표지인물과의 만남 - 민경석 (사)한국물환경학회 회장

민경석,Min, Gyeong-Seok 한국환경기술인연합회 2005 환경기술인 Vol.22 No.9

연구2 단 UASB 시스템의 운전특성

민경석,안영호 경북대학교 환경과학연구소 1995 環境科學硏究所論文集 Vol.9 No.1

Performance of two-in-series UASB system separated with hydrogen partial pressure phase was estimated. And behavior of each reactor and reaction product as well as characteristic of biopellets were investigated as a function of pH condition. From two-in-series UASB(high/low PHa) system, effective phase separation in hydrogen partial pressure was observed. In the first stage UASB reactor operated with high Pxz condition, a lot of soluble organic degradation and pelletization of biopellets with high activity were carried. And in the second stage UASB reactor operated with low PH2 condition. autolysis of biopellets as well as removal of reaction products as SCFAs were observed. Optimum pH conditions for the first and second UASB reactor were 7.0 each. Especially, in high PHZ reactor, it was observed pelletization process with high specific cell yields and extracellular polymer(ECP) excretions due to adequate growth environment.

국가수준 학업성취도 평가의 초등학교 표집방법 비교

민경석,박인용,김경희 한국교육과정평가원 2014 교육과정평가연구 Vol.17 No.2

이 논문에서는 국가수준 학업성취도 표집평가의 중요성과 기능 확대가 지속적으로 논의됨에 따라 기존 2단계 층화군집표집방법과 표집학교의 모든 학생을 표본으로 선정하는 ‘학교군집표집’방법, 기존 표집방법에 시 · 도별 최소 학교 수 조건을 추가한 ‘최소학교수표집’방법을 비교하였다. 구체적으로, 표본 대표성과 국가 및 시 · 도교육청 수준에서의 표본 통계치 정확성 측면에서 세 표집방법을 통계적으로 비교하였다. 연구결과로서, 표집 가중치를 적용한 경우, 세 표집방법 모두 모집단을 적절히 대표하는 표본분포를 산출하고 있었으며, 국가수준에서의 성취수준 비율과 척도점수 평균 추정치가 모집단의 모수치와 유사하였으며, 표집오차가 작아 표본 통계치의 정확성이 높았다. 반면 시 · 도교육청 수준의 성취수준 비율과 척도점수 평균 추정치는 대규모 시 · 도교육청에서는 세 표집방법 모두에서 정확성이 높게 나타난 반면, 소규모 시 · 도교육청에서는 ‘최소학교수표집’을 통한 표본 통계치의 정확성이 두 표집방법에 비해 상대적으로 높게 나타났다. This study evaluated three sampling methods on a representativeness perspective and compared accuracy of national and provincial sample statistics. Three sampling methods included 1) two-stage stratified cluster sampling method already adopted in NAEA, 2) school-cluster sampling method selecting all student in sampled schools, and 3) two-stage stratified cluster sampling with a minimum number of schools selecting one class per a sampled school under the condition of minimum number of schools in 16 provinces. The results showed that all sample distributions with sampling weights based on each sampling method sufficiently represented the population distribution. And all sampling methods also yielded accurate national sample statistics. However, the accuracy of provincial sample estimates depended on the size of a province (i.e. the number of sampled schools and students). That is, In large provinces, three sampling methods provided accurate sample statistics. whereas, in small provinces with small number of schools and students, the third method (two-stage stratified cluster sampling with a minimum number of schools) yielded more accurate estimates (i.e., less sampling errors) than those of other sampling methods.

회전매체를 이용한 완전혼합 활성슬러지공법에 관한 연구

민경석,김홍태 한국물환경학회 1993 한국물환경학회지 Vol.9 No.3

This study was carried out to obtain the basic design and operating parameters of Moving Media Complete Mixing Activated Sludge (MMCMAS) system for the wastewater treatment. A laboratory MMCMAS reactor was operated at the hydraulic loading of 17∼340ℓ/㎡/d, and the rpms of the moving media were varied with the operational hydraulic loading. Following conclusions from this study were drawn ; (1) The laboratory MMCMAS reactor demonstrated that SBOD removal efficiencies of more than 90% were achieved at the hydraulic retention time(HRT) of 1.5 hours that was relatively shorter HRT than conventional activated sludge process. The nitrification rates of MMCMAS reactor varied in the range of 6 to 90%, depending on the hydraulic loading rates. (2) The optimum rotational speed of moving media were 5∼15rpm and 25rpm at the hydraulic loading rates of 17∼122ℓ/㎡/d and 169∼340ℓ/㎡/d, respectively. The organic removal efficiencies were little affected by the variation of rpms of the moving media at the lower hydraulic loading rates, whereas the organic removal efficiencies were reduced at higher hydraulic loading rates. It is therefore concluded that the rpm of the moving media would be an important operating parameter at higher organic loading. (3) The attached biomass on the moving media varied in the range of 32 to 94% of total biomass in the system depending on the hydraulic loading rates. The ratio of attached biomass to total biomass was increased with the increment of hydraulic loading rate. In addition, it was noticed that the concentration of suspended biomass in the system was strongly correlated with the rpms of the moving media. The finding indicates that the shear forces due to the rotational speed of moving media govern the suspended biomass concentration in the system. The biofilm thickness on the moving media was increased with the increment of hydraulic loading rates. It was also found that the density of biofilm was consistently 50±10㎎/c㎥ at the various hydraulic loading rates as well as rpms of the moving media.

