• Title/Summary/Keyword: floating prevention

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Tension calculation on trash curtain in current (흐름중 부유쓰레기 차단막에 작용하는 장력계산)

  • Cho I.H;Choi H.S.;Yu J.S.
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.4 no.3
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    • pp.65-73
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    • 2001
  • Herein, a theoretical method based on the catenary model Is applied to obtain the tension and drag forces acting on the trash curtain which is deployed at river for the prevention of floating debris inflow into the ocean. Under the assumption that fluid drag is perpendicular to the trash curtain, the tension and drag forces are uniform along the trash curtain. As a numerical model, the trash curtain is moored both symmetrically and asymmetrically with respect to the flow. The tension and drag forces on the trash curtain are investigated according to the change of Bap ratio and inclined angle of the trash curtain. Numerical results show that tension parameter is increased as the gap ratio is increased. It is found that tension parameter is reduced as the inclined angle is increased in the case of asymmetric deployment. The numerical model is applied to the specific problem for the trash curtain (200m) deployed at the Tancheon on the Han river. The maximum inflow velocity that anchor system can endure is 2m/sec.

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Studies on a Plan for Afforestation at Tong-ri Beach Resort - Analysis of Factors Causing Disasters around Beach - (통리해수욕장(桶里海水浴場) 녹지대조성(綠地帶造成)에 관(關)한 연구(研究)(I) - 사구지주변(砂丘地周邊)의 재해요인분석(災害要因分析) -)

  • Cho, Hi Doo
    • Journal of Korean Society of Forest Science
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    • v.77 no.2
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    • pp.178-185
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    • 1988
  • This study is carried out for analyzing the factors causing several disasters occurring around beach area in order to set a plan for an afforestation which will fulfill its function as facilities for prevention of disasters and for relaxation around beach resort at Tong-ri, Pokil-my$\bar{o}$n, Wando-gun. The results are as follows : 1. The main wind direction was summer was SE. 2. The first class in the rate of frequency of the hourly average wind speed and the instantaneous wind speed in summer were 2.1-3.0m/sec (29.2%) and 1.1-2.0m/sec (30.6%) respectively. 3. The particle sizes of the dune sands was a little small (82.5% in 0.125 to 0.25mm, $D_{50}=0.178mm$). 4. The mineral composition and the chemical components were as follows : The main mineral : Quartz The accessary minerals : Calcite, Feldspars(Orthoclase), Sericite. The chemical components : $SiO_2$ ; 75.6%. $Al_2O_3$ ; 8.1%, CaO ; 7.76%, Ign. loss ; 6.8%, MgO ; 0.23%, $K_2O$ ; 0.72%, $Na_2O$ ; 0.41%, $Fe_2O_3$ ; 0.32%. 5. The threshold friction velocity equation for the diameter class of the dune sands was $y=4.191x^{0.221}$. 6. The amount of floating salt was maximum at the point of 65m away from beach line, dropped abruptly at 135m and remained almost same on its way to the inland. The equation of the amount of floating salt was $y=28.181{\times}(-0.369^x)$. 7. The amount of extracted salt(33%) in seawater in summer was the same as the one of the nearest seawater of Korea.

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Experimental and Numerical Study of Berthing and Unberthing of LNG-Bunkering Vessels (실험 및 수치해석을 통한 LNG 벙커링 선박들의 이접안 안정성 평가 연구)

  • Jung, Sung-Jun;Oh, Seung-Hoon;Jung, Dong-Woo;Kim, Yun-Ho;Jung, Dong-Ho
    • Journal of Navigation and Port Research
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    • v.44 no.6
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    • pp.439-446
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    • 2020
  • The IMO has adopted emission standards through Annex VI of the International Convention for the Prevention of Pollution from Ships (MARPOL) that strictly prohibit the use of bunker C oil for vessels. In this study, we have adopted the turret-moored Floating LNG-Bunkering Terminal (FLBT) which is designed to receive the LNG from LNGCs and transfer it to LNG-bunkering shuttles in side-by-side moored condition. Numerical analyses were carried out using the high-order boundary-element method for four vessels at various relative distances. Mean wave drift forces were compared in an operational sea state. A model test was performed in the ocean engineering basin at the Korea Research Institute of Ships & Ocean Engineering (KRISO) to verify the safety of the berthing/unberthing operation. In the model test, a jig was designed to simulate tug boats pushing or pulling the bunkering vessels, so that the friction force of the g operation was not affected. Safety depended on the environmental direction, with more stable operation possible if the heading-control function of FLBT is applied to avoid beam-sea conditions.

