• Journal of Korean Library and Information Science Society
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• v.9
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• pp.179-211
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• 1982

Many problems which today's research libraries are confronted with should be taken the measures to find some solutions in any ways. The purpose of this study is to identify the main stream of chaining of research libraries as an existing collector and distributor of scholarly information into a communication system adopting the concept of resource sharing and on-line bibliographic search as some possible ways for solutions. The conclusions of this study can be summarized as follows: 1) The research libraries will be imposed on more and more responsibilities to be a reservoir of the intellectual heritage of an individual, a nation and mankind. 2) The research libraries in the near future will have to develop their collections in the new environment of austerity with the limited budget. 3) It is more desirable for the future research libraries to have the attitude that they are in the business of information and communication rather than being an entity as "a library". 4) The resource sharing developed to solve the severe problems confrontal by research libraries will improve the organizational and technical mechanism for the access to the scholarly information. 5) The research libraries will produce more and more bibliographic database to expand the library materials which can be available and shared. 6) Though on-line search service will be sure to provide a considerable profit to the scholarly information users, it will take a long time for this service to be popularize because of the high ratio of service fee. 7) Two problems should be solved for the efficient service by on-line search. One is the continuous, updating training for the professional librarians. The other is that the common efforts for the quality control and standardization of data base by the data base producers should be made. 8) Taking all the items of the conclusions derived from the study of research libraries mainly in the United States into a consideration, the followings should be paid an attention. - The status-quo of the research libraries in Korea should be analyzed in very detailed and accurate way. - The problems of research libraries in Korea as the major scholarly communication system should be clarified based on the analysis. - The measures for the problems should be taken in the light of the unique characteristics of korean environment. - For the developing the most efficient measures, the formal organize action to lead and govern the long-aimed study on the problems of research libraries should be established and the government-level su n.0, pport for the legislation and finance should be provided for the realization of the result of the study.

• Korean Journal of Ecology and Environment
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• v.34 no.3 s.95
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• pp.192-198
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• 2001

The Kyongan Stream and the inlet part of Paltang Reservoir are under significant influence of the effluent of sewage wastewater treatment plant (SWTP) and untreated domestic wastewater (DOW). The fertility of wastewater was evaluated through bioassay using natural phytoplankton population diluted in five levels. The concentrations of $NH_4$, SRP and SRSi were positively correlated with the biomass of phytoplankton. P concentration showed stronger correlation (r = 0.959, p<0.001)than other nutrients. Compared with the initial concentrations, $NH_4$ concentrations in samples from SWTP and DOW decreased 96% and 7%, respectively during the cultivation, and those of SRSi decreased 97% and 60%. However, $NO_3$ concentrations in samples neither showed any particular change nor any increase. Chl-a concentration ranged between $20\;{\mu}g/l$ and $125\;{\mu}g/l$, which maximum value increased up to 83 times. Estimated from the relationship between chl-a and SRP, the P concentration that can maintain the biomass of algae under mesotrophic state (<25\;{mu}g$\;chl-a/l$) was $83\;{mu}g\; P/l$. The volume of flow to maintain this level solely by natural dilution was about $16{\sim}25$ times of in flowing volume in the stream. However, it is not feasible to tap water of such quantity. Therefore, it is imperative to build an advanced sewage wastewater treatment facility that can reduce $NH_4$ and SRP concentrations that promote the growth of phytoplankton in discharged water.

• Korean Journal of Environmental Biology
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• v.29 no.2
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• pp.107-112
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• 2011

The relationships between the phytoplankton community and sizes of reservoirs are investigated from 29 reservoirs in Yeongsan and Seomjin River Basins, Korea. As a microalgal flora, a total of 371 species of phytoplankton were identified. There were spatial and seasonal variations in standing crops and species diversity of phytoplankton. Statistical analysis showed that the size of reservoirs did not affect greatly on the community of phytoplankton. Species diversity and standing crops were higher in reservoirs of smaller surface area. However, there were no distinctive relationships between the size of basins of reservoirs and standing crops, species diversity, and chlorophyll $a$ concentrations. Relationships between the constructed years of reservoirs and standing crops, species diversity, and chlorophyll $a$ concentrations also showed very low level.

• Journal of Korea Water Resources Association
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• v.48 no.3
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• pp.149-158
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• 2015

It is well known that emergency outlet works have to be provided for the safety of dams. However, concept of emergency outlet works did not applied for the design of the most dams in Korea. Korean design standard for low-level outlet works does not provide enough design criteria which could be used in design of emergency outlet works. In this research, as-built status and hydraulic design criteria of outlet works, such as drawdown rate or hydraulic pressure due to the impounded water depth, were examined. Another relationship between drawdown rate and the dam slope stability was also examined with SEEP model. It was found that 25% reduction of impounded water depth decreases the pressure forces about 50%. Therefore, outlet works should be designed to drawdown properly at the beginning of the emergency. Seepage analysis of dam bodies showed that most of Korean dams could safely stand for 1m/day drawdown rate. Higher drawdown rate could result high discharge so the drawdown rate must be related with the flood risk of downstream. Finally, multi-stage design was recommended that faster discharge for the initial 25% of water depth in 7-10 days than the rest of it in 1-2 months.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.442-442
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• 2011

