• 한국항공우주학회지
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• 제37권12호
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• pp.1232-1237
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• 2009

국제민간항공기구 및 미 연방항공청에서는 항공기 이 착륙에 적용될 수 있는 지역위성항법보강시스템 (GBAS)에 대한 연구 개발을 수행하고 있다. 항공기 이 착륙에 위성항법시스템이 사용되는 만큼 시스템에 대한 무결성 확보가 최우선시 되어야 한다. 이를 위해 GBAS에서는 발생 가능성이 있는 오차 모델을 통해 위치 오차 예측값을 계산하고 이를 허용 한계치를 초과 하는 지 확인하고, 만약 초과하였을 경우 항공기는 GBAS 시스템 활용을 중단하고 다른 항법수단을 강구하게 된다. 하지만 높은 위치 오차 예측값은 시스템의 무결성 확보에는 도움이 되겠지만, 가용성 확보에 어려움이 있다. 본 논문에서는 제주도 국제공항에 설치되어 있는 항공우주연구원 GBAS 기준국의 실제 데이터를 사용하여, 위치 오차 예측값 계산에 사용될 수 있는 B-Value 기반의 지상국 오차 표준편차 모델 제시하였다. 또한 제시된 오차 표준편차 모델에 시그마 인플레이션을 적용하여 GBAS의 가용성 향상을 검증하였다.

• 노동경제논집
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• 제25권2호
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• pp.33-78
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• 2002

본 논문은 법정근로시간 단축에 대한 이론적 및 실증적 효과를 분석한다. 법정근로시간 단축은 이론적으로 임금소득을 상승시키며 소비를 촉진하는 효과가 있는 반면 실근로시간은 약간 줄어들거나 정체하며 비용 상승이 클 경우 고용이 감소하는 효과를 일으킨다. 거시모형을 통한 실증분석은 법정근로시간 단축으로 실질임금이 상승하고 소비가 증대하는 반면 실근로시간의 단축은 법정근로시간 단축 크기의 절반 정도에 그치고 비용 인상 인플레이션이 일어나 GDP와 투자가 감소하는 결과를 낳는 것으로 나타났다. 그리고 법정근로시간 단축이 단계적으로 시행될수록, 그리고 월차휴가, 생리휴가 폐지와 같은 보완장치가 더불어 시행될수록 이 같은 부정적인 효과는 줄어드는 것으로 나타났다.

• Fisheries and Aquatic Sciences
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• 제16권4호
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• pp.253-260
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• 2013

We investigated the toxicological effects of Aroclor 1254 on the fertilized eggs, embryos and larvae of the olive flounder Paralichthys olivaceus. The survival rate and hatching success of the embryos decreased significantly in treated groups in an Aroclor 1254-dose-dependent manner. Significant differences were found at ${\geq}5{\mu}g/L$ Aroclor 1254 compared to the control group. Hatching success occurred at ${{\leq}}10{\mu}g/L$ Aroclor 1254, which was not significantly different to the control. Embryo malformation increased significantly at ${\geq}1{\mu}g/L$, and included yolk-sac and tail-flexure abnormalities. There was a significant decrease in the survival rate of the larvae at ${\geq}5{\mu}g/L$, which was accompanied by the malformations described above. Notably, concentrations as low as $1{\mu}g/L$ caused a significant increase in abnormalities in the larvae, including incidences of multi-focal hemorrhages, pericardial and yolk-sac edema, inhibition of swim bladder inflation and severe developmental delay. The responses to Aroclor 1254-induced toxicity were generally similar among fertilized eggs, embryos and larvae from three separate flounder hatcheries: Cheju Island, Yeosu and Chungnam, South Korea. These results indicate the high acute toxicity of Arolcor 1254 concentrations of which as low as $1{\mu}g/L$ in olive flounder larvae can affect unhatched embryos. To conclude, the average $LC_{50}$ values for Aroclor 1254 in the embryos and larvae were 50.92 and $3.08{\mu}g/L$, respectively. Additionally, the average $EC_{50}$ values, based on the rate of damage were 14.72 and 5.6$1{\mu}g/L$, respectively.

