A method of forming a doped silicon film on a substrate. According to the present invention, a substrate is placed in a reaction chamber and heated. Next, a silicon containing gas is fed into the reaction chamber to produce a silicon containing gas partial pressure of between 4 and 20 torr.

1. Field of the Invention
The present invention relates to the field of semiconductor fabrication, and more particularly, to a method and apparatus for depositing amorphous and polysilicon films with improved step coverage.
2. Discussion of Related Art
Polysilicon crystalline (polysilicon) and amorphous silicon thin films are used throughout the many semiconductor integrated circuit manufacturing processes. These films are used, for example, in the fabrication of gate electrodes, stack or trench capacitors, emitters, contacts, fuses, and antifuses. As device dimensions decrease to below 0.25 microns in order to increase packing density, aspect ratios (aspect ratio=depth/width) of holes, vias, and trenches in the integrated circuit are also increasing. In order to fill high aspect ratio openings (aspect ratios.gtoreq.to 2.5), deposition processes which are capable of good step coverage (step coverage %=film thickness on a step surface/film thickness on a flat surface.times.100%) are required to ensure complete hole filling without the creation of voids.
One current method which can provide adequate step coverage is low pressure chemical vapor deposition (LPCVD). In LPCVD processes, reaction vessels are evacuated to relatively low pressures of between 100-1000 mtorr. The low pressures associated with LPCVD processes cause silicon films to be deposited at low rates (about 100 angstroms (.ANG.)/minute for undoped films and about 20 .ANG./minute for doped films). The low deposition rates enable the films to be deposited with good step coverage. When n-type dopants are introduced in a LPCVD batch system to produce an insitu doped film, poor step coverage results. Further reducing the deposition rate is necessary to get good step coverage. Although LPCVD processes can form high quality films, their low deposition rates necessitate the processing of multiple wafers (i.e. up to 100) at one time in a batch type reaction vessel. A problem with processing a plurality of wafers in a single machine at a single time is that it is difficult to obtain uniform film thicknesses and dopant compositions from wafer to wafer and from batch to batch. Nonuniformity in film thickness and doping profiles can drastically affect the electrical characteristics of the fabricated film and therefore, the performance and reliability of the fabricated device. Controlling film thickness and sheet resistance uniformity will be an even greater challenge for LPCVD batch systems when wafer size is increased to 300 mm and above.
To fabricate polysilicon and amorphous silicon films with precise thickness and doping uniformity across a wafer and from wafer to wafer, single wafer CVD processes are used. A single wafer CVD process for producing a silicon layer on a silicon wafer is described in U.S. Ser. No. 07/742,954, filed Aug. 9, 1991, entitled Low Temperature High Pressure Silicon Deposition Method and is assigned to the present assignee. In such a process, a pressure between 10-350 torr is achieved and maintained in a reaction chamber. Hydrogen gas at about 10 liters/minutes is fed into the chamber along with less than 525 sccm of silane (SiH.sub.4) (silane partial pressure is less than 4 torr) while the substrate is heated to a temperature of between 600.degree.-750.degree. C. An undoped polysilicon film is deposited under these conditions at a rate of up to about 2000 .ANG./minute. The higher pressure used in the single wafer method increases deposition rate of the polysilicon film. A phosphorous insitu doped polysilicon film can be deposited by including 300 sccm of 1% phosphine (PH.sub.3) in hydrogen (PH.sub.3 partial pressure of about 0.023 torr) into the gas mix and by heating the substrate to a temperature of about 650.degree. C. With such a process, a polycrystalline silicon film containing about 1.5.times.10.sup.21 /cm.sup.3 of phosphorous can be deposited at a rate of up to about 1500 .ANG./minute.
A problem with the above referenced single wafer CVD processes is that step coverage is poor and so cannot be used to fill high aspect ratio openings without causing the formation of voids. Voids can cause reliability problems and failures in the fabricated integrated circuits. Additionally, if dopants are included into the gas mix to form a low resistivity insitu doped silicon film, step coverage becomes even worse.
Thus, what is desired is a method for depositing in a single wafer CVD apparatus and insitu doped silicon film at a high deposition rate and with good step coverage so that high aspect ratio openings can be filled void free in a manufacturable amount of time.

Method of forming doped silicon in high aspect ratio openings


The present invention provides for calculating a shift amount as a function of a plurality of numbers. At least one decoder and the at least one adder are coupled in parallel. A shifter is configured to compute a value in a plurality of shift stages, and wherein a bit group of the shift amount is employable to affect at least one of the plurality of shift stages, thereby decreasing processing time.

In data processing, there are various devices employed for the manipulation of numbers and data. One of these devices is a "floating point unit" (FPU), which is typically used to add and multiply floating point numbers to one another. There are complexities, however, to designing and operating an FPU. One such problem concerns the alignment of numbers. For numbers to be added, they should be expressed in a form that is easy to add to one another, with additional exponent information. For instance, if the number 11100011 with exponent value 3 were to be added to 11000111 with an exponent value of −2, the two numbers would be added as follows. The first number used is extended on the least significant digit by 5 zeroes before it can be added to the second number.
In FPUs, featuring a fused-multiply-add instruction, three floating point operands A, B and C are combined to one result, "R" by R=A*B+C. Other, operations, such as multiplication or addition, are obtained by forcing C=0 or A=1, respectively. The floating point operands are given in IEEE format. In this format, every number has a sign bit, an exponent and a fraction, which shall be designated sa, ea, fa, for operand A, respectively. Sb, eb, bf, sc, ec and fc for operands for B and C, respectively. The value of A is given by ((−1)sa*2ea*fa), for example. The product of A and B is denoted P, which consists of sp, ep, and fp.
One of the central components of such FPU designs is the alignment shifter, which aligns the fraction of operand "c" to the fraction of the intermediate product "P" with respect to the exponents of C and P. This alignment shift yields an alignment of the binary points of C and P before these two numbers are added. For this alignment, the fraction fc is shifted. A shift amount "sha" is computed as sha=ea+eb−ec+constant. The constant arises as a matter of system design. If the shift amount is in a given range, the alignment is performed by an actual shifter. If the shift amount is outside of a given range, these other cases are handled as "special" cases, that is, the shift amount (sha) underflow and overflow, respectively.
Generally, in a conventional multiply-add FPU, there are three exponent numbers that are added. These three numbers generate in turn, two numbers, which are in turn added by a 2:1 adder, thereby producing a shift amount. In conventional technology, the shift amount ("sha") is sent to decoders, such as a 1b decoder, a 2b decoder, and a 3b decoder. These decoders then determine the number of bits by which the fractional part of the addend, the fraction fc, is to be shifted. Typically, the shift is broken up into several shift stages.
However, there are problems associated with this technology. Specifically, the shift amount adders and decoders are both on the timing-critical path of the aligner.
Therefore, there is a need for an aligner that addresses at least some of the issues associated with conventional aligners.

Apparatus and method for reducing the latency of sum-addressed shifters

International Business Machines Corporation


Disclosed is a process for the preparation of a compound of Formula IV having the structure: ##STR1## wherein R.sub.6 is N(R.sub.6a)(R.sub.6b);. R.sub.3 represents a C.sub.2-8, alkyl which is unbranched or branched and unsubstituted or substituted; C.sub.3-8 cycloalkyl which is unsubstituted or substituted; C.sub.4-8 cycloalkylalkyl wherein the cycloalkyl portion is unsubstituted or substituted; aryl or benzyl which is optionally unsubstituted or substituted; ar(C.sub.1-4)alkyl; a heterocyclyl group, ring optionally substituted; heterocyclyl (C.sub.1 -C.sub.4) alkyl ring optionally substituted; PA1 (a) treating a compound of Formula I: ##STR2## with an effective amount of a dethionating agent to produce a compound of Formula II: ##STR3## (b) treating a compound of Formula II with an effective halogenating agent under conditions effective to produce a compound of Formula III: ##STR4## and (c) treating a compound of Formula III with an effective aminating agent under conditions effective to produce a compound of Formula IV.. which comprises:

