• 제목/요약/키워드: Theoretical block

검색결과 189건 처리시간 0.024초

공공부문 건강증진사업의 발전방향 (Future Directions for Health Promotion Programs in the Public Sector)

  • 이주열
    • 보건교육건강증진학회지
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    • 제29권4호
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    • pp.29-38
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    • 2012
  • Objectives: This paper aims to suggest some ways we could improve the efficiency and equity in health promotion programs in the public sector. Methods: Reports published by the Minister of Health and Welfare and web-site information were reviewed. And, the empirical results and theoretical considerations provided in this study could be used in making future direction for health promotion programs in the public sector. Results and conclusion: The public sector should play a leading role in health promotion programs. The role of public sector in health promotion program is to establish the health promotion plan based on the health survey, to develop the scientific programs, to provide the free health services, and to maintain a cooperative relationship with the private sector. In order to activate the health promotion programs in the public sector, establishing the role of the public sector, changing the operation of health promotion fund, block grants for health promotion, local health promotion fund, and integration of health statistics were suggested.

유압 피스톤 펌프의 밸브 플레이트 랜드부 압력 특성 (Pressure characteristics at the land of valve plate in the oil hydraulic axial piston pump)

  • 최형완;김종기;정재연
    • 한국윤활학회:학술대회논문집
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    • 한국윤활학회 2000년도 제32회 추계학술대회 정기총회
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    • pp.221-227
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    • 2000
  • The design of the valve plate is most important to increase efficiency in the oil hydraulic axial piston pump. A theoretical study was carried out to clarify the pressure characteristics at the land of the valve plate in the oil hydraulic axial piston pump. Dynamic pressure acts on the land of the valve plate was computed numerically with discharge pressure, rotational speed and swash plate angle. Pressure distribution between the valve plate and the cylinder block also was obtained with dynamic pressure. The results are applicable to improve the design technique of the valve plate in the oil hydraulic axial piston pump.

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Theoretical Optical Waveguide Investigation of Self-Organized Polymer Thin Film Nanostructures with Nanoparticle Incorporation

  • Lau, King Hang Aaron;Knoll, Wolfgang;Kim, Dong-Ha
    • Macromolecular Research
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    • 제15권3호
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    • pp.211-215
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    • 2007
  • Hybrid thin film nanostructures composed of metal nanoparticles (NPs) and self-assembled polymer films with different spatial distributions of NPs were analyzed by optical waveguide spectroscopy (OWS). Specifically, the dielectric constants were calculated using effective medium theory for the incorporation of 1 vol% Au NP into the block copolymer (BCP) films having a cylindrical nanodomain morphology. Three cases were considered: uniform distribution of NPs in the film; selective distribution of NPs only in the cylindrical domains; and segregation of NPs to the center of the cylindrical domains. The optical waveguide spectra derived from the calculated dielectric constants demonstrate the feasibility of experimentally distinguishing the composite nanostructures with different inner morphologies in the hybrid metal NP-BCP nanostructures, by the measurement of the dielectric constants using OWS.

2차원 유동 해석을 위한 OpenFOAM용 격자 생성 프로그램 개발 (DEVELOPMENT OF OPENFOAM GRID GENERATION PROGRAM FOR TWO-DIMENSIONAL FLOW ANALYSIS)

  • 김왕현;김병수
    • 한국전산유체공학회지
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    • 제21권2호
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    • pp.25-31
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    • 2016
  • In this paper, a study on the development of OpenFOAM grid generation program for two-dimensional flow analysis is described. By using the pre-processor(eMEGA) of EDISON_CFD system, grids for OpenFOAM flow calculation were obtained. Resultant two-dimensional grids were used to calculate flow fields by applying simpleFoam, one of the OpenFOAM's popular solvers, and the obtained flow results were compared with theoretical and experimental data available. Also grids generated by present program were compared with grids by a commercial pre-processor Pointwise for the purpose of verification. Verification work includes three cases(single block, O-type single block, and multi block grid), and all results show reasonable matches. According to the current achievement, it can be concluded that OpenFOAM grid can be constructed conveniently by using eMEGA with GUI.

Sound transmission of lightweight block walls and panels-Theory and Experiments

  • S Kandaswamy;A Ramachandraiah
    • 한국음향학회:학술대회논문집
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    • 한국음향학회 2004년도 춘계학술발표대회 논문집 제23권 1호
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    • pp.235-239
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    • 2004
  • Sound transmission either as airborne or structure borne is a potential problem that occurs in buildings either from sources within or from outside. With the expansion of real estate activities in countries like India, the need to attend sound insulation requirements also assumes greater dimensions. The focus of this research is on studying the sound transmission characteristics of building structures made of hollow blocks, neocrete block, aerocon block and prefabricated panels such as Ferrocement panel. The tests were carried out the blocks with and without plastering and their sound reduction index was measured at one-third octave frequencies. In the case of ferrocement panels, different types of systems were tested in the TL suite. Panels with cavity, with cavity ties, with insulation, with stiffeners and with plasterboard were investigated. Sound reduction index of these panels was measured with additional quantities like longitudinal wavespeed, and loss factors (internal and total loss factor). Tests were also conducted on Cypcrete wall panel and Sandwiched wooden panel in a similar way. Theoretical investigations were carried out using Statistical Energy Analysis (SEA) for the above systems. Sound reduction index was then compared between the predicted and the measured values.

