• Journal of the Korea institute for structural maintenance and inspection
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• v.18 no.3
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• pp.40-48
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• 2014

In this study, experimental research was carried out to evaluate and improve the seismic performance of reinforced concrete beam-column joint regions using strengthening materials (embedded CFRP rod and CFRP sheet) in existing reinforced concrete building. Therefore it was constructed and tested six specimens retrofitting the beam-column joint regions using such retrofitting materials. Specimens, designed by retrofitting the beam-column joint regions of existing reinforced concrete building, were showed the stable failure mode and increase of load-carrying capacity due to the effect of crack control at the times of initial loading and confinement of retrofitting materials during testing. Specimens RBCJ-SRC2, designed by the retrofitting of CFRP Rod and CFRP Sheet in reinforecd beam-column joint regions were increased its maximum load carrying capacity by 1.97 times and its energy dissipation capacity by 2.08 times in comparison with standard specimen RBCJ for a displacement ductility of 4 and 7. Also, specimens RBCJ-SRC2 were increased its maximum load carrying capacity by 1.09~1.11 times in comparison with specimen RBCJ-SR series. And Specimens RBCJ-CS, RBCJ-SR series, RBCJ-SRC2 were increased its energy dissipation capacity by 1.10~2.30 times in comparison with standard specimen RBCJ for a displacement ductility of 5, 6.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.27 no.5
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• pp.428-434
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• 2001

After miniplate fixation of mandibular angle fractures, fracture line stability during functional loading was evaluated. Using panoramic radiographs, 15 mandibular angle fracture patients who were treated by open reduction and one miniplate fixation along the external oblique ridge, were evaluated at postoperative 1, 4 and 8 weeks. At each time, 2 radiographs were taken: one taken during maximum biting of hardened silicone sheet on the affected side molar area and the other on the non-affected side. The distraction gap of inferior border of mandible at each time and each side was measured and these data were analysed statistically with clinical findings. The differences of inferior border distraction gap during hardened silicone sheet biting on the affected side molar area and on the non-affected side molar area at 4 week radiographs were smaller than those of 1 week's except one case. At 8 week's radiographs, the fracture lines were so stabilized that it was almost impossible to find the gap differences except one case and there were increased radiopacity along the entire fracture lines. Clinically, bony union was confirmed in all cases during plate removal performed at postoperative 6 month. By statistical analysis(paired t-test), the inferior border distraction gap during biting of hardened silicone sheet on the affected side was significantly reduced during 1 and 4 week interval(p<0.01). The differences of inferior border distraction gap during biting on the affected side molar area and on the non-affected side molar area were also significantly reduced at 1 and 4 week interval(p<0.01). But the inferior border distraction(compression) gap during non-affected side biting was not significantly changed. From these findings, it could be concluded that fracture line stability during functional loading after one miniplate fixation of mandibular angle fractures stems mainly from reduction of inferior border distraction gap during affected side biting on time interval. According to these radiographic and clinical findings, the clinical superiority of one miniplate fixation technique in mandibular angle fracture treatment could be confirmed.

• Clean Technology
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• v.17 no.4
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• pp.285-299
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• 2011

As one of the REACH obligations, the extended safety data sheet (eSDS) should be communicated within the supply chain under the REACH Regulation. Based on technical guidance documents published on the ECHAs website and survey of EU's recent REACH-related informations, this paper includes a study on details of how to develop exposure scenarios (ES) such as structure of ES, process of ES develpoment, standard workflows and key input data to develop ES with an introduction of eSDS concept. This paper also contains an overview on operational conditions (OCs) and risk management measures (RMMs) that are what to consider when building an ES. The structure of Chesar (Chemical Safety Assessment and Report tool) developed by European Chemicals Agency (ECHA) is studied with a review of the available exposure estimation tools for workers, environment and consumers. Case example of generic exposure scenario (GES) for organic solvent is presented. To guide Korean EU-exporting companies, their participating roles in three steps of preparing ES are addressed.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.2A
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• pp.169-176
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• 2010

