A position system and method utilizes a plurality of range transceivers located at known fixed locations and which are adapted to transmit approximately synchronized digital range signals for receipt by both a primary receiver and a supplemental receiver, the former disposed at a known location and the latter disposed at an unknown location. The range transceivers are adapted to transmit pulse sequences which include an error portion corresponding to the approximate synchronization error of each range signal. This error portion is constantly updated in accordance with the last determined synchronization errors of the corresponding range signals received by a secondary transceiver. In an alternative embodiment employing Code Division Multiple Access (CDMA) technology, the range transceiver time stamp on transmitted range signals may be adjusted to account for the measured timing error for a given range transceiver. The supplemental receiver receives the range signals and uses the same in accordance with known time of arrival or time difference of arrival calculation techniques to determine the position of the supplemental receiver.

Most metropolitan areas are now equipped with one or more forms of wireless communications networks which provide mobile telephone and other related services to customers across a broad frequency spectrum. Consider, for example, what has come to be known as "cellular" telephone services or Personal Communication Services (PCS), i.e., radio transmissions in the microwave band between approximately 800 MHZ and 2.2 GHZ. As shown in FIG. 1, prior art cellular telephone systems 10 include a Mobile Telephone Switching Center (MSC) 12 and a plurality of cell site transceivers 14a-14c. The cell site transceivers transmit radio signals to and receive radio signals from one or more mobile units 16 that move about a cellular service area 20. A mobile unit, as the term is used herein, refers to a wireless voice telephone or data receiver that can be permanently installed at a fixed location or within a vehicle or that can be portable. Each cell site transceiver 14 is able to broadcast and receive the radio signals within a geographic area 18 called the cell site coverage area. Together, the areas 18 comprise the entire cellular service area 20. Typically, a cellular service area comprises a metropolitan area or larger region.
When a telephone call to a called mobile unit 16 originates from either another mobile unit or a land-based telephone via a Public Switched Telephone Network (PSTN) 22, a caller must first access the cellular telephone system 10. This task is accomplished by dialing the mobile unit's unique identification number (i.e., its phone number). The MSC 12 receives the call request and instructs a central call processor 24 to begin call processing. The central call processor 24 transmits a signal over a dedicated line 26 (such as a telephone line or microwave link, etc.) to each of the cell site transceivers 14a-14c causing the cell site transceivers to transmit a page signal that the mobile unit 16 receives. The page signal alerts a particular mobile unit 16 that it is being called by including as part of the page signal the paged mobile unit's identification or phone number.
Each cell site transceiver 14 transmits the page signal on one or more dedicated forward control channels that carry all pages, as well as control signals, channel assignments, and other overhead messages to each mobile unit. The forward control channel is distinct from the voice channels that actually carry voice communications between a mobile unit and another mobile unit or a land-based telephone. Each cell site transceiver may have more than one forward control channel upon which pages can be carried.
When a mobile unit is not engaged in a telephone call, it operates in an idle state. In the idle state, the mobile unit will tune to the strongest available forward control channel and monitor that channel for a page signal or other messages directed to it. Upon determining that a page signal is being transmitted, the mobile unit 16 again scans all forward control channels so as to select the cell site transceiver transmitting the strongest signal. The mobile unit then transmits an acknowledgement signal to the cell site transceiver over a reverse control channel associated with the strongest forward control channel. This acknowledgement signal serves to indicate to the MSC 12 which of the forward control channels (associated with the several cell site transceivers 14a-14c) to use for further call processing communications with mobile unit 16. This further communication typically includes a message sent to the mobile unit instructing it to tune to a particular voice channel for completion of call processing and for connection with the calling party. The details of how the cell site transceivers transmit the signals on the forward and reverse control channels are typically governed by standard protocols such as the EIA/TIA-553 specification and the air interface standards for Narrowband Analog Mobile Phone Service (NAMPS) IS-88 and IS-95 air interface standards for digital communications, all of which are well known to those of ordinary skill in the wireless telephone communications art and therefore will not be discussed.
The EIA/TIA/IS-95 "Mobile Station-Base Station Compatibility Standard for Dual-Mode Wideband Spread Spectrum Cellular System" defines a digital cellular radio common air interface. The standard makes use of Code Division Multiple Access (CDMA) technology, where both the base station and the mobile transmit a Pseudo-random Noise (PN) spreading sequence, resulting in a 1.23 MHz transmission bandwidth.
The forward link transmission from each base station consists of four types of channels: pilot, paging, synchronization (sync), and traffic. The channels are all transmitted on the same carrier frequency, using the same PN spreading code; however, the channels are distinguished through binary orthogonal codes based on Walsh functions. Each base station transmits 1 pilot channel, 1 sync channel, and multiple paging and traffic channels. Forward link signals from different base stations are distinguished through PN spreading code phase offsets. In other words, every base station uses the same PN spreading code, but the code is transmitted using different time offsets (i.e., code phases) from the master code. There are 512 allowable code phase offsets.
The CDMA reverse link from the mobile to base station are differentiated by the use of a long PN spreading code (2.sup.42 -1), where each mobile transmits at a code phase time offset determined by a user address. Before being assigned to a reverse link traffic channel, the mobile must contact the base station using a reverse link access channel. The mobile station receiver employs multiple demodulators, which allows simultaneous demodulation of signals from up to three base stations.
While wireless communication services have been quickly embraced by those people whose business requires them to travel frequently and to be in constant communication with their clients, many individuals are discouraged from utilizing present wireless telephone systems. The main reason for this discouragement is the relatively high price charged by the service providers for a wireless telephone call. In conventional land-based telephone systems, the price of a telephone call can be tailored to reflect the supply and demand of the telephone resources available to a given area. For example, in large metropolitan areas or financial districts, users can typically expect to pay more for a telephone call than in a residential area. With current wireless technology, however, available position data is strictly limited to relatively large coverage areas and sectors thereof as defined by the RF characteristics, i.e. "footprints" of the associated transceiver. As explained below, these coverage areas are generally unsuitable for most commercial and consumer applications.
With reference again to prior art cellular telephone systems of the type shown in FIG. 1, for example it is known by those skilled in the art that typical cell sites are divided into three "sectors" 27. Each of these sectors 27 operates as a nearly independent cell site in that it is independently controlled by the associated switch. In operation, the wireless service provider must identify user location to the coverage area of one or more of these cell sites or sectors of cell sites with the associated dependence on erratic RF propagation as a definition tool. Cell site coverage areas and sectors vary widely in size. However, they are typically on the order of several square miles in less populated rural and residential areas and decrease accordingly in more densely populated metropolitan areas. Against this background, there have been previous attempts to provide methods and systems which generally identify the positions of wireless communication system users in the above cell site coverage areas and sectors. See, for example, U.S. Pat. No. 4,876,738 issued to Selby and assigned to U.S. Philips Corporation. Selby discloses a registration procedure in which the base station monitors the location of the mobile unit by cell site. The effect is to allow enlargement of the registration area if the mobile unit consistently roams between two cells.
See also, U.S. Pat. No. 5,179,721 issued to Comroe et al and assigned to Motorola Inc. Comroe discloses a method for inter-operation of a cellular communication system and trunking communication system by transmitting an access number for each system such that the mobile unit may be used as a cellular telephone and a trunking communication device.
Finally, see U.S. Pat. No. 5,097,499 issued to Consentino and assigned to AT&T Bell Laboratories. Consentino teaches a method for preventing an overload in a reverse channel by delaying the time of the generation of timing stamps on markers.
These methods and systems, however, have proven unsuitable for commercial and consumer applications where users may, at any given time, travel through very small portions of numerous cell site coverage areas and sectors. Consider, for example, a wireless telephone customer who resides in Boulder, Colo. and who commutes to work on a daily basis to downtown Denver. The customer may typically place and receive wireless telephone calls only in the approximate 45 mile geographic area between the two cities during her commute to and from work. In fact, the customer may not even wish to be provided telephone service outside of this limited geographic area. Alternatively, she may wish to restrict telephone service outside of this area to selected hours on weekends and evenings only. This desired service area, however, most likely spans small portions of the numerous cell site coverage areas, the latter portions of which the customer has no desire of using and does not wish to be billed for. However, under current wireless technology, and as described in the prior art referenced above, presently available positioning methods and systems are limited to a determination of whether the user is within one or more predetermined cell site coverage areas or sectors. These prior art systems are incapable of providing further detail, i.e. exactly where in the cell site coverage area the user is located. The prior art systems, which might be implemented in this example to determine that the customer has passed through one or more large cell site coverage areas, does not meet the objectives of the customer and is thus not a commercially marketable product.
Prior art attempts to design higher accuracy positioning systems which utilize commercial broadcast transmissions, for example, have also met with limited success. See, for example, U.S. Pat. Nos. 4,054,880 (Dalabakis et al) and 3,889,264 (Fletcher) which disclose what are known as "Delta-Position" systems. These prior art patents describe systems using three spectrally spaced-apart radio signals, each of which is an independent AM radio signal. The systems typically have a vehicle carried mobile receiver, with a separate tuner for each station, and a second receiver at a fixed, known position. As disclosed, these systems count "zero crossings", each of which indicates that the user has moved a certain distance from his or her previous location. In operation, if a user requires knowledge of his or her current position, the user must first specify a starting position. A fixed position receiver detects frequency drift of the transmitters, which is used to adjust and coordinate the zero crossing counts made by the mobile receivers.
These systems are termed "Delta-Position" systems because they determine only the distance and direction traveled by a mobile user from any particular starting point. Neither Dalabakis nor Fletcher actually determines the position of the mobile user.
See also, U.S. Pat. No. 5,173,710 to Kelley et al which discloses the use of a fixed position receiver which is adapted to determine frequency drift along with the relative phases of various unsynchronized FM broadcast signals originating from known fixed locations. As disclosed by Kelley, each of the fixed transmitters transmits a beacon signal having a phase that is unsynchronized with the phases of the beacon signals of the other transmitters. These signals are 19 kilohertz analog pilot tones generated by commercial broadcast stereo FM stations. The fixed receiver receives the beacon signals, determines the relative phases of the beacon signals, and broadcasts data representing these relative phases for receipt by the mobile receiver which is at an unknown location. Each mobile receiver includes phase measurement circuitry that detects the phases of the beacon signals at the mobile receiver's current position on multiple distinct carrier frequencies such that the current position of the mobile unit may be determined when used in conjunction with the fixed receiver broadcast data.
None of the systems referenced above, as well as general time difference of arrival location systems such as LORAN, NAVSTAR, and GPS, as used, for example, in U.S. Pat. No. 4,833,480 issued to Palmer et al, have proven suitable for commercial applications since, by design, they require specially adapted receivers to receive and process the pilot tones, GPS signals, etc. at the mobile unit. This sophisticated end equipment, of course, significantly adds to the cost of the corresponding mobile unit. In the case of hand portable units, this additional equipment further results in a handset which is extremely bulky and difficult to handle. As a result, these systems have proven unsuitable for both large-scale commercial applications, as well as ordinary consumer use.
When applied to wireless communications of interest to the present invention, i.e., communications in the microwave band from 800 MHZ to 2.5 GHZ, these prior art systems are further considered unsuitable for commercial applications in view of their anticipated use of excessive frequency spectrum. More specifically, it is anticipated that for proper operation these systems would necessarily require transmission of signals on separate channels which would utilize an unacceptable amount of additional spectrum.
Consequently, a need has developed to provide a positioning system and method which may be practically and economically implemented for use in wireless communications systems and, in particular, in the microwave band from 800 MHZ to 2.5 GHZ. Still further, a need has developed to provide such a positioning system which may be used by wireless telephone customers to determine, in advance, customized service zones for billing and access purposes. Still further, a need has developed to provide such a positioning system and method that allows a user to determine whether she is in one of the predefined customized zones within the wireless communications service area and to convey that information to the wireless communications service system. It is further desirable that such a system and method be compatible with existing wireless telephone technology and should not degrade the operation of an existing system. Finally, such a system should neither require the allocation of more radio frequencies than are currently allocated to wireless telephone systems, nor require a substantial portion of existing wireless frequencies.

