• Korean Chemical Engineering Research
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• v.55 no.6
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• pp.762-766
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• 2017

Energy recovery device (ERD) is used to save energy consumption in seawater reverse osmosis processes. However, small-scale ERDs (<$100m^3/d$) are hardly observed in seawater desalination market. In South Korea, most of seawater desalination plants for drinking water production are small-scaled and have been operated in island areas or on ships. Thus, the effect of ERDs for these small-scale SWRO processes should not be neglected. In this work, the small-scale SWRO processes are designed and analyzed in terms of energy consumption with/without ERD. The realistic efficiencies of high pressure pumps are considered for the energy analyses. The unit cost of electricity depending on the application place (e.g., inland and island areas, on ships) is investigated to calculate the energy cost for unit water production in various SWRO applications classified by plant capacity, application place, and the installation of ERD. As a result, the energy cost can be saved up to $1,640.4KRW/m^3$ when ERD is applied, and the saving effect increases at smaller plants on ships. In conclusion, the development of small-scale ERDs are necessary because small-scale SWRO processes are dominant in Korean seawater desalination market, and the electricity saving effect becomes higher at smaller-scaled system.

• Korean Parent-Child Health Journal
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• v.8 no.1
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• pp.49-63
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• 2005

Purpose: The present study is a descriptive research on the content of sex education conducted at home by the mothers of young children who are attending five kindergartens located in Busan, Korea. This study aims to provide basic materials for systematic sex education at home and in the school. Method: Based on the literature review and prior researches, the writer made a questionnaire consisting of 30 items regarding necessities, contents and difficulties of sex education. The 307 questionnaires were collected out of 480 which were distributed by the kindergarten teachers. Data was analysed with frequency and percentage using the SPSS Win 10.0 Program. The main subjects of the study were mothers in their thirties, who understood the necessity of sex education. However, they were lack of enough sexual knowledge in accordance with the transforming sexual culture and lack of suitable materials. They did not plan to educate their children according to their developmental stages, but just taught them verbally rather than using common materials for the situation. Result Regarding the origin of life that children often asks, mothers did not give a scientific and correct response to satisfy their curiosity about sex, saying that a baby was created after marrying a loved one. While more mothers than the prior research responded correctly to the queries of the path of delivery, some mothers did not. It may cause some children to suppress the questions, which may result a distorted sexual knowledge. That is because mothers understood that sex education was to deliver sexual knowledge, but not realized that sex education was a human education carried out throughout life. Mothers fell short of sexual knowledge, capability, and confidence, comparing with swift social changes and children's capacity. As a result, it is necessary to inspire sexual awareness into mothers and educate them through training. It is also needed to secure a training program similar to a teacher training program. Conclusion: It is essential to develop and to provide evaluation tools as well as proper materials in accordance with the children's developmental stage, so that organic management system among home, education institute and society must lead sex education Further, it is necessary to provide teaching methods and materials to mothers regularly, so that the school and home may conduct sex education together to cope with difficulties.

• KIPS Transactions on Software and Data Engineering
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• v.7 no.5
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• pp.177-188
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• 2018

The scale of graph data has been increased rapidly because of the growth of mobile Internet applications and the proliferation of social network services. This brings upon the imminent necessity of efficient distributed and parallel graph processing approach since the size of these large-scale graphs are easily over a capacity of a single machine. Currently, there are two popular parallel graph processing approaches, vertex-centric graph processing and block centric processing. While a vertex-centric graph processing approach can easily be applied to the parallel processing system, a block-centric graph processing approach is proposed to compensate the drawbacks of the vertex-centric approach. In these systems, the initial quality of graph partition affects to the overall performance significantly. However, it is a very difficult problem to divide the graph into optimal states at the initial phase. Thus, several dynamic load balancing techniques have been studied that suggest the progressive partitioning during the graph processing time. In this paper, we present a load balancing algorithms for the block-centric graph processing approach where most of dynamic load balancing techniques are focused on vertex-centric systems. Our proposed algorithm focus on an improvement of the graph partition quality by dynamically reassigning blocks in runtime, and suggests block split strategy for escaping local optimum solution.

