• 한국환경보건학회지
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• 제23권4호
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• pp.57-66
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• 1997

Successful energy conservation and good indcfor air quality (IAQ) are highly dependent on ventilation system. Air filtration is a primary solution of indoor air control strategies in terms of reducing energy consumption and improving ihdoor air quality. A conventional system with bypass filter, as it is called variable-air-volume/bypass filtration system (VAV/BPFS), is a variation of the conventional variable air volume (VAV) systems, which is designed to eliminate indoor air pollutant and to save energy. Bypass filtration system equipped with a high-efficiency particulate filter and carbon absorbent provides additional cleaned air into indoor environments and maintain good IAQ for human health. The objectives of this research were to compare the relative total decay rate of indoor air pollutant concentrations, and to develop a mathematical model simulating the performance of VAV/BPFS. All experiments were performed in chamber under the controlled conditions. The specific conclusions of this research are: 1. The VAV/BPFS system is more efficient than the VAV system in removing indoor air pollutant concentration. The total decay rates of aerosol, and total volatile organic compound (TVOC) for the VAV/BPFS system were higher than those of the conventional VAV system. 2. IAQ model predictions of each pollutant agree closely with the measured values. 3. According to IAQ model evaluation, reduction of outdoor supply air results in decreased dilution removal rate and on increased bypass filtration removal rate with the VAV/BPFS. As a results, we recommends the VAV/BPFS as an alternative to conventional VAV systems.

• 한국자동차공학회논문집
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• 제3권5호
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• pp.122-134
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• 1995

The present study was investigated combustion characteristics of methane-air mixtures at stratified charge in a constant volume combustion chamber. The main results obtained from this study can be summarized as follows. In case of ${\phi}_s=1.0$, total burning times greatly affected rather than initial time of pressure increase and maximum combustion pressure. In case of ${\phi}_t=1.0$, initial time of pressure increase and total burning times were affected considerably in comparison with the case of ${\phi}_s=1.0$. Also, even the very lean mixture which total equivalence ratio is ${\phi}_t=0.69$(${\phi}_s=1.0$, ${\phi}_m=0.65$), by changing configuration of the critical passage-hole and using a stratified mixture, it is possible to decrease substantially the initial time of pressure increase. total burning times and NOx concentration without deteriorating combustion characteristics such as maximum combustion pressure, rate of heat release etc. in comparison with the use of single chamber(in case of ${\phi}=1.0$) only. Specifically, our trends were revealed remarkably in the case of Type D which is reduced a flame contact area of sub-chamber side of the passage-hole.

• 대한방사선치료학회지
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• 제24권1호
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• pp.31-37
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• 2012

목 적: Total Scalp의 방사선 치료 시 표면선량(surface dose)을 증가시키기 위해 조직보상체(bolus)를 사용한다. 이에 본 저자는 두피(scalp) 전체를 덮는 조직보상체로서 Bolx-II, paraffin wax, solid thermoplastic물질을 각각 적용한 Helmet bolus를 제작하여 유용성을 비교 평가해보고자 한다. 대상 및 방법: Rando 팬톰을 이용하여 두피 고정용구(mask)를 만든 후 전체 두피에 Bolx-II (Action Products, USA), paraffin wax (Densply, USA), solid thermoplastic 물질(Med-Tec, USA)을 0.5 cm 두께로 동일하게 적용한 Helmet bolus를 각각 제작 하였다. 각 Helmet bolus에 대한 물리적 특성을 평가하기 위해 전산화 단층촬영(computed tomography) (GE, Ultra Light Speed16)을 시행 후 방사선치료계획시스템(radiation therapy planning system) (Philips, Pinnacle)을 이용하여 최적의 치료 계획(radiationtherapy plan)을 세웠으며, 각 조직 보상체(bolus)에 대한 밀도 변화(density variation)화를 분석하였다. 선량 분포(dose distribution)평가(evaluation)를 위해 선량체적히스토그램(Dose-Volume Histogram) (DVH)을 이용해 임상표적체적(Clinical Target Volume) (CTV)에 대한 Dose-homogeneity index (DHI, $D_{90}/D_{10}$), Conformity index (CI, $V_{95}/TV$)를, 정상 뇌 조직(Normal brain tissue)에 있어$V_{20}$, $V_{30}$을 각각 구하여 비교 하였다. 또한 총 제작시간을 측정하여 제작과정에서의 효율성을 평가하였고, 열형광선량계 (Thermoluminescent Dosimeter)를 사용하여 실제 치료 시 각 두피의 표면선량을 확인 하였다. 결 과: Bolx-II, paraffin wax, solid thermoplastic 물질에 대한 밀도측정(density measurement) 결과 $0.952{\pm}0.13g/cm^3$, $0.842{\pm}0.17g/cm^3$, $0.908{\pm}0.24g/cm^3$로 Bolx-II의 밀도변화(density variation)가 가장 작았다. Bolx-II, paraffin wax, solid thermoplastic 물질을 적용한 각 Helmet bolus DHI는 0.89, 0.85, 0.77, CI는 0.86, 0.78, 0.74로 Bolx-II가 가장 우수 하였으며, 정상조직에 있어 뇌(braintissue)의 $V_{20}$은 11.50%, 10.80%, 10.07%, $V_{30}$은 7.62%, 7.40%, 7.31%로 나타났다. 제작 시 총 소요 시간은 30분, 120분, 90분 이였으며, Bolx-II를 적용한 Helmet bolus 제작과정이 가장 간단하였다. 열형광선량계(Thermoluminescent Dosimeter) 측정 결과세 Helmet bolus 모두 ${\pm}7%$ 이내의 선량오차를 보였다. 결 론: Total Scalp의 방사선치료 시 Bolx-II를 사용한 Helmet bolus의 적용은 CTV (Clinical Target Volume)에 대한 Homogeneity와 Conformity를 높여 줄 뿐만 아니라 제작시간 및 제작방법이 간단하여 임상 적용 시 유용하리라 생각된다.