Method and system for determining the position of a mobile receiver


A can holder has oppositely extending hook members adapted to suspend the can from a ladder rung in a forwardly inclined position. The bail of the can is accommodated by a groove open to the top of the holder and located forwardly of the hook members to hold the bail rearwardly from the mouth of the can to facilitate the transfer of material into and out of the can.

The invention relates to the field of holders for containers. The holders are container mounted holders releasably attachable to a horizontal extending support, such as a ladder rung and the like.
Many different types of paint can holders have been used in the past and in the present. Some are made out of metal, plastic, rubber, rope, twine or cloth and hung from an extension ladder step and attached to the handle of a paint can that may contain a paint, stain, varnish, shellac and the like. These existing devices, whether bought from a supplier or retailer, or made by an individual themselves, hold a paint can to, and from, an extension ladder step. They all have one deficiency in common, namely, it is difficult to get a paint brush or roller into the hanging paint can. The handle must be repeatedly moved or the paint can itself must be moved to allow an easier access to the material inside the paint can.
Emery in U.S. Pat. No. 1,024,841 discloses a bail for a paint bucket inclined slightly toward the back of the bucket for the purpose of holding the bucket slightly forward or toward the person using the bucket to facilitate the insertion and removal of a paint brush from the bucket.
Tattrie in U.S. Pat. No. 3,204,907 discloses a paint can hanger having an arcuate section that curves around the rim of a paint can and a top section that engages the wire handle mounted to opposite sides of the can.
Tibbs in U.S. Pat. No. 4,491,293 discloses a can holder having a handle having a hook engageable with the bail of a can. The length of the handle can be varied to vary the angular relation of the can to the horizontal when the can is suspended by a S-hook.
Hunt el al in U.S. Pat. No. 5,226,623 disclose a paint bucket holder having an ear component that is manually grasped to facilitate movement of a paint bucket between ladder rungs without removing the bail of the bucket from hook.
The invention comprises a container holder useable to suspend a container from a horizontal support in a forwardly inclined position and hold the bail of the container rearwardly from the open top of the container allowing free and easy access to the material, such as paint, varnish, stain, inside of the container. The holder has a first body portion and a second body portion. The first body portion has a downwardly extending hook member adapted to accommodate a horizontal support member, such as a rung of a ladder. The first body portion has a groove adapted to accommodate a bail pivotally mounted on the upright side wall of a container having an open top. The second body member has an upwardly extending hook member adapted to engage the inwardly directed rim joined to the side wall of the container and the inside surface of the side wall thereby suspending the container in a forwardly inclined position from the horizontal support and holding the bail rearwardly from the open top of the container.


An adjustable contour and slope practice putting green assembly having a base (22) and a practice putting green platform (21) mounted to the base for support of the platform (21) and a player standing on a support area (28) of the platform (21) over the base (22). The base (22) is formed for selective tilting of the platform (21). The weight of a player standing on the putting green platform (21) is used to hold or fix the platform (21) to the base (22) in an adjusted position. The platform (21) is cantilevered away from the base (22) and preferably the base assembly (22) includes a spherical surface structure (34,51) and a ring (23) cooperatively formed to enable universal adjustment of the slope of the platform (21) about the center of a spherical surface (34,51) when the player is not standing on the platform. The platform may be deformable, for example, by including a deformable peripheral frame (42) which enables adjustment of the contour of the playing surface (29) in addition to adjustments to the slope of the surface (29). The contour adjustment is independent of the slope adjustment. A method of using an adjustable slope, contour and length practice putting green assembly also is provided.

There are numerous golf practice putting systems or devices which allow a golfer to practice his or her putting at home or away the golf course. Many of these devices include a "cup" with a short ramp to the cup that can be placed on a carpet or rug to allow the golfer to practice putting on the carpet. While these practice devices have some value, they do not allow the golfer to practice while putting on sloped or contoured surfaces, thus practice putts with such prior art devices are essentially flat.
Various golf practice systems have been devised, however, in which tilting or adjustment of the slope of the surface on which the golfer is practicing is possible. Thus, U.S. Pat. Nos. 5,518,245; 5,333,876; 5,046,741; and 2,937,875 all disclose tiltable practice surfaces on which a golfer can practice hitting up-hill or down-hill lies with various non-putter clubs. These systems tend to be based upon the use of a tiltable platform or table, but they are not intended for putting practice.
U.S. Pat. Nos. 6,146,284; 5,431,403; 4,709,538; 3,366,388; and 2,334,540 disclose devices which are designed to enable putting practice and they disclose structures which enable adjustment of the slope or contour of the putting green. These systems range in sophistication and complexity from a relatively simple tiltable surface of U.S. Pat. No. 5,431,403 to complex contour adjustable systems as is shown in U.S. Pat. No. 4,790,538. Most of these systems, however, have tended to be unduly complex and costly, and therefore, they often are not well suited for home use.
An example of a commercially available practice putting green is the system sold under the trademark PUTTGOLF. The PUTTGOLF system is capable of adjustment of both the slope and contour of the putting surface. It employs a plurality of support rods and adjustable feet and can be assembled at home and adjusted periodically by the user. While capable of a wide range of adjustments, the PUTTGOLF system is time-consuming to assemble and tedious to adjust.
Accordingly, it is an object of the present invention to provide an adjustable contour and slope putting device which can be easily assembled and in which at least one of the contour and the slope of the putting surface can be rapidly adjusted.
A further object of the present invention is to provide an adjustable practice putting green assembly which is durable, capable of length adjustments as well as slope and contour adjustments, is relatively inexpensive to manufacture and can be easily transported from place to place and reassembled and used.
The adjustable practice putting green assembly and method of the present invention have other objects and features of advantage which will become apparent from, and are set forth in more detail in, the following description of the Best Mode of Carrying Out the Invention and the accompanying drawing.

Adjustable slope and contour practice putting green assembly and method


A data collection system collects statistics related to each visit to each web-page within a web-site. In addition to collecting path information related to traversals to and from each web-page, the system collects information regarding the particular session, such as the visitor's connection speed, the time required to download the web-page to the visitor's system, the duration of time that the visitor spent at the page, whether the user clicked the ‘back’ button to leave the site, and so on. The data reporting system presents statistics based on the collected data in an easy-to-use and easy-to-understand form that is customizable by the user. By collecting and reporting performance factors related to each web-page, or sets of web-pages within a web-site, marketers and webmasters can address any perceived deficiencies and/or can optimize the performance of select pages to achieve specific marketing objectives. To optimize performance and minimize storage requirements, the data collection system uses a two-stage storage architecture. Data is collected in one or more registers in a sequential fashion, and transferred to a database periodically.

