Shimawaki H.,Hachinohe Institute of Technology
Journal of the Vacuum Society of Japan | Year: 2017
Field emitter arrays (FEAs) have been investigated as potential cold cathodes in variety of applications such as ‰at-panel displays and image sensors, microwave and further high frequency vacuum electronic devices. The density modulated electron beam (a train of electron bunches) at high frequency generated directly from the cathodes oŠers opportunities for dramatic improvements in performance of microwave vacuum electronic devices. The paper discusses the emission characteristics and optical response of gated p-type siliconeld emitter arrays under irradiation of laser pulses.
Takahashi R.,Hachinohe Institute of Technology
2016 IEEE Symposium Series on Computational Intelligence, SSCI 2016 | Year: 2016
In this paper, the effectiveness of methodologies for changing crossover operators (CXOs) to solve function optimization problems (FOP) are empirically validated in order to solve the problems of premature convergence in genetic algorithms. CXOs are methods of finding solutions for combinatorial optimization problems through genetic algorithms (GAs) while maintaining the balance of satisfying the contrary requisites for GAs: to sustain the diversity of the population and to improve the efficiency of searching for solutions. CXOs measure the diversity of the population on each end of a generation and dynamically alternate global search methods and local search methods according to the degree of that diversity. With the above devices, CXOs can decrease the probability of falling into local optima compared to using only one kind of crossover operator in the crossover operation. In FOP, considering the continuity of functions, real-coded crossover operators such as BLX-α (Blend Crossover) and SPX (Simplex Crossover) are invented and added to general crossover operators such as Two-point Crossover operators. In our investigation, we studied CXOs that exchange Two-point crossover for BLX-α and SPX for BLX-α when the diversity of the generated children drops below the required threshold. We verified experimentally that CXOs can improve the accuracy of searched solutions beyond singly used crossover operators such as Two-point Crossover, BLX-α and SPX. Two well-known multimodal functions are also investigated in this report - Shubert's test function and the Six-hump camel back function. © 2016 IEEE.
Takahashi R.,Hachinohe Institute of Technology
Electronics and Communications in Japan | Year: 2010
In order to efficiently obtain an approximate solution of the traveling salesman problem (TSP), the use of extended changing crossover operators (ECXO) which can substitute for any crossover operator of genetic algorithms (GAs) and ant colony optimization (ACO) for another crossover operator at any time is proposed. In this investigation, ECXO uses both ACO or edge recombination crossover (EX) and edge exchange crossover (EXX) in the early generations in order to create local optimum subpaths, and it uses edge assembly crossover (EAX) to create a global optimum solution after a certain number of generations. In EX or ACO any individual or any ant determines the next city it visits from the lengths of the edges or the amounts of pheromone deposited on the edges, where the pheromone indicates the lengths of tours that other ants have completed, thus generating local optimum paths. In EXX, the generated paths converge to a provisional optimal path. In EAX, a parent exchanges edges with another parent to create subcyclic paths, before restructuring the total cyclic path by combining the subcyclic paths so as to minimize the distances between them. In this paper the validity of ECXO is experimentally verified by using medium-sized problems from TSPLIB, and it is shown that ECXO can find the best solution earlier than EAX. © 2010 Wiley Periodicals, Inc.
Sasahara T.,Hachinohe Institute of Technology
Journal of Geometry and Physics | Year: 2010
We classify biminimal Lagrangian surfaces in complex space forms under the condition that the integral curves of Maslov vector field are geodesics. © 2010 Elsevier B.V.
Shibata K.,Hachinohe Institute of Technology
Progress in Electromagnetics Research Symposium | Year: 2014
Various studies on specific absorption rates (SARs) have been carried out with liquid phantoms representing human body tissues in the field of electromagnetic compatibility (EMC) research. As a faithful representation of human body tissue is needed to establish an accurate SAR for measurement, knowledge regarding the precise measurement of sample materials with high permittivity and high loss is very important. In this study, the complex permittivity of a liquid phantom material was measured using the open-ended cut-off circular waveguide reflection method. The effectiveness of the proposed approach for measuring a liquid phantom with high permittivity and high loss was also confirmed by comparing the measurement results with those obtained using the TM010 circular cavity resonator method.
