A lockout apparatus for use on a valve's latching mechanism. The lockout apparatus is a rigid framework formed to encage the exterior structure of a valve and to provide a locking structural member for selective locked securement of the valve's movable latching mechanism, by example in a closed position. The lockout apparatus is sized according to the diameter and size of a valve, by example a ball valve, and includes opposing open-ended structure for accommodating attachment of piping to the inlet and outlet ends of an encaged valve. The locking apparatus is useful in meeting environmental protection requirements for locking outside valves, typically ball valves, an oil tanks and tanker trailers to avoid vandalism and accidental spills.

Valves are used extensively by industry in controlling the flow of fluids, by example oil and gas, from a storage facility to an end use application. The flow of the fluids may be controlled by valves located on pipelines, on transport trailers, or by valves on fluid storage tanks at a refinery or at a convenient fluid distribution center. As can be appreciated, when the fluid does involve oil and gas, the environmental protection officials, such as the Environmental Protection Agency (EPA), requires that the supplier of the oil and gas fluids take the proper precautions to lock the valves on the oil tanks and tanker trailers to avoid vandalism and accidental spills. While lockout devices are known, see for example the ball valve lockout device covered under U.S. Pat. No. 5,003,797, and illustrated at page 132 of BRADY, Signmark Division's, Catalog S-13, Effective February 1993, these known structures are detachable, costly, and do not encourage usage, either because of the cost, or because the device are not attached to the valves for immediate use when the need arises to lockout a valve.
Thus, a need is seen to exist for a valve lockout device that is more suitable for long term applications, rather than the shorter term maintenance lockout devices. A need is seen for a simple valve lockout structure that is designed for being installed on the valve to promote an immediate, and readily accessible use. A need is also seen for a simple valve lockout apparatus that is not costly, and which promotes availability and use to meet EPA requirements.

Apparatus and method for locking valves on oil tanks, tank trailers and the like


The semiconductor pressure sensor has a pressure sensor unit with a pressure sensor chip for detecting pressure, peripheral circuitry for converting the pressure detected by the pressure sensor unit to an electrical signal and processing the electrical signal, a lead frame for fastening and electrically connecting peripheral circuitry, a package in which the peripheral circuitry and lead frame are integrated in a resin molding including a cavity in which the pressure sensor unit is housed, a cover for closing the opening of the cavity in which the pressure sensor unit is housed, and a pressure opening for conveying a pressure-conveying medium to the pressure sensor chip. The pressure sensor unit is fastened to the inside bottom of the cavity and is electrically connected to a particular part of the lead frame exposed inside the cavity.

1. Field of the Invention
The present invention relates to a pressure sensor used in such fields as automotives, home appliances, instrumentation and measuring devices, and medical equipment, and relates particularly to a semiconductor pressure sensor in which the peripheral circuitry integrated with the pressure sensor are manufactured as an integrated module.
2. Description of the Prior Art
Hybrid pressure sensor modules are one type of pressure sensor commonly used today in such fields as automotives, home appliances, instrumentation and measuring devices, and medical equipment. An overview of such a conventional pressure sensor is shown in FIG. 18.
The semiconductor pressure sensor 100 shown in FIG. 18 comprises a pressure opening 102 to a molded resin casing 101 having an airtight hollow core. A pressure sensor chip (not shown in the figures) is fastened on a pedestal by an adhesive and is electrically connected using gold wire or other conductor to the lead frame 103 inside the molded resin casing 101, thus forming the pressure sensor module 104. The thick-film circuit board 105 of the semiconductor pressure sensor 100 comprises a thick-film resistor and a printed multiple layer wiring pattern. The clip leads 106 disposed to the thick-film circuit board 105 are used to mount the semiconductor pressure sensor 100 on a printed circuit board.
The pressure sensor chip mentioned above comprises a pressure sensor element and a conversion circuit for converting the pressure detected by the pressure sensor element to an electrical signal. The pressure sensor module 104 is also mounted on the thick-film circuit board 105, and capacitors, resistors, and other chip components 107 that cannot be formed on the pressure sensor chip are surface mounted on the thick-film circuit board 105 and pressure sensor module 104.
The lead frame 103 is electrically connected to the wiring pattern of the thick-film circuit board 105, and the pressure sensor chip is electrically connected to the wiring pattern of the thick-film circuit board 105 by means of the lead frame 103 that is connected by gold wire or other conductor to the wiring pattern of the thick-film circuit board 105. The various terminals of the chip components 107 are electrically connected to the wiring pattern of the thick-film circuit board 105, and the clip leads 106 are also electrically connected to the wiring pattern of the thick-film circuit board 105.
The pressure opening 102 of this configuration is used to conduct a pressure-conveying medium to the pressure sensor element. The pressure-conveying medium applied from the pressure opening 102 enables the pressure sensor element of the pressure sensor module 104 to detect the applied pressure, and the detected pressure is then converted to an electrical signal by the conversion circuit. This semiconductor pressure sensor 100 and the signal processing circuit for accomplishing a particular process based on the electrical signal obtained from the conversion circuit are mounted on a printed circuit board and electrically connected to each other by the wiring pattern of that printed circuit board.
With rising demand for smaller, multiple function semiconductor pressure sensors in various fields, it has become necessary to develop integrated circuits combining the conversion circuit, thick-film circuit board 105, and a multifunction-capable signal processing circuit in what is essentially an IC package configuration. The semiconductor pressure sensor, however, is an element subject to mechanical displacements, and the area surrounding the pressure sensor element must be a hollow or airtight hollow. This has made it necessary to use a premolded hollow package to manufacture integrated pressure sensor modules containing a pressure sensor element and peripheral circuitry IC containing the conversion circuit, thick-film circuit board 105, and signal processing circuit. Furthermore, when the overall package is hollow, the peripheral circuitry IC must be protected because outside air and various pressure-conveying media may enter the airtight hollow chamber depending upon the pressure detection method used.


A new and distinct cultivar of Antirrhinum plant named ‘Keianichigorum’, characterized by its vigorous, upright and mounded plant habit; freely branching habit and short internodes; dense and bushy plant form; numerous red purple and white bi-colored flowers; long flowering period; and good garden performance.

The present invention relates to a new and distinct cultivar of Antirrhinum, botanically known as Antirrhinum hybrida and hereinafter referred to by the name 'Keianichigorum'.
The new Antirrhinum is a product of a planned breeding program conducted by the Inventor in Chiba, Japan. The objective of the breeding program is to create new compact and freely flowering potted Antirrhinums with unique flower coloration.
The new Antirrhinum originated from a cross-pollination in Chiba, Japan in June, 2000 of two unidentified proprietary selections of Antirrhinum hybrida, not patented. The cultivar Keianichigorum was discovered and selected by the Inventors as a flowering plant from within the progeny of the stated cross-pollination in a controlled environment in Chiba, Japan.
Asexual reproduction of the new Antirrhinum by cuttings in a controlled environment in Chiba, Japan since May, 2001, has shown that the unique features of this new Antirrhinum are stable and reproduced true to type in successive generations.


A simplified comparator circuit (10) having hysteresis and lower power requirements for its implementation. The circuit (10) includes 2 minimum-sized MOSFETs (MN4, MN5) providing feedback from the circuit output to an input device (MN1) body to produce hystereis, requiring very little power. This invention is suitable for applications not requiring a precisely set hysteresis magnitude.

Comparator circuits often are implemented with hysteresis from output to input to prevent noise on the input from causing multiple switches in output, or chatter. There have been many means devised to accomplish the hysteresis, such as using a resistor network from input to output dissipating power in at least one state. Examples of some are shown in U.S. Pat. No. 4,110,641 to Robert L. Payne entitled "CMOS Voltage Comparator with Internal Hysteresis" and U.S. Pat. No. 4,394,587 to McKenzie et al entitled "CMOS Differential Comparator with Hysteresis". Such previous solutions have required the addition of several devices creating a more complex design and requiring additional power.

Method to implement hysteresis in a MOSFET differential pair input stage


A method for forming an isolation filled trench (25) in a silicon layer (21) of an SOI structure (20). The trench (25) is relieved adjacent its open mouth (30) in order to displace the commencement of bridging of the trench (25) with the filling material, to a level (36) well below a first surface (27) of the silicon layer (21) for in turn displacing voids (35) from the open mouth (30) into the trench (25) below the level (36). The trench may be relieved by forming tapered portions (40) in the side wells (29) adjacent the open mouth (30), and/or by relieving one or more lining layers (32) in the trench (25) adjacent the open mouth (30) to form tapered portion (52) and (53). Instead of relieving the trench (25) by tapering the side walls (29) relieving recesses may be formed into the first surface (27) of the silicon layer (21) adjacent the open mouth (30). By relieving the trench (25) or one or more of the lining layers (32) adjacent the open mouth (30) the commencement of bridging of the trench with the filling material is displaced downwardly to a level (36), which displaces voids formed in the trench below the level (36). By sufficiently relieving the trench (25) and/or lining layers (32) adjacent the open mouth to a sufficient depth the formation of voids in the trench may be completely avoided.