The present invention relates to novel and improved methods for preparing adenine and purine derivatives and in particular the present invention relates to improved methods for preparing 3-substituted adenines and 3,8-di-substituted 6-aminopurine derivatives for use as phosphodiesterase inhibitors. The methods according to the invention provide a surprising and unexpectedly improved process that eliminates the need for thionation steps, and further helps avoid reactions under pressure with volatile aminating reagents in the preparation of cyclic nucleotide phosphodiesterase inhibitors.
Cyclic nucleotide phosphodiesterases (PDE's) have received considerable attention as molecular targets for anti-asthmatic agents. Cyclic 3',5'-adenosine monophosphate (cAMP) and cyclic 3',5'-guanosine monophosphate (cGMP) are known second messengers that mediate the functional responses of cells to a multitude of hormones, neurotransmitters and autocoids. At least two therapeutically important effects could result from phosphodiesterase inhibition, and the consequent rise in intracellular adenosine 3',5'-cyclic monophosphate (cAMP) or guanosine 3',5'-cyclic monophosphate (cGMP) in key cells in the pathophysiology of asthma. These are smooth muscle relaxation (resulting in bronchodilation) and anti-inflammatory activity.
It has become known that there are multiple, distinct PDE isoenzymes which differ in their cellular distribution. A variety of inhibitors possessing a marked degree of selectivity for one isoenzyme or the other have been synthesized.
The structure-activity relationships (SAR) of isozyme-selective inhibitors has been discussed in detail, e.g., in the article by Theodore J. Torphy, et al., "Novel Phosphodiesterases Inhibitors For The Therapy Of Asthma", Drug News & Prospectives, 6(4) May 1993, pages 203-214. The PDE enzymes can be grouped into five or more families according to their specificity toward hydrolysis of cAMP or cGMP, their sensitivity to regulation by calcium, calmodulin or cGMP, and their selective inhibition by various compounds. PDE I is stimulated by Ca.sup.2+ /calmodulin. PDE II is cGMP-stimulated, and is found in the heart and adrenals. PDE III is cGMP-inhibited, and possesses positive inotropic activity. PDE IV is cAMP specific, and possesses airway relaxation, antiinflammatory and antidepressant activity. PDE V appears to be important in regulating cGMP content in vascular smooth muscle, and therefore PDE V inhibitors may have cardiovascular activity.
While there are compounds derived from numerous structure activity relationship studies which provide PDE III inhibition, the number of structural classes of PDE IV inhibitors is relatively limited.
It has previously been shown that the 3,8-di-substituted 6-thioxanthine derivatives as described in EP-A-0256692 exhibit enhanced bronchodilator and anti-inflammatory activity compared to the corresponding xanthine derivatives. Transformation of these 6-thioxanthine derivatives to the corresponding isoguanines substantially reduces the bronchodilator and anti-inflammatory activity in certain tests.
A different preparation of 3-methyl-6-dimethyl amino-3H-purine, 3-benzyl-6-methyl amino-3H-purine and 3-benzyl-6-isopropyl amino-3H-purine was reported in J. Org. Chem., 55, 5761-5766 (1990). No biological activity was disclosed for these compounds.
PDE IV (and possibly PDE V) is present in all the major inflammatory cells in asthma including eosinophils, neutrophils, T-lymphocytes, macrophages and endothelial cells. Its inhibition causes down regulation of cellular activation and relaxes smooth muscle cells in the trachea and bronchus. On the other hand, inhibition of PDE III, which is present in myocardium, causes an increase in both the force and rate of cardiac contractility. These are undesirable side effects for an anti-inflammatory agent. Theophylline, a non-selective PDE inhibitor, inhibits both PDE III and PDE IV, resulting in both desirable anti-asthmatic effects and undesirable cardiovascular stimulation. With this well-known distinction between PDE isozymes, the opportunity for concomitant anti-inflammation and bronchodilation without many of the side effects associated with theophylline therapy is apparent. The increased incidence of morbidity and mortality due to asthma in many Western countries over the last decade has focused the clinical emphasis on the inflammatory nature of this disease and the benefit of inhaled steroids. Development of an agent that possesses both bronchodilatory and antiinflammatory properties would be most advantageous. It appears that selective PDE IV inhibitors should be more effective with fewer side effects than theophylline. Clinical support has been shown for this hypothesis. Attempts have therefore been made to find new compounds having more selective and improved PDE IV inhibition.
It has been shown in published international patent application WO 95/00516 (assigned to Euro-Celtique, S. A. and incorporated by reference in its entirety herein) that the analogous transformation of 3 and 3,8-di-substituted thiohypoxanthines into the corresponding purine derivatives gives compounds having PDE IV inhibitory activity comparable to or in some cases greater than 6-thioxanthine derivatives of EP-A-0256692.
WO 95/00516 discloses that 3- and 3,8-substituted 6-aminopurine derivatives possess potent PDE IV inhibitory and related antiinflammatory activity. However, the synthetic methods reported in that publication for the preparation of the 3- and 3,8-substituted 6-aminopurine derivatives of interest require a thionation step and require that the reaction be conducted under pressure in order to contain the necessary low boiling amines, both of which requirements create economic and processing inefficiencies during synthesis of these desirable compounds on a larger scale.

Methods for the synthesis of chemical compounds having PDE-IV inhibitory activity


An amniotic membrane perforator comprising an elongated shaft portion having an arcuate bend at the proximal end of the shaft and a hook at the distal end of the shaft. A flag portion extends perpendicularly to the shaft substantially adjacent the distal end of the shaft, opposite the hook. The cross-section of an extended length of the shaft inward the distal end is substanially oval. During use, the physician's index finger is placed along the flat portion, and the thumb and second finger adjacent the oval cross-section portion.

During the labor stage of childbirth, it is sometimes necessary to enhance or accelerate the birthing process. Rupturing the amniotic sac or "bag of water" to allow the amniotic fluid to escape from the sac typically enhances uterine contractions. In rupturing the sac, hook type instruments are generally used by the physician to hook and pierce a part of the amniotic sac.
Amniotic hook instruments are typically flat, elongated stick-like structures having a sharp hook at the distal end thereof. These instruments can be cumbersome and difficult to maintain in a stable position and maneuver within the birth canal and womb.
An alternate amniotic membrane perforator design is disclosed in U.S. Pat. No. 5,087,262 to Sheahon. The '262 patent discloses a similarly structured, flat, stick-like device with a sharp prong extending axially from the distal end of the stick. As with most hook-type instruments, the device disclosed in the '262 patent is likewise difficult to maintain in a stable position and maneuver.


An evaporated fuel adsorbing apparatus includes a surge tank provided in an intake system for an internal combustion engine; a resonator connected with only the surge tank; and a fuel adsorbing member that adsorbs evaporated fuel. The fuel adsorbing member is provided in the resonator.

1. Field of the Invention
The invention relates to an evaporated fuel adsorbing apparatus for an internal combustion engine.
2. Description of the Related Art
In an internal combustion engine, fuel in cylinders may be evaporated and diffused in an intake passage after the engine stops. Thus, for example, Japanese Patent Application Publication No. 2002-39025 (JP-A-2002-39025) describes a technology in which a concave portion is formed in the inner wall of a surge tank that constitutes the intake passage of an internal combustion engine, and a fuel adsorbing member that adsorbs fuel is provided in the concave portion. With this configuration, the fuel adsorbing member adsorbs the evaporated fuel that remains in the intake passage. Therefore, it is possible to reduce the concentration of fuel in the intake passage.
In some internal combustion engines, a blow-by passage may be connected to the portion of the intake passage upstream of a throttle valve. Blow-by gas in a crankcase is introduced into the intake passage through the blow-by passage. Because the blow-by gas contains evaporated fuel and oil mist, the oil mist flows into the intake passage through the blow-by passage. Thus, in the technology described in Japanese Patent Application Publication No. 2002-39025, the fuel adsorbing member may adsorb the oil mist, and accordingly, the fuel adsorbing member may deteriorate,
Japanese Patent Application Publication No. 2003-214263 (JP-A-2003-214263) describes a technology in which a fuel adsorbing member is provided in a resonator that is provided upstream of a throttle valve in an intake passage. With this configuration, because the fuel adsorbing member is provided in the resonator, the fuel adsorbing member is unlikely to contact the oil mist in the intake passage. However, with this configuration, because the fuel adsorbing member is provided upstream of the throttle valve in the intake passage, that is, the fuel adsorbing member is provided at a position far from the cylinders, it is not possible to suppress an increase in the concentration of fuel in the intake passage at a position near the cylinders, i.e., an increase in the concentration of fuel in an intake manifold or a surge tank. Therefore, when flame is generated during a combustion stroke, and the flame is not extinguished and remains until a next intake stroke, for example, at the time of cold start, it is not possible to sufficiently suppress the phenomenon that the flame in the cylinder flows back to the intake passage through an intake port, i.e., so-called back fire. This back fire may decrease the durability of an intake pipe.


A currency identification system comprising at least two laterally displaced scanheads, one or more laterally moveable scanheads, or at least two laterally displaced sensors of a linear scanhead. The scanheads or sensors are positioned so as to permit scanning along at least two segments on a first side of a bill. The scanheads or sensors are capable of detecting characteristic information from the bill along the segments and generating corresponding output signals representing variations in the detected characteristic information from which scanned patterns of characteristic information may be generated. The system also comprises a pattern generator for generating at least one scanned pattern from the output signals, the scanned pattern representing analog variations in the characteristic information along a segment of the bill. The system also comprises a memory for storing at least one master pattern associated with each genuine bill which the system is capable of identifying, the master pattern representing analog variations in characteristic information along a segment of an associated genuine bill. The system further comprises a signal processor for performing a pattern comparison wherein at least one of the scanned patterns or portions thereof is compared with at least one of the master patterns or portions thereof. The signal processor generates an indication of the identity of the bill based on the pattern comparison when the bill is one that the system is capable of identifying.

