수학 기초학습부진학생 집단의 특징 연구

이대식(李大植),최종근(崔種根),전윤희(全允姬),김연진(金延眞) 서울대학교 교육연구소 2007 아시아교육연구 Vol.8 No.1

어장정화·정비 방법에 따른 어장환경 개선효과 분석 및 정책 제언

이대인,김형철,이원찬 한국해양환경·에너지학회 2022 한국해양환경·에너지학회지 Vol.25 No.1

This paper analyzed short-term environmental improvements of the sediment quality (organic pollution) and proposed several methods for management policy according to the four types of purification and maintenance projects in the marine aquaculture farms such as sediment dredging, plowing, coating the improving material (in-situ capping), and farm relocation (rest for a period). The decrease of TOC (Total Organic Carbon) concentration was shown the highest through the sediment dredging and capping, while that of AVS (Acid Volatile Sulfide) was improved by dredging. Especially, the initial concentration of TOC and AVS reduced considerably in the farm relocated during 11 months. AVS had more rapid initial response and better improvement than TOC relatively. It was assessed that the dredging and the relocation in the area which had high contamination of sediment had distinct improvements. On the other hand, the results observed in the area which had low contamination and satisfying environmental standards were insignificant. In the aspect of the organic pollution improvement, resting, dredging, and coating the material were diagnosed to have about 10~30% improvement. But considering the expense, field applicability, and the probability of the second pollution impact, the resting by marine self-purification will be more effective. Henceforth, as for the policy consideration, it is necessary to implement measures as follows: obtaining the reasonable evidence for the natural recovery concerning restoration index and period by farming species and region, enhancing the systematic pollutant management and the contribution assessment by each pollution source, setting further differentiated guideline according to its purposes such as environmental improvement for the dredging material and seashell, and establishing a monitoring and information system (platform) to share and analyze the effects of purification and maintenance projects. 어장정화·정비사업의 4가지 유형인 해저 퇴적물 준설, 해저 경운, 어장개선물질 살포 및 어장재배치(휴식)에 따른 퇴적물의 환경개선효과를 현장 실증실험을 통해 비교 분석하였고, 정책 활용성 제고를 위한 방안을 제시하였다. 총유기탄소의 단기적(60일) 저감은 준설과 개선물질의 살포를 통해서 가장 높았고, 산휘발성황화물은 준설에 의해 많이 개선되었다. 특히, 인위적인 준설 및 개선장비가 필요하지 않은 약 11개월간의 어장휴식은 총유기탄소와 산휘발성황화물의 저감효과를 상당히 높이는 것으로 평가되었다. 산휘발성황화물이 유기탄소보다는 초기 반응이 빠르고 개선효과가 상대적으로 더 컸다. 초기 농도가 매우 오염된 지역에서의 준설 및 어장재배치 효과는 상대적으로 명확하게 나타나는 반면, 초기 농도가 낮거나 어장환경기준을 만족한 곳에서는 정화·정비사업에 대한 효과는 뚜렷하지 않은 것으로 평가되었다. 유기물의 개선 측면에서 어장휴식, 개선물질 살포와 준설 등이 약 10~30%의 효과를 나타내었지만, 비용 소모와 현장 적용성 및 2차 환경오염 가능성을 고려하면 자연정화능력을 활용한 어장재배치에 따른 휴식이 효과적일 것이다. 향후 정책적 고려사항으로 바다 자체가 갖고 있는 자연정화능력을 활용하는 어장재배치에 따른 양식품종 및 지역별로 회복지표와 회복기간을 산정하여 어장휴식에 대한 근거 마련과 휴식년제 적극 도입, 각 오염원인 인자별 기여도 평가를 위한 안정동위원소 조사 등의 강화로 오염원과 오염물질 관리체계 구축, 준설물질과 굴 패각의 어장환경개선 등 활용목적에 따라 보다 차별된 기준 정립, 어장정화·정비사업에 따른 효과 분석과 지속적 관리체계를 위한 모니터링과 통합 정보시스템(플랫폼) 구축을 지속적으로 추진해야 할 것이다.

