• 한국수자원학회논문집
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• 제44권12호
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• pp.991-1000
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• 2011

저수지 탁수 모델링에서 실측자료가 없는 경우 유입하천 부유사 농도(SS) 산정을 위해 유량(Q)과 SS 관계식이 자주 사용된다. 일반적으로 하천을 통과하는 SS 부하율은 유량에 의해 변동된다는 가정 하에 유량과 SS의 멱함수(SS=aQb) 관계가 가장 빈번히 적용되고 있다. 그러나 Q-SS 관계는 측정 지점에 따라 배타적 특성을 가지며, 동일 지점에 대해서도 연중 계절적 변동성이 있다. 더욱이, Q-SS 관계는 동일한 수문곡선에서도 유량 상승기와 하강기에 이격현상을 보이기도 한다. 본 연구의 목적은 용담댐 저수지와 소양강댐 저수지 유입 하천에서 강우시 연속 실측한 자료를 바탕으로 Q-SS 관계의 이격현상을 고찰하고, SS 부하율 산정 오차에 미치는 영향을 분석하는데 있다. 연구결과, Q-SS 관계는 홍수사상 동안 높은 분산도와 시계방향의 이격현상을 보였으며, 동일한 유량에 대해 유량 상승기가 하강기보다 SS 농도가 높게 나타났다. 이러한 이격현상은 저수지로 유입하는 SS 부하량 산정에 있어 유의할 만한 오차로 작용하였으며 Q-SS 멱함수는 실측 부하량을 과소평가하는 결과를 가져왔다. 이것은 저수지 탁수모델링에서 중요하게 고려해야 할 사항이다. 본 연구에서는 Q-SS 관계식의 대안으로 탁도-SS관계가 제시되었다. 탁도-SS 관계는Q-SS 관계보다 분산도가 작았으며 실측 부하량과의 오차를 획기적으로 줄였다. 따라서 저수지로 유입하는 SS 부하율의 보다 정확한 산정과 탁수모델링의 신뢰도를 높이기 위해서는 유입 탁도에 대한 실시간모니터링이 필요하다.

• 산업기술연구
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• 제21권B호
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• pp.233-240
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• 2001

This research was conducted with the aim of efficiently managing large scale of rivers such like Songyang-river through predicting water quality change with analyzing the characteristics of the flowing in nutrients and pollutants. The main result will be used as basic data for effectively operating reservoirs through controling water quality and quantity. The relationship between quantity of flow and water quality was analyzed and pollution loading into the basin was estimated. Three areas of Soyang-river upstream and one area of Suip-cheon in Yanggu-gun were selected as research sites. Flow and water quality were measured simultaneously. The relation between quantity of discharge and pollution concentration and between quantity of discharge and pollution loading were analyzed by statistical method, respectively. We provided a rating curve through measuring quantity of discharge(collecting quantity of discharge) and pollutograph and pollution loading curve through water quality data. Also, we analyzed the correlation between quantity of discharge per unit area and pollution loading per unit area in each basin. As resurt of this research, Buk-cheon spot revealed an excellent first grade water quality for the items including $BOD_5$, DO, and SS. The correlation coefficient between Buk-cheon spot's quantity of discharge and pollution loading was 0.896~0.996, showing the validity of analysis applying correlation curve formula of quantity of discharge and pollution loading in the same spot. Also, pollution loading per unit area of the items including $BOD_5$, COD, DO, SS, T-N, T-P increased as the area of basins get increased following the sequence of Buk-cheon, Suip-cheon, Naelin-cheon spots.

• 한국물환경학회지
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• 제26권5호
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• pp.789-795
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• 2010

Suspended Solid (SS) is one of the main pollutants and discharges with attached other pollutants such as heavy metal and toxic substance. It is very important to estimate and forecast the release characteristics of SS for water quality improvement. The current studies assumed that SS release rate is proportional to the rain intensity and suggested exponential washoff models. These models related to the shear force of flow. In this study, a new washoff model is suggested based on relation with SS release rate and mean flow rate of the basin surface which is closely related to the shear force. The proposed model is applied to the Goonja drainage district in Seoul, Korea. The new washoff model simulates the SS discharge more accurately in the various rainfall types. The model can be widely applied to the real problems such as the management of non-point source pollutant and the design of treatment facilities.

