• Proceedings of the Korea Society for Industrial Systems Conference
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• 1998.10a
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• pp.563-568
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• 1998

응용시스템 개발생산성에 대한 연구는 지금까지 프로그래머의 생산성이라는 미시적 수준에 그치는 경향을 보여왔으며 시스템개발 생명주기의 전반적 영향에 중점을 둔 거시적수준의 생산성의 개념으로 확대되지 못해왔다. 더욱이 그들의 생산성 측정은 미시적 측정단위를 사용함으로써 조직 내 응용시스템 개발요구의 백로그의 증가라는 거시적 문제 해결과는 거리가 있어왔다. 본 연구는 정보시스템 조직의 생산성 향상에 기여할 수 있는 도구 및 방법이 실무적으로 어떻게 사용되고 있고 그 효과가 어느 정도인지를 관찰하는 탐색적 연구로써 응용 시스템 개발 생산성에 기술적 방법과 관리적 방법을 거시적 생산성 향상의 관점에서 분석하고자 한다.

• Journal of the Society of Disaster Information
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• v.17 no.3
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• pp.655-666
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• 2021

Purpose: This study is to develop a method for measuring dynamic speeding risks using vehicle trajectory big data and to demonstrate the feasibility of the devised speeding index. Method: The speed behaviors of vehicles were analysed in microscopic space and time using individual vehicle trajectories, and then the boundary condition of speeding (i.e., boundary speed) was determined from the standpoint of crash risk. A novel index for measuring the risk exposure of speeding was developed in microscopic space and time with the boundary speed. Result: A validation study was conducted with vehicle-GPS trajectory big data and ground-truth vehicle crash data. As a result of the analysis, it turned out that the index of speeding-risk exposure has a strong explanatory power (R²=0.7) for motorway traffic accidents. This directly indicates that speeding behaviors should be analysed at a microscopic spatiotemporal dimension. Conclusion: The spatial and temporal evolution of vehicle velocity is very variable. It is, hence, expected that the method presented in this study could be efficaciously employed to analyse the causal factors of traffic accidents and the crash risk exposure in microscopic space using mobility trajectory data.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2019.11a
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• pp.5-6
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• 2019

최근 보행자 행태를 반영한 미시적 시뮬레이션 분석이 가능하게 되었다. 차량 분석과 유사하게 보행자 행태 중 가장 빈번히 사용되는 것은 보행속도로 이는 횡단보도 보행자 녹색시간 산정과도 매우 밀접한 관계가 있다. 또한 보도의 밀도를 산정함에 있어서 보행자 속도는 중요한 역할을 담당한다. 이에 본 논문에서는 횡단보도의 보행자 속도를 실측하고, 이를 기반으로 미시적 시뮬레이션인 VISSIM의 주요 파라메타인 보행속도를 이용하여 역삼역 일대의 보행실태를 점검해 보았다. 분석에 사용된 보행속도 실측자료는 서울시 16개 횡단보도에서 조사되었으며, 연령별로 일반인(64세 이하)과 노인(65세 이상)을 구분하여 분석하였다.

• The Korean Journal of Applied Statistics
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• v.29 no.2
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• pp.389-398
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• 2016

In this paper, we examine the financial performance of credit guarantee programs. We compared financial performance of guaranteed firms of KODIT and non-guaranteed firms. The of covariate adjusted propensity score method is used because a selection bias problem could occur if t-test or regression analysis were used. The results show that a credit guarantee program enhances the financial performance of beneficiary firms.

• Journal of the Korean Society of Hazard Mitigation
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• v.8 no.1
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• pp.31-37
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• 2008

Traffic flow which is prescribed under previous traffic effect/access act is analyzed by traffic volume, V/C, mean speed on road and LOS on the intersection. These indexes based on analytical method can not consider stochastic characteristics of traffic flow. Moreover it is hard to analyze traffic flow visually in whole traffic effect area because only individual road and intersections are targeted. In this study, it is devised to show traffic flow analysis method within traffic effect area visually applying microscopic-simulation by car-following theory, and then based on this, effect analyze ways are studied according to space range plan, improvement measure establishment and etc. To execute this study, effect area is set up using V/C, and the change of traffic current around development area is analyzed using microscopic-simulation program.

