• 제목/요약/키워드: Water movement

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Principles and Directions for Urban-Rural Living Community Movement (도농공동체 운동의 추진방향)

  • Kim, Ho
    • Korean Journal of Organic Agriculture
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    • v.12 no.1
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    • pp.67-80
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    • 2004
  • Farm economy is getting worse because of the free trade trends in agriculture sector and unreasonable application of market economy principles to agricultural products. And The worldwide issues of environmental pollution as well as want of food, water and energy make human future be anxious. In addition, consumers raise questions in argument about safety of foods produced by traditional farming or imported. So I propose the urban-rural living community movement(URLCM) as an alternative plan for sustainable domestic agriculture. URLCM based on environmentally friendly agriculture and community consciousness will be able to solve many of present issues on agriculture and rural society through incessant interchanges between urban and rural community. This URLCM has to be basically founded on principles of symbiosis-coexistence and life circulation. So those that have to be driven forward arc organizing producers and consumer cooperatives, making environmentally friendly rural region and products, combining with consumer cooperatives, training the participants and so forth.

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Groundwater Characterization according to Hydraulic Conductivity Input Method (수리전도도 적용 방식에 따른 지하수특성 분석)

  • Ahn, Seung-Seop;Park, Dong-Il
    • Journal of Environmental Science International
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    • v.24 no.7
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    • pp.939-946
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    • 2015
  • Hydraulic conductivity is an important parameter in the analytical model of groundwater. This study analyzed the groundwater movement characteristics by estimating optimal parameters according to hydraulic conductivity input methods with the MODFLOW model which is widely used. It first estimated the optimal parameters by dividing hydraulic conductivity zones by attitude. Next, it estimated optimal parameters by geological characteristic. It analyzed the groundwater movement characteristics by applying the recharge quantity and amount of evapotranspiration of drought periods and flood years with the estimated parameters. As the result was analyzed that there are differences of observation water level values according to hydraulic conductivity input methods but there is no big differences of overall groundwater movement characteristics by hydraulic conductivity input method, the two methods have found to be applicability in analyses of groundwater. So, it is judged that studies on more exact application of hydraulic conductivity and the application methods are needed.

Estimation of Maximum Inundation Zone due to Tsunamis with Moving Boundary (이동경계를 이용한 지진해일의 최대범람구역 추산)

  • 조용식;서승원
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.13 no.2
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    • pp.100-108
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    • 2001
  • Along the shoreline a special treatment is required to simulate movement of periodic waves such as tsunami and tide because of continuous movement of shoreline as waves rise and recede. A moving boundary treatment is first proposed to track the movement of shoreline in this study. The treatment is then employed to obtain a maximum inundation area to be used for mitigation of coastal flooding. The obtained maximum inundation zone for a specific location is compared to that of available observed data. A reasonable agreement is observed.

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Measurement of Variation in Water Equivalent Path Length by Respiratory Organ Movement

  • Minohara, Shinichi;Kanai, Tatsuaki;Endo, Masahiro;Kato, Hirotoshi;Miyamoto, Tadaaki;Tsujii, Hirohiko
    • Proceedings of the Korean Society of Medical Physics Conference
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    • 2002.09a
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    • pp.90-93
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    • 2002
  • In particle radiotherapy, a shape of the beam to conform the irradiation field is statically defined by the compensator, collimator and potal devices at the outside of the patient body. However the target such as lung or liver cancer moves along with respiration. This increases the irradiated volume of normal tissue. Prior discussions about organ motions along with respiration have been mainly focused on inferior-superior movement that was usually perpendicular to beam axis. On the other hand, the change of the target depth along the beam axis is very important especially in particle radiotherapy, because the range end of beam (Bragg peak) is so sharp as to be matched to distal edge of the target. In treatment planning, the range of the particle beam inside the body is calculated using a calibration curve relating CT number and water equivalent path length (WEL) to correct the inhomogeneities of tissues. The variation in CT number along the beam path would cause the uncertainties of range calculation at treatment planning for particle radiotherapy. To estimate the uncertainties of the range calculation associated with patient breathing, we proposed the method using sequential CT images with respiration waveform, and analyzed organ motions and WELs at patients that had lung or liver cancer. The variation of the depth along the beam path was presented in WEL rather than geometrical length. In analyzed cases, WELs around the diaphragm were remarkably changed depending on the respiration, and the magnitude of these WEL variations was almost comparable to inferior-superior movement of diaphragm. The variation of WEL around the lung was influenced by heartbeat.

