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ABSTRACT: This paper introduces a high-performance optical depth sensor in a 0.18μm CMOS technology. At the core of the sensor, macro pixels consisting of 6×2 single-photon detectors enable accurate and selective time-of-flight measurements by taking advantage of temporal and spatial correlations of photons. An array of 32 high-throughput time-to-digital converters allows for the digitization of time-of-flight data with a resolution of 208ps within a range of 853ns, thus resolving distances up to 128 meters. Quantitative characterization of the chip sensor is reported. Depth map data acquired in a real-world situation illustrates the effectiveness of the approach in a road traffic environment.
ESSCIRC (ESSCIRC), 2011 Proceedings of the; 10/2011
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ABSTRACT: This paper presents a Hierarchical Scheduling Framework (HSF) recorder for Linux-based operating systems. The HSF recorder is a loadable kernel module that is capable of recording tasks and servers without requiring any kernel modifications. Hence, it complies with the reliability and stability requirements in the area of embedded systems where proven versions of Linux are preferred. The recorder is built upon the loadable real-time scheduler framework RESCH (Real-time Scheduler). We evaluate our recorder by comparing the overhead of this solution against another (patched) recorder. Also, the tracing accuracy of the HSF recorder is tested by running a media-processing task together with periodic real-time Linux tasks in combination with servers. The tests are recorded with the HSF recorder, and the Ftrace recorder, in order to show the correctness of the experiments and the HSF recorder itself.
Embedded and Real-Time Computing Systems and Applications (RTCSA), 2011 IEEE 17th International Conference on; 10/2011
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ABSTRACT: This article presents and assesses an algorithm that constructs 3D distributions of cloud from passive satellite imagery and collocated 2D nadir profiles of cloud properties inferred synergistically from lidar, cloud radar and imager data. It effectively widens the active–passive retrieved cross-section (RXS) of cloud properties, thereby enabling computation of radiative fluxes and radiances that can be compared with measured values in an attempt to perform radiative closure experiments that aim to assess the RXS. For this introductory study, A-train data were used to verify the scene-construction algorithm and only 1D radiative transfer calculations were performed.The construction algorithm fills off-RXS recipient pixels by computing sums of squared differences (a cost function F) between their spectral radiances and those of potential donor pixels/columns on the RXS. Of the RXS pixels with F lower than a certain value, the one with the smallest Euclidean distance to the recipient pixel is designated as the donor, and its retrieved cloud properties and other attributes such as 1D radiative heating rates are consigned to the recipient. It is shown that both the RXS itself and Moderate Resolution Imaging Spectroradiometer (MODIS) imagery can be reconstructed extremely well using just visible and thermal infrared channels. Suitable donors usually lie within 10 km of the recipient. RXSs and their associated radiative heating profiles are reconstructed best for extensive planar clouds and less reliably for broken convective clouds.Domain-average 1D broadband radiative fluxes at the top of the atmosphere (TOA) for (21 km)2 domains constructed from MODIS, CloudSat and Cloud–Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) data agree well with coincidental values derived from Clouds and the Earth's Radiant Energy System (CERES) radiances: differences between modelled and measured reflected shortwave fluxes are within ±10 W m−2 for ∼35% of the several hundred domains constructed for eight orbits. Correspondingly, for outgoing longwave radiation ∼65% are within ±10 W m−2. Copyright © 2011 Royal Meteorological Society and Crown in the right of Canada
Quarterly Journal of the Royal Meteorological Society 05/2011; 137(657):1042 - 1058. · 2.91 Impact Factor
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ABSTRACT: Calculating current distributions along conducting straight wires reveals that the electric influence of the wires is more effectively reduced by loading reactances than it is by disconnecting the loading ports. With the electric influence almost eliminated, a sheet consisting of reactively loaded straight wires can almost perfectly transmit a radio wave of a frequency determined by the interval between the loading ports and the reactance value. The frequency responses of radio wave transmissions for a normal incident plane wave are numerically calculated, and it is shown that by controlling the reactance value, the transmission can be changed more than 30 dB. Thus, a sheet by which radio wave transmission can be electronically controlled is proposed, and its operation is experimentally examined.
IEEE Transactions on Antennas and Propagation 02/2011; · 2.15 Impact Factor
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ABSTRACT: For a long period, many researches about the human spatial recognition are being carried on. They are needed to make robot and automatic driving system for a car or wheelchair with functions as high as those of humans: spatial perception, decision-making, and determining direction. The final goal of our measuring brain activity research is to contribute to developing of welfare robots with functions that are responsive like human. In this paper, the hemoglobin density change of human frontal lobe is measured. As the first step, to and analyze human spatial perception, experiments using a driving movie were designed. As the second, experiments were performed for measuring the brain activity during car driving. In the experiments NIRS (Near Infrared Reflectance Spectroscopy) was used.
