• 정보학연구
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• 제5권1호
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• pp.29-37
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• 2002

분산 프로그래밍은 분산된 통신에 대한 언어 지원에 의해서 크게 단순화될 수 있다. 많은 웹 브라우저는 현재 분산 객체의 많은 형태를 제공하고 있으며 분산 객체의 형태와 개수는 계속 흥미롭고 혁신적인 방법으로 바뀌고 있다. 분산 객체 모델의 전형적인 모델인, CORBA IDL과 Java RMI는 분산처리 환경에 대하여 서로 다른 접근 방법을 제공하고 있다. CORBA의 접근방법은 Java RMI에 의해 생성된 어플리케이션을 제공하지 않지만 다중 프로그래밍 언어를 지원한다. RMI와 CORBA사이의 객체 번역 시스템은 두개의 다른 분산 프로그래밍 환경에서 분산 객체의 정보처리 상호운용을 고려하여 디자인되어 구현되었다. 이 제안된 시스템은 분산 객체에서의 중요한 속성인 바인딩, 상속성, 다형성, 객체 패싱과 콜백을 고려하였다. 우리가 제안한 번역 시스템은 Windows/NT(version4.0)와 Java Development Kit(version 1.1.6)을 사용하여 구현되었다.

• 한국물환경학회지
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• 제36권3호
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• pp.229-244
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• 2020

Hydrologic models, as a useful tool for understanding the hydrologic phenomena in the watershed, have become more complex with the increase of computer performance. The hydrologic model, with complex configurations and powerful performance, facilitates a broader understanding of the effects of climate and soil in hydrologic partitioning. However, the more complex the model is, the more effort and time is required to drive the model, and the more parameters it uses, the less accessible to the user and less applicable to the ungauged watershed. Rather, a parsimonious hydrologic model may be effective in hydrologic modeling of the ungauged watershed. Thus, a semi-distributed hydrologic partitioning model was developed with minimal composition and number of parameters to improve applicability. In this study, the validity and performance of the proposed model were confirmed by applying it to the Namgang Dam, Andong Dam, Hapcheon Dam, and Milyang Dam watersheds among the Nakdong River watersheds. From the results of the application, it was confirmed that despite the simple model structure, the hydrologic partitioning process of the watershed can be modeled relatively well through three vertical layers comprising the surface layer, the soil layer, and the aquifer. Additionally, discussions were conducted on antecedent soil moisture conditions widely applied to stormwater estimation using the soil moisture data simulated by the proposed model.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2005년도 학술발표회 논문집
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• pp.220-224
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• 2005

칼만필터 알고리즘을 분포형 유출모형에 적용하였다. 관측 유량과 상태변수인 유역내 저류량을 갱신하고자 Q-S curve를 도입하였고, 갱신된 저류량과 모형에 의해 모의된 저류량의 비율을 유역 내 각 지점의 수위에 적용하므로써 분포화 된 상태변수를 효율적으로 갱신하였다. 갱신된 상태변수와 상태변수 오차의 시간갱신은 몬테 카를로 시뮬레이션을 이용하여 모의하였다.

• 연구논문집
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• 통권32호
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• pp.111-120
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• 2002

In this paper, the design of a decatizing cylinder with uniformly distributed pressure in a decatizing system is investigated by using the Finite Element Method. Particularly, since deflection of a cylinder will not perform to iron the fabrics, the cylinder design insuring uniform pressure is very important. In this paper proposed two improved cylinder model obtained by changing the support type of the bean and the support location. And perform optimization with two improved cylinder model.

• Journal of the Korean Statistical Society
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• 제20권1호
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• pp.85-92
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• 1991

A set of conditions ensuring local asymptotic normality for independent but not necessarily identically distributed observations in semiparametric models is presented here. The conditions are turned out to be more direct and easier to verify than those of Oosterhoff and van Zwet(1979) in semiparametric models. Examples considered include the simple linear regression model and Cox's proportional hazards model without censoring where the covariates are not random.

• Structural Engineering and Mechanics
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• 제75권3호
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• pp.327-337
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• 2020

The stability and dynamic performance of a flapper-nozzle servo valve depend on several factors, such as the motion of the armature component and the deformation of the spring tube. As the only connection between the armature component and the fixed end, the spring tube plays a decisive role in the dynamic response of the entire system. Aiming at predicting the vibration characteristics of the servo valves to combine them with the control algorithm, an innovative dynamic stiffness based on a distributed parameter model (DPM) is proposed that can reflect the dynamic deformation of the spring tube and a suitable discrete method is applied according to the working condition of the spring tube. With the motion equation derived by DPM, which includes the impact of inertia, damping, and stiffness force, the mathematical model of the spring tube dynamic stiffness is established. Subsequently, a suitable program for this model is confirmed that guarantees the simulation accuracy while controlling the time consumption. Ultimately, the transient response of the spring tube is also evaluated by a finite element method (FEM). The agreement between the simulation results of the two methods shows that dynamic stiffness based on DPM is suitable for predicting the transient response of the spring tube.

