and touring, for many years. They provide increased comfort and decreased weight as compared with old style bicycle clips and pedals. Several disadvantages of prior clipless pedal systems were eliminated by the clipless pedal system disclosed in U.S. Pat. No. 4,942,778 issued Jul. 24, 1990 to the present inventor. One of the major disadvantages of earlier pedals was that the locking mechanism was in the pedal itself, limiting engagement of pedal and cleat to only one side of the pedal. As disclosed in the '778 patent, the locking mechanism is in the cleat which attaches to the sole of the shoe such that the mechanism is recessed and, thus, protected from damage.
Mountain biking introduces additional concerns beyond those for road bikes. The pedal bodies themselves are broader because they must bear a considerable amount of stress and strain when riding in rough terrain and during sudden changes of direction. Also, dirt and debris can build up on the pedals and in the cleats when riding off-road, so considerations must be made to avoid jamming the locking mechanism so that it will not engage or disengage when desired. Finally, because a rider may wish to leave his or her feet free when riding in rough terrain, it may be preferable to provide for a choice between locking the cleat and pedal together and riding "unattached". Thus, in a race situation, for example, the rider could be locked in when riding in areas where the course is predictable to achieve maximum pedalling efficiency, then release the pedals when he or she wants to be sure that a foot will be available to push off of an obstacle, to pivot in a sudden turn or to prevent a fall.

Locking mechanism for a clipless bicycle pedal


Disclosed is a collapsible assembly for adjustably supporting a net for pitching back, rebounding, or otherwise returning various types of game balls, the assembly including first and second U-shaped stand members, each having a crossbar and a pair of spaced apart leg elements, the cross bar being adapted for engaging a horizontal surface such as a floor or the ground, and the upper ends of the leg elements mounted to a pair of hub plates from which the leg elements diverge at a substantial angle to form a stand. An inverted U-shaped net support member has its lower ends connected to the hub plates by way of mechanism that allows the support member to be angularly adjusted about a horizontal axis and releasably locked at a chosen orientation. The assembly is capable of being folded to a storage position in which the net support member is locked in its upright position and the two stand members are rotated to upright positions adjacent and generally parallel to the net support member, whereby the bottom of the hub plate is then engagable with a floor or the ground to support the assembly in a stable free-standing manner.

1. Field of the Invention
The present invention relates to devices for supporting a net for pitching back or otherwise rebounding a game ball, such as a baseball or a soccer ball for example, and used as a training and practice device, and more particularly to such devices that allow the inclination of the net to be adjusted, and which are foldable for storage and transport.
2. Description of the Prior Art
There are devices available for supporting a net for the purpose of returning or restraining a sports game ball. For example such devices have been provided for footballs, soccer balls and golf balls, and others serve as a pitchback and target for baseballs and softballs. Unfortunately these devices are not without their limitations and shortcomings. Conventional support devices for nets are often in the form of metallic constructions that can be cumbersome and unwieldy, and not easy to transport and store efficiently, particularly when they cannot be collapsed or folded for that purpose. Often in such devices the inclination at which the net is held cannot be adjusted, and they are generally restricted to being used with balls of one particular sport, and do not lend themselves to being used in conjunction with a variety of sports.


A feedback mechanism for adaptively enabling and disabling an advanced prediction mode for video data processing is disclosed. A quantization parameter (QP) threshold is set and a QP mean for an error frame is determined. The advanced prediction mode is enabled if the QP mean is less than the QP threshold.