Robotics and Biomimetics (ROBIO), 2010 IEEE International Conference on; 01/2011
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ABSTRACT: Si CMOS power amplifier based on source common circuit for millimeter wave super broadband wireless systems using beam forming antenna has been designed. Requirement of output power of each beam forming antenna elements can be reduced to less than 3dBm because of power combining at the air after radiation. Instead of reduction of output power requirement, power added efficiency (PAE) has been improved in our design. Maximum PAE of 18.3% and PAE at operation point of 15.9% have been achieved by simulation. Measured PAE has been evaluated to be 12.5% at the operation point. AM-AM and AM-PM conversion of designed power amplifier has been modeled using modified Rapp model for system simulation. Degradation of Eb/N0 at bit error rate of 10<sup>-3</sup> using QPSK has been evaluated to be less than 0.5 dB considering with AM-AM and AM-PM conversion.
Microwave Conference Proceedings (APMC), 2010 Asia-Pacific; 01/2011
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ABSTRACT: Cancer treatment is one of several new applications which use nanosecond and subnanosecond high-voltage pulses. This study focuses on the design of a compact highpower pulsed electromagnetic wave generator using a nanosecond pulsed power generator to apply a high-intensity electric field for the treatment of cancer; the pulses cause apoptosis in cancer cells. We applied an L-C inversion circuit to the pulsed power generator to obtain a voltage waveform with a single frequency, which is applied to an antenna. A water gap switch and water capacitors were used in the L-C inversion circuit to obtain a pulsed voltage with a frequency element of 250 MHz. In this experiment, an electromagnetic wave was radiated underwater by a loop antenna. A measuring double loop antenna placed 0.15 m and 0.3 m from the radiating antenna detected electric field intensities of 112 kV/m and 49 kV/m, respectively. A focusing bowl was attached to the radiating antenna to obtain a higher electric field. The electric field intensity of the radiating antenna with the focusing bowl, 300 kV/m, was 6 times higher than that without the focusing bowl. The intensity distribution of the electric field focused by the focusing bowl was measured. A measuring small loop antenna detected peak electric field intensity of 11.3 kV/cm at a focal point. Areas with electric field intensity greater than 10.8 kV/cm were approximately 5 mm square and 3 mm wide in the x-z plane and y-axis, respectively.
IEEE Transactions on Dielectrics and Electrical Insulation 01/2011; · 1.09 Impact Factor
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ABSTRACT: This paper introduces a low-noise single-photon sensor in a 0.18 μm CMOS technology for scanning-based coaxial optical rangefinders. At the core of the sensor, macro pixels consisting of 10×10 single-photon detectors enable time-of-flight measurements by taking advantage of temporal and spatial correlations. Unlike conventional silicon photo-multipliers, or multi-pixel photon counters, our sensor features a pulse-shaping and summing stage that accurately resolves the number of quasi-simultaneous photon detections. Sensor characterization data are reported. When mounted on a practical rangefinder setup, the sensor enables distance measurements up to 50 meters with 1σ repeatability error lower than 26 cm throughout the range, using 10 laser pulses.
Solid State Circuits Conference (A-SSCC), 2010 IEEE Asian; 12/2010
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ABSTRACT: Recent annual CO<sub>2</sub> emission from Japan sums up to 1.2 billion ton, and about 17 percent of it is from automobile traffic. There are many approaches to reduce CO<sub>2</sub> emission and to prevent the global warming, and one of the important approaches is the Intelligent Transport Systems. This article surveys the effects of the ITS on the energy saving and global warming prevention based on the data in Japan, focusing on the applications of vehicular communication technologies. The ITS could contribute to the energy saving on two aspects: one is to eliminate the congestion, which enables each automobile to drive at the fuel optimal speeds, and the other is to provide means for modal shift, which reduces the traffic. This article surveys the ITS technologies for energy saving and CO<sub>2</sub> emission reduction, which include traffic signal control, ETC, route guidance, cruise control, and automated driving. The road-to-vehicle and vehicle-to-vehicle communications play an essential role in energy saving as well as in the safety of automobiles and road transportation.