1. Field of the Invention
The present invention relates, in general, to document identification. More specifically, the present invention relates to an apparatus and method for discriminating among a plurality of document types such as currency bills of different denominations and/or from different countries.
2. Background
A variety of techniques and apparatus have been used to satisfy the requirements of automated currency handling systems. At the lower end of sophistication in this area of technology are systems capable of handling only a specific type of currency, such as a specific dollar denomination, while rejecting all other currency types. At the upper end are complex systems which are capable of identifying and discriminating among and automatically counting multiple currency denominations.
Currency discrimination systems typically employ either magnetic sensing or optical sensing for discriminating among different currency denominations. Magnetic sensing is based on detecting the presence or absence of magnetic ink in portions of the printed indicia on the currency by using magnetic sensors, usually ferrite core-based sensors, and using the detected magnetic signals, after undergoing analog or digital processing, as the basis for currency discrimination. A variety of currency characteristics can be measured using magnetic sensing. These include detection of patterns of changes in magnetic flux, patterns of vertical grid lines in the portrait area of bills, the presence of a security thread, total amount of magnetizable material of a bill, patterns from sensing the strength of magnetic fields along a bill, and other patterns and counts from scanning different portions of the bill such as the area in which the denomination is written out.
The more commonly used optical sensing techniques, on the other hand, are based on detecting and analyzing variations in light reflectance or transmissivity characteristics occurring when a currency bill is illuminated and scanned by a strip of focused light. The subsequent currency discrimination is based on the comparison of sensed optical characteristics with prestored parameters for different currency denominations, while accounting for adequate tolerances reflecting differences among individual bills of a given denomination. A variety of currency characteristics can be measured using optical sensing. These include detection of a bill's density, color, length and thickness, the presence of a security thread and holes, and other patterns of reflectance and transmission. Color detection techniques may employ color filters, colored lamps, and/or dichroic beamsplitters.
In addition to magnetic and optical sensing, other techniques of detecting characteristic information of currency include electrical conductivity sensing, capacitive sensing (such as for watermarks, security threads, thickness, and various dielectric properties) and mechanical sensing (such as for size, limpness, and thickness).
A major obstacle in implementing automated currency discrimination systems is obtaining an optimum compromise between the criteria used to adequately define the characteristic pattern for a particular currency denomination, the time required to analyze test data and compare it to predefined parameters in order to identify the currency bill under scrutiny, and the rate at which successive currency bills may be mechanically fed through and scanned. Even with the use of microprocessors for processing the test data resulting from the scanning of a bill, a finite amount of time is required for acquiring samples and for the process of comparing the test data to stored parameters to identify the denomination of the bill.
Recent currency discriminating systems rely on comparisons between a scanned pattern obtained from a subject bill and sets of stored master patterns for the various denominations among which the system is designed to discriminate. For example, it has been found that scanning U.S. bills of different denominations along a central portion thereof provides scanning patterns sufficiently divergent to enable accurate discrimination between different denominations. Such a discrimination device is disclosed in U.S. Pat. No. 5,295,196. However, currencies of other countries can differ from U.S. currency and from each other in a number of ways. For example, while all denominations of U.S. currencies are the same size, in many other countries currencies vary in size by denomination. Furthermore, there is a wide variety of bill sizes among different countries. In addition to size, the color of currency can vary by country and by denomination. Likewise, many other characteristics may vary between bills from different countries and of different denominations.
As a result of the wide variety of currencies used throughout the world, a discrimination system designed to handle bills of one country generally can not handle bills from another country. Likewise, the method of discriminating bills of different denominations of one country may not be appropriate for use in discriminating bills of different denominations of another country. For example, scanning for a given characteristic pattern along a certain portion of bills of one country, such as optical reflectance about the central portion of U.S. bills, may not provide optimal discrimination properties for bills of another country, such as German marks.
Furthermore, there is a distinct need for an identification system which is capable of accepting bills of a number of currency systems, that is, a system capable of accepting a number of bill-types. For example, a bank in Europe may need to process on a regular basis French, British, German, Dutch, etc. currency, each having a number of different denomination values.

Method and apparatus for document identification


A videoendoscopic system (1) including an endoscope optical system (2) and a camera portion (3), the endoscope optical system (2) having an elongated shaft (4) through which an optical image guide (5) and a fiber light guide (6) pass, and an end housing (7), which is proximally connected to the shaft (4) and has an image exit window (10) and a light entry window (8) with radiation directions that are parallel to one another and to the axis of the shaft (4). The camera portion (3) includes a camera housing (15), from which an image signal cable (24) and a light guide cable (20) pass out, and an image entry window (18) and a light exit window (19), which are arranged with parallel radiation directions at a distance from the windows (8, 10) in the end housing (7) and the end housing (7). The camera housing (15) is constructed with a rotationally fixedly lockable coupling device (7, 16, 25, 26, 19) for coupling the windows (8, 19; 10, 18) to one another in a centering manner. The the coupling device has a cylinder (7) on one of the housings and a matching bore (16) on the other housing (15). The windows (8, 10; 19, 18) are arranged in the end wall (11) of the cylinder (7) and the base wall (17) of the bore (16).

1. Field of the Invention
The invention relates to a videoendoscopic system.
2. Description of Related Art
Such systems are disclosed in US 5,682,199 and US 6,494,826 B1. These prior systems both consist of an endoscope optical system and a camera housing which may be connected by means of a coupling, whereby both the image is coupled in one direction and the light is coupled in the other direction through the coupling point with appropriate windows. This manner of construction provides a series of advantages.
Of disadvantage with the known devices is the construction of the coupling with two parallel cylinders, which are arranged next to one another and fit into corresponding parallel bores in the opposing housing. The result of this is a complex housing structure with correspondingly large manufacturing costs and difficulties in handling.


A sensor apparatus and a method of manufacturing the same are disclosed. The sensor apparatus includes: a sensor chip; a housing receiving the sensor chip; an electric conductive member connected with a terminal of the sensor chip; and a molded member covering a covered portion including a connection portion where the terminal and the electric conductive member are connected. The sensor chip is bonded to a bonding member of the housing via an adhesive member. A surface of the housing, a surface of the adhesive member, and a front surface of the sensor chip are in the same plane at a boundary part of the covered portion.

1. Field of the Invention
The present invention relates to a sensor apparatus including an insulating material that covers a terminal for outputting a signal from an exposed sensing member to an external element. The present invention also relate to a method of manufacturing such a sensor apparatus.
2. Description of Related Art
JP-A-2007-33411 corresponding to US Patent Application Publication No. 2007/0022808 proposes a method of manufacturing such a sensor apparatuses that includes an insulating material that covers a terminal for outputting a signal from an exposed sensing member to an external element. According to JP-A-2007-33411, a sensor apparatus is manufactured through: attaching a buffer member made of rubber to a boundary part of a region where a molded member is to cover; deforming the buffering member in closing a mold; and filling a ditch between a sensor chip and a support member to prevent a molding material from leaking toward a sensing member in injection molding.
According to the above method, however, since the buffer member is so tiny, the buffer member and a part to which the buffer member is attached are required to have high dimensional accuracy, and thus, it is difficult to improve a production yield of the sensor apparatus. Further, since the buffer member is required to be attached with high accuracy, it is difficult to improve production efficiency of the sensor apparatus.

Method of manufacturing a sensor apparatus


A computer system having a number of circuits and error detection circuitry for detecting errors in the circuits and providing error signals. Error recovery is provided by detecting an error with checking logic, turning off system clocks and invoking error recovery software, executing recovery software to recover from the error and set an action latch, turning on system clocks, taking hardware recovery action in response to the action latch, resetting the action latch and continue processing. Action latches are used extensively throughout the computer system.