1. Field of the Invention
This invention relates to the field of computer networks, and in particular to a system and method that facilitates an analysis of the traffic patterns and performance of sites on a network.
2. Description of Related Art
Traffic analysis is a necessary tool for effective web-site management and on-going web-site development, as well as for the development of effective marketing strategies. Web-site managers, hereinafter webmasters, desire information that can be used to enhance the web-site's performance or appearance. Electronic-commerce marketing managers, hereinafter marketers, desire information that can be used to enhance the sales resulting from visits to a web-site, to enhance advertising revenue from the web-site, and/or to determine the effectiveness of advertising expenses to other web-site providers.
Tools are commonly available for collecting traffic data. A fundamental tool, for example, collects data regarding the number of times each page at a web site is accessed within a given period of time (e.g. 'hit-rate' statistics). A more sophisticated tool, such as the Netflame™ product from Fireclick, Inc., collects data regarding entries to and exits from each page at a web site. By tracking visitor' paths through the website, a Netflame™-enabled web-site can be configured to anticipate a next-page that a visitor is likely to visit, and can initiate a download of some or all of the anticipated next-page while the visitor is viewing the current page. In this manner, the performance of the web-site is significantly enhanced, because, from the visitor's perspective, the anticipated next-page appears to download instantaneously. Only if the visitor chooses an unanticipated next-page will the visitor experience the true download delay duration.
Copending U.S. patent application Ser. No. 09/734,910, filed Dec. 11, 2000 and entitled "Predictive Pre-Download Using Normalized Network Object Identifiers", discloses a preferred technique for determining and downloading the anticipated next-page. Of particular note, this copending application also discloses the concept of a "normalized" web-page, wherein alternative versions of a web-page are analyzed and processed as a single web-page. That is, alternative versions of a web-page may include an element that varies, depending upon the environment, the particular viewer, the class of viewer, a currently advertised special, and so on. Each version may potentially correspond to a different web-page, because each version may have a different URL (Uniform Resource Locator). If processed and analyzed separately, the individual statistics that are associated with each of the different versions of a web-page would generally be meaningless. A normalized web-page comprises all of the non-varying elements of the alternative versions, and the data collected corresponding to each of the alternative versions is associated with the normalized web-page. In this manner, statistics are provided for the web-page, independent of variables associated with the web-page. For ease of reference and understanding, the term web-page as used herein includes a normalized web-page, and other collections of pages, files, and data that form a cohesive entity for traffic-analysis reporting purposes. For example, copending U.S. patent application Ser. No. 10/079,932, filed Feb. 19, 2002, entitled "Predictive Predownload of Templates with Delta Encoding," discloses the use of "templates" that correspond to the relatively unchanging portions of a web-page, and "delta-encoding" to encode the portions of a web-page that change. As defined herein, the templates with multiple and varied delta-encodings correspond to a web-page. Other examples of collections of material forming a cohesive entity for traffic-analysis will be evident to one of ordinary skill in the art.
The information provided by traffic or path analysis tools is useful, but somewhat limited. While knowledge of how visitors typically arrive at a web site, which pages they typically visit while at the site, and where they go to when they depart the web site, is useful for determining the effectiveness of the site in satisfying marketing objectives, such as the effectiveness of a page layout for directing visitors to select targets, it is somewhat limited in providing insight as to where problems may lie.
Collecting information for a more detailed analysis, however, requires substantial memory resources, particularly for web-sites that are visited hundreds or thousands of times per hour. Even if one could initially afford the memory resources to collect a detailed record of each visit to a web-page, the amount of memory resources required can be expected to grow non-linearly as the analysis system provides the feedback that is expected to facilitate a substantial increase in the popularity of the web-site. Also, as the size of the database that contains the detailed information increases with time and/or site popularity, the time to access the information in the database will increase, thereby diminishing the analysis tool's effectiveness as an interactive query system.

Web-site performance analysis system and method utilizing web-site traversal counters and histograms


Switching regulator circuits and methods are provided for regulating output voltage that include an adjustable minimum peak inductor current level and adjustable burst comparator hysteresis for Burst Mode operation in switching regulators. Control over minimum peak inductor current level and burst comparator hysteresis is achieved during Burst Mode operation by allowing external user control of the burst threshold level and the burst comparator hysteresis. A single user-accessible input pin, two user-accessible input pins, or three user-accessible input pins may be used to distinguish between forced continuous and Burst Mode operations, set a burst threshold level, and set a burst comparator hysteresis during Burst Mode operation. The present invention may be applied to buck, boost, buck-boost, or any other suitable regulator circuit configuration. The present invention also may be employed with synchronous and non-synchronous switching regulators.

The present invention relates to voltage regulators. More particularly, this invention relates to circuits and methods that provide the ability to adjust the minimum peak inductor current level and hysteresis for Burst Mode in current-mode DC-DC regulators (i.e. regulators that respond to measurements of output current or of signals indicative of output current).
Voltage regulators are power supply circuits that use a closed loop design to provide a predetermined and substantially constant output voltage, even while using an input voltage source which may be poorly specified or fluctuating. Furthermore, many electronic products use voltage regulators to convert an input voltage into a regulated output voltage that may be higher or lower than the input voltage. Accordingly, voltage regulators function as both a voltage converter in addition to a voltage stabilizer.
There are two major types of regulators: linear regulators and switching regulators. In a typical linear regulator, the output voltage is regulated by adjusting a passive element (e.g., a variable resistor) to control a continuous flow of current from the voltage source to the load.
Switching regulators, on the other hand, are essentially DC-DC converters that operate by switching current ON and OFF to control the output voltage. Switching voltage regulators typically employ one or more switching devices, along with an inductor and a capacitor in order to store and transfer energy to a load. These regulators are able to regulate the voltage being supplied to the load by turning the switching element(s) ON and OFF, thereby controlling the amount of power being transmitted through the inductor in the form of discrete current pulses. The inductor and the capacitor convert the supplied current pulses into a steady load current so that the load voltage is regulated. Ultimately, regulation of the output voltage is achieved through adjustment of the switch ON-OFF timings based on feedback signals indicative of the output voltage and load current.
Switching regulators that operate in current-mode are particularly desirable. They provide good line and load transient signal rejection, and possess inherent current-limiting capabilities during fault conditions (e.g., output short circuits). Many current-mode switching regulators monitor the inductor current and compare it with a peak inductor current level to determine when it is appropriate to turn OFF the main switching element, thereby eliminating the supply of excess current.
Many current-mode switching regulator circuits include the following: a logic section, an output switch or switches controlled by the logic section, an oscillator for providing periodic timing signals to turn ON the main switch, a current amplifier that relays a sense voltage that is dependent on the inductor current, an error amplifier that adjusts its output voltage depending on load conditions, and a current comparator that produces a signal that causes the logic section to turn OFF the main switch when the sense voltage compares in a predetermined manner with the voltage emerging from the error amplifier.
A particular type of regulator which often operates in current-mode as described above is the synchronous switching regulator. These regulators have a main switching element and a synchronous switching element which are driven out-of-phase with respect to each other in order to supply current at a regulated voltage to a load. Synchronous switching regulators differ from non-synchronous switching regulators in that a diode is replaced with a synchronous switching element, and the result, typically, is decreased power loss in the switching regulator.
A major benefit of switching regulators, such as synchronous switching regulators, is that they typically exhibit greater efficiency (where efficiency is defined as the ratio of the power provided by the regulator to the power provided to the regulator) than can be found in linear regulators, thereby leading to significant reductions in unwanted heat dissipation. As a result, many switching regulators can eliminate the use of a heat sink that an equivalent linear design would require.
In particular, synchronous switching regulators that employ MOSFET (metal-oxide semiconductor field-effect transistor) switches are widely used in portable battery-powered electronic products and products in which only limited heat generation can be tolerated. Because these voltage regulators exhibit higher efficiency, they provide relatively long battery life with little heat generation. For this reason, these regulators are often employed in systems such as cellular telephones, cordless telephones, personal pagers, laptop computers, and wireless modems.
The efficiency of switching regulators, however, is not always maximized and varies proportionally to the size of the load. It is a function of output current and typically decreases when the switching regulator is providing small amounts of current to the load. This occurs because even as the load decreases, a fixed amount of power is dissipated in the drive circuitry irrespective of the load size.
The above-described loss of efficiency at lighter loads is common in switching regulators that operate in a forced continuous mode of operation. In forced continuous mode, the efficiency loss at lighter loads for switching regulators becomes greater because the main switch is periodically turned ON and OFF regardless of operating conditions. Therefore, these regulators may become inefficient for smaller loads because of the energy, in the form of gate charge, that is required to constantly turn the main switch and synchronous switch ON and OFF regardless of load conditions.
An effective alternative to operating in forced continuous mode is to allow the regulator to enter Burst Mode operation. When operating in this mode, the regulator may omit switching cycles when the load is light, thereby reducing transistor gate charge losses. This is possible because, when operating in Burst Mode, the active switching elements (e.g., the switching transistor(s)) and optionally other unneeded portions of the regulator circuit are made to remain OFF as the load current drops below a specified value. The mode of operation when the active switching elements are made to remain OFF also is referred to herein as sleep mode. In a synchronous switching regulator, both the main and synchronous switching elements are made to remain OFF during sleep mode. In a non-synchronous switching regulator, only the main switching element is made to remain OFF. As one of ordinary skill in the art will understand, there may be different implementations of Burst Mode operation in different switching regulators. For example, different implementations may include different circuits and methods (1) to determine when a switching regulator enters sleep mode and/or (2) to charge the output capacitor. Burst Mode operation is used to reduce switching losses in a switching regulator and increase the operating efficiency at low output current levels.
Available regulators capable of operating in Burst Mode use essentially the same circuitry as described above for typical switching regulators, with the addition of a burst comparator and circuitry that provides a burst threshold level. This additional circuitry may be used to shut down part of a regulator circuit under specified conditions in order to reduce power consumption. Examples of regulators that use Burst Mode and forced continuous mode are marketed by Linear Technology Corporation, Milpitas, Calif., and include the LTC1435 and LTC1735 series products.
A disadvantage of some Burst Mode type regulators results from the inability to externally control the burst threshold level, which sets the minimum peak inductor current level. For higher burst threshold levels, the efficiency at light loads is higher at the expense of higher output voltage ripple (an undesirable characteristic). For lower burst threshold levels, the output voltage ripple is lower at the expense of slightly reduced efficiency for light loads. Accordingly, because the burst threshold level, which sets the minimum peak inductor current level, is fixed internally in current regulators that operate in Burst Mode, the output voltage ripple and efficiency of the regulator cannot be tailored to fit the requirements of different applications.
One way to adjust the output voltage ripple and efficiency of the regulator to fit the requirements of different applications is by externally setting the burst threshold level, as described in U.S. Pat. No. 6,724,174 to Esteves et al. This sets the minimum peak inductor current level, thereby permitting the output voltage ripple and efficiency to be adjusted to suit the requirements of various applications. At higher burst threshold levels, the efficiency at light loads would be higher at the expense of higher output voltage ripple (which, depending on the application, is an undesirable characteristic). At lower burst threshold levels, the output voltage ripple would be lower at the expense of slightly reduced efficiency for light loads. Externally setting the burst threshold level allows the switching regulator's output voltage ripple and efficiency to be tailored to the needs of a particular application.
Available Burst Mode regulators that permit external setting of the burst threshold level may use essentially the same circuitry as described above for regulators that use Burst Mode and forced continuous mode, with the addition of an adjustable burst clamp. This circuitry sets the minimum peak inductor current level according to the burst threshold level, which is set externally. Examples of Burst Mode regulators that use an adjustable burst clamp are the LTC3412, LTC3414, and LTC3418 series products marketed by Linear Technology Corporation, Milpitas, Calif.
In those Burst Mode regulators that use an adjustable burst clamp, the burst comparator hysteresis is fixed internally within the switching regulator. Since the only way to adjust the output voltage ripple amplitude and frequency in Burst Mode regulators using an adjustable burst clamp is by varying the minimum peak inductor current, the user has only one degree of control over the output voltage ripple and efficiency in tailoring them to fit the different requirements of each application.
Furthermore, for higher burst threshold levels, the efficiency at light loads is generally higher at the expense of higher output voltage ripple for those Burst Mode regulators that use an adjustable burst clamp. When the output voltage ripple exceeds a certain magnitude, however, there is a loss of efficiency in such regulators because of DC losses in the conduction path.
In view of the foregoing, it would be desirable to provide circuits and methods for permitting a user to externally set the minimum peak inductor current level.
It would also be desirable to provide circuits and methods for permitting a user to externally set the hysteresis of a Burst Mode comparator in switching regulators to increase efficiency of a regulator.
It further would be desirable to provide circuits and methods for permitting a user to more fully adjust the voltage ripple of the regulated output voltage of a regulator over a continuous range of values.