• Archives of Plastic Surgery
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• 제45권4호
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• pp.333-339
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• 2018

Background Flap volume is an important factor for obtaining satisfactory symmetry in breast reconstruction with a transverse rectus abdominis myocutaneous (TRAM) free flap. We aimed to develop an easy and simple method to estimate flap volume. Methods We performed a preoperative estimation of the TRAM flap volume in five patients with breast cancer who underwent 2-stage breast reconstruction following an immediate tissue expander operation after a simple mastectomy. We measured the height and width of each flap zone using a ruler and measured the tissue thickness by ultrasound. The volume of each zone, approximated as a triangular or square prism, was then calculated. The zone volumes were summed to obtain the total calculated volume of the TRAM flap. We then determined the width of zone II, so that the calculated flap volume was equal to the required flap volume ($1.2{\times}1.05{\times}$the weight of the resected mastectomy tissue). The TRAM flap was transferred vertically so that zone III was located on the upper side, and zone II was trimmed in the sitting position after vascular anastomosis. We compared the estimated flap width of zone II (=X) with the actual flap width of zone II. Results X was similar to the actual measured width. Accurate volume replacement with the TRAM flap resulted in good symmetry in all cases. Conclusions The volume of a free TRAM flap can be straightforwardly estimated preoperatively using the method presented here, with ultrasound, ruler, and simple calculations, and this technique may help reduced the time required for precise flap tailoring.

• 한국의류산업학회지
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• 제19권4호
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• pp.434-447
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• 2017

This study investigated the effects of influencing factors on the sales volume of apparel products. Based on previous studies, weekend effect, discount rate, and meteorological factors including daily average temperature, rainfall, sea level pressure, and fine dust were selected as independent variables to calculate their effects on sales quantity of apparel products. The daily sales data during 2015 - 2016 were collected from casual brands and outdoor brands which "A" apparel manufacturing company had operated. The actual data of "A" company were analyzed using SAS(R) 9.4 and SAS(R) Enterprise Miner 14.1. The results of this study were as follows: First, the influencing factors on total sales volume of apparel products were proved to be the weekend effect, discount rate, and fine dust. Second, the analysis of influencing factors on sales volume of apparel products according to season showed: 1) In casual brands, the average temperature had a significant influence on the sales volume of spring/summer products, and the sea level pressure affected the sales volume of summer/fall/winter products significantly. 2) In outdoor brands, the average temperature and the fine dust had a significant influence on the sales volume of all season's products. The sea level pressure affected the sales volume of summer/fall/ winter products significantly. The weekend effect and the discount effect affected the sales volume of apparel products partly. Third, the effect of rainfall was not proven significant, which was different from the results of past studies.

• 한국방사선학회논문지
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• 제11권5호
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• pp.407-412
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• 2017

본 연구는 혈액 검사 결과인 전립선특이항원(PSA) 및 전립선특이항원밀도 (PSAD), 전립선 경직장 초음파 (TRUS)를 이용한 전립선 전체용적 (TPV), 나이등 변수와 전립선이행대용적 (PTZV)과 상관관계를 연구하여 임상적 지표로 활용하고자 한다. 2007년 6월부터 2016년 4월 까지 전립선에 대한 치료력이 없는 건강한 30대 성인 남성으로 TRUS와 PSA, PSAD 혈액 검사를 실시한 총 68명을 후향적으로 분석하였다. 초음파 장비는 Siemens Acuson sequoia 512)와 탐촉자 Siemens EC~10C5 Endocavitary를 이용하였다. 통계 처리의 경우, SPSS 18.0 각 변수와 표준 편차의 평균을 계산하는 데 사용하고, 피어슨 상관관계 분석을 수행 하였다. 변수들의 기술 통계량은 TPV; $24.27{\pm}6.60$, PTZV; $6.99{\pm}6.60$, PSA; $2.12{\pm}2.76$와 PSAD; $0.281{\pm}0.1$이고. 전립선 이행용적과 변수의 상관 계수는 PSAD; 0.831, TPV; 0.707, 나이; 0.398, 그리고 PSA; 0.118이었다. PSA 및 연령과의 양의 크기의 상관관계지만, PSAD, TPV가 높은 상관관계를 보였다. 따라서, 기저 질환이 없는 30대 남성의 PTZV는 TPV와 PSAD를 통해 예측할 수 있다.

