• 자원환경지질
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• 제21권2호
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• pp.185-191
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• 1988

A two channel seismic recorder suitable for long-term observation of microearthquakes is developed. The direct analogue recording on cassette tape is adopted in the recorder whose circuits of amplifier and mortor units of an audio cassette recorder are modified. The recorder provides contineous record of 10 days with DC 12V battery (100AH) and with standard cassette tape of 60 minute use. The binary coded time signals of date, hour, and minute are generated once a minute by the timing system and absolute time input using radio to measure the time drift is also possible. For the seismic signal processing, the analogue signals from audio cassette player pass A/D converter and digitized data are stored in personal computer. Then visual records can be obtained using computer graphic mode. Basic programs "ADCONVO" and "DRAWO" to accomplish A/D conversions, the creation of data files and visualization of signals were written. Some sample signals reproduced from the recorded tape are presented.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2008년도 춘계 학술발표회 제20권1호
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• pp.689-692
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• 2008

본 연구는 친환경 콘크리트의 개발을 위하여 시멘트 대체재료인 혼화재료로서 황토, 슬래그 및 PET보강섬유를 혼입한 콘크리트의 역학적 특성을 분석하는데 목적이 있다. 이를 위하여 콘크리트(SC), 황토콘크리트(HTC), 황토 및 PET보강섬유가 혼입된 시험체(HTPC)를 대상으로 재령별 압축강도 실험을 실시하였으며, 시험체의 장기특성을 분석하기 위한 크리프 및 건조수축 실험을 실시하였다. 실험결과, 재령별 압축강도는 시험체 별로 큰 차이를 나타내지 않았으나, HTC 시험체의 압축강도가 가장 큰 것으로 나타났으며, 크리프 및 건조수축의 실험결과 HTC 시험체의 장기특성이 가장 우수한 것으로 판명되었다.

• 대한토목학회논문집
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• 제39권4호
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• pp.469-475
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• 2019

구조물의 장기적인 안전관리를 위하여 교량 장기계측시스템이 도입되어 운영 중에 있다. 그러나 일반적인 교량 장기계측시스템은 응답만 측정하고 입력하중은 측정하지 못하고 있기 때문에, 추세분석에 의한 관리기준 상회여부만을 판단하고 있어 정량적인 구조계의 상태평가가 어려운 실정이다. 이러한 단점을 극복하기 위하여 본 논문에서는 도로교 입력하중 측정을 위한 FBG 기반 입력하중 측정센서를 개발하였으며, 실내실험을 통하여 그 타당성을 검증하였다.

• 융합경영연구
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• 제12권1호
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• pp.53-64
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• 2024

Purpose: The purpose of this study is to develop a satisfaction evaluation survey tool that reflects the characteristics of the program for housing welfare supported in long-term public rental housing in Seoul. Research design, data and methodology: The main research methods of the study were review of previous studies, literature review, and expert consultation. Results: First, the characteristics of each housing welfare program being promoted by Seoul City were summarized, and the characteristics were reflected in the evaluation survey tool. Second, the SERVOUAL model, a service quality model, was used to measure satisfaction with the housing welfare program and modified to suit the characteristics of the program. Third, an evaluation survey tool was constructed by dividing the evaluation tool into common questions and individual questions, and for the operation and sustainability of the housing welfare program, rather than just evaluating satisfaction, program loyalty was used as a survey item. Fourth, through expert advice, more than 10 evaluation questions for each housing welfare program were revised. Conclusions: The results of future research are expected to be used to prepare practical operation plans through annual monitoring of housing welfare programs and comparative analysis between programs.

• Nuclear Engineering and Technology
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• 제56권3호
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• pp.1081-1090
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• 2024

The liquid Lead-bismuth eutectic is used as the coolant for Gen-IV reactor concepts. However, due to its strong corrosive and high operating temperature, it is difficult to accurately measure the flow rate in long-term operating conditions. Venturi flowmeter is a simple structured flowmeter, which plays a very important role in the flow measurement of high-temperature liquid metals, especially since the existing flowmeters are difficult to be competent. It has the advantages of easy maintenance and stable operation. Therefore, it is necessary to study the operating conditions of the venturi flowmeter under high-temperature conditions. This work performs a series of simulations of the fluid-solid interaction between the flow liquid metal and venturi flowmeter with COMSOL software, including the dimensional sensitivity analysis of the venturi flowmeter to explore the most suitable structure and parameters for liquid heavy metal, the sensitivity analysis of the geometric parameters of the venturi tube on the varying conditions. It shows that when the contraction angle of the venturi flowmeter is 33°, the diffusion angle is 13°, the diameter of the throat is 8 mm, and the temperature of the lead-bismuth eutectic is 733.15 K, it is most suitable for the measurement in the lead-bismuth circuit.

• 디지털산업정보학회논문지
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• 제7권3호
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• pp.63-74
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• 2011

Credit cards are more convenient than cash of heavy. Therefore, credit cards are used widely in on_line (internet) and off_line in nowadays. To use credit cards on internet is commonly secure because client identification based security card and authentication certificate. However, to use in off_line as like shop, store, department, restaurant is unsecure because of irregular accident. As client identification is not used in off_line use of credit cards, the irregular use of counterfeit, stolen and lost card have been increasing in number recently. Therefore, client identification is urgently necessary for secure card using in off_line. And the method of client identification must be simple, don't take long time, convenient for client, card affiliate and card company. In this paper, we study a reform measure of the structure and transaction process for the safety improvement of a credit cards. And we propose several authentication method of short-and long-term for client identification. In the proposal, the client authentication method by OTP application of smart-phone is efficient nowadays.

