A system for preparing an administration plan using a computer, includes an inputting function, a risk calculating function, an optimizing function, and an outputting function. The optimizing function prepares the administration plan by optimizing and adjusting distribution between investment levels in investment items and the risk levels for a planning term.

1. Field of the Invention
This invention relates to a method for optimizing an administration plan of an enterprise by evaluating investments in various resources such as facilities, man power, and material from the viewpoint of effect-on-investment and, more particularly, to a system for optimizing the administration plan containing risk costs, as caused by suppressing investment cost as the standard of evaluating of the effect-an-investment.
2. Description of the Related Art
In the method of making the administration plan of an enterprise, as represented by the supply chain management system, there is known a system for making an assignment plan to maximize the entire profits on the items such as the throughput of products, the procurement of materials, the running scheme of facilities or the arrangement of talents by predicting the future demands. In the supply chain management, the target throughput is achieved within a designated period to maximize the profits by optimizing the amounts of resources needed at the individual manufacture steps till the products are shipped, under the constraining conditions of the processing abilities (of facilities and operators) of the individual steps and the throughputs (of materials or intermediates). One example of the supply chain management is described in JP-A-10-97574.
The administration planning system of the related art such as the supply chain management is a system for determining an optimum distribution method for achieving a given target with finite resources (e.g., facilities, operators or materials). If the qualities of resources to be assigned are at a predetermined standard or higher, the efficiency of the administration can be expected by using the optimum plan obtained. However, no consideration is given to the risk factors (e.g., troubles of facilities, the skills of operators or the defects of materials) of the resources to be assigned. For the expenses for mantaining the qualities of the resources to be assigned, therefore, plans for expense assignment (e.g., the cost for inspections and maintenance or the cost for education and training) have to be made individually on the basis of the results of the preceding year. In other words, the production plan and the planning work to run the resources for production are so independent as to make it difficult to prepare the optimum administration plan for the entire enterprise activities.


A hybrid dredging apparatus uses a clamshell attached to a rigid boom to dig and remove material. The clamshell then deposits the material into the hopper of a positive displacement pump for discharge at low velocities and with minimal water content. Transducers are be used to determine and control the area of excavation.

The present invention relates generally to apparatus for removing material from the bottom of a water filled reservoir and more particularly to a dredge which uses a novel combination of both mechanical clamshell and hydraulic dredge technology.
It will be appreciated by those skilled in the art that there are two primary types of dredges currently in use. A mechanical dredge uses a clamshell or dragline positioned from a floating base to dig and remove solid material from beneath the water. There are a number of difficulties created by the use of conventional clamshell and dragline dredges. First, the clamshell is typically suspended and allowed to free fall through the water so that it will impact the bottom with sufficient force to penetrate and dig into the material to be removed. This disturbs the surrounding sediments, causing re-suspension into the water of particles and contaminants. Similar disturbances are produced by pulling a dragline randomly through the sediments. The accuracy of positioning of the clamshell or dragline during these operations is less than optimal as well. Second, the clamshell or dragline bucket must be dumped either immediately behind the dredge, or in a scow or dump truck, for transportation to a disposal site. The cost and difficulty of this type of transportation limits the application of the clamshell dredge.
To address some of the drawbacks of mechanical dredges, many have begun using the hydraulic dredge which uses a cutting device to loosen material from the bottom and a centrifugal pump to transport the dredged material in the form of a slurry. Typically, the water content of the slurry ranges from seventy percent (70%) to one hundred percent (100%), with pipe line velocities maintained at between seven (7) feet to fifteen (15) feet per second in order to achieve adequate particulate suspension. Because of the high water content of the slurry and high pump velocities, disposal of the slurry is a problem, particularly if it contains hazardous waste material. A common method of dealing with the disposal problem is to pump the slurry into a lagoon or settling basin and let the excess water run-off. This may or may not be permitted by regulatory authorities because the water may contain hazardous constituents. Conventional hydraulic dredges are sometimes inappropriate for use with materials such as paper mill sludge that, when disturbed, change characteristics to the point that they cannot effectively settle or de-water in the disposal lagoon.
Finally, prior art dredging systems do not easily accommodate either visual inspection of the removed sediment or pre-pumping processing of the sediment by screening, grinding and the like.
U.S. Pat. No. 3,352,035 issued to F. Joyce on Nov. 14, 1967, discloses one type of hydraulic dredge. Unfortunately, this type of dredge is only useable with fine and soft material because of the limitation created by the dredge hose.
U.S. Pat. No. 3,973,575 issued to A. Sullivan, et al on Aug. 10, 1976, discloses another type of hydraulic dredge which uses a shovel which is dragged along the ocean bottom. This type of cutter creates a large amount of re-suspension thereby decreasing the efficiency of the hydraulic dredge. Further, it is difficult to control the area of excavation with a dragline.
U.S. Pat. No. 4,052,800 issued to A. Fuhrboter, et al on Oct. 11, 1977, also discloses a shovel which is towed by one boat and a hydraulic dredge which is towed by another boat. As stated above, the problem with this apparatus is that the centrifugal pump has a low solid to water content thereby decreasing the efficiency of the hydraulic dredge. Further, the dragline causes significant re-suspension of materials. Also, the area of excavation is difficult to control.
U.S. Pat. No. 4,357,764 issued to P. Lemercier on Nov. 9, 1982, discloses a vehicle which uses a vertical auger system. Unfortunately, this device has very limited application because the vehicle will quickly fill up and will not be able to carry any more dredged material. Further, the device is very complicated in that the vehicle must drive under water.
U.S. Pat. No. 4,680,879 issued to C. Hill, et al on Jul. 21, 1987, discloses a hydraulic dredge having a cutter head. As stated repeatedly throughout, the standard hydraulic dredge pulls in water at a low solid to water ratio thereby decreasing the efficiency of the dredge.
U.S. Pat. No. 5,042,178 issued to B. Dutra on Aug. 27, 1991, discloses a clamshell dredge and hopper which uses water jets for the reduction of relatively dry solids into a high density slurry for the purpose of filling a barge. The clamshell is suspended from a line thereby making it difficult to control excavation.
What is needed, then, is a dredge apparatus which can move dredged material a substantial distance away from the dredge without a high concentration of water and at low velocities. This apparatus also should allow for precise control of the removal process underneath the water and without significant re-suspension of particulate at the dredging location. This device is presently lacking in the prior art.


A gauge assembly having a pointer and gauge surface area with a scale representing operating parameters. The pointer has a first half and second half that are illuminated by light sources. The second half selectively changes color according to the portion of the scale that the pointer is indicating. This is accomplished by light isolation between the first and second halves as well as a prism to direct light from the midpoint of the pointer to the tip of the second half of the pointer. As the pointer moves about an axis, the prism for second half illumination aligns with respective chambers formed in a reflector to direct illumination from the different color lights. The second half color changes whenever the light source color under the prism is different. When the pointer is within predetermined ranges on the scale, the second half illumination changes color to represent that respective range.

In the field of vehicle electronics and instrumentation, instrument clusters contain many different gauges indicating various desirable and undesirable vehicle conditions. Conventional instrument clusters often times include warning lights that are used to indicate when certain undesirable conditions exist, which can be seen on respective instrument gauges. For example, if a vehicle fuel gauge is within a certain low range, indicating that the vehicle's fuel tank is near empty, a low fuel indicator light is illuminated. This can be a re-fuel icon or other telltale for example. Another example is the fuel gauge having a red band portion located at a certain low range on the gauge scale, indicating that the vehicle's fuel tank is near empty, and a digital or rotatable pointer moving into the red band area indicates that the fuel level is low. Other warning lights, telltales, or the entire pointer changing to a color are also known. Yet another example includes indicator light source illumination when the vehicle's rotations per minute (RPMs) exceeds a predetermined desired range indicating high load conditions, elevated engine temperature, engine conditions, (ECO) driving, low tire pressure, low oil, and low battery warning lights/gauges that illuminate when predetermined undesirable conditions reach certain warning/alarm or cautionary ranges.
Some designs have a pointer typically provided that rotates about a fixed axis that points to value on the gauge face to communicate current values of an operational parameter. Pointers are often illuminated in a single color to further enhance visibility and appearance. Light sources direct light along the axis and the geometry of the pointer provides a means of propagating light from a hub to a pointer tip.
One problem with using these various warning lights is that an alarm condition is not easily recognized or noticed by an operator. An operator must also be able to decipher the symbol or what the light is indicating quickly, which is not always obvious from a quick glance at the instrument cluster. Another problem is the light sources and pointer can also cause a bright spot at the axis on the pointer.
It is therefore desirable to provide gauge assemblies for instrument clusters or other control units with innovative styling features and that increase light homogeneity and are easily recognizable and stand out to an operator by having a quick look at the instrument cluster. It is also desirable to provide gauge assemblies that provide the operator with cautionary indicators that a certain issue can be addressed prior to the issue or problem developing to a point where a heightened or severe warning indication is needed.


