• Journal of Chest Surgery
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• v.19 no.3
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• pp.412-420
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• 1986

From 1968 through September 1986, the authors have experienced 34 cases of peripheral arterial surgery using various vascular grafts. Almost all patients [32] were men, and age distribution was variable according to the disease entities. There were twenty eight cases of chronic occlusive peripheral vascular disease including ASO [21], Buerger`s disease [6], Aortoenteric fistula complicating infrarenal abdominal aortic aneurysm [1], four cases of vascular trauma, one case of acute arterial embolism [1] and one case of unknown etiology. The indications of operations for chronic vascular disease was intermittent claudication in 48%, rest pain in 45%, ischemic pregangrene or gangrene in 28%, and sensory change in 10% of patients. Types of operation used were arterial bypass in 28 cases [Aortobifemoral in 5, Aortoiliac in 3, Aortofemoral in 4, Aortoiliac with Aortofemoral in 1, Femorofemoral in 1, Femoropopliteal in 8, Femoroperoneal in 2, Axillofemoral in 3 cases of patients], graft interposition in four and patch angioplasty in three cases. Thirty four prosthetic vascular grafts including Dacron, Gore-Tex, Nylon and two autogenous saphenous vein graft and patch were used for vascular reconstruction in thirty four patients. Unfortunately recently performed one vein bypass was failed immediate postoperatively due to severity of disease and poor case selection. The authors experienced five post operative complications: wound infection [1], graft infection [1], bleeding [1], great saphenous neuralgia [1], pseudoaneurysm [1]. Twenty two of thirty four patients were followed up for more than one month and their cumulative patency rate was 81% [17/22] at 1 month and, 31% [7/22] at 5 month.

• Water for future
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• v.24 no.1
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• pp.63-71
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• 1991

This study represents the methodology for feasibility analysis of small hydro power plants. Cumulative density function of Weibull distribution and Thi-essen method were adopted to beside flow duration curve at candidate sites. The performance prediction model and construction cost estimation model for tunnel-type small hydro power plants were developed. Eight candidate sites existing on Han river selected and surveyed for actual sites reconnaissance. The performance characteristics and economical feasibility for these sites were analyzed by using developed models. As a result, it was found that the optimum design flowrates with the lowest unit generation cost for tunnel-type small hydro power plants were the flowrate concerning with between 20 % and 30 % of time ratio on the flow duration curve. Additionally, primary design specifications such as design flowrate, effective head, capacity, annual average load factor, annual electricity production were estimated and discussed for surveyed sites.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2011.11a
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• pp.349-352
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• 2011

모바일 IPTV는 이동통신망을 이용하여 방송서비스를 제공한다. 이동통신망을 통해 원활하게 방송서비스를 제공하기 위해서는 극복해야 할 기술적인 장벽이 몇 가지 존재한다. 그 중 하나로, 사용자가 기지국과 기지국 사이를 이동하는 경우 통신망은 연속적으로 서비스를 제공하기 위해 상대 기지국에 사용자의 정보를 전달하는 핸드오버 절차가 수행된다. 핸드오버 절차가 수행되면 시간의 지연이 발생하는데, 시간 지연은 방송 품질에 영향을 미칠 수 있다. 따라서 핸드오버의 발생에 따른 성능 분석은 원활한 방송 서비스를 제공하는데 있어 필수적인 과정으로 볼 수 있다. 본 논문은 핸드오버 성능을 분석하기 위하여 기본적인 무선 액세스 네트워크의 기능이 이미 구현되어 있는 NLS(Network-level Simulator)를 이용한 모의실험 방법을 제시한다. 하지만, 성능 분석에 필요한 기능이 모두 NLS에 포함되어 있지는 않다. 따라서 본 논문에서는 NLS 중 하나인 QualNet을 이용하여 핸드오버 성능 분석에 필요한 기능을 구현하는 방법을 예로 설명한다. 성능은 핸드오버 지연시간과 지연시간의 CDF(Cumulative Distribution Function) 로서 나타낸다.

• International Journal of Human Ecology
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• v.9 no.2
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• pp.117-126
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• 2008

The study identifies gender stereotypes, examines the level of women's economic empowerment at the household level and explores the influence of factors on it. Data were collected from 159 randomly selected farm women using both qualitative and quantitative survey methods between January and March 2007 from three villages of the Mymensingh District of Bangladesh. Four key informants (2 local leaders and 2 development personnel) were questioned to elicit views in the light of boosting women's empowerment. Five constructs of empowerment covering 30 indicators were aggregated together to develop a cumulative economic empowerment index (CEEI) to obtain multidimensional views of women's empowerment. The findings show that there were some prejudices against women in allocating divisions of labour and access to education, food, property, decision-making and institutions. The distribution of the CEEI demonstrates that the majority of the respondents (86%) had a low to moderate level of empowerment. A multiple regression analysis showed positive significant effects of education, training, media contact and freedom of mobility on women's CEEI, while domestic abuse restrained it. It is concluded that interventions by development agencies in co-ordination with the local community was necessary to attain women's self-reliance in the study area. Development actors can undertake some core strategies to enhance women's level of awarencess, knowledge, skills, and productive resources through providing training, loans, and information. To change traditional beliefs, it is important to create awareness of various gender issues amongst rural people through different methods and media.

