A system for seismic prospecting by using reflections of acoustic waves and an operation method thereof. Unprocessed raw data from a plurality geophone sensors and other processed data are stored in a storage unit further processing and analysis. The preferred operation comprises four stages, performing test sweeps no and analyzing results thereof (testing stage), determination of control parameters for the spatial distribution of sensor array and data-collection sweeps based on the analysis of test sweeps (parameter-determination stage), performing data-collection sweeps (data collecting stage), and analysis and processing of the data-collection sweeps (data processing stage). Test sweeps and availability of unprocessed raw data allow optimization of the system to achieve maximal resolution and signal-to-noise ratios.

Seismic exploration uses information in an attempt to determine the character of the ground without actually drilling into the ground. Many seismic exploration systems are based on launching acoustic probe waves with a vibratory element and measuring reflected probe waves from underground layers with an array of detectors distributed on ground surface. An example of such technique is illustrated with reference to FIG. 1.
An acoustic probe wave or seismic wave is initiated at a point on the surface of the ground shown as shock point 100. The acoustic wave essentially emanates from a point at the source point 100. The wavefront would approach a spherical shape and travel outward in all directions if the underground is a homogeneous medium. Various geological formations exist and interact with the acoustic wave. In particular, the acoustic wave is reflected from various layers in the ground. Detection of the spatial and temporal characteristics of the reflections from these underground formations forms the basis for seismography.
The acoustic probe wave can be generated by a blast of dynamite. Alternatively, the probe ware may be generated by using a mechanized vibrator which vibrates the ground at certain frequencies. The vibrator can be controlled by a central control unit (e.g. a computer), for example, to produce a swept frequency signal for improved signal-to-noise ratios.
A plurality of sensors are spatially distributed on or near the ground surface to measure the reflections of the acoustic wave from the layers. Well-known sensors, such as geophones, are normally used to detect the reflected seismic waves. Geophones are miniature force sensors operable to convert vibrations into electrical signals. Geophones are spread over the surface or near the surface of the ground in an array to determine magnitudes of vibrations caused by the reflected acoustic waves. Hundreds or thousands of geophones can be used in an array. A single, or groups of geophones (e.g., geophone station), are attached by cables to a central processing element which receives the geophone data and processes it to extract various information about the structure of the earth from these seismic reflection paths.
FIGS. 2A and 2B show an example to illustrate the basic process. A rectangular area is assumed to be the area of interest on or near the ground surface (FIG. 2A). A line A-A' indicates a survey trace in the east-west direction. Seismic data is taken along line A-A' to extract geological information thereunder. A multiplicity of such east-west survey traces of a predetermined spacing are surveyed and a multiplicity of north-south traces (e.g., line B-B') are also surveyed to obtain a 2D mapping of the geological profile of the earth under survey area. FIG. 2B shows a seismic vertical cross-section with three reflection surfaces Ri, R2, and R3 underneath the line A-A' in the mapping area for illustration purpose.
One way to perform the survey is to initiate acoustic probe waves at successive locations along the line A-A' to obtain sufficient data to represent the geological profile underneath line A-A'. For example, an acoustic wave is sent to the earth at a source point SP1. Arrays of geophones are symmetrically distributed with a predetermined spacing about SP1 along line A-A'. The spatial spread of the geophone array is usually chosen so that a sufficient field of view can be achieved to receive reflections from the deep as well as shallow reflection layers of interest. The spacing or density of the geophone arrays is selected for a desired mapping resolution and full coverage of the survey area. One or more acoustic waves are initiated and the respective reflections from the reflection surfaces Rl, R2, and R3 are measured by the geophone arrays.
A subsequent detection location SP2 along line A-A' should be chosen so that every location between SP1 and SP2 is covered by the acoustic waves from either source point. FIG. 2B shows that SP2 to the east of SP1 should be no further than the location of the outer most geophone in the array on the east side of SP1. Otherwise, reflection surface R1 will not be fully covered.
The processing of the information from these geophones is well-known in the art. Modern trends have attempted to correlate the data from these geophones for various reasons, including to enhance the signal-to-noise ratio. Specifically, a signal received by a geophone due to an acoustic probe wave is correlated with a reference signal with a waveform identical to that of the probe wave using the central processing element. A seismogram can be composed from the correlation signals for each source point and thereby a 2D mapping of the geometric profile of the reflection surfaces underneath the rectangular area can be constructed.
The system and signal processing are complicated by noise. Seismic detections often have signal to noise ratios less than 1, sometimes as low as 0.01. Said another way, there is usually three to 100 times as much noise as signal. The correlation techniques are crucial for extracting desired signals from noise and proper understanding of the data in many detection systems. Sometimes, the correlations may not be done properly or in the best way possible in retrospect. These detections are often carried out multiple times in attempts to average out noise.
One prior-art technique for extracting a weak correlation signal from a noisy background was developed by Continental Oil Company, named "VIBROSEIS". It is similar to the well-known "chirp radar" technique for detecting a radar signal embedded in noise. A sweep signal in a pre-selected frequency range is initiated repeatedly several times at each source point. The signals received by each geophone due to multiple "sweeps" in the same frequency range are summed to form a composite signal. Next, a reference signal with the same frequency chirp as each sweep signal is correlated with the composite signal to produce a correlation signal. This improves the signal-to-noise ratio in the detection.
However, "Vibroseis" produces undesired side lobes near the main correlation peak, which constitute damaging noise on the final processed seismic cross sections. These side lobes are the well-known Klauder wavelets that are caused by the limited frequency bandwidth of the sweep signal. It is known that increasing the bandwidth and/or the time duration of the sweep can reduce the amplitude of the side lobes. Usefulness of such methods of reducing side lobes is essentially eliminated by practical limitations inherent in seismic prospecting. In addition, the process of first summing multiple sweeps and then performing correlation in "Vibroseis" actually amplifies the side lobes since all side lobes are in phase with respect to one another and add constructively.
Martin recognized the problems of the "Vibroseis" technique and developed an improved chirp technique called VARISWEEP.TM.. This is disclosed in U.S. Pat. No. 4,037,190, the content of which is incorporated herewith by reference. The VARISWEEP.TM. technique makes a plurality of passes of vibration with each having a chirp in a different frequency range. The bandwidth of each sweep can be chosen to be approximately within the frequency range to which the earth is most responsive (e.g., from 10 Hz and 100 Hz). The sweeps, for example, might include 10-48 Hz for sweep 1, 12-52 Hz for sweep 2, 14-56 Hz for sweep 3, etc.
In VARISWEEP.TM., each of the multiple different frequency sweeps is correlated with a respective reference signal for that particular sweep. Instead of having only one correlation signal in Vibroseis, there are a multiplicity of correlation signals in VARISWEEP.TM.. Next, all correlation signals from the multiple sweeps are summed to generate one composite correlation signal. Contrast to Vibroseis, the side lobes from different sweep correlation signals are out of phase with respect to one other due to the relative frequency shift, resulting in destructive summation thereof. Thus, the side lobes are substantially minimized in the composite correlation signal in VARISWEEP.TM..
VARISWEEP.TM. has other beneficial features. For example, the multiple frequency ranges of the multiple sweeps can be purposely selected in a way such that some frequency ranges are in a high frequency range well above the frequency range of the ground roll while other sweeps have spectral overlaps with the ground-roll frequency range. Therefore, sweeps with frequencies above ground-roll frequency can be individually correlated and then summed together to generate a first composite correlation signal that is substantially free of ground-roll noise. Meanwhile, all sweeps are used as in conventional VARISWEEP.TM. processing to generate a second composite correlation signal of lower frequency for better resolution of deep reflectors. This can further improve the accuracy in seismic profiling.
For another example, the frequency ranges of the multiple sweeps in VARISWEEP.TM. can include high frequencies for detecting shallow reflectors and low frequencies for detecting deep beds. This is because the earth attenuates high frequency seismic waves faster and at a higher degree of completeness than it does to waves at lower frequencies.
One common limitation in prior-art techniques for seismic prospecting including VARISWEEP.TM. lies in lack of mechanisms to adjust the characteristics of the probe waves for optimizing detection of locations within the mapping area that have anomalies not best resolved by predetermined probe waves. Anomalous results in the past have often been discarded. The inventor of the present invention recognized that anomalies often reveal important seismic information and provide critical evidence in explorations such as oil exploration. Thus, prior art techniques can produce an erroneous profiling in these anomalous locations and lose valuable information.
FIG. 3 shows a seismic cross section across Delaware basin to Central Basin Platform in west Texas near the boundary of New Mexico and Texas. The edge of the Central Basin Platform 302 is somewhat like a cliff, a significant portion of which is very steep, approaching vertical. A fault 304 that is substantially vertical is located to the east of the edge 302. A reef 306 is formed close to the top of the platform edge 302. In addition, a fill zone 308 is also located near the ground surface within a general area 310 having the edge, the fault, and the reef. A person skilled in the art would recognize adverse effects caused by the these geological formations in seismic profiling the area 310. Many prior-art systems based on detection of reflected acoustic waves cannot produce an accurate seismic cross section for regions like 310 due to their incapability in reducing noise caused by these unusual formations including wavefront deformation, scattering, absorption, etc. Region 310 in FIG. 3 may represent an extraordinary collection of irregular formations. However, some of these anomalies and others alike often appear in seismic prospecting.
Another common limitation is that many prior-art systems only have the processed data stored in memory such as data for a final correlation signal from each geophone. Unprocessed raw data representing the signals directly generated by each geophone is not saved and therefore is not available for further analysis and processing. This, however, is not because the prior-art systems cannot implement appropriate means for saving the raw data but rather because the established survey techniques and the seismic survey industry fail to recognize the significance and necessity to save such raw data. The present inventor realized that unprocessed raw data from geophones, if obtained in a proper manner, can be used to provide important and sometimes critical information on the geological structures under survey. Such properly obtained raw data is particularly vital to reveal unusual geological formations as illustrated in region 310 of FIG. 3.
The present inventor further recognized that, for a given geological environment and survey hardware system, various processing techniques and possibilities can be utilized to analyze the properly obtained raw data to achieve a maximized resolution and signal-to-noise ratios that are difficult to obtain with many prior-art techniques.
It is therefore an object of the present invention to obviate these problems and limitations by going beyond the established techniques in the art. More specifically, the present invention teaches a vibratory seismic prospecting system based on a novel method of raw data collection, data storage, and data processing and analysis beyond conventional correlation approaches.
In a preferred embodiment, a plurality of geophone sensing arrays with different spatial spread and density of the geophones and other spatial parameters (e.g. azimuth coordinates) are determined based on prior knowledge or current testing for a given survey area. This, at least in part, constitutes the geometry test in accordance with the present invention. A plurality of test sweeps with predetermined different sweep frequency ranges and optionally different bandwidth are used for each of the geophone configurations in the geometry test to obtain a preliminary correlation results. Different time durations for the test sweeps can be used to further examine the temporal characteristics of the survey area.
Next, results of test sweeps are analyzed from a number of aspects, including frequency domain analysis, spatial domain analysis, and time domain analysis.
Based on analysis of the test sweeps, parameters of multiple data-collection sweeps are determined to optimize the detection of the survey area, including but not limited to, frequency range, sweep bandwidth, time duration of a sweep, amount of energy in a sweep signal, distribution of the source points in the survey area, and spatial configuration of the geophone arrays (e.g., spread, density, and azimuth coordinate). Data-collection sweeps are then initiated and the raw data is collected from the geophones and saved for subsequent analysis and processing. In this way, sweep frequencies can be chosen to best resolve the geologic beds which usually vary widely from the surface downward and also horizontally.
Next, a plurality of data processing techniques are used to analyze the raw data to achieve the maximal resolution and signal-to-noise ratio. Particularly, raw data is processed to further reveal anomalous features in the survey area. Each of the sweeps can be processed individually or can be grouped with other sweeps in any systematic, or weighted manner to achieve a desired result.


