• 제목/요약/키워드: confined system

검색결과 387건 처리시간 0.032초

고경력/퇴직 과학기술자의 기술정보분석 실적평가 방안 (A Development of Evaluation System on Technological Information Analysis by Retired Scientists & Engineers)

  • 김석진;조흥곤;유영복;민완기
    • 기술혁신학회지
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    • 제5권3호
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    • pp.307-320
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    • 2002
  • The purpose of this paper was to design evaluation process on technological information analysis done by re-tired scientists and engineers. Existing studies on evaluation system and methodology were analyzed and their implications are as follows. To provide useful feedback to the retired scientists, indicators of evaluation should be simplified and method of evaluation confined to the quantitative one. And the results of evaluation need to be utilized in direction to encourage the old scientists and engineers.

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누수대수층에 대한 수리상수 추정과 해석 (Parameters Estimation and Analysis for Leaky Aquifer System)

  • 김민환
    • 대한지하수환경학회지
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    • 제5권3호
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    • pp.123-128
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    • 1998
  • 본 연구에서 고려한 누수대수층 구조는 상부의 자유면대수층과 하부의 피압대수층으로 구성되어있으며 이들 사이에 누수층(leaky layer)이 있다. 상부 지하수 수위의 하강에 따른 피해 방지와 효율적인 지하수 관리를 위해서 상부와 하부의 지하수 수두 변화가 동시에 파악되어야 한다. 누수대수층 구조의 피압대수층(하부)에서 양수를 할때 자유면대수층(상부)은 하부와 상부 대수층을 구분하는 누수층의 영향을 받게 된다. 누수층을 해석하기 위해서 이 층에 대한 수리상수의 결정이 필요하다. 본 논문에서 수리상수를 결정하기 위한 개선된 SM(slope-matching)방법을 제시하였다. 그리고 누수대수층 구조에서 상부와 하부의 지하수 수두를 예측하기 위해 유한차분법을 이용하여 수치모형을 구성하였다. 수치모형의 검증을 위해 1차원 누수대수층 구조에 대한 해석해를 이용하여 정상류 상태에서 수두를 비교하였다. 그 결과는 잘 일치하고 있으며 2차원 누수대수층의 하부층인 피압대수층에서 양수를 할 때 상부 대수층과 하부 대수층에서 지하수 수두의 거동을 고찰하였다.

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Effects of confinement on physiological and psychological responses and expression of interleukin 6 and brain derived neurotrophic factor mRNA in primiparous and multiparous weaning sows

  • Zhang, Mingyue;Li, Xiang;Li, Jianhong;Sun, Hanqing;Zhang, Xiaohui;Bao, Jun
    • Asian-Australasian Journal of Animal Sciences
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    • 제30권9호
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    • pp.1350-1357
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    • 2017
  • Objective: The present study aimed to investigate whether the long-lasting, recurrent restricting of sows leads to the physiological and psychological reaction of discomfort. Methods: Sows (Large White) that had experienced restricting for about 0.5 or 3 years and agematched sows kept in a group housing system (loose sows) were compared. Pupillary light reflex parameters were measured at the weaning stage. Immediately after slaughter, blood samples were taken to measure serum cortisol levels, and the brain was dissected, gene expression in the hippo-campus, frontal cortex and hypothalamus was analyzed. Results: The serum cortisol levels were higher in the confined sows than in the loose sows. The full maturity, but not the young adolescent, confined sows had longer latency time in the onset of pupil constriction than their loose counterparts. Real-time polymerase chain reaction analyses revealed an increased expression of interleukin 6 mRNA in the hippocampus and decreased expression of brain derived neurotrophic factor mRNA in hippocampus and hypothalamus and to a lesser extent in the frontal cortex of the full maturity confined sows, compared with the full maturity loose sows. Conclusion: Taken together, these data indicated that recurrent restricting stress in full maturity sows leads to the physiological and psychological reaction of discomfort.

산화 그래핀 맴브레인의 물투과 속도와 차압 조건 간 상관관계에 대한 실험적 연구 (Experimental Study of Water Penetration Rate Via Graphene Oxide Membrane According to Driven Pressure Difference)

  • 김지민
    • 한국기계기술학회지
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    • 제20권6호
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    • pp.858-864
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    • 2018
  • Graphene oxide (GO) laminate is a new promising material for water purification system, which has extraordinary permeability only for water molecule. It consists of numerous nano-channels, in which water molecules could be nano-confined, resulting in slip of the molecules for very fast transportation speed. In this study, water penetration rate via different thickness of GO membrane according to driven pressures are measured experimentally, so that speed of water molecules and permeability are evaluated. Generally, water penetration rate via a membrane with macroscopic-sized channel increases linearly with pressure difference between up and bottom side of the membrane, but that via GO membrane approaches asymptotic value (i.e. saturation) as like a log function. Moreover, the permeability of GO membrane was observed in inverse proportion to its thickness. Based on the experimental observations, a correlation for volume flux via GO membrane was suggested with respect to its thickness and external pressure difference.