A trench isolated silicon layer in a semiconductor substrate is commonly required. For example, where it is desired to electrically insulate discrete areas of a silicon layer one from the other trenches filled with electrically insulating filling material are formed in the silicon layer for electrically insulating the respective discrete areas. Commonly, such layers requiring trench filled isolation may be a silicon layer of a silicon on insulator (SOI) structure. A buried insulating layer, typically, an oxide layer is located under the silicon layer, and the silicon layer and oxide layer are in turn supported on a handle layer. Where trench filled electrical isolation is required, the trench or trenches are formed through the silicon layer to the buried insulating layer. After forming of the trenches, the trenches are filled with an appropriate electrical insulating material, which may be an oxide or silicon nitride. The oxide or silicon nitride are generally deposited by a chemical vapour deposition process. Alternatively, in order to strengthen the SOI structure, the trenches may be initially partially filled with an electrical insulating material, such as for example, an oxide, which would form a lining layer in the trench. The remaining part of the trench would then be filled with polysilicon. Typically, the oxide is deposited in one or more layers in the trench which line the base which is formed by the buried oxide layer, and the side wells of the trench. The remaining unfilled portion of the trench is then filled with polysilicon. Typically, the polysilicon is deposited by a chemical vapour deposition process.
Whether the trenches are entirely filled with a single filling material, for example, oxide or silicon nitride, or partially filled with oxide or silicon nitride and then with polysilicon, problems arise in the filling of such trenches.
As the filling material, be it oxide silicon nitride or polysilicon, or a combination of such materials are being sequentially deposited, a layer of the filling material of progressively increasing depth forms on the base of the trench and on the side walls of the trench, as well as on the surface of the silicon layer through which the trench is formed into the silicon layer. Unfortunately, the depth of the layers of the filling material formed on the base and the side walls of the trench, and on the surface of the silicon layer do not increase in depth at a uniform rate. Typically, the depth of the filling material on the surface of the silicon layer increases at a greater rate then the depth of the filling material on the side walls of the silicon layer. This, thus, leads to an effect commonly referred to as "bread-loafing". Bread-loafing causes the depth of the layer of the filling material on the side walls of the trench adjacent the open mouth thereof to increase in a direction towards the other side wall at a greater rate than the rate at which the depth of the layer of the filling material on the remainder of the side wells below the open mouth increases. Accordingly, in due course as the filling of the trench progresses the bread-loafing of the filling material causes the layers of the filling material on the side walls adjacent the open mouth to meet and thus bridge the trench. Once the bread-loafing of the filling material has caused bridging of the trench, no further filling material can be filled into the trench, thus leading to the creation of a longitudinally extending void in the trench. Where the trench is to be entirely filled with deposited oxide the bread-loafing effect causes bridging of the trench with the oxide adjacent the open mouth of the trench. On the other hand, where the trench is to be lined with one or more layers of oxide, and then subsequently filled with polysilicon, the bread-loafing effect causes bridging of the trench with the polysilicon material.
Reference is now made to FIGS. 1 and 2 which are photomicrographs of different magnifications, which illustrate a cross-section of a silicon layer showing one trench formed in the silicon layer which demonstrate the effect of bread-loafing in the formation of a void in the trench. The silicon layer is indicated by the reference numeral 1 and the trench is indicated by the reference numeral 2. In this case the trench 2 was lined with an oxide layer 3 which was deposited on side walls 4, a base and on a surface 6 of the silicon layer 1. The bread-loafing effect of the oxide layers 3 can be seen at 7 adjacent the open mouth 8 of the trench 2. The bread-loafing effect of the oxide layers 3 at 7 has not caused the oxide layers 3 to bridge the trench 2. However, it has significantly narrowed the remainder of the open mouth 9 into the trench 2. A polysilicon layer 9 was then deposited over the oxide layer 3, and as can be seen the bread-loafing effect rapidly caused the polysilicon adjacent the open mouth 8 to bridge the trench. At that stage no further polysilicon could be deposited into the trench beyond the bridged open mouth 8, and thus, a void 10 extending longitudinally along the length of the trench was formed. As can be seen the void 10 extends from the open mouth downwardly towards the base. Furthermore, the void 10 terminates at the open mouth at a level substantially co-planar with the surface 6 of the silicon layer 1.
While, in general, the existence of such voids do not affect the electrical insulating characteristics of the filled trenches, they do lead to areas of entrapment where gases and liquids used in subsequent processing steps of the silicon layer can become entrapped, and subsequently lead to contamination of the silicon layer. Typically after the trenches have been filled the oxide and polysilicon layers are etched or ground back to the surface level of the silicon layer. As can be seen from FIGS. 1 and 2 etching or grinding the oxide and polysilicon layers 3 and 9 back to the surface 6 of the silicon layer 1 will remove the portion of the oxide and the polysilicon layers 3 and 9 which are bridging the trench, thus providing an opening to the void 10. Accordingly, if the silicon layer is cleaned by washing and rinsing, cleaning chemicals and/or rinsing water readily become entrapped in the void 10. Such cleaning chemicals, in general, would be contaminants in subsequent processing steps of the silicon layer, and on leaking out through the voids would lead to contamination in the subsequent processing steps which is unacceptable.
Another problem arises where a photoresist layer is to be formed on the surface 6 of the silicon layer through which voids have been exposed. In general, during the formation of a photoresist layer on a silicon or other layer the structure is spun in order to spread the photoresist layer over the surface on which the photoresist layer is to be formed. The spinning of the photoresist over areas where voids are exposed leads to uneven coating in the form of streaking of the photoresist over the surface of the silicon layer. This, thus, prevents accurate patterning of the photoresist layer. Additionally, the photoresist may become entrapped in the voids, thus leading to contamination in subsequent processing steps.
Indeed, in many cases after the filling of trenches in a trench isolated silicon layer, as well as the oxide and/or polysilicon or other such filling layers being etched or ground to the original surface of the silicon layer, the silicon layer is further ground to reduce the depth of the silicon layer. In such cases, even where a void formed in a trench does not extend up to the open mouth of the trench, subsequent grinding of the silicon layer, can lead to the removal of the bridging of the trench, thus exposing the void.
There is therefore a need for a method for forming a filled trench in a semiconductor layer of a semiconductor substrate in which the effect of trench voids is minimised. There is also a need for a semiconductor substrate with a semiconductor layer having filled trenches therein in which the effect of trench voids is minimised.
The present invention is directed towards providing such a method and a semiconductor substrate.

Method for forming a filled trench in a semiconductor layer of a semiconductor substrate, and a semiconductor substrate with a semiconductor layer having a filled trench therein


A system is configured to authorize client access to an application programming interface (API) of a host device. A proxy is configured to handle network traffic between a host and a client. Clients engage the host through the proxy to access an API of the host. An authorized client-side application permitted use of the API includes an API request to the proxy. The proxy determines whether an internet protocol (IP) address of the client and the token match an existing IP-token pair. If no match exists, the proxy determines whether the token matches an existing token. The proxy authorizes the client access to the API when the IP and token match an existing pair or if the token does not match an existing token and the token is verified by the proxy.

Internet enabled clients, such as smart phones, personal computers, tablets, gaming systems and the like have become prevalent in recent years. Given the proliferation of Internet enabled clients and far-reaching Internet access, an increasing number of users access online content which is hosted by servers, known as a host device, host server, or a host. A common method for providing online content to clients is through an application programming interface, or API, at the host. The vast majority of users access online content provided by hosts for legitimate reasons through authorized applications. However, there are illegitimate users who access the hosts of online content with unauthorized applications, whether to simply access the host for legitimate purposes through alternative means, or for more malicious purposes such as to scrape host data or to deny services to legitimate users. These activities may, at minimum, violate terms of service for utilizing an API and, at worst, impact legitimate user experience or deny revenue to the content provider.
Currently, techniques for protecting APIs from unauthorized access are limited because client-host communications associated with APIs are typically occur over lightweight data-interchange formats such as WebSocket or WebSocket API (WebSocket or WebSockets, collectively), JavaScript Object Notation (JSON) or eXtensible Markup Language (XML). While the use of these lightweight formats provides an efficient client-host communication scheme, protection options for APIs are very limited because traditional protection methods for features and functionality provided by a host rely on monitoring client activity through fully featured interchange formats. Additionally, with respect to WebSockets, there is a host resource cost to maintain an open WebSocket on a per-user basis, which illegitimate users may exploit. Fully featured interchange formats allow for more granular client identification than just an internet protocol (IP) address level as is generally possible with a lightweight data-interchange format. Thus, current protection schemes for protecting APIs are mainly IP level rate limiting rules that set a number of requests over time period threshold. IP level rate limiting provides some benefit in increasing the time it takes to scrape a host or mitigating a denial of service type attack from a single IP. However, IP level rate limiting may also severely impact legitimate users that share a same IP address as illegitimate users (e.g., when accessing a network from a same megaproxy, Internet Service Provider, network access point etc.). Moreover, aside from blocking an IP address itself (e.g., preventing access by the IP address), which captures both legitimate users and illegitimate users alike in the block, rate limiting does little to restrict unauthorized access as it only increases the amount of time it takes to scrape a host.

