• Title/Summary/Keyword: k-Center Problem

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Discrete-Time Robust $H_{\infty}$ Filter Design via Krein Space

  • Lee, T.H.;Jung, S.Y.;Seo, J.E.;Shin, D.H.;Park, J.B.
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.542-547
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    • 2003
  • A new approach to design of a discrete-time robust $H_{\infty}$ filter in finite horizon case is proposed. It is shown that robust $H_{\infty}$ filtering problem can be cast into the minimization problem of an indefinite quadratic form, which can be solved by implementing the Kalman filter defined in Krein space. The proposed filter is readily derived by simply augmenting the state space model and has the robustness property against the parameter uncertainties of a given system.

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A Mechanism for Configurable Network Service Chaining and Its Implementation

  • Xiong, Gang;Hu, Yuxiang;Lan, Julong;Cheng, Guozhen
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.10 no.8
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    • pp.3701-3727
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    • 2016
  • Recently Service Function Chaining (SFC) is promising to innovate the network service mode in modern networks. However, a feasible implementation of SFC is still difficult due to the need to achieve functional equivalence with traditional modes without sacrificing performance or increasing network complexity. In this paper, we present a configurable network service chaining (CNSC) mechanism to provide services for network traffics in a flexible and optimal way. Firstly, we formulate the problem of network service chaining and design an effective service chain construction framework based on integrating software-defined networking (SDN) with network functions virtualization (NFV). Then, we model the service path computation problem as an integer liner optimization problem and propose an algorithm named SPCM to cooperatively combine service function instances with a network utility maximum policy. In the procedure of SPCM, we achieve the service node mapping by defining a service capacity matrix for substrate nodes, and work out the optimal link mapping policies with segment routing. Finally, the simulation results indicate that the average request acceptance ratio and resources utilization ratio can reach above 85% and 75% by our SPCM algorithm, respectively. Upon the prototype system, it is demonstrated that CNSC outperforms other approaches and can provide flexible and scalable network services.

PBL Based Engineering Education to Cultivate Leadership Spirit in Postgraduate Students

  • Yokota, Kazutaka;Maruoka, Masatomo;Takaki, Junji;Watanabe, Shinichi
    • Journal of Engineering Education Research
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    • v.15 no.5
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    • pp.3-7
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    • 2012
  • Utsunomiya University started a 3-year project to develop an education program for postgraduate students to cultivate leadership spirits. The program is centered on a PBL in which each group of students is required to find an engineering or social problem themselves and start a project to solve the problem. Projects vary widely, from a straight product development to a summer program for children or local area development. Student groups are advised by senior engineers from industries. They give advice as to how a project should be managed and run, but will not give instructions. The PBL is compulsory for all students in the engineering master course students. The new education program also includes a series of lectures by engineers to show engineers' job, activities, and career in the industry. Internship programs are also provided, in which students will be given opportunities to actively apply their knowledge and skills to real engineering tasks offered by the industry. The students are expected to gain something more than just experiences.

Real-Time Generation of Humanoid Motion with the Motion-Embedded COG Jacobian

  • Kim, Do-Ik;Choi, Young-Jin;Oh, Yong-Hwan;You, Bum-Jae
    • 제어로봇시스템학회:학술대회논문집
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    • 2005.06a
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    • pp.2148-2153
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    • 2005
  • For a legged robot such as a humanoid, balancing its body during a given motion is natural but the most important problem. Recently, a motion given to a humanoid is more and more complicated, and thus the balancing problem becomes much more critical. This paper suggests a real-time motion generation algorithm that guarantees a humanoid to be balanced during the motion. A desired motion of each arm and/or leg is planned by the conventional motion planning method without considering the balancing problem. In order to balance a humanoid, all the given motions are embedded into the COG Jacobian. The COG Jacobian is modified to include the desired motions and, in consequence, dimension of the COG Jacobian is drastically reduced. With the motion-embedded COG Jacobian, balancing and performing a task is completed simultaneously, without changing any other parameters related to the control or planning. Validity and efficiency of the proposed motion-embedded COG Jacobian is simulated in the paper.

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A Study on Emotional Behavioral Problem of Children in Low-Income Family (일 지역 저소득 가정 아동의 정서행동문제)

  • Lee, Chung-Sook;Kim, Soo-Jin;Kim, Bo-Young;Kweon, Young-Ran;Joung, Hey-Joung;Jeung, Soon-Bok
    • Journal of the Korean Society of School Health
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    • v.22 no.2
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    • pp.113-124
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    • 2009
  • Purpose : This study was to examine the emotional behavioral problem of children in low-income family who were participating in local children care center. Method : From June 2 to September 9, 2008, 322 elementary school children were surveyed using structured questionnaire. Emotional behavioral problem were measured using K-YSR. Result : In the distribution of three groups by emotional behavioral problems scores of subjects, normal group was 83.23%, borderline group was 9.32%, clinical group was 7.45% among 322 children. The emotional behavioral problem score of subjects showed attention problem .62(5.61), aggressive behavior .52(9.87), anxiety and depression .50(7.89), withdrawn .49(3.46), social problem .43(3.50), somatic complaints .35(3.17), thought problem .32(2.27), delinquent behavior .31(3.11) and total behavioral problem scores were .44(44.55). Also, total behavioral problem scores was not significantly difference by sex and grade, but the scores of girls students was higher compared with boys. Conclusion : This finding will be significant in that it can provide basic data for school mental health services, which can provide early intervention program for the students who belong to borderline and clinical groups.

