• KIPS Transactions on Software and Data Engineering
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• v.2 no.8
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• pp.535-542
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• 2013

Since case-based reasoning(CBR) has many advantages, it has been used for supporting decision making in various areas including medical checkup, production planning, customer classification, and so on. However, there are several factors to be set by heuristics when designing effective CBR systems. Among these factors, this study addresses the issue of selecting appropriate neighbors in case retrieval step. As the criterion for selecting appropriate neighbors, conventional studies have used the preset number of neighbors to combine(i.e. k of k-nearest neighbor), or the relative portion of the maximum similarity. However, this study proposes to use the absolute similarity threshold varying from 0 to 1, as the criterion for selecting appropriate neighbors to combine. In this case, too small similarity threshold value may make the model rarely produce the solution. To avoid this, we propose to adopt the coverage, which implies the ratio of the cases in which solutions are produced over the total number of the training cases, and to set it as the constraint when optimizing the similarity threshold. To validate the usefulness of the proposed model, we applied it to a real-world target marketing case of an online shopping mall in Korea. As a result, we found that the proposed model might significantly improve the performance of CBR.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.31 no.5
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• pp.267-274
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• 2018

For successful BIM settlement, it is a key technic for engineer to design structures in the 3-dimensional digital space and to work out related design documents directly. Lately many BIM tool has been released and each supports their 3-dimensional object libraries. But it is not easy to apply those libraries to design transportation infra structures that were placed along the route(3-dimensional line). Moreover, in case of design changes, it is so difficult to reflect those changes with the integrated model that was assembled by them. Because of they were developed without consideration for redundancy of parameters between objects that were placed nearby or were related each other. In this paper, a method to develop module for modeling and placing 3-dimensional object for transportation infra structures is presented. The modules are employed by a parametric method and can deal with design changes. Also, for a railroad bridge, through developing user interface of the integrated 3-dimensional model that was assembled by those modules the applicability of them was reviewed.

• Management & Information Systems Review
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• v.36 no.3
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• pp.51-70
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• 2017

The purpose of this study is to examine the level and effectiveness of youth entrepreneurship and to analyze the relationship between entrepreneurship level and career change perceptions, And suggested ways of mutual cooperation and cooperation for activating entrepreneurship education and career education. The research hypothesis is the effect of entrepreneurship on career recognition, the mediating effect of program satisfaction on entrepreneurship and career awareness, and the difference in entrepreneurship change before and after participation in the program First, all factors such as innovativeness, risk sensitivity, entrepreneurship, autonomy, achievement desire, etc., Which are components of entrepreneurship, have positive influence on career recognition. Second, the mediating effect of program satisfaction on entrepreneurship and career recognition has positive effects on innovativeness, enthusiasm, autonomy and achievement desire. However, the risk sensitivity was not significant. Third, as a result of analyzing the difference of change before and after entrepreneurship education, all components of entrepreneurship were analyzed as positive (+). Considering these findings, it is necessary to improve the current method and content of entrepreneurship education to focus on student participation and experience. Second, it is necessary to coordinate and manage entrepreneurship education councils in government ministries with various stakeholders. Third, it is expected that future-oriented education will be possible if software education, entrepreneurship education and career education are integrated and operated in preparation for the fourth industrial revolution.

• Proceedings of the Korea Society for Simulation Conference
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• 1999.10a
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• pp.70-74
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• 1999

