• The Journal of Industrial Distribution & Business
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• v.11 no.2
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• pp.41-48
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• 2020

Purpose: This study is to examine the intention of the elderly who live alone in the customized AI speaker for the elderly living alone to improve the quality of life service for the elderly living alone in the smart city environment. Based on the quality of life model of the elderly, this study is applied to the technology acceptance model to investigate the relationship between perceived usefulness and ease of use on the sustained use intention. Research design, data and methodology: Residents in Suwon, Gyeonggi-do, selected as candidate local governments for the Smart City Challenge Project of the Ministry of Land, Infrastructure and Transport in June 2019 to measure the perceived technology acceptance of potential users for the AI technology for the elderly living alone as part of the smart city technology. In order to evaluate the intention of using AI speaker, which is the target system of this study, a video of a chatbot using experience of elderly people living alone was produced. Results: First of all, in order for the elderly living alone to have an attitude to use AI-based speakers, there should be a perceived usefulness of the quality of life of the elderly. However, ease of use did not show any significant causal relationship to attitude toward use. In addition, the attitude toward use weakly influenced the intention to use. In other words, elderly people living alone were not likely to have a significant effect on their attitude toward use. However, feeling that AI speakers are easy to use will help to improve the quality of life, which in turn led to the attitude toward using AI speakers, which could lead to indirect effects. Finally, the perceived usefulness of quality of life was found to have a weak effect on direct use intentions. Conclusions: This study conducted a study on the technology acceptance of service environment to improve the quality of life for the specific user group who live alone in the smart seat environment. In this study, we examined the effects of AI speaker on the elderly living alone to improve the quality of life for the elderly living alone.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.23 no.1
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• pp.79-92
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• 2011

In this study, wave pressure of short-period gravity waves and tsunami acting on the upright section of the horizontal-slit type caisson placed on the impermeable or permeable seabed, which is a well-known permeable breakwater with a good wave controlling ability, are investigated via numerical simulations. Further, the permeable seabed was modeled as the porous media with porosity of 0.4. Using the numerical results, the effects of the seabed conditions on the wave pressure on the front wall and inside wall of the chamber have been studied. In the numerical simulations, short-period gravity waves and tsunami(solitary wave or bore) with the same amplitude to the gravity wave are considered. A numerical wave tank is used, which is able to consider a gas-liquid two-phase flow in the same calculation zone. Numerical results show that the wave pressure of the tsunami was 3~5 times higher than the short-period gravity waves acting on the front wall and it was 2~4 times higher than the short-period gravity waves acting on the inner wall.

• Korean Journal of Environmental Agriculture
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• v.29 no.2
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• pp.146-151
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• 2010

In order to improve T-N and T-P removal in HF (horizontal flow)-HF hybrid constructed wetlands by natural purification method for treating the hydroponic wastewater in greenhouses, the efficiency of water treatment as affected by the injection method of hydroponic wastewater, the addition of special filter media, the particle size of filter media, and the injection ratio of hydroponic wastewater in $1^{st}$ HF and $2^{nd}$ HF beds were investigated in small-scale HF-HF hydroponic wastewater treatment apparatus. Removal rate of T-P in the water in HF-HF hydroponic wastewater treatment apparatus with calcite as affected by addition method of special filter media was higher than that in HF-HF hydroponic wastewater treatment apparatus with other filter media. Removal rate of BOD, COD, SS, T-N and T-P in the water in mixed filter media with calcite were 86, 84, 87, 50 and 97%, respectively. Removals of pollutants except for T-P in the water were slightly different. Therefore, it should be considered that the removal rate of T-P was good for calcite in HF-HF hydroponic wastewater treatment apparatus. To improve T-N and T-P removal, the optimum particle size of filter media was 1.2 mm, and the optimum injection ratio ($1^{st}$ HF bed : $2^{nd}$ HF bed) of hydroponic wastewater was 60:40.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.4
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• pp.280-287
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• 2012