Generally, poly-urea is widely used as waterproof coating material due to its superior adhesiveness, elongation capacity, and permeability resistance. In addition, it can be quickly and easily applied on structure surfaces using spray application. Since it hardens in about 30 seconds after application, its construction efficiency is very high and its usage as a special functional material is also excellent. However, currently, poly-urea is mostly used as waterproof coating material and the researches on its usage as a retrofitting material is lacking at best. Therefore, basic studies on the use of poly-urea as a general structural retrofitting material are needed urgently. The objective of this study is to develop most optimum poly-urea composition for structure retrofitting purpose. Moreover, the structural strengthening capacity of the developed poly-urea is evaluated through flexural capacity experiments on RC beams and RC slabs. From the results of the flexural test of poly-urea strengthened RC beam and slab specimens, the poly-urea and concrete specimen showed monolithic behavior where ductility and ultimate strength of the poly-urea strengthened specimen showed slight increase. However, the doubly reinforced specimens with FRP sheet and poly-urea showed lower capacity than that of the specimen reinforced only with FRP sheet.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.23 no.3
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• pp.287-298
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• 2013

Objectives: Workers who use chemicals are exposed to safety accidents and occupational diseases. Employers are required to provide workers with Material Safety Data Sheets (MSDSs) in order to prevent accidents and diseases related to chemicals. Thus, it is very important to offer reliable MSDSs. In this paper, we assessed the reliability of MSDSs for chemicals including formaldehyde. Methods: To evaluate MSDS reliability, we collected 14 MSDSs and bulk samples from the chemical industry. MSDS reliability was evaluated by the completeness of details. In order to evaluate the adequacy of the formaldehyde contents in a mixture, bulk samples were collected and analyzed by HPLC. The result of Globally Harmonized System (GHS) classification was confirmed by identifying physical chemical properties, toxicology information and ecological information. Results: The result of the evaluation of 14 MSDSs showed 76.29% average reliability on each item, especially 53.9% average appropriate rate on hazard risk classification. No chemicals failed to match between the content (%) in MSDSs and the result of analysis. Conclusions: To elevate MSDSs reliability, the certified education of MSDS drafters and reorganization of the MSDS circulation system is required.

• Journal of Korean Elementary Science Education
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• v.20 no.1
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• pp.107-122
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• 2001

The Purpose of this study is to find the effects of the portfolio assessment on elementary students' scientific knowledge, inquiry process skill, scientific attitudes in the teaching of science. And finally the parents' response to the portfolio assessment is also investigated. In order to reach the goal of this study, the investigator developed the evaluation instrument such as an experimental report and a cumulative observation sheet for the 4th-grade Unit-1 'Light Propagation' and Unit-3 'Separating Mixtures', and then these were administered to 42 4th-grade elementary students in Inchon. Based upon the findings and within the limitations of this study, several conclusions can be drawn regarding the problems investigated. First, as the portfolio assessment offers enough information about individual student's performance, it has a highly positive effect on evaluating the students' scientific knowledges. It can also make possible to grasp the several aspects of the student's progress. Second, the portfolio assessment can be implemented without giving students any psychological pressure from testing itself. Therefore, the portfolio assessment is an effective means of appraising inquiry process skills. Third, the portfolio assessment is effective to evaluate the students' attitude toward science by means of individual records which include such aspects that is hardly found by the teacher who teaches science in the class. Fourth, as most parents showed a positive response to this portfolio assessment, it is considered to be effective method of appraising the result of teaching science at elementary school. Accordingly, this study demonstrated that the portfolio assessment is an effective method that can assess students' scientific knowledges, inquiry process skills, and scientific attitudes gained from science teaching-learning. Therefore, it is necessary to implement the portfolio assessment to other grade students as well in the following study where teacher may give more encouragements and suggestions to sti dents for the better learning motives. Also teachers should suggest more definite evaluation criteria to students so that they may improve the students' self and peer evaluation skills.