The present teaching includes a speed control of a side shaft of a drive train connected to a dynamometer on a drive train test stand in which a torque (MFxi) caused by the longitudinal force (FXi) calculated in a simulation model is additionally transferred to the control unit, and from this a compensation torque (MKi) is calculated in the control unit as a function of the longitudinal force (FXi) caused by the torque (MFxi) and a deviation (AJi) between a moment of inertia (JBi) of the dynamometer and a moment of inertia (JRi) of the simulated vehicle wheel, the control unit calculates a torque (MREi,) from the setpoint speed (nBi,set) with a speed controller and a torque (MBi,soll) to be set with the dynamometer is calculated as the sum of the compensation torque (MKi) and the torque (MREi) calculated by the speed controller and set by the dynamometer.

In order to develop a drive train, it must often be tested during the development process, i.e., subjected to certain loads in accordance with a test run in order to test the response of the drive train. With the result of the tests, appropriate steps can then be taken to further develop or improve the drive train. There are several known approaches to testing a drive train.
The drive train can be installed, for example, in a real vehicle and test drives can be carried out with the vehicle, on a real road or on a test site. During the test drives, measurements can be made on the vehicle or on the drive train and evaluated after the test drive. Of course, this procedure is very expensive. In addition, a test drive is hardly reproducible, since a test driver is not able to run a test drive several times exactly the same way. Driving robots and shifting robots (if a manual transmission is available) could be used on the test site in order to make the test drive more reproducible, but this significantly increases the effort further. Such test drives are therefore rather disadvantageous and are used today, if at all, only in a very late stage of development of a drive train or a vehicle. However, this is hardly suitable for an early stage of development, where frequent changes and tests are necessary.
Instead of a real test drive on the road, a chassis dynamometer could be used, where the vehicle is arranged on the chassis dynamometer on rollers of the test stand. But with such chassis dynamometers, due to the high inertia of the rollers, dynamic tests (in the sense of a rapid or transient change in the manipulated variables, such as speed and torque) are hardly possible. Chassis dynamometers are also therefore not suitable, or only to a very limited extent, for the testing of drive trains, at least not for very dynamic tests.
To overcome these problems, drive train test stands have already become known where at least at the driven side shafts of the drive train a dynamometer (for example, an electric motor) is arranged which imposes predetermined torques or speeds in the drive train to load the drive train and thus simulate a real drive of a vehicle with the drive train. The speed/torque to be set via the dynamometer (s) is calculated in a simulation model. The simulation model often includes a vehicle model, one (or more) wheel model(s), a road model, a driver model, and also other models that work together and together simulate the movement of the vehicle.
For example, EP 1 037 030 A2 describes a drive train test stand with a simulation model for simulating the movement of a vehicle. For the control of the test run, a tire model is used in combination with a vehicle model that calculates a setpoint value for the torque. The speed of the side shaft is measured and made available to the simulation model. The calculated setpoint value for the torque is provided directly to the dynamometer for implementation. The dynamometer is thus torque-regulated in an open loop. The disadvantage of this approach is that for realistic tests, the moment of inertia must correspond as closely as possible to the moment of inertia of the true wheel, which is normally arranged on the drive train. Since the moment of inertia of a wheel is usually low, this places high demands on the dynamometers. These must therefore be designed generally as electric synchronous machines, with their known disadvantages in terms of cost and reliability. Furthermore, a demanding adjustment of the torque in the inverter of the dynamometer is required.
In addition, an open-loop control, of course, has no possibility of compensating a control error, as in the case of a closed-loop control, and also provides no interference suppression. Thus, unavoidable, production-related or operational deviations of the individual dynamometers already have a direct (negative) influence on the control of the drive train test stand.
Such a drive train test stand is also disclosed in DE 38 01 647 C2 for a four-wheel drive train. The rotational speeds and the torques of the side shafts are measured on the drive train test stand and from this, setpoint speeds for the speed-controlled dynamometers on the side shafts are calculated in the simulation model. For the simulation model, however, a slightly different approach is chosen because a wheel model (which also includes the simulation of the tire) is used instead of a tire model. Therein the co-operation of the different models is also described in detail. For a dynamic test, in particular the consideration of tire slip is important, for which a tire model is needed. This is also described in DE 38 01 647 C2.
AT 508 031 B1 also shows a drive train test stand with vehicle model and wheel models and speed control of the dynamometers on the test stand.
The disadvantage of DE 38 01 647 C2 and AT 508 031 B1 is that the speed control causes a delay and damping, whereby the prevailing speed on the side shaft always lags behind the speed simulated in the simulation model speed. Thus, the current state of the drive train on the drive train test stand does not correspond to the desired, simulated state, which adversely affects the test of the drive train. In order to enable dynamic state changes, which are always to be expected during tests of a drive train, the speed controller must have a high gain, which has negative effects on the stability of the control. In the worst case, the speed control may become unstable, which could damage or even destroy the drive train test stand, or at least interrupt the test run. The controller must therefore be optimized to meet the requirements, which requires a more elaborate controller design or controller tuning.
To solve this problem, in Bauer, R., "Neues Regelkonzept für die dynamische Antriebsstrangprüfung", 17th Styrian Seminar on Control Engineering and Process Automation from Sep. 5-8, 2011, conference volume pp. 104-116 it was proposed to adapt the wheel model, which includes the tire model, in the simulation. However, this requires an intervention in the simulation environment and an exchange or adaptation of the wheel model. However, such interventions are often not acceptable to the operator of the drive train test stand, since usually known standard models for the wheel and the tire are used, and are therefore not possible. Often, the simulation environment with the simulation models already exists at an early development stage before being used on the test stand and is to be used unchanged at the test stand. The test stand only provides an interface at which a setpoint speed is output and through which the variables measured at the drive train test stand are transferred to the simulation model. Which wheel model is used in the simulation environment is therefore often not even known, whereby a change of the wheel model in practice is often hardly possible.

Method for controlling a load machine during a test run with a drive train and test stand


An elastic surface acoustic wave filter device provides balanced operation with a neutral terminal kept at a ground potential and is adaptable for any system of unbalanced input-to-balanced output or balanced input-to-unbalanced output even with an input and an output having a different characteristic impedance. A first elastic surface acoustic wave filter having a first predetermined phase is connected in a cascade arrangement to a second elastic surface acoustic wave filter having a phase that is different by about 180 degrees from the first predetermined phase to form a first set of cascaded elastic surface acoustic wave filters. A third elastic surface acoustic wave filter having the first predetermined phase is connected in a cascade arrangement to a fourth elastic surface acoustic wave filter having the predetermined phase to form a second set of cascaded elastic surface acoustic wave filters. One of input/output terminals of the first set of cascaded elastic surface acoustic wave filters and one of input/output terminals of the second set of cascaded elastic surface acoustic wave filters are electrically connected in parallel to an unbalanced input/output terminal. The other of input/output terminals of the first set of cascaded elastic surface acoustic wave filters and the other of input/output terminals of the second set of cascaded elastic surface acoustic wave filters are electrically connected in series to balanced input/output terminals.

1. Field of the Invention
The present invention relates to an elastic surface acoustic wave filter device.
2. Description of the Related Art
Recently, with mobile body terminals becoming smaller and less expensive, it has become desirable to reduce the number of parts in mobile body terminals and to combine several parts into an integral composite unit in the circuit configuration. Recent elastic surface acoustic wave filter devices have succeeded in reducing insertion loss and have begun to be provided in antenna top units as well.
FIG. 17 shows one example of an elastic surface acoustic wave filter device used in mobile body terminals, taking the reception side (RX) as an example. Generally, an RF signal is input from an antenna (ANT) through a switch (SW) to an elastic surface acoustic wave filter device (SAW) with unbalanced terminals and a characteristic impedance of 50 .OMEGA.. On the other hand, an amplifier (LNA) is an operational amplifier and has balanced terminals in many cases. This means that the amplifier requires a characteristic impedance of about 150-200 .OMEGA. to receive an input if unbalanced terminals are used. However, most elastic surface acoustic wave filter devices (SAW) usually have an input/output impedance of 50 .OMEGA. within the SAW device and unbalanced input/output terminals. For this reason, although elastic surface acoustic wave filter devices can be directly connected to the antenna (ANT) side, a matching circuit for impedance conversion and an unbalanced-to-balanced transformer have been required for connection to the amplifier (LNA) side. A balun circuit (hereinafter referred to simply as a balun) has been used for that function, but the use of a balun has increased the number of parts and cost. There has been thus a demand for eliminating the use of a matching circuit and an unbalanced-to-balanced transformer.
Recently, a variety of studies have been made to satisfy the above demand. Japanese Unexamined Patent Publication No. 7-288442, for example, achieves a filter of balanced input-to-balanced output type by connecting elastic surface acoustic wave resonators in a symmetrical grid pattern.
FIG. 18 shows the construction of an elastic surface acoustic wave filter device disclosed in the above-cited Japanese Unexamined Patent Publication No. 7-288442. As shown in FIG. 18, an elastic surface acoustic wave filter device 100 comprises two serial arm resonators 101, 101 and two parallel arm resonators 102, 102. Input terminals of one serial arm resonator 101 and one parallel arm resonator 102 are connected to an input terminal 105, and input terminals of the other serial arm resonator 101 and the other parallel arm resonator 102 are connected to an input terminal 106.
Output terminals of one serial arm resonator 101 and the other parallel arm resonator 102 are connected to an output terminal 107, and output terminals of the other serial arm resonator 101 and one parallel arm resonator 102 are connected to an output terminal 108. Also, an inductor 109 is connected in series to each of the four resonators 101, 102.
The elastic surface acoustic wave filter device of balanced input-to-balanced output type is realized with the above construction. But the disclosed elastic surface acoustic wave filter device cannot be used, as it is, to a system having a unbalanced input-to-balanced output. As described in "A New Balanced to Unbalanced Type RF-Band SAW Filter", 1996 IEEE MTT-S Digest WE1A-5 (p 417-420) and Japanese Unexamined Patent Publication No. 8-65098, therefore, a filter of an unbalanced input-to-balanced output type is realized by connecting one of the input IDTs to a ground terminal and the output IDTs to the input terminals 105, 106 of the elastic surface acoustic wave filter device shown in FIG. 18.
Although a filter of unbalanced input-to-balanced output type can be realized according to the method of the above-cited Japanese Unexamined Patent Publication No. 8-65098, the elastic surface acoustic wave filter device still has a conventional characteristic impedance therein. Therefore, equal input and output impedance values such as 50 .OMEGA.--50 .OMEGA., and a matching device for impedance matching is required for connection to the amplifier side having input impedance of about 150-200 .OMEGA.. Further, because the balanced output can be only realized in a floating type device, there arises a problem that a degree of balance outside the band is not complete and direct incoming waves cannot be sufficiently canceled out or suppressed.
An elastic surface acoustic wave filter device of a floating type experiences a problem in that the presence of a ground terminal in the filter input side affects an output terminal and a filter characteristic is varied from a desired value.
Additionally, to achieve connection to the amplifier side without a matching circuit, the impedance on the output side should not be equal to the impedance on the input side, but is required to be about 150-200 .OMEGA., i.e., about three or four times as much as the input impedance. A problem of increasing mismatching loss would result if attempting to achieve such an unbalanced impedance construction is done only by improving a design of an elastic surface acoustic wave filter itself.