Association between Smoking and Mortality: Khon Kaen Cohort Study, Thailand

  • Kamsa-ard, Siriporn;Promthet, Supannee;Lewington, Sarah;Burrett, Julie Ann;Sherliker, Paul;Kamsa-ard, Supot;Wiangnon, Surapon;Parkin, Donald Maxwell
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.4
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    • pp.2643-2647
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    • 2013
  • Background: Despite anti-smoking campaigns, smoking prevalence among Thai males aged 30 or older is high, at around 50%. The purpose of this study was to determine the relationship between smoking and mortality in a rural Thai community. Materials and Methods: Subjects enrolled into the Khon Kaen cohort study between 1990 and 2001 were followed up for their vital status until $16^{th}$ March 2012. The death resource was from the Bureau of Policy and Strategy, Ministry of Interior, Thailand. A Cox proportional hazards model was used to analyse the association between smoking and death, controlling for age, education level and alcohol drinking, and confidence intervals were calculated using the floating risk method. Results: The study recruited 5,962 male subjects, of whom 1,396 died during a median 13.5 years of follow-up. Current smokers were more likely to die than never smokers after controlling for age, education level and alcohol drinking (HR, 95%CI: 1.41, 1.32-1.51), and the excess mortality was greatest for lung cancer (HR, 95%CI: 3.51, 2.65-4.66). However, there was no increased risk with increasing dose of tobacco, and no difference in risk between smokers of yamuan (hand-rolled cigarettes) and manufactured tobacco. Conclusion: Mortality from cancer, particularly lung cancer, and from all causes combined is dependent on smoking status among men in rural Thailand, but the relative risks are lower than have been reported from studies in high income countries, where the tobacco epidemic is more established.

A Study on the Planning Methods for Pollution Prevention of Building Exterior - Focused On the Public Borough Offices in Seoul - (건축물 외관의 오염방지를 위한 계획적 방안 연구 - 서울시 구청을 대상으로 -)

  • Choi, Myung-Hwan;Choi, Moon-Gyu
    • Journal of the Architectural Institute of Korea Planning & Design
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    • v.36 no.4
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    • pp.71-81
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    • 2020
  • The purpose of this study is to propose the planning methods for pollution prevention in the initial design stage by identifying the pollution phenomena on the exterior of the building. It is important to catch the problem early on because exterior troubles begin with an initial design defect and causes rapid aging. The scope of this study is seoul public borough offices that should be sustainable for long as landmark located at the center of the district. Field survey was conducted three times in six months. Twenty-six borough offices were diagnosed with three levels of contamination through visual inspection and the contaminated locations, types, materials, and characteristics were checked. Fourteen common contaminated locations were identified in the first and intensively rechecked in the second. Five locations vulnerable to contamination were designated and the contamination and cleanliness situations were checked by location in the third. As a result, main polluted types and locations are sloping wall, upper wall, protruded wall, canopy, and wall under window. The key to avoiding these pollution problems is to minimize the horizontal plane on which dust can be deposited. In other words, it can be considered variously by shape and location, such as the slope of the horizontal plane, the floating of the surface, the installation of the roof surface, and the vertical louvers. And throating plans and material plans suitable for each location are presented. Various methods of the shape and location, material are expected to use as useful basic data for preventing pollutions during the initial design stage.

