Vagus nerve stimulation (VNS) is a palliative treatment for intractable epilepsy. Therapeutic mechanisms of VNS have not been elucidated. In this study, we measured the local field potential (LFP) with high-spatial resolution using a microelectrode array in adult rats, and analyzed VNS-induced phase modulation at a local network level. Eight adult Wistar rats (270-330 g) were used. Each rat underwent implantation of VNS system under 1.5% isoflurane anesthesia. One week after implantation, right temporal craniotomy was performed under the same as previous anesthesia. Subsequently, a microelectrode array was placed in the temporal lobe cortex, and LFP was recorded with sampling rate of 1000 Hz. Phase-locking values (PLV) between all pairs of electrodes in varied frequency bands were calculated in order to evaluate the effect of VNS in terms of synchrony of neuronal activities. PLV was calculated both in a normal state and in an epileptic state induced by kainic acid. VNS increased PLV in a normal state, particularly in the high-γ band. In an epileptic state, on the other hand, VNS increased PLV in high-γ band, and decreased PLV in the δ and low-β bands. These results suggest that VNS modulates neural activities in a band-specific and state-dependent manner so as to keep cortical synchrony within the optimal state.

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Spatio-temporal neural patterns depend on the physical structure of neural circuits. Neural plasticity can thus be associated with changes in the circuit structure. For example, newborn neurons migrate towards existing, already matured neural networks in order to participate in neural computation. In the present study, we have conducted two experiments to investigate how neural migration is associated with the development of neural activity in primary dissociated cultures of neuronal cells. In Experiment 1, using a mature culture, a high-density CMOS micro-electrode array was used to continuously monitor neural migration and activity for more than two weeks. Consequently, we found that even in mature neuronal cultures neurons moved 2.0±1.0 µm a day and that the moving distance was negatively correlated with their firing rate, suggesting that neurons featuring low firing rates tend to migrate actively. In Experiment 2 using a co-culture of mature and immature neurons, we found that immature neurons moved more actively than matured neurons to achieve functional connections to other neurons. These findings suggest that neurons with low firing rates as well as newborn neurons actively migrate in order to establish their connections and function in a neuronal network.

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Emerging applications of active 3D technology have raised expectations on development of more user-friendly stereoscopic 3D content. To optimize stereoscopic 3D content by taking into account human factor, understanding how user gazes at 3D direction in virtual space is an important research topic. In this paper, we suggest a novel approach to estimate 3D point of gaze on stereoscopic display using optimized geometric method. Dual-camera system and Direct Linear Transformation (DLT) algorithm have been utilized to compute user dependent parameters and 3D coordinate of pupil. Instead of asking user to perform a time-consuming 3D calibration session using more than twenty calibration points, a simplified 3D calibration method using only three calibration points is proposed. Our experimental results show that the proposed method achieves better accuracy compared with conventional geometric method by average errors 0.83, 0.87, and 1.06cm in X, Y, and Z dimension, respectively. Compared with subjective depth judgment, the proposed gaze tracking system is more robust in measuring depth of virtual 3D object with various sizes.

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This letter shows the relationship between amusement feeling expression and skin temperature of cheeks. We measured skin temperature of cheeks and nose using thermography in 30 fps when subjects rest and watching TV-comedy program as emotion-eliciting stimuli. The results for five persons show that the cheek temperature rises immediately when amusement feeling is expressed in most cases.

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On the system with gated clock, NBTI causes the unbalanced degradation in the threshold voltage of PMOSFETs. In this paper, we clarify the impact of NBTI degradation on timing characteristics such as setup time, hold time and clock skew. We demonstrate that the maximum operating frequency regarding setup time violation becomes worse, hold time constraint becomes better, and clock skew after a gated clock cell operates better with stopped time.

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Inverse filter is used in many fields such as audio circuit, telecom line equalization both metal and optical, and wireless equalization. The purpose of the filter is to compensate the distortion of the signal caused by the transmission media. Design methods of inverse filter using IIR filter, using FFT/IFFT and adaptive FIR filter are available. However IIR filter has some problem of stability, FFT/IFFT method needs a lot of calculation and adaptive FIR filter needs a lot of time. This paper proposes a new method to generate FIR inverse filter coefficients by serial calculation of impulse response and it's expecting value. At first all coefficients of FIR filter except the first one are zero. If the input of impulse response data X_N is applied to the filter, the temporal output of the FIR filter W_N is compared to the expectation value E_N, each FIR inverse filter coefficient g_N is calculated by g_N=(E_N-W_N)/X₀ step by step. This algorism is simulated by Excel calculation. The FPGA base circuit is synthesized by VHDL and behavior model is also simulated by ISE design tool. The coefficients of the filter is generated during the input period of data X_N, therefore real-time inverse filter circuit generation is available.