Circuits and methods for adjustable peak inductor current and hysteresis for burst mode in switching regulators


A semiconductor device (10) has a decoupling capacitor (55) which is formed of a ground paddle (37), a dielectric element (57), and a power paddle (23). The power paddle is formed as a conductive element of a first TAB leadframe (12) and is contiguous with power leads (19). The first TAB leadframe also includes signal leads (16). The ground paddle is formed as a conductive element of a second TAB leadframe (14) and is contiguous with ground leads (36). The two leadframes are superimposed with one another to form the decoupling capacitor and to intersperse the ground leads with the power and signal leads. In one embodiment of the invention, power paddle (23) is raised above the leads to accommodate the dielectric element. The invention permits all power and all ground leads to be electrically coupled to the decoupling capacitor while keeping the decoupling capacitor very close to a semiconductor die (38).

A continuing object of high performance semiconductor manufacturers is to increase power and speed of a semiconductor device while keeping device size to a minimum. However by increasing device and system density to reduce size, electrical performance of the device is often adversely affected. For instance, inductance of an integrated circuit and a device package can induce spurious voltage spikes in a power supply system which can in turn couple to signal leads of the device and cause timing problems in signal switching.
A common method of negating the effects of inductance and rapid voltage changes in a device is to use a decoupling capacitor. Decoupling capacitors shunt power and ground planes or power and ground leads so that rapid voltage changes in the device result in an electrical short circuit across the capacitor, translating voltage spikes into a stored charge on the decoupling capacitor. The stored charge either dissipates or is used as a local power supply to device inputs during subsequent signal switching stages, allowing the decoupling capacitor to negate the effects of voltage noise induced into the system by parasitic inductance.
One way in which decoupling capacitors have been used in the past is by mounting a discrete decoupling capacitor next to a semiconductor device on a substrate, such as a PC board. Conductive traces on the substrate are used to electrically couple the decoupling capacitor to power and ground pins of the semiconductor device. Another approach is to attach a discrete decoupling capacitor directly to the face of a semiconductor die such that the decoupling capacitor is electrically coupled to power and ground bond pads of the die or to power and ground leads. Yet another technique is to electrically couple a discrete decoupling capacitor to adjacent power and ground leads of a tape automated bonding (TAB) device.
Each of the known methods of using decoupling capacitors mentioned above serves to negate the effects of rapid voltage swings in a semiconductor device to a degree. However, a disadvantage of some known decoupling capacitors is that the capacitors require additional area on a substrate or increase the size of a semiconductor device. Therefore, many of the decoupling capacitors currently in use go against a primary objective of semiconductor manufacturers and users to reduce device size and area. Another disadvantage with some known decoupling capacitors is that an undesirable amount of inductance is associated with the interconnection between the semiconductor die and the decoupling capacitor. For this reason, it is desirable to have a decoupling capacitor which is as close to the die as possible in order to shorten the interconnection distance, thereby lowering inductance. An additional disadvantage with some known methods of employing a decoupling capacitor is that not all power and ground leads are electrically coupled to the capacitor. Therefore, rapid voltage swings in a device are not countered fast enough or are not countered as effectively as desired.

Semiconductor device with integral decoupling capacitor


Apparatus including a manually operated electrical switch operably connected through electrical and pneumatic systems to a hydraulic system for remote manual control of hydraulically actuated devices, such as hydraulically actuated throttling valves. The apparatus is particularly useful as a remote manual override for malfunctioning automatic hydraulic controllers.

1. Field of the Invention
This invention relates to apparatus for controlling hydraulically actuated devices, and in particular to apparatus for remotely controlling hydraulically actuated devices, such as throttling valves.
2. Description of the Prior Art
The use of hydraulic actuator systems to mechanically adjust the position of levers, valve stems and the like is commonplace in a wide variety of activities. For example, fluid flow processes, such as refinery processes and other chemical processes, typically require one or more hydraulically actuated throttling valves to regulate the flow rate of fluids through fluid-conducting conduits. These processes typically require frequent or even substantially continuous repositioning of the throttling mechanism of the throttling valve in order to compensate for changes in liquid levels, pressures, fluid compositions and the like. While such repositioning can be done manually, usually the repositioning of the throttling mechanism is performed automatically by the hydraulic actuator system in response to a signal from an automatic controller. Under normal operating conditions automatic controllers can enhance the efficiency of the process unit of which they are a part.
However, during severe upsets of the process units or during normal start-up or shut-down operations, it is possible for automatic controllers to become unstable and fail to properly compensate for changes in the process conditions. In addition, automatic controllers occasionally malfunction even in an otherwise properly operating process unit. Under such circumstances, rather than aid in the control of the process, the automatic controller may actually hinder an operator's attempts to bring the process unit to the desired operating conditions. Accordingly, most automatic controllers can be inactivated and the throttling mechanism can be manually repositioned by an operator stationed at the throttling valve.
While these prior art methods for overriding a malfunctioning automatic controller may be suitable where there is sufficient manpower to attend the valve and the valve is readily accessible, as a practical matter, such override systems are not suitable in the more complex, highly automated process units of modern refineries and chemical plants. Besides having fewer operators to attend to the throttling valves, such process units generally have more throttling valves, at least several of which are not readily accessible from the central control room. Moreover, the same unit upsets which would require an operator to manually override a valve also require that more operator attention be given to other parts of the process unit in order to find and correct the cause of the upset. For these reasons even a relatively minor problem, such as a plugged hydraulic line between the automatic controller and the throttling valve, could force a complete shutdown of the process unit. For example, a large fluid catalytic cracking (FCC) unit may be shut down at a cost of $50,000 per day by the loss of control of a slide valve due to a malfunctioning automatic controller. Thus a need exists for an apparatus for remotely overriding malfunctioning automatic controllers so as to allow remote manual positioning of the hydraulically-actuated device.
Accordingly, a primary object of this invention is to provide an apparatus for remotely controlling hydraulically-actuated devices.
Another object of the invention is to provide an apparatus for remote manual override of a malfunctioning automatic control valve.
Yet another object of this invention is to provide a simple and effective remote control apparatus for positioning the throttling mechanism of a hydraulically-actuated throttling valve.
Still another object of this invention is to provide a readily installable remote control apparatus which is compatible with the existing control mechanisms of conventional hydraulically-actuated throttling valves.
Other objects, advantages and features of this invention will become apparent to those skilled in the art from the following description when taken in conjunction with the accompanying drawing.

