• Title/Summary/Keyword: flood pressure

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Effects of Dams and Water Use on Flow Regime Alteration of the Geum River Basin (금강 유역의 댐과 물이용에 의한 유황의 변동특성 분석)

  • Kang, Seong-Kyu;Lee, Dong-Ryul;Moon, Jang-Won;Choi, Si-Jung
    • Journal of Korea Water Resources Association
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    • v.43 no.4
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    • pp.325-336
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    • 2010
  • This study presents the alteration of flow regime by effects of dams and water use in the Geum River Basin. The surface water use rate and the Impounded Runoff (IR) index were examined to assess the pressure indicators of the flow alteration. We applied the flow duration curve, flow regime coefficient, flood and low-flow frequency analysis as well as Range of Variability Approach (RVA) to investigate the quantitative changes in natural flow regimes. The results indicate that the high flow decreased and low flow increased respectively compared to the natural flow regimes at eight gauging stations. The Geum river is regulated by 139 dams and reservoirs storing 24% of the annual mean discharge and has high surface water use rate of 36%. These indicators are main pressure factors to alter flow regimes.

An Experimental Study on the Performance of Liquid Spill Stopper to Prevent Flood through the Hull Punctures (선박파공으로 인한 선박침수 방지를 위한 파공봉쇄장치 성능의 실험적 연구)

  • Moon, Jung-Hwan;Kim, Jin-Kyeong;Kwon, Ki-Seng;Jung, Kyung-Tae;Yun, Jong-Huwi
    • Journal of Navigation and Port Research
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    • v.37 no.2
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    • pp.149-154
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    • 2013
  • This paper considers the issue of LSS(Liquid Spill Stopper)'s performance verification testing against external resisting force. The importance of the test is to ascertain the possibility of liquid spill stop quickly and efficiently by LSS. The method adopted in this research is the experimental device for puncture's inflow pressure and test the adhesive (magnetic) force on shell plates during the sailing. The major results of the paper are the followings : (a) The performance of LSS against 40 and 100mm diameter puncture was confirmed under 1.0bar. (b) LSS near bow detached first at 20.2 knots. This indicates that LSS can recover the damaged movability needed to naval warships' operation as well as merchant ships.

A Study on Sodium and Potassium Balance of College Women in Seoul (서울지역 일부 여대생의 나트륨과 칼륨평형에 관한 연구)

  • 이영근;승정자;최미경
    • Korean Journal of Community Nutrition
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    • v.4 no.3
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    • pp.375-381
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    • 1999
  • The purpose of this study was to investigate Na and K balances in healthy adult women. Anthropometric assessments, biochemical analysis of blood, 3-day dietary flood records and collections of 3-day food, 24-hr urine and faces were performed to evaluate intakes and excretions of Na and K in 20 college women living in Seoul. The mean BMI and blood pressure of the subjects were 21.08 and 110.25/67.50mmHg, respectively. Mean daily intake of energy was 1578.84kcal, 79% of Korean RDA. Also, daily intakes of Na and K ware 120.86mEq and 44.20mEq. The urinary and fecal excretions of Na were 99.88 and 4.45mEq/day, and those of K were 30.41 and 8.66mEq/day, respectively. The body retention, retention rate, and apparent absorption of Na were 17.11mEq, 13.23%, and 96.31%, and those of K were 5.82mEq, 8.69%, and 80.12%, respectively. The urinary and fecal Na/K ratio were 3.48 and 0.52. There were significantly positive correlations between 1) urinary Na, K excretions and intakes of Na or K, 2) urinary K and BMI, 3) serum K and serum globulin, and 4) urinary Na excretion and serum haptoglobin level, respectively. The results of this study show that Na intake was higher and K intake was lower than those of other advanced nations. Therefore, nutrition education show instruct people to reduce Na intake and to increase K intake.

