A track access apparatus is provided by the present invention in which a reference drive signal 90 proportional to the reference acceleration of a beam spot 22 is generated according to the contents of a track counter 34. A signal 92 indicating the reference velocity of the beam spot 22 is generated by an integrator 40 in accordance with reference drive signal 90. A signal 82 indicating the position of an objective lens 20 relative to a coarse actuator 26, a signal 84 indicating a relative velocity, and a signal 94 indicating the difference between the actual velocity of beam spot 22 and a reference velocity are supplied to coarse actuator 26 and to a fine actuator 28. Reference drive signal 90 is supplied to coarse actuator 26. The present invention makes maximum use of the rapid acceleration and deceleration capability of the coarse actuator and moves the beam spot to a target track accurately at high speed. The present invention also controls the velocity of the beam spot relative to an optical recording medium by using a simple hardware structure.

On an optical disk, tracks for writing information are arranged in a concentric circular form or in a spiral form on the recording surface. When information is to be written to or read from such an optical disk, a beam focused by an objective lens is radiated onto the disk in spot form and the desired tracks are traced. Since an objective lens and its support are heavy, a two-stage configuration is employed to enable the actuator to move a beam spot at high speed. A coarse actuator moves an objective lens and thus a beam spot roughly, while a fine actuator controls the position of the beam spot on the recording medium precisely. Conventional track access techniques are explained below with reference to pertinent documents.
PUPA No. 62-51037 discloses a technique for moving a beam spot mainly by means of a fine actuator. That is, a fine actuator is first driven so that the velocity of the beam spot relative to a disk matches a reference velocity. Then, a coarse actuator is driven by a signal indicating the displacement of the beam spot that is caused by the fine actuator, and this displacement is compensated for. Since the driving of the coarse actuator is delayed, it is difficult to make maximum use of its acceleration and deceleration capability. Moreover, at the time of acceleration and deceleration, the beam spot is displaced. Since the amount of displacement is proportional to the acceleration and deceleration, the beam spot is widely displaced when the acceleration or deceleration is great. The impossibility of obtaining reliable tracking error signals (hereafter referred to as TES) causes problems. Furthermore, because of this large displacement, there is a problem in that a large transient shock is transmitted from the coarse actuator to the fine actuator and the beam spot leaves the desired track when an attempt is made to hold the position of the beam spot in the center of tracks in order to write or read information after track access.
PUPA No. 1-290176 discloses a technique for transmitting to a coarse actuator a signal representing the difference between the drive signal (reference velocity signal) and the travel velocity signal of a beam spot, and for transmitting a high-frequency component of the signal to a fine actuator. In general, a coarse actuator cannot respond quickly, because its moving parts are heavier than those of a fine actuator. Therefore, the unit is designed to supply a quick response component to a fine actuator so that an objective lens can move over a disk surface correctly. However, this technique has problems in that the beam does not pass through the center of the objective lens when the objective lens slides slowly due to the movement of the coarse actuator, especially since, for an axial rotating-type fine actuator, it is difficult to manufacture an optical head so that the rotation shaft strictly matches the center of gravity of the fine actuator. Therefore, in reality, an objective lens driven by a fine actuator is accelerated proportionally to the acceleration of the coarse actuator. As a result, it slides slowly. However, this kind of movement cannot be compensated for by the high-frequency component of the above difference signal. If the objective lens is not positioned at the center of the beam by means of a spring when the fine actuator is not being driven, the beam cannot be controlled so that it passes through the center of the objective lens unless a direct current component is added to the difference signal.
In the conventional technology, when the velocity of a beam spot relative to an optical disk is to be controlled, a reference velocity generally recorded in ROM is read out according to the distance (number of tracks) from the current position of the beam spot to a target track. The reference velocity can be determined precisely according to the number of tracks, so that the velocity will be zero at the beginning and end of track access, and greatest in the middle. However, increasing the ROM capacity is problematic because a large amount of information must be stored in ROM. Neither of the aforementioned references shows an effective solution to this problem.

International Business Machines Corporation


A fluorescent lamp apparatus includes a fluorescent tube, a ballast circuit for lighting the fluorescent tube, a case for housing the ballast circuit and a holder provided at the end of the case for holding the fluorescent tube. The ballast circuit includes at least a first circuit board and a second circuit board, and the first and second circuit boards are arranged substantially perpendicular to each other in the case. This configuration can suppress an increase in the size of the apparatus and prevent thermal damage to the circuit elements during lamp operation.

1. Field of the Invention
The present invention relates to a self-ballasted fluorescent lamp, particularly, to an improvement in the arrangement of circuit boards that constitute a ballast circuit.
2. Description of the Related Art
As a conventional fluorescent lamp apparatus, e.g., a bulb-shaped fluorescent lamp has been known, including a fluorescent tube, a ballast circuit for lighting the fluorescent tube, and a case (cover) for housing the ballast circuit. JP 2000-21351 A discloses such a bulb-shaped fluorescent lamp, where a circuit board of a ballast circuit is divided into two parts and the two circuit boards are arranged in parallel to each other, so that the area of the ballast circuit is small and the size of circuit-mounted structure is reduced. Those two circuit boards are connected electrically by a cable or the like.
In the conventional bulb-shaped fluorescent lamp, the number of electronic components (hereinafter, referred to as circuit elements) required for electronic lighting is generally about 30 to 40.
In recent years, it has been desired to apply the conventional bulb-shaped fluorescent lamp to a dimmable lighting fixture. For this reason, a ballast circuit having a dimming function has been proposed, which is formed by adding the circuit elements for dimming to a conventional ballast circuit.
However, in the ballast circuit having a dimming function, the number of circuit elements is increased from two to four times that of the conventional ballast circuit by the addition of the circuit elements for dimming. Therefore, the circuit board becomes large, which in turn increases the size of the case that houses the circuit board. Consequently, the lamp apparatus itself becomes large as well.
Moreover, the dimming circuit elements to be added include circuit elements that are easily damaged by heat. Thus, those circuit elements are damaged by heat radiated from the fluorescent tube during lamp operation, making the lifetime shorter than that of the conventional lamp.
Therefore, with the foregoing in mind, it is an object of the present invention to provide a fluorescent lamp apparatus with longer lifetime that can suppress an increase in the size of a case for housing a ballast circuit, i.e., a lamp apparatus, and prevent the thermal damage to circuit elements during lamp operation, even if the number of the circuit elements is increased like a ballast circuit having a dimming function.
A fluorescent lamp apparatus of the present invention includes a fluorescent tube, a ballast circuit for lighting the fluorescent tube, a case for housing the ballast circuit, and a holder provided at the end of the case for holding the fluorescent tube. The ballast circuit includes at least a first circuit board and a second circuit board, and the second circuit board is arranged to be substantially perpendicular to the first circuit board.
This enables the effective utilization of space in the case when the ballast circuit is housed therein. Thus, even if the number of circuit elements is increased, the above configuration can suppress an increase in the case size. In addition, the circuit elements that are affected easily by heat can be separated from the fluorescent tube.
It is preferable that the first circuit board is arranged between the holder and the second circuit board so as to be substantially perpendicular to the central axis of the case.
It is preferable that the second circuit board is arranged so that a portion of its periphery comes into contact with the first circuit board.
It is preferable that the width of the second circuit board is reduced in the direction opposite to the fluorescent tube.
It is preferable that the second circuit board is displaced from the central axis of the case.
It is preferable that circuit elements that generate heat by electrical loss are mounted on the first circuit board, while circuit elements that are affected easily by heat are mounted on the surface of the second circuit board that does not face the circuit elements generating heat by electrical loss.

Matsushita Electric Industrial Co., Ltd.


This invention involves a novel paint formulation comprising a phosphate or metal sulfide heavy metal reactive compound, a binder, a solubilizing compound and a buffer which acts as a carrier for heavy metal reactive chemicals so that when this novel paint is applied to a heavy metal painted surface and both are subsequently removed, the heavy metal paint waste is rendered non-hazardous under the TCLP test.

