• Nuclear Engineering and Technology
• /
• 제46권4호
• /
• pp.475-480
• /
• 2014

We developed a simple method to prepare the displacement damage cross section of SiC using NJOY and SRIM/TRIM. The number of displacements per atom (DPA) dependent on primary knock-on atom (PKA) energy was computed using SRIM/TRIM and it is directly used by NJOY/HEATR to compute the neutron energy dependent DPA cross sections which are required to estimate the accumulated DPA of nuclear material. SiC DPA cross section is published as a table in DeCART 47 energy group structure. Proposed methodology can be easily extended to other materials.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
• /
• 제4B권2호
• /
• pp.54-58
• /
• 2004

This paper presents the iron core design method of a high temperature superconducting (HTS) transformer considering voltages per turn (V/T). In this research, solenoid type HTS coils were selected for low voltage (LV) winding and double pancake coils for high voltage (HV) winding, just as in conventional large power transformers. V/T is one of the most fundamental elements used in designing transformers, as it decides the core cross sectional area and the number of primary and secondary winding turns. By controlling the V/T, the core dimension and core loss can be changed diversely. The leakage flux is another serious consideration in core design. The magnetic field perpendicular to the HTS wire causes its critical current to fall rapidly as the magnitude of the field increases slowly. Therefore in the design of iron core as well as superconducting windings, contemplation of leakage flux should be preceded. In this paper, the relationship between the V/T and core loss was observed and also, through computational calculations, the leakage magnetic fields perpendicular to the windings were found and their critical current decrement effects were considered in relation to the core design. The ％ impedance was calculated by way of the numerical method. Finally, various models were suggested.

• 한국자동차공학회논문집
• /
• 제22권7호
• /
• pp.135-143
• /
• 2014

Electrified vehicles can be classified with hybrid electric vehicles, battery electric vehicles and fuel cell electric vehicles. These vehicles have two more than energy converters which are the part of a powertrain. It is particularly difficult to estimate the power of hybrid electric vehicles due to two different energy converters with different power characteristics. Therefore, a new power concept for these vehicles is needed. The vehicle power as the new concept for solving this problem was defined in this study. The test method and the procedure were made a development in this study. Four electrified vehicles with different electric fraction were used to validate the method. Two percentage of COV was suggested as a criterion for the maximum vehicles power based on the previous studies. The repeatability of this method was within ${\pm}2$ per cent for the maximum vehicle power and within ${\pm}5$ per cent for the vehicle speed at maximum vehicle power.

• Ocean and Polar Research
• /
• 제29권1호
• /
• pp.69-80
• /
• 2007

This paper attempts to measure the environmental value of the Nakdong-river estuary, which is ecologically important but confronted with the threat of development. Especially, in order to elicit the environmental values of its four attributes, contingent valuation method(CVM) based on multi-attribute utility theory is applied and the CVM survey was rigorously designed to comply with the guidelines for best-practiced CVM studies. We surveyed a randomly selected sample of 400 and 350 households in Busan and six large cities(Seoul, Incheon, Daegu, Daejeon, Gwangju, and Ulsan), respectively and asked respondents questions in person-to-person interviews about how they would willing to pay for the estuary conservation and management program. Respondents overall accepted the contingent market and were willing to contribute a significant amount(2,457 won in Busan and 3,560 won in six large cities), on average, per household per year, which implies that there exists a large difference between the two. The aggregate values of the Nakdong-river estuary in Busan and six large cities amount to 2.92 and 22.32 billion won, respectively, per year. In addition, expanding the values to Korea produces 51.34 billion won per year. The quantitative values can be utilized in planning and decision-making about development versus conservation of the estuary.

• Journal of Mechanical Science and Technology
• /
• 제14권11호
• /
• pp.1286-1295
• /
• 2000

The ventilation effectiveness is evaluated as a function of air exchange rate and supply / extract locations in a simplified model chamber using a tracer gas technique of CO$_2$ gas injected into a supply duct. Ventilation systems consist of supply and extract fans, a CO$_2$gas generator, a CO$_2$gas analyzer and a test chamber. The ventilation effectiveness is evaluated using a step-down method based on ASTM Standard E741-83. The room mean age of the model chamber is decreased with increasing air exchange rate fanged from 6to 10 air changes per hour. The ventilation effectiveness of the mechanical inlet/natural extract system is better than that of the mechanical extract system.

