Showing papers by "Mitsubishi Electric published in 1997"

Design galleries: a general approach to setting parameters for computer graphics and animation

Abstract: Image rendering maps scene parameters to output pixel values; animation maps motion-control parameters to trajectory values. Because these mapping functions are usually multidimensional, nonlinear, and discontinuous, finding input parameters that yield desirable output values is often a painful process of manual tweaking. Interactive evolution and inverse design are two general methodologies for computer-assisted parameter setting in which the computer plays a prominent role. In this paper we present another such methodology. Design GalleryTM (DG) interfaces present the user with the broadest selection, automatically generated and organized, of perceptually different graphics or animations that can be produced by varying a given input-parameter vector. The principal technical challenges posed by the DG approach are dispersion, finding a set of input-parameter vectors that optimally disperses the resulting output-value vectors, and arrangement, organizing the resulting graphics for easy and intuitive browsing by the user. We describe the use of DG interfaces for several parameter-setting problems: light selection and placement for image rendering, both standard and image-based; opacity and color transfer-function specification for volume rendering; and motion control for particle-system and articulated-figure animation. CR Categories: I.2.6 [Artificial Intelligence]: Problem Solving, Control Methods and Search—heuristic methods; I.3.6 [Computer Graphics]: Methodology and Techniques—interaction techniques; I.3.7 [Computer Graphics]: Three-Dimensional Graphics and Realism.

Bayesian color constancy.

Abstract: The problem of color constancy may be solved if we can recover the physical properties of illuminants and surfaces from photosensor responses. We consider this problem within the framework of Bayesian decision theory. First, we model the relation among illuminants, surfaces, and photosensor responses. Second, we construct prior distributions that describe the probability that particular illuminants and surfaces exist in the world. Given a set of photosensor responses, we can then use Bayes’s rule to compute the posterior distribution for the illuminants and the surfaces in the scene. There are two widely used methods for obtaining a single best estimate from a posterior distribution. These are maximum a posteriori (MAP) and minimum mean-squared-error (MMSE) estimation. We argue that neither is appropriate for perception problems. We describe a new estimator, which we call the maximum local mass (MLM) estimate, that integrates local probability density. The new method uses an optimality criterion that is appropriate for perception tasks: It finds the most probable approximately correct answer. For the case of low observation noise, we provide an efficient approximation. We develop the MLM estimator for the color-constancy problem in which flat matte surfaces are uniformly illuminated. In simulations we show that the MLM method performs better than the MAP estimator and better than a number of standard color-constancy algorithms. We note conditions under which even the optimal estimator produces poor estimates: when the spectral properties of the surfaces in the scene are biased. © 1997 Optical Society of America [S0740-3232(97)01607-4]

New Block Encryption Algorithm MISTY

Abstract: We propose secret-key cryptosystems MISTY1 and MISTY2, which are block ciphers with a 128-bit key, a 64-bit block and a variable number of rounds. MISTY is a generic name for MISTY1 and MISTY2. They are designed on the basis of the theory of provable security against differential and linear cryptanalysis, and moreover they realize high speed encryption on hardware platforms as well as on software environments. Our software implementation shows that MISTY1 with eight rounds can encrypt a data stream in CBC mode at a speed of 20Mbps and 40Mbps on Pentium/100MHz and PA-7200/120MHz, respectively. For its hardware performance, we have produced a prototype LSI by a process of 0.5Μ CMOS gate-array and confirmed a speed of 450Mbps. In this paper, we describe the detailed specifications and design principles of MISTY1 and MISTY2.

Concordia: An Infrastructure for Collaborating Mobile Agents

Abstract: Use of the Internet and the World-Wide-Web has become widespread in recent years and mobile agent technology has proliferated at an equally rapid rate. In this paper, we introduce the Concordia infrastructure for the development and management of network-efficient mobile agent applications for accessing information anytime, anywhere, and on any device.