• Korean Journal of Construction Engineering and Management
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• v.10 no.4
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• pp.129-138
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• 2009

The role and importance of VE have been enlarged since VE application was mandatory by law in public sector in March, 2000. Public organizations have widened the technological horizon through VE competitions and applied VE technique to private investment projects. Many studies have been carried out on function analysis and VE procedure. In practice it is common that clients make a decision one-sidedly on whether or not VE proposals are selected. The VE procedure itself is not smooth. This study gives some suggestions on VE appraisal procedure and criteria at the last phase on VE process in order to smooth the progress of VE. The results of this study can be used as a tool to improve efficiency in the management of VE.

• Journal of Korean Society on Water Environment
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• v.26 no.3
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• pp.432-438
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• 2010

LIDMOD2 was developed for evaluation of low impact development (LID) and best management practice (BMP) by modification of Site Evaluation Tool (SET). The modification includes employment of SCS-CN method for annual runoff simulation, unit load method for annual pollutant loads simulation, and the method proposed by Korean TMDL for calculating pollutant reduction by BMPs. The CN values were updated with regionalized parameters within Nack-Dong River basin because these are important parameters for simulating hydrology. LIDMOD2 was tested by applying to Andong Bus terminal. As a simulation results, pollutant loads and surface runoff will be significantly increased by post-development without LID compared with those from pre-development. LID technique was simulated to efficiently reduce surface runoff and pollutant load and increase infiltration. LIDMOD2 is screening level tool and easy to use because LIDMOD2 is based on spread sheet and most of parameters are regionalized. LIDMOD2 was illustrate that it could evaluate LID well by summarizing and graphing annual hydrology, annual pollutant loading, and hydrograph for event storm. The calculation methods related with pollutant loads are employed from the guideline of Korean TMDL and it can be useful tool for Korean TMDL to evaluate the effect of LID/BMP on developing area.

• Journal of the Korean Society of Earth Science Education
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• v.1 no.1
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• pp.1-13
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• 2008

The purpose of this research is to accomplish the goal of science education based in the seventh science course of study by suggesting the plan for development of executable method in the learning process of Earth Science education and establishing a practical model to evaluate its achievement. Furthermore, the idea of this research is to recognize a way of using and consideration at practical use of the model. Since the purpose of the educational evaluation is to maximize the efficiency of school studying, there are some negative aspects in our current method of evaluation to achieve the purpose. New system has been introduced into the educational evaluation to resolve such a critical issue. Despite some positive aspects in the system, it could not be escaped from the multiple choice and pens examination. This could be caused by in various limitations, especially the insufficiency of teachers' awareness and the data about the Performance assessment. This research is to develop and use the practical model for the Performance assessment in consideration of current educational circumstances of Junior and High school. The model of the Performance assessment in this research is to sufficiently evaluate student's ability and skill in the learning process of Earth Science education. Hence, it is dedicated to the education for human being and improve quality in the learning process of the Earth Science education among the modern society, which is characterized globalization and information. Furthermore, it may promote the growth of various character of students and increase creativity and skill for the problem solving.

• Korean Journal of Construction Engineering and Management
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• v.10 no.3
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• pp.92-101
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• 2009

The purpose of this study was to develop the curtain-wall structure design evaluation manual that can easily examine the curtain-wall structural members (Mullion and Transom) stability from the position of the construction managers. Through analyzing the structural design reports in the previous studies and interview with industry experts, the curtain-wall structural member design process was elicited. The manual, which consists of Microsoft Excel-based work sheet and its manual, was applied to a real curtain-wall design project to make sure its usability. A workshop with three curtain-wall experts and three construction managers was conducted to identify pros and cons of the manual, thereby enhancing its applicability in the future.