Remote control apparatus for hydraulically actuated devices


A system for detecting a particular cycle of a received Loran-C signal in a Loran-C receiving apparatus, recognizes the envelope of a carrier wave in each Loran-C pulse for a predetermined duration after the onset of the Loran-C pulse. The system compares the detected envelope to reference envelope data so as to identify where on the actual Loran-C envelope the measured envelope lies in order to identify the particular cycle of the received Loran-C pulse.

1. Field of the Invention
The present invention relates generally to a receiving apparatus used in a Loran-C navigation system on a basis of a hyperbolic electromagnetic navigation technique, and relates particularly to a Loran-C signal receiving apparatus capable of accurately and speedily identifying a particular cycle of a carrier wave in each received Loran-C pulse.
2. Description of the Prior Art
A Loran (Long range navigation)-C system employs a chain comprising one master transmission station and two or more secondary transmission stations.
The master transmission station transmits nine Loran pulses as shown by M of (a) in FIG. 1.
Each secondary transmission station transmits eight Loran pulses as shown by S.sub.1 and S.sub.2 of (a) in FIG. 1. Each transmission station generates the above-described Loran pulses at a pulse repetition rate prescribed for each chain. In addition, each secondary transmission station generates its secondary station Loran pulses with a coding delay with respect to the transmission pulse of the master transmission station distinct from other secondary transmission stations.
Hence, in the Loran-C signal receiving apparatus, the difference in distance to the two fixed points represented by the master and each secondary transmission station can be obtained from the delay between receipt of the secondary transmission station pulses and the master transmission station pulses so that the location of the Loran-C signal receiving apparatus is specified by the intersection of Loran hyperbolics drawn for each of the two sets of two fixed points.
In the above-described Loran-C signal receiving apparatus, a particular cycle of the carrier wave in each received pulse (generally, the third cycle of the carrier wave) is tracked in order to measure the reception delay time of the pulses from the secondary transmission stations with respect to those from the master transmission station.
The carrier wave Ca of the above-described Loran-C signal has a frequency of 100 killohertz and hence a period of 10 microseconds as appreciated from (c) in FIG. 1 drawn on an expanded time axis.
A conventional Loran-C receiving apparatus performing this function is disclosed in Japanese Patent Application Open Nos. 55-2938, No. 55-6261, and Patent Publication No. 56-2312. In addition, the general concepts of Loran-C receiving apparata are disclosed in U.S. Pat. No. 4,268,830 to Lester R. Brodeur filed on Apr. 9, 1979.
The method for identifying the third cycle of the carrier wave Ca in conventional Loran-C receiving apparata is that once the Loran-C pulse LP is received, a sampling pulse is generated in synchronization with the pulse repetition rate (for example, in the Japanese Maritime Area 99.7 milliseconds) of the Loran-C pulse LP. If the time-integrated value of the signal amplitude sampled in response to sampling pulses exceeds a predetermined threshold value, the corresponding phase of the signal is determined to be one of the peaks P.sub.1, P.sub.2, and P.sub.3 of the carrier wave Ca. After detecting the accompanying peaks of the carrier wave, the third cycle of the carrier wave Ca in each pulse is identified by determining that the third sampled value in excess of the threshold is the peak of the third cycle.
However, since conventional Loran-C receiving apparatus identifying the third cycle of the carrier wave by detecting the peak of the carrier wave, due to the difficulty in detecting first and second peaks accurately in cases where the S/N ratio (Signal-to-Noise) is excessly low due to external noise, the third cycle may easily be improperly identified.
If the above-described Loran-C receiving apparatus is mounted in an automotive vehicle in order to monitor the position of the moving vehicle, since the Loran-C signal will be highly attenuated in urban or mountainous areas, the S/N ratio of the received signal will often be extremely low. Therefore, the above-described problem would be significant.


A DC-based power system including: an AC power distribution system for providing AC power to a first node and a second node; a first converting system coupled to the first node that converts AC power to DC power and outputs the DC power to a first distributed bus bar; a second converting system coupled to the second node that converts AC power to DC power and outputs the DC power to a second distributed bus bar; a first set of DC/DC converters that steps down the DC power from the first distributed bus bar to a first stepped down DC voltage; a second set of DC/DC converters that steps down the DC power from the second distributed bus bar to a second stepped down DC voltage; and a critical load distribution system that is powered by both the first stepped down DC voltage and the second stepped down DC voltage.

With the advent of the information technology age, data center have become critical to the operation of almost all large scaled enterprises. Illustrative enterprises that rely on data centers include: financial service companies, government agencies, defense operations, hospitals, commercial Websites, etc. As the need to accommodate and process more and more data grows, greater and greater demands are placed onto the infrastructure of the data center.
Issues that must be addressed include: providing an infrastructure that can maintain 24/7 operations; controlling the amount of physical space required; providing the necessary cooling requirements; and managing the power consumption. As availability requirements (i.e., the amount of uptime) placed on data centers increase, these issues will continue to drive up the costs associated with operating data centers.
Power consumed by the equipment found in a data center can account for up to 50% of the total cost of operating such a facility. One of the main culprits of this power consumption lies in the fact that most data centers rely on AC to power the servers and other equipment. In a typical computer power supply distribution architecture, AC power is delivered to a component (e.g., a server), which then converts the power to DC to operate the various controllers, drives, memory, etc., associated with the component. Traditional AC power supplies operate at about a 70% efficiency level, which results in a significant waste of energy resources.
In addition to providing relatively low power efficiency, such configurations also generate a significant amount of heat that must be dealt with. The thermal load problem is further exacerbated by the use and introduction of technologies such as "blading" into the data center architecture. Blading utilizes high density blade chassis installed in cabinets into which "blades" can be plugged. Each blade incorporates a device (such as a server) that is significantly smaller and denser than traditional rack mounted components.
One solution that would address the issues faced by data centers is to utilize a DC-based architecture to power the equipment in the data centers. Unfortunately, no DC-based architectural infrastructure has been developed or proposed that will adequately address the major operational issues faced by data centers. Accordingly, a need exists for a DC-based architecture for data centers.

Hewlett-Packard Development Company, L.P.


Thermal chemical vapor deposition processes and coated articles are disclosed. The coated article includes a surface having a surface impurity and a coating on the surface formed by thermally reacting a gas. In comparison to a comparable coating without the surface impurity, the coating on the surface has substantially the same level of adhesion, corrosion resistance over 24 hours in 6M HCl, corrosion resistance over 72 hours in NaClO, and electrochemical impedance spectroscopy results. Additionally or alternatively, the surface impurity has properties that reduce or eliminate adhesion of a comparative coating produced by decomposition of silane on a comparative surface following exposure of the surface to a temperature.

To ensure maximum coating quality and customer satisfaction, coating services providers go through great efforts to make sure that all parts are clean (free of oil, grease, embedded particles, and other impurities) before they are coated. For example, parts usually go through surface preparation steps to clean and prepare parts before initiating thermal chemical vapor deposition processes. Such efforts can be costly and can require substantial infrastructure. In addition, such cleaning procedures are incompatible with certain parts and materials.
Such contaminants impact different coating techniques in different ways. For example, depending upon the nature of the contaminants, unclean substrates may outgas under heat during a thermal chemical vapor deposition run, which results in poor adhesion and/or cosmetic defects. Sometimes these defects can become initiation points for corrosion, and can cause a protective coating to fail sooner than expected. Additionally or alternatively, the cosmetic defects can be highlighted by the chemical vapor deposition coatings.
Thermal chemical vapor deposition processes and coated articles that show one or more improvements in comparison to the prior art would be desirable in the art.

Thermal chemical vapor deposition process and coated article


A device for improving motion, extension and control of an arm of a person playing a game such as bowling comprising a band of flexible material having an inner surface which is in firm contact with the arm of the person in the area of the wrist and above the hand when the device is worn during use and having an oppositely-directed outer surface. A weight is fixedly held on the outer surface of the band and comprises a quantity of closely-packed metal pellets within a flexible container. A pair of loop-like elements are fixed in spaced relation to the band along one end thereof, and a pair of flexible straps extend in spaced-apart, generally parallel relation outwardly from the opposite end of the band. Each of the straps is provided with a fastener on the outer surface thereof, and a pair of mating fasteners is provided on the outer surface of the band. When the device is worn for use each of the straps extends from the end of the band laterally along the surface of the person's arm, extends through a corresponding one of the loops, and then is returned back past the end of the band to be in mating engagement with the fastener on the band, each strap serving to draw the band tightly against the surface of the person's arm.

