• The Journal of Korean Academy of Prosthodontics
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• v.47 no.2
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• pp.125-135
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• 2009

Statement of problem: Loosening or fracture of the abutment screw is one of the common problems related to the dental implant. Generally, in order to make the screw joint stable, the preload generated by tightening torque needs to be increased within the elastic limit of the screw. However, additional tensile forces can produce the plastic deformation of abutment screw when functional loads are superimposed on preload stresses, and they can elicit loosening or fracture of the abutment screw. Therefore, it is necessary to find the optimum tightening torque that maximizes a fatigue life and simultaneously offer a reasonable degree of protection against loosening. Purpose: The purpose of this study was to present the influence of tightening torque on the implant-abutment screw joint stability with the 3 dimensional finite element analysis. Material and methods: In this study, the finite element model of the implant system with external butt joint connection was designed and verified by comparison with additional theoretical and experimental results. Four different amount of tightening torques(10, 20, 30 and 40 Ncm) and the external loading(250 N, $30^{\circ}$) were applied to the model, and the equivalent stress distributions and the gap distances were calculated according to each tightening torque and the result was analyzed. Results: Within the limitation of this study, the following results were drawn; 1) There was the proportional relation between the tightening torque and the preload. 2) In case of applying only the tightening torque, the maximum stress was found at the screw neck. 3) The maximum stress was also shown at the screw neck under the external loading condition. However in case of applying 10 Ncm tightening torque, it was found at the undersurface of the screw head. 4) The joint opening was observed under the external loading in case of applying 10 Ncm and 20 Ncm of tightening torque. 5) When the tightening torque was applied at 40 Ncm, under the external loading the maximum stress exceeded the allowable stress value of the titanium alloy. Conclusion: Implant abutment screw must have a proper tightening torque that will be able to maintain joint stability of fixture and abutment.

• Korea journal of population studies
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• v.20 no.2
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• pp.161-180
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• 1997

There are about 400, 000 Korean ethnics living in Central Asia. Most of Koreans in Central Asia are leading a stable middle class life mostly engaged in farm work. With increase of educational attainment of their children, a number of Koreans are launching into political and academic circles as well as in the cultural world or the press. In recent years, however, the countries in this area(Uzbekistan and Kazakstan) for this study advocate an ethnic united policy to stabilize the politics and society and to carry out efficient transformation from the former socialistic economy to a market oriented economy. In addition, they are trying to recover the culture and the language of each nation which has been forgotten in the assimilation of Russia policy. Koreans have difficulty in adaption to this kind of change. In fact, a number of Koreans lost traditional culture and could not speak their mother language - Korean. Although they more or less maintain national consciousness, they recognize Uzbekistan or Kazakstan as their nation politically. They associated with North Korea unilaterally before the launching of the Perestroika policy. But after the Seoul Olympics held in 1998, there was movement to know and understand South Korea. There has been increased in the investment by Korean companies in Central Asia. Now, what is an alternative idea for Korean community consciousness\ulcorner It can be summarized as follows: 1) The increase of aid to Korean education institute : Considering the last few decades of Russia's strong racial assimilation policy, which leads most Koreans to lost their language and national culture, the priority should go to Koreans education. 2) Local Korean press support : Though Korean newspaper are published and Korean broadcasting is on the air currently in Uzbekistan and Kazakstan, they are suffering from qualified staff and poor financial status. Therefore, positive support should be established for these Korean mass communication media outlets to recover their own function and expand their dissemination powers quickly. 3) Research on the actual condition for Korean Community : It is essential to directly examine the local Korean community's regional distribution, population structure, Korean group's formation and operation, social and cultural understanding, racial consciousness, hope for their mother land and much more. 4) Increase of mother land and education opportunity : To stir up national culture and national consciousness within the Korean community, it is necessary to expand continuous opportunities for mother land visits and education training for local Koreans, especially for second and third generations.