• The Journal of the Petrological Society of Korea
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• v.24 no.3
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• pp.253-272
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• 2015

The necessity of aggregate resources in Korea has been increased with a rapid economic growth since the 1990s. Construction activities have been increased drastically for last two decades. Such economic activities are much concentrated at big cities in Korea, and recently new neighbouring cities, such as multifunctional administrative city, enterprise city and innocity, are under construction at the surroundings of the cities. This new urbanization asked for an appropriate supply of raw construction materials such as cement, sands and gravels. The aim of this study is to understand and discuss the analysis and prospect of supply and demand of domestic sand and gravel. On the early years, 1990s, about 25% of the total consumption of these sands and gravels comes from riverine deposits; 20% to 25% from marine sands, 40% to 45% from forest rocks and the rest 5% to 15% from old fluvial deposits and crushed rocks. But nowaday the river aggregate, including both sands and gravels of a present river channel and those of the old fluviatile system are decreasing, while the crushed and forest aggregates and marine sand are now the main source of infrastructure resources. Thus it is increasingly necessary to investigate the forest and crushed aggregate resources potential in Korea where a current analysis indicate that the supply of riverine aggregates gradually decreases.

• Informatization Policy
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• v.19 no.1
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• pp.74-90
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• 2012

This thesis analyzes the Apple Inc.'s case from the viewpoint of the necessity for the protection of information privacy related to location data as for information society and ubiquitous community. Meanwhile, the regulatory conformity to equilibrium of contradictional value between personal data protection and utilization of information is debated from the fundamental right as for constitutional law concept to the commercial and technological structure in terms of economic and business point. Therefore, this paper reaches the conclusion that the legislative system should form a harmonious relationship between legal protection and lawful utilization to reappraise the present condition of legalization on personal data protection from guaranteeing rights and interests of information subject in the perspective of human rights to information guarantee consequently. As a result, it is required to revaluate the lawfulness of the fine on the violation of administrative duty levied by KCC(Korea Communications Commission).

• Journal of the Korean Magnetics Society
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• v.10 no.5
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• pp.203-209
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• 2000

Top synthetic spin valves with structure Ta/NiFe/CoFe/Cu/CoFe(P 1)/Ru/CoFe(P2)/FeMn/Ta on Si (100) substrate with natural oxide were prepared by dc magnetron sputtering system. We have changed only the thickness in free layers and the thickness difference (Pl-P2) in two ferromagnetic layers separated by Ru, and investigated the effect of magnetic film thickness on interlayer coupling field in spin valve with synthetic antiferromagnet. According to the decrease of free layer thickness, interlayer coupling field was increased due to the magnetostatic coupling(orange peel coupling). In case of t$\_$P1/>t$\^$P2/, interlayer coupling field agreed well with the modified Neel model suggested in conventional spin valve structures by Kools et al. However, in case of t$\_$P1/>t$\^$P2/, it was found that the interlayer coupling field was not explained by the Modified Neel Model and was confirmed the necessity of further remodeling. The dependence of Cu thickness on the interlayer coupling field was investigated and 10 Oe of interlayer coupling field was obtained when the Cu thickness is 32 $\AA$.

• Korean Journal of Digital Imaging in Medicine
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• v.5 no.1
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• pp.32-44
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• 2002

The role of radiology department has been greatly increased in the past few years as the technology in the medical imaging devices improved and the introduction of PACS (Picture Archiving and Communications System) to the conventional film-based diagnostic structure is a truly remarkable factor to the medical history. In addition, the value of using digital information in medical imaging is highly expected to grow as the technology over the computer and the network improves. However, the current medical practice, using PACS is somewhat limited compared to the film-based conventional one due to a poor image quality. The image quality is the most important and inevitable factor in the PACS environment and it is one of the most necessary steps to more wide practice of digital imaging. The existing image quality control tools are limited in controlling images produced from the medical modalities, because they cannot display the real image changing status. Thus, the image quality is distorted and the ability to diagnosis becomes hindered compared to the one of the film-based practice. In addition, the workflow of the radiologist greatly increases; as every doctor has to perform his or her own image quality control every time they view images produced from the medical modalities. To resolve these kinds of problems and enhance current medical practice under the PACS environment, we have developed a program to display a better image quality by using the ROI optical density of the existing gray level values. When the LUT is used properly, small detailed regions, which cannot be seen by using the existing image quality controls are easily displayed and thus, greatly improves digital medical practice. The purpose of this study is to provide an easier medical practice to physicians, by applying the technology of converting the H-D curves of the analog film screen to the digital imaging technology and to preset image quality control values to each exposed body part, modality and group of physicians for a better and easier medical practice. We have asked to 5 well known professional physicians to compare image quality of the same set of exam by using the two different methods: existing image quality control and the LUT technology. As the result, the LUT technology was enormously favored over the existing image quality control method. All the physicians have pointed out the far more superiority of the LUT over the existing image quality control method and highly praised its ability to display small detailed regions, which cannot be displayed by existing image quality control tools. Two physicians expressed the necessity of presetting the LUT values for each exposed body part. Overall, the LUT technology yielded a great interest among the physicians and highly praised for its ability to overcome currently embedded problems of PACS. We strongly believe that the LUT technology can enhance the current medical practice and open a new beginning in the future medical imaging.

