A gel, which has characteristics of both a solid and a liquid is called a "soft material", is widely used in various industrial fields. But there are a lot of uncertain points about the electrical properties of the gel. In order to understand the growth mechanism of pearl-chain-type electrical trees in a polymer gel, and investigate about the relationship between the liquids and gels for the high electric field phenomena, the electric field distribution must be measured in the gel. This paper reports on the measurement of the electric field strength in a certain gel using Kerr effect. It is interesting that Kerr constant of the gel depend on the weight percent of a solvent.
X-ray imaging has been widely used for applications such as non-destructive inspection. This study aims at high-contrast imaging for low-absorption materials using refraction-contrast imaging with a high-coherence X-ray source. In this letter, we report the results of imaging experiments using seeds inside fruits via conventional imaging and refraction contrast imaging. Although a seed was difficult to be detected using the conventional method, it was clearly observed in the refraction contrast imaging. This letter describes the possibility of a non-destructive food inspection.
In recent years, a number of studies of neural networks have been conducted with the purpose of applying engineering to the brain. Previously, we proposed a pulse-type hardware neuron model, which can make an integrated circuit with field effect transistors and capacitors. However, the proposed model needed capacitors of [pF] order.
In this paper, we propose the constitution of the low capacitor implementation model. As a result, it is shown that the proposed model is able to achieve chaotic oscillation using 1fF capacitors.
To solve the problem of traffic proliferation in the mobile communications, traffic offload over wireless LAN systems has been proposed as the one of promising solutions. High-speed and large-capacity communication has been realized by wireless LAN systems, but in the high-speed moving environments, BER performances degrade due to influence of Doppler frequency spread. In this study, the entrance link using the IEEE802.11ac standard for public wireless LAN services in high-speed trains is proposed for improving the capacity of the whole system by employing not only MIMO (Multiple Input Multiple Output) to increase the transmission rate, but also STBC (Space-Time Block Coding) to extend the distance. By applying unsymmetrical STBC for up and down-link, the communication distance between a base station and a train can be extended and it is confirmed by simulation including a passing pattern and stopping/starting pattern that the communication capacity can be increased.
Measurement of blood viscosity is highly desired during extracorporeal circulation treatment. Extracorporeal circulation treatment is considered to be an opportunity for estimating the aggregation degree of red blood cells, which strongly corresponds to blood viscosity, because flow channels have known materials and dimensions. In a flow situation, single red blood cells would easily change their relative positions to each other; however, the relative positions among the red blood cells inside an aggregation would be highly maintained. These phenomena can be optically observed over a transparent blood circuit tube, thus, the aggregation degree of the red blood cells is expected to be obtained by conducting a cross-correlation process between time difference images. The increase of the image-correlation level in accordance with the increase of the aggregation degree was confirmed through experiments.
This paper focuses on a distributed solar energy network composed of multiple clusters, which correspond households equipped with PV units, rechargeable batteries, electrical appliances, and an electric power router. The routers manage the power transfer over the clusters. We obtain the optimal power transfer for the most efficient power utilization using a linear programing model. In the numerical experiments, we use real data of power generation and consumption sampled by monitoring in a local city in Japan. First, the power usage efficiensies are compared among the networks with various consumption distributions over the clusters and various battery capacities using the obtained optimal solutions. As the result, the wider distribution of the consumption amount and an appropriate capacity of battery gives the higher efficiency. Second, the sensitivity analysis on the linear programming model shows when, where and how the optimal solution is affected by the change of generation or consumption amount.
In this paper, unequal interval stepped multiple frequency Linear Frequency Modulation (LFM) pulse radar is modified to improve the side-lobe characteristics of Synthetic Wideband Waveform Processing (SWW). The proposed Constrained Minimum Square Error (CMSE) method, which employs some constraints on the output level of SWW, provides the parameters associated with the intervals of frequencies to mitigate problems associated with the side-lobe level in the vicinity of main-lobe. The parameters of the unequal interval frequency step are obtained by solving the optimization problem with the constraint condition that the side-lobe level of SWW is lowered in the vicinity of the main-lobe while it is increased at the null of LFM pulse compression. The simulation results are shown that unequal interval stepped multiple frequency LFM using CMSE method with only 8 frequencies, Discrete Fourier Transformation without weighting, suppressed the side-lobe level below -20dB.