발전소 시뮬레이션 시스템 기술은 종합적인 지식을 바탕으로 자료수집 및 분석, 소프트웨어 개발 환경, 수학적 모델, 전산기 구성, 각종 계기류 설계 및 구매 장착 등의 노하우를 알아야만 제작할 수 있는 종합적인 기술이다. 또 지시기반의 기술이며 부가가치가 높은 기술이기 때문에 선진 각국에서는 계측제어 시스템의 기술개발 및 시장 확대를 위하여 힘을 쓰는 동시에 타국으로의 기술정보 유출을 경계하는데 신경을 곤두세우고 있다. 현재 복잡화되어 가고 있는 산업 사회의 전력 수요에 대한 대폭적인 증가 추세에 따라 발전소에서는 보다 효율적이며 합리적이고 경제적인 전력 공급을 위해서 전력 생산에 대한 신뢰성 향상 및 안정성 확보는 물론, 효율성 높은 운전이 절실히 요구되고 있다. 한편, 국내의 시뮬레이션 시스템 분야 기술은 아직도 완벽한 수준에는 미치지 못하며, 이 분야의 기술력 확보 및 신기술 개발은 향후 미래의 모든 시스템산업의 성쇄를 판가름하는 아주 중요한 척도가 될 것이다. 이 중에서 접지 분야는 고전압 혼촉에 의한 저압측 선로의 전압상승 방지, 모선(Bus)이나 전력 기기의 절연보호 및 회로전압의 안정등으로 시스템 성능을 한층 증가 시켜줄 뿐아니라 기기의 오동작이나 낙뇌등으로 인명피해 발생을 없애주는 아주 중요한 분야임에도 불구하고 이 분야의 국내 관련법규등이 미비한 사항이다. 그래서 발전소 분산제어 시스템분야의 장기간 신뢰성 및 안정성을 가지고 있고, 국내에서 많이 사용하는 미국 Bailey의 infi-90 및 독일 ABB의 Procontrol-P를 비교 분석하여 발전소 시뮬레이션 시스템의 접지에 응용 하고져 한다.상호 발생기를 이용한 다양한 시스템 검증 및 분석에 이용할 수 있을 것이다. 본 논문은 가상호 발생기의 구조와 최대 용량 시험 방법을 소개하고, 더 나아가 호 Traffic에 대한 최대 용량 시험뿐 아니라 QoS를 향상시키기 위한 교환 시스템의 제반 성능 시험 및 분석에 이를 이용하기 위해 개선이 필요함을 서술하고자 한다.textrm{m}$~3.4$\mu\textrm{m}$ 범위에서의 투과 및 흡수 스펙트럼을 측정하였다. 결정 성장 결과 B3+, Er3+, Cr3+ 이온은 Ti4+ 이온과 이온의 크기 차이가 심하여 결정의 정상적인 성장을 방해하는 물성을 나타냈고, V5+, Cr3+ 이온은 흑색의 결정, Fe3+ 이온은 적갈색의 결정으로 성장되었다. Al3+, Zr4+, Al3+의 순서로 투과도가 높아지는 것이 관찰되었다. 불순이온의 농도에 따른 영향으로서 Al3+ 이온의 경우 주입농도가 높아질수록 low angle boundary와 oxygen deficiency가 감소하였고, 투과율은 조금 감소하거나 큰 차이가 없는 것으로 나타났다. 반면에 Cr3+ 이온을 주입한 경우 0.003 atomic%에서 최적의 물성을 보였으며, 주입농도가 높아질수록 결정성장이 어려워지고 광의 투과도가 급격히 저하되었다.은 1.3을 나타내었다.로 보인다.하면 수평축과 수직축의 분산 장벽의 비에 따라 cluster의 두께비가 달라지는 성장을 볼 수 있었고, 한 축 방향으로의 팔 넓이는 fcc(100) 표면의 경우 동일한 Ed+Ep값에 대응하는 팔 넓이와 거의 동일한 결과가 나타나는 것을 볼 수 있다. 따라서 이러한 비대칭적인

• Journal of the Korea Society for Simulation
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• v.15 no.1
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• pp.35-42
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• 2006

Sensor network, that is an infrastructure of ubiquitous computing, consists of a number of sensor nodes of which hardware is very small. The network topology and routing scheme of the network should be determined according to its purpose, and its hardware and software may have to be changed as needed from time to time. Thus, the sensor network simulator being capable of verifying its behavior and estimating performance is required for better design. Sensor network simulators currently existing have been developed for specific hardwares or operating systems, so that they can only be used for such systems and do not provide any means to estimate the amount of power consumption and program execution time which are major issues for system design. In this study, we develop the sensor network simulator that can be used to design and verify various sensor networks without regarding to types of applications or operating systems, and also has the capability of predicting the amount of power consumption and program execution time. For this purpose, the simulator is developed by using machine instruction-level discrete-event simulation scheme. As a result, the simulator can be used to analyze program execution timings and related system behaviors in the actual sensor nodes in detail. Instruction traces used as workload for simulations are executable images produced by the cross-compiler for ATmega128L microcontroller.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.7 no.1
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• pp.59-66
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• 2013

This study rehabilitation assistive technology system for people with disabilities employed by a company in the field of occupations and job satisfaction have adapted to, and for the rehabilitation assistive technology support(rehabilitation assistive technology hardware and the software) and service quality based on the quality of convenient for employees to work life by analyzing the factors that can act on adaptation employees on behavioral intentions was to determine the overall impact. Seoul, Gyeonggi, Incheon companies based in vocational education and training received in the employment of the disabled subject questionnaires were distributed, and finally 594 valid questionnaires were minor. In order to test the hypothesis SEM(structural equation model) were used, the results of this study can be summarized as follows. First, rehabilitation assistive technology hardware quality of the quality of rehabilitation assistive technology software affected. Second, rehabilitation assistive technology software quality on the quality of the service quality affected. Third, rehabilitation assistive technology hardware quality on the quality of the service quality affected. Fourth, quality of service, the quality of the adaptation of action for employees affected also. Fifth, rehabilitation assistive technology software for adaptive quality of the employees also had an impact on behavior. Sixth, rehabilitation assistive technology hardware to adapt the quality of the employees affected. And parameters (quality of service quality) influenced to as indirect effects. The results of this study support the rehabilitation assistive technology and rehabilitation assistive technology hardware and software) based, quality of service and quality of fused form acceptable to, the degree of action for employees to adapt more implications that may affect have provided.

