동물 플랑크톤섭식에 의한 인공 연못의 조류 제거

김의식,손광수,지해성,명남진,백운화 ( Eui Sik Kim,Kwang Soo Son,Hae Sung Jee,Nam Jin Myung,Un Hua Pek ) 한국하천호수학회 1996 생태와 환경 Vol.29 No.1

This study was proposed to control algal biomass in order to improve transparency of an artificial pond, using the manipulation of a pond ecosystem. Zooplanktons isolated from natural populations were tested for their algal clearance rate. The size of two ponds were 1,500 and 2,000 m^3, respectively. Average depth of two ponds was shallow around 1 m. Fish were completely excluded from Pond-A instead of introducing zooplanktons, and Pond-B was added fish with the same condition of Pond-A. Turbidity of Pond-A was less than 10 FTU and transparency was about 1 meter depth during the experimental periods(May-Aug., 1995). In contrast, Chl-a and turbidity of Pond-B were 40 FTU and 55㎍·1^-1 and transparency was mostly less than 20 cm during summer season.

우유가공 폐수 처리장 활성슬러지에서의 거품 발생 및 제어

조정섭(Jeong Sub Cho),지해성(Hae Sung Jee) 大韓環境工學會 1998 대한환경공학회지 Vol.20 No.7

CO₂ 용접에서 용접변수의 변화에 따른 용접흄 제어방법에 관한 연구

오광중,김현수,손병현,지해성,Oh, Kwang-Joong,Kim, Hyun-Soo,Shon, Byung-Hyun,Jee, Hae-Sung 한국산업보건학회 1998 한국산업보건학회지 Vol.8 No.1

The concentration of welding fume was measured by 221 welders themselves in chassis frame workplace of the manufactory from February, 1, 1996 to May, 31, 1997. Welding parameters were the welding current and the distance between helmet and arc. Those two optimum conditions were proposed by excess probability analysis using logistic regression, so the best position in the workplace was proposed considering two factors to control the welding fume. The results are as followings; 1) The excess proability of welding fume TLV was over 99% in above 260 Amperes of welding current and also in below 30cm of distanced between helmet and arc. 2) The equation from logistic regression analysis using SPSS/PC+5.02 had the welding current as a independent variable and the excess of welding fume TLV as a dependent variable (p<0.05). Logit(welding fume TLV) = 0.1296 ${\times}$ wlding currnet - 28.8750 3) The equation from logistic regression analysis using SPSS/PC+5.02 had the distance between helmet and arc as a independent variable and the excess of welding fume threshold limit value a, a dependent variable (p<0.05). Logit (welding fume TLV) = -0.6809 ${\times}$ distance between helmet and arc +25.1665 4) Considering both cases or 2) and 3). the result equation is following. (p<0.05). Logit (welding fume TLV) = 0.1346 ${\times}$ welding current -0.3859 ${\times}$ distance between helmet and arc -15.7382 5) The excess probability of welding fume threshold limit value was 100% in above 240 Ampere of welding current. Thus, below 220 Ampere can be suggested to reduce the 40% number of welders who have a excess welding fume threshold limit value. 6) The excess probability of welding fume TLV was 100% in below 34cm of distance between helmet and arc. Thus, over 38cm can be suggested to reduce the 33% number of welders who have a excess welding fume TLV. 7) Considering both 5) and 6) cases, first of all, the best welding current can be 200 Ampere to have a below 15% of welding fume excess probability for the welders who works in distance of 34-37cm. Secondly, to have a below 30% excess probability of welding fume TLV, the working distance must be over 38cm in 220 Ampere and 32cm in 200 Ampere. 8) To reduce the average exposure concentration of welding fume ($8.21{\pm}5.83mg/m^3$), the movable local exhaust system equipped with flexible hoods can be used.

UASB 공법 적용에 의한 식품가공 폐수의 처리비용 절감

이익재(Ig Jae Lee),지해성(Hae Sung Jee) 大韓環境工學會 1999 대한환경공학회지 Vol.21 No.4

인공연못에서 동물플랑크톤을 이용한 조류 성장 억제 2차 년도 실험

김의식(Eui Sik Kim),지해성(Hae Sung Jee) 한국하천호수학회 1997 생태와 환경 Vol.31 No.1

N/A

분뇨처리시설의 질소·인 제거공정

조정섭(Jeong Sub Cho),지해성(Hae Sung Jee) 大韓環境工學會 1998 대한환경공학회지 Vol.20 No.8

제관공정의 불소폐수 처리공정 개선

고종호(Jong Ho Koh),지해성(Hae Sung Jee) 大韓環境工學會 1998 대한환경공학회지 Vol.20 No.9

기계.시스템 디자인 공학 교과과정 개발을 위한 설문조사 사례 연구

한병기,최성준,김병주,조성산,김정수,지해성,박승호,Han Byoung-Kee,Choi Sung-Joon,Kim Byung-Joo,Cho Sung-San,Kim Jung-Soo,Jee Hae-Seong,Park Seoung-Ho 한국공학교육학회 2004 공학교육연구 Vol.7 No.2

