The risk assessment carried out on the construction site at the beginning of the implementation depends on the subjective judgment of risk of general contractor and subcontractors, whose opinion about frequency and intensity of risk is different. In this paper, research the awareness of general contractors and subcontractors about process of risk assessment at the construction site and its effectiveness. Researching of the main factors "frequency", "intensity" which determines the degree of risk gives the opportunity to find an option for improving the effective implementation of risk assessment.

한국산 억새를 산, 알칼리 및 증기폭쇄법으로 전처리한 시료의 최적 효소당화조건을 탐색하고, 당화물을 이용한 에탄올 생산성을 구명하였다. 억새의 화학적 조성은 저분자화합물이 5.0%, lignin 17.0%, hemicellulose 55.1%, cellulose 22.7%이었다. 효소 당화율은 단용효소 처리구보다 혼용효소 처리구에서 높았다. Celluclast 처리구는 Viscozyme보다 높은 당화율을 보였으며, 가장 높은 당화율을 보인 효소 처리구는 EM-3(Celluclast 24.3FPU/g 기질+Viscozyme 80.6FBG/g 기질)로 약 70%의 당화율을 보였다. 산,알칼리 전처리를 통해 정제된 α-cellulose의 효소 당화율은 1% NaOH 처리 증기폭쇄재 보다 16% 높게 나타났다. 효소 cocktail의 당화에 가장 적합한 온도는 50℃였고, 모든 기질에서 효소 반응시간이 증가할수록 당화율이 증가하였다. 억새의 당화물은 오탄당으로 xylose가 육탄당으로 glucose가 주를 이루었다. S. cerevisiae KCCM 11215를 이용한 당화물의 에탄올 발효에서도 각 효소조합과 시료 전처리가 매우 중요한 것으로 나타났다. 억새시료 1kg 당 350g 이상의 에탄올 생산성을 보였으며, 1% NaOH 및 1% KOH를 처리한 증기폭쇄 시료보다 α-cellulose를 기질로 사용한 처리구에서 에탄올 생산성이 높았다.

This research carried out an analysis on input cost and leakage reduction effect by leakage reduction method, focusing on the project for establishing an optimal water pipe network management system in the Taebaek region, which has been executed annually since 2009. Based on the result, optimal cost-benefit analysis models for water distribution network rehabilitation project were developed using DEA(data envelopment analysis) and multiple regression analysis, which have been widely utilized for efficiency analysis in public and other projects. DEA and multiple regression analysis were carried out by applying 4 analytical methods involving different ratios and costs. The result showed that the models involving the analytical methods 2 and 4 were of low significance (which therefore were excluded), and only the models involving the analytical methods 1 and 3 were suitable. From the result it was judged that the leakage management method to be executed with the highest priority for the improvement of revenue water ratio was installation of pressure reduction valve, followed by replacement of water distribution pipe, replacement of water supply pipe, and then leakage detection and repair; and that the execution of leakage management methods in this order would be most economical. In addition, replacement of water meter was also shown to be necessary in case there were a large number of defective water meters.

순수 베타 핵종인 90Sr 분석은 화학적 거동이 유사한 알칼리 토금속(Ca, Ba, Ra)등 방해 원소를 제거할 분리 공정이 필요하다. 본 연구는 Sr을 추출/정제하기 위해 추출크로마토그래피법을 이용한 최적의 절차를 마련하는 것을 목적으로 한다. Sr resin 1.5 mL BV(Bed Volume)의 최대 Sr 흡착량은 6 mg이었다. 유량 1 mL min-1과 Ca 200 mg 이하에서는 Sr resin 1.5 mL(BV) 의 Sr 회수는 정량적이었으나, 유량을 5 mL min-1으로 중가 시키면 Sr 회수율이 감소하였다. 같은 양(BV)의 Sr resin을 사용 할 경우, 컬럼의 단면적이 작을수록 Sr resin의 분리능이 향상되었다.

