본 연구는 도로터널, 철도터널, 지하철, 전력구 등 각종 터널 시공을 위한 TBM(Tunnel Boring Machine) 기술의 시공성 향상을 위한 연속굴착형 TBM 장비와 나선형 세그먼트 통합 시공기술 개발 및 실증과 관련된 것으로 핵심모듈인 추진잭, 세그먼트 이렉터의 선제적인 유지관리를 통해 다운타임 을 최소화하고 굴진율을 안정적으로 확보하기 위한 연속굴착형 TBM 핵심모듈의 유지관리 및 장애대 응 기술에 대한 연구를 수행하였으며, 굴착환경과 연속굴착 운영특성을 고려한 시공 및 장비 운용 절 차를 정의하였다.

In this study, a model to optimize residual chlorine concentrations in a water supply system was developed using a multi-objective genetic algorithm. Moreover, to quantify the effects of optimized residual chlorine concentration management and to consider customer service requirements, this study developed indices to quantify the spatial and temporal distributions of residual chlorine concentration. Based on the results, the most economical operational method to manage booster chlorination was derived, which would supply water that satisfies the service level required by consumers, as well as the cost-effectiveness and operation requirements relevant to the service providers. A simulation model was then created based on an actual water supply system (i.e., the Multi-regional Water Supply W in Korea). Simulated optimizations were successful, evidencing that it is possible to meet the residual chlorine concentration demanded by consumers at a low cost.

There are several methods of peak-shaving, which reduces grid power demand, electricity bought from electricity utility, through lowering “demand spike” during On-Peak period. An optimization method using linear programming is proposed, which can be used to perform peak-shaving of grid power demand for grid-connected PV+ system. Proposed peak shaving method is based on the forecast data for electricity load and photovoltaic power generation. Results from proposed method are compared with those from On-Off and Real Time methods which do not need forecast data. The results also compared to those from ideal case, an optimization method which use measured data for forecast data, that is, error-free forecast data. To see the effects of forecast error 36 error scenarios are developed, which consider error types of forecast, nMAE (normalizes Mean Absolute Error) for photovoltaic power forecast and MAPE (Mean Absolute Percentage Error) for load demand forecast. And the effects of forecast error are investigated including critical error scenarios which provide worse results compared to those of other scenarios. It is shown that proposed peak shaving method are much better than On-Off and Real Time methods under almost all the scenario of forecast error. And it is also shown that the results from our method are not so bad compared to the ideal case using error-free forecast.

The concept of carsharing involves sharing a small number of reserved cars to be used individually by a larger number of people as required. This study examines the operating parameters of one-way carsharing systems in order to determine the appropriate operating conditions that minimizes the lost sales rate. Five operating parameters are tested in this study: the number of stations, the average number of vehicles per station, the rate of one-way trip, the average number of staffs per station, and the relocation policy. The performance of round-trip carsharing systems is also compared to that of one-way carsharing systems. A simulation model is developed and simulations are performed to determine the appropriate combination of operating parameter and levels. The simulation results show that the average number of vehicles per station is the most critical parameter. Other key findings obtained from this research are as follows. First, applying the appropriate relocation policy to one-way carsharing systems can allow more customers to rent vehicles than the traditional round-trip carsharing systems. Second, the appropriate relocation policy should be selected based on the average number of vehicles per station in order to minimize the lost sales rate. Third, the number of stations does not affect the lost sales rate. This study findings will provide tools to understand impact of the carsharing system parameters on the efficiency of the carsharing operations.

Water supply/intake pumps operation use 70~80% of power costs in water treatment plants. In the water treatment plant, seasonal and hourly differential electricity rates are applied, so proper pump scheduling can yield power cost savings. Accordingly, the purpose of this study was to develop an optimal water supply pump scheduling scheme. An optimal operation method of water supply pumps by using genetic algorithm was developed. Also, a method to minimize power cost for water supply pump operation based on pump performance derived from the thermodynamic pump efficiency measurement method was proposed. Water level constraints to provide sufficient disinfection performance in a clearwell and reservoirs were calibrated. In addition, continuous operation time constraints were calibrated to prevent frequent pump switching. As a result of optimization, savings ratios during 7 days in winter and summer were 4.5% and 5.1%, respectively. In this study, the method for optimal water pump operation was developed to secure disinfection performance in the clearwell and to save power cost. It is expected that it will be used as a more advanced optimal water pump operation method through further studies such as water demand forecasting and efficiency according to pump combination.

Recently, interest in the development of alternative water resources has been increasing rapidly due to environmental pollution and depletion of water resources. In particular, seawater desalination has been attracting the most attention as alternative water resources. As seawater desalination consumes a large amount of energy due to high operating pressure, many researches have been conducted to improve energy efficiency such as energy recovery device (ERD). Consequently, this study aims to compare the energy efficiency of RO process according to ERD of isobaric type which is applied in scientific control pilot plant process of each 100 m3/day scale based on actual RO product water. As a result, it was confirmed that efficiency, mixing rate, and permeate conductivity were different depending on the size of the apparatus even though the same principle of the ERD was applied. It is believed that this is caused by the difference in cross-sectional area of the contacted portion for pressure transfer inside the ERD. Therefore, further study is needed to confirm the optimum conditions what is applicable to the actual process considering the correlation with other factors as well as the factors obtained from the previous experiments.