• 대한토목학회논문집
• /
• 제30권3D호
• /
• pp.263-270
• /
• 2010

본 연구는 경제분석기법에서 편익항목의 통행시간절감편익의 개선안을 살펴보았다. 기존의 경제성분석 시 통행시간절감편익의 계산방법은 피크시간대의 O/D를 이용하여365를 곱하여 산정하고 있다. 이 계산방법의 문제점은 요일에 대한 교통량변화, 달에 대한 교통량변화를 고려하지 못하는 것이다. 이러한 분석점을 개선하기 위하여, 군집분석과 t-검증을 통하여 달별, 요일별 비슷한 교통량 패턴이 가지는 것끼리 묶었다. 이러한 결과값은 요일별과 월별로 교통량의 차이가 발생하는 것으로 나타났다. 본 연구에서는 이러한 요일별, 월별 가중치를 적용하여 pilot 예제를 통해 통행시간절감분을 계산하였더니 기존의 방법에 비해 다소 적게 도출되는 것을 알 수 있었다. 본 연구는 교통량의 변화패턴을 고려한 가중치 연구에 의의를 둘 수 있다.

• Ocean and Polar Research
• /
• 제30권2호
• /
• pp.141-148
• /
• 2008

This paper aims at estimating consumer surplus for recreational sea fishing in Tongyeong coastal area using individual travel cost method. A Poisson model (PM), a negative binomial model (NBM), a truncated Poisson model (TPM), and a truncated negative binomial model (TNBM) are applied for individual travel cost method in order to account characteristics of count data (non-negative discrete data.) The survey was conducted for 462 inshore anglers using personal interview method in Tongyeong during July and October 2007. Respondents were asked about how often they do fishing, travel costs, catch, income, and so on. Because of over-dispersion problem in PM and TPM, NBM and TNBM were considered to be more appropriate statistically. All parameters estimated are statistically significant and theoretically valid. As the results based on TNBM, consumer surplus per trip was estimated to be 183,486 won, total consumer surplus per person and per year 3,399,658 won, and the marginal effect of consumer surplus on % changes in catch rate is 185,372 won.

• 간호행정학회지
• /
• 제23권2호
• /
• pp.139-150
• /
• 2017

Purpose: The purpose of this study was to identify nursing service costs associated with all health care costs incurred by the institution. Methods: This study was an empirical case study research in which the nursing cost was separated from total medical cost. The nursing cost index was calculated through a cost allocation method after summarizing costs for personnel, raw materials and administration of each department in one public hospital. The 2014 budget plan, published in 'Public Hospitals Alert', was used as data and the data were analyzed using the Microsoft Office EXCEL 2013 program. Results: When comparing total medical costs and nursing costs, the nursing cost were 27.14% of the total medical cost. The nursing cost per nurse per hour was calculated as \29,128 The nursing cost per inpatient per day was calculated as \157,970, and the administration cost per patient was calculated as \133,710. Conclusion: The results of the research present the process of cost allocation of specific cost elements in the hospital and evidence for administrative costs which in the past have been only vaguely formulated. These are the significant implications of this study.

• Journal of Microbiology and Biotechnology
• /
• 제15권2호
• /
• pp.310-320
• /
• 2005

A membrane-based oligonucleotide array was used to detect predominant bacterial species in human fecal samples. Digoxygenin-labeled 16S rDNA probes were generated by PCR from DNA that had been extracted from fecal samples or slurries. These probes were hybridized to an array of 120 oligonucleotides with sequences specific for 40 different bacterial species commonly found in human feces, followed by color development using an alkaline phosphatase-conjugated antibody and NBT /BCIP. Twenty of the species were detected by this method, but E. coli, which was present at $\~$1 $\times 10$^5$ CFU per gram feces, was not detected. To improve the sensitivity of this assay, reverse transcriptase-PCR was used to generate probes from RNA extracted from fecal cultures. Coupled with a chemiluminescence detection method, this approach lowered the detection limit for E. coli from $\~1$ $\times 10$^6$ to ${\leq}$ 1 $\times 10$^5$ These results indicate that the membrane-array method with reverse transcriptase-PCR and chemiluminescence detection can simultaneously identify bacterial species present in fecal samples at cell concentrations as low as${\leq}$ 1 $\times 10$^5$ CFU per gram.

• 대한의용생체공학회:의공학회지
• /
• 제14권3호
• /
• pp.265-272
• /
• 1993

We present a new waveform detection method, based on the search of distinctive line-segments. The method is based on the basic assumption that the waveform morphology of biological signals is readily characterized by a sequence of the distinctive line-segments and their structural features. In this method, the distinctive line-segments are first searched for, and a structural feature analysis is performed an the distinctive line-segments found. Experiments of detecting epileptic spikes were carried out to evaluate the detection per formance of the method. Two subjects were used for training and tuning the algorithm and four subjects for testing the method. The results were obtained on two different performance indices, detection ratio and the number of false detections per minute.