Reverse electrodialysis (RED) is a promising technology for converting salinity gradient energy into electricity. RED stacks contain alternating anion and cation exchange membranes (AEMs and CEMs) that separate salt solutions of different concentrations. Selective transport of ions through the membranes creates an electric potential across pairs of AEMs and CEMs, and large numbers of cell pairs are used in a stack to increase the total potential and drive electric current through an external circuit. In this work, parameters of the ion exchange membrane is an ion exchange capacity, membrane resistance, ion selectivity, and the like thickness. Find out how these parameters affect the RED performance. The further proposed a model of the ion exchange membrane to improve the performance on the basis of these studies RED. (No. 10047796)

국내에서 생산되는 바이오가스는 경제적 가치를 창출하지 못하고 있어 활용 방안 확대를 위한 고효율의 바이오가스 정제 및 메탄 농축시스템 개발이 필요한 상황이다. 본 연구에서는 바이오매스 기반의 바이오가스를 도시가스로 공급하기 위한 최적의 정제 및 메탄 농축시스템 개발을 목적으로 하였다. 농축 공법으로는 멤브레인 공법이 최적의 결과를 도출하였고 다단 멤브레인 공법별 비교분석을 통하여 상황별 최적의 시스템을 개발하였다.

The expansion of the display market could mass-produce the product which becomes the super-slim and ultra-lighting according to the demand of customer. This change etched the mobile display panel in order to make the thin glass. The wet etching refers to the process of removing selectively the unnecessary part in order to form the circuit pattern among the semi-conductor or the LCD manufacturing process. The wet etching can progress the etching about a large amount at a time but the thickness of glass is not smooth or not etched according to the process condition. In this study, the defect factor in the etching process tries to be analyze. The experimental design was established and the processing condition was optimized in order to minimize under non-etch part generation by the experiment of design.

Response surface methodology (RSM) based on a Box-Behnken Design (BBD) was applied to optimize the thermal-alkaline pre-treatment operating conditions for anaerobic digestion of flotation scum in food waste leachate. Three independent variables such as thermal temperature, NaOH concentration and reaction time were evaluated. The maximum methane production of 369.2 mL CH4/g VS was estimated under the optimum conditions at 62.0°C, 10.1% NaOH and 35.4 min reaction time. A confirmation test of the predicted optimum conditions verified the validity of the BBD with RSM. The analysis of variance indicated that methane production was more sensitive to both NaOH concentration and thermal temperature than reaction time. Thermal-alkaline pretreatment enhanced the improvement of 40% in methane production compared to the control experiment due to the effective hydrolysis and/or solubilization of organic matters. The fractions with molecular weight cut-off of scum in food waste leachate were conducted before and after pre-treatment to estimate the behaviors of organic matters. The experiment results found that thermal-alkaline pre-treatment could reduce the organic matters more than 10kD with increase the organic matters less than 1kD.

본 연구에서는 파라매트릭 모델링 기법을 통해 다양한 대안을 고려할 수 있도록 개발된 StrAuto(이하 전산플랫폼)을 이용하여 감쇠장치에 따른 감쇠비 증가 효과와 풍하중 저감효과를 평가하였다. 비정형 초고층구조물의 수많은 구조시스템 대안선정을 지원하는 전산플랫폼은 설계자 또는 엔지니어에게 초기 대안을 결정하는데 있어 유용한 도구가 된다. 감쇠장치의 용량 및 추가 요구감쇠비의 크기를 산정하는 과정에서 중요한 원 구조물의 감쇠비에 대한 추정은 풍하중에 대한 실계측 자료를 기반으로 수행된 국내외 관련 연구의 결과를 사용하였다. 감쇠장치는 층간 설치형 수동형 감쇠장치와 질량형 능동형 감쇠장치 두 가지 유형을 고려하였다. 감쇠장치에 의해 추가되는 감쇠비는 FEMA에서 제안한 식을 이용하여 등가 정적 해석을 수행하여 산정하였다. 전산 플랫폼 내부에 감쇠장치의 용량을 최적화하는 알고리즘을 내장함으로써 최적의 감쇠장치 설계안을 자동적으로 도출할 수 있다. 감쇠장치 설치에 따른 물량저감 효과는 풍하중 저감계수로 평가될 수 있으며, 455m 높이의 초고층구조물을 대상으로 제안한 방법의 유효성을 검증하였다. 제안한 방법을 사용하여 비선형 시간이력 해석을 통해 얻어진 지붕층 변위와 층별 전단력을 근사적으로 추정할 수 있음을 확인하였다.