A spark plug connector, in particular for large engines, includes an inductive interference suppression device having a ferromagnetic core. The inductive interference suppression device also has at least one winding, preferably a coil, and an ohmic d.c. resistance of at least 20Ω at 20° C.

The present invention relates to a spark plug connector, in particular for large engines such as large gas engines.
Spark plug connectors form a substantially rigid connection between spark plugs, which primarily in the case of large engines are recessed deep into bores in the engine block, and the spark plug leads which lead to at least one ignition coil. They may attain a length of more than half a meter. Their rigidity is selected such that, on the one hand, it is readily possible to push them onto the spark plug, preferably without the need for further tools, while on the other hand, the spark plug connectors typically have a certain residual flexibility. Thus, in most cases, they are not completely rigid.
It is furthermore known from the prior art that ohmic resistor elements can be used to suppress interference in ignition systems. The disadvantage of these interference suppression resistors is that they consume an unnecessarily high quantity of useful energy in order to damp the radio frequency disturbance. This lost energy must on the one hand be made available by the ignition system and on the other hand results in the components concerned, such as the spark plug connector, becoming hot. This heating is highly problematic since, as a result of the electrical insulation resistance demanded among other things of the spark plug connector, materials which may also be poor heat conductors are used. This problem becomes particularly acute if—as is conventional with large engines—ignition systems which generate very high levels of ignition power are employed.


An antenna includes a radiating resonant member for transmitting polarized microwaves. A first diffracting system radiates waves at an angle greater than the transmission angle of the radiating member. A second diffracting system corrects the purity of polarization of the waves for some directions at least.

1. Field of the Invention
The invention concerns a microwave transmit or receive antenna. It is more particularly concerned with a flat resonant antenna, for example one implemented using microstrip technology.
2. Description of the Prior Art
Antennas of the above type are compact and lightweight. They are therefore used in vehicular applications, in particular in spacecraft and satellites.
There is often a need, in particular in space applications, for omnidirectional antennas, i.e. antennas that can send or receive within a large solid angle.
However, it has been found that the requirement for omnidirectionality is difficult to reconcile with the need to conserve the purity of the polarization of the electromagnetic waves transmitted or received.
In particular, when the wave to be transmitted (or received) must have circular polarization it is necessary to conserve an ellipticity close to 1 in all transmission (or reception) directions.
The purity of polarization is usually degraded most in the directions farthest from the antenna axis.
The invention aims to provide a resonant antenna of maximal angular coverage within which coverage the purity of polarization is preserved.

Resonant antenna for transmitting or receiving polarized waves


An endoscope operating instrument system which includes a back-and-forth movement mechanism for providing a back-and-forth movement drive force required to operate a forceps located at a distal end of the operating instrument and an insertion/withdrawal mechanism designed to insert and withdraw the insert section via an endoscope channel. A winding unit for winding the insert section of the operating instrument is provided and the insertion/withdrawal mechanism is adapted to insert and withdraw the insert section by rotating the winding unit together with the back-and-forth movement mechanism. Thus, a compact system structure is obtained.

1. Field of the Invention
The present invention relates to an operating instrument system for an endoscope.
2. Description of the Related Art
Since an operating instrument system for an endoscope has a long insert section (an insert section of the operating instrument), handling of the insert section of the operating instrument gives an operator a lot of trouble when inserting the same through an endoscope channel into a body cavity. Therefore, an endoscope provided with a mechanized insertion/withdrawal device for inserting and withdrawing the operating instrument automatically from an operating instrument insertion port of the endoscope has been proposed, for example, as shown in FIG. 1 of JP-A-57-117823.
There is also proposed an endoscope provided with an operating instrument drive unit separately from an endoscope body and the operating instrument, which is operated by engaging an operating unit of the operating instrument with the operating instrument drive unit and operated by a foot switch that enables the operation of the operation instrument to be performed electrically by the operator of the endoscope. For an example, see FIG. 1 in JP-A-2003-111769.
There is also proposed an endoscope which is operated by connecting a power pack and a foot switch, which are provided separately from the endoscope, to a power unit, which is detachably attached to the endoscope. For example, see FIG. 6 and FIG. 8 in JP-A-2000-207.

Operating instrument system for endoscope


The present invention allows a mobile station to receive a command entered by a user for selecting among a plurality of possible values for an authentication key (A-key) stored in its memory, including a default value, a random value and a custom (user-defined) value for the A-key. In response to the command, the mobile station can set the A-key in its memory to the default value or to an internally generated or previously stored random value, or to the custom value entered by the user. The command, whether for selecting the default, random or custom A-key value, may be entered during number assignment module (NAM) programming of the mobile station.