Authenticating access configuration for application programming interfaces


A method for analyzing service in a wireless communication network, which includes multiple antennas, which are assigned to transmit signals over the air to mobile units on respective sets of one or more frequency channels, such that at least two of the antennas transmit the signals on a common frequency channel. The method includes recording levels of the signals received at multiple locations within a service area of the network, while the antennas are transmitting the signals on the respective sets of frequency channels, including simultaneous transmission by the at least two of the antennas on the common frequency channel. The recorded levels and the frequency channels of the received signals are analyzed so as to classify the received signals at each of the locations according to the antennas transmitting the signals.

In a cellular communication network, the region served by the network is divided into a pattern of cells. Each cell has one or more antennas that communicate with mobile units (cellular telephones and/or data terminals) within its service area. The cell may be divided into sectors, each of which is typically served by a different antenna. In the context of the present patent application, the terms "cell" and "sector" are used interchangeably. The present invention deals with classifying signals received at various locations in the service region of the network according to the antenna transmitting the signals. (Such operations are also referred to herein as assigning the received signals to antennas, or associating the signals with antennas). In the context of a cellular network, it will be understood that classifying the signals according to the transmitting antenna has substantially the same meaning as classifying the signals according to cell or sector.
Each cell in a narrowband cellular network is assigned a fixed set of frequencies, also referred to as channels. Narrowband networks currently in use include primarily Time Division Multiple Access [TDMA] networks, such as Global System for Mobile [GSM] communication networks. In such networks, each traffic channel may be further divided into time slots, while control channels are transmitted continuously. (In contrast, Code Division Multiple Access [CDMA] networks assign a broad frequency band to each cell, and all operating channels are generally transmitted continuously.) In order to reduce interference between calls, the frequency channels in a narrowband cellular network are typically distributed among the different cells so that nearby cells use different channels.
The strengths of the signals reaching the mobile units from the antennas, and vice versa, are determined by the path loss of electromagnetic waves propagating between the antennas and the mobile unit locations. If the received signal level at a given location is too low, poor quality or coverage holes will result. On the other hand, during a call between a given mobile unit and a given antenna, the power of the traffic signals transmitted by the antenna on the channel or slot serving the mobile unit may be intentionally reduced, by a mechanism known as transmission power control (TPC). The object of this mechanism is to reduce interference with other calls on the same channel or adjacent channels in other nearby cells, while still providing the given mobile unit with a sufficient carrier/interference (C/I) ratio.
Because of the limited available spectrum, channel allocation generally involves tradeoffs between coverage of the service area and potential interference between different cells. If an inadequate number of channels are available at the location, calls will be blocked or dropped. On the other hand, if cells whose service areas overlap significantly use the same channels, mobile units in the overlap area will experience substantial interference. Therefore, an accurate map of cell service areas and signal strengths can be very useful in optimizing cellular network performance.
In planning cellular networks, path loss maps are typically used to locate and orient the antennas and determine channel allocations and transmission power levels. Such maps may be based on analysis of the topography and other characteristics of the network service area. In actual operation, however, the transmitted signals are subject to variable and unexpected attenuation, and the a priori path loss estimates are rarely completely accurate. To get a better picture of the actual distribution of cellular signals transmitted by the various antennas, cellular operators use drive tests, in which the actual antenna signals are measured at different locations by a test van driving through the service region.
At any location in the service region that is visited by the test van, it is likely to measure signals on multiple different frequency channels. The source of a signal on a given channel at a given location may be ambiguous, since as noted above, multiple cells may transmit on the same channel, and the received power is subject to TPC and fading, which may be difficult to predict. This problem can be resolved in part by assigning each cell a particular "color code," i.e., a signal pattern that distinguishes its signals from those of other cells. In practice, however, the color code is not always available. Therefore, correctly associating each drive test measurement with a transmitting cell may be a difficult task.
U.S. Pat. Nos. 5,926,762 and 6,405,043, whose disclosures are incorporated herein by reference, describe methods for interference prediction and frequency planning for cellular networks based on drive test results. In order to avoid ambiguity in associating the signals measured in the drive test with the transmitting antennas, a single channel is transmitted from each cell site or sector, and all cells in the test area transmit on different channels. By transmitting from each cell on a single, unique channel, interference that might complicate the readings is eliminated, so that the cell from which any channel is transmitted is positively known. By implication, however, this test method can be carried out only when the cellular network is off-line, serving only the drive test and not serving network customers (or at best serving the customers on a very limited basis permitted by the restricted, single-channel spectrum allocated to each cell or sector.) There remains a need for a reliable method for processing drive test measurements that are gathered while the network is in normal operation.

Classification of cellular network drive test results


An electronic device includes a first mode, a second mode, a mode transition accepting unit, a state confirmation unit, and a transition determination unit. The mode transition accepting unit is configured to accept from a plurality of demanding sources a transition demand to transition from the first mode to the second mode. The state confirmation unit is configured to confirm a device state of the electronic device. The transition determination unit is configured to determine whether or not a transition from the first mode to the second mode is possible based on a demanding source of the transition demand accepted by the mode transition accepting unit, and the device state confirmed by the state confirmation unit. When the device state is a predetermined device state, the transition determination unit makes a determination that the transition is possible for some of the plurality of demanding sources that issued the transition demand and not possible for others of the plurality of demanding sources that issued the transition demand.

1. Field of the Invention
The present invention relates to electronic devices having an energy saving mode to save electric power consumption, and in particular, to a multi-function peripheral having a copy function, a printer function, a facsimile function, and the like.
2. Description of the Related Art
In an electronic device including an image forming unit such as a copying machine, a printer, a facsimile, and the like, an energy saving mode is set through a predetermined operation to suppress the electric power consumption.
Recently, a multifunction peripheral called an MFP (Multifunction Peripheral) having a copy function, a printer function, and a facsimile function is in widespread use. Similar to the copying machine, the printer, the facsimile, and the like, the MFP also generally has the energy saving mode for saving the electric power consumption.
In the energy saving mode of the MFP, a control unit, for example, carries out controls such as turning OFF a backlight of an operation display unit, setting a fixing unit to a preheat temperature, setting a scanner unit to an OFF state, and the like.
The control unit can transition to the energy saving mode based on a transition demand generated when a user operates a predetermined input key, for example.
If a stopped state of each unit of the device is continued beyond a predetermined time, the control unit can transition to the energy saving mode based on a transition demand generated by a timer that measures a duration time.
Furthermore, when a current time and a set predetermined date and time correspond, the control unit can transition to the energy saving mode based on a transition demand generated by a time specifying unit.
A demanding source that generates the transition demand to change to the energy saving mode conventionally includes an electronic device that uses the input key and the time specifying unit, or an electronic device that uses the input key and the timer.
The electronic device does not determine if the demanding source of the transition demand to the energy saving mode is the input key, the timer, or the time specifying unit. Therefore, when accepting the transition demand to the energy saving mode from any one of the input key, the timer, or the time specifying unit, the control unit sets each unit of the device to the energy saving mode.
Thus, if an error state such as paper jam of a paper transporting unit, paper out, toner empty, and the like is occurring when the transition demand to the energy saving mode is accepted, the printing may not be carried out at the time of facsimile reception if the control unit transitions to the energy saving mode without the error state resolved.
Thus, if a predetermined error state such as paper jam of the paper transportation unit, paper out, toner empty, and the like is occurring, the control unit does not transition to the energy saving mode and notifies the error state to the user even if the transition demand to the energy saving mode is made.
In this case, the control unit does not transition to the energy saving mode even if the user cannot resolve the error state that is occurring, and thus an effective electric power saving effect cannot be obtained. For example, when the time specifying unit generates the transition demand to the energy saving mode outside of working hours of an office, the error state remains unresolved if the office is unoccupied, and hence the transition to the energy saving mode cannot be made.