Lead in the form of Pb.sub.3 O.sub.4, known as "red lead," has been widely used in rust-inhibiting paints and primers for iron and steel. Other lead compounds have also been important in paint pigments. Lead chromate, PbCrO.sub.4, is a brilliant yellow and is used in road markings. A mixture of PbCO.sub.3 and Pb(OH).sub.2, is the traditional formulation of the pigment used in white paint. In the last twenty years, lead-based pigments for use in household paints have been abandoned. Lead is a toxic heavy metal and the sweet flavor which it can impart to paints has been the cause of incidents of lead poisoning among small children who eat paint flakes. Due to a heightened awareness of the danger of the release of heavy metals into the environment, the abandonment of lead pigment from structures such as bridges, watertowers and heavy machinery has also resulted. The massive historic use of lead-containing paints on these same structures has lead to considerable costs and difficulty in their maintenance. Bridges watertowers, heavy equipment and the like, must periodically be stripped of their paint coating and repainted. This stripping of lead-based paints can result in releasing considerable amounts of lead into the environment.
Safe elimination of these hazardous materials is gaining more attention due to the new Environmental Protection Agency (EPA) laws imposed because of the extreme toxicity of many of the resulting lead waste products. Wastes from lead paint removal are often hazardous due not only to the high lead content but also from the presence of zinc, cadmium, copper, nickel, barium and other heavy metals present. Handling and disposal of these hazardous wastes is far more complicated and expensive than if they were nonhazardous.
A key element of the EPA regulatory scheme for protecting the environment from heavy metal toxins is determining when regulations apply. A material such as lead paint is not a toxic waste when it is fulfilling its intended purpose as a protective coating on a bridge or structure. Hence, there is a regulatory and logical distinction between toxic materials and toxic wastes. The distinction is that many toxic materials perform useful and even essential functions in our society and it is only the improper disposal thereof that causes harm to the environment. However, once a toxic waste is generated by sandblasting a bridge to remove lead paint for example, the sandblasting operation is considered to generate a toxic waste material which falls under the governing EPA regulations. Thus, it is extremely beneficial if the lead paint is rendered nonhazardous prior to its removal from the surface. This eliminates the production of hazardous wastes thereby avoiding the requirement of adhering to strict EPA regulations since no hazardous wastes are ever produced. This reduces costs greatly and simplifies the methods of handling and disposal of the resulting nonhazardous waste.
The EPA laws and regulations recognize the distinction between lead which is soluble and, therefore, hazardous and lead which is not soluble and, therefore, nonhazardous. This recognition comes about in terms of tests which define the toxicity of the material by the amount of lead which can be leached from a waste sample under standard test conditions. Environmental regulations which have been drawn up to deal with heightened awareness of lead as a source of toxicity in the environment has divided all materials into two classes, toxic and nontoxic wastes. Toxic wastes are defined by a standard test which determines the leachability of a toxin such as lead. The most common test which is used by the EPA is the Toxicity Characteristic Leaching Procedure (TCLP) which measures the amount of leaching of various hazardous contaminants from a solid waste.
The chemistry involved behind rendering leaded paint nonhazardous is controlled both by the pH as well as by forming insoluble compounds with the lead. Any chemical compound or element which achieves those goals can be used, however, a compound containing phosphorus and a pH buffer may sufficiently bind the lead and cause a favorable pH condition, thereby immobilizing it.
U.S. Pat. No. 5,637,355 entitled "Method of Nonhazardous Removal of Paint Containing Heavy Metals and Coating Preparation for Same" by Robert Stanforth and Paul Knopp outlining this technology is herein incorporated by reference.
Current techniques to avoid EPA regulation by eliminating generation of a hazardous waste include adding lead-reactive treatment chemicals directly to the blasting media. As the lead paint is removed by blasting, it is mixed with the treatment chemicals present in the blasting media. Due to the fact that the treatment chemical is directly added to the grit of blasting media (e.g. sand or zircon) and preblended, and subsequently blasted on the steel surfaces of bridges, watertowers, etc., production of hazardous wastes is avoided. Typically, the lead-reactive chemical is a cement-type compound. This method has several drawbacks. First, this method produces excessive dusting resulting in personnel safety hazards, reduced visibility and breathing control problems for workers. Additionally, the cement treatment additives to the grit must be in a fairly high dose of approximately 20%. The cement treatment chemical is not a good cutting medium (not as good as the zircon or sand grit) and, therefore, the cutting efficiency of the blasting is reduced by 20%, resulting in the lead paint removal taking 20% longer.
Another method of rendering the lead paint nonhazardous is via a treatment process which introduces an additive which renders heavy metals nonhazardous to a coating preparation formula. This coating preparation is then applied over an existing lead paint before the lead paint is removed from the surface. The lead paint is thereby rendered nonhazardous before it is removed from its surface and becomes a waste material. A problem associated with this method is that there are no coating preparations currently available which would sufficiently carry the lead-reactive compound and have properties to facilitate proper treatment.
The key to the present invention is producing an adequate carrier for the lead-reactive additives. In the present invention, this carrier for the lead-reactive additive is a paint formulation. This paint must contain a sufficient quantity of the lead treatment additives which will immobilize the lead contained in the paint. It is also important that the carrier be able to hold substantial amounts of the lead reactive additives without having to be repeatedly applied or result in extremely thick layers of carrier to the lead-painted surface. Also, it would be advantageous if the carrier paint holds the lead treatment additives uniformly throughout thereby enabling the entire leaded surface to be treated in a consistent manner. In addition, it would be advantageous if the carrier paint could be removed by a number of different lead-paint removal systems such as sandblasting and other hard grit methods as well as soft grit methods utilizing water, plastic or even simple mechanical wire brush means. The TCLP test requires that the waste materials be water-soluble and, therefore, the carrier paint should be water-soluble for sufficient TCLP testing. The carrier paint should be able to cover and be subsequently removed from a myriad of different surfaces including steel, wood surfaces, gypsum, dry wall and plaster boards. The carrier paint must have the ability to coat leaded surfaces using conventional means ranging from an airless spray gun to a roller or brush and yet properly cover the lead-painted item with adequate thickness and consistency.
A problem encountered with simply utilizing off-the-shelf paints as the carrier is that off-the-shelf formulas do not provide some or all of the aforementioned characteristics for a number of reasons.

Paint for nonhazardous removal of heavy metals and method for using the same


A power output system that provides power to a driveshaft is provided which includes an internal combustion engine, an electric motoring mechanism, an electric storage device, a first exhaust gas channel that guides exhaust gas from the engine directly to an exhaust gas purifying catalyst, a second exhaust gas channel which guides the exhaust gas from the engine to the exhaust gas purifying catalyst via an unburned-component adsorber, a channel switching mechanism operable to switch a channel of the exhaust gas from the engine between the first exhaust gas channel and the second exhaust gas channel, a pressure accumulator operable to accumulate therein a negative pressure produced through rotation of the engine, a negative-pressure introducing/releasing mechanism that selectively permits and inhibits introduction of the negative pressure from the pressure accumulator into the channel switching mechanism, and a controller that controls the electric motoring mechanism and the negative-pressure introducing/releasing mechanism.

1. Field of the Invention
The invention relates to a power output system that provides power to a driveshaft, a vehicle including the power output system, and a method of controlling the power output system.
2. Description of Related Art
Japanese Patent Application Publication No. 2001-41026 (JP-A-2001-41026) discloses an internal combustion engine including a HC adsorption apparatus provided upstream of a catalytic converter in an exhaust passage. The HC adsorption apparatus of this engine includes a main passage, a switching valve that opens and closes the main passage, and a bypass passage that bypasses the main passage, and a HC adsorbent that adsorbs hydrocarbon (HC) contained in exhaust gas is disposed in the bypass passage. The switching valve is coupled to a diaphragm of a diaphragm mechanism, and a variable pressure chamber of the diaphragm mechanism is connected to an intake manifold via a negative pressure feed line and a vacuum switching valve (VSV). When the VSV is turned on, a negative pressure produced through the operation of the engine is supplied to the variable pressure chamber of the diaphragm mechanism so as to deform the diaphragm, and the switching valve operates, in accordance with the deformation of the diaphragm, to close the main passage, so that the exhaust gas of the engine passes through the HC adsorbent in the bypass passage and then flows into the catalytic converter. When the VSV is turned off, the atmospheric pressure is introduced into the variable pressure chamber of the diaphragm mechanism via the negative pressure feed line, causing no deformation of the diaphragm, and the switching valve is placed in the fully opened state, so that the exhaust gas of the engine flows into the catalytic converter via the main passage, without passing through the HC adsorbent.
In the internal combustion engine as described above, when the catalytic converter has not been sufficiently warmed up, the negative pressure produced through the operation of the engine is used to switch the exhaust gas channel from the main passage to the bypass passage, so that hydrocarbon as an unburned component in the exhaust gas is adsorbed by the HC adsorbent in the bypass passage. After the catalytic converter is sufficiently warmed up, the exhaust gas channel is switched from the main passage to the bypass passage again, so that the adsorbed unburned hydrocarbon can be cleaned (i.e., converted into harmless substances) by the catalytic converter. However, the negative pressure cannot be produced while the engine is at rest or stopped, and, even if the engine is operated, a sufficiently reduced pressure may not be developed, depending on the operating conditions (load) of the engine. Thus, in the internal combustion engine as described above, switching of the exhaust gas channel from the main passage to the bypass passage may not be accomplished because of a shortage or lack of the negative pressure when the switching is to be done, and an unburned component, such as hydrocarbon, in the exhaust gas may be discharged to the outside without being converted into harmless substances.

Power output system, vehicle including the same, and method of controlling power output system


A substrate inspection apparatus 1-1 (FIG. 1) of the present invention performs the following steps of: carrying a substrate “S” to be inspected into an inspection chamber 23-1; maintaining a vacuum in said inspection chamber; isolating said inspection chamber from a vibration; moving successively said substrate by means of a stage 26-1 with at least one degree of freedom; irradiating an electron beam having a specified width; helping said electron beam reach to a surface of said substrate via a primary electron optical system 10-1; trapping secondary electrons emitted from said substrate via a secondary electron optical system 20-1 and guiding it to a detecting system 35-1; forming a secondary electron image in an image processing system based on a detection signal of a secondary electron beam obtained by said detecting system; detecting a defective location in said substrate based on the secondary electron image formed by said image processing system; indicating and/or storing said defective location in said substrate by CPU 37-1; and taking said completely inspected substrate out of the inspection chamber. Thereby, the defect inspection on the substrate can be performed successively with high level of accuracy and efficiency as well as with higher throughput.

