• Korean Journal of Construction Engineering and Management
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• v.13 no.5
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• pp.84-93
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• 2012

Most of the studies on reduction of buildings' environmental burden in the construction industry have been focused on carbon dioxide emission, although there are various kinds of environmental issues such as global warming, acidification, and etc. which are considered by many researchers. Therefore, this study defined and suggested six impact categories and the principles to assess each impact for the assessment of comprehensive environmental impacts of buildings. The six impact categories are abiotic depletion, global warming, ozone layer depletion, acidification, eutrophication, and photochemical oxidation. A case study has been conducted through comparative analysis of two structural design alternatives to confirm the necessity of assessing the six impact categories. That is, the results of global warming potential and the six impacts proposed in this study were compared. By comparing the results of only global warming potential, the second design alternative using 24MPa concrete was chosen as a better alternative, while the first design alternative using 21MPa concrete was resulted as a better alternative when six impact categories were considered. The results mean that the assessment of various environmental impacts is an appropriate and reasonable approach and the comprehensive assessment offers more reliable results of environmental impacts in the building construction.

• Journal of Educational Research in Mathematics
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• v.22 no.4
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• pp.581-602
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• 2012

For developing mathematics teachers' professionalism, it is necessary to construct PDS to provide training programs which are appropriate for Korean context and needed by mathematics teachers. This study is a preliminary study for constructing PDS and aims to design PDS model for Korean mathematics teachers. Firstly, components of model were elicited by theoretical review. Secondary, focus group discussion with 8 teachers and individual interview with 1 educational profession and 3 foreign mathematics education researchers were conducted. Finally, by reflecting FGD and interview results, the final version of PDS model was designed. The final model is constructed by 3 components, which are life cycle, program types, and participants. In addition, professional development topics for each life cycle according to PDS model are presented.

• The Journal of the Korea Contents Association
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• v.15 no.8
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• pp.37-45
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• 2015

With advancement in information technologies and a better mobile environment, the paradigm of service is shifting again from web portals to networked-applications based on individual application programs. Furthermore, as more investment is being made in R&D, the efforts to enhance R&D productivity are becoming important. In this paper, we designed a personalized service model for developing a tool to assist researchers in their R&D activities. To do this, we first compared services and tools in terms of information activities of researchers in R&D. In addition, we also analyzed changes of information environment such as open expansion of information and data, enhancement of personal information protection, popularization of social networking service, very big contents, advances in web platform technology in terms of personalization, and defined some directions of developing a personalized service. Subsequently we designed a personalized service model of research support tool in the views of functions, contents, operation, and defined personalized design goals and principles for implementing it as standard, participation, and open.

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.190-195
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• 2004

The compression-compression fatigue properties of the closed cell Al-Si-Ca alloy foams have been studied. The monotonic and cyclic compressive properties were compared with each other and the fatigue stress-life (S-N) curves were presented. In compression-compression fatigue, the crushing was found to initiate in a single band which broadens gradually with additional fatigue cycles. Progressive shortening of the specimen took place due to a combination of low cycle fatigue failure and cyclic ratcheting which is in accordance with the findings of previous researchers [1-3]. Young's modulus of the foam was found to decrease with the increasing strain in case of fatigue test however in case of monotonic compression test the value of Young's modulus increased with the strain (number of cycles). The endurance limit on the basis of $10^{7}$ cycles obtained by extrapolating the experimental results were 0.98 MPa and 1.70 MPa for load ratios 0.1 and 0.5 respectively which are 34 % and 59 % of the plateau stress.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.464-467
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• 2005

Among several polishing techniques for micro structures, polishing process using magnetorheological(MR) fluid has advantages in the finishing process of 3-D micro structures because abrasives in the fluid can reach surfaces with complex feature and play their role. Although many researchers have been trying to reveal its polishing mechanism of the MR polishing, it has not been successful because in-situ measurement of state variables is difficult and process parameters are complex. In fact, one of the key factors for applying process control methodologies, such as Run-to-Run control, is the measuring and monitoring of slurry quality because the process strongly depends on the fluid property. Therefore, it is necessary to maintain consistent slurry quality to guarantee the process repeatability. The proposed equipment achieves the longer life cycle of MR fluid and reduces the variability of products. A new method to measure the material removal rate in MRF polishing process is also proposed and discussed.

• Women's Health Nursing
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• v.6 no.4
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• pp.528-548
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• 2000

The purpose of this study was to identify the effect of college women s active and passive smoking on menstrual discomfort. The subjects were 252 college female students (active smokers, 71; people who passively inhaled others smoke, 104; nonsmokers who also didn't inhale others smoke, 77). Subjects were selected from 5 colleges in North Kyong Sang Province, Korea. Data was collected from March to June of 2000 with a structured questionnaire. The instruments used for this study were the revised Menstrual Distress Questionnaire (MDQ) developed by Moos(1968), general characteristic, menstrual characteristic, and smoking characteristic scale developed by researchers. The data were analysed by the SPSS/PC+ program. The results were as follows 1. There was no statistically significant difference of menstrual discomfort level among the active smokers, those who passively inhaled others smoke, and who did not inhale others smoke(F= 2.613, p= .075). 2. The mean score of menstrual discomfort was moderate(M= 60.8008, SD= 17.9243). The level of menstrual discomfort was various (minimum score 29.00- maximum score 110.0). 3. Factors influencing menstrual discomfort were on life stress events(F= 4.057, p = .045), irregular menstrual cycle(t = 3.968, p = .047), and amount of flow during menstruation(F = 4.018, p = .019). The recommendations from this study are necessity of further studies to investigate how heavy active and passive smoking have effect on menstrual discomfort.