COLLAGEN: when agents collaborate with people

Abstract: We take the position that autonomous agents, when they interact with people, should be governed by the same principles that underlie human collaboration. These principles come from research in computational linguistics, specifically collaborative discourse theory, which describes how people communicate and coordinate their activities in the context of shared tasks. We have implemented a prototype toolkit, called Collagen, which embodies collaborative discourse principles, and used it to build a collaborative interface agent for a simple air travel application. The potential benefits of this approach include application-independence, naturalness of use, and ease of learning, without requiring natural language understanding by the agent. Superseded by TR97-21. First International Conference on Autonomous Agents, Marina del Rey, CA, February, 1997, pp. 284-291 and reprinted in M. Huhns and M. Singh, editors, Readings in Agents, Morgan Kaufmann, San Francisco, CA, 1997, pp. 117–124 This work may not be copied or reproduced in whole or in part for any commercial purpose. Permission to copy in whole or in part without payment of fee is granted for nonprofit educational and research purposes provided that all such whole or partial copies include the following: a notice that such copying is by permission of Mitsubishi Electric Research Laboratories, Inc.; an acknowledgment of the authors and individual contributions to the work; and all applicable portions of the copyright notice. Copying, reproduction, or republishing for any other purpose shall require a license with payment of fee to Mitsubishi Electric Research Laboratories, Inc. All rights reserved. Copyright c ©Mitsubishi Electric Research Laboratories, Inc., 1996 201 Broadway, Cambridge, Massachusetts 02139

Simulating arthroscopic knee surgery using volumetric object representations, real-time volume rendering and haptic feedback

Abstract: A system for simulating arthroscopic knee surgery that is based on volumetric object models derived from 3D Magnetic Resonance Imaging is presented. Feedback is provided to the user via real-time volume rendering and force feedback for haptic exploration. The system is the result of a unique collaboration between an industrial research laboratory, two major universities, and a leading research hospital. In this paper, components of the system are detailed and the current state of the integrated system is presented. Issues related to future research and plans for expanding the current system are discussed.

A microwave miniaturized linearizer using a parallel diode with a bias feed resistance

Abstract: A miniaturized linearizer using a parallel diode with a bias feed resistance has been proposed. The linearizer has positive gain and negative phase deviations and can be used as a linearizer for power amplifiers. These characteristics are provided by a nonlinearity of the diode and movement of bias point caused by a voltage drop at the bias feed resistance. By applying this linearizer to an S-band power amplifier, improvement of adjacent channel leakage power of 5 dB and improvement of power-added efficiency of 8.5% have been achieved for the /spl pi//4-shift QPSK modulated signal.

Measurements of reflection and transmission characteristics of interior structures of office building in the 60-GHz band

Abstract: We have measured (at 57.5 GHz) the reflection and transmission coefficients of typical walls, floor, ceiling, window, and partitions and have compared the measured reflection characteristics with the reflection characteristics estimated by multilayer dielectric models. Although the positional inhomogeneity of structures gives rise to some variation from one measured position to another, these positional variabilities are not large. The overall trend of reflection coefficients calculated by multilayer dielectric models thus agrees fairly well with the trend of the measurements. We have shown that the use of circular polarization can reduce the reflection even if the interior parts of the structure have complicated structures. In addition, the shadowing effects of several types of partitions were measured. The transmission coefficients of partitions depend on the materials. The transmission losses of plywood-made partitions are found to be fairly low.

3D virtual environment creation management and delivery system

Abstract: A virtual reality environment creation, modification and delivery system stores information representing the virtual reality environment in a database where portions of it may be created, modified or delivered without affecting other portions. The database may be accessed, for example, over a network such as a wide area network, to allow database records to be individually updated without affecting other records in the database. In this manner, it is not necessary to read and store an entire virtual reality environment file in order to make changes to it. In addition, characteristics of target machines dictate what version the database reads out, thus to provide a version compatible with the target machine.