The present invention relates to the field of computers and that operate in accordance with the IBM ESA/390 architecture and particularly to error handling and recovery of computers after an error occurs. Error recovery is important to computer system operation. Error handling in prior art computer systems has followed the process described below:
1. The error is detected by conventional checking logic and an Error History Latch is set. PA1 2. Some small number of clock cycles later, system clocks are turned off and error recovery soft ware is invoked. PA1 3. Recovery software, based on history information provided by the hardware, attempts to recover from the error. PA1 4. If recovery is successful, processing continues. PA1 1. The error is detected by conventional checking logic and an Error History Latch is set. PA1 2. Some small number of clock cycles later, system clocks are turned off and error recovery software is invoked. PA1 1. The error is detected by conventional checking logic. PA1 2. System clocks are turned off and error recovery software is invoked. PA1 3. Recovery software attempts to recover from the error. When a need to invoke a recovery action exists, an appropriate action latch is set. PA1 4. When recovery software completes and system clocks are turned on, the action latch forces the hardware to take recovery action. PA1 a. Interrupts: For certain related interrupts, such as malfunction alert, domain damage, and external damage, the interrupt is generated through the use of an action latch. The action latch is cleared when the appropriate interrupt is taken. PA1 b. Entry: When appropriate, recovery software can force the CPU to enter check stop state when system clocks are turned on. This action latch is reset on entry to check stop state. PA1 c. Timer Facility Recovery: When recovery software detects that a free running timer register (e.g., the Time Of Day clock) is damaged, an action latch can be set that will set the appropriate register's Error bit, effectively marking it as damaged, when clocks resume. PA1 d. Instruction Retry: When appropriate, recovery software can set an action latch that will mark a certain instruction unit pipeline state (e.g., A state) to be damaged. When the algorithm flow in that state completes an instruction retry will be forced.
Historically, error recovery software has been complex and difficult to test and validate. One of the leading causes of this problem has been the need for recovery software to issue multiple system clocks as part of its recovery actions.
The IBM ESA/390 architecture defines a number of timers and system implementations of that architecture may provide additional timers. The operation of such timers including the setting, resetting, stopping and starting becomes complex in large systems that have many different modes of operation and that operate with units of operation designated as UO in TABLE A. The IBM ESA/390 architecture defines a unit of operation that is used to control the instants when an interruption can be examined and serviced. Interruptions can occur at any point in time; however, they are only examined and serviced during the interrupt processing time, designated as IPT in TABLE A, between the end of one unit of operation and the start of the next unit of operation. TABLE A depicts the relationship between units of operation and instruction processing time.
TABLE A ______________________________________ ##STR1## ______________________________________
Most instructions consist of only one unit of operation. However, long and more complex or repetitive instructions such as MOVE LONG, COMPARE LOGICAL LONG, TEST BLOCK and UPDATE TREE consist of many units of operation.
The unit of operation is needed in large computer systems because of the need for having a reasonable response time for interruptions while avoiding complex instruction processing unit. If the interruptions have to be taken at any point in time during the instruction processing time, then the CPU design will be considerably more complex than if the interruptions are only taken at the end of instruction processing time.
ESA/390 architecture computers are controlled in part by a Program Status Word. The Program Status Word includes the instruction address, condition code, and other information used to control instruction sequencing and to determine the state of the computer. The active or controlling Program Status Word is called the current Program Status Word. It governs the program currently being executed.
The CPU has an interruption capability, which permits the CPU to switch rapidly to another program in response to exception conditions and external stimuli. When an interruption occurs, the CPU places the current Program Status Word in an assigned storage location, called the old Program Status Word location, for the particular class of interruption. The CPU fetches a new Program Status Word from a second assigned storage location. This new Program Status Word determines the next program to be executed. When it has finished processing the interruption, the interrupting program may reload the old Program Status Word, making it again the current Program Status Word, so that the interrupted program can continue.
The status of the CPU can be changed by loading a new Program Status Word or part of a Program Status Word. Control is switched during an interruption of the CPU by storing the current Program Status Word, so as to preserve the status of the CPU, and then loading a new Program Status Word.
A new or modified Program Status Word becomes active (that is, the information introduced into the current Program Status Word assumes control over the CPU) when the interruption or the execution of an instruction that changes the Program Status Word is completed.
A storage key is associated with each 4K byte block of storage that is available in the configuration. The storage key has the following format. ##STR2##
The bit positions in the storage key are allocated as follows:
Access Control Bits (ACC):
If a reference is subject to key controlled protection, the four access control bits, bits 0-3, are matched with the four bit access key when information is stored, or when information is fetched from a location that is protected against fetching.
Fetch Protection Bit (F):
If a reference is subject to key controlled protection, the fetched protection bit, bit 4, controls whether key controlled protection applies to fetch type references are monitored and that fetching with any access key is permitted; a one indicates that key controlled protection applied to both fetching and storing. No distinction is made between the fetching of instructions and of operands.
Reference Bit (R):
The reference bit, bit 5 normally is set to one each time a location in the corresponding storage block is referred to either for storing or for fetching of information.
Change bit (C):
The change bit, bit 6, is set to one each time information is stored at a location in the corresponding storage block.
Protection
Protection facilities are provided to protect the contents of main storage from destruction or misuse by programs that contain errors or are unauthorized. Key controlled protection, access list controlled protection, page protection, and low address protection are forms of protection available in ESA/390.
Key Controlled Protection
When key controlled protection applies to a storage access, a store is permitted only when the storage key matches the access key associated with the request for storage access; a fetch is permitted when the keys match or when the fetch protection bit of the storage key is zero.
The keys are said to match when the four access control bits of the storage key are equal to the access key, or when the access key is zero.
Fetch Protection Override Control
Bit 6 of control register 0 is the fetch protection override control. When the bit is one, fetch protection is ignored for locations at effective addresses 0-2047. An effective address is the address which exists before any transformation by dynamic address translation or prefixing. However, fetch protection is not ignored if the effective address is subject to dynamic address translation and the private space control, bit 23, is one in the segment table designation used in the translation.
Fetch protection override has no effect on accesses which are not subject to key controlled protected.
Access List Controlled Protection
In the access register mode, bit 6 of the access list entry, the fetch only bit, controls which types of operand references are permitted to the address space specified by the access list entry. When the entry is used in the access register translation part of a reference and bit 6 is zero, both fetch type and store type references are permitted, and an attempt to store causes a protection exception to be recognized and the execution of the instruction to be suppressed.
Page Protection
The page protection facility controls access to virtual storage by using the page protection bit in each page table entry. It provides protection against improper storing.
One of the instructions that is able to modify part of a Program Status Word is the Set Program Status Word Key From Address instruction. The ESA/390 architecture requires the Set Program Status Word Key From Address instruction to load the architecturally defined Program Status Word "access key" from four bits extracted from the effective address of the Set Program Status Word Key From Address instruction. The access key is used to limit the access of future instructions to certain storage areas to aid in providing protection and privacy of information.
One well known computer operating with the IBM ESA/390 architecture is the Amdahl 5995-A computer. In that computer, the instruction unit, I-Unit, pipeline is a six stage pipeline consisting of stages D, A, T, B, X, and W that process instructions.
One of the functions of the D stage is to collate the necessary information to reference storage in the A, T, and B stages. This D stage function includes generation of the effective address and selection of the access key to be used by the reference. The A, T, and B stages fetch operands/data using the current valid key that is defined by the architecture, Program Status Word KEY.sub.A.
One of the Functions of the W stage is to write results of operations to architecturally defined registers or storage. The W stage in the pipeline comes after the fetch operands/data stages (A, T, and B) and the arithmetic functions stage X. The access key used is the key, Program Status Word KEY.sub.A, from the architecturally defined Program Status Word register. After the access key in the Program Status Word has been updated in the W stage, the new key, Program Status Word KEY.sub.N, is available for future operations/instructions and the new key becomes the architecturally defined key, Program Status Word KEY.sub.A. The ESA/390 architecture requires that the new key be effective starting from the instruction immediately following the Set Program Status Word Key From Address instruction. The new Program Status Word key can be used in a subsequent D segment while being updated in the W segment.
In computer systems, a system control program is responsible for resource management and often uses architectural registers. Computer systems under control of the control program operate in User State and in Control State. In User State, user programs and vendor-provided operating systems execute. IBM system control programs run in User State. Certain instructions and facilities of User State may be emulated by Control State software.
Control State is for controlling system resources and they may be shared by multiple domains and provide emulation when necessary. Emulation may be used for enhancing the IBM ESA/390 architecture or may be used so that User State programs that run on one manufacturer's machines having one set of hardware may run on another manufacturer's machines with different hardware. Control State operation is based on the IBM ESA/390 architecture. Entry to Control State from User State is vectored, invoked by Control Interceptions that require assistance by Control State software.
Transitions from User State to Control State occur under a number of conditions. For example, a transition may occur when an instruction occurs that is defined as an emulated instruction when an instruction occurs for which a specific interception control is set, when an interruption occurs for which a specific interception control is set, when an interruption occurs that is defined as a mandatory Control Interception.
The system control program in some environments operates the machine hardware and multiplexes the physical resources of the computing system into multiple logical entities called virtual machines, each of which is a simulation of a computer dedicated to the servicing of a single user or (in the case of a server) a single application. Virtual machines are software entities that can be easily configured to running a particular program rather than to a user. A virtual machine configured in this manner is referred to as a virtual machine server. By virtualizing, operating systems can link guest systems together without the need for guest specific actual hardware. Also, operating systems allow multiple guest systems to share devices and other resources to simplify configuration and maintenance.
Resource management (system control program) and user management (Conversational Monitor System) are separate. When a Conversational Monitor System) user logs on to the system, the system control program creates a virtual machine for that user that includes, among other things, storage address space. An address space is a sequence of addresses that starts at one address and extends up to a value that varies according to size. Storage management is an important task of the supervisor or host which must create, share, and otherwise manage address spaces, gain and relinquish access to an address spaces, and map data on external devices.
Virtual machines running in the ESA/390 architecture have at least one address space, the primary address space, given to the user by the system control program when the user logs on to the system. The size of this address space is determined from the entry describing that user in the user directory, or from a subsequent DEFINE STORAGE command. After logging on, if authorized in the user directory, a user may create other address spaces and share them with other logged on users.
Interpretive Execution
The IBM Interpretive Execution Facility allows a computer system running under a host System Control Program to interpret a virtual machine called the guest. The term "host" refers to the real machine together with the system control program running on the real machine. The host manages real machine resources and provide services to the guest programs which execute in an interpreted machine. The interpreted and host machines execute guest and host programs, respectively. For a transfer of control from a guest virtual machine back to its host System Control Program, an "interception" occurs.
In the existing computer architecture, when a guest issues a START INTERPRETIVE EXECUTION instruction, the instruction is intercepted and emulated by the host program at a significant performance cost. Through emulation, the host provides the functions of a selected architecture which may be available on some other real machine or which may be available only in the virtual machine environment. Privileged and problem program instruction execution, address translation, interruption handling, timing and other functions are interpreted so that those functions are executed in the context of the virtual machine. With the addition of special purpose hardware, interpreted execution can approach speeds that are comparable to native mode execution, that is, execution by a non interpretive version of the architecture.
In the virtual machine environment, the guest program has access to all the functions defined for the designated architecture either through an interpretive execution facility or by the host system control program. For VM/ESA, the control program provides functions through simulation. Simulation generally executes guest functions transparently so that the guest program is unaware as to whether a function is performed by the machine or the host except that simulation usually requires more time.
When an Start Interpretive Execution instruction is executed, the operand of the Start Interpretive Execution instruction containing the State Description is fetched to obtain information about the current state of the guest. When execution of Start Interpretive Execution ends, information representing the state of the guest, including the guest program status word, is saved in the state description before control is returned to the host. The information in the state description, as used and modified by the host during simulation, allows the guest to start and stop execution with valid information. The state description also determines the mode and other environmental conditions in which the guest is to execute.
While in interpretive execution mode the host, in order to be protected from interference by guests or interference among guests, allocates portions of the real machine resources to the virtual machine. Guest storage is confined to a portion of host real storage or to host virtual address spaces controlled by the host system. Host enabled and disabled states generally are undisturbed by execution of the guest. A complete and logically separate set of control registers is maintained by the machine for use by the host and another set for each guest is maintained for use by the guest. Other registers are shared between the host and guests.
In some cases, the host intercepts operations normally performed by the machine. The state description includes control bits which are set by the host to cause intercept operations under specific conditions. When the specific condition are met, the machine returns control to host simulation. Intervention controls capture the introduction of an enabled state into the Program Status Word, so that the host can present an interruption which it holds pending for the guest. Intervention controls may be set asynchronously by the host on another real processor while interpretation proceeds. The machine periodically refetches the controls from storage, so that updated values will be recognized. Guest interruptions can thereby be made pending without prematurely disturbing interpretation.
Guest Storage
Preferred storage mode and pageable storage mode are provided for in the interpretive execution architecture. In preferred storage mode, a contiguous block of host absolute storage is assigned to the guest and in pageable storage mode, dynamic address translation at the host level is used to map guest main storage. In the preferred storage mode, the lower addresses of the machine storage are dedicated to the guest and only one guest can obtain production mode performance.
Multiple High performance Guests
The Multiple Domain Facility.TM. available on Amdahl computers provided concurrent execution of two or more operating systems with high performance on a single shared central computing complex. Such operation permits the reassignment of resources dynamically with minimal performance penalty for a variety of different architectures or systems.
Error Handling
Error recovery is important to computer system operation Error handling in prior art computer systems has typically followed the process described below:
3. Recovery software, based on history information provided by the hardware, attempts to recover from the error.
4. If recovery is successful, processing continues.
Historically, error recovery software has been complex and difficult to test and validate. One of the leading causes of this problem has been the need for recovery software to issue multiple system clocks as part of its recovery actions.
In prior art systems, if an error occurred in many situations, a machine check resulted and the entire computer system was checkstopped resulting in significant reduction in the performance of the computer system. The more complex that computers become, the more severe becomes the impact of check stopping the computer.
Historically, error recovery software has been complex and difficult to test and validate. One of the causes of this problem has been the need for recovery software to issue multiple system clocks as part of its recovery actions. Accordingly, there is a need for a computer system having improved error recovery and handling.

