• The Journal of Engineering Geology
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• v.18 no.4
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• pp.359-369
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• 2008

For the design and effective management of underground storage caverns, preliminary investigation on the hydrogeologic parameters around caverns and analysis on the groundwater flow must be carried out. The data collection is very imporatnat task for the hydrogeologic design so various hydraulic tests have been performed. When analyzing the injection/fall off test data, existing graphical method to estimate the parameters in Theis' equation is widely used. However this method has some sources of error when estimating parameters by means of human faults. Therefore the method of estimating parameters by means of statistical methods such as regression type is evaluated as a useful tool. In this study, nonlinear regression analysis for the Theis' equation is suggested and applied to the estimation of parameters for the real field interference data around underground storage caverns. Damping parameter which reduce the iteration numbers and inhance the convergence is also introduced.

• Science of Emotion and Sensibility
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• v.15 no.3
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• pp.367-380
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• 2012

The purpose of this research was to implement and verify an information retrieval(IR) system based on users' relevance criteria for information search tasks. For this purpose, we implemented an IR system with a dynamic ranking model using users' relevance criteria varying with the types of information search task and evaluated this system through user experiment. 45 participants performed three information search tasks on both IR systems with a static and a dynamic ranking model. Three Information search tasks are fact finding search task, problem solving search task and decision making search task. Participants evaluated top five search results on 7 likert scales of relevance. We observed that the IR system with a dynamic ranking model provided more relevant search results compared to the system with a static ranking model. This research has significance in designing IR system for information search tasks, in testing the validity of user-oriented relevance judgement model by implementing an IR system for actual information search tasks and in relating user research to the improvement of an IR system.

• Science of Emotion and Sensibility
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• v.17 no.3
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• pp.49-56
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• 2014

This study aims at providing basic data for product planning to design smart clothing and to develop applications, focusing on consumers by satisfying their emotions through analyzing emotional factors on smart clothing, comparing emotional differences between conventional clothing and it, reviewing changes of consumers' emotion by integrating the product and clothing and researching differences of preference and purchase intention between smart clothing and traditional one. As the results of the study, emotional factors for smart clothing were analyzed with total 6 including 'technical', 'comfort', 'aesthetic', 'modern', 'fun' and 'multiple' factors. Among them, except for 'comport', five emotional factors showed emotional factors between conventional sport-casual clothing and smart clothing. That is, emotional factors of 'technical', 'aesthetic', 'modern', 'fun' and 'multiple' were emphasized more in smart clothing than conventional ones, indicating that they should be considered in planning products of smart clothing. Though there was no significant difference of preference between smart clothing and conventional clothing, in case of comparison of averages, that of smart clothing was a little higher. For purchase intention, smart clothing was lower than the conventional clothing. So preference seems to be not directly related to consumers' immediate purchase. To make consumers' interests and preference to result in purchase, it is necessary to develop smart clothing with more various applications and to prepare commercializing strategies. As the results of the analysis on free-descriptive questionnaire survey, consumers were interested in development of smart clothing to help diet with functions including energy harvesting from body motion, calorification and perspiration, measurement of motion and calory consumption as well as health-care type smart clothing to measure heartbeat and ECG. Reflecting these requirements from the consumers, they should be utilized as guidance to develop smart clothing in the future.

• The Journal of the Korea Contents Association
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• v.13 no.9
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• pp.236-247
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• 2013

This study examines the impact of school violence on South Korean students' psychological well-being. The research is designed to analyze how different types of experiences of school violence-victim, perpetrator, victim-perpetrator, and non-involvement-influence students' suicidal impulse and sense of happiness. Empirical data was gained from a national-scale survey conducted by Social Development Research Institute at Yonsei University in 2013, and was analyzed using binary logistic and multiple regression methods. Findings suggest that any types of experiences of school violence had significant effect on suicidal impulse. In particular, the likelihood of victim-perpetrator to experience suicidal impulse was 7.1 times stronger than non-involvement. However, the effect of experiences of school violence on students' sense of happiness was insignificant. While the impact of school violence on sense of happiness among victims and victim-perpetrators was significant, its impact among perpetrators proved insignificant. Rather, stress factor-in particular, stress from peers-had more significant impact on the level of students' happiness. This study contributes to understanding the multiple effect of school violence by examining both negative and positive dimensions of psychological well-being.