• Journal of The Korean Astronomical Society
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• v.27 no.2
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• pp.103-117
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• 1994

To extend the work of Gott, Park, and Lee (1989), statistical properties of gravitational lensing in a wide variety of cosmological models involving non-zero cosmological constant is investigated, using the redshifts of both lens and source and observed angular separation of images for gravitational lens systems. We assume singular isothermal sphere as lensing galaxy in homogenous and isotropic Friedmann­Lemaitre-Robertson- Walker universe, Schechter luminosity function, standard angular diameter distance formula and other galaxy parameters used in Fukugita and Turner (1991). To find the most adequate flat cosmological model and put a limit on the value of dimensionless cosmological constant $\lambda_0$, the mean value of the angular separation of images, probability distribution of angular separation and cumulative probability are calculated for given source and lens redshifts and compared with the observed values through several statistical methods. When there is no angular selection effect, models with highest value of $\lambda_0$ is preferred generally. When the angular selection effects are considered, the preferred model depends on the shape of the selection functions and statistical methods; yet, models with large $\lambda_0$ are preferred in general. However, the present data can not rule out any of the flat universe models with enough confidence. This approach can potentially select out best model. But at the moment, we need more data.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.23 no.9A
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• pp.2305-2312
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• 1998

This paper analyzed the delay characteristics of speech packets in virtual cellular network(VCN). The probability distribution of packet delay is obtained using the markov chain model when periodic speech packets are transmitted by slotted-ALOHA protocol. The effects of probility of capture and retransmission policy on the performance were also analyzed. At first, the probability cumulative function of packet delay is calculated from the probability of capture as a function of location of mobile terminal. In order to investigate the effects of backoff delay, we defined a parameter NPr, where N is the period (frame size) of the speech packets and Pr is the retransmission probability for each speech packet. We also obtained the 1% outage delay for various frame size N.

• The Korean Journal of Ceramics
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• v.6 no.3
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• pp.267-271
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• 2000

The influence of photoexcited nonequilibrium carriers on domain switching and photovoltaic current was investigated in two kinds of poled La-modified PbTiO$_3$ferroelectric ceramics, (Pb$_{0.85}$La$_{0.15}$)TiO$_3$and (Pb$_{0.76}$La$_{0.24}$)TiO$_3$, under illumination in the absence of external electric field. Both photovoltaic current and cumulative AE event counts increased with illumination time. The observed nonsteady-state photovoltaic current could be explained on the basis of the cycles of a series of physical events consisting the establishment of space charge field by photoexcited carriers trapped at the grain boundaries, the photoinduced domain switching, and the increase in the remanent polarization. An analysis of energy distribution of the observed AE signals also revealed that the space charge field in (Pb$_{0.85}$La$_{0.15}$)TiO$_3$allowed both 18$0^{\circ}C$ and 90$^{\circ}$domains to be switched during illumination.

• Nuclear Engineering and Technology
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• v.28 no.6
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• pp.507-521
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• 1996

Quantification of uncertainties in the source term estimations by a large computer code, such as MELCOR and MAAP, is an essential process of the current Probabilistic safety assessment. The main objective of the present study is to investigate the applicability of a combined procedure of the response surface method (RSM) based on input determined from a statistical design and the Latin hypercube sampling (LHS) technique for the uncertainty analysis of CsI release fractions under a Hypothetical severe accident sequence of a station blackout at Younggwang nuclear power plant using MAAP3. OB code as a benchmark problem. On the basis of the results obtained in the present work, the RSM is recommended to be used as a principal tool for an overall uncertainty analysis in source term quantifications, while using the LHS in the calculations of standardized regression coefficients (SRC) and standardized rank regression coefficient (SRRC) to determine the subset of the most important input parameters in the final screening step and to check the cumulative distribution functions obtained by RSM. Verification of the response surface model for its sufficient accuracy is a prerequisite for the reliability of the final results that can be obtained by the combined procedure proposed in the present work.

• Asian Journal of Atmospheric Environment
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• v.2 no.1
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• pp.47-53
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• 2008

In this study, we analyzed how ozone pollution could be differently measured and how these different measures varied year to year and across the ten most populated cities in the United States, from 1980 to 2000. Although peak values of ozone concentration have been significantly reduced in most polluted U.S. cities for the last 20 years, the annual average values of ozone concentration have not been lowered as much as peak values. Ozone concentration data for each city shows a unique pattern of distribution, central tendency, and also there is a wide variation among different ozone measures. Two different cities with the same annual mean concentration of ozone can experience very different distributions of ozone concentration within a year. Ozone measures also show a wide margin of variability as they are estimated from different ozone monitoring sites within each city. Ozone pollution statistics can be largely varied depending on the choice of measures, monitoring sites, and averaging time period. EPA's new ozone standard of 0.08 ppm averaged over an eight-hour appears to be more stringent than the current maximum ozone standard of 0.12 ppm averaged over one hour.

• Journal of the East Asian Society of Dietary Life
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• v.26 no.2
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• pp.117-124
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• 2016

As the number of cafeterias at universities has increased, studies on student perception of price sensitivity at cafeterias have gained increased attention. Therefore, the study investigated the relationship between students and university cafeterias according to price sensitivity measurement (PSM). According to the analysis, the indifference price (IDP) was 3,444.06 Korean Won while the subsequent cumulative distribution percentage was approximately 17.68%. The optimal pricing point (OPP) was 3,233.73 Korean Won and the stress price (IDP-OPP) was 210.33 Korean Won. The point of marginal expensiveness (PME) was 4,602.24 Koean Won and the point of marginal cheapness (PMC) was 2,036.29 Korean Won. Therefore, the range of acceptable prices (RAP) was established as 2,565.95 Korean Won. In addition, the study examined differences between price sensitivity measurement (PSM) for the respondent subgroups. Hence, the results will provide a practical background for development of business plans for university cafeterias.