• Title/Summary/Keyword: scale-model

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Preliminary Study on the Enhancement of Reconstruction Speed for Emission Computed Tomography Using Parallel Processing (병렬 연산을 이용한 방출 단층 영상의 재구성 속도향상 기초연구)

  • Park, Min-Jae;Lee, Jae-Sung;Kim, Soo-Mee;Kang, Ji-Yeon;Lee, Dong-Soo;Park, Kwang-Suk
    • Nuclear Medicine and Molecular Imaging
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    • 제43권5호
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    • pp.443-450
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    • 2009
  • Purpose: Conventional image reconstruction uses simplified physical models of projection. However, real physics, for example 3D reconstruction, takes too long time to process all the data in clinic and is unable in a common reconstruction machine because of the large memory for complex physical models. We suggest the realistic distributed memory model of fast-reconstruction using parallel processing on personal computers to enable large-scale technologies. Materials and Methods: The preliminary tests for the possibility on virtual manchines and various performance test on commercial super computer, Tachyon were performed. Expectation maximization algorithm with common 2D projection and realistic 3D line of response were tested. Since the process time was getting slower (max 6 times) after a certain iteration, optimization for compiler was performed to maximize the efficiency of parallelization. Results: Parallel processing of a program on multiple computers was available on Linux with MPICH and NFS. We verified that differences between parallel processed image and single processed image at the same iterations were under the significant digits of floating point number, about 6 bit. Double processors showed good efficiency (1.96 times) of parallel computing. Delay phenomenon was solved by vectorization method using SSE. Conclusion: Through the study, realistic parallel computing system in clinic was established to be able to reconstruct by plenty of memory using the realistic physical models which was impossible to simplify.

A Basic Study for Wind Energy of Building Cladding using Computational Fluid Dynamics (CFD를 이용하여 건물 외피의 바람에너지에 관한 적용연구)

  • Chung, Yung-Bea
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2011년도 추계학술대회 초록집
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    • pp.39.2-39.2
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    • 2011
  • The new and renewable energy today has a great interest in all countries around the world. In special it has need more limit of the fossil fuel that needs of low carbon emission among the social necessary conditions. Recently, the high-rise building demand the structural safety, the economic feasibility and the functional design. The high-rise building spends enormous energy and it satisfied the design in solving energy requirements. The requirements of energy for the building depends on the partly form wind energy due to the cladding of the building that came from the surroundings of the high-rise building. In this study of the wind energy, the cladding of the building was assessed a tentative study. The wind energy obtains from several small wind powers that came from the building or the surrounding of the building. In making a cladding the wind energy forms with wind pressure by means of energy transformation methods. The assessment for the building cladding was surrounded of wind speed and wind pressure that was carried out as a result of numerical simulation of wind environment and wind pressure which is coefficient around the high-rise building with the computational fluid dynamics. In case of the obtained wind energy from the pressure of the building cladding was estimated by the simulation of CFD of the building. The wind energy at this case was calculated by energy transform methods: the wind pressure coefficients were obtained from the simulated model for wind environment using CFD as follow. The concept for the factor of $E_f$ was suggested in this study. $$C_p=\frac{P_{surface}}{0.5{\rho}V^{2ref}}$$ $$E_c=C_p{\cdot}E_f$$ Where $C_p$ is wind pressure coefficient from CFD, $E_f$ means energy transformation parameter from the principle of the conservation of energy and $E_c$ means energy from the building cladding. The other wind energy that is $E_p$ was assessed by wind power on the building or building surroundings. In this case the small wind power system was carried out for wind energy on the place with the building and it was simulated by computational fluid dynamics. Therefore the total wind energy in the building was calculated as the follows. $$E=E_c+E_p$$ The energy transformation, which is $E_f$ will need more research and estimation for various wind situation of the building. It is necessary for the assessment to make a comparative study about the wind tunnel test or full scale test.

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Application of SWAT for the Estimation of Soil Loss in the Daecheong Dam Basin (대청댐 유역 토양 침식량 산정을 위한 SWAT 모델의 적용)

  • Ye, Lyeong;Yoon, Sung-Wan;Chung, Se-Woong
    • Journal of Korea Water Resources Association
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    • 제41권2호
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    • pp.149-162
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    • 2008
  • The Soil and Water Assessment Tool (SWAT) developed by the USDA-Agricultural Research Service for the prediction of land management impact on water, sediment, and agricultural chemical yields in a large-scale basin was applied to Daecheong Reservoir basin to estimate the amount of soil losses from different land uses. The research outcomes provide important indications for reservoir managers and policy makers to search alternative watershed management practices for the mitigation of reservoir turbidity flow problems. After calibrations of key model parameters, SWAT showed fairly good performance by adequately simulating observed annual runoff components and replicating the monthly flow regimes in the basin. The specific soil losses from agricultural farm field, forest, urban area, and paddy field were 33.1, $2.3{\sim}5.4$ depending on the tree types, 1.0, and 0.1 tons/ha/yr, respectively in 2004. It was noticed that about 55.3% of the total annual soil loss is caused by agricultural activities although agricultural land occupies only 10% in the basin. Although the soil erosion assessment approach adopted in this study has some extent of uncertainties due to the lack of detailed information on crop types and management activities, the results at least imply that soil erosion control practices for the vulnerable agricultural farm lands can be one of the most effective alternatives to reduce the impact of turbidity flow in the river basin system.