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Driving Mechanism of Tapered Pistons in Bent-Axis Design Axial Piston Pumps

  • Kim, Jong-Ki;Jung, Jae-Youn
    • Journal of Mechanical Science and Technology
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    • 제17권2호
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    • pp.181-186
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    • 2003
  • In order to assure the quality of the bent axis design axial piston pumps driven by tapered pistons, it is necessary to know the characteristics of force applied to tapered pistons and the mechanism for driving the tapered pistons. Since they are able to perform both reciprocating and spinning motions in cylinder block, it is difficult to understand the driving mechanismand-tomeasure the forces applied to tapered pistons experimentally In the present study, the theoretical mechanism for driving the tapered pistons is studied by use of the geometric method. The driving area of the tapered pistons is measured by measuring the strain of a cylinder forced against a tapered piston using an electric strain gauge and a slip ring. The forces applied to tapered pistons is also investigated with the change of discharge pressure and the rotational speed. As a results of this investigation, it is concluded that the cylinder block is driven by one tapered piston in a limited area and the driving area is changed due to space angle of the tapered pistons and the swivel angle of the cylinder block. It is also observed that the force applied to tapered pistons increases as the discharge pressure and the rotational speed increase.

양바퀴 이동로봇의 자세제어에 대한 연구 (A study on the Posture control of a two-wheeled mobile robot)

  • 주진화
    • 한국정보전자통신기술학회논문지
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    • 제10권6호
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    • pp.587-593
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    • 2017
  • 본 논문에서는 로봇제어분야의 이론적인 내용에 대해서 실제 실습교육이 가능한 환경을 구축하는데 따른 애로를 해결하기 위한 하나의 방안을 제시하기 위해서 세그웨이 구조의 양바퀴 이동로봇을 레고(LEGO) 블록을 사용하여 제작하고, 제작된 로봇이 로봇공학 교육의 동적시스템이나 비선형 시스템과 같은 고급제어 이론기술을 적용하는 실습용으로 활용하는 것에 대한 타당성을 제시하기 위하여 로봇이 주행 중에 중력의 변화에 대해서도 균형을 유지하면서 안정된 자세를 취하도록 하는 자세제어에 대한 실험을 수행하고 그 결과를 제시하였다. 로봇의 자세제어 주행 실험은 평면과 경사로에서 각각 수행하였으며, 평면 주행실험에서는 장애물을 인식하고 회피하는 실험을 병행하여 그 결과도 함께 제시함으로써 로봇공학의 고급제어 이론의 실습교육용으로 레고(LEGO) 블록을 이용해서 제작한 로봇이 효과적인 실습도구로 활용될 수 있음을 확인하였다.

퍼지제어를 이용한 마이크로 로보트 핑거의 힘제어 (Force Control of Micro Robotic Finger Using Fuzzy Controller)

  • 류재춘;박종국
    • 한국지능시스템학회논문지
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    • 제7권5호
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    • pp.67-76
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    • 1997
  • In this paper, a theoretical study is presented for the force control of a miniature robotic manipulator which is driven by a pair of piezo-electric bimorph cells. In the theoretical analysis, one finger is modeled as a flexible cantilevers with a force sensor at the tip and the finger is a solid beam. The robotic finger is used to hold the objects with different stiffness such as an iron block and a living insect and a moving objcet. So it is very important to develop an adequate controller for the holding operation of the finger. The main problems in force controlling are overdamping, overshoot and unknown environment(such as the stiffness of object and unknown plant parameters). So, the main target is propose the new fuzzy compensation for unknown environment and incease the system performance. The fuzzy compensation is implemented by using PI-type fuzzy approach to identified unknown environment. And the result of proposed controller was compared with the conventaional PID and optimal controller.

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A theoretical mapping model for bridge deformation and rail geometric irregularity considering interlayer nonlinear stiffness

  • Leixin, Nie;Lizhong, Jiang;Yulin, Feng;Wangbao, Zhou;Xiang, Xiao
    • Steel and Composite Structures
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    • 제46권1호
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    • pp.93-105
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    • 2023
  • This paper examines a high-speed railway CRTS-II ballastless track-bridge system. Using the stationary potential energy theory, the mapping analytical solution between the bridge deformation and the rail vertical geometric irregularity was derived. A theoretical model (TM) considering the nonlinear stiffness of interlayer components was also proposed. By comparing with finite element model results and the measured field data, the accuracy of the TM was verified. Based on the TM, the effect of bridge deformation amplitude, girder end cantilever length, and interlayer nonlinear stiffness (fastener, cement asphalt mortar layer (CA mortar layer), extruded sheet, etc.) on the rail vertical geometric irregularity were analyzed. Results show that the rail vertical deformation extremum increases with increasing bridge deformation amplitude. The girder end cantilever length has a certain influence on the rail vertical geometric irregularity. The fastener and CA mortar layer have basically the same influence on the rail deformation amplitude. The extruded sheet and shear groove influence the rail geometric irregularity significantly, and the influence is basically the same. The influence of the shear rebar and lateral block on the rail vertical geometric irregularity could be negligible.

절리면이 발달한 골재석산의 최적개발을 위한 발파 및 사면유지 (Stability Evaluation and Blasing of Slopes for Optimal Development of Aggregate Quarry with Highly Damaged Discontinuities)

  • 양형식;김남수;김형근
    • 터널과지하공간
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    • 제7권2호
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    • pp.150-157
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    • 1997
  • Various analytical, empirical and theoretical methods for slope stability assessment were applied on slopes to develop aggregate quarry optimally. Among them are block theory, stereographic analysis, RMR, SMR, limit equilibrium method and maximum likelihood. Test site was estimated that slopes were apt to fail although rock quality was good. Modified direction and dip angle was suggested for stability. To reduce the overbreak and to improve the stability, the vertical blasting was recommended for new subground level.

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