• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제24권4호
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• pp.331-350
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• 2020

Exploding gradient is a widely known problem in training recurrent neural networks. The explosion problem has often been coped with cutting off the gradient norm by some fixed value. However, this strategy, commonly referred to norm clipping, is an ad hoc approach to attenuate the explosion. In this research, we opt to view the problem from a different perspective, the discrete-time optimal control with infinite horizon for a better understanding of the problem. Through this perspective, we fathom the region at which gradient explosion occurs. Based on the analysis, we introduce a gradient-explosion-free algorithm that keeps the training process away from the region. Numerical tests show that this algorithm is at least three times faster than the clipping strategy.

• 디지털융복합연구
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• 제18권8호
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• pp.103-109
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• 2020

이 연구는 설득에 있어서 사람들이 시간을 어떻게 모니터링 하는 지 그리고 목표 지향과 설득적 메시지 유형이 어떻게 시간 모니터링과 설득 사이의 관계에서 조절 역할을 하는 지를 살펴보는 데 목적이 있다. 실험을 통해 시간 지평 관점(제한 vs. 확장)과 목표 지향(접근 vs. 회피 vs. 통제), 그리고 메시지 유형(정서적 vs. 지식 관련)의 상호작용 효과가 검증되었다. 구체적으로, 제한된 THP를 갖는 참가자들은 회피 목표를 지향할 때 지식 관련 메시지에 더 설득된 반면, 접근 목표를 지향할 때는 정서적 메시지에 더 설득되는 것으로 나타났다. 반면 확장된 THP를 가진 참가자들은 목표 추구 유형과 상관없이 모두 지식 관련 메시지에 더 설득되었다. 이 같은 결과는 광고 등으로 대표되는 설득적 메시지의 효과에 있어 피험자의 연령과 그들이 갖고 있는 시간 지평 관점에 대한 고려 뿐 아니라 캠페인 등을 통해 유발할 수 있는 목표의 유형, 그리고 메시지의 구성이 상호유기적으로 영향을 미친다는 것을 보여준다.

• 복식
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• 제58권1호
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• pp.17-32
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• 2008

This study focuses on the analysis of Baudelaire's aesthetic perspective which has established a theoretical basis on research of the critical reviews' salon exhibitions as written by Baudelaire. Charles Pierre Baudelaire(1821-1867) having lived during the latter part of Neo-classicism and the era of Romanticism and Impressionism, Baudelaire displayed opposition to customary realities such as social ideology or religious authority that suppressed human nature. Also he pioneered a new genre known as art criticism and wrote much that provided important insights on the essential elements of artistic work, modernity and trend, as well as art definition and art categories. The aesthetic perspective and creative spirit were formed by Baudelaire, during his age were also reconfirmed in the successive ages of modernism and postmodernism. As such, this study sheds light on how Baudelaire's aesthetic perspective was not only temporarily assertion but it is consistently applied to modern art and fashion area. What is more important that, Baudelaire admired new artificial beauty that is created by the human soul liberated from natural instincts or desires. Especially, informed by strangeness and distinctiveness, Baudelaire's view of fashion ran along the same vein as his view of art, and these views form the basis of that creative spirit which situated western fashion on a center of the world. In conclusion, the research on Baudelaire's aesthetic perspective will reaffirm a firm awareness of the creative spirit essential to globally-oriented creative artists and designers who work within the circumstance of the 21st century, a time when the paving of new aesthetic paths is necessary. The research also offers a clear understanding of the aesthetic values demanded by this age.

• 약학회지
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• 제54권2호
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• pp.126-133
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• 2010

This study was conducted to analyze cost-utility of bosentan versus iloprost indicated for pulmonary arterial hypertension (PAH) in a Korean healthcare setting from a payer's perspective. We constructed a Markov model to estimate total costs and outcomes for 1-year time horizon in a hypothetical cohort of 50-year-old patients with PAH. Base analysis showed that bosentan resulted in KW 5.5 billions saving and 18 quality-adjusted life year (QALY) gains per 100 patients compared to iloprost. Bosentan as a dominant strategy was found to be robust through various sensitivity analyses.

