• Title/Summary/Keyword: Fourth-order system

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Numerical simulation of tuned liquid tank- structure systems through σ-transformation based fluid-structure coupled solver

  • Eswaran, M.;Reddy, G.R.
    • Wind and Structures
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    • v.23 no.5
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    • pp.421-447
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    • 2016
  • Wind-induced and earthquake-induced excitations on tall structures can be effectively controlled by Tuned Liquid Damper (TLD). This work presents a numerical simulation procedure to study the performance of tuned liquid tank- structure system through ${\sigma}$-transformation based fluid-structure coupled solver. For this, a 'C' based computational code is developed. Structural equations are coupled with fluid equations in order to achieve the transfer of sloshing forces to structure for damping. Structural equations are solved by fourth order Runge-Kutta method while fluid equations are solved using finite difference based sigma transformed algorithm. Code is validated with previously published results. The minimum displacement of structure is observed when the resonance condition of the coupled system is satisfied through proper tuning of TLD. Since real-time excitations are random in nature, the performance study of TLD under random excitation is also carried out in which the Bretschneider spectrum is used to generate the random input wave.

Improvement of Tansient Response Characteristics of a Position Control Hydraulic Servosystem Using Observer (II) -Experimental Results Using Analog Observer- (觀測器를 利용한 位置制御 油壓 서보 시스템의 過度應答 特性 改善 (II) -애널로그 관측기를 이용한 실험결과-)

  • 이교일;조승호
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.12 no.2
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    • pp.215-220
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    • 1988
  • The oscillatory hydraulic servosystem and the stable hydraulic servosystem under proportional control were feedback-controlled respectively using the estimated states of the observer. The observer was constructed in the analog computer and then it was interfaced with the real hydraulic servosystem to excute the experiment. As a result of experiment, the system that had been stable under proportional control responded more rapidly than before and the system that had shown oscillatory phenomenon under proportional control became stable with the same maximum acceleration and velocity that it had started under proportional control.

Some Suggestions for Development of Maritime High School in Korea (우리나라 해운계 고등학교의 발전 과제와 대응 방안)

  • 이학헌
    • Journal of the Korean Institute of Navigation
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    • v.21 no.1
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    • pp.57-73
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    • 1997
  • This paper deals with internal and outernal factors of Maritime High School in Korea, and suggests the followings. The fist, superintendent authority of schools should be transferred to ministry of education from ministry of marine. The second, education system should be upgraded to junior college or 5 years education course. The third, the door of maritime university permission should be opened for maritime high school graduates. The fourth, training ship should be built for effective training course required form STCW 95. The fifth, if the graduates form maritime high school engage board, all of them should be exempted from military service responsibility. The sixth, the on board-training system for teachers and instructors should be programmed in order to help them keep and utilize the on board experience in actural education situation. The seventh, the school location should be placed in order to increase the efficiency of the education.

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A Comparative Study of Employment Support System for Unemployed Youth : Linking the British Experience to the Korean Context (청소년 실업자를 위한 고용지원제도 비교 연구 : 영국과 한국을 중심으로)

  • Chung, Young-Soon;Seok, Jae-Eun;Kim, Hyun-Joo
    • Korean Journal of Social Welfare
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    • v.46
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    • pp.427-458
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    • 2001
  • The present study is designed to trace the successful reform steps taken within the employment support system in the UK and to extract a set of instructive implications for Korea's future reform path towards an efficient employment support system conductive to youth employment by setting out an analytical framework that links the British experience to the Korean context. To this end, this study focuses on three major aspects of employment support system: delivery mechanism, method of delivery, and programs. Implications drawn from the comparative analysis are as follows. First, the current employment support services in Korea-including job placement service, vocational training, and public works-should be more tightly integrated and delivered in a more consistent fashion in order to become highly accessible to the unemployed. Second, the cooperative network between employment service providers and the corporate sector as demander of labor should be institutionalized in order to make the employment support system more responsive to labor demand. Third, to create an enhanced employment support system that counts in individual differences of the unemployed would require continued, in-depth consultation and case management services along with fully specialized employment caseworkers who would provide them. Fourth, the government should take the initiative and be unflaggingly supportive both institutionally and financially in making future efforts to continuously improve the employment support system on the basis of the implications mentioned above.

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A Study on the Automated Drawing and Grading of a man′s DURUMAGI by Apparel CAD SYSTEM (어패럴 CAD SYSTEM을 이용한 남자 두루마기의 자동제도 및 그레이딩에 관한 연구)

  • 한문정;송명견
    • Journal of the Korean Society of Clothing and Textiles
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    • v.24 no.6
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    • pp.799-809
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    • 2000
  • This study was designed for automated pattern drawing and grading a man's Durumagi, Korean traditional coat in order to reestablished and grade the pattern by Apparel CAD SYSTEM. For the study, AM-250 systems of Gerber as the computer and Macro program as the automated drawing were used. Also, PDS(Pattern Design System) was used for the grading of the original Durumagi pattern. Results were followings; First, the size data that could be standardized by reestablishing the pattern of a man's Durumagi by each size was presented. Second, The pattern was developed by each size. Third, new design was propose for mass production with the traditional design of the DURUMAGI Fourth, The time for making DURUMAGI pattern and the cost through the automated drawings by using the Macro program were reduced. Moreover, was presented the basic data for a ready to made garment like the Western garment. Five, A man's DURUMAGI by CAD System was graded that could be applied to ready to made Hanbok