In the field of semiconductor processes, the design rule is going into an age of 100 nm and the production form is on a transition from a mass production with a few models representative of a DRAM into a small-lot production with a variety of models such as a SOC (Silicon on chip). This results in an increase of a number of processes, and thus an improvement in yield for each process becomes essential, which makes more important an inspection for a defect possibly occurring in each process. The present invention relates to an apparatus to be used in the inspection of a wafer after respective processes in the semiconductor processes, and in particular to an inspection method and apparatus using an electron beam and also to a device manufacturing method using the same.
In conjunction with a high integration of semiconductor device and a micro-fabrication of pattern thereof, an inspection apparatus with higher resolution and throughput has been desired. In order to inspect a wafer substrate of 100 nm design rule for any defects, a resolution in size equal to or finer than 100 nm is required, and the increased number of processes resulting from a high integration of the device has called for an increase in the amount of inspection, which consequently requires higher throughput. In addition, as a multi-layer fabrication of the device has been progressed, the apparatus has been further required to have a function for detecting a contact failure in a via for interconnecting wiring between layers (i.e., an electrical defect). In the current trend, an inspection apparatus of optical method has been typically used, but it is expected that an inspection apparatus using an electron beam may soon be of mainstream, substituting for the inspection apparatus of optical method in the viewpoint of resolution and of inspection for contact failure. The inspection apparatus of electron beam method, however, has a weak point in that the inspection apparatus of electron beam method is inferior to the inspection apparatus of optical method in view of throughput.
Accordingly, it would be desirable to develop an apparatus having higher resolution and throughput and being capable of detecting the electrical defects. It is known that the resolution in the inspection apparatus of optical method is limited to ½ of the wavelength of the light to be used, and it is about 0.2 μm for an exemplary case of a visible light having put to practical use.
On the other hand, in the method using an electron beam, typically a scanning electron microscope (SEM method) has been put to practice, wherein the resolution thereof is 0.1 μm and the inspection time is 8 hours per wafer (20 cm wafer). The electron microscope method further has a distinctive feature that it is able to inspect for any electrical defects (breaking of wire in the wirings, bad continuity, bad continuity of via). However, the inspection speed (sometime also referred to as inspection speed) thereof is very low, and so the development of an inspection apparatus with higher inspection speed has been expected.
Generally, since an inspection apparatus is expensive and a throughput thereof is rather lower as compared to other processing apparatuses, therefore the inspection apparatus has been used after an important process, for example, after the process of etching, membrane deposition, CMP (Chemical-mechanical polishing) planarization or the like.
The inspection apparatus of scanning method using an electron beam (SEM) will now be described. In the inspection apparatus of SEM method, the electron beam is contracted to be narrower (the diameter of this beam corresponds to the resolution thereof) and this narrowed beam is used to scan a sample so as to radiate it linearly. On the other hand, moving a stage in the direction normal to the scanning direction allows an observation region to be irradiated by the electron beam as a plane area. The scanning width of the electron beam is typically some 100 μm. Secondary electrons emitted from the sample by the irradiation of said contracted and narrowed electron beam (referred to as a primary electron beam) are detected by a detector (a scintillator plus photo-multiplier (i.e., photoelectron multiplier tube) or a detector of semiconductor type (i.e., a PIN diode type) or the like). A coordinate for an irradiated location and an amount of the secondary electrons (signal intensity) are combined and formed into an image, which is stored in a storage or displayed on a CRT (a cathode ray tube). The above description shows the principle of the SEM (scanning electron microscope), and defects in a semiconductor wafer (typically made of Si) in the course of process may be detected from the image obtained in this method. The inspection speed (corresponding to the throughput) is varied in dependence on an amount of primary electron beam (the current value), a beam diameter, and a response time of the detector. The beam diameter of 0.1 μm (which may be considered to be equivalent to the resolution), the current value of 100 nA, and the response time of the detector of 100 MHz are the currently highest values, and in the case using those values the inspection speed has been evaluated to be about 8 hours for one wafer having the diameter of 20 cm.
In order to improve the inspection apparatus of said SEM method to work at much higher speed (to increase the throughput), a new method referred to as an image projecting method has been suggested. According to this method, an observation region on a sample is irradiated in block by a primary electron beam (i.e., no scanning but an irradiation covering a certain area), and secondary electrons emitted from the irradiated region are formed into an image in block by a lens system on a detector (a micro-channel plate (MCP) plus fluorescent screen) as an image of electron beam. That image is used in a two-dimensional CCD (charge coupled device) or a TDI-CCD (Time Delayed Integration-CCD) to convert the image data into an electric signal, and from this image data, defects in the sample wafer (the semiconductor (Si) wafer in the course of process) may be detected.
Accordingly, there has arisen a demand for constructing an overall system for inspecting such as a substrate with high level of accuracy and efficiency by using a defect inspection apparatus of said image projecting method having an advantage of higher throughput. Almost no study has made clear an overall structure of such an inspection apparatus that, for example, feeds a sample to inspection as in a clean state to an irradiating location in the image projecting optical apparatus, allowing for an association with the other subsystems to be brought in alignment with it. In addition, in such an environment where the diameter of a wafer subject to inspection has been made larger and larger, there has arisen a demand that the subsystems also should be correspondingly modified to be suitable for the wafer having a large diameter.
In the inspection system, maintaining a vacuum atmosphere within the chamber is one of the important terms. In an apparatus such as a defect inspection apparatus that provides an ultraprecision processing, a stage for accurately positioning a sample in the vacuum atmosphere has been used, wherein in the case where said stage is required to be positioned highly accurately, one structure has been conventionally employed, in which the stage is supported in non-contact manner by a hydrostatic bearing. In this case, the vacuum level in a vacuum chamber is maintained by forming in an extent of the hydrostatic bearing a differential pumping mechanism for exhausting a high pressure gas so that the high pressure gas supplied from the hydrostatic bearing may not be directly exhausted into the vacuum chamber. Aiming at such a stage, specifically a stage including a combination of the hydrostatic bearing and the differential pumping mechanism has been proposed, as shown in FIGS. 29 [A] and [B]. In this configuration, when the stage moves, guide planes 6a–7 and 7a–7 facing to the hydrostatic bearing 9-7 move forth and back between the high pressure gas atmosphere in the hydrostatic section and the vacuum environment within the chamber. For this period, the gas is adsorbed onto the guide plane during it being exposed to the high pressure gas atmosphere and the adsorbed gas is discharged once the guide plane is exposed to the vacuum environment, which will repeatedly occur. Owing to this, every time when the stage moves, there occurs such an event that the vacuum level within the chamber C is deteriorated, which disadvantageously has inhibited the processing including the aforementioned exposure, inspection and process by using the charged particle beam from being performed stably, or otherwise the sample has been contaminated.
Further, there have been such problems in the above-described stage including a combination of the hydrostatic bearing and the differential pumping mechanism that because of the differential pumping mechanism having been added, the structure has become more complicated and the reliability as a stage has decreased in contrast with the increased cost.
As for the electron beam apparatus of the image projecting method by itself, since a plurality of signals from a plurality of pixels on the sample surface can be captured all at once, therefore this method is advantageous in the point of the pattern inspection with the high throughput, while the method is problematic in the point that the sample may be charged due to a plurality of pixels being exposed to the irradiation of the electron beam all at once. On the other hand, in the case where a mark for positioning on the wafer is to be detected during the processes, a field of view may not necessarily be such wide that would be required by the image projection in the pattern inspection but a narrower field of view may be sufficient, wherein it is rather problematic that an insufficiently small pixel size may result in an insufficient mark detection accuracy.
Besides, for the MCP, as a total output charge amount (screen current×time period) is increased over a long-time use, the MCP multiplication factor is decreased, and therefore there has been a problem in that a defective image contrast may change or deteriorate with the same MCP applied voltage upon picking up the defective images successively for a long period in the defect inspection apparatus.
Further, an amplification factor in the image beam current amount is determined by a voltage applied between a first MCP and a second MCP and for example, the amplification factor should be 1×104 with the applied voltage of 1.4 kV. Additionally, a voltage on the order of 3 kV is applied between the second MCP and the fluorescent screen in order to inhibit the expansion of the image beam output from the second MCP. A detector of a conventional electron beam apparatus, in which a camera sensor and a vacuum flange have been separately formed, is disadvantageous in that it has a longer signal line, it is susceptive to signal latency or disturbance, and it prohibits the fast driving of the detector, which has been factors to decrease the throughput in the inspection (a process volume per time).
Further, to perform the defect inspection by using the electron beam, an emission current flow to an electron gun is required to be controlled so as to keep the contrast in the picked-up image at a constant level, and typically the emission current has been controlled by adjusting a voltage applied to the Wehnelt electrode made of such material as LaB6 (lanthanum hexaboride) disposed downstream to the electron gun. FIG. 15 is a graph illustrating a relationship between the voltage (in volt) applied to the Wehnelt electrode and the emission current (in microampere) of the electron gun, and it is seen from this graph that if the voltage applied to the Wehnelt electrode exceeds the level of −300 volt, the emission current increases rapidly.
However, if the electron gun operates for a long time under the condition that the applied voltage to the Wehnelt electrode is maintained at a constant level, an oxide film including La and B emitted from the electron gun may adhere to the inside of the Wehnelt electrode and form an insulating film thereon, which will be positively charged. This is because the electron emitted from the electron gun has an accelerating energy as much as the applied voltage to the Wehnelt electrode, and such electrons impinging upon said insulating film may cause the insulating film to emit the secondary electrons more than the electrons flowing into the Wehnelt electrode. As a matter of fact, there has been a problem in that the applied voltage to the Wehnelt electrode shifting to the positive direction causes a gradual increase in the emission current of the electron gun, which makes it difficult to hold the constant emission current.
On the other hand, advantageously the inspection apparatus having a function as the scanning electron microscope according to the prior art, as compared to the inspection apparatus of the image projecting method, has no such problem that the sample is charged but has a sufficient mark detection accuracy. Individually, either of them has to solve the following problems.
For example, if a sample wafer includes a via formed therein, then a care must be taken upon performing an evaluation procedure for the sample wafer. This is because if a large decelerating electric field as well as the primary electron beam by the amount of not less than a certain value is applied between the objective lens and the wafer, a discharge occurs between the via and the objective lens, and said discharge may possibly cause a damage to a device pattern formed in the wafer. There are a wafer of one type that is apt to incur such a discharge and a wafer of other type that hardly incurs the discharge, wherein the wafer of either type has a different condition of inducing the discharge (different decelerating electric field voltage value and different primary electron beam amount).
Further, it has been known that an edge portion of a pattern is apt to dazzle due to a higher secondary electron emission rate. With the higher secondary electron emission rate, the detection signal of the secondary electron beam to be output by the detector has an increasing signal intensity, and disadvantageously this detection signal results in a masking of a signal generated by a defect, thereby deteriorating the inspection speed.
In an apparatus for evaluating the post-process condition of a wafer according to the prior art, the inspection is performed to encompass the entire area of the wafer, and therefore the wafer is moved within a working chamber so that an arbitrary point on the wafer surface may be positioned in alignment with the optical axis of the electron beam. Accordingly, the evaluation apparatus of the conventional example needs a bottom area extended in the forth and back and the left and right directions by such an amount that can accommodate the movement of the wafer, and inevitably the evaluation apparatus has an enlarged floor area. This enlargement of the floor area is a counter trend toward the effective use of the clean room, thus it is desired to make the evaluation apparatus compact.
Further, said conventional apparatus requires an inspection time of a few hours for a single wafer (a few hours/wafer) to accomplish the inspection covering the entire surface of the wafer. On the other hand, the throughput in the wafer processing apparatus reaches to approximately 100 wafers in 1 hour (about 100 wafers/hour), which means that the inspection time of the wafer is equivalent to dozen times of the process time. Thus, in the circumstance that there is a mismatch between the throughput of the evaluation apparatus and the throughput of the processing apparatus, it would be desirable that those throughputs are matched to each other by reducing the inspection time.
A gate oxide of the semiconductor device is apt to be made thinner year by year, and it has been believed that the thickness of the film may be on the order of 1 nm in the year of 2005 and 0.5 nm in the year of 2005. In addition, the minimum line width "d" of the pattern formed in the sample subject to the inspection is getting narrower, and in proportion to that, it is required to reduce the pixel size used in the evaluation. On the other hand, in order to secure an S/N ratio of the signal at a certain level, it is required to obtain a certain amount of detected secondary electrons per pixel, consequently leading to the trend of increasing the amount of the primary electron per unit area. As a result, the gate oxide is likely to be damaged (including breakdown) as it is getting thinner, while the voltage generated between both sides of the gate oxide increases as the dose increases, thereby the gate oxide is more apt to be damaged. In this viewpoint, it is strongly desired that such an electron beam apparatus be provided which would not give any damage to a thin gate oxide of a sample to be inspected.
Besides, there is a need for improving the throughput as much as possible, and thus it is desired that a sample such as a single wafer (hereafter referred to as a sample for simplicity) may be completely inspected or evaluated within a process time as long as that taken by a process prior to the inspection process. In this regard, it is also conceivable that the inspection time per sample may be reduced by evaluating an arbitrary small number of chips among many chips in a single sample.
Further, there has been no study on how to inhibit an aberration due to forming the primary beam into a multi-beam. In specific, such a method is strongly required that forms the multi-beam by using an optical system which prevents an image field curvature aberration, which is a most serious aberration among aberrations associated with the primary beam.
In conjunction with a defect inspection apparatus described above which uses the image projecting system and the multi-beam scanning method, it has been also suggested that an image recognition technology should be improved so as to achieve a fast and highly accurate defect inspection on a patter of micro-fabrication. However, the prior art has a problem that there may be a position mismatch between an image of the secondary electron beam obtained by irradiating the primary electron beam onto a region to be inspected on a surface of a sample and a reference image which has been prepared in advance, thereby resulting in the deterioration in the accuracy in the defect inspection. This position mismatch could be a serious problem specifically when the irradiating region of the primary electron beam is in the misalignment with respect to the wafer and a part of the inspected pattern falls out of the detected image of the secondary electron beam, which could not be compensated for properly by simply using the technology for optimizing the matching region within the detected image. This problem could be a critical drawback specifically in the inspection of a pattern of high-precision.
An object of the present invention is to provide an inspection method and an apparatus using an electron beam which have overcome those aforementioned problems and can detect a defect in a sample with high level of throughput and accuracy, and also to provide a semiconductor device manufacturing method using these inspection method and apparatus.

