• 복식문화연구
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• 제20권3호
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• pp.451-462
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• 2012

Drawing on the literature on TAM and presence, this study proposes a model of the extended TAM by identifying factors that affect the motivations to enhance our understanding of online consumers' acceptance of an e-tail website. This study conceptualizes that consumers' perceived presence variables such as telepresence and social presence are the antecedents to the motivations of TAM. Empirical tests using regression analyses generally supported the proposed model. The overall conclusion from the current data is that our integrated model is useful in understanding consumers' acceptance of an apparel e-tail website. The findings show that perceived usefulness, perceived ease of use, and perceived interest motivations act as strong determinants of consumers' attitude toward an e-tailer, which leads to their behavioral intentions about the e-tailer. This suggests that apparel e-tailers should consider these three motivations when they design their websites. As one way to influence these three factors, this study showed the role of perceived presence in the usage of an apparel e-tail website. The findings suggest that online consumers' perceptions of "being there" and "socialness" stimulate their perceptions of usefulness and interest in the website use. Thus, e-tailers should consider effective ways to increase consumers' perceived presence.

• 대한조선학회논문집
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• 제44권2호
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• pp.55-63
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• 2007

Fins are widely used for roll stabilization of car ferries and passenger ships as well as high performance naval ships. In the present study, model experiments and numerical simulations are performed to investigate the influence of tail blades on the performance of a fin stabilizer for various angles of attack. It is found that a considerable improvement in performance of the fin stabilizer is achieved with adoption of the tail blades. The results can be utilized for the design of a high-lift control surfaces including fin stabilizers.

• 대한임베디드공학회논문지
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• 제17권4호
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• pp.199-208
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• 2022

Korean is an agglutinative language, and one or more morphemes are combined to form a single word. Part-of-speech tagging method separates each morpheme from a word and attaches a part-of-speech tag. In this study, we propose a new Korean part-of-speech tagging method based on the Head-Tail tokenization technique that divides a word into a lexical morpheme part and a grammatical morpheme part without decomposing compound words. In this method, the Head-Tail is divided by the syllable boundary without restoring irregular deformation or abbreviated syllables. Korean part-of-speech tagger was implemented using the Head-Tail tokenization and deep learning technique. In order to solve the problem that a large number of complex tags are generated due to the segmented tags and the tagging accuracy is low, we reduced the number of tags to a complex tag composed of large classification tags, and as a result, we improved the tagging accuracy. The performance of the Head-Tail part-of-speech tagger was experimented by using BERT, syllable bigram, and subword bigram embedding, and both syllable bigram and subword bigram embedding showed improvement in performance compared to general BERT. Part-of-speech tagging was performed by integrating the Head-Tail tokenization model and the simplified part-of-speech tagging model, achieving 98.99% word unit accuracy and 99.08% token unit accuracy. As a result of the experiment, it was found that the performance of part-of-speech tagging improved when the maximum token length was limited to twice the number of words.

• Communications for Statistical Applications and Methods
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• 제21권5호
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• pp.445-459
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• 2014

This paper investigates the dependence structure of Korean financial markets (stock, foreign exchange (FX) rates and bond) using copula-GARCH and dynamic conditional correlation (DCC) models. We examine GJR-GARCH with skewed elliptical distributions and four copulas (Gaussian, Student's t, Clayton and Gumbel) to model dependence among returns, and then employ DCC model to describe system-wide correlation dynamics. We analyze the daily returns of KOSPI, FX (WON/USD) and KRX bond index (Gross Price Index) from $2^{nd}$ May 2006 to $30^{th}$ June 2014 with 2,063 observations. Empirical result shows that there is significant asymmetry and fat-tail of individual return, and strong tail-dependence among returns, especially between KOSPI and FX returns, during the 2008 Global Financial Crisis period. Focused only on recent 30 months, we find that the correlation between stock and bond markets shows dramatic increase, and system-wide correlation wanders around zero, which possibly indicates market tranquility from a systemic perspective.

