• 한국병원경영학회지
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• 제13권3호
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• pp.69-93
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• 2008

Rising healthcare cost is a global phenomenon that justifies governments' introduction of 'incentive regulation' plan for the improvement of hospital efficiency. A number of previous studies tried to evaluate the efficiency of healthcare organization by using Data Envelopment Analysis(DEA), a common efficiency benchmarking method. However, there is a concern that this kind of efficiency evaluation could induce "quantity-quality trade-off". Moreover, as quality aspect is especially important in terms of 'effectiveness' of health care, it should be considered in efficiency evaluation of healthcare organization. A number of different models were tried so far to incorporate quality aspect into DEA, however, none is universally recognized as a standard. Thus, in this study, previous quality-incorporating DEA models were categorized into 6 types according to the way of incorporating quality aspect, and strengths and limitations of each type were reviewed with a set of artificial data as an example. Based on this review, a new quality-incorporating efficiency evaluation model, named Quality-adjusted output DEA(QAO-DEA), was suggested. As an exploratory empirical analysis, technical efficiency of human resource were measured with different quality-incorporating DEA models, using 2004 data from National University Hospitals. In conclusion, Quality-adjusted output DEA(QAO-DEA) model seems to be one of the most desirable alternatives to incorporate quality aspect in efficiency evaluation of hospital, and deserves the consideration as a policy tool to induce simultaneous improvement of both efficiency and quality.

• Ocean and Polar Research
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• 제37권4호
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• pp.265-278
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• 2015

We analyzed the North Pacific Intermediate Water (NPIW) that was simulated in 25 coupled general circulation models (CGCMs) using historical and Representative Concentration Pathway 4.5 (RCP4.5) scenario experiments of Coupled Model Intercomparison Project Phase 5 (CMIP5), focusing on the evaluation of the performance of HadGEM2-AO. A large inter-model diversity in salinity, density, and depth of the NPIW exists even though the multi-model ensemble mean (MME) is comparable to observations. It was found that the depth of the NPIW tends to be deeper in the models in which the NPIW is relatively saltier. HadGEM2-AO simulates the lightest NPIW having the lowest salinity at shallower depth, compared with other CGCMs. Future projections of the NPIW show that the temperature of the NPIW increases, but the density decreases in all CMIP5 models. It was shown that the salinity of the NPIW decreases in most models and the decrease tends to be larger in models simulating the lighter NPIW. The HadGEM2-AO projects moderate changes in the temperature and density of the NPIW out of the CMIP5 models.

• International Journal of Computer Science & Network Security
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• 제21권12호
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• pp.157-164
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• 2021

The aim of this study is to provide empirical evaluation of the accuracy of data-model fit using growing levels of invariance models. Overall model accuracy of factor solutions was evaluated by the examination of the order for testing three levels of measurement invariance (MIV) starting with configural invariance (model 0). Model testing was evaluated by the Chi-square difference test (∆𝛘²) between two groups, and root mean square error of approximation (RMSEA), comparative fit index (CFI), and Tucker-Lewis index (TLI) were used to evaluate the all-model fits. Factorial invariance result revealed that stability of the models was varying over increasing levels of measurement as a function of variable-to-factor ratio (VTF), subject-to-variable ratio (STV), and their interactions. There were invariant factor loadings and invariant intercepts among the groups indicating that measurement invariance was achieved. For VTF ratio (3:1, 6:1, and 9:1), the models started to show accuracy over levels of measurement when STV ratio was 6:1. Yet, the frequency of stability models over 1000 replications increased (from 69% to 89%) as STV ratio increased. The models showed more accuracy at or above 39:1 STV.

• Journal of Korea Artificial Intelligence Association
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• 제1권1호
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• pp.11-16
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• 2023

Accurate hospital case modeling and prediction are crucial for efficient healthcare. In this study, we demonstrate the implementation of regression analysis methods in machine learning systems utilizing mathematical statics and machine learning techniques. The developed machine learning model includes Bayesian linear, artificial neural network, decision tree, decision forest, and linear regression analysis models. Through the application of these algorithms, corresponding regression models were constructed and analyzed. The results suggest the potential of leveraging machine learning systems for medical research. The experiment aimed to create an Azure Machine Learning Studio tool for the speedy evaluation of multiple regression models. The tool faciliates the comparision of 5 types of regression models in a unified experiment and presents assessment results with performance metrics. Evaluation of regression machine learning models highlighted the advantages of boosted decision tree regression, and decision forest regression in hospital case prediction. These findings could lay the groundwork for the deliberate development of new directions in medical data processing and decision making. Furthermore, potential avenues for future research may include exploring methods such as clustering, classification, and anomaly detection in healthcare systems.