수도권 공장 허가와 상수원 보호

민경석,Min, Gyeong-Seok 한국환경기술인연합회 2007 환경기술인 Vol.24 No.2

전기침투식 Belt Press Filter 를 이용한 슬러지탈수에 대한 연구

민경석,김홍태,황상철,안영호,남광현,서광희 한국폐기물자원순환학회 1995 한국폐기물자원순환학회지 Vol.12 No.5

효과적인 설계VE 활동을 위한 기능분석 유형조사

민경석,Min Kyung-Seok 한국건설관리학회 2004 건설관리 : 한국건설관리학회 학회지 Vol.5 No.6

This study is an analysis the function Analysis Patterns for the effective application of VE(Value Engineering) and a presentation of the function analysis methods. 1. The function analysis of VE activities can be summarized 6 patterns as follows ; a generated ideas without function analysis process, a function analysis make use of inspection tools for generated idea, an illogical jump as a using of subjective terms, a using of duplication terms for same functions, a subjective ranking as function definitions for function analysis, and a large classification for a for approaching function definition. 2. In order for the effective function analysis, the process requires as follows; a check level by project advanced, a reclassified main nouns in the order of frequency of use, a main check objects by concepts of importance and satisfaction degree. It is not only good for the effective function analysis, it also induces effective turn out of the FAST Diagram for function arrangement. 설계VE 활동작업 중 대상의 기능을 철저하게 분석할 수 있는 기능분석 활동은 그 중요성에도 불구하고 수행자의 인식부족, 분석방법에 대한 어려움 및 설계VE 활동 시간적 제약 등의 이유로 활동 자체가 약화, 변형되거나, 생략되는 경우가 발생하고 있다. 이와 같이 기능분석이 변형된 VE활동은 아이디어 창출과정에 있어서 기능부분이 약화된채 아이디어의 결과를 창출함으로 신뢰성이 매우 떨어진다고 할 수 있다. 따라서 본 연구는 현재 시행되어진 설계VE작업중 기능분석활동 부분을 분석하여 이를 활동유형별로 분류, 그 특징을 파악한다. 이를 통해 기능분석 활동에 대한 올바른 이해를 확립하고, 기능분석 활동의 개선부분을 도출하여 올바른 설계VE 활동을 유도하고자 한다.

고효율 UASB 반응조를 이용한 유가공폐수의 처리

민경석,안영호,남광현 ( Kyung Sok Min,Young Ho Ahn,Kwang Hyun Nam ) 한국물환경학회 1997 한국물환경학회지 Vol.13 No.1

In application of enhanced UASB(EUASB) reactor using fat-free milky waste(carbohydrate:protein=60:40) as substrate, degradation of carbohydrate showed priority as compared with that of protein. In HRT 20hrs, maximum SCOD removal was 92% at organic loading rate of 8 ㎏COD/㎥/d. For SCOD removal of 80% over in HRT 10hrs, allowable organic loading rate was to 20㎏COD/㎥/d and then, methane production was 0.27 ℓ CH₄/gCOD-(rm). Enhanced UASB reactor showed phase separation in hydrogen partial pressure phase, but at the lower sludge bed zone, nitrogen utilization was different with that of l00% carbohydrate. It might be due to deamination stage of protein. At the upper sludge bed and blanket zone, it could be found autolysis of organisms except for substrate as well as deamination process. Morphological characterization with SEM showed that biopellets with milky waste was less uniform and packed loosely. These characteristics might be due to deficient condition of directly utilizable nitrogen for production of extracellular materials as well as utilization priority between carbohydrate and protein involved in substrate.

전국 대학생 학술발표대회 건설 아이디어 경진대회 소개

민경석,Min, Gyeong-Seok 한국건설관리학회 2011 건설관리 : 한국건설관리학회 학회지 Vol.12 No.1

VE 技法 活用에 관한 硏究

閔庚奭 淸州大學校 理工大學 工業經營學科 1984 工業 經營 論集 Vol.2 No.-