1. Field of the Invention
The present invention relates to wireless communication systems, and more particularly, to a method and apparatus for the management of authentication keys (A-keys) which are used to authenticate mobile stations in a cellular radio system.
2. Related Prior Art Systems
The prior art includes cellular radio systems which have been operating in the United States since the early 1980s, and providing telephone service to an ever growing subscriber base, presently estimated at over 20 million subscribers. Cellular telephone service operates much like the fixed, wireline telephone service in homes and offices, except that radio frequencies rather than telephone wires are used to connect telephone calls to and from the mobile subscribers. Each mobile subscriber is assigned a private (10 digit) directory telephone number and is usually billed based on the amount of "airtime" he or she spends talking on the cellular telephone each month. Many of the service features available to landline telephone users (e.g., call waiting, call forwarding, three-way calling, etc.) are also generally available to mobile subscribers.
In the United States, cellular licenses have been awarded by the Federal Communications Commission (FCC) pursuant to a licensing scheme which divided the country into geographic service markets defined according to the 1980 Census. Only two cellular licenses are awarded for each market. The two cellular systems in each market are commonly referred to as the "A" system and "B" system, respectively. Each of the two systems is allocated a different frequency block in the 800 MHz band (called the A-band and B-band, respectively). To date, the FCC has released a total of 50 Mhz for cellular services (25 MHz per system). Mobile subscribers have the freedom to subscribe to service from either the A-system or the B-system operator (or both). Each system will assign each of its own subscribers a mobile identification number (MIN). The local system from which service is subscribed is called the "home" system. When travelling outside the home system, a mobile subscriber may be able to obtain service in a distant system if there is a "roaming" agreement between the operators of the home and "visited" systems.
The architecture for a typical cellular radio system is shown in FIG. 1. A geographical area (e.g., a metropolitan area) is divided into several smaller, contiguous radio coverage areas, called "cells," such as cells C1-C10. The cells C1-C10 are served by a corresponding group of fixed radio stations, called "base stations," B1-B10, each of which includes a plurality of RF channel units (transceivers) that operate on a subset of the RF channels assigned to the system, as well known in the art. For illustration purposes, the base stations B1-B10 are shown in FIG. 1 to be located at the center of the cells C1-C10, respectively, and are shown to be equipped with omni-directional antennas transmitting equally in all directions. However, the base stations B1-B10 may also be located near the periphery or otherwise away from the centers of the cells C1-C10, and may illuminate the cells C1-C10 with radio signals directionally (e.g., a base station may be equipped with three directional antennas each covering a 120 degrees sector).
The RF channels allocated to any given cell (or sector) may be reallocated to a distant cell in accordance with a frequency reuse plan as is well known in the art. In each cell (or sector), at least one RF channel is used to carry control or supervisory messages, and is called the "control" or "paging/access" channel. The other RF channels are used to carry voice conversations, and are called the "voice" or "speech" channels. The cellular telephone users (mobile subscribers) in the cells C1-C10 are provided with portable (hand-held), transportable (hand-carried) or mobile (car-mounted) telephone units, collectively referred to as "mobile stations," such as mobile stations M1-M5, each of which communicates with a nearby base station. Each of the mobile stations M1-M5 includes a controller (microprocessor) and a transceiver, as well known in the art. The transceiver in each mobile station may tune to any of the RF channels specified in the system (whereas each of the transceivers in the base stations B1-B10 usually operates on only one of the different RF channels used in the corresponding cell).
With continuing reference to FIG. 1, the base stations B1-B10 are connected to and controlled by a mobile telephone switching office (MTSO) 20. The MTSO 20, in turn, is connected to a central office (not specifically shown in FIG. 1) in the landline (wireline) public switched telephone network (PSTN) 30, or to a similar facility such as an integrated system digital network (ISDN). The MTSO 20 switches calls between wireline and mobile subscribers, controls signalling to the mobile stations M1-M5, compiles billing statistics, stores subscriber service profiles, and provides for the operation, maintenance and testing of the system.
When turned on (powered up), each of the mobile stations M1-M5 enters the idle state (standby mode) and tunes to and continuously monitors the strongest control channel (generally, the control channel of the cell in which the mobile station is located at that moment). When moving between cells while in the idle state, the mobile station will eventually "lose" radio connection on the control channel of the "old" cell and tune to the control channel of the "new" cell. The initial tuning to, and the change of, control channel are both accomplished automatically by scanning all the control channels in operation in the cellular system to find the "best" control channel (in the United States, there are 21 "dedicated" control channels in each cellular system which means that the mobile station has to scan a maximum number of 21 RF channels). When a control channel with good reception quality is found, the mobile station remains tuned to this channel until the quality deteriorates again. In this manner, the mobile station remains "in touch" with the system and may receive or initiate a telephone call through one of the base stations B1-B10 which is connected to the MTSO 20.
To detect incoming calls, the mobile station continuously monitors the current control channel to determine whether a page message addressed to it (i.e., containing its MIN) has been received. A page message will be sent to the mobile station, for example, when an ordinary (landline) subscriber calls the mobile subscriber. The call is directed from the PSTN 30 to the MTSO 20 where the dialed number is analyzed. If the dialed number is validated, the MTSO 20 requests some or all of the base stations B1-B10 to page the called mobile station throughout their corresponding cells C1-C10. Each of the base stations B1-B10 which receive the request from the MTSO 20 will then transmit over the control channel of the corresponding cell a page message containing the MIN of the called mobile station. Each of the idle mobile stations M1-M5 which is present in that cell will compare the MIN in the page message received over the control channel with the MIN stored in the mobile station. The called mobile station with the matching MIN will automatically transmit a page response over the control channel to the base station, which then forwards the page response to the MTSO 20. Upon receiving the page response, the MTSO 20 selects an available voice channel in the cell from which the page response was received (the MTSO 20 maintains an idle channel list for this purpose), and requests the base station in that cell to order the mobile station via the control channel to tune to the selected voice channel. A through-connection is established once the mobile station has tuned to the selected voice channel.
When, on the other hand, a mobile subscriber initiates a call (e.g., by dialing the telephone number of an ordinary subscriber and pressing the "send" button on the telephone handset in the mobile station), the dialed number and MIN/ESN pair for the mobile station are sent over the control channel to the base station and forwarded to the MTSO 20, which validates the mobile station, assigns a voice channel and establishes a through-connection for the conversation as described before. If the mobile station moves between cells while in the conversation state, the MTSO 20 will perform a "handoff" of the call from the old base station to the new base station. The MTSO 20 selects an available voice channel in the new cell and then orders the old base station to send to the mobile station on the current voice channel in the old cell a handoff message which informs the mobile station to tune to the selected voice channel in the new cell. The handoff message is sent in a "blank and burst" mode which causes a short but hardly noticeable break in the conversation. Upon receipt of the handoff message, the mobile station tunes to the new voice channel and a through-connection is established by the MTSO 20 via the new cell. The old voice channel in the old cell is marked idle in the MTSO 20 and may be used for another conversation. Furthermore, when travelling outside the system, the mobile station may be handed off to a cell in an adjacent system if there is a roamning agreement between the operators of the two systems.
In order to properly direct incoming calls to a mobile station which is moving around between different cells or systems, it is necessary to keep track of the location and activity of the mobile station. For this purpose, an autonomous registration process has been used in which the mobile station sends a registration message to the system upon entering a new system area or a new location area (i.e., a predefined group of cells in the system), or at predetermined intervals defined by the system operator. The system area and location area registration functions can be used to identify the current location of the mobile station so that it can be paged in its actual (or most likely) location rather than in all locations in the system. Each time the system receives a registration message from a mobile station in its area, it marks this mobile station as being active and present in its system area, or in the particular location area containing the cell of the base station which received the registration message, and then sends a registration confirmation message to this mobile station. The periodic registration function, on the other hand, is used to determine whether a mobile station is active (powered and within radio range) in a cellular system. Incoming calls to inactive mobile stations can be routed immediately to a recorded message (e.g., "The mobile customer you have called has turned off the mobile unit or travelled out of the service area.") without ever paging these mobile stations. This reduces the paging load and results in more efficient use of the limited control channel capacity.
The primary parameters that regulate the various mobile registration functions include the next registration (NXTREG) value which is stored in each mobile station and the system identification (SID), location area identification (LOCAID), registration identification (REGID) and registration increment (REGINCR) values which are broadcast by the system on the control channel of each cell. The SID is a digital number which uniquely identifies the serving cellular system. The LOCAID is a digital number which identifies a particular location area comprised of one or more cells in the system. The REGINCR defines the length of the periodic registration interval. The REGID is a 20-bit counter that is stepped by one unit in every REGID message transmitted to the mobile station. The NXTREG value indicates when periodic registration is due and is calculated internally in the mobile station by adding the current values of REGID and REGINCR. A mobile station will register with the serving system if either the SID or LOCAID received over the control channel is different from the corresponding value which it stored the last time it received a registration confirmation message (thus implying that the mobile station has travelled to a new system or location area, respectively), or if the REGID value received over the control channel is greater than or equal to the stored NXTREG (thus implying that a periodic registration is due). The mobile station updates the NXTREG value (with the sum of the current REGID and REGINCR values) upon the receipt of each registration confirmation message and, also, after every successful voice channel designation (i.e., call originations and receptions are treated like normal periodic registrations since by making or receiving a call a mobile station shows its activity and location).
Access to the cellular system of FIG. 1 by any of the mobile stations M1-M5, whether for call origination or reception or for registration purposes, is controlled on the basis of a mobile identification number (MIN) and an electronic serial number (ESN) which are stored in the mobile station. The MIN identifies the service subscription and is a binary representation of the 10-digit directory telephone number of the mobile subscriber. The MIN is assigned by the cellular service provider (home system operator) and is usually programmed into a mobile station either when purchased by the original user or when sold to another user (i.e., at the time of service installation). The MINs of legitimate (paying) subscribers are stored by the MTSO 20. The ESN uniquely identifies the mobile station and is a digital number which is supplied by the manufacturer and permanently stored in the mobile station (i.e., factory-set, not to be altered in the field). The ESNs of mobile stations which have been reported to be stolen can be appropriately marked by the MTSO 20 and denied service permanently.
Besides the MIN and ESN, each mobile station is also identified by a station class mark (SCM) which designates the transmit power class, mode and bandwidth for the mobile station. Mobile stations in different power classes (portable, transportable or vehicular) will transmit at one of several specified power levels within different output power ranges (0.6, 1.6 or 4.0 Watts). The transmit power level within a given range can be increased or decreased by a power change command from the base station. Furthermore, some mobile stations have the ability to operate in a "discontinuous" transmission (DTX) mode in which they can switch autonomously between two transmitter power level states ("DTX high" and "DTX low"). In addition, some mobile stations are set to operate within only the "basic" frequency range initially allocated to cellular systems while others are also set to operate in the "extended" frequency range which was later allocated. Like the MIN and ESN, the relevant SCM information is stored in each mobile station.
