• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2010년도 춘계 학술논문 발표대회 1부
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• pp.167-170
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• 2010

In tall building construction, It is important to reduce construction duration of slab form work. Therefore, the purpose of this study is to assess the required performance for reduction of construction duration in slab form work of tall buildings. We surveyed the required performance and their degrees of importance and economical efficiency through the interview and questionnaire survey by related experts. This study proposes the guideline to develop improved formwork system for reduction of construction duration.

• International Journal of Industrial Entomology and Biomaterials
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• 제19권2호
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• pp.215-219
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• 2009

The effect of mating duration and multiple use of male on fecundity and fertility was investigated in the hybrids of Silkworm, Bombyx mori L. One hour to five hours of mating duration did not affect egg laying (fecundity) significantly, while fertilization affected significantly. Below 50% fertility was noticed when mating duration was reduced to below two hours. Similarly multiple use of male caused significant reduction in fertility but not fecundity. Till fourth mating no significant reduction in fertility was observed, thereafter fertility reduced considerably.

• 음성과학
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• 제14권4호
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• pp.81-98
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• 2007

This study aims to investigate whether shortened vowel duration conditioned by a following voiceless stop induces phonetic reduction of vowel space in English, and whether the reduction appears more in the height dimension than in the backness dimension (Lindblom, 1963; Flemming, 2005). Fifteen native speakers of American English read minimal pairs containing ten American English vowels in [bVd] and [bVt] syllables in a carrier phrase. All the subjects produced shorter vowels in the voiceless than in the voiced context. However, a reduction in vowel space and a raising of low vowels due to the shortened vowel duration were generally not found. To the contrary, the speakers tended to exhibit even more lowering of low vowels in the voiceless context, and vowel space was more commonly compressed in the backness dimension than in the height dimension. Many speakers, in particular, demonstrated fronting of the high back vowel [u] in the voiceless context. It was interpreted that due to a relatively large number of English vowels in the narrower low vowel space, the raising of low vowels may give rise to confusion in vowel contrasts, and therefore the degree of phonetic vowel reduction is restricted in that region. On the other hand, the high vowel region, being relatively spacious in English, allows a certain degree of phonetic vowel reduction in the F2 dimension. It is possible that heavy requirements for maintaining vowel contrasts may cause speakers to overachieve vowel target values, especially when faced with vowels which are difficult to distinguish due to shortened vowel duration, leading to an over-lowering of the low vowels.

• 한국건설관리학회논문집
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• 제7권1호
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• pp.138-147
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• 2006

최근에는 주 5일 근무제도, 공기단축형 입찰제도의 도입, 후분양제도의 도입 등의 제도적 변화로 건설공사의 성공적 수행에 중대한 영향을 미치는 공사기간에 대한 관심이 증대되고 있다. 또한 건설시장의 축소와 최저가 입찰제도하에서 건설수주 경쟁은 더욱 치열해짐에 따라 적정 공사기간의 산정과 예측은 매우 중요하다. 이러한 공사기간에 대한 중요성을 인지하고 공사기간을 비교 분석하거나 예측하고자 하는 연구들이 진행되었다. 국내에서 공사기간의 비교연구는 공동주택과 사무소 건축에 국한되었고 국외에서는 통계적 분석과 시뮬레이션을 통한 공사기간의 예측에 대한 연구가 많이 수행된 반면, 건물에 대한 수요의 변화로 발생된 주상복합건물과 오피스텔건물에 대한 공사기간의 실제 사례비교에 대한 연구는 거의 없다. 이에 본 연구는 국내 건설사들의 주상복합 및 오피스텔 건물의 실적공기와 가상사례를 활용하여 공사기간을 비교 분석한 후 공기 경쟁력 확보를 위한 공사단계 별 대응현황을 분석하는 것을 목적으로 한다.

• 한국농공학회논문집
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• 제60권5호
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• pp.17-27
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• 2018

The objective of this study is to identify the priority area where the nonpoint source pollution (NPS) management is required and to set up the load reduction goals for the identified priority area. In this study, the load duration curve (LDC) was first developed using the flow and water quality data observed at 286 monitoring stations. Based on the developed LDC, the priority area for the NPS pollution management was determined using a three-step method. The 24 watersheds were finally identified as the priority areas for the NPS pollution management. The water quality parameters of concern in the priority areas were the total phosphorus or chemical oxygen demand. The load reduction goals, which were calculated as the percent reduction from current loading levels needed to meet target water quality, ranged from 67.9% to 97.2% during high flows and from 40.3% to 69.5% during moist conditions, respectively. The results from this study will help to identify critical watersheds for NPS program planning purposes. In addition, the process used in this study can be effectively applied to identify the pollutant of concern as well as the load reduction target.

