Abstract: A roots type fluid machine includes a case having a side wall, a pair of rotary shafts provided in the case, a pair of rotors engaged with each other and fixed to the pair of rotary shafts so as to extend axially, respectively, a suction space formed by the case and the pair of rotors for introducing fluid, a discharge space formed by the case for discharging fluid and the pair of rotors and a transfer chamber formed by the case and the rotor. The rotor has a rotor end surface. A clearance is formed between the side wall and the rotor end surface. The transfer chamber transfers gas introduced in the suction space to the discharge space in accordance with the rotation of the pair of rotors. The case has a guide groove formed in the side wall facing the rotor end surface. Gas leaked from the discharge space into the clearance is introduced to the transfer chamber through the guide groove.

Abstract: The variable displacement gear pump for a loading system in an industrial vehicle has main and sub gear pump portions, suction, discharge and bypass passages, and check and opening valves. The main gear pump portion has main drive and driven gears, and has suction and discharge side spaces. The sub gear pump portion has sub drive and driven gears, and has suction and discharge side spaces. The bypass passage returns hydraulic fluid in the discharge-side space of the sub gear pump portion to the suction passage. The check valve prevents hydraulic fluid in the discharge-side space of the main gear pump portion from flowing to that of the sub gear pump portion. The opening valve is used for opening and closing the bypass passage, and closes the bypass passage due to a pressure in a discharge conduit of the loading system increased by the load applied to the loading system.

Abstract: A variable displacement rotary pump includes a main pump unit, an auxiliary pump unit, a discharge passage, a bypass passage, a suction passage, a check valve and a control valve. The suction passage is in communication with the discharge passage through the bypass passage and a second discharge port. The check valve is disposed in the discharge passage for preventing fluid in a first discharge port of the main pump unit from flowing into the bypass passage. The control valve is operable for opening and closing the bypass passage. When the control valve opens the bypass passage and the check valve closes the discharge passage, flow rate of the fluid discharged from the discharge passage is reduced. A throttle passage is provided in the bypass passage or the control valve for regulating flow of the fluid in early phase of operation of the control valve to open the bypass passage.

Abstract: A received signal delivered through a transmission line can be compensated for carrier frequency offset and direct-current offset to improve the signal-to-noise ratio of the received signal, eventually resulting in an effective improvement in the error rate. The received signal has convoluted influences through the transmission line, so that observation of continual symbols of periodic pilot signals on the frequency axis shows just a phase shift by the carrier frequency offset. Therefore, the carrier frequency offset can be analytically found from the continual symbols of periodic pilot signals, thereby allowing the direct-current offset to be estimated and both the carrier frequency offset and the direct-current offset to be compensated for.

Abstract: A roots type fluid machine includes a case having a side wall, a pair of rotary shafts provided in the case, a pair of rotors engaged with each other and fixed to the pair of rotary shafts so as to extend axially, respectively, a suction space formed by the case and the pair of rotors for introducing fluid, a discharge space formed by the case for discharging fluid and the pair of rotors and a transfer chamber formed by the case and the rotor. The rotor has a rotor end surface. A clearance is formed between the side wall and the rotor end surface. The transfer chamber transfers gas introduced in the suction space to the discharge space in accordance with the rotation of the pair of rotors. The case has a guide groove formed in the side wall facing the rotor end surface. Gas leaked from the discharge space into the clearance is introduced to the transfer chamber through the guide groove.

Abstract: In a transmit/receive system, the carrier frequency offset (CFO), I/Q imbalance, and DC offset (DCO) can cause serious signal distortions. These analog losses can be compensated for individually or in combination of any two of them by following various methods that have been suggested. However, there have suggested no methods of simultaneously compensating, for these three types of losses that occur in actual devices at the same time. The present invention suggests a novel pilot signal that has a cyclic signal portion and a portion of two equally spaced continual signals. The invention provides a method for compensating for the CFO, I/Q imbalance, and DCO by simultaneously performing the time domain compensation and the channel estimation using those signal portions. The method also compensates for the I/Q imbalance and the channel response on the transmitter side in the OFDM scheme.

Abstract: A received signal delivered through a transmission line can be compensated for CFO and DCO to improve the SNR of the received signal, eventually resulting in an effective improvement in the error rate. In this context, methods for estimating and compensating for CFO and DCO have been studied, for example, using pilot signals or a blind method. However, the methods would require a huge amount of calculations for the estimation of CFO in the presence of DCO, as with the ML method, or never essentially eliminate errors from an estimated value. The received signal has convoluted influences through the transmission line, so that observation of the continual symbols of periodic pilot signals on the frequency axis shows just a phase shift by the CFO. Therefore, the CFO can be analytically found from the continual symbols of periodic pilot signals, thereby allowing the DCO to be estimated and both the CFO and the DCO to be compensated for.