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Evaluation of Machinability of Micro groove by Cutting Environments in High Speed Machining using Ball End Mill (소구경 미세홈 고속가공시 가공환경변화에 따른 가공성 평가)

  • 정연행;이태문;강명창;이득우;김정석
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2002.04a
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    • pp.32-37
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    • 2002
  • High speed machining is one of most effective technologies to improve productivity. It can give great advantage for manufacture of die and Moulds. However, when the high speed machining of materials, especially in machining of micro groove, a severely thermal demage was generated on workpiece and tool. Generally, the cutting fluid is used to improve penetration, lubrication, and cooling effect. In order to rise the performance of lubrication, it contains extreme pressure agents (Cl, S, P). But the environment of work room go bad by those additive Therefore, the compressed chilly air with Oil mist system was developed to replace the conventional cutting fluid system. This paper carried out the tests to evaluate the machinability by the cutting environment in high speed micro groove machining of NAK80 (HRC40). Compressed chilly air with oil mist was ejected on the contact area between cutting edge and workpiece. The effectiveness of this developed compressed chilly air with oil mist system was evaluated in terms of tool life. The results showed that the tool life of carbide tool coated TiAIN with compressed chilly air mist cooling was much longer than with dry and flood coolant when cutting the material.

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A Case Study on Deformation Conditions and Reinforcement Method of Cavity behind the Lining of Domestic Old Tunnel (국내 재래식 터널의 변상현황과 배면공동 보강 사례연구)

  • Kim, Young-Muk;Lim, Kwang-Su;Ma, Sang-Joon
    • Proceedings of the Korean Geotechical Society Conference
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    • 2005.03a
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    • pp.1343-1350
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    • 2005
  • In this study, the whole deformation conditions of domestic old tunnels and reinforcement methods for deformation tunnels were investigated and analysed, and the present conditions, occurrence cause and reinforcement methods of cavity behind the tunnel lining were investigated and analysed comprehensively. The deformation causes of domestic old tunnels could be classified in three kinds : change of earth pressure operating tunnel ground, material problem of concrete lining, mistake of design and construction. As a result of analysis, the tunnel deformation was occurred by not specific cause but various cause As a result of investigation for 455 domestic tunnel data, more than 70% of the tunnel deformation was related to leakage and the other deformation cause also accompanied leakage mostly. An applied reinforcement method was related to leakage and flood prevention measures, but application of reinforcement method for boundary area between tunnel and ground and tunnel periphery which influence on the tunnel stability was still defective. The cavity of domestic old tunnel occupied about 16% of the total tunnel length and about 68% of cavity was located in the crown of tunnel, and besides, the occurrence cause of cavity was analysed to design, construction and management cause. The filling method for cavity using filling material was comprehensively appling to cavity behind tunnel lining.

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Identifying Spatial Hazard Ranking Using Multicriteria Decision Making Techniques (다기준 의사결정기법을 이용한 공간위험 순위산정)

  • Chung, Eun-Sung;Lee, Kil-Seong
    • Journal of Korea Water Resources Association
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    • v.40 no.12
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    • pp.969-983
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    • 2007
  • This study developed a ten-step procedure of integrated watershed management (IWM) for sustainability to rehabilitate the distorted hydrologic cycle and identified spatial hazard ranking(step 2). Spatial hazard indices, Potential flood damage (PFD), potential streamflow depletion (PSD), potential water quality deterioration (PWQD), and watershed evaluation index (WEI) were developed using multi-criteria decision making (MCDM) techniques and sustainability evaluation concept(pressure-state-response model). The used MCDM techniques are composite programming, compromise programing, Regime method, and EVAMIX approach which are classified by data availability and objectives (prefeasibility and feasibility).

Cutting Characteristics of Micro grooving by Cutting Environments in High Speed Machining using Ball End Mill (미세홈 고속가공시 절삭유제 공급방식에 따른 가공성 평가)

  • 배정철;정연행;강명창;이득우;김정석
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2002.10a
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    • pp.172-175
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    • 2002
  • High speed machining is one of the most effective technologies to improve productivity. It can give great advantage for manufacture of die and Moulds. However, when machining of micro groove in high speed machining a severely thermal damage was generated on workpiece and cutting tool. Generally, the cutting fluid is used to improve penetration. lubrication. and cooling effect. In order to rise the performance of lubrication. it contains extreme pressure agents (Cl, S, P). But the environment of work room go bad by those additive. Therefore, the compressed chilly air with oil mist system was developed to replace the conventional cutting fluid system. This paper carried out the tests to evaluate the machinability by the cutting environment in high speed micro groove machining of NAK80 (HrC40). Compressed chilly air with oil mist was ejected on the contact area between cutting edge and workpiece. The effect of this developed compressed chilly air with oil mist system was evaluated in terms of tool life. The results showed that the tool lift of carbide tool coated TiAlN with compressed chilly air mist cooling was much longer than that of the dry and flood coolant when cutting the material.

