• Journal of the Korea Organic Resources Recycling Association
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• v.27 no.2
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• pp.67-73
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• 2019

In this study, to optimize the production and utilization of biogas for organic waste resources, the precision monitoring of on-site facilities and the energy balance by facility were analyzed, and the solutions for field problems were investigated, and the design and operation guidelines for pretreatment facilities and generators were presented. Gas pre-treatment is required to solve frequent failures and efficiency degradation in operation of high quality refining facilities, and processing processes such as desulfurization, dehumidification, deoxidization, dust treatment, volatile organic compounds, etc. Since these processes are substances that are also eliminated from the high-quality process, quantitative guidelines are not presented in the gas pretreatment process, but are suggested to operate during the processing process as a qualitative guideline. In particular, dust, siloxane, and volatile organic compounds are the main cause of frequent failure of high-quality processes if they are not removed from the gas pretreatment process. Design of the biogas high-quality process. The operation guidelines provide quality standards [Methane content (including propane) of 95% or more] with 90% or more utilization of the total gas generation, two systems, and a margin of 10% or more. It also proposed installing gas equalization tank, installing thermal automatic control system for controlling equalization of auxiliary fuel, installing dehumidification device at the back of high quality for removing moisture generated in the process of gas compression, installing heat-resisting facilities to prevent freezing of facilities in winter and reducing efficiency, and installing membrane facilities in particular.

• Journal of Internet Computing and Services
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• v.20 no.3
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• pp.43-59
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• 2019

Today, with the spread of smartphones and the development of social networking services, structured and unstructured big data have stored exponentially. If we analyze them well, we will get useful information to be able to predict data for the future. Large amounts of data need to be collected first in order to analyze big data. The web is repository where these data are most stored. However, because the data size is large, there are also many data that have information that is not needed as much as there are data that have useful information. This has made it important to collect data efficiently, where data with unnecessary information is filtered and only collected data with useful information. Web crawlers cannot download all pages due to some constraints such as network bandwidth, operational time, and data storage. This is why we should avoid visiting many pages that are not relevant to what we want and download only important pages as soon as possible. This paper seeks to help resolve the above issues. First, We introduce basic web-crawling algorithms. For each algorithm, the time-complexity and pros and cons are described, and compared and analyzed. Next, we introduce the state-of-the-art web crawling algorithms that have improved the shortcomings of the basic web crawling algorithms. In addition, recent research trends show that the web crawling algorithms with special purposes such as collecting sentiment words are actively studied. We will one of the introduce Sentiment-aware web crawling techniques that is a proactive web crawling technique as a study of web crawling algorithms with special purpose. The result showed that the larger the data are, the higher the performance is and the more space is saved.

• 한국노년학
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• v.37 no.4
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• pp.853-870
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• 2017

This study examined the changes of depression and life satisfaction among the elderly living together in group-home and congregate housing. And in this course, it was to verify the practical effects of the recent government and local authority community life of elderly people by comparing them with the groups of elders living alone. The study was divided into Time 1 and Time 2, and 205 person's data were used for the final analysis. PASW Statistics 18.0 was utilized to analysis the data of this study, because it is difficult to explain the results of this analysis, secondary qualitative research has been used to identify additional contextual information. The major results of this study are as follows. First, the depression of the subjects was significantly improved in the case of living in group-home and congregate housing, and it was significantly worse in the group of elders living alone. Second, the life satisfaction of survey subjects was significantly improved when living in congregate housing, group-home was significantly worse, and the group of elders living alone were not statistically significant but slightly worse. Third, mixed research methods were applied to make accurate interpretation of changes of life satisfaction of the elderly living in group-home. Based on the results of this study, it is possible to establish appropriate measures for the elderly to improve early adjustment and quality of life in community life. And the community life of the elderly can contribute to a real social safety net by solving the blind spot of welfare. At the national level, it can be utilized as a standard reference to improve and strengthen existing policies by providing data that can simultaneously examine the performances and problems of various policies related to housing or the welfare of the elderly.