• Journal of Surface Science and Engineering
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• v.57 no.2
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• pp.57-70
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• 2024

Nickel-cobalt-manganese (NCM) lithium-ion batteries(LIBs) are increasingly prominent in the energy storage system due to their high energy density and cost-effectiveness. However, they face significant challenges, such as rapid capacity fading and structural instability during high-voltage operation cycles. Addressing these issues, numerous researchers have studied the enhancement of electrochemical performance through the coating of NCM cathode materials with substances like metal oxides, lithium composites, and polymers. Coating these cathode materials serves several critical functions: it acts as a protection barrier against electrolyte decomposition, mitigates the dissolution of transition metals, enhances the structural integrity of the electrode, and can even improve the ionic conductivity of the cathode. Ultimately, these improvements lead to better cycle stability, increased efficiency, and enhanced overall battery life, which are crucial for the advancement of NCM-based lithium-ion batteries in high-demand applications. So, this paper will review various cathode coating materials and examine the roles each plays in improving battery performance.

• International conference on construction engineering and project management
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• 2013.01a
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• pp.14-20
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• 2013

Substantial research has been performed on the data standards and exchanges in the AEC/FM industry over the past several years. The growing popularity of BIM technology is based heavily upon a perception that the technology can facilitate the sharing and reuse of information during a project life-cycle. Although many researchers and practitioners are in agreement about the potential applicability and benefit of BIM in construction, it is still unclear why BIM is adopted, and what factors enhance implementation of BIM. Thus, BIM acceptance and use remains a central concern of BIM research and practice. Therefore, we propose the key factors affecting the acceptance of BIM in construction organizations using factor analysis. The key factors for BIM acceptance are identified through a literature review in TAM (Davis 1989) and related theories, and consolidated by interviews and pilot studies with professionals in construction industry. Based on the factors, a questionnaire was designed and sent out to construction organizations such as contractors, architects, and engineers in Korea. Total 148 completed questionnaires were retrieved. Using factor analysis, key factors were grouped into six dimensions. These findings will clarify what the highly prioritized factors are, and can also be used in an assessment tool for the performance of BIM utilization.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.11a
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• pp.81-82
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• 2015

BIM has been a reliable construction project management tool to handle various kinds of construction information generated in the facility life cycle. To take these advantages, researchers have been promoted numerous studies in a residential, a commercial, and an educational facilities with a large number of on-going projects. However, despite running as the role of essential energy supplier, power plant related BIM research is relatively insufficient than others. In particular, due to the extending of the facility service period and the requirement of the complicated construction project management for 'overhaul' and 'repowering' in the power plant maintenance phase, the needs for using BIM have been increased gradually. For using BIM based maintenance, it is needed to consider an information collecting methods and necessary to develop an appropriate breakdown structure to share information. Therefore, 'EBS' is produced by reviewing the previous research related to BIM and analyzing the repair activities in the maintenance phase. Proposed 'EBS' must be useful not only a judgment between capital expenditure versus revenue expenditure but also appropriate maintenance strategies development for property management.

• Journal of the Korean Institute of Landscape Architecture
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• v.13 no.1
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• pp.109-121
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• 1985

A study on the image identification of urban streetscape is valuable for illuminating identity that is not yet fully approached in the field of environmental design. This analysis of urban streetscape for image identification allows us to make a more detailed exploration of an important approaching methods in dealing with the structural characteristics of identity. As a matter of fact, the earlier indirect studies on this image identification were made by environmental designers, such as architectural and urban designer in the field of environmental perception and came to its environmental cognition & environmental pattern research with assistances by such researchers as K. Lynch A. Rapoport & Christopher Alexander. Through its environmental perception research, we can see its structural characteristics that is aesthetic & visual structural contents of physical environmental elements. And we can see its cognitive characteristics through the environmental cognitive research, that is continuity, territoriality, identity of place, uniqueness or individuality, meaning & symbolism. Through its environmental pattern research, we can see its physical, socio - economic, cultural and symbolic pattern identification contents, that is physical form of the city, style of the street, pattern of streetscape, socio- economic & geographical locality, arid life cycle, life style, common style of the behavior, cultural pattern of the activity, socio - cultural expression of the symbol. In these process, we can set up a set of the environmental design criterias from those three integral studies for identity. And for an environmental research, Tongsung-Ro around the CBD (central business district) in Taegu City was selected for a case study, because this streetscape is suitable for that approaching methods in this study.