Effects of geometric shape of LWSCR (lazy-wave steel catenary riser) on its global performance and structural behavior

  • Kim, Seungjun;Kim, Moo-Hyun
    • Ocean Systems Engineering
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    • v.8 no.3
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    • pp.247-279
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    • 2018
  • This study aims to investigate the behavioral characteristics of the LWSCR (lazy-wave steel catenary riser) for a turret-moored FPSO (Floating Production Storage Offloading) by using fully-coupled hull-mooring-riser dynamic simulation program in time domain. In particular, the effects of initial geometric profile on the global performance and structural behavior are investigated in depth to have an insight for optimal design. In this regard, a systematic parametric study with varying the initial curvature of sag and arch bend and initial position of touch down point (TDP) is conducted for 100-yr wind-wave-current (WWC) hurricane condition. The FPSO motions, riser dynamics, constituent structural stress results, accumulated fatigue damage of the LWSCR are presented and analyzed to draw a general trend of the relationship between the LWSCR geometric parameters and the resulting dynamic/structural performance. According to this study, the initial curvature of the sag and arch bend plays an important role in absorbing transferred platform motions, while the position of TDP mainly affects the change of static-stress level.

Apoplexy and Hyungsang Medicine (중풍의 형상의학적 고찰)

  • Jung, Haeng-Gyu;Lee, Yong-Tae
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.19 no.3
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    • pp.573-579
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    • 2005
  • The followings are the conclusions drawn from the clinical cases of apoplexy; The main cause of apoplexy is the deficiency of both Jung and Ki. dam typed persons are stricken with paralyses because of the insufficiency of the kidney water. On the other hand, bangkwang typed persons' apoplexy comes from the deficiency of Ki and dump-phlegm. The prevention of apoplexy is very important so that porpe medical care should be taken at the appearance of premonitory symptoms like vertigo, dim sight tinnitus, stiff neck, numbness and others. It appears very reasonable both clinically and pathologically that Li dongyuen classified the apoplexy in to three groups : the first group is apoplexy involving meridians ; the second. involving Bu ; the third, involving Jang. The accurate diagnosis of apoplexy regulates com prehension consideration of four factors configuration color, pulse and symptoms and distinction from the similar diseases. Apoplexy is the up wand floating of Yaug in deficiency due to the deficiency of genuine Yim. In its early stages it should be treated by eliminating the excess in the upper pant. In the lower pant becomes the fundamental treatment.

Experimental Performance Evaluation of Complex Behavior Connector by Scaled Model (축소모형에 의한 복합거동 연결체의 실험적 성능 평가)

  • Kim, Kisung;Kang, Hyounhoi;Park, Jeongjun
    • Journal of the Society of Disaster Information
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    • v.13 no.2
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    • pp.130-138
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    • 2017
  • The connector of the complex behavior is to connect the individual piles of the pile to the lower foundation of the oil sand plant where the floating foundation is used. In this study, to verify the shape of a connector of the complex behavior for applying the advantages of existing group pile and piled raft foundation to an oil sand plant, a scaled model was constructed to measure the behavior of the load.

A Study on Preventive Measures against Large Oil Spills in the Korean Coastal Waters-1 - Analyzing the Spill Accident from M/T Hebei Spirit - (우리나라 연안역에서의 대형해양오염사고 방지책에 관한 연구-1 - Hebei Spirit 호 오염사고를 중심으로 -)

  • Yun, Jong-Hwui
    • Proceedings of KOSOMES biannual meeting
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    • 2008.05a
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    • pp.249-255
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    • 2008
  • IOn 7th of Dec. 2007, large oil spill took place the seas off the Taean coast caused by the collision between VLCC Hebei Spirit and crane floating barge Samsung-1 and a lot of problems were revealed during response to the accident. The author, accordingly, examined to analyze the cause of this accident on the aspect of spill prevention and presented some preventive measures, such as strictness to the current standard for tug operation, expansion of VTS service area and transfer of the VTS responsibility to Korea Coast Guard, designation of appropriate anchorage per ship's type, cargo and visiting purpose, and special management for dangerous goods carriers.

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A Study on the Prevention of Appropriate Store and Gentrification to Restore the Function of the Commercial District in the Original City

  • RYU, Tae-Chang
    • Journal of Distribution Science
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    • v.20 no.11
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    • pp.109-120