An experimental SAR (Specific Absorption Rate) estimation system based upon the thermograph method using a thermograph camera and newly developed homogeneous dry-phantom human models are presented. Experiments are conducted using this system and UHF fields to obtain SAR distributions in the human head irradiated by hand-held portable radios. Experiment results show that the estimated peak SAR's due to the radiation waves from radios of 1W transmitting power are lower than 2W/kg and so conform to the recommendations of the radio-frequency radiation safety guidelines. The developed system enables the surface SAR distributions on the phantom model to be precisely estimated; a function not available with the original system. System parameters required for providing precise estimations are discussed first, and then experiments are conducted to estimate SAR's in the human head exposed to a UHF hand-held portable radio's near field. Finally, estimated data are examined from the viewpoint of radio-frequency exposure safety guidelines.

To study the biological effects of the ion-current commonly found under ultra-high voltage DC transmission lines, a technique was developed to evaluate the human exposure to the ion-current field. This technique is based on numerical analysis using the boundary element method. The difficulty of handling the space charge in the calculation was overcome by assuming a lumped source ion-current. This technique is applicable to a three-dimensionally complex object such as a human body. In comparison with theoretical values, the accuracy of this technique was evaluated to be satisfactory for our purposes. It was then applied to a human body in an ion-current field. The distribution of the electric field along the body surface was obtained. The general characteristics of the field distribution were essentially the same as in those without space charges. However, it was found that the strength of the field concentration was significantly enhanced by the space charges. Further, the field exposure when a human body was charged by an ion-current was evaluated. As the charged voltage increases, the position of the field concentration moves from a human's head toward his legs. But the shock of micro spark increases. This technique provides a useful tool for the study of biological effects and safety standards of ion-current fields.

This paper surveys the researches on biological and electeromagnetic environments in RF (radio frequency) and microwave regions in Japan. Publicized research reports on biological objectives, evaluation of exposure rate, electromagnetic environments and guideline for the protection from radio wave nuisances are briefly introduced. Some researches on the evaluation of the exposure rate caused by the near field effect of portable radio transceiver are reviewed. Radio frequency exposer protection guidelines in Japan are also described.

The frequency characteristics of whole-body averaged specific absorption rates (SARs) in a human model exposed to a near field of an electric dipole or a magnetic dipole are calculated, using a finite-difference time-domain method. The dependences of the characteristics on the orientation of the dipole and on the distance from the source to the model are investigated. It is shown that the resonant peak of the SAR that appears in the E-polarized far-field exposure is observed only when the source is E-polarized and is located at 80cm, while the peak vanishes or is not noted when the source is located at 40cm and 20cm nor when it is H-polarized. The relationships between the whole-body averaged SARs and the incident electromagnetic field strengths are also investigated. It is suggested that the spatially-averaged value of the dominating component between the electric field and the magnetic field over the space where a human body would occupy provides a relevant measure to estimate the whole-body averaged SAR of a body in the vicinity of a small radiation source.

Myoelectric (ME) signals during dynamic movement suffer from motion arifact noise caused by mechanical friction between electrodes and the skin. It is difficult to reject artifact noises using linear filters, because the frequency components of the artifact noise include those of ME signals. This paper describes a nonlinear method of eliminating artifacts. It consists of an inverse autoregressive (AR) filter, a nonlinear filter, and an AR filter. To deal with ME signals during dynamic movement, we introduce an adaptive procedure and fuzzy rules that improve the performance of the nonlinear filter for local features. The result is the best ever reported elimination performance. This fuzzy rule based adaptive nonlinear artifact elimination filter will be useful in measurement of ME signals during dynamic movement.

Electrical and optical properties of organic multilayer structure have been investigated. Two types of current-voltage characteristics have been found for thin multilayer structure of organic films. Optical property and its application for electroluminescent diode have been presented. The diode characteristics have been discussed in terms of energy band scheme.

We have aimed at constructing a forward dynamics model (FDM) of the human arm in the form of an artificial neural network while recordings of EMG and movement trajectories. We succeeded in: (1) estimating the joint torques under isometric conditions and (2) estimating trajectories from surface EMG signals in the horizontal plane. The human arm has seven degrees of freedom: the shoulder has three, the elbow has one and the wrist has three. Only two degrees of freedom were considered in the previous work. Moreover, the arm was supported horizontally. So, free movement in 3D space is still a necessity. And for 3D movements or posture control, compensation for gravity has to be considered. In this papre, four joint angles, one at the elbow and three at the shoulder were estimated from surface EMG signals of 12 flexor and extensor muscles during posture control in 3D space.