The sources of greenhouse gases (GHG) at Hanyang University Ansan campus, including direct sources, indirect sources, and others, were investigated in order to establish the GHG inventory. Emission of GHG was calculated with the energy use from each source from 2007 and 2009. The indirect emission (56.7%) due to the electricity significantly contributed to total GHG emission. The scenario for the GHG reduction was designed for both campus administration and members. The reduction potential of GHG was simulated from 2007 to 2020 using Long-range Energy Alternatives Planning (LEAP) model. In case of GHG reduction scenario by campus administration, the GHG can be reduced by 63.34 ton $CO_{2eq}/yr$ for stationary combustion in the direct source, by 221.1 ton $CO_{2eq}/yr$ for mobile combustion in the direct source, and by 4,637.34 ton $CO_{2eq}/yr$ for lighting in the indirect source, compared to 2020 Business As Usual (BAU). In case of GHG reduction action scenario by campus members, the reduction potential of GHG was 1293.76 ton $CO_{2eq}/yr$. Overall, the total GHG emissions in 2020 by the both scenarios can be decreased by 24% compared to 2020 BAU.

• The Journal of Industrial Distribution & Business
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• v.10 no.3
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• pp.45-58
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• 2019

Purpose - The purpose of this study was to investigate the effects of the chatbot's characteristics (ease of use, social presence, playfulness, usefulness) on service value, customer satisfaction and reuse intention when consumers purchased fashion products in the mobile shopping environments. Research design, data, and methodology - Data were collected from Korean consumers from ages 20 to 59 who have experienced using chatbot in a mobile shopping for fashion products. After a pilot survey to 53 customers, the preliminary questionnaire was revised for the final test, and the final questionnaire was administered to 1500 customers. Out of these, 300 were collected. After deleting 48 incomplete ones, 252 questionnaires were used in the statistical analysis. Frequency analysis and exploratory factor analysis using SPSS 23.0 and confirmatory factor analysis and structure equation analysis using AMOS 18.0 were employed for data analyses. Results - First, four factors were extracted for the chatbot's characteristics: ease of use, social presence, playfulness and usefulness. Second, regarding the effect of chatbot's characteristics on service value when purchasing fashion products in the mobile shopping environment, ease of use, playfulness and usefulness of chatbot significantly affected service value. Social presence did not have significant effects on service value. Third, in terms of the effect of the chatbot's characteristics on customer satisfaction when purchasing fashion products in the mobile shopping environment, social presence, playfulness and usefulness of chatbot significantly had an effect on customer satisfaction. Ease of use did not have a significant effect on customer satisfaction. Fourth, service value of chatbot when purchasing fashion products in mobile shopping environment was found to have an effect on customer satisfaction with chatbot. Fifth, service value of chatbot on reuse intention when purchasing fashion products in the mobile shopping environment was found to have an effect on reuse intention of chatbot. Sixth, customer satisfaction with chatbot had a significant impact on the reuse intention of the chatbot when purchasing fashion products in the mobile shopping environment. Conclusions - The present study provide dimensions on the chatbot's characteristics and these may provide helpful data for further studies in this area and for marketers as well.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.4
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• pp.664-673
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• 2018

The industrial control system (ICS) has operated as a closed network in the past, but it has recently been linked to information and communications services and has been causing damage due to cyber attacks. As a countermeasure, the Information Communication Infrastructure Protection Act was enacted, but it cannot be applied to various real control environments because there is only a one-way policy-from a control network to a business network. In addition, IEC62443 defines an industrial control system reference model as an international standard, and suggests an area security model using a firewall. However, there is a limit to linking an industrial control network, operating as a closed network, to an external network only through a firewall. In this paper, we analyze the security model and research trends of the industrial control system at home and abroad, and propose an industrial control system security model that can be applied to the actual interworking environments of various domestic industrial control networks. Also, we analyze the security of firewalls, industrial firewalls, network connection equipment, and one-way transmission systems. Through a domestic case and policy comparison, it is confirmed that security is improved. In the era of the fourth industrial revolution, the proposed security model can be applied to security management measures for various industrial control fields, such as smart factories, smart cars, and smart plants.