• 한국노년학
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• v.37 no.3
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• pp.583-600
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• 2017

The purpose of this study is to explore qualitatively what kind of coping strategy the Korean older adults use when they are depressed and why. Participants were users, older than 60, of an elderly welfare center in Seoul, and answers of 34 respondents who experienced depression were included in the analysis. The collected data were analyzed through content analysis. The results of the analysis showed that strategies to cope with depression used by participants were composed of 6 domains and 11 sub-domains: health behavior (medical approach / exercise and diet), family and social contact (social interaction / going out and going on a trip / communication with family), Religious activities (Religious activities), lifelong education (hobbies / educational activities), productive activities (labor), health risk behaviors (drinking and gambling / resignation). The depression coping strategies of the older adults and their characteristics are as follows. First, older adults used diverse problem-focused coping strategies to cope with depression. Second, older adults considered various coping strategies together and used them simultaneously. Third, the facility space for older adults functions as a shelter. Fourth, although there were cases where medical approach was used, the intention to reuse was very low. Through this study, the following suggestions were made to help older adults cope with depression more successfully. First, access to various coping strategies should be promoted. Second, more places where older adults can spend their time comfortably need to be provided. Third, resistance to mental health care should be resolved.

• Tunnel and Underground Space
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• v.28 no.6
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• pp.692-705
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• 2018

Ground vibration is one of the remarkable issues in tunnel blasting. In recent studies, to improve the fragmentation with reduction of ground vibration in tunnel blasting, a vibration-controlled blasting method with artificial cutting slot near the center-cut holes has been suggested. This study examines the effect of the different arrangement of artificial cut-slot on the vibration reduction and fragmentation by performing the full-scaled concrete block blast experiments and the numerical simulations with 3D-DFPA. The results show that the existence of artificial slot contributes to the improvement of vibration reduction, blast fragmentation and the efficiency of the cutting slot blast. It can be explained that the artificial slot play a free surface role and should decrease the burden between the cut holes. Crater volumes of the blasted concrete blocks were measured by 3-dimensional digital image analysis and compared with the ideal standard crater volume which can be calculated by theoretical standard blast design method. As a result, the ratio of burden and hole diameter which should achieve the standard crater in the cut-hole blasting were suggested.

• Korean Journal of Construction Engineering and Management
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• v.20 no.2
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• pp.53-59
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• 2019

As solve the shortage problems of storage space for exhibition facilities, the South Korean government is establishing plans to expand storage space for exhibition facilities. From a medium- to long-term perspective, an energy-efficient storage space for exhibition facility is needed to implement efficient state budget execution and achieve national greenhouse gas reduction goals. In this regard, this study analyzed the energy consumption of storage space for exhibition facilities according to the use of absorption materials. To this end, a case study was conducted on 12 storage spaces for exhibition facilities in South Korea. Compared to the storage space using the absorption material, the storage space without using the absorption material showed an increase in HVAC system operation time by 47.50% during summer periods and 58.85% in non-summer periods. In particular, the analysis found that in the case of storage for 'H' exhibition facility, the energy cost was reduced by 2,721,700 won/year after remodeling work using the absorption material. It is expected that the findings of this study can help the government and the person in charge from construction companies to construct energy-efficient storage space room for exhibition facilities.

• Journal of Cadastre & Land InformatiX
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• v.48 no.2
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• pp.31-49
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• 2018

The boundaries of administrative districts are the basic system for the whole country and are closely related to the daily life of the residents. The administrative boundary of Korea is registered and managed in the cadastral study based on the intellectual study of cadastral system. There is a non-conforming land where the registration details of some cadastral studies do not match the actual situation of the land, and the cadastral rehabilitation project is implemented as a national project to create a new digital cadastral study. However, due to the cadastral rehabilitation project, there is an unreasonable parcel that the past administrative boundaries and newly registered boundaries are different from each other due to the registration of the past administrative boundaries for the newly registered cadastral studies. The purpose of this study is to identify the unreasonable administrative boundaries arising from the cadastral rehabilitation project and to identify problems in order to effectively manage the number of branches in terms of administrative and administrative efficiency in terms of registration and inhabitants management. It is expected that the legal system will be improved to legitimately control the boundary of the administrative district and to manage the boundaries of the administrative district accordingly and to provide the service and to solve the inconvenience of the nation.

