• Asian Journal of Atmospheric Environment
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• 제7권2호
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• pp.114-119
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• 2013

The characteristics of Asian dust (AD) in Korea between 1997 and 2005 were investigated, focusing on peak 1-hour $PM_{10}$ concentrations during AD events at seven cities over the Korean Peninsula. The frequency of AD events decreased from Seoul to Busan, indicating the major pathway of AD in Korea was from northwest to southeast. AD events were most frequent in 2001 while peak concentrations during AD events were much higher in 2002. Recent works show that the trajectories from northerly directions increased during the 2000s and later (Chun, 2009; Kim, 2008). In this work, the fraction of trajectories from the northwest was the largest on the whole, although trajectories from each direction varied by city and year. It is presumed that high concentrations of $PM_{10}$ during AD events are generally associated with trajectories from the northwest rather than from the source region.

• 한국안전학회지
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• 제12권3호
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• pp.155-160
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• 1997

The conventional fault tree and reliability analysis gives in many cases insufficient information concerning the relative frequencies of hazard events. This stems from that the basic events are not stationary and ergodic, and therefore the tolerances of the induced and top events cannot be calculated reliably based on the classical probability theory. To overcome this difficulty, the paper considers the relative frequencies of the basic events as fuzzy numbers and uses instead of probability, possible considerations for evaluating the mean values and tolerances of the top events. The possibility distribution of the basic events can be approximated based on heuristic considerations. This paper shows the use of these operators for constructing fault trees. The use of the method for numerical calculation is demonstrated on a field safety problem.

• Wind and Structures
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• 제9권3호
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• pp.193-215
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• 2006

This paper presents an analysis of wind velocity measurements obtained from four ultrasonic anemometers arranged in a vertical formation. The anemometers were located in a rural environment with a view to providing detailed information on the flow statistics of the lower part of the atmospheric boundary layer, particularly for the extreme wind events that are important in loading calculations. The data is analysed using both conventional analysis and conditional sampling. The latter is combined with wavelet analysis in order to provide a detailed analysis of the energy/frequency relationship of the extreme events. The work presented in this paper suggests that on average the extreme events occur as a result of the superposition of two independent mechanisms - large scale events that scale on the atmospheric boundary layer thickness and small scale events a few tens of metres in size.

• 천문학논총
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• 제14권1호
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• pp.9-22
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• 1999

Current searches for gravitational microlensing events are being carried out only by a photometric method. In this review paper, we demonstrate that the nature of Galactic lenses can be significantly better constrained with the additional astrometric observations of microlensng events. First, by astromerically observing lensing events, one can resolve the lens parameter degeneracy, and thus the lens mass can be determined with improved precision. Second, by being free from the blending problem, astrometric observations of lensing events will allow one to improve the uncertainties in the determined Einstein time scales. Third, the lens brightness, which could not be measured photometrically, can be measured from the astrometric observations of lensing events, and thus the nature of lens matter can be better constrained. Finally, with the help of astrometric followup observations of a binary-lens event, one can uniquely determine the solution of lens parameters, allowing one to obtain important astronomical information about the source star and the lens itself.

• 아동학회지
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• 제19권2호
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• pp.35-47
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• 1998

Negative life events, self-esteem, perceived social support, and maladjustment were studied longitudinally among late elementary children. Subjects were 241 boys and girls for depression and 258 for antisocial behavior. The instruments were the Adolescent Perceived Events Scale, the Rosenberg Self-Esteem Scale, the Social Support Scale for Children, the Revised Korean Version of the Center for Epidemiologic Studies' Depression Scale, and the Antisocial Behavior Scale. The results showed that the way variables were reciprocally related to one another in patterns over a period of one year differed by internal and external adjustment. For depression, depression at Time 1 had effects on self-esteem, social support, and depression at Time 2. For antisocial behavior, negative life events at Time 1 influenced negative life events, self-esteem, social support, and antisocial behavior at Time 2. The findings were discussed in relation to the effects of negative life events, self-esteem, and perceived social support on maladjustment.

• 천문학회지
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• 제44권4호
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• pp.109-113
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• 2011

In current microlensing planet searches that are being carried out in a survey/follow-up mode, the most important targets for follow-up observations are lensing events with high magnifications resulting from the very close approach of background source stars to the lens. In this paper, we investigate the dependence of the sensitivity to planets on detailed properties of high-magnification events. From this, it is found that the sensitivity does not monotonically increase as the impact parameter between the lens and the source trajectory decreases. Instead, it is roughly the same for events with impact parameters less than a certain threshold value. It is also found that events involving main-sequence source stars are sensitive to planets in a much wider range of separation and mass ratio, than those events involved with giant source stars. Based on these results, we propose observational strategies for maximal planet detections considering the types of telescopes available for follow-up observations.

