• 정보처리학회논문지:컴퓨터 및 통신 시스템
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• 제3권9호
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• pp.273-278
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• 2014

최근 전력의 수요공급 불균형으로 전력사용 피크시간대의 전력사용 강제 제한이 불가피하다. 따라서, 본 논문에서는, 피크전력이 발생하지 않는 시간대의 전기를 저장하고 전력부족이 예상되는 피크전력 시간대에는 저장전력을 공급하는 병렬운전 기기의 회로를 설계하는데 있다. 이 회로설계를 통하여, PRS의 핵심기능인 상용전원과 인버터 발생전원의 병렬연결 운용으로, 상용전원의 피크치 전력을 조절할 수 있었다. 또한 효율을 높이기 위하여 Transless Power Circuit DC-AC 인버터를 개발하였다. 더 나아가, 가변임피던스 제어를 적용하여 무정전 전원장치의 저장전력을 상용전원과 연계함으로써, 기존의 무정전 전원장치에서 구현을 못하고 있는 저장전력 사용시간을 획기적으로 늘릴 수 있는 기술구현 가능성을 입증하였다.

• 복식
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• 제57권7호
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• pp.70-83
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• 2007

Contemporary fashion design has been made a new attempt to extend restricted expressions through fusion with other genres in art. The recognition of fashion has recently been changed not only product but as a piece of work in specific value, concept and meaning created by fashion designer. It is observed that the contemporary fashion design has a notion to persue formative intentions and manners of Conceptual Art in Post-modern era. This study is to define this region of fashion design represented in cultural phenomena as 'Conceptual Fashion', also analyze the formative feature of this from a point of view in Conceptual art. The results which are analyzed according to outward techniques and forms, meanings and elements immanent in aesthetic contemplation of conceptual fashion lead to four distinctive things in such as anti-form, intervention and appropriation, metaphor and detour, process and series. The intrinsic values in conceptual fashion through aesthetic contemplation are indicated the four significant values in the following: the pluralistic interpretation, the parody and amusement, the pursuit of essence and truth and the participation and interaction. Conceptual fashion design is appeared complex not doing separate through classified formative features previously. And It has been evolved as a indeterminate concept which is able to variable elucidation by a non-player, as a instrument for communication on fashion culture which is aggrandized. The purpose of this study is to present of theoretical foundation about Conceptual fashion design and also to make proper understanding about interrelationship between contemporary fashion and art.

• Animal cells and systems
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• 제4권1호
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• pp.1-7
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• 2000

The genus Dendronephthya, generally known as soft corals, is reported as an abundant and variable taxon. They mostly distribute in warmer waters of the Undo-Pacific Ocean region including Korea. In spite of their abundance and ecological importance as habitats of marine organisms, there are difficulties in the study of their identification and systematics because they have morphological variabilities and limited taxonomec characters. To resolve the problems, we attempted to elucidate the genetic relationships in the genus Dendronephthya by using random amplified polymorphic DNA (RAPD) analysis. This study was based on eight dendronephthian species and one Alcyoniidae species, Alcyonium gracillimum, as an outgroup. The results from all analysis suggest that they could be classified into four groups by the growth form and the anthocodial grades as follows: the first one,D. putteri and D. suensoni with the divaricate form and VI grade; the second one,D. sp.1 and D. sp.2 with the divaricate form and III or IV grade; the third one, D. gigantea and D. aurea being closer than D. spinifera with the glomerate form and III grade; the last one, D. castanea related to D. gigantea rather than D. putteri with the umbellate form and IV grade. Moreover, the divaricate form was separated from the group of the glomerate and umbellate form. At the intraspecies level, the types of the D. castanea, D. gigantea and D. spinifera were separated depending on the feature of spicules in the polyp head, and the coloration could not influence genetic variation. From this study, we can confirm that their morphological characters are compatible with the genetic variation, also RAPD analysis is a very useful method for resolving the systematic relationships of den-deonephthians.