Theoretical and experimental study on ozone generation characteristics of an oxygen-fed ozone generator in silent discharge

Abstract: Experimental and theoretical investigations have been carried out on the ozone generation characteristics of oxygen-fed ozone generators with various discharge gap lengths. In this paper, a new theoretical model considering the dependence of ozone dissociation rate by electron impact on the electric field strength is suggested. Assuming a stationary and uniform discharge in time and space, ozone concentrations obtained experimentally under various discharge power densities and gas pressures are well explained by this model. It is concluded that the operation under a high electric field has a potential advantage in producing high-concentration ozone efficiently because of the reduction in the population density of low-energy electrons which decompose generated ozone.

Analysis of very fast transient overvoltage in transformer winding

Abstract: Owing to the operation of disconnector switches, very fast transient overvoltages can generate a voltage oscillation inside power transformers connected to them. A practical method to analyse such oscillations is developed based on multiconductor transmission-line theory. The analysis is conducted in two steps in the frequency domain: first the whole transformer winding is simulated using a single transmission-line model; and secondly, the phenomena in the first coil are analysed using a multiconductor transmission-line model. The numerical results for an actual 525 kV power transformer conform with experiments. The interturn voltage shows a resonance determined by the travelling waves in the coil. The propagation of travelling waves is visualised using time domain analysis.

System for modifying lighting in photographs

Abstract: A system for creating lighting for a photograph generates a large number ofmages based upon structures determined from the photograph and randomly selected light positions, types and directions. One or more photographs are analyzed to determine the three-dimensional structures in the photographs. These structures are represented as gray surfaces, to which lighting is applied. The images are culled to provide a set of images which best spans the lighting space represented by the large number of images. The culling process is iterative; at each iteration, the image which is most dissimilar from a nearest neighbor in the selected set is added to the selected set. The images are organized in a hierarchical structure. A user interface allows the user to review and select images in the hierarchical structure. The images selected by the user are combined to create a final image with composite lighting. The lighting specifications can be saved for future reference by the lighting system or other applications. The lighting of the gray surface images are used to modify the intensity of pixels in the photograph in order to change lighting in the photograph.

Very low bit-rate video coding with block partitioning and adaptive selection of two time-differential frame memories

Abstract: Several studies on very low bit rate video coding have been reported. One of the major goals of the studies is to improve the coding performance, which gives better subjective and objective quality than conventional coding methods at the same bit rate. As the shape and structure of an object in a picture are arbitrary, the performance of traditional coding with block-based motion compensation (MC) is not satisfactory. We present advanced MC schemes for very low bit-rate video coding. The major features of the proposed MC are block-partitioning prediction and the utilization of two time-differential reference frames. This coding scheme improves the image quality around the objects' boundaries and consequently reduces prediction errors. It also works well in the case of object occlusions. The combination of the proposed MC and discrete cosine transformation (DCT) shows a better performance in several test sequences than full-spec H.263.

Diamond park and spline: Social virtual reality with 3d animation, spoken interaction, and runtime extendability

Abstract: Diamond Park is a social virtual reality system in which multiple geographically separated users can speak to each other and participate in joint activities. The central theme of the park is cycling. Human visitors to the park are represented by 3D animated avatars and can explore a square mile of 3D terrain. In addition to human visitors, the park hosts a number of computer simulations, including tour buses and autonomous animated figures. Diamond Park is implemented using a software platform called Spline, which makes it easy to build virtual worlds where multiple people interact with each other and with computer simulations in a 3D visual and audio environment. Spline performs all the processing necessary to maintain a distributed, modifiable, and extendable model of a virtual world that is shared between the participants. For more information visit http://www.merl.com.

Synchronous semiconductor memory device and synchronous memory module

Abstract: A first clock signal for controlling the inputting of an external signal and for controlling internal operation and a second clock signal for controlling data output are applied to separate clock input nodes, respectively. Data output timing with respect to the first clock signal can be adjusted and thus clock access time and data hold time can be adjusted. Internal data read path is pipelined to include a first transfer gate responsive to the first clock signal for transferring internal read data and a second transfer gate responsive to the second clock signal for transferring the internal read data from the first transfer gate for external outputting through an output buffer. A synchronous semiconductor memory device is provided capable of setting clock access time and data hold time at the optimal values depending on the application and of reducing the clock access time.

