A STUDY ON THE DESIGN OF CTBA CONSIDERING REDUCTION OF BRAKE MOAN NOISE

Chung, Seung Hyun,Kim, Gueng Su,Kim, Gwang Yun,Jeong, Jihoon,Yang, Moonho 한국소음진동공학회 2008 한국소음진동공학회 국제학술대회논문집 Vol.2008 No.7

춘천지역 노인 안 보건사업 운영연구 : 1997-1999년도 사업

이선자,정문호,김신자,이미자 서울大學校 保健大學院 2001 보건학논집 Vol.38 No.1

This study was conducted during the year of 1977-1999 at the three Myun of chunchoen Rural Area in Kangwon Province. The study subjects were the elderly aged 60 years and over in total 786: men were 286 (36.4%) women were 500 (63.6%). Eye health care services rendered 18 times during the study period. The family type were divided into : live alone 95 (14.3%), live with married partner 277 (41.6%), live with adult married child 232 (34.8%). Eye diseases detected : cataract were 402 (26.3%), refractive error were 254 (16.6%), pterygium 200 (13.1%), conjunctivitis 181 (11.9%), degenerative disease of retina 82 (5.4%) and other disease were 224 (14.7%), hyperopia were 88 (57.1%) hyperopia/astigmatism 27 (17.5%), myopia/astigmatism 15 (9.7%). The eye care treatment offered to the aged were; continuous follow up care 474 (37.8), drug treatment 386 (31.5%) glass185 (15.1%) operation 181 (14.8%).

브레이크 몬 노이즈 저감을 위한 CTBA 형상에 관한 연구

정승현(Seung Hyun Chung),김경수(Gueng Su Kim),김광윤(Gwang Yun Kim),정지훈(Jihoon Jeong),양문호(Moonho Yang) 한국자동차공학회 2010 한국자동차공학회 부문종합 학술대회 Vol.2010 No.5

Coupled Torsion Beam Axle (CTBA) type rear suspension is being widely used in automotive industry because of its low cost, however, this type of suspension is liable for moan noise frequently. In this paper, through the investigation on the moan improvement cases and experimental analysis including TPA and EMA, we propose a design modification of CTBA to prevent the outbreak of moan noise. The proposal was validated through the dynamic stiffness analysis of caliper attachment point numerically.

Temporal variation in the vertical distribution of microphytobenthos in intertidal flats of the Nakdong River estuary, Korea

Du, Guo Ying,Son, Moonho,An, Soonmo,Chung, Ik Kyo Elsevier 2010 Estuarine, coastal and shelf science Vol.86 No.1

<P><B>Abstract</B></P><P>The vertical distribution of microphytobenthos (MPB) was investigated in intertidal flats of the Nakdong River estuary over different temporal periods. The MPB biomass were measured as chlorophyll <I>a</I> concentration in the sediment, and monitored at two different depth scales. From August 2006 to August 2007, monthly sampling was carried out at four sites to a depth of 10cm. The vertical distribution exhibited an exponential decline with depth and the slope was closely related to sediment composition and MPB biomass in the surface sediment. The two slightly muddy sand (5–25% mud, <63μm) sites presented similar trends of seasonal variation to a sediment depth of 10cm, and no statistical difference was observed in their initial values and the slope of the exponential curves applied to each data set. The site with higher mud content also had higher surface biomass, and the fitted exponential curve had a larger slope than sites with more sand content. The seasonal variations of phaeo-pigments compared to chlorophyll <I>a</I> revealed higher grazing stress on the MPB in summer at the three slightly muddy sand sites, and low grazing stress all year around at the sand (<5% mud) site. In January, April and October 2007, and January 2008, diurnal sampling was conducted at hourly intervals at one slightly muddy sand site. The investigation in January 2007 which was conducted at 1cm intervals to a depth of 10cm sediment showed the migration mainly existed in the upper 1cm. The other diurnal sampling was undertaken to a 1cm depth at 0.5mm intervals. An evident migratory rhythm was present, with migration up to the surface during daytime emersion and down into deeper sediment during night and high tide submersion. Migrating cells could reach sediments as deep as 6 or even 10mm. When the visible thick biofilms formed, the migratory rhythm changed by keeping higher biomass at the surface even at night and during high tide submersion. Generally, the MPB surface biomass was an important factor in structuring the MPB vertical distribution. The vertical distribution to depths of 10cm was closely related to the sediment composition over the long term, while the MPB migration influenced the vertical distribution over the short term in the top 1cm of the sediment.</P>