• 대한교통학회지
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• 제25권2호
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• pp.145-155
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• 2007

본 연구는 출발시각기준 실시간 통행시간 정보를 제공을 위한 공간적 설계의 적절성을 판단하는 것이다. 그리고 적정 링크길이를 평가하기 위해 실시간 통행시간 정보제공 오차를 정의하고, 기존의 방법보다 개선된 실시간 통행시간 제공방법을 제시하였다. 이를 연구대상에 적용한 결과 첫째, 실시간 통행시간 정보제공을 위한 공간적 설계는 경로단위보다는 링크단위가 오차가 적은 것으로 나타났다. 둘째, 실시간 통행시간 정보 제공방법 비교에서는 기존방법보다 본 연구에서 제시한 방법(동적특성 반영)이 오차가 적은 것으로 나타났다. 그리고 셋째, 적정 링크길이는 약 4km가 적정한 것으로 나타났다. 결론적으로, 출발시각기준 실시간 통행시간 정보제공을 위한 공간적 설계는 동적특성을 반영한 링크단위로 적용하는 것이 효과적이다.

• 한국임상약학회지
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• 제20권3호
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• pp.268-277
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• 2010

This study was conducted to analyze the cost-utility of ramosetron monotherapy, trimebutine monotherapy and trimebutine+loperamide combination therapy in male diarrhea-predominant patients with irritable bowel syndrome (IBS) in Korean healthcare setting. We constructed a decision-analytical model to estimate both total costs for each state of health and outcomes such as IBS-symptoms improvement for 3 and 6 months time horizon. Base analysis found that for ramosetron treatment with the price of KW910 for 5 ${\mu}g$ tablet, incremental cost effectiveness ratios (ICERs, cost per quality-adjusted life day) were KW85,000 and KW62,000 for 3 months and 6 months, respectively, compared with trimebutine. But ramosetron was a dominant strategy when compared with trimebutine+loperamide for both 3 months and 6 months. Sensitivity analyses showed robust results for drug acquisition costs till ramosetron price of KW950/tablet. In conclusion, ramosetron was a cost-effective regimen compared with trimebutine or trimebutine+loperamide from the societal perspective.

• Acta Via Serica
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• 제3권1호
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• pp.11-25
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• 2018

The Renaissance is generally said to be the rebirth of the ancient civilizations of Greece and Rome, and was centered around Italy from the 14th to the 16th century. This includes the temporal peculiarity of the Renaissance as a sudden phenomenon after the Medieval Ages, and the spatial peculiarity of what happened only in Europe. However, if we remove the European-centered bias here, the horizon for interpreting the Renaissance becomes much wider. There have been claims that similar cultural phenomena resembling the Renaissance existed in other civilizations at the same time. This paper seeks to investigate two possibilities. The first is the possibility of a spatial expansion of the Renaissance. This suggests that the Renaissance was created by long-term exchanges with the Eastern, Middle and Western Hemispheres. The second is the possibility of a simultaneity of the Renaissance in the 14th and 16th centuries. This suggests that it was a global phenomenon that occurred in different civilizations. The Renaissance, therefore, was a crystallization of a complex of civilizations created by the crossing of various cultures along the Silk Road, and should be referred to as the 'Global Renaissance' instead of the 'Western Renaissance.'

• 한방안이비인후피부과학회지
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• 제23권1호
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• pp.260-269
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• 2010

Background : Bojungikgitang(BJT) and Banhabaekchulchonmatang(BBT) are known to treat the tinnitus patients, which were registered Korean National Health Insurance coverage lists. Objective : Few studies have evaluated economic benefits of both herbal medicines. This research is to investigate the cost-effectiveness of Bojungikgitang(BJT) and Banhabaekchulchonmatang(BBT) in chronic tinnitus patients over nineteen years old. Method : We built the decision tree model of chronic tinnitus and executed the deterministic analysis and threshold sensitivity analysis based on randomized clinical trial. Effectiveness was measured in quality-adjusted life-years(QALYs), and costs were in 2009 KRW(South Korean Currency). The perspective is societal, time horizon is 10 weeks, and Korean willingness to pay threshold is assumed to 20,000,000KRW. Results : In the base case analysis, BJT treatment resulted is better outcomes as low cost, so BJT is dominant medicine and BBT is dominated. But both cost per QALYs (BJT is 3,120,339KWN per QALY, BBT is 3,505,780KWN per QALY) are lower than the threshold, that could be covered by Korean National Health Insurance(KNHI). Conclusion : This study results showed that BJT was more cost-effective than BBT treating tinnitus patients for 10 weeks, and the cost per QALYs of both alternatives were lower than Korean national threshold.

