• Title/Summary/Keyword: circulation of water

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Preliminary Study on the MR Temperature Mapping using Center Array-Sequencing Phase Unwrapping Algorithm (Center Array-Sequencing 위상펼침 기법의 MR 온도영상 적용에 관한 기초연구)

  • Tan, Kee Chin;Kim, Tae-Hyung;Chun, Song-I;Han, Yong-Hee;Choi, Ki-Seung;Lee, Kwang-Sig;Jun, Jae-Ryang;Eun, Choong-Ki;Mun, Chi-Woong
    • Investigative Magnetic Resonance Imaging
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    • v.12 no.2
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    • pp.131-141
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    • 2008
  • Purpose : To investigate the feasibility and accuracy of Proton Resonance Frequency (PRF) shift based magnetic resonance (MR) temperature mapping utilizing the self-developed center array-sequencing phase unwrapping (PU) method for non-invasive temperature monitoring. Materials and Methods : The computer simulation was done on the PU algorithm for performance evaluation before further application to MR thermometry. The MR experiments were conducted in two approaches namely PU experiment, and temperature mapping experiment based on the PU technique with all the image postprocessing implemented in MATLAB. A 1.5T MR scanner employing a knee coil with $T2^*$ GRE (Gradient Recalled Echo) pulse sequence were used throughout the experiments. Various subjects such as water phantom, orange, and agarose gel phantom were used for the assessment of the self-developed PU algorithm. The MR temperature mapping experiment was initially attempted on the agarose gel phantom only with the application of a custom-made thermoregulating water pump as the heating source. Heat was generated to the phantom via hot water circulation whilst temperature variation was observed with T-type thermocouple. The PU program was implemented on the reconstructed wrapped phase images prior to map the temperature distribution of subjects. As the temperature change is directly proportional to the phase difference map, the absolute temperature could be estimated from the summation of the computed temperature difference with the measured ambient temperature of subjects. Results : The PU technique successfully recovered and removed the phase wrapping artifacts on MR phase images with various subjects by producing a smooth and continuous phase map thus producing a more reliable temperature map. Conclusion : This work presented a rapid, and robust self-developed center array-sequencing PU algorithm feasible for the application of MR temperature mapping according to the PRF phase shift property.

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A Study on Environmental Impact Assessment Guidelines for Marine Environments in Harbor Construction Projects (항만건설사업의 해양환경 환경영향평가 가이드라인 개발 연구)

  • Maeng, Junho;Kim, Taeyun;Lee, Haemi
    • Journal of Environmental Impact Assessment
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    • v.31 no.3
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    • pp.141-160
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    • 2022
  • The harbor construction projects can lead to various marine environmental problems including habitat degradation and loss, marine water pollution, change of flow patterns, erosion, scour, sedimentation, and so on. The EIA is a measure to prevent various environmental problems in advance from examining and minimizing the environmental impacts before the proposed developments are implemented. In addition, institutions reviewing EIA reports have made efforts to conduct scientific and standardized EIA by applying EIA guidelines for each project. This study aims to create a EIA guideline focusing on the harbor construction projects. Based on the review comments of the harbor construction EIA reports for the past 13 years (2009-2021) and the EIA guidelines of different types of projects, we identified the marine environmental problems and provided the appropriate guideline. This guideline summarizes and presents the contents which must be reviewed in the baseline condition survey, impact assessment, mitigation, and post-environmental impact investigation in the fields of marine fauna and flora, marine physics, and marine water and sediment quality. In the case of a baseline condition survey of marine fauna and flora, a method for selecting survey points considering the characteristics of sea area and project was presented. When estimating the impact of marine fauna and flora, we presented methods for predicting the impact on them due to the spread of suspended sediments and the damage to benthic habitats due to dredging and reclamation. In consideration of the characteristics of the sea area, we divided the survey items of the marine physics into essential items and supplementary items. In predicting the impact of marine physics, various methods for major issues such as seawater circulation, suspended sediment and bottom sediment transport, water temperature and salinity diffusion, seawater exchange, wave transformation, harbor tranquility, and shoreline change were presented. The research results will contribute to protect the marine environment by inducing more systematic and scientific surveys, impact assessments, and mitigation in the EIA process.

