• Journal of Information Processing Systems
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• 제13권5호
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• pp.1397-1409
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• 2017

For text categorization task, distinctive text features selection is important due to feature space high dimensionality. It is important to decrease the feature space dimension to decrease processing time and increase accuracy. In the current study, for text categorization task, we introduce a novel statistical feature selection approach. This approach measures the term distribution in all collection documents, the term distribution in a certain category and the term distribution in a certain class relative to other classes. The proposed method results show its superiority over the traditional feature selection methods.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 추계학술대회 논문집
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• pp.1574-1585
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• 2007

In the more and more continues traffic difficulty which comes to be serious it is for solve, in order to like this used plan for new town light train automatic fare collection system, the city development which is balance and the passenger whom it uses, in consequence of the fact that recently believer instruction, the automatic fare collection system the reverse which is convenient is used in the scripture season which is embossed with means it introduces it operates and a manpower with the scientific service control which leads the electric computer anger of passenger service improvement and accounting and statistical business it reduces, the use is convenient and the possibility facility of operating efficiently in rational plan in order to be, description below for the service automation equipment where the efficiency improves it is. Service automation equipment uses a scripture season to be the first boundary gate of the passenger, there must be a place where it uses a service automation facility and in order to be convenient, it considers the moving area and a wait of the reverse station passenger moving area and the space where, must secure the automatic fare collection system which it follows in automation of facility and the service operation of the reverse station which is ticket sale, the collection of tickets back the passenger is convenient and in order it will be able to use, must do and must consider, must arrange the efficient characteristic of the maintenance civil official services.

• Journal of Astronomy and Space Sciences
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• 제17권1호
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• pp.99-106
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• 2000

When a deployed probe is biased by a high positive potential during a space experiment, the payload is induced to a negative voltage in order to balance the total current in the whole system. The return currents are due to the responding ions and secondary electrons on the payload surface. In order to understand the current collection mechanism, the process was simulated with a combination of resistor, inductor, and capacitor in SPICE program which was equivalent to the background plasma sheath. The simulation results were compared with experimental results from SPEAR-3 (Space Power Experiment Aboard Rocket-3). The return current curve in the simulation was compatible to the experimental result, and the simulation helped to predict the transient plasma response to a high voltage during the plasma sheath formation.

• Journal of Astronomy and Space Sciences
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• 제34권1호
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• pp.55-65
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• 2017

We studied the hour-lines of six extant Yangcheon-cheoks in Korea. To find whether Yangcheon-cheok was used in the whole area of Korea, we calculated the length of shadows of Yangcheon-cheok on the Korean Peninsula, Nanjing and Beijing as well as Hanyang (Seoul), according to 24 solar terms. Comparing the length of shadows with hour-lines of those relics, we could find that Yangcheon-cheok was suitable for use at limited times (from 9:00 to 15:00) during the year. Also, this sundial is more appropriate for use at low latitudes than high ones. Among existing relics, that of Seoul Museum of History made with porcelain was much more suitable to use at Hanyang and its higher latitude. Lee's collection was also suitable to use at Nanjing. It is certain that Yangcheon-cheok was a portable sundial which could be used from nine to fifteen of clock all the year around except for the winter season.

• 대한원격탐사학회지
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• 제37권3호
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• pp.463-473
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• 2021

본 연구에서는 최근 USGS에서 공개한 Landsat 8 Collection 2 Level 2 Science Product (L2SP) 위성 영상을 이용하여 국내 지표면 온도를 산출하였고, 기존 Landsat 8 Collection 1 Level 1 Terrain Precision (L1TP) 위성 영상을 활용하여 산출한 국내 지표면 온도와의 비교와 기상청 종관기상관측자료(Automated Synoptic Observing System, ASOS)와의 검증을 통해 L2SP 기반 지표면 온도 자료의 국내 영역에 대한 적합성을 평가하고자 하였다. L2SP는 연구 및 분석에 용이하도록 Landsat 8 Collection 2 Level 1 데이터를 기반으로 만든 Level 2 자료로, 기존의 계산식을 통해 산출해야 하는 지표면 반사도 자료와 지표면 온도 자료를 계산 처리 없이 바로 사용할 수 있다는 장점이 있다. 2018년부터 2020년까지 3년간의 Landsat 8 지표면 온도 산출물과 관측소 지점 8개소 주변 3×3 격자 영역과의 비교한 결과, 8개 관측소 기준 L2SP 지표면 온도와 L1TP 지표면 온도의 평균 피어슨 상관계수(Pearson correlation coefficient)는 각각 0.971, 0.964로 두 자료 모두 상당히 강한 양의 상관관계를 보여주었으며, RMSE (Root Mean Square Error)의 경우 각각 4.029℃, 5.247℃로 L2SP 지표면 온도 자료가 더 낮은 RMSE를 보여주는 것을 확인 하였다. 이는 관측소 위치별로 값에 차이가 생길 수 있지만 평균적인 지표 결과를 보았을 때, L2SP 지표면 온도 자료가 L1TP를 통해 산출되는 지표면 온도 자료와 비교했을 때 준수하거나 그 이상의 정확도를 보여주어 국내 지표면 온도 산출 연구에 적합하다고 판단된다. 따라서 향후 계절적 요인과 고도에 따른 온도 차이 등의 환경 및 지형적인 요인도 고려를 하거나, 본 연구 과정에서 발생한 Science Product의 고정적인 영상 품질 문제 등이 개선된다면 보다 더 안정적이고 정확도 높은 지표면 온도 참조 자료로써의 유용성이 클 것이라 판단된다.

