• 로봇학회논문지
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• 제13권3호
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• pp.151-156
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• 2018

Military robots are expected to play an important role in the future battlefield, and will be actively engaged in dangerous, repetitive and difficult tasks. During the robots perform the tasks a human operator controls the robots in a supervisory way. The operator recognizes battlefield situations from remote robots through an interface of the operator control center, and controls them. In the meantime, operator workload, controller interface, robot automation level, and task complexity affect robot operability. In order to assess the robot operability, we have developed ROSim (Robot Operational Simulator) incorporating these operational factors. In this paper, we introduce the results of applying ROSim experimentally to the assessment of reconnaissance robot operability in a battle field. This experimental assessment shows three resulting measurements: operational control workload, operational control capability, mission success rate, and discuss its applicability to the defense robot research and development. It is expected that ROSim can contribute to the design of an operator control center and the design analysis of a human-robot team in the defense robot research and development.

• Smart Structures and Systems
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• 제22권2호
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• pp.151-159
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• 2018

Maintenance activities are regarded as a key part of the repairable deteriorating system because they maintain the equipment in good condition. In practice, many maintenance policies are used in engineering fields to reduce unexpected failures and slow down the deterioration of the system. However, in traditional maintenance policies, maintenance activities have often been assumed to be performed at the same time interval, which may result in higher operational costs and more system failures. Thus, this study presents two non-periodic preventive maintenance (PM) policies for repairable deteriorating systems, employing the failure rate of the system as a conditional variable. In the proposed PM models, the failure rate of the system was restored via the failure rate reduction factors after imperfect PM activities. Operational costs were also considered, which increased along with the operating time of the system and the frequency of PM activities to reflect the deterioration process of the system. A numerical example was provided to illustrate the proposed PM policy. The results showed that PM activities performed at a low failure rate threshold slowed down the degradation of the system and thus extended the system lifetime. Moreover, when the operational cost was considered in the proposed maintenance scheme, the system replacement was more cost-effective than frequent PM activities in the severely degraded system.

• Journal of Korea Trade
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• 제23권3호
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• pp.52-67
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• 2019

Purpose - This study analyzes the effect of the authorized economic operator-mutual recognition arrangement (AEO-MRA) on the performance of Korean exporters and importers. The effect of the import-export companies' characteristics, such as annual sales, the number of foreign markets, and overseas experience, on the AEO-MRA is deduced; the relationship between this effect and firm performance is analyzed. Design/methodology - An empirical research model was constructed and analyzed using structural equation modeling. The effect of AEO-MRA on logistics and operational performance was derived from the aforementioned characteristics as leading factors of the AEO-MRA. The regulatory influence of cooperation with logistics companies was analyzed in the AEO-MRA effect on logistics performance. Thus, 172 valid samples were obtained from import-export companies certified by the AEO-MRA. Findings - Among the aforementioned characteristics, only "annual sales" has a positive effect on the AEO-MRA, whose effect enhances logistics and operational performances. The AEO-MRA effect did not directly affect operational performance. Owing to the adjustment effect analysis, the AEO-MRA effect and logistics performance relationship is strengthened if the cooperative relationship with the logistics company is higher than a certain level. If this cooperation falls below a certain level, the AEO-MRA effect on logistics performance reduces. Thus, logistics cooperation is an important factor in the AEO-MRA effect and logistics performance relationship. Originality/value - Hinging on the resource-based theory and relational viewpoint, an empirical model that explains the relationship between the AEO-MRA effect and firm performance is established.

• 한국시뮬레이션학회논문지
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• 제30권1호
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• pp.87-101
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• 2021

무기체계의 성능을 뜻하는 작전운용성능(Required Operational Capability)은 신규 무기체계의 소요 결정 시 함께 결정되며, 무기체계의 획득부터 전술적인 운용에 이르기까지 결정적인 영향을 미치기 때문에 이를 정의하는 것은 매우 중요한 일이다. 본 연구에서는 새롭게 개발되는 무기체계인 관측포탄의 ROC를 검증하기 위한 시뮬레이션 기반의 방법론을 제안한다. 이를 위해, ROC를 구성하는 무기체계의 주요 성능과 무기체계의 성능에 영향을 미치는 외부환경요인을 입력값으로 하고, 작전운용효과를 결과값으로 출력하는 이산사건 시뮬레이션 모델을 제안한다. 시뮬레이션 모델을 구현하는데 필요한 모의논리를 설명하고 민감도 분석 등 다양한 시뮬레이션 결과를 활용하여 ROC를 검증할 수 있는 방법에 대해 설명한다. 본 연구는 관측포탄과 같이 유사무기체계가 없고 군의 분석모델을 직접적으로 활용하기 어려운 무기체계의 ROC를 분석하고 작전효과를 예측할 수 있는 방법론으로 활용이 가능할 것이다.

• 시스템엔지니어링학술지
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• 제15권2호
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• pp.87-97
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• 2019

This paper focuses on the SE concept based on the weapon system design, which is the lack of systematic research at the stage of military requirements creation prior to acquisition management phase. Influence factors were derived by focusing on the core issues that were at issue in the process of requirements analysis, requirements verification, and business management in recent years. Next, the impact factor was prioritized using the AHP technique and then alternatives were suggested. As a result, through the hierarchical analysis process, 'substantiation of necessity' was found to be the most important factor in the large category, and 'satisfaction of the operating concept' was the most important factor. In addition, as a result of calculating the final weight for each nutritional factor, it was analyzed in order of 'enemy threat response ability', 'response to operational environment change', 'performance considering operational environment', and 'guaranteed power generation'. The results of this analysis suggest which factors should be focused on, firstly, based on the concept of SE by the military and JCS.