Invoking hardware recovery actions via action latches


Substrates, assemblies, and techniques for an apparatus, where the apparatus includes a gate, where the gate includes a first gate side and a second gate side opposite to the first gate side, a gate dielectric on the gate, where the gate dielectric includes a first gate dielectric side and a second gate dielectric side opposite to the first gate dielectric side, a first dielectric, where the first dielectric abuts the first gate side, the first gate dielectric side, the second gate side, and the second gate dielectric side, a channel, where the gate dielectric is between the channel and the gate, a source coupled with the channel, and a drain coupled with the channel, where the first dielectric abuts the source and the drain. In an example, the first dielectric and the gate dielectric help insulate the gate from the channel, the source, and the drain.

Most, if not all, logic devices require some type of memory cell such as random access memory (RAM). Dynamic random-access memory (DRAM) is a type of random-access memory that stores each bit of data in a separate capacitor. The capacitor can be charged or discharged and these two states are taken to represent the two values of a bit, (i.e., 1 and 0). DRAM is widely used in digital electronics where low-cost and high-capacity memory is required. One of the largest applications for DRAM is the main memory, or RAM, in modern computers and electronics. The DRAM is typically coupled to a transistor. However, transistors leak a small amount current and can cause the capacitor of the DRMA to discharge and fade.
The figures of the drawings are not necessarily drawn to scale, as their dimensions can be varied considerably without departing from the scope of the present disclosure.


An endoscope 2 has a CCD 9 incorporated in the distal part of an insertion unit 6 thereof. The sensitivity of the CCD 9 can be varied by applying a plurality of pulsating driving signals so as to change an electron multiplication rate. The endoscope 2 is connected to a processor 3 so that it can be disconnected freely. Information representing a type of endoscope stored in advance in a ROM 48 is transmitted to a controller 21 incorporated in the processor 3. The control means 21 uses a CCD sensitivity control means 12 to control the sensitivity of the CCD 9 according to the type of connected endoscope 2. Consequently, a view image of proper brightness can be produced irrespective of the type of endoscope 2.

An endoscope system having a solid-state imaging device consists mainly of an endoscope such as an electronic endoscope, a processor, a light source unit, and a monitor. In the endoscope system, the insertion unit of the endoscope is inserted into a body cavity, and illumination light emanating from the light source unit is irradiated to an object over a light guide lying through the endoscope. The solid-state imaging device incorporated in the distal part of the endoscope photoelectrically converts the light to produce a video signal. The processor processes the signal and displays an image on the monitor according to the signal.
Talking of the endoscope system, a field-sequential endoscope system like the one disclosed in, for example, Japanese Unexamined Patent Application Publication No. 1-221135 is known as a modality enabling observation under ordinary light by utilizing illumination light of wavelengths falling within the visible spectrum. In the endoscope system, as described in Japanese Unexamined Patent Application Publication No. 9-70384, an endoscope designed for fluorescence diagnosis is often employed in order to discover an early-stage carcinoma or the like. Specifically, excitation light is irradiated to a living tissue, and light stemming from fluorescence exhibited by the living tissue is observed in order to discover an early-stage carcinoma or the like.
An imaging device included in such a fluorescence diagnosis endoscope system is requested to offer so high sensitivity as to enable observation of feeble light stemming from fluorescence. For this reason, a pickup tube is often employed. Japanese Unexamined Patent Application Publication No. 5-252450 has disclosed a technology of controlling a drain voltage occurring due to overflow in a solid-state imaging device according to an output signal of the solid-state imaging device. The technology thus enables visualization of a region whose image cannot be corrected by controlling an amount of light using an iris diaphragm.
Problems to be Solved by the Invention
In the foregoing endoscope system, various types of endoscopes are switched for use according to a region to be assessed or a method of assessment. For example, an endoscope dedicated to examination of the bronchi is thinner than an endoscope dedicated to examination of the large intestine.
The diameter of an endoscope affects the number of optical fibers constituting a light guide lying through the endoscope, and brings about a difference in the amount of irradiated light. Moreover, an f-number varies depending on the purpose of use of an endoscope. In particular, when an endoscope having a large f-number set therefore is used to observe an object located at a far point, the amount of light is so small that a view image is dark.
This causes a range, within which a proper amount of light necessary for picking up image data is collected, to greatly vary depending on a type of endoscope. On the other hand, as mentioned above, the endoscope system is usable not only for observation under ordinary light but also for observation under special light such as light stemming from fluorescence intended to assess a lesion. For the observation under light stemming from fluorescence, very feeble light stemming from auto-fluorescence must be collected. Therefore, a solid-state imaging device to be incorporated in the distal part of an endoscope is requested to offer much higher sensitivity than a solid-state imaging device designed for observation under ordinary light.
In general, when the endoscope system is used to observe an object that makes quick motion or to produce a still image, the solid-state imaging device is driven using an electronic shutter. In this case, the amount of irradiated light is increased in order to optimize an exposure value. However, when an iris diaphragm is fully opened in order to adjust the amount of irradiated light, if the electronic shutter is activated, the exposure value becomes insufficient. This results in a dark image. Automatic gain control (AGC) may be utilized to compensate the insufficient exposure value. However, this poses a problem in that a noise is intensified.
An object of the present invention is to provide an endoscope system capable of producing a view image of proper brightness irrespective of a type of endoscope. Specifically, the sensitivity of a solid-state imaging device is controlled depending on the type of endoscope, that is, the diameter of an insertion unit of an endoscope, an f-number set for an endoscope, or whether an endoscope is designed for observation under ordinary light or observation under special light such as light stemming from fluorescence.
Another object of the present invention is to provide an endoscope system capable of offering a proper exposure value by controlling the sensitivity of a solid-state imaging device according to movement information concerning the light source, whether an amount of light supplied from a light source is insufficient or not.
Still another object of the present invention is to provide an endoscope system capable of producing a view image less affected by a noise by controlling the sensitivity of a solid-state imaging device according to the driven state of the solid-state imaging device.

This patent is subject to a terminal disclaimer.

Endoscope system with irradiated light switching feature


The invention fulfills new goals for redundancy resolution based on manipulator dynamics and end-effector characteristics. These goals are accomplished by employing the recently developed configuration control approach. Redundancy resolution is achieved by controlling the joint inertia matrix or the end-effector mass matrix that affect the inertial torques, or by reducing the joint torques due to gravity loading and payload. The manipulator mechanical-advantage and velocity-ratio are also used as performance measures to be improved by proper utilization of redundancy. Furthermore, end-effector compliance, sensitivity, and impulsive force at impact are introduced as redundancy resolution criteria. The new goals for redundancy resolution allow a more efficient utilization of the redundant joints based on the desired task requirements.