To keep pace with rapidly changing social and technological trends, the Department of Mechanical and System Design Engineering at Hongik University is in the process of updating teaching materials and learning methodologies while evaluating/revising our existing curriculum. In order to be better apprised of the employment needs and student aspirations, we have conducted three separate but related surveys by targeting experienced professionals and managers, alumni working in industries as practising engineers, and our current students. The surveys have furnished us with valuable insights that, we hope, will lead to a new curriculum and learning methods more in tune with needs of our students as well as their future employers. Among other findings, the analysis of the survey responses points towards expansion of integrated laboratory and design experiences, cultivation of improved written and oral communication capabilities involving individual and team efforts, and development of interdisciplinary courses encompassing related fields of engineering as well as emerging fields such as nano and information technologies. 최근 홍익대학교 기계 시스템디자인공학과에서는 급변하는 시대 조류에 부응하도록 교과목 체계를 검증하고, 신규 교과목, 교수-학습 방법 및 교과과정을 개발하며, 산업체에서 필요로 하는 기술 인력을 양성하기 위해 전문가, 졸업생 및 재학생을 대상으로 설문조사를 실시하였다. 본 연구에서는 이 설문조사에 근거하여 산업체 중역과 현장 실무자가 필요로 하는 인재를 양성하는 동시에 재학생들의 요구도 충족할 수 있는 신규 교과목과 교수-학습 방법을 개발하고 적합한 교과목 체계를 검증하고자 한다. 재학생, 졸업생 및 전문가를 대상으로 한 설문조사를 분석한 결과, 신규 교과목 및 교수-학습 방법은 다양한 실습 경험 기회를 제공하고 언어 소통 능력을 교육하며 첨단/연계분야에 적합한 학과목을 개설함으로써 산업체에서 요구하는 인재를 양성하고, 재학생에게는 동기를 부여할 수 있는 방향으로 개발되어야 할 것으로 나타났다.

폐기물 회수 농약병의 전기 화학적 잔류농약 처리

김학준,지해성,이주환 경남대학교 환경문제연구소 1998 환경연구 Vol.21 No.-

By electrochemical oxidation remaining pesticides treatment of recovered pesticide bottle wastes were oxidized and decomposed in a particle packed-bed electrode cell that it was increasing in an anodic reaction area by the proper packing materials. Air flotation oxidation treatment was used to compare organic oxidation by oxygen being generated at the anode with organic oxidation by electrolysis. Obtained the data from the results of batch style particle packed-bed electrode cell were applied to flow style and investigated necessary the some parameters to treat the remaining pesticides wastewater of recovered pesticide bottle wastes. At the removal COD of remaining pesticides wastewater of recovered pesticide bottle wastes PbO₂ was the best anode packing particle and optimum current condition was 3.33A/dm² at the batch style cell. When this condition was applied continuous flow style, the current was 0.69A/dm² at the 30 ml/min flow rate. Also incase of circulation COD was more decreased than not. Removal COD appeared a good tendency, when not only NaCl was added into the wastewater, but also wastewater was a high temperature. At performance comparison of reactor type rectangle type appeared a good tendency and special per-treatment of wastewater was unnecessary. Degradation of TOC was about 70% and COD was obtained about 92% after 85min, when this experiment were carried out electrolysis condition of 0.69A/dm², current density, and 30ml/min, flow rate.

CO2 용접에서 용접변수의 변화에 따른 용접흄 제어방법에 관한 연구

김현수,오광중,손병현,지해성 한국산업위생학회 1998 한국산업보건학회지 Vol.8 No.1

The concentration of welding fume was measured by 221 welders themselves in chassis frame workplace of the manufactory from February, 1, 1996 to May, 31, 1997. Welding parameters were the welding current and the distance between helmet and arc. Those two optimum conditions were proposed by excess probability analysis using logistic regression, so the best position in the workplace was proposed considering two factors to control the welding fume. The results are as followings; 1) The excess probability of welding fume TLV was over 99% in above 260 Amperes of welding current and also in below 30㎝ of distanced between helmet and arc. 2) The equation from logistic regression analysis using SPSS/PC+5.02 had the welding current as a independent variable and the excess of welding fume TLV as a dependent variable (p$lt;0.05). Logit(welding fume TLV) = 0.1296 × welding current - 28.8750. 3) The equation from logistic regression analysis using SPSS/PC+5.02 had the distance between helmet and arc as a independent variable and the excess of welding fume threshold limit value as a dependent variable (p$lt;0.05). Logit (welding fume TLV) = -0.6809 × distance between helmet and arc+25.1665. 4) Considering both cases of 2) and 3), the result equation is following. (p$lt;0.05). Logit (welding fume TLV) = 0.1346 × welding current -0.3859 × distance between helmet and arc-15.7382. 5) The excess probability of welding fume threshold limit value was 100% in above 240 Ampere of welding current. Thus, below 220 Ampere can be suggested to reduce the 40% number of welders who have a excess welding fume threshold limit value. 6) The excess probability of welding fume TLV was l00% in below 34㎝ of distance between helmet and arc. Thus, over 38㎝ can be suggested to reduce the 33% number of welders who have a excess welding fume TLV. 7) Considering both 5) and 6) cases, first of all, the best welding current can be 200 Ampere to have a below l5% of welding fume excess probability for the welders who works in distance of 34-37㎝. Secondly, to have a below 30% excess probability of welding fume TLV, the working distance must be over 38㎝ in 220 Ampere and 32㎝ in 200 Ampere. 8) To reduce the average exposure concentration of welding fume (8.21±5.83㎎/㎥), the movable local exhaust system equipped with flexible hoods can be used.