Elastic surface acoustic wave filter device with balanced and unbalanced input/output terminals


For use with a wireless computer network having a plurality of access points, a mobile station adapted for communicating with the network via a current access point and having a scanning circuit for locating a new access point, the scanning circuit requiring a scanning period of time to locate the new access point, a method of operation of the mobile station and a wireless computer network infrastructure. The mobile station comprises: (1) a detection circuit that generates a ready-to-scan signal indicating that the mobile station is about to activate the scanning circuit and (2) a suspension circuit, coupled to the detection circuit, that receives the ready-to-scan signal and generates, in response thereto, a data suspend signal for transmission to the current access point, the data suspend signal causing the current access point to suspend transmission of data to the mobile station, thereby preventing loss of the data during the scanning period.

Computer systems configured as local area networks have been common for nearly two decades and are popular in a wide variety of business and educational applications. The most common LANs comprise a number of processing devices and a server that are coupled together by a hard-wired connection. Since about 1990, however, wireless local area networks (LANs) have become more common in the marketplace. Although the concept behind wireless LANS had been described a decade earlier, interest in LAN networks was limited until the release of the 2.4 GHz unlicensed band for industrial, scientific and medical (ISM) applications. Wireless LAN products most often employ either direct sequence spread spectrum (DSSS) or frequency hopping spread spectrum (FHSS) techniques to communicate between roaming mobile stations and network access points.
In a typical wireless computer network environment, the "backbone" of the LAN is a central server that communicates with a number of network access points through a hard-wired connection. Each access point (AP) includes a transceiver for communicating with at least one roaming mobile station (MS). The mobile station may be a point-of-sale terminal (i.e., an electronic cash register), a bar code reader or other scanner device, or a notepad, desktop or laptop computer. Each MS establishes a communication link with an AP by scanning the ISM band to find an available AP. Once a reliable link is established, the MS interacts with other mobile stations and/or the server. This allows the user of the MS to move freely in the office, factory, hospital or other facility where the wireless LAN is based, without being limited by the length of a hard-wired connection to the LAN.
Eventually, as a roaming mobile station moves in a multi-channel wireless LAN environment, the mobile station will move out of the range of its current access point. When this occurs, a "handover" takes place that breaks down the communication link between the mobile station and the current access point and establishes a new communication link between the mobile station and a new access point. The mobile station initiates this process when it detects that the link quality with the current access point has degraded below a specified threshold. The mobile station then begins looking for another access point, probably in a different frequency channel.
During this frequency scanning period, however, the mobile station will be tuned to a different frequency channel than is used by the current access point. Thus, any messages that are received by the current access point and destined for the mobile station that is scanning will be lost if transmitted during the scanning period. Present IEEE communication standards do not define protocols which allow the mobile station to inform the current access point that the mobile station is scanning and to request that the mobile station buffer any received messages for a short period of time.
Accordingly, there is needed in the art systems and methods that prevent loss of data during the scanning period of a roaming mobile station. There is a further need for systems and methods that prevent loss of data during the scanning period of a mobile station without modification of existing access points or wireless LAN systems.

System and method for providing seamless handover in a wireless computer network


Aspects of the invention are directed to a multilevel power converter the includes a DC power supply assembly having a positive terminal, a negative terminal, and a zero terminal; a first semiconductor switch series circuit composed of first through sixth semiconductor switches connected in series between the positive terminal and the negative terminal. The converter can include a second semiconductor switch series circuit composed of a first bidirectional switch, seventh and eighth semiconductor switches, and a second bidirectional switch connected in series between the connection point of the first and second semiconductor switches and the connection point of the fifth and sixth semiconductor switches, a first capacitor connected in parallel with a series circuit of the third and fourth semiconductor switches and a second capacitor connected in parallel with the second semiconductor switch series circuit.

1. Field of the Invention
Embodiments of the invention are related to semiconductor power converter technology, and in particular, to technology related to constructing multilevel power conversion circuits.
2. Description of the Related Art
FIG. 7 shows an example of seven level power conversion circuit according to a conventional technology disclosed in Japanese Unexamined Patent Application Publication No. H11-164567. The circuit of FIG. 7 is a partial circuit for one phase of a multilevel, seven level in the conventional circuit of FIG. 7, power conversion circuit. A single phase conversion circuit can be composed by using two partial circuits of FIG. 7 and a three phase conversion circuit can be composed by using three partial circuits of FIG. 7. Referring to FIG. 7, a DC power supply assembly BA2 comprises series-connected single DC power supplies b11, b12, b13, b21, b22, and b23. The DC power supply assembly BA2 has seven terminals P1, P2, P3, M, N1, N2, and N3 at seven different voltage levels. A series connection circuit of semiconductor switches Q1 through Q12, which are IGBTs in this example, is connected between the positive terminal P3 and the negative terminal N3. The connection point of the semiconductors Q6 and Q7 is connected to an AC output terminal U. A diode arm pair DA1 composed of series-connected diodes D1 and D2 is connected between the connection point of the semiconductor switches Q1 and Q2 and the connection point of the semiconductor switches Q7 and Q8. The middle terminal of the diode arm pair DA1 is connected to the connection point of the single DC power supplies b11 and b12.
Similarly, a diode arm pair DA2 composed of series-connected diodes D3 and D4 is connected between the connection point of the semiconductor switches Q2 and Q3 and the connection point of the semiconductor switches Q8 and Q9. The middle terminal of the diode arm pair DA2 is connected to the connection point of the single DC power supplies b12 and b13.
A diode arm pair DA3 composed of series-connected diodes D5 and D6 is connected between the connection point of the semiconductor switches Q3 and Q4 and the connection point of the semiconductor switches Q9 and Q10. The middle terminal of the diode arm pair DA3 is connected to the connection point of the single DC power supplies b13 and b21.
The diode arm pair DA4 composed of series-connected diodes D7 and D8 is connected between the connection point of the semiconductor switches Q4 and Q5 and the connection point of the semiconductor switches Q10 and Q11. The middle terminal of the diode arm pair DA4 is connected to the connection point of the single DC power supplies b21 and b22.
A diode arm pair DA5 composed of series-connected diodes D9 and D10 is connected between the connection point of the semiconductor switches Q5 and Q6 and the connection point of the semiconductor switches Q11 and Q12. The middle terminal of the diode arm pair DA5 is connected to the connection point of the single DC power supplies b22 and b23.
In this circuit construction, when the semiconductor switches Q1 through Q6 are in the ON state and the semiconductor switches Q7 through Q12 are in the OFF state, the AC terminal U outputs a voltage +3E; when the semiconductor switches Q2 through Q7 are in the ON state and the semiconductor switches Q8 through Q12 and Q1 are in the OFF state, the AC terminal U outputs a voltage +2E; when the semiconductor switches Q3 through Q8 are in the ON state and the semiconductor switches Q9 through Q12 and Q1 and Q2 are in the OFF state, the AC terminal U outputs a voltage +1E; when the semiconductor switches Q4 through Q9 are in the ON state and the semiconductor switches Q10 through Q12 and Q1 through Q3 are in the OFF state, the AC terminal U outputs a voltage 0 (zero); when the semiconductor switches Q5 through Q10 are in the ON state and the semiconductor switches Q11 and Q12 and Q1 through Q4 are in the OFF state, the AC terminal U outputs a voltage −1E; when the semiconductor switches Q6 through Q11 are in the ON state and the semiconductor switches Q12 and Q1 through Q5 are in the OFF state, the AC terminal U outputs a voltage −2E; and when the semiconductor switches Q7 through Q12 are in the ON state and the semiconductor switches Q1 through Q6 are in the OFF state, the AC terminal U outputs a voltage −3E. Thus, the AC terminal U can deliver seven levels of output voltages by adjusting ON/OFF of the semiconductor switches Q1 through Q12.
In the conventional circuit of FIG. 7, six series-connected semiconductor switches at the maximum carry the output current from the DC power supply assembly BA2 to the AC terminal U. This causes large steady-state ON-state loss in the semiconductor switches and deterioration of the overall conversion efficiency of the conversion device. Down-sizing and cost reduction are also difficult. Additionally in the multilevel power conversion circuit as shown in FIG. 7, the single DC power supplies b11, b12, b13, b21, b22, and b23 do not bear an equal power in principle even though the output voltage and current from the AC terminal U have AC wave forms symmetrical with respect to electrical polarity. Thus, the single DC power supplies need to be independent on each other. The DC power supply assembly BA2, an input device of the multilevel power conversion circuit, needs six single DC power supplies each delivering a power independently, which imposes a severe limitation in production of the device. The problem of unbalance of DC power supplies is disclosed in IEEE-PESC 1995 Conference Record pp. 1144-1150 entitled "A multi-level voltage source converter system with balanced DC voltage." Thus, as described above, there exists certain shortcomings in the art of DC power supplies.