• Journal of Korean Society of Transportation
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• v.16 no.2
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• pp.53-65
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• 1998

합류구간에 설치된 차량검지기에서 수집된 조사자료들을 이용하여 본 연구는 교통와해 발생원인과 용량감소 문제를 분석하였다. 본 연구에서는 거시적 및 미시적인 방법을 가지고 수행하였으며 거시적인 방법으로는 연결로 교통량의 상대적 비중차이를 분석하였고 미시적으로는 본선에 진입하는 차량들의 패턴을 분석하였다. 거시적인 측면에서 합류부의 교통와해는 같은 합류교통량에 대한 연결로교통량의 비중 차이레 의해 발생된다. 즉, 연결로교통량 비중이 높아질수록 교통와해 발생확률은 증가할 것이다. 또한 미시적인 측면에서는 연결로 교통량이 같을 때 본선에 진입하는 차량군의 크기 및 발생회수, 표준편차가 높아진다고 할 수 있다. 따라서 교통와해의 주요한 원인은 연결로교통량의 영향에 기인한다고 할 수 있고 이러한 영향을 감소시키기 위하여 램프미터링과 같은 고속도로 교통통제 기법이 요구된다.

• Journal of the Korean Chemical Society
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• v.64 no.1
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• pp.30-37
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• 2020

The purpose of this study was to identify the problems faced by students in sub-microscopic representation of acid-base reactions. Herein, we selected 30 students of 12^th grade science classes, who had studied various acid-base models. In order to investigate the sub-microscopic representation ability of the students, we developed nine items related to various contexts, such as one type of solute and solvent, two types of solutes and solvent, cases with water as solvent or with nonaqueous solvents. For all items, we consistently observed lack of concept of chemical change. In context of aqueous and nonaqueous solutions, the frequency of lack of concept of chemical bonding was high if ammonia was the solute or solvent. Moreover, the frequency of lack of concept related to the degree of electrolytic dissociation was high. Therefore, chemistry teachers should understand that students' ability to sub-microscopic representation of acid-base reactions can be enhanced by analyzing the difficulties faced by the students in solving diverse acid-base problems.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.1
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• pp.384-390
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• 2019

The importance of architecture design focused on eco-friendly and low energy continues to grow. In addition, the energy conservation design is required from a micro-perspective. Energy simulations based on BIM have attracted recent attention because of the high efficiency. On the other hand, the parameters concerned with microscopic energy are not included in BIM data. This study examined the necessity of the sensor-light parameter using a simulation of illuminance sensor light. In this study, illuminance sensors were installed into the BIM data and the operating schedule data of sensor light were generated by an illuminance simulation. The schedule data was then inputted into the simulation application, and the reduction ratio of power consumption was verified by the simulation. According to research, the power consumption and thermal load decreased by more than 20 %. Therefore, it is necessary to supplement the sensor-light parameter into BIM data for microscopic energy conservation design. This study was not confined to checking whether sensor-light parameter is necessary or not, but to ascertaining the necessary of applying a microscopic factor to generate BIM data.

• Journal of the Korean Chemical Society
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• v.56 no.6
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• pp.731-738
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• 2012

The purpose of this study is to analyze the understandings of science high school students on the conception of chemical cell in relation to chemical equilibrium from the microscopic viewpoint at molecular level through questionnaires and follow-up interviews. The results show that they have high understandings on the chemical equilibrium states in the electrochemical cell and on the redox reaction taking place simultaneously when a metal electrode is immersed in the metal ion solution. However, they do not fully comprehend the development of electrical potential difference, electron movement, electrode potential measurement in the half-cells, and calculation of the net cell voltage between anode and cathode in the chemical cell because of difficulties in the microscopic understanding the interaction on the interface at the electrode and the electrolyte solution.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.12
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• pp.54-62
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• 2007

Mobile IPv6 is the representative standard protocol proposed to offer mobility of mobile hosts, but it has drawbacks such as high handover latency and packet loss during handover. To complement these drawbacks, several protocols have been proposed and they can support faster handover than the Mobile IPv6, but there still exists inevitable packet loss during handover in those protocols. In this paper, we propose a new handover procedure of mobile host who has a dual link for minimizing packet loss rate during micro handover to improve mobility capability of Cellular Ethernet system that supports mobility at layer 2. And we derive the superiority of proposed scheme by comparing in terms of packet loss rate, handover latency and throughput of proposed scheme with those of Hierarchical Mobile IPv6 which is the representative IP-layer micro mobility protocol by simulation.