Takahashi R.,Hachinohe Institute of Technology
Proceedings - 10th International Conference on Machine Learning and Applications, ICMLA 2011 | Year: 2011
The subject of the Genetic Algorithm (GA) is to devise methodologies that can efficiently locate the optimum solution which must satisfy the contrary requirements of preserving population diversity and speeding up convergence on the optimum solution. In this paper, a new hybrid method iterative Extended Changing Crossover Operators (i-ECXO) combining Edge Assembly Crossover (EAX) and Ant Colony Optimization (ACO) is proposed to solve the Traveling Salesman Problem (TSP). In EAX, parent A's edge EA is exchanged for parent B's edge EB finally to generate new off spring, where EA and EB alternate in forming so-called A-B cycles. ACO simulates swarm intelligence in ants' feeding behavior. In ACO, ants tend to create various kinds of cyclic paths with different sequences of visiting cities in early stage of generations. In this paper, the diversity of generations is strictly measured by the entropy H in Thermo Dynamical Genetic Algorithm (TDGA). With the measure H, the validity of i-ECXO is experimentally verified by using medium sized TSP data. © 2011 IEEE.
Xiamuxi A.,Hachinohe Institute of Technology |
Xiamuxi A.,Xinjiang University |
Hasegawa A.,Hachinohe Institute of Technology
Journal of Constructional Steel Research | Year: 2012
It is clear from former researches on reinforced concrete filled tubular steel (RCFT) columns that RCFT columns have better performance than concrete filled steel tubular (CFT) columns. The enhancements may be mainly due to the improvements in performance of the concrete core because of the confinement pressure imposed by both steel tube and reinforcement. To clarify the effect of confinement on concrete core and propose evaluation equation for axial compressive strength of RCFT columns, numerical analyses of RCFT columns are conducted by matching the numerical results with experimental results via parametric study. According to the results of the analyses, effect of confinement on concrete and effect of stress state on steel tube of RCFT columns are discussed, as a result, a non-conventional method for evaluating the confinement effect which is concerned with load-sharing ratio of RCFT columns is proposed, and the evaluation equation for axial compressive strength of RCFT columns is obtained and validated through the experimental data. © 2012 Elsevier Ltd. All rights reserved.
Kosakaya J.,Hachinohe Institute of Technology
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2013
Local traditional arts people and the city's traditional music preservation society have eagerly wished a technology to accurately score traditional music, especially Tsugaru Shamisen. This music will be preserved as scores, which avoids relying solely on the oral transmission of this music to the young performers. At this time, we have experimentally produced an "Electronic Shamisen" equipped with a pick-up microphone attached to each string and automatic scoring equipment, which automatically records scores from the sound source with an agent method. © Springer International Publishing 2013.
Masuda S.,Advantest Laboratories Ltd. |
Seki A.,Advantest Laboratories Ltd. |
Masuda Y.,Hachinohe Institute of Technology
Applied Physics Letters | Year: 2010
We describe here how we have improved the crystal qualities and controlled the crystal phase of the lanthanum-modified lead zirconate titanate (PLZT) film without changing the composition ratio using an oxygen-pressure crystallization process. A PLZT film deposited on a SrTiO3 substrate with the largest electro-optic (EO) coefficient of 498 pm/V has been achieved by controlling the crystal phase of the film. Additionally, a fatigue-free lead zirconate titanate (PZT) capacitor with platinum electrodes has been realized by reducing the oxygen vacancies in the films. © 2010 American Institute of Physics.
Tsukidate T.,Hachinohe Institute of Technology
Vernacular Architecture: Towards a Sustainable Future - Proceedings of the International Conference on Vernacular Heritage, Sustainability and Earthen Architecture | Year: 2015
How fire was used in vernacular houses before modernization was a reflection of life in dwellings adapted to the natural environment. In vernacular houses fire has been used as a heat source for heating and cooking, and its flames for lighting. The author carried out literature research and a field survey on the use of fire in vernacular houses in Eurasia. Fire is used for cooking in hot areas and in temperate areas in winter, and in cold areas for heating, cooking, and lighting. The paper shows that the change from using fire for cooking to using fire for cooking and heating in vernacular houses occurs at around Lat. 40°N. on the west of Eurasia and around Lat. 35°N. on the east of Eurasia. © 2015 Taylor & Francis Group.