• Journal of the Korea Society of Computer and Information
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• v.28 no.12
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• pp.221-229
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• 2023

Recently, Grid-forming(GFM) converter, which offers features such as virtual inertia, damping, black start capability, and islanded mode operation in power systems, has gained significant attention. However, in low-voltage microgrids(MG), it faces challenges due to the coupling phenomenon between active and reactive power caused by the low line impedance X/R ratio and a non-negligible power angle. This power coupling issue leads to stability and performance degradation, inaccurate power sharing, and control parameter design problems for GFM converters. Therefore, this paper serves as a review study on not only control methods associated with GFM converters but also power decoupling techniques. The aim is to introduce promising control methods and enhance accessibility to future research activities by providing a critical review of power decoupling methods. Consequently, by facilitating easy access for future researchers to the study of power decoupling methods, this work is expected to contribute to the expansion of distributed power generation.

• Journal of Korean Library and Information Science Society
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• v.53 no.1
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• pp.55-79
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• 2022

In this study, the current status of operation was analyzed with a view to analyze the areas in need of improvement and the status of portals of similar institutions. Based on which, a proposal was made to help improve the function of utilization as well as search the products of studies by and for the research institutes funded by the government having jurisdiction by applying the information service technology developing in line with the fourth industrial revolution for the purposes of aiding and fostering with efficiency toward achieving the goal of establishment for such institutes, while strengthening the utility of NKIS. First, in order to secure the membership, it is necessary to find the targets for policy information and promotion, and it is also necessary to increase the demand for policy information, such as by preparing the people friendly policy reports, infographics, and information delivery in an easy manner. Second, it is necessary to provide customized services in the manner which reinforces reports and policy data on the social issues and education topics, which are among the interests of the primary user base by considering the ratio of visiting occupations. Third, for the diversification and expansion of video data services, it is necessary to prepare alternatives, such as by setting regulations and encouraging the institutions of jurisdiction to upload the video data. Fourth, it will be necessary to improve the overall public relations service. It is also necessary to proceed with the NKIS' publicity webtoon serialization with the latest contents or abolish the current webtoon promotion, while it is necessary to derive the plans for the efficient implementation of the contest, further to the need to discuss the secondary publicity after the contest rather than halting after it.

• Journal of Distribution Science
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• v.12 no.8
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• pp.5-15
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• 2014

Purpose - The method of TV home shopping is a kind of retail method that provides the viewer with information about products and, further, sells the products to consumers through the media of television. The domestic home-shopping industry has been expanding since 1995, and there are six companies in this arena as of 2012. In this study, we evaluate the management efficiency of TV home-shopping companies and provide suggestions for improving efficiency, using the DEA (data envelopment analysis) model. Hence, we expect to contribute to the progress of the companies' efficiency and the development of the TV home-shopping industry, where deepening competition is inevitable because it is experiencing the maturing market stage in its life cycle. Research design, data, and methodology - Efficiency is the ratio of the quantity of input to the quantity of output of a product or service. It is necessary to estimate aggregate inputs and aggregate outputs, which are calculated by applying a weighting to a number of input and output factors, to measure the efficiency. The DEA model is divided into the CCR model and the BCC model. The CCR model is a basic model that assumed constant returns to scale (CRS), and the BCC model extends the CCR model to accommodate technologies exhibiting variable returns to scale (VRS), and concerns only the technical efficiency without considering the efficiency of returns to scale. In this study, we consider six companies each year from 2008 to 2012 as a DMU (Decision Making Unit) and analyze the differences in efficiency for each company in each year. Furthermore, we evaluate the operating characteristics of TV home-shopping companies, using three models, in accordance with the overall performance, profitability, and marketability of the business. Results - The result of the analysis, using DEA models, shows that Hyundai Home Shopping (2009, 2010, 2011), GS Home Shopping (2011), NS Home Shopping (2011) and CJ O Shopping (2012) possess MPSS (most productive scale size), with a score 1.0 in CCR, BCC, and scale efficiency. Particularly, Hyundai Home Shopping is shown to be the most efficient in terms of overall business performance, marketability, and profitability. The overall efficiency of the home shopping industry has displayed an increasing trend since 2008, even though it decreased marginally in 2012; further, we can observe that home shopping companies operate with increasing efficiency with the passage of time. Conclusions - Home shopping companies have focused on market expansion rather than profits, as they displayed better efficiency in marketability than increase in profitability during the period 2008-2012. In addition, the main reason for the increased efficiency in the home shopping industry is the market expansion through the revenue increase of each home shopping company. This study can be used as a reference when home shopping companies attempt to devise future strategies, as it suggests efficiency benchmarks and development levels for each home shopping company.