• 음성과학
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• 제1권
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• pp.153-200
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• 1997

In languages such as Japanese, it is very common to observe that short peripheral vowel are completely voiceless when surrounded by voiceless consonants. This phenomenon has been known as Montreal French, Shanghai Chinese, Greek, and Korean. Traditionally this phenomenon has been described as a phonological rule that either categorically deletes the vowel or changes the [+voice] feature of the vowel to [-voice]. This analysis was supported by Sawashima (1971) and Hirose (1971)'s observation that there are two distinct EMG patterns for voiced and devoiced vowel in Japanese. Close examination of the phonetic evidence based on acoustic data, however, shows that these phonological characterizations are not tenable (Jun & Beckman 1993, 1994). In this paper, we examined the vowel devoicing phenomenon in Korean using data from ENG fiberscopic and acoustic recorders of 100 sentences produced by one Korean speaker. The results show that there is variability in the 'degree of devoicing' in both acoustic and EMG signals, and in the patterns of glottal closing and opening across different devoiced tokens. There seems to be no categorical difference between devoiced and voiced tokens, for either EMG activity events or glottal patterns. All of these observations support the notion that vowel devoicing in Korean can not be described as the result of the application of a phonological rule. Rather, devoicing seems to be a highly variable 'phonetic' process, a more or less subtle variation in the specification of such phonetic metrics as degree and timing of glottal opening, or of associated subglottal pressure or intra-oral airflow associated with concurrent tone and stricture specifications. Some of token-pair comparisons are amenable to an explanation in terms of gestural overlap and undershoot. However, the effect of gestural timing on vocal fold state seems to be a highly nonlinear function of the interaction among specifications for the relative timing of glottal adduction and abduction gestures, of the amplitudes of the overlapped gestures, of aerodynamic conditions created by concurrent oral tonal gestures, and so on. In summary, to understand devoicing, it will be necessary to examine its effect on phonetic representation of events in many parts of the vocal tracts, and at many stages of the speech chain between the motor intent and the acoustic signal that reaches the hearer's ear.

• 한국음향학회지
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• 제39권4호
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• pp.263-269
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• 2020

본 논문에서는 정상상태와 8가지의 고장이 재현가능한 회전체를 제작하고 진동 데이터를 취득하였다. 취득한 데이터로 특징을 계산하여 인공신경망과 유전알고리즘을 적용한 고장진단을 통해 정확성을 분석한다. 최적의 시간과 높은 정확성의 구현을 위해 특징을 3가지 영역으로 구분하여 고장진단에 적용하였다. 설정변수는 학습수로 설정하였다. 회전체 고장진단의 결과는 다른 영역보다 주파수영역에서 높은 정확성을 보였으며 학습수 5000, 8000회에서 10회의 구동 모두 정확한 고장진단을 하였다. 시간의 효율성을 고려하였을 경우, 학습수가 5000회일 때 가장 우수하다고 판단하였다.

• 한국환경과학회지
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• 제23권4호
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• pp.625-635
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• 2014

Temporal variation of groundwater levels in Jeju Island reveals time-delaying and dispersive process of recharge, mainly caused by the hydrogeological feature that thickness of the unsaturated zone is highly variable. Most groundwater flow models have limitations on delineating temporal variation of recharge, although it is a major component of the groundwater flow system. A new mathematical model was developed to generate time series of recharge from precipitation data. The model uses a convolution technique to simulate the time-delaying and dispersive process of recharge. The vertical velocity and the dispersivity are two parameters determining the time series of recharge for a given thickness of the unsaturated zone. The model determines two parameters by correlating the generated recharge time series with measured groundwater levels. The model was applied to observation wells of Jeju Island, and revealed distinctive variations of recharge depending on location of wells. The suggested model demonstrated capability of the convolution method in dealing with recharge undergoing the time-delaying and dispersive process. Therefore, it can be used in many groundwater flow models for generating a time series of recharge.

• 한국광학회지
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• 제33권6호
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• pp.310-316
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• 2022

Presampled 변조전달함수(MTF) 측정에서 slant 표적각도 변화에 따라 MTF 결과의 차이가 있음을 확인하였고, 표적각도 변화에 대한 오차를 줄이기 위하여 획득한 edge spread function 그래프를 fitting하여 측정값의 오차를 줄일 수 있는 측정기법을 연구하였다. Presampled MTF 방법의 특성상 표적이 회전함에 따라 투영되는 공간주파수의 강도분포는 표적의 회전각도에 따라 변화하며, 이로 인하여 MTF 차이가 발생함을 확인하였다. 이 연구에서는 획득한 영상의 1개의 열에 대해서만 fitting을 한 후 MTF를 계산하였다. Fitting을 이용한 계산은 기존의 presampled MTF 방법과 비교하여 표적 회전에 따른 오차가 줄어듬을 확인하였다. 이 방법은 MTF를 이용한 자동 초점 등 다양한 각도의 표적에 응용이 가능할 것으로 기대된다.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• 제2권1호
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• pp.1-14
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• 2021