• Advances in pediatric surgery
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• 제3권2호
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• pp.126-132
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• 1997

Reduction of intussusception using air or oxygen has wide acceptance as an alternative to conventional hydrostatic reduction. This study was undertaken to evaluate the results and complications of air pressure enema in 948 pediatric intussusception. One hundred and twenty nine cases were operated on at the Department of Surgery, Masan Samsung Hospital from 1985 to 1996 because of air reduction failure. The success rate was 86.4 %. Twenty-one patients(2.2 %) showed perforation during air reduction. Risk prone factors of perforation were; age less than 3 months(42.9 % vs 11.1 %), duration of symptoms greater than 48 hours (66.7 % vs 33.3 %), and presence of pathologic leading point(28.6 % vs 3.7 %). Vomitting and spontaneous rectal bleeding revealed higher prediction to the complication. In nineteen cases, bowel infarction, coagulated necrosis and hemorrhage suggested that the cause of perforation was due to the preexisting strangulation. In conclusion, when doing an air pressure enema reduction, care must be taken if the patient is of a young age or the symptoms are of long duration.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제52권12호
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• pp.649-654
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• 2003

The simplest method for measuring output currents of the three phase inverters is to measure them with three current sensors such as hall sensors. This method requires at least two current sensors, and these types of sensors are somewhat expensive. More economical method is measuring DC link current with a simple shunt resistor, then, reconstructing output current using the DC link current value and the switching status. However, in low speed region, the measurement becomes difficult and even impossible due to the requirement of minimum switching duration for A/D conversion. These problems can be overcome by limitation of switching duration. Limitation of switching, however, causes voltage and current distortion. Owing to compensation, distortion can be effectively suppressed. However these increase acoustic noise due to increment of current ripple. In this paper, a current measurement method is proposed, which can reduce minimum switching duration resulting in reduction of acoustic noise. The validity of proposed method is confirmed through experiment.

• 셀메드
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• 제12권3호
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• pp.10.1-10.12
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• 2022

Objective: The objective of the study was to evaluate the effect of Sharbat Afsantin in Polycystic Ovarian Disease. Methods: An open observational study was carried out in the Department of Ilmul Qabalat wa Amraze Niswan. Diagnosed cases(n=30) of PCOD were included in the study. Patients with thyroid dysfunction, systemic diseases, on hormonal treatment in last three months, pregnancy and lactation were excluded. Research drug (Sharbat Afsantin) was administered orally in a dose of 25ml twice daily for 15 days/cycle for three consecutive cycles. Outcome measures were, changes in subjective parameters (duration of cycle, duration and amount of flow and weight reduction) and objective parameters {pictorial blood loss assessment chart (PBAC) score, basal metabolic index (BMI), modified Ferriman Gallwey (mFG) score, acanthosis nigricans scale and pelvic ultrasonography}. Data were analyzed using paired Student 't' test. Results: Changes in duration of cycle, duration and amount of flow were achieved in 83.3%, 50% and 40% patients respectively and weight reduction in 30% patients. Changes in PBAC score and BMI were achieved in 50% and 30% patients respectively and 30% patients showed normal findings on pelvic ultrasonography. Conclusion: Sharbat Afsantin can be used as an alternate remedy in PCOD patients, as it has significant effect to regularize menstruation by reduction in BMI and probably by improving insulin resistance in PCOD. No adverse effect of Sharbat Afsantin was noted during the trial.

• 한국습지학회지
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• 제22권1호
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• pp.1-7
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• 2020

비점오염은 수계에 악영향을 끼치며 그 영향은 점차 커지고 있다. 이러한 비점오염을 관리하기 위해 정부에서는 LID(Low Impact Development) 시설의 연구와 다양한 효율평가를 시행하고 있다. 본 연구에서는 다양한 LID 시설 중 실제 설치된 투수 블록 시설의 강우 유출 억제를 위한 유출 저감율, 저류 강우량 분석 및 유출 지연시간 그리고 최대 유입 및 유출의 저감율을 분석했으며, 그 결과를 각 시설 간 비교했다. 불투수블록, 필터형 투수블록, 틈새형 투수블록 순서대로 분석 결과 저감 효율이 높게 나타났으며, 이를 통해 강우강도-유출지연시간간의 관계를 나타낸 그래프를 제시하였다. 이 그래프를 통해 앞으로 설계 시, 본 시설과 유사한 투수블록 시설의 재현 기간에 따른 시설 용량 선정 등의 설계에 도움을 줄 수 있으리라 생각한다.

• 한국수소및신에너지학회논문집
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• 제21권5호
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• pp.355-363
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• 2010

High purity hydrogen, 97-99 vol.%, with CO at just ppm levels was obtained in a fixed bed of iron oxide employing the steam-iron cycle operation with reduction at 823K and oxidation in a steam-$N_2$ mixture at 773K TGA experiments indicated that temperature of the reduction step as well as its duration are important for preventing carbon build-up in iron and the intrusion of $CO_2$ into the hydrogen product. At a reduction temperature of 823K, oxide reduction by $H_2$ was considerably faster than reduction by CO. If the length of the reduction step exceeds optimal value, low levels of methane gas appeared in the off-gas. Furthermore, with longer durations of the reduction step and CO levels in the reducing gas greater than 10 vol.%, carbidization of the iron and/or carbon deposition in the bed exhibited the increasing pressure drop over the bed, eventually rendering the reactor inoperable. Reduction using a reducing gas containing 10 vol.% CO and a optimal reduction duration gave constant $H_2$ flow rates and off-gas composition over 10 redox reaction cycles.