• KSCE Journal of Civil and Environmental Engineering Research
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• v.39 no.5
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• pp.561-568
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• 2019

Recently, Korea has suffered from severe droughts due to climate change. Therefore, we need to pay attention to the change of drought risk to develop appropriate drought mitigation measures. In this study, we investigated the changes of hydrologic risk of extreme drought using the current observed data and the projected data according to the RCP 4.5 and 8.5 climate change scenarios. The bivariate frequency analysis was performed for the paired data of drought duration and severity extracted by the threshold level method and by eliminating pooling and minor droughts. Based on the hydrologic risk of extreme drought events Jeonbuk showed the highest risk and increased by 51 % than the past for the RCP 4.5 scenario, while Gangwon showed the highest risk and increased by 47 % than the past for the RCP 8.5 scenario.

• Hwankyungkyoyuk
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• v.13 no.1
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• pp.65-74
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• 2000

Environmentally literated students and adults should be able to use and apply the basic ecological concepts when considering environmental problems and issues. Because ecology forms the foundation of environmental education, a review of the literatures on the degree of students' understanding for ecological concepts can provide useful insights for environmental educators. The purposes of this study were as follows: first, to analyse the parts connected with ecological knowledge of two environmental education books, ‘environments’(middle school) and ‘environmental science’(high school), second, to investigate the level of understanding on ecological concepts by the use of new developed instrument. The 20 most important ecological concepts from Cherrett(1989) and the important ecological concepts' lists from Hungerford and Volk(1990), Ramsey, Hungerford and Volk(1992), Volk(1993) would be recognized and endorsed by most environmental educators as concepts essential to environmental literacy, We referenced these informations and sequenced ecological knowledge as four main categories(communities, populations, ecosystem, man as a component of the nature systems). We have used it as a criterion in the analysis of teaching materials and the development of a new test instrument($\alpha$=0.81). According to the analysed results, the understanding levels for scales and relationships of communities, populations, ecosystem were high but those for individual concepts and differences were low. By the analysis of Korean High School EE book, ‘environmental science’, learning for some concepts(succession, material cycling, niche etc.) has pointed out as one of problems. Environmental educators must pay a careful attention to the concepts that showed high rates of incorrect answer and this work will contribute toward consolidating the basis of EE and help the accomplishment of the ultimate goals in EE.

• International Area Studies Review
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• v.13 no.3
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• pp.51-71
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• 2009

We pursue empirically influential determinants of risk-sharing across various groups in the United States. We consider all the possible combinations out of the eight BEA economic regions and relate the risk-sharing measure for each group to sectoral composition difference under the control of the state-level macroeconomic and financial characteristics. Our results show that more active risk-sharing via cross-ownership market is observed in groups exhibiting more different sectoral composition. The evidence implies that, given other economic and financial conditions equal, economic union tends to share more consumption risk among its members that are more heterogeneous in their sectoral composition. These days, many countries aim to form FTA and other forms of economic integration. We suggest that they should pay attention to sectoral composition for member countries to minimizes income shock in the integrated economy.

• Journal of dental hygiene science
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• v.19 no.3
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• pp.205-212
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• 2019

Background: Sleep disorder is a precursor to depression, which is one of the psychological factors associated with periodontal disease that, in turn, affects general and periodontal health. This study aimed to investigate the relationship between sleep duration, depression, and periodontitis in older people aged over 65 years. Methods: A total of 2,002 older adults aged 65 years or older were included in the study. Their general and health aspects, including smoking, drinking, diabetes, hypertension, and depression, were investigated. Periodontitis was examined using the Community Periodontal Index (CPI). Data were analyzed through a complex sampling design method. Frequency and crossover analyses were conducted to investigate the relationship between depression and periodontitis. To investigate the effect of depression on periodontitis, a logistic regression analysis was performed. Results: Regarding depression and participants' general characteristics, statistically significant differences were found in sex, economic activity, smoking habit, and CPI (p<0.05). In the presence of depression, the odds ratio for periodontitis was 1.84, and the adjusted odds ratio for age, sex, economic activity, residence type, household income, education level, smoking habit, drinking, hypertension, and diabetes was 1.72, representing a significant difference (p<0.05). Conclusion: This study examined the relationship between depression and periodontitis in older persons and confirmed a significant correlation. As the population of older adults increases, we should pay attention to their mental and oral health as well as systemic diseases. Various programs for the health promotion of older persons need to be implemented to improve the quality of life of older people.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.12
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• pp.416-431
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• 2018

The purpose of this study was to analyze in-depth the nurses' experience of hospital work and the factors affecting career interruption of nurses. For this purpose, 20 inactive nurses aged 26-55 participated in interviews about their experience as nurses, characteristics of nursing work, and reasons for retirement, and applied the analysis method of Colaizzi among phenomenological research methods. The analysis resulted in 104 significant statements, 17 formulated meanings, 6 clusters of theme, and 2 categories. The two categories are nursing work characteristics and work environment characteristics. In the characteristics of nursing work, there are four clusters of theme of 'time pressure', 'lack of autonomy', 'physical and emotional labor', 'low wage increase', and in the characteristics of nursing work environment, there are two clusters of theme of 'physical environment' and 'human environment'. Therefore, in order to improve the nurse career interruption, efforts should be made to alleviate excessive work intensity, raise the appropriate level of pay and provide a safe working environment.

