• 산업공학
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• 제12권2호
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• pp.222-236
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• 1999

This paper presents a design and implementation of an intelligent-integrated production-logistics systems. The situation considered here is that there are multiple manufacturing plants and multiple distribution centers. Effective distribution resource and production planning are required to reduce inventory cost and to avoid inventory shortage. We propose an intelligent forecasting scheme of each distribution centers, adaptive inventory replenishment planning, distribution resource planning, and integrated production planning system. In forecasting a huge number of on-line model identification is performed using neural network approximation capability. An efficient adaptive replenishment planning and distribution resource planning are also presented in connection with forecasting scheme. An appropriate production is also requested based on production lead-time and the results of distribution planning. Experimental simulations are presented to verify the proposed approach using real data.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 B
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• pp.1438-1440
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• 2005

A power control and distribution unit(PCDU) plays roles of protection of battery against overcharge by active control of solar array generated power, distribution of unregulated electrical power via controlled outlets to bus and instrument units, distribution of regulated electrical power to selected bus and instrument units, and provision of status monitoring and telecommand interface allowing the system and ground operate the power system, evaluate its performance and initiate appropriate countermeasures in case of abnormal conditions. In this work, we perform the preliminary design of a PCDU scheme for the small LEO Satellite applications. The main constitutes of the PCDU are the battery interface module, the auxiliary supply modules, solar array regulators with maximum power point tracking(MPPT) technology, heater power distribution modules, internal converter modules for regulated bus voltage generation. and instrument power distribution modules.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 1999년도 추계 학술발표회 논문집 Proceedings of EESK Conference-Fall
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• pp.273-280
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• 1999

The base shear and the veritcal distribution of shears along the height of a building are two fundamental measures that define the design seismic load. But the method specified in Korean building code does not give an appropriate distribution for buildings of tall or longer period because it roughly account for the contributions of the higher modes. several methods to give a better distribution of seismic forces have been proposed. But they have not been introduced into the seismic codes yet probably because they cannot solve all the above-mentioned problems. This paper deals with the distribution of lateral seismic forces along the height of a building to account for the contribution of the higher modes. After reviewing some existing distributions in seismic codes and literatures moment-resisting frames with various stories were studied by modal analysis for a wide range of fundamental period and the stiffness ratio of the buiding. As a result of the analysis a new expression for the distribution of seismic forces is proposed and compared with those of some codes and dynamic analysis.

• Wind and Structures
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• 제28권1호
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• pp.63-70
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• 2019

Due to developing environmental concern use of renewable energy source is very essential. The great demand for the energy supply coupled with inadequate energy sources creates an emergency to find a new solution for the energy shortage. The appropriate wind energy distribution is the fundamental requirement for the assessment of wind energy potential available at the particular site essential for the design of wind farms. Hence the proper specification of the wind speed distribution plays a vital role. In this paper the Bimodal Weibull distribution is used to estimate the Capacity factor at the proposed site. The shape and scale parameters estimated using Maximum likelihood method is used as the initial value for extrapolation. Application of this model will give an accurate result overwhelming the concept of overestimation or underestimation of Capacity factor.

• Structural Engineering and Mechanics
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• 제63권3호
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• pp.281-292
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• 2017

Architecture constraints in buildings may typically cause irregularities in the distribution of stiffness and mass and consequently causes non-compliance of centers of mass, stiffness and strength. Such buildings are known as asymmetric buildings the distribution of strength and stiffness is one of whose main challenges. This distribution is more complicated for concrete buildings with RC shear walls in which stiffness and strength are interdependent parameters. The flexibility under the foundation is another subject that can affect this distribution due to the variation of dynamic properties of the structure and its constituting elements. In this paper, it is attempted to achieve an appropriate distribution pattern by expressing the effects of foundation flexibility on the seismic demand of concrete shear walls and also evaluate the effects of this issue on strength and stiffness distribution among lateral force resistant elements. In order to understand the importance of flexibility in strength and stiffness distribution for an asymmetric building in different conditions of under-foundation flexibility, the assigned value to each of the walls is numerically calculated and eventually a procedure for strength and stiffness distribution dependencies on flexibility is provided.

• 전기학회논문지
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• 제60권1호
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• pp.26-31
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• 2011

In this paper, we focused on the loop distribution system to solve the international issues of energy depletion and global warming. The conventional method of reconfiguration of distribution system was moving open points of switches from an actual switch position to another, while an appropriate switch must be opened to preserve the radial structure and this procedure is continued til there is no further loss reduction. However, the loop distribution system is the best optimization method to minimize loss than the other methods which is preserving radial structure. So we analyzed 3 types of loop distribution system upgraded from radial distribution system by changing normally open switch to normally closed switch. The simple 3 types of model system for simulation were composed, and each types of loop system were simulated in accordance with varying parameters. As a result of simulations, the loss reduction was different for each types of loop distribution system and each loop types have constraints for composing loop distribution system. The algorithms propose the method how to construct loop distribution system regarding constraints. Type I that needs least requirements get least loss reduction and Type III that needs most requirements get maximum loss reduction. On the other hand, Type I was most feasible distribution system to be realized.