Invariant Biometric Key Extraction based on Iris Code (홍채 코드 기반 생체 고유키 추출에 관한 연구)

  • Lee, Youn-Joo;Lee, Hyung-Gu;Park, Kang-Ryoung;Kim, Jai-Hie
    • Proceedings of the IEEK Conference
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    • 2005.11a
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    • pp.1011-1014
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    • 2005
  • In this paper, we propose a method that extracts an invariant biometric key in order to apply this biometric key to the crypto-biometric system. This system is a new authentication architecture which can improve the security of current cryptographic system and solve the problem of stored template protection in conventional biometric system, also. To use biometric information as a cryptographic key in crypto-biometric system, same key should be generated from the same person. However, it is difficult to obtain such an invariant biometric key because biometric data is sensitive to surrounding environments. The proposed method solves this problem by clustering Iris Codes obtained by using independent component analysis (ICA).

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A Study On Database Improvement Of The Power System Protection Program (계통보호 정정 프로그램의 데이터베이스 개선에 관한 연구)

  • Kim, S.H.;Lee, S.J.;Choi, M.S.;Min, B.U.
    • Proceedings of the KIEE Conference
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    • 2002.11b
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    • pp.193-195
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    • 2002
  • This paper presents the methods to solve the problem about Power System Protection Program(PROSET) and describe the database relation and schema with UML. PROSET is a overall program system to protect power system and correct it. In the context of the PROSET it is so difficult to edit database data when topology is changed. When the renewal of data is performed. all changed values are disappeared. Therefore, it will not be expected to know the present situation by using the information of the databases data. So it is necessary to solve this problem. Solution is copy of the user. Only E.R diagram is used to express database schema and relation. So, in this paper, UML(Unified Modeling Language) will be used to express PROSET and database of MCD-H and MDT-H.

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A on Permeability Characteristics of Soil-Bentonite Mixture (Soil-Bentonite 혼합토의 투수 특성 연구)

  • Im, Eun-Sang;Snin, Dong-Hoon;Cho, Seong-Eun;Kim, Jea-Hong
    • Proceedings of the Korean Geotechical Society Conference
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    • 2009.03a
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    • pp.852-857
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    • 2009
  • Recently the centrifuge test has been used increasingly to clarify a problem of seepage in dam. However, one of the most difficult challenges in the testing is to conform permeability properties of model ground to the prototype. In order to resolve the problem, a few solutions, such as an increase of pore water viscosity and a regulation of water permeability, are suggested. Although the use of prototype materials is principles if a model test is carried out, the materials of similarity gradation is used in the centrifuge model test because of the nature of the model test for dam. Therefore, we choose the latter method for model ground materials. In this study, the permeability properties of soil-bentonite mixtures are studied through the permeation test using triaxial compaction test apparatus.

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A Study On Database improvement Of The Power System Protection Program(II) (계통보호 정정 프로그램의 데이터베이스 개선에 관한 연구(II))

  • Kim, S.H.;Lee, S.J.;Choi, M.S.;Min, B.U.
    • Proceedings of the KIEE Conference
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    • 2003.07a
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    • pp.302-304
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    • 2003
  • This paper presents the methods to solve the problem about Power System Protection Program(PROSET). PROSET is a overall program system to protect power system and correct it. In the context of the PROSET, it is so difficult to edit database data when topology is changed. When the renewal of data is performed, all changed values are disappeared. Therefore, it will not be expected to know the present situation by using the information of the databases data. So it is necessary to solve this problem. Solution is copy of the user. Database of GRL,GRZ,KYP2D1,KYD2X1,L90 Relay module were developed. We made a database management system for PROSET, therefore I will show this management system briefly.

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An educational effect analysis of a short-term TRIZ program in industry-university cooperation (산학연계 트리즈(TRIZ) 단기 프로그램의 교육적 효과 분석)

  • Han, Jiyoung;Kim, Sung-Hui
    • Journal of Engineering Education Research
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    • v.19 no.2
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    • pp.26-33
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    • 2016
  • A camp program where the theory of inventive problem solving TRIZ is applied to real problems of the industry was developed and taught at a five-day seminar apart from the standard curriculum at a university D in Gyeonggido. This study focuses on the educational effect that the TRIZ method has on the engineering students when their creative problem solving skills are required to solve industry problems on their own with the knowledge from their courses. For five days, the students were educated about TRIZ and assigned a real industry problem "Removal of friction caused by bubble formation in water heating pipelines". By applying TRIZ to the problem, the students developed an "Air removing Air Arrester" which received the evaluation, "with understanding the system architecture and the task objective causes and formation of the problem could be handled which directly helps the company's R&D". In this case, TRIZ offers the students a guideline and knowledge on how to approach problems and as a result the students provided a practical solution. During the process, the TRIZ method instilled confidence in the students and proved to be a motivation. It becomes obvious that this short-term program has a positive effect on students' way of thinking creatively and increasing their problem-solving abilities.