• 대한교통학회지
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• 제11권1호
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• pp.67-86
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• 1993

A formulation of dynamic traffic assignment between multiple origins and single destination was first introduced in 1987 by Merchant and Nemhauser, and then expanded for multiple destination in the late 1980's (Carey, 1987). Based on behavioral choice theory which provides proper demand elasticities with respect to changes in policy variables, traffic phenomena can be analysed more realistically, especially in peak periods. However, algorithms for these models are not well developed so far(working with only small toy network) and solutions of these models are not unique. In this paper, a new model is developed which keeps the simplicity of static models, but provides the sensitivity of dynamic models with changes of O-D flows over time. It can be viewed as a joint departure time and route choice model, in the given time periods(6-7, 7-8, 8-9 and 9-10 am). Standard multinomial logit model has been used for simulating the choice behavior of destination, mode, route and departure time within a framework of the incremental network assignment model. The model developed is workable in a PC 386 with 175 traffic zones and 3581 links of Seoul and tested for evaluating the exclusive use of Namsan tunnel for HOV and the left-turn prohibition. Model's performance results and their statistical significance are also presented.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2003년도 봄 학술발표회 논문집
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• pp.313-320
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• 2003

The efficient and well organized database is essential for the management of information in every industrial field. In this study, a practical and effective database which can handle 3-D information of steel bridges is built on the basis of a STEP-based data model. The data model of steel bridge information is classified into geometric and non-geometric part and the design information is represented by linking geometric information and life cycle supported non-geometric information. Especially, the shape information is represented by boundary representation method, which is one of the representative methods of solid model information. In this study, ISO/STEP(STandard for the Exchange of product model data) AP203(configuration controlled design) EXPRESS schema is used to represent the shape information of steel bridge. The syntax of EXPRESS schema of developed data model is verified by NIST Expresso - is a tool for parsing and compiling EXPRESS schema. Also, this study verifies the conformance of the data model by applying to the real data of Hannam bridge. Therefore, the constructed database using STEP-based data model of steel bridges can be used effectively in the concurrent engineering point of view with transferring and sharing steel bridge information.

• Geomechanics and Engineering
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• 제30권6호
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• pp.551-564
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• 2022

Fragmenting the rock mass is considered as the most important work in open-pit mines. Ground vibration is the most hazardous issue of blasting which can cause critical damage to the surrounding structures. This paper focuses on developing an explicit model to predict the ground vibration through an multi objective evolutionary polynomial regression (MOGA-EPR). To this end, a database including 79 sets of data related to a quarry site in Malaysia were used. In addition, a gene expression programming (GEP) model and several empirical equations were employed to predict ground vibration, and their performances were then compared with the MOGA-EPR model using the mean absolute error (MAE), root mean square error (RMSE), mean (𝜇), standard deviation of the mean (𝜎), coefficient of determination (R²) and a20-index. Comparing the results, it was found that the MOGA-EPR model predicted the ground vibration more precisely than the GEP model and the empirical equations, where the MOGA-EPR scored lower MAE and RMSE, 𝜇 and 𝜎 closer to the optimum value, and higher R² and a20-index. Accordingly, the proposed MOGA-EPR model can be introduced as a useful method to predict ground vibration and has the capacity to be generalized to predict other blasting effects.

• 한국과학교육학회지
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• 제36권1호
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• pp.29-43
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• 2016

미국과 유럽의 여러 국가에서 과학의 학문 내 핵심 개념을 중심으로 과학 교육과정을 재구성하려는 노력이 시도되고 있으며 그 중 대표적인 변화가 학습발달과정을 이용한 교육과정을 설계하는 것이다. 학습발달과정은 과학의 핵심 개념과 과학적 활동과정을 논리적이며 단계적으로 정교하게 기술한 틀로서 학생이 학습하는 동안 연속적이며 체계적으로 확립되어 가는 이해의 과정을 설명한다. 미국의 차세대과학기준(NGSS)에서 제시한 생명과학 핵심 개념 중 하나인 생태계에 관하여 학습발달과정을 개발하고 개발된 학습발달과정을 평가하고자 하였다. 이를 위해 학습발달과정에 대한 문헌 연구를 통해 개발 절차를 Development, Assessment, Analysis, Amendment의 네 단계로 설정하고 순차적이며 반복적인 과정을 통해 생태계에 관한 학습발달과정을 개발하였다. 그리고 개발된 학습발달과정의 분석 결과 학습 발달과정에 기반을 둔 평가는 학생의 능력을 파악하는데 신뢰할 수 있는 정보를 제공한다는 결론을 도출하였다. 이를 통해 학습발달과정의 개발 과정에 효과적인 방법으로 핵심 성취기준을 이용한 Framework의 개발, OMC 문항 형식과 Rasch 모델을 이용한 평가와 분석 과정을 제안한다. 또한 경험적으로 검증된 학습발달과정을 이용하여 교육 내용, 교육 방법, 교육 평가가 연계된 교육과정 강화 방안을 제안한다. 국내 학습발달과정에 대한 연구가 부족한 시점에 이 연구를 통해 제안된 학습발달과정 개발 절차를 활용하여 학습발달과정의 개발에 수월성을 제공하고, 개발된 학습발달과정의 적용으로 교육과정의 표준과 방향을 제시할 수 있을 것이다.

