• Ocean Systems Engineering
• /
• 제10권1호
• /
• pp.49-65
• /
• 2020

In this study, the effects of inclined shaft angle on the hydro-acoustic performance of cavitating marine propellers are investigated by a numerical method developed before and Brown's empirical formula. The cavitating blades are represented by source and vortex elements. The cavity characteristics of the blades such as cavitation form, cavity volume, cavity length etc., are computed at a given cavitation number and at a set advance coefficient. A lifting surface method is applied for these calculations. The numerical lifting surface method is validated with experimental results of DTMB 4119 model benchmark propeller. After calculation of hydrodynamic characteristics of the cavitating propeller, noise spectrum and overall sound pressure level (OASPL) are computed by Brown's equation. This empirical equation is also validated with another numerical results found in the literature. The effects of inclined shaft angle on thrust coefficient, torque coefficient, efficiency and OASPL values are examined by a parametric study. By modifying the inclination angles of propeller, the thrust, torque, efficiency and OASPL are computed and compared with each other. The influence of the inclined shaft angle on cavity patterns on the blades are also discussed.

• 한국멀티미디어학회논문지
• /
• 제11권6호
• /
• pp.891-902
• /
• 2008

The software once developed enters in to the $2^{nd}$ phase of its useful operational life, where it performs its functions for which it has been developed. This is an important phase of software life, wherein the developers and users have to assess the performance of the software to prolong its operational life with efficiency, effectiveness and economy. Performance of the software is based on the measurement of the quality characteristics to ascertain that it is meeting or exceeding the needs of customers in terms of its functionality, usability, efficiency, reliability, availability, maintainability, portability etc. These software quality attributes defined under ISO 9126 provide an overall good framework for assessing the performance of the software. This paper describes a Software Performance Assessment (SPA) model using the Goal-Question-Metric (GQM) paradigm which has been applied to the operational software in real context with successful results.

• 농업과학연구
• /
• 제48권1호
• /
• pp.59-71
• /
• 2021

This study investigated the extent to which rice producers from the Ayeyarwaddy Region of Myanmar could improve their productivity if inputs were used efficiently in rice cultivation. To achieve this objective, simple random sampling was used to collect data from 300 rice growers in the study area. Data were analyzed with the translog stochastic frontier approach to understand the production efficiencies. The study further estimated the influencing factors that affect the efficiency levels of rice farmers. The empirical result reveals that the average technical, allocative, and economic efficiencies were at 76.11, 47.85, and 34.15%, respectively. This suggests that there is considerable room for improving rice production by better utilization of the available resources at the current level of technology. This study suggests that strenthening agricultural training programs and adoption of improved rice varieties may reduce overall inefficiencies among rice farmers in Myanmar. Factors like age, household size, education, farming experience, farm size, rice variety, training, and off-farm income have a significant impact on increasing/decreasing farmer's efficiency. Efficiency can be improved by establishing farmer field school programs to increase the scale of operations. The government should encourage young educated people to participate in paddy production and also intervene to reduce input prices and control the quality of seeds.

• 산업진흥연구
• /
• 제7권2호
• /
• pp.59-73
• /
• 2022

본 논문은 현재 생산량을 유지하면서 투입량을 줄이기 위해 중국 동부지역의 대외무역 지속가능 발전의 효율성을 분석하는 것을 목적으로 한다. 2016년부터 2020년까지 중국 동부 11개 성 및 도시의 관련 입출력 지표를 채택하고 DEA모형을 이용하여 종합적 효율성, 순기술 효율성 및 규모 효율성을 측정하였다. MPI 산정에 Malmquist 지수를 사용한 결과 2016년부터 2020년까지 중국 동부 전 성의 MPI는 1.035로 1보다 높았고, 순기술 효율성은 0.911로 1보다 낮았다. 전체적으로 평균 기술진보지수는 4.045로 4.5% 증가했다. 대외무역의 지속 가능한 발전 효율성은 종합적 효율성, 순기술 효율성, 규모 효율성에 전반적으로 영향을 미치고 있음을 알 수 있다. 대외무역의 지속 가능한 발전 효율성은 규모에 의해 주로 제한을 받았다. 총요인 생산성 향상은 주로 기술적 진보로 부터 효과를 얻는 것으로 나타났다. 내부요소의 영향을 받는 성들에 대해서는 내부조률을 강화하여야 한다. 외부요인의 영향을 받은 성은 외부요인에 대비해야 한다.