• International journal of advanced smart convergence
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• v.8 no.2
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• pp.109-115
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• 2019

Currently, LPWA(Low Power Wide Area) communication technology is widely used due to the development of IoT(Internet of Things) technology. Among the LPWA technologies, LoRaWAN(Long Range Wide Area Network) is widely used in many fields due to its wide coverage, stable communication speed, and low-cost modem module prices. In particular, LoRa(Long Range) can easily construct LoRaWAN with a dedicated gateway. So many organizations are building their own LoRaWAN-based networks. The LoRaWAN Gateway receives the LoRa packet transmitted from an End-device installed in the adjacent location, converts it into the Internet protocol, and sends the packet to the final destination server. Current LoRa Gateway uses a single-hop method, and each gateway must include a communication network capable of the Internet. If it is the mobile communication(i.e., WCDMA, LTE, etc.) network, it is required to pay the internet usage fee which is installed in each gateway. If the LoRa communication is frequent, the user has to spend a lot of money. We propose an idea on how to design a multi-hop protocol which enables packet routing between gateways by analyzing the LoRaWAN communication method implemented in its existing single-hop way in this paper. For this purpose, this paper provides an analysis of the standard specification of LoRaWAN and explains what was considered when such protocol was designed. In this paper, two gateways have been placed based on the functional role so as to make the multi-hop protocol realized: (i) hopping gateway which receives packets from the end-device and forwards them to another gateway; and (ii) main gateway which finally transmits packets forwarded from the hopping gateway to the server via internet. Moreover, taking into account that LoRaWAN is wireless mobile communication, a level-based routing method is also included. If the protocol proposed by this paper is applied to the LoRaWAN network, the monthly internet fee incurred for the gateway will be reduced and the reliability of data transmission will be increased.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.39 no.5
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• pp.637-645
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• 2019

Global warming and a new energy policy request the energy saving and pollutant emission control in municipal level. Previous studies focus on transportation in the Seoul metropolitan area which can easily meet the policy goal by reducing it. This study expands the area of urban energy planning to the industries and land use which takes up most of energy use of the city. We empirically study the Busan metropolitan area's 5 years natural gas and electricity consumption data by the industries and land use. Results show that energy usage significantly depends on not only population but also urbanizing intensity and industrial category. This paper address that the policy maker need to pay attention on energy usage pattern of each sectors during the planning.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.36 no.2
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• pp.25-32
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• 2020

The purpose of this study is to estimate the economic value of architectural aesthetic using the contingent valuation method and to analyze the value-giving characteristics. The site survey was conducted based on the scenario of Dong-daemun Design Plaza, which is recognized as a work of outstanding architectural aesthetic. Based on 307 opinions collected, the main results are as follows: First, it could be confirmed that the higher the level of architectural aesthetic, the higher the payment amount was. The result of estimating the value of the architectural aesthetic on the basis of the fixed amount levy showed that the average payment amount was 8,859 won per person. The average payment amount was 13,014 won per person when the rejector of payment was excluded. The value of architectural aesthetic was about 13.72% of total construction cost. Second, free riding, which occurs mainly in the measurement of the value of public goods or environmental goods, appeared. This tendency is stronger in the elderly than in the younger, and in the differential amount levy than in the fixed amount levy. Third, the extreme subjectivity of architectural aesthetic value could be confirmed. While there are a lot of extreme denials of payments such as 0 won, the high-income was willing to pay a substantial amount. Fourth, it was confirmed that income factors was partly involved in the measured value.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.1
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• pp.58-73
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• 2021

Cloud Service Providers (CSPs) enable their users to access Cloud computing and storage services from anywhere in quick and flexible manners through the Internet. With the basis of 'pay-as-you-go' model, it makes the interactions between CSPs and the users play a vital role in shaping the Cloud computing market. A pool of virtualized and dynamically scalable Cloud services that delivered on demand to the users is associated with guaranteed performance and cost-provisioning. It needed a costing scheme for determining suitable charges in order to secure lease pricing of the Cloud services. However, it is hard to meet the satisfied prices for both CSPs and users due to their conflicting needs. Furthermore, there is lack of Service Level Agreements (SLAs) that allowing the users to take part into price negotiating process. The users may lose their interest to use Cloud services while reducing CSPs profit. Therefore, this paper proposes a generic costing scheme for Cloud services using General Equilibrium Theory (GET). GET helps to formulate the price function for various services' factors to match with various demands from the users. It is initially determined by identifying the market circumstances that a general equilibrium will be hold and reached. Specifically, there are two procedures of agreement made in response to (i) established equilibrium supply and demand, and (ii) service price formed and constructed in a price range. The SLAs in our costing scheme is integrated to satisfy both CSPs and users' needs while minimizing their conflicts. The price ranging strategy is deliberated to provide prices' options to the users with respect their budget limit. Meanwhile, the CSPs can adaptively charge based on users' preferences without losing their profit. The costing scheme is testable and analyzed in multi-tenant computing environments. The results from our simulation experiments demonstrate that the proposed costing scheme provides better users' satisfaction while fostering fairness pricing in the Cloud market.

• Knowledge Management Research
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• v.22 no.2
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• pp.55-76
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• 2021

The real estate market is a representative imperfectly competitive market. Real estate information is characterized by being collected and utilized in a closed environment, and market participants have to pay a lot of time, effort, and costs to acquire such information. Korea's real estate public data is increasing year by year, but it is scattered by relevant ministries. So it is difficult to search and analyze, and the level of development of the industry using it is low. In the recent 4th industrial revolution, the proptech industry has developed as an industry to efficiently provide necessary information to the real estate market. In this study, based on the case of major companies in the real estate platform field among proptech companies, we looked at the types of information provided to users, and on the contrary, explored ways to utilize the data collected from users. The results of this study are expected to provide theoretical and practical implications for ways to reduce information asymmetry in the real estate market and contribute to the development of the real estate industry.