• Childhood Kidney Diseases
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• v.18 no.2
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• pp.98-105
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• 2014

Purpose: Nafamostat mesilate (NM), a synthetic serine protease inhibitor, has been investigated as an anticoagulant for adult patients with a high risk of bleeding, who need chronic renal replacement therapy (CRRT). However, little is known about the use of NM as an anticoagulant in pediatric CRRT. The aim of this study was to evaluate the ideal dosage, efficacy, and safety of NM in pediatric CRRT. Methods: We conducted a retrospective study of 40 pediatric patients who had undergone at least 24 h of venovenous CRRTs between January 2011 and October 2013. We divided the patients according to risk of bleeding. Those at high risk received no anticoagulation (group 1) or NM as an anticoagulant (group 2), while those at low risk received heparin (group 3). Results: Forty patients (25 male and 15 female; mean age, $8.2{\pm}6.6$ years) were enrolled. The mean duration of CRRT was 13.0 days, and the survival rate was 57.5%. The mean hemofilter lifespan was 39.3 h in group 1 and 11.3 h in group 3. In group 2, hemofilter lifespan was extended from 7.5 h to 27.4 h after the use of NM (P =0.001). The mean hemofilter lifespan with NM was greater than with heparin (P =0.018). No patient experienced a major bleeding event during treatment with NM. Conclusion: NM may be a good alternative anticoagulant in pediatric patients with a high risk of bleeding requiring CRRT, and is not associated with bleeding complications.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 1999.04a
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• pp.29-52
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• 1999

본 연구는 강원도 고랭지에서 자생되는 산채류를 이용하여 총질소함량을 기준으로 소맥대신 이들 산채류를 일정비율로 대체하여 더덕 및 산채혼합 간장을 제조하여 그 특성을 조사하였으며 또한, 감마선조사 또는 블랜칭처리가 참나물 즙액의 선도유지연장에 미치는 영향을 조사하였다. 제조된 간장의 총 질소함량은 일반적으로 산채 대체량의 증가에 따라 증가하였다. 숙성 4개월 후의 무기질 함량에 있어 더덕 20% 대체간장은 Ca, K 함량이 각각 1.3배, 1.5배의 증가율을 나타내었으며, 산채 혼합 10% 대체간장도 Ca 함량이 1.5배 증가하였다. 대체량 별로 아미노산 함량 변화를 살펴보면 더덕간장 10% 대체군의 경우 threonine과 aspartic acid가, 산채 혼합 10% 대체군은 tyrosine과 arginine이 높은 증가율을 나타내었다. Rec assay system을 이용한 항돌연변이 시험에서, 더덕간장은 10%와 20% 대체군이, 산채혼합 간장은 7%와 10% 대체군이 다른 시료에 비해 높은 항돌연변이성을 나타내었다. 관능검사 결과, 전체적 기호도에 있어 더덕간장은 7% 대체군, 산채혼합 간장은 5% 대체군이 가장 우수하였다. 미생물의 생육변화는 감마선 조사를 하였을 때 두처리구 모두 0.5 kGy 조사에서도 무처리구에 비하여 현저한 생육감소를 나타내었으며 감마선 처리된 녹즙을 저온에서 저장하였을 때는 미생물의 생육억제효과가 높았으나 상온에서는 감마선 효과가 매우 감소함을 나타내었다. 색도변화는 블랜칭한 녹즙이 블랜칭하지 않은 녹즙보다 색깔이 훨씬 선명하고 맑은 녹색을 띄었으며 시간이 경과함에 따라 감마선 조사구가 시간이 경과함에 따라 무처리구에 비하여 L값, a값 및 b값이 훨씬 적게 변화함을 나타내었다. 비타민 C의 변화는 블랜칭 처리한 녹즙의 비타민 C의 함량변화는 블랜칭 처리를 하지않은 녹즙보다 적었으며 감마선 처리구와 거의 차이가 없었으며 온도가 낮을수록 두 처리구 모두 비타민 C의 손실율이 적게 나타났다. 감마선을 조사하였을 때 블랜칭하지않은 녹즙에서는 무처리구와 비교하여 볼 때 밝기, 풀냄새, 쓴맛, 신선감 및 수용성에서 차이가 없었으며 블랜칭한 녹즙에서는 무처리구가 감마선처리구에 비하여 풀냄새와 쓴맛이 증가하였고 신선감과 수용성이 감소되었다.