This study was performed to determine the total anthocyanin contents, DPPH radical scavenging activity, and SODlike activity of extracted anthocyanins from Bokbunja for analyzing the optimal conditions of enzyme treatment by response surface methodology (RSM) based on three factors: concentration of Pectinex Ultra SP-L, reaction temperature, and reaction time. The optimal enzyme treatment conditions of Pectinex Ultra SP-L concentration, reaction temperature, reaction time, and overall desirability by analysis of multiple response surface methodology with the same weighed value of each dependent variable were 0.5 mL/100 L, 20oC, 2 hr, and 0.63, respectively. Total anthocyanin content, DPPH radical scavenging activity, and SOD-like activity of the conditions stated above were 5.2 mg/ 100 g, 61.3% and 30.5%, respectively. Meanwhile, those of the control were 1.1 mg/100 g, 11.8% and 1.1%, respectively.method.

PURPOSES : Although signalized intersections have been considered the best way to control traffic volume in urban areas for several decades, roundabouts are currently being discussed as an alternative way to control traffic volume, especially when traffic is light. Because a roundabout’s efficiency depends on the load geometry as well as the traffic volume, design guidelines for roundabouts are recommended only if the incoming traffic volume is very low. It is rare to substitute a roundabout for an existing signalized intersection in urban areas. This study aims to estimate the benefits from the transformation of an existing signalized intersection into a roundabout in an urban area. When there is a more moderate volume of traffic, roundabouts can be effectively used by optimizing signals located at an approaching roadway. METHODS : The methodologies of this paper are as follows: First, a signalized intersection was analyzed to determine the traffic characteristics. Second, the signalized intersection was transformed into a roundabout using VISSIM microscopic traffic simulation. Then, we estimated and analyzed the effects and the performance of the roundabout. In addition, we adjusted a method to improve the benefits of the transformation via the optimization of signals located at an approaching road to control the incoming traffic volume. RESULTS : The results of this research are as follows: The signal-optimized roundabout improved delays compared with the signalized intersection during the morning peak hour, non-peak hour, and evening peak hour by 1.78%, 12.45%, and 12.72%, respectively. CONCLUSIONS : According to the simulation results of each scenarios, the signal-optimized roundabout had less delay time than the signalized intersection. If optimized signal control algorithms are installed in roundabouts in the future, this will lead to more efficient traffic management.

목 적: 기존의 콘택트렌즈 분석기에서 1매의 렌즈를 삭제하여 시스템을 간소화하고, 수차를 감소시켜 콘택트렌즈 표면의 선명한 상을 얻는 저가격 고성능의 광학계를 최적화 설계하였다. 방 법: 기존의 콘택트렌즈 분석기의 광학적 성능 분석과 최적화 설계에 사용한 파장은 프라운호퍼 C, d, F선(0.656 ㎛, 0.587 ㎛, 0.486 ㎛)이며 기준파장은 d선으로 하였다. Full field는 object height를 5 mm로 설정하였다. 참고모델의 광학적 성능 분석과 분석기의 최적화 설계에는 Zemax 14.2 설계 프로그램을 사용하였다. 결 과: 최적화 설계한 콘택트렌즈 분석기는 기존의 콘택트렌즈 분석기보다 Spot diagram RMS radius는 42.51% 성능이 향상되었다. 상질에 영향을 주는 구면수차는 96.96%, 비점수차는 68.39%, 종 방향 색수차는 39.29%, 횡 방향 색수차는 95.97% 향상되었고, 상면만곡과 왜곡수차는 각각 82.09%와 66.05%로 수차 성능이 향상되었다. 결 론: 기존의 콘택트렌즈 분석기보다 적은 수차와 적은 렌즈 매수를 갖는 새로운 광학계를 설계하였다. 설계한 콘택트렌즈 분석기는 저가격, 고성능의 성능 최적화가 이루어졌다고 볼 수 있다.

