• Title/Summary/Keyword: Key Constraints

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Development of a Redundant Shoulder Complex Actuated by Metal Wire Tendons (텐던 구동 기반 여유자유도를 가지는 로봇의 어깨 메커니즘 구현)

  • Choi, Taeyong;Kim, Doohyung;Do, Hyunmin;Park, Chanhun;Park, Dongil
    • Journal of Institute of Control, Robotics and Systems
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    • v.22 no.10
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    • pp.853-858
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    • 2016
  • Cooperation and collaboration with robots are key functions of robotic utility that are currently developing. Thus, robots should be safe and resemble human beings to cope with these needs. In particular, dual-arm robots that mimic human kinetics are becoming the focus of recent industrial robotics research. Their size is similar to the size of a human adult; however, they lack natural, human-like motion. One of the critical reasons for this is the shoulder complex. Most recent dual-arm robots have only 2 degrees of freedoms (DOFs), which significantly limits the workspace and mobility of the shoulders and arms. Therefore, a redundant shoulder complex could be very important in new developments that enable new capabilities. However, constructing a kinematically redundant shoulder complex is difficult because of spatial constraints. Therefore, we propose a novel, redundant shoulder complex for a human-like robot that is driven by flexible wire tendons. This kinematically redundant shoulder complex allows human-like robots to move more naturally because of redundant DOFs. To control the proposed shoulder complex, a hybrid control scheme is used. The positioning precision has also been considered, and the ability of the shoulder complex to perform several human-like motions has been verified.

Time-use and Activity Pattern Analysis of Full-time Workers Based on the Classification of Trip-chains in Seoul Metropolitan Area (통행사슬 유형 구분을 통한 수도권 전일제 근로자의 시간이용 및 활동패턴 분석)

  • Park, Woonho;Joh, Chang-Hyeon
    • Journal of the Economic Geographical Society of Korea
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    • v.17 no.4
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    • pp.759-770
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    • 2014
  • The aim of this study is to examine how time-use and activities are affected by work hours. To achieve this, we focused on the weekday time-use of full-time workers in Seoul Metropolitan Area(SMA). The long 'work hours' are under active discussions since it is related to the quality of life. However, many Social researcher thought that problem of Korean working hours is linked to quality of life in the abstract. Because activity connects time-use and quality of life, the key point is activity under time constraints. Therefore, travel patterns should be understood by time-use and activity patterns. This study composes trip-chains from travel data of 2010 Household Travel Survey(HTS). Grouping trip-chains by activity patterns, we could make sure that a few of activities after work is affected by a short free time. This study has potential implications for the policy of work hours and traffic problems in the evening, and will provide new geographical perspective related to measuring quality of life.

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Periodic and Pseudo-static Channel Time Allocation Scheme for IEEE 802.15.3 High-Rate Wireless PANs (IEEE 802.15.3 고속율 무선 팬을 위한 주기적인 유사 정적 채널 시간 할당 방법)

  • Kim, Sun-Myeong
    • Journal of the Korea Society for Simulation
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    • v.17 no.4
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    • pp.89-97
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    • 2008
  • In wireless personal area networks (WPANs), the successful design of channel time allocation algorithm is a key factor in guaranteeing the various quality of service (QoS) requirements for the stringent real-time constraints of multimedia services. In this paper we propose a channel time allocation algorithm for achieving a high quality transmission and high channel error tolerance of MPEG stream in the IEEE 802.15.3 high-rate wireless PANs. Our algorithm exploits the characteristics of MPEG stream. When a new MPEG stream arrives, a DEV models it by the traffic envelope and delivers the traffic envelope to the piconet coordinator (PNC) along with the channel time request. The PNC performs channel time allocation according to the envelope. Performance of the proposed scheme is investigated by simulation and analysis. Our results show that compared to conventional scheme, the proposed scheme is very effective and provides a good performance under typical channel error conditions.