Sea Water Type Classification Around the Ieodo Ocean Research Station Based On Satellite Optical Spectrum (인공위성 광학 스펙트럼 기반 이어도 해양과학기지 주변 해수의 수형 분류)

  • Lee, Ji-Hyun;Park, Kyung-Ae;Park, Jae-Jin;Lee, Ki-Tack;Byun, Do-Seung;Jeong, Kwang-Yeong;Oh, Hyun-Ju
    • Journal of the Korean earth science society
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    • v.43 no.5
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    • pp.591-603
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    • 2022
  • The color and optical properties of seawater are determined by the interaction between dissolved organic and inorganic substances and plankton contained in it. The Ieodo - Ocean Research Institute (I-ORS), located in the East China Sea, is affected by the low salinity of the Yangtze River in the west and the Tsushima Warm Current in the south. Thus, it is a suitable site for analyzing the fluctuations in circulation and optical properties around the Korean Peninsula. In this study, seawater surrounding the I-ORS was classified according to its optical characteristics using the satellite remote reflectance observed with Moderate Resolution Imaging Spectroradiometer (MODIS)/Aqua and National Aeronautics and Space Administration (NASA) bio-Optical Marine Algorithm Dataset (NOMAD) from January 2016 to December 2020. Additionally, the variation characteristics of optical water types (OWTs) from different seasons were presented. A total of 59,532 satellite match-up data (d ≤ 10 km) collected from seawater surrounding the I-ORS were classified into 23 types using the spectral angle mapper. The OWTs appearing in relatively clear waters surrounding the I-ORS were observed to be greater than 50% of the total. The maximum OWTs frequency in summer and winter was opposite according to season. In particular, the OWTs corresponding to optically clear seawater were primarily present in the summer. However, the same OWTs were lower than overall 1% rate in winter. Considering the OWTs fluctuations in the East China Sea, the I-ORS is inferred to be located in the transition zone of seawater. This study contributes in understanding the optical characteristics of seawater and improving the accuracy of satellite ocean color variables.

Application of SP Monitoring in the Pohang Geothermal Field (포항 지열 개발지역에서의 SP 장기 관측)

  • Lim Seong Keun;Lee Tae Jong;Song Yoonho;Song Sung-Ho;Yasukawa Kasumi;Cho Byong Wook;Song Young Soo
    • Geophysics and Geophysical Exploration
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    • v.7 no.3
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    • pp.164-173
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    • 2004
  • To delineate geothermal water movement at the Pohang geothermal development site, Self-Potential (SP) survey and monitoring were carried out during pumping tests. Before drilling, background SP data have been gathered to figure out overall potential distribution of the site. The pumping test was performed in two separate periods: 24 hours in December 2003 and 72 hours in March 2004. SP monitoring started several days before the pumping tests with a 128-channel automatic recording system. The background SP survey showed a clear positive anomaly at the northern part of the boreholes, which may be interpreted as an up-flow Bone of the deep geothermal water due to electrokinetic potential generated by hydrothermal circulation. The first and second SP monitoring during the pumping tests performed to figure out the fluid flow in the geothermal reservoir but it was not easy to see clear variations of SP due to pumping and pumping stop. Since the area is covered by some 360 m-thick tertiary sediments with very low electrical resistivity (less than 10 ohm-m), the electrokinetic potential due to deep groundwater flow resulted in being seriously attenuated on the surface. However, when we compared the variation of SP with that of groundwater level and temperature of pumping water, we could identify some areas responsible to the pumping. Dominant SP changes are observed in the south-west part of the boreholes during both the preliminary and long-term pumping periods, where 3-D magnetotelluric survey showed low-resistivity anomaly at the depth of $600m\~1,000m$. Overall analysis suggests that there exist hydraulic connection through the southwestern part to the pumping well.