• Korean journal of communication and information
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• v.24
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• pp.37-67
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• 2004

본 연구는 인터넷 이용수준이 전통적 미디어의 이용수준에 미치는 영향과 수용지들의 미디어 소비 패턴에 대해 살펴보았다. 미디어 대체이론, 이용과 충족이론, 미디어 레퍼토리 연구를 바탕으로 인터넷 이용이 전통적 미디어의 이용에 미치는 영향을 중심으로 개인들의 정보와 오락 미디어 레퍼토리, 인터넷 레퍼토리에 영향을 미치는 사회적, 심리/태도적 변인과 인구통계학적 특징 등도 검토하였다. 이를 위해 전국에 있는 18세 이상 성인들을 대상으로 성별, 나이별, 지역별 층화표집방법을 이용해 표본을 추출하고 500개의 유효 서베이 설문지를 수집하였다. 데이터의 분석결과, 인터넷 이용정도가 다른 매체에 미치는 영향은 각 미디어별로 세 가지 다른 양상을-상호보완적 영향, 대체 치환의 영향, 그리고 영향을 받지 않음-보였으나 대체로 인터넷은 다른 미디어의 대체 미디어라기보다는 보완적인 매체로 현재 이용되고 있음이 나타났다. 또, 전반적인 미디어 이용시간 측면에서는 인터넷을 많이 이용하는 응답자일수록 오락과 정보 미디어 레퍼토리 크기가 더 컸던 것으로 나타나, 현재까지는 인터넷이 다른 미디어와 상호 보완하는 양상, 피들러(Fidler)의 미디어 변형이론 가운데 공존 공진화 현상을 보여주었다. 응답자들은 평균 2.01개와 2.25개의 오락과 정보 미디어 레퍼토리를 가졌으며 텔레비전, 신문, 인터넷을 두 미디어 레퍼토리의 3대 주요 미디어로 꼽았다. 또한 인터넷 레퍼토리와 사회적, 태도적 변인들간의 상관관계는 최근의 이용 충족이론과 미디어 레퍼토리 연구에서 나타났던 결과들과 일치해 사회적, 심리 태도적 요인들이(친밀도, 접근성, 유용성, 여가시간) 미디어 레퍼토리의 크기에도 영향을 미친다는 사실이 검증되었다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.7
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• pp.102-108
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• 2017

The phenomenon of technological discontinuity which occurs during technological diffusion and substitution between incumbents and new technology is important to understand the behavior of technology diffusion and substitution of single and multiple technologies. Our research defined the concept of technological discontinuity and developed a model capable of measuring the region of technological discontinuity. Based on a literature review and a model development, we proposed a definition and a model regarding technological discontinuity.The accuracy of the model is verified by applying it on a semiconductor industry case. The technological discontinuity is defined as the region in which both the incumbent and new technology co-exist and the performance of the incumbent technology is better than that of the new technology. In addition, we can model the technological discontinuity using discontinuous time and discontinuous performance. This research will be very useful to understand not only technological discontinuity but also technology diffusion or substitution.

• The Korean Journal of Applied Statistics
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• v.26 no.5
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• pp.697-712
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• 2013

When analyzing repeated binary data, the generalized estimating equations(GEE) approach produces consistent estimates for regression parameters even if an incorrect working correlation matrix is used. However, time-varying covariates experience larger changes in coefficients than time-invariant covariates across various working correlation structures for finite samples. In addition, the GEE approach may give biased estimates under missing at random(MAR). Weighted estimating equations and multiple imputation methods have been proposed to reduce biases in parameter estimates under MAR. This article studies if the two methods produce robust estimates across various working correlation structures for longitudinal binary data with time-varying covariates under different missing mechanisms. Through simulation, we observe that time-varying covariates have greater differences in parameter estimates across different working correlation structures than time-invariant covariates. The multiple imputation method produces more robust estimates under any working correlation structure and smaller biases compared to the other two methods.

