• 한국물환경학회지
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• 제32권3호
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• pp.253-260
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• 2016

To reduce energy consumption in wastewater treatment plants (WWTPs), renewable energy applications such as small hydropower, solar energy, and wind energy are popular. However, it should be noticed that energy originated from operation of wastewater treatment process can be reduced through optimized operation based on analysis of factors affecting energy. In this research, the relationship to the various operational variables and influent factors was explored using correlation analysis and decision tree algorithm. Due to the non-linear characteristics of the process, it was difficult to find clear linear patterns through correlation analysis. However, decision tree algorithm showed its usefulness in uncovering hidden patterns that consume energy. As operational factors, influent flowrate, the amount of aeration, nitrate recycling pumping rate, and sludge wasting pumping rate were selected as important factors. For environmental factors associated with influent compositions and removal rate, BOD and T-N removal rate were selected as significant factors.

• 인터넷정보학회논문지
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• 제21권1호
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• pp.231-236
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• 2020

본 논문은 드론 운영개념에 따라 체공시간, 총 운영시간, 적정 소요량 등 작전운용성능과 소요량의 과학적 검증이 필요하나, 이를 체계적으로 분석할 수 있는 방법론이 없어 본 연구를 수행하였다. 본 연구는 임무기반한 모의분석을 통한 검증 6단계의 분석 방법론 연구 및 제안을 통해 드론의 운용개념 기반의 최적 ROC와 소요량을 제시할 수 있으며, 그 결과 기술적, 경제적 효과를 제시 하였다.

• 한국정보과학회논문지:정보통신
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• 제29권1호
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• pp.40-47
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• 2002

본 논문은 작업분석(Operational Analysis)을 이용하여 ATM 기반 수동 광 가입자 망(Passive Optical Network: PON)에서 광선로 종단 시스템의 성능을 분석하였다. 이를 위해 ATM-PON을 구성하는 각 블록에서 버퍼 구조에 따른 이용율, 쓰루풋, 그리고 라우팅 속도와 같은 시스템 파라미터를 사용하였다. 특히, 각 블록의 평균 응답시간과 방문률(visit ratio)를 구하고 시스템 성능을 저해하는 병목점을 찾았다. 본 논문에서는 622Mb/s 16x16 스위칭 블록이 병목점 블록임을 확인하였으며, 이 병목점은 셀 도착율이 증가함에 따라 손실률이 급격하게 증가함에 확인하였다.

• 유통과학연구
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• 제13권11호
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• pp.111-121
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• 2015

Purpose - This study's purpose is to investigate the impact of supply chain management (SCM) factors among targeted Korean distribution firms. Antecedents are established for supply chain orientation (SCO) for the management and organization of cultural assets. The research sets up SCO corresponding to management cultural assets and to organizational factors in the results. The research model is created to examine the SCO based on a strategic perspective and the operational performance of the SC and SCM. In addition, an integrated model is constructed to analyze the moderating effect by setting partner cooperation as a relational capital factor. The main aim of this study is to analyze the characteristics of the supply chain structure as a source of competitive advantage for distribution service firms participating in the supply chain. In the moderating effects analysis, the role of partner cooperation as relational capital is examined in detail. Research design, data, and methodology - The study examined the existing research related to supply chains, discussing the antecedents of the performance of SCM and SCO. SCM was established with the partner's cooperation as relational capital. Including the moderating effects of the partner cooperation, the research proposed a seven hypotheses path analysis model. The samples were collected from the Korean export enterprises in the distribution service sector, with 185 samples selected for the final analysis. To try and measure the four latent variables presented in the analysis model based on existing studies, 22 measurement items were used. The empirical analysis used the appropriate PLS (partial least squares) method on the path analysis reliability and validity and for common method bias. After testing the seven hypotheses, the research tested the moderating effects to the path analysis. Using PLS as structural equation modeling, the seven hypotheses were tested including the moderating effects of the partner relational capital on the 185 samples. Results - In the results, the SCO had a positive impact on both SCM and the relational capital of partner cooperation. The SCM had a significant impact on the operational performance of the SC. Further, partner cooperation also had a significant impact on SCM and the operational performance of the SC. The moderating effect analysis of the SCM and partner cooperation found a significant impact on the operational performance of the SC. On the other hand, the moderating effect of the SCO and partner cooperation did not affect the SCM. Conclusion - The results of this research show that the existing supply chain-related research can be applied to the operational performance of the SC for a Korean distribution service firm. In view of the fact that SCO is a source of competitive advantage, it should be taken into account when a firm wants to improve the performance of the SCM of the distribution service. This is because it can be assumed that SCO plays a role in supply chain management for the distribution firm.

• 보건의료산업학회지
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• 제11권2호
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• pp.1-15
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• 2017

Objectives : This study aimed to identify the perception of quality improvement in health care and operational performance after the implementation of the Healthcare Accreditation. Methods : Data were collected from 5 hospitals that have experienced the 2th Healthcare Accreditation in Busan, South Korea. A Likert 5-point scale was used to measure the research variables and a structured questionnaire was used. Finally, 206 valid cases were analyzed using SPSS win 18.0. For hypothesis testing, hierarchical multiple regression analysis were performed. Results : The perception of quality improvement in health care after the implementation of the Healthcare Accreditation was higher than the operational performance. In the customer orientation and job performance, the perception of quality improvement in health care and operational performance had a significant influence. Conclusions : It is necessary to use the Healthcare Accreditation as a virtuous cycle of management that can ensure enforcement of workplace regulations and improve the members'ability to provide high quality medical services.