IEEE Communications Magazine 12/2010; · 3.79 Impact Factor
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ABSTRACT: This paper proposes the implementation of 4 different scheduling strategies for combining multi-core scheduling with hierarchical scheduling. Three of the scheduling schemes are analyzable with state-of-the-art schedulability analysis theory, available in the real-time systems community. Our idea is to implement these hierarchical multi-core scheduling strategies in a Linux based operating system, without modifying the kernel, and evaluate them. As of now, we have developed/implemented a prototype two-level hierarchical scheduling framework (HSF) in Linux (uni-core), which supports fixed priority preemptive scheduling (FPPS) of periodic servers at the top level, and FPPS of periodic tasks at the second level. The HSF is based on the REal-time SCHeduler (RESCH) framework.
Emerging Technologies and Factory Automation (ETFA), 2010 IEEE Conference on; 10/2010
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ABSTRACT: A method for adding a target emotion to arbitrary body movements of a human form robot (HFR) is developed. The additional emotion is pleasure, anger, sadness or relaxation. This paper proposes a motion rendering system that modifies arbitrary basic movements of a certain real HFR to add the target emotion at intended strength. The system is developed on the assumption that movements can be emotive by processed on the basis of the correlations between movement features and expressed emotions. The movement features based on Laban movement analysis (LMA) are adopted. An experiment using a real HFR are conducted to test how well our system adds a target emotion to arbitrary movements at intended strength. The results of experiments suggest that our method succeeded in adding a target emotion to arbitrary movements.
RO-MAN, 2010 IEEE; 10/2010
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ABSTRACT: In this paper, GaN power transistors on Si substrates for power switching application are reported. GaN heterojunction field-effect transistor (HFET) structure on Si is an important configuration in order to realize a low loss and high power devices as well as one of the cost-effective solutions. Current collapse phenomena are discussed for GaN-HFETs on Si substrate, resulting in suppression of the current collapse due to using the conducting Si substrate. Furthermore, attempts for normally off GaN-FETs were examined. A hybrid metal-oxide-semiconductor HFET structure is a promising candidate for obtaining devices with a lower on-resistance (Ron) and a high breakdown voltage (Vb).
Proceedings of the IEEE 08/2010; · 6.81 Impact Factor
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ABSTRACT: Adaptive directional wavelet transform is an effective alternative of the traditional 2-D wavelet transform for image coding. It is able to transform an image adaptively along diagonal orientations as well as conventional vertical/horizontal directions. However, it requires to transmit transform direction information to the decoder side. For image coding at very low bitrates, the bit budget of the direction information degrades a reconstructed image quality. In this paper, a method to construct a scalable bitstream for transform directions is presented. We utilize the fact that the matrix yielded by transform direction indices still contains the original image characteristics. The matrix is transformed by a block-lifting based DCT, then encoded by SPIHT to yield a scalable bitstream. Our method is effective for very low bitrate image coding, and is comparable to the non-scalable one for middle-to-high bitrates.
Circuits and Systems (ISCAS), Proceedings of 2010 IEEE International Symposium on; 07/2010
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ABSTRACT: Idea of a very short time annealing technology has evaluated in 1980s. Engineers tried to use Flash lamp, laser or some other lamps. In 1990s, W-halogen lamp annealing replaced furnace annealing in activation and silicidation process. Thermal budget has reduced from minutes to seconds. Eager for Milli-second Annealing (MSA) really came out in 2000s. Since dopant diffusion and an activation ratio have been considered to be more critical obstacle in scaled down microstructure devices, FLA activation technology came into spotlight again. A 65 nm device was a first product which used Flash Lamp Annealing (FLA) in manufacturing. Today, milli-second process has become an indispensable method in device manufacturing. But device generation keeps proceeding 45 nm, 32 nm and so on. Furthermore, a new material like high-k/metal is selected as a latest device material. Difficulty in MSA for 32 and 22 generation devices is reported recently.
Junction Technology (IWJT), 2010 International Workshop on; 06/2010
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ABSTRACT: We have proposed a group exercise for beginners using LEGO Mindstorms robot kit. It is pre-education for introductory programming lesson. The educational purpose is to promote problem solving skill by control programming. It also aims to keep learning motivation during group collaboration works. We summarize some educational practices for college freshmen and high school students. We construct communication support system LegoWiki based on PukiWiki. It helps to raise group activity with strategy discussion and progress report. We offer some plug-in tools for friendly user-interface. Moreover, we discuss some project support functions about planning by road map and task control by ticket.