• Nuclear Engineering and Technology
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• 제54권7호
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• pp.2510-2518
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• 2022

The main purpose of collecting and analyzing operating experience events is to look for insights to improve safety. The underlying assumption is the correlation and causality between events with different safety significances. The analysis of this assumption could be valuable to optimize operating experience feedback programs and to enhance safety. This paper analyses the correlation between events with different safety significances. Groups of events from six nuclear energy related databases are considered. The findings are that a correlation exists but with various levels and not as large or consistent as might be expected across different databases. These results might be the basis for further work to analysis causality, to find out how a similarity in causes influences the correlation, and finally to improve the operating experience program.

• 건축역사연구
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• 제14권2호
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• pp.143-157
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• 2005

This study aims to analyze functions and characteristics of 'Cha-il(遮日)' which was used at ritual events(宮中儀禮行事) in the Joseon dynasty, Joseon dynasty had many ritual events related with O-Rae(五禮). Cha-il was almost used at important ritual events, especially at the congratulatory events. The congratulatory events(宮中宴享) are the representative events were held with many temporary install facilities(假設施設) in a palace. Cha-il was a kind of Korean traditional membrane structures. Cha-il was set up for cutting off interior space from sunlight and rain. In general, Cha-il was Consisted of Cha-il-jang(遮日帳:woven fabric), Cha-il-jook(遮日竹:bamboo column), some ropes, and fixing wares. In the congratulatory events, three types of Cha-il. were set up. Baek-mok-Dae-Cha-il(白木大遮日)was made of cotton cloth. Yu-Dun-Cha-Il(油芚遮日) was made of oiled paper or oiled cotton cloth. Man-Joen-Cha-Il(滿箭遮日) consisted of wooden structure. Baek-mok-Dae-Cha-il(白木大遮日)was set up on the most important area of stage for protecting from sunlight. Yu-Dun-Cha-Il was set up on less important area of stage for protecting from sunlight and rain. Man-Joen-Cha-Il was set up below Baek-mok-Dae-Cha-il for supporting and draining raindrops off. The results of this study were as follows; Functions of Cha-il were to protect ritually space from sunlight and rain, and to extend ritually space, and to reconstruct ritually space. Cha-il was the peculiar temporary install facility which differed from other countries.

• 한국의류학회지
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• 제35권1호
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• pp.37-50
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• 2011

This study analyzed the content of special selling events in internet shopping malls to establish academic standards for special selling events as tools for sales promotions and to suggest systematic guidelines for marketers designing special selling events. Based on a content analysis, the titles of special selling events from four internet shopping malls selling women's apparel were analyzed. A total of 692 titles were analyzed. The results are as follow. First, the contents categories of special selling events could be classified into two groups such as 'theme' and 'tool'. Season, product characteristics, style, advice/information, brand, annual/social events, and marketing events were the main content categories that came under the 'theme' group; in addition, the price benefit, free offers, product mix, and marketing technique were the main content categories that came under the 'tool' group. Each main content category was subdivided into several segment content categories. Second, most of the titles were composed of more than two segment content categories that involved various information and benefits; however, the portion of titles composed of only theme related content categories or only tool related content categories was substantial. Furthermore, the theme related content categories were more than the tool related content categories. Third, the usage frequencies of the contents categories were analyzed. The upcoming season, single brand, sale/discount, item/material/color, special price/lowest price, and period/time/quantity limits were the segment content categories that held a high rank. Forth, most of the factors that evoked the unplanned purchases of consumers were related to the content categories of special sale events.

• International Journal of Contents
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• 제14권3호
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• pp.7-16
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• 2018

The extent and depth of the event plan determines the scope of pedagogical experience in situations and consequently the quality of immersive learning based on our simulated world. In contrast to planning in conventional narrative-based systems mainly pursuing dramatic interests, planning in virtual world-based pedagogical systems strive to provide realistic experiences in immersed situations. Instead of story plot comprising predetermined situations, our inter-event planning method aims at simulating diverse situations that each involve multiple events coupled via their associated agents' conditions and meaningful associations between events occurring in a background world. The specific techniques to realize our planning method include, two-phase planning based on inter-event search and intra-event decomposition (down to the animated action level); autonomous and independent agents to behave proactively with their own belief and planning capability; full-blown background world to be used as the comprehensive stage for all events to occur in; coupling events via realistic association types including deontic associations as well as conventional causality; separation of agents from event roles; temporal scheduling; and parallel and concurrent event progression mechanism. Combining all these techniques, diverse exogenous events can be derived and seamlessly (i.e., semantically meaningfully) integrated with the original event to form a wide scope of situations providing chances of abundant pedagogical experiences. For effective implementation of plan execution, we devise an execution scheme based on multiple priority queues, particularly to realize concurrent progression of many simultaneous events to simulate its corresponding reality. Specific execution mechanisms include modeling an action in terms of its component motions, adjustability of priority for agent across different events, and concurrent and parallel execution method for multiple actions and its expansion for multiple events.