계면활성제를 함유한 폐수의 효율적 처리 방법에 관한 연구

Shin, Myoung-Ok,Chung, Moonho 한국환경보건학회 1997 한국환경보건학회지 Vol.23 No.3

The purpose of this study is to evaluate the effectiveness of wastewater treatment containing surfactant. For that, comparative analysis of effectiveness of Featon Oxidation, Aluminum Sulfate, PAC (Poly Aluminum Chloride) on the treatment of the synthetic wastewater containing LAS (Linear Alkyl Sulfate), a main component of the commercial detergent was carried. Then, the optimum pH, the dosage of reagents, and the concentration of the LAS in each treatment were determined. The results of the study were summarized as following. 1. In Fenton Oxidation, optimal pH was 3 and 97.92% removal of LAS was achieved. However, the increase of the pH reduced the efficiency of LAS removal. The proper chemical dosages of FeSO$_4$ and $H_2O_2$ were 300 mg/l and the increase of dosages didn't affected the removal efficiency. Therefore, it was concluded that the economic chemical dosage was 300 mg/l of FeSO$_4$ and $H_2O_2$. 2. In case of Alum treatment, optimal pH was 11 with 61.13% removal efficiency. At other pH range, the removal efficiency was very low indicating that removal efficiency is greatly influenced by pH. The proper chemical dosage was 200 mg/l with the removal efficiency of 77.65%. The increase of chemical dosage, however, reduced the removal efficiency. 3. In case of using PAC, optimal pH was 6 with 97.99% removal efficiency. The result showed that wastewaters containing surfactant were almost completely removed at pH 6 by PAC. Removal efficiency was decreased by increasing PAC dosage higher than 400 mg/l and dosage over 700 mg/l of PAC abolished the treatment. 4. The comparative analysis of three methods revealed that the effective pH ranges were at pH 2-5 with Fenton oxidation, at pH 6-11 with PAC, and pH 11 with Alum. The removal efficiencies at these pH were 83.95-97.92%, 75.98-97.99% and 61.13%, respectively. 5. Increase in LAS concentration reduced the removal efficiencies of all three methods. In the case of PAC or Alum treatment, treatment abolished at LAS concentration higher than 700 mg/l.

계면활성제를 함유한 폐수의 효율적 처리 방법에 관한 연구

Shin,Myoung-Ok,Chung,Moonho 한국환경보건학회 1997 한국환경보건학회지 Vol.23 No.3

The purpose of this study is to evaluate the effectiveness of wastewater treatment containing surfactant. For that, comparative analysis of effectiveness of Featon Oxidation, Aluminum Sulfate, PAC (Poly Aluminum Chloride) on the treatment of the synthetic wastewater containing LAS (Linear Alkyl Sulfate), a main component of the commercial detergent was carried. Then, the optimum pH, the dosage of reagents, and the concentration of the LAS in each treatment were determined. The results of the study were summarized as following. 1. In Fenton Oxidation, optimal pH was 3 and 97.92% removal of LAS was achieved. However, the increase of the pH reduced the efficiency of LAS removal. The proper chemical dosages of FeSO$_4$ and $H_2O_2$ were 300 mg/l and the increase of dosages didn t affected the removal efficiency. Therefore, it was concluded that the economic chemical dosage was 300 mg/l of FeSO$_4$ and $H_2O_2$. 2. In case of Alum treatment, optimal pH was 11 with 61.13% removal efficiency. At other pH range, the removal efficiency was very low indicating that removal efficiency is greatly influenced by pH. The proper chemical dosage was 200 mg/l with the removal efficiency of 77.65%. The increase of chemical dosage, however, reduced the removal efficiency. 3. In case of using PAC, optimal pH was 6 with 97.99% removal efficiency. The result showed that wastewaters containing surfactant were almost completely removed at pH 6 by PAC. Removal efficiency was decreased by increasing PAC dosage higher than 400 mg/l and dosage over 700 mg/l of PAC abolished the treatment. 4. The comparative analysis of three methods revealed that the effective pH ranges were at pH 2-5 with Fenton oxidation, at pH 6-11 with PAC, and pH 11 with Alum. The removal efficiencies at these pH were 83.95-97.92%, 75.98-97.99% and 61.13%, respectively. 5. Increase in LAS concentration reduced the removal efficiencies of all three methods. In the case of PAC or Alum treatment, treatment abolished at LAS concentration higher than 700 mg/l.

The e tTects of Sodium Thiosulfate 00 Metal Toxicity io Wastewater

Sonn Oh,Jungkon Kim,Minjung Lee,Moonho Chung,Kyungho ChOl 한국환경보건학회 2005 한국환경보건학회 학술대회 자료집 Vol.2005 No.-

물질수지식을 이용한 이산화질소 침착속도 예측

양원호(Wonho Yang),유승진(Sungjin Yoo),배현주(Hunjoo Bae),정문호(Moonho Chung) 한국환경보건학회 2001 한국환경보건학회 학술대회 자료집 Vol.2001 No.-