Abstract: The OFDM scheme based communication system is currently being put into practical use because of its effective use of frequencies and its enhanced resistance to multipath. However, since the OFDM scheme treats multiplexed signals with overlapped spectra, the orthogonality between carriers are corrupted and the error rate characteristic is degraded in the presence of CFO. Furthermore, since locally oscillated signals different by a phase of ?/2 are difficult to obtain in demodulating the I/Q signal, an imbalance is caused between the I/Q signals, resulting in degradation in the error rate characteristic. The invention suggests a novel pilot signal, and a method for analytically determining compensation values for CFO and I/Q imbalance and compensating for those distortions using the resulting values. Furthermore, the invention is applicable not only to the OFDM scheme but also to any protocol that involves pilot signals.

Abstract: A frequency offset (CFO) and a direct current component offset (DCO) occur in an OFDM scheme signal. To address this, such a method has been suggested which allows a pilot signal to be mixed with a communicated signal for compensation. However, if the pilot signal has a long duration, then a compensation method without the pilot signal is required to compensate signals during that period. However, no such a method is conventionally available which compensates for both the CFO and DCO without the pilot signal. Using the orthogonality of the OFDM signal, the matrix of a system in which CDO and DCO have occurred is subjected to the singular value decomposition, thereby predetermining the CFO candidate value which allows for demodulating zero from the received signal and an array of numerical values of CFO check data. Then, in a compensation section (17), the received signal is successively multiplied by the numerical values.

Abstract: A variable displacement rotary pump includes a main pump unit, an auxiliary pump unit, a discharge passage, a bypass passage, a suction passage, a check valve and a control valve. The suction passage is in communication with the discharge passage through the bypass passage and a second discharge port. The check valve is disposed in the discharge passage for preventing fluid in a first discharge port of the main pump unit from flowing into the bypass passage. The control valve is operable for opening and closing the bypass passage. When the control valve opens the bypass passage and the check valve closes the discharge passage, flow rate of the fluid discharged from the discharge passage is reduced. A throttle passage is provided in the bypass passage or the control valve for regulating flow of the fluid in early phase of operation of the control valve to open the bypass passage.

Abstract: The variable displacement gear pump for a loading system in an industrial vehicle has main and sub gear pump portions, suction, discharge and bypass passages, and check and opening valves. The main gear pump portion has main drive and driven gears, and has suction and discharge side spaces. The sub gear pump portion has sub drive and driven gears, and has suction and discharge side spaces. The bypass passage returns hydraulic fluid in the discharge-side space of the sub gear pump portion to the suction passage. The check valve prevents hydraulic fluid in the discharge-side space of the main gear pump portion from flowing to that of the sub gear pump portion. The opening valve is used for opening and closing the bypass passage, and closes the bypass passage due to a pressure in a discharge conduit of the loading system increased by the load applied to the loading system.

Abstract: In a variable displacement type gear pump, each of a main gear pump portion and a sub gear pump portion has a drive gear, a driven gear engaging with the drive gear, and an urging portion applying radial load to the drive and driven gears. A bypass passage returns fluid in a discharge-side space of the sub gear pump portion to a suction passage. An opening and closing valve opens the bypass passage in a small displacement operational state. A drive shaft supports the main drive gear and the sub drive gear. A driven shaft supports the main driven gear and the sub driven gear. The drive gears and the driven gears are rotated in accordance with a rotation of the drive shaft. The drive and driven shafts transmit the radial load in the main gear pump portion to the sub gear pump portion in the small displacement operational state.

Abstract: A variable displacement type gear pump has gear chambers, one of which is a specific gear chamber. A suction passage is formed in the housing so as to communicate with suction-side spaces. An outlet passage communicates with discharge-side spaces. A return passage returns the fluid discharged to the discharge-side space of the specific gear chamber to the suction passage. The return passage communicates with the suction passage at a confluence portion located upstream side of the suction-side space. An opening and closing valve opens the return passage in a small displacement operational state. A check valve is located between the discharge-side space of the specific gear chamber and the outlet passage for preventing the fluid discharged from the gear chamber other than the specific gear chamber from flowing into the discharge-side space of the specific gear chamber in the small displacement operational state.

Abstract: A non-aqueous electrolyte containing propylene carbonate and 1,3-propanesultone as additives can reduce the amount of a gas evolved during storage at a high temperature of a non-aqueous electrolyte secondary cell comprising the electrolyte, a non-aqueous electrolyte containing at least one compound selected from the group consisting of vinylene carbonate, diphenyl disulfide, di-p-tolydisulfide and bis(4-methoxyphenyl)disulfide as comprising the electrolyte, and a non-aqueous electrolyte containing a combination of the above-two types of additives can provide a non-aqueous electrolyte secondary cell exhibiting excellent retention of capacity and storage stability.

