• Title/Summary/Keyword: 시뮬레이션모형

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Developing a Quantitative Evaluation Model for Screening the Research Grant Applications (연구지원 대상자 선정을 위한 정량평가 모형개발)

  • Yoo, Jin-Man;Han, In-Soo;Oh, Keun-Yeob
    • The Journal of the Korea Contents Association
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    • v.17 no.4
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    • pp.541-549
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    • 2017
  • This research investigates the quantitative screening methods for the Grant Funding system and seeks for the efficient evaluation of a number of proposals. We search foreign cases of Grand Funding, but we found no appropriate model for using in Korea. Thus, we had to develope our own model for better screening. First, we analyse the existing evaluation system and find some problems and challenges. Second, we suggest a quantitative screening system for Grant Funding with a numeric model, and operates a tedious simulation by using the previous data and our suggested model. Third, we test the suggested model and find the optimal model by using simulation method The number of data analysed for simulation is larger than 200 thousands. Last, we suggest some brief policy implications based on the results in the paper.

Inventory Control Policies for a Hospital Blood Bank: A Simulation and Regression Approach (병원의 혈액 재고관리를 위한 평가 모형 : 시뮬레이션 및 회귀분석 방법)

  • Suh, Jeong-Dae
    • IE interfaces
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    • v.10 no.1
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    • pp.119-134
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    • 1997
  • The management of blood inventory is very important within the medical care system. The efficient management of blood supplies and demands for transfusions is of great economic and social importance to both hospitals and patients. For any blood type, there is a complex interaction among the optimal inventory level, daily demand level, daily supply level, transfusion to crossmatch ratio, crossmatch release period, issuing policy and the age of arriving units that determine the shortage and outdate rate. In this paper, we develop an efficient decision rule for blood inventory management in a hospital blood bank which can support efficient hospital blood inventory management using simulation. The primary use of the efficient decision rule will be to establish minimum cost function which consists of inventory levels, period in inventory, outdate and shortage rate for whole blood and various component inventories for a hospital blood bank or a transfusion service. If the administrator compute the mean daily demand for each blood type, the mean daily supply for each blood type, the length of the crossmatch release period and the average transfusion to crossmatch ratio, then it is possible to apply the efficient decision rule to compute the optimal inventory level, inventory period, outdate and shortage rate. This rule can also be used as a decision support system that allows the blood bank administrator to do sensitivity analysis related to controllable blood inventory parameters.

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Evaluation of university funding research program via social network analysis (사회 네트워크 분석을 이용한 대학 자체학술지원 프로그램 성과 평가)

  • Choi, Seung-Il
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.11 no.8
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    • pp.2882-2887
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    • 2010
  • This research develops an evaluation framework of social network analysis, overlooked in traditional program evaluation, and applies to university funding research program. By setting degree increase, an indicator of level of research collaboration, as a goal from the viewpoint of network, we can conclude that researchers funded by university in a form of competition show statistically significant changes in degree increase via one-way ANOVA and permutation-based simulation. This research provides a tool for measuring and managing the degree of contribution of university funding to promoting research collaboration.

Stabilized Multi-Channel Adoptive IIR Filters for Active Mufflers (능동머플러를 위한 안정한 다중채널 적응 IIR 필터)

  • Nam, Hyun-Do;Suh, Sung-Dae;Bang, Kyung-Uk
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.20 no.5
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    • pp.99-106
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    • 2006
  • In this paper, implementation of active mufflers using multiple channel adaptive IIR filter is presented. Usually, recursive LMS(RLMS) algorithms for adaptive IIR filters are highly efficient than filtered-X LMS(FXLMS) algorithms, when the order of both algorithms are the same. However, RLMS algorithms usually diverge before the algorithms arenot yet converged. So, the prefilters are presented to improve the stability by pulling the poles of feedback control transfer function in the beginning of active noise control and returning the original poles after the filters converge. The engine noises of diesel engine automobiles and gasoline engine automobiles are analyzed and the mathematical model of an active muffler is derived. Computer simulations and experiments are performed to show the effectiveness of the proposed systems.

Air-conditioner cycle simulation using tube-by-tube method (관순법을 이용한 공조기 사이클 시뮬레이션)

  • Yoon, Baek;Park, Hyun-Yeon;Yoo, Guk-Chul;Kim, Yong-Chan
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.11 no.4
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    • pp.499-510
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    • 1999
  • A computer program was developed for simulating performance(capacity, power consumption and etc.) of air-conditioners using compressor, fin-tube heat exchanger and capillary tube. The program consists of five modules, condenser, evaporator, compressor, capillary tube simulation modules and properties modules of refrigerant and moist air, The present program is focused on R22 only, however can be easily extended for other refrigerants such as R407C and R410A just by adding property modules. The compressor simulation module utilizes performance maps supplied by manufacturers-map-based model. The condenser and evaporator simulation modules are modeled using tube-by-tube method. Simulation results(capacity and power consumption) were compared with calorimeter test results of actual air-conditioners of window and split types, where more than 82% of the data lied within ${\pm}5$% of the predicted results.