Apparatus for inspection with electron beam, method for operating same, and method for manufacturing semiconductor device using former


A hinge assembly adapted for a housing having a main body and a sub-body rotatably positioned on the main body, the hinge assembly including: a first hinge portion adapted to rotatably support both lower sides of the sub-body; and a second hinge portion adapted to rotatably support a rear surface of the sub-body with a surface contact and to maintain a rotated angle of the sub-body. The first hinge portion includes: a hinge protrusion arranged on one side surface of the sub-body; a hinge protrusion inserting-hole arranged on one side surface of a sub-body rotational space and adapted to receive the hinge protrusion; a hinge-hole arranged on the other side surface of the sub-body; a through-hole arranged on the other side surface of a sub-body rotational space to correspond to the hinge-hole; and a hinge locker passing through the through-hole and the hinge-hole. The second hinge portion includes: a curved portion protruding from a bottom surface of the sub-body and having a gear groove arranged on the surface thereof; a window arranged on the sub-body rotational space of the main body and passing through the curved portion; and a pinion rotatably positioned at a predetermined position, the pinion arranged to be rotated together with the sub-body upon the sub-body being rotated in engagement with the gear groove.

1. Field of the Invention
The present invention relates to a hinge assembly adapted for use with a housing having a sub-body positioned on a main body at an adjustable angle and, more particularly, to a hinge assembly adapted for use with a housing, the hinge assembly increasing the accuracy of an angle adjustment and increasing its strength by improving a structure for rotating the sub-body. The present invention also relates to a housing having such a hinge assembly.
2. Description of the Related Art
Generally, in devices such as a telephone (for example, a key-phone terminal), a printer, etc., a liquid crystal display (hereinafter referred to as an "LCD") is used to display an operation mode or an operation state of the device as a user presses a button, etc. of the device.
The LCD is designed to allow its angle with respect to a main body of the device housing to be adjusted, thereby facilitating convenience of its use.
U.S. Pat. No. 6,618,903, entitled "Hinge Device," issued on Sep. 16, 2003, relates to an angle adjustment device of an LCD. The patent recites a foldable appliance which comprises a main body, an openable sub-body positioned on the main body and a hinge device for hinging the sub-body to the main body, the hinge device comprising: a hinge shaft having one end mounted to the sub-body and the other end mounted to the main body, wherein the one end is movably fixed together with the sub-body, and the other end partially passes through the main body to run at idle; a fixed disk, penetrated by the other end of the hinge shaft and fixed to the main body, having at least one notch and at least one protrusion continued from the notch, on an opposite surface of a surface contacted with the main body; a movable disk penetrated by the other end of the hinge shaft, surface contacted with the fixed disk, and positioned to rotate together with the hinge shaft, the movable disk having at least one protrusion extending from a surface contacted with the fixed disk; elastic means positioned to axially press the movable disk; and fixing means for fixing the fixed disk, the movable disk and the elastic means penetrated by the hinge shaft.
However, such a hinge device has a problem in that its structure is very complex and manufacture and assembly thereof are very costly.
Furthermore, when the sub-body is maintained at a predetermined angle by a friction force of the disk, the hinge assembly has another problem in that the sub-body can move when the friction force is weak, and alternatively, a high force is required to move the main body when the friction force has been increased to prevent the sub-body from moving.
In addition, the hinge assembly has still another problem in that a spring back phenomenon occurs when the sub-body is rotated due to the friction force of the disk.
The following patents each discloses features in common with the present invention but do not teach or suggest the inventive features specifically recited in the present application: U.S. Pat. No. 5,187,743 to Gumb et al., entitled TELEPHONE BASE WITH A DISPLAY UNIT, issued on Feb. 16, 1993; U.S. Pat. No. 6,351,535 to Nogas et al., entitled VARIABLE ANGLE MECHANISM FOR DESKTOP TELEPHONE, issued on Feb. 26, 2002; U.S. Pat. No. 6,088,447 to Aggus et al., entitled TELEPHONE BASE INCLUDING VISUAL DISPLAY MODULE, issued on Jul. 11, 2000; U.S. Pat. No. 5,761,297 to Kingsbury et al., entitled INTERCONNECTION MECHANISM FOR A TILTABLE TELEPHONE DISPLAY UNIT, issued on Jun. 2, 1998; U.S. Pat. No. 6,445,793 to Vassallo et al., entitled ADJUSTABLE TELEPHONE SYSTEM AND METHOD, issued on Sep. 3, 2002; U.S. patent application No. 2003/0221288 to Kim et al., entitled HINGE ASSEMBLY FOR A FLAT DISPLAY MONITOR published on Dec. 4, 2003; U.S. patent application No. 2002/0092129 to Brewington et al., entitled TILT HINGE, published on Jul. 18, 2002; and U.S. patent application No. 2003/0163900 to Rude et al., entitled POP-UP FRICTION HINGE HAVING MULTIPLE LE VELS OF TORQUE, published on Sep. 4, 2003.