A constant current source for generating a constant reference current that is relatively temperature insensitive. The constant current source comprises: i) first circuitry for generating a first output current that increases with increases in temperature; ii) second circuitry for generating a second output current that decreases with increases in temperature; and iii) a current combiner circuit that combines the first and second output currents to thereby generate the constant reference current. A change in the first output current caused by a temperature change is at least partially offset by a change in the second output current caused by the temperature change.

There are a myriad number of applications in which an integrated circuit (IC) requires a constant current source (or reference current generator). These applications encompass both digital devices and analog devices. Many constant current sources are based on the principle of creating a constant voltage drop across a fixed on-chip resistor, thereby getting a constant current source. These types of constant current sources are suitable for most of the common application.
However, many applications require high precision and operate under extreme temperature conditions. One typical example is a cell phone, which typically includes high-precision components and must operate in sub-zero temperatures and in 100+ degree temperatures. For these types of applications, a constant current source based on a fixed on-chip resistor cannot be used. This is because the on-chip resistor is temperature sensitive. As the resistance increases with temperature, the current through the on-chip resistor must be reduced in order to maintain a constant voltage across the on-chip resistor. Thus, the supposedly constant current decreases with increasing temperature. This problem is often addressed by adding cooling equipment that maintains the integrated circuit in a narrow operating temperature range, thereby minimizing the variation in the desired constant current.
Therefore, there is a need in the art for improved constant current sources. In particular, there is a need for a reference current generator that is highly temperature insensitive across a relatively wide range of operating temperatures.

Apparatus and method for generating a temperature insensitive reference current


Disclosed is a method of excavating large quantities of non-homogenous radioactive contaminated waste, desirably without releasing radioactive contaminated dust or exposing personnel to its hazards. The excavation of buried waste is performed in the presence of a suppression fluid that coats the waste and captures and retains particles so that they do not become airborne. Use of this suppression fluid technique allows larger mechanized excavation equipment to be used to perform the work. This keeps workers away from the waste. The waste is excavated and placed inside large steel boxes, such as a roll-off box, by the excavator. The suppression fluid covers the waste in the boxes and prevents particulate emissions from the waste.

The safe excavation of buried radioactive waste is very difficult because highly radioactive material may be dispersed and released to the air. In the past, excavation of low-level radioactive material has often been performed inside closed temporary buildings, with workers wearing protective suits and digging with tools. This can be a very labor-intensive process, and workers are protected only by protective gear and strict adherence to decontamination procedures. Excavation of very large sites could take decades to complete and require hundreds of thousands of man-hours of workers exposed to these hazards. Some waste releases large amounts of highly penetrating radiation, requiring handling by remote means. With such highly radioactive waste, conventional excavation processes might not be feasible because a protective suit might not protect the worker from the more intense radiation.
The United States Government has buried vast amounts of radioactive waste in unlined holes in the ground. Certain waste from the federal government's production of nuclear weapons is transuranic, remaining radioactive for many thousands of years. This transuranic waste may be only slightly radioactive and very hard to detect, or highly radioactive, but it still remains so for a very long time. In many cases, the federal government has entered into agreements with state and local governments that it will remove waste that is classified as transuranic from the burial sites and place the waste in specially designed facilities, such as in a salt dome or inside a mountain in another state. Removal can be difficult, however, once the waste has been buried in the ground with other non-transuranic waste in mixed layers, often up to 20 feet deep. In many cases, records may have been lost or may be incomplete. Determining what is transuranic and what is not may require digging it all up and placing it in special detection instruments.
Some transuranic waste is known to be self-dispersing due to the energetic alpha particles that essentially knock radioactive particles off the surface and create airborne dust spontaneously. Therefore, over time the interior of any building or container where the waste is stored or exposed to atmosphere may become contaminated with particles that can be hazardous to workers.
Waste at these landfills is commonly comprised of contaminated soil and debris. The debris often includes cardboard boxes, wooden crates, carbon steel drums, and other solid objects. The cardboard boxes as well as the drums are potentially decomposed to an extent that they may rupture if disturbed. The waste may contain larger pieces of debris made of metal, wood, or concrete. In some sites, large pieces of machined beryllium metal from the core of a nuclear reactor are buried. These objects may be as large as a refrigerator, highly radioactive, and contain traces of transuranic materials.

Process for the excavation of buried waste


A method and apparatus for allocating subcarriers in a broadband wireless communication system using multiple carriers are provided. In the wireless communication system where the total available frequency band is divided into a plurality of subcarriers and subchannels each are formed with a predetermined number of subcarriers, the subcarriers are grouped into subcarrier groups, subcarriers are selected from the subcarrier groups according to predetermined sequences, and the selected subcarriers are allocated as a subchannel to a cell in a predetermined time period.

1. Field of the Invention
The present invention relates generally to a method of allocating communication resources in a broadband wireless communication system, and in particular, to a method and apparatus for allocating subcarriers in a broadband wireless communication system using multiple carriers.
2. Description of the Related Art
The first MCM (Multi-Carrier Modulation) systems appeared in the late 1950's for military high frequency radio communication. OFDM (Orthogonal Frequency Division Multiplexing), a special case of MCM with overlapping orthogonal subcarriers, was initially developed in the 1970's. With OFDM, a serial symbol sequence is converted to parallel symbol sequences and modulated to mutually orthogonal subcarriers before transmission. Because of difficulty in orthogonal modulation between multiple carriers, OFDM has limited practical application to communication systems.
However, in 1971, Weinstein, et. al. proposed an OFDM scheme that applies DFT (Discrete Fourier Transform) to parallel data transmission as an efficient modulation/demodulation process, thereby creating a driving force for OFDM development. In addition, the introduction of a guard interval further reduced adverse effects of multi-path propagation and delay spread in communication systems. Although complex hardware created an obstacle to the widespread use of OFDM, recent advances in digital signal processing technology including FFT (Fast Fourier Transform) and IFFT (Inverse Fast Fourier Transform) have enabled practical OFDM implementation.
OFDM can be implemented for digital data communications such as DAB (Digital Audio Broadcasting), digital TV broadcasting, WLAN (Wireless Local Area Network), and W-ATM (Wireless Asynchronous Transfer Mode). OFDM also exhibits high frequency use efficiency, reduces effects of ISI (Inter-Symbol Interference) by guard intervals, and is robust against multi-path fading. Therefore, OFDM provides optimum transmission efficiency for high-speed data transmission.
OFDM-based multiple access techniques are divided into OFDMA (Orthogonal Frequency Division Multiple Access) and FH (Frequency Hopping)-OFDM. FH-OFDM is a combination of FH and OFDM. Both OFDMA and FH-OFDM commonly seek to achieve frequency diversity gain by distributing data tones across the total frequency band. OFDMA is a scheme of transmitting each OFDM symbol across a plurality of subcarriers that form one subchannel.
OFDMA applications for broadband wireless communication systems include systems defined in the IEEE 802.16a and IEEE 802.16e standards. Such OFDMA systems adopt a 2048-point FFT, for example that divides 1702 tones into 166 pilot tones and 1536 data tones. The 1536 data tones are further divided into 32 subchannels for allocation to users, each subchannel including 48 data tones. OFDMA is a multiple access technique where the frequency domain is divided into subchannels, each having a plurality of subcarriers. The time domain is divided into a plurality of time slots, and the subchannels are allocated to users.
The IEEE 802.16a or IEEE 802.16e system divides a broad frequency band of 10-MHz into subchannels on the frequency domain only. About 1600 to 1700 subcarriers are allocated to one OFDM symbol using 2048 points FFT. Thus, the number of cells can be increased depending on subcarrier allocation. Yet, only about 40 cells are identifiable when subchannels are formed by subcarrier allocation in the prior art, considering collision between channels in a multi-cell environment. To facilitate deployment of a broadband wireless network, the number of identifiable cells should be about 100. In this context, a conventional subchannel/subcarrier allocation method in an OFDMA scheme is limited in the number of cells it can service.

