• 한국수자원학회논문집
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• 제41권6호
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• pp.597-603
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• 2008

본 연구는 수자원정책의 효율성 제고를 위한 정책 방안 마련의 토대를 제공하고자 제조업체에서 투입요소로 사용하고 있는 공업용수의 기술적 효율성을 추정하였다. 이를 위하여 자료포락분석(DEA:Data Envelopment Analysis)기법을 이용하였으며 분석 결과에 의하면 공업용수의 기술적 효율성은 전 산업 평균이 0.407로 추정되어 모든 투입요소가 가변적인 경우의 연구 사례에 비하여 낮은 추정치를 보여준다. 이는 공업용수에 대한 비용이 다른 투입요소에 비하여 낮아 기업 경영진이 공업용수의 효율적인 활용 필요성에 상대적으로 둔감한 결과로 볼 수 있다. 그리고 낮은 기술적 효율성 추정치는 모든 투입요소가 효율적이라고 가정하고 분석한 기존 연구들의 가정에 한계가 있음을 보여 준다.

• 한국콘텐츠학회논문지
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• 제8권5호
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• pp.192-206
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• 2008

우리나라의 생명보험산업은 IMF 사태와 방카슈랑스의 도입 등 많은 변화를 겪어왔으며 앞으로 시행될 자본통합법의 시행도 추후에는 생명보험산업에 많은 영향을 미칠 것으로 보이며 생명보험회사의 경쟁력 강화를 위해서는 효율성의 분석이 필수적이다. 본 논문은 DEA 모형을 이용하여 우리나라에서 영업 중인 생명보험회사들의 효율성을 분석했다. 이를 위해 투입변수는 두 가지 범주로 나누어서 분석을 시도하였고 동태적 효율성을 분석하기 위해서 DEA/WINDOW 모형을 도입하였다. 이를 통하여 생명보험회사들의 CCR, BCC, 규모효율성을 알 수 있었고 7년간(1998년$\sim$2004년)의 효율성의 추세와 안정성을 파악할 수 있었다.

• 품질경영학회지
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• 제37권2호
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• pp.1-11
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• 2009

Recently, many companies have been very interested in CRM(Customer Relationship Management). Most companies have been also considering the contact center as a key CRM channel, because it is a contact point between customers and companies. It turns out that the contact center handles over 70% of all customer-company interactions and the success or failure of a company can be determined by the customer satisfaction with contact center experiences. Despite of the strategic importance of the contact center, there has been few empirical study on the efficiency of contact center operations in the literature. One of the main purposes of this study is to evaluate the efficiency of contact centers so as to not only identify the current status of contact center operations, but also suggest ways to improve operational efficiency. For this purpose, we apply a non-parametric efficiency measurement method, DEA (Data Envelopment Analysis), to 57 domestic contact centers in order to compare their relative efficiency. It is expected that the measurement methods suggested in this study can be applied to various issues such as service KS certification, outsourcing service management, and the productivity analysis of service personnel.

• Journal of Communications and Networks
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• 제9권4호
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• pp.473-481
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• 2007

Energy efficiency is one of the most critical concerns for wireless sensor networks. By allowing sensor nodes in close proximity to cooperate in transmission to form a virtual multiple-input multiple-output(MIMO) system, recent progress in wireless MIMO communications can be exploited to boost the system throughput, or equivalently reduce the energy consumption for the same throughput and BER target. However, these cooperative transmission strategies may incur additional energy cost and system overhead. In this paper, assuming that data collectors are equipped with antenna arrays and superior processing capability, energy efficiency of relevant traditional and cooperative transmission strategies: Single-input-multiple-output(SIMO), space-time block coding(STBC), and spatial multiplexing(SM) are studied. Analysis in the wideband regime reveals that, while receive diversity introduces significant improvement in both energy efficiency and spectral efficiency, further improvement due to the transmit diversity of STBC is limited, as opposed to the superiority of the SM scheme especially for non-trivial spectral efficiency. These observations are further confirmed in our analysis of more realistic systems with limited bandwidth, finite constellation sizes, and a target error rate. Based on this analysis, general guidelines are presented for optimal transmission strategy selection in system level and link level, aiming at minimum energy consumption while meeting different requirements. The proposed selection rules, especially those based on system-level metrics, are easy to implement for sensor applications. The framework provided here may also be readily extended to other scenarios or applications.

• 경영과학
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• 제30권2호
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• pp.43-61
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• 2013

With the recent introduction of supply chain management (SCM), quality management has extended from within companies to between companies. As a result, supply chain quality management (SCQM) has received increased attention. However, existing SCQM studies only focus on what impact quality control in supply chains have on company performance while virtually no studies examine quality control efficiencies. This paper, therefore, evaluated the SCQM efficiency of a parent company and its partner companies by using Data Envelopment Analysis (DEA) based on the Quality Collaboration Index for Supply Chain Management (QCI-SCM) conducted by the Korean Standards Association for its 'Quality Innovation-Based Building and Expansion of Business.' Study results showed that a parent company and its partners showed an overall average efficiency of approximately 80% (parent company 80.37%, partner company 79.05%). By also performing a discriminant analysis based on the calculated efficiency scores using DEA, factors that made companies efficient or inefficient were different between the two groups. In parent companies, efficiency and inefficiency were determined by factors such as communication, infra-structure, support, delivery of quality, and benefit sharing, whereas in partner companies, talent development, infrastructure, crisis management, and delivery of quality were the determining factors. In this paper, we examined the efficiency of SCQM and analyzed them from the perspective of both the parent company and partner companies to offer strategic SCQM insights.