• Journal of Korea Water Resources Association
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• v.41 no.3
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• pp.277-291
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• 2008

In order to carry out river basin management, it is necessary to evaluate the state of the river basin and make site-specific measures on the basis of management goals and objectives. A river basin is divided into several watersheds, which are composed of several components: water resources, social and economic systems, law and institution, user, land, ecosystems, etc. They are connected among them and form network holistically. In this study, a methodology for evaluating watershed management was developed by consideration of the various features of a watershed system. This methodology employed factor analysis to develop sub-indexes for evaluating water use management, environment and ecosystem management, and flood management in a watershed. To do this, first, the related data were gathered and classified into six groups that are the components of watershed systems. Second, in all sub-indexes, preliminary tests such as KMO (Kaiser-Meyer-Olkin) measure of sampling adequacy and Bartlett's test of sphericity were conducted to check the data's acceptability to factor analysis, respectively. Third, variables related to each sub-index were grouped into three factors by consideration of statistic characteristics, respectively. These factors became indicators and were named, taking into account the relationship and the characteristics of included variables. In order to check the study results, the computed factor loadings of each variable were reviewed, and correlation analysis among factor scores was fulfilled. It was revealed that each factor score of factors in a sub-index was not correlated, and grouping variables by factor analysis was appropriate. And, it was thought that this indicator system would be applied effectively to evaluating the states of watershed management.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38C no.9
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• pp.822-829
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• 2013

Hypertension is one of the most common clinical diseases, with an increasing prevalence globally. Hypertension triggers various harmful consequences and affects multiple organs. Life-long care may be required in some cases. According to the Korea Center for Disease Control and Prevention, the prevalence of hypertension is gradually increasing. A 2011 survey revealed that 28.9% of Korean adults had hypertension. The prevalence rates were slightly higher among men than women. Accurate measurement of blood pressure(BP) is crucial to classify patients, to identify BP-related risks, and to inform correct treatment. For accurate blood pressure measurement, the use of a cuff bladder size appropriate for the mid-upper arm circumference(MUAC) is essential. Incorrect sized cuff bladder is one of the main causes of equipment error affecting sphygmomanometer accuracy. When commercial sphygmomanometers were examined, the cuff bladders differed from the dimensions specified in the ISO 81060-1:2007 standards. Undercuffing is responsible for a spurious overestimation of BP in patients with large arms leading to overdiagnosis of hypertension, whereas overcuffing (that is, use of relatively large cuffs with small arms), may be responsible for an opposite problem, leading to erroneous underestimation of BP levels. The cuff bladder sizes recommended by the American Heart Association(AHA) are an arm circumference(AC) of 17-25 cm for small-sized adults, AC of 24-32 cm for adults, AC of 32-42 cm for normal-sized adults, and AC of 42-50 cm for obese adults. In contrast, the AC of Korean adults ranges from 23-31 cm, belonging to a single type of adult bladder. Three types of bladders are necessary for Korean adults with an AC of 23-31cm. Hospitals often use one or two differently-sized Western cuffs for adult patients, which can yield inaccurate BP determinations. Cuff bladders with dimensions based on anthropometric reference data obtained from Koreans will aid hospitals to measure BP more accurately.

• Journal of Korean Society of Forest Science
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• v.98 no.1
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• pp.94-105
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• 2009

Black locust (Robinia pseudoacacia) stand is representative lowland exotic plantation with low ecological quality and arrested succession in South Korea. To facilitate succession and restore natural vegetation, small canopy gaps (${\sim}57m^2$), which can modify minimally structural variables and reduce restoration related disturbances on stand, was established in the black locust stand, and oak (Quercus serrata) seedlings were introduced in the gap. Two types of varying levels were introduced for gap creation; cutting (C) and girdling (G) on canopies. Understory removal (CU and GU) treatment was applied as subtypes of structural modification. Growth (diameter, height and leaf area) of target species and responses (species composition, diversity and coverage) of understory community were monitored during study years (2007~2008). Canopy openness was different significantly among treatments but not for light availability. Based on the result of logistic regression, growth of height and leaf area of seedlings were significant variables on seedling survival. Height and leaf area of seedlings were increased during study years, although radial growth was reduced. During study years, there were no significant differences in species composition and diversity, and total coverage increased about 20%. Increase of resources by gap creation and understory removal likely affect growth of target species. Small gap creation was effective to reduce understory responses in composition and diverstiy. Synthesized, growth of target species and responses of understory community to small canopy gap creation exhibited, in short term, possibility of utilization in alternative forest restoration and management option. Long-term monitoring is necessary to certificate effect of artificial gap creation on forest restoration.