• Journal of Preventive Medicine and Public Health
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• 제27권1호
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• pp.107-116
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• 1994

The United States adopted DRG based prospective payment system (PPS) in order to control the inflation of health care costs. No study used statistical test while many studies reported the cost containing effect of the PPS. To study impacts of the PPS on the Medicare expenditure, this study set the following three hypotheses (1) The PPS decelerated the increase in the hospital expenditure (Part A), (2) the PPS accelerated the increase in the expenditure of outpatients and physicians (Part B), (3) the increase in total expenditure was decelerated inspite of the spill over (substitution) effect because saving in the Part A expenditure were greater than losses in the Part B expenditure. The dependent variables are per capita hospital expenditure, per capita Part B expenditure, and per capita total expenditure for the Medicare beneficiaries. An intervention analysis, which added intervention effect to the time series variation on the Box-Jenkins model, was used. The observations included 120 months from 1978 to 1987. The results are as follows : (1) The annual increase in the per capita Part A expenditure was $5.11 after the implementation of DRG where as that before the PPS had been $11.1. The effect of the reduction ($5.99) was statistically significient (t=-3.9). (2) The spill over (substitution) effect existed because the annual increase in the per capita Part B expenditure was accelerated by $1.73 (t=1.91) after the implementation of the PPS. (3) The increase in the total Medicare expenditure per capita was reduced by $4.26 (t=-2.19) because the spill over effect was less than cost savings in the Part A expenditure.

• Archives of Plastic Surgery
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• 제44권6호
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• pp.523-529
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• 2017

Background Serial tissue expansion is performed to remove giant congenital melanocytic nevi. However, there have been no studies comparing the expansion rate between the subsequent and preceding expansions. In this study, we analyzed the rate of expansion in accordance with the number of surgeries, expander location, expander size, and sex. Methods A retrospective analysis was performed in pediatric patients who underwent tissue expansion for giant congenital melanocytic nevi. We tested four factors that may influence the expansion rate: The number of surgeries, expander location, expander size, and sex. The rate of expansion was calculated by dividing the 'inflation amount' by the 'expander size'. Results The expansion rate, compared with the first-time group, was 1.25 times higher in the second-or-more group (P=0.04) and 1.84 times higher in the third-or-more group (P<0.01). The expansion rate was higher at the trunk than at other sites (P<0.01). There was a tendency of lower expansion rate for larger expanders (P=0.03). Sex did not affect the expansion rate. Conclusions There was a positive correlation between the number of surgeries and the expansion rate, a positive correlation between the expander location and the expansion rate, and a negative correlation between the expander size and the expansion rate.

• Journal of Biosystems Engineering
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• 제27권6호
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• pp.501-512
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• 2002

Traction performance of off-road vehicles is estimated using slip-traction relationships Two zero condition accepted by ASAE have been used widely to obtain the slip-traction relationships of off-road vehicles. This study was carried out using the soil bin systems to investigate the characteristic of slip-traction curves obtained using two zero conditions defined by ASAE. which are driving and driven zero condition, and to present disadvantage of slip-traction relationship based on two zero conditions of ASAE. The results of this study are summarized as follows : 1. For the driving zero condition, the curve of slip-traction relationship shows some issues. The first question is that the slip is zero when the traction is zero. The second question is that the value of slip is smaller than that of corresponding real slip, as the rolling radius decreased f3r the setting zero condition with driving wheel. 2. For the driven zero condition. slip occurs when the traction is zero, which is more realistic results than driving zero condition. But when a zero condition is set, skid occurs and this result increased the rolling radius of tire and increased slip value f3r the specific traction value of whole slip range. This kind of trend was getting bigger as the soil is softer, or the tire inflation pressure is higher. 3. From the results of this study, it was found that slip-traction relationship obtained by two zero conditions of ASAE is not realistic in estimating the traction performance of off-road vehicles. And also slip-traction relationship obtained for the same experimental condition showed different result in accordance with chosen zero condition,

• Agribusiness and Information Management
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• 제4권1호
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• pp.24-31
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• 2012

This case study investigates the KIKO currency option that has been a social issue in recent years among developing countries, especially Korea, where the financial derivatives market is in a state of rapid growth. The forward transaction which becomes a basis of derivatives is intended to hedge risks that may be caused by a future change in asset prices. Although it originates from a simple form of agricultural transactions, there currently exists a variety of derivatives in more sophisticated forms. In the Korean agricultural industry, the need to use such derivatives is great, as there is a huge risk of price fluctuation in agricultural products due to frequent adverse weather. In addition, many developing countries with export-led industrial structures similar to Korea's, of necessity must resort to currency hedging as a method of reducing relevant risk. However, in most cases, the lack of understanding about financial derivatives results in an inappropriate application of these derivatives. The KIKO in this study represents such cases. Since 2007, KIKO has been sold in Korea to many small- and medium-sized export companies for the purpose of currency hedging when the exchange rate between the Korean won and the U.S. dollar was in a downward spiral. The main focus of this study is a case which is most representative of KIKO. As inflation rapidly increased during the financial crisis in the U.S. at the end of 2007, derivatives became a hot issue in the courts rather than in the financial markets. This case study investigates what KIKO and the fierce legal debates over it imply, from the perspective of the option of value evaluation in order to suggest not only a direction in which companies can utilize financial derivatives, but also a roadmap for the future derivatives market.