User authorization for cellular service is usually performed at every system access (i.e., registration request, call origination or page response) by a mobile station. When making an access, the mobile station forwards the MIN, ESN and SCM to the system. The MTSO 20 maintains a "white list" containing the MIN/ESN pairs of valid home subscribers and a "black list" containing the ESNs of stolen or otherwise unauthorized mobile stations. The MTSO 20 checks the received MIN/ESN pair to determine whether it belongs to a valid home subscriber and, if not, whether the MIN belongs to an authorized "roamer" from another system and whether the ESN has been blacklisted. If the MIN/ESN pair is not valid, or if the MIN is not recognized or if the ESN is blacklisted, the mobile station may be denied access. Otherwise, the user is considered legitimate and the access is accepted. Service is then provided and controlled according to the received SCM information.
The original cellular radio systems, as described generally above, used analog transmission methods, specifically frequency modulation (FM), and duplex (two-way) RF channels in accordance with the Advanced Mobile Phone Service (AMPS) standard. According to the AMPS standard, each control or voice channel between the base station and the mobile station uses a pair of separate frequencies consisting of a forward (downlink) frequency for transmission by the base station (reception by the mobile station) and a reverse (uplink) frequency for transmission by the mobile station (reception by the base station). The AMPS system, therefore, is a single-channel-per-carrier (SCPC) system allowing for only one voice circuit (telephone conversation) per RF channel. Different users are provided access to the same set of RF channels with each user being assigned a different RF channel (pair of frequencies) in a technique known as frequency division multiple access (FDMA). This original AMPS (analog) architecture forms the basis for an industry standard sponsored by the Electronics Industries Association (EIA) and the Telecommunication Industry Association (TIA), and known as EIA/TIA-553.
In the late 1980s, however, the cellular industry in the United States began migrating from analog to digital technology, motivated in large part by the need to address the steady growth in the subscriber population and the increasing demand on system capacity. It was recognized early on that the capacity improvements sought for the next generation cellular systems could be achieved by either "cell splitting" to provide more channels per subscribers in the specific areas where increased capacity is needed, or by the use of more advanced digital radio technology in those areas, or by a combination of both approaches. According to the first approach (cell splitting), by reducing the transmit power of the base station, the size of the corresponding cell (or cell radius) and, with it, the frequency reuse distance are reduced thereby resulting in more channels per geographic area (i.e., increased capacity). Additional benefits of a smaller cell include a longer "talk time" for the user since the mobile station will use substantially lower transmit power than in a larger cell and, consequently, its battery will not need to be recharged as often.
While cell splitting held the promise of improving both capacity and coverage for the growing mobile subscriber base, the actual capacity gains were limited by the use of the analog AMPS technology. It was commonly believed that the desired capacity gains, and indeed the effectiveness of the microcellular (cell splitting) concept in increasing capacity, can be maximized only by the use of digital technology. Thus, in an effort to go digital, the EIA/TIA developed a number of air interface standards which use digital voice encoding (analog-to-digital conversion and voice compression) and time division multiple access (TDMA) or code division multiple access (CDMA) techniques to multiply the number of voice circuits (conversations) per RF channel (i.e., to increase capacity). These standards include IS-54 (TDMA) and IS-95 (CDMA), both of which are "dual mode" standards in that they support the use of the original AMPS analog voice and control channels in addition to digital speech channels defined within the existing AMPS framework (so as to ease the transition from analog to digital and to allow the continued use of existing analog mobile stations). The dual-mode IS-54 standard, in particular, has become known as the digital AMPS (D-AMPS) standard. More recently, the EIA/TIA has developed a new specification for D-AMPS, which includes a digital control channel suitable for supporting public or private microcell operation, extended mobile station battery life, and enhanced end-user features. This new specification builds on the IS-54B standard (the current revision of IS-54), and it is known as IS-136. (All of the foregoing EIA/TIA standards are hereby incorporated herein by reference as may be necessary for a full understanding of these background developments. Copies of these standards may be obtained from the Electronics Industries Association, 2001 Pennsylvania Avenue, N.W., Washington, D.C. 20006).
In addition to providing for a new, digital radio transmission format, each of IS-54B and IS-136 specifies an authentication procedure for confirming the identity of mobile stations demanding service in a cellular system. This procedure, which also has been imported into newer analog standards such as IS-91 for narrowband AMPS (N-AMPS) and Revision A of EIA/TIA-553 (EIA/TIA-553A currently under development), was developed in response to the widespread, fraudulent use of MIN/ESN pairs to steal cellular service from existing analog systems. Many of the mobile stations which have been sold to date do not comply with the tamper-proof requirement for ESN and, consequently, can be easily programmed with a new ESN (there is no tamperproof requirement for MIN and, hence, all mobile stations are easily programmed with a new MIN). Thus, these mobile stations can be programmed to transmit any MIN/ESN pair so as to "trick" the system into granting access. Further background on this MIN/ESN "tumbling" and the resultant revenue and service losses can be found in the article entitled "Cellular Fraud" by Henry M. Kowalczyk, in Cellular Business, dated March 1991, at pp. 32-35.
Fraud in the form of MIN/ESN tumbling arose primarily in a "manual roaming" environment where the cellular systems were not interconnected on a real-time basis. Since each MTSO usually contained a list only of valid MIN/ESN pairs belonging to the home subscribers, it did not have immediate access to the counterpart lists in the other systems. Hence, by using a roamer MIN (i.e., a 10-digit directory telephone number containing an area code other than the local area code of the home system operator) and a non-blacklisted ESN, a fraudulent mobile station could receive service from the local cellular system until an indication of the invalidity of the MIN/ESN pair has been received (perhaps hours later) from the home system of the pretending roamer (or from a clearing house). In an "automatic roaming" environment, however, the cellular systems are networked together on a real-time basis in accordance with the provisions of the EIA/TIA standard IS-41 (or through a proprietary signalling protocol). Consequently, the serving cellular system can obtain verification of a MIN/ESN pair from the home system virtually immediately and can, therefore, deny service to a MIN/ESN tumbler without significant delay.
Of more concern recently has been a type of fraud known as "cloning" in which a fraudulent user adopts the bona fide MIN/ESN pair of a valid (paying) subscriber. The fraudulent user may surreptitiously acquire a bona fide MIN/ESN pair, or even a list of valid MIN/ESN pairs, in several ways. For example, in some instances, bona fide MIN/ESN numbers are printed on, and may be read from, a label which is affixed to a mobile station belonging to a valid subscriber. In other instances, a list of bona fide MIN/ESN pairs may be purchased on the "black market" or directly from an employee of the cellular operator. In addition, since each mobile station transmits the MIN/ESN pair to the serving exchange at every system access, one or more bona fide MIN/ESN pairs may be intercepted by listening to radio transmissions on the (analog) control channel.
The authentication procedures in the newer industry standards seek to distinguish between legitimate mobile stations and fraudulent clones through the synchronized generation of cryptovariables from identical sets of shared secret data (SSD) which are stored and periodically updated in a mobile station and its serving base station. These cryptovariables are exchanged between the mobile station and the base station for the purpose of confirming the identity of the mobile station. Since a clone mobile station is assumed not to have access to the initial value of the SSD or the subsequent history of SSD updates in the legitimate mobile station, its cryptovariables will not match those of the base station and therefore it can be identified as a clone. The SSD for each mobile station is stored in the MTSO of the home system, or in a separate subscriber database called a "home location register" (HLR) which is connected to that MTSO, and provided to the serving base station. Each mobile station also stores its SSD in memory.
In the process of authentication, the base station generates and sends to the mobile station a random bit pattern, called RAND or RANDU, on the analog control channel (ACCH), digital control channel (DCCH), analog voice channel (AVCH) or digital traffic channel (DTCH). Each of the mobile station and the base station uses RAND or RANDU, a portion of SSD called SSD-A (the remaining portion, SSD-B, is used for encryption, and not for authentication), along with other parameters (e.g., the MIN and ESN of the mobile station) as inputs to a Cellular Authentication and Voice Encryption (CAVE) algorithm, which is defined in Appendix A to each of IS-54B and IS-136, to generate an authentication response called AUTHR or AUTHU (depending on whether RAND or RANDU is used, respectively). The authentication response computed in the mobile station is sent to the base station to be compared with the authentication response computed in the base station. If the authentication responses match, authentication is considered successful (i.e., the base station and the mobile station are considered to have identical sets of SSD). However, if the comparison at the base station fails, the base station may deny service to the mobile station or commence the process of updating the SSD.
The procedure for updating SSD for any mobile station involves the application of CAVE initialized with mobile station-specific information (ESN), certain random data (RANDSSD), and a secret, permanent authentication key (A-key) which is uniquely assigned to the mobile station. For security reasons, the A-key is never transmitted over the air interface between the base station and the mobile station, or over the network interface between different cellular systems. The A-key is stored in the MTSO or the HLR and must be entered into the memory of the mobile station for use in updating the SSD. The A-key can be entered into the mobile station at the time of mobile service activation by an authorized technician using the standard number assignment module (NAM) programming mode, or at any time by the mobile subscriber using a separate Akey programming mode as disclosed in U.S. Pat. No. 5,551,073, which is incorporated herein by reference. For any mobile stations which have multiple NAMs and use multiple MINs (i.e., where the user subscribes to service from multiple home systems in order to avoid roamer charges in those systems), multiple A-keys may have to be entered into the mobile station, one for each NAM (MIN). A different A-key should be entered for each MIN since, for security reasons, the A-key can be known only to the mobile station and the MTSO or HLR of the home system, and should not be passed from system to system as the mobile station roams. Thus, SSD updates (in which the A-key is used to generate new SSD values) are carried out only in the mobile station and its associated home system MTSO or HLR, which then sends the SSD values (but not the A-key) to the serving system.
Because of the importance of the A-key for authentication purposes, the issue of A-key security management has been of concern to the industry. It was originally envisioned that each mobile station would be shipped from the factory with a default A-key consisting of all binary zeros and that an operational value for the A-key would be assigned by the system operator when a mobile subscriber signed up for service. The assigned A-key value then would be entered by the service technician or the user. However, because of the administrative burden and the security risk associated with the delivery (e.g., through the post) of numerous A-keys to service technicians or mobile subscribers, it was deemed more preferable that the manufacturers of the mobile stations would ship each of the mobile stations with a random A-key value. Any manufacturer then could provide any system operator with a list of ESN/random A-key combinations in a secure database, for example. The A-key values from this list, in turn, would be programmed into the home system MTSO or HLR and used by the system operator for authenticating the corresponding mobile stations.
At present and for the foreseeable future both of the foregoing approaches to A-key management (default A-key and random A-key) have been and are expected to be used in the cellular industry. The default A-key approach is followed by some operators because of its simplicity and/or because of the inability of some MTSOs to be programmed with specific A-key values (random or otherwise) for all of the various subscribers. A few of these operators have even resorted to resetting the A-key to the default value in all cases, including those in which the A-key may have been initially set to a random value. Other operators, however, prefer to use the random A-key approach because of its added security. Still other operators who seek additional security recognize that an ESN/random A-key list can become excessive, unmanageable or corrupted, and that for multiple NAM mobile stations the same random A-key will be available to multiple carriers thus compromising security (unless the manufacturer is willing to program different random A-key values for the different NAMs in which case the ESN/A-Key list may become even larger). Such operators may prefer to have an individual (custom) A-key assigned to the mobile subscriber at the time of service activation for entry into his mobile station.
Given this background and the proclivity of some subscribers to switch between different service providers (operators) possibly having different A-key management policies, there is a need for an A-key management procedure which integrates the existing approaches, while at the same time avoiding their shortcomings such as the cost of maintaining lists of random A-keys for the mobile stations from each manufacturer.

