• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제49권12호
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• pp.665-672
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• 2000

This paper described the measurement technology to analyze the partial discharge characteristics for long term aging of insulations. This system was consisted of high voltage generation and measurement part, PD detection part, digital conversion and signal processing part. We used the VXI system for digital conversion and signal processing part. In the digital conversion part, we studied the error of partial discharge magnitude and memory capacity for reading digital signal with the sampling rate. In the signal processing part, we showed the program algorithm to count pulses and read peak values of partial discharge. The allowable minimum sampling rate of digizer was decided to 250kS/s through analyzing test. We confirmed that this system was very useful in the study of $\phi-q-n$ characteristics of long term PD experiments with specimens being consisted of internal void defects and CIGRE II electrodes.

• Earthquakes and Structures
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• 제23권4호
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• pp.385-401
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• 2022

Uncertainty quantification is the most important challenge in seismic fragility assessment of structures. The precision increment of the quantification method leads to reliable results but at the same time increases the computational costs and the latter will be so undesirable in cases such as reliability-based design optimization which includes numerous probabilistic seismic analyses. Accordingly, the authors' effort has been put on the development and validation of an approach that has reduced computational cost in seismic fragility assessment. In this regard, it is necessary to apply the appropriate methods for consideration of two categories of uncertainties consisting of uncertainties related to the ground motions and structural characteristics, separately. Also, cable-stayed bridges have been specifically selected because as a result of their complexity and the according time-consuming seismic analyses, reducing the computations corresponding to their fragility analyses is worthy of studying. To achieve this, the fragility assessment of three case studies is performed based on existing and proposed approaches, and a comparative study on the efficiency in the estimation of seismic responses. For this purpose, statistical validation is conducted on the seismic demand and fragility resulting from the mentioned approaches, and through a comprehensive interpretation, sufficient arguments for the acceptable errors of the proposed approach are presented. Finally, this study concludes that the combination of the Capacity Spectrum Method (CSM) and Uniform Design Sampling (UDS) in advanced proposed forms can provide adequate accuracy in seismic fragility estimation at a significantly reduced computational cost.

• 한국조경학회지
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• 제31권2호
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• pp.28-35
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• 2003

This study was conducted to identify the characteristics of social carrying capacity at mega-events, especially the 2000 Kwangju Biennale in Korea. In particular, this paper has proposed some management policies for mega events taking into account the relations between social carrying capacity, satisfaction and crowding. The research method was to look into the general characteristics and distributive forms of the location, and then to confirm the possibility of sampling the factors involved in satisfaction degree; last, A factor analysis for causal analysis of perceived crowding was performed. The study needed correlation analysis in order to compare expected crowding and perceived crowding, and performed regression to examine the causality of perceived crowding and satisfaction. The research results were as follows: the correlation of expected crowding, perceived crowding, and the total satisfaction was very low or meaningless. The relation between satisfaction and elements for factor analysis such as convenient facilities and value experience showed partial meaningfulness. The factors of convenient facilities, entrance fee, parking lot use, toilet convenience, and exhibit room use had meaningful results; on the other hand, the factors of value experience showed a meaningful result in the guide service of an event place. In conclusion when those holding an event make a basic project, they should consider management measures for convenience of facilities, proper education for guide service, and systematic guidance. Also, as a method for perceived crowding lower than expected crowding, the study has proposed that it is possible to lower expected crowding by providing appropriate information on the number of tourists expected on the weekends and weekdays. Future research should control variables such as personal characteristics, seasons proper for vacation and holidays, and carefully consider their investigation and design. Moreover, it is necessary to study variables involved in expected crowding of more various space-intensive sightseeing places (mesa-events).

• 한국조경학회지
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• 제30권6호
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• pp.79-97
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• 2003