Method and apparatus for allocating subcarriers in a broadband wireless communications system using multiple carriers


The instant invention relates to combinations of the compound of formula (I) or pharmaceutically acceptable salts thereof with other active pharmaceutical ingredients

Aberrant gene expression in affected tissue as compared to normal tissue is a common characteristic of many human diseases, including cancer. Gene expression patterns are controlled at multiple levels in the cell. Control of gene expression can occur through modifications of DNA: DNA promoter methylation is associated with suppression of gene expression. Several inhibitors of DNA methylation are approved for clinical use including the blockbuster Vidaza™. Another class of modifications involve histones which form the protein scaffold that DNA is normally associated with (coiled around) in eukaryotic cells. Histones play a crucial role in organizing DNA and the regulated coiling and uncoiling of DNA around the histones is critical in controlling gene expression—coiled DNA is typically not accessible for gene transcription. A number of histone modifications have been discovered including histone acetylation, histone lysine methylation, histone arginine methylation, histone ubiquinylation, and histone sumoylation, many of which modify accessibility to the associated DNA by the cells transcriptional machinery. These histone marks serve to recruit various protein complexes involved in transcription and repression. An increasing number of studies are painting an intricate picture of how various combinations of histone marks control gene expression in cell-type specific manner and a new term has been coined to capture this concept: the histone code.
The prototypical histone mark is histone acetylation. Histone acetyl transferase and histone deacetylases are the catalytic machines involved in modulation of this histone mark although typically these enzymes are parts of multiprotein complexes containing other proteins involved in reading and modifying histone marks. The components of these protein complexes are typically cell-type specific and typically comprise transcriptional regulators, repressors, co-repressors, receptors associated with gene expression modulation (e.g., estrogen or androgen receptor). Histone deacetylase inhibitors alter the histone acetylation profile of chromatin. Accordingly, histone deacetylase inhibitors like Vorinostat (SAHA), Trichostatin A (TSA), and many others have been shown to alter gene expression in various in vitro and in vivo animal models. Clinically, histone deacetylase inhibitors have demonstrated activity in the cancer setting and are being investigated for oncology indications as well as for neurological conditions and other diseases.
Another modification that is involved in regulating gene expression is histone methylation including lysine and arginine methylation. The methylation status of histone lysines has recently been shown to be important in dynamically regulating gene expression.
A group of enzymes known as histone lysine methyl transferases and histone lysine demethylases are involved in histone lysine modifications. One particular human histone lysine demethylase enzyme called Lysine Specific Demethylase-1 (LSD1) was recently discovered1 to be involved in this crucial histone modification. LSD1 has a fair degree of structural similarity, and amino acid identity/homology to polyamine oxidases and monoamine oxidases, all of which (i.e., MAO-A, MAO-B and LSD1) are flavin dependent amine oxidases which catalyze the oxidation of nitrogen-hydrogen bonds and/or nitrogen carbon bonds. LSD1 has been recognized as an interesting target for the development of new drugs to treat cancer, neurological diseases and other conditions.
Cyclopropylamine containing compounds are known to inhibit a number of medically important targets including amine oxidases like Monoamine Oxidase A (MAO-A; or MAOA), Monoamine Oxidase B (MAO-B; or MAOB), and Lysine Specific Demethylase-1 (LSD1). Tranylcypromine (also known as 2-phenylcyclopropylamine), which is the active ingredient of Parnate® and one of the best known examples of a cyclopropylamine, is known to inhibit all of these enzymes. Since MAO-A inhibition may cause undesired side effects, it would be desirable to identify cyclopropylamine derivatives that exhibit potent LSD1 inhibitory activity while being devoid of or having substantially reduced MAO-A inhibitory activity.
In view of the lack of adequate treatments for conditions such as cancer, there is a desperate need for disease modifying drugs and drugs that work by inhibiting novel targets. There is thus a need for improved methods and compositions that can be used to treat hyperproliferative diseases, particularly hematological malignancies.
International Patent Application WO 2013/0573222 discloses a number of LSD1 inhibitors, including the compound of formula (I):
also known as ORY-1001 or (trans)-N1-((1R,2S)-2-phenylcyclopropyl)cyclohexane-1,4-diamine.

Combinations of LSD1 inhibitors for the treatment of hematological malignancies

Abstract: pharmaceutical compositions comprising them, and their use as medicaments, particularly for the treatment of hematological malignancies.


A composition for acrylic artificial stone, the composition including a (meth)acrylic monomer and an inorganic material. At least one of the (meth)acrylic monomer and the inorganic material may be contained in a component generated by decomposing a polymeric (meth)acrylic resin.

1. Field of the Invention
Embodiments relate to a method of recycling acrylic resin, a composition for acrylic artificial stone, and an article of artificial stone.
2. Description of the Related Art
Artificial marble is generally fabricated using an acrylic artificial marble, which is polymerized from acrylic and/or methacrylic monomers, or an unsaturated polyester artificial marble. Acrylic artificial marble has been in demand for a long time, as it can be widely used for various architectural elements, furniture, etc., e.g., counter tops, due to its excellent appearance, superior texture, and good weatherability.
When disposing of dust or scraps resulting from the preparation of acrylic artificial marble, or when disposing of products such as artificial marble architectural elements, furniture, etc., there may be problems in that the disposal of such waste by incinerating is difficult to implement due to the flameproof property of acrylic artificial marble. Further, the waste may contaminate soil in a landfill because the waste does not biodegrade.
Attempts to reutilize waste materials of artificial marble have been made. However, methods requiring dissolution of polymeric material, e.g., polymethylmethacrylate, in a matrix, e.g., methylmethacrylate, are restricted to polymeric materials having an average molecular weight of about 30,000 to about 150,000 at the highest.
Therefore, there is a need for a method to decomposing a polymeric (meth)acrylic resin and the re-use of products obtained thereby.

Method of recycling acrylic resin, composition for acrylic artificial stone, and article of artificial stone


An automatic document feeder for use with an electrophotographic copier, digital copier or similar image recorder capable of transporting ordinary documents in the form of separate sheets and a continuous document in the form of computer form (CF) paper which is formed with equally spaced sprocket holes, as desired. A sprocket hole sensor is disposed on an imaginary line along which the sprocket holes of the CF paper are moved. A control device reversibly controls the transport of the CF paper to a predetermined reference position on a glass platen in association with the number of sprocket holes being counted. The document feeder is capable of not only copying a desired page of the CF paper but also implementing jam recovery in the event when a paper sheet jams the image recorder.

The present invention relates to an automatic document feeder (ADF) for use with an electrophotographic copier, digital copier or similar image recorder for selectively feeding ordinary documents in the form of separate sheets and a continuous document in the form of computer form (CF) paper.
An ADF is extensively used with the above-stated kind of image recorder for automatically feeding a document to a glass platen of the image recorder, then stopping it on the glass platen, and then discharging it after an image printed thereon has been scanned. An ADF having a capability for transporting a document in the form of CF paper or similar elongate paper to the glass platen in addition to ordinary documents has been proposed, as disclosed in Japanese Laid-Open Patent Publication No. 59-72455 by way of example. In general, CF paper or similar document has a plurality of pages printed side by side thereon. A drawback with a prior art ADF having such a capability is that the document feed control cannot be readily implemented for each of different kinds of documents. Moreover, it is difficult to accurately position a document in a predetermined position of a glass platen for imagewise exposure. Especially, sequentially locating consecutive pages provided on CF paper in the particular position on the platen is extremely difficult.

Switchable automatic document feeder capable of feeding continuous form documents or single sheet documents


A computer-implemented method according to one embodiment includes identifying a plurality of storage systems within a storage environment, determining characteristics of each of the plurality of storage systems, the characteristics including one or more data reduction techniques implemented by each of the plurality of storage systems, performing a plurality of storage simulations of one or more data volumes, utilizing the characteristics of each of the plurality of storage systems, and determining one of the plurality of storage systems to store the one or more data volumes, based on results of the plurality of storage simulations.

The present invention relates to data storage management, and more specifically, this invention relates to dynamically determining an optimal storage location for data, based on characteristics of various available data storage.
Large-scale data storage can be implemented utilizing storage centers that contain a plurality of storage devices. Current data placement techniques only address storage devices having a single shared storage type within a storage center. However, current data placement techniques are not operable with respect to storage devices within a storage center that have different storage types, and that implement different data reduction techniques.

Distributing data across a mixed data storage center

International Business Machines Corporation


A method and system for facilitating communications between technical support specialists in a call center environment. Under control of a first computer, the system displays on a display device a form for tracking time of a technical support specialist. The system then receives a request to communicate with a second technical support specialist and sends to an internet protocol address of the second computer request to communicate with the first technical support specialist. At the second computer system, the system displays on a second display device a form for tracking time of the second technical support specialist. In response to receiving a request sent by the first computer system, the second system displays on the second display device a window informing the second technical support specialist that the first technical support specialist has requested to communicate. In response to receiving an approval from the second technical support specialist to communicate with the first technical support specialist, the second system sends a notification of the received approval to the internet protocol address of the first computer. The first technical support specialist can then communicate with the second technical support specialist by inputting data to the first computer which is transmitted for display on the second computer, and the second technical support specialist communicates with the first technical support specialist by inputting data to the second computer which is transmitted for display on the first display device.

