• 한국시스템다이내믹스연구
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• 제6권1호
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• pp.5-15
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• 2005

This paper investigates psychological differences between constructors and interpreters of causal maps. This paper argues that dissipation effects and dilution effects applies to those who are to interpret causal maps not to those who construct them. Dissipation effects are psychological tendency that people perceive causal effect as weak as the number of causal links increases. Dilution effects occur when people undervalue the strength of causal relation as the number of causal variables increases. Experimental results show that concentration effects opposite to the dissipation effects and dilution effects explain more correctly the perception of constructors of causal maps. This paper points out that this asymmetric psychological tendencies between constructors and interpreters of causal maps is the psychological source of the communication problems between systems thinkers and their clients.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2012년도 제45회 KOSCO SYMPOSIUM 초록집
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• pp.61-62
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• 2012

The present study has numerically investigated the effects of fuel-side dilution and pressure on flame structure and extinction scalar dissipation rate of turbulent syngas nonpremixedd flames. Numerical results indicate that for highly diluted case, peak temperature is decreased and stoichiometric mixture fraction is increased. By decreasing the pressure and the nitrgen dilution levelcreased, the extinction scalar dissipation rate is increased.

• 국제초고층학회논문집
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• 제10권2호
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• pp.137-147
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• 2021

The principle of energy dissipation technology is to dissipate or absorb the seismic energy input through the deformation or velocity change of dampers installed in the main structure of high-rise buildings, so as to reduce the seismic response of the buildings. With the development of energy dissipation technology, recognized as an effective and new measurement for reducing seismic effects, its application in high-rise buildings has become more and more popular. The appropriate energy dissipation devices suitable for high-rise buildings are introduced in this paper. The effectiveness of energy-dissipation technology for reducing the seismic response of high-rise buildings with various structural forms is demonstrated with a number of actual examples of high-rise buildings equipped with various energy dissipation devices.

• 대한기계학회논문집
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• 제19권11호
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• pp.3072-3083
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• 1995

The numerical simulation on the three-dimensional natural convection heat transfer in the enclosure with heat generating chip is performed, and the effects of convective heat loss and vents are also examined. The effects of the Rayleigh number and outer Nusselt number (Nu$_{0}$) on the maximum chip temperature and the fractions of heat loss from the hot surfaces are investigated. The results show that conduction through the substrate is dominant in heat dissipation. With the increase of Rayleigh number, heat dissipation through the chip surfaces increases and heat loss through the substrate decreases. Maximum dimensionless temperature with vents is found to decrease about 40% compared to the one without vents at Nu$_{0}$=0.l. It is also shown that effects of size and location of the vents are negligible.ble.

• Journal of Information Display
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• 제13권1호
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• pp.1-6
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• 2012

Decreasing the thermal resistance is the critical issue for high-brightness light-emitting diodes. In this paper, the effects of some design factors, such as chip size (24 and 35 mil), substrate material (AlN and high-temperature co-fired ceramic), and die-attach material (Ag epoxy and PbSn solder), on the thermal-dissipation characteristics were investigated. Using the thermal transient method, the temperature sensitivity parameter, $R_{th}$ (thermal resistance), and junction temperature were estimated. The 35-mil chip showed better thermal dissipation, leading to lower thermal resistance and lower junction temperature, owing to its smaller heat source density compared with that of the 24-mil chip. By adopting an AlN substrate and a PbSn solder, which have higher thermal conductivity, the thermal resistance of the 24-mil chip can be decreased and can be made the same as that of the 35-mil chip.

• 대한수학회지
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• 제33권3호
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• pp.557-573
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• 1996

When we attempt to describe the propagation of nonlinear dispersive waves, it is frequently necessary to take account of diffipative effects.

• 대한기계학회논문집
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• 제18권4호
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• pp.967-976
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• 1994

A tensor invariant model equation for the turbulent energy dissipation rate is proposed in the present study, which is able to simulate secondary straining effects such as curvature effects without the introduction of additional empirical input. The source term in this model has a combined form of the generation term due to the mean vorticity with the conventional one due to the mean strain rate. An extended low-Reynolds-number $k-\epsilon$ turbulence model involving this new model equation is tested for a turbulent Coutte flow between coaxial cylinders with inner cylinder rotated, which is a well defined example of curved flows. The predicted results indicate that the present model works much better for this flow, compared with previous models.

• 전기전자학회논문지
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• 제8권2호
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• pp.181-185
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• 2004

본 논문에서는 산술 연산을 수행하는 연산자의 수가 많은 펑션유닛의 입력 데이터의 스위칭을 최소화하여 소비 전력을 줄인다. 따라서 회로전체의 전력 소모를 줄이기 위해 연산자가 소모하는 전력을 우선적으로 최소화하는 것은 전력 감소의 큰 효과를 가진다. 본 논문은 VLSI회로에서 전력소비에 가장 영향을 많이 미치는 펑션유닛의 연산과정에서 소비하는 전력을 최소화하는 알고리즘을 제안한다. 펑션유닛에서 모든 연산은 전력소비 정보를 가진 전력 라이브러리를 이용하여 피연산자를 스케줄링한다. 전력 라이브러리는 펑션유닛의 모든 입력에 대해 각각의 컨트롤 스텝마다 입력 데이터의 정보를 갱신하고, 그 정보는 스케줄링 과정에서 사용되어진다. 따라서 모든 연산에서 최적화된 데이터를 펑션유닛의 입력으로 하여 전력소비를 최소화 할 수 있다. 본 논문은 상위 레벨 합성 과정에서 펑션유닛에 대한 최소의 전력소비를 위하여 제안하는 알고리즘을 적용하여 실험한 결과 최대 9.4%의 전력 감소효과가 있었다.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2002년도 춘계 학술발표회 논문집
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• pp.297-305
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• 2002

As advanced earthquake analysis/design methods such as the nonlinear static analysis are developed, it is required to estimate precisely the cyclic behavior of reinforced concrete members that is characterized by strength, deformability, and capacity of energy dissipation. However, currently, estimation of energy dissipation depends on empirical equations that are not sufficiently accurate, or experiment and sophisticated numerical analysis which are difficult to use in practice. In the present study, nonlinear finite element analysis was performed to investigate the behavioral characteristics of flexure-dominant RC members under cyclic load. The effects of axial force, arrangement of reinforcing bars, and reinforcement ratio on the cyclic behavior were studied. Based on the investigation, a simplified method to estimate the capacity of energy dissipation was proposed, and it was verified by the comparison with the finite element analyses and experiments. The proposed method can estimate the energy dissipation of RC members more precisely than currently used empirical equations, and it is easily applicable in practice.

• Korean Chemical Engineering Research
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• 제53권1호
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• pp.91-102
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• 2015

Analytical solutions for the forced convection heat transfer of viscoelastic fluids obeying the Giesekus model are obtained in a concentric annulus under laminar flow for both thermal and hydrodynamic fully developed conditions. Boundary conditions are assumed to be (a) constant fluxes at the walls and (b) constant temperature at the walls. Temperature profiles and Nusselt numbers are derived from dimensionless energy equation. Subsequently, effects of elasticity, mobility parameter and viscous dissipation are discussed. Results show that by increasing elasticity, Nusselt number increases. However, this trend is reversed for constant wall temperature when viscous dissipation is weak. By increasing viscous dissipation, the Nusselt number decreases for the constant flux and increases for the constant wall temperature. For the wall cooling case, when the viscous dissipation exceeds a critical value, the generated heat overcomes the heat which is removed at the walls, and fluid heats up longitudinally.