• 한국건축시공학회지
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• 제15권6호
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• pp.653-660
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• 2015

Technologies for reducing construction duration are key factors in nuclear power plant construction projects, as a reduction in construction duration at the construction phase leads to a reduction in construction cost and an increase in profits through the early operation of the nuclear power plant. To analyze the constructability of the height of single-layer placement of formwork for the Reactor Containment Building (RCB) exterior wall through lateral pressure according to the height of concrete placement, the deformation criteria for formwork, and a new form design, 'MIDAS GEN (hereinafter referred to as MIDAS)' is used in this study. The cost and workload of formwork are derived according to the unit of height of the RCB exterior wall. Based on the result, it was found that the higher the RCB exterior wall, the higher the material cost, and the less the construction duration and the less the total number of formwork layers. Based on this result, it is believed that the material cost and the construction duration can be appropriately determined according to the formwork height.

• 정보처리학회논문지D
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• 제10D권6호
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• pp.917-926
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• 2003

데이터웨어하우스내에서 실체뷰의 개수가 많을수록 사용자의 질의요구를 실체뷰내에서 처리할 수 있는 확률이 높아지므로 신속한 응담이 가능하다. 그러나, 실체뷰가 많아지면 전체적인 실체뷰 갱신시간이 길어진다. 실체뷰 갱신작업 동안에는 데이터웨어하우스로의 접근이 통제되기 때문에 사용자의 질의요구를 처리할 수 없다. 따라서, 실체뷰의 갱신시간을 단축시킬 수 있는 알고리즘을 제안한다. 실험결과, 삽입/삭제 구분을 위한 오버헤드를 감안하더라도 제안한 알고리즘의 성능이 기존 기법에 비하여 우수함을 알 수 있었다.

• 한국전문물리치료학회지
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• 제20권2호
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• pp.11-19
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• 2013

Delayed onset muscle soreness (DOMS) is a painful condition that arises from exercise-induced muscle damage after unaccustomed physical activities. Various therapeutic interventions have been applied to reduce the intensity and duration of DOMS-related symptoms. Recently, pulsed electromagnetic field (PEMF) intervention has been introduced as an alternative noninvasive treatment for DOMS. This randomized, double-blind, placebo-controlled experiment was conducted to examine the effects of PEMF therapy on DOMS in elbow flexors at 24, 48, and 72 hours after the experimental DOMS induction. Thirty healthy volunteers ($23{\pm}2.4$ yrs, $175{\pm}5.7$ cm, and $74{\pm}7.8$ kg) participated in this study. Each was randomly assigned to a PEMF or placebo group. On the first day, DOMS was induced in the elbow flexors by repeated isokinetic motions at low ($60^{\circ}/s$) and fast ($120^{\circ}/s$) speeds in all subjects. Thereafter, the PEMF group received 15-min daily treatment with a PEMF device. The placebo group received sham treatment of the same duration. Overall, PEMF application was more effective than the sham treatment in reducing the physiological symptoms associated with the DOMS including perceived soreness, median frequency, and electromechanical delay of the surface electromyography. In addition, median frequency and isokinetic peak torque of the PEMF group recovered to the pre-DOMS induction level earlier than the placebo group. In conclusion, this study suggests that PEMF can be applied as a new recovery strategy in reducing DOMS symptoms. Further experiments are required to examine the effect of the PEMF treatment on different types of exercise conditions and to determine the optimal treatment dosage and duration in a real clinical setting.

• 한국산학기술학회논문지
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• 제19권1호
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• pp.587-595
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• 2018

세계에서는 지구온난화 등에 따른 기후 변화에 대응하여 원전 건설을 금지해오던 국가들도 점점 허용하는 추세이다. 따라서 앞으로의 원전 건설이 늘어날 것이며 이에 대한 경쟁 또한 심화될 것이다. 원전 프로젝트는 일반 건설 공사와 비교하여 공사 기간이 매우 길다. 원전 건설 프로젝트에서 경쟁 우위를 확보하기 위해 원전 공사 기간을 줄일 수 있는 기술을 개발하는 것이 필요하다. 따라서 본 연구의 목적은 원자로 건물 외벽 거푸집의 높이를 3m에서 4m로 증가시킴으로써 공사 기간을 감소시키기 위한 원자로 건물 외벽 거푸집을 개발하는 것이다. 개발된 거푸집을 원전 프로젝트에 적용하기 위해 구조적 안전성과 시공성 및 경제성을 분석하였다. 현장 적용 가능성을 평가한 결과 개발된 거푸집은 구조적으로 안전했다. 그리고 시공 단수가 감소함으로써 공사 기간이 단축되고 공사비 또한 절감되는 효과를 확인하였다. 본 연구의 결과는 향후 원자로 건물의 공사 기간 단축을 위한 지속적인 기술 개발을 위한 자료로 활용하여 한국의 세계 원전시장에서의 경쟁력 확보에 기여할 수 있을 것으로 사료된다.