• Structural Engineering and Mechanics
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• 제66권5호
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• pp.631-636
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• 2018

This study aims to investigate the flexural behaviour of glass fibre reinforced polymer (GFRP) laminated hybrid fibre reinforced concrete (HFRC) beams. The flexural and ductility performance of GFRP laminated HFRC beams having different proportions of polyolefin and steel fibres with 1.0% of total volume fraction were investigated. The parameters of this investigation included: load and deflection at first crack, yield, and ultimate stages, ductility and crack width. A total of seven beams of $150{\times}250mm$ in cross-section were tested in the laboratory over an effective span of 2800 mm. One reinforced concrete (RC) beam without any internal or external GFRP was taken as the reference beam. Of the remaining six beams, one beam was strengthened with GFRP, one beam with 100% steel fibres was strengthened with GFRP and four beams, each with different volume proportions of polyolefin and steel fibres (20:80, 30:70, 40:60, 50:50) were strengthened with GFRP. All the above beams were tested until failure. The experimental results show that a fibre volume proportion of 40:60 (polyolefin-steel) has significantly improved the overall performance of the tested beams.

• 생물정신의학
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• 제21권1호
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• pp.1-13
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• 2014

Normal aging causes changes in the brain volume, connection, function and cognition. The brain changes with increases in age and difference of gender varies at all levels. Studies about normal brain aging using various brain magnetic resonance imaging (MRI) variables such as gray and white matter structural imaging, proton spectroscopy, apparent diffusion coefficient, diffusion tensor imaging and functional MRI are reviewed. Total volume of brain increases after birth but decreases after 9 years old. During adulthood, total volume of brain is relatively stable. After 35 years old, brain shrinks gradually. The changes of gray and white matters by aging show different features. N-acetylaspartate decreases or remains unchanged but choline, creatine and myo-inositol increase with aging. Apparent diffusion coefficient decreases till 20 years old and then becomes stable during adulthood and increase after 60 years old. Diffusion tensor properties in white matter tissue are variable during aging. Resting-state functional connectivity decreases after middle age. Structural and functional brain changes with normal aging are important for studying various psychiatric diseases such as dementia, schizophrenia and bipolar disorder. Our review may be helpful for studying longitudinal changes of these diseases and successful aging.

• 펄프종이기술
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• 제42권3호
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• pp.67-73
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• 2010

Pine (Pinus densiflora) and aspen (Populus euramericana) wood meals were treated with ozone at various time schedule in acidic condition. The lignin contents and surface area of the ozone treated wood meals were determined and the enzymatic hydrolysis rate of ozonated wood meals was evaluated. The feasibility of enzymatic hydrolysis of the ozone treated wood meal was obviously influenced with the degree of delignification. After ozone treatment of wood meal for 10min, total pore volume were slightly increased in the surface of wood meal. When wood meals were treated with ozone longer than 10min, few change in the pore volume was observed. However, the area of over $50{\AA}$ of pore size is increased with ozonation time. As a conclusion, the rate of enzymatic hydrolysis of wood is more effective with the pore size distribution than the total pore volume.

• 약학회지
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• 제53권2호
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• pp.45-50
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• 2009

The purpose of this study is to investigate the best way that health functional food contributes the diversification of pharmacy management at the new point after the separation of prescribing and dispensing practice. In the question of the number of prescription paper, it was more than 200 papers (18.9%), next 100 papers (11.3%). In case of daily total sales volume except prescription fee, it was more than 1,000,000won (28.3%). About the motivation using health functional food, the reason for activation of pharmacy management was 66%. The selling method was mainly by pharmacist recommendation and consumer's need. In comparison with after and before the separation of prescribing and dispensing, more than 60% of subjects answered that sales volume was decreased and no changed. Concerning the ratio of total sales volume to health functional food within 5 years, 66% of subjects expected that it will be increased positively. The type of best pharmacy to handle health functional food was community pharmacy. These results suggest that the handling of health functional food by pharmacist will greatly increase in near futures and will be very important portion for pharmacy management.