Electronic device with energy saving mode and error state detection


In order to enhance dispersion control, the apparatus includes a dispersion controller; a quality index generator generating a quality index representing a quality of an optical signal output from the dispersion controller; and a searching unit searching for an amount of dispersion control applying to the dispersion controller which amount optimizes the quality index, wherein the searching unit includes a splitting-half searching unit roughly searching, in a splitting half method, a range in which dispersion is controllable by the dispersion controller for an amount of dispersion control such that the quality index generated by the quality index generator becomes preferable, and a sweep searching unit thoroughly searching, by sweeping, a limited range based on the amount of dispersion searched by the splitting-half searching unit for an amount of dispersion control that optimizes the quality index generated by the quality index generator.

A recent optical transmission system has been further enhancing the transmission speed and has put transmission at 10 Gb/s into practice. In addition, an optical transmission system at the transmission speed 40 Gb/s has been under development. Further, there has been developed an optical transmission system in which 1000-multiplexed optical signals with a bit rates of 10 Gb/s are multiplexed in use of a wavelength multiplexing technique and the resultant wavelength-multiplexed signal is collectively amplified and transmitted.
In conjunction with enhancement in transmission speed, chromatic dispersion of an optical fiber intensifies deterioration in waveform of an optical signal and is therefore one of the causes of the restriction on transmittable distances. For this reason, a dispersion compensation fiber that compensates such chromatic dispersion of an optical fiber makes long distance transmission as far as several hundreds kilometers possible. Since the transmission speed further increased to approximately 40 Gb/s causes chromatic dispersion to more largely impinges, realization of long distance transmission as far as several hundreds kilometers prefers exact compensation for chromatic dispersion of an optical fiber and concurrently cannot neglect a variation in chromatic dispersion characteristics caused from a variation in temperature of the optical fiber and a variation in chromatic dispersion caused from polarization mode dispersion.
Optical transmission at a high transmission speed, such as 40 Gb/s as above, higher than at 10 Gb/s, tightens the restriction on the tolerance of chromatic dispersion, which accompanies desire for strict conditions on a residual amount of chromatic dispersion obtained after the chromatic dispersion has been compensated for. Therefore, dispersion has to be compensated for which is caused by a variation in temperature of an optical fiber and by polarization mode dispersion in order to reduce residual chromatic dispersion while the apparatus is in operation.
Various approaches have conventionally been proposed in order to compensate chromatic dispersion. For example, FIG. 7 is a diagram illustrating a conventional technique including a dispersion compensator, in which the drawings illustrates optical receiver 100, wavelength compensator 101, optical filter 102, optical-to-electrical converter (O/E) 103, data identifying section 104 with clock regenerating means, error detector 105, error rate calculator 106, error-rate variation amount calculator 107, compensation amount calculator 108, and dispersion compensating unit 111 placed at a distance.
Optical receiver 100 receives optical signal transmitted through an optical fiber; dispersion compensator 101 compensates chromatic dispersion of the received optical signal; optical filter 102 extracts an optical signal containing a signal components; optical-to-electrical converter 103 converts the extracted optical signal into an electric signal; data identifying section 104 extracts the clock (from the electric signal), identifies the data on the basis of the extracted clock, and inputs the data into error detector 105; and error detector 105 carries out error detection or error correction and outputs the data, serving as a received signal, to a subsequent apparatus which is however not illustrated in the drawing.
Error rate calculator 106 calculates an error rate based on an error detection signal of error detector 105 and error-rate variation amount calculator 107 calculates a variation in error ratio and inputs the error ratio into compensation amount calculator 108, which calculates an amount of dispersion control and controls dispersion compensator 101. Specifically, compensation amount calculator 108 controls the amount of dispersion control to be used in dispersion compensator 101 such that the error ratio is not increased.
The optical receiver 100 is configured to search, on the basis of signal quality information, such as error ratio, calculated from an optical signal transmitted through the optical transmission line serving as a connection path for an amount of dispersion control to be used in dispersion compensator 101 and sets the searched amount of dispersion control into dispersion compensator 101 at the initial setting stage (until communication has been established between a non-illustrated optical transmitter and optical receiver 100). Described in detail, optical receiver 100 sweeps a range of an amount of dispersion control variable in dispersion compensator 101 and successively measures the error ratio associated with the amount of dispersion control, and finally sets the amount of dispersion control associated with the most preferable error ratio into dispersion compensator 101.
Here, dispersion compensator 101 is exemplified by a configuration in which optical or mechanical variation in length of a dispersion compensation fiber controls an amount of dispersion control or a configuration in which a heater that searches for the temperature by supplying electricity corresponding to an amount of dispersion compensation is provided on the basis of knowledge of a temperature variation varying an amount of chromatic dispersion. Either configuration of a dispersion compensator requires tens of milliseconds or more to respond to, for example, a single control. Accordingly, it means that sweeping a compensatable range requires, for example, time as long as tens of seconds or more.
Therefore, if an amount of dispersion control is searched for in such a method, sweeping performed in search of an amount of dispersion control by dispersion compensator 101 usually requires relatively long time, optical receiver 100 requires a certain time for searching for an amount of dispersion control in order to secure a desired signal quality.
In other words, reduction in time required for the initial setting need reduction in time required for searching for the desired amount of dispersion control to be set.
Patent reference 1 sweeps a variable range at the initial setting to calculate a bit error rate and concurrently carries out synchronization detection such as frame synchronization. The disclosed configuration enhances the speed of searching for a amount of dispersion control by setting, sweeping the width of a range in which synchronization detection cannot be carried out larger than that of the range in which synchronization detection can be carried out.
The technique disclosed in Patent Reference 2 can be listed among conventional techniques related to the present invention.
[Patent Reference 1] Japanese Patent Application Laid-Open (KOKAI) No. 2004-236097
[Patent Reference 2] Japanese Patent Application Laid-Open (KOKAI) No. 2002-208892
However, even the technique disclosed in above Patent Reference 1 requires sweeping a range at least from the lower limit to the upper limit of the variable range of the dispersion compensator. Therefore, it is difficult for the technique to satisfactorily enhance the searching speed for an amount of dispersion control.
If the compensation at even the amount of dispersion control initially set in the dispersion controller worsens the error rate or the like due to a variation in temperature of the optical fiber, polarization mode dispersion and/or other reasons, another sweeping has to be made search of an amount of dispersion control of the dispersion compensator. The sweeping which likewise requires a relatively long time needs be repetitiously carried out even during the operation, and consequently a variation in temperature of the optical fiber, polarization mode dispersion and/or other reasons make it difficult to set a stable amount of dispersion control.
Further, as described below, it is problematically difficult to optimally compensated for dispersion caused by a phenomenon peculiar to optical transmission, that is, fluctuation in level of an optical input (i.e., fluctuation in Optical signal to Noise Ratio (OSNR)) and fluctuation in characteristics of Polarization Mode dispersion (PMD).
Specifically, dispersion of an optical signal being received by an optical receiver is represented by values on the x axis and Q penalty of the same optical signal is represented by values on the y axis, a dispersion value close to the center of abscissa is associated with a lower Q penalty value (i.e., representing more preferably quality) and the Q penalty value increases (i.e., the quality deteriorates) as departing from the center of abscissa (i.e., as the dispersion value decreases or increases from the center value). Namely, the relationship between the dispersion and the Q penalty of an optical signal in this case is represented by a parabola waveform (a tolerance curve) having the bottom at the center thereof.
In this case, fluctuation in light input level on the time axis causes the characteristics of OSNR to irregularly fluctuate on the time axis. For this reason, the waveform representing the relationship between the dispersion and Q penalty value varies with time in the y-axis direction (up and down) as illustrated in, for example, FIG. 8. In addition, the characteristics of PMD possessed by the optical transmission path varies on the time axis, so that the waveform representing the relationship between the dispersion and the Q penalty of the optical signal varies with time in the x-axis direction as illustrated in, for example, FIG. 9.
The fluctuation in characteristics of PMD and that of OSNR are not associated with each other, so that the combination of both fluctuations does not substantially vary in gradient of the tolerance curve but does randomly shifts on both x and y axes as illustrated in, for example, FIGS. 10 and 11 (see tolerance curves TC1 to TC6 in FIG. 10 and tolerance curves TC11 to TC16 in FIG. 11). Here, FIG. 10 shows an example of a shift in tolerance curve of receipt of an optical signal having transmission speed of 10 Gbit/s and FIG. 11 shows an example of a shift in tolerance curve of receipt of an optical signal having transmission speed of 40 Gbit/s.
As illustrated in FIGS. 10 and 11, the optimum amount of dispersion control when the optical receiver receives an optical signal and the Q penalty values corresponding to the optimum amount that are representing the coordinates at the bottom of a tolerance curve randomly shift on the xy coordinates. Further, an optical signal at a transmission speed as high as 40 Gbit/s has a narrower width than that of a transmission speed of about 10 Gbit/s and therefore has a stricter demand for dispersion.
FIGS. 12 and 13 show a relationship between the dispersion tolerance width and Q penalty values of an optical signal respectively at transmission speeds of 10 Gbit/s and 40 Gbit/s. Trapezoids L1 and L2 in FIGS. 12 and 13 represent a coordinate region defined by a dispersion value and a Q penalty value which can establish communication even under the influence of variations in OSNR and PMD.
As illustrated in FIG. 12, in receipt of an optical signal at a transmission speed of 10 Gbit/s, the width (i.e., the dispersion tolerance width) of dispersion value that can ensure communication establishment even if the tolerance curve shifts as illustrated in above FIG. 10 has a small variation with the variation in Q penalty value represented by the ordinate.
Namely, since the variation in Q penalty from the finest value Q11 to limit value Q12 in trapezoid L1 illustrated in FIG. 12 is followed by the variation in dispersion width from the lower base length L11 of trapezoid L1 to the upper base length L12 of trapezoid L2, dispersion tolerance has a small amount of variation in accordance with a variation in Q penalty (in other words, the slope of right oblique L13 and that left oblique L14 of trapezoid L1 with respect to variation in the ordinate direction are gentle).
In contrast, as illustrated in FIG. 13, in receipt of an optical signal at a transmission speed of 40 Gbit/s, the width (i.e., the dispersion tolerance width) of dispersion value that can ensure communication establishment when the tolerance curve shifts as illustrated in above FIG. 11 has a relatively large variation with the variation in Q penalty value represented by the ordinate.
Namely, since the variation in Q penalty from the finest value Q21 to limit value Q22 in trapezoid L2 illustrated in FIG. 13 is followed by the variation in dispersion width from the lower base length L21 of trapezoid L2 to the upper base length L22 trapezoid L2, dispersion tolerance has a large amount of variation in accordance with a variation in Q penalty (in other words, the slope of right oblique L23 and left oblique L24 of trapezoid L2 with respect to the ordinate direction are sharp).
As described above, for an optical signal transmitted at the transmission speed 40 Gbit/s, even if the OSNR value is fine because a dispersion value corresponding to either end of the lower base of trapezoid L2 in FIG. 13 is applied to the optical signal, deterioration in Q penalty value caused from a variation in OSNR due to the variation in PMD or the like as illustrated by arrow A in FIG. 13 causes the Q value to deviate from the dispersion tolerance width, so that the communication may not be secured.
Here, as illustrated by arrow B in FIG. 13, the Q penalty even which deteriorates due to PMD fluctuation or the like may remain inside the dispersion tolerance. However, as another problem, on the basis of the OSNR value in a stationary state, whether or not the deterioration in Q penalty shifts the Q penalty to an error region as illustrated by arrow A or to a region in which an error does not occur as illustrated by arrow B.
In short, the problem is also that, in spite of a preferable OSNR value, an optical signal with a transmission speed of 40 Gbit/s may have errors caused not only by narrowing the dispersion tolerance width but also by sharpening the variation in dispersion tolerance according to deterioration in Q penalty value.
In other words, as increasing in bit rate from about 10 Gbit/s to about 40 Gbit/s, the setting of dispersion of optical signal that are capable of establishing communication becomes more sensitive to OSNR, PMD and the like, and therefore, dispersion compensation requires higher accuracy.
The Patent Reference 2 discloses a technique with a configuration that chirps an optical signal at an optical transmitter in advance to compensate for both chromatic dispersion and polarization dispersion at an optical receiver. However, since the technique of the Patent Reference 2 assumes that an optical signal that is to be compensated for previously undergoes a particular process of being chirped at an optical transmitter, the Patent Reference 2 does not provide a technique to rapidly set an amount of compensation for chromatic dispersion which amount minimizes the influence of a variation in temperature of an optical fiber and the influence of PMD without depending on whether or not an optical signal to be received has been chirped.