• 원예과학기술지
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• 제18권3호
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• pp.327-333
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• 2000

Priming시 처리기간과 처리온도가 종자의 발아성에 미치는 효과를 구명하고자 하였다. 이때 사용한 약제는 당근은 -0.50MPa PEG 8000, 상추는 50mM $K_3PO_4$, 양파는200mM $KH_2PO_4$, 파는 100 mM $Ca(NO_3)_2$였으며, 작물별로 처리기간은 12시간에서 5일, 처리온도는 $10^{\circ}C$에서 $25^{\circ}C$까지로 달리하였다. 당근의 발아율은 종자처리와 처리온도에 따른 유의차가 있었으며, $20^{\circ}C$에서 3일 priming시 T50 및 MDG 단축에 효과적이었다. 그리고 $20^{\circ}C$에서 4일처리시 priming 용액속에 유근이 14% 돌출되었다. 상추의 발아율은 종자처리와 처리기간에 따라 유의차가 있었다. $20^{\circ}C$에서 2일 priming시 발아율이 높고 T50과 MDG 단축에 효과적이었으며 유근돌출은 발생하지 않았다. 양파의 발아율은 종자처리, 처리기간 및 처리온도 모두에서 유의차가 있었다. $10^{\circ}C$ 혹은 $15^{\circ}C$에서 3일, 4일 및 5일 처리시 발아율은 향상되지 않았으나 T50과 MDG 단축에는 효과적이었으나, priming 기간이 3일에서 5일로 길어질수록 발아율은 낮아졌다. 파의 발아율은 처리기간 및 처리온도에 따른 유의차가 없었지만, $15^{\circ}C$에서 4일 처리시 T50 및 MDG 단축에 효과적이었고 $15^{\circ}C$ 혹은 $20^{\circ}C$에서 처리기간이 길어질수록 유근돌출이 많이 발생되었다.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2007년도 정기학술발표대회 논문집
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• pp.368-372
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• 2007

최근 건설 회사들은 기능 인력의 부족현상과 고령화 현상, 그리고 선 시공 후 분양 제도의 도입 가능성 등에 대비하기 위하여 대형 시스템 거푸집의 사용을 선호하고 있다. 이러한 관심과 노력의 결과로 국내 초고층 건축의 경우는 층당 3-4일의 골조공기를 달성하고 있으나, 우리나라 건설사업의 90%이상을 차지하고 있는 공동주택, 그 중 대부분을 차지하고 있는 중층 RC조 아파트의 경우는 6-8일 정도의 층당골조공기를 형성하고 있다. 이는 북미 일반 RC조 주거건축 층당공기 대비 50%수준에 머물러 있는 실정이다. 이에 본 연구에서는 선행 연구를 통하여 도출된 공기단축의 가능성을 가진 요소기술들을 적용한 Mock-up Test를 통하여 현장적용가능성 및 개선방안을 검토하였다. 또한 기존 6day-Cycle의 단위생산성 및 T/C 가용율에 대하여 분석하고, 기존공정대비 공기단축형 공정모델의 단위생산성 및 T/C 가용율을 비교하였다.

