University of Electro-Communications

About: University of Electro-Communications is a education organization based out in Tokyo, Japan. It is known for research contribution in the topics: Laser & Robot. The organization has 8041 authors who have published 16950 publications receiving 235832 citations. The organization is also known as: UEC & Denki-Tsūshin Daigaku.

An algorithm for optimal static load balancing in distributed computer systems

Abstract: The authors propose a load-balancing algorithm that determines the optimal load for each host so as to minimize the overall mean job response time in a distributed computer system that consists of heterogeneous hosts. The algorithm is a simplified and easily understandable version of the single-point algorithm originally presented by A.N. Tantawi and D. Towsley (1985). >

A multi-objective optimization-based layer-by-layer blade-coating approach for organic solar cells: rational control of vertical stratification for high performance

Abstract: A major breakthrough in organic solar cells (OSCs) in the last thirty years was the development of the bulk heterojunction (BHJ) solution processing strategy, which effectively provided a nanoscale phase-separated morphology, aiding in the separation of Coulombically bound excitons and facilitating charge transport and extraction. Compared with the application of the layer-by-layer (LbL) approach proposed in the same period, the BHJ spin-coating technology shows overwhelming advantages for evaluating the performance of photovoltaic materials and achieving more-efficient photoelectric conversion. Thus, in this study, we have further compared the BHJ and LbL processing strategies via the doctor-blade coating technology because it is a roll-to-roll compatible high-throughput thin film fabrication route. We systematically evaluated multiple target parameters, including morphological characteristics, optical simulation, physical kinetics, device efficiency, and blend stability issues. It is worth emphasizing that our findings disprove the old stereotypes such as the BHJ processing method is superior to the LbL technology for the preparation of high-performance OSCs and the LbL approach requires an orthogonal solvent and donor/acceptor materials with special solubility. Our studies demonstrate that the LbL blade-coating approach is a promising strategy to effectively reduce the efficiency-stability gap of OSCs and even a superior alternative to the BHJ method in commercial applications.

Protocols for negotiating complex contracts

Abstract: Research to date on negotiation protocols has focused almost exclusively on defining simple contracts consisting of one or a few independent issues and a relatively small number of possible contracts. Many real-world contracts, in contrast, are much more complex, consisting of multiple interdependent issues and intractably large contract spaces. The family of negotiation protocols we've developed make substantial progress toward achieving near-optimal outcomes for negotiations with binary issue dependencies. We propose a simulated annealing-based approach, a refined version based on a parity-maintaining annealing mediator, and an unmediated version of the negotiation protocol.

Cavity quantum electrodynamics on a nanofiber using a composite photonic crystal cavity.

Abstract: Spontaneous emission from a cavity made of an optical nanofiber and a nanostructured grating is demonstrated, which would allow single quantum emitters to be easily integrated into an optical network.

Trajectory Tracking Control of Snake Robots Based on Dynamic Model

Abstract: In this paper, we derive a dynamic model and a trajectory tracking control law for snake robots, which have passive wheels and active joints, based on the dynamic model. For a trajectory tracking control of snake robots, it is one of the important problem to avoid the singular configuration like a straight line. Using input-ouput linearization for the head position of snake robots based on dynamic model, we can control the head position by PD feedback, but the robot will converge to the singular configuration. In order to solve this problem, we propose a control law that controls shape controllable points for avoiding the singular configuration. Using the proposed control law, the robot can accomplish trajectory tracking of the head position without converging to the singular configuration. Simulation results show the effectiveness of the proposed control law.