• Title/Summary/Keyword: Four Linkages

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Development of a Passive Knee Mechanism for Lower Extremity Exoskeleton Robot (근력 지원용 외골격 로봇을 위한 수동형 무릎 관절 메커니즘 개발)

  • Kim, Ho-Jun;Lim, Dong-Hwan;Han, Chang-Soo
    • The Journal of Korea Robotics Society
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    • v.12 no.2
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    • pp.107-115
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    • 2017
  • In this paper, four-bar linkage mechanism for the knee joint is developed which is used in prosthetics. But unlike the prosthetics, the feature of this mechanism is that the instantaneous center of rotation of the four-bar linkages can be moved behind the ground reaction force vector so that it can be passively supported without any external power. In addition, this mechanism is developed similar to the structure of the human knee joint for eliminating the sense of heterogeneity of the wearer. In order to design the mechanism with these two objectives, optimization design process is done using the PIAnO tool and detailed design is carried out through optimized variable values. The developed mechanism is attached to the robot which can assist the hip and ankle joints. In order to verify the operation of the developed knee mechanism, an insole type sensor was attached to the shoes to compare data values before and after wearing the robot. Result data showed that wearer wearing the exoskeleton robot with the knee mechanism was the same value regardless of whether the heavy tool is loaded or not.

Mammalian Sialyltransferase Superfamily : Structure and Function

  • Lee, Young-Choon
    • Proceedings of the Korean Society of Life Science Conference
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    • 2002.12a
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    • pp.13-19
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    • 2002
  • To elucidate the regulatory mechanism for expression of sialyl-glycoconjugates and their biological functions, ninetheen sialyltransferase cDNAs including eleven by our group or co-works have been cloned and characterized so far. The cloned sialyltransferases are classified into four families according to the carbohydrate linkages they synthesize: ${\alpha}2,3-sialyltransferase$ (ST3Gal I-VI), ${\alpha}$ 2,6-sialyltransferase (ST6Gal I), GalNAc ${\alpha}$ 2,6-sialyltransferase (ST6GalNAc I-VI), and ${\alpha}2,8-sialyltransferase$ (ST8Sia I-VI). Each of the sialyltransferase genes is differentially expressed in a tissue-, cell type-, and stage-specific manner. These enzymes differ in their substrate specificity and various biochemical parameters. However, enzymatic analysis conducted in vitro with recombinant enzyme revealed that one linkage can be synthesized by multiple enzymes. We present here an overview of structure and function of sialyltransferases performed by our group and co-works. Genomic structures and transcriptional regulation of two kinds of human sialyltransferase gene are also presented.

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The Study on Designing and Making Power Standing Wheelchair (파워 스탠딩 휠체어의 설계 및 제작에 관한 연구)

  • Jo, Jang-Hyen;Song, Yo-Chang
    • Journal of the Korean Society for Precision Engineering
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    • v.25 no.10
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    • pp.92-98
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    • 2008
  • This paper is concerned with the designing and making power standing wheelchair. This wheelchair is studied based on the mechanical and electrical engineering concepts and theories. The mechanical theories are composed of statics and dynamics knowledges that are related with moving and standing position. Basically the static and dynamic stability is the most important element in designing and making the real size model. The linear actuator is used in the standing mechanism and the joystick controlled by hand is attached on the arm rest. The real size model is made and also investigated through the design specifications by test drive. Finally, this paper proves the possibility of commerical production of power standing wheelchair.

A Study on the Depopulation Village Improved Settlement Environment (농어촌 과소화마을의 정주여건 개선방안 연구)

  • Lee, Chang-Woo
    • Journal of Korean Society of Rural Planning
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    • v.20 no.2
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    • pp.91-102
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    • 2014
  • The purpose of this study is to analyse the over-depopulation characteristics of village unit in rural and fishery region. In addition, improvement in rural living environment for residents wish to raise. The main results are summarized as follows. First, increasing depopulation village, and the poor living environment for the depopulation of villages. Second, depopulation village characterize the type of hardware and software is required. Finally, this four type of policy is needed to fit characteristics. These findings further improve the depopulation village environment, improve satisfaction in that you can plan the basis for an effective strategy can be. Ongoing analysis of forward linkages and establish future policy measures are needed.

What Drives Growing Currency Co-movements with the Renminbi?

  • Park, Bokyeong;An, Jiyoun
    • East Asian Economic Review
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    • v.24 no.1
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    • pp.31-59
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    • 2020
  • China's increasing trade volume and continuous integration with global financial markets have strengthened the influences of the renminbi on the exchange rates of different currencies. Previous studies find closer co-movements between the renminbi and other currencies. This paper is novel to investigate the underlying determinants of the co-movement further, using panel data of over thirty-four countries. Our results show that stronger bilateral trade and financial linkages with China have a positive association with the currency co-movement. Moreover, countries with greater flexibility in exchange rate regimes show stronger co-movements. These findings imply that growing co-movements are the consequence of autonomous decisions at the market rather than that of management by governments or central banks.

