• Proceedings of the Korea Concrete Institute Conference
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• 2006.11a
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• pp.25-28
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• 2006

In general, post-installed dowel bars are used as a shear connector to ensure the composite actions between new slabs and existing slabs in an apartment remodelling constructions expecially for enlarging the interior space outward the existing buildings. But, it has not been checked that the connection performance between existing and new slab is satisfactory not only for the structural safety condition but also the for serviceability and dwelling requirements. In this research, an experimental works were presented to evaluate the load transfer capacity for the planar joints between existing and new slab. The existing slabs were obtained from the existing apartment housing which will be demolished, and were retrofitted with carbon fiber plate. Test results showed that the planar joints with post-installed dowel bars behaved in full composite modes until ultimate capacity of test specimens, so sufficient ultimate and serviceability performance are confirmed.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.258-258
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• 2010

레이저 유기 형광법은 비침투적인 방법으로 플라즈마를 진단할 수 있는 장점이 있다. 특히 헬륨 플라즈마 내에서 전기장이 존재하는 경우에 헬륨의 에너지 준위가 분리되는 STARK 효과를 이용하여 기판 부근에 발생한 쉬스 내의 전기장을 측정할 수 있다[1]. 그러나 플라즈마의 생성을 위한 RF 소스와 레이저 간의 위상이 동기화 되지 않는 경우엔, 그 결과 값의 보정이 필요하다. 외부의 전기장이 시변하는 경우에 각각의 위상에서 헬륨의 여기종이 느끼는 전기장의 세기는 다르다. 따라서 레이저가 어떤 타이밍에 입사되는 가에 따라 신호의 분리되는 정도가 달라지는데, 레이저와 외부 전기장의 위상을 동기화하지 않은 경우에는 관측된 신호는 각각의 위상에서 여러 가지로 분리된 신호가 더해진 합의 형태로 나타난다. 이는 외부에서 인가된 전기장의 가장 큰 값을 나타낸다고 알려져 있었다[2]. 그러나 레이저 유도 형광 신호는 넓게 분산을 가지므로 이는 보정되어야 한다. 본 연구에서는 각각의 위상에서 출력되는 형광 신호를 구하고 시간의 영역에서 1주기 동안 적분하여 실제로 관측될 레이저 유도 형광신호의 보정치를 계산하였다. 이를 실험적으로 검증하기 위해서 유도 결합 플라즈마 반응 챔버 내에서 플라즈마를 방전시킨 후에, 레이저 유도 형광법을 사용하여 기판 위에 생성된 쉬스 내의 전기장을 측정하였다. 그리고, 랑뮤어 프루브를 이용하여 벌크 플라즈마 내의 플라즈마 전압을 구하고, 이를 적분 상수로 삼아 쉬스 내의 전위 분포를 구하였다. 또한 기판에 인가되는 전압을 직접 측정하여 위에서 구한 전위 분포치와 보정을 한 후의 전위 분포치를 비교, 검토하여 보정치를 검증하였다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.10a
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• pp.675-676
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• 2010

As the number of documents rapidly increases in the web environment, the efficient document classification approaches have been required to retrieve the desired information from too many documents. In this paper, we propose a corpus construction tool to annotate document classification information such as category, keywords, and usage to each product description document. The proposed tool can help a human annotator to correctly identify this information by providing the verification step to check the input results of other human annotators. Also, the human annotator can construct the corpus anytime anywhere by using the web-based proposed system.

• The Journal of Korean Obstetrics and Gynecology
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• v.22 no.1
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• pp.182-190
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• 2009

Purpose: The pilot study was done for checking the efficacy of using functional soap, containing medicinal herbs on acne skin. Methods: 30 participants with acne skin was recruited. They used functional soap during 8 weeks. Before and after the study, we checked the KAGS(Korean Acne Grading System) grade, and compared those score. For examining the clinical effect, global evaluation was done by both investigator and participants. Results: KAGS grade decreased from 1.6316 to 1.4211(p value = 0.042). And the clinical global evaluation was improved. Conclusion: This pilot test showed that using functional soap, containing medicinal herbs would be one of treatment on acne skin.

• The Journal of Korean Obstetrics and Gynecology
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• v.22 no.3
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• pp.185-196
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• 2009

Purpose: This study aims to estimate the effects of on acustimulation for Gynecological surgery induced nausea and vomiting through reviewing the tendency of the studies. Methods: Literature searches were made through Pubmed, Koreanstudies Information Service System(KISS) and Korean Oriental medical Society database. Data were extracted according to pre-defined criteria. The methodological quality was assessed using Modified Jadad scale. Results: 8 studies were met the condition among the 43 searched studies. They were designed as double blind or observer blind and randomized controlled trial, and were analyzed statistically. 6 studies out of the 8 reported that acupuncture could prevent PONV effectively. Conclusion: The hypothesis that acustimulation may be effective for the prevention of Gynecological surgery induced PONV is supported by the data in recent literatures.