• 영어영문학
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• 제58권6호
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• pp.1023-1039
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• 2012

The rising urban space in the United States at the turn of the twentieth century was an exemplary site of struggles between the dominant white population and those who migrated from the imperial peripheries. By setting up the space of Chinatown as a segregated sphere within the urban space, the dominant white American society attempted to recreate the sense of distance between themselves and the racial "others." Accordingly, the dominant narrative representations of San Francisco Chinatown at the turn of the century endeavored to produce and maintain the spatial dichotomies between the orderly spaces of natives and the disruptive immigrant communities within the larger boundary of modern American city space. As a Eurasian woman writer, Sui Sin Far attempted to provide distinctive portrayals of the space of Chinatown and its inhabitants that were far different from those of her contemporaries. Through her portrayals of San Francisco Chinatown in her collection of short-stories, Mrs. Spring Fragrance and Other Writings (1912), Far challenges against the false stereotypes and misreading of this unique immigrant space within and efforts to present the Chinatown as a heterotopic diaspora space where the "insiders" and the "outsiders" of the American urban space intermingle and influence each other.

• 한국환경보건학회지
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• 제46권1호
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• pp.78-87
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• 2020

Objectives: To identify the degree of physical burden, a determination was undertaken of dust collection efficiency, inhalation pressure, and CO₂ concentration related to health masks certified by the Ministry of Food and Drug Safety (MFDS). Methods: Twenty health masks were purchased on the market. Dust collection efficiency and inhalation pressure were determined in the same manner as in MFDS certification testing, respectively using TSI Model 8130 (TSI, U.S.) and ART Plus (Korea). CO₂ concentrations for 20 subjects using a CO₂ analyzer (G100, G150, Geotechnical Instrument Ltd., UK) were measured with a similar method as a total inward leakage test. In addition to CO₂ levels, dead space volumes in the masks was determined for predicting concentrations of CO₂ in inhalation air. Results: Most of the dust collection efficiencies found for the 20 masks were far higher than the standard. Four KF94s met KF99 and four KF80s even met KF94. Most inhalation pressures were also much lower than the standard, with many almost one-half of the standard. The mean and standard deviation of CO₂ concentration in the mask were 2.9±0.44%. Considering dead volume, the prediction for CO₂ concentration in the inhalation air was 4,395±1,266 ppm. Conclusions: For healthy men and women, the dust collection efficiency and inhalation pressure of health masks were not at a level that would affect their health. Although CO₂ levels in the inhalation air were predicted not to affect health, research on the physiological effects of health masks on Koreans is needed for more precise research.

• 한국가구학회지
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• 제23권1호
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• pp.75-83
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• 2012

Space dominates all the art activities human do and plays a role of providing aesthetic emotion. Architecture, sculpture, painting, and furniture, etc. these two and three dimensional works are represented in space and interpreted the role of its form, structure and function. Each area is different, but space has been studied in philosophy, physics, geometry, and mathematical studies, etc. and has been consistently interpreted and represented relating to a variety of human creative activity. Furniture is also three dimensional art being dependent on space. In the United States in 2004, I made the living room bench by applying the spatial concept at Rochester Institute of Technology. Two years later, this design was adopted by wendell Castle Collection, an American furniture company, then prototype were made and tested three times during a year, and then since 2007 as indoor benches it has been manufactured in the United States. The study's purpose is to order the process of its development based on the experience of bench production applied the spatial concept, and by analyzing the properties of spatial concept, I am planning to propose a new concept on interaction with the space and furniture for next.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 1998년도 The Third Asian Fuzzy Systems Symposium
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• pp.95-100
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• 1998

A notion of 'fuzzy' convergence of filters on a set is introduced. We show that the collection of fuzzy L-limit spaces forms a cartesian closed topological category and obtain an interesting relationship between the notions of 'fuzzy' convergence structure and convergence approach spaces.

• 대한수학회논문집
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• 제11권1호
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• pp.169-174
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• 1996

Let $C_\alpha$ be the collection of those members of $C[0,1]$ which are H$\ddot{o}lder $\alpha$-continuous functions on [0,1]. In this paper, I will show that $\mu(C_{\frac{1}{2}) = 0$ for Wiener measure $\mu$.