• Journal of Preventive Medicine and Public Health
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• 제39권1호
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• pp.74-80
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• 2006

Objectives: The purpose of this study is to examine the factors affecting the rate and duration of breastfeeding. Methods: We analyzed the data from the year 2000 Korea National Fertility Survey that was collected through direct interviews. In particular, the mothers who delivered their last child and the child was under 1 year of age from January 1998 to June 2000 (N=1,066) were analyzed via a logistic model to assess the factors affecting the breastfeeding rate. Among the study subjects, those who had initiated breastfeeding (N=740) were analyzed through Cox's proportional hazard model to evaluate the factors affecting the duration of breastfeeding. Results: The multivariate logistic model showed that the delivery type and the baby's birth-weight have a statistically significant influence on the breastfeeding rate. Women who delivered their babies through Cesarean section were less likely than others to breastfeed. In contrast, the women whose babies weighed 2.5Kg or more were more likely than others to breastfeed. The results obtained from the survival analysis are as follows: the higher the mother's education level, the shorter is the breastfeeding duration. The mother's work status played a significant role in the early termination of breastfeeding. Women aged 35 or older showed a longer breastfeeding duration than the younger age groups, whereas the maternal age was not a significant factor in affecting whether or not a mother would breastfeed. Conclusions: Reducing the cases of operative delivery (Cesarean section) and low weight births, enlightening young and highly educated women on breastfeeding and improving the environment for breastfeeding on the job are important strategies to encourage women to breastfeed.

• Preventive Nutrition and Food Science
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• 제13권4호
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• pp.321-326
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• 2008

In order to improve the market competitiveness of the processed products of Undaria pinnatifida, various extraction conditions of Undaria pinnatifida were examined to determine the optimal conditions for the extraction of its valuable components. The highest level of alginic acid content was detected after 90 min of typical extraction or after 20 min of pressure extraction, after which the levels decreased slightly. The concentrations of reducing sugar and crude protein were also high after 90 min of typical extraction. Both alginic acid and reducing sugar were extracted in greater amounts using pressure extraction. The reducing sugar content was $2.8{\sim}3.2$ times higher using pressure extraction rather than typical extraction. Furthermore, the extraction results were superior with the, pressure extraction method. The appropriate temperature and duration of extraction were found to be $120^{\circ}C$ for 20 min. The use of a single enzyme yielded better results during extraction compared to the use of a mixture of enzymes. 20 min of pressure extraction followed by the addition of 0.1% pectinase and 2 hr of further extraction at $50^{\circ}C$ yielded high contents of alginic acid and reducing sugar from Undaria pinnatifida.

• 한국전문물리치료학회지
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• 제15권3호
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• pp.53-61
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• 2008

The purpose of this study was to examine the path analysis of factors related to musculoskeletal diseases of shipbuilding workers by considering related factors synthetically. The survey was completed by 1,536 shipbuilding workers and except for poor responses, 1,532 were analyzed. The survey consisted of questions about lifestyle, duration of service, physical and mental stress, and musculoskeletal diseases. The collected data was analyzed with SPSS/PC+ (a descriptive statistics program) and with AMOS 4.0 (a statistical program for path modeling) to test whether the hypothesized path model fitted the collected data. The results of the correlation analysis showed that musculoskeletal disease was associated with duration of service (r=-.095), physical stress (r=.077), and mental stress (r=.602). The results of the hypothesized path model satisfied the criteria required in relation to fitting the collected data. Musculoskeletal disease was directly affected by mental stress but not by physical stress, duration of service and life style. Thus, it is suggested that reducing mental stress is a strategy for the prevention for musculoskeletal disease.

• 대한한방소아과학회지
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• 제32권2호
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• pp.64-71
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• 2018

Objectives The purpose of this study is to examine the correlation of antibiotics administration duration and antimicrobial resistance by reviewing domestic and foreign literatures. Methods We searched literatures dated up to 23 February, 2018 in PubMed and Cochrane Library using terms of "Anti-Bacterial Agents", "Carrier State", "Nasopharynx", "Drug Administration Schedule", and also searched via RISS (Research Information Service System), KISS (Koreanstudies Information Service System), DBpia (DataBase Periodical Information Academic) using terms of antibiotics, resistance, and dose. Results In comparison with shortened and standard antibiotic course, longer treatment duration is associated with greater antimicrobial resistance or non-significant difference, but we cannot find literature that shortened antibiotic course increases antimicrobial resistance on human nasopharyngeal flora. Conclusions Currently, there is no evidence that completing the standard antibiotic course reduces antimicrobial resistance. It can be a strategy for reducing antibiotic use to apply Korean medicine treatment, as well as short-course antibiotic therapy or delayed antibiotic prescription. Additional well-designed trials should be conducted in domestic and foreign settings about the appropriate duration of antibiotic therapy.