• The Korean Journal of Applied Statistics
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• v.30 no.3
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• pp.377-390
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• 2017

When conducting a survey, item nonresponse occurs if the respondent does not respond to some items. Since analysis based only on completely observed data may cause biased results, imputation is often conducted to analyze data in its complete form. The panel study is a survey method that examines changes of responses over time. In panel studies, there has been a preference for using information from response values of previous waves when the imputation of item nonresponses is performed; however, limited research has been conducted to support this preference. Therefore, this study compares the performance of imputation methods according to whether or not information from previous waves is utilized in the panel study. Among imputation methods that utilize information from previous responses, we consider ratio imputation, imputation based on the linear mixed model, and imputation based on the Bayesian linear mixed model approach. We compare the results from these methods against the results of methods that do not use information from previous responses, such as mean imputation and hot deck imputation. Simulation results show that imputation based on the Bayesian linear mixed model performs best and yields small biases and high coverage rates of the 95% confidence interval even at higher nonresponse rates.

• Composites Research
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• v.24 no.1
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• pp.31-36
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• 2011

Adhesive shear strengths of the established adhesives and the alternative adhesives were evaluated and their chemical structures were analyzed in order to investigate the possibility of replacing the established adhesives with the alternative adhesives applicable to the seeker for the guided missiles. Two types of the adhesives such as the structural adhesives and the sealant adhesives were considered. Those adhesives were exposed to the combined environmental factors consisting of temperature, moisture and ultraviolet over 1000 hours. Adhesive shear test was conducted to evaluate adhesive shear strengths and ATR FT-IR was utilized to investigate chemical structures. According to the results, the adhesive shear strengths of the alternative adhesives revealed higher than those of the established adhesives. Also the alternative adhesives were more stable to the combined environmental condition than the established adhesives. Therefore, it is found that the established adhesives were able to be replaced by the alternative adhesives.

• Journal of the Korea institute for structural maintenance and inspection
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• v.17 no.1
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• pp.76-84
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• 2013

In this study, some engineering properties of OPC and GGBFS shotcrete mortars with alkali-free or aluminate accelerator were experimentally examined. As a result, GGBFS mortars with alkali-free accelerator were significantly similar to OPC mortars with same accelerator with respect to both setting time and compressive strength. Comparatively, GGBFS mortars with aluminate accelerator showed a good performance with an increased replacement of GGBFS. Furthermore, when replaced with GGBFS over 50%, the mortars exhibited superior performances of electrical resistivity and chloride ions penetration resistance. Accordingly, it is suggested that GGBFS has a beneficial effect as shotcreting materials in the condition of proper replacement levels.

• Journal of the Korea Computer Industry Society
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• v.5 no.9
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• pp.1031-1042
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• 2004

A renewable energy resource data has the characteristic that its measurement value changes every moment. So the amount of primitive data which is produced by the change of time arevast. Therefore researches are needed for the construction of history database which can save and manage vast amount of history information of renewable energy resource data systematically, the estimation system of renewable energy resources. In this paper, to solve these problems, the estimation method of renewable energy resources is suggested. The method makes it possible to estimate momently changing data of the past systematically.

• Journal of Korean Institute of Industrial Engineers
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• v.7 no.1
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• pp.13-20
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• 1981

Three inspection-ordering policies of a part with three types of lead times, i. e., expedited lead time, special lead time and regular lead time are considered. Policy I : The original part is replaced by a spare immediately after delivery, even if the original part is still operating. Policy II : The delivered spare is put into inventory until the original part failes. Policy III : The original part is inspected once again immediately after the delivery of the spare. If it is in a good state, the original part is used up to its mean degradation time, then replaced. If it is in a degradation state, the original part is replaced by a spare. A cost effectiveness for each policy is analyzed. Optimal inspection-ordering policy which maximizes a cost effectiveness is obtained. Time to degradation distribution and time to failure distribution are assumed to be Weibull and exponential, respectively. Variations of policies are observed with respect to variations of associated costs.