[Problem to be Solved]

With an engine of a vehicle and the like, blow-by gas is emitted from a combustion chamber toward the inside of a crankcase through a gap between a piston and a cylinder. This blow-by gas is an unburned mixture, and is thus returned to the engine. However, this blow-by gas also contains oil mist. Accordingly, at the time of returning the blow-by gas to the engine, the oil mist is separated from the blow-by gas by a ventilator.
For example, a device described in PTL 1 accelerates the flow of blow-by gas by a nozzle, and injects the blow-by gas against a collision wall opposite the nozzle. This collision wall is covered with a textile or non-woven cloth, and is structured to absorb the oil mist.

Abstract: [Problem to be Solved]

Abstract: To enhance the performance for separation of oil mist from blow-by gas.

Abstract: [Solution]

Abstract: A filter element 13 which is to be attached to an oil separator unit 3 includes a core 31. This core is a double tube having an internal cylindrical member 34 and an external cylindrical member 35, and a space between the internal cylindrical member and the external cylindrical member is used as a separation chamber 36. An injection hole 39 for injecting blow-by gas while increasing its flow velocity is provided in the internal cylindrical member. A surface which is an inner wall surface of the external cylindrical member and which faces the injection hole is a spraying surface onto which the blow-by gas injected from the injection hole is sprayed. Moreover, an opening for oil discharge from which oil OL condensed on the spraying surface is discharged, and an opening for discharge from which the blow-by gas from which oil mist has been separated is discharged are provided in the core.


The embodiments of the present invention provide a system and method for light and shadow guided needle positioning. DICOM images of a patient are captured for identifying a point of insertion of a needle on the patient's body and a target point inside the patient's body. Needle coordinates are computed based on the captured DICOM images to position the mechanical arms. Light is projected at a particular angle on the needle to form shadows of the needle. Laser light beams are projected to form cross hair at the point of insertion. Images or videos of the point of insertion, shadow of the needle and the cross hair are captured and displayed on a monitoring unit. A virtual circle is projected on the displayed image and is aligned with the point of insertion, shadow of the needle and cross hair in order to insert the needle precisely.

In the field of interventional medicine, a medical procedure is performed for diagnostic or treatment purposes by taking a sample from a patient's body. For example, a sample tissue of a specific internal organ from the patient's body is collected by inserting a medical device such as a needle. As an insertion of the needle at correct angle and to a right depth is critical, the needle needs to be guided into a desired location within the body using various imaging and positioning techniques. These positioning techniques are typically used for purpose of biopsy, fluid drainage, catheter placement biopsy, amniocentesis, precision injections, cell aspiration, tumor ablation and the like. The advent of cross-sectional imaging techniques such as computed tomography (CT), magnetic resonance imaging, fluoroscopy and ultrasound, etc., have given rise to the use of image-guided interventions.
A common issue in conducting the core biopsies is in the identification of an exact location of a lesion and thereafter the accurate guiding of the biopsy needle to that lesion. Several methods and apparatus have been developed for core biopsies in connection with mammography and ultrasound. For example, a rigid frame-based system is used for collecting the sample from the brain.
The frame-based system requires an attachment of a frame to the skull of a patient to assist the surgeon in locating and collecting the sample from a targeted location within the brain. The frame is typically attached to the patient in an invasive manner. Such methods and apparatus still pose several issues and do not solve the problems entirely. For example, many such solutions are invasive and cause discomfort to the patient. Similarly, the accuracy of insertion is human based or dependent on individual skill set and requires a deep learning and heavy expertise in the field.
A common drawback of the existing systems is the need for multiple X-ray images of the lesion, thereby exposing the tissue to hazardous levels of radiation. These systems also do not provide a real-time imaging of the needle trajectory as the needle is inserted into the body. Most of the times, as the biopsy needle is secured in a fixed device and these systems do not provide a freedom of movement for the needle relative to the target tissue. Consequently, several needle insertions and manipulations are required for precise placement of the needle on the target point.
Thus, the conventional systems and methods for collection of a biopsy sample are complicated, cumbersome, and overlay invasively to the patient. Further, the use of such equipment is expensive, time consuming, and unjustified in small practices.
Hence, there is a need for a system and a method for accurately positioning the needle towards a point of insertion on a patient body without making any direct contact with the patient body. There is also a need for a needle positioning system and method that requires only one time calibration even for repeated usage. Further, there is a need for a system and method that promptly identifies any erroneous tilting of a needle.
Yet there is a need for a system and method for assisting the doctor or medical personnel while inserting the needle at precise location and at precise angle when performing the medical procedure such as biopsy procedure and other procedures which require the insertion of needle at the patient body. Yet there is a need for a system and method for positioning a needle using a camera. Yet there is a need for a system and method for positioning the needle using the shadows.
The above mentioned shortcomings, disadvantages and problems are addressed herein and which will be understood by reading and studying the following specification.

Light and shadow guided needle positioning system and method


A method for preparing 2,3,3,3-tetrafluoropropene comprising contacting a reactant comprising CCl2═CFCH2Cl with a fluorinating agent, such as HF, under conditions effective to produce a reaction product comprising CF3CF═CH2.

(1) Field of Invention
This invention relates to novel methods for preparing fluorinated organic compounds, and more particularly to methods of producing fluorinated olefins.
(2) Description of Related Art
Hydrofluorocarbons (HFCs), including particular hydrofluoroalkanes such as tetrafluoropropenes (e.g., 2,3,3,3-tetrafluoro-1-propene (HFO-1234yf)) are effective refrigerants, fire extinguishants, heat transfer media, propellants, foaming agents, blowing agents, gaseous dielectrics, sterilant carriers, polymerization media, particulate removal fluids, carrier fluids, buffing abrasive agents, displacement drying agents and power cycle working fluids. Unlike chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs), both of which potentially damage the Earth's ozone layer, HFO-1234yf does not contain chlorine and, thus, poses no threat to the ozone layer. Also, HFO-1234yf possesses a relatively low Global Warming Potential (GWP) compared to most CFCs and HCFCs.
Methods of synthesizing certain HFOs are known. For example, preparation of HFO-1234yf from trifluoroacetylacetone and sulfur tetrafluoride has been described. See Banks, et al., Journal of Fluorine Chemistry, Vol. 82, Iss. 2, p. 171-174 (1997). Also, U.S. Pat. No. 5,162,594 (Krespan) discloses a process wherein tetrafluoroethylene is reacted with another fluorinated ethylene in the liquid phase to produce a polyfluoroolefin product. These starting materials can be expensive, difficult to handle, and/or result in low yields. However, CCl2═CClCH2Cl can be used as an inexpensive and readily available starting material for the preparation of CH2═CFCF3 using the following three-step process:
However, such multistep processes are generally more complicated and less economical compared to shorter synthesis routes. Accordingly, there remains a need for a direct route to convert readily available and inexpensive starting materials. Such starting materials for the synthesis of HFO-1234yf have heretofore been unknown.

Method for producing 2,3,3,3-tetrafluoropropene


The present invention provides a pesticidal composition with an extraordinarily lethal effectiveness that can also be used to remove and repel parasites, such as lice. The pesticidal composition preferably contains a cleansing agent and a pesticidal agent such as citronellal, citronellol, citronellyl or a mixture thereof. The composition more preferably utilizes citronellyl acetate as the pesticidal agent. The compositions can be administered topically to humans, animals or any infested areas.

Pesticides and insects repellents have long been sought for use against harmful or annoying parasites. Pests such as lice and fleas are irritating and painful to their human and animal hosts, and can also be vectors for other agents of disease. The pesticides and repellents available in the prior art, however, suffer from various deficiencies. Often, compositions provided as insect repellents are not insecticidal. Furthermore, many compositions are either toxic or generally unpleasant to the host. Still others require too many separate active ingredients for efficient production and regulation.
Many synthetic prior art compositions have been proposed as insect repellents, but have later been determined to be unsuitable for safe use by humans. One common active ingredient in prior commercial compositions is
N,N-Diethyl-m-toluamide (DEET). However, DEET has recently been associated with causing various undesirable side-effects, such as stinging, damage to mucous membranes, and possibly seizures. In 1989, the Centers for Disease Control issued a cautionary statement regarding the use of DEET. Many other prior art compounds proposed for use as a repellent have proven unsuitable for topical application to humans or other animals due to their toxic or noxious effect on the infested individual.
Various crude oil extracts of certain plants, such as citronella oil obtained from Cymbopogon citrata, or eucalyptus oil obtained from Eucalyptus citriodora, have been provided in the prior art as pest repellents. However, the oil complex itself is greasy and may have an unpleasant odor, which makes its use undesirable. Furthermore, consistent production of a safe and effective product is difficult, due to varying amounts of constituent compounds within batches of these complex oils and the difficulty of monitoring a large number of components. Therefore, insect repellents containing the whole oil of citronella, for example, are undesirable due to their limited repellency, unpleasant odor and consistency, and unreliable composition of potentially harmful and unnecessary agents.
Most prior art insect repellents are taught to be effective only in specific synergistic compositions. In the art, there has not been recognized a simple but effective pesticidal composition which does not require a combination of excess multiple pesticidal ingredients. There has heretofore not been provided a pesticide in a simple but effective composition that is acceptable for human use.
What is needed in the art is an especially effective pesticidal composition with fewer active components that is easier to consistently produce and monitor. The composition should also be able to cleanse an individual being treated for infestation.
Therefore, it is an object of the present invention to provide a pesticide that is mortally effective against parasites, such as lice. It is further an object to provide a composition that may be used as a cleansing shampoo, soap, cream, lotion or spray. These and other objects of the invention will be apparent to those skilled in the art.