In Japan, an increase of elderly people living alone has become a serious problem with the progress of aging. After 2013, the number of lonely death of elderly people living alone is increasing rapidly. Since lonely death tends to increase in the future, it is one of the problems to be solved by the government agencies and the families. The tracking system of elderly has been researched and developed by a number of companies and universities. However, many of those systems have required an operation of the elderly his/herself, or have become a large-scale system configuration. In this study, we propose an elderly monitoring system which is able to detect the abnormal state without stress of elderly. The proposed system consists of single monitoring device and several sensor nodes, and provides elderly state information to the family and/or government agencies, at the specified time and at the time that abnormal state is detected.
In this paper, we propose a design method of an inverse LQ regulator for neutral systems with a time-varying delay, in which the resulting system is assured to have a pre-assigned degree of exponential stability. Using this method, the closed-loop system is asymptotically stabilized and a feedback law constructed easily is the optimal control minimizing a class of a cost functional without relation to the exponential stability assignment. In addition, the regulator promises to have a good robust stability as same as ordinary finite dimensional LQ regulators, even when a static nonlinear or a dynamic linear perturbation is inserted in the control input. Finally, the method is demonstrated by numerical examples with and without the exponential stability assignment. In the simulation, it is shown that the proposed method allows designers to seek more fast closed-loop responses by selecting two scalar parameters and the degree of exponential stability in a condition given by LMIs.
In this paper, we propose a novel contrast enhancement algorithm. The contrast enhancement is an important for preprocessing of image processing because video processing for outdoor surveillance is always influenced by the weather. Most of conventional algorithms premise that images are clear. We try to highlight the invisible objects obscured by weather, such as rainy, snowfalls, night vision, and so on.
There are two critical problems in field of contrast enhancement. One is to preserve brightness and the other is to suppress false color. We employ the contrast enhancement algorithm based on histogram stretch because histogram stretch is able to preserve brightness of input images. In order to greatly improve contrast of images, we combine the clustering with histogram stretch. In addition, we divide color into brightness and saturation because false color is caused by an over-enhancement of saturation. So our algorithm preserves brightness and suppresses the false color generation. Furthermore, in various weathers, our algorithm can obtain the stable images. To this end, our algorithm estimates the degree of histogram stretch in any images automatically. Experimental results show that the proposed algorithm can make images clear effectively, even if original images are unclear by any weather.
In this study, we propose the new location search by use of relative position of landmarks in user's memory. Previous location search methods which are the way of using search keywords or handwritten map require high level Map-Reading skill. On the other hand, our proposal method can search a location map by an intuitive and simple operation. In this paper, the proposal method is called ILS (Incremental Location Search). ILS evaluates the similarity of the shape from the relative position relations of plotted landmarks and real map data. As an experimental result, we confirmed that the map of the location where I expected has been searched by plotting average 4.9 landmarks. In addition, our proposal location search method is found to discover an unexpected landmark. When user wants to recall an ambiguous sightseeing spot which has gone in old days, it seems that this method is useful to search the place.
In this letter, a new type of tunable resonator is introduced. First, a circuit theory of proposed resonator is reported. The proposed resonator is constructed by all five tunable capacitance elements and two uniform transmission lines. The length of transmission lines can be arbitrarily given within the constraints conditions. By such reason, miniaturization of the resonator can be expect. Next, attenuation characteristics of the resonator are presented, and effectiveness of the circuit theory is confirmed.
Pedestrians frequently collide visually impaired persons when they operate a smartphone while walking. To prevent that, the studies research calculates the risk of careless pedestrians from the cognitive characteristics using surveillance cameras, sends the degree of risk to the smart phone of the visually impaired person, and navigates the visually impaired person. In this paper clarifies the relationship between their avoidance behavior and cognitive characteristics. As the cluster analysis, it divided into three groups that are the lost in the decision-making and the avoidance behavior of no time to spare and safely avoidance. These results suggest that the risk of careless pedestrians can be calculated from their cognitive characteristics.
This letter proposes a new formulation for single-objective optimization problems and a Firefly Algorithm (FA) based optimization method. The formulated problem requires a set of solutions that have not only almost the same evaluation value but also appropriate differences in decision variables. While the development of FA based method on the basis of the analysis of search mechanism of FA is carried out, the performance of the developed method is verified.