Various types of organizations (e.g., developers of computer programs and manufacturers of computer systems) provide telephonic customer support services. To use such customer support services, a customer places a call to a customer support center for the organization. When the call is received at the customer support center, the call is distributed to one of the available customer service representatives. Each customer service representative typically has a computer system through which the representative can access information needed to respond to a customer. These computer systems are typically personal computers that are connected through a network to a server computer system. The server computer system provides access to the information needed to respond to the customers. For example, manufacturers of personal computers typically provide technical support via telephone to their customers. When a technical support specialist of the manufacturer is routed a telephone call, the specialist assesses the needs of the customer and prepares and provides an appropriate response, such as how to repair the configuration file of the customer's computer system.
The cost of providing such a customer service center for technical support can be very high. In addition to the salaries of each of the technical support specialists, the manufacturer typically spends significant amounts on training the technical support specialists and on providing computer systems to aid the specialists in servicing the customers. Therefore, it is very important that these highly trained specialists operate as productively as possible. Unfortunately, it has been very difficult to assess the productivity of technical support specialists. In particular, technical support specialists may work on various tasks other than receiving incoming calls from customers. For example, in order to respond to a customer, the technical support specialist may need to spend some time researching the customer's problem. The specialist may need to present the customer's problem to an experienced systems programmer who can then help provide a solution to the problem. A technical support specialist may also need to discuss a customer's problem with another more experienced specialist who may have encountered that problem before. Also, the technical support specialist often needs to place a follow-up call to the customer to provide the response. In addition, technical support specialists may need to attend various meetings and classes when they would otherwise be available to receive incoming calls from customers. For example, a technical support specialist may need to attend a class on a new feature of a computer system that will soon be sold by the manufacturer.
Because the technical support specialists can spend their day performing a variety of tasks, it has been difficult to assess their productivity. Consequently, supervisors of the technical support specialists have in the past requested that each specialist provide a tracking of the time in which the technical support specialist was not available to respond to an incoming call. The technical support specialists would typically hand write a log of their time spent other than answering incoming calls and forward the log to the supervisor. The supervisor would then correlate the information in the logs and attempt to evaluate the productivity of the technical support specialist. Using such information, the supervisor can identify ways to improve the availability of specialists to receive incoming calls. For example, the supervisor may request that systems programmers provide prompt attention or that additional specialists be hired.
Unfortunately, such an informal technique for the tracking time of specialists has serious disadvantages. First, if specialists do not record their time in the logs contemporaneously with the activity, then the accuracy of the logs suffers. Second, different specialists may record different levels of detail. For example, one specialist may record that time was spent generally on research, while another specialist may record that time was spent reviewing manuals to respond to a configuration file problem, talking to a systems programmer, and placing a follow-up call to the customer. Third, because the logs are handwritten, the supervisor is likely not able to perform a meaningful analysis of the logs in a reasonable amount of time.
Even if these problems of tracking the time of the specialists can be solved, the solution does not necessarily by itself increase the productivity of the specialists. In particular, specialists may spend a considerable amount of time discussing customer problems with other specialists. Although the fact that specialists are spending considerable amounts of time discussing problems with other specialists may become apparent if the tracking problem is solved, a supervisor would still need to devise a way to reduce that amount of time.

Method and system for communicating between users of a productivity tracking system


A drive circuit for a brushless DC fan motor for rotating a rotor (permanent magnet) by a rotating magnetic field produced by turning on/off the flow of electric current to field coils by a signal to control terminals of switch elements in which switch sections are each connected in series with the field coils. When connecting capacitors for absorbing a current spike in parallel with the switch sections of the switch elements, resistors are each connected between the field coil and switch section, through which the capacitors are connected in parallel with the switch sections. A discharge current of the capacitors which absorbed a current spike when turning on the switch elements is passed via the resistors, thereby eliminating a current spike.

1. Field of the Invention
The present invention relates to a brushless DC fan motor suitably radiating heat generated in a housing of electronic equipment, more particularly, to a drive circuit therefor.
2. Description of the Related Art
For example, in electronic equipment having a large number of electronic parts housed in a relatively narrow housing, such as OA (office automation) equipment including a personal computer, a copying machine and so on, the housing may be filled with heat generated from the above electronic parts, thereby breaking the electronic parts by heat.
Therefore, an air blower is provided in a wall surface or a ceiling surface of the housing of the electronic equipment, to which a fan motor is attached, thereby externally exhausting the heat in the housing.
While a brushless DC fan motor is often used as this type of fan motor, a conventional drive circuit for driving such a brushless DC fan motor will be shown in FIG. 4.
In the drawing, reference numeral 41 denotes a drive circuit for a brushless DC fan motor, here, which indicates a drive circuit in a brushless DC fan motor 42 of a two-phase unipolar drive type. Symbols + and − indicate the anode and the cathode of a DC source, respectively.
As shown in the drawing, the brushless DC fan motor 42 includes field coils (motor coils) L1 and L2. The field coils L1 and L2 are provided at a stator (not shown) and the flow of electric current is switched alternately by switch elements of the drive circuit 41, which are NPN transistors T3 and T4 here, to establish a rotating magnetic field. A rotor (not shown) of the fan motor 42 includes a permanent magnet, the permanent magnet being rotated following the rotating magnetic field to rotate the rotor.
The drive circuit 41 is constituted by a control circuit CC, resistors R1 to R9, PNP transistors T1 and T2, Zener diodes ZD1 to ZD4, diodes D1 and D2, and the above-mentioned transistors T3 and T4.
The control circuit CC receives a signal from a hall element 43 for detecting the location of the rotor (permanent magnet) and outputs a signal for performing an on-off control of the transistors T3 and T4. In other words, after the output signal from the control circuit CC the polarity of which has been reversed and the signal has been amplified by the transistors T1 and T2, it is input to the transistors T3 and T4, thereby performing the on-off control of the transistors T3 and T4.
Accordingly, the flow of electric current to the magnetic fields L1 and L2 is alternately switched in accordance with the location of the aforesaid rotor to produce a rotating magnetic field, and the rotor is rotated as described above, thereby externally exhausting the heat in the housing.
In such a fan motor, there is a possibility of generating a high voltage (generating a high voltage periodically) when the electricity is turned off, thereby destroying elements including the transistors T3, T4 and so on.
Accordingly, in the above-described conventional circuit, the Zener diodes ZD1 and ZD2, and ZD3 and ZD4 are connected between a collector and the base of each of the transistors T3 and T4, respectively, thereby preventing the generation of the high voltage.
However, even if the Zener diodes ZD1 and ZD2, and ZD3 and ZD4 are connected, in the conventional circuit shown in FIG. 4, a current spike flows toward the collector of the transistors T3 and T4 when the electricity of the field coils L1 and L2 is turned off, thereby causing noise.
Also, upon starting the motor, a current spike flows toward the collector of the transistors T3 and T4, causing noise.
FIG. 5 is a view of the conventional circuit for reducing a current spike to the transistors T3 and T4, as described above.
Referring to FIG. 5, the same elements as those in FIG. 4 are denoted by the same reference numerals. Here, capacitors C1 and C2 are connected in parallel between the collector and an emitter of each of the transistors T3 and T4 in FIG. 4, respectively.
With such a construction, in the conventional circuit shown in FIG. 5, a current spike which tends to flow toward the collector of each of the transistors T3 and T4 flows toward the capacitors C1 and C2, respectively, and is then absorbed. Accordingly, the noise due to the above current spike can be reduced.
However, the effect of preventing noise was not enough even in the conventional circuit shown in FIG. 5.
More specifically, the current spike which tends to flow toward the collector of each of the transistors T3 and T4 can be securely absorbed by the capacitors C1 and C2. Consequently, the noise produced by current spike flow toward the collector of each of the transistors T3 and T4 can be prevented.
However, when turning on the transistors T3 and T4 after the current spike has flowed toward the capacitors C1 and C2, a current discharge spike of each of the capacitors C1 and C2 flows toward the collector of each of the transistors T3 and T4, respectively.
In the conventional circuit shown in FIG. 5, the noise produced by such discharge current flow poses a new problem, which was brought to the fore when chip capacitors (not shown) were used as the capacitors C1 and C2.
Accordingly, one of the solving means is to not use the chip capacitors as the capacitors C1 and C2. However, the chip capacitors (not shown) are often used as the capacitors C1 and C2 in order to respond to a requirement for miniaturization of a drive circuit board. At any rate, conventionally, reduction of the noise caused by the current discharge spike from the capacitors C1 and C2 is earnestly required to realize a low noise level.

Drive circuit for brushless DC fan motor


A fluid filtration system may include a fluid filter assembly that includes a filter element configured to filter a fluid and a sensor probe incorporated into the fluid filter assembly. The sensor probe may include a chemically reactive material sensitive to at least one property of the fluid and at least a portion of the sensor probe may be exposed to the fluid.