• Journal of Electrical Engineering and Technology
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• 제10권6호
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• pp.2211-2220
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• 2015

This paper analyzes multiple active management (AM) techniques of active distribution network (ADN), and proposes an optimal coordination model of intermittent distributed generation (IDG) accommodation considering the timing characteristic of load and IDG. The objective of the model is to maximize the daily amount of IDG accommodation under the uncertainties of IDG and load. Various active management techniques such as IDG curtailment, on-load tap changer (OLTC) tap adjusting, voltage regulator (VR) tap adjusting, shunt capacitors compensation and so on are fully considered. Genetic algorithm and Primal-Dual Interior Point Method (PDIPM) is used for the model solving. Point estimate method is used to simulate the uncertainties. Different scenarios are selected for the IDG accommodation capability investigation under different active management schemes. Finally a modified IEEE 123 case is used to testify the proposed accommodation model, the results show that the active management can largely increase the IDG accommodation and penetration.

• 한국물환경학회지
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• 제25권1호
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• pp.125-135
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• 2009

Reliable long-term flows by SWAT-K model were applied to the relationship between stream flow and pollutant load derived from 8-day measured data of Ministry of Environment (MOE) in order to obtain continuous loadograph and evaluate accuracy in water quality modeling for the Chungju dam watershed. The measured flow were compared with flow duration curve from the model, and it showed that measured values corresponded to the almost full range of stream flow conditions except at Odae A. And there was significant relationship ($R^2=0.60{\sim}0.97$) between measured flow and water quality load at all unit-watersheds. Applying this relationship to simulated flows, continuous loadograph was obtained and compared with modeled pollutant loads. Although there were some differences during some dry and flood seasons, those were not significant and overall trend showed a good agreement. From the results, we would be able to derive a continuous loadograph based on measured data at total maximum daily loads (TMDLs) unit-watersheds on a national scale, in which stream flow and water quality have been measured at 8-day intervals since 2004, and this could be helpful to utilize distributed water quality models with difficulty in calibrating and validating parameters from lack of measured data at present.

• 한국컴퓨터산업학회논문지
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• 제3권8호
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• pp.1049-1062
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• 2002

네트워크 상의 분산 자원이 급증하면서 분산 자원에 대한 접근이 활성화되고 있다. 특히, 이동 에이전트 기술을 이용한 분산 자원의 접근은 고정 네트워크 상의 자원들에 대한 동적인 접근 뿐 아니라 이동 네트워크상의 사용자를 위한 이동성 지원 메커니즘을 제공한다. 프록시 기반의 이동 에이전트 모델은 동적으로 변화하는 분산 자원들에 대하여 계층적으로 도메인을 할당하고 도메인 별로 프록시 서버를 배치하여 이동 에이전트의 관리와 이동 에이전트간의 상호작용을 촉진시킬 수 있는 이동 에이전트 네트워크 모델이라고 할 수 있다. 본 논문에서는 계층적인 관리 분야에 적합한 프록시 기반의 이동 에이전트 모델의 구조 및 동작 시나리오를 소개하고 시뮬레이션을 통해서 프록시 서버의 경로 최적화 기능과 이동 에이전트의 실행 시간 단축 성능을 평가한다.

• Structural Engineering and Mechanics
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• 제69권3호
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• pp.243-255
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• 2019

Utilization of fiber beam-column element has gained considerable attention in recent years due mainly to its ability to model distributed plasticity over the length of the element through a number of integration points. However, the relatively high sensitivity of the method to modeling parameters as well as material behavior models can pose a significant challenge. Residual drift is one of the seismic demands which is highly sensitive to modeling parameters and material behavior models. Permanent deformations play a prominent role in the post-earthquake evaluation of serviceability of bridges affected by a near-fault ground shaking. In this research, the influence of distributed plasticity modeling parameters using both force-based and displacement-based fiber elements in the prediction of internal forces obtained from the nonlinear static analysis is studied. Having chosen suitable type and size of elements and number of integration points, the authors take the next step by investigating the influence of material behavioral model employed for the prediction of permanent deformations in the nonlinear dynamic analysis. The result shows that the choice of element type and size, number of integration points, modification of cyclic concrete behavior model and reloading strain of concrete significantly influence the fidelity of fiber element method for the prediction of permanent deformations.