• 한국도서관정보학회지
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• 제40권2호
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• pp.243-265
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• 2009

본 연구에서는 디지털도서관의 서비스 품질 평가에 관한 최근 문헌을 전반적으로 고찰함으로써 서비스 품질 평가에 관한 연구동향 및 시사점을 도출하고자 하였다. 구체적으로 디지털도서관의 e-서비스 품질 평가 관련 국내 외 최신 연구동향을 전반적으로 살펴보고, 국내 선행연구 문헌을 대상으로 비판적 비교 분석을 시도하였다. 비교 분석의 관점은 서비스 품질 평가모형과 측정방법을 중심으로 이루어졌으며 이를 통해 국내 실정에 적합한 표준화된 디지털도서관의 서비스 품질 평가모형 개발의 필요성과 개발 지침의 수립이라는 두 가지 시사점을 도출하였다.

• Earthquakes and Structures
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• 제10권5호
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• pp.1089-1109
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• 2016

Modified two-surface model (M2SM) is one of the steel elasto-plastic hysteretic constitutive models that consider both analysis accuracy and efficiency. However, when M2SM is used for complex strain history, sometimes the results are irrational due to the limitation of stress-strain path judgment. In this paper, the defect of M2SM was re-modified by improving the judgment of stress-strain paths. The accuracy and applicability of the improved method were verified on both material and structural level. Based on this improvement, the nonlinear time-history analysis was carried out for a deck-through steel arch bridge with a 200 m-long span under the ground motions of Chi-Chi earthquake and Niigata earthquake. In the analysis, we compared the results obtained by hysteretic constitutive models of improved two-surface model (I2SM) presented in this paper, M2SM and the bilinear kinematic hardening model (BKHM). Results show that, although the analysis precision of displacement response of different steel hysteretic models differs little from each other, the stress-strain responses of the structure are affected by steel hysteretic models apparently. The difference between the stress-strain responses obtained by I2SM and M2SM cannot be neglected. In significantly damaged areas, BKHM gives smaller stress result and obviously different strain response compared with I2SM and M2SM, and tends to overestimate the effect of hysteretic energy dissipation. Moreover, at some position with severe damage, BKHM may underestimate the size of seismic damaged areas. Different steel hysteretic models also have influences on structural damage evaluation results based on deformation behavior and low cycle fatigue, and may lead to completely different judgment of failure, especially in severely damaged areas.

• 한국시뮬레이션학회논문지
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• 제2권1호
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• pp.31-44
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• 1993

Zeigler's DEVS(Discrete Event Systems Specification) formalism supports formal specification of discrete event systems in a hierarchical , modular manner. Associated are hierarchical, distributed simulation algorithms, called abstract simulators, which interpret dynamics of DEVS models. This paper deals with performance evaluation of P-DEVSIM ++, a parallel simulation environment which implements the DEVS formalism and associated simulation algorithms in a parallel environment. Performance simulator has been developed and used to experiment models of parallel simulation executions in different conditions. The experimental result shows that simulation time depends on both the number of processors in the parallel system and the communication overheads among such processors.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2005년도 봄학술 발표회 논문집(I)
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• pp.407-410
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• 2005

This paper describes an evaluation of reinforcement tension in RC beams using the variable truss models. The models were examined with the beam test results by Kim, Kim and White. Consequently, a fixed inclination $\theta$ at the support un-explains global state of internal force flow in cracked reinforced concrete beams subjected to shear and bending. Accordingly, we must introduce the arch factor for development of consistent model in reinforced concrete beams subjected to shear and bending

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 하계종합학술대회 논문집(1)
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• pp.105-108
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• 2002

This paper analytical models of a centralized approach based on SNMP Protocol, distributed approach based on mobile agent, and mixed model which is tile existing mobile agent model in order to overcome large communication numbers of SNMP and accumulated data of mobile agent. And then, we compare and analyze these analytical models. Performance evaluation results show that performance of mobile agent and the mixed model is less sensitive to the network traffic and more profitable for complex network environment than that of SNMP.

• 정보보호학회논문지
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• 제19권3호
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• pp.95-105
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• 2009

본 논문은 VoIP의 주요 보안 위협인 스팸에 대응하기 위한 목적으로 VoIP 스팸 탐지 기술의 성능평가를 위한 시뮬레이션 모델을 설계하고 있다. 성능평가 시뮬레이션 모델은 입력 데이터를 제공하는 기능과 출력 데이터를 분석하는 기능을 갖는다. 본 논문에서는 VoIP스팸 탐지 기술의 성능평가 입력 데이터를 위하여 VoIP 발신자 특성을 고려하여 네 종류의 Caller 모델을 개발하였고, 각 caller 모델은 결정된 패턴 내에서 call을 생성하게 된다. 성능평가는 SPIT (Spam over Internet Telephony) Level 결정 알고리즘을 대상으로 수행하고, 성능평가의 지표 도출을 통해 평가 알고리즘의 성능 지수를 산정한다. 성능평가 모델은 DEVS 형식론 기반으로 설계하였으며 DEVSJAVA$^{TM}$를 이용한 모델링 및 시뮬레이션을 통해 설계된 모델을 검증하였다.