• Journal of the Korean Society for Library and Information Science
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• v.48 no.1
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• pp.27-52
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• 2014

The employment prospects of graduates in the Library and Information academic has largely concentrated in the field of librarianship as well as the curriculum of the academic itself. Since there are limitations in increasing the number of libraries and the available posts in the librarianship, the full-time jobs in the field are also limited. Even for the available posts in the field of librarianship, the majority is in contract based posts which does not guarantee a good working environment. The purpose of this research is to make policy implications to improve the employment rates of librarians. The main research methods include literature review of the previous studies and available statistical data, and a questionnaire targeting students and librarians. The targeting policy implications can be categorized into 4 factors, including, as supply side, improvements in the qualification of librarian certificate, in training for librarians, and as demand side, laws on library employment, and improvement of library services for co-operatives. There are 15 detailed strategies to support the 4 factors. For the improvement of strategies in library related laws, the following elements will be considered; supporting system for temporary jobs, the title of librarian post and the library itself, and librarian placement criteria in terms of its realization and mandatory, and obligations in library evaluation. The Council discussions propose the expansion of librarian award system, provision of information systems for librarian jobs, and developments in promotional materials and their deployment for librarians.

• Journal of Intelligence and Information Systems
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• v.22 no.4
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• pp.123-138
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• 2016

This study investigates intents of acquisitions in information technology industries. Mergers and acquisitions are a strategic decision at corporate-level and have been an important tool for a firm to grow. Plenty of firms in information technology industries have acquired startups to increase production efficiency, expand customer base, or improve quality over the last decades. For example, Google has made about 200 acquisitions since 2001, Cisco has acquired about 210 firms since 1993, Oracle has made about 125 acquisitions since 1994, and Microsoft has acquired about 200 firms since 1987. Although there have been many existing papers that theoretically study intents or motivations of acquisitions, there are limited papers that empirically investigate them mainly because it is challenging to measure and quantify intents of M&As. This study examines the intent of acquisitions by measuring specific intents for M&A transactions. Using our measures of acquisition intents, we compare the intents by four acquisition types: (1) the acquisition where a hardware firm acquires a hardware firm, (2) the acquisition where a hardware firm acquires a software/IT service firm, (3) the acquisition where a software/IT service firm acquires a hardware firm, and (4) the acquisition where a software /IT service firm acquires a software/IT service firm. We presume that there are difference in reasons why a hardware firm acquires another hardware firm, why a hardware firm acquires a software firm, why a software/IT service firm acquires a hardware firm, and why a software/IT service firm acquires another software/IT service firm. Using data of the M&As in US IT industries, we identified major intents of the M&As. The acquisition intents are identified based on the press release of M&A announcements and measured with four categories. First, an acquirer may have intents of cost saving in operations by sharing common resources between the acquirer and the target. The cost saving can accrue from economies of scope and scale. Second, an acquirer may have intents of product enhancement/development. Knowledge and skills transferred from the target may enable the acquirer to enhance the product quality or to expand product lines. Third, an acquirer may have intents of gain additional customer base to expand the market, to penetrate the market, or to enter a foreign market. Fourth, a firm may acquire a target with intents of expanding customer channels. By complementing existing channel to the customer, the firm can increase its revenue. Our results show that acquirers have had intents of cost saving more in acquisitions between hardware companies than in acquisitions between software companies. Hardware firms are more likely to acquire with intents of product enhancement or development than software firms. Overall, the intent of product enhancement/development is the most frequent intent in all of the four acquisition types, and the intent of customer base expansion is the second. We also analyze our data with the classification of production-side intents and customer-side intents, which is based on activities of the value chain of a firm. Intents of cost saving operations and those of product enhancement/development can be viewed as production-side intents and intents of customer base expansion and those of expanding customer channels can be viewed as customer-side intents. Our analysis shows that the ratio between the number of customer-side intents and that of production-side intents is higher in acquisitions where a software firm is an acquirer than in the acquisitions where a hardware firm is an acquirer. This study can contribute to IS literature. First, this study provides insights in understanding M&As in IT industries by answering for question of why an IT firm intends to another IT firm. Second, this study also provides distribution of acquisition intents for acquisition types.

• Women's Health Nursing
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• v.10 no.3
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• pp.190-199
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• 2004

This thesis explores the actual circumstances of Korean nursing by investigating its present situations. Ultimately, the intent of this study aims to establish a future direction of Korean Nursing. As such, the current conditions of Korean nursing is analyzed in the following categories: education, practice, research, nursing policy, expansion of nursing field, and entrepreneurship. In the final conclusion, an appropriate orientation of the future of Korean nursing is discussed. There are two primary Nursing programs, a three-year(63) and a four-year(53), in Korean Nursing education. Master's programs are available at 32 nursing schools or 32 professional graduate schools. A total of 15 nursing schools have a doctoral program in Korea. The ratio of graduates between the three-year and four year programs is 76:24. Hence, it is highly encouraged to expand four-year nursing programs, because it will help raise the social status of nursing professionals as well as the quality of nursing. In the clinical nursing field, independency and self regulation are critical. As such, organizational change, implementation of a standardized nursing m information system, appropriate workforce, and improvement of the reimbursement system in nursing is recommended. In community nursing, the following should be resolved to provide better nursing services: improvement of working condition and benefits, establishment of a law enforcing the hiring of nurses, and providing continuing education. The number of nursing research has increased and nursing studies are in great quantity. However, research in practices and theories are more in demanded. Hence, research that integrates theories and practices are very significant. Ultimately, it is critical to support nursing studies that will influence nursing policy. The Korean Nurses Association(KNA) is an organization that supervises the nation's nursing policy. The primary focus of KNA is to combine the three and four year undergraduate education systems into 4 years and to establish the Nursing Practice Act. The Ministry of Health and Welfare has adapted a system to educate and certify nurse specialists in 10 nursing areas in 21 nursing graduate schools expecting high-quality nursing services and a decrease of cost. The government also allowed nurses to operate facilities for health management or welfare agencies.