Dispersion compensation controlling apparatus and method for searching for amount of dispersion control


A computer implemented method on a computer readable media is provided for determining the source of a problem in a complex system of managed components based upon symptoms. The problem source identification process is split into different activities. Explicit configuration non-specific representations of types of managed components, their problems, symptoms and the relations along which the problems or symptoms propagate are created that can be manipulated by executable computer code. A data structure is produced for determining the source of a problem by combining one or more of the representations based on information of specific instances of managed components in the system. Computer code is then executed which uses the data structure to determine the source of the problem from one or more symptoms.

1. Technical Field
This invention relates to the field of event correlation and, more particularly, to a method and apparatus for efficiently determining the occurrence of and the source of problems in a complex system based on observable events. The invention has broad application to any type of complex system including computer networks, satellites, communication systems, weapons systems, complex vehicles such as spacecraft, medical diagnosis, and financial market analysis.
2. Related Information
As computer networks and other systems have become more complex, their reliability has become dependent upon the successful detection and management of problems in the system. Problems can include faults, performance degradation, intrusion attempts and other exceptional operational conditions requiring handling. Problems generate observable events, and these events can be monitored, detected, reported, analyzed and acted upon by humans or by programs. However, as systems have become more complex, the rate at which observable events occur has increased super-linearly, making problem management more difficult.
As an example, when the number of computer nodes in a network increases, the network complexity increases super-linearly with the number of nodes, with a concomitant increase in the fault rate. Compounding this problem of network complexity is fault propagation between both machines and network protocol layers; these propagated faults can generate additional events.
Automated management systems can help to cope with this increase in the number and complexity of events by (1) automating the collection and reporting of events, thereby reducing the load on human operators or programs; (2) using event correlation techniques to group distinct events, thereby compressing the event stream into a form more easily managed by human operators; (3) mapping groups of events to their underlying causes, thus reducing the time between faults and repairs; and (4) automatically correcting diagnosed problems, thereby minimizing operator intervention.
Event correlation and management techniques are a particularly important method of reducing the number of symptoms in a system which need to be analyzed and accurately determining the number and identity of discrete problems which need to be rectified. Unless events are correlated, a single problem in a single subsystem could result in multiple, uncoordinated corrective actions. This can lead to wasteful resources spent on duplicate efforts and inconsistent corrective actions which result in an escalation of problems.
Conventional and previously proposed approaches to managing faults in a system have failed to fully address the increase in complexity and have failed to provide adequate performance for large systems, as outlined more particularly herein. In order to discuss these problems, it is first necessary to understand these other approaches.
Event correlation and management approaches can be generally grouped into five categories: (1) rule-based reasoning; (2) case-based reasoning; (3) reasoning with generic models; (4) probability networks; and (5) model-based reasoning. In addition, a number of different architectures have been considered to carry out event correlation and management. In order to review these approaches, the following terminology is defined:
KNOWLEDGE REPRESENTATION: The format and means for representing knowledge about the system being monitored, such as the types of network components and the network topology. Such knowledge may be stored in a hierarchical relational or object-oriented database.
KNOWLEDGE ACQUISITION: The methods and means for acquiring the knowledge about the system to be monitored. Ideally, knowledge is automatically obtained during system operation to minimize human resource requirements. However, in actuality much knowledge acquisition involves humans familiar with the operation and idiosyncrasies of a system.
EVENT CORRELATION: The methods and means for detecting the occurrence of exceptional events in a complex system and identifying which particular event occurred and where it occurred. The set of events which occur and can be detected in the system over a period of time will be referred to as an "event stream." It will be noted that the location of the event is not necessarily the location where it is observed, because events can propagate across related entities in a system. Although every possible reportable measurement (such as voltage level, disk error, or temperature level) could be considered to be an "event", many of these measurements do not contribute to identifying exceptional events in the system. Event correlation takes as input an event stream, detects occurrence of exceptional events, identifies the particular events that have occurred, and reports them as an output.
Event correlation can take place in both the space and time dimensions. For example, two events whose sources are determined to be in the same protocol layer in the same network element may be related spatially. However, they may not be correlated if they occur on different days, because they would not be related temporally.

Apparatus and method for event correlation and problem reporting


An apparatus, a system and a method secure, mount and/or attach a device to a fixture. The apparatus has an arm, a housing, a cable, and/or a locking member. The arm has a bracket which attaches to the device. The arm inserts into a housing and/or an opening in a head. A cable connects the head to a base which attaches to the fixture. A locking member receives the arm and/or locks the device to the cable, the base and/or the fixture. The cable extends outward with respect to a fixture allowing the device to be manipulated, to be examined and/or to be utilized by a person while the device remains secured to the fixture.