(1) Field of the Invention
The present invention is related to the field of video coding, more specifically, the present invention is a method and an apparatus for adaptively enabling and disabling the advanced prediction mode in an H.263 video coder.
(2) Related Art
The International Telecommunication Union (ITU) Telecommunication Standardization Sector H.263 standard (ITU-T std. H.263-1995, published March 1996) is a standard for a coded representation which can be used for compressing the moving picture component of audio-visual services at low bit rates. The coding algorithm of the H.263 is a hybrid of inter-picture prediction which utilizes temporal redundancy, and transform coding of the remaining signal to reduce spatial redundancy.
There are numerous different optional modes in H.263 including an advanced prediction mode. In this mode, overlapped block motion compensation (OBMC) is utilized for the luminescence portion of P-pictures. Four 8 by 8 vectors are used instead of one 16 by 16 vector for the sum of the macro-blocks in a given picture. The tradeoff is that 4 vectors utilize more bits but produce better prediction. The use of this mode generally provides a considerable improvement because OBMC results in decreased blocking artifacts.
There are various trade-offs in selecting an optional mode provided by H.263. Because the modes are optional, it is not necessary for the decoder to support any of the optional modes. If a decoder supports a given mode, the encoder has the option to enable or disable that given mode.
Currently few methods exist for determining whether to enable or disable an optional mode for H.263. Typically, an optional mode is enabled at the beginning of a video data sequence and stays on throughout the entire length of the video data sequence. The disadvantage of this method is that with some types of video, the optional mode results in decreased video quality. For other types of video, the increase in video quality does not justify the increase in the computational overhead associated with the optional mode being enabled.
Therefore a method and an apparatus are desirable for allowing a feedback mechanism to determine whether to enable or disable an optional mode to produce the best video quality given a video data sequence.

Method and apparatus for adaptively switching on and off advanced prediction mode in an H.263 video coder


A pneumatic downhole impact drill has a backhead for mounting an inlet check valve and a mounting hub for mounting a fluid delivery tube. A split ring has an interior circumferential groove forming upper and lower shoulders and comprises two substantially identical semi-circular ring segments. The ring segments are positioned around flanges on the backhead and the mounting hub such that the upper shoulder of the split ring slidably engages the upper surface of the backhead flange and the lower shoulder slidably engages the lower surface of the mounting hub flange to mount the backhead to the mounting hub. A first gap is formed between the outside surface of the split ring and the inside surface of the casing. A second gap is formed between the inside surface of the groove and the outside surfaces of the mounting hub and backhead flanges. Taken together, the gaps allow lateral relative movement between the mounting hub and backhead flanges.

This invention relates generally to pneumatic impact hammers of the type having an impact piston and a fluid delivery tube received within a coaxial bore in the piston for supplying pneumatic pressure fluid to one or both ends of the piston operating chamber for and upon reciprocation of the piston.
U.S. Pat. No. 5,205,363 discloses a conventional hammer and percussion bit assembly having a backhead for mounting an inlet check valve and a mounting hub for mounting a fluid delivery tube. A compression ring or belleville washer is compressed between the backhead and the mounting hub to bias the backhead and mounting hub into engagement with respective snap rings. The snap rings are subject to vibration induced-wear which can lead to failure of the snap rings. In addition, the compression ring/belleville washer was also subject to failure.


An interactive voice response (IVR) system which assists in identifying repeat callers, understanding whether they are calling for the same reason as one of their previous calls, and properly disposing of the call. If the repeat caller is calling for the same reason, information from the previous call (or the previous calls) is retrieved and an action based on a defined business logic for repeat callers may then be executed for the current call.