• Journal of Trauma and Injury
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• 제20권2호
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• pp.138-143
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• 2007

Purpose: $S100{\beta}$, a marker of traumatic brain injury (TBI), has been increasingly focused upon during recent years. $S100{\beta}$, is easily measured not only in cerebrospinal fluid (CSF) but also in serum. After TBI, serum S 10019, has been found to be increased at an early stage. The purpose of this study was to evaluate the clinical correlations between serum $S100{\beta}$, and neurologic outcome, and severity in traumatic brain injury. Methods: From August 2006 to October 2006, we made a protocol and studied prospectively 42 patients who visited the emergency room with TBI. Venous blood samples for $S100{\beta}$, protein were taken within six hours after TBI and vital signs, as well as the Glasgow Coma Scale (GCS), were recorded. The final diagnosis and the severity were evaluated using the Abbreviated Injury Score (AIS), and the prognosis of the patients was evaluated using the Glasgow Outcome Score (GOS). Results: Thirty-eight patients showed a favorable prognosis (discharge, recovery, transfer), and four showed an unfavorable prognosis. Serum $S100{\beta}$, was higher in patients with an unfavorable prognosis than in patients with a favorable prognosis, and a significant difference existed between the two groups ($0.74{\pm}1.50\;{\mu}g/L$ vs $7.62{\pm}6.53\;{\mu}g/L$ P=0.002). A negative correlation existed between serum $S100{\beta}$, and the Revised Traumatic Score (R2=-0.34, P=0.03), and a positive correlation existed between serum $S100{\beta}$, and the Injury Severity Score (R2=0.33, P=0.03). Furthermore, the correlation between serum $S100{\beta}$, and the initial GCS and the GCS 24 hours after admission to the ER were negative (R2=-0.62, P<0.001; R2=-0.47, P=0.005). Regarding the GOS, the mean serum concentration of $S100{\beta}$, was $7.62\;{\ss}{\partial}/L$ (SD=${\pm}6.53$) in the expired patients, $1.15\;{\mu}g/L$ in the mildly disable patient, and $0.727\;{\mu}g/L$ (SD=${\pm}0.73$) in the recovered patients. These differences are statistically significant (p<0.001). Conclusion: In traumatic brain injury, a higher level of serum concentration of $S100{\beta}$, has a poor prognosis for neurologic outcome.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2012년도 춘계학술발표대회
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• pp.81.2-81.2
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• 2012

To fabricate a metal mold for injection molding, hot-embossing and imprinting process, mechanical machining, electro discharge machining (EDM), electrochemical machining (ECM), laser process and wet etching ($FeCl_3$ process) have been widely used. However it is hard to get precise structure with these processes. Electrochemical etching has been also employed to fabricate a micro structure in metal mold. A through mask electrochemical micro machining (TMEMM) is one of the electrochemical etching processes which can obtain finely precise structure. In this process, many parameters such as current density, process time, temperature of electrolyte and distance between electrodes should be controlled. Therefore, it is difficult to predict the result because it has low reliability and reproducibility. To improve it, we investigated this process numerically and experimentally. To search the relation between processing parameters and the results, we used finite element simulation and the commercial finite element method (FEM) software ANSYS was used to analyze the electric field. In this study, it was supposed that the anodic dissolution process is predicted depending on the current density which is one of major parameters with finite element method. In experiment, we used stainless steel (SS304) substrate with various sized square and circular array patterns as an anode and copper (Cu) plate as a cathode. A mixture of $H_2SO_4$, $H_3PO_4$ and DIW was used as an electrolyte. After electrochemical etching process, we compared the results of experiment and simulation. As a result, we got the current distribution in the electrolyte and line profile of current density of the patterns from simulation. And etching profile and surface morphologies were characterized by 3D-profiler(${\mu}$-surf, Nanofocus, Germany) and FE-SEM(S-4800, Hitachi, Japan) measurement. From comparison of these data, it was confirmed that current distribution and line profile of the patterns from simulation are similar to surface morphology and etching profile of the sample from the process, respectively. Then we concluded that current density is more concentrated at the edge of pattern and the depth of etched area is proportional to current density.