우리나라는 홍수조절이나 통제를 목적으로 10개의 다목적댐을 통한 홍수방재시스템을 운영하고 있다. 다목적댐 또한 방류능력과 저류능력에 한계가 있기 때문에 안정적인 홍수조절을 위해서는 유입량과 유출량을 미리 예측할 수 있어야 한다. 하지만, 강수량은 그 변동이 심하여 정확한 예측이 어렵기 때문에 합리적인 하천 구조물의 설계와 홍수예측기술의 발전을 위해서는 강우-유출 해석뿐만 아니라 과거의 수문자료를 사용한 통계적인 분석이 요구된다. 최근 기후변화로 인해 과거에 겪지 않았던 이상 기후현상이 빈번하게 나타나고 있다. 기상청발표에 따르면 최근 10년간(1996~2005) 15개 지점의 평균 연강수량은 1,458.7 m로 약 10 �時貂� 하였고, 특히 여름철은 18 %로 증가폭이 가장 크며 호우일수는 30년 평균이 2일인데 비하여 2.8일로 0.8일 증가하였다. 이러한 강수량 및 호우일수 증가는 여름철 심각한 수해를 초래할 수 있다. 본 연구는 기후변화로 인한 수해를 대비하여 홍수기중 저수지 제한수위운영의 안정성을 검토하였다. 연구 대상 지역은 광교저수지로 수원천 상류부인 경기도 수원시 장안구 연무동에 위치한다. 유역면적은 10.98 km, 유효저수량은 250.0 만$m3$이며, 현재 예비취수원으로 사용되고 있다. 기후변화에 따른 하류지역의 예상치 못한 홍수피해를 사전에 예방하기 위해 광교저수지 유역의 설계 강수량과 설계 홍수량을 산정하였다. 제한수위의 시나리오는 현재 시행중인 제한수위와 만수위를 포함하여 5개로 설정하였다. 설계 홍수량이 광교저수지로 유입될 때 시나리오에 따른 월류량은 웨어공식을 이용하여 산정하였으며 결론은 다음과 같다. 1. 39년간의 최다 일 강수량 자료를 사용하여 100년 빈도의 설계 강수량을 Gumbel 분포법으로 산정한 결과 344.4 mm임을 알 수 있었다. 2. 광교저수지 유역의 설계 홍수량을 SCS 방법을 이용하여 산정한 결과 $216.2\;m^3/s$/s로 나타났으며, 총 유입량은 $301.0\;m^3$/day로 파악되었다. 3. 광교저수지로 설계홍수량이 유입될 때 제한수위 시나리오에 따른 최대 방류량은 EL. 87 m의 경우 $23.1\;m^3/s$, EL. 89 m의 경우$27.5\;m^3/s$ EL. 91.36 m의 경우 $79.6\;m^3/s$, EL. 93 m의 경우 $121.1\;m^3/s$ EL. 95.2 m의 경우 $137.`\;m^3/s$이다. 광교저수지 하류부분의 하천정비기본계획상의 설계 홍수량은 $114\;m^3/s$로 홍수기중 저수지의 제한수위는 EL. 91.36 m이하로 설정하는 것이 바람직한 것으로 판단된다.

• Analytical Science and Technology
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• v.23 no.3
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• pp.240-246
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• 2010

A technique for the determination of trace Cu(II) in various real samples by FAAS after the column preconcentration onto p-dichlorobenzene-SA adsorbent, which is microcrystalline p-dichlorobenzene loaded with salicylaldoxime (SA) has been developed. Several experimental conditions such as pH of the sample solution, the amount of chelating agent salicylaldoxime, the amount of adsorbent p-dichlorobenzene-SA, and flow rate of sample solution were optimized. The interfering effects of various concomitant ions were investigated. $CN^-$ interfered more seriously than any other ions. However, the interference by $1\;{\mu}g\;mL^{-1}\;CN^-$ could be overcome completely by controlling the concentration of Ni(II) to $20\;{\mu}g\;mL^{-1}$. The linear range, correlation coefficient ($R^2$) and detection limit obtained by this technique were $3.0\sim100\;ng\;mL^{-1}$, 0.9901, and $3.1\;ng\;mL^{-1}$, respectively. For validating this technique, the aqueous samples (wastewater, reservoir water and stream water) and the food samples (orange juice, fresh egg and skim milk) were used. Recovery yields of 93~104% were obtained. These measured mean values were not differents from ICP-MS data at 95% confidence level. The good results were obtained from the experiments using the rice flour certified reference material (CRM) sample. Based on the experimental results, it was found that this technique could be applied to the preconcentration and determination of Cu(II) for various real samples.

