• 설비공학논문집
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• 제10권6호
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• pp.658-665
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• 1998

This paper investigates local exhaust effectiveness in a room with a supply and an exhaust slots on the ceiling. The mean age of air is an indicator of supply effectiveness, while the mean residual life time can be used as an indicator of exhaust effectiveness. The distribution of local mean residual life time in a space is calculated by four different numerical procedures. The reverse-flow calculation method has been proved to show quite accurate results while it can save considerable amount of computation time and efforts, compared to the method by its original definition. It is concluded that the diffusion term in the equation of mean residual life time can be neglected. The spatial and temporal diffusion characteristics of the contaminant are also discussed.

• 대한화장품학회지
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• 제39권2호
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• pp.133-140
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• 2013

항균비누에 흔히 사용되는 항균성분인 PCMX와 IPMP에 대하여 ASTM E2752-10 (Standard Guide for Evaluation of Residual Effectiveness of Anti- bacterial Personal Cleansing Products)에 기술된 cup scrub method에 따라 항균 지속력을 평가하였다. 건강한 남녀 총 80명의 피험자를 대상으로 한 실험에서 5% PCMX와 0.1% IPMP를 함유한 액체비누는 대조군에 비해서 E. coli와 S. aureus의 수를 통계학적으로 유의하게 감소시켰으며 27시간 동안 항균효과가 지속되는 것을 확인하였다. 항균성분의 지속력에 대한 인체적용 시험은 국내에서는 처음 시행된 것으로 결과와 함께 보고하는 바이다.

• Restorative Dentistry and Endodontics
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• 제12권1호
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• pp.25-37
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• 1986

This study was undertaken to measure the diffusibility and antimicrobial effectiveness of the medication used in clinical practice. To study the diffusibility of the root canal medicament, loss of formocresol and camphorated phenol from a cotton pellet after insertion into the pulp chamber of 260 molars prepared as routine endodontic treatment was measured. Measurement was done for the one time insertions and for the reinsertions using ultraviolet spectrophotometer. Antibacterial effectiveness against three microoganisms, Staphylococcus aureus, Staphylococcus epidermidis and a-hemolytic streptococcus, on the blood agar plate was observed by measurement of the inhibition zone with. various amount of medicaments. The following results were observed. 1. Nearly all of the medication were lost in the first day after insertion and the residual amount of camphorated phenol was greater than that of formocresol. 2. Residual amounts of medication in the reinsertion group were greater than that of the one time insertion group. 3. Within the pulp chamber diffusibility of formocresol was greater than that of camphorated phenol. 4. The amount of formocresol diffusing out from the tooth was greater than that of camphorated phenol. 5. Antibacterial effectiveness was observed from the residual amount of formocresol in the reinsertion group and in other groups no antibacterial effectiveness was observed.

• Steel and Composite Structures
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• 제4권5호
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• pp.355-365
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• 2004

A new reduction method of residual stress in welding joint is proposed where welded metals are shaken during welding. By an experiment using a small shaker, it can be shown that tensile residual stress near the bead is significantly reduced. Since tensile residual stress on the surface degrades fatigue strength for cumulative damage, the proposed method is effective to reduction of residual stress of welded joints. The effectiveness of the proposed method is demonstrated by the response analysis using one mass model with nonlinear springs.

• International Journal of Air-Conditioning and Refrigeration
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• 제10권4호
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• pp.177-183
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• 2002

A pulsed tracer gas technique is applied to measure the distributions of local mean age and local mean residual-life-time of air in a half-scale experimental chamber, The airflow patterns in the chamber are visualized by a Helium bubble generator for three different exhaust locations. A supply slot is located at the top of a right wall, and an exhaust slot is at either bottom-left (Case 1), bottom-right (Case 2), or top-left (Case 3) location. Results show that the distributions of local mean age and local mean residual-life-time are different from each other, but both of them are closely related to the airflow pattern in the space. Included are discussions on explaining the variations of overall room ventilation effectiveness depending upon airflow rates for three different supply-exhaust configurations.