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Hearing information is very important role in visual information limited. Sound source localization is nominated for particularly ability in a hearing information processing. Barn owls have excellent processing for hearing. We propose a hardware model which construct by auditory sense mechanism of barn owls. In this paper, we consider the model of external nucleus of the inferior colliculus (hereafter “ICx”), which locate the source of a sound by interaural time difference (hereafter “ITD”) for localization in the horizontal direction, and interaural level difference (hereafter “ILD”) for localization in the vertical direction. As a result, we show clearly that the detection position of an ITD model and detection position of an ILD model can converge. Also the output position of ICx model change with the position of sound source.

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In this paper, we proposed an equal power allocation method to two receivers with high efficiency in two-dimensional wireless power transfer (2D-WPT). We conducted the computer simulation of the 2D-WPT to two receivers by using the circuit simulator that applied the equivalent circuit of magnetic resonance coupler arranged on 3×3 layout. As the result, the 2D-WPT showed unequal power allocation to two receivers because of the interference between multiple paths with different hop counts. Therefore we developed the single-path control method that improves efficiency by ON-OFF control of intermediates so as to form only one path to each receiver. As the result of circuit simulation and experiments, the efficiency using single-path control achieved higher and equal power allocation to two receivers.

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The ZigBee has attracted attention as the smart home network. Already the wireless LAN (WLAN) has been introduced in the home network. Both the ZigBee and WLAN use 2.4 GHz frequency band, and the carrier sensing mechanism is used for contentions, but the collisions are occurred because the access control procedure is different. Therefore, it is necessary to improve the transmission success ratio for the sensing data periodically sent by the ZigBee. This paper proposes a media access control for improving the transmission success ratio in coexistence environment between the ZigBee and WLAN. The point of proposal is the collaboration between the ZigBee coordinator and WLAN access point. When the ZigBee coordinator detects the signal for ZigBee, the access parameter, DIFS, for the WLAN is changed. Simulation results show the transmission success ratio is improved by reducing the collisions between the ZigBee and WLAN.

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Muscular activity is investigated by analyzing the action potential generated by motor units. The multi-channel surface electromyogram (EMG) is used to analyze the conduction of muscle potential. It is recorded as the interference electric potential generated by motor units. The multi-channel surface EMG includes waveforms that conduct in several channels (conducting waves). We believe that it may be possible to analyze the change in surface muscle potential caused by muscular activity to examine the composition of conducting waves in the multi-channel surface EMG. Thus, we herein propose a new method by which to analyze the multi-channel surface EMG. The proposed method involves searching all conducting waves appearing quantitatively in the multi-channel surface EMG to calculate the similarity of the waveforms. Using this method, which is referred to as the multi-channel method for conducting waves (m-ch method), various types of data for each wave, including the conduction velocity and amplitude, over channels can be examined. Using the m-ch method, we analyzed the multi-channel surface EMG for subjects holding a load. Moreover, we examined the change in the composition of conducting waves. We believe that muscular activity can be analyzed based on conducting waves from the surface EMG.

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Power supply was disrupted in several parts of Japan in the aftermath of the 2011 Great East Japan Earthquake. We conducted an internet survey on the residents of Sendai city, Miyagi Prefecture, and Kanagawa Prefecture in order to understand the nature and extent of the power outages and the influence of these disruptions on customers. We also investigated the impact of the rolling blackouts in Kanagawa that started in mid-March, 2011. On the basis of the survey results, this paper presented the quantitative effects of the lifeline disruptions on people's behavior, particularly, on the evacuation and sheltering behavior. In future studies, we would like to identify the minimum energy demand in emergency situations on the basis of the average energy consumption in smart houses that control energy use using Information and Communication Technology (ICT).

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Home security sensor becomes more and more practical today for the protection against intruder, and several types of sensor such as infrared, video camera and microwave radio are commonly used. Ultra-wideband impulse-radio (UWB-IR) sensor has lately attracted considerable attention because it is expected to measure not only motion of an intruder but also the distance. This paper presents an indoor intruder detection sensor system using stepped-fm based on UWB radio which can detect and track the movement of intruder. The usefulness is experimentally investigated by using our fabricated sensor. The measurements were conducted for various intrusion scenarios inside a typical house.

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Kamo Lake, located in Sado city, Niigata prefecture, Japan is approximately 4.9 km² in circumference, 17 km in overall length, and 2 km across, at its widest point. While it is the largest lake in Niigata prefecture and ranks 46th in Japan, its deepest point lies about 10 meters below the surface. Being tidal in nature, with constant injections of seawater from the northern inlet, it has tended to be a bit brackish, making it suitable for the many oyster-farms dotting the area. But, the recent influx of red tide has resulted in a die-off of these oysters, costing local fishermen more than 100 million yen in lost revenue. Prefectural authorities have so far been unable to find a practical solution. The objective of the present research is to develop an original, automatic water temperature-sensing network in Kamo Lake to provide a web-based information-network that will allow fishermen to better understand the relationship between water temperature, red tides and dissolved oxygen. Based on our experimental results, we believe that the amount of dissolved oxygen has a clear connection with oyster die-off, and elevated water temperatures would seem to be the culprit. Network communications for water-temperature measurement achieved a 95% reliability-rating, for the past three years.