Association of Depressive/Anxiety Symptoms with Ego Resilience and Social Conflict/Support in Patients with Diabetes Mellitus (당뇨병 환자에서 우울 및 불안증상과 자아탄력성, 사회적 갈등 및 지지 사이의 연관성)

  • Jung, Hoe-Woon;Kim, Sang Hoon;Park, Sang Hag;Kim, Seung-Gon;Kim, Jung Ho;Seo, Eun Hyun;Yoon, Hyung-Jun
    • Anxiety and mood
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    • 제16권1호
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    • pp.9-17
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    • 2020
  • Objective : The purpose of this study was to investigate the association of depressive/anxiety symptoms with psychosocial factors including ego resilience, social conflict, and social support as well as hemoglobin A1c in patients with diabetes mellitus (DM). Methods : The subjects were 144 patients with DM. Depressive/anxiety symptoms were evaluated by the Hospital Anxiety and Depression Scale. Sociodemographic factors, hemoglobin A1c, ego resilience, social conflict, and social support were measured. Multiple regression analyses were performed to examine the impact of hemoglobin A1c, ego resilience, social conflict, and social support on depressive/anxiety symptoms. Results : A total of 32.6% and 24.3% of participants were identified with depressive and anxiety symptoms, respectively. Depressive/anxiety symptoms positively correlated with the social conflict score. Conversely, ego resilience and social support negatively correlated with depressive/anxiety symptoms. In the final model of the multiple regression analyses, ego resilience was associated with a lower level of depressive (β=-0.083, p=0.019)/anxiety (β=-0.125, p=0.001) symptoms whereas social conflict was related to a higher level of depressive (β=0.353, p=0.011)/anxiety (β=0.460, p=0.003) symptoms. Also, hemoglobin A1c positively associated with anxiety symptoms (β=0.495, p=0.012) whereas social support negatively related to depressive symptoms (β=-0.464, p=0.004). Conclusion : We found possible risk and protective psychosocial factors of underlying depressive/anxiety symptoms among patients with DM. Our findings suggest that enhancing ego resilience and social support as well as decreasing social conflict would be crucial in the prevention and management of depressive/anxiety symptoms in patients with DM.

A Prospect and Tasks for Regional Development of Youngnam Area: (2) Conditions on Future Development and Alternative Regional Planning (영남지역 발전의 전망과 과제 : (2) 발전여건과 대안적 개발계획)

  • Choi, Byung-Doo
    • Journal of the Korean association of regional geographers
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    • 제2권1호
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    • pp.87-114
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    • 1996
  • This paper is the second part of a research which aims to look into the regional development process and the quality of life of Youngnam area. and to suggest a prospect and tasks for the future development of the region. All cities and regions including Youngnam area seem to be involved in a rapidly changing process of conditions for development, because of a recent economic and political transformation in the national and global scale. It can be thus said that, taking such a process into consideration seriously, each city or region needs to establish a long-term prospect and goal, and to set up and practicize its development plan. From this point of view, this paper reconsiders the changing process of conditions for development of Youngnam region, and suggests an alternative development plan. At the first, the changing conditions of regional development are investigated in economic, political, social, cultural and environmental aspects. Secondly, some actual planning practices in this regions are examined and their problems are pointed out. Thirdly, an alternative model for regional development is suggested and development tasks in each aspects are discussed in relation to each other. Finally some regional development strategies are provided in the spatial as well as the sectoral dimision. As a results of this research, it is argued that the development of Youngnam region should pursue both an improvement of socio-cultural and ecological institutions for ensuring humane life of dwellers within the region, and a enforcement of economic and political self-sufficiency in an organic relation between regions and to the whole society. This kind of argument can be applied to every city or region. But it would more significant for Youngnam region, because this region, which once experienced a rapid economic growth but now is fallen into a serious economic stagnation, tends to contrive material plans to redevelop regional economy, while ignoring social plans to improve quality of life.