The present invention generally relates to an apparatus, a system and a method for securing a device. More specifically, the present invention relates to an apparatus, a system and a method for securing a device to a fixture. The device may be a portable electronic device, such as, for example, a laptop computer, a cellular phone, a portable compact disc player, a portable MP3 player, a personal data assistant and/or the like. The apparatus, the system and the method for securing the device may attach the device to a fixture to prevent theft of, damage to and/or destruction of the device. The fixture may be, for example, a table, a shelf, a display unit, a display cabinet and/or the like.
The apparatus, the system and the method for securing a device may have an arm, a housing, a cable, and/or a locking member. The arm may have a first end and/or a second end. The first end may have a bracket which may be attached the device. The cable may have a first end and/or a second end. The second end may be opposite to the first end of the cable. The first end of the cable may be connected to the bracket. The second end of the cable may be attached to the fixture. As a result, the device may be manipulated, may be examined and/or may be utilized by a person while remaining secured to the fixture.
It is generally known that, for example, a vendor, a wholesaler and/or a retailer displays portable electronic devices in showrooms. The vendor, the wholesaler and/or the retailer have other units of the portable electronic devices in storage for sale to customers. The portable electronic devices are, for example, laptop computers, cellular phones, portable compact disc players, portable MP3 players and/or personal data assistants. Often, the customers examine and/or utilize the portable electronic devices on display before deciding to purchase one of the units of the portable electronic devices from the vendor, the wholesaler and/or the retailer. The vendor, the wholesaler and/or the retailer secures the portable electronic devices to fixtures in the showroom to prevent theft of the devices by the customers. The devices on display may be secured to the fixtures by cables and/or assemblies. Traditionally, the cables may be thin which may allow the cables to be easily cut and/or the devices to be easily separated from the fixtures. The assemblies attach and/or lock the devices to the fixtures. The assemblies may be easily disassembled and/or may allow the devices to be easily separated from the fixtures. Further, the cables and/or the assemblies prohibit the customers from lifting, manipulating and/or examining the devices on display in the showrooms. Still further, the cables and/or the assemblies are expensive, complicated to assemble and/or are ineffective in securing the devices to the fixtures. Moreover, the cables and/or the assemblies fail to prevent the device from being separated from the fixtures. As a result, the cables and/or the assemblies are ineffective in preventing the theft of and/or the destruction of the devices on display by the customers.
Often, the assemblies secure the devices, such as, for example, laptop computers to the fixtures with rods. The rods extend across the laptop computers and attach to the fixtures. As a result, the laptop computers are secured between the rods and the fixtures. However, the rods prohibit the customers from lifting the laptop computers from the fixtures for examination. The laptop computers can only be lifted from the fixtures by detaching the rods and/or separating the laptop computers from the fixtures. As a result, a person can not examine and/or utilize the laptop computers while the laptop computer connected to the fixtures.
A need, therefore, exists for an apparatus, a system and a method for securing a portable electronic device to a fixture. Additionally, a need exists for an apparatus, a system and a method for securing the device to the fixture to prevent the device from being separated from the fixture. Further, a need exists for an apparatus, a system and a method for securing the device to the fixture which may allow the device to be attached to the fixture via a cable. Still further, a need exists for an apparatus, a system and a method for securing the device to the fixture which may allow the device to be lifted off the top surface of the fixture for examination while remaining connected to the fixture. Moreover, a need exists for an apparatus, a system and a method for securing the device to the fixture which may be easy to assemble and/or may be inexpensive.

Apparatus, a system and a method for securing a device to a fixture


A method, system, and apparatus of determining optimal viewing planes for cardiac image acquisition, wherein the method includes acquiring a set of sagittal, axial, and coronal images of a heart, where the axial and coronal images intersect with the sagittal image orthogonally, and where the heart has a natural axis and a left ventricle (“LV”) with a bloodpool, a bloodpool border, and an apex. The method also includes making a map of the bloodpool border, and using the map to create a full coordinate frame oriented along the natural axis.

1. Technical Field
The present invention relates to medical imaging, and more particularly, to determining the short and long axis viewing planes for cardiac image acquisitions.
2. Discussion of the Related Art
In the field of medical imaging, images oriented around the short and long axis normals of the heart are the standard format for evaluation by clinicians. The orientation of the heart, and therefore its short and long axis normals, are unique to individuals. Thus, in acquiring such images, the orientation of the individual's heart and its associated coordinate frame (short axis, long axis, and the direction orthogonal to both) need to be determined.
In related art, an average Left Ventricular coordinate system is computed from a database of 50 subjects and used as a starting point. From this initial short axis orientation, several short axis images are sampled. Then the Expectation-Maximization algorithm is used to segment the left and right ventricles in these images. The centroids of the Left Ventricle ("LV") are found in the short axis image stack. These are connected to form the final short axis normal. Then the Right Ventricular point farthest from this axis is found and used to determine the long-axis normal direction. Since ventricular shapes can vary, some even being banana-shaped, this method does not always yield an appropriate coordinate frame.

Automatic optimal view determination for cardiac acquisitions


A polycarboxylic acid mixture comprising 80% by weight or more of 1,3,6-hexanetricarboxylic acid, wherein the polycarboxylic acid mixture has a psychometric lightness L-value of 98 or more, a psychometric chroma a-value of from −2.0 to 2.0 and a psychometric chroma b-value of from −2.0 to 3.0, and has a nitrogen content of 5,000 ppm by weight or less.