• 지질동맥경화학회지
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• 제5권1호
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• pp.61-77
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• 2016

Objective: This study aims to analyze cost-effectiveness of two most-commonly used statins from the perspective of the Korean national health system. Methods: The scope of the analysis included rosuvastatin (5 mg, 10 mg, and 20 mg) and atorvastatin (10 mg, 20 mg, 40 mg, and 80 mg). Effectiveness was defined as percentage (%) and absolute (mg/dL) reductions of low-density lipoprotein cholesterol (LDL-C) from the baseline. They were derived from published randomized controlled studies for rosuvastatin and atorvastatin. Effectiveness was defined as reductions in LDL-C levels per mg dose of the drugs. The annual direct medical costs including drug acquisition costs and monitoring costs over the one-year time horizon were calculated for each alternative. The average cost-effectiveness ratios (ACERs) and incremental cost-effectiveness ratios (ICERs) for each statin dose were calculated. Results: The ACERs for all doses of rosuvastatin (5 mg, 10 mg, and 20 mg) were lower than those for all doses of atorvastatin (10 mg, 20 mg, 40 mg, and 80 mg). Rosuvastatin 10 mg was the most cost-effective statin for LDL-C reduction. In cost-effectiveness analyses for corresponding doses of rosuvastatin and atorvastatin, rosuvastatin was the superior strategy which suggests both higher effectiveness and lower costs than atorvastatin. However, we have to consider this analysis is highly influenced by current price of statins in each market. Conclusion: For reduction of LDL-C levels in Korean patients with dyslipidemia, rosuvastatin 10mg is the most cost-effective statin in the current Korean market.

• 한국GIS학회:학술대회논문집
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• 한국GIS학회 2004년도 GIS/RS 공동 춘계학술대회 논문집
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• pp.173-187
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• 2004

기존 GIS는 고정적인 공간데이터를 저장 편집 삭제하기 위한 시스템으로만 활용되고 있는 것이 사실이다. 이는 기존에 구축되었거나 현재 진행중인 지리정보 시스템의 대부분이 시간의 변화에 따른 공간적 변화를 처리할 수 없는 정적인 데이터만을 처리하고 있고 효율적 관점에서도 경제성이 없기 때문이다. 이와 같은 이유로 기존의 기존 GIS에서는 공간데이터를 저장할 때, 시간의 개념을 제외한 정적인 시점에서의 공간정보만을 저장하고 있고 그에 따라 시간의 변화에 따른 공간정보의 이력정보가 저장될 수 없기 때문에 과거에서부터 현재까지의 공간변화정보를 분석하기가 어려우며 미래의 공간변화정보를 예측하기도 쉽지 않다. GIS를 위한 미래의 이상적인 목표는 시간 정보와 연계하여 공간정보를 획득하고 시간을 통한 공간적 정보에서의 변화들을 파악하고 분석하는 것이나 이와 같이 어떤 현상에 대해 시간적 변화를 반영할 수 없는 것은 모델화된 세계에 대한 역동적인 분석이나 이해를 하는데 어려움을 준다. 따라서 본 논문에서는 기존 GIS에서 처리하지 못하였던 공간현상들은 ‘어떠한 현상들인지’를 규명하고 이러한 ‘공간현상들이 어떠한 기술들에 의해 처리될 수 있는지’ 기술 적용 모델을 제안하는 것으로 두 가지 사항을 핵심 연구사항으로 보고 있다. 첫 번째 ‘어떠한 공간현상을 4D GIS에서 처리하려고 하는가’에 대한 핵심 연구사항에서는 기존 GIS에서 간과하였던 ‘시간’과 ‘다차원’의 요소로 인해 변화하는 공간현상은 무엇인가를 규명하려고 하였다. 두 번째 ‘4D GIS를 통해 동적인 공간현상을 어떠한 기술로 처리하고 분석하여 시각화하였는가’에 대한 핵심 연구사항에서는 실세계의 동적인 공간현상을 어떠한 기술로써 처리ㆍ분석ㆍ시각화할 수 있는지 다양한 공간현상을 적용하여 보았다. 본 논문에서 제시한 4D GIS 기술적용 모델은 기술적 관점에서의 한계로 처리하지 못하였던 동적인 공간현상들을 처리ㆍ분석ㆍ시각화하려는 차세대 GIS의 기술개발 가이드 역할을 수행할 것으로 기대된다.