An electron beam cell projection system has been developed that can effectively expose the fine, demagnified resultant pattern of repeated and non-repeated patterns such as the 256 Mb DRAM on a semiconductor wafer. Particular attention was given to the beam shaping and deflecting optics, which has two stage deflectors for the cell projection beam selection as well as the beam sizing, and three stage deflectors for objective deflection. The cell mask with a rectangular aperture and multiple figure apertures is fabricated by modified Si wafer processes. A new exposure control data for the cell projection is proposed. This data is fitted for the combination of pattern data for the cell mask projection and pattern data for the variable rectangular shape beam within the divided units of the objective deflection. On this exposure system, selective exposure of the desired pattern becomes possible on the semiconductor wafer while a mounting stage of the wafer is being moved, even if the pattern exposure of the repeated and non-repeated patterns is to be carried out. The total overhead time for selecting a subset of multiple figures and a rectangular aperture of the cell mask is less than 5 seconds/wafer. The estimated throughput of this system is approximately 20 wafers/hour.

A new phase shift lithography method has been developed that allows different integrated circuit features to be focused on different optical planes that conform to the wafer surface topography. In principle, each pattern in the circuit has its own unique focal plane. The direction and magnitude of each focus shift is determined by the design of the shifter patterns. This method is applicable for use with conventional opaque mask patterns and unattenuated phase shift patterns. The characteristics of this multiple-focus-plane technique have been evaluated experimentally and confirmed theoretically through mathematical modeling using TCC optical imaging theory. Experiments were conducted using i-line positive resist processes for different phase-shift patterns. This paper discusses the effects of changes in phase shift and recommends practical mask design approaches.

A new method for simulation of etching and deposition processes has been developed. This method is based on fundamental morphological operations derived from image and signal processing. As the material surface during simulation moves in time, the geometry either increases or decreases. If the simulation geometry is considered as a two-valued image (material or vacuum), etching and deposition processes can be simulated by means of the erosion and dilation operation. Together with a cellular material representation this method allows an accurate and stable simulation of three-dimensional arbitrary structures. Simulation results for several etching and deposition problems demonstrate accuracy and generality of our method.

In this paper, we present a new technique for the semantic analysis of sentences, including an ambiguity-packing method that generates a packed representation of individual syntactic and semantic structures. This representation is based on a dependency structure with constraints that must be satisfied in the syntax-semantics mapping phase. Complete syntax-semantics mapping is not performed until all ambiguities have been resolved, thus avoiding the combinatorial explosions that sometimes occur when unpacking locally packed ambiguities. A constraint satisfaction technique makes it possible to resolve ambiguities efficiently without unpacking. Disambiguation is the process of applying syntactic and semantic constraints to the possible candidate solutions (such as modifiees, cases, and wordsenses) and removing unsatisfactory condidates. Since several candidates often remain after applying constraints, another kind of knowledge to enable selection of the most plausible candidate solution is required. We call this new knowledge a preference. Both constraints and preferences must be applied to coordination for disambiguation. Either of them alone is insufficient for the purpose, and the interactions between them are important. We also present an algorithm for controlling the interaction between the constraints and the preferences in the disambiguation process. By allowing the preferences to control the application of the constraints, ambiguities can be efficiently resolved, thus avoiding combinatorial explosions.

Reflection type optical switches with intersecting waveguides and curved electrodes are newly proposed. The guided incident mode is expanded into an infinite spectrum of plane wavelets. The effects of light tunneling into the transmission port is taken care of by treating the 3-layer structure and using its reflection and transmission coefficients in estimation of the extinction ratios. It is found that the electrode curved in the form of an exponential spiral provides remarkably improved power reflectivity. This is because it poses a constant angle of incidence (smaller than the critical angle) to all variously oriented impinging wavelets. In this way, all plane wavelets are made to undertake total reflections. These total reflections result in considerably high extinction ratios to be achivable at the transmission port. It is also shown that the electrode length is shorter and the intersection angle is wider than those corresponding to a straight electrode. Therefore, it is concluded that the curvature of the electrode improves the switching characteristics of the device.

It was more than 10 years ago that the first map navigation system, as an example of invehicle information system, has appeared in the market in Japan. Today's navigation system has been improved to the level that the latest system has 10 micro-processors, 7 MBytes of memories, and 4 GBytes of external data storage for map database. From the viewpoint of the automobile driver, there are still some problems with the system. Major problems in general are a lack of traffic information, better human interface, and a need for cost-reduction. The introduction of application specific ICs (ASICs) is expected to make systems smaller, costless, and give higher speed response. Today's in-vehicle information systems are reviewed function by function to discover what functions need to be implemented into ASICs for future systems, what ASICs will be required, and what technology has to be developed. It is concluded that more integration technology is expected including high parformance CPUs, large capacity memories, interface circuits, and some analog circuits such as DA converter. To develop this technology, some, major problems such as power consumption, number of input/output signals, as well as design aid and process technology are pointed out.