In order to provide prompt and convenient service for customers, many companies have established customer support call centers. These centers provide one or more telephone numbers a customer can use to receive service and support information about various products. Typically, a customer experiencing a problem with or having a question about a particular product or service or having questions or difficulty installing or configuring a product or service will call the corresponding support center to receive specific information relating to the question or problem and preferably, instructions for resolving the problem.
However, these customer support call centers suffer from at least the following problems. First, staffing a call center with enough knowledgeable operators, also called agents or customer service representatives, to address a meaningful range of likely problems can be very expensive. The call center must hire enough agents to handle those times when most calls occur, or callers could have excessively long hold times before speaking to an agent. Long hold times are annoying to customers and hurt a company's reputation for providing quality customer service. Long hold times are an even bigger problem when the company does not provide a toll-free number and the caller is required to pay for the call. Thus, a call center might have more agents than needed at any given time with their associated costs.
Second, the time and cost required to train new agents is considerable and in some cases it could be weeks before an agent is allowed to answer a call on his own. Agents staffing the support center must be provided with the knowledge necessary to resolve common product and service related questions and problems. Often, because of the large scope of potential problems, it is simply not practical to impart the required information (i.e. the problem knowledge base) to each agent. For example, many of today's complex products require a team of engineers—each having a specialized area of expertise—to design, build, and service the products. Thus, a single person may not have all the information needed to solve a particular problem.
Third, the job of an agent is often very repetitive, and turnover can be high as agents lose interest in their work and quit their jobs. The most common customer support questions can represent up to 80% of all calls received. Turnover of 50% or greater is not unusual. For example, for a company with 100 agents experiencing 50% turnover, 50 agents would quit in a 12-month period. High turnover adds additional costs to the customer support call center for recruiting and training.
In an attempt to automate call centers, some companies have tried using prerecorded messages to provide answers to various common problems. Typically, a caller will hear simple audio recordings of portions of a spoken dialog that identify specific topics or problems. The caller is asked to press a certain key on his phone to identify the problem he is having. The caller will then hear another simple audio recording in the form of instructions for resolving a particular problem. These automated recordings are presented to the caller using what is called touch-tone Interactive Voice Response systems or IVR. Although the IVR instructions may resolve the aforementioned problems, the prerecorded solutions lack the flexibility to accept spoken inputs from the customer and tailor the response to the customer's specific situation. In addition, in order that the recordings be kept within a reasonable amount of time (since callers must memorize the instructions), the instructions may be simplified and generalized to such an extent that they do not provide sufficient help for the caller. Often, this results in unresolved problems and customer frustration.
In an IVR system, based on speech recognition technology, which implements a customer care service, for a given call-flow, the call may end in a defined final state (e.g. the caller successfully completes the call) or it may be prematurely interrupted. Typical reasons a call may be interrupted include a loss of connectivity, the caller requests to speak to a live operator, the caller hangs up, etc . . . . In any of those situations, the caller may choose to call back to: a) resume the previous service where he left off, in an attempt to complete it, or b) request a different service.
A common problem in traditional IVR systems is that repeat calls are processed without taking advantage of the knowledge of the outcome of the previous call from the same user. Because of this, callers always start the interaction from the beginning, as scripted, even if they have already performed several steps of it during a previous call. This common situation reduces customer satisfaction and unnecessarily increases call handling time for repeat callers. Moreover, the initial call of a repeat interaction may be wrongly classified as successfully solving the customer's problem, thereby affecting IVR call quality and performance evaluation and possibly call billing.

Methods and apparatus for call back disposition and re-evaluation in interactive voice response based customer care


A method of determining the presence of a paraffinophilic microorganism in a specimen taken from a patient. The method includes providing a receptacle containing an aqueous solution and adjusting the solution to mimic the in vivo clinical conditions of the patient. The method then further includes inoculating the solution with the specimen and then placing in the receptacle a paraffin coated slide to bait the paraffinophilic microorganism. The slide is then analyzed after exposure to the specimen to determine the presence or absence of the paraffinophilic microorganism. An associated apparatus is also disclosed.

This invention relates to a method of identifying a paraffinophilic microorganism using various milieus and an associated apparatus and, more particularly, to a receptacle containing an aqueous solution that mimics the in vivo conditions of a patient. A paraffin coated slide is used to bait a paraffinophilic organism that can grow on the slide. The organism then can be identified by a number of different methods.
U.S. Pat. Nos. 5,153,119 and 5,316,918, the disclosures of which are incorporated by reference herein, disclose methods and apparatus for identifying and testing the antibiotic sensitivity of Mycobacterium avium-intracellulare ("MAI"). One of the co-inventors herein, Robert-A. Ollar, was the named inventor on these patents. The method of identifying MAI includes placing a paraffin coated slide in a receptacle containing a sterile aqueous solution inoculated with a specimen from a patient and analyzing the slide after exposure to the specimen to determine the presence or absence of MAI. The analysis step involves performing a number of speciation assays, such as a tellurite reduction test. The method for testing the sensitivity of MAI to different antimicrobial agents and dosages thereof includes providing a plurality of test tubes adapted to contain an amount of an antimicrobial agent to be tested and MAI to be assayed and a separate paraffin coated slide adapted for placement in each of the test tubes. Observing the growth of MAI on the slide can be used to determine the concentration of the antimicrobial agent necessary to resist MAI growth on the slide.
The inventions provide effective, efficient and economical methods for identifying MAI and testing MAI for antimicrobial agent sensitivity. These methods avoid the use of expensive, complicated equipment, and thus can be used in places such as field hospitals and third world locations where the more expensive and hard to use equipment is not available.
Despite the effectiveness of the methods and apparatus disclosed in the above-mentioned patents, it would be desired to refine the process of identifying MAI, as well as other paraffinophilic microorganisms.