1. Technical Field
The invention relates to robotic control methods using configuration control techniques disclosed in U.S. Pat. No. 4,999,553.
2. Background Art
1. Introduction
Redundant robot manipulators possess more joint degrees-of- freedom than are required for the basic task of controlling the end-effector motion. The "extra" joints can provide high dexterity and versatility by enabling the robot to accomplish additional tasks. This is based on the observation that for a given end-effector location, the manipulator can assume infinite distinct configurations, each with a different measure of task performance, such as manipulability index. This provides a basis for utilization of redundancy to improve the task performance measure by formulating this requirement as an additional task. However, since the robot performs a variety of diverse tasks, the motivation for utilizing the redundancy in each task can be widely different. For instance, in a free-space motion task, the redundancy can be used to reduce the inertial torques or increase the efficiency of end-effector motion; whereas in a constrained contact task, improvement of mechanical-advantage or reduction of impulsive impact force are appropriate goals. Therefore, the resolution of redundancy must be based on the particular task to be performed.
In the description that follows, reference is made to individual publications listed numerically at the end of this specification by number (e.g., such as "[1]").
While redundancy is a desirable feature in a robot manipulator, the presence of redundant joints complicates the manipulator control problem considerably. The control of redundant robots has been the subject of considerable research during the past two decades. Despite this long history, previous investigations are often focused on the Jacobian pseudoinverse approach proposed originally by Whitney [1] in 1969 and improved subsequently by Liegois [2] in 1977. This approach resolves the redundancy at the velocity level by optimizing an objective function, and produces non-cyclic motions. For instance, using the Jacobian pseudoinverse approach, Suh and Hollerbach [3] suggest methods for minimization of instantaneous joint torques. Khatib [4] proposes a scheme to reduce joint torques by using the inertia-weighted Jacobian pseudoinverse. Dubey and Luh [5] and Chiu [6] use the pseudoinverse approach to optimize the manipulator mechanical-advantage and velocity-ratio using the force and velocity manipulability ellipsoids. Walker [7] resolves the redundancy by reducing the impulsive force at impact using the Jacobian pseudoinverse approach. Maciejewski and Klein [ 8] describe a method for obstacle avoidance based on pseudoinverse control.
In recent specifications [9-16], a new approach called configuration control is proposed for resolution of redundancy and control of redundant manipulators. This approach is based on task augmentation and resolves the redundancy at the position (i.e., task) level, thereby yielding cyclic motions. In this approach, the basic task of end-effector motion is augmented by a user-defined additional task for redundancy resolution. In previous specifications, the additional task is chosen as posture or self-motion control [15,16], optimal joint movement [14,16], or collision avoidance [13,16]. This specification introduces further options for additional task based on manipulator dynamics and end-effector characteristics.
The structure of the specification is as follows. Section 2 describes new additional task options for redundancy resolution within the configuration control framework. A simple planar three-link manipulator is used in the computer simulation studies of Section 3 to illustrate some of the concepts introduced in the specification. Section 4 discusses the results of the specification and draws some conclusions.

Kinematic functions for redundancy resolution using configuration control

The United States of America as represented by the Administrator of the National Aeronautics and Space Administration


A migration control apparatus includes a processor configured to, acquire a first communication log regarding a first virtual machine when execution of migration of the first virtual machine is not completed in a specific time, perform calculation of a first response time of a first processing request to the first virtual machine, acquire a second communication log regarding the first virtual machine after lowering frequency of assignment of a computing resource to the first virtual machine to a first rate, perform calculation of a second response time of a second processing request to the first virtual machine, calculate a second rate to which the frequency of assignment of the computing resource is permitted to be lowered, after starting re-execution of the migration, perform calculation of a third rate of the frequency of assignment of the computing resource for completing the re-execution, and perform determination of whether to cease the re-execution.

For example, a cloud computing user that provides services to users constructs and runs an information processing system for providing various services. For example, the cloud computing user constructs the information processing system by renting a virtual machine (VM) from a cloud computing business operator that carries out lending of the virtual machine.
In the above-described information processing system, for example, when a physical machine is desired to be stopped for carrying out maintenance or the like, the cloud computing business operator carries out live migration in which a virtual machine that is running is moved to another physical machine without being stopped. Due to this, in the migration control system, it becomes possible to keep services provided to users from being affected even when stop or the like of a physical machine is carried out.
For example, related arts are disclosed in Japanese Laid-open Patent Publications No. 2015-156585, No. 2016-184252, and No. 2013-047920.

Migration control apparatus and migration control method


A device for finely adjusting stop members, locating bolts, contoured fitting pieces or adapters and similar components on chucking devices, particularly for measuring machines and machine tools, includes a base member to be fastened to the chucking device and a tightening screw. A first guide member which is adjustable in the axial direction of the tightening screw is mounted on the base member. A second guide member mounted on the first guide member is adjustable transversely of the axial direction of the tightening screw. Mounted on the second guide member is an end member which is adjustable in the adjusting plane of the second guide member but transversely of the adjusting direction of the second guide member. The tightening screw extends through bores formed in the base member, the first and second guide members and the end member which are arranged one on top of the other.

1. Field of the Invention
The present invention relates to a device for finely adjusting stop members, locating bolts, contoured fitting pieces or adapters and similar components on chucking devices, particularly for measuring machines and machine tools.
2. Description of the Related Art
In chucking devices of this type, a number of stop members, locating bolts and similar components are provided which, after a first coarse positioning, must be adjusted very accurately in all three axial directions. In the past, this has only been possible in an unsatisfactory manner. It is either necessary to adjust the entire chucking device or the individual stop member, or the respective locating bolt must be worked on or aligned individually in another manner.

Device for finely adjusting stop members, locating bolts, fitting pieces and the like on chucking devices, particularly for measuring machines and machine tools

Horst Witte Entwicklungs- und Vertriebs-KG


A system for monitoring the toner content in ink. The system comprising a light source and a photo-detector disposed in a ink chamber wall, a controller and a display unit. A content-monitoring voltage V1 and an operation-checking voltage V2 are determined from experiments in advance. V1 and V2 are such light source voltages when a predetermined current Ith is obtained from the photo-detector for the minimum and maximum allowable toner contents, respectively. In usual operation in user site, operation of the system is checked with the light source voltage set for V2 in response to a power-on or a reset. Then, a monitoring of the toner content is started with the light source voltage set for V1. In a toner content monitoring, the sensor current is checked to see if it is equal to or larger than Ith.

The present invention relates generally to a method and a system for measuring the content of particles dispersed in a solvent and, more specifically, to a method and a system for monitoring the toner content in ink contained in a recording head for a printer.
There are electrostatic ink-jet printers in which high-speed high-quality printing is achieved by discharging a jet of charged toner contained in liquid ink by means of electric field.
In such an ink-jet printer, just after discharging a jet of charged toner, a jet of toner has to be quickly prepared for the next discharge for a higher speed, and the toner content in a jet of toner (to be more precise, a jet of toner is a mixture of charged toner and ink) has to be more than a certain level for a higher printing quality without any blot or blur. Thus, in order for this kind of ink-jet printer to exhibit its advantages such as a high speed and a high printing quality, the toner content in ink has to be kept at a sufficient level.
There have been proposed techniques for detecting the presence of electrified toner by means of actinometry or resistance measurement and for warning the user to supply toner. However, since the measurements are performed only in a binary fashion, such toner detecting techniques can not be used for maintaining a predetermined charged toner content in ink.
Japanese unexamined patent publication No. Hei2-102061 (1990) discloses a system for detecting the ink residual quantity. In this system, the level of the surface of ink is detected by knowing whether the optical path of the detecting system is above the surface level or not. For this reason, this system can not measure the charged toner content in ink.

Toner content monitoring system for use in a recording head for ink-jet printer


An ink eraser including an eraser housing defining a housing chamber and a nib opening; a first fibrous wick container positioned within the housing chamber; a first section of fibrous wicking material positioned within the fibrous wick container; a supply of erasing agent within the fibrous wick container, the erasing agent including a mixture of vinegar and an organic bleach; and a delivery nib having a wick contacting portion, a central portion and a delivery portion, the wick contacting portion being positioned within the fibrous wick container in contact with the first section of fibrous wicking, the central portion being disposed through the nib opening, the delivery portion extending exteriorly of the eraser housing. In a preferred embodiment the eraser housing further defines a fill opening and the ink eraser further includes a sealing cap. The sealing cap preferably defines a recharging port that is sealable by a reusable sealing device such as a screw in cap.

Highlighter and other ink dispensing pens are a convenient tool for writing, note taking, etc. The ink dispensing pens typically contain a supply of ink that is dispensed onto a paper or other writing surface through a porous nib. Although this is an effective mechanism for writing on a surface, mistakes are often difficult to erase. It would be desirable, therefore, to have an erasing device for erasing undesirable ink that has been applied to a surface. Because such erasing devices can include an organic bleach, such as a chlorine based bleach, for bleaching organic pigments found in inks, it would be further desirable to have such an erasing device that included an erasing agent delivery system that minimized release of the organic bleach into the air during the manufacturing process.


The present disclosure relates to methods for profiling subject specific and personalized T cell receptor (TCR) repertoires using a single-cell sequencing method. More particularly, disclosed are methods for determining binding of T cell receptors to subject specific neoantigens. In addition, the techniques herein may identify the antigenic targets of T cell receptors in the context of tumor neoantigens. Moreover, the present disclosure enables the discovery of T cell targets in numerous diseases, with implications for understanding the basic mechanisms of the mammalian immune response and for developing antigen-specific diagnostic markers and therapies. Finally, cloned TCRs can be used to formulate personalized immunotherapies for those inflicted with a disease, such as cancer.