Beamforming experiment with a DBF multibeam antenna in a mobile satellite environment

Abstract: This paper describes a digital beamforming (DBF) multibeam antenna that incorporates a compact digital signal processor (DSP) engine, and the results of using it in a beamforming experiment receiving a satellite signal in a land-mobile environment. A considerable reduction in the scale of the DSP engine has been achieved by using field programmable gate arrays (FPGAs). To capture a satellite signal arriving from an unknown direction, a two-dimensional (2-D) spatial FFT signal processing provides orthogonal multibeam patterns on the broad side of a planar array antenna. The experimental results demonstrated the features of coarse acquisition and tracking of a signal arrival by selecting the strongest of the beams without assistance from direction finding sensors or microwave phase shifters. The DBF multibeam antenna will provide high-quality communications and increase traffic capacity if it is applied to high-gain mobile antennas or multispot-beam base station antennas in cellular or satellite mobile communications.

Multiple user/agent window control

Abstract: A system is provided to automatically control input permission when multi users and/or software agents interact with a single, shared application in a window-based computing environment, and to indicate to all users which user or software agent currently is providing input or seeking input permission. The system operates by providing each user and agent with a specialized cursor icon that is used for displaying input-permission status and for requesting and relinquishing input-permission. Cursors have three modes with distinct appearances indicating whether the corresponding user or agent has, does not have, or desires input permission. Cursors are replicated on all displays, so that all users can at all times easily see who has or desires input permission. Users interact with the input-permission system by moving and clicking their mouse. Software agents achieve the same effects by sending control requests directly to a software interface provided as part of the invention. In one embodiment, each user and agent also has an assigned Home Window, which is used for identification and to compose and display text messages.

Segmented interaction history in a collaborative interface agent

Abstract: We have developed an application-independent toolkit, called Collagen, based on the SharedPlan theory of collaborative discourse, in which interaction histories are hierarchically structured according to a user's goals and intentions. We have used Collagen to implement an example collaborative interface agent with discourse processing, but not natural language understanding. In this paper, we concentrate on how a segmented interaction history supports user orientation, intelligent assistance, and transformations, such as returning to earlier points in the problem solving process and replaying segments in a new context. To appear in Third Int. Conf. on Intelligent User Interfaces, Orlando, FL, January 1997. This work may not be copied or reproduced in whole or in part for any commercial purpose. Permission to copy in whole or in part without payment of fee is granted for nonpro t educational and research purposes provided that all such whole or partial copies include the following: a notice that such copying is by permission of Mitsubishi Electric Information Technology Center America; an acknowledgment of the authors and individual contributions to the work; and all applicable portions of the copyright notice. Copying, reproduction, or republishing for any other purpose shall require a license with payment of fee to Mitsubishi Electric Information Technology Center America. All rights reserved. Copyright c Mitsubishi Electric Information Technology Center America, 1996 201 Broadway, Cambridge, Massachusetts 02139 Lotus Development Corporation Publication History:{ 1. First printing, TR-96-14, June 1996 Charles Rich MERL{A Mitsubishi Electric Research Laboratory 201 Broadway Cambridge, MA 02139 USA +1-617-621-7507 rich@merl.com Candace L. Sidner Lotus Development Corporation 55 Cambridge Parkway Cambridge, MA 02142 USA +1-617-693-7737 csidner@lotus.com ABSTRACT We have developed an application-independent toolkit, called Collagen, based on the SharedPlan theory of collaborative discourse, in which interaction histories are hierarchically structured according to a user's goals and intentions. We have used Collagen to implement an example collaborative interface agent with discourse processing, but not natural language understanding. In this paper, we concentrate on how a segmented interaction history supports user orientation, intelligent assistance, and transformations, such as returning to earlier points in the problem solving process and replaying segments in a new context.We have developed an application-independent toolkit, called Collagen, based on the SharedPlan theory of collaborative discourse, in which interaction histories are hierarchically structured according to a user's goals and intentions. We have used Collagen to implement an example collaborative interface agent with discourse processing, but not natural language understanding. In this paper, we concentrate on how a segmented interaction history supports user orientation, intelligent assistance, and transformations, such as returning to earlier points in the problem solving process and replaying segments in a new context.