• 한국IT서비스학회지
• /
• 제16권4호
• /
• pp.15-31
• /
• 2017

This study analyzes 45 Korea IT service companies from 2012 to 2016 using DEA analysis. Large enterprises, medium enterprises and small and medium enterprises (SMEs). CCR model and BCC model were used for efficiency analysis. Among the various analytical objects, the decision objects which yield the maximum output with minimum input are compared with other analysis objects. The relative inefficiency was measured through this, and Technical Efficiency (TE), Pure Technology Efficiency (PTE), Scale Efficiency (SE), scale profit, reference frequency were analyzed. Also, we analyzed the Technology Gap Ratio (TGR), which is the distance between production function and Meta-Frontier for each firm, using Meta-Frontier analysis. Finally, the Tobit model is used to analyze the sources of efficiency and inefficiency. The inputs are assets, capital, and employees, and the output factor is sales. The analysis shows that large firms are achieving technological achievements more efficiently than small and medium enterprises. As a result, medium-sized enterprises and SMEs can improve efficiency overall through efficient operation of workforce and appropriate combination of inputs such as assets and capital. Also, as a result of the influence factor analysis, it was found that the ratio of the managed asset ratio and the management cost ratio were significant factors influencing the efficiency of the IT service companies. This study suggests the efficiency analysis using DEA for many Korea IT service companies. Inefficient parts of each company are classified according to size and technology. Also, we identify the most efficient companies and analyze the causes of those companies whose profits are lower than their size.

• The Journal of Asian Finance, Economics and Business
• /
• 제7권11호
• /
• pp.779-788
• /
• 2020

Commercial banks play an important role as the main source of funding in the transition process of Vietnam as a market economy. As a result, enhancing the efficiency and productivity of Vietnamese banks can decrease the lending cost for individuals and enterprises. This study is to measure and analyze the productivity change of Vietnamese banking system in different ownership cohorts and sources of this change during the period of restructuring (2011-2019). The Hicks-Moorsteen total factor productivity index is utilised to measure the productivity change and to identify the sources of this change. For an empirical analysis, the data of 28 Vietnamese commercial banks from 2011 to 2018 is collected from their financial statements including balance sheets and income statements. The results show an increase of Vietnamese bank productivity due to the technological progress. While foreign and joint-venture banks are the most advanced cohort, state-owned banks have the lowest rate of productivity growth. The restructuring program negatively impacts scale efficiency and this measure attributes to a decline in the overall efficiency of the banks. We also found that state-owned commercial banks are the most efficient group in the sense that they can achieve the maximal level of revenue from a given amount of expense.

• 한국콘텐츠학회논문지
• /
• 제17권2호
• /
• pp.316-326
• /
• 2017

본 연구에서는 대표적인 지역단위 직업능력개발 공공서비스인 지역맞춤형일자리창출지원사업의 효율성을 분석하기 위해서, 충청남도에서 2014년에 수행된 27개 사업을 대상으로 DEA를 사용하여 효율성을 분석하고, 2013년에 수행된 18개 사업의 효율성과 비교분석했으며, 비효율성에 대한 개선방안을 제시하기 위해서 대표적인 3개의 DMU에 대해서 비효율정도를 살펴봤다. DEA 모형은 CCR모형, BCC모형 및 SE(CCR/BCC)에 의한 규모효율성에 대해서 살펴봤다. 분석결과 2014년은 2013년보다 총사업비와 사업개수가 증가하였지만, 비효율적인 사업이 증가하여 전체 효율성은 감소한 것으로 나타났다. 따라서 효율성 개선을 위해서는 사업비에서 많은 부분을 차지하는 인건비와 직접경비를 사업별로 적절히 배분함으로써 전체 사업의 효율성을 제고할 것을 제시하였으며, 특히 사업비가 큰 대형사업의 경우에는 사업규모를 줄이는 것이 전체 효율성을 제고하는데 가장 중요한 요인이라는 점을 확인하였다. 본 연구를 통해서 직업능력개발 공공서비스의 효율성을 분석하고 효율성 제고방안을 도출하는 연구모형을 제시했으며, 이에 기반하여 성과관리 연구의 영역을 다양한 공공서비스의 효율성을 분석하는 분야로 확대할 수 있었다.