Oil drain intervals for internal combustion engines are determined by engine manufacturers through rigorous testing. However, a manufacturer cannot simulate all the conditions under which an engine can subject the lubricating oil to. Determining the quality of the in-service lubricating oil in-situ would provide a more accurate assessment of when the oil should be changed. In addition to assessing quality, assessing oil chemical constituents of the in-service lubricating oil in-situ would be useful.
Similarly, the reliability and/or performance of high pressure common rail diesel fuel injection systems may be adversely impacted by the presence of certain contaminants in the fuel, such as water. Typically, the end user would not be aware of the presence of these contaminants until engine performance has been impacted. As such, the ability to detect the presence of contaminants and advise the operator or service personnel accordingly is desirable.
A polymeric bead matrix (PBM) sensor probe is a known type of sensor used to sense the quality of a fluid such as oil. Examples of PBM sensor probes and how they work are described in U.S. Pat. Nos. 5,435,170; 5,777,210; 5,789,665; 7,521,945; and 7,928,741. It is known to use PBM sensors on oil sumps in engines.

Fluid quality monitoring and filtration system


An embodiment of an ignition system for a gas turbine engine includes a high pressure engine case, a torch ignitor disposed at least partially within the high pressure engine case, the torch ignitor having a combustion chamber oriented about a torch axis, the combustion chamber having axially upstream and downstream ends defining a flow direction through the combustion chamber, along the axis. The ignition system also includes an access hatch configured to allow access through a high pressure engine case to the cap and to seal against the high pressure engine case when not accessing the cap. An embodiment of a method includes removing a hatch from a high pressure engine case to open a hatch opening, performing maintenance on a torch ignitor that is inside the high pressure engine case by accessing the torch ignitor through the hatch opening, replacing the hatch to close the hatch opening after completion of maintenance on the torch ignitor.

The present disclosure relates to gas turbine engines and, more particularly, torch ignitors and methods suitable for use in torch ignitors used in the combustor section of a gas turbine engine.
Torch ignitors can be used in lieu of spark ignitors to provide an ignition source for combustors located in gas turbine engines. Torch ignitors provide a flame to the combustion chamber of a gas turbine engine as an ignition source rather than the electric current provided by spark ignitors. Consequently, torch ignitors can provide a larger target for fuel injectors within the combustor, allowing for utilization of a greater range of fuel injector designs. Torch ignitors are intended to remain active while the gas turbine is operating. Due to their position, torch ignitor components can often be difficult to reach for routine maintenance or replacement. There remains a need for improved access to ignitor components allowing for line replacement and/or repair within the system.

Access hatch for internally mounted torch ignitor


A communication resource is subdivided as a function of time into a plurality of time slots (210), which may then be further subdivided on a non-periodic basis into a number of sub-slots (220). In a slot or sub-slot, communication units (101) may utilize the communication resource according to a specific set of access methods defined for that slot or sub-slot. In one embodiment the time slots are subdivided on a non-periodic basis into a least two random access sub-slots, during which communication units may either request one or more reserved time slots, or send unreserved data packets (240). In response to requests for reserved time slots from a requesting communication unit, one or more reserved time slots are provided for the use of the requesting communication unit.

Multiple access communication systems are well understood in the art. Multiple access communication systems are designed to provide access to limited communication resources by a plurality of communication units for the purpose of transmitting communication messages, referred to as packets. The access methodology, referred to as a multiple access protocol, is chosen such that some appropriate set of performance constraints are met. Typical performance constraints include efficiency of communication resource use, communication message delay, and other similar factors. Multiple access protocols can generally be regarded as belonging to one of two general types, contention and non-contention.
Non-contention protocols are designed such that a communication unit desiring to send a packet is permitted exclusive use of a communication resource. One example of this type of protocol is time-division multiple access (TDMA) where the communication resource is divided into a plurality of time frames that are further subdivided into a plurality of time slots and each communication unit is assigned exclusive use of one or more time slots in each time frame. This type of protocol is inefficient for communication units that source substantially infrequent messages since the assigned time slot remains substantially unused by anyone in between messages. The practical number of communication units that can be accommodated by such a protocol is also limited by the delay incurred while waiting for one's assigned slot. This wait usually increases proportionally to the number of communication units that have assigned slots.
Contention protocols are characterized by communication units that actively compete with each other to gain access to the communication resource. The slotted ALOHA protocol is an example of this type of protocol. In slotted ALOHA, a communication resource is divided into a plurality of time slots. A communication unit desiring to send a packet may transmit in the first subsequent time slot, taking care not to transmit outside of the boundaries of that time slot. If no other communication unit also transmitted in that same time slot, the packet transmission is considered successful. (Note that other factors, such as communication channel noise, may ultimately result in failure of the message, but that these other factors are not related to the access protocol.) If one or more other communication units, however, did transmit a packet in the same time slot, generally all transmissions would fail due to collision. Thus contention protocols generally work well for lightly loaded systems, but performance suffers as load increases because the likelihood of collisions also increases. Further, communication messages longer than the time slot duration must be sent in a plurality of time slots and are subject to collision in each time slot used.
Reservation protocols, a sub-class of contention protocols, are also known. Reservation protocols attempt to combine certain aspects of contention and non-contention protocols to provide improved performance for a wider variety of communication system conditions. A typical reservation protocol divides a communication resource into a series of fixed-size time frames further divided into a series of time slots. The time slots are comprised of two types, a reservation time slot and a data time slot, with equal numbers of each in each time frame. The reservation time slots are generally smaller than the data time slots and are grouped together at the beginning of each time frame. A communication unit desiring access to the communication resource transmits randomly in one of the reservation time slots for the purpose of reserving an associated data time slot. If the unit successfully avoids contention and is therefore the only unit to transmit a reservation request in a given reservation time slot, it is permitted exclusive access of the associated data time slot occurring later in the time frame.
Although reservation protocols improve the effectiveness by which a communication resource may be utilized by a plurality of competing communication units, particularly when there are a wide range of communication requirements, some drawbacks exist with these schemes. A communication unit wishing access to the channel must first wait for the reservation time slots. If no messages are currently being sent, this represents a delay which would not have occurred if the unit had been allowed to transmit immediately, in random access fashion. Further delay is encountered between the time the unit successfully accesses the reservation time slot, via random access, and the time it receives confirmation of its reservation.
One particular reservation protocol, the Reservation-ALOHA (R-ALOHA) protocol, should be mentioned. Like TDMA, the communication resource is divided into time frames that are further divided into time slots. When the communication resource is unused, however, the protocol operates similarly to slotted ALOHA. When a communication unit desires to send a packet, it transmits in one of the unused time slots, referred to as a random access slot. If the transmission is successful, i.e., it does not collide with another transmission, the communication unit is permitted exclusive use of that same time slot in subsequent time frames, referred to as reserved access slots until the packet is completely transmitted. Thus the initial ALOHA transmission results in a subsequent reservation of a communication resource. (Note that some method of feedback to the communication units regarding the success or failure of initial ALOHA transmissions is necessary in order for this protocol to be effective.)
R-ALOHA is quite efficient for communication systems accommodating a wide variety of packet frequencies and sizes. However some limitations can be noted. The ultimate efficiency of the protocol is governed by the size of the random access portion of a packet relative to the complete packet, since it is only this portion that is subject to contention failure. In R-ALOHA, this size is equivalent to a time slot. There are many competing factors that contribute to the determination of time slot duration in the design of a communication system. The final embodiment may not result in optimum access protocol performance. For example, longer time slots increase transmission efficiency because requisite overhead requirements are reduced, but a longer time slot decreases the effectiveness of R-ALOHA. Also due to the contention for unused time slots in R-ALOHA, several unused slots may need to pass before a successful random access is accomplished. These unused slots represent wasted communication capacity.
Accordingly, a need exists for a communication method that provides increased utilization of a communication resource by a plurality of communication units with widely varying communication requirements. This need can be substantially met by a communication method that provides an opportunity for communication units to choose from a set of available multiple access methods.

Method for multi-purpose utilization of resources in a communication system


A production assembly for a subsea well, the assembly comprising a tubing hanger landed in the production assembly, the tubing hanger suspending production tubing from the production assembly, an annulus surrounding the production tubing, and an actuatable rotary disc valve comprising a disc and two seats, wherein the disc is rotatable between two seats to an open position in which one or more apertures in the rotary disc valve are aligned with one or more apertures in the seats, and a closed position in which the one or more apertures in the rotary disc valve are offset from the one or more apertures in the seats, wherein, the annulus is not capable of fluid communication through the tubing hanger when the actuatable rotary disc valve is in the closed position.