Since carelessness in driving causes a terrible traffic accident, it is an important subject for a vehicle to avoid collision autonomously. Real-time collision detection between a vehicle and obstacles will be a key target for the next-generation car electronics system. In collision detection, a large storage capacity is usually required to store the 3-D information on the obstacles lacated in a workspace. Moreover, high-computational power is essential not only in coordinate transformation but also in matching operation. In the proposed collision detection VLSI processor, the matching operation is drastically accelerated by using a Content-Addressable Memory (CAM) which evaluates the magnitude relationships between an input word and all the stored words in parallel. A new obstacle representation based on a union of rectangular solids is also used to reduce the obstacle memory capacity, so that the collision detection can be parformed only by parallel magnitude comparison. Parallel architecture using several identical processor elements (PEs) is employed to perform the coordinate transformation at high speed based on the COordinate Rotation DIgital Computation (CORDIC) algorithms. The collision detection time becomes 5.2 ms using 20 PEs and five CAMs with a 42-kbit capacity.

A new concept for a positioning satellite system based on a new satellite constellation has been studied. The system needs a minimum of four satellites injected into quasi-geostationary orbit (QGEO) with high inclination. Due to the QGEO characteristic, the satellites are orbiting within continuous visibility range of ground control stations (GCS), from which the satellite time is controlled through the link connections of the feeder and the intersatellite communication (ISC). Consideration is made for the required high accuracy and quality checks against malfunction, wherever the satellites may be positioned. The orbit data processing function, another major function, is performed independently of the time control. The case of global coverage attained by twelve satellites has been studied in this paper. When a constellation of satellites for a global navigation satellite system (GNSS) is designed, conditions to obtain a good geometric dilution of precision (GDOP) at all places and times should be considered. Therefore, the satellites will be spread out in wide directions and are in an asymmetrical arrangement when seen by an observer are considered when setting the parameters of the ephemerides of the constellation. Under the restraints of the designed constellation, the GDOP value distribution for a third of the world map with area time parameters is computed and summarized in histograms for the system evaluation.

When orignal signals are contaminated by both additive and signal-dependent noise components, the test statistics of locally optimum detector are obtained for detection of weak composite signals based on the generalized Neyman-Pearson lemma. In order to consider the non-additive noise as well as purely-additive noise, a generalized observation model is used in this paper. The locally optimum detector test statisics are derived for all different cases according to the relative strengths of the known signal, random signal, and signal-dependent noise components. Schematic diagrams of the structures of the locally optimum detector are also included. The finite sample-size performance characteristics of the locally optimum detector are compared with those of other common detectors.

A fast and efficient heuristic hierarchical global router for Sea-of-Gates(SOG) with embedded macro-blocks is described. The key point in the method is carry out a new optimal domain decomposition scheduling at every hierarchical level. This scheduling is intended to avoid macro-block-through wirings and to reduce wiring congestion near macro-blocks which may occur at lower levels. The new global router yielded superior results compared with previous hierarchical routers and a non-hierarchical maze router by evaluating with several actual SOG circuits including a 300K gate master chip and benchmark data supplied from MCNC. Overflows were reduced to one-half or one-quarter for macro-block embedded data compared with previous hierarchical routers. Concerning the running time, the router remarkably outperformed the non-hierarchical maze router, which took more than 390 times longer time for the tested large data.

Reducing communication complexity is a viable approach to multilevel logic synthesis. A communication complexity based approach was proposed previously. In the previous works, only disjoint input decomposition was considered. However, for certain types of circuits, the circuit size can be reduced by using overlapped decomposition. In this paper, we consider overlapped decompositions. Some design issues for overlapped decompositions such as detecting globals" and deriving subfunctions are addressed. Moreover, the Decomposition Don't Cares (DDC) is considered for improving the decomposed results. By using these techniques together, the area and delay of circuits can be further minimized.

This paper presents a technique by which any linear CCD camera, be it one with lens distortions, or even one with misaligned lens and CCD, may be calibrated to obtain optimum performance characteristics. The camera-image formation model is described as a polynomial expression, which provides the line-of-sight flat-beam, including the target light-spot. The coefficients of the expression, which are referred to as camera parameters, can be estimated using the linear least-squares technique, in order to minimize the discrepancy between the reference points and the model-driven flat-beam. This technique requires, however, that a rough estimate of camera orientation, as well as a number of reference points, are provided. Experiments employing both computer simulations and actual CCD equipment certified that the model proposed can accurately describe the system, and that the parameter estimation is robust against noise.

Reflection mode diffraction tomography is expected to reconstruct a higher resolution image than transmission mode. Its image reconstruction problem, however, in the many cases of practical uses becomes ill-posed one. In this paper, a new reconstruction method of limited angle reflection mode diffraction tomography using maximum entropy method is proposed. Results of simulation showed that the method was able to reconstruct the better quality images than IR method poposed by Kak, et al.