• Land and Housing Review
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• v.2 no.1
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• pp.9-17
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• 2011

A urban regeneration project of Korea has been promoted highly attaching to physical reforms, but without fulfilling the basic goal of reactivating city functions through concerning overall areas. Moreover, the general rule and its system of urban regeneration project which would provide roles of public and civilians as well as facilitate cooperative urban regeneration, are currently missing. Thus, social stratum continuously requests a framework act for urban regeneration project called Control Tower, to be a guide to the evidently right path to step up. The research analyzes the current status and problems of urban regeneration projects in Korea to examine the necessity of Control Tower, and to bring up the way to move on for its efficiency presented below: First, the law should be declarative; possess general, prospective influences on laws and systems related to urban regeneration. Second, the nonbinding guideline on a urban regeneration project should be suggested to reflect the conditions by the regions. Last, propulsions should be framed such as administrative principles of strengthening publicity and connection of urban regeneration projects, a committee and fund to promote the former, and a research for problem solution.

• The Journal of the Korea Contents Association
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• v.14 no.9
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• pp.285-297
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• 2014

This research is involved in looking into the cognition pattern of social worker position of a fourth-year student majoring in Social Welfare. The purpose of this research is to offer a basic data needed for education of the students who are preparing to get a job of a social worker. For this, applying Q methodology, this research made an objective analysis of their subjective response to social worker position targeting the 30 students in the department of social welfare at the four-year-course college located in Gyeongsangbuk-do and Gyeongsangnam-do. The research results showed that the cognition pattern of the college students' occupational view on social welfare position could be categorized into the three; The first pattern is a "job-skeptic & reality-evasive" type, who tends to perceive the position of a social worker as the one having a lot of job exhaustion and much workload, showing a pessimistic view on the meaning or a sense of mission of a social worker position. The second pattern is a "practice-centered & specialized-job-seeking type" who tends to think much of practical aspects of a social worker job and to seek after the position of a social worker as a specialized job, and at the same time to rely on the policy or system for a social worker position. The third pattern is a "value-oriented & self-achievement type", who tends to think much of the necessity of value or ethics in putting social welfare into practice and also to make much of self-achievement through the channel of a social welfare worker position. Taken together, it might be possibile to turn out professional human resources, but this research thinks it is more necessary to place the education of values of a social welfare worker.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.12 no.1
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• pp.69-77
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• 2014

Unsaturated hydraulic conductivity of the bentonite-buffer was evaluated using the relative humidity data. The method for calculating unsaturated hydraulic conductivity was deduced from the general analytical equation representing the movement of water in unsaturated media, which was applied to the experimental results of water infiltration tests for identifying the behavior of unsaturated hydraulic conductivity according to the water saturation. Unlike the saturated condition, the hydraulic gradient and water flux were irregularly changed, and the unsaturated hydraulic conductivity was increased with increasing the experimental time. Swelling of bentonite grains due to the water absorption increased the volume and size of pore within bentonite, resulting in the increase of water velocity and unsaturated hydraulic conductivity. This result suggested the necessity of further investigation on the correlation between the swelling degree of bentonite-buffer and unsaturated hydraulic conductivity. The method used in this study can be useful technique for evaluating long-term hydraulic performance of bentonite-buffer in the radioactive waste disposal system.