Authentication key management for mobile stations


There is provided a technique for securing a large examination space in a tunnel type MRI device without inviting increase of manufacturing cost and without significantly reducing irradiation efficiency or uniformity of the irradiation intensity distribution in an imaging region. Between rungs of a partially cylindrical RF coil, which coil corresponds to a cylindrical RF coil of which part is removed, there are disposed half-loops generating magnetic fields, which are synthesized with magnetic fields generated by loops constituted by adjacent rungs of the partially cylindrical RF coil and rings connecting the rungs to generate a circularly polarized or elliptically polarized magnetic field. Further, high-frequency signals of the same reference frequency having a desired amplitude ratio and phase difference are supplied to the partially cylindrical RF coils and half-loops.

An MRI device is a medical diagnostic imaging apparatus, which induces magnetic resonance in nuclear spins in an arbitrary section of a test subject, and provides a tomogram for the section from generated magnetic resonance signals. When a high-frequency magnetic field is irradiated on a test subject rested in a static magnetic field with a high-frequency coil (RF coil) with applying a gradient magnetic field, nuclear spins of atomic nuclei in the test subject, for example, hydrogen nuclei, are excited, and when the excited nuclear spins return to the equilibrated state, circularly polarized magnetic fields are generated as magnetic resonance signals. These signals are detected with an RF coil and subjected to signal processing to visualize hydrogen nucleus distribution in the living body.
As such an RF coil, there are transmit coil only for irradiating high-frequency magnetic fields, a receive coil only for receiving magnetic resonance signals, and a transceive coil that serves as both the coils. In order to efficiently obtain high quality images, various coils have been developed for each type of coil. For example, when nuclear spins are excited in a test subject, uniform irradiation intensity distribution is required. As for the degree of the uniformity, it is desirable that irradiation intensity in a region to be imaged is 70% or more of the maximum intensity in the irradiation intensity distribution of the region. This is because, if non-uniformity of irradiation intensity is significant, excited states of nuclear spins differ depending on sites in the test subject, and therefore non-uniformity of contrast and artifacts are induced in the obtained image. As RF coils showing such uniform irradiation intensity distribution, there are known cylindrical RF coils such as birdcage coils (refer to, for example, Patent document 1) and TEM coils (refer to, for example, Non-patent document 1).
Moreover, it is also necessary to improve irradiation efficiency. As a technique for improving the irradiation efficiency, there is the QD (Quadrature Detection) method (refer to, for example, Patent document 2, Non-patent documents 2 and 3). The QD method is a method of irradiating high-frequency magnetic fields by using two RF coils that irradiate high-frequency magnetic fields of which directions are perpendicular to each other so that phase difference of time phases of the high-frequency magnetic fields irradiated by the RF coils is 90 degrees. Since circularly polarized magnetic fields for exciting nuclear spins of hydrogen atoms can be highly efficiently irradiated by using the QD method, the irradiation intensity is theoretically improved √2 times compared with irradiation with one RF coil. Moreover, electric power is halved in terms of irradiation electric power, and therefore irradiation efficiency is improved twice. In the case of a birdcage coil or TEM coil (henceforth called cylindrical RF coil), by disposing two electric feeding ports used for irradiation at such positions that they intersect orthogonally to each other, high-frequency magnetic fields can be irradiated with one coil according to the QD method.
A cylindrical RF coil is generally used for a cylindrical (tunnel type) MRI device. Since such a tunnel type MRI device has a tunnel having a small diameter and a long length, it imposes much stress on a fat person or claustrophobic person. In order to eliminate this problem, there is desired an MRI device having a large examination space, i.e., a short tunnel of a large diameter, and thus giving superior spaciousness. Moreover, in recent years, detailed examination or treatment may be performed by disposing a contrast medium injector or a nonmagnetic treatment apparatus in the inside of an MRI device. Therefore, also in order to secure an installing space for installing various instruments near a test subject, there is desired an MRI device having a large examination space.
The tunnel type MRI device has a structure that a static magnetic field magnet, a gradient magnetic field coil, an RF shield, and an RF coil are successively disposed from the outside to the inside of the tunnel. The space inside the RF coil is the examination space in which a test subject is placed. Therefore, in order to make the examination space into which the test subject is entered larger, the internal diameter of the static magnetic field magnet located at the outermost position can be made larger. However, increase of the size of the static magnetic field magnet invites significant increase of the manufacturing cost.
There is generally required a space of 10 to 40 mm between the RF shield and the RF coil. For example, it may also be contemplated to make the examination space larger by making this distance smaller. However, if the RF shield and the RF coil are closely disposed, high-frequency eddy currents that cancel the magnetic fields to degrade the magnetic field generating efficiency are increased, and the high-frequency magnetic field distribution is suddenly changed near the RF coil to make non-uniformity of the irradiation intensity distribution of the high-frequency magnetic field in the imaging region more significant.
It is also contemplated to remove a part of coil conductors of the RF coil to enlarge the examination space. As an example of such a scheme, there is a semicylindrical birdcage coil, which corresponds to a cylindrical RF coil a part of which is removed (refer to, for example, Non-patent document 4).

