Complaints about foul odors are emerging as an issue, and the number of complaints is steadily increasing every year. Biofiltration is known to remove harmful or odorous substances from the atmosphere by using microorganisms, and full-scale biofilters are being installed and operated in various environmental and industrial facilities. In this study, the current status and actual odor removal efficiency of full-scale biofilters installed in publicly owned treatment facilities such as sewage, manure, and livestock manure treatment plants were investigated. In addition, the effects of design and operating factors on their efficiency were also examined. As a result, it was found that odor prevention facilities with less than 30% odor removal efficiency based on complex odors accounted for 40%-50% of the biofilters investigated. In investigating the appropriate level of operating factors on odor removal efficiency, it was found that compliance with the recommended values p lays a significant role in improving odor removal efficiency. In the canonical correlation analysis for the on-site biofilter operation and design data, residence time and humidity were found to be the most critical factors. The on-site biofilter operation and design data were analyzed through canonical correlation analysis, and the residence time and humidity maintenance were found to be the most important factors in the design and operations of the biofilter. Based on these results, it is necessary to improve the odor removal efficiency of on-site biofilters by reviewing the effectiveness of the operation factors, improving devices, and adjusting operating methods.

Eutrophication and algal blooms can lead to increase of taste and odor compounds and health problems by cyanobacterial toxins. To cope with these eco-social issues, Ministry of Environment in Korea has been reinforcing the effluent standards of wastewater treatment facilities. As a result, various advanced phosphorus removal processes have been adopted in each wastewater treatment plant nation-widely. However, a lot of existing advanced wastewater treatment processes have been facing the problems of expensive cost in operation and excessive sludge production caused by high dosage of coagulant. In this study, the sedimentation and dissolved air flotation (SeDAF) process integrated with sedimentation and flotation has been developed for enhanced phosphorus removal in wastewater treatment facilities. Design and operating parameters of the SeDAF process with the capacity of 100 m3/d were determined, and a demonstration plant has been installed and operated at I wastewater treatment facility (located in Gyeonggi-do) for the verification of field applicability. Several empirical evaluations for the SeDAF process were performed at demonstration-plant scale, and the results showed clearly that T-P and turbidity values of treated water were to satisfy the highest effluent standards below 0.2 mg/L and 2.0 NTU stably for all of operation cases.

The computing environment has changed rapidly to enable large-scale finite element models to be analyzed at the PC or workstation level, such as multi-core CPU, optimal math kernel library implementing BLAS and LAPACK, and popularization of direct sparse solvers. In this paper, the design considerations on a parallel finite element code for shared memory based multi-core CPU system are proposed; (1) the use of optimized numerical libraries, (2) the use of latest direct sparse solvers, (3) parallelism using OpenMP for computing element stiffness matrices, and (4) assembly techniques using triplets, which is a type of sparse matrix storage. In addition, the parallelization effect is examined on the time-consuming works through a large scale finite element model.

In this study, to estimate the combination of earthquake magnitude (Mw) and distance (R) corresponding to the design spectrum defined in Korean Building Code (KBC) 2016, the response spectra predicted from the attenuation relationships with the variation of Mw (5.0~7.0) and R (10~30km) are compared with the design spectrum in KBC 2016. Four attenuation relationships, which were developed based on local site characteristics and seismological parameters in Southern Korea and Eastern North America (ENA), are used. As a result, the scenario ground motions represented by the combinations of Mw and R corresponding to the design spectrum for Seoul defined in KBC 2016 are estimated as (1) when R =10 km, Mw = 6.2~6.7; (2) when R = 15 km, Mw = 6.5~6.9; and (3) when R = 20 km, Mw = 6.7~7.1.

In this study, the results of the load carrying capacity evaluation were compared for old small bridges. From this study, it can be seen that there are bridges in the old bridges that exceed the design load and ensure the bridging performance higher than the rated load. The evaluation results will manage by data that confirms whether the safety of heavy weight vehicles is secured.

현재 저류시설과 같은 유출저감시설은 국내에 적용된 사례가 거의 없고, 구체적인 설치 기준 및 설계 방법에 대한 기준이 미비하며, 저감량을 정량화하는 것이 곤란한 문제점을 지니고 있다. 이에 따라 유출저감시설의 정량화 지표가 개발될 때까지 국내에서 보편화되어 있는 유역출구 저류시설인 저류지를 기본 저감시설의 형식으로 채택하고 추가적으로 침투형 저감시설을 최대한 적용하고 있는 실정이다. 이러한, 저류지의 설계는 저류용량 및 방류시설에 이르기까지 까다로운 절차를 거쳐 제원을 결정하고 있어 계획단계에서는 불필요한 인력 및 시간이 소모되기도 한다. 따라서 본 연구에서는 기존 FFC11-SimPOND 모형의 저류지 규모결정 과정과 방류암거의 간편설계절차를 일원화하여 계획단계에서 저류지 용량과 방류암거의 설계제원을 손쉽게 산출할 수 있도록 SimPOND-CO 모형을 구축하였다.

본 연구는 실측자료가 확보된 중규모 하천유역에서 최대 첨두유량을 발생시키는 설계강우의 시간분포모형을 밝혀내고, 결정된 시간분포모형을 바탕으로 하여 유역특성과 임계지속기간의 관계를 규명하는 것이다. 50-5,000의 44개 유역을 통하여 수문분석을 실시하였으며, SCS 유효우량 산정방법으로 결정된 유효우량을 사용하여 최대 첨두유량을 발생시키는 시간분포모형은 Huff의 4분위 시간분포모형으로 나타났다. 유역면적 50-600인 유역에서는 24시간 강우지속기간