Information Technology Based Higher Education and Training (ITHET), 2010 9th International Conference on; 06/2010
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ABSTRACT: This paper proposes an efficient approach for adaptive directional wavelet transform (WT) based on directional prefiltering. Although the adaptive directional WT is able to transform an image along diagonal orientations as well as traditional horizontal and vertical directions, it sacrifices computation speed for good image coding performance. We present two efficient methods to find the best transform directions by prefiltering using 2-D filter bank or 1-D directional WT along two fixed directions. The proposed direction calculation methods achieve comparable image coding performance comparing to the conventional one with less complexity. Furthermore, transform direction data of the proposed method can be used for content-based image retrieval to increase retrieval ratio.
IEEE Transactions on Image Processing 05/2010; · 3.04 Impact Factor
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ABSTRACT: We describe the results of the in-orbit radiometric calibration of the remote sensing instrument (RSI) onboard Formosat-2, based on the ground data collected by the advanced spaceborne thermal emission and reflection radiometer (ASTER) calibration team at Ivanpah Playa and Railroad Valley during the regular field campaigns in 2006 and 2008. These results are normalized by the preflight values provided by Astrium, France, and are compared with the results of in-flight calibrations made by Centre National d'Etudes Spatiales, France. The radiometric calibration coefficients and the long-term degrading trend of RSI are derived from the results of vicarious calibration, which estimate that the degradations of sensor sensitivity until 2008 are 2.2% (B4), 8.0% (B3), 9.6% (PAN), 10.3% (B2), and 12.0% (B1). Considering the fact that the ASTER calibration team is able to achieve an accuracy of vicarious calibration better than 5%, we estimate a 7.3% to 13.4% overestimate would be incurred by using the existing in-flight cross calibration coefficients to calculate the spectral radiances. This paper supports the use of vicarious calibration as a reliable approach for the in-orbit radiometric calibration of RSI onboard Formosat-2 on a regular basis.
IEEE Transactions on Geoscience and Remote Sensing 05/2010; · 2.89 Impact Factor
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ABSTRACT: Image concentration is an image resizing technique which shrinks an image size but does not change important region(s) in the original image, whereas image dilution is the reverse process to image concentration. In this paper, we incorporate image concentration/dilution process in image coding. An image retargeting method called seam carving is used for image concentration. Furthermore, it is modified to yield rate-distortion optimized seams by a hierarchical search process. Our method can be incorporated into any image encoder since the image concentration (dilution) is a pre(post)- processing of image encoder (decoder). In the experimental results, JPEG/SPIHT with image concentration/dilution presents significant bitrate savings compared with the original JPEG/SPIHT alone and reconstructed image qualities are very similar to each other.
Acoustics Speech and Signal Processing (ICASSP), 2010 IEEE International Conference on; 04/2010 · 4.63 Impact Factor
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ABSTRACT: An exact expression of the average error rate is developed for a band-limited binary phase-shift keying (BPSK) system in the presence of adjacent channel interference (ACI) considering a Nakagami fading channel. The system employs a root-raised cosine (RRC) filter both in the transmitter and receiver sides and a transmitter power amplifier (PA) that may have nonlinear input/output characteristics. These practical considerations are accurately taken into account. By utilizing the characteristic function (CF) method of error-rate analysis, we interestingly blend the concepts of time and frequency domains and develop an error-rate expression that is simple and general for several system parameters, including adjacent channel separation, RRC filter roll-off factor, and PA output back-off (OBO). Hence, the error rate in the presence of cochannel interference (CCI) is obtained as a special case. The developed results for a single-branch receiver are then extended for diversity receivers, and several interesting observations are made.
IEEE Transactions on Vehicular Technology 04/2010; · 1.92 Impact Factor
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ABSTRACT: It is fundamental work to translate the historical characters called "kuzushi-ji" into the contemporary characters in Japanese historical studies. In this paper, we develop the Japanese historical character recognition system using the directional element features and modular neural networks. Modular neural networks consist of two kinds of classifiers: a rough classifier to find the several candidates of categories for the input pattern, and a set of fine-classifiers that determine the category of the input pattern as the final result of character recognition. We construct the rough-classifier using the self-organizing maps (SOM), which can derive the multi-templates for each category from input data. The fine-classifiers are realized using multilayered neural networks, each of which solves the two-category classification problem. We also use the rough-classifier for the selection the training samples in the learning process of multilayered neural networks in order to reduce the learning time. Through the experiments of historical character recognition for 57 character categories, we confirmed the effectiveness of our proposed method compared with the conventional research.
Innovative Computing, Information and Control (ICICIC), 2009 Fourth International Conference on; 01/2010
