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Study on Kinematics and Dynamics of the Modular Robot (모듈러 로봇의 기구학/동력학에 관한 연구)

  • 강희준
    • Journal of the Korean Society for Precision Engineering
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    • v.19 no.11
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    • pp.46-53
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    • 2002
  • In order to overcome the conventional robot's physical limitation to frequent changes in operational requirements, it is quite appealing to modularize its system components and allow them to be combined into various configurations to best suit the needs to a particular application. Several researchers have presented the concept of modular robot. In this paper, the kinematics and dynamics of modular robot are studied, which concretes the concept of modular robot. This study includes the selection of individual module, the definition of their parameters and the development of module based manipulate. analysis software package (MBMAP).

A Study on Relationships between Problems of a Geographical Cluster and its Performance (지리적 클러스터의 문제점과 성과간의 관련성에 관한 연구: 구미국가산업단지를 중심으로)

  • Rhee, Jae-Hoon;Kim, Ki-Keun
    • Journal of Technology Innovation
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    • v.16 no.1
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    • pp.165-190
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    • 2008
  • The purpose of this study is to find problems of Geographical Cluster and to analyze relationships between problems of a Geographical Cluster and its performance. The problems of geographical cluster include those of technical fusion, increase of incidental expenses, conditions of settlement, and absence of industrial infrastructures, and performance factors are satisfaction with the cluster policy and within cluster firm's performance. According to the results of analyses based on the data collected from 75 firms located in the Gumi electronic industry cluster complex, first, problems of technical fusion, and absence of industrial infrastructures had a negative(-) effect on satisfaction with the cluster policy. Second, absence of industrial infrastructures had also a negative(-) effect on within cluster firm's performance. In the conclusion, further discussion, limitation of this study and future direction were suggested.

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A Study on Advanced Small Punch Test for Evaluation of Material Degradation in Weldment Microstructures (용접부 미세조직의 재질열화 평가를 위한 Advanced Small Punch 시험에 관한 연구)

  • 이동환;이송인;박종진;유효선
    • Journal of Welding and Joining
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    • v.21 no.1
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    • pp.99-106
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    • 2003
  • This research was aimed to evaluate the material degradation with various microstructures of X20CrMoV121 steel weldment by Advanced Small Punch(ASP) test. Due to the regional limitation on constitutive structures, the minimized loading ball(${\varphi}1.5mm$) and bore diameter of lower die(${\varphi}3mm$) were designed for the ASP test. The micro-hardness test was also performed to assess the mechanical properties with artificial aging heat treatment. Material degradation was estimated by ductile-brittle transition temperature(DBTT). The results obtained from the ASP test were compared with those from conventional small punch(CSP) test and CVN impact test for several weldment microstructures. It was found that the ASP test clearly showed the microstructural dependance on the material degradation in the weldment.

Research Trends of Ecotoxicity of Nanoparticles in Water Environment (수환경에서 나노입자의 생태독성 연구동향)

  • Lee, Woo-Mi;An, Youn-Joo
    • Journal of Korean Society on Water Environment
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    • v.26 no.4
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    • pp.566-573
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    • 2010
  • Nanotechnology has been applied to various fields in our life. Although there is a limitation of nanoparticle monitoring so far, it is expected that nanoparticles are widely distributed in environmental multimedia. Nanoparticle is known to be more toxic than its corresponding bulk material. For this reason, developed countries and international organizations are preparing for future regulation. To evaluate the safety of nanoparticles, nanotoxicity studies are internationally underway. In this study, we evaluated the research trends of ecotoxicity of nanoparticles in water environment. Test species include fish, water flea, and algae. Nanoecotoxicological studies are rapidly increasing and the experimental designs become more sophisticated. Physicochemical properties of nanoparticles should be measured and the ionization potential is important for metal-based nanoparticles. We analyzed the research trends based on the type of nanoparticles and test species. Also experimental aspects of nanoecotoxicology are considered.

New Approaches for IT Human Resource Development: Korean Cases and the Applicability to Other Countries

  • Hwang, Gyu-Hee;Park, SeonHye
    • Asian Journal of Innovation and Policy
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    • v.3 no.2
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    • pp.154-171
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    • 2014
  • This article aims to examine the achievement and limitation of adaptation of supply chain management (SCM) to IT human resource development (HRD) in Korea and to derive the implication of the Korean experience to other countries. In late 1990s, the IT New Deal Policy and the quantitative expansion of IT HR were introduced. Since mid-2000s, there has been much innovation in IT products as well as increased demand of highly qualified IT experts. The SCM in IT HRD was introduced in 2004 and continuously developed more. Since the late 2000s, IT convergence expanded to traditional industries and the new IT-based-industries were created in Korea. In this regard, Korea established the Seoul Accord as an international IT engineering education accreditation system in 2008. In response to the paradigm change, in 2011, the Korean government developed TOPCIT, which is a kind of competency test for evaluating IT competency.