This invention relates to the art of athletic goods, and more particularly to a new and improved device for improving the motion, extension and control of the arm of a person playing a game such as bowling.
One area of use of the present invention is in the game of bowling, although the principles of the present invention can be variously applied. In games such as bowling, the arm action of the player is of primary importance. For example, as the player swings his arms during delivery of the bowling ball he must control the swing, try for full extension of the arm, keep any turning action on the ball under control and avoid over-turning, release the ball properly and try for a good follow-through. The foregoing obviously requires much practice and concentration by the player. It would, therefore, be highly desirable to provide a device worn on the arm of a bowler for improving the motion, extension and control of the bowler's arm.


A folding accordion sweep partition assembly is presented. The partition has a plurality of partition panels, the panel having a front face, a rear face, a bottom edge, and two opposing open sided panel keyway channels. A hinge having two side walls, the side wall terminating in a hinge key hinges two panels by having a first hinge key slidably received and retained in a first partition panel keyway channel and a second hinge key slidably received and retained in a second partition panel keyway channel. The partition panel has a mounting bracket affixed to it, a bottom bracket removably retained to the mounting bracket, and a sweep affixed to the mounting bracket.

Side folding accordion partitions are used to provide space separation, often with the additional goal of providing one or more of security separation and sound control.
Panels which form the partition are hinged to one another and attached to ball bearing rollers which ride within a mounted overhead track. A lead panel is attached to a lead post which in turn is attached to a trolley having ball bearing rollers which also rides within the overhead track. Either a powered, or more commonly, a manually operated trolley provides the mechanical action required to open and close the partition.
When the partition is activated, the ball bearing rollers and lead post trolley roll in the overhead track causing the partition to traverse open or closed. The partition may or may not be slidably mounted to a floor channel. A partition slidably mounted to a floor channel ensures that the partition remains in the vertical thereby keeping the sweep at the bottom of the partition in contact with the floor. The floor channel provides lateral stability to the door curtain during travel towards or away from the closed position.
Certain applications require a contiguous floor surface, that is, unbroken by a floor channel. Examples include shop floors where a channel could interfere with rolling carts or emergency egress lanes where a floor channel could create a tripping hazard. In those situations, door assemblies that do not mount the partition to a floor channel are utilized.
Regardless of whether or not a floor channel is utilized, the sweep at the bottom of the partition is used to maintain a predetermined relationship to the floor, thereby, for example, helping to control sound.
Known designs for mounting the sweep to the partition leave an unfinished, sharp surface as further described below. Accordingly, there is still a continuing need for improved designs for mounting the sweep to a partition. The present invention fulfills this need by presenting a novel sweep assembly and further provides related advantages.


A polyhedral display system is disclosed. The polyhedral display system may include three or more flat-panel displays shaped as polygons and connected to form a non-planar polyhedral display surface. Further, at least one of the three or more flat-panel displays may be shaped as a non-rectangular polygon. The polyhedral display system may further include a controller coupled to the flat-panel displays. The controller may receive visual content, divide the visual content into three or more segments for display on the three or more flat-panel displays based on their relative positions, and provide data signals to the three or more flat-panel displays based on the three or more segments for displaying the visual content.

Immersive displays typically include a display surface that is larger than a field of view of a user such that the user may view different portions of displayed image or video content by turning his or her head. In some cases, the display surface is shaped to at least partially surround the user to provide increasingly immersive experiences. Immersive displays have many potential uses including, but not limited to, recreational displays, immersive gaming platforms, simulators for aircraft or automotive applications, and real-time displays in place of transparent windows in supersonic or hypersonic aircraft where windows may be undesirable or infeasible.
Immersive displays may typically include a system for projecting images onto a display surface, in part due to challenges associated with creating seamless arbitrarily-shaped display surfaces using flat-panel displays that have been traditionally fabricated in rectangular shapes. However, projection systems may impose requirements on system size or weight that may limit their effective implementation or reliability in some applications.

Polyhedral display device using shaped flat-panel displays


An automatic dispersion equalization apparatus in a high-speed optical transmission system, which performs continuous automatic dispersion equalization with the help of analog circuits without employing external digital processors by performing automatic compensation of optical fiber chromatic dispersion.

The present invention relates to automatic dispersion equalization apparatus in high-speed optical transmission systems, with bit rates exceeding several tens of Gbit/s.
Recently, various communication service applications, for example, email, Internet, telebanking, teleshopping, videoconference, and other multimedia services have become required. To keep pace with such trends in the communication area, data transmission speed in optical communication has increased substantially. Currently, optical communication systems with 10 Gbit/s speed are widely used, and it is not difficult to expect optical communication systems with 40 Gbit/s or faster to be extensively used in the near future.
However, as the transmission speed of the optical communication systems increases to the range of several tens of Gbit/s, the chromatic dispersion effect of optical fibers becomes one of the most troublesome barriers against efficient high-speed data transmission. In fact, since the allowable amount variation of chromatic dispersion in 40 Gbit/s optical communication systems is within several tens of ps/nm, accurate chromatic dispersion compensation and equalization is required.
An alternative is to build a whole new optical communication systems with optical fibers that can handle chromatic dispersion efficiently. But the expense for this alternative is quite enormous. Linear chromatic dispersion compensation is becoming popular since a pre-installed optical fiber network can be used without additional expense. In linear chromatic dispersion compensation, optical transmitters and receivers are equipped with chromatic dispersion equalizers.
There are three conventional ways to compensate optical fiber chromatic dispersion.
First, linear passive chromatic dispersion method is available. Devices such as dispersion compensating fiber (DCF) and fiber grating implement it
Second, non-linear active chromatic dispersion method is available. devices such as mid-span spectral inversion (MSSI) implement it.
Third, an electric compensation method such as pre-chip, dispersion supported transmission (DST), and duobinary coding which is implemented in transmitters and receivers is available.
In super high-speed optical network systems like systems with 40 Gbit/s, however, it is not easy to equalize chromatic dispersion because the allowable amount of chromatic dispersion is very small, and it is sensitive to environmental factor change like temperature.
Due to reasons stated above, an automatic dispersion equalizer that automatically compensates chromatic dispersion becomes a necessary device in super high-speed optical network systems.
Generally, a chromatic dispersion detector and a chromatic dispersion-variable equalizer are needed in order to implement automatic dispersion equalizer. A detector detects optimal chromatic dispersion value from the physical amount that is repeatedly changed by chromatic dispersion value. An equalizer has a capability of changing its chromatic dispersion value. [xe2x80x9cAutomatic dispersion equalization by monitoring extracted-clock power level in a 40-Gbit/s, 200 km transmission linexe2x80x9d, Sano, Akihide et al., 22nd European Conference on Optical Communication ""96, pp207xcx9c210]
Signals measured by the detector are supplied back to the chromatic dispersion equalizer and automatic dispersion equalization is performed. A well-known technique for detection is to measure error bit ratio, eye opening, and size of clock component of signals transmitted to an optical receiver. Until recently, chromatic dispersion has been measured by this technique and measured data has been provided to external processors for computations. Then, a controller controls the chromatic dispersion generator to equalize chromatic dispersion.
A widely used chromatic dispersion equalizer is an individual linear passive device such as dispersion compensating fiber (DCF), fiber grating, and planar lightwave circuit. Another technique in which feedback signals of a detector are supplied to a transmitter and the output signal frequency of optical source is modified have been introduced.
However, since these techniques require external measurement devices, a processor, and a controller, it is complicated to apply them to high-speed optical communication systems. In addition, from a system perspective, when the system is being used, the chromatic dispersion equalization may degrade performance of system.
The present invention provides an automatic dispersion equalization apparatus in a high-speed optical transmission system, which performs continuous automatic dispersion equalization without the help of external digital processors and performance degradation.
An automatic dispersion equalization apparatus in high-speed optical transmission system is composed of means for generating electric signals in accordance with chromatic dispersions and means for equalizing optical fiber chromatic dispersion by using the electric signals.
More particularly, the automatic dispersion equalization apparatus in a high-speed optical transmission system is composed of the following devices. A chromatic dispersion-variable equalizer adds chromatic dispersion to a positive positive (+) or a negative (xe2x88x92) direction with the help of a positive positive (+) or a negative (xe2x88x92) DC electric signal and thereby equalizes optical fiber chromatic dispersion. An optical coupler receives optical signals from the chromatic dispersion-variable equalizer and splits them into two paths. A chromatic dispersion generator generates chromatic dispersion to the positive (+) or negative (xe2x88x92) direction to add to the optical signals of the optical coupler.
A signal generator generates sine or trigonometrical functions to control chromatic dispersion of the dispersion generator. A photo detector converts the optical signals of the chromatic dispersion generator into electric signals. A narrow band amplifier amplifies electric signals of the photo detector. A narrow bandpass filter extracts clock components of signal speed from the amplified signals. An amplitude detector extracts magnitude variation from clock components extracted by the narrow bandpass filter. A phase shifter adjusts the phase of the output signal of the detector to match with phase of the signal of the signal generator. A multiplier detects the phase difference between the phase of the signals from the phase shifter and the phase of the signals from the signal generator. A low pass filter extracts DC components from output signals of the multiplier. An integrator continuously loads a positive (+) or negative (xe2x88x92) DC value to the chromatic dispersion-variable equalizer as the DC value of the signals from the low pass filter varies between positive (+) and negative (xe2x88x92).

