• 로봇학회논문지
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• 제7권2호
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• pp.120-128
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• 2012

The loop closure problem is one of the most challenging issues in the vision-based simultaneous localization and mapping community. It requires the robot to recognize a previously visited place from current camera measurements. While the loop closure often relies on visual bag-of-words based on point features in the previous works, however, in this paper we propose a line-based method to solve the loop closure in the corridor environments. We used both the floor line and the anchored vanishing point as the loop closing feature, and a two-step loop closure algorithm was devised to detect a known place and perform the global pose correction. We propose an anchored vanishing point as a novel loop closure feature, as it includes position information and represents the vanishing points in bi-direction. In our system, the accumulated heading error is reduced using an observation of a previously registered anchored vanishing points firstly, and the observation of known floor lines allows for further pose correction. Experimental results show that our method is very efficient in a structured indoor environment as a suitable loop closure solution.

• 대한치과보철학회지
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• 제39권4호
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• pp.376-390
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• 2001

Alveolar bone changes after immediate loading on implants up to one year were observed by means of standard intraoral X-ray measurement which were taken at 3 month intervals. At the same time, bone density changes were observed according to digital subtraction method which is a becoming a more and more promising diagnostic tool for implants. Following results were obtained ; 1. There was no significant difference in the amount of alveolar bone loss implant type, sex and implant diameter, but there was difference according to case selection. In fully bone anchored prostheses cases, bone loss was $1.16{\pm}0.15m$ whereas, in partial edentulous cases, it was $1.84{\pm}0.08mm$. 2. Alveolar bone loss after immediate loading showed a higher degree of bone loss than after submerged loading in the initial three months. But there were no significant difference at the 12th month. 3. According to the one year bone density change observation at the alveolar bone surrounding the implant, significant change was observed vertically, whereas no significant change could observed horizontally. According to the above mentioned results, we can conclude that immediate loading of implants results in a higher degree of alveolar bone loss in one year than submerged loading. But since alveolar bone loss rate decreases to a reasonable rate after the initial 3 months of rapid bone loss, immediate loading of implants seems to be an acceptable treatment modality for patients with good bone conditions. Fully bone anchored cases showed an favorable outcome, but partial edentulous cases showed more bony resorption. So this cases considered in case selections. Bone density changes observation in the study was performed for only one year therefore a more longitudinal observation may be studied.

• Ocean and Polar Research
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• 제43권3호
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• pp.193-203
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• 2021

In-situ experiment using ocean buoys is a direct ocean observation and has been playing an important role from the past to the present based on high reliability. The ocean buoy is operated more stable than before due to the technological development of communication (GPS, satellite, …) and equipment, but still moored buoys are not free from various accidents occurring in the ocean. Nevertheless, there is currently a lack of countermeasures or manuals about mooring accidents. Therefore, in this study, based on the experience of operating buoys conducted for many years, the advantages and disadvantages of ocean buoys according to size were analyzed. and legal procedures before and after buoy mooring were presented to enhance the use of buoys. And it is suggested to realize successful experiment by proposing considerations before mooring the buoy in preparation for an accident.

• 한국안전학회지
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• 제31권1호
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• pp.132-138
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• 2016

The purpose of this study was to develop safety competences, a set of behavioral indicators of each competence and measuring methods of behavioral indicators for preventing human error of nuclear power plants(NPPs). The safety competences and behavioral indicators were derived from the five steps consisted of derivation of preliminary competence items through literature review, content analysis, interview(FGI, BEI), examination of content validity and decision making of final indicators. The results showed that 13 core safety competences and 35 behavior indicators were derived finally. In addition, the methods of measuring safety competences or behavioral indicators such as Behaviorally Anchored Rating Scale (BARS), Behavior Observation Scale (BOS) were developed and suggested.

• International Journal of Railway
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• 제3권1호
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• pp.1-6
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• 2010

The steel plate-girder bridges with concrete gravity piers have possibilities of overturning by lateral inertial force which can be reproduced by sudden earthquake attack. This paper explores an overturning mechanism of existing concrete gravity pier onto the sandy soil in the event of lateral push-over load by in-situ experimental observation. The in-situ push-over experiment for pier with earth anchors between spread footing and rock beds exhibits a reasonable enhancement of ductility against overturning. In unanchored system, a flexural crack at cold joint of concrete pier is not developed because of the over-turning of the pier. This leads a global instability (rotation) of pier-footing system with relatively low stresses in pier itself. While a lateral load is persistently increased in anchored system, the successive flexural cracking failure at cold joint is observed even after the local shear failure of soil due to redistribution of stress equilibrium between soil and pier structure as long as a tensile action of anchor cable is active.