Pesticidal composition and method of use


A method for calibrating operational parameters of a charged particle beam device comprises generating a plurality of distinct spots on a specimen, each spot being generated in response to adjusted operational parameters of the charged particle beam device, and registering said respective operational parameters.

There are known in the art charged particle beam devices. For example, scanning electron microscopes are disclosed in U.S. Pat. No. 5,659,172 of Wagner which describes a method for reliable defect detection using multiple perspective Scanning Electron Microscope (SEM) images. A SEM usually includes an electron gun for generating an electron beam, a SEM lens system for focusing and converging the electron beam, a deflection coil for deflecting the electron beam, a detector for detecting electrons, such as secondary emitted electrons or reflected electrons that are emitted/reflected from an object and a processor that is operative to construct SEM images in response to detection signals provided from the detector. Usually, the electron gun, the SEM lens system and the deflection coil are located within a column, which is commonly referred to as SEM column. The resolution of a SEM and its power consumption are inversely proportional to the distance between the SEM column and the object. This distance is also referred to as a working distance. The detector can also be placed within the SEM column.
Another type of known Charged particle beam device is the Focused ion beam (FIB) device. FIB systems are generally utilized to perform die milling and cross sectioning. The milled or cross sectioned die is usually analyzed by an inspection device, such as a SEM, to detect defects. FIB systems can also be utilized to generate FIB images. FIB systems include an ion source for generating an ion beam, a FIB lens system for focusing the ion beam to provide a focused ion beam and an ion beam deflector for deflecting the focused ion beam. A FIB system that is operative to generate a FIB image also has a detector and a processor. Usually, the ion source, the FIB lens system and the ion beam deflector are located within a column, which is commonly referred to as FIB column. The detector can also be placed within the FIB column.
SEM images are generated by irradiating an object with an electron beam, collecting signals resulting from an interaction of the electron beam with at least one portion of the object and processing the collected signals. FIB images are generated in a similar analogues manner, except that the object is irradiated with a focused ion beam.
Systems that include both FIB and SEM systems are known in the art and are referred to as FIB/SEM systems. SEM system allows to inspect a surface of an inspected object, such as a surface of a multi layered die. FIB systems allow for milling the surface and exposing inner layers to inspection. Usually, after the FIB mills the die, the SEM system is utilized to inspect the revealed layers and to further analyze the milled die for detecting defects.
There are known in the art other types of Charged particle beam devices such as Transmission Electron Microscope (TEM), and Scanning Transmission Electron Microscope (STEM).
Calibrating column parameters of a charged particle beam device is essential in order to obtain an optimal spot on the target surface (wafer). The characteristics of optimal spot are, for instance, spot size and how round and symmetric is the spot and it means whether the spot has astigmatism deviations for the x and y axes. When using high current beam, say ≧1 nA, the spot is milled into the substrate, or in other words the process is destructive. In the case that the so milled spot is not optimal, it would be desired to adjust the operational parameters for generating a better spot. However, since the generation of the spots is "destructive" hampers, subsequent attempts to generate spots using possibly other parameters. The reason is that, when a high current beam is used, the resulting image is, in many cases, not clear, thereby hindering to inspect and determine the characteristics of the resulting spot.
Accordingly, the process of calibrating the operational parameters of high beam current charged particle beam device (such as FIB) is, in many cases, manual and time-consuming. It also strongly depends on the skills of the technician who performs the task, and therefore the quality of the resulting calibration process may vary from one individual to the other.
There is, thus a need in the art to provide for a new system and method facilitating calibration of column parameters of Charged particle beam devices, in particular those operating in high current.

Method and system for controlling focused ion beam alignment with a sample


An apparatus and method for configuring a subframe to support a relay service in a multi-hop relay BWA communication system are provided, in which a first zone of a subframe is configured for at least one of communication between a BS and a first MS within the coverage area of the BS and communication between at least one RS and a second MS within the coverage area of the at least one RS, and a second zone of the subframe is configured for at least one of communication between the BS and the at least one RS and communication between the at least one RS and another RS.

1. Field of the Invention
The present invention relates generally to a multi-hop relay Broadband Wireless Access (BWA) communication system, and in particular, to an apparatus and method for synchronously providing a direct link service and a relay link service in a multi-hop relay BWA communication system.
2. Description of the Related Art
One of the most critical requirements for deployment of a 4th Generation (4G) mobile communication system is to build a self-configurable wireless network. The self-configurable wireless network refers to a wireless network configured in an autonomous or distributed manner without control of a central system to provide mobile communication services. For the 4G mobile communication system, cells of very small radii are defined for the purpose of enabling high-speed communications and accommodating a larger number of calls. The conventional centralized wireless network design is not self-configurable. Rather, the wireless network should be built to be under distributed control and to actively cope with an environmental change like addition of new Base Stations (BSs). That is why the 4G mobile communication system requires the self-configurable wireless network.
For real deployment of the self-configurable wireless network, techniques used for an ad hoc network should be introduced to a wireless access communication system. Such a major example is a multi-hop relay BWA communication system configured by applying a multi-hop relay scheme used for the ad hoc network to a BWA network with fixed BSs.
In general, since a BS and a Mobile Station (MS) communicate with each other via a direct link, a highly reliable radio link can be established easily between the BS and the MS in the BWA communication system. However, due to the fixedness of the BSs, the configuration of a wireless network is not flexible, making it difficult to provide an efficient service in a radio environment experiencing a fluctuating traffic distribution and a great change in the number of required calls.
The above drawback can be overcome by a relay service that delivers data over multiple hops using a plurality of neighbor MSs or neighbor Relay Stations (RSs). The use of the multi-hop relay scheme facilitates fast network reconfiguration adaptive to an environmental change and renders the overall wireless network operation efficient. Also, a radio channel in a better channel status can be provided to an MS by installing an RS between the BS and the MS and thus establishing a multi-hop relay path via the RS. High-speed data channels can be provided to MSs in a shadowing area or an area where communications with the BS are unavailable, and cell coverage can be expanded.
FIG. 1 illustrates the configuration of a typical multi-hop relay BWA communication system.
Referring to FIG. 1, in the multi-hop relay BWA communication system, MSs 140, 150, 160 and 170 (MS1 to MS4) can receive BWA services through a BS 100, a primary RS (RS1) 110, and secondary RSs (RS2) 120 and 130.
MS1 and MS2 within the coverage area 101 of the BS 100 communicate with the BS 100 via direct links L1. MS2, which is located at the cell boundary of the BS 100 and thus placed in a poor channel state, can receive a higher-speed data channel via an RS-MS link L2 provided by RS2 130 compared to the speed via the direct link L1.
MS3 and MS4 outside the coverage area 101 of the BS 100 communicate with the BS 100 via RS-MS links L3 provided by RS1 110. The communication links between the BS 100 and MS3 and MS4 via RS1 110 expand the cell coverage. MS4, which is located at the cell boundary of RS1 110 and thus placed in a poor channel state, can increase its transmission capacity using an RS-MS link L4 provided by RS2 120.
As described above, when an MS is in a poor channel state at a cell boundary of a BS or in a shadow area suffering from a severe shielding effect due to, for example, buildings, the BWA communication system enables the MS to communicate with the BS by providing a better-quality radio channel to the MS via an RS. In other words, the BS can provide a high-speed data channel to the cell boundary and the shadow area and expand its coverage area by the multi-hop relay scheme.
The RSs 110, 120 and 130 are classified into RS1 (RS 110) that expands cell coverage and RS2 (the RSs 120 and 130) that increases capacity according to their operation capabilities.
As stated above, RS1 110 serves to expand the cell coverage of the BS 100. Because MS3 and MS4 have difficulty in receiving services directly from the BS 100, they acquire synchronization to the BS 100 and perform network entry to the BS 100 via RS1 110. Therefore, RS 110 provides functionalities for the initial access of the MSs 160 and 170, that is, provides a control channel (or traffic channel) and a random access channel to MS3 and MS4.
RS2 120 and RS2 130 relay services to MS2 and MS4 within their cell coverage area, for the purpose of increasing service capacity. MS2 receives a control channel and a random access channel from the BS 100 and a traffic channel from RS2 130. MS4 receives a control channel and a random access channel from RS1 110 and a traffic channel from RS2 120.
Typically, transmission/reception is carried out between a BS and an MS in frames having the configuration illustrated in FIG. 2 in the BWA communication system. FIG. 2 illustrates a Time Division Duplex (TDD) frame structure compliant with the Institute of Electrical and Electronics Engineers (IEEE) 802.16 standard, for data transmission/reception, between the BS and the MS.
Referring to FIG. 2, a TDD frame 200 is divided into a DownLink (DL) subframe 210 and an UpLink (UL) subframe 220 with a guard region called Transmit/receive Transition Gap (TTG) in between. A guard region called Receive/transmit Transition Gap (RTG) is interposed between TDD frames.
A preamble and a common control channel are included in mandatory slots of the DL subframe 210 and broadcast to the cell coverage area of a BS. MSs within the coverage area of the BS acquire synchronization and control information from the preamble and the common control channel.
As described above, RS1 provides BWA services to MSs or RSs which have difficulty in establishing direct links with the BS as they are located outside the coverage area. Therefore, RS1 must provide control information and initial ranging slots to the MSs or the RSs, for network entry as well as user traffic service. Especially, RS1 must provide a service via an indirect link in the same configuration as via a direct link as illustrated in FIG. 3, in order to ensure backward compatibility for the MSs.
For a relay service, after receiving a control channel or a traffic channel from a BS or an MS, an RS relays them. That is why the RS carries out both transmission and reception within a single-directional subframe.
FIG. 3 illustrates a TDD frame structure in a conventional multi-hop relay BWA communication system.
Referring to FIG. 3, a single-directional subframe 300 is divided into a direct link zone 301 and an indirect link zone 303, and another single-directional subframe 310 is divided into a direct link zone 311 and an indirect link zone 313. For a relay service, predetermined parts of the subframes 300 and 310 are allocated to the indirect link zones 303 and 313. Thus, an RS receives information and data for relaying in the direct link zones 301 and 311 and relays them in the indirect link zones 303 and 313.
For instance, RS1 receives control information and a traffic burst to be relayed from the BS or an MS in the direct link zone 301 or 311 and then relays them to the BS or the MS in the indirect link zone 303 or 313.
RS2 receives unicast traffic bursts to be relayed from an MS or the BS in the direct link zone 311 or 301 and then relays them to the MS or the BS in the indirect link zone 303 or 313.
When communications are conducted in the frame structure illustrated in FIG. 3, a different node that provides a BWA service has a different frame timing, i.e. different nodes operate asynchronously in the BWA communication system, as illustrated in FIG. 4.
FIG. 4 is a diagram illustrating transmission and reception timings of MSs in the conventional multi-hop relay BWA communication system.
Referring to FIG. 4, an MS that receives a direct link service from a BS has the timing of a BS frame 421 because communications are made in direct link zones 401 and 411. On the other hand, an MS that receives a relay link service from an RS has the timing of an RS frame 423 because communications are made in indirect link zones 403 and 413.
Typically, synchronization and handover are carried out based on control information and preamble transmitted to a fixed position in a frame in the BWA communication system. However, since MSs operate asynchronously depending on the subject that provides them with service as illustrated in FIG. 4, the handover and synchronization are very difficult as illustrated in FIG. 5.
FIG. 5 illustrates signal flows when MSs move in the conventional multi-hop relay BWA communication system.
Referring to FIG. 5, when an MS 520 (MS1) moves from a BS 500 to the coverage area of RS1 510 while receiving a service from the BS 500, MS1 must receive a preamble and control information from RS1 510.
When an MS 530 (MS2) moves from RS1 510 to the BS 500 during receiving a service from RS1 510, MS2 must receive a preamble and control information from the BS 500.
As illustrated in FIG. 3, however, the BS 500 and RS1 510 operate asynchronously, thereby making it difficult for MS1 and MS2 to acquire the preamble and the control information after the handover.
Moreover, since the BS provides a service to the MSs and the RS simultaneously in a direct link subframe, as illustrated in FIG. 3, the freedom of configuring a system in which the BS supports the RS is low.