Abstract: A non-aqueous electrolyte containing propylene carbonate and 1,3-propanesultone as additives can reduce the amount of a gas evolved during storage at a high temperature of a non-aqueous electrolyte secondary cell comprising the electrolyte, a non-aqueous electrolyte containing at least one compound selected from the group consisting of vinylene carbonate, diphenyl disulfide, di-p-tolyldisulfide and bis(4-methoxyphenyl)disulfide as an additive can improve cycle characteristics of a non-aqueous electrolyte secondary cell comprising the electrolyte, and a non-aqueous electrolyte containing a combination of the above two types of additives can provide a non-aqueous electrolyte secondary cell exhibiting excellent retention of capacity and storage stability.

Abstract: In order to allow an amphibious traveling vehicle to safely travel along rails on the land and in the water, or underwater even off the rails, a system for transmitting information of amphibious traveling vehicle comprising a traveling vehicle-side control system (51) which controls the operating state of the traveling vehicle and is provided on the traveling vehicle for traveling under water or underwater and in the air, a host-side control system (53) which instructs the system (51) to operate the traveling vehicle and is provided separately from the traveling vehicle, and communication means (60 and 61) which transmit information between the systems (51 and 53) and are connected to these systems (51 and 53), said system being characterized in that said communication means (60 and 61) is constituted of modulators (54 and 55) which modulate received instruction information into light beams, demodulators (56 and 57) which demodulate received beams of light into the instruction information and a light beam tra

Abstract: A material testing machine includes a control system for feedback-controlling the operation of a servo system, including an actuator for applying a load to a test piece, during material testing. Prior to the material testing, the stiffness of the test piece is estimated on the basis of the actual load and displacement which are detected after the displacement of the test piece is stabilized while maintaining the load observed when a minute displacement is generated in the test piece as the control gain is increased from its minimum value. In accordance with the estimated stiffness, the initial value of the control gain for the control system is set. During the material testing, the control gain is corrected in accordance with the stiffness of the test piece estimated based on the actual load and displacement of the test piece.

Abstract: Cobalt-coated acicular magnetic iron oxide particles of the present invention have an average major axial diameter of 0.15 to 0.50 .mu.m, and comprise:as seed crystal particles, acicular magnetic iron oxide particles containing 0.05 to 1.0 wt % of phosphorus, calculated as P, based on the weight of the cobalt-coated acicular magnetic iron oxide particles;as inner layers, spinel ferrite layers containing cobalt formed on the surfaces of said seed crystal particles; andas outer layers, coating layers comprising a hydroxide of magnesium formed on said spinel ferrite layers.Such cobalt-coated acicular magnetic iron oxide particles show a smaller change of coercive force with temperature, have a small switching field distribution and, hence, are suitable as magnetic particles for magnetic recording media.

Abstract: A nickel-metal hydride storage battery having a high capacity and excellent cycle life is disclosed. The battery employs, as its material for the negative electrode, a hydrogen storage alloy powder having a composition represented by the general formula Zr.sub.1-x M3.sub.x Mn.sub.a Mo.sub.b Cr.sub.c M1.sub.d M2.sub.e Ni.sub.f, where M1 represents at least one element selected from the group consisting of V, Nb and rare earth elements, M2 represents at least one element selected from the group consisting of Fe, Co and Cu, and M3 represents at least one element selected from the group consisting of Ti and Hf, and where 0.ltoreq.x.ltoreq.0.3, 0.3.ltoreq.a.ltoreq.0.7, 0.01.ltoreq.b.ltoreq.0.2, 0.05.ltoreq.c.ltoreq.0.3, 0.ltoreq.d.ltoreq.0.1, 0.ltoreq.e.ltoreq.0.2, 0.8.ltoreq.f.ltoreq.1.3, and 1.6.ltoreq.a+b+c+d+e+f.ltoreq.2.2, and wherein said hydrogen storage alloy has at least one of a Laves phase having a crystal structure of the MgCu.sub.2 -type (C15) and a Laves phase having a crystal structure of the MgZn.

Abstract: The disclosure describes a process for producing Co-coated acicular magnetite particles each comprising:acicular magnetite particle as the core particle;a lower coating layer of Co-containing spinel ferrite having a spinel structure, which is formed on the surface of said acicular magnetite particle; andan upper coating layer of Co- and Mg-containing spinel ferrite having a spinel structure, which is formed on said lower coating layer.