재래식 해수담수화 수평적 압력용기 설계는 후단에 있는 역삼투막에는 농축수에 의해 수질악화 및 생산수저감 등이 동반된다. 이를 해결하기 위해 본 연구에서는 개념적인 중앙 주입식 압력용기가 생산수 단가에 미치는 영향과 역삼투 공정 설계 시 주요 인자들이 성능에 미치는 영향을 조사를 위해 상업화된 역삼 투 프로그램인 ROSA를 이용하여 분석하였다. 그 결과 중앙 주입식 압력용기를 이용할 경우 총괄적인 회수율과 SEC 측면에서 성능이 저하하지만, 막 모듈 당 생산되는 생산수량이 증가하는 것으로 나타났다. 또한 생산수의 수질개선은 2단 설계의 용량 감소로 인하여 건설비 저감으로 연계되는 것으로 조사되었다. 본 연구는 국토교통부 플랜트연구사업의 연구비지원(과제번호 16IFIP-B089908-03)에 의해 수행되었습니다.

Recently, the Ministry of Labour, published clause 2 of Article 41 (Risk Assessment) of the Act "Industrial Safety and Health" dated 12 June 2013 in connection with continuous increase of accidents at construction sites in order to prevent accidents in industrial safety and health in new construction in accordance with the risk assessment on construction projects are realized after March 13, 2014. In this paper, positive method of calculating risk discussed by performing research the awareness of general contractors and sub-contractors with presenting risky situation is considered. The purpose will be a positive method of calculating risk and would be a sufficient basе and give a positive direction in the development of new systems currently working in the construction and risk assessment which consider the characteristics of sufficient risk assessment system for future research.

본 연구에서는 막여과공정, 오존접촉공정, 활성탄흡착공정, 자외선소독공정 등이 계층형으로 배치된 정수처리 실증시설의 설계 및 운영을 통해 수직형 정수 처리시설의 최적 설계/운영방안을 도출하고자 하였다.

본 연구는 국내 최초로 도입된 Y 정수장의 세라믹막 고도정수처리를 위한 최적 운영 인자를 도출하기 위하여 수행되었다. 경제성과 수질조건을 만족하면서도 세라믹막 여과성능을 지속⋅유지할 수 있는 최적 운영조건을 도출한 결과, Y 정수장의 평상시 수질 조건에서 막역세척으로 인한 배출수 발생량을 최소화시키면서도 막여과성능을 유지할 수 있는 최적 여과지속시간(역세척 주기)은 시설용량(16,000 m3/일) 기준 시 4.0시간으로 조사되었다. 또한 화학세척(CIP)에 따른 막차압 회복력을 조사한 결과, 구연산을 이용한 산세정을 통하여 철, 망간, 알루미늄 등의 막 파울링을 일으키는 무기오염물질은 제거되지만 막 회복률은 낮았다. 반면 차아염소산나트륨을 사용한 알칼리 세정을 통해서는 막 운영 초기 막차압으로 회복되는 것으로 나타났다. 막차압을 발생시키는 파울링 주요 원인물질은 친수성 고분자 유기오염물인 polysaccharides로 조사되었으며, 화학세척(CIP)시 막성능 회복률은 세척약품 온도에 의한 영향이 매우 크며, 온도가 높은수록 막성능 회복률이 향상되는 것으로 조사되었다.

The purposes of this study were to identify the relative importance attributes, deduct the ideal combination of total utility and establish the marketing strategies for quality improvement of foodservice at funeral halls of medical centers. Data were collected using self-administered questionnaires from 102 funeral foodservice employees and 71 chief mourners or the bereaved. According to the results from a conjoint analysis, among foodservice employees at funeral hall, the relatively important attributes were 'taste (52.84%)', 'menu variety (24.419%)' and 'price (22.741%)'; among chief mourners or the bereaved, they were 'taste (50.004%)', 'price (31.388%)' and 'menu variety (18.008%)'. The ideal combination of total utility was different between funeral foodservice employees and chief mourners or the bereaved; it was higher among chief mourners or the bereaved (1.211) compared to funeral foodservice employees (1.169). Thus, there should an endeavor to improve the foodservice quality in funeral halls of medical centers through better taste, low price and similar menu variety.

PURPOSES : The purpose of this study is to propose delay-minimizing operation methodology of a signalized intersection based upon optimization of lane-uses on approaching lanes for an intersection. METHODS: For the optimization model of lane-uses, a set of constraints are set up to ensure feasibility and safety of the lane-uses, traffic flow, and signal settings. Minimization of demand to saturation flow ratio of a dual-ring signal control system is introduced to the objective function for delay minimization and effective signal operation. Using the optimized lane-uses, signal timings are optimized by delay-based model of TRANSYT-7F. RESULTS : It was found that the proposed objective function is great relation with delay time for an intersection. From the experimental results, the method was approved to be effective in reducing delay time. Especially, cases for two left-turn lanes reduced greater delays than those for a left turn lane. It is noticed that the cases for different traffic volume by approach reduced greater delays than those for the same traffic volume by approach. CONCLUSIONS : It was concluded that the objective function is proper for lane-uses optimizing model and the operation method is effective in reducing delay time for signalized intersections.

District heating is a system of distributing heated water from centralized facilities to local homes and buildings. In this paper, we model the distribution planning problem as a supply chain planning problem and propose an explicit column generation algorithm to handle large scale data as well as nonlinear constraints. The algorithm has been successfully applied to a Korean district heating company and the computational experiments show that the integrated operation of district heating network improves the total profit compared to the previous isolated network operation.