• Journal of Cadastre & Land InformatiX
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• v.48 no.2
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• pp.65-77
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• 2018

It is very important to understand the factors affecting the occurrence of vacant houses in research on them. The purpose of this study is to analyze the factors affecting the rural vacancy occurrence. This study set 121 research areas and selected eight independent variables (Aged house rate, housing transaction rate, house diffusion ratio, local extinction index, net migration rate, regional aging index, the ratio of the number of employees to population and financial independence rate) and one dependent variable (vacant house rate). As a result of the study, first, both Model 1 for the entire general agricultural fishing village area and Model 2 for the county (gun) area were statistically significant, there was no problem with the independence of residual. Second, local extinction index and aged house rate had a statistically significant positive (+) relationship in both Model 1 and Model 2. Third, diffusion ratio of house had a statistically significant positive (+) relationship only in Model 1, and housing transactions rate had a statistically significant negative (-) relationship in Model 2. The implications of the study were drawn as follows: First, the increase in the house diffusion ratio without growth in households and population suggests the increase of the probability of the vacancy occurrence in the area, and the higher the aged house rate, the higher the probability of the vacancy occurrence. Second, for the revitalization of housing transactions, it is necessary to have an investment inflow in the area for mid- to long-term development. Third, local extinction index has a significant relationship with vacant house rate, it is necessary to introduce a local revitalization policy from a long-term perspective for the permanence of the area.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.39 no.1
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• pp.93-103
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• 2019

In metropolitan cities have been reorganizing the routes of the city buses periodically due to changes in the spatial structure and traffic pattern and the lack of supply due to new developments. However, there is a lack of system to comprehensively evaluate the routes. Even if the evaluation index is not clearly defined, it may not be reasonable. Therefore, it is difficult to set the improvement direction when the bus route is reorganized. In this study, the existing evaluation indexes were reviewed and further investigation was conducted on the problematic indexes. In particular, the degree of curvature has been used as a very important index in the evaluation of the route system, but the existing curvature based curvature has a limitation in considering the traffic characteristics of individual users. For this purpose, a virtual city bus network was set up and the degree of curvature was calculated and compared based on the point - based curvature and stopping point based on individual user O/D. In this study, it is considered that more efficient and practical analysis and evaluation are possible in the evaluation of the city bus route system through the curvature considering the individual user O/D based on the stopping point. It is expected that it will be used at the time of reorganization of city bus route performed by individual local governments in the future.

• Journal of Cadastre & Land InformatiX
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• v.49 no.1
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• pp.45-63
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• 2019

Until recently, most people have invested in a traditional portfolio consisting of stocks, bonds and real estates based on the three-division method of properties in Korea. However, this study analyzed the impact of the composition of a portfolio combining representative real estate indirect investment products such as Reits and real estate funds on the investment performance. For this purpose, the empirical analysis using the mean variance model, which is the most appropriate method for the portfolio composition, was used. For variables used in this study, mixed asset portfolios were classified into Portfolio A through Portfolio G depending on the composition of assets, and the price indices selected as Kospi, Krx bond, Reits Trus Y7, Hanwha-Lasal fund, and Office (Seoul). The results are as follows; first Portfolio D, which combined bonds, stocks, Reits and Real Estate funds, and Portfolio G, which added the office, the actual real estate, were shown to have the lowest risk. second, Portfolio B composed of bonds, stocks and Reits and Portfolio D with added real estate funds had the lowest risk while Portfolio F composed of bonds, stocks, offices and real estate funds, and Portfolio G with added Reits were the most profitable. As a result, it has been analyzed that it was more effective to compose a portfolio including Reits and real estate funds, which were real estate indirect investment products that eliminated the illiquidity limitation of real estates than real estates, the traditional three-division method of properties. Therefore, it is possible to minimize the risk of investors and reduce the cost of ownership of the real estate by solving the illiquidity problem that is the biggest disadvantage of the direct investment, In addition, it is considered that it is more necessary to reinvigorate the real estate indirect investment market where small amounts can be invested.