The purpose of this paper is to analyze a causal model determining social carrying capacity(SCC) in natural parks, to answer the research question: What is the mechanism for determining SCC in natural parks (NP)\ulcorner After reviewing the literature on SCC and recreation activities in Korean natural parks, we constructed a conceptual framework and formulated the hypothesis of this research. We obtained data through a questionnaire which surveyed 487 visitors at 6 of the 73 NP in Korea during 2001, based on a stratified sampling method. We analyzed the data using descriptive statistical methods, the mean difference test, Pearson's correlation analysis, and path analysis method. We found that 1) The direct effect of resources, activity space(AS), visitor's expectation(VE), encounter, crowding, damage of resources(DR), maintenance condition of resources and facility(MCRF) to SCC are 3.45, 3.62, 2.75, 2.72, 1.32, and 4.77 times more important than that of crowding, respectively, while the indirect effect of resources, AS, VE, encounter, and DR to SCC is 13.03, 11.19, 3.34, 1.3, 2.05, 1.10, 0.05 and 2.30 times more important then that of crowding, respectively, 2) Causal effects of resources, facility, AS, VE, number of visitors(NV), encounter, crowding, VM, DR, and MCRF to SCC turned out to have 0.3523, 0.3321, 0.1751, 0.1465, 0.0307, 0.0762, 0.0604, -0.0510, -0.1177 and 0.2165, respectively, and 3) The causal effect of activity base(AB) and activity atmosphere(AA) to SCC turned out to have 2.57 and 1.1 times higher than that of MCRF, respectively. The research results suggest that 1) this conceptual framework is highly useful for the development of substantive theory and methodology; 2) management issues of AA and MCRF turned out to have 0.81 times in SCC that of AB, i.e, SCC can be significantly improved from control of AA and MCRF; and 3) supply of excellent resources and convenient facilities is needed to increase social carrying capacity. It is recommended that more empirical studies be performed in the future according to the season, visitor characteristics, and AS by NP.

• 보건교육건강증진학회지
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• 제26권3호
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• pp.35-48
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• 2009

Objectives: The community network is a foundation laid by the local community which has been formed historically and geographically to develop itself. This paper as a Korean way of healthy network survey for the community capacity building is an exploratory research to grasp the character of Korean society and then to organize an resident-governing partnership for that. Methods: Research objectives are CBOs(Community-Based Organizations) in S-district of Seoul. This region is a new town, however the solidarity and volunteerism of this resident is lively. The survey tool is Cho's CBOs Evaluation Questionnaire which was originated to measure the community capacity. The period of survey is from the January 2009 to the March 2009 and the study organizations which were collected by snowball sampling were 80. Results: The result shows two main networks: one is the civil society and craft union cluster, the other is welfare organization cluster. Groups of high centrality were organizations whose members are mainly women and craft organizations which were organized before 1990's. The group of high betweenness was the Association of Women's Organizations(0.188). Bi-components were six and they could be divided by organization's aim. In terms of the determinants of the participation to the health center enterprise, only the number of link(B=-0.60, p<0.04) was statistically significant. It means that when organization variables are controlled a tendency appears: the more the voluntary associations network, the less participation in the health enterprise. Conclusion: CBHOs(Community-Based Health Organizations) enhances residents' spontaneity and cohesion to increase the capability of the local community. If the surveyed healthy network, together the community health project, are used for various community development projects, the existing CBOs including CBHOs will be reorganized and furthered newly. For this it will be needed to construct an effective partnership of healthy network by restructuring the existing networks of voluntary associations.

• 인간식물환경학회지
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• 제24권2호
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• pp.219-227
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• 2021

Background and objective: Urban street trees play an important role in carbon reduction in cities where greenspace is scarce. There are ongoing studies on carbon reduction by street trees. However, information on the carbon reduction capacity of street trees based on field surveys is still limited. This study aimed to quantify carbon uptake and storage by urban street trees and suggest a method to improve planting of trees in order to increase their carbon reduction capacity. Methods: The cities selected were Sejong, Chungju, and Jeonju among cities without research on carbon reduction, considering the regional distribution in Korea. In the cities, 155 sample sites were selected using systematic sampling to conduct a field survey on street environments and planting structures. The surveyed data included tree species, diameter at breast height (DBH), diameter at root collar (DRC), height, crown width, and vertical structures. The carbon uptake and storage per tree were calculated using the quantification models developed for the urban trees of each species. Results: The average carbon uptake and storage of street trees were approximately 7.2 ± 0.6 kg/tree/yr and 87.1 ± 10.2 kg/tree, respectively. The key factors determining carbon uptake and storage were tree size, vertical structure, the composition of tree species, and growth conditions. The annual total carbon uptake and storage were approximately 1,135.8 tons and 22,737.8 tons, respectively. The total carbon uptake was about the same amount as carbon emitted by 2,272 vehicles a year. Conclusion: This study has significance in providing the basic unit to quantify carbon uptake and storage of street trees based on field surveys. To improve the carbon reduction capacity of street trees, it is necessary to consider planning strategies such as securing and extending available grounds and spaces for high-density street trees with a multi-layered structure.