• Communications for Statistical Applications and Methods
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• 제26권3호
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• pp.239-259
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• 2019

The transmuted generalized extreme value (TGEV) distribution was first introduced by Aryal and Tsokos (Nonlinear Analysis: Theory, Methods & Applications, 71, 401-407, 2009) and applied by Nascimento et al. (Hacettepe Journal of Mathematics and Statistics, 45, 1847-1864, 2016). However, they did not give explicit expressions for all the moments, tail behaviour, quantiles, survival and risk functions and order statistics. The TGEV distribution is a more flexible model than the simple GEV distribution to model extreme or rare events because the right tail of the TGEV is heavier than the GEV. In addition the TGEV distribution can adjusted various forms of asymmetry. In this article, explicit expressions for these measures of the TGEV are obtained. The tail behavior and the survival and risk functions were determined for positive gamma, the moments for nonzero gamma and the moment generating function for zero gamma. The performance of the maximum likelihood estimators (MLEs) of the TGEV parameters were tested through a series of Monte Carlo simulation experiments. In addition, the model was used to fit three real data sets related to financial returns.

• 대한수학회지
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• 제51권4호
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• pp.735-749
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• 2014

This paper studies the asymptotic behavior of the finite-time ruin probability in a jump-diffusion risk model with constant force of interest, upper tail asymptotically independent claims and a general counting arrival process. Particularly, if the claim inter-arrival times follow a certain dependence structure, the obtained result also covers the case of the infinite-time ruin probability.

• 스마트미디어저널
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• 제11권5호
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• pp.17-25
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• 2022

기존의 한국어 품사 태깅 방식은 복합어를 단위 형태소들로 분해하여 품사를 부착하므로 형태소 태그가 세분화되어 있어서 태거의 활용 목적에 따라 불필요하게 복잡하고 다양한 어절 유형들이 생성되는 단점이 있다. 딥러닝 언어처리에서는 키워드 추출 목적으로 품사 태거를 사용할 때 복합조사, 복합어미 등 문법 형태소들을 단위 형태소로 분할하지 않는 토큰화 방식이 효율적이다. 본 연구에서는 어절을 형태소 단위로 토큰화할 때 어휘형태소 부분과 문법형태소 부분 두 가지 유형의 토큰으로만 분할하는 Head-Tail 토큰화 기법을 사용하여 품사 태깅 문제를 단순화함으로써 어절이 과도하게 분해되는 문제점을 보완하였다. Head-Tail 토큰화된 데이터에 대해 통계적 기법과 딥러닝 모델로 품사 태깅을 시도하여 각 모델의 품사 태깅 정확도를 실험하였다. 통계 기반 품사 태거인 TnT 태거와 딥러닝 기반 품사 태거인 Bi-LSTM 태거를 사용하여 Head-Tail 토큰화된 데이터셋에 대한 품사 태깅을 수행하였다. TnT 태거와 Bi-LSTM 태거를 Head-Tail 토큰화된 데이터셋에 대해 학습하여 품사 태깅 정확도를 측정하였다. 그 결과로, TnT 태거는 97.00%인데 비해 Bi-LSTM 태거는 99.52%의 높은 정확도로 품사 태깅을 수행할 수 있음을 확인하였다.

• Current Optics and Photonics
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• 제1권2호
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• pp.132-137
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• 2017

To investigate the usefulness of optical coherence tomography (OCT) for imaging lymphedema, we directly compared it to other histological methods in a mouse model of lymphedema. We performed detailed imaging of the lymphedema lesion on a mouse tail. We imaged the mouse tail in vivo with OCT and created histopathological samples. We constructed a spectrometer-based OCT system using a fiber-optic Michelson interferometer. The light was directed to 50:50 couplers that split the light into reference and sample arms. Backscattered light from a reference mirror and the sample produced an interference fringe. An OCT image of the lymphedema model revealed an inflammatory reaction of the skin that was accompanied by edema, leading to an increase in the light attenuation in the dermal and subcutaneous layers. Similar to OCT image findings, histological biopsy showed an inflammatory response that involved edema, increased neutrophils in epidermis and subdermis, and lymphatic microvascular dilatation. Furthermore, the lymphedema model showed an increase in thickness of the dermis in both diagnostic studies. In the mouse tail model of lymphedema, OCT imaging showed very similar results to other histological examinations. OCT provides a quick and useful diagnostic imaging technique for lymphedema and is a valuable addition or complement to other noninvasive imaging tools.