洛東江 河口海城의 식물플랑크톤 極大城 變動에 관한 數値시뮬레이션 : Ⅱ. 식물플랑크톤 극대역 변동의 수치시뮬레이션 Ⅱ. The numerical simulation on variation of phytoplankton maximum region

이대인,김동명,김형철,이석모,박청길 한국환경과학회 2000 한국환경과학회지 Vol.9 No.5

It is very important to interprete and simulate the variation of phytoplankton maximum region for the prediction and control of red tide. This study was composed of two parts, first, the hydrodynamic simulation such as residual current and salinity diffusion, and second, the ecological simulation such as phytoplankton distribution according to freshwater discharge and pollutant loads. Without the Nakdong river discharge, residual current was stagnated in inner side of this estuary, and surface distribution of salinity was over 25psu. On the contrary, with summer mean discharge, freshwater stretched very far outward and some waters flowed into Chinhae Bay through the Kadok channel, and low salinity extended over coastal sea and salinity front occurred. From the result of contributed physical process to phytoplankton biomass, the accumulation was occurred at the west part of this estuary and the Kadok channel with the Nakdong river discharge. When more increased input discharge, the accumulation band was transported to outer side of this estuary. The frequently outbreak of red tide in this area is caused by accumulation of physical processes. The phytoplankton maximum region located inner side of this estuary without the Nakdong river discharge and with mean discharge of winter, but it was moved to outer side when mean discharge of the Nakdong river was increased. The variation of input concentration from the land loads was not largely influenced on phytoplankton biomass and location of maximum region. When discharge was increased, phytoplankton maximum region was transferred to inner side of the Kadok channel. On the other hand, when discharge was decreased, phytoplankton maximum region was transferred to inner side of this estuary and chlorophyll a contents increased to over 20㎍/L. Therefore, if any other conditions are favorable for growth of phytoplankton, decrease of discharge causes to increase of possibility of red tide outbreak.

駕莫灣 流域의 汚染負荷 特性에 관한 硏究

이대인,조현서 한국환경과학회 2002 한국환경과학회지 Vol.11 No.9

The objective of this study is understanding and evaluation of temporal and spatial variation of pollutant loads by input sources for water quality management in Kamak Bay. Flow rate of rivers and ditches ranges from about 2,592-63,072㎥/d in October to 864-55,296㎥/d in January. In particular, the R2 predominated flow rate among input sources. Total COD, BOD, DIN and DIP loadings in January were about 896㎏/d, 718㎏/d, 2,152㎏/d, and 154㎏/d, respectively, which exceeded those of October. Lower POC/TOC levels are estimated in R2, and also in October. Temporal variation of pollutant loads were closely related to the human activity. Total discharging loadings of BOD, TN and TP by unit loading estimation were 4,993.0㎏/d, 2,558.7㎏/d, and 289.2㎏/d, respectively, and were mainly affected by the population. Runoff ratio of BOD was about 0.14 in January. Mean NH_4^+-N and PO_4^3--P loadings from sediment were 16.23㎎/㎡/d and 7.26㎎/㎡/d, respectively. For the improvement of water quality in this area, not only pollutant loads of rivers and ditches but also benthic flux from sediment should be reduced within the limits of the environmental capacity.