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Experimental Studies for Analyzing Salt Movement and Desalinization Effects on Reclaiming New Manguem Tideland (새만금지구 간석지토양의 염분거동해석 및 제염효과분석을 위한 실험적연구)

  • 구자웅;한강완;서승덕
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.31 no.2
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    • pp.92-103
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    • 1989
  • This study was performed in order to produce the basic data for devising irrigation project and desalinization countermeasure through analyzing salt movement and desalinzation effects. The Desalinization experiments with water management practices were carried out, using the soil samples collected in New Manguem tideland. The changes of electrical conductivity, exchangeable sodium percentage, pH and hydraulic conductivity during the desalinization experiments, and the correlations between various factors influencing desalinization, were analyzed by the statistical method. The results obtained from this study were summarized as follows: 1. The sample soils used in this study were salin-sotlic soils with the high electrical conductivity and the high exchangeable sodium percentage, and the soil texture was silt loam. 2. A large amount of the soluble salts was removed in the begining of desalinization experiments. The initial electrical conductivity and the initial exchangeable sodium percentage decreased considerably in the beginning, and were gradually slow in the rate of decrease 3. The value of pH showed a tendency to increase during the desalinization and were little by little slow in the rate of increase, and could be estimated by the regression equation. 4. The initial hydraulic conductivity were raised greatly with gypsum treatment and the penmeability was maintained adequately, The hydraulic conductivity and the leaching time elapsed during the desalinization could be estimated by the regression equation. 5. The water requirement for desalinization with various water management practices could be estimated for a given electrical conductivity, exchangeable sodium percentage, and pH reading respectively.

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Experimental Study on Freezing Soil Barrier Wall for Contaminant Transfer Interception (오염물질 이동 차단을 위한 동결차수벽 형성에 관한 실험적 연구)

  • Shin, Eun-Chul;Kim, Jin-Soo
    • Journal of the Korean Geosynthetics Society
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    • v.10 no.2
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    • pp.29-34
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    • 2011
  • The purpose of this study was to prevent spreading of contaminants from movement of underground water by creating a barrier using artificial freezing method on a soil contaminated by oils and various DNAPLs. Specimens with 80% and 90% degrees of saturation were prepared to form freezing barrier using artificial freezing method. As the results of freezing specimen within soil bin with artificial ground freezing system, artificial contaminated soil cut off wall formed the thinnest wall after 12 hours. It is judged that this cut off wall will control the second soil pollution by intercepting expansion and movement of pollutants and DNAPLs within artificial contaminated soil cut off wall by underground water, intercepting inflow or outflow of underground water. Cut off walls formed by artificial ground freezing system had each other freezing speed according to degree of saturation.

Study on the Theory of Mind and Body Practice in Dan-Jeon-Ju-Seon (단전주선(丹田住禪)에 나타난 심신수행론)

  • Kim, Su-In
    • Korean Journal of Acupuncture
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    • v.28 no.4
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    • pp.177-198
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    • 2011
  • Objectives : The purpose of this study is to examine the theory of mind and body practice in Dan-Jeon-Ju-Seon from the point of views of Taoism, Buddhism, and Oriental medicine. Methods : An ideological background and development of Dan-Jeon-Ju-Seon was first examined. Then, the definition of, other descriptions of, and various locations of, Dan-Jeon were investigated. In addition, the theory of Qi movement of Shui Sheng Huo Jiang (ascent of water Chi and descent of fire Chi) in Dan-Jeon-Ju-Seon was taken into consideration from perspectives on the thought of Taoist Nei Dan (internal alchemy) and Oriental medicine. Finally, the characteristics of mind and body practice in Dan-Jeon-Ju-Seon. Results & Conclusions : Dan-Jeon in Dan-Jeon-Ju-Seon consists of three parts, upper, middle, and lower Dan-Jeon, which is related to Jing (sperm, essence) Qi (breath, eneregy) Shen (spirit, intellect) of our body. Jing Qi Shen is a crucial part in our mind and body, mind and body are connected by energy, and the energy flow is possible by ascent of water Chi and descent of fire Chi. Ultimately, Dan-Jeon-Ju-Seon is a method of practice to keep one's mind and body healthy, and its purpose is to do timeless meditation in our daily lives regardless of time and place.