EXperimental Studies on the Hair Growth Activity of Mylabris Phalerata Pall. Extracts and Fractions in C57BL/6N Mice (C57BL/6N 생쥐에서 반모추출물과 분획물을 이용한 발모(發毛)효과에 대한 실험적 연구)

  • Jo, Han-Young;Kim, Tae-Heon;Kim, Ho;Jeong, Han-Sol;Lee, Chang-Hyun;Lee, Gwang-Gyu
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.22 no.2
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    • pp.357-364
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    • 2008
  • Mylabris is the dried body of the chinese blister beetle. The species used in medicine are Mylabris phalerata and M. cichorii. In recent studies, it has been found that Mylabris possesses antitumor properties, increases the number of leukocytes, and has irritant effects on the urinary organs. The crude extracts of Mylabris have been noted for their highly irritant action and other traditional uses of Mylabris include treatment of poor local blood circulation. The active constituent of Mylabris is cantharidin. The chemical is notable for its vesicant properties, but with severe side effects such as nephrotoxicity. This experiment examined the effect of extracts and fractions, obtained from Mylabris phalerata Pall. on hair growth activity of the C57BL/6N mice after topical application to skin. First, we examined the effect of an extracts, obtained from the alcohol extracts of dried Mylabris phalerata Pall. on hair growth activity of the C57BL/6N mice after topical application to skin. Second, we examined on hair growth activity of the cantharidin fraction of Mylabris phalerata Pall. compared to the control and 1% minoxidil groups. Third, we investigated the number of hair follicle and mast cells after topical application of extracts of Mylabris phalerata Pall. to skin for 16 days. The results were as follows: Hair growth effect from the extracts of Mylabris phalerata Pall.(0.312%) was observed in 80% of mice whose hair had been removed in 13 days. Hair growth effect from the extract of Mylabris phalerata Pall.(0.312 and 0.625%) and 1% minoxidil group was observed in 100% of mice whose hair had been clipped in 20 days. Hair growth effect from the cantharidin fraction(0.5%) and water fraction(0.5%) of Mylabris phalerata Pall. was observed in 100% of mice whose hair had been clipped in 24 days. The hair growth effect on the cantharidin fraction(0.125%) was observed to be strong compared with the minoxidil(3%) group, commercial hair growth agents, in mice whose hair had been clipped in 19 days. In the spontaneous alopecia mice model, the hair growth effect from the cantharidin fraction (0.125%) was observed to be strong as compared with the states before the 13 days experiment. These experiments suggest that extracts and fractions of Mylabris phalerata Pall. may stimulate the topical hair growth activity in low doses.

Literature Review on Spirit and Qi Regimen (정.기(精.氣) 양생법(養生法)에 관한 문헌연구)

  • Baek, Suk-Hee;Sok, So-Hyun;Oh, Hae-Kyung;Moon, Hee-Ja
    • Journal of East-West Nursing Research
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    • v.2 no.1
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    • pp.96-106
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    • 1997
  • In Chinese medicine, the activities of removing and solving the inner cause are called the regimen in preventing the disease and the good condition of mind emphasizes us to practice ourselves the doctrine of regimen of the mind to promote the health and long life of the living body, in other words, it means we should have clean mind, less desire, less thought, less agony and widely open our emotion and will, and it also means the raising of good nature, the moral cultivation, and we can be healthy when we live by good virtus as the root of regiem. The meaning of the Qi has been expanded more and more since its origination throught the process of practice and perception of man. 1) Matter is changed to the smoke when burned, the energy of water becomes the rain in the sky and the rain raises all living creatures by making them wet. Throught these changes of circulation, men could realize the energy to be the common and original matter of forming all the creatures. 2) The direction of showing the breathing of men in and out has been expended. 3) It was widely understood as the meaning of showing vitality of men, and it was the original root of chinese medicine. 4) It was expended to be showing spirit of nature such as the sun, moon, star, sky, land, mountain and the moral spirit of men as peacefullness. By the original meaning of the word of energy expanded to the wider side of sky, land, men and things, nature, society, man and the moral spirit could get the unified basis of the matter. As the above, the word of Qi has been used in wider meaning at this time from the past. In other words, all things in the universe come into being and extinct by the chang of motion of the Qi and it is recognized to be the living activity in human body. The Qi-kong based on this energy and the motion applied to our daily life are very extensive (Lee, Hye - lung, 1997). Here are the summaries of the effect of the Qi-kong ; 1) The physical constitution is strenthened, physiological function is prosperous and we are free from various geriatric disease and psychosomatic disease not to mention the cold and indigestion. 2) It maintains the clear spirit, elevates intelligence, strengthens the spiritual power and demonstrates the potentiality at the amximum. 3) It maintain beautiful figure and clean skin never losing the charm but full of energy and vitality. 4) It keeps the balanced body never suffering from the unbalance of the bones, various and neuralgia. 5) It maintain the spiritual comfort, the natural posture in everything and real happiness (Lee, Hye-Jung, 1997 : Suh, Yong Kyu, 1989). Chinese medicine mentions the motion by Qi with Qi - kong. But the motion does not require special method in Western medicine. I t is the only way of living of our ancestor indaily life. It is maintaining the healthy lifr by training the Qi, and it is the motion of being with the nature with the open mind in breathing rather than artificially restricting our daily life, it is the motion of the body.