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Crew Recovery Problem frequently appears in transport industries. This problem is to modify schedules of crews who cannot perform their tasks in their duties given beforehand as the result from Crew Scheduling Problem because of delays of trains or flights. To obtain a good modified schedule of crews is needed when delay occurs while it is more important to find alternative and acceptable schedule(s) quickly. In this paper, we formulate the problem in railways as an integer programming problem and propose an approach to this as a basic framework for similar problems arising in transport industries. Our heuristic approach is based on the idea of column generation method, which is one of the effective and powerful methods for large scale integer programming problems. The procedure generates various schedules for a certain instance by gradually increasing the number of crews to be rescheduled, giving the lower bound to the optimal value of the objective function in each iteration. Numerical experiments are performed to instances from Japanese railway. The results indicate that our approach successfully gives good schedules in short computation time.

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In this paper, we propose an L₁-approximation for the design of FIR digital filters with complex coefficients. The L₁-approximation has the advantage of having a flat passband and a small overshoot around the discontinuity point as compared with L₂-approximation and L_∞-approximation. As the obtained filter has complex coefficients, it can be reduced group delay and designed a digital filter with an asymmetric amplitude characteristic with respect to the origin. Algorithm proposed in this paper is based on Newton's method which is an efficient iterative approximation algorithm. We show effectiveness of the proposed method through a design example.

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A fish has excellent swimming ability in underwater. An airship robot capable of performing a low-speed, low-altitude flying low energy has been researched. Aquatic organism type airship robot “swimming in the air” combines these features have been researched and developed. BFR (Balloon Fish Robot) is one of this type robots. This paper is concerned with the simulation motion of BFR and parameter optimization for the propulsion efficiency of the aquatic organism type airship robot propelled by Traveling Wave. The controlling expression of BFR is written by Traveling-Wave Equation. And the equation of motion is defined through the controlling expression and drag force. The comparative experiments on forward air speed of the BFR of simulation and experiment evaluated the validity. The highest propulsion efficiency parameter is investigated by calculating using the experimental air speed and the maximum amplitude of the tail fin and Traveling-Wave frequency.

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This paper proposes a method that obtains a high-tone images from the ultra-low-tone image using the spatial features. Those areas are smoothed when the adjacent tone value of attention area is continuous. On the other hand, those areas save as an edge when the adjacent tone value of attention area is discontinuous. From this premise, that attention area can be classified into six patterns by each area. And, the low-gradation image is changed into a highly-gradating image by processing with each pattern. As a result of the comparative experiments, the proposed method was better quantitatively and visually than existing methods. The proposed method can change ultra-low-tone image into naturally-Highly-gradating image.

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Statistical learning methods for human detection require large quantities of training samples and thus suffer from high sample collection costs. Their detection performance is also liable to be lower when the training samples are collected in a different environment than the one in which the detection system must operate. In this paper we propose a generative learning method that uses the automatic generation of training samples from 3D models together with an advanced MILBoost learning algorithm. In this study, we use a three-dimensional human model to automatically generate positive samples for learning specialized to specific scenes. Negative training samples are collected by random automatic extraction from video stream, but some of these samples may be collected with incorrect labeling. When a classifier is trained by statistical learning using incorrectly labeled training samples, this can impair its recognition performance. Therefore, in this study an improved version of MILBoost is used to perform generative learning which is immune to the adverse effects of incorrectly labeled samples among the training samples. In evaluation tests, we found that a classifier trained using training samples generated from a 3D human model was capable of better detection performance than a classifier trained using training samples extracted by hand. The proposed method can also mitigate the degradation of detection performance when there are image of people mixed in with the negative samples used for learning.

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We evaluated the storage I/O response time with the volume tiering method and the SSD cache method on the tiered storage having SSD and HDD. The simulation result shows the volume tiering method improves the storage performance with low I/O locality workload and small SSD capacity. The SSD cache method is effective with read-intensive and high I/O locality workload. Utilizing both methods simultaneously reduces the storage I/O response time by up to 20% with write-intensive workload and large SSD capacity compared to using the volume tiering method or the SSD cache method separately.

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It is known that neighborhood search methods such as Tabu Search have the high performances for single-objective combinatorial optimization problems. In this paper, we develop a new method based on Tabu Search for multi-objective combinatorial optimization problems by using multi-point search and interaction among search points. The performance of the developed optimization method is examined using 3 types of 2-objective 0-1 knapsack problems.

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