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Protein unfolding by ATP-dependent proteases

  • Lee, Cheolju;Michael Schwartz;Sumit Prakash;Masahiro Iwakura;Andreas Matouschek
    • Proceedings of the Korean Biophysical Society Conference
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    • 2003.06a
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    • pp.34-34
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    • 2003
  • Protein unfolding is a key step in several cellular processes, including protein translocation across some membranes and protein degradation by ATP-dependent proteases. C1pAP protease and the proteasome can actively unfold proteins in a process that hydrolyzes ATP, These proteases catalyze unfolding by processively unraveling their substrates from the attachment point of the degradation signal. As a consequence, the ability of a protein to be degraded depends on its structure as well as its stability. An ${\alpha}$-helix is easier to unravel than a ${\beta}$-strand. In multidomain proteins, independently stable domains are unfolded sequentially. The steric constraints imposed on substrate proteins during their degradation by the proteasome were investigated by constructing a model protein in which specific parts of the polypeptide chain were covalently connected through disulfide bridges. The cross-linked model proteins were fully degraded by the proteasome, but two or more cross-links retarded the degradation slightly. Our results suggest that the pore of the proteasome allows the concurrent passage of at least three stretches of a polypeptide chain, and also explain the limited degradation by the proteasome that occurs in the processing of the transcription factor NF-KB, and also implicate difficulty in degradation of amyloidal aggregates by the proteasome

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Following the Cold War, both the United States' military operational concept and the Republic of Korea Army's developmental study (탈냉전기 미국의 군사작전 개념과 한국군 발전방향 연구-합동작전을 중심으로)

  • Lee, Se-Han
    • Journal of National Security and Military Science
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    • s.2
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    • pp.121-163
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    • 2004
  • Science technique development expanded into, not only land, sea, and air operations but also those of airspace, and cyber battle spaces. It is generally accepted at this time that space centric operations currently cannot be effectively divided from air operations. However, science and technology advancements make it possible to integrate Army, Navy, Airforce, and Marine forces into effective operations as never before. The Republic of Korea Armed Forces needs to establish a more effective joint concept. The US military, considered by many experts as the most effective in the world, understands the necessity of joint operations and accordingly has highly developed its own concept of joint operations. The US joint operational concepts demonstrated their effectiveness during the Iraqi War by dominating the battlefield through effective use of all combat and non-combat power. Following the US Iraqi War experience, the US Department of Defense continued to enhance Joint Capability through the acceleration of US Military Transformation involving all components. The future national security of the Republic of Korea, faced with the peculiarity of communist threat in the form of North Korea, and the conflicting interest of four strong powers; the United States, China, Japan, and Russia, depends on small but strong armed forces employing all available combat power through effective National and Military Strategy, and considering domestic and international constraints. In order to succeed in future wars, military operations following joint operational concepts must effectively employ all available combat power in a timely manner. The Republic of Korea Armed Forces must establish a joint forces concept in order to integrate all available combat power during employment. Therefore we must establish military operations that develop the military structure and organization, doctrine, weapon systems, training and education of our armed forces based on the key concept of joint operations.

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Realistic Keyboard Typing Motion Generation Based on Physics Simulation (물리 시뮬레이션에 기반한 사실적인 키보드 타이핑 모션 생성)

  • Jang, Yongho;Eom, Haegwang;Noh, Junyong
    • Journal of the Korea Computer Graphics Society
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    • v.21 no.5
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    • pp.29-36
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    • 2015
  • Human fingers are essential parts of the body that perform complex and detailed motion. Expression of natural finger motion is one of the most important issues in character animation research. Especially, keyboard typing animation is hard to create through the existing animation pipeline because the keyboard typing typically requires a high level of dexterous motion that involves the movement of various joints in a natural way. In this paper, we suggest a method for the generation of realistic keyboard typing motion based on physics simulation. To generate typing motion properly using physics-based simulation, the hand and the keyboard models should be positioned in an allowed range of simulation space, and the typing has to occur at a precise key location according to the input signal. Based on the observation, we incorporate natural tendency that accompanies actual keyboard typing. For example, we found out that the positions of the hands and fingers always assume the default pose, and the idle fingers tend to minimize their motion. We handle these various constraints in one solver to achieve the results of real-time natural keyboard typing simulation. These results can be employed in various animation and virtual reality applications.

Auction Design Strategies for Radio Spectrum Rights : Theory and Experience (주파수 재산권 경매방식의 설계 전략 : 이론과 경험)

  • 조성하
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.3 no.3
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    • pp.485-499
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    • 1999
  • Auctions are appealing market-type mechanisms because they can be deployed to solve the twin problems of resources pricing and allocation. Nonetheless the effectiveness of an auction mechanism in radio spectrum property rights should not be taken for granted. Policymakers need to be aware of the complexity of introducing market discipline in an area where none existed before. Auction design is critical to the success of the allocation process. However, a poorly designed auction mechanism can have detrimental effects on the spectrum rights allocation process. This study discusses some of the key elements and issues of auction design of radio spectrum rights for its efficient allocation. Particularly this study discusses, based on the existing auction theory and other countries' experiences, such issues as bidding rule, value interdependency and sequence of auction, information structure and asymmetric bidder, and wealth constraints and imperfect capital market.

