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.

본 연구의 목적은 융설모형을 국내에 도입하고 이를 강우-유출모형과 결합하여 우리나라 북부 산간지방의 장기 유출해석을 위한 융설의 영향을 고찰하는데 있다. 선택된 모형은 미국 국립기상청의 온도지수 융설모형이며, 이를 유연면적이 1,059.6 인 내린천 유역에 적용.검토하였다. 모형에 의해서 계산된 강설의 지역적 분포에 대한 시간적 변동성은 인제 측후소에서 관측된 강설량의 변동성과 잘 일치하는 것으로 나타났다. 또한 모형에 의해서 계산된 토양수분 및 하천유

Today the number of high school drop-outs is increasing , and also it is serious social problems. But almost factor analyses on the drop-outs are projected by questionnaire. This paper find out by the real data form the concerned documents what factors of drop-outs are. In order to accomplish this study purpose, the methodology are used such as Fequency Analysis, Correlation Analysis, Crosstabulation Analysis. Through the this study this paper could siome suggestions as followings. The first , all education authority should analysis what factors of drop-outs and what drop-out situation is . The second, every teacher should counsel with all problem students sincerely regarding to their characters, future occupations, life course and etc. The third, the most and worst important factors of drop-out is runaway. Because it is very difficult for teacher to teach, lead and guide a runaway student, therefore thepreventino of runaway is efficient for reducing of drop-outs. The fouth, the students violating rules are retrained propoerly in view of guide for good path. The fifth, besides of the above factors. there are drop-out factors such as the health, disease, dafety accidents . All parents. teachers, and students should try their best to solve. To the end, education authority try to encourage teachers to do their role with maximum sense of duty.

A preliminary study on the chemical compositions of forty seven precipitations from March 1994 to May 1995 in Yeoncheon-gun, which is adjacent to the southern boundary of demilitarized zone (DMZ) in the northernmost tip of Kyunggi province has been performed. The metal cation and anion concentrations were measured by atomic absorption spectrometer and ion chromatography, respectively. pH/Ion meter and direct nesslerization method were used for the concentration measurements of H- ion and NH_4+ ions, respectively. Based on the data, the quantitative orders of the cation and anion average concentrations were Ca2+ > NH_4+ > Na+ > K+ > Mg2+ > H+ and SO_42- > Cl- > NO_3-, respectively. The ratio of average total anion concentration to average total cation concentration was 0.97. The average pH value of the precipitations was 5.60. These results, correlation coefficients between the ion concentrations, and monthly variations of pH value and precipitation amount are used for chemical analysis on the environmental pollution and pollutant sources in Yeoncheon-gun of Kyunggi province near DMZ.

The objective of this study is the investigation and analysis of information on the conservation and the sustainable use of coastal wetlands based on the awareness of local residents in Kang-hwa island, Tae-an and Seo-chon. The results are summarized as follows: The degree of the satisfaction on the natural environment is in the order of Tae-an, Kang-hwa and Seo-chon. This order is accorded with the order of the goodness of natural environment. The order for the degree of the satisfaction on the living environment is same as the order for the satisfaction degree on the natural environment. Especially, residents of Seo-chon are not satisfied with the living environment. The residents of all regions are not satisfied with the socio . economic environment. The local resident of Kang-hwa and Tae-an, where natural environment is well-conserved, prefer conservation to development of the region. On the other hand, the local residents of Seo-chon have relatively low preference for conservation of the region. These results show the following consideration for the ideal method of management for the conservation and sustainable development of coastal wetlands. In case of Kang-hwa island, where the, condition the natural environment is well conserved, should be managed with the minimum development with maintenance of the current state must be driven.

Ion exchange performance to remove nitrate in water was studied using commercially available strong base anion exchange resin of Cl^- type in the batch and continuous column reactors. The performance was tested using the effluent concentration histories for continuous column or equilibrium concentrations for batch reactor as a function of time until resins were exhausted or reached ionic equilibrium between resin and solution. Anion exchange resin used in this study was more effective than activated carbon or zeolite for nitrate removal. With large resin amount or low initial concentration, nitrate removal characteristics for a typical gel-type resin was increased. On considering the relation between the breakthrough capacity and nitrate concentration of the influent, the use of anion exchange resin were suitable for the higher order water treatment. The nitrate removal of above 90% could be possible until the effluent of above 650 BV was passed to the column. Thus, the commercially available strong base anion exchange resin of Cl^- type used in this study could be effectively used as economic material for treatment of the groundwater. The breakthrough curves showed the sequence of resin selectivity as SO_4^2- > NO_3, > NO^2- > HCO_3^-. The results of this study could be scaled up and used as a design tool for the water purification system of the real groundwater and surface water treatment processes.

감자의 생장점 배양을 통하여 생산된 소량의 소괴경(microtuber)을 경삽하여 균일하게 생장된 플러그우량묘를 대량생산할 수 있는 기술을 개발하기 위하여 삽수를 정단 및 기부부위로 구분하고 NAA 및 IAA 10 mg /1 용액에 2시간 침지하여 cocopeat, vermiculite, perlite, peatmoss 혼용배지를 이용한 삽목과 온로장 처리 ,포장정식후 괴경형성효을에 대하여 시험한 결과를 요약하면 다음과 같다. 1. 감자의 소괴경 유내 줄기를 이용한 플러그 삽목시 고체배지는 cocopeat, vermiculite, perlite, peatmoss를 이용한 혼합배지에서 플러그의 형성율이 양호하게 나타났다. 2. 고온장일조건(20℃ 이상, 16시간의 일장)에서는 지상부생육 및 지하부발근이 양호하였으나, 외부방치구에서는 발근이 부진하고 복지가 발생하여 소괴경이 형성되었다. 3. 지상, 지하부 생체중은 생장조절제 전처리시 NAA 10mg/1 및 IAA 10mg/1 간에 차이가 없었다. 4. 삽수부위별로는 삽목묘의 초기생육은 초장에서는 비슷한 경향이었고, 그 외 엽수, 근수, 근장 등의 형질은 정단부위묘가 양호하였지만, 포장정식 후에는 큰 차이가 없었다. 5. 삽목묘를 봄재배하여 괴경형성여부를 시험한 결과 초장은 70~80cm, 복지수 10여개, 괴경수는 7~8개가 형성되었다.

This paper is aimed at investigating environmental indicators and needs based on residents' perception at Seosan city, Chungnam province. The results can be summarized as follows ; 1) On the average, the environmental level perceived by residents at Seosan city lies somewhat above the middle one, three points. 2) The perceived environmental level in rural areas is hither than that in urban and suburban ones, 3) There is a difference in residents'environmental needs between rural and urban areas. 4) It is proposed that a long-term and systematic environmental planning for Seosan city should be established to improve the environmental level.