• Journal of Soil and Groundwater Environment
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• v.11 no.6
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• pp.61-68
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• 2006

Soil washing techniques coupled with high pressure air jet were applied for diesel-contaminated soils sampled by an underground oil reservoir of which the initial total petroleum hydrocarbon (TPH) ($2,828{\pm}206\;mg/kg$) exceeded 5 times of current standard level (500 mg/kg) regulated by the Soil-Environment Conservation Law. Through several tests, we found that the position of impeller has a critical impact for washing efficiencies. The highest washing efficiency was obtained at an oblique angle (30 degree) for the impeller and optimized mixing speed (300 rpm) that could have high shearing forces. Considered economical and feasible aspects, the optimum mixing time was 10 min. Rate constants of TPH removal derived from the first-order equation were not linearly increased as mixing speed increased, indicating that mechanical mixing has some limits to enhance the washing efficiencies. Application of high-pressure air jet in washing process increased the washing efficiency. This increase might be caused by the fact that the surface of micro-air bubbles strongly attached hydrophobic matters of soil particles. As the pressure of air jet increased, the separation efficiencies of TPH-contaminated soil particles increased. In the combined process of high-pressure air jet and mixing by impeller, the optimum mixing speed and air flow-rate were determined to be 60 rpm and $2\;kg/cm^2$, respectively. Consequently, the washing technique coupled with high-pressure air jet could be considered as a feasible application for remediating petroleum-contaminated soils.

• Korean Journal of Environmental Biology
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• v.36 no.2
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• pp.165-173
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• 2018

We sampled vomit of black-faced spoonbills(Platalea minor) during the brood-rearing season (from June 2011 to June 2014) at the Namdong reservoir in Incheon and analyzed the food components in the vomit using microscopy and next-generation sequencing (NGS). Microscopic observations primarily helped in identifying osteichthyes (bony fishes), crustaceans, and polychaetes. In particular, species belonging to the families Mugilidae and Gobiidae among the fish, and Macrophthalmus japonicas among the crustaceans, were observed at high frequency. Results of NGS analysis revealed the predominant presence of bony fish (42.58% of total reads) and crustaceans (40.75% of total reads), whereas others, such as polychaetes (12.66%), insects (0.24%), and unidentified species (3.78%), occurred in lower proportions. At the species level, results of NGS analysis revealed that Macrophthalmus abbreviates and Macrobrachium sp. among the crustaceans, and Acanthogobius hasta, Tridentiger obscurus, and Pterogobius zacalles among the bony fish, made up a high proportion of the total reads. These food species are frequently found at tidal flats in the Songdo and Sihwa lakes, emphasizing the importance of these areas as potential feeding sites of the black-faced spoonbill. Feed composition of the black-faced spoonbill, as evaluated by analyzing its vomit, differed when the evaluations were done by microscopic observation or by NGS analysis. Evaluation by microscopic observation is difficult and not error free, owing to the degradation of the samples to be analyzed; however, NGS analysis is more accurate, because it makes use of genetic information. Therefore, accurately analyzing food components from morphologically indistinguishable samples is possible by using genetic analysis.

• Journal of Navigation and Port Research
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• v.30 no.8 s.114
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• pp.649-655
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• 2006

Waves progressing into the coastal area can be amplified, swashed and overtopped by a wave overtopping control structure, and it converts the kinetic energy of the waves to the potential energy with a hydraulic head above the mean sea level by conserving the overflow in a reservoir. Then the potential energy in the form of hydraulic head can be converted to electric power utilizing extremely low-head hydraulic turbine. This study aims to find the most optimal shape of wave overtopping structure which maximizes overtopping volume rate of sea water. Laboratory experiments for the performance evaluation of wave overtopping control structures were carried out in three dimensional wave tank, and the three dimensional structure models with planar wave concentration shapes(B/b) were manufactured into five classes, which were optimized by cross sectional parameters of the structure, ie, length of ramp(l), gradient of inclined ramp($cot{\phi}$) and freeboard height of the wave overtopping structure($h_e$) proposed by Shin and Hong(2005). The wave overtopping discharges were investigated with 20 incident wave conditions and wave directions of $0^{\circ},\;15^{\circ},\;30^{\circ}$.

• Journal of Environmental Impact Assessment
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• v.29 no.1
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• pp.61-77
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• 2020

In South Korea, major public waters have been systematic management under national level. Water environment network has been continuous monitoring for change of aquatic ecosystem, river and reservoir. In Water Quality Monitoring Networks, the data have been generally monitored Per eight days or month, while in Automatic Water Quality Monitoring Network the data have been monitored at daily intervals. Therefore, we were compared and analyzed water quality data between the networks using statistic method for same water quality item. Mann-kendall test results confirm that all points in Water Temperature (WT) and DO were not statistically significant. In particular, the result revealed that there is significant variation of TOC in the four different sites, TN in two different sites, TP in three different sites, WT in seven different sites, pH in two different sites between Water Quality Monitoring Network and Automatic Water Quality Monitoring Network. As a result firm LOWESS, TOC and pH clearly shows different trend. Among different sites, the water quality show the significantly positive correlations between at Sinam-Sangju2 and Namgang-Namgang4. Negative correlation significantly appeared in TP (ADD_Lower-AD1 site), TOC (DG-SG site), pH (GR-GR site), TP (JP-CN) and TN, TP, pH, EC, DO (GC-GC2-1 site).