Apparatus and method for supporting relay service in a multi-hop relay broadband wireless access communication system


An information display method and an information display system are provided. The information display method includes: capturing a background image of an information display area of the transparent display; using critical contrast values and color levels of the background image to calculate a display threshold; using the color levels of the background image and color levels of display information to calculate a recognition evaluation score; and determining whether the recognition evaluation score is greater than or equal to the display threshold. If the recognition evaluation score is greater than or equal to the display threshold, the display information is displayed in the information display area. If the recognition evaluation score is less than the display threshold, an optimized display parameter is calculated by using the display threshold, and optimized display information is displayed in the information display area of the transparent display.

A transparent display itself has a certain degree of transparency. The transparent display may not only allow a user to view a background on the other side of the transparent display relative to the user, but also display information related to the background. Based on this transparent property, transparent displays may be widely applied in various fields as, for example, building windows, automobile windows, or shop windows.
When a background image and display information are simultaneously displayed on the transparent display, the display information may overlay the background image. When a background luminance is too high or the background image is too complicated, the display information may not be clearly viewed. Therefore, how to improve the recognizability of the display information has become one of the problems that researchers in this field are eager to solve.

Information display method and information display system

Industrial Technology Research Institute


A graphics pipeline reduces the number of tessellation factors written to and read from a graphics memory. A hull shader stage of the graphics pipeline detects whether at least a threshold percentage of the tessellation factors for a thread group of patches are the same and, in some embodiments, whether at least the threshold percentage of the tessellation factors for a thread group of patches have a same value that either indicates that the plurality of patches are to be culled or that the plurality of patches are to be passed to a tessellator stage of the graphics pipeline. In response to detecting that at least the threshold percentage of the tessellation factors for the thread group are the same (or, additionally, that at least the threshold percentage of the tessellation factors have a value that either indicates that the plurality of patches are to be culled or that the plurality of patches are to be passed to a tessellator stage of the graphics pipeline), the hull shader stage bypasses writing at least a subset of the tessellation factors for the thread group of patches to the graphics memory, thus reducing bandwidth and increasing efficiency of the graphics pipeline.

A graphics processing unit (GPU) processes three-dimensional (3-D) graphics using a graphics pipeline formed of a sequence of programmable shaders and fixed-function hardware blocks. For example, a 3-D model of an object that is visible in a frame can be represented by a set of triangles, other polygons, or patches which are processed in the graphics pipeline to produce values of pixels for display to a user. The triangles, other polygons, or patches are collectively referred to as primitives. The process includes mapping tessellation factors to the primitives to represent finer levels of detail as indicated by the tessellation factors that specify the granularity of the primitives produced by a tessellation process. The GPU includes a dedicated memory that is used to store tessellation factors so that the tessellation factors are available for mapping to primitives that are being processed in the graphics pipeline. The tessellation factors stored in the dedicated GPU memory are populated by procedurally generating the data. The dedicated GPU memory is typically a relatively small memory, which limits the amount of tessellation factors that can be stored in the dedicated GPU memory. Furthermore, the overhead required to write the tessellation factors to and read the tessellation factors from memory can be significant.


Synthetic surfaces suitable for culturing stem cell derived oligodendrocyte progenitor cells contain acrylate polymers formed from one or more acrylate monomers. The acrylate surfaces, in many cases, are suitable for culturing stem cell derived oligodendrocyte progenitor cells in chemically defined media.

Pluripotent stem cells, such as human embryonic stem cells (hESCs) have the ability to differentiate into any of the three germ layers, giving rise to any adult cell type in the human body. This unique property provides a potential for developing new treatments for a number of serious cell degenerative diseases, such as diabetes, spinal cord injury, heart disease and the like. For example, spinal cord damage is generally irreversible with current treatments, leaving approximately 250,000 Americans in a devastating position. However, as stem cell research has developed, new exciting possibilities have arisen for people suffering from spinal cord injury. ES cell-derived neural cells have been used by researchers to treat nervous system disorders in animal models. In earlier work, researchers showed that mouse ES cells could be stimulated to differentiate into neural cells that, when transplanted into mice with neurological disorders, helped to restore normal function.
However there remain obstacles in the development of such hESC-based treatments. Such obstacles include obtaining and maintaining adequate numbers of undifferentiated hESCs in tissue culture and controlling their differentiation in order to produce specific cell types. Stem cell cultures, such as hESC cell cultures are typically seeded with a small number of cells from a cell bank or stock and then amplified in the undifferentiated state until differentiation is desired for a given therapeutic application To accomplish this, the hESC or their differentiated cells are currently cultured in the presence of surfaces or media containing animal-derived components, such as feeder layers, fetal bovine serum, or MATRIGEL®. These animal-derived additions to the culture environment expose the cells to potentially harmful viruses or other infectious agents which could be transferred to patients or compromise general culture and maintenance of the hESCs. In addition, such biological products are vulnerable to batch variation, immune response and limited shelf-life.
Some steps have been taken to culture hESCs either in media or on surfaces that are free of animal-derived components. However, the response of hESCs or their differentiated derivatives is difficult to predict as components of the surface or culture medium change. Yet some advances have been made. For example, hESC-derived oligodendrocyte progenitor cells (OPCs) have been cultured in defined serum-free medium. While such culture systems are not completely xeno-free culture systems when the matrices employed contain animal-derived components, such as gelatin and MATRIGEL, they do provide a step toward the eventual clinical application of hESC-derived OPCs. By way of further example, some synthetic surfaces have been identified that can support differentiation of human epithelial stem cells into epithelial cells. However, the systems employed relied on serum medium for the cell culture, which still potentially causes problem as described before for all biological animal derived components. To date, a completely animal free system employing a chemically defined medium and a synthetic surface has not yet been identified for culturing stem cells or cells derived from stem cells.

This patent is subject to a terminal disclaimer.

Synthetic surfaces for culturing stem cell derived oligodendrocyte progenitor cells


A thermal transfer image receiving sheet comprising a substrate sheet, a dye receptor layer disposed on at least one surface side of the substrate sheet, and an antistatic agent layer disposed on the surface of the dye receptor layer; wherein the dye receptor layer comprises a solvent soluble antistatic agent.. When the above thermal transfer image receiving sheet is used, a sufficient antistatic property can be maintained so as to prevent the occurrence of the attachment of foreign substance such as dust even a full-color image is intended to be formed and the same region of the dye receiving layer is subjected to the dye transfer operation. As a result, there may be provided a full-color image of high quality free of a color dropout, etc.