• Korean Journal of Environmental Agriculture
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• v.21 no.1
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• pp.31-37
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• 2002

In order to select proper plants for phytoremediation at heavy metal contaminated areas, eight species of non-edible plants were cultivated at the heavy metal contaminated soils near a metal smelter. The content of the absorbed heavy metals (Cd, Cu, Pb and As) at different part of the plants were analyzed. Plants included five tree species (Populus nigra x P. maximowiczii, Euonymus japonica, Acer palmantum, Celtis sinensis, Buxus microphylla), two flower species (Rhododendron lateritium, Calendula officinalis), and lawn (Zoysia japonica). Biomass yield of tree species was higher than those of flower or lawn species. Heavy metals were highly accumulated in roots compared to those In leaves and stems. The concentrations of Cd, Cu, Pb, and As in Buxus microphylla were greater than those in other plant species. Total absorbed Cd and Pb contents, from high to low by each plant in experimental plots were in the order of Populus nigra x P. maximowiczii, Celtis sinensis and Acer palmantum. They were Celtis sinensis, Populus nigra x P. maximowiczii and Buxus microphylla for Cu, and Buxus microphylla, Acer palmantum and Populus nigra x P. maimowiczii for As. It was estimated that among eight plant species used in the experiment Populus nigra x P. maximowiczii, Buxus microphylla, Acer palmantum, and Celtis sinensis were the most effective species for phytoremediation in the heavy metals polluted areas considering biomass yield and heavy metal uptake.

• Analytical Science and Technology
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• v.16 no.3
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• pp.249-260
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• 2003

The disinfection of drinking water to control microbial contaminants results in the formation of secondary chemical contaminants, DBPs (disinfection by-products). It was studied the formation pattern of DBPs in drinking raw water after hypochlorite, chlorine disinfectant, was added in this study. It was determined TOC (total organic carbon), residual chlorine, turbidity and DBPs in raw water from Han-river during 1~14 days. Total DBPs was $101.3ng/m{\ell}$ (789.6 nM) after 7days and THMs (trihalomethanes) are the dominant portion of 69%. HAAs (haloacetic acids) and chloral hydrate were determined 19% and 10% respectively, and HANs (haloacetonitriles), HKs (haloketones) and chloropicrin were analyzed in trace level. Chloroform occupied about 89% in total THMs in concentration of $61.5ng/m{\ell}$, 95% of HANs was DCAN (dichloroacetonitrile) in $0.72ng/m{\ell}$, 50% of HAAs was TCAA (trichloroacetic acid). On the study of relationship in formation among the DBPs, HANs forms with THMs competitively to the point of the concentration of $40ng/m{\ell}$ of THMs. For HAAs, it did not show the prominent tendency. But it was observed that the compounds of large oxidation state are formed at first, and becomes to the compounds of low oxidation states.

• Analytical Science and Technology
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• v.17 no.1
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• pp.69-81
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• 2004

The formation pattern of DBPs (disinfection by-products) in raw water treated with hypochlorite, chlorine disinfectant was studied. TOC (total organic carbon), residual chlorine, turbidity and 14 DBPs in raw water from Han-river and Nakdong river during 1 ~ 14 days were determined. Total DBPs in Han river was 101.3 ng/mL (789.6 nM) after 7days and THMs (trihalomethanes) are the dominant portion of 68%. HAAs (haloacetic acids) and chloral hydrate were determined 19% and 10% respectively. In Nakdong river total DBPs was 98.4 ng/mL (678.6 nM) and dominant class was HAAs. (55.8 ng/mL, 57%) THMs(34%) and N-compounds like HANs (haloacetonitriles, 5%) and chloropicrin were increased. It may be explained that high concentration of NH4-N in Nakdong river react with chlorine produced chloramine and this formed different pattern of DBPs. As a result, total DBPs formation pattern depends on raw water and disinfectant and in generally the initial concentration of acidic HAAs was high and THMs was increased gradually.