High-frequency coil unit and magnetic resonance imaging device


A conversion adapter according to an embodiment of the invention is connected between a control apparatus that controls a medical appliance and the medical appliance and operates as the virtual control apparatus and medical apparatus. Thus, the communication between the control apparatus and medical appliance having different protocols and communication speeds can be performed efficiently. The conversion adapter includes an appliance information managing section, a control section, a first buffer, a second buffer, an appliance-specific command interpreting section, a communication I/F, and a communication I/F.

1. Field of the Invention
The present invention relates to a conversion adapter that connects medical appliances and a control apparatus for controlling the medical appliances, a medical system that includes the conversion adapter that connects medical appliances and a control apparatus for controlling the medical appliances, and a communication method for a conversion adapter that connects medical appliances and a control apparatus for controlling the medical appliances.
2. Description of the Related Art
In recent years, various types of medical appliance have been proposed as the medical technologies advance, and the functions of those medical appliances have been expanded. For example, those medical appliances may include an electric knife apparatus, an ultrasonic suction apparatus and laser knife apparatus and so forth. These kinds of medical appliances may be used as a stand-alone basis, or multiple kinds of medical appliances may be used in combination as a medical system.
Such a medical system may connect multiple medical appliances to a control apparatus and centrally control the medical appliances. Japanese Unexamined Patent Application Publication No. 2005-95567 proposes an endoscopic system having a central control apparatus that can connect multiple medical appliances each having a different interface and can reproduce details of a treatment performed during an operation faithfully by reducing a time lag caused between/among the medical appliances.

Conversion adapter, medical system and communication method


A thin film transistor (“TFT”) array panel includes; a substrate including a display and peripheral area, a display area signal line and a display area TFT disposed in the display area, the display area TFT connected to the display area signal line, a plurality of peripheral area signal lines, a light blocking member disposed on the display area signal line, the display area TFT, and the peripheral area signal lines, a transparent connector connecting one of peripheral area signal lines and another one of the peripheral area signal lines through a contact hole passing through the light blocking member, a pixel electrode connected to the display area TFT, a spacer disposed on a layer above the light blocking member, and a light blocking assistance member composed of the same material as the spacer on the transparent connector, the light blocking assistance member covering at least the contact hole.

(a) Technical Field
The present invention relates to a thin film transistor array panel, a liquid crystal display including the same, and a method for manufacturing a liquid crystal display.
(b) Discussion
A liquid crystal display ("LCD") is one type of flat panel display that is now widely used. The typical LCD includes two display panels, each having field generating electrodes such as pixel electrodes and a common electrode, and a liquid crystal layer interposed between the display panels. In the LCD, a voltage is applied to the field generating electrodes to generate an electric field in the liquid crystal layer, which determines the direction of liquid crystal molecules of the liquid crystal layer, and an image is displayed by controlling the polarization of incident light.
Among the various types of LCDs, a liquid crystal display including a light blocking member (a black matrix) formed in a thin film transistor array panel to improve the transmittance and to simplify the manufacturing process has been developed. However, the light blocking member does not cover contact holes disposed in a region outside the display area in this liquid crystal display such that the light reflected through the contact holes may deteriorate the display quality of the liquid crystal display.

Thin film transistor display panel, liquid crystal display having the same, and method of manufacturing liquid crystal display


It is intended to achieve a sufficiently-small SRAM cell area and a stable operation margin in a Loadless 4T-SRAM comprising a vertical transistor SGT. In a static type memory cell made up using four MOS transistors, each of the MOS transistor constituting the memory cell is formed on a planar silicon layer formed on a buried oxide film, to have a structure where a drain, a gate and a source are arranged in a vertical direction, wherein the gate is formed to surround a pillar-shaped semiconductor layer. The planar silicon layer comprises a first active region having a first conductive type, and a second active region having a second conductive type. The first and second active regions are connected to each other through a silicide layer formed in a surface of the planar silicon layer to achieve an SRAM cell having a sufficiently-small area.

With a view to achieving higher integration and higher performance of a semiconductor device, an SGT (Surrounding Gate Transistor) has been proposed which is a vertical transistor comprising a pillar-shaped semiconductor layer formed on a surface of a semiconductor substrate, and a gate formed to surround a sidewall of the pillar-shaped semiconductor layer (as disclosed, for example, in Patent Document 1: JP 2-188966A). In the SGT, a source, a gate and a drain are arranged in a vertical direction, so that an occupancy area can be significantly reduced as compared with a conventional planar transistor.
In cases where an LSI (large-scale integration) circuit is made up using an SGT, it is essential to employ an SRAM comprising a combination of a plurality of SGTs, as a cache memory for the LSI circuit. In recent years, there is an extremely strong need for increasing a capacity of an SRAM to be mounted on an LSI circuit. Thus, in the SGT-based LSI circuit, it is also essential to achieve an SRAM having a sufficiently-small cell area.
FIG. 24(a) and FIG. 24(b) are, respectively, a top plan view and a sectional view of a CMOS 6T-SRAM disclosed as one embodiment in Patent Document 2 (JP 7-99311A), wherein an SRAM cell comprises six transistors each designed using an SGT. With reference to FIGS. 24(a) and 24(b), a structure of the SRAM cell will be described below. A bit line, a ground line GND, and a power supply potential line Vcc, are formed by an N+ diffusion layer (601a, 601b), an N+ diffusion layer 602, and a P+ diffusion layer 603. Six pillar-shaped silicon layers are formed on the diffusion layers to constitute two access transistors 610a, 610b each operable to allow access to a memory cell, two driver transistors 611a, 611b each operable to drive the memory cell, and two load transistors 612a, 612b each operable to supply electric charges to the memory cell. Further, a gate (604a, 604b, 604c, 604d) is formed to surround each of the pillar-shaped silicon layers. A storage node is made up of an interconnection layer (607a, 607b). In each of the transistors constituting the SRAM cell, a source, a gate and a drain are vertically formed on and along the pillar-shaped silicon layer, so that the SRAM cell can be designed to have a sufficiently-small cell area.
Patent Document 1: JP 2-188966A
Patent Document 2: JP 7-99311A (paragraph [0051], FIG. 75)
Patent Document 3: JP 2000-12705A
In reality, the above SRAM cell involves the following problem. In the SRAM discloses in the Parent Document 2, each of the power supply potential line 603 and the ground line 602 in an SRAM cell array can be formed at a level of minimum size so as to achieve a sufficiently-small cell area. However, the power supply potential line 603 and the ground line 602 are formed by the P+ diffusion layer and the N+ diffusion layer, respectively. Thus, if each of the power supply potential line 603 and the ground line 602 is formed at a level of minimum size, a resistance thereof will be extremely increased, which makes it impossible to ensure a stable operation of the SRAM. Conversely, if the size of each of the power supply potential line 603 and the ground line 602 is increased so as to allow the SRAM to stably operate, the SRAM cell area will be increased.
As an SRAM capable of achieving a greater reduction in SRAM cell area than the CMOS 6T-SRAM, a Loadless 4T-SRAM (the Patent Document 3: JP 2000-12705A) has been proposed. FIG. 1 shows an equivalent circuit of a Loadless 4T-SRAM cell. The Loadless 4T-SRAM cell comprises total four transistors consisting of two PMOS access transistors each operable to access to the memory cell, and two NMOS driver transistors each operable to the memory cell.
As one example of an operation of the memory cell in FIG. 1, a data holding operation under a condition that data "L" is stored in a storage node Qa1, and data "H" is stored in a storage node Qb1, will be described below. During the data holding operation, each of a word line WL1 and two bit lines BL1, BLB1 is driven to an "H" potential. A threshold voltage of the access transistor (Qp11, Qp21) is set to be less than that of the driver transistor (Qn11, Qn21), and an OFF-leak current of the access transistor is set to be greater (e.g., on average, about 10 to 1000 times greater) than a leak current of the driver transistor. Thus, an OFF-leak current flows from the bit line BLB1 to the storage node Qb1 through the access transistor Qp21, so that the "H" level in the storage node Qb1 is held. Meanwhile, the "L" level in the storage node Qa1 is stably held by the driver transistor Qn11.
Even in SGT-based SRAMs, the Loadless 4T-SRAM can achieve a smaller SRAM cell area as compared with the CMOS 6T-SRAM.
In view of the above circumstances, it is an object of the present invention to provide an SGT-based Loadless 4T-SRAM capable of achieving a sufficiently-small SRAM cell area, while ensuring a sufficient operation margin thereof.