The present invention relates to a thermal image receiving sheet, more particularly to a thermal transfer image receiving sheet which is capable of providing a full color image having a high quality without a color dropout, etc.
Heretofore, various thermal transfer methods have been known. Among these, there has been proposed a method wherein a sublimable dye (or subliming dye) is used as a recording agent, and is carried on a substrate sheet such as paper and plastic film to obtain a thermal transfer sheet, and various full color images are formed on an image receiving sheet such as paper and plastic film having thereon a dye receptor layer, by using the resultant thermal transfer sheet.
In such a case, a thermal head of a printer is used as heating means so that a large number of color dots of three or four colors are transferred to the image receiving sheet under heating in a very short period of time. As a result, a full color image of an original is reproduced by using the multi-color color dots.
The thus formed images are very clear and are excellent in transparency, since the dyes are used therein as a colorant. Accordingly, these images are excellent in half tone reproducibility and gradation characteristic, and are substantially the same as the images formed by the conventional offset printing and gravure printing. Further, when the above image forming method is used, there can be formed images of high quality which are comparable to full color photographic images.
In order to effectively carry out the thermal transfer method as described above, not only the structure of the thermal transfer sheet but also the structure of the image receiving sheet on which an image is to be formed is important. More specifically, at the time of the formation of the image, both of the thermal transfer sheet and the image receiving sheet are conveyed in a printer to be used for such image formation, and both of these sheets are rubbed with each other. As a result, the image receiving sheet may generally be charged and foreign substance such as dust is attached to the dye receiving surface of the image receiving sheet on the basis of the above charging, whereby a problem such as color dropout is posed. In general, it is necessary to solve such a problem by subjecting the thermal transfer sheet and/or the image receiving sheet to an antistatic treatment. For example, Japanese Laid-Open Patent Application (JP-A, KOKAI) No. 56489/1988 discloses a thermal transfer image receiving sheet wherein the surface of a dye receiving layer provided on one side surface of a substrate sheet is subjected to an antistatic treatment. However, in a case where a full-color image is intended to be formed by use of a thermal transfer system, since the same region of the dye receiving layer is subjected to the dye transfer operation three to four times, a sufficient antistatic property cannot be maintained when an antistatic agent is simply applied onto the dye receiving surface of the thermal transfer image receiving sheet. As a result, the above problem is not sufficiently solved and therefore a full-color image of high quality free of the color dropout has not been formed yet. Such a problem is posed not only in the case of a thermal transfer image receiving sheet to be used in combination with a thermal transfer sheet of a sublimable dye type, but also in the case of a thermal transfer image receiving sheet to be used in combination with a thermal transfer sheet of a melt transfer type.


A radio control method is arranged to use a mobile station 10, an active set 20 to perform radio communication with the mobile station 10, and a radio control apparatus 30 for controlling the radio communication between the mobile station 10 and the active set 20, and the radio control method has a determination step wherein in a situation where the mobile station 10, while performing radio communication through A-DPCH with the active set 20, performs radio communication through HS-PDSCH with one radio base station included in the active set 20, the radio control apparatus 30 makes a determination of maintenance to perform a process of maintaining the radio communication through the HS-PDSCH, on the occasion when the mobile station 10 gives a change command to change a configuration of the active set 20 so as to result in failure in maintenance of the radio communication through the HS-PDSCH.

1. Field of the Invention
The present invention relates to a radio control method and radio control apparatus.
2. Related Background of the Invention
Non-patent Document 1 (3GPP Specification detail, 3GPP TS 25.331. [online]. version 6.10.0. [retrievedon 2006-09-07]. Retrieved from the Internet: <URL:http://www.3gpp.org/ftp/Specs/html-info/25331.htm>) and Non-patent Document 2 (3GPP Specification detail, 3GPP TS 25.308. [online]. version 5.7.0. [retrievedon 2006-09-07]. Retrieved from the Internet: <URL:http://www.3gpp.org/ftp/Specs/html-info/25308.htm>) describe the standard specification of the W-CDMA system, and Non-patent Document 3 (cdma2000 High Rate Packet Data Air Interface Specification. [online]. [retrievedon 2006-09-07]. Retrieved from the Internet: <URL:http://www.3gpp2.org/Public_html/specs/C.S0024-A_v1.0—040331.pdf>) describes the standard specification of the cdma2000 system. Furthermore, Non-patent Document 2 describes the specification of HSDPA (High Speed Downlink Packet Access) which is a high-speed downlink packet transmission system, and Non-patent Document 3 describes the specification of a high-speed downlink data transmission system (1xEV-DO). In the case of the W-CDMA system, a mobile station monitors the quality of radio communication with radio base stations (which is evaluated, for example, using CPICH-RSCP, CPICH-Ec/N0, pathloss, or the like indicating received signal power, which will be referred to hereinafter as radio quality, and which will be assumed to be based on CPICH-RSCP), and determines which should be performed, branch addition, branch elimination, or branch replacement, based on this radio quality. The mobile station notifies a radio control apparatus of this determination and the radio control apparatus performs control of soft hand over (SHO), based on this determination notified of by the mobile station.
A branch is a radio link between a mobile station and a radio base station and sometimes represents this radio base station itself. A collection of radio base stations (radio base station group) in radio communication through the use of SHO with a mobile station is referred to as an active set. The branch addition means adding a radio base station to perform communication through a radio link with a mobile station, to the active set. The branch elimination means eliminating any one of a plurality of radio base stations constituting the active set. The branch replacement means replacing a radio base station with the lowest radio quality among a plurality of radio base stations constituting the active set, with another radio base station which has a radio quality relatively better than that of the foregoing radio base station and which is not included in this active set.

Radio control method and radio control apparatus


A data session with a wireless device ordinarily cannot be initiated from the network side because the wireless device has no predetermined IP or other network address. Methods are disclosed for instead causing the wireless unit to initiate a data session with a target destination, thereby obviating the IP addressing problem. A voice call is first initiated by a requester application to a remote wireless unit. The requester transmits a request message to the remote wireless unit via the wireless voice channel using in-band techniques; preferably including a payload in the polling message that identifies the target destination. In response, the remote wireless unit initiates a packet data session with the target destination.

Data transfer services in the wireless domain are known and certainly still evolving. Examples include SMS (short messaging service) and other SS7 control channel services. They can be used, for example, for text messaging. They do not affect the voice channels, but offer very limited bandwidth, so the amounts of data transferred are quite limited.
The WAP (Wireless Application Protocol) specifications and software offer some improved services. For example, they can be implemented to provide limited Internet access to a mobile unit. (We use the term "mobile unit" herein to refer broadly to any device with wireless connectivity, including without limitation a cell phone, PDA, laptop computer, palmtop, motor vehicle, etc.). The WAP services, however, require that the mobile unit itself be WAP enabled, and that the wireless carrier network also be WAP enabled. Thus, wireless carriers have to deploy and maintain WAP gateways at the edges of the network to provide WAP services. Some mobile units, and some networks or geographic areas may not be WAP enabled, so these services would not be available for data communication.
One approach to wireless data transfer that does not require changes in the wireless network infrastructure, although it requires specific implementation at both endpoints of a session, is the use of "in-band" data transfer. As the name implies, this technique transfers data in the voice channel, using carefully selected and timed audio frequency tones. (Commonly, wireless data transfer services do not use the voice channel at all.) In-band or voice channel data transfer can be done with little or no interruption of a voice conversation. Details of in-band signaling are explained in U.S. Pat. Nos. 6,144,336; 6,690,681 and 6,493,338 all incorporated wherein by this reference. These types of in-voice-channel data communications have two primary advantages: the wireless voice channel is reliable, and the technique works transparently across networks and carriers throughout the country and beyond. The data simply passes transparently through the voice service, as it "looks" like voice. However, in-band signaling provides only a very low bandwidth up to around 400 bps. That makes it almost useless for transferring significant amounts of data.
Higher bandwidth wireless data services are rapidly becoming available throughout the world. These services operate over dedicated data channels, not the voice channels. The newer specifications, so-called "3G" or third generation wireless technologies, while not yet widely implemented, promise packet data rates as follows, according to IMT-2000 standards:                2 Mbps for fixed environment        384 Mbps for pedestrian (i.e. slow-moving mobile unit)        144 kbps for vehicular traffic
One problem, however, with virtually all wireless data services, is the difficulty in accessing those services in a network "polling" type of application. Polling (or "pulling data") here refers to contacting a mobile unit to pull or retrieve digital data needed by a requester. (The "requester" typically would be an application program.) Preferably, an authorized requester should be able to poll remote mobile units, and fetch data, without manual user intervention at the remote location. In other words, a polling process should be able to be completely automated, although for some applications it can be advantageously initiated by a user at the requester end.
To illustrate, a wireless automated inventory control system may seek to poll units, say trucks or tanks, to learn their present location, fuel supply, operator ID, etc. A packet data connection, for example an IP connection, cannot be established with a mobile unit from the network side (we call this "network initiated") using prior technology, because the mobile device has no predetermined IP address. Rather, an IP address is dynamically assigned to a mobile unit only if and when it initiates a session to an IP network. Accordingly, a user application cannot poll a remote mobile unit to establish a packet data transfer session using known technologies.
A system has been suggested for IP addressing of GPRS mobile terminals that purportedly would enable TCP/IP connection without a phone call. That proposal recognized that there are not enough IP addresses available (under the current Ipv4 regime) to assign one to every wireless terminal. The proposal calls for a combination of Public Addresses (registered with public routing tables) and Private addresses, not to be routed on the public Internet. Rather, the private (IP-like) addresses would only be used within a GPRS operator's own network. This would require network address translation (NAT) facilities and is generally impractical. Even if implemented, such a scheme does not solve the problem that the mobile (or wireless) terminal address is unknown, and is not publicly discoverable in a convenient way.
The need remains for a convenient and effective way to poll a remote mobile unit, that is, to request a data packet session, for uploading or downloading data via the wireless network, without changing the wireless carrier infrastructure and in a manner compatible with existing packet data networks and protocols such as IP.

Voice channel control of wireless packet data communications