• Smart Structures and Systems
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• 제15권2호
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• pp.395-408
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• 2015

This study aims to propose a Bayesian approach to consider changes in temperature and vehicle weight as environmental and operational factors for vibration-based long-term bridge health monitoring. The Bayesian approach consists of three steps: step 1 is to identify damage-sensitive features from coefficients of the auto-regressive model utilizing bridge accelerations; step 2 is to perform a regression analysis of the damage-sensitive features to consider environmental and operational changes by means of the Bayesian regression; and step 3 is to make a decision on the bridge health condition based on residuals, differences between the observed and predicted damage-sensitive features, utilizing 95% confidence interval and the Bayesian hypothesis testing. Feasibility of the proposed approach is examined utilizing monitoring data on an in-service bridge recorded over a one-year period. Observations through the study demonstrated that the Bayesian regression considering environmental and operational changes led to more accurate results than that without considering environmental and operational changes. The Bayesian hypothesis testing utilizing data from the healthy bridge, the damage probability of the bridge was judged as no damage.

• 시스템엔지니어링학술지
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• 제9권1호
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• pp.13-23
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• 2013

Operational Concept Descriptions or Document(OCD) shall be developed to understand stakeholder's desire for to-be-delivered system. But there is little study on methodology of OCD generation and many developers do not understand importance of OCD in Korea. According to Nicole Roberts' industry(18 U.S. companies and organizations) survey, only 30% of system development projects had OCD, too. Researchers and developers have opposing views regarding the generation of an OCD. Many researchers believe that the development and use of operational concepts at the start of large projects is essential. Alternatively, developers may view the OCD as a burden to the development process rather than an enabler due to the extensive documentation requirement. In this paper a couple of OCD guidelines were investigated to clarify how to build a CONOPS effectively and what to include. Finally, OCD for rotorcraft based Personal Air Vehicle System(PAVS) was developed as a case study. In the future, a template for generating OCD appropriate to Korean environment could be proposed.

• 설비공학논문집
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• 제30권4호
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• pp.167-174
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• 2018

The geothermal heat pump systems were installed for heating and cooling of public buildings in Jincheon Eco-friendly Energy town. The heat pump system was operated at night to save on operational costs, and the cold heat was stored in thermal energy storage (TES). In this study, the performance of geothermal heat pump systems with the TES during the summer season was analyzed, and the operational costs with and without the TES were compared. The electric chiller model was used to simulate a heat pump applied without the TES system. Electric rates of each system were measured to calculate operational costs. When the TES is used in the air conditioning system, the electric load (30.4 MWh) calculated in the daytime can move to off-peak load time, and the operational cost is reduced by 36~54%.

• The Journal of Asian Finance, Economics and Business
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• 제8권3호
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• pp.1035-1044
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• 2021

Corporate longevity is an interesting issue from a theoretical point of view. In today's uncertain economic climate, the first priority for a company is survival. The longevity of an organization is basically one of the areas that can classify the sustainability of a company. Known as the cultural heritage of Indonesia, the traditional herbal medicine industry faces challenges of longevity. The word Jamu is a generic expression for traditional herbal medicine in Indonesia. The Jamu industry as Indonesia's cultural heritage must be preserved with good support from a technical, regulatory, and commercial perspective so that Jamu companies do not go into the decline stage. Operational resilience is usually defined as the ability of an organization to adapt rapidly to changing environments. This study aims to identify the effect of operational resilience and human capital on corporate sustainable longevity through innovation performance. The questions are addressed through empirical research of 108 small companies that produce Jamu, traditional herbal medicine in Java, Indonesia. This study was conducted during July-September 2020. Data analysis is carried out with SEM-PLS using SmartPLS software version 3.0 to evaluate the data collected. The results indicated that operational resilience influences corporate sustainable longevity directly and indirectly through innovation performance. However, human capital could not play the antecedent role to corporate sustainable longevity directly or even indirectly through innovation performance. Human capital indicators require deeper exposure in the context of small industries.

• 무역학회지
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• 제44권3호
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• pp.25-42
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• 2019

This research examined the mediation effect of Workforce Agility (WA) on the relationship between environmental uncertainty and operational performance. We manipulated the control variables that are known to be affected by employment flexibility. Employment flexibility is caused by idiosyncratic characteristics of Korean port system. The analysis was tested by Baron & Kenny's method. The result indicates that each path of the proposed model is significant. Furthermore, the mediation effect was checked with the Sobel Test. The research revealed that environment uncertainty poses an indirect effect on operational performance. Both supply/demand uncertainty and technological uncertainty affected operational performance through the mediation effect of WA. Most of the distribution centers located in Busan Newport Distripark are operated in a bimodal labor (human resource) system which includes both permanent employees (workers) and temporary employees (workers). This empirical research provides theoretical and managerial implications by suggesting ways to increase efficiency in distribution center operation through WA enhancement, and to improve the unloading labor system.