• Title/Summary/Keyword: Keio University

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INFLUENCE OF THE MIXING RATIO OF DOUBLE COMPONENTIAL FUELS ON HCCI COMBUSTION

  • Sato, S.;Kweon, S.P.;Yamashita, D.;Iida, N.
    • International Journal of Automotive Technology
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    • v.7 no.3
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    • pp.251-259
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    • 2006
  • For practical application on the HCCI engine, the solution of subjects, such as control of auto-ignition timing and avoidance of knocking, is indispensable. This study focused on the technique of controlling HCCI combustion appropriately, changing the mixture ratio of two kinds of fuel. Methane and DME/n-Butane were selected as fuels. The influences, which the mixing ratio of two fuels does to ignition timing, ignition temperature, rate of heat release and oxidation reaction process, were investigated by experiment with 4-stroke HCCI engine and numerical calculation with elementary reactions.

Searching biologically plausible synteny blocks among multiple genomes

  • Hachiya, Tsuyoshi;Sakakibara, Yasubumi
    • Proceedings of the Korean Society for Bioinformatics Conference
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    • 2005.09a
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    • pp.113-117
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    • 2005
  • In comparative genome analyses, synteny blocks play important roles for finding ortholog genes, reconstructing phylogenetic tree and predicting genome rearrangement events. In this paper, we propose a novel method to search biologically plausible synteny blocks not only from the viewpoint of finding highly preserved regions but also from the viewpoint of analyzing genome rearrangements. We have applied the method to our experiments on four fungal organisms, and succeeded to obtain some biologically interesting results.

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Method and Procedure for Economic Evaluation of Improvement Activities

  • Kono, Hirokazu;Ichikizaki, Osamu
    • Industrial Engineering and Management Systems
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    • v.14 no.2
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    • pp.122-128
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    • 2015
  • The purpose of this paper is to propose an appropriate evaluation scheme for improvement activities, based on a simple model comprising cash inflow by sales as well as variable and fixed cost expenditures. The paper distinguishes capacity surplus and capacity shortage situations, and examines economic benefits gained by yield increase improvement and capacity increase. The paper then proposes a basic rule of thumb for economic evaluation of improvement activities. The logic is simple but useful in practice, being conducive towards improvement activities under current economic conditions with uncertainties.

Stabilization of discrete-time semilinear heat processes by boundary inputs

  • Koay, S.P.;Sano, H.;Ito, K.;Kunimatsu, N.
    • 제어로봇시스템학회:학술대회논문집
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    • 1990.10b
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    • pp.1284-1288
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    • 1990
  • In this paper, we are going to study the stabilization of the semilinear heat equation with inhomogenous boundary conditions, whose solutions are not (in general) stable. Here, we use the discrete-time feedback inputs through the boundary of geometric domain to the semilinear system under some additional conditions and assumptions. It is shown that under these conditions, the stabilization can be realized by applying pole assignment argument to the principal linear part of the system and that the solutions exist globally in discrete-time t without any finite escape time.

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Development and Implementation of Training Program for Information System Design Using Material Requirements Planning

  • Yamazaki, Tomoaki;Yin, Rui;Kawaguchi, Seisuke;Hayasaka, Hirotatsu;Matsumoto, Toshiyuki;Ichikizaki, Osamu;Kanazawa, Takashi
    • Industrial Engineering and Management Systems
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    • v.11 no.3
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    • pp.255-265
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    • 2012
  • Environments surrounding production sites have changed greatly in recent years. Accommodating environmental changes calls for the design and development of information systems that center on production lines. There is a need for a training program that teaches learners to understand the particulars of an operation and apply that knowledge to an information system. In this research, we used material requirements planning (MRP) as the subject for which basic skills are to be taught and developed an MRP exercise-based training program. The program is designed for 13 lectures of 90 minutes each, and it consists of MRP exercises, modeling methods to represent them, the use of a programming language for system development, and finally, evaluation of the exercises. Lecture materials are described in 505 lecture slides using Microsoft PowerPoint to allow visualization of topics through graphs and models. The developed training program was then delivered to 86 college students, and its results were measured through quizzes to verify educational effectiveness.

A Multi-agent based simulation Model for evacuees escaping from Tsunami disaster -To evaluate the evacuees escaping program in Fujisawa city, Japan-

  • Fujioka, Masaki;Ishibashi, Kenichi;Kaji, Hideki;Tsukagoshi, Isao
    • Proceedings of the Korea Society for Simulation Conference
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    • 2001.10a
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    • pp.306-312
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    • 2001
  • In this research, we are trying to develop a framework to evaluate the prevention program for Tsunami disaster based on the Multi-agent simulation model. Tsunami has arisen by the earthquake. It happened after flew minutes or few hours when it occurred. It is clear that Tsunami will come after earthquake and from seashore. If we prevent the damage by Tsunami, we should make people who is in the seashore and lived near the seaside escape from there. Moreover we must forecast the escape activity from Tsunami. Former research of this field, some researches try to forecast the escape activity as macro level. However, people who escape from Tsunami is differ from their physical ability and ability of information processing. It needs a more accuracy model to forecast the escape activity of them. Furthermore they make a decision step by step using the various information. Therefore escape activity from Tsunami will describe using an agent based model which can only treat the information processing of human being. In this paper, we develop the evacuation model from Tsunami disaster using the Multi agent based model. The purpose of this study is to analyze the human action pattern when Tsunami occurred, and to make an accurately assessment for damages by Tsunami. The Fujisawa city government is planning and operating the various prevention program far Tsunami. However nobody assess it, because they do not have any simulation models for Tsunami disaster. If they want to set an effective prevention program for Tsunami, they should have any kinds of simulation model. The results of this study are 1) To develop the Multi agent based evacuees escape activity model. 2) Assess the damage of Tsunami in Fujisawa-City.