The T cell receptor (TCR) is a molecule found on the surface of T lymphocytes (i.e. T cells) that is responsible for recognizing antigens bound to major histocompatibility complex (MHC) molecules. The TCR is a heterodimer composed of two different protein chains. In most T cells (about 95%), these two protein chains are termed the alpha (α) and beta (β) chains. However, in a small percentage of T cells (about 5%), these two protein chains are termed the gamma and delta (γ/δ) chains. The ratio of TCRs comprised of α/β chains versus γ/δ chains may change during a diseased state. When the TCR engages with antigenic peptide and MHC (peptide/MHC), the T lymphocyte is activated through a series of biochemical events mediated by associated enzymes, co-receptors, specialized adaptor molecules, and activated or released transcription factors.
The genetically programmed variability of TCRs and immunoglobulins (Ig) underlies immune recognition of diverse antigens. The selection of antigen-specific T and B cells under different pressures—such as infections, vaccines, autoimmune diseases, allergy, and tumors—can dramatically alter the repertoire in individuals either transiently or permanently. However, since the active receptor consists of paired chains (e.g., TCRα/TCRβ or IgH/IgL) within single cells, determination of active paired chains requires the sequencing of single cells.
The immune system is a vital component in preventing and eliminating cancer. Cytotoxic T cells (CTL) and natural killer cells (NK) have potent ability to kill tumor cells and numerous studies show that effector T cells at the tumor site predict favorable outcome across many cancers. Additionally, tumors vary greatly between each individual, requiring subject specific T cells targeting subject specific tumor antigens to kill a tumor.
Methods for sequencing TCR receptors have been described. Linnemann, et al., describe a method for identifying unpaired TCR sequences using genomic DNA from a large number of samples and assemble a library of TCRs (Nature Medicine 2013 November; 19(11):1534-41). The library was proposed to be used for autologous TCR gene therapy without knowledge of antigen specificity. Dössinger, et al., describe isolation of paired full-length TCR sequences from non-expanded antigen-specific T cells using a PCR-based method (TCR-SCAN) (PLoS One. 2013 Apr. 26; 8(4):e61384). The method allowed isolation of TCRs of known oncogenes. Seitz, et al., describes a method to identify TCRαβ pairs from archival tissue (Proc Natl Acad Sci USA. 2006 Aug. 8; 103(32):12057-62). However, TCR transfected cells were not reactive to the antigens assayed.
Personalized treatments based on the matching of neoantigens to T cells has not been previously described. Thus, there remains an unmet need in the art to develop methods to treat cancer patients in need thereof with a personalized immunotherapy.
Citation or identification of any document in this application is not an admission that such document is available as prior art to the present invention.

Methods for profiling the t cell repertoire


A tubular member for use as a fishing rod, a golf club shaft or the like, in which the member is formed of a plurality of layers containing carbon fiber impregnated with resin, with the layers being overlaid one on another. According to the present invention, the tubular member includes an inner layer formed of carbon fiber and resin and configured into a tubular shape, an intermediate layer including a plurality of layers formed of carbon fiber and resin, and an outer layer formed of carbon fiber and resin and configured into a tubular shape. At least one of the plurality of layers together forming the intermediate layer contains pitch type carbon fiber.

In a conventional tubular member of the above-described type, an intermediate layer thereof is formed by winding prepreg of PAN type carbon fiber. PAN type carbon fibers are manufactured from acrylic fibers, and are widely used in sporting goods, aerospace, industrial and other applications. PAN type carbon fibers display a good balance of high specific strength and modulus of elasticity.
With the above construction, the tubular member provides a progressively higher modulus of elasticity with increase in a bending amount of the member, thus tending to lose its flexibility gradually. For instance, Table 1 and FIG. 1 show ratios a between measured values of flexion amount and theoretically calculated values (i.e. theoretical values) of the same. For obtaining the theoretical flexion amount values, a modulus of elasticity obtained by a flexion experiment using a flat plate is newly calculated through its conversion into a volumetric content of the amount of carbon fiber, and then from this converted bending elastic modulus (shown, e.g., in Tables 1 and 2 below) the theoretical value is derived.
TABLE 1 ______________________________________ Bending .alpha. = measured Elastic Load Flexion W (mm) calculated .times. Modulus (g) measured calculated 100 (%) (ton/mm2) ______________________________________ PAN 200 80.3 84.0 95.5 60 ton/mm.sup.2 * 400 166.8 177.6 93.9 29.90 600 259.3 276.4 93.8 PAN 200 87.0 86.9 100.1 55 ton/mm.sup.2 400 181.3 183.8 98.6 28.50 600 281.5 288.6 97.5 PAN 200 91.0 94.0 96.8 50 ton/mm.sup.2 400 191.3 198.8 96.2 25.00 600 298.0 312.1 95.5 PAN 200 97.5 96.8 100.7 46 ton/mm.sup.2 400 203.8 204.9 99.4 23.40 600 317.3 321.7 98.6 PAN 200 106.3 107.9 98.5 40 ton/mm.sup.2 400 221.0 228.5 98.7 19.50 600 344.0 358.9 95.8 PAN 200 110.3 114.7 96.1 35 ton/mm.sup.2 400 230.3 245.1 93.9 17.60 600 359.5 384.9 93.4 PAN 200 124.8 125.0 99.8 30 ton/mm.sup.2 400 263.5 269.6 97.7 15.30 600 410.0 419.9 97.6 ______________________________________ *Figures indicate fiber modulus of elasticity.
However, in many cases, the measured flexion amount value and the theoretical flexion amount value do not agree with each other due to, e.g., possible variations in the amount of carbon fiber or the amount of resin due to the composition of the employed materials. As may be clearly understood from FIG. 1, in the case of a tubular member comprised of PAN carbon fiber prepreg, the ratio .alpha. between the measured flexion amount value and the theoretical flexion amount value becomes smaller with increase of the load used in the experiment, i.e. with increase in the amount of flexion. This means that with an increase in the flexion amount the measured elastic modulus becomes higher than that used in the theoretical calculation, thus resulting in decrease of flexibility.
For this reason, with the conventional fishing rod having an intermediate layer formed of PAN carbon fiber, when the rod is bent by pulling a fish, the rod loses its flexibility. The rod thus fails to provide sufficient elasticity to cope with a relatively strong pulling force from the fish, whereby breakage of the fishing line or detachment of the hook from the fish tends to occur. Further, because of the difference between the flexion amount when a fish is hooked and that when no fish is hooked, the rod provides different feels, which make the fishing activity per se difficult.
Similarly, if the above-described tubular member is employed as a shaft of a golf club, when the face of the club is hard struck deep into the ground, the club shaft is significantly bent and loses much of its flexibility at the same time. Hence, the club shaft may be readily damaged thereby.
One conceivable method to solve the above-described inconvenience is use of the pitch carbon fiber along the axial (or longitudinal) direction of the intermediate layer. Pitch carbon fibers, used in spacecraft and other applications, are produced from highly refined petroleum or coal tar pitch, and are characterized by high thermal conductivity and low coefficient of thermal expansion, among other properties. The modulus of elasticity of pitch carbon fibers can range from 60 to 900 GPa.
Table 2 and FIG. 2 show characteristics relating to flexion amounts W of rods having an intermediate layer formed of prepreg containing pitch type carbon fiber impregnated with resin.
TABLE 2 ______________________________________ Bending .alpha. = measured Elastic Load Flexion W (mm) calculated .times. Modulus (g) measured calculated 100 (%) (ton/mm2) ______________________________________ pitch 200 89.8 94.7 94.8 60 ton/mm.sup.2 * 400 190.8 200.4 95.2 27.70 600 307.0 314.6 97.6 pitch 200 86.8 87.4 99.3 65 ton/mm.sup.2 400 182.0 184.8 98.5 31.00 600 288.3 290.1 99.4 pitch 200 77.5 83.6 92.7 70 ton/mm.sup.2 400 163.5 176.8 92.5 33.50 600 257.5 275.1 93.6 pitch 200 75.5 79.6 94.8 75 ton/mm.sup.2 400 159.5 166.9 95.6 36.00 600 250.3 261.8 95.6 ______________________________________ *Figures indicate fiber modulus of elasticity.
Referring to FIG. 2, relative to the ratio between the measured flexion amount and the theoretical flexion amount for a load of 200 g, the ratio .alpha. remains substantially unchanged for a load of 400 g. Further, in comparison with the case of 400 g load, the characteristics improve in all the respects for the load of 600 g. This means that the tubular member still retains sufficient elasticity when the flexion amount W, i.e. the magnitude of bending is significantly increased. Hence, if this tubular member is used as a fishing rod, this rod may sufficiently cope with a sudden strong pulling force from fish.
However, if the tubular member is formed solely of the pitch carbon fiber, the member cannot provide sufficient mechanical strength while being capable of providing high elasticity. If this tubular member is subjected to a bending force, a bent portion of the tubular member is squeezed so that the cross section of the tubular member is deformed into a substantially oval shape.
With this, an inner layer of the major-axis portion of the substantially oval cross section is subjected to a compressing force, while an outer layer of the same is subjected to a tensile force. If such bending force is intensified, cracking tends to occur in the tubular member.
Thus, in order to allow the tubular member to be used as, e.g., a fishing rod, the member needs to have a high modulus of elasticity while retaining a necessary amount of mechanical strength.
Table 3 shows characteristics of typical pitch type and PAN type carbon fibers. As may be seen from Table 3, the PAN type carbon fiber provides a higher compression strength than the pitch type carbon fiber, while providing a lower modulus of tensile elasticity than the latter.
TABLE 3 ______________________________________ tensile elastic compression strength modulus of fiber in fiber orientation ______________________________________ pitch carbon fiber 60 ton/mm.sup.2 53 kg/mm.sup.2 PAN carbon fiber 40 ton/mm.sup.2 120 kg/mm.sup.2 ______________________________________
Accordingly, a primary object of the present invention is to overcome the above-described drawbacks of the conventional art by providing a tubular member for use in, e.g., a fishing rod or a golf club, which is superior in both controllability and strength.


The invention is directed to data receivers such as those used in semiconductor devices. Embodiments of the invention provide a loop unrolling DFE receiver that uses analog control signals from each equalizer to avoid timing delays associated with the use of latched digital control signals in the conventional art. In addition, embodiments of the invention implement each equalizer with a single sense amplifier based flip flop (SAFF) to reduce circuit size and power consumption.