• Journal of the Korean Institute of Landscape Architecture
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• v.38 no.5
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• pp.53-63
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• 2010

The purposes of this study are to classify the characteristics of parks by park use patterns and the understanding of design concepts and to analyze the difference of cognition of design concept between designers and park users. The literature studies and surveys were performed to analyze park use patterns and understanding of design concepts for Seoul Forest Park, Yeouido Park and Seonyudo Park. Several statistical methods have been used such as descriptive analysis and importance-performance analysis. The results of this research are as follows. As the results of an analysis of park use patterns, Seonyudo Park may he qualified as an urban landmark park, while Yeouido Park can he classified as a neighborhood park. Seoul Forest Park bas characteristics of both. Second, the higher frequency of visits generally leads higher preference. Third, the overall cognition of the design concepts of parks shows 3.51 on average, which is comparatively high. The functional concepts are better transmitted to the users compared to abstract concepts. The cognition of the design concepts of each park are evaluated in the higher order of Seonyudo Park, Seoul Forest Park and Yeouido Park. Fourth, the cognition levels of detailed design concepts for each place are lower than the overall design concepts. On the other hand, levels of satisfaction are increased after the design concepts are noticed. It would he necessary make the effort to give information about the design concept of each space. The results of this study are limited in that it covers only three parks in Seoul, and did not consider seasonal variables. Nevertheless, this study may he significant in that it dealt with the cognition of design concepts for urban parks, focusing on the difference between designers and visitors.

• Archives of design research
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• v.12 no.4
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• pp.33-44
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• 1999

Fashion is subjected to newness and change by itself. Fashion trend and tendency which could predict next season akeady indicated that digital and cybel11ation environment lliould be factors in fashion. Changes in future life styles and values caused by digital environment must be variables as fashion objects by themselves. Therefore digital environment of a fashion itself and that all encountered in fashion will not only be an existing situation but also an objective and a factor which must be pursued with fashionable sense in future fashion. Advanced technology and social change in relation to digital environment requires that educational method as well as its content will be changed on the scene of education for future. Thus we should seek an educational direction in fashion design for future society in which digital environment requires new paradigm. Subject to these backgrounds this study has an intension to study the change in fashion extensively influenced by expanded digital environment on a limited situational level of fashion design education and to suggest an educational direction for professional in future fashion design who will serve as a core of fashion area in the future. It is essential that education of professional in fashion for future should be achieved by digital-minded level that eagerly understands and accepts future society in which digital environment will be a main axis. It is necessary for this to make them expetience computers, digital media including CAD program. We have to note that education of digital media is more effective and applicable when accomplished in CAI level which can be related and expetienced with fashion education rather than mere functional training in media themselves. Intellectual creativity will be a vety source of producing values and national competence in 21st centtury. Education of design professional in fashion area must positively accept these environmental charactetistics in future society, as well as deeply reflect the education for the future.

• Korean Journal of Agricultural and Forest Meteorology
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• v.8 no.2
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• pp.86-96
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• 2006

Ecoclimap-1, a new complete surface parameter global database at a 1-km resolution, was previously presented. It is intended to be used to initialize the soil-vegetation- atmosphere transfer schemes in meteorological and climate models. Surface parameters in the Ecoclimap-1 database are provided in the form of a per-class value by an ecoclimatic base map from a simple merging of land cover and climate maps. The principal objective of this ecoclimatic map is to consider intra-class variability of life cycle that the usual land cover map cannot describe. Although the ecoclimatic map considering land cover and climate is used, the intra-class variability was still too high inside some classes. In this study, a new strategy is defined; the idea is to use the information contained in S10 NDVI SPOT/VEGETATION profiles to split a land cover into more homogeneous sub-classes. This utilizes an intra-class unsupervised sub-clustering methodology instead of simple merging. This study was performed to provide a new ecolimatic map over Northeast Asia in the framework of Ecoclimap-2 global database construction for surface parameters. We used the University of Maryland's 1km Global Land Cover Database (UMD) and a climate map to determine the initial number of clusters for intra-class sub-clustering. An unsupervised classification process using six years of NDVI profiles allows the discrimination of different behavior for each land cover class. We checked the spatial coherence of the classes and, if necessary, carried out an aggregation step of the clusters having a similar NDVI time series profile. From the mapping system, 29 ecosystems resulted for the study area. In terms of climate-related studies, this new ecosystem map may be useful as a base map to construct an Ecoclimap-2 database and to improve the surface climatology quality in the climate model.