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Ecological Comparison of Several Lakes in Summer Stagnation Period (하계정체기에 있어서 수개호소의 생태학적 비교연구)

  • 엄규백
    • Journal of Plant Biology
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    • v.16 no.3_4
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    • pp.17-34
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    • 1973
  • The physico-chemical factors, the distribution of chlorophyll and the primary production of the lakes Hwajinpo, Yongrangho, Chunchonho, Uiamho, Soyangho and Changjamot have been studied in order to make ecological comparison among these lakes during summer stagnation period of August to September of 1973. On the basis of the characteristics of these lakes, the lake types have been discussed. Thermocline is observed at 3-4m zone in the lake Changjamot and 4-5m zone in the lake Yongrangho. In the case of lake Hwajinpo and impoundments, the distinct thermal stratification is not observed at the summer stagnation period. As to vertical distribution of dissolved oxygen, a positive heterograde curve is obtained in the lakes Hwajinpo and Yongrangho. In the lake Changjamot the typical clinograde curve and the oxygen depletion in hypolimnion are observed. In the case of impoundments, however, the orthograde curve is observed in the lakes Chunchonho and Uiamho. While in the lake Soyangho, any stratification of the disssolved oxygen is not found. In the brackish lakes, such as lakes Hwajinpo and Yongragho, the salinity of hypolimnion is found to be much higher than that of epilimnion. In the lake Hwajinpo, the salinity of hypolimnion is exhibited 32.7$\textperthousand$, which is nearly the same as sea water. The distribution of nitrogenous compounds and phosphates is found to be high in the lake Changjmot. The silicate is also found in high concentration in the lake Chunchonho, and the distribution of nutrients in the brackish lakes is generally low. As to the vertical distribution of chlorophyll level, the lake Changjamot shows a stratum type and the brackish lakes L-type stratification. In the impoundments, lakes Chunchonho and Uiamho appear to be homogeneous type. Seasonal variation of chlorophyll level in the lake Changjamot is examined from January to September 1973. The vertical distribution of chlorophyll during the period of circulation from January to April is homogeneous type and is stratum type thereafter. The maximum chlorophyll level is 277.4mg/$m^2$ on June 23 and the pattern of seasonal variation of chlorophyll level is comparable to the type of eutrophy. The horizontal distribution of chlorophyll level is studied in the brackish lakes, Hwajinpo and Yongrangho. The pattern of distribution is found to be an irregular type. On the basis of measurements of primary production by means of the carbon-14 method and the distribution of chlorophyll level, it is concluded that the interior part of the lake Hwajinpo and Changjamot are eutrophic and the exterior part of the lake Hwajinpo, lake Yongrangho and the impoundments, lake Uiambo and Soyangho are mesotrophic.

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Complementary measures for Environmental Performance Evaluation Index of External Space of Green Standard for Energy and Environmental Design for Apartment Complex - Focused on the Respect of Response to Climate Change - (공동주택 녹색건축인증기준의 외부공간 환경성능 평가지표 보완방안 - 기후변화 대응 측면을 중심으로 -)