• Asian-Australasian Journal of Animal Sciences
• /
• 제24권11호
• /
• pp.1629-1636
• /
• 2011

Global pork markets are becoming more competitive, riding the wind of the bilateral free trade agreement. China is the world's largest pork producer with nearly 50% of the world's total production. China's fast growing economy has provided its people with higher purchasing power, resulting in a rapid expansion of the Chinese swine industry over the past decades. Worldwide, China consumes the greatest amount of pork and it is believed that this trend will continue. Japan is the world's largest pork importing country, even though it also produces a lot of pork. The Japanese swine industry encounters weighty obstacles in production costs and environmental limitations which result in reduced domestic supply and creates the situation in which Japan has to import a significant amount of pork for their consumption. South Korea is also a large buyer of pork, with a status greatly influenced by the struggle that the country has faced with Foot and Mouth Disease (FMD) which occurred in 2000, 2002 and 2010. High production costs, low production efficiency, and forced culling following the FMD outbreak resulted in the loss of many hog farming households in the country, reducing supply of domestic pork in the face of continued demand. Overall, pork production in these economically important countries can greatly impact the industry globally. The goal of this review paper is to describe pork production in China, Japan, and South Korea and discuss these countries' role in global pork export markets.

• Safety and Health at Work
• /
• 제12권2호
• /
• pp.154-166
• /
• 2021

Background: Occupational health and safety (OHS) is a significant interest of all governments to prevent workplace hazards. Although appropriate legislation and regulations are essentials for the protection of workers, they are solely not enough. Application of them in practice should be secured by an efficient inspection system. Fundamental components of an inspection system are inspectors and their audit tasks. Maintaining the fair balanced task assignment among inspectors strictly enhances the efficiency of the overall system. Methods: This study proposes a two-phased goal programming approach for OHS inspectors' task assignments and presents a case study. Results: The solution approach gives the balanced assignment of inspectors to the workplaces in different cities of the country in the planning period. The obtained schedule takes into account the distances covered by the work places and the number of the workplaces' employees to be audited and pays attention to the human factors by considering the preferences of the inspectors. The comparisons between the obtained optimal schedule and the implemented one that is produced manually show that the approach not only maintains the technical requirements of the problem, but also provides social and physical balance to the task assignment. Conclusion: Both the approach and the application study are expected to offer fruitful inspirations in the area of safety management and policy and they provide a good guide for social policy and organizational aspects in the field of OHS inspectors' task assignment.

• Journal of Information Processing Systems
• /
• 제6권4호
• /
• pp.597-608
• /
• 2010

Software evolution is an ongoing process carried out with the aim of extending base applications either for adding new functionalities or for adapting software to changing environments. This brings about the need for estimating and determining the overall impact of changes to a software system. In the last few decades many such change/impact analysis techniques have been developed to identify consequences of making changes to software systems. In this paper we propose a new approach of estimating change/impact analysis by classifying change based on type of change classification e.g. (a) nature and (b) extent of change propagation. The impact set produced consists of two dimensions of information: (a) statements affected by change propagation and (b) percentage i.e. statements affected in each category and involving the overall system. We also propose an algorithm for classifying the type of change. To establish confidence in effectiveness and efficiency we illustrate this technique with the help of an example. Results of our analysis are promising towards achieving the aim of the proposed endeavor to enhance change classification. The proposed dynamic technique for estimating impact sets and their percentage of impact will help software maintainers in performing selective regression testing by analyzing impact sets regarding the nature of change and change dependency.