• Journal of Energy Engineering
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• v.23 no.4
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• pp.176-182
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• 2014

The project of promoting the economy has attracted attention as on strategy for the economic revitalization of abandoned mine areas which is promoting by local government based on the "Special law on the development of abandoned mine areas". Through the analysis of economic feasibility analysis, the government is trying to determine the presence or absence of budget support to project of promoting the economy of local government. Furthermore, this paper attempts to conduct a cost-benefit analysis, using net present value(NPV), benefit/cost(B/C) ratio, internal rate of return(IRR) techniques for project of promoting the economy of Samcheok City. The project of promoting the economic of Samcheok City is promoting the Yukbaeksan flowers rest park and Glass Art Culture and Tourism theme park. The results indicate that NPV, B/C ratio and IRR of Yukbaeksan flowers rest park are 3,937 million won, 1.06, 6.18% and NPV, B/C ratio and IRR of Glass Art Culture and Tourism theme park are 8,311 million won, 1.34 and 9.47. Accordingly, the projects of promoting the economic of Samcheok City ensure economic feasibility that the three indicators have exceeded 0, 1.0 and 5.5% respectively. Moreover, the analysis results can be used effectively in the decision for the project of promoting ecomony of Samcheok city.

• Journal of Navigation and Port Research
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• v.39 no.1
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• pp.23-28
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• 2015

This paper is to identify the dynamic phenomenon of the marine pollution management that is connected directly or indirectly by using system dynamics analysis. The method used herein is based on system dynamics analysis that analyzed the sub-systems for marine pollution management. Furthermore designed feedback loop between system elements. And made total casual map of marine pollution management. The main results of the paper are the following : 1. It's necessary to equipments and technology development and law revision for feedback loop slump of initial measures delay in oil spill. 2. It should be come up with partnerships and new business for community corrosion non-proliferation caused by social conflicts. 3. Marine pollution management should be an obligation that must be minimized to include social conflicts in the community and national levels besides oil spill response on-site. This model confirmed the hidden cause of delay by existing response plans, manuals and programs. And oil spill response in broader sense is more important from now on. The result can be useful in the guidance of marine pollution and management.

• Korean Journal of Remote Sensing
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• v.32 no.5
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• pp.499-509
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• 2016

The occurrence of sand dust has been steadily increased since 1990 and the amount of damage was also increased. In most of previous studies, ground based observations were used for sand dust analyses, but its high spatio-temporal variability has not been well understood. In this study, satellite aerosol observations were used to overcome current limitations of the sand dust variability in space and time and to estimate associations with morbidity of respiratory and cardiovascular ailments. In general, high AODs were observed in the west part of the Koran peninsula in spring. The reasonable associations between the morbidity and sand dust were observed from April to July with highest positive correlation (~0.6) at three month lags (lag 3). Based on the results, we found a utility of the satellite aerosol observations for sand dust analyses by considering of morbidity effects. In addition, health effect against the sand dust is proved to be examined and smooth medical supplies and prevention of undesired medical expenses would be possible.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.24 no.3
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• pp.359-364
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• 2014

Objectives: The principal aim of this study is to provide fundamental data for suggesting substantial management plan of personal air sampler by investigating current situation of work environment monitoring service provider. Materials and Methods: The questionnaires regarding a personal air sampler were sent by electronic mail to 150 institutions, except for 22 institutions which are out of business or closed temporarily, among total 172 domestic work environment monitoring service providers designated by Ministry of Employment and Labor based on 2013. The institutions which did not reply to the questionnaire for 30 days were required directly by phone call. Finally 97 institutions gave an answer to the questionnaire and therefore the respondence rate was 65%. Results: The normal operation rate of personal air sampler exceeded 70% in all the types (particle, gas and both combination) in terms of purchased year. Furthermore the personal air sampler purchased recently showed a trend of high operation rate compared to the personal air sampler purchased previously. The distribution patterns of personal air sampler In terms of manufacturers were Gillian>MSA>SKC for particle, Gillian>SKC>AMETEK for gas and Gillian>MSA>Casella for both combination, respectively. As a result, it was found that the personal air sampler manufactured by Gillian company was utilized the most in domestic work environment monitoring service provider regardless of types of personal air sampler. Conclusions: Based on the results obtained from this study, the normal operation rate according to types of personal air sampler was as follows: 94% for personal air sampler for collecting particle only, 93% for personal air sampler for collecting gas only and 89% for collecting both particle and gas. Overall, the numbers of personal air sampler possessed and operated normally in domestic work environment monitoring service provider were 5,458 and 5,062, which indicates the normal operation rate of personal air sampler in total aspect is 93%.