  • Ye, Tae-Gon;Kim, Kwang-Hyun;Kwon, Young-Sang
    • Journal of the Architectural Institute of Korea Planning & Design
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    • v.34 no.1
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    • pp.3-14
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    • 2018
  • An apartment complex is a building use with great potential to contribute to solving problems related to urban ecological environment and climate change. The first goal of this study is to grasp the current situation of application and limitations of the ecological area rate, which is a representative evaluation index used to evaluate the environmental performance of the external space of an apartment complex in Green Standard for Energy and Environmental Design (G-SEED). The second goal is to propose a prototype of the evaluation index for evaluating greenhouse gas (GHG) reduction performance in order to supplement the evaluation index for the environmental performance of the external space in terms of response to climate change. We analyzed 43 cases of apartment complexes certified according to G-SEED, which was enforced since July 1, 2010, and found application characteristics of each space type and the limitations of ecological area rate. We analyzed overseas green building certification systems such as LEED and BREEAM that derived implications for supplementing the limitations of ecological area rate, which is focused on the evaluation of soil and water circulation function, and set up a development direction of complementary measures. Through analysis of previous studies, relevant regulations and standards, and technical documents of the manufacturer, the heat island mitigation performance of the pavement and roof surfaces of the apartment complex and the carbon uptake performance of the trees in the apartment complex was selected as parameters to yield the GHG reduction performance of the external space of the apartment complex. Finally, a quantitative evaluation method for each parameter and a prototype of the evaluation index for the GHG reduction performance were proposed. As a result of applying the prototype to an apartment complex case, the possibility of adoption and applicability as an evaluation index of G-SEED were proved.

Model Test on the Opening Efficiency of the Midwater Pair Trawl Net (쌍끌이 중층망의 전개성능에 대한 모형실험)

  • 김정문;김진건
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.36 no.2
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    • pp.73-88
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    • 2000
  • A series of analysis and experiment on the fishing gear and method of the existing midwater pair trawl net with 12,800mm of maximum mesh size is carried out to determine the most effective shape factor. As the first step of this study, the fishing gear and method for the existing net are analyzed to solve problems, such as being low of the net height by increasing the towing speed, twist of net pendant and twine, suspension of float between knots of mesh. etc. Standing on these results, the existing net are modified by very effective shape based on the theory and technology designing the fishing gear. Also, the model experiment is carried out to determine the most effective shape factor of the modified net in the circulation water channel. The obtained results can be summarized as follows : 1. On the length of net pendants(No.2 and No.3) connected with side line, opening efficiency of net with length 8.0cm of net pendant is the greatest and in the order of 11.5cm, 15.0cm. 2. On the number of the net pendant, opening efficiency of net with 4 lines of net pendant is the greatest and in the order of 3 lines, 2 lines. Center part of side panel is pushed out backward, and the pushed length is increasing by increasing flow speed. 3. On the sinking force, opening efficiency of the net is increasing by increasing sinking force. And opening efficiency shows almost the same when sinking force is greater about 1.5 times than that of the existing net in case of the net with 3 lines of net pendant, and about 1.6 ~ 1.7 times than that of the existing net in case of the net with 2 lines.

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Computational Fluid Analysis for Otter Boards ( 1 ) - Pattern of Fluid Flow Besides Otter Board - (전개판에 대한 수치해석 ( 1 ) - 전개판 주위에서의 유체흐름의 패턴 -)

  • Ko, Kwan-Soh;Kwon, Byeong-Guk;Ro, Ki-Deok
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.26 no.4
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    • pp.333-340
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    • 1990
  • The authors carried out a visiualizational model test by the hydrogen bubble method to examine the pattern of the fluid flow besides the simple camber type and plane type otter board in circulation water channel. The experimental conditions are velocity of flow 0.05 and 0.1m/sec, angle of attack 0$^{\circ}$~45$^{\circ}$(5$^{\circ}$step). The results obtained are as follows: 1. In the case of the simple camber type otter board located angle of attack 25$^{\circ}$, vortex at the leading edge was geneated at 1/2 of chord length. 2. Size of the vortex generated in the trailing edge was about 2~3 times larger then that of the leading edge. 3. In the case of the simple camber type otter board located angle of attack 30$^{\circ}$, separation of stream-line at leading edge was generated at 1/3 of chord length. 4. Nearest stream-line in the back side of the simple camber type otter board was bent in the direction of otter board when the angle of attack was 25$^{\circ}$ and 30$^{\circ}$, and in the case of plane type otter board was expanded outside of the flow direction. 6. Area separated of the simple camber type otter board at the angle of attack 30$^{\circ}$ was smaller then that of plane type otter board. 7. Flow speed in the back side of the simple camber type otter board was about 1.4 times faster then that in the front side, and in the case of the plane otter board about 1.2 times faster.

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