• Korean Journal of Materials Research
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• v.30 no.9
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• pp.465-473
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• 2020

For surface hardening of a continuous casting mold component, a fundamental metallurgical investigation on dissimilar laser clads (Cu-NiCrBSi) is performed. In particular, variation behavior of microstructures and mechanical properties (hardness and wear resistance) of dissimilar clads during long-term service is clarified by performing high-temperature post-clad heat treatment (temperature range: 500 ~ 1,000 ℃ and isothermal holding time: 20 ~ 500 min). The microstructures of clad metals (as-clads) consist of fine dendrite morphologies and severe microsegregations of the alloying elements (Cr and Si); substrate material (Cu) is clearly confirmed. During the post-clad heat treatment, the microsegregations are totally homogenized, and secondary phases (Cr-based borides and carbides) precipitated during the short-term heat treatment are also almost dissolved, especially at the heat treatment conditions of 950 ℃ for 500 min. Owing to these microstructural homogenization behaviors, an opposite tendency of the surface mechanical properties can be confirmed. In other words, the wear resistance (wear rate) improves from 4.1 × 10^-2 ㎣/Nm (as-clad condition) to 1.4 × 10^-2 ㎣/Nm (heat-treated at 950 ℃ for 500 min), whereas the hardness decreases from 453 HV (as-clad condition) to 142 HV (heat-treated at 950 ℃ for 500 min).

• Proceedings of the Korean Geotechical Society Conference
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• 2008.10a
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• pp.1727-1734
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• 2008

After the final closure of sea dyke, seepage behaviour of embankment is highly changed by variation of water head different between tide wave and controlled water level at fresh lake. Especially, the seepage behaviour of bottom protection layer of final closure section is more important factor for structural and functional stability of sea dyke, because of the bottom protection layer of final closure section is penetrated sea side to fresh lake. Even though bottom protection layer was filled with dredged fine sand, it has a high permeability. In this paper, mainly described about the seepage velocity and borehole image of bottom protection layer filled with dredged sand after final closure. Various in-situ tests such as BIPS (Borehole Image Processing System) and ABI (Acoustic Borehole Imager) survey, wave velocity measuring, and color tracer survey were conducted to evaluate the seepage behavior of bottom protection layer. Based on the in-situ tests, the bottom protection layer of final closure section was almost filled with dredged sand which is slightly coarse grain sand and there have sea water flow by water head different between tide wave and controlled water level at fresh lake. Also, comply with tracer survey results, the sea water flow path was not exist or generated in the bottom protection layer. However, because of this result not only short term survey but also just one test borehole survey results, additional long term and other borehole tests are needed.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.05a
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• pp.730-732
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• 2017

While the short term effect of diet and exercise therapy has been proven, there has still been a problem of its long term effect. So, researchers has utilized behaviour modification therapy. It is expected to lead to natural weight loss by modifying wrong dietary life patterns and practices. However, this approach has turned out to be a more effective method for weight maintenance than loss of weight. In spite of its strength, as a matter of fact, persistent and continuous effort for weight management has not worked properly. This study proposes an artificial intelligence approach with the advantages of behaviour modification therapy, overcoming current approaches which is goal-driven and too uniform. For this, we plan to develop a health management program in which users get the messages that are customized for themselves according to different situations so that it can promotes persistent effort for exercise. Here, customized messages are handled by AI techniques, which eventually promotes soft persuasion, encouragement, and motivation.

• International Journal of Highway Engineering
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• v.9 no.3
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• pp.101-110
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• 2007

Joint Spacing of Jointed Concrete Pavement has been uniformly designed and constructed as six-meter in Korea. However, engineering backgrounds to show the appropriateness of six-meter Joint Spacing has not been provided. In the on-going reseach of the development of Korea Pavement Reseach Program(KPRP), the optimum Joint Spacing is suggested as 6 to 8 meters according to the regional climatic conditions based on the mechanical-empirical analysis of short-term and long-term pavement distress. This study is a part of the investigation on the adequateness of Joint Spacing design specification suggested in KPRP. Joint Spacing was design and constructed as seven-meter Joint Spacing suggested as design specification in Korea Reseach Program(KPRP) and monitored the Load Transfer Efficiency(LTE), Random crack and compared with those of adjacent $6{\sim}7$ meter Joint Spacing concrete section.

• Journal of the Korean Geotechnical Society
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• v.24 no.8
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• pp.149-160
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• 2008

Offshore pile foundations are prone to lateral soil pressures resulting from embankment construction for the reclamation on deepwater soft clay. Since the 1990s, offshore reclamation has actively progressed in Korea, connecting with the development of Songdo newtown, Incheon newport, and Busan newport representatively. Special attention has been given to lateral soil-structure interaction problems related to passively-loaded offshore pile foundations. Based on a plane strain large deformation finite element (LDFE) approach, this paper presents the results of investigation into undrained (short-term) and drained (long-term) behavior of passively-loaded offshore pile foundations. This study examines the effects of major factors, such as soil profile, pile head boundary condition, magnitude of embankment load, and average degree of consolidation. The results allowed quantification of differences in the magnitude of lateral soil pressure acting on the piles between undrained and drained phases.