• 패션비즈니스
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• 제4권4호
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• pp.1-16
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• 2000

The purpose of this study is to investigate the formative beauty, changes in fashion and aesthetical sense that can be seen in the bias drapings of Madeleine Vionnet and her influences on modern fashion since she used draping as a new fashion means to represent the new feminine images which modernism of the early 20th century and social changes from the two great World War's generated, and to provide proper data to encourage designers' creativity that is wanting in the circle of Korea fashion. Bias draping led women to respect worship their body from the heart with seductive modernism enriching the material's texture to the utmost through geometrical patterns of triangle, quartered plane and quardrants and simple cylindrical cuts and with an attribute adapting itself to the wearer's body. Bias draped wear consisted of light and transparent materials and overall surface decoration revealed women's movements and sought the extension of environmental movements and demonstrated its eroticism. On the other hand, biased daywear gained anonymity through cutting true to body line and psychological protective quality as of cape, and this went well with the independent femininity accepting difference as well as pursuing revolution from the inside. The great inflation and the 2nd World War gave birth to escape from reality like surrealistic artistic tendencies and Hollywood films and increased romanticism. Bias draping once underwent unpopularity except in expensive clothes due to knit wear boom and the utilization of new elastic materials, however, it began to receive lights again from pluralization waves and retro tendencies and to be introduced in many designers' collections. A young genius of England, John Galliano improved functions of Haute Couture through creation of new styles and fantastic shows to promote profits in the fashion markets. Bias draping fitted in human body line provides us comfort and aesthetic qualities through careful choice of material and elegance by delicate cutting.

• 한국건설관리학회논문집
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• 제10권2호
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• pp.132-144
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• 2009

본 연구에서는 기 준공된 국내 공공주택의 실적공사비 분석을 토대로 공공주택 공사비 추정을 위한 기초자료를 제시하고자 하였다. 이에 대한주택공사(이하 주공)에서 발주하여 2004년부터 2007년까지 준공된 각 지역별 23개의 공공주택을 연구 대상으로 선정하여, 실제 투입 및 정산된 실적공사비를 분석하였다. 분석항목으로는 주요 직접비 항목인 공통가설, 건축, 토목, 기계설비 4개의 공종을 대상공종으로 하였으며, 물가상승률을 고려한 경상가 기준의 투입 공사비를 준공연도, 지역, 연면적, 분양방식별로 분류하고, 이에 따른 $3.3m^2$당 실적공사비를 각 공종별로 비교 분석하여 평균 실적공사비를 토대로 한 공사비의 유추와 산정식을 분석 제시하였다.

• 한국디지털건축인테리어학회논문집
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• 제12권4호
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• pp.49-57
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• 2012

With regard to the culture in cities this study aims to essential understanding and systematic approach to the culture. The "2011 Seoul Survey"report has been used to find out causality among the related variables. In the first place 'satisfaction of cultural condition' was operationally selected as a dependent variable for regression. For the purpose of controlling confounding factors for ceteris paribus effect correlation analysis was done between the dependent variable and all other variables respectively, which resulted in two groups of variables: group (1) - 6 variables of very significant correlations(p-value<0.01) and (2) - the other 6 variables of significant correlations(p-value<0.05). Then hierarchical regression was adopted to these 2 groups to analyse $R^2$ increment, statistical significance of independent variables, and multicollinearity(VIF; variance inflation factor). At last a regression model specified by group (1) as independent variables(they are 'social trust', 'satisfaction of walking condition', 'happiness index', 'preparation against old age', 'satisfaction of traffic condition' and 'hours for internet') shows that only 'social trust' variable has statistically significant and substantially strong effect on 'satisfaction of cultural condition.' This finding should be accepted on the following understanding; (1) urban culture has a collective attribute formed between people and society, (2) culture is somewhat telling and hearing stories and the confidence between tellers and hearers is essential in the mutual response and (3) stimulus is received by relationship in company with sense, emotion, thinking and action. In spite of restrictive external validity this finding can be used as a direction for promoting culture and a basis for related policy choice in cities.