• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.24 no.4
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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.

• Journal of Digital Convergence
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• v.18 no.8
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• pp.103-109
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• 2020

The aim of this research is to investigate the effect of how individuals monitor the time in their life on persuasion and the moderating role of goal orientation and types of persuasive message in the relationship between time monitoring and persuasion. By controlling participants' time horizon perspectives (THPs), an experiment using a 2 (THP: limited vs. expansive) × 3 (goal orientation: approach vs. avoidance vs. control) × 2 (message type: emotional vs. knowledge-related) between-subjects design was conducted.. Results showed that when participants with limited THP, those who oriented avoidance goals were more favorable to knowledge-related messages, whereas those who oriented approach goals preferred emotional messages. Participants with expansive THP were more persuaded by knowledge-related messages, regardless of pursuing goal types.

• Journal of the Korean Society of Costume
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• v.58 no.1
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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.

• YAKHAK HOEJI
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• v.54 no.2
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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.

• Journal of Korean Society of Transportation
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• v.25 no.2 s.95
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• pp.145-155
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• 2007

The objectives of this study aye to develop an on-line departure time-based travel time estimation method and to determine an optimal link length for the estimation. This study developed a link-based rolling horizon logic as the travel time estimation method. In order to determine an optimal link length, the information error of the travel time provision from the user's perspective was defined and employed as a selection criterion. It was found that, when the travel time aggregation size was set as five minutes, a link length of four kilometers gave the most accurate result.

• Korean Journal of Clinical Pharmacy
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• v.20 no.3
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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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• v.3 no.1
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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.'

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.23 no.1
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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.

• Journal of Lipid and Atherosclerosis
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• v.5 no.1
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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.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2004.03a
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• pp.173-187
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• 2004

The horizon of using GIS technologies can be expanded to analyzing spatial changes by time in reality. Traditional GIS technologies usually use maps for a snapshot aspect of spatial information. Limitations of the present GIS technologies in terms of dealing with spatial changes require more solutions for collecting, processing and analyzing spatial data with time. Traditional GIS technologies include Temporal GIS, Real-time GIS and Virtual GIS respectively but those are not capable enough to represent spatial change in an overall perspective. By reflecting dynamic changes the current GIS technologies can be more useful and valuable than before. This study assumes that '4D GIS', a composite of temporal, realtime and virtual GIS technology, will open a new horizon for the future sophisticated GIS applications. By identifying a technology application model for 4D GIS the new concept of 4D GIS can be clarified. The model is established by combining dynamic spatial information types and applicable 4D GIS technologies, which are identified from the most current 4D application and research efforts. The technology application model for 4D GIS can be expected to contribute to efficient in planning for 4D GIS technology development in the future.he future.