• Journal of the Korean Institute of Landscape Architecture
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• v.42 no.6
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• pp.39-49
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• 2014

Unpleasant facilities have been unwelcomed by residents within the region since they are considered to negatively influence the living conditions of the region. Yet recently, a park project within these unpleasant facility areas has begun to improve the negative impression of the region and the satisfaction of local residents has been shown to be very high. Also a park project within unpleasant facilities is found to have significant influence on the community, including resolving conflicts and building mutual friendships among residents by creating pleasant living conditions and improving the quality of life of local residents. The purpose of this study is to investigate how the park project within unpleasant facilities changes the satisfaction level of local residents and affects the sense of community. In order to do so, surveys were given to visitors of Seoul Maru Park, which was turned into a park from a sewage treatment center. According to the analysis result, after the sewage treatment center was recreated as Maru Park, citizen satisfaction was found to be very high. The sense of community that the visitors feel was found to be high in general, but the 'sense of connection and neighbor bonds' turned out to be lower compared to the 'sense of settlement and belonging.' A regression analysis was performed to determine the relative influence of visitor satisfaction on the sense of community. As a result, in the division of 'sense of settlement and belonging,' the satisfaction with ecological health was affected the most, followed by satisfaction with scenic beauty, whereas satisfaction with cleanness had no influence. In the division of 'sense of connection and neighbor bond,' none of the satisfaction with cleanness, ecological health and scenic beauty showed any influence in the analysis. According to the above result, a park project within unpleasant facilities brings a positive influence on the 'sense of settlement and belonging,' yet in order to improve the 'sense of connection and neighbor bond,' which is not influenced by the project, the adequate facilities and activity programs are considered to be necessary to change the residents' of sense of community.

• Korea journal of population studies
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• v.10 no.1
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• pp.50-69
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• 1987

There are about 400, 000 Korean ethnics living in Central Asia. Most of Koreans in Central Asia are leading a stable middle class life mostly engaged in farm work. With increase of educational attainment of their children, a number of Koreans are launching into political and academic circles as well as in the cultural world or the press. In recent years, however, the countries in this area(Uzbekistan and Kazakstan) for this study advocate an ethnic united policy to stabilize the politics and society and to carry out efficient transformation from the former socialistic economy to a market oriented economy. In addition, they are trying to recover the culture and the language of each nation which has been forgotten in the assimilation of Russia policy. Koreans have difficulty in adaption to this kind of change. In fact, a number of Koreans lost traditional culture and could not speak their mother language - Korean. Although they more or less maintain national consciousness, they recognize Uzbekistan or Kazakstan as their nation politically. They associated with North Korea unilaterally before the launching of the Perestroika policy. But after the Seoul Olympics held in 1998, there was movement to know and understand South Korea. There has been increased in the investment by Korean companies in Central Asia. Now, what is an alternative idea for Korean community consciousness\ulcorner It can be summarized as follows: 1) The increase of aid to Korean education institute : Considering the last few decades of Russia's strong racial assimilation policy, which leads most Koreans to lost their language and national culture, the priority should go to Koreans education. 2) Local Korean press support : Though Korean newspaper are published and Korean broadcasting is on the air currently in Uzbekistan and Kazakstan, they are suffering from qualified staff and poor financial status. Therefore, positive support should be established for these Korean mass communication media outlets to recover their own function and expand their dissemination powers quickly. 3) Research on the actual condition for Korean Community : It is essential to directly examine the local Korean community's regional distribution, population structure, Korean group's formation and operation, social and cultural understanding, racial consciousness, hope for their mother land and much more. 4) Increase of mother land and education opportunity : To stir up national culture and national consciousness within the Korean community, it is necessary to expand continuous opportunities for mother land visits and education training for local Koreans, especially for second and third generations.