A Study on fluvial Phenomena in the Bended Alluvial Rivers (만곡유로에서의 하상변동에 관한 연구)

  • 고재웅
    • Water for future
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    • v.8 no.2
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    • pp.75-80
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    • 1975
  • The fluvial phenomena in the bended natural river course are studied experimentally. Some theoretical and empirical conclusions were derived in prior to this study by some authors but the limitation of applicability of those results are not clearly known because of the sensitibitys of the flow regime in the reach. The main objective of this study is directed to evaluate the mechanism of sedimentation and the cross sectional changes in the equilibrium status. the most governing factor influenced to the cross sectional changes in the bended reach is the occurance of spiral flow. In this study, the streamlines and velocity distributions are checked at given interval by the hydraulic model to find out the place where spiral flow are existing under the various flow magnitudes.

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Kim on Critical Thinking (김영정 교수의 비판적 사고론)

  • Choi, Hoon
    • Korean Journal of Logic
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    • v.13 no.2
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    • pp.1-26
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    • 2010
  • The primary purpose of this paper is to examine critically the theory of critical thinking proposed by the late Professor Young-Jung Kim. He defined the basic properties of critical thinking as active reflectivity, and listed deepness, multilaterality and domain-transitivity as primary properties for which critical thinking aims. He, then, pursued how critical thinking can be merged with creativity and proposed the concept 'critico-creative thinking'. I argue that his theory of critical thinking has some limitation, but we can develop his critico-creative thinking further.

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A Study on the Development methods of Operating Systems Concurrent Spare Parts (CSP 운영체계 개선방안에 관한 연구)

  • 이규헌;김현호;조경익;최광묵;오혁재
    • Journal of the military operations research society of Korea
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    • v.30 no.1
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    • pp.15-29
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    • 2004
  • The existing CSP systems is inefficient and brings about waste of budget in some operating aspects which show accumulation of unnecessary items, omitted or running short items and limitation of timely use of them. The purpose of this study is to analyze the actual situation of existing CSP(calculation and estimation of CSP requirements), and to suggest a few methods (post control system by activating buy-back system, and middle and long term operating system itself in relation to budget) to improve the CSP operating systems in order to maximize the effectiveness of combat strength and to contribute to the economic efficiency of defense management. The results show that improved method is efficient and effective by comparing with some actual data.

Ride Quality Assessment of Automative Seats by Simultaneous 3-Axis Excitation (동시 3축 가진에 의한 자동차 의자류의 승차감 평가)

  • 정완섭;우춘규;박세진;김수현
    • Journal of KSNVE
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    • v.7 no.1
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    • pp.143-152
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    • 1997
  • This paper introduces experimental results of the ride qulaity characteristics of automotive seats fixed on the vibration table that is noving simultaneously to the three-axis in a similar way to the real running condition. Vibration experiment was carried out for five different automotive seats and four Korean individuals. The assessment of the ride quality characteristics for each seat and indiviual was made not only from the analysis of vibration measurements but also from the evaluation of weighied vibration signals, which were obtained using the frequency weighting function and the multiplication factor dependent on the position and axis of vibration exposure to wehole-body. The usefulness of those assessment results in analysis of the ride quality of seats is discussed and their limitation is also pointed out in this paper.

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A Study on the Support Toning Method of High-Speed Chip-Mounter (고속 표면실장기의 지지부 개선 방법에 관한 연구)

  • Oh, Chang-Kyun;Park, Heung-Keun;Park, Jin-Moo
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2006.11a
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    • pp.597-602
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    • 2006
  • In this paper, a proper support tuning method is established by identifying the dynamic characteristics of the machine, the floor. and the inertia force. Also, the limitation of a passive isolation is presented. To simplify the dynamic analysis and to establish a proper design method for supporting system, each of the machine and the floor is modeled as a single degree of freedom spring-mass-damper system under careful investigation of the dynamic characteristics of each system and appropriate assumptions. Then, the dynamic behavior of a 2DOF system and the effect of the mass and the damping are investigated. Also, the characteristics of motion profiles are investigated. In addition, a quasi-static analysis on the transmitted force through support is performed and related tests are performed.

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