Apparatus for determining the presence or absence of a paraffinophilic microorganism


According to one aspect of the disclosure, the present invention provides methods and arrangements for testing a flip chip SOI semiconductor device after the back side of the chip has been thinned to expose a selected region in the substrate. For some chips, thinning removes substrate material useful for drawing heat away from the internal circuitry when the circuitry is running at high speeds. To compensate for this material loss, a special test fixture having a passive, corrosion-resistant heat-dissipating device is arranged to draw heat from the device.

The present invention relates to semiconductor device assemblies, and more particularly to techniques for analyzing and debugging circuitry as may be applied, for example, to a flip-chip bonded integrated circuit.
In recent years, the semiconductor industry has seen tremendous advances in technology which have permitted dramatic increases in circuit density and complexity, and equally dramatic decreases in power consumption and package sizes. Present semiconductor technology now permits single-chip microprocessors with many millions of transistors, operating at speeds of tens (or even hundreds) of MAPS (millions of instructions per second) to be packaged in relatively small, air-cooled semiconductor device packages. A by-product of such high-density and high functionality in semiconductor devices has been the demand for increased numbers of external electrical connections to be present on the exterior of the die and on the exterior of the semiconductor packages which receive the die, for connecting the packaged device to external systems, such as a printed circuit board.
In the past, the die and package were first attached and then the electrical connections from the die to the package were made by wire bonding. The wire bonding procedure is simple in concept. A thin (0.7 to 1.0 mil) wire is first bonded to the chip bonding pad and spanned to the inner lead of the package lead frame. The third action was to bond the wire to the inner lead. Lastly, the wire is clipped and the entire process repeated at the next bonding pad. While simple in concept and procedure, wire bonding was critical because of the precise wire placement and electrical contact requirements. In addition to accurate placement, each and every wire must make a good electrical contact at both ends, span between the pad and the inner lead in a prescribed loop without kinks, and be at a safe distance from neighboring lead wires.
To increase the number of pad sites available for a die and to address other problems, a different chip packaging technique called controlled collapse chip connection or flip chip packaging is being adopted. In this technology, the bonding pads are provided with metal (solder) bumps. The bonding pads need not be on the periphery of the die and hence are moved to the site nearest the transistors and other circuit devices formed in the die. As a result, the electrical path to the pad is shorter. Electrical connection to the package is made when the die is flipped over the package with corresponding bonding pads and soldered. As a result, the dies are commonly called flip chips in the industry. Each bump connects to a corresponding package inner lead. The packages that result are lower profile and have lower electrical resistance and a shortened electrical path. The output terminals of the package may be ball-shaped conductive bump contacts (usually solder, or other similar conductive material) are typically disposed in a rectangular array. These packages are occasionally referred to as xe2x80x9cBall Grid Arrayxe2x80x9d (BAG). Alternatively, the output terminals of the package may be pins, and such a package is commonly known as pin grid array (PA) package.
Once the die is attached to the package, the backside portion of the die remains exposed. The transistors and other circuitry are generally formed in a very thin epitaxially grown silicon layer on a single crystal silicon wafer of which the die is singulated from. In a structural variation, a layer of insulating silicon dioxide is formed on one surface of a single crystal silicon wafer followed by the thin epitaxially grown silicon layer containing the transistors and other circuitry. This wafer structure is termed xe2x80x9csilicon on insulatorxe2x80x9d (SOI) and the silicon dioxide layer is called the buried oxide layer (BOX). The transistors formed on the SOI structure show decreased drain capacitance, resulting in a faster switch transistor.
The side of the die including the epitaxial layer containing the transistors and the other active circuitry is often referred to as the circuit side of the die or front side of the die. The circuit side of the die is positioned very near the package. The circuit side opposes the backside of the die. Between the backside and the circuit side of the die is single crystalline silicon and, in the case of SOI circuits, also a buried oxide layer. The positioning of the circuit side provides many of the advantages of the flip chip.