• 한국소음진동공학회논문집
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• 제19권11호
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• pp.1126-1132
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• 2009

Bridge structures are designed to support ordinary loadings such as vehicles, wind, temperature and current as well as unexpected loadings like earthquakes and storm. Especially, the displacement of Flexible bridges like an suspension bridge under ordinary loading conditions is necessary to be monitored. In case of long span bridges, there are some difficulties in monitoring the displacement of center of the main span using traditional laser displacement sensors. In this study, the static and dynamic displacement responses due to vehicle loadings were measured by DGPS(differential global positioning system) technique. The displacement response data were compared with data obtained from traditional laser displacement sensors so that the static and dynamic behavior of the bridge under vehicle loadings was examined and the applicability of the displacement response measurement using DGPS technique was verified. The static and dynamic loading test for an self-anchored suspension bridge, So-rok Bridge, was performed using vehicles. The displacement response from DGPS technique and that from laser displacement sensors of the bridge monitoring system were compared. The amplitude of white noise from DGPS based measurement was about 7 mm and that of laser displacement sensor based measurement was about 3 mm. On the other hand, dynamic behavior of the center of main span from DGPS based measurement showed better agreement with influence line of the bridge than that from laser displacement sensors. In addition, there were some irregular and discontinuous variation of data due to the instability of GPS receivers or frequent appearance of GPS satellites. Post-processing via the reference station close to an observation post provided by NGII(National Geographic Information Institute) will be a counter-plan for these defects.

• 방송공학회논문지
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• 제21권2호
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• pp.180-191
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• 2016

일반 가시광선 영상의 확대를 위한 알고리즘을 선명도가 떨어지는 적외선 영상에 적용시켰을 때 개선효과가 미흡한 문제점을 해결하기 위해 본 논문은 적외선 영상을 위한 영상 확대 알고리즘을 제안한다. 제안 알고리즘은 적외선 영상이 가시광선 영상에 비해 디테일이 적다는 특성과 에지 영역에 대해 사람이 시각적으로 민감하다는 특성을 고려하여 ADRC(Adaptive Dynamic Range Coding)와 같은 단순한 분류기법을 적용시켰으며, 에지 영역에 대해서만 알고리즘을 적용시켜 연산량을 절약한다. 또한 확대 영상의 선명도 개선을 위해 합성과정에서 전처리나 후처리를 추가시키는 방법 대신 학습과정에서 전처리를 추가하여 합성과정에서 연산량 증가 없이 확대 영상의 선명도를 개선하였다. 제안 알고리즘은 크게 학습과정과 합성과정으로 나뉜다. 이와 같은 방법으로 영상 확대 알고리즘을 수행하였을 때 최신의 영상확대 기법인 A+ (Anchored neighborhood regression)기법 대비 JNB(Just Noticeable Blur)수치가 평균 0.0201만큼 높은 결과를 확인할 수 있었다.

• 성인간호학회지
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• 제12권4호
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• pp.690-705
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• 2000

This ethnography was based on Kleinman's explanatory model of a health care system. It is conducted to make thick discription of illness conception of the elderly in a sociocultural context. The basic assumptions were as follows. 1) A health care system is a cultural system, and as with any other cultural system, it is a system of symbolic meanings anchored in a particular arrangement of social institutions and patterns of interpersonal relationships; 2) In all societies health care activities are more or less interrelated. Therefore, they need to be in a holistic manner as socially organized responses to disease that constitute a special cultural system; health care system; 3) Health and illness experiences are the natural process of disease. Individuals who recognized a for state of health, their family, neighbors, and communities define the state, search for causes of the health problems, and response to it. According by, they proceed to search for healing stratagies. So, understanding of the illness experience is the starting point for health care. The study participants were 12 elders aged 60 or more. The fieldwork was conducted in an agricultural clan village of Namwon city. The data collection and analysis were cyclic, from descriptive observation, domain analysis, focused observation, taxanomic analysis, selected observation, componential analysis, and finally cultural themes were all analysed. Proxemic and text analysis techniques were used according to the characteristics of the data. The data of sociocultural context and descriptive data were collected from 1990 to 1992. Informations on illness concepts were collected during 1994 using focused observation. Data confirming and contrast observations were conducted from 1997 and 1999. Illness concepts of the elderly were taxonomized supernatural cause, non-supernatural cause, immediate cause, and ultimate cause. The supernatural ones were ancestors, god of home, god of village, and ghost such as 'sal(evil force of dead man)' and 'gagqui(ghost of begger)'. The non-supernatural ones were Ki, natural phenomenones, natural objects, foods, human and human behaviors. Immediate ones were insufficiency and overflows, discretion and consolidation, disorder and out of order, cloudness and contamination, and fluctuation and stagnation of supernatural cause and non-supernatural ones. Ultimate causes were intrusion and loss of supernatural and nonsupernatural ones. The cultural themes of illness concepts of the elderly are: 1) illness concepts are not based on causality principle, but on reciprocal principle; 2) illness concepts are affected by social level and charicteristics of the patients; 3) the causes of disease are recognized as imposed both positive and negative effects on health based on interpretation of the indiviuals; 4) illness concepts reflects on principles of everyday life of the society members such as hierachial structure and group cohesiveness; 5) illness concepts are ruled on principle of reciprocity and spread; 6) illness concepts are interrelated with physical environment of the participants. It can be concluded that the illness concepts of the elderly in a traditional clan village are a component of health care system as a cultural system based on these results. The these results can be a useful basis for gerontological nursing practice and education.