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The New International Division of Labor:Re-evaluation (신국제노동분업의 재평가)

  • 고태경
    • Journal of the Korean Regional Science Association
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    • 제11권1호
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    • pp.79-91
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    • 1995
  • As an exit to solve the economic depression of the development countries in the early twentieth century, the 'old international division of labor' developed. The economic crisis(i.e., under-consumption crisis) was due to the absence of the mode of regulation compatible with the extensive regime of accumulation(i.e., "Fordist" regime). The crisis was solved by the state intervention through the creation on institutions in order to increase the level of consumption. Until the late 1960s when "high Fordism" reached(i.e., a harmonious relation between the monopoly mode of regulation and the intensive accumulation of capital), the developed core countries enjoyed a remarkable economic growth. The external market was not a necessity for the economic growth because there were increases in labor productivity and proportional increases in real wages and thus increases in consumption level. In the 1970s, however, the core faced with economic crisis again. Due to the breakdown of the postwar "Fordist" regime of capital accumulation and the post 1973 world depression, the core needed the Third World as a solution for their internal and international economic crisis. Thus the 'new international division of labor'(NIDL) arose. The "Fordist" method of production(i.e., the divisions of production process) led to the territorial division of labor and to the detailed division of labor. The aim of the NIDL is to exploit reserve armies of labor on a world scale and thus to reduce production costs. According to the NIDL model, the Third World countries have been developing by the core countries' investment on mainly labor-intensive industries and thus have been playing an important role in the global economy. And the NIDL theorists argue that multinational corporations have increasingly invested in the Third World nations and contributed to the economic growth in those regions. Tables presented in the paper show that the global trend since the 1970s does not follow the argument exactly as the NIDL theorists predicted. On the contrary, the core countries focus on developing technology, adopting the automation of production process, and trading within the core countries rather than on investing in the periopheral countries. The continuing investment of multinational corporations into the periphery is not because of cheap labor force but because of the market potentials in the regions. Majority of corporations of the core tries to reduce production costs by investing in technological development more intensively and also by changing regional strategies (i.E., investment from metropolitan areas to medium - or small - size cities, focusing on agglomeration economy, boosting regional diversification, etc.) within their own countries. The main purpose of the paper is to review and to criticize the NIDL theory based on some empirical data.IDL theory based on some empirical data.

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A study on the self-evaluation of job performance and creativity of dental hygienists (치과위생사 직무와 개인의 창의성에 의한 자기평가 연구)

  • Hong, Sun-Hwa;Goo, Kyong-Mi
    • Journal of Korean society of Dental Hygiene
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    • 제10권6호
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    • pp.1037-1048
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    • 2010
  • Objectives : The awareness of health care need increasing attention from the public along with changing professional human-resources activity. As there are increasing social demand for the roles and professionalism of dental hygienists, the purpose of this study was to examine the job performance, creativity and organizational climate of dental hygienists by their own self-diagnostic evaluation in an attempt to help enhance their work ability. Methods : According to the data released as August 2008 by the Dental Association and public health centers in Gwangju, 735 dental hygienists worked at 425 dental clinics. The subjects in this study were 156 dental hygienists at 85 dental clinics who were selected by proportionate sampling method from among the dental hygienists. After an interview survey was conducted in person, the answer sheets from 132 respondents were analyzed except 24 incomplete ones. The questionnaire used in this study consisted of 49 items. A five-point Likert scale was used and SPSS 12.0 program was analyzed the data. Results : 1. As a result of checking the types of works, treatment cooperation(54%), and oral health education often(45%), They weren't responsible for preventive treatment(42%). 2. When they made a self-diagnostic evaluation of creativity and organizational climate, they put the highest value on their autonomy(2.21), followed by positive attitude(2.10). Out of seven organizational climate, challenging spirits(2.81) ranked highest, followed by reliability(2.66). 3. Major management eopmubyeol individual creativity compared with three business relationships and a positive attitude in the case of the high group received oral health education and care management services in a group doing the most was General office work and office assistance work in the medical assistance group that was doing business primarily. 4. In the relationship between self-assesment score and three performance duties, Positive difference was noted in the group with positive attitude and elevated autonomy in terms of performing oral health education. Conclusions : As a result, individual creativity and organization of the atmosphere, each detail, through analysis of the self-assessment model, developed guide on the investigation by doing a dental hygienist, a unique business promotion and Enlargement of the study suggested the need to be considered is.