A peroxisome proliferator activated receptor regulator containing a carboxylic acid derivative of formula (I)

Recently in the study of transcription factors concerned with genes expression in adipocytes differentiation, peroxisome proliferator activated receptor (abbreviated as PPAR hereinafter) has been focused. cDNAs of PPAR were cloned from various kinds of animals, and plural isoform genes were found, particularly in mammals three types of isoforms (α, δ, γ) are known (see J. Steroid Biochem. Molec. Biol., 51, 157 (1994); Gene Expression, 4, 281 (1995); Biochem Biophys. Res. Commun., 224, 431 (1996); Mol. Endocrinology., 6, 1634 (1992)). PPAR γ isoform is predominantly expressed in adipose tissues, immune cells, adrenal gland, spleen, small intestine. PPAR α isoform is mainly expressed in adipose tissue, liver, retina, and δ isoform shows the expression with no tissue specificity, which is widely expressed (see Endocrinology., 137, 354 (1996)).
On the other hand, the following thiazolidine derivatives are known as agents for the treatment of non-insulin dependent diabetes mellitus (NIDDM) and are hypoglycemic agents which are used for the improvement of hyperglycemia in the patients suffering from diabetes. They are also effective for the improvement of hyperinsulinemia, glucose tolerance and decrease of serum lipid and therefore they are thought to be considerably hopeful as agents for the treatment of insulin resistance.

One of the target proteins in the cells of these thiazolidine derivatives is exactly PPAR γ and it is resolved that they enhance the transcription activity of PPAR γ (see Endocrinology., 137, 4189 (1996); Cell., 83, 803 (1995); Cell., 83, 813 (1995); J. Biol. Chem., 270, 12953 (1995)). Therefore, a PPAR activator (agonist) which enhances its transcription activity is thought to be hopeful as a hypoglycemic agent and/or a hypolipidemic agent. Furthermore, since a PPAR γ agonist is known to promote the expression of PPAR γ protein itself (Genes & Development., 10, 974 (1996)), an agent which increases the expression of PPAR γ protein itself as well as PPAR γ activating agent is also clinically useful.
Among all of nuclear receptors, PPAR γ is related to adipocytes differentiation (see J. Biol. Chem., 272, 5637 (1997) and Cell., 83, 803 (1995)). It is known that thiazolidine derivatives which activate this receptor promote adipocytes differentiation. Recently it was reported that thiazolidine derivatives increase fat mass and cause man to gain weight and to become obese (see Lancet., 349, 952 (1997)). Therefore, it is also thought that antagonists which inhibit PPAR γ activity and agents that decrease the expression of PPAR γ protein itself are also clinically applicable. On the other hand, a compound that phosphorylates PPAR γ protein and decreases its activity is reported (Science., 274, 2100 (1996)). This implies that an agent which does not bind on PPAR γ protein as a ligand, but inhibits its activity is also clinically applicable.
From these, PPAR γ activators (agonists) and PPAR γ regulators for its expression that can increase the expression of the protein itself are expected to be useful as hypoglycemic agents, hypolipidemic agents, preventives and/or remedies for diseases associated with metabolic disorders (diabetes, obesity, syndrome X, hypercholesterolemia, hyperlipoproteinemia, etc.), hyperlipidemia, atherosclerosis, hypertension, circulatory diseases, overeating, etc.
On the other hand, antagonists that inhibit the transcription activity of PPAR γ or PPAR γ regulators that inhibit the expression of the protein itself are expected to be useful as hypoglycemic agents, preventives and/or remedies for diseases associated with metabolic disorders (diabetes, obesity, syndrome X, etc.), hyperlipidemia, atherosclerosis, hypertension, overeating, etc.
The following fibrate compound (e.g. chlofibrate) is known as a hypolipidemic agent.

It is also resolved that one of the target proteins in the cells of fibrate compounds is PPAR α (See Nature., 347, 645 (1990); J. Steroid Biochem. Molec. Biol., 51, 157 (1994); Biochemistry., 32, 5598 (1993)). From these facts, PPAR α regulators, which can be activated by fibrate compounds are thought to have a hypolipidemic effect, and so they are expected to be useful as preventives and/or remedies for hyperlipidemia etc.
Besides, it was recently reported that biological activation of PPAR α linked anti-obese effect in the specification of WO 9736579. It was reported that the elevation of high density lipoprotein (HDL) cholesterol and the reduction of low density lipoprotein (LDL) cholesterol, very low density lipoprotein (VLDL) cholesterol and triglyceride were induced by PPAR α activation (J. Lipid Res., 39, 17 (1998)). It was also reported that improvement of fatty acid composition in the blood, hypertension and insulin resistance by the treatment of bezafibrate (one of fibtrate compounds) (Diabetes., 46, 348 (1997)). Therefore, agonists that activate PPAR α and PPAR α regulators that promote expression of PPAR α protein itself are useful as hypolipidemic agents and remedies for hyperlipidemia, and are expected to have HDL cholesterol-elevating effect, LDL cholesterol and/or VLDL cholesterol-lowering effect, inhibition on the progress of atherosclerosis and anti-obese effect. Therefore, they are thought to be hopeful agents for the treatment and/or prevention of diabetes as hypoglycemic agents, for the improvement of hypertension, for the relief from risk factor of syndrome X and for the prevention of occurrence of coronary heart diseases.
On the other hand, few reports are found on ligands that activate PPAR δ significantly or on biological activities associated with PPAR δ.
PPAR δ is sometimes called PPAR β, or it is also called NUC1 in human. So far it was shown that in the specification of WO 9601430 hNUC1B (PPAR subtype whose structure is different from that of human NUC1 in one amino acid) inhibited the transcription activities of human PPAR α and thyroid hormone receptor. Recently in the specification of WO 9728149, it was reported that compounds bound to PPAR δ protein with high affinity activated PPAR δ significantly (i.e. agonists) and they had HDL (high density lipoprotein) cholesterol-elevating activity. Therefore, agonists that activate PPAR δ are expected to have HDL cholesterol-elevating effect, and so they are expected to be useful for the inhibition on the progress of atherosclerosis and its treatment, as hypolipidemic agents and/or hypoglycemic agents, for the treatment of hyperlipidemia, as hypoglycemic agents, for the treatment of diabetes, for the relief from risk factor of syndrome X, and for the prevention of occurrence of coronary heart diseases.
The following PPAR regulators have been reported.    (1) For example, in the specification of WO 9728115, it is described that a compound of formula (A)
(wherein R1A is selected from hydrogen, C3˜10 cycloalkyl, etc., R2A is selected from hydrogen, C5˜10 aryl, C5˜10 heteroaryl, etc., R4A is selected from R2A etc., (ZA-WA—) is ZA-CR6AR7A or ZA-CR6AR7A—R8A—, etc., R8A is selected from CR6AR7A, O, S(O)pA, etc., R6A and R7A are each independently, selected from hydrogen, C1˜6 alkyl, etc., X1A and X2A are each independently, hydrogen, C1˜15 alkyl, halogen, etc., YA is selected from S(O)pA, —O—, etc., Y1A is selected from O, C, etc., ZA is selected from CO2R3A etc., tA and vA are each independently 0 or 1, tA+vA is 1, QA is saturated or unsaturated 2˜4 straight-chained hydrocarbon, pA is 0˜2, R3A is hydroxy, C1˜15 alkoxy, etc.) or a pharmaceutically acceptable salt thereof is a PPAR δ modulator (necessary part is extracted in the explanation of the group). In the specifications of WO 9727857 and WO 9728137, it is described that analogous compounds therewith are also PPAR δ modulators.    (2) In the specification of WO 9731907, it is described that a compound of formula (B)
(wherein AB is phenyl, said phenyl may be substituted by one or more of halogen, C1˜6 alkyl, C1˜3 alkoxy, C1˜3 fluoroalkoxy, nitrile or    —NR7BR8B (R7B and R8B are each independently hydrogen or C1˜3 alkyl);    BB is 5 or 6-membered hetero ring—C1˜6 alkylene-, said hetero ring may be substituted by C1˜3 alkyl;    AlkB is C1˜3 alkylene;    R1B is hydrogen or C1˜3 alkyl;    ZB is selected from —(C1˜3 alkylene)phenyl or —NR3BR4B) or a pharmaceutically acceptable salt thereof has PPAR γ agonist activity (necessary part is extracted in the explanation of the group).    (3) In the specification of JP Kokai Hei 9-323982, it is described that a propionic acid derivative of formula (C)
(wherein R′C is an optionally substituted aromatic hydrocarbon, an optionally substituted cyclic aliphatic hydrocarbon, an optionally substituted hetero ring or an optionally substituted fused hetero ring and R5C is lower alkyl), R4C is hydrogen or lower alkyl, R6C is hydrogen or taken together with R9C to form a double bond, R7′C is hydrogen, hydroxy, carboxy, acyl, optionally substituted alkoxycarbonyl, optionally substituted lower alkyl, optionally substituted carbamoyl, optionally substituted aryloxycarbonyl, optionally substituted aralkyloxycarbonyl or a group represented by formula —YC—R8C (wherein YC is —NH— or oxygen, R8C is optionally substituted acyl, optionally substituted alkoxycarbonyl, aryloxycarbonyl or aralkyloxycarbonyl), R9C is hydrogen, optionally substituted lower alkyl or optionally substituted lower alkoxycarbonyl, R10C is hydroxy, optionally substituted amino, optionally substituted lower alkoxy, optionally substituted lower alkyl, optionally substituted aryloxy or optionally substituted aralkyloxy) or a pharmaceutical composition containing a pharmaceutically acceptable salt thereof has hypoglycemic effect and hypolipidemic effect. In the specifications of JP Kokai Hei 8-325264, JP Kokai Hei 8-325250, WO 9638415 and WO 9800137, it is described that analogous compounds therewith have hypoglycemic effect and hypolipidemic effect.    (4) In the specification of JP Kokai Hei 8-104688, it is described that a compound of formula (D)
(wherein RD is an optionally substituted hydrocarbon residue or a hetero ring which may be bound through carbon chain(s), nD is 0 or 1, XD is CH or N, YD is a bivalent hydrocarbon residue. R1D and R2D are the same or different to represent hydrogen, halogen, optionally substituted hydroxyl or an optionally substituted hydrocarbon residue, and either of R1D or R2D may be taken attached to a part of YD to form a ring) or a salt thereof has hypoglycemic effect and hypolipidemic effect. In the specification of JP Kokai Sho 61-85372, it is described that analogous compounds therewith also have hypoglycemic effect and hypolipidemic effect.    (5) In the specification of JP Kokai Hei 1-143856, it is described that a compound of formula (E)
(wherein XE is —CR4E═ or —N═, YE is —CR4E═N—, —N═CR4E—, —CR4E═CR4E—, —O—, —S— or —NR4E—, ZE is —(CH2)nEO—, —(CH2)nES—, etc., R1E is —(CHR7E)nECOOR6E etc., nE is each independently 0˜5, R2E is each hydrogen, lower alkyl, lower alkoxy, trifluoromethyl, nitro, cyano or halogen, etc., R3E is
WE is a bond or —O—, —S— or —NR4E—, mE is 1˜15, R4E is each independently hydrogen or lower alkyl, R7E is hydrogen or methyl) or a pharmaceutically acceptable salt thereof has an inhibitory activity against lipoxygenase and a competitive activity against leucotriene.    (6) In the specification of JP Kohyo Hei 8-504194, it is described that a compound of formula (F)XF—YF-ZF-"ArylF"-AF-BF  (F)(wherein "Aryl F" is a monocyclic 6-membered hetero ring system containing 0, 1, 2, 3 or 4 of N atom and having no substituents or substituted by R5F;    XF is a mono- or multi-cyclic aromatic or non-aromatic 4˜10 membered ring system etc. containing 0, 1, 2, 3 or 4 of hetero atom selected from N, O and S and having no substituents or substituted by R1F, R2F, R3F or R4F,    R1F, R2F, R3F and R4F are independently selected from a group of hydrogen, C1˜10 alkyl, C3˜8 cycloalkyl, aryl C0˜8 alkyl, amino C0˜8 alkyl, C1˜6 alkylamino C0˜8 alkyl, C1˜6 dialkylamino C0˜8 alkyl, C1˜4 alkoxy C0˜6 alkyl, etc.;    YF is C0˜8 alkyl, C0˜8 alkyl-O—C0˜8 alkyl, C0˜8 alkyl-SOnF—C0˜8 alkyl, etc., wherein nF is an integer of 0˜2,    ZF and AF are independently selected from (CH2)mF, (CH2)mFO(CH2)mF, (CH2)mFSO2(CH2)nF, (CH2)mFS(CH2)nF, (CH2)mFSO(CH2)nF, etc., wherein mF and nF are integers independently selected from 0˜6, with the proviso that when AF is (CH2)mF, "Aryl F" which is attached to ZF and AF must contain at least 1 hetero atom;    R5F is is hydrogen, C1˜6 alkyl, C0˜6 alkyloxy C0˜6 alkyl, or halogen, etc.,    BF is
wherein R6F, R7F, R8F, R9F, R10F and R11F are independently selected from hydrogen, C1˜8 alkyl, etc.,    R12F is selected from hydroxy, C1˜8 alkyloxy, etc.) and a pharmaceutically acceptable salt have fibrinogen receptor antagonist activity (necessary part is extracted in the explanation of the group).