Automatic dispersion equalization apparatus in high-speed optical transmission system

Electronics and Telecommunications Research Institute


A method of administering a drug into the brain of a mammal (human or nonhuman) is described. In this method, a magneto-electric nanoparticle (MENP) and a drug are injected into the blood stream of a mammal. The MENP attaches to the blood-brain barrier (BBB) and a non-alternating electric or magnetic field is applied. In an alternative, the non-alternating field could be replaced by a slowly alternating field so as to avoid localized heating. The step of applying an electric or magnetic field causes an increase in the permeability of the BBB to the drug so that the drug passes into the brain while the MENP remains attached to the BBB.

There have been great efforts devoted to improving methods for safely transporting drugs across the blood brain barrier (BBB). Recently, a large amount of research has been directed to the application of electric or magnetic fields to facilitate the transport of drugs across the BBB.
Martel et al. in US 2015/0126964 state that magnetically heatable entities (MHEs) can be piloted from an injection point to a location of the BBB and then using an alternating magnetic field to heat the MHEs. Advantageously the MHEs are superparamagnetic. Application of an AC field heats the MHEs leading to transient disruption of the BBB, thus facilitating delivery of therapeutic agents. A scientific paper by several of the inventors of the Martel patent application is Tabatabaei S J, Girouard H, Carret A-S, Martel S., entitled "Remote control of the permeability of the blood-brain barrier by magnetic heating of nanoparticles: A proof of concept for brain drug delivery", Journal of Controlled Release, 206 (2015) page 49-57. The authors reported that "we show that the thermal energy generated by magnetic heating (hyperthermia) of commercially available magnetic nanoparticles (MNPs) in the brain capillaries of rats can transiently increase barrier permeability . . . . Results indicate a substantial but reversible opening of the BBB where hyperthermia is applied." In this paper, the authors stated that "when MNPs are deposited, they remain on the surface of the target endothelium for the duration of our technique."
Several patents have discussed nanoparticles and the BBB. International patent application no. WO201474584 describes a method comprising administering to a subject a plurality of magneto-electric nanoparticles (MENP) having a drug associated thereto through an ionic bond; and applying a magnetic field to the subject to weaken the ionic bond thereby releasing at least a portion of the drug from the MENP. The MENP may be CoFe2O4@BaTiO3. Khizroev et al. in US 20130317279 describe a method of using magneto-electro nanoparticles that pass through the BBB into the brain where they are actuated by an external AC magnetic field. Jin et al. in U.S. Pat. No. 8,968,699 describe hollow nanospheres comprising a drug (such as an anti-nerve agent) and further comprising magnetically actuable superparamagnetic nanoparticles and a polymer coating. A magnetic field can be used to activate the nanospheres and release drug inside the brain. The nanoparticles can be heated to disrupt the BBB for easier crossing.
WO2014125256 describes a method of delivering at least one agent to the central nervous system (CNS). The composition comprises: (a) a nanoparticle comprising: (i) a magnetic core; (ii) a corona comprising a plurality of ligands covalently linked to the core, wherein said ligands comprise a carbohydrate, insulin and/or a glutathione; and (b) at least one agent to be delivered to the CNS.
Gordon in U.S. Pat. No. 4,813,399 states that ferromagnetic particles that are under 1 μm in size can be injected into a patient. A steady magnetic or electric field may be used to enhance uptake of the particles by neuronal cells. Example IV describes a colloidal solution of Fe3O4-dextran-transferrin injected into a myelinated nerve.
Friedman et al. in WO 2015/038924 describes coating paramagnetic nanoparticles with a lipophilic drug and a polymer. The drug-bearing nanoparticles cross the BBB with the aid of a magnetic field. Although not described in detail, Friedman et al. suggest that the drug-bearing nanoparticles can be combined with chemotherapeutic agents.
Pell et al. in WO2013121359 describes a method for a temporary increase in a permeability of the blood brain barrier and administering a pharmaceutical substance to the brain, the method comprising: providing a system for transcranial magnetic stimulation in a range of at least 0.2 Hz; placing said system on a scalp; and providing a series of magnetic pulses to the brain via the system. Nanoparticles are not mentioned in this reference.
Numerous papers describe using a magnetic field to facilitate transport of drug-carrying superparamagnetic nanoparticles across the BBB. Nair et al. in US 20110213193, entitled Magnetic nanoparticle to transport API across brain blood barrier, use of magnetic field discuss the use of superparamagnetic nanoparticles to carry drugs through the BBB. Thomsen L B, Linemann T, Pondman K M, Lichota J, Kim K S, Pieters R J, Visser G M and Moos T., "Uptake and Transport of Superparamagnetic Iron Oxide Nanoparticles through Human Brain Capillary Endothelial Cells", ACS Chem Neurosci. 2013 Oct. 16; 4(10), pages 1352-1360 investigated the ability of fluorescent superparamagnetic iron oxide nanoparticles (SPIONs) to pass through human brain microvascular endothelial cells facilitated by an external magnet. The ability of SPIONs to penetrate the barrier was shown to be significantly stronger in the presence of an external magnetic force in an in vitro BBB model. The SPIONs can be coated with ligands or antibodies. Yan F, Wang Y, He S, Ku S, Gu W, Ye L., "Transferrin-conjugated, fluorescein-loaded magnetic nanoparticles for targeted delivery across the blood-brain barrier", J Mater Sci Mater Med. 2013 October; 24(10), pages 2371-2379 reported a strategy for brain targeted delivery utilizing the targeting of ligand conjugated nanoparticles to trigger the receptor-mediated transcytosis. In this study, transferrin (TO was employed as a brain targeting ligand to functionalize the fluorescein-loaded magnetic nanoparticles (FMNs). The Tf conjugated FMNs (Tf-FMNs) were characterized by transmission electron microscopy, thermal gravimetric analysis, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. Using fluorescein as an optical probe, the potential of Tf-FMNs as brain targeting drug carriers was explored in vivo. It was demonstrated that Tf-FMNs were able to cross the intact BBB, diffuse into brain neurons, and distribute in the cytoplasm, dendrites, axons, and synapses of neurons. In contrast, magnetic nanoparticles without Tf conjugation did not cross the BBB efficiently under the same conditions. Fan C H, Ting C Y, Lin H J, Wang C H, Liu H L, Yen T C, Yeh C K., "SPIO-conjugated, doxorubicin-loaded microbubbles for concurrent MRI and focused-ultrasound enhanced brain-tumor drug delivery", Biomaterials 2013 May; 34(104), pages 3706-3715. DOX-SPIO-MBs ((doxorubicin; DOX), superparamagnetic iron oxide (SPIO), circulating microbubbles (MBs)) were designed to concurrently open the BBB and perform drug delivery upon FUS exposure, act as dual MRI and ultrasound contrast agent, and allow magnetic targeting (MT) to achieve enhanced drug delivery. The authors reported that DOX-SPIO-MBs were stable and provided significant superparamagnetic/acoustic properties for imaging. BBB-opening and drug delivery were achieved concurrently during the FUS exposure. Kong et al. in "Magnetic targeting of nanoparticles across the intact blood-brain barrier", Journal of Controlled Release 164 (2012) pages 49-57 "demonstrate in a mouse model that magnetic nanoparticles (MNPs) can cross the normal BBB when subjected to an external magnetic field . . . . Atomic force microscopy demonstrated that MNPs were internalized by endothelial cells, suggesting that trans-cellular trafficking may be a mechanism for the MNP crossing of the BBB."
Despite these references and other work, there remains a need for improved methods of transporting drugs across the BBB.

Administration of a drug through the blood brain barrier using stimuli-responsive nanoparticles


The present invention relates to ruggedized downhole tools and sensors, as well as uses thereof. In particular, these tools can operate under extreme conditions and, therefore, allow for real-time measurements in geothermal reservoirs or other potentially harsh environments. One exemplary sensor includes a ruggedized ion selective electrode (ISE) for detecting tracer concentrations in real-time. In one embodiment, the ISE includes a solid, non-conductive potting material and an ion selective material, which are disposed in a temperature-resistant electrode body. Other electrode configurations, tools, and methods are also described.

Geothermal energy provides an alternative sustainable energy source. Harnessing such energy requires an understanding of geothermal reservoir properties, such as the extent and interconnectivity of subsurface rock networks, characteristics of various geologic formations, and chemical analyses of existing and injected fluids within geothermal wells.
Enhanced or Engineered Geothermal Systems (EGS) extract heat by circulating fluid through subsurface fracture networks in a geothermal reservoir. An EGS plant generally includes an injection well that injects fluid into high temperature fractures within the reservoir and numerous production wells that pump the hot geothermal brine to the surface. The thermal energy from the geothermal brine is then converted into electricity, and the spent brine is then re-injected into the reservoir via injection wells.
In order to develop and maintain EGS plants, tracer experiments are generally used to characterize the fracture networks. Most tracer experiments involve injecting a tracer at the injection well, manually collecting liquid samples at the wellhead of the production well, and sending the samples off-site for laboratory analysis. While this method provides accurate tracer concentration data at very low levels of detection, it does not provide information regarding the location of the fractures that were conducting the tracer between wellbores.
Real-time measurements could provide location-specific information for tracer experiments. However, due to the harsh conditions present in these wellbores, any useful sensor or tool should be able to withstand excessive temperature, pressure, and/or pH. New sensors and tools capable of operating under harsh conditions for geothermal reservoirs and providing real-time measurements are needed.