Spectral characteristics of an all solid-state frequency-shifted feedback laser

Abstract: A laser cavity closed via the first-order diffracted light of an acoustooptic modulator is referred to as a frequency-shifted feedback laser (FSF laser). This laser exhibits outstanding features in its oscillation spectrum. We previously demonstrated the first oscillation of an all solid-state FSF laser, and it turned out experimentally that the oscillation spectrum consists of a continuously chirped comb of frequency components. Furthermore, we have been investigating oscillation dynamics both experimentally and analytically for a better understanding of FSF laser. Here experimental results and analyses on the spectral characteristics of the laser are discussed.

Noncontact IC card

Abstract: A noncontact IC which transmits and receives data to and from a host computer using RF signals has a buffer for storing received data temporarily and a control circuit for controlling operation of the buffer main memory thereof, wherein the control circuit starts processing data stored in the buffer only when no further data is input after a predetermined data receiving time period has elapsed from the latest data input to the buffer.

Error concealment algorithms for robust decoding of MPEG compressed video

Abstract: This paper provides some research results on the topic of error resilience for robust decoding of MPEG (Moving Picture Experts Group) compressed video. It introduces and characterizes the performance of a general class of error concealment algorithms. Such receiver-based error concealment techniques are essential for many practical video transmission scenarios such as terrestrial HDTV broadcasting, packet network based teleconferencing/multimedia, and digital SDTV/HDTV delivery via ATM (asynchronous transfer mode). Error concealment is intended to ameliorate the impact of channel impairments (i.e., bit-errors in noisy channels, or cell-loss in ATM networks) by utilizing available picture redundancy to provide a subjectively acceptable rendition of affected picture regions. The concealment process must be supported by an appropriate transport format which helps to identify image pixel regions which correspond to lost or damaged data. Once the image regions (i.e., macroblocks, slices, etc.) to be concealed are identified, a combination of spatial and temporal replacement techniques may be applied to fill in lost picture elements. A specific class of spatio-temporal error concealment algorithms for MPEG video is described and alternative realizations are compared via detailed end-to-end simulations for both one- or two-tier transmission media. Several algorithm enhancements based on directional interpolation, ‘I-picture motion vectors’, and use of MPEG-2 ‘scalability’ features are also presented. In each case, achievable performance improvements are estimated via simulation. Overall, these results demonstrate that the proposed class of error concealment algorithms provides significant robustness for MPEG video delivery in the presence of channel impairments, permitting useful operation at ATM cell-loss rates in the region of 10 −4 to 10 −3 and 10 −2 to 10 −1 for one- and two-tier transmission scenarios, respectively.

Dynamic synchronous collaboration framework for mobile agents

Abstract: A dynamic synchronous collaboration framework utilizes a distributed synchronizated point to permit synchronous collaboration of mobile agent objects (28, 30, 32) in a distributed computer system. The framework simplifies agent collaboration for applications which divide a complex problem into multiple tasks and delegate tasks to multiple mobile agents. The collaboration framework also enables mobile agents (28, 30, 32) within an application to perform synchronous collaboration with affiliated agents in the native language of an associated software application. Such collaboration is accomplished by joining collaborating agents to an agent group (26). Member agents periodically correlate results through a collaborative sharing within the agent group, and may adopt new behaviors based on the results of the collaboration.