• Journal of the Korean Geosynthetics Society
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• v.19 no.2
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• pp.13-21
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• 2020

In Korea, small reservoirs have been constructed for the supply of agricultural water, but most of them have been over 50 years from the year of construction. Aging agricultural reservoirs are being investigated for serious defects such as leaks and movements in slope, which are very vulnerable to safety. Accordingly, grouting methods are used to reinforce aging agricultural reservoirs in Korea. However, cement used as a grouting injection material consumes natural resources and generates a large amount of greenhouse gases during production. In addition, there is a problem that sufficient reinforcement is not made due to various factors such as the injection amount, the compounding ratio, the injection pressure, and etc. Therefore, due to these problems, the development of new materials and methods that can replace the grouting method and cement is required. In order to solve these problems, this study conducted an laboratory test on the surface stabilizer used to secure the stability of road and rail slopes. In addition, the program was analyzed and the reinforcing effect was examined when the surface stabilizer was used as reinforcement material for aging agricultural reservoir. As a result of the laboratory test, when the surface stabilizer is mixed, the increase of cohesion is possible up to 9% and there is no change in the friction angle. The results of the program analysis showed that the 1.0m reinforcement of slopes increased the factor of safety by 1.4 times, making it possible to reinforce the aging agricultural reservoir using surface stabilizers. And as a reinforcement method, it was analyzed that it is most appropriate to reinforce the slope and the bottom of slope simultaneously.

• Resources Recycling
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• v.25 no.5
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• pp.64-74
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• 2016

Titanium and iron are closely related in nature, although titanium is the ninth most abundant element in the Earth's crust. Iron in titanium ores must be removed for use as feedstocks in the manufacture of titanium dioxide pigments and pure $TiCl_4$ for metal titanium. In this study, various beneficiation processes of ilmenite for production of $TiO_2$ have been reviewed and compared. Most of these processes involve a combination of pyrometallurgy and hydrometallurgy. These beneficiation processes of ilmenite generate considerable quantities of wastes primarily in the form of iron salt, iron oxide and acidic effluents. Therefore, it is important that recovery of acid value from waste and conversion of iron bearing waste to useful materials for development of new beneficiation processes of ilmenite.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.7
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• pp.697-703
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• 2005

Iron-coated sand(ICS) was prepared with variation of particle size of Joomoonjin sand, primary and secondary coating temperature, coating time, and dosage of initial Fe(III). An optimum condition of the preparation ICS was selected from the coating efficiency, stability of coated Fe(III), and removal efficiency of As(V). Coated amount of Fe(III) increased as primary coating temperature increased with smaller particle size of sand. Coating efficiency was quite similar over the investigated secondary coating temperature and time, while adsorption efficiency of As(V) onto ICS was severely reduced with ICS prepared at higher secondary coating temperature. By considering these results, an optimum secondary coating temperature and time for the preparation of ICS was selected as $150^{\circ}C$ and 1-hr, respectively. Coating efficiency increased us the dosage of initial Fe(III) up to 0.8 Fe(III) mol/kg sand and then no distinct increase was noted. Maximum As(V) adsorption was observed at 0.8 Fe(III) mol/kg sand. Secondary coating temperature and time were important parameters affecting stability of ICS, showing decreased dissolution of Fe(III) from ICS prepared at higher coating temperature and at longer coating time. From anionic type adsorption of As(V) onto ICS, it is possible to suggest the application of ICS for the removal of As(V) contaminated in acidic water system.

• Clean Technology
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• v.16 no.3
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• pp.162-171
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• 2010

The objective of this study is to develop cleaning agents for the indoor water supply pipe which is environmentally friendly and suitable for removing scale by using various organic acids, inorganic acids, and some additives. Among various organic acids, oxalic acid, citric acid, and malic acid showed good cleaning efficiency of iron oxides which were main components of the indoor water supply pipe scale. Several cleaning agents were formulated by adding chemical additives into these organic acids and evaluated for removal of iron oxides. In this study, it was found that nonionic surfactants were excellent for the removal of iron oxide scale among various additives. Two types of cleaning agents($F_1$, $F_2$) with comparatively high solvent power for iron oxides were formulated in this study. The cleaning agents $F_1$ made by organic acids and some additives were formulated to be safe and environmentally friendly, but seemed to have disadvantage due to their comparatively low cleaning efficiency of iron oxide than $F_2$. But, the cleaning agents $F_2$ prepared by adding inorganic acid a little to $F_1$ showed comparatively good cleaning efficiency of iron oxide and could be recommended for removing hard scale of iron oxides in the indoor water supply pipe. Thus, it is considered that the formulated cleaning agents should be selected based on the extent of scale in the indoor water supply pipe.

• Journal of the Korean GEO-environmental Society
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• v.16 no.12
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• pp.45-52
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• 2015

With the rising interest in the environment, more attention on ecological restoration for damaged slope surface to restore its original state has been drawn. Generally, the most useful method is vegetation based spray work. This method uses green soil including sewage sludge, sawdust, paper sludge, and weathered granite soil. However, because there are neither accurate information nor test values about green soil, green soil is often lost by environmental factors such as rainfalls and strong winds. To solve the problem of green soil, it is necessary to prepare design standards about green soil, and conduct studies to deal with green soil loss in consideration of various variables including basic material property, soil quality of slope surface, and weather. This study was conducted in the mixture of green soil and eco-friendly soil stabilizer. With green soil, basic material property test and compaction test were conducted for the analysis on the basic characteristics of green soil. In the mixture with soil stabilizer at a certain ratio, we conducted shear strength test depending on the ratio in order to analyze the maximum shear strength, cohesion and the change in internal friction angles. Furthermore, in the mixture ratio of green soil and soil stabilizer, which is the same as the ratio in the shear strength test, an inclination of slope surface was made in laboratory for the analysis on erosion and germination rate. Finally, this study evaluated the most effective and economic mixing ratio of soil stabilizer to cope with neighboring environmental factors. According to the test, the shear strength of green soil increased up to 51% rely onto the mixing ratio of and a curing period, and its cohesion and internal friction angle also gradually increases. It is judged that the mixture of soil stabilizer was effective in improving shear strength and thereby increased the stability of green soil.