• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.5
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• pp.964-973
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• 2015

Ship Area Network(SAN) can monitor the status of ship in real time and minimize the maintenance costs by connecting various devices to the network. In particular, among researches on SAN, Wireless Sensor Network using sensor nodes that is low-cost, low-power, and multifunctional has a number of advantages. In this paper, we propose cluster-based multi-channel algorithm considering the energy efficiency in wireless sensor network in a ship. The proposed algorithm shows the result of improvement of throughput and energy efficiency, because it reduces interference between clusters by using channel allocation algorithm that is distributed and dynamic.

• ETRI Journal
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• v.33 no.4
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• pp.497-505
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• 2011

Image fusion is a technical method to integrate the spatial details of the high-resolution panchromatic (HRP) image and the spectral information of low-resolution multispectral (LRM) images to produce high-resolution multispectral images. The most important point in image fusion is enhancing the spatial details of the HRP image and simultaneously maintaining the spectral information of the LRM images. This implies that the physical characteristics of a satellite sensor should be considered in the fusion process. Also, to fuse massive satellite images, the fusion method should have low computation costs. In this paper, we propose a fast and efficient satellite image fusion method. The proposed method uses the spectral response functions of a satellite sensor; thus, it rationally reflects the physical characteristics of the satellite sensor to the fused image. As a result, the proposed method provides high-quality fused images in terms of spectral and spatial evaluations. The experimental results of IKONOS images indicate that the proposed method outperforms the intensity-hue-saturation and wavelet-based methods.

• Journal of the Earthquake Engineering Society of Korea
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• v.17 no.4
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• pp.181-186
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• 2013

The construction costs for nonstructural systems such as mechanical/electrical equipment, ceiling system, and piping system occupy a significant proportion of the total cost. These nonstructural systems can also cause considerable economic losses and loss of life during and after an earthquake. Therefore, reduction of seismic risk of nonstructural components has been emerging as a key aspect of research in recent year. The primary objective of this study was to evaluate the seismic performance of a single-story and multi-story piping system installed in low-rise building and to identify the seismic vulnerability of the current piping systems. The seismic performance evaluation of the piping systems was conducted with 5 different earthquakes to account for the ground motion uncertainty and the preliminary results demonstrated that the maximum displacements of each floor in the multi-story piping system increased linearly with increasing floor level in the building system. This study revealed that the current design piping systems are significantly sensitive to the effect of floor height, which stress the necessity to improve the seismic performance of the current piping systems by, for example, strengthening with seismic sway bracing using transverse/longitudinal bracing cables or hangers.

• Research in Community and Public Health Nursing
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• v.12 no.3
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• pp.589-599
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• 2001

The purpose of this study was to analyze the relation amongst health status, health care costs. health service utilization among the low income elderly who were 60 years of age or older, earning a half of the average Korean family income. The cross-sectional descriptive survey research we conducted used families randomly sampled nationwide. The data were collected from July 12 to August 7, 1999 and the total sample was 1.259 household members (421 households). These were the major findings. 1. As for the health status. 72.4% of respondents fell ill in the last 1 month; 54% of respondents had chronic disease. 2. As for the health care cost. the cost of hospitalization and the medical treatment were 1.069,000 won and 226.000won. respectively. 59.3% of respondents experienced a burden from the monthly health care expenses. 3. As for the health service utilization for the last 3months. 28.5% of respondents didn't utilize the health service. In addition, 22.2% of respondents gave up a medical treatment because of economic situation (88.8%). 4. The statistically significant determinants of health service utilization are old age, female, living with a spouse, unemployed state, medicare, and more days sick. 5. It is shown conclusively that equity and efficacy of the health care policy are to be considered for lower income older adult.

• Journal of KIBIM
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• v.5 no.4
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• pp.11-22
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• 2015

Government efforts for green growth policy initiatives demand low-carbon technologies in the road construction industry. The purpose of this paper is to develop an algorithm of a road alignment design solution for establishing the multi-dimensional information, and to calculate carbon emission quantity due to the geometric design elements in the planning phase of road alignment. The paper developed a calculation method for carbon emission quantity by drawing a speed profile reflected in the operating speed, acceleration and deceleration, which are majors factor of carbon emissions while driving and by applying a carbon emission factor. From this effort, it enabled alignment planning to reduce carbon emission. Object-based parametric design methods of the cross-sections were proposed for alignment planning, and the paper demonstrated a BIM-based road alignment planning solution. The proposed solutions can provide multi-dimensional information on carbon emission quantity and cross section elements through driving simulation. It is expected to allow construction of eco-friendly roads by deriving optimal road alignment to minimize environmental costs.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.11
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• pp.2223-2228
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• 2009

Dye sensitized solar cells(DSCs) have been very economical and easy method to convert solar energy to electricity. DSC can reach low costs in future outdoor power applications. However, to commercialize the DSC, there are still many shortages to overcome such a low efficiency in a large size DSC. In this study, DSCs were fabricated by an electrospray coating method for the $TiO_2$ thin film. They were compared with DSCs prepared by conventional coating methods. We conducted an experiment to obtain the optimized parameters of voltage, flow rate, incident angle and distance in the electrospray method. After we fabricated $TiO_2$ film using that way, we investigated the characteristics of DSC through I-V Curve, SEM and EIS. This novel method shows stable performance with an energy conversion efficiency of 3.44 % under 1 sun illumination (AM 1, $P_{in}$ of $100\;mW/cm^2$).