Modeling of a 4-axis redundant stage by using SimMechanics (SimMechanics를 이용한 4축 과구동 스테이지의 모델링)

  • Lee, Jin-Young;Park, Won-Jun;Won, Chong-Jin;Jeong, Jay-I.
    • Proceedings of the KSME Conference
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    • 2008.11a
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    • pp.827-831
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    • 2008
  • In this paper, kinematic analysis for a planar 3-DOF redundant stage which has four actuators is presented by using SimMechanics software package. SimMechanics is a block sets of the Matlab/Simulink package. The SimMechanics enables a simplified model for a complex kinematic mechanism, since kinematic relationship between joints and linkages for the kinematic chains are expressed as line vectors and block diagrams. Here, positional error and limit values of movement ranges of the stage are evaluated by using the SimMechanics. The validity of the kinematic characteristics model was compared with theoretical kinematic analyses for the 3-DOF stage.

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The Modern Approach to Agricultural Extension;T&V, FSR&E, FF (농촌지도사업(農村指導事業)의 새로운 접근(接近);T&V, FSR&E, FF)

  • Choi, Min-Ho;Choe, Young-Chan
    • Journal of Agricultural Extension & Community Development
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    • v.1 no.1
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    • pp.57-65
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    • 1994
  • This study undertakes a critical survey of literatures on the nest development in agricultural extension system; T&V(Traininig and Visit Extension), FSR&E(Fanning Systems Research and Extension), and FF(Farmer First). The study compares the three extension systems in their establishment, objectives, charactersistics, and methods. to find the minor factors for the betterment of agricultural extension system. Those are; 1) client-oriented program, 2) educational service, 3) comprehensive goal and work, 4) benefit to wide range of customers, 5) democratic program, 6) participatory approach, 7) four based experiment, 8) linkages among participants, 9) specialization of extensionists, 10) autonomy of extension offices, 11) humanstic program.

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Systems Thinking on the Dynamics of Knowledge Growth - A Proposal of Dynamic SICI Model -

  • Kim, Sang-Wook;Lee, Bum-Seo
    • Korean System Dynamics Review
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    • v.6 no.2
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    • pp.5-23
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    • 2005
  • This paper investigates a dynamic mechanism underlying the process of knowledge creation and evolution with a focus on the SECI model(standing for Socialization, Externalization, Combination, Internalization) as proposed by Nonaka and Takeuchi(1991) and broadly accepted especially among the practitioners in knowledge management field. The SECI model provides with intuitive logic and clear delineation of knowledge types between the tacit and the explicit, and embodies an interaction dynamic. However explanations of the propelling forces for the knowledge transfer over the four quadrants of the model is yet to be made. And the transmission mechanisms are not prescribed though the model mentions knowledge is created and evolved in a spiral process. This paper, therefore attempts first to extend and elaborate it into a dynamic SECI model by identifying those propelling factors and their relationships(linkages) based on the systems thinking.

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Dynamic Relationship between Stock Prices and Exchange Rates: Evidence from Nepal

  • Kim, Do-Hyun;Subedi, Shyam;Chung, Sang-Kuck
    • International Area Studies Review
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    • v.20 no.3
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    • pp.123-144
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    • 2016
  • This paper investigates the linkages between returns both in foreign exchange and stock markets, and uncertainties in two markets using daily data for the period of 16 July 2004 to 30 June 2014 in Nepalese economy. Four hypotheses are tested about how uncertainty influences the stock index and exchange rates. From the empirical results, a bivariate EGARCH-M model is the best to explain the volatility in the two markets. There is a negative relationship from the exchange rates return to stock price return. Empirical results do provide strong empirical confirmation that negative effect of stock index uncertainty and positive effect of exchange rates uncertainty on average stock index. GARCH-in-mean variables in AR modeling are significant and shows that there is positive effect of exchange rates uncertainty and negative effect of stock index uncertainty on average exchange rates. Stock index shocks have longer lived effects on uncertainty in the stock market than exchange rates shock have on uncertainly in the foreign exchange market. The effect of the last period's shock, volatility is more sensitive to its own lagged values.

How Does Foreign Direct Investment Affect Unbundled Institution? (외국인 직접투자는 제도에 어떻게 영향을 미치는가?)

  • Suh, Hanseok
    • International Area Studies Review
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    • v.15 no.3
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    • pp.535-558
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    • 2011
  • Based on the Rodrik's four-way partition of institutions; market creating, market regulatory institution, market stabilizaing and market legitimizing institution, we analyze how FDI and interaction between FDI and democracy affect four kinds of institutions. By using fixed effect and system GMM model we estimate the direct and indirect effect of FDI on institutions within a large panel data set of 186 developing and developed countries for the period 1985-2009. We show that FDI inflows do not have a positive and significant impact on most kinds of institutions while interaction between democracy and FDI inflows have a significant and positive effect on market creating, market legitimizing and market stabilizing institution. The implication is FDI inflow does not directly lead to change the quality of institution but can indirectly improve it on the condition that democracy of host country become mature. To our knowledge this is the first article to empirically test the FDI and four-way unbundled institutions linkages.