• 한국정보전자통신기술학회논문지
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• 제12권4호
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• pp.327-335
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• 2019

본 연구는 5년간의 세탁기 및 화장실 용수의 실측 자료를 기반으로 표본가구의 가구 및 주택, 월 특성들을 나타내는 변수들을 조사하여 위의 두 가지 용수에 대한 수요예측모형을 개발하는 것이다. 그러나 반응변수인 세탁기 및 화장실 용수의 분포를 확인한 결과 양의 왜도, 즉, 왼쪽으로 치우친 형태로 정규분포를 따르지 않기 때문에 다중회귀모형 적용 시 추정치가 편의되는 문제가 있다. 따라서 이에 대한 대안으로 세탁기 및 화장실 용수 수요 예측모형을 와이블 및 대수정규회귀모형으로 가정하고, 3가지 모형을 적용하여 최적모형을 제시하고 이에 대한 해석을 제시하였다. 그 결과 와이블 분포를 가정한 회귀모형이 가장 적합하다고 나타났으며, 이에 대한 각 용수별 예측모형을 제시하고 해석하였다. 그 결과 두 용수 모두 공통적으로 실거주인원이 용수사용에 가장 큰 영향을 주는 인자로 나타났다. 분석결과를 토대로 세탁기 및 화장실 용수의 수요를 예측시 실거주인원에 대한 고려가 필요하다는 점을 시사하며, 예측모형을 통한 관리부서에서 장기적으로 물 수요관리에 대한 정책 수립, 수도 관련 시설 규격 및 기자재 결정 등의 기초자료로 활용 할 수 있을 것이라 판단된다. 추후 연구에서는 1인 가구 등과 같은 실태를 반영한 독립변수들을 고려한 실측연구 등이 필요할 것이다.

• 정보보호학회논문지
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• 제13권4호
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• pp.85-98
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• 2003

현재 co-processor를 탑재한 IC 칩이 계속 출시되고 있어 IC 칩의 연산 능력이 나날이 발전하고 있다. 또한, 무선 단말기 시장에는 간편하고 다양한 서비스를 제공하기 위해 IC 칩(Integrated Circuit Chip)을 내장한 무선 단말기 제품이 많이 출시되고 있다. 하지만 현재 IC 칩에 탑재된 co-processor의 연산 능력은 아직 유선 통신 환경의 연산 능력에 미치지 못하고 있어 기존 유선 통신 환경의 키 분배 프로토콜을 무선 통신 환경에 그대로 활용하기 어렵다. 따라서 본 논문에서는 무선 단말기의 제한적인 연산 능력을 고려하여 암호 전용 연산을 하는 co-processor를 무선 단말기에 탑재함으로써 연산 능력을 보완하고, 기존의 이동 통신 환경에서의 키 분배 프로토콜에서 제공하지 않는 보안 요구 사항을 만족하며, 사용자와 서버 양측에 연산 부담을 줄일 수 있는 무선 단말기 환경에 적합한 키 분배 프로토콜을 제안한다.

• 대한토목학회논문집
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• 제28권2A호
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• pp.197-205
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• 2008

본 연구에서는 광양-묘도 지역의 평균풍속을 추정하기 위하여, 일별 최대 풍속과 해당 방향에 대한 결합분포확률의 통계학적 해석에 극한값 확률분포 모델이 사용되었다. 이를 위하여, 교량 가설지점 인근의 기상관측소에 대한 일별 최대풍속 및 해당풍향의 데이터로부터 각각의 관측소에 대한 일별 최대기록의 빈도를 조사하였으며, 16방위 및 전방위에 대한 년 최대풍속의 표본을 추출하였다. 이러한 풍속기록은 Gumbel 및 Weibull 분포모델에 적용하였으며, 모멘트방법 및 최소제곱법 등을 통해 모수를 추정하였다. 또한, PPCC 검사를 통해 분포모델 및 모수의 적합 여부를 검사하였다. 적합 여부가 판단된 모수로부터, 해당 관측소별로 데이터의 표본 크기 및 교량 가설지점으로부터의 거리에 대한 요소를 고려하여 16방위 및 전방위에 대한 년 최대풍속을 추정하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.492_493
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• 2009

In this paper, we analyzed relation between weather distribution and output of PV module. Equivalent circuit of PV module was derived. Output of PV array was calculated considering temperature and insolation as input. Output of PV array installed on the roof top was also measured. Then, comparison between results was carried out to verify that relation between input and output is appropriate. Distribution of insolation and temperature was derived from KMA (Korea Meteorological Administration). Distribution of PV output was deduced, by considering weather distribution. The result of this paper can be used in economic analysis and reliability calculation.