Carboxylic acid derivative and a pharmaceutical composition containing the derivative as active ingredient

Abstract: (wherein all symbols are as defined in the specification), a non-toxic acid thereof or a hydrate thereof as active ingredient.

Abstract: Because of having an effect of regulating PPAR, a compound of formula (I) is useful as a hypoglycemic agent, a hypolipidemic agent, a preventive and/or a remedy for diseases associating metabolic disorders (diabetes, obesity, syndrome X, hypercholesterolemia, hyperlipoproteinemia, etc.), hyperlipemia, atherosclerosis, hypertension, circulatory diseases, overeating, coronary heart diseases, etc., an HDL cholesterol-elevating agent, an LDL cholesterol and/or VLDL cholesterol-lowering agent and a drug for relief from risk factors of diseases or syndrome X.


When a predetermined condition for measurement is selected from a plurality of conditions for measurement by operating one of measurement switches before measuring the blood pressure, a pressure begins to be applied to a bladder in response to the selection and the measurement of the blood pressure starts. The measured data of the blood pressure and the selected condition for measurement are linked to each other and stored in a memory. Because the measurement of the blood pressure starts upon selection of the predetermined condition by operating one of the measurement switches, one operation can serve both as switching to instruct the starting of the measurement and selecting the predetermined condition for measurement. Thus, an additional operation for inputting a condition for measurement is not necessary, and this makes it possible to prevent forgetting to input or incorrectly inputting a condition for measurement from occurring.

1. Field of the Invention
This invention relates to an electronic blood pressure monitor and a blood pressure measuring system, and in particular, to an electronic blood pressure monitor which can measure and record information specifically on cardiovascular risk, as well as a blood pressure measuring system.
2. Description of the Background Art
Blood pressure is a barometer for analyzing cardiac function, and risk analysis on the basis of blood pressure is effective for preventing cardiovascular system diseases, such as, for example, cerebral strokes, heart failure and myocardial infarction. For example, there is a cause and effect relationship between the surge in blood pressure that occurs between one hour and one and a half hours after waking up, which is referred to as morning surge, and cerebral stroke, and it is necessary to grasp the reciprocal relation between changes in blood pressure and health, for risk analysis of cardiovascular system diseases. As described above, blood pressure changes on the basis of individual physical activities, response to stress and reaction of the cardiovascular system to patterns of behavior, and in addition, there is a fluctuation rhythm during the course of the day, such that blood pressure drops during sleep and increases before or after waking up.
Focusing on the factors relating to the above described fluctuation in blood pressure, the applicant has proposed the blood pressure monitor that is described in Japanese Patent Laying-Open No. 2004-261452. This blood pressure monitor links the measured value of blood pressure to the information on measured time and measurement conditions, and stores these, and thus, the average values of blood pressure, which are measured within particular time slots, such as a morning time slot and an evening time slot, are respectively calculated, and the risk value is calculated and displayed on the basis of these calculation results. In this blood pressure monitor, information on the measured time is taken from the time gained through a clock function that is provided in the blood pressure monitor, and the measured values are linked to the gained information on measured time and automatically sorted and stored.
In addition, focusing on the factors relating to fluctuation, which are the same as the above, that is to say, the fact that the physiological and psychological state of the patient affects the measurement of the blood pressure when the blood pressure is measured, the blood pressure monitor that is described in Japanese Utility Model Registration No. 3070676 has been proposed. When the patient turns on the power ON this blood pressure monitor and operates the startup key so as to start the measurement of blood pressure, the results of the measurement of blood pressure are displayed, and then, the patient can operate a selection key for the state at the time of measurement (drunk, tinnitus, immediately after waking up, after exercising, after taking a bath), so that the measured value and the selected state are linked to each other and stored in a memory.
In the case where a measured value is linked to information on the measured time and stored in the blood pressure monitors of Japanese Patent Laying-Open 2004-261452 and Japanese Utility Model Registration No. 3070676, incorrect information on the measured time is linked to the measured value when the setting of the clock in the blood pressure monitor is incorrect. In addition, problems remain, such that the risk value is calculated on the basis of the time slot when blood pressure is measured, even in the case of a person such as a shift worker whose life cycle, including waking time and sleeping time, is different from ordinary people, and therefore, the risk value deviates from the risk value that is calculated from the true measured values after waking up and before sleeping.
In addition, the conditions for measurement are inputted for every measurement, by operating condition input switches provided in the blood pressure monitor. Therefore, the condition input switches must be operated for every measurement, making switching operation troublesome. In addition, problems remain, such that the correct risk value is not calculated when incorrect conditions for measurement are linked to the measured values because of the user forgetting to operate the condition input switches.

Electronic blood pressure monitor and blood pressure measuring system