• 한국신뢰성학회지:신뢰성응용연구
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• 제15권4호
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• pp.222-232
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• 2015

Purpose : The purpose of this study is to analyse affecting factors of Test and Evaluation and to improve the institution of Test and Evaluation in the Domestic purchase program. Methods : The domestic acquisition program is currently small in terms of size, but it is gradually increasing every year. Still, the domestic purchase program has insufficient regulations and procedures compared to the other procurement methods including research & development. Various problems are likely to occur between test and evaluation group, and defense industries regarding the regulations during Test & Evaluation. Therefore, the regulations and methods need to be amended to upgrade the current domestic purchase program into an effective and flawless one. In this paper, six variables have been chosen by the help of experts working in Ministry of National Defense (MND), Joint Chiefs of Staff (JCS), Army Headquarters and DAPA. Results : The six variables are effectiveness of proposal evaluation, fairness of test and evaluation, sufficiency of operational capabilities, seasonal period of test and evaluation, fulfillment in Integrated Logistics Support (ILS) of the industries, and guaranteeing appropriate environment for related enterprises' participation. Conclusion : This paper can help defense industries to enhance their development capabilities, and to perform tests more fairly and effectively considering the key factors identified in this research.

• 한국항해항만학회지
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• 제39권2호
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• pp.107-113
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• 2015

This paper analyzes and evaluates the importance of energy saving measures based on qualitative survey. Through literature review and group interviews with specialists, 4 factors, 13 measures for energy savings, and 4 evaluation criteria were selected to carry out an Analytic Hierarchy Process (AHP) analysis. At the first stage of AHP analysis, the importance of factors was derived, and then the importance of 13 measures. Lastly, the cross examination of 4 factors was carried out in order to evaluate the best possible qualitative considerations. The result revealed that 'choosing the best course weather', is the most important factor with the highest value on applicability and operational complexity criteria. These results may imply that operational considerations are regarded as a main factor to be taken into account when considering appropriate energy saving measures.

• 한국정보시스템학회지:정보시스템연구
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• 제14권1호
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• pp.19-40
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• 2005

The history of computer virus comes along with that of computer. Computer virus han surfaced as a serious problem in information age. The advent of open network and widespread use of Internet made the problem even more urgent. As a method of defense for computer virus most companies use anti-virus software. Selecting appropriate anti-virus software involves various criteria and thus it is a multiple-attribute decision making problem. The purpose of this study is to prioritize anti-virus software evaluation factors. To do that, first of all, important evaluation factors are selected based on previous research on anti-virus software as well as general software evaluation models. Then, a questionnaire survey was conducted on end-users, system administrators and anti-virus software developers. The survey result was analyzed with ExpertChoice 2000 which is based on Analytic hierarchy Process technique. This study found that there are clear differences among three survey groups regarding the relative importance of overall evaluation factors. End-user group ranked "cost" first, but it was the least important factor to developer group. Developers pointed out "operational support" ad the most important factor. There were also obvious differences in the relative importance of detail evaluation items. Both end-users and system administrators shared 7 common items among top 10 most important items. Moreover, neither of the two groups ranked any of the items in the "operational support" factor in top 10, whereas all 4 items in the factor were included in top 10 by developer group.

• 산업경영시스템학회지
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• 제21권47호
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• pp.57-68
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• 1998

Work environments have been changed with the advent of new technologies, such as computer technology. However, human cognitive limits can't pace up with the change of work environment. Designing human-computer system requires knowledge and evaluation of the human cognitive processes which control information flow workload. Futhermore, under limited reaction time and/or urgent situation, human operator may the work stress, work error and resultant deleterious work environment. This paper evaluate the visual factors of major information processing factors(information density, amount of information, operational speed of speed)on operator performance of supervisory control under urgent(limited reaction time)environments which require deleterious work condition. To describe the work performance int the urgent work situations with time stress and dynamic event occurrence, a new concept of information density was introduced. For a series of experiments performed for this study, three independent variables(information amount, system proceeding speed, information density) were evaluated using five dependent variables. The result of statistical analyses indicate that the amount of information affected on all of five dependent measure. Number of failure and number of secondary task score were influenced by both amount of information and operational speed of system. However reaction time of secondary task were affected by both amount of information and information density. As a result, the deleterious factors for the performances seemed to be a scanning time to supervise each control panel. Consequently, a new display panel was suggest to reduce operator work load for scanning task showing better operator performance.

• 대한영양사협회학술지
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• 제16권3호
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• pp.208-225
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• 2010

Our research consisted of a qualitative study investigating the quality attributes of university foodservices through focus group interviews and a quantitative study evaluating service quality of university foodservices through a survey. Sixteen quality attributes were derived and customer satisfaction questionnaires included these 16 quality attributes with a five-point Likert scale. An Importance-Performance Analysis (IPA) model was applied in order to identify operational strategies necessary to improve service quality. The survey questionnaires were distributed to 600 university students enrolled in a university located in Kwangju and statistical analysis was performed on 555 surveys using an SPSS package. Overall customer satisfaction with the quality of university foodservices was relatively low (under 3.0) while the expectation was inclined to be high (over 4.0). The main reasons for using the university foodservice were given as inexpensive price (67.6%) and time saving (22.9%). A factor analysis of 16 quality attributes revealed two separate factors: food quality (Cronbach's alpha=0.911) and service quality (Cronbach's alpha=0.934). Variety of menu, convenient location, and sanitation of utensils and facilities were identified by an IPA model as factors needing improvement in operational strategies.