A study on the oral-health belief and oral-health care of company employees (직장인들의 구강건강신념과 구강건강관리 행태에 관한 연구)

  • Lim, Mi-Hee
    • Journal of Korean society of Dental Hygiene
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    • 제8권4호
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    • pp.205-217
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    • 2008
  • The purpose of this study was to provide information on the development of an oral-health promotion program geared toward office workers. The subjects in this study were 240 employees at the headquarters of S construction company. After a survey was conducted in July and August 2008, the answer sheets from 208 respondents were gathered, and 191 answer sheets were analyzed except 17 unanalyzable ones. The findings of the study were as follows: 1. In regard to subjective oral health status, the largest number of the participants that accounted for 37.2% found their mouth to be neither healthy nor unhealthy. The greatest number of them that represented 58.1% had never visited a dentist's office to receive preventive treatment. 2. Regarding relationship between toothbrushing education experience and toothbrushing frequency, the most common toothbrushing frequency was three times a day( 46.5%) among the company employees who had ever received that education. In the event of the office workers without that experience, the most prevalent frequency was three times(63.6%). The toothbrushing frequency was statistically significantly different according to the toothbrushing education experience(p<0.05). As to the relationship of toothbrushing education experience to tooth- brushing method, the largest number(48.2%) of those who had ever received that education brushed their upper and lower teeth along with the gums by rotating the toothbrush downward from the top and upward from the bottom respectively. In the event of the office workers without that experience, 49.4 percent brushed their teeth and gums by rotating the toothbrush up and down. Thus, whether they had ever received education about toothbrushing made a statistically significant difference to their toothbrushing method(p<0.05). 3. As a result of evaluating their oral health belief by utilizing a five-point scale, they got a mean of 2.95. In each area of oral health belief, they got the best marks in benefit(3.66), salience(3.42), barrier(2.84), susceptility(2.58) and seriousness(2.23). Given the above-mentioned finding of the study, two sorts of oral health beliefs, which are benefit and salience, should be stressed in the development of oral health education programs that cater to company employees. And sustained research efforts should be channeled into finding out the relationship between oral health and actual oral health care.

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A Study on Development of Common Criteria for Evaluation of Internet Ethics Index (인터넷윤리 지수의 평가를 위한 공통 기준 개발에 관한 연구)

  • Lee, Young-Han;Kim, Jeong-Dong;Park, Jeong-Ho
    • Journal of Internet Computing and Services
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    • 제17권3호
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    • pp.75-85
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    • 2016
  • Changes in the distribution and sharing information using the Internet is changing the most part in our daily life, Utilizing the Internet of our lives to the rapid development of IT technology, are living in the off-line (off-line) and online (on-line) a mix of life, We expect now online life specific gravity is further increased. However, do not systematically implement the education of Internet ethics awareness deficiencies of objective indicators to assess the current knowledge level of the Internet ethics is the actual situation. Therefore, in this paper, it provides a development process in order to establish a common standard for the evaluation of Internet ethics index. Development procedure of Internet ethics index in order to establish a common standard, "evaluation item (draft) derivation", "Creating a questionnaire", "the calculation of the analysis and item-by-item weight of the questionnaire", and a common reference determination of the stage having. Was also a questionnaire that target 46 people to calculate the weight of the common reference. Internet ethics index evaluation model through the establishment of the common standards developed in this paper, municipal road Office of Education, related organizations, high school, such as small, medium, can be utilized as an indicator to measure the Internet ethics education level.

Application of Particle Swarm Optimization(PSO) for Prediction of Water Quality in Agricultural Reservoirs of Korea (농업용 저수지의 수질 예측 모델을 위한 PSO(Particle Swarm Optimization) 알고리즘의 적용)

  • Kwon, Yong-Su;Bae, Mi-Jung;Hwang, Soon-Jin;Park, Young-Seuk
    • Korean Journal of Ecology and Environment
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    • 제41권spc호
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    • pp.11-20
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    • 2008
  • In this study, we applied a Particle Swarm Optimization (PSO) algorithm to predict the changes of chlorophyll-${\alpha}$ related to environmental factors in agricultural reservoirs in Korean national scale. Data were obtained from water quality monitoring networks of reservoirs operated by the Ministry of Agriculture and Forestry and the Ministry of Environment of Korea. From the database of the monitoring networks, 290 reservoirs were chosen with variables such as chlorophyll-${\alpha}$ and 13 environmental factors (COD, TN, TP, Altitude, Bank height, etc.) measured in 2002. Based on Carlson's trophic status index, reservoirs were divided into five groups, and most agricultural reservoirs $(TSI_{CHL}\;64.1%,\;TSI_{TP}\;75.5%)$ were in the eutrophic states. The groups were discriminated with environmental variables, showing that COD, DO, and TP were important factors to determine the trophic states. MLP-PSO (Multilayer perceptron (MLP) with PSO for the optimization) was applied for the prediction of chlorophyll-${\alpha}$ with environment factors, and showed high predictability (r=0.83, p<0.001). Additionally, the sensitivity analysis of the MLP-PSO model showed that COD had the strongest positive effects on the concentration of chlorophyll-${\alpha}$, and followed by TP, TN, DO, whereas altitude and bank height had negative effects on the concentration of chlorophyll-${\alpha}$.