However, in some instances the orientation of the die with the circuit side face down on a substrate may be a disadvantage or present new challenges. When a circuit fails, when circuit testing is desired, or when it is necessary to modify a particular chip, access to the transistors and circuitry near the circuit side is obtained only from the back side of the chip. This is challenging for SOI circuits since the transistors are in a very thin layer (about 10 micrometers) of silicon covered by the buried oxide layer (less than about 1 micrometer) and the bulk silicon (greater than 500 micrometers). Thus, the circuit side of the SOI flip chip die is not visible or accessible for viewing using optical or scanning electron microscopy.
Although the circuit of the SOI integrated circuit (IC) is buried under the bulk silicon, infrared (IR) microscopy is capable of imaging the circuit because silicon is relatively transparent in these wavelengths of the radiation. However, because of the absorption losses of IR radiation in silicon, it is generally required to thin the die to less than 100 microns in order to view the circuit using IR microscopy. On a die that is 725 microns thick, this means removing at least 625 microns of silicon before IR microscopy can be used. Thinning the die for failure analysis of a flip chip bonded IC is usually accomplished in two or three steps. First, the die is thinned across the whole die surface. This is also referred to as global thinning. Global thinning is done to allow viewing of the active circuit from the backside of the die using IR microscopy. Mechanical polishing is one method for global thinning.
Once an area is identified as an area of interest and it is determined that access is needed to a particular area of the circuit, local thinning techniques can be used to thin an area smaller than the die size. Laser microchemical etching of silicon is one method of local thinning.
Sometimes it is necessary for failure analysis, or for design debug, after global and/or local thinning, to make electrical contact and probe certain nodes in the circuit. This testing can be performed via the thinned backside or via pads on the circuit side of the SOI chip. When testing via pads on the circuit side of the chip, the SOI chip is typically placed in a test fixture having a circuit connector arranged to connect to these circuit-side pads. The SOI chip is activated through the test fixture, and signals at the nodes are analyzed. For certain applications, it has been discovered in connection with the present invention that the above-described thinning to remove substrate material results in the circuitry over-heating. When there is insufficient substrate material for drawing heat away from the internal circuitry, for example, when the circuitry is running at high speeds, the internal circuitry overheats and becomes inoperative. Consequently, the analysis/debug efforts are defeated.
Accordingly, there is a need for a testing approach that overcomes the abovementioned shortcomings.
According to one aspect of the disclosure, the present invention provides an approach for testing a flip chip SOI semiconductor device after the backside of the chip has been thinned to expose a selected region in the substrate. Thinning removes substrate material useful for drawing heat away from the internal circuitry when the circuitry is running at high speeds. To compensate for this material loss, a test fixture having a passive, corrosion-resistant heat-dissipating device is arranged to draw heat from the backside of the device.
In one example embodiment, the present invention is directed to a method for testing a SOI semiconductor device having a circuit side and a backside. The method includes: thinning the SOI semiconductor device and exposing a selected region in the SOI semiconductor device at its back side; securing the SOI semiconductor device in a test fixture and arranging the SOI semiconductor for testing via its circuit side; and activating the SOI semiconductor device while using the passive, corrosion-resistant heat-conductive element to dissipate heat generated by the SOI semiconductor device.
In another example embodiment, the present invention is directed to an arrangement for testing a SOI semiconductor device having a circuit side and a backside. The test arrangement comprises: a test fixture adapted to secure the SOI semiconductor device; a passive, corrosion-resistant heat sink coupled to the SOI semiconductor device and adapted to conduct heat generated by the SOI semiconductor device. The test fixture is adapted to test the SOI semiconductor device while the SOI semiconductor device is activated and while the passive, corrosion-resistant heat sink dissipates heat generated by the SOI semiconductor device. In a more particular embodiment, the SOI semiconductor device includes a circuit die and a package, with the passive, corrosion-resistant heat sink coupled to the package and drawing heat from the device through the package.
The above summary is not intended to describe each illustrated embodiment or every implementation of the present invention. The figures and the detailed description, which follow more particularly, exemplify these embodiments.