• Journal of Preventive Medicine and Public Health
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• 제41권5호
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• pp.331-338
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• 2008

Objectives : The purpose of this study was to measure the workload of home visit care activities and their relative values. This study examined also factors that affect the workload of home visit care activities. Methods : The participants of this study were 126 home-helpers of 50 home visit care agencies at the 2nd Long-term Care Insurance Demonstration Project. The workload of home visit care activities was divided into total work and four dimensions ; physical efforts, mental efforts, stress and time. Home visit care activities consisted of four categories with 24 items. We used magnitude estimation method to measure their relative values of the four dimensions. The participants answered the relative values of each activities based on the reference service. We used the activity for supporting their elderly's evacuation as the reference service. Results : Most of the respondents were over 40 years old female. They consumed most their time supporting elderly's going out. They consumed their highest physical, mental efforts, and stress for activities of coping with emergency situation. The Pearson correlation coefficients showed significant relationships between workload and each dimensions. This study showed that all four dimensions are statistically significant predictors of workload of home visit care activities. Also, we found that the home-helper's career affects the workload of home visit care activities. Conclusions : The workload of home visit care activities could be explained by physical efforts, mental efforts, stress and time.

• 대한약침학회지
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• 제18권4호
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• pp.12-19
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• 2015

Objectives: This study was done out to evaluate the effects of Sida rhombifolia methanol extract (SRM) on diabetes in moderately diabetic (MD) and severely diabetic (SD) Sprague-Dawley rats. Methods: SRM was prepared by soaking the powdered plant material in 70% methanol and rota evaporating the methanol from the extract. Effective hypoglycemic doses were established by performing oral glucose tolerance tests (OGTTs) in normal rats. Hourly effects of SRM on glucose were observed in the MD and the SD rats. Rats were grouped, five rats to a group, into normal control 1 (NC1), MD control 1 (MDC1), MD experimental 1 (MDE1), SD control 1 (SDC1), and SD experimental 1 (SDE1) groups. All rats in the control groups were administered 1 mL of distilled water (DW). The rats in the MDE1 and the SDE1 groups were administered SRM orally at 200 and 300 mg/kg body weight (BW), respectively, dissolved in 1 mL of DW. Blood was collected initially and at intervals of 1 hour for 6 hours to measure blood glucose. A similar experimental design was followed for the 30-day long-term trial. Finally, rats were sacrificed, and blood was collected to measure blood glucose, lipid profiles, thiobarbituric acid reactive substances (TBARS) and reduced glutathione (GSH). Results: OGTTs indicated that two doses (200 and 300 mg/kg BW) were effective hypoglycemic doses in normal rats. Both doses reduced glucose levels after 1 hour in the MDE1 and the SDE1 groups. A long-term trial of SRM in the MD group showed a reduced glucose level, a normal lipid profile, and normal GSH and TBARS levels. In SD rats, SRM had no statistically significant effects on these parameters. Normal weight was achieved in the MD rats, but the SD rats showed reduced BW. Conclusion: The study demonstrates that SRM has potential to alleviate the conditions of moderate diabetic, but not severe diabetes.

• 대한정형도수물리치료학회지
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• 제16권1호
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• pp.50-56
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• 2010

Purpose : To evaluate effects of joint mobilization on the range of motion of chronic low back pain patients. Methods : The subjects were consisted of sixty patients who had non specific chronic low back pain(10 females. 10 males; mean aged 36.5). All subjects received modalities treatment with therapeutic massage for 10minutes and joint mobilization or manipulation for 10minutes per day and three times a week during 4 weeks period. The Multilevel Roland-Morris Disability Questionnaire(MR-MDQ) was used to measure functional disability level. Visual Analogue Scale(VAS) was used to measure subjective pain level. Remodified Schober test(RST) was used to measure forward flexion range of motion of lumbar segment. Finger-to-Floor test(F-T-FT) was used to measure forward flexion range of motion of full spine of low back pain patients. All measurements of each patients were measured at pre-treatment and 4 week post-treatment. Results : The MR-MDQ, VAS, RCT and F-T-FT were significantly different within-subjects(p<.05), Conclusion : The manual therapy included therapeutic massage and joint mobilization found that improved chronic low back pain patients. Further studies are needed to including more subjects on long-term outcomes.

• 한국전자거래학회지
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• 제22권4호
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• pp.1-19
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• 2017

위키피디아는 콘텐츠 협업을 위한 사이트들 중에서 사용자가 가장 많이 사용하는 사이트이다. 위키피디아의 성공은 수많은 자원 봉사자들이 자신의 지식을 제공하려는 동기와 지속적인 몰입 때문이다. 이 논문에서는 Cox 회귀 모델을 사용하여 에디팅에서의 셀프 루프(Self-loop)가 위키피디아 알찬글(Featured articles)로의 승급에 미치는 효과를 평가하였다. 2,978개의 위키피디아 알찬글에 대해서 글이 시작된 시점부터 2011년까지의 편집 내역을 수집하였다. 아티클 편집에서 자기가 수정한 후에 다른 사람이 수정하기 전에 다시 자기가 수정하는 셀프 루프를 사용자의 몰입에 대한 프록시로 사용하였으며, 셀프 루프의 수가 알찬글로의 승급에 긍정적인 영향을 미치는 것을 파악하였다. 추가적으로 자기 루프를 단기와 장기로 더 상세하여 구분하였고, 장기 셀프 루프가 단기 셀프 루프보다 더 긍정적인 영향을 미치는 것을 파악하였다.