Stress Analysis for Differential Drying Shrinkage of Concrete (콘크리트의 부등건조수축으로 인한 응력의 해석)

  • 김진근;김효범
    • Magazine of the Korea Concrete Institute
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    • v.6 no.4
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    • pp.102-112
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    • 1994
  • The drying shrinkage of concrete has a close relation to the water movement. Since the diffusion process of water in concrete is strongly dependent on the temperature and the pore humidity, the process is highly nonlinear phenomena. This study consists of two parts. The first is the development of a finite element program which is capable of simulating the rnoisture distri- ,bution in concrete, and the other is the estimation of the differential drying shrinkage and stress considering creep by using the modified elastic modulus due to inner temperature change and maturity. It is shown that the analytical results of this study are in good agreement with experlimental data in the literatures, and results calculated by BP-KX model. The internal stress caused by moisture distribution which was resulted from the diffusion process, was calculated :quantitatively. The tensile stress which occured in the drying outer zone mostly exceeded the tensile strength of concrete, and necessarily would result in crack formation.

The Effect of the Deformation on the Sensitivity of a Flexible PDMS Membrane Sensor to Measure the Impact Force of a Water Droplet (액적의 충격력 측정을 위한 유연 멤브레인 센서의 PDMS 변형에 의한 민감도의 영향)

  • Kang, Dong Kwan;Lee, Sangmin
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.21 no.5
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    • pp.16-21
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    • 2022
  • This study investigates the effect of the deformation on the sensitivity of a flexible polydimethylsiloxane (PDMS) membrane sensor. A PDMS membrane sensor was developed to measure the impact force of a water droplet using a silver nanowire (AgNW). The initial deformation of the membrane was confirmed with the application of a tensile force (i.e., tension) and fixing force (i.e., compressive force) at the gripers, which affects the sensitivity. The experimental results show that as the tension applied to the membrane increased, the sensitivity of the sensor decreased. The initial electrical resistance increased as the fixing force increased, while the sensitivity of the sensor decreased as the initial resistance increased. The movement of the membrane due to the impact force of the water droplet was observed with a high-speed camera, and was correlated with the measured sensor signal. The analysis of the motion of the membrane and droplets after collision confirmed the periodic movement of not only the membrane but also the change in the height of the droplet.

A Policy Study to Preserve the Water Quality through the Activation of Local Autonomy (지방자치의 활성화를 통한 수질보전정책연구: 낙동강 수계오염과 위천공단 조성에 관한 갈등해결의 모색)

  • 김성수
    • Journal of Environmental Science International
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    • v.5 no.3
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    • pp.297-316
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    • 1996
  • This research emphasizes the necessity of the understanding and cooperation among focal governments to preserve the water quality of the Nak-dong river that runs through four local governments. First, this research considers the status of water-pollution in the Nakdong river, describes and finds problems within the central government's. "Clean Water Supply Plan" and local governments' water quality-related policies. Second, it deals with the conflict among local governments concerning the planning and building of "Wicheon Industrial Complex" in the middle-upstream of the Nakdong river which has triggered the opposition movement of the local governments and residents of the river's downstream area. With stressing the necessity of the understanding and cooperation among local governments, this research emphasizes roles of central government, of academic experts, and of local news-media in preserving the water quality. Key words : the Nakdong river, water quality policy, the conflict among local governments, the activation of local autonomy, Wicheon Industrial Complex, the cooperation among local governments.

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