The study has been carried out with an objective to prepare Siberian roe deer habitat potential maps in South Korea based on three geographic information system-based models including frequency ratio (FR) as a bivariate statistical approach as well as convolutional neural network (CNN) and long short-term memory (LSTM) as machine learning algorithms. According to field observations, 741 locations were reported as roe deer's habitat preferences. The dataset were divided with a proportion of 70:30 for constructing models and validation purposes. Through FR model, a total of 10 influential factors were opted for the modelling process, namely altitude, valley depth, slope height, topographic position index (TPI), topographic wetness index (TWI), normalized difference water index, drainage density, road density, radar intensity, and morphological feature. The results of variable importance analysis determined that TPI, TWI, altitude and valley depth have higher impact on predicting. Furthermore, the area under the receiver operating characteristic (ROC) curve was applied to assess the prediction accuracies of three models. The results showed that all the models almost have similar performances, but LSTM model had relatively higher prediction ability in comparison to FR and CNN models with the accuracy of 76% and 73% during the training and validation process. The obtained map of LSTM model was categorized into five classes of potentiality including very low, low, moderate, high and very high with proportions of 19.70%, 19.81%, 19.31%, 19.86%, and 21.31%, respectively. The resultant potential maps may be valuable to monitor and preserve the Siberian roe deer habitats.

• 산업경영시스템학회지
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• 제44권4호
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• pp.12-22
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• 2021

This article suggests the machine learning model, i.e., classifier, for predicting the production quality of free-machining 303-series stainless steel(STS303) small rolling wire rods according to the operating condition of the manufacturing process. For the development of the classifier, manufacturing data for 37 operating variables were collected from the manufacturing execution system(MES) of Company S, and the 12 types of derived variables were generated based on literature review and interviews with field experts. This research was performed with data preprocessing, exploratory data analysis, feature selection, machine learning modeling, and the evaluation of alternative models. In the preprocessing stage, missing values and outliers are removed, and oversampling using SMOTE(Synthetic oversampling technique) to resolve data imbalance. Features are selected by variable importance of LASSO(Least absolute shrinkage and selection operator) regression, extreme gradient boosting(XGBoost), and random forest models. Finally, logistic regression, support vector machine(SVM), random forest, and XGBoost are developed as a classifier to predict the adequate or defective products with new operating conditions. The optimal hyper-parameters for each model are investigated by the grid search and random search methods based on k-fold cross-validation. As a result of the experiment, XGBoost showed relatively high predictive performance compared to other models with an accuracy of 0.9929, specificity of 0.9372, F₁-score of 0.9963, and logarithmic loss of 0.0209. The classifier developed in this study is expected to improve productivity by enabling effective management of the manufacturing process for the STS303 small rolling wire rods.

• The Journal of Asian Finance, Economics and Business
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• 제9권6호
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• pp.389-402
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• 2022

The purpose of the study is to analyze the significant impacts of expectations, performance, complaints, and fairness that affect consumer satisfaction. The methodology involves reviewing and referencing relevant literature carefully, then proposing a model for customer satisfaction. This study is empirically based on a survey with 50 respondents who work in the field of import and export in the region stretching from the north to the south of Vietnam. The sampling method used in this study is the in-depth interview method. The results show that: (1) expectation has a specific impact on customer satisfaction, (2) performance has a positive impact on customer satisfaction, and (3) complaint which is an intermediary factor between expectation, performance, and fairness has an impact on satisfaction, (4) fairness has a positive effect on satisfaction, in addition, fairness is an extremely important feature when customers choose an import-export service. Research implies that increasing expectations, performance, and fairness results in an improved customer experience and satisfaction when they use the service. It is suggested that the complaint factor continue to be studied and looked into because it still has some effect on satisfaction and is an intermediate variable that changes how the other factors relate to each other.