• Journal of Convergence for Information Technology
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• v.8 no.1
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• pp.227-233
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• 2018

The purpose of this study was to develop a warm cover for greenhouse with excellent thermal insulation and to propose ways of commercialization of the product. Feathers were used as filling materials because they formed the air layer to enhance insulation. Instead of downs for clothing or other textile products, we used disposed feathers. The developed product covers the outside of the greenhouse to keep the crops warm. It has multiple layers including feathers as filling materials, padding, inside fabric, heat insulation materials and outer fabric. It has proven to improve the insulation ratio. We developed other kinds of warm covers that are applicable to the inside of the greenhouse or the small houses in the greenhouse. Also, R&D system of educational industrial complex enables us to commercialize the products and building marketing strategies for them. This technology contributes to the expansion of energy-saving facilities for farmers, and it can serve the development and spread of various products utilizing feather.

• The Journal of Internal Korean Medicine
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• v.38 no.3
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• pp.336-352
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• 2017

Objective: This study investigated the perception, utilization, and satisfaction (in the general population), of the common cold treatment at the Korean Medical Clinic, to provide basic information for the development of Korean medicine clinical practice guidelines for the common cold. Method: A questionnaire was developed that consisted of questions about the general perception, utilization status, degree of satisfaction, willingness to use, and the improvement of the common cold treatment at the Korean Medical Clinic. An online survey was conducted using this questionnaire. Results: Three-hundred subjects responded to the survey. The results of the analysis were as follows. 1. 73.7% of the subjects recognized the common cold treatment at the Korean Medical Clinic. 2. 72% of the subjects had a positive perception of Korean medicine for common cold treatment. The major reason for the positive perception was the expectation about improving immunity and preventing recurrence. 3. Only 20% of the subjects had visited the Korean Medical Clinic for common cold treatment. The expensive cost was the major reason for not visiting the Korean Medical Clinic for common cold treatment. 4. The ratio of subjects who were willing to visit the Korean Medical Clinic for common cold treatment was 70%. 5. The expansion of health insurance coverage (67.7%), the activation of public relations (54.7%), and the development of a new herb medicine preparation that was easy to take (43.3%) were found to be necessary for improving the Korean medical service for common cold treatment. Conclusion: In spite of high recognition and positive perception, actual utilization of common cold treatment at the Korean Medical Clinic was relatively low. Multifaceted efforts are necessary to enhance the competitiveness of Korean medical service for treatment of the common cold.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.36S no.12
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• pp.34-40
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• 1999

In conventional color television systems color edges of highly saturated color pictures are deteriorated because of bandwidth limitation of the color-difference signal. In this paper a modified hue-weighted luminance demodulation method with low noise is proposed for the edge correction. The weighting coefficients are given by ratios of the gadient of color-difference signal to the gradient of band-limited luminance signal. Proposed method is theoretically complete for the 1st order lowpassed color-difference signals and well separated luminance/chrominance signal. Noise reduction technique is also considered because of impulse noise generation in the gradient ratio processing of noisy pictures. In computer simulation with noisy pictures proposed technique gives a visual effect of the bandwidth expansion and detail improvement in highly saturated color edge area.

• Geomechanics and Engineering
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• v.20 no.1
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• pp.67-73
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• 2020

With the increasing number of underground projects, the problem of rock-water coupling catastrophe has increasingly become the focus of safety. Grouting reinforcement is gradually applied in subway, tunnel, bridge reinforcement, coal mine floor and other construction projects. At present, cement-based grouting materials are easy to shrink and have low strength after solidification. In order to overcome the special problems of high water pressure and high in-situ stress in deep part and improve the reinforcement effect. In view of the mining conditions of deep surrounding rock, a new type of cement-based reinforcement material was developed. We analyses the principle and main indexes of floor strengthening, and tests and optimizes the indexes and proportions of the two materials through laboratory tests. Then, observes and compares the microstructures of the optimized floor strengthening materials with those of the traditional strengthening materials through scanning electron microscopy. The test results show that 42.5 Portland cement-based grouting reinforcement material has the advantages of slight expansion, anti-dry-shrinkage, high compressive strength and high density when the water-cement ratio is 0.4, the content of bentonite is 4%, and the content of Nano Silica is 2.5%. The reinforcement effect is better than other traditional grouting reinforcement materials.