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Optical Design of an Image-space Telecentric Two-mirror System for Wide-field Line Imaging

  • Lee, Jong-Ung;Kim, Youngsoo;Kim, Seo Hyun;Kim, Yeonsoo;Kim, Hyunsook
    • Current Optics and Photonics
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    • v.1 no.4
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    • pp.344-350
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    • 2017
  • We present a new design approach and an example design for an image-space telecentric two-mirror system that has a fast f-number and a wide-field line image. The initial design of the telecentric mirror system is a conventional axially symmetric system, consisting of a flat primary mirror with fourth-order aspheric deformation and an oblate ellipsoidal secondary mirror to correct spherical aberration, coma, and field curvature. Even though in the optimized design the primary mirror is tilted, to avoid ray obstruction by the secondary mirror, the image-space telecentric two-mirror system shows quite good imaging performance, for a line imager.

Production of educational video contents in online market using VR (VR을 활용한 온라인 마켓에서의 교육영상콘텐츠 제작)

  • Ahn, In-Soo
    • Proceedings of the Korean Society of Computer Information Conference
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    • 2017.07a
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    • pp.374-375
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    • 2017
  • As the distribution of image contents is activated, users can easily access image contents through various routes and media.In this paper, we propose a new virtual reality (VR) system, which is based on the development of IT technology, in order to prepare for the fourth industrial revolution era.We propose a method of producing educational video contents that combines maximized virtual reality.

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A Study on the Realization of Infrastructure for Electronic Trade (전자무역 기반사업의 구현에 관한 연구)

  • Lee, Bong-Soo
    • International Commerce and Information Review
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    • v.12 no.1
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    • pp.55-73
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    • 2010
  • The thesis examines new innovation of various aspect to overcome lots of problems which come by when we execute simplification of trade procedure and administration fairly. Practical implications regarding the innovation of electronic trade infrastructure are as follows. First, it will propel the standardization of electronic trade section in the technical side and the construction atmosphere of international authentication system must be created. The work process should be redesigned in order to implement export-import procedures that meet the relevant standards. Second, the improvement of system for electronic process is necessary in the law and institutional aspect. In order to eliminate any obstacles to the trade procedure, clearer legal grounds regarding legitimate controls and minimum necessity must be established. Also, laws should be revised to admit mutual recognition among certification organizations, in lieu of international agreement-based mutual recognition between government. Third, the detailed improvement for the integration of the electronic trade infrastructure will be demanded. Additionally, user-centered quality management protocols should be established via connections with the systems already existing in governmental bodies. Fourth, various trade institution should harmonized and interconnected with other partners through mutual cooperation for standardization of operational system. A system which can monitor and remotely diagnose and resolve system errors should be established to provide tailor-made service and improve operational efficiency. At the same time, it is necessary to build a cooperative system to share information and promote comprehensive management for efficient operation.

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Case Study of Software Reverse Engineering using McCabe and BP/Win Tools (McCabe 및 BP/Win도구를 이용한 소프트웨어 역공학 사례연구)

  • Jo, Hyeon-Hun;Choe, Yong-Rak;Rhew, Sung-Yul
    • Journal of KIISE:Computing Practices and Letters
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    • v.6 no.5
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    • pp.528-535
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    • 2000
  • This paper aims at providing guidelines enabling productive software construction by offering reusable modules which is used not only for effective maintenance for each step, but also for a re-engineering process after analyzing developed source code. There are four processing steps. The first is to analyze source code. The second is module slicing and clustering using McCabe and BP/Win Tools, The third is to transform the outputs extracted from the business model to reusable modules. The final step is to design repository and to construct a system. In this paper, we applied the fourth step to our case study, which was specified from the first step to the fourth. The specified fourth step contains various things for constructing repository. And the fourth step reanalyzes informal and unstructured information by using reverse engineering tools, in order to provide effective guidelines for productive software maintenance and re-engineering.

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Study on Agricultural Science Convergence R&D Agenda under the Fourth Industry Revolution (4차 산업혁명 관련 농학계 융·복합 R&D 어젠다 연구)

  • Lee, Dong-Hoon;Kim, So-jin;Jang, Keum-Il;Sa, Tong-min;Yoo, Do-il
    • The Journal of the Korea Contents Association
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    • v.19 no.7
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    • pp.323-334
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    • 2019
  • The purpose of this study is to propose agenda concerning the direction of agricultural science convergence research and development (R&D) under the fourth industrial revolution. For this study, we apply the Analytic Hierarchy Process (AHP) targeted at experts in the fields of agricultural academia and research operating R&D currently. Results suggest the following agendas; first, human resource training toward future is more emphasized rather than fragmentary technology innovation. Second, a flexible road map for agricultural science R&D need to be made for responding to short and long term issues relevant to the innovation. Third, mutual exchange and cooperative system need to be constructed between academia and research in order to create synergy effects. Finally, both institutional improvement and humanistic literacy should be emphasized for rapidly changing conditions and better human life under the fourth industrial revolution.