• Journal of the Korea Society for Simulation
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• v.16 no.1
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• pp.11-19
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• 2007

Under ubiquitous environment, applications can gather and utilize various sensing information. There are many issues such as energy management, protocol standardization, independency on sensor fields, and security to be resolved for the complete ubiquitous computing. Especially, the independent information access in the sensor field is one of the most important issues to maximize the usability of sensors in various sensor fields. However, existing frameworks are not suitable for the ubiquitous computing environment because of data heterogeneity between data elements in sensor fields. Existing applications are dependent to sensor fields and sensors in the existing ubiquitous computing on environment is dependent to the application in the sensor field. In other word, an application can utilize just information from a specific sensor field. To overcome this restriction, many issues from a hardware or software view must be resolved. In this paper, we provide the design and implementation of the Metadata Registry-based framework (UbiMDR) of the Ubiquitous environment. This framework can provides the semantic interoperability among ubiquitous applications or various sensor fields. In addition, we describe comparison evaluation between conventional Ubiquitous computing framework and UbiMDR framework with data accuracy of interoperability.

• Journal of the Korea Society for Simulation
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• v.26 no.2
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• pp.41-49
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• 2017

In the acquisition program, the conceptual design is the most important step toward specifying the military objectives, establishing requirements and determining future developmental directions, of a target system. However, if both the requirements and directions are incorrectly set due to the lack of development experiences and literature backgrounds in the target systems, such as future ground combat vehicles, it may become a major risk in the future design phases and the entire acquisition program. In order to correct these errors in the future phases, time, effort and cost are required. Therefore, it is necessary to reduce the errors that occur in the initial stages to effectively acquire the future ground combat vehicles. This paper describes the initial design method for verifying the requirements and the developmental directions and estimating the system performance at the conceptual design through the system-level physical modeling and simulation (M&S) and the target system performance analysis. The system-level physical M&S use cutting-edge design tools, model-based designs and geometric-based designs. The system performance estimation is driven from the results of the system-level physical M&S and the specialized system analysis software.

• Journal of the Korean Society for Marine Environment & Energy
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• v.11 no.1
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• pp.13-23
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• 2008

In coastal region, eutrophication, Do deficit and red tide are frequently occurred by influx of fresh water. When the fresh water containing pollutants is discharged into the sea, the surrounding water is contaminated by dispersion of freshwater flowing into coastal waters. The prediction and analysis about the dispersion process of the discharged fresh water should be conducted. A modeling system using GUI was developed to simulate hydrodynamic flow and fresh water dispersion in coastal waters and to analyze the results efficiently. The modeling module of the system includes a tide model using a finite element method and a fresh water dispersion model using a particle-tracking method. This system was applied to predict the tidal currents and fresh water dispersion in Mokpo coastal zone. To verify accuracy of the hydrodynamic model, the simulation results were compared with observed sea level and time variations of tidal currents showing a good agreement. The fresh water dispersion was verified with observed salinity distribution. The dispersion model also was verified with analytic solutions with advection-diffusion problems in 1-dimensional and 2-dimensional simple domain. The system is operated on GUI environment, to ease the model handling such as inputting data and displaying results. Therefore, anyone can use the system conveniently and observe easily and accurately the simulation results by using graphic functions included in the system. This system can be used widely to decrease the environmental disaster induced by inflow of fresh water into coastal waters.

• Journal of KIISE:Software and Applications
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• v.33 no.11
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• pp.942-952
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• 2006

We propose an automatic segmentation method for identifying pulmonary structures using gray-level information of chest CT images. Our method consists of following five steps. First, to segment pulmonary structures based on the difference of gray-level value, we select the threshold using optimal thresholding. Second, we separate the thorax from the background air and then the lungs and airways from the thorax by applying the inverse operation of 2D region growing in chest CT images. To eliminate non-pulmonary structures which has similar intensities with the lungs, we use 3D connected component labeling. Third, we segment the trachea and left and right mainstem bronchi using 3D branch-based region growing in chest CT images. Fourth, we can obtain accurate lung boundaries by subtracting the result of third step from the result of second step. Finally, we select the threshold in accordance with histogram analysis and then segment radio-dense pulmonary vessels by applying gray-level thresholding to the result of the second step. To evaluate the accuracy of proposed method, we make a visual inspection of segmentation result of lungs, airways and pulmonary vessels. We compare the result of the conventional region growing with the result of proposed 3D branch-based region growing. Experimental results show that our proposed method extracts lung boundaries, airways, and pulmonary vessels automatically and accurately.