• 설비공학논문집
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• 제26권11호
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• pp.535-540
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• 2014

This paper investigates the exhaust effectiveness of smoke, in the case of fire in a large atrium space. Numerical analysis was conducted to simulate transient fire growth in a test room, modeled by the Murcia atrium fire test. Various indices representing the exhaust performance of the exhaust system were obtained, such as the height of the smoke layer, and the instantaneous and accumulative capture efficiency of the smoke. The residual life time of smoke from the fire was also obtained, by injecting tracer gases at the fire location, depending on the airflow rate, and the location of the exhausts. The capture efficiency based on smoke concentration at the exhausts exhibits how much smoke can be removed by the exhaust system; whereas, the exhaust effectiveness based on residual life time indicates how rapidly the smoke can reach the exhaust locations, before being exhausted. The definitions and meanings of the indices to be used in representing the exhaust performance of a smoke exhaust system installed in a large space are discussed.

• 소성∙가공
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• 제26권3호
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• pp.162-167
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• 2017

The tensile surface residual stress in the multi-pass drawn wire deteriorates the mechanical properties of the wire. Therefore, the evaluation of the residual stress is very important. Especially, the axial residual stress on the wire surface is the highest. Therefore, the objective of this study was to propose an axial surface residual stress prediction model of the multi-pass drawn steel wire. In order to achieve this objective, an elastoplastic finite element (FE) analysis was carried out to investigate the effect of semi-die angle and reduction ratio of the axial surface residual stress. By using the results of the FE analysis, a surface residual stress prediction model was proposed. In order to verify the effectiveness of the prediction model, the predicted residual stress was compared to that of a wire drawing experiment.

• 상하수도학회지
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• 제30권5호
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• pp.587-596
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• 2016

This study attempts to draw factors for an analysis of the operation effect of a rechlorination facility and autodrain equipment for residual chlorine equalization by installing and operating a rechlorination facility and autodrain equipment in P City and analyzing the practical evaluation method and operation effect. For this purpose, this study selected three indicators for an analysis of the effectiveness of residual chlorine equalization and conducted a comparative analysis before and after the implementation of the residual chlorine equalization. As a result of estimation, (1) the reduction of the residual chlorine concentration range from a water treatment plant to the pipe end was 16.0%; (2) the total reduction of chlorination input was 18.0%; and (3) the reduction of the generation of disinfection by-products was 19.5%. In addition, this achieved enough residual chlorine equalization in the supply process and shows that it could successfully achieve the economic feasibility of investment in equipment and the reduction of the generation of disinfection by-products. Like this, it is judged that the three indicators suggested in this study will be used sufficiently as indicators of an analysis of the effectiveness of residual chlorine equalization according to the operations of the rechlorination facility and autodrain equipment.

• Journal of Acupuncture Research
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• 제26권4호
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• pp.115-123
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• 2009

Objectives : This study was to investigate the effectiveness of bee venom phamacopuncture complex therapy on the sequelae of peripheral facial palsy. Methods : We observed the effectiveness of bee venom pharmacopuncture complex therapy on three patients who have residual symptoms of Bell's palsy although early stage(0 to 3months) elapsed. H-B grade and Yanagiha's total score was used for evaluating the patient. Results : 1. Deviation of the bee venom therapy on the sequelae of peripheral facial palsy, One patient was improved from 19 to 39, another patient was improved from 25 to 40, the third patient was improved from 15 to 26 on Yanagiha's total score. 2. In the bee venom therapy on the sequelae of peripheral facial palsy, compared with baseline, at final, H-B grade and Yanagiha's total score was increased. Conclusions : Bee venom phamacopuncture can be available for relieving residual symptom of bell's palsy after the early stage.

• 대한기계학회논문집A
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• 제29권5호
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• pp.716-725
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• 2005

The method of substructure synthesis o. component mode synthesis(CMS) provides an effective means of dynamic analysis of very large and/or complex structures. In this study, residual dynamic flexibility attachment modes in hybrid component mode synthesis are considered for the purpose of exactly compensating the effect of higher order truncated modes. Following this way, the analysis accuracy of the synthesized structure can be improved effectively with less computational effort. In order to show the accuracy and effectiveness of the proposed hybrid component mode synthesis(HCMS), numerical experiments were carried out for the models of a clamped-clamped beam. The results verified the effectiveness of the proposed method.