랭킹개미군전략을 이용한 리포팅셀 위치관리시스템 최적 설계 (Optimal Design of Reporting Cell Location Management System using Ranking Ant Colony System)

  • 김성수;김근배
    • 산업공학
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    • 제19권2호
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    • pp.168-173
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    • 2006
  • In the Reporting Cell Location Management (RCLM) system, a subset of cells in the network is designated as the reporting cells. Each mobile terminal performs location update only when it enters one of these reporting cells. When a call arrives, the paging is confined to the reporting cell the user last reported and the neighboring bounded non-reporting cells. Frequent location update may result in degradation of quality of service due to interference. Miss on the location of a mobile terminal will necessitate a search operation on the network when a call comes in. We must decide the number of reporting cells and which cell should be reporting cell to balance the registration (location update) and search (paging) operations to minimize the cost of RCLM system. This paper proposes a ranking ant colony system (RACS) for optimization of RCLM system.

Interfacial Charge and Mass Transfer at Graphene-SiO2 Substrates: Raman Spectroscopic Studies

  • 류순민
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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    • pp.115.1-115.1
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    • 2014
  • Atom-thick 2-dimensional materials such as graphene, h-BN and MoS2 hold substantial potential for applications in future molecular-scale integrated electronics, transparent conducting membranes, nanocomposites, etc. From a fundamental point of view, 2-dim crystal-solid substrates can also serve as a unique system to study various physicochemical phenomena occurring at low dimensions or interfaces. In this talk, I will present our recent Raman spectroscopy studies on the surface science problems of graphene: interfacial charge transfer, molecular diffusion in confined space and structural deformation.

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고에너지원을 이용한 폭발 현상 모델링

  • 이경철;여재익
    • 한국추진공학회:학술대회논문집
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    • 한국추진공학회 2007년도 제28회 춘계학술대회논문집
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    • pp.349-352
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    • 2007
  • In this paper, we describe the modeling of ablation based laser applications for innovative use in the military In the laser ignition system, a metal confinement is ablated with the high intensity pulsed energy, triggering a thermal ignition of the confined high explosives. The constitutive equations for the laser source, deformation of metals, and explosion of energetic materials are described.

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On the Size of Quantum Dots with Bound Hydrogenic Impurity States

  • Sun, Ho-Sung
    • Bulletin of the Korean Chemical Society
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    • 제30권2호
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    • pp.315-318
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    • 2009
  • Some particular bound state energies of an electron, under Coulomb potential field, confined in a two-dimensional circle and a three-dimensional sphere are analytically derived. The derivation shows that the electron cannot be bound in a negative energy state when the circle (or sphere) is smaller than a certain critical size. The critical size dependency on the strength of Coulomb potential and the angular momentum of the electron is also analytically derived. This system mimics quantum dots. Therefore the derivation provides new information on a minimum critical size of quantum dots with hydrogenic impurity.

시뮬레이티드어닐링을 이용한 리포팅셀 위치관리시스템 최적 설계 (Optimal Design of Reporting Cell Location Management System using Simulated annealing System)

  • 김성수;문재기
    • 산업기술연구
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    • 제28권B호
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    • pp.9-14
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    • 2008
  • In the Reporting Cell Location Management (RCLM) system, a subset of cells in the network is designated as the reporting cells. Each mobile terminal performs location update only when it enters one of these reporting cells. When a call arrives, the paging is confined to the reporting cell the user last reported and the neighboring bounded non-reporting cells. Frequent location update may result in degradation of quality of service due to interference. Miss on the location of a mobile terminal will necessitate a search operation on the network when a call comes in. We must decide the number of reporting cells and which cell should be reporting cell to balance the registration (location update) and search (paging) operations to minimize the cost of RCLM system. This paper proposes a simulated annealing (SA) for optimization of RCLM system.

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적응 퍼지 제어기를 이용한 수경재배 자동화를 위한 연구 (A Study on Implementation of Hydroponics Automation System using Adaptive Fuzzy Control)

  • 노명균;김승우;홍상은
    • 한국지능시스템학회:학술대회논문집
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    • 한국퍼지및지능시스템학회 1996년도 추계학술대회 학술발표 논문집
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    • pp.111-114
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    • 1996
  • Hydroponics is to grow plants, not in soil but in water which the quantity of necessary chemical food can be controlled. In this paper, this is designed in the automatic system. The closed culture reduces cost of production and produces a many kinds of agricultural products in a confined place. An adaptive fuzzy control in the best method to solve and to overcome parametric uncertainties and non-linearity of the controlled system. A hydroponics automation system which is able to overcome these control problems. It is used in implementation of the hydroponics automation system. The performance is analyzed through an experiment in which the new adaptive fuzzy control method is applied to the automatic control of tomato hydroponics.

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