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Mutual Authentication and Secure Session Termination Scheme in iATA Protocol

  • Ong, Ivy;Lee, Shirly;Lee, Hoon-Jae;Lim, Hyo-Taek
    • Journal of information and communication convergence engineering
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    • v.8 no.4
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    • pp.437-442
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    • 2010
  • Ubiquitous mobile computing is becoming easier and more attractive in this ambient technological Internet world. However, some portable devices such as Personal Digital Assistant (PDAs) and smart phones are still encountering inherent constraints of limited storages and computing resources. To alleviate this problem, we develop a cost-effective protocol, iATA to transfer ATA commands and data over TCP/IP network between mobile appliances and stationary servers. It provides mobile users a virtual storage platform which is physically resided at remote home or office. As communications are made through insecure Internet connections, security risks of adopting this service become a concern. There are many reported cases in the history where attackers masquerade as legitimate users, illegally access to network-based applications or systems by breaking through the poor authentication gates. In this paper, we propose a mutual authentication and secure session termination scheme as the first and last defense steps to combat identity thief and fraud threat in particular for iATA services. Random validation factors, large prime numbers, current timestamps, one-way hash functions and one-time session key are deployed accordingly in the scheme. Moreover, we employ the concept of hard factorization problem (HFP) in the termination phase to against fraud termination requests. Theoretical security analysis discussed in later section indicates the scheme supports mutual authentication and is robust against several attacks such as verifiers' impersonation, replay attack, denial-of-services (DoS) attack and so on.

Partitioning and Constraints Generation for the Timing Consistency in the Hierarchical Design Method (계층적 설계 환경에서 일관된 타이밍 분석을 위한 분할 및 제한 조건 생성 기술 개발)

  • Han, Sang-Yong
    • The Transactions of the Korea Information Processing Society
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    • v.7 no.1
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    • pp.215-223
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    • 2000
  • The advancements in technology which have lead to higher and higher levels of integration have required advancements in the methods used in designing VLSI chip. A key to enable a complicated chip design is the use of hierarchy in the design process. Hierarchy organizes the function of a large number of transistors ito a particular, easy-to-manage function. For these reasons, hierarchy has been used in the design process of digital functions for many years. However, there exists differences in a design analysis phase, especially in timing analysis, due to multiple views for the same design. In timing analysis of the hierarchical design, every path is analyzed within partitioned modules independently and the global timing analysis is applied to the whole design considering each module as a single timing component. Therefore, timing results of the hierarchical design could not be same as those of non-hierarchical flat design. In this paper, we formulate the timing problem in the hierarchical design and analyze the possible source of timing differences. We define a new terminology of "consistent result" between different views for the same design. We also propose a new partitioning algorithm to obtain the consistent results. This algorithm helps to enhance the design cycle time.

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An Empirical Study on Relationships among Contents Quality, Trust, and Intention to Use of e-Learning (e-러닝 컨텐츠 품질, 신뢰, 이용의도의 관계에 대한 실증 연구)

  • Lim, Se-Hun;Kim, Dae-Kil;Lee, Sang-Heon
    • Journal of Digital Convergence
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    • v.9 no.4
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    • pp.267-279
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    • 2011
  • A variety of Web Services are being existences based on the development of the Internet. Especially, e-Learning services in the Universities make the temporal and spatial constraints overcome, and e-Learning services have gained great popularity to the students who use because those provide various convenience and usefulness. e-Learning studies have been actively performed based on the spread of e-Learning in the various industries. A number of studies suggest the diffusion plan of e-Learning applying the Technology Acceptance Model studies. Those studies focused on the ease of use and usefulness of e-Learning. The explanation about educational contents perspectives, which is the key factor in e-Learning, is very weak. Therefore, this study suggested the strategy for spreading the e-Learning adoption through in terms of e-Learning educational contents and trust perspectives. This research results would provide the strategic implications to boost the e-Learning adoption in the various universities in terms of e-Learning educational contents and trust perspectives.