駕莫灣에서의 基礎生産力 향상방안에 관한 生態系모델링

이대인,조은일,박청길 한국환경과학회 1999 한국환경과학회지 Vol.8 No.5

From the environmental aspects, primary productivity of phytoplankton plays the most important role in enhancement of marine culture oyster production. This study may be divided into two branches; one is estimation of maximum oyster meat production per unit facility(Carrying Capacity) under the present environmental conditions in Kamak Bay, the other is improvement of carrying capacity from increase of primary productivity by changing the environmental conditions that cause not to form an unfavorable environment such as the formation of oxygen deficient water mass using the eco-hydrodynamic model. By simulation of three-dimensional hydrodynamic model and ecosystem model, the comparison between observed and computed data showed good agreement. The results of sensitivity analysis showed that phytoplankton maximum growth rate was the most important parameter for phytoplankton and dissolved oxygen. The estimation of mean primary productivity of Wonpo, Kamak, Pyongsa, and Kunnae culture grounds in Kamak Bay during culturing period were 3.73gC/㎡/d, 2.12gC/㎡/d, 1.98gC/㎡/d, and 1.26gC/㎡/d, respectively. Under condition not to form the oxygen deficient water mass, four times increasing of pollutants loading as much as the present loading from river increased mean primary productivity of whole culture grounds to 4.02gC/㎡/d. Sediment N, P fluxes that allowed for 35% increasing from the present conditions increased mean primary productivity of whole culture grounds to 3.65gC/㎡/d. Finally, ten times increasing of boundary loadings from the present conditions increased mean primary productivity of whole culture grounds to 3.95gC/㎡/d. The maximum oyster meat production per year and that of unit facility in actual oyster culture grounds under the present conditions were 6,929ton and 0.93ton, respectively. This 0.93ton/unit facility is considered to be the carrying capacity in study area, and if the primary productivity is increased by changing the environmental conditions, oyster production can be increased.

해역이용협의제도와 준설사업 스코핑

이대인 한국퇴적환경준설학회(구 한국환경준설학회) 2013 한국환경준설학회 학술대회논문집 Vol.2013 No.-

생태-유체역학 모델링에 의한 낙동강하구해역의 물질수지 산정

이대인 전남대학교 수산과학연구소 2004 수산과학연구소논문집 Vol.13 No.-

The Nakdong river estuary was eutrophicated and frequently outbreak of red tide by pollutants inputed from the effulent of which sewage disposal plant and the Nakdong river. This study is performed to countermeasures for these problems, Firstly, water and COD fluxes are estimated in case of both river discharge is considered and ignored. The residual current and saliniψ front are simulated by the three dimentional hydrodynamic model, and also residence time of water, COD are calculated. The salinity front is apparently formed and low salinity water dispersed to open sea if consider of the Nakdong river discharge. Seawater exchange flux by residual current is very fluctuated accoding to the Nakdong river discharge. When consider of the Nakdong river discharge, the output flux of COD is more than input flux, and residence time of that is very shortened. It is suggested that concentration of COD in study area is very high contrast to input loads, because of autochthonous COD by nutrient uptake of phytoplankton is increased. Therefore, adequate reduction of input loads of COD, DIN, and DIP by study the response of water quality is necessary.

연안의 효율적 수질관리 방향과 해양환경영향평가

이대인,엄기혁,김귀영,홍석진,이원찬,장주형,Lee, Dae-In,Eom, Ki-Hyuk,Kim, Gui-Young,Hong, Sok-Jin,Lee, Won-Chan,Jang, Ju-Hyoung 해양환경안전학회 2008 해양환경안전학회지 Vol.14 No.1