Context based system for accessing dictionary entries

Abstract: A context-based dictionary entry access system includes selecting and rang an entry based on the part-of-speech assigned to the given word in a sentence. The entries corresponding to the word in context are first selected, followed by availability of entries that are not relevant to the current context. The part of speech of the given word in context is selected based on the utilization of a part-of-speech tagger such that only those entries are selected in which the corresponding word makes syntactic sense in the sentence.

Synchronous semiconductor memory device operable in a plurality of data write operation modes

Abstract: A synchronous semiconductor memory device can achieve either of a pipelined mode and a prefetch mode with one chip. In accordance with CAS (column address strobe) latency 4 instructing signal MCL4 stored in a mode register, a sequence of generation of control signals from a control signal generating circuit is set to either the pipelined mode or the prefetch mode. A mode switching circuit merely switches reset timings of a write buffer in accordance with a CAS latency. Therefore, the internal data write mode can be easily switched in accordance with an operation environment, and the synchronous semiconductor memory device can implement multiple data write modes with one chip.

The sound dimension

Abstract: Although the spotlight of virtual reality research has been on providing views of simulated scenes and objects, some researchers have chosen to study how to fool other senses: hearing, touch, and even smell, into perceiving what is not there. They have good reason: the virtual environments that are best at stimulating multiple senses are also best at evoking a feeling of presence and immersion. Next to sight, hearing is the sense on which people rely the most. So sounds, too, can play an extremely critical role in a distributed virtual environment (DVE). The virtual reality (VR) experience is more satisfying when sound adds to or reinforces other DVE information. The paper discusses the variety of sound in VR systems and considers the selection of software and hardware for these uses of audio in DVE systems.

System for the reliable, fast, low-latency communication of object state updates over a computer network by combining lossy and lossless communications

Abstract: A system for fast, efficient and reliable communication of object state irmation among a group of processes combines the use of a fast, but lossy and thus unreliable communications channel to the group of processes and a server coupled to the group for providing data which has been lost in the multicasting In one embodiment, a central server supports reliability and rapid joining while using UDP multicast messaging to achieve rapid interaction and low bandwidth Differential messages are sent over the lossy channel to compactly describe how to compute the new state of an object from any of several previous states Such a description can be interpreted even if some number of prior descriptions were not received, greatly reducing the need for explicit, round-trip message repairs while also conserving bandwidth In one embodiment, the central server communicates with each member of the group over a reliable channel to robustly detect and repair objects affected by lost messages

An artificial retina chip with current-mode focal plane image processing functions

Abstract: This paper describes an artificial retina chip consisting of an array of Variable Sensitivity Photo-Detector cells (VSPDs) which accomplishes both nondestructive output and programmable positive or negative sensitivity. Despite its simple structure, this VSPD array realizes programmable focal plane image processing by employing between-pixel current mode calculations, together with a novel addressing method in which filtering is executed by varying the addressing pattern generated by a scanning unit. The n-MOS VSPD pixel which we have designed consists of a pn photodiode and an n-MOS differential amplifier; the VSPD circuit has been optimized by SPICE simulation. Using a 2-/spl mu/m n-MOS process gives a pixel size of 35 (H)/spl times/26 (V) /spl mu/m/sup 2/ with a photodiode fill factor of 25%. The artificial retina chip which has been fabricated incorporates 256/spl times/256 pixels, 16 parallel output ports, and a random access function. The photosensitivity is 0.8 /spl mu/A/lx for a 1-ms accumulation time. We demonstrate image capture in video mode and edge extraction mode, and light spot tracing using pattern matching in conjunction with the random access function.

Device, system, and method for distributing video data

Abstract: In a video data distributing system in which video data are trasmitted to a video data reproducing device from a video data distributing device (5) through a network (4) and the reproducing device reproduces the received video data, a network load measuring section (18) always monitors the load of the network (4). When the load of the network (4) is light, the distributing device (5) transmits all MPEG data (D1). When the load is heavy, the device (5) generates data (D3) of a small quantity obtained by thinning out as many frames as corresponding to the degree of the load from the MPEG data, etc., and transmits the data (D3) to the reproducing device.