1. Field of the Invention
The present invention relates generally to a data receiver, and more particularly, but not by way of limitation, to a data receiver of a semiconductor device.
This application claims the benefit of Korean Patent Application No. 10-2006-0100513, filed on Oct. 16, 2006, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.
2. Description of the Related Art
The data transmission speed between semiconductor chips has increased. However, in the improvement of system performance, the increase of the data transmission speed is restricted due to the physical limit of a channel. A transmission line on a printed circuit board (PCB) has a feature of a low pass filter. Accordingly, when a data signal is transmitted at a speed of several gigabits per second (Gb/s), a gain of the transmitted data signal through the transmission line decreases, and inter symbol interference (ISI) of the transmitted data signal is generated.
Also, the ISI is generated by a reflection wave due to the discontinuation of impedance on the channel. In particular, the ISI becomes more severe on a dynamic random access memory (DRAM). This is because the signal transmission method of the DRAM is a single ended signaling method and the ISI may increase due to a multi load and a connector.
An equalizer may be used to remove the ISI. The equalizer includes a pre-conditioner at a transmission end, a linear equalizer at a receiving end, and a decision feedback equalizer (DFE). In particular, the DFE is widely used because it does not amplify a high frequency noise. A DFE receiver of a DRAM using the DFE method removes the ISI from the currently received signal based on a previously input data value. The DFE receiver can be embodied in many ways and, as an example, there is a method in which the ISI is removed by changing a reference voltage of a receiver.
FIG. 1 is a circuit diagram of a single tap DFE receiver for removing ISI by changing a first reference voltage VR of a receiver 10. Referring to FIG. 1, the receiver 10 includes an amplifier 20, a latch 30, a tap 40, and an adder 50. The amplifier 20 receives a first data signal DQ and outputs a second data signal DQ′ based on the input first data signal DQ and the first reference voltage VR. The latch 30 latches the second data signal DQ′ in response to a clock signal CLK. A coefficient Cf of the tap 40 is updated based on the second data signal DQ′ latched in the latch 30. The adder 50 is added the updated coefficient Cf of the tap 40 and a second reference voltage Vref. The output of the adder 50 is the first reference voltage VR.
FIG. 2 is a conceptual view for explaining the operation of the single tap DFE receiver 10 of FIG. 1. Referring to FIG. 2, the input data DQ (for example, the first data signal of FIG. 1) is sampled at predetermined sampling times S1 through S7 in response to the clock signal CLK. When a value of the data DQ input in a previous sampling time (for example, the data sampled at time S3) is in a low level, gain of the present data DQ, (for example, the data sampled at time S4) may be decreased due to the ISI. In this case, the tap 40 determines the coefficient Cf (=−C1) based on the data value input at the previous sampling time. For example, the data value sampled at time S3 is in a low level (DQ=low). The adder 50 adds the determined coefficient −C1 of the tap 40 and the second reference voltage Vref.
The amplifier 20 determines the present data value based on a result of comparison between the output VR (=Vref−C1) of the adder 50 and a value of the present data DQ (i.e., the data value sampled at time S4). Also, the coefficient Cf (=+C1) of the tap 40 is determined based on the data value of the input data DQ at a previous sampling time, for example, the data value sampled at time S1 (DQ=high). Thus, the first reference voltage VR=Vref+C1. Accordingly, the single tap DFE receiver 10 removes noise due to the ISI during the determination of the present data by controlling the reference voltage VR based on an input data value at a previous sampling time.
However, in the single tap DFE receiver 10, the feedback loop that includes tap 40 causes delay. The maximum operation speed of a semiconductor device (for example a DRAM) is thus limited. To address the above problem, a loop unrolling DFE method may be used for the receiver.
The loop unrolling DFE method is an unrolling method for reducing the feedback delay. In the loop unrolling DFE method, two comparison blocks are used to make two decisions for each data cycle, and one of the two decisions is selected as a final data output value based on the data value determined in a previous cycle.
FIG. 3 is a circuit diagram of a conventional loop unrolling DFE receiver 300. Referring to FIG. 3, the loop unrolling DFE receiver 300 uses a four interleaved method for determining input data DQ based on four clock signals CLK0, CLK90, CLK180, and CLK270, each clock having a phase difference of about 360°/4, that is, 90°. The receiver 300 includes a first equalizer DFE1, a second equalizer DFE2, a third equalizer DFE3, and a fourth equalizer DFE4. Each of the first through fourth equalizers DFE1-DFE4 has the same structure except for input and output signals.
The first through fourth equalizers DFE1-DFE4 determine data values DV1, DV2, DV3, or DV4 of the input data DQ based on the respective first through fourth clock signals CLK0, CLK90, CLK180, and CLK270, each of the clocks having a different phase. For example, the clock signals CLK90, CLK180, and CLK270 of the second through fourth equalizers DFE2, DFE3, and DFE4 have phase differences of 90°, 180°, and 270° compared to the phase of the clock signal CLK0 of the first equalizer DFE1. As a result, each of the equalizers DFE1 through DFE4 sequentially determines the input data DQ based on each of the clock signals CLK0 through CLK270, respectively, and outputs determined data values DV1 through DV4.
Equalizer DFE1 includes a first SAFF (sense amplifier-based flip flop) 310, a second SAFF 320, a multiplexer (MUX) 330, and a third SAFF 340. The first SAFF 310 includes a first differential amplifier 312 and a first latch 314. The first differential amplifier 312 differentially amplifies the difference between the input data DQ and the first voltage VH (a high level voltage), based on the first clock signal CLK0. The first latch 314 latches the output of the first differential amplifier 312.
The second SAFF 320 includes a second differential amplifier 322 and a second latch 324. The second differential amplifier 322 differentially amplifies the difference between the input data DQ and the second voltage VL (a low level voltage) based on the first clock signal CLK0. The second latch 324 latches the output of the second differential amplifier 322.
The multiplexer 330 outputs one of the outputs of the first latch 314 and the second latch 324 based on the value DV4 of the data DQ determined by the fourth equalizer DFE4.
The third SAFF 340 detects the output of the multiplexer 330, amplifies the detected signal, and outputs the amplified signal as a determined data value DV1 based on the first clock signal CLK0. Thus, the data value DV1 output by the first equalizer DFE1 is determined in part by the data value DV4 output by the fourth equalizer DFE4 in a previous cycle. For example, when the value of the data DQ determined by the fourth equalizer DFE4 is at a high level, the multiplexer 330 of the first equalizer DFE1 selects the output of the first latch 314. In this instance, the data value DV1 output from the first equalizer DFE1 is then determined based on the result of comparison between the input data DQ and the first reference voltage VH, (a high level voltage).
In contrast, when the value of the data DQ determined by the fourth equalizer DFE4 is at a low level, the multiplexer 330 of the first equalizer DFE1 selects the output of the second latch 324. In this instance, the data value DV1 output from the first equalizer DFE1 is determined based on the result of comparison between the input data DQ and the second reference voltage VL (a low level voltage).
The maximum operation speed of the semiconductor device having the loop unrolling DFE receiver 300 of FIG. 3 is limited by the time consumed by the latches 314 and 324 and the multiplexer 330. Also, since each of the equalizers DFE1 through DFE4 include three SAFFs, a DRAM or other semiconductor using the DFE receiver 300 has large circuit size and high power consumption. Therefore, there is a need to reduce the circuit size and power consumption of the conventional loop unrolling DFE receiver and decrease time delay during the data determination.

Data receiver and semiconductor device including the data receiver


An automatic controller for the helm of a watercraft uses sensors responsive to starboard and port contacts, with the predominating of the starboard and port contacts signalling the heeling of the watercraft. A transmitter attached to the person of the operator of the vessel is triggered should the operator fall into the water, to transmit a signal to the receiver attached to the electronic controller and thereby cause the watercraft to turn into the wind and prevent the distance between the vessel and the overboard person from increasing.

At the present time, pleasure craft, sailboats, and similar watercraft use a variety of self-steering systems and autopilots. These self-steering systems differ according to two different operating principles:
First, there are self-steering systems in the form of wind vanes that have a purely mechanical mode of operation, whereby the direction of movement of the watercraft is manipulated by the mechanical transmission of force between a wind vane and a pendulum-type rudder that works in the opposite direction. Self-steering systems of this kind are used exclusively on sailboats, and are suitable only for keeping the watercraft or the sailboat on the correct course relative to the wind. As soon as the direction of the wind changes, the sailboat leaves its compass course and follows the rotation of the wind. Self-steering systems of this kind operate without using any electrical current. They can only be manipulated mechanically.
There are, secondly, also self-steering systems that operate electronically. These are the so-called flux gate compass systems. These self-steering systems sample the Earth's magnetic field by means of built-in field coils and determine the angle between the longitudinal axis of the vessel and the lines of force that run between the Earth's poles. Such electronic self-steering systems always steer the watercraft on the compass course that is set at the time the self-steering system is switched on. Such electronic self-steering systems can also be combined with wind vanes. The steering movements that are required to keep on course, and which have to adjust the helm, are transmitted by means of a control device in the form of adjusting or servomotors.
The autopilots described above can keep a watercraft on course with sufficient safety and can provide the crew, which is usually small, with adequate relief from monotonous spells of work at the helm. Providing they are functioning properly, the steering accuracy offered by autopilots is much greater than can be achieved by a human helmsman or operator.
The great disadvantage of autopilots of this kind is that the watercraft will continue its course without change if the sole skipper or operator who is at the helm goes overboard. This danger exists not only for solo sailors, but also for crews such as families. There have been cases of the total loss of both crew and boat when the skipper or operator has gone overboard and the crew, frequently wife and children, were unable to turn the vessel, pick up the skipper or operator, and continue their voyage.