• Journal of Welding and Joining
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• 제25권4호
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• pp.49-57
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• 2007

The optimization of the cladding parameters was studied to maximize the deposition efficiency in the laser cladding using a low power pulsed Nd:YAG laser. STS304 stainless steel plate and Co alloy powder were used as a substrate and powder for cladding, respectively. The six cladding parameters were selected through preliminary experiments and their effects on the deposition efficiency were analyzed statistically. Experiments were designed and carried out using the Taguchi experimental method using a L18 orthogonal array. It was found from the results of analysis of variance(ANOVA) that the powder feed position and powder feed angle had the most significant effects on the deposition efficiency, but the powder feed rate and laser focal position had nearly no effects. The deposition efficiency could be maximized at 0mm of the powder feed position and 50o of the powder feed angle in the experimental range. From this experimental analysis, a new laser cladding head with 20o of the powder feed angle was designed and manufactured. With a new laser cladding head, the highest deposition efficiency of 12.2% could be obtained.

• 농업생명과학연구
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• 제45권6호
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• pp.279-289
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• 2011

이 논문에서는 부트스트래핑 DEA 모형을 이용하여 품목농협의 효율성 분석 값의 통계적 유의성을 분석하였다. 분석결과, 첫째, 일반적 DEA모형에 의한 기술효율성은 0.878로 추정된 반면, 부트스트래핑 기법을 적용하면 0.804로 추정되었다. 그러나 두 값의 차이는 신뢰구간 범위 내에 있기 때문에 통계적으로는 유의하지 않다. 또한 95% 유의수준하에서 기술효율성의 통계적 신뢰수준은 0.726에서 0.874로 분석되었다. 둘째, 일반적 DEA모형에서 효율적인 품목농협으로 추정된 19개 농협 모두 부트스트래핑 기법을 적용한 경우 비효율적인 것으로 추정되었다. 이는 일반적 DEA모형의 경우 비효율적인 품목농협이 효율적인 것으로 추정될 수 있다는 것이다.

• 한국유기농업학회지
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• 제31권4호
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• pp.357-380
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• 2023

This study analyzed the management efficiency of jujube, bitter persimmon, and chestnut farms using data envelopment analysis (DEA). And this study analyzed causes affecting management inefficiency of those farms using the two-step method. The main findings are as follows. First, as self and employment labor costs are increased, it is important to reduce labor costs which account for 60~70% of the total production cost. Second, efforts to improve management efficiency are needed as overall efficiency of farms were decreased. Third, a pesticide cost per 10a representing a level of pesticide had a negative effect or did not have a statistically significant effect on the management efficiency. This implies that expanding environment-friendly production by reducing pesticides is effective for improving the management efficiency. Fourth, as leading farms were more efficient than general farms, technology dissemination and education through leading farms are important for improving efficiency, and efforts are needed to promote exchange between leading and general farms.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2006년도 추계학술대회 논문집(제1권)
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• pp.163-170
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• 2006

본 연구에서는 국내 컨테이너 전용 터미널(부산항 8개 터미널, 광양항 6개 터미널)을 대상으로 DEA(Data Envelopment Analysis) 분석을 통해 효율성을 분석하였다. 일정 시점을 대상으로 한 분석이 아니라 1998년$^{\sim}$2005년 동안의 효율성 분석을 실시하였으며, 이를 통해 각 터미널의 효율성 변화를 살펴보았다. 본 논문의 분석 결과는 우리나라 터미널의 상대적인 효율성 값을 제시해 줄 뿐만 아니라 신규 터미널 생성, 운영사의 변화, 터미널의 통합 운영 등에 따른 터미널 생산성의 변화 등을 제시하여 줌으로써 터미널 운영사의 향후 운영전략에 시사점을 제공하고 있다.

• 한국기계가공학회지
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• 제20권7호
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• pp.89-96
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• 2021

In this study, a mini hydro cyclone was designed and manufactured to achieve an inlet flow rate of 2 L/min in the experiment, which was conducted using alumina powder with a specific gravity of 3.97. This hydro cyclone was studied for using in steam and water analysis system (SWAS) of thermal power plant and was manufactured by 3D printing. Numerical analysis was performed with Solidworks Flow Simulation, utilizing the reynolds stress method (RSM) of fluid multiphase flow analysis models. Experimental and numerical analysis were performed under the three conditions of inlet velocity 2.0, 4.0, and 6.0 m/s. The separation efficiency was over 80% at all inlet velocity conditions. At the inlet velocity 4m/s, the separation efficiency was the best, and it was confirmed that the efficiency was more than 90%.