• 동남아시아연구
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• 제21권3호
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• pp.1-42
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• 2011

In terms of seaborne contacts of Vietnamese court with foreign countries had two directions in the 19th century. One was with Island Southeast Asian ports such as Singapore, Malacca, Penang, Batavia, and Manila. The other direction was to Canton. The Canton contact of Vietnam again can be interpreted as one of the two directions of Vietnamese contact with China. The inland route far to Beijing was based on the political and diplomatic consideration, while the closer route to Canton by the court vessels was more for the economic consideration as the case for the contact with the Island Southeast Asia. In this article, author discusses three issues to illuminate the nature of the trips of the court vessels of the Nguyễn dynasty to Canton. First is to clarify detail itinerary of the trip from the Thuận An Estuary to the City of Canton via Đà Nãng and Hanan. Unlike to the Western ships that visited Canton but anchored at the Huang Fu, Vietnamese square-rigged/copper-bottomed ships sailed up the Pearl river to the Guangzhou city front to stay for four or five months before they returned to Vietnam. In the second chapter, various kinds of observation of the Vietnamese officials are discussed. If the objects of the observation are divided into two categories, one is the world Westerners in Canton, and the other is the world of Chinese. In a same place, Canton, the Vietnamese officials could have enough chance to compare the two worlds clearly. An important consequence for the Vietnamese officials was to conclude that the mechanical technology of the Westerners was better than that of Chinese. This kind of conclusion led the Vietnamese court to send court personnels to learn Western technologies and languages in the port cities of Island Southeast Asia and to enlarge contacts with them. In the last chapter, author tries to find out the items that the Vietnamese mission purchased in Canton in exchange to the Vietnamese products. The items that the Vietnamese mission purchased included ceramics, silk, books, and medicines. With the support of the Chinese settlers in Vietnam the mission was able to be involved in the deal of illegal items such as opium, and possibly some kinds of precious ginseng from Korea. Overall, the process of the itinerary, observation, and purchase during the trip to Canton was the way to form the new point of view of Vietnamese intellectuals towards China standing from the side of Westerners. To the Vietnamese who experienced both Canton/Macao and the Western worlds in the port cities of Island Southeast Asia China was not the only center of the world, nor the Westerners could be looked down as the barbarians. In Canton, a peripheral region looked from the imperial capital Beijing, but the most internationalized city of China at that time, Vietnamese officials were training themselves to overcome China.

• 수산해양기술연구
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• 제22권2호
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• pp.1-6
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• 1986

Even though it is well known that the tidal current in the East China Sea rotates clockwise, few report can be found about the precise pattern of it. To furnish some information available for the stow net fishermen, the author carried out the observation over 235 semidiurnal tidal cycle to investigate the pattern of the set and the rate of tidal current in the Korean fishing section 250 and 494, by reading the current meter and by tracing the corner reflectors with radar onboard the anchored obsen'ation vessel, from May 12, 1984 through February 27, 1986. The results obtained are as follows: 1. The mean semidiurnal tidal cycle was 12 h 20 m during spring tide, and 12 h 30 m during neap tide. 2. The mean interval from the calculated time of high water until the current began to set north was 2 h 30 m and 2 h 15 m in the fishing section 250 and 494 respectively, and the mean interval from the time of low water current began to set south was about 2 h 0 m in both sections. 3. In comparison of the occupied times to vary the set from one of 8 principal bearing points to the neighboring one, the shortest was while the set varied from N to NE and S to SW in the section 250 and 494 respectively. Contrary the longest was while the set varied from SE to S and from W to NW in the section 250 and 494 respectively. 4. In comparison of the rate while the set varied from one of 8 principal bearing points to the neighboring one, the fastest was while the set varied from SE to Sand NW to N in the section 250, and E to SE and W to NW in the section 494. Contrary the slowest was while the current set to NE and S W in the section 250, and N, NE and S W in the section 494.