본 연구는 연안의 수질개선과 오염제어의 관점에서 효율적인 수질관리의 원리와 기법, 연안오염총량관리제 및 선진사례를 검토하였고, 현재 오염총량 산정시 나타나는 문제점 및 개선사항을 지적하였다. 또한, 오염총량제와 환경용량과의 관계, 해양환경 예측 모델로 활용되고 있는 생태계모델의 연구접근에서 중점적으로 검토해야 하는 사항을 토의하고, 나아가서 연안수질 관련 제도와 정책에서 반영하고 흡수해야 할 수질관리 내용과 개선방안을 제시하였다. 연안오염총량제의 대상이 되는 연안에서는 환경영향평가와 사전환경성검토에서 해당하는 개발사업이나 계획 중 신규 오염원에 대해서는 오염부하삭감량과 할당량을 산정해서 평가서에 구체적으로 제시할 필요가 있고, 연안관리지역계획에서는 환경관리계획에 좀 더 중심을 옮겨 기본적으로 관할 해역으로 유입하는 오염원과 오염부하량 자료를 구축할 필요가 있다. 특별관리해역 등 향후 연안오염총량제 적용대상이 되는 지자체에서는 하수도관리계획 등 도시계획을 수립할 때 이러할 점을 고려해서 장기적이고 일관성있는 하수도정책이 수립되어야 할 것이다. 연안오염총량제도는 다른 환경관리해역으로 점진적으로 확대 시행되어야 할 것이로, 그 외의 지역은 지자체장이 주부장관과의 협의를 통해 자발적으로 시행하고 인센티브를 주는 것도 검토해야 할 것이다. 해역의 수질개선을 위해서는 생태계모델링에 의한 환경용량(수질적 차원의 총허용오염부하량) 산정이 필수적이며, 이와 관련한 적용모델의 신뢰성과 과학적 타당성 확보는 환경영향평가 관련 협의시 매우 중요한 검토항목으로 고려되고 있다 연안 육역에 존재하는 오염원에 대해서는 연안환경을 관리하는 주무부처가 주도적으로 감시 감독하고 관리체제에 환한 법적 거를 마련하거나 관련 법률을 정비해서 통합 운영해야 할 것으로 사료되었다. This study examined principles and techniques of efficient water quality management as well as total coastal pollutant loads and the relevant examples in the advanced countries from the viewpoints of water quality improvement and pollution control in coastal areas. The problems and improvements in an estimation of the current total pollutant loads were also pointed out. In addition, discussion was made on the relationship between total pollutant loads and environmental capacity as well as particulars requiring extensive examination on access to and study on water quality model used as prediction tool for marine environment. Furthermore, this study proposed details of and improvement plans for water quality control to be reflected and absorbed into systems and policies related to coastal water quality. In coastal areas, which are subject to total coastal pollutant loads, it is necessary to calculate pollutant loads reduction and allocation, to propose them in detail in statement in relations to new pollution sources for the corresponding projects or plans in environmental impact assessment and prior environmental review system. Also, in relations to regional plans for coastal management, the local government concerned must focus more on environmental management plan to implement data on pollution sources and pollutant loads flown into sea areas under basic jurisdiction, therefore it is required to actively respond to expansion and introduction of total coastal pollutant loads system in the future. Total coastal pollutant loads system must be expanded and executed by considering characteristics of sea area and changes in the environment of land. For pollution sources in land, the competent authorities in charge of coastal environment will need to initiatively administer supervision, monitoring activities and achieve integration and operation of the related laws by preparing legal bases for management system or adjusting the related laws.

해역이용협의 제도와 준설사업 환경 평가 스코핑

이대인 한국퇴적환경준설학회(구 한국환경준설학회) 2013 한국환경준설학회지 Vol.3 No.1

Unusual Polymorphic Ventricular Tachycardia Originating from the Pulmonary Artery

이대인,Sang Weon Park,국형돈,Woohyeun Kim,김동혁,이선기,Suk-Kyu Oh,Young-Hoon Kim 대한심장학회 2013 Korean Circulation Journal Vol.43 No.2

We report a case about a 27-year-old healthy young male who developed syncope during exercise, which was subsequently identified to be attributable to non-sustained polymorphic ventricular tachycardia (VT). Occurrence of polymorphic VT was neither related to a pro-longed QT interval nor a fixed short coupling interval. Standard examinations including echocardiography, coronary angiography, isopro -terenol infusion study, and cardiac MRI showed no structural heart disease. On the electrophysiology study, activation mapping revealed that a discrete potential preceded the premature ventricular complex (PVC) triggered polymorphic VT, which was recorded just above the pulmonary valve. After radiofrequency ablation at this area, PVC and polymorphic VT disappeared and did not recur after a 2 month fol-low up.