• Land and Housing Review
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• v.11 no.1
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• pp.1-10
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• 2020

The purpose of this study is to identify the characteristics of residents for purchased public housing in Seoul, using empirical panel data. The scope of the study will be targeted at the Seoul, as of 2017. The research method includes literature review, statistical analysis, and spatial analysis using QGIS software program. The data used in the research is the Panel Survey of Public Housing in Seoul(2017). The main results of the research are briefly summarized as follows; Firstly, Living in a housing with an increased area compared to the previous housing. Secondly, they can live for a long time with low rent. The burden on housing costs is 71.8% in the case of the deposit. Thirdly, there is little concern about social stigma. Purchased public housing was found to be good in terms of stigmatization due to low-income clusters. Lastly, the accessibility in the city center was good condition. In particular, commuting time was 34.79 minutes on a one-way basis, saving about 4 minutes compared to other types of public housing.

• Journal of the Korean Society for Library and Information Science
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• v.37 no.2
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• pp.169-186
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• 2003

Most of the university libraries in Korea provide digital reference service(DRS), but the use of DRS is very low. The low usage of DRS seems to result from the lack of subject librarians, of staff, of public relations, and of managers' enthusiastic attitude and understanding of DRS. It is difficult to solve these problems because of the poor circumstances in universities. The collaborative digital reference service(CDRS) is a solution to these problems. Not only CDRS costs little but also can provide reference services in many different subject areas. Though subject specialist librarian, user-friendly system interface, system programs and administrative supports are necessary to implement CDRS, the education and training of the subject specialist librarians is the most important work to be done in the university library situation in Korea.

• Proceedings of the Ginseng society Conference
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• 2002.10a
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• pp.212-226
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• 2002

North American ginseng production may have been maximized in the traditional growing areas in the last decade and further increases may be in woods grown root, for niche markets. The marketplace demands high quality roots. Most problems leading to low quality roots start with the grower and can be avoided. These include poor site selection, inadequate soil drainage, untimely and poorly applied pesticides, and neglect of good sanitary practices. Selection of low lying sites increased the plant damage from frost in Ontario in May 2002. Seeding is still the major method of propagation of ginseng in spite of some success in culturing different parts of the plant. Opportunities exist for shortening the stratification period of North American ginseng seed to allow spring planting. This may reduce disease incidence. Since only one-third of ginseng seed sown ultimately produces plants harvested after 3 years any approach that reduces disease incidence and improves seed germination, seedling emergence and crop stand must be pursued. Disease is the major problem in ginseng cutivation from seed stratification, soil preparation prior to planting, right through to drying of the roots. Replant disease remains as an unresolved problem and needs full characterization and new approaches for control. Much progress has been made in research and related extension activities in disease control although challenges will arise such as with Quintozene and its replacement with Quadris for control of diseases caused by Rhizoctonia. Decreased labor populations and increased associated costs for ginseng production are causing rapid mechanization in every aspect of the ginseng industry. Engineers, machinery dealers, and fabricators, and growers are being challenged to increase efficiency by mechanization.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.11
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• pp.79-86
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• 2021

In recent years, firm performance has been a topic that attracts many researchers. It is extremely important to identify the factors that change firm performance. In the current trend of competition and integration, foreign ownership, product market competition is found to reduce agency costs and impact firm performance. The purpose of this research is to investigate the relationship between foreign ownership, product market competition, and firm performance. Our research using a quantile regression model, through panel data of 290 companies listed on the Vietnam stock exchange (include Ho Chi Minh and Hanoi stock exchanges) from 2017 to 2019 that was collected by Thomson - Reuters DataStream has shown that foreign ownership and product market competition have a positive impact on Tobin's Q but are not statistically significant with ROA. Critically, our quantile regression results suppose foreign ownership, product market competition have a significantly larger positive impact in high-performing firms relative to low-performing firms. The results help propose solutions to planners and managers to change foreign ownership and product market competition to increase business performance. Besides, through quantile regression analysis, managers need to pay attention to the impact on foreign ownership, product market competition; there will be a difference between high-performing firms relative to low-performing firms.