Ruggedized downhole tool for real-time measurements and uses thereof

National Technology & Engineering Solutions of Sandia, LLC


A device and method is shown for electrically heating a vehicle. The heating device has positive temperature coefficient (PTC) heating thermistors connected in groups, and a circuit for selectively turning on one or more groups. At least two of the groups have different rated heating powers. The circuit turns on the selection of the groups at least on the basis of the available electrical power.

The present invention relates to an electrical heating device, and in particular to a PTC heating device, for a vehicle, and to a method for electrically heating a vehicle.
Besides the known heating/cooling circuits with corresponding heat exchangers, increasing use has been made of electrical heating devices in recent years for heating the passenger compartment of a vehicle. These can be used both as units for assisting known heat exchangers, and as units for replacing them. In order to convert electrical energy into heat, conventional heating resistors and so-called positive temperature coefficient thermistors (hereafter PTC heating thermistors) are generally used. It is also known to combine both types of resistors, see e.g. FR-A-2 690 112.
PTC heating thermistors have a resistance that changes significantly as a function of temperature. Above a threshold temperature, it increases steeply so that PTC heating thermistors provide a certain degree of self-regulation in the operating range, for which reason the use of PTC heating thermistors has gained popularity in recent years.
FR-A-2 742 384 discloses a heating device of the generic type having the features of the preamble of claim 1. This known device comprises a heat-exchanger body whose configuration is chosen in order to integrate PTC thermistors. The PTC thermistors are arranged and connected in groups. Individual or multiple groups can be turned on selectively by means of a circuit, e.g. in order to provide different temperatures for different regions of the heat exchanger.
Since, owing to different vehicle operating conditions, the levels of electrical power vary, very substantial power losses occur in the known devices, and there is also a risk of overloading the vehicle electrical system. In order to solve the aforementioned problems, various attempts have been made to provide an improved control system for PTC heating elements. These include, inter alia, the relay-controlled switching of heating circuits with equal power, as e.g. indicated in FR-A-2 742 384 cited above. Although this does provide at some degree of improvement in terms of the power loss that occurs, it cannot be regarded as any more than an interim solution.
An alternative approach consists in controlling the power continuously on the basis of pulse-width modulation. Although this method promises a low corresponding power loss, it unfortunately entails the disadvantage of additional sources of interference. The use of the linear controller has also been found to be unfeasible owing to the very high power losses.
The object of the invention is accordingly to develop an electrical heating device of the generic type, and a method of the generic type for electrically heating a vehicle, in such a way as to minimize the power loss, with the further intention of guaranteeing as continuous as possible an adjustment of the heating power. The device and the method are also intended to contain the fewest possible sources of interference, or to function with the least possible susceptibility to interference.
According to one aspect of the invention, there is provided an electrical heating device, in particular a PTC heating device, for a vehicle, having a plurality of heating resistors, in particular PTC heating thermistors, which are connected in groups, and having a circuit by means of which one or more groups can be turned on selectively, wherein the circuit turns on a selection of the groups at least on the basis of the available electrical power.
According to another aspect of the invention there is provided a method for electrically heating a vehicle by using electrical heating elements, in particular PTC heating elements, which are connected in groups, with the step of turning on one or more groups, wherein the said step of turning-on is carried out in relation to a selection of groups, at least on the basis of the available power.
The electrical heating device according to the invention is, in particular, preferably a PTC heating device for a vehicle. It comprises a plurality of heating resistors, in particular PTC heating thermistors, which are connected in groups. It further comprises a circuit by means of which one or more groups can be turned on selectively. The device according to the invention is distinguished in that at least two of the groups have different rated heating powers, and in that the circuit turns on, or supplies with electricity, a selection of the groups at least on the basis of the available electrical power.
The method according to the invention for electrically heating a vehicle by using electrical heating elements, in particular PTC heating elements, which are connected in groups, with the stept of turning on one or more groups, is distinguished in that at least two of the groups have different heating powers, and in that the stept of turning-on is carried out in relation to a selection of groups, at least on the basis of the available power.
The device according to the invention, and the method according to the invention, hence make it possible to select groups with different heating power, on the basis of the available electrical power, in order to obtain optimally efficient heating of the passenger compartment at all times, in particular in the operating range of the individual groups of PTC heating thermistors. Accordingly, overloading of the electrical system built into the vehicle and the occurrence of power losses can be prevented to all practical intents and purposes.
In order to make it possible to obtain a heating function even when the available electrical power is relatively low, the group with the lowest heating powers should advantageously provide a temperature increase, for the medium to be heated up, in particular air, of at most 1 kelvin in the operating range of the group of PTC heating thermistors.
Advantageously, the maximum difference in rated heating power between at least two groups provides a temperature increase, for the medium to be heated up, of at most 1 kelvin in the operating range, so that the heating power can be controlled continuously to all practical intents and purposes.
In a preferred embodiment, a total rated heating power graduation is provided, in particular with an increment which corresponds to a respective temperature increase, for the medium to be heated up, of at most 1 kelvin in the operating range, by means of respective selection. In other words, groups of PTC thermistors, or even conventional heating resistors, can be combined in such a way that various total rated heating powers can be obtained.
In a particularly preferred embodiment, the heating power of at least one group substantially satisfies the equation
Pn=P1+(nxe2x88x921)xc3x97P1
where, in a series of groups with different rated heating power in order of increasing heating power, n denotes one of the groups. Consequently, for example, the desired graduation of the total heating power may be obtained, in the case of four groups, by providing the first group with a rated power of 100 watts, a second group with a rated power of 200 watts, a third group with 300 watts and a fourth group with 400 watts of electrical power. In the example indicated, it is therefore possible to obtain total heating powers of up to 1000 watts with a 100-watt interval. If e.g. an electrical power of 900 watts is available from the vehicle electrical system, and the user desires and sets a maximum heating power, the groups with respective powers of 200 watts, 300 watts and 400 watts may be operated together, so as to provide an overall optimized efficiency.
In an alternatively preferred embodiment, the rated heating of a group satisfies the following equation
Pn=2(nxe2x88x921)xc3x97P1
where again, in a series of groups with different rated heating power in order of increasing heating power, n denotes one of the groups. Assuming a rated heating power P1=100 watts for the first group, corresponding approximately to a temperature increase of 1 kelvin in the air flowing past, the group with the next heating power up has a rated electrical power of 200 watts. The following groups should then approximately have electrical powers of 400 and 800 watts. With this configuration of the individual groups as well, it is possible to graduate the total heating power with an increment equal to the smallest rated heating power, the maximum total rated heating power, if the vehicle can provide sufficient power, amounting to 15 times the rated heating power of the group with the lowest power.
Both in the device according to the invention and in the method according to the invention, the turning-on of individual groups may be carried out, as well as on the basis of the available electrical powers, also on the basis of sensor signals and/or of user-setting signals. The signals provided by means of sensors may, inter alia, comprise external temperature signals, passenger-compartment temperature signals and the like. The user-setting signals may, inter alia, cause the entire device to be switched on and off, or may lead to the desired thermostatic regulation within the limits of the available electrical power.


In a mobile-unit positioning device, phases of pseudo noise codes carried on satellite signals from satellites are observed at a mobile unit to measure a position of the mobile unit. A pseudo distance between one of the satellites and the mobile unit is measured for every satellite during a stop of the mobile unit using an observed value of the phase acquired during a stop of the mobile unit. An error index value indicating an error of the measured distance is computed based on the distances measured at points in time during a stop of the mobile unit. A weighting factor is determined based on the index value computed for every satellite. A weighted positioning computation using the determined weighting factor is performed to determine a position of the mobile unit during movement using an observed value of the phase acquired during movement.

Conventionally, there is known the method of computing a user speed on the geocentric orthogonal coordinate system and its time offset rate by simultaneous speed equations. The simultaneous speed equations are constructed using a user position on the geocentric orthogonal coordinate system determined by simultaneous position equations, and the time offset. The differentiated value of the speed on the geocentric orthogonal coordinate system with respect to time is determined by solving the simultaneous speed equations. Each value required by the user is computed by obtaining the differentiated value of the speed on the geocentric orthogonal coordinate system with respect to time through transforming of the geocentric orthogonal coordinate system into the geocentric orthogonal coordinate system at the user position. For example, refer to Japanese patent No. 2963912.
Generally, in GPS (global positioning system) positioning, measurement of a position of a mobile unit is performed based on the results of received signals from a plurality of satellites. At this time, the radio propagation paths from the respective satellites to the mobile unit are different from each other, and a different error for each satellite may be included in the measured value (for example, pseudo distance) obtained based on the received signals from the respective satellites. For this reason, when performing GPS positioning, there are cases in which a weight is assigned for each satellite.
Conventionally, in many cases, the weighting factors used in the above-mentioned weighting are determined in accordance with the residual difference at the previous instant of the positioning computation, the difference in the elevation angle of each satellite, or the difference in the intensity of the signal received from each satellite. However, there is a problem that using the determined weighting factors is not appropriate for reflecting a different error for every satellite.