This study was performed to determine the optimal composition of muffins added with dropwort powder, egg and sugar. The experiment was designed based on BBD (Box-behnken design), and evaluation was carried out by means of RSM (response surface methodology), consisting of 13 experimental points with three replicates each for three independent variables dropwort powder, eggs and sugar. Using F-test, height, moisture, 1,1-diphenyl-2picriylhydrazyl (DPPH) radical scavenging activity, L-value, a-value, springiness, cohesiveness, chewiness, brittleness, color, and appearance acceptability were expressed as a linear model, whereas pH, b-value, flavor, taste, and texture were expressed as a quadratic model. After swallow and overall acceptability were expressed as a 2FI model. As dropwort powder content increased, 1,1-diphenyl-2picriylhydrazyl (DPPH) radical scavenging activity increased. Increasing amounts of dropwort powder led to reduction of sensory scores for color, appearance, flavor, taste, and texture quality. The optimum formulation determined by the numerical and graphical methods were similar: dropwort powder 6 g, egg 77 g, and sugar 60 g.

모바일 및 무선 정보통신 기술은 기존의 유선 기반의 정보통신 기술이 가지는 기술적, 지리적 제약을 극복할 수 있는 획기적인 대안으로 최근 주목받고 있지만, 지역에 따라 다양한 인구학적 특성과 지역 인프라의 편재적 분포는 여전히 무선 정보통신 서비스에 대한 차별적 접근성을 가져오고 있다. 이는 기존의 정보 인프라 시설 및 서비스에 대한 정보 격차를 넘어 새로운 모바일환경에서의 모바일 격차가 존재함을 함의하고 있다. 하지만 현재까지 공간적 측면에서 모바일 격차의 실태 측정과 모바일 격차해소를 위한 실제적인 대안들에 대한 연구가 매우 부족한 실정이다. 이러한 측면에서 본 연구는 모바일 격차 지수를 통해 우리나라의지역 간 모바일 격차를 실증적으로 파악하고, 모바일 격차를 완화시키기 위한 대안으로 공공 와이파이 AP의 최적 입지 솔루션들을제시하고 있다. 연구 결과, 기존의 유선 기반 정보 격차와 마찬가지로 모바일 격차에서도 도시와 농촌 간의 지역적 격차가 존재하고 있음을 확인할 수 있었으며, 공공 와이파이 AP의 최적 입지를 통한 모바일 인프라 환경의 개선이 지역 간 모바일 격차를 완화시키는데 효과적인 대안이 될 수 있음을 확인하였다. 본 연구에서 도출된 결과들은 향후 지역 정보통신 인프라 구축이나 계획에 있어 매우 유용한 가이드라인을 제공해 줄 수 있을 것으로 기대된다.

The objectives of this study were to evaluate the antimicrobial effects of ε-poly-L-lysine mixture (EPM) on cheon-ggukjang and to determine the optimal mixing ratio in cheonggukjang. Increasing the EPM up to 2% decreased via-ble cell counts at both 15oC and 30oC storage. The pH of cheonggukjang without EPM increased slowly over thestorage periods, but cheonggukjang with EPM showed a slight increasing tendency, with the highest pH at 2% EPM.The sensory scores, such as texture and flavor, were highest in samples containing 2% EPM; however, overall pref-erence was not significantly different when compared to the control. For the optimum cheonggukjang processingconditions, 13 experimental points were selected. Soybean and EPM were chosen as independent variables. Viablecell count, pH, texture, and overall preference were measured. The optimum formulation of cheonggukjang usingthe numerical analysis was found to be 98.52% soybean and 1.48% EPM, resulting in a 0.722 desirability value.

The purpose of this study was to determine the optimal mixing ratio of Gynura procumbens and milk in the preparation of beef patties. The experiment was designed according to the central composite design for estimating the response surface, demonstrating 10 experimental points including 2 replicates for Gynura procumbens and milk. The physical, mechanical and sensory properties of the test materials were measured, and a canonical form and perturbation plot were used to show the influence of each ingredient on the final product mixture. Results of the measurements showed significant increases or decreases in the following properties: dough moisture (p＜0.05); beef patty a (p＜0.001) and b (p＜0.001); hardness (p＜0.01), adhesiveness (p＜0.05), chewiness (p＜0.05), and gumminess (p＜0.05). In addition, the sensory measurements showed significant improvements in color (p＜0.001), flavor (p＜0.05), greasy (p＜0.05) and overall quality (p＜0.05). The optimum formulation calculated from the numerical and graphical analysis was 1.75 g Gynura procumbens and 20.44 g of milk.