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A Study on the Identification Method for Flutter Derivatives of Bridge Girders using Displacement Time History Data (변위 시계열 데이터를 이용한 교량거더의 Flutter 계수 추정기법에 관한 연구)

  • Lee, Jae Hyung;Min, Won;Lee, Yong Jae
    • Journal of Korean Society of Steel Construction
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    • v.13 no.5
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    • pp.525-533
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    • 2001
  • The wind resistant design of long-span bridges has urged a special attention to the prevention of the flutter occurrence Therefore calculation of flutter derivatives is indispensable to this prediction. A used system identification method must identify all the flutter derivatives from noisy experimental data In this paper MITD(Modified Ibrahim Tim Domain) method and AKF (Adaptive Kalman Filter) method are applied to extract flutter derivatives from section-model tests. The robustness and reliability of proposal SI methods under a high signal-to-noise ratio is demonstrated through numerical simulation for windtunnel test.

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Mathematical Model Simulations Assessing the Effects of Temperature on Residual Chlorine Concentrations in Water Storage Tanks (온도 변화에 따른 수돗물 저장 저수조 내 잔류염소에 관한 수학적 모형 시뮬레이션)

  • Noh, Yoorae;Park, Joonhong
    • Journal of Korean Society on Water Environment
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    • v.33 no.2
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    • pp.187-196
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    • 2017
  • To ensure hygienic safety of drinking water in a water storage tank, the concentrations of residual chlorine should be above a certain regulation level. In this study, we conducted model simulations to investigate the effects of temperature on residual chlorine in water storage tank conditions typically used in Seoul. For this, values of model parameters (decomposition rate constant, sorption coefficient, and evaporation mass transfer coefficient) were experimentally determined from laboratory experiments. The model simulations under continuous flow conditions showed that the residual chlorine concentrations were satisfied the water quality standard level (0.1 mg/L) at all the temperature conditions ($5^{\circ}C$, $10^{\circ}C$, $15^{\circ}C$, $20^{\circ}C$ and $25^{\circ}C$). Meanwhile, when the tanks had a no flow condition (i.e., no tap-water influent due to a sudden shut-down), the concentrations became lower than the regulatory level after certain periods. The findings from this modeling works simulating Seoul's water storage tanks suggested disappearance rate of residual chlorine could be reduced through the tanks design optimization with maintenance of low water temperature, minimization of air flow and volume, suppression of dispersion and the use of wall materials with low sorption ability.

Dynamic Characteristic Analysis of 3-Level Half-bridge SSSC (3-레벨 반브리지로 구성된 SSSC의 동특성 분석)

  • 박상호;하요철;백승택;김희중;한병문
    • The Transactions of the Korean Institute of Power Electronics
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    • v.6 no.4
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    • pp.317-324
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    • 2001
  • This paper proposes a SSSC based on 3-level half-bridge inverters. The dynamic characteristic of the proposed SSSC was analyzed by EMTP simulation and a scaled hardware model, assuming that the SSSC is inserted in the transmission line of the one-machine-infinite-but power system. The proposed SSC has six 3-level half-bridge inverters per phase, which operates in PWM mode. The proposed SSSC generates a quasi-sinusoidal output voltage by 90 degree phase shift to the line current. The proposed SSSC does not require the coupling transformer for voltage injection, and has a flexibility in operation voltage by increasing the number of series connection.

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A study on the spatial neighborhood in spatial regression analysis (공간이웃정보를 고려한 공간회귀분석)

  • Kim, Sujung
    • Journal of the Korean Data and Information Science Society
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    • v.28 no.3
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    • pp.505-513
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    • 2017
  • Recently, numerous small area estimation studies have been conducted to obtain more detailed and accurate estimation results. Most of these studies have employed spatial regression models, which require a clear definition of spatial neighborhoods. In this study, we introduce the Delaunay triangulation as a method to define spatial neighborhood, and compare this method with the k-nearest neighbor method. A simulation was conducted to determine which of the two methods is more efficient in defining spatial neighborhood, and we demonstrate the performance of the proposed method using a land price data.

Development & Application of Generator Control System Models of EUROSTAG for Stability Study of Power Systems (전력계통의 안정도 해석용 발전기제어계의 EUROSTAG 모형 개발 및 적용)

  • 김학만;오태규
    • Journal of Energy Engineering
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    • v.12 no.2
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    • pp.109-117
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    • 2003
  • Because of the difficulty of acquiring new generation sites and right-of-way, additional units have been added to the existing generation sites and the transmission system has been developed into highly meshed configuration. This structural characteristics may cause restriction on the reliable operation of power systems. In other to meet with this problem, the enhancement of system analysis techniques and establishment of appropriate measures have been required in this situation. In addition the deregulation of electric power industry in Korea would require better tools for power system analysis and control. In this paper, exciter system models, speed governor system models and PSS models of EUROSTAG for stability study are developed. Comparison with simulation results of PSS/E is performed for verification of EUROSTAG models.