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A simple calculation for the preoperative estimation of transverse rectus abdominis myocutaneous free flap volume in 2-stage breast reconstruction using a tissue expander

  • Kono, Hikaru;Ishii, Naohiro;Takayama, Masayoshi;Takemaru, Masashi;Kishi, Kazuo
    • Archives of Plastic Surgery
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    • v.45 no.4
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    • pp.333-339
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    • 2018
  • Background Flap volume is an important factor for obtaining satisfactory symmetry in breast reconstruction with a transverse rectus abdominis myocutaneous (TRAM) free flap. We aimed to develop an easy and simple method to estimate flap volume. Methods We performed a preoperative estimation of the TRAM flap volume in five patients with breast cancer who underwent 2-stage breast reconstruction following an immediate tissue expander operation after a simple mastectomy. We measured the height and width of each flap zone using a ruler and measured the tissue thickness by ultrasound. The volume of each zone, approximated as a triangular or square prism, was then calculated. The zone volumes were summed to obtain the total calculated volume of the TRAM flap. We then determined the width of zone II, so that the calculated flap volume was equal to the required flap volume ($1.2{\times}1.05{\times}$the weight of the resected mastectomy tissue). The TRAM flap was transferred vertically so that zone III was located on the upper side, and zone II was trimmed in the sitting position after vascular anastomosis. We compared the estimated flap width of zone II (=X) with the actual flap width of zone II. Results X was similar to the actual measured width. Accurate volume replacement with the TRAM flap resulted in good symmetry in all cases. Conclusions The volume of a free TRAM flap can be straightforwardly estimated preoperatively using the method presented here, with ultrasound, ruler, and simple calculations, and this technique may help reduced the time required for precise flap tailoring.

Drilling force and speed for mandibular trabecular bone in oral implant surgery

  • bin Kamisan, Mohammad Aimaduddin Atiq;Yokota, Kenichiro;Ueno, Takayuki;Kinoshita, Hideaki;Homma, Shinya;Yajima, Yasutomo;Abe, Shinichi;Takano, Naoki
    • Biomaterials and Biomechanics in Bioengineering
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    • v.3 no.1
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    • pp.15-26
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    • 2016
  • Based on a survey done recently in Japan, 30 percent of the serious accidents occurred in oral implant surgery were concerned with the mandibular canal and 3/4 of them were related to drilling. One of the reasons lies in the lack of the education system. To overcome this problem, a new educational system focusing on drilling the mandibular trabecular bone has been developed mainly for dental college students in the form of an oral implant surgery training simulator that enables student to sense the reaction force during drilling. On the other hand, the conventional system uses polymeric model. Based on these systems, two approaches were proposed; the evaluation by experienced clinicians using the simulator, and experimental works on the polymeric model. Focusing on the combination of the drilling force sensed and drilling speed obtained through both approaches, the results were compared. It was found that the polymeric models were much softer especially near the mandibular canal. In addition, the study gave us an insight of the understanding in bone quality through tactile sensation of the drilling force and speed. Furthermore, the clinicians positively reviewed the simulator as a valid tool.

On the Dynamics of Multi-Dimensional Lotka-Volterra Equations

  • Abe, Jun;Matsuoka, Taiju;Kunimatsu, Noboru
    • 제어로봇시스템학회:학술대회논문집
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    • 2004.08a
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    • pp.1623-1628
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    • 2004
  • In the 3-dimensional cyclic Lotka-Volterra equations, we show the solution on the invariant hyperplane. In addition, we show the existence of the invariant hyperplane by the center manifold theorem under the some conditions. With this result, we can lead the hyperplane of the n-dimensional cyclic Lotka-Volterra equaions. In other section, we study the 3- or 4-dimensional Hamiltonian Lotka-Volterra equations which satisfy the Jacobi identity. We analyze the solution of the Hamiltonian Lotka- Volterra equations with the functions called the split Liapunov functions by [4], [5] since they provide the Liapunov functions for each region separated by the invariant hyperplane. In the cyclic Lotka-Volterra equations, the role of the Liapunov functions is the same in the odd and even dimension. However, in the Hamiltonian Lotka-Volterra equations, we can show the difference of the role of the Liapunov function between the odd and the even dimension by the numerical calculation. In this paper, we regard the invariant hyperplane as the important item to analyze the motion of Lotka-Volterra equations and occur the chaotic orbit. Furtheremore, an example of the asymptoticaly stable and stable solution of the 3-dimensional cyclic Lotka-Volterra equations, 3- and 4-dimensional Hamiltonian equations are shown.

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