• 융합정보논문지
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• 제7권4호
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• pp.113-119
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• 2017

본 연구의 목적은 사회복지시설종사자의 융합적 직무역량강화가 삶의 질에 영향을 미치는지를 검증하는 것이다. 연구의 목적을 달성하기 위해 서울시 20개, 경기지역 20개 사회복지시설에 근무하는 사회복지종사자들을 대상으로 설문을 하였고, 회수된 188부를 연구에 사용하였다. 표본추출법은 비확률표집법에서 임의표집법을 활용하였다. 연구결과, 사회복지종사자의 역량강화정도와 삶의 질간의 관계에서 살펴보면 개인역량과 만족감, 환경역량과 불만족감, 관계역량과 만족감에서만 정적인 상관이 있었고, 나머지영역에서는 상관이 없는 것으로 나타났다. 그리고 사회복지종사자의 개인역량, 환경역량이 불만족감에 정(+)적인 역할을 하는 것으로 나타났다. 또한, 관계역량이 불만족감에 부(-)적인 역할을 하는 것을 볼 수 있다. 개인역량정도, 이직하고자 하는 마음을 통제하는 역량정도, 관계역량이 만족감에 정(+)적인 역할을 하는 것을 볼 수 있다. 따라서 사회복지종사자의 삶의 질을 향상시키기 위해서는 사회 복지종사자들을 대상으로 직무역량강화 교육프로그램을 실행할 때에 긍정적인 효과가 있을 것으로 기대한다.

• The Journal of Asian Finance, Economics and Business
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• 제7권12호
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• pp.355-363
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• 2020

This study aims to investigate whether financial attitude links financial literacy to financial capability. To make sound financial decisions, one essentially requires a certain level of financial literacy - knowledge and skill in finance. Even more effective is when one's financial literacy could be developed into financial capability. The samples comprised 342 individuals from informal labor in the South of Thailand. The stratified multistage sampling technique was utilized to select the respondents, while the interview questionnaires were used to collect the data. By using SmartPLS 3.0, the data analysis included descriptive statistics and structural equation modeling (SEM). The result revealed that the one with the highest debt was Gen Y compared to Gen B and Gen X. Considering financial literacy, financial attitude, and financial capacity across generations, it was found that Gen Y had the highest average score in financial literacy and financial capacity, higher than that of Gen X and Gen B. The impact of financial literacy on financial capability through financial attitude, it was found that the impact on Gen B was higher than that of Gen X and Gen Y. With the right financial attitude, people of all generations would be equipped with a higher level of financial capability.

• Spatial Information Research
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• 제11권1호
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• pp.23-32
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• 2003

GIS분야에서 불규칙삼각망은 저수량계산, 지형분석 등에 활용되며 표고, 경사, 방향 정보를 가지고 있기 때문에 처리시간과 용량이 많이 소요된다. 등고선을 활용하여 TIN을 구축하는 과정에서, 선의 단순화를 위해 사용하는 weed tolerance는 등고선상의 샘플 간격에 영향을 미치게 된다. 본 연구에서는 다양한 크기의 weed tolerance에 따른 TIN의 처리시간과 용량을 계산하였으며, 적절한 weed tolerance를 제시하기 위해 TIN으로부터 생성된 수치표고모형의 표준오차를 평가하여 허용오차 범위를 만족하는 weed tolerance를 결정하였다. 평가결과, DEM 표준오차 5m를 만족하는 TIN의 weed tolerance 는 70m였으며, DEM의 해상도는 20m로 나타났다.

• 한국농림기상학회지
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• 제4권4호
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• pp.237-247
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• 2002

Air pollution by acid pollutants is problematic in the whole world. Water acidification has already been deteriorating the forest ecosystem. This study was conducted to analyze the acidity and chemical composition of the open precipitation and throughfall at forests with various geographic locations in Korea. The results of this study are as follows; The open precipitation pH was lowest in Seochun. The throughfall pH showed some buffering capacity in only Quercus mongolica stands. In Pinus rigida(Shingal and Seochun) stands, there was little difference from the open precipitation. Chemical composition of the open precipitation for each sampling site showed that $Ca^{2+}$, N $H_{4}$$^{+}$ and S $O_{4}$$^{2-}$ concentrations had higher value than other ions, and except these ions, the small quantity of ions showed different properties to each site. Changes of ion concentrations in the throughfall showed a tendency to increase. ion concentrations of the throughfall increased with washout and nutrient leaching from the trees. In conclusion, the influence was extended to the pure zone, and the frequency of acid rain is increasing. But, if the deposition of pollutants exceeds the capacity of purification, it would damage forest ecosystem. Further investigations are necessary to identify tolerant tree species to acid pollutants.nts.