1. Field of the Invention
The present invention relates to a polycarboxylic acid mixture. More particularly, the present invention is concerned with a polycarboxylic acid mixture comprising 80% by weight or more of 1,3,6-hexanetricarboxylic acid, wherein the polycarboxylic acid mixture has a psychometric lightness L-value of 98 or more, a psychometric chroma a-value of from −2.0 to 2.0 and a psychometric chroma b-value of from −2.0 to 3.0, and has a nitrogen content of 5,000 ppm by weight or less. The polycarboxylic acid mixture of the present invention has not only excellent color tone (i.e., not discolored and substantially colorless and transparent) but also excellent color tone stability under heating (hereinafter, this stability is frequently referred to simply as "heat stability"). Therefore, the polycarboxylic acid mixture of the present invention can be advantageously used for producing, for example, a paint, a detergent, a builder for a cleaning agent, an anti-limescale agent, a lubricating oil, and various polycarboxylic acid derivatives, such as esters. The present invention relates also to a method for producing the above-mentioned polycarboxylic acid mixture in high yield.
2. Prior Art
1,3,6-Hexanetricarboxylic acid is water-soluble and has good biodegradability. Therefore, recently, various application fields of 1,3,6-hexanetricarboxylic acid have been proposed.
For example, it has been reported that 1,3,6-hexanetricarboxylic acid which is derived from 1,3,6-tricyanohexane, as well as a salt of 1,3,6-hexanetricarboxylic acid, can be advantageously used as a raw material for preparing a detergent and as a lubricating agent for a chain belt for a toothed wheel (see Unexamined German Patent Application Laid-Open Specification No. 19637428).
1,3,6-Hexanetricarboxylic acid is a trifunctional acid; therefore, when it is used as a curing agent for, e.g., an epoxy compound, a cured product having a high crosslinkage density can be obtained. Especially, 1,3,6-hexanetricarboxylic acid can be advantageously used as a crosslinking agent for a paint.
Generally, 1,3,6-hexanetricarboxylic acid can be easily obtained by hydrolyzing 1,3,6-tricyanohexane. 1,3,6-Tricyanohexane can be obtained as a by-product in a process for producing adiponitrile from acrylonitrile by electrodimerization. 1,3,6-Tricyanohexane can also be produced by reacting acrylonitrile with adiponitrile in the presence of a base.
When an electrodimerization reaction of acrylonitrile is conducted, 1,3,6-tricyanohexane is obtained as a by-product and contained in a mixture of nitrites including adiponitrile as a main product. By removing the adiponitrile from the mixture by distillation or the like, the content of 1,3,6-tricyanohexane in the mixture can be increased.
However, the nitrile mixture comprised mainly of 1,3,6-tricyanohexane, which is obtained by the above-mentioned methods, is usually markedly discolored to assume a color of yellow or black.
For example, in Unexamined Japanese Patent Application Laid-Open Specification No. Sho 62-270550, 1,3,6-tricyanohexane is purified by molecular distillation, but the resultant purified product is a yellow liquid having a Hazen value of 400 or more.
A polycarboxylic acid mixture comprised mainly of 1,3,6-hexanetricarboxylic acid, which is conventionally obtained by hydrolyzing such a markedly discolored nitrile mixture as mentioned above, is also markedly discolored to assume a color of, for example, yellow brown or red brown. Further, such a discolored polycarboxylic acid mixture has a problem in that, when the mixture is heated, for example, at 80° C. or more, it exhibits an increased degree of discoloration; specifically, the color difference (ΔE) as between before and after the heating tends to be far greater than 1 and, hence, the color tone stability of the discolored polycarboxylic acid mixture under heating is poor. Therefore, a number of attempts have been made to obtain a polycarboxylic acid mixture which has an improved color tone by removing the undesired color from the discolored polycarboxylic acid mixture comprised mainly of 1,3,6-hexanetricarboxylic acid.
For example, Unexamined German Patent Application Laid-Open Specification No. 19637428 discloses the following method for producing a colorless or light yellow 1,3,6-hexanetricarboxylic acid. A nitrile mixture comprised mainly of 1,3,6-tricyanohexane, which is by-produced in an electrodimerization reaction of acrylonitrile, is hydrolyzed by heating, under reflux, the nitrile mixture together with a 20% aqueous sodium hydroxide solution to thereby obtain a hydrolysis reaction mixture, followed by cooling of the reaction mixture. A concentrated sulfuric acid is added to the obtained hydrolysis reaction mixture to thereby obtain a carboxylic acid mixture. The obtained carboxylic acid mixture is thoroughly dried to thereby obtain a beige residue. The beige residue is subjected to an extraction treatment with a dehydrated alkyl acetate by means of a Soxhlet's extractor, to obtain an extract, followed by removal of the alkyl acetate from the obtained extract under reduced pressure, thereby obtaining a colorless or light yellow 1,3,6-hexanetricarboxylic acid. Also, in this patent document, as a method other than the above-mentioned method using a Soxhlet's extractor, there is also described the following method for producing a colorless or light yellow 1,3,6-hexanetricarboxylic acid. The above-mentioned carboxylic acid mixture is extracted with tert-butyl methyl ether three times to thereby obtain an extract. Water is removed from the obtained extract by using magnesium sulfate, and the resultant is subjected to distilling off of the extraction solvent to thereby obtain a residue. The obtained residue is introduced into a mixture of acetone and cyclohexane, and the resultant mixture is cooled to thereby deposit crystals, followed by recovery of the crystals by filtration, thereby obtaining a colorless or light yellow 1,3,6-hexanetricarboxylic acid.
Further, in the above-mentioned Unexamined German Patent Application Laid-Open Specification No. 19637428, there is also described the following method for producing a colorless or light yellow 1,3,6-hexanetricarboxylic acid. 1,3,6-Tricyanohexane is mixed with crushed ice and a concentrated sulfuric acid, and the resultant mixture is subjected to hydrolysis at 140° C. to thereby obtain an aqueous mixture. The obtained aqueous mixture is extracted with tert-butyl methyl ether three times to thereby obtain an ether mixture. Water is removed from the obtained ether mixture by using magnesium sulfate, and the resultant is subjected to distilling off of the ether, thereby obtaining a colorless or light yellow 1,3,6-hexanetricarboxylic acid.
However, a 1,3,6-hexanetricarboxylic acid obtained by any of the above-mentioned methods described in Unexamined German Patent Application Laid-Open Specification No. 19637428 is disadvantageous in that it has a psychometric lightness L-value of less than 98 or a psychometric b-value of 3 or more and has poor heat stability such that the color difference (ΔE) as between before and after the 1,3,6-hexanetricarboxylic acid is allowed to stand for 18 hours at 80° C. is more than 2. (With respect to the above-mentioned color difference, explanations are given below.) Further, in any of the above-mentioned methods described in Unexamined German Patent Application Laid-Open Specification No. 19637428, it is necessary to use a large amount of an extraction solvent and, therefore, these methods are commercially disadvantageous.
Further, Agric. Biol. Chem., 45 (1) 57-62, 1981 discloses the following method for producing a colorless crystal of 1,3,6-hexanetricarboxylic acid. 1,3,6-Tricyanohexane is hydrolyzed with hydrochloric acid, and the resultant hydrolysis reaction mixture is allowed to stand at room temperature to thereby precipitate an ammonium salt (ammonium chloride), followed by filtration of the resultant to remove the ammonium salt and obtain a filtrate. The obtained filtrate is dried to obtain a crystal of 1,3,6-hexanetricarboxylic acid having a low purity. The obtained low purity crystal is dissolved in hot water, and the resultant solution is treated with activated carbon, followed by recrystallization, thereby obtaining a colorless crystal of 1,3,6-hexanetricarboxylic acid. The obtained 1,3,6-hexanetricarboxylic acid has a psychometric lightness L-value of 98 or more, a psychometric chroma a-value of 0.8 and a psychometric chroma b-value of 1.1, and is colorless. However, 1,3,6-hexanetricarboxylic acid produced by this method exhibits poor heat stability such that, when the 1,3,6-hexanetricarboxylic acid is heated, for example, at 160° C. for one hour or more, it is likely to suffer a marked discoloration. Further, the 1,3,6-hexanetricarboxylic acid produced by this method tends to disadvantageously contain a chlorine ion.


An ultrasonic transducer acquires a series of ultrasound tomograms as it continuously rotates through a range of angles. When positioned in a left ventricular long axis view, serial sectional slices are acquired within 6 seconds from which a 3D image is reconstructed. The boundary of the left ventricle is identified in this 3D image using a reference database produced by a learning process that captures expert knowledge of left ventricle cavity shapes.