• 한국디지털정책학회:학술대회논문집
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• 한국디지털정책학회 2004년도 International Conference on Digital Policy & Management
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• pp.343-358
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• 2004

Many IT specialists say that ERP (Enterprise Resource Planning) is the best way to manage resources in enterprise effectively. Actually lots of companies are using ERP solutions in the hope of getting competitiveness and employing global standard business practice. Wishing to take advantage of ERP S/W, companies have a preference for purchasing it and outsourcing ERP project. This paper is focusing on ERP Package assessment model in business firms. This paper finds out what differences there are in purchasing ERP S/W for organization characteristics and building characteristics, and suggests some guidelines of S/W development to venders. The results would be strong implications for ERP vendors. Especially this paper identify what the reasons and the checkpoints are when firms introduce ERP S/W. To do this, this paper used empirical data obtained from companies in South Korea and analyzed it using statistical software.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 1998년도 유체기계 연구개발 발표회 논문집
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• pp.27-32
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• 1998

This paper presents the development of a two-dimensional model for investigating the fluid flow in water jet and calculating the velocity and pressure distributions. The mathematical formulation as a standard k-$\epsilon$ model was solved employing a general thermofluid-mechanics computer program, PHOENICS code, which is based on the Semi-Implicit Method Pressure Linked Equations(SIMPLE) algorithm. The developed code was applied to water jet design to determine the nozzle size, and investigated the effect of the change of nozzle location. Calculated results showed that the flow pattern is not changed as the change of nozzle location.

• 디지털융복합연구
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• 제2권2호
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• pp.101-118
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• 2004

Many IT specialists say that ERP (Enterprise Resource Planning) is the best way to manage resources in enterprise effectively Lots of companies are using ERP solutions in the hope of getting competitiveness and employing global standard business practice. Wishing to take advantage of ERP S/W, companies have a preference for purchasing it and outsourcing ERP project. This paper focuses on ERP Package assessment model in business firms. This paper finds out what differences there are in purchasing ERP S/W for organization characteristics and building characteristics, and suggests some guidelines of S/W development to vendors. The results would be strong implications for ERP vendors. Especially this paper identifies what the reasons and the checkpoints are when firms introduce ERP S/W. To do this, this paper uses empirical data obtained from companies in South Korea and analyzes it using statistical software.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 추계학술대회 논문집
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• pp.567-573
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• 2008

Life cycle costing is one of the most effective approaches for the cost analysis of long-term life products, like as railroad vehicle. Life cycle costing includes the cost of concept design, development, manufacture, operating, maintenance and disposal. Especially, life cycle costing in the railroad industry has been focused on the maintenance cost. In this paper, we investigated the standard, guide and maintenance information of railroad vehicle. For this purpose, we suggested the cost model of railroad vehicle maintenance information. We also performed maintenance cost analysis on the some sub-system of railroad vehicle for the case study.

• 한국산업융합학회 논문집
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• 제26권5호
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• pp.733-741
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• 2023

The purpose his study was a descriptive research study to identify the influencing factors of mentoring for nursing students, and was conducted with 120 nursing students. The collected data were subjected to real number and percentage, mean and standard deviation, t-test, ANOVA, Scheffe test, Pearson's correlation, and multiple regression analysis using SPSS/WIN 25.0. As a result of the study, mentoring was found to have a significant positive correlation with organizational socialization, core nursing competency, and clinical performance competency, and the explanatory power of the regression model was 64.1%. Since mentoring is an effective teaching method, based on this study, we propose a study to develop a structured mentoring program including organizational socialization, core nursing competency, and clinical performance competency to test the effectiveness. In addition, proposes a study to identify the relationship with various variables by dividing mentoring into sub-competencies of career development function, psychological stability function, and role model function.

• 한국시뮬레이션학회논문지
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• 제28권2호
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• pp.169-177
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• 2019

전장상황의 변화와 첨단정보통신기술의 발전에 따라 과학화된 훈련체계인 LVC 훈련체계가 주목을 받고 있다. 대한민국 공군은 전투기 시뮬레이터를 중심으로 공중전투기동장비(ACMI), 워게임모델을 가상의 합성전장환경에 구현하여 실전적이고 과학적인 훈련이 가능한 LVC 훈련체계를 구축하고자 한다. 본 논문에서는 공군의 Virtual 체계인 전투기 시뮬레이터와 Constructive 체계인 전구급 연습용 모델의 V-C 연동시험 수행결과에 대해 다루고자 한다. 기종별로 각각 상이한 연동방식을 갖춘 F-15K, KF-16, FA-50 전투기 시뮬레이터를 표준 연동방식으로 변환하였으며, 합성 전장환경 모의 도구를 활용하여 3개 기종의 전투기 시뮬레이터가 상호 연동이 가능한 환경을 구축하였다. 그리고 공군의 연습용 모델인 창공모델도 표준 연동방식으로 변환하였으며, 연동 최적화를 위해 SW 일부를 수정하였다. 이를 통해 공군의 전투기 시뮬레이터와 워게임 모델이 연동이 가능함을 확인할 수 있었다. 본 연구결과는 향후 공군 LVC 훈련체계 개념연구 및 체계개발 간에 유의미하게 참조할 만한 근거가 될 것임을 기대한다.