• 환경영향평가
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• 제22권6호
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• pp.591-607
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• 2013

본 연구에서는 생물학적 바이오마커, 물리적 서식지 지표 및 화학적 수질지표를 종합하여 12-메트릭 생태평가 모형을 확립하였고, 도심하천에 적용하여 수생태계 평가를 실시하였다. 생태모형 적용을 위해 도심하천의 상류역의 대조군 지역($C_Z$), 중류의 전이대($T_Z$) 및 하류역의 오염지역(IZ)을 선정한 후, 모델값에 대한 계절별 변이특성을 분석하였다. DNA 손상도 분석은 혈액을 이용한 단세포 전기영동법(Single-cell gel electrophoresis, SCGE)인 Comet assay 지표에 의거한 생지표 메트릭으로 이용되었고, Tail moment, Tail DNA(%) 및 Tail length(${\mu}m$)값이 분석되었다. DNA의 손상은 하류역의 오염지역($I_Z$)에서 분명하게 나타났지만, 대조군($C_Z$) 지역에서는 그렇지 않았다. 개체군 지표로서 비만도 지수인 $C_F$ 값 분석, 체장빈도 분포 지표 및 개체 이상도(Abnormality) 지표가 생물지표로서 이용되었다. 물리적 서식지 지표는 QHEI 모델을 이용하였고, 4개 메트릭이 분석되었다. 화학적 수질지표는 부영양화 지표인 인(P)/질소(N), 화학적 산소요구량 및 전기전도도 지표가 이용되었다. 본 연구를 종합해보면, 12-메트릭 생태모형의 생지표 속성은 대조군($C_Z$)지역에 비해 오염지역($I_Z$)에서 화학적 스트레스 지표(부영양화 지표)에 아주 민감하게 반응 하는 것으로 나타났으며, 또한 이들은 부분적으로 서식지 평가지표에 의해 영향 받는 것으로 분석되었다.

• Korean Journal of Acupuncture
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• 제33권2호
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• pp.58-66
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• 2016

Objectives : In order to find a possible non-invasive manipulation tool for maintenance of the cardiovascular functions in hemorrhagic shock, this study was aimed at evaluating effects of acupoints acupressure on the changes in blood pressure and heart rate from an animal model of hemorrhagic shock. Methods : In adult Sprague-Dawley rats, hemorrhagic shock was induced by a withdrawal of arterial blood from the femoral artery with volume of 0.8 ml per 100 g of body weight using peristaltic syringe pump. We applied the acupressure with a pressure oscillator to tail as a control and 2 different acupoints of sobu(HT8), youngchun(KI1) under 3 different conditions : 1) normal arterial blood pressure without bleeding, 2) at the beginning of bleeding, and finally 3) hemorrhagic shock. Results : Under normal arterial blood pressure without hemorrhage, there was a significant increase in systolic and diastolic blood pressures by the acupressure to the tail, HT8 and especially KI1 for 30 sec compared with before acupressure. Under hemorrhagic shock condition, the tail acupressure had minimal changes in cardiovascular parameters. Either the HT8 or KI1 acupressure resulted in a significant increase in arterial pressure but did not heart rate. At the beginning of bleeding, tail acupressure failed to change the reduction of arterial pressure and heart rate. However, there was a significant increase in blood pressure and heart rate following either the HT8 or especially KI1 acupressure. Conclusions : HT8 and KI1 acupressure affected cardiovascular signs but tail acupressure did not in rat model of hemorrhagic shock. These experimental data suggest that a acupressure with a pressure oscillator to HT8 or KI1 can be one of alternative emergency manipulations to ameliorate compromised cardiovascular functions under hemorrhagic shock condition.