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Selection of Evaluation Indicators for Flood Risk Assessment Using DPSIR Framework (DPSIR 체계를 이용한 홍수위험도 평가을 위한 평가인자의 선정)

  • Lee, Gyu-Min;Chung, Eun-Sung;Jun, Kyung-Soo
    • Proceedings of the Korea Water Resources Association Conference
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    • 2011.05a
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    • pp.51-51
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    • 2011
  • 유역의 홍수위험도를 산정하기 위해서는 홍수의 발생가능성과 유역의 홍수방어 능력 등의 환경적, 공학적 요소 이외에도 홍수로 인한 피해 및 영향의 종류에 따라 사회적, 경제적, 문화적, 공학적인 요소를 반영해야 한다. 이들 홍수 피해 요소는 그 중요성이나 특성별로 홍수로부터의 방어 비중이 다르게 설정될 수 있으며 지역별로도 차이를 나타낼 수 있다. 본 연구에서는 홍수위험도를 평가하기 위한 인자 선정에 지속가능성 평가 모형인 DPSIR (Driving force-Pressure-States-Impacts-Response)을 이용하여 환경적, 공학적 요소뿐만 아니라 사회적, 경제적, 문화적인 요소를 반영하고자 한다. DPSIR 모형은 유역의 영향 인자들을 지표로 선정하며 각 지표간의 유기적 관계를 반영하는 구조로 이루어져 홍수로 인하여 인자 간에 발생하는 반응을 묘사할 수 있는 장점이 있다. 또한 인자를 선정함에 있어서 전문가 및 이해당사자들의 견해에 따른 평가 지역의 특성과 지속적인 변화 가능성 등을 유기적으로 연결될 수 있도록 평가요소로 반영할 수 있다. 본 연구는 추가 연구를 통해 남한강의 하도구간 별로 적용될 예정이며 각 인자들에 대한 자료는 문헌조사, 통계자료 조사 및 수리학적 수치모형 등의 분석을 통해 수집될 예정이다. 인자들에 대한 가중치는 전문가들의 의견을 반영할 예정이다. 향후 하천의 구간별 상대적 홍수취약도를 사회, 경제, 문화, 환경적인 측면을 고려한 인자들을 반영하여 정량적으로 제시하므로 하천 구간별 치수관리 우선순위를 결정하는데 적극적으로 활용될 수 있다.

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Forecasting of Various Air Pollutant Parameters in Bangalore Using Naïve Bayesian

  • Shivkumar M;Sudhindra K R;Pranesha T S;Chate D M;Beig G
    • International Journal of Computer Science & Network Security
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    • v.24 no.3
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    • pp.196-200
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    • 2024
  • Weather forecasting is considered to be of utmost important among various important sectors such as flood management and hydro-electricity generation. Although there are various numerical methods for weather forecasting but majority of them are reported to be Mechanistic computationally demanding due to their complexities. Therefore, it is necessary to develop and build models for accurately predicting the weather conditions which are faster as well as efficient in comparison to the prevalent meteorological models. The study has been undertaken to forecast various atmospheric parameters in the city of Bangalore using Naïve Bayes algorithms. The individual parameters analyzed in the study consisted of wind speed (WS), wind direction (WD), relative humidity (RH), solar radiation (SR), black carbon (BC), radiative forcing (RF), air temperature (AT), bar pressure (BP), PM10 and PM2.5 of the Bangalore city collected from Air Quality Monitoring Station for a period of 5 years from January 2015 to May 2019. The study concluded that Naive Bayes is an easy and efficient classifier that is centered on Bayes theorem, is quite efficient in forecasting the various air pollution parameters of the city of Bangalore.

Determination of Surge Tank Scale for Dam Safety Management (댐 안전관리를 위한 조압수조의 규모 결정)

  • Lee, Ho Jin
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.11 no.2
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    • pp.164-174
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    • 2007
  • Phenomena of hydraulic transient such as water hammer should be analyzed to design the pipeline systems effectively in dam. Surge tanks generally are used to reduce change in pressure caused by hydraulic transient from load changes on the turbines. In this study, the appropriate scale of surge tank with chamber is investigated for dam safety management. The variation of water level in the surge tank are computed using governing equation. Using the Thoma-Jaeger's stability condition, static and dynamic stability are investigate for the cases of flood water level, normal high water level, rated water level and low water level. Finally appropriate diameters of shaft and chamber are determined in the surge tank with chamber.