The field of the invention is echocardiography and particularly, the measurement of left ventricular volume using 3D ultrasound data.
Assessment of left ventricular ("LV") function is clinically important. Diastolic and systolic volumes and derived parameters, such as ejection fraction, are generally accepted indicators of LV function. Echocardiography is a widely available clinical method which allows measurement of these parameters. Precision and accuracy of echocardiographic measurements is typically compromised by user's subjectivity, limited windows of access for obtaining echocardiographic scans, and ultrasound signal attenuation and scattering resulting in image artifacts.
In the past decade, compared to single or biplane tomographic techniques that require geometrical assumptions about LV shape, three-dimensional (3D) echocardiography has been shown to provide more precise and accurate evaluation of cardiac volumes. This is particularly relevant in patients with irregular LV geometry, detected during an initial echocardiographic study through multiple tomographic projections. So far, however, the 3D technique has been limited to experimental use due to cumbersome image acquisition (i.e. restricted access windows, long acquisition times, custom probes and special probe holders), time consuming and subjective data processing (i.e. digitization from video tapes and manual delineation of boundaries in numerous serial tomograms), the use of special projections (i.e. parallel or rotational scans with specific incremental steps), and mapping of endo- and epicardium to multiparameter (i.e. computationally intense and subjective for required adjustment of multiple features) models and allowed only limited objective utilization of a priori knowledge about LV geometry.
The concept of 3D ultrasound data acquisition was first described by Baum and Greenwood in 1961, (G. Baum and J. Greenwood, "Orbital Lesion Location by Three-Dimensional Ultrasonography", N.Y. State J Med, 61:4149,4157, 1961). They obtained serial parallel ultrasound images of the human orbit and created a 3D display by stacking together sequential photographic plates bearing the ultrasound images.
Using a transthoracic echocardiographic (TTE) approach, Dekker et al., (D. L. Dekker, R. L. Piziali and D. Dong Jr., "A System For Ultrasonically Imaging The Human Heart In Three Dimensions", Comput. Biomed. Res., 7:544-553, 1974), were among the first to obtain a 3D computer matrix of ECG and respiratory gated image data with a probe attached to a mechanical arm which tracked its spatial motion. Images were subsequently displayed as selected 2D sections. Geiser et al., (E. A. Geiser, L. G. Christie, Jr., D. A. Conetta, C. R. Conit and G. S. Gossman, "A Mechanical Arm For Spatial Registration Of Two-Dimensional Echocardiographic Sections", Cathet. Cardiovasc. Diagn., 8:89-101, 1982), and other investigators have also employed mechanical location systems because of their relative simplicity and low cost.
Ghosh et al., (A. Ghosh, N. C. Nanda and G. Maurer, "Three-Dimensional Reconstruction Of Echocardiographic Images Using The Rotation Method", Ultrasound Med. Biol., 8:655-661, 1982), used a mechanical arm which permits rotation of the transducer only about its imaging axis. Rotation was registered by a precision potentiometer. Although still relying on mechanical parts, this approach introduced a fixed polar coordinate system resulting in a proportionally sampled LV contour in 30.degree. angular increments. Several other investigators have pivoted or rotated the transthoracic transducer at a single location in an effort to obtain tomograms for 3D reconstruction of the LV from a single acceptable acoustic window. The quality of these reconstructions was often limited by the available window and variations in contact of the transducer face with the skin surface during the lengthy acquisition.
Mortiz et al., (W. E. Moritz, and P. L. Shreve, "A Microprocessor-Based Spatial-Locating System For Use With Diagnostic Ultrasound", Pro. IEEE, 64:966-974, 1976), introduced an acoustic position location system ("spark gap"). They employed this device to obtain an arbitrary series of sector scans through the heart which were used to create a computer 3D wire frame model of the LV and calculate its volume (W. E. Moritz, A. S. Pearlman, D. H. McCabe, D. K. Medema, M. E. Ainsworth and M. S. Boles, "An Ultrasonic Technique For Imaging The ventricle In Three-Dimensions And Calculating Its Volume", IEEE Trans. Biomed. Eng., 30:482-492, 1983). King and his coworkers applied this system to guided image acquisition for clinical quantitative evaluation of the LV (D. L. King, M. R. Harrison, D. L. King Jr., A. S. Gopal, R. P. Martin and A. N. DeMaria, "Improved Reproducibility Of Left Arterial And Left Ventricular Measurement By Guided Three-Dimensional Echocardiography", J. Am. Coll. Cardiol., 20:1238-1245, 1992; P. M. Sapin, K. D. Schroder, A. S. Gopal, M. D. Smith, A. N. DeMaria and D. L. King, "Comparison Of Two- And Three-Dimensional Echocardiography With Cineventriculography For Measurement Of Left Ventricular Volume In Patients", J. Am. Coll. Cardiol., 24:1054-1063, 1994; A. S. Gopal, M. J. Schnellbaecher, Z. Shen, O. O. Akinboboye, P. M. Sapin and L. D. King, "Freehand Three-Dimensional Echocardiography For Measurement of Left Ventricular Mass: In Vivo Anatomic Validation Using Explanted Human Hearts", J. Am. Coll. Cardiol., 30:802-810, 1997). Other investigators have also used the spark gap system for calculation of left ventricular volume, mass and for determination of the mitral valve shape. This transducer location technique eliminated the physical connection between the transducer and the reference system thus overcoming some of the restrictions imposed by mechanical transducer location systems. The technique, however, requires a clear line of sight between the transmitting and receiving elements which may not always be feasible. Another disadvantage is that taking tomograms at arbitrary angles may cause unnecessary over-sampling of certain regions and under-sampling elsewhere.
Maehle and coworkers (J. Maehle, K. Bjoernstad, S. Aakhus, H. G. Torp and B. A. J. Angelsen, "Three-Dimensional Echocardiography For Quantitative Left Ventricular Wall Motion Analysis: A Method For Reconstruction Of Endocardial Surface And Evaluation Of Regional Dysfunction", Echocardiography, 11:397-408, 1994), evaluated rotational acquisition system using only 3 or 4 tomograms acquired in polar coordinate. The rest of the LV contour was restored using spline interpolation. This "triplane" or "quadruplane" approach has expectably proven to be superior over single- or biplane methods. The limited number of views makes this method sensitive to foreshortening of the LV apex and may not be sufficient for reproduction of LVs with complicated shape. This work, however, highlighted the fact that a limited number of tomograms greatly reduces an elaborate outlining of an LV contour while still providing valuable information about its function.
The transesophageal echocardiographic (TEE) technique provided a new window to the heart after its clinical introduction in the 1980's (J. B. Seward, B. K. Khandheria, J. K. Oh, M. D. Abel, B. W. Hughes, W. D. Edwards, B. A. Nichols, W. K. Freeman and A. J. Tajik, "Transesophageal Echocardiography: Technique, Anatomic Correlation, Implementation And Clinical Applications", Mayo Clin. Proc., 63:649-680, 1988). Close proximity of the transducer to the heart allowed uniformly higher quality images than those provided by transthoracic echocardiography. Kuroda, Greenleaf, et al. (T. Kuroda, T. M. Kinter, J. B. Seward, H. Yanagi and J. F. Greenleaf, "Accuracy Of Three-Dimensional Volume Measurement Using Biplane Transesophageal Echocardiographic Probe: In vitro Experiment", J. Am. Echo., 4:475-484, 1991) describe 3D LV reconstruction for morphology and volume assessment using a set of sequential 2D tomographic longitudinal images acquired by rotation of the shaft of a transesophageal probe. Martin et al. (R. W. Martin and G. Bashein, "Measurement Of Stroke Volume With Three-Dimensional Transesophageal Ultrasonic Scanning: Comparison With Thermodilution Measurement", Anesthesiology, 70:470-476, 1989; R. W. Martin, G. Bashein M. L. Nessly and F. H. Sheehan, "Methodology For Three-Dimensional Reconstruction Of The Left Ventricle From Transesophageal Echocardiography", Ultrasound Med. Biol., 19:27-38, 1993) have devised an endoscopic micromanipulator for multiplanar transesophageal echocardiographic (TEE) imaging. This system requires a modified transesophageal probe which allows controlled "fan" sweeping with the transducer, thus collecting a pyramidal volume of images. This system capitalizes on an unlimited ultrasound window through the transesophageal access.
Pandian et al. (N. G. Pandian, N. C. Nanda, S. L.
Schwartz, P. Fan, Q. Cao, R. Sanyal, T. Hsu, b. Mumm, H.
Wollschlager, A. Weintraub, "Three-Dimensional And Four-Dimensional Transesophageal Echocardiographic Imaging Of The Heart And Aorta In Humans Using A Computed Tomographic Imaging Probe", Echocardiography 9:677-687, 1992) have evaluated the first commercially available Echo-CT system (Tomtec Imaging Systems, Inc.) for LV function assessment. This PC-based system processes the video signal from an ultrasound scanner and features a model for ECG and respiratory gating. It uses movable holders for TTE probes and a dedicated TEE probe which is made straight and stiff after insertion for an incremental parallel scanning. This system provides dynamic 3D images and can be accommodated to virtually any acquisition geometry and imaging system (N. C. Nanda, R. Sanyal, S. Rosenthal and J. K. Kirklin, "Multiplane Transesophageal Echocardiographic Imaging And Three-Dimensional Reconstruction", Echocardiography, 9:667-676, 1992). However, complicated articulation of the TEE probe and rather bulky mechanical adapters for TTE probes make a routine use of this system difficult.
Variable plane (multiplane) transducers have recently been introduced by all major ultrasonic transducer manufacturers (Hewlett Packard, Acuson, Aloca, Toshiba, etc.). A miniature transducer array is mechanically rotated inside the probe tip to acquire successive tomographic views, which combined form a 3D image data set. Typically, both ECG and respiratory gating are used so that each incremental view is acquired during the same phase of the cardiac and respiratory cycles. This requires several minutes to collect a complete 3D data set and it is difficult to keep the patient motionless and the transducer in proper position.
Another factor contributing to extended scan time is the fact that ultrasound cardiac images are prone to noise, signal dropout, and other artifacts. This and an intrinsic variability of biological shapes make it very difficult to identify heart cavity boundaries without an extensive 3D data set which requires a long time to acquire.
A single application of noise removal and edge detection operators, such as those described by Pitas and Venetsanopoulos (I. Pitas and A. N. Venetsanopoulos, "Order Statistics In digital Image Processing", Proceedings of IEEE 80:1892-1921, 1992) results in sparse information about cardiac boundaries. Additional a priori knowledge about LV shape consuming manual delineation.
Coppini et al. (G. Coppini, R. Poli and G. Valli, "Recovery Of The 3-D Shape of The Left Ventricle From Echocardiographic Images", IEEE Transactions On Medical Imaging 14:301-317, 1995) combine conventional edge detection methods and edge grouping through a curvature analysis with a conventional, two-layer neural network, trained on edge position, direction length, angle, and other local parameters to determine which edge was associated with the LV boundary. Subsequently, an elastic, closed surface ellipsoidal model is used to form the endocardial surface by fitting into the recognized edges. Parametrization of the model represents a significant computer load and requires user-guided adjustment of values controlling flexibility and expansion of the model.
Manhaeghe et al. (C. Manhaeghe, I. Lemahieu, D. Vogelaers and F. Colardyn, "Automatic Initial Estimation Of The Left Ventricular Myocardial Midwall In Emission tomograms Using Kohonen Maps", IEEE Transactions on Pattern Analysis and Machine Intelligence 16:259-266, 1994) use self-organizing maps (SOM) to delineate myocardial midwall in emission tomograms. The SOM is an unsupervised neural network technique, introduced by T. Kohonen (T. Kohonen, "Self-Organizing Maps", Springer-Verlag, N.Y., 1995). The SOM consists of nodes that distribute themselves according to intensities in the emission images. Connection of neighboring nodes results in a closed outline of the myocardial midwall.

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