This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present invention, which are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present invention. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.
Tubing hangers are used in completion of oil and gas wells. A typical completion system comprises a wellhead housing which is installed at the upper end of a well bore, optionally a tubing spool connected to the top of the wellhead housing including a central bore and a tubing hanger which is landed in the central bore. The process of installing a tubing hanger into a flow completion system involves positioning the tubing hanger into the tubing spool/wellhead using a tubing hanger running tool or similar device. In subsea applications, the tubing hanger is generally run through a marine riser and blowout preventer stack before landing in the tubing spool/wellhead.
The tubing hanger supports production tubing or tubing string for producing fluids from the well. The tubing string extends down into the production zone of the well and includes a production bore and defines an annulus bore surrounding the tubing string. Often, the tubing hanger provides porting to allow communication of hydraulic, electric and other downhole functions, as well as chemical injection. The tubing hanger can also serve to seal-in annulus and production areas.
For a tubing hanger installed inside a wellhead, the annulus bore which flows through the tubing hanger can be used for monitoring pressure or communicating fluid to and from the annulus below the tubing hanger. After well completion, a Christmas tree can be installed above the wellhead assembly to control production from the well. Before the Christmas tree is installed, all flow passages including the annulus bore must be sealed off to provide a temporary fluid barrier so that the blowout preventer, connected to the wellhead during completion, can be removed.
Typically, annulus isolation valves are installed inside of the tubing hanger to provide a barrier preventing annulus bore fluid communication through the tubing hanger. Traditional tubing hanger annulus isolation valves present a number of problems, including: space limitation, reliability, durability, restricted flow area, added cost and inconvenience of employing wireline tools to open and/or close the valves, and potential flow erosion of sealing surfaces. The present invention solves and/or mitigates one or more of the issues set forth above by providing a rotary disc valve capable of isolating annulus fluid communication through the tubing hanger.


A method for fabricating a transistor includes the steps of forming a gate insulation film on a substrate, forming a gate electrode on the gate insulation film and forming a first insulation film pattern on the gate electrode. A side wall spacer is formed at side surfaces of the first insulation film pattern and the gate electrode. The gate insulation film is etched to expose a portion of a surface of the substrate. An epitaxial layer is formed on the substrate where the gate insulation film is etched. The side wall spacer is removed and a thermal oxide film is grown on a portion corresponding to where the side wall spacer is removed and on an upper portion of the epitaxial layer. A source/drain region is formed by ion-implanting an impurity into the epitaxial layer.

1. Field of the Invention
The present invention relates to a method for fabricating a transistor, and more particularly, to a method for fabricating a transistor having an elevated source/drain construction.
2. Discussion of the Related Art
A conventional elevated source/drain transistor is shown in FIGS. 1A through 1D.
Referring to FIG. 1A, a conventional elevated source/drain transistor includes a gate insulation film 12 formed on a silicon substrate 10. A poly-silicon film 14 is deposited on the gate insulation film 12. The poly-silicon film 14 is etched so as to expose a predetermined portion of the gate insulation film 12. Thus, a poly-silicon gate 14' is formed, as shown on FIG. 1B. An oxide film (first insulation film 16) is deposited on the gate insulation film 12 and the gate 14' through a chemical vapor deposition method.
Thereafter, as shown in FIG. 1C, a first insulation side wall spacer 16' is formed at a side surface of the poly-silicon gate 14' by etching-back the first insulation film 16 without using a mask. A predetermined portion of the surface of the silicon substrate 10 is exposed by etching a corresponding portion of the gate insulation film using the first insulation side wall spacer 16' as a mask.
Next, as shown in FIG. 1D, an epitaxial layer is selectively deposited on the surface of the exposed silicon substrate 10, and a source/drain 18 is formed by ion-implanting n.sup.+ or p.sup.+ impurity into the deposited epitaxial layer.
However, the transistor fabricated in the above-explained method has a disadvantage in that a short channel effect may occur due a pattern size reduction as the integration scale of the semiconductor device becomes larger.


In accordance with an embodiment, a method of controlling a switched-mode power includes generating a feedback signal proportional to an output of the switched-mode power supply, and operating the switched-mode power supply in a normal mode. If the feedback signal crosses a first threshold, the switched-mode power operates in a second operating mode. In the first operating mode the pulse modulated signal is adjusted to regulate a feedback signal to a first signal level, and in the second operating mode, a dead-time of the pulse modulated signal is adjusted to signal to regulate a feedback signal to a second signal level different from the first signal level. The method further includes driving a switch of the switched-mode power supply with the pulse modulated signal.

Switching converters are widely used in the field of power conversion. A switching converter includes at least one switch that is configured to generate a pulse-width modulated (PWM) voltage from an input voltage, and a rectifier arrangement that receives the PWM voltage and generates an output voltage to be supplied to a load. Usually the rectifier arrangement includes at least one inductive storage element, such as a choke, and at least one capacitive storage element, such as a capacitor. The PWM voltage is generated by switching the switching element on and off in accordance with a PWM drive signal. The drive signal is provided by a controller dependent on the output voltage. The controller is configured to vary the duty cycle of the drive signal in order to control the output voltage such that it assumes a given set-voltage.
The duty cycle of the drive signal is dependent on a power consumption of the load, whereas the duty cycle increases when the power consumption increases, and the duty cycle decreases when the power consumption decreases. Under low-load conditions, which occur when a power consumption of the load is very low, some modern controllers enter a burst mode. In the burst mode, the switching element is cyclically switched on and off during a burst-on period and the switching element remains permanently in an off-state during a burst-off period subsequent to the burst-on period. The burst-on period and the burst-off period define a burst period TBP and a burst frequency fBP, where fBP=1/TBP. The burst frequency may be dependent on several parameters, such as the input voltage, and the power consumption of the load.

Multi-mode operation and control of a resonant converter


A disc (1) has formed therein a header area (21) in which management information is recorded, and a data area (22) in which content information is recorded. Content information is recorded in units of an access block each including a succession of frames into the data area (22). The leading frame of the access block is taken as a base point of decoding. In the header area (21), there are recorded recording-position information for each access block and output-time information for the leading frame of each access block. At the top of the access block, there are recorded recording-position and output-time information for frames other than the leading frame. Thus, skip reproduction can be done by reading the recording-position and output-time information in the access block into a memory.

The typical formats for transmitting and recording compressed music and image data (will be referred to as "A content data" hereunder) include the so-called MPEG-2PS (PS: program stream) file format established as ISO/EEC 13818-1 and MPEG-4 file format established as ISO/IEC 14496-1 (will also be referred to as "MP4" hereunder).
In MPEG-2PS, it is required that AV content data, recording position necessary for reading and output of the AV content data, output-time information, etc. (will be referred to as "reference information" hereunder) should be allocated fragmentally and alternately. In MP4, it is required that compressed AV content information and all reference information should be collected and grouped by genre.
Note that when AV content data is recorded to a recording medium according to either or MPEG-2PS or MP4, there arise the following problems.
When MPEG-2PS is used, AV content data and reference information are allocated near each other. Streams recorded in the recording medium should be read sequentially at the normal speed in order to read the AV content data from the recording medium in succession at the normal speed. However, for special modes of reproduction such as fast-forward reproduction, jump reproduction and the like, streams recorded in the recording medium should be read at a high speed and the reference information be analyzed to locate a play-start point or to generate and pre-hold a list of reference information for the special modes of reproduction.
When MP4 is used, reference information on the entire recording medium are collectively recorded in one place. So, the reference information can be read first and held in a memory in a player. Thus, a play-start position can easily be figured out from the information in the memory, and reproduction can be done in special modes such as fast-forward reproduction, jump reproduction and the like than according to MPEG-2PS. However, since reference information is increased with an increased total time for AV content data, the memory should have a larger storage capacity.
Patent document 1:                Japanese Patent No. 3240017
Non-patent document 1:                Home page Hi-MD of the Sony Corporation. [retrieved on Jun. 18, 2004],        Internet <URL:http://www dot sony dot co dot jp/Products/Hi-MD/>

Recording device and method, reproduction device and method, and recording medium


In the manufacturing method of a semiconductor device according to the present embodiment, a resist is supplied on a base material. A template including a first template region having a device pattern and a second template region being adjacent to the device pattern and having supporting column patterns is pressed against the resist on the base material. The resist is cured, thereby transferring the device pattern to the resist on a first material region of the base material corresponding to the first template region and at the same time transferring the supporting column patterns to the resist on a second material region of the base material corresponding to the second template region to form supporting columns. The supporting columns are contacted with the first template region when the device pattern is transferred to a resist supplied to the second material region.

Along with downscaling of semiconductor devices, nanoimprint lithography (hereinafter, also NIL) is developed as an alternative lithography technique to photolithography. In the NIL, a template having concave or convex patterns is pressed against a substrate on which a resist is applied or dripped and then the resist is cured. This transfers the patterns of the template to the resist on the substrate.
In the NIL, when the resist is removed from the template after the resist is cured, tensile stress and shear stress occurs between the template and the resist. At this time, the resist may be stripped from the substrate together with the template. To suppress such resist stripping, the resist is caused to remain between the convex patterns of the template and the substrate to adjust the thickness of a residual layer of the resist (hereinafter, also RLT (Residual Layer Thickness)) between the convex patterns of the template and the substrate. The RLT is generally adjusted according to a pressure at which the template is pressed against the substrate. However, because the resist before curing is liquid, the RLT is likely to vary if the RLT is controlled according to a pressure applied between the template and the substrate. If the RLT of the resist varies, the size, height, taper angle, and the like of the resist may also vary during processing of a base material. When the base material is processed using such a resist as a mask, the size, height, taper angle, and the like of the base material also disadvantageously vary.

Manufacturing method of semiconductor device and lithography template