• Journal of Korea Trade
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• v.27 no.1
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• pp.60-78
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• 2023

Purpose - The study analyzed 90 online firms worldwise and observed them for ten years to investigate their investments and firm performance variabilities. This study attemped to verify the existence of agency problems in online firms. Through this, the paper intends to expand the scope of research in the fields of investment and firm value both empirically and in theory. This study also attempted to supplement the insufficient logic of previous studies by analyzing the relationship between investment and profitability. Design/methodology - In this study, the investment is subdivided into over-, under-, and neutral investments, and an empirical analysis of the firm performance was conducted. As investment generally has long-term effects, the impact of a firm's investment on future firm performance and variabilities in firm performance was considered over the short-and medium-term period. Findings - It was found that there was a negative relationship between firms with an overinvestment and future firm performance. Underinvestment has no clear statistically significant results on firm performance. This implies that overinvestment causes more reduction in future firm performance than underinvestment. It was also found that underinvestment and overinvestment significantly increased the variability of firm performance. A positive significance was found between under- and over- investment with a variability of 3 years and overinvestment with a variability of 4 years in the future. A negative relationship was found between neutral investment propensity and future performance variabilities. Neutral investment has less effect on the future performance variability of a firm than a firm's overinvestment and underinvestment. For online firms, underinvestment and overinvestment have a greater effect on the firm's future performance variability than neutral investment. Originality/value - The agency theory predicts that information asymmetry and adverse selection problems exacerbate conflicts of interest among stakeholders, thus firm performance. The study contributed to accumulating research on online firms that are currently underexplored by analyzing the investment behavior of major firms in the online industry.

• Journal of Oriental Neuropsychiatry
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• v.27 no.2
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• pp.43-55
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• 2016

Objectives The aim of this systemic review was to summarize medical records of Korean medicine based psychotherapy and investigate its therapeutic mechanism.Methods We searched articles on Korean neuropsychiatry in Korean databases. Subsequently, we selected and analyzed medical records on Korean medicine based-psychotherapy that met inclusion criteria.Results Fifty-five medical records were included. They were classified into the following 5 categories. Five minds mutual restriction therapy in 19 medical records; counseling and persuading therapy in 12 medical records; moving essence and changing Qi therapy in 10 medical records; Kyungjapyungji psychotherapy in 2 medical records; and suggestion psychotherapy in 11 medical records.Conclusions The results indicated that emotion is mainly used for cure. Buddhism affects Korean medicine based psychotherapy. Korean medicine based psychotherapy corresponds to western psychotherapy such as short-term dynamic psychotherapy (STDP), supportive psychotherapy, cognitive therapy, behavior therapy, and guided imagery.

• Asian Journal of Atmospheric Environment
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• v.4 no.3
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• pp.166-176
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• 2010

In this research, the environmental behavior of carbon dioxide ($CO_2$) was investigated in a mountainous site in the proximity of a highly industrialized megacity, Seoul, Korea. The concentration data of $CO_2$ monitored routinely at hourly intervals at Mt. Gwan-Ak (GA), Seoul, Korea throughout 2009 were analyzed in several respects. The mean $CO_2$ value was $405{\pm}12.1$ ppm (median=403 ppm) with a range of 344 to 508 ppm (N=8548). The analysis of its seasonal trend indicated that the $CO_2$ levels peaked in the winter but reached a minimum in fall. If the short-term trend is analyzed, the $CO_2$ values generally peaked during daytime along with the presence of two shoulders; this is suspected to be indicative of strong man-made effects (e.g., traffic activities). It is seen that the general patterns of $CO_2$ distribution in this study area are highly comparable to those typically found in urban areas with strong signals of anthropogenic activities.

• Journal of Nutrition and Health
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• v.23 no.4
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• pp.279-286
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• 1990

A nutrition education program has been designed for the children of obese or unbalanced dietary habits. A total of 120 children(60-obese and 60-unbalanced dietary habits) who were in 5th-6th grade was chosen for the program and the effectiveness of the nutrition education was evaluated. The nutrition education program was organized into daily lessons(3 wks). A booklet was made for the education and used during the education period, dealing with 5-Basic Food Groups and their functions, excess or deficiency in a human body, food exchange list, importance of health, obesity, unbalance dietary habits and of school lunch program were emphasized in every day session. dietary recall records were collected to assess their daily food intake and the amounts of meals were discussed. During the education period, booklets, wall charts, photographs, food models, VTR films and slide films were utilized. Assessment of effects of the nutrition education program was carried out by a nutrition knowledge test, food habit records, anthropometric measurements and food preference test. The nutrition knowledge scores were significantly improved after the education and the scores were higher on the children in the school with school lunch program. The anthropometric measurements and food preference test revealed no significant influences of the education on the children, showing that the education period was too short to change their eating behavior any may need a long-term education program. Food habit scores were improved after the education in both experimental and control groups. The experimental groups showed higher scores than the control group.

• Journal of Nutrition and Health
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• v.37 no.6
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• pp.493-501
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• 2004

The purpose of this study was to evaluate weight control program provided by university health care center for female college students. The program was 8-week long and composed of diet, exercise, and behavioral modification. Evaluation was made on the completion of 8-week program and a follow-up survey was done at 3-24 months after the end of program by telephone or bye-mail. Total of 76 women completed the 8-week program and 51 for follow-up survey. On the completion of 8-week program, significant decreases in body weight, BMI, body fat (kg), ％ body fat, and WHR were resulted, however, no change in muscle mass was found. Even the subjects without weight change showed significant reduction in body fat (kg) and ％ body fat. Total food intake was decreased resulting in reduced intakes of most nutrients. Meal distribution of energy was changed; ％energy from snack decreased from 22％ to 14％, and proportion for breakfast increased. Blood values of hemoglobin, hematocrit, total cholesterol, HDL-cholesterol, LDL-cholesterol, and triglyceride were within normal range, and no changes were observed by this program. The follow-up survey revealed that 88.3％ of the subjects continued to lose weight after completion of the program, while only 7.8％ gained weight. And 78.4％ of the subjects considered the program effective. In conclusion, the weight reducing regime with education is effective for long lasting weight control and health conscious behavior for female college student. Since the subjects reduced the size of meal, instead of cutting only calories down, food selection to meet all the nutrient requirements except energy should be emphasized.