• Journal of Information Management
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• v.42 no.1
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• pp.113-135
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• 2011

The final report of the Functional Requirement of Subject Authority Data(FRSAD), the 3rd report of the FRBR family model, is announced by IFLA in June, 2010. This model represents the international trends of subject authority control and suggests a direction to the future subject authority record suitable for the FRBR system. Therefore aims of this study are to analysis the FRSAD model in context of the FRBR family and apply the model to the subject headings and bibliographic records of Korean National Library. For these aims, we analyse the model focused on the entities, attributes, and relationships between entities. From this analysis, we have found the openness of the FRSAD, which does not force a certain entity types and has focus on the conceptual aspects of the entity not only the form of the headings. Moreover, we suggest examples by applying the FRSAD frame and facets of the FAST to the Headings of the NLSH and related KORMARC fields. The scope of this study is the additional entities of the FRBR groups, so personal names, corporate names, family names and titles are not included. As a result, it is necessary to determine the criteria for the types of thema and to apply the types consistently in bibliographic records. A follow up research will be needed to suggest more detailed examples.

• Restorative Dentistry and Endodontics
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• v.33 no.5
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• pp.457-462
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• 2008

"Residual stress" can be developed during polymerization of the dental composite and it can be remained after this process was completed. The total amount of the force which applied to the composite restoration can be calculated by the sum of external and internal force. For the complete understanding of the restoration failure behavior. these two factors should be considered. In this experiment. I compared the residual stress of the recently developed nanofilled dental composite by ring slitting methods. The composites used in this study can be categorized in two groups. one is microhybrid type-Z250, as control group, and nanofilled type-Grandio, Filtek Supreme. Ceram-X, as experimental ones. Composite ring was made and marked two reference points on the surface. Then measure the change of the distance between these two points before and after ring slitting. From the distance change, average circumferential residual stress $({\sigma}{\theta})$ was calculated. In 10 minutes and 1 hour measurement groups, Filtek Supreme showed higher residual stress than Z250 and Ceram-X. In 24 hour group, Filtek showed higher stress than the other groups. Following the result of this experiment, nanofilled composite showed similar or higher residual stress than Z250, and when comparing the Z250 and Filtek Supreme, which have quite similar matrix components. Filtek Supreme groups showed higher residual stress.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.30-30
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• 2007

현재 다양한 종류의 RF 통신 제품이 시장에 등장하면서 제품의 경쟁력 확보에 있어 소형화 정도가 중요한 이슈가 되고 있다. Passive Device는 RF Circuit을 제작할 때 많은 면적을 차지하고 있으며 이를 감소시키기 위해 여러 연구가 진행되고 있다. 가장 효과적인 방법으로 반도체 집적기술로 크기를 줄이는 방법이 있으나, 공정이 비싸고 제작 시간이 오래 걸려 제품개발 시간과 개발비용이 상승하게 된다. 반면에 SoP-L 공정은 PCB 제작에 이용되는 일반적인 재료와 공정을 사용하므로 개발 비용과 시간을 줄일 수 있다. SoP-L의 또 하나 장점은 다종 재료를 다층으로 구성할 수 있다는 점이다. 최근 chip-type의 Device를 PCB 기판 안에 내장하는 방법의 RF Circuit 소형화 연구가 많이 진행되고 있다. 본 연구에서는 SoP-L 공정으로 chip-type 수동소자를 PCB 기판 내에 함몰하여 수동소자회로를 구현, 분석하여 보았다. 수동소자회로는 880 MHz~960 MHz(GSM) 영역과 1.71 GHz~1.88 GHz(DCS) 영역을 나누는 Diplexer를 구성하였다. 1005 size의 chip 6개로 구현한 Diplexer를 표면실장과 함몰공정으로 제작하고 Network Analyzer로 측정하여 비교하였다. chip 표면실장으로 구현된 Diplexer는 GSM에서 최대 0.86 dB의 loss, DCS에서 최대 0.68 dB의 loss가 나타났다. 표면실장과 비교하였을 때 함몰공정의 Diplexer는 GSM 대역에서 약 0.5 dB의 추가 loss가 나타났으며 목표대역에서 0.6 GHz정도 내려갔다. 이 결과를 바탕으로 두 공정 간 차이점을 확인하고, 함몰공정으로 chip-type 수동소자를 사용하였을 때 고려해야 할 점을 분석하였다. 이를 바탕으로 SoP-L 함몰공정의 안정성을 높여서 이것을 이용한 회로의 소형화에 적용이 가능할 것으로 기대한다. 특히 능동소자의 DC Power Control에서 고용량의 수동소자를 이용할 때 집적도를 높일 수 있을 것이다.