• Journal of Mechanical Science and Technology
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• v.18 no.4
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• pp.689-698
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• 2004

Uncertainties generated from the individual measured variables have an influence on the uncertainty of the experimental result through a data reduction equation. In this study, a performance test of a single stage axial type turbine is conducted, and total-to-total efficiencies are measured at the various off-design points In the low pressure and cold state. Based on an experimental apparatus, a data reduction equation for turbine efficiency is formulated and six measured variables are selected. Codes are written to calculate the efficiency, the uncertainty of the efficiency, and the sensitivity of the efficiency uncertainty by each of the measured quantities. The influence of each measured variable on the experimental result is figured out. Results show that the largest uncertainty magnification factor (UMF) value is obtained by the inlet total pressure among the six measured variables, and its value is always greater than one. The UMF values of the inlet total temperature, the torque, and the RPM are always one. The uncertainty percentage contribution (UPC) of the RPM shows th, lowest influence on the uncertainty of the turbine efficiency, but the UPC of the torque has the largest influence to the result among the measured variables. These results are applied to find the correct direction for meeting an uncertainty requirement of the experimental result in the planning or development Phase of experiment, and also to offer ideas for preparing a measurement system in the planning phase.

• The Journal of the Korea Contents Association
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• v.20 no.2
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• pp.27-35
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• 2020

The Korean semiconductor industry is the top export item, and its technological prowess is also higher than that of its competitors. However, the technology gap with rivals will narrow. And the semiconductor industry is facing difficulties due to trade friction. Therefore, semiconductor firms should be more efficient in their production. we study analyzes the efficiency semiconductor firms using DEA model. We evaluate the CCR, BBC efficiency and RTS(return to scale) of 30 Korean semiconductor firms. There are a total of 13 efficient DMUs with a BCC of 1. There are a total of 6 efficient DMUs with a CCR of 1. A total of 10 DMUs were IRS in Scale Efficiency and a total of 9 DMUs were CRS in Scale Efficiency and a total of 11 DMUs were DRS in Scale Efficiency. We also suggest the semiconductor firms which can be benchmarked based on analyzed information.

• International Journal of Quality Innovation
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• v.2 no.1
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• pp.1-9
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• 2001

As all the other managerial activities, total quality management (TQM) has also inputs into and outputs from the process. Therefore, the principal managerial efficiency criteria of maximum outputs with minimum inputs should be applied to TQM. In this paper, the methodology for the performance evaluation of TQM by Data Envelopment Analysis (DEA) was proposed. DEA is used to measure the efficiency of TQM for each firm with the input and output data obtained by questionnaire. It is found that there are not significant differences between the firms with and without IS09000 certification and between the large and small-sized firms with respect to the TQM efficiency.

• 유체기계공업학회:학술대회논문집
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• 1998.12a
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• pp.240-247
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• 1998

Leakage vortices formed near blade tip causes an increase of total pressure loss near casing endwall region and as a result, the efficiency of rotor decreases. The reduction of rotor efficiency is related to the size of tip clearance. In this study, the three-dimensional flowfields in an axial flow rotor were calculated with varying tip clearance under various flow rates, and the numerical results were compared with experimental ones. The effects of tip clearance and attack angle on the leakage vortex and overall performance, and the less distributions were investigated through numerical calculations. In this study, tip leakage flow rate and total pressure loss by tip clearance were evaluated using numerical results and aprroximate equations were presented to evaluate the reduction of rotor efficiency by tip leakage flow.

• The KSFM Journal of Fluid Machinery
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• v.2 no.1 s.2
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• pp.73-80
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• 1999

Leakage vortices formed new blade tip causes an increase of total pressure loss near the casing endwall region and as a result, the efficiency of rotor decreases. The reduction of rotor efficiency is related to the size of the tip clearance. In this study, the three-dimensional flowfields in an axial flow rotor were calculated by varying the tip clearance under various flow rates, and the numerical results were compared with experimental ones. The effects of tip clearance and attack angle on the leakage vortex and overall performance, and the loss distributions were investigated through numerical calculations. In this study, tip leakage flow rate and total pressure loss by tip clearance were evaluated using numerical results and approximate equations were presented to evaluate the reduction of rotor efficiency by tip leakage flow.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.11
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• pp.1033-1039
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• 2020

Vietnam is conducting an export-led growth model and labour-intensive industries contributing majorly to the total export value. In the context of Industry 4.0, the labour-based industries are significantly affected; hence, enhancing productivity is the key measure to maintain these industries. The garment industry contributes significantly to the total export value of Vietnam. Based on meta-frontier framework, the approach of data envelopment analysis is used to measure technical efficiency of Vietnamese garment firms and the global Malmquist TFP index is utilised to identify productivity change and its components including efficiency, technology and technical gaps between different groups of firms. The data of Vietnamese garment firms from 2013 to 2018 collected from the Vietnam General Statistic Office is used in this study. The results show that: (i) The total factor productivity of Vietnamese garment firms growth, technical progress is the main contributor; (ii) The private garment sector is the leading group; (iii) There is a large technological gap among Vietnamese garment sectors. The private and FDI garment firms have experienced a growth in all components of total factor productivity change. Meanwhile, technological progress change is the main reason to constrain the productivity growth of state-owned garment firms.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.12
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• pp.3357-3368
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• 1994

Total pressure losses required to calculate the total-to-total efficiency are estimated by integrating empirical loss coefficients of four loss mechanisms along the mean-line of blades as follows; blade profile loss, secondary flow loss, end wall loss and tip clearance loss. The off-design points are obtained on the basis of Howell's off-design performance of a compressor cascade. Also, inlet-outlet air angles and camber angle are obtained from semi-empirical relations of transonic airfoils' minimum loss incidence and deviation angles. And nominal point is replaced by the design point. It is concluded that relatively simple loss models and Howell's off-design data permit us to calculate the off-design performance with satisfactory accuracy. And this method can be easily extended for off-design performance prediction of multi-stage compressors.

• The Journal of Korean Medicine
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• v.41 no.1
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• pp.1-10
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• 2020

Objectives: This study investigated the financial performance of Korean Medicine hospitals in Korea in order to understand the current status of hospital management and improve its efficiency. Methods: Financial statements of 24 medical corporations, 19 juridical foundations and 18 school hospitals from 2016 to 2018 were obtained from the secondary data published by the Health Insurance Review and Assessment Service, the National Tax Service and the Korea Advancing Schools Foundation. Financial performance was measured on 6 dimensions: liquidity, profitability, activity, growth, cost and productivity (investment efficiency) by analyzing 8 financial indicators: Liability to Total Assets, Net Profit to Patient Service Revenues, Total Assets Turnover, Growth Rate of Patient Service Revenues, Operating Expenses to Patient Service Revenues, Value Added to Patient Service Revenues, Value Added to Total Assets, and Value Added to Personnel Expenses. Results: Korean Medicine hospitals showed lower Liability to Total Assets, Liquidity and Value Added to Total Assets than Western Medicine hospitals did. They also showed higher Value Added to Patient Service Revenues and Value Added to Personnel Expenses than Western Medicine hospitals did. They also showed higher Value Added to Patient Service Revenues and Value Added to Personnel Expenses than those of Western Medicine hospitals do. The net profit decreased significantly (-50.8%) in 2018 whereas Patient Service Revenues increased (6.9%) for the same period due to Operating Expenses increase and Non-Operating loss. Conclusions: These findings suggest that the Korean Medicine hospital sector in Korea needs to improve liquidity and financial structure and to enhance profitability by reducing Personnel Expenses and generating Non-operating revenues in order to improve its investment efficiency and competitiveness.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.6
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• pp.807-812
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• 2013

The energy budget of the larvae of pandalid shrimp, Pandalopsis japonica, reared in the laboratory from zoea to post-larva was investigated. Energy used during the growth of the shrimp larvae was calculated daily for feeding, growth, molting, and metabolism. The total energy used was 16.2 J for the entire larval stage. Molting energy loss was estimated at a total 1.03 J. Energy used for respiration was estimated at a total of 1.85 J. The intake energy by feeding reached a total of 77.69 J. The total sum of energies used by excretion and egestion was 58.61 J. Larvae assimilated 24.57% of ingested food and used 84.91% for somatic growth. The gross growth efficiency ($K_1$) was 22.19% for the entire larval stage, and the net growth efficiency ($K_2$) was 90.31%. Maintenance costs were estimated at 9.69% of assimilated energy for the entire larval stage.

• Journal of Korean Society for Quality Management
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• v.26 no.3
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• pp.100-107
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• 1998

To evaluate the total quality activities is the most fundamental and critical process as one of the PDCA cycle. The quality award criteria such as Malcolm Baldrige National Quality Award and Deming Award can be a, pp.ied to the guideline for evaluating quality activities. We can identify several important factors for TQM by referring quality award criteria, but they don't suggest how efficiently implement TQM. In this paper, two methodologies are a, pp.ied to evaluate the TQM activities comparatively. One of them is the traditional scoring system (TSS) by analytic hierarchy process (AHP). TSS is the system which evaluates the performance of TQM by the weighted sum of critical success factors. Several quality award system are typical examples of TSS. The other is the efficiency measuring system (EMS) by data envelop analysis (DEA). DEA outperformed other alternative methods to measure the efficiency and it can be a, pp.ied to evaluate the TQM activities. The evaluation system by DEA can be named as EMS. The objective of this paper is to suggest a model called TAE (Total quality management Activities Evaluation), for evaluating TQM activities. In this model TQM organizations are classified into four types by considering TSS and EMS. Those types are high weighted sum and high efficiency type, high weighted sum and low efficiency type, low weighted sum and high efficiency type, and low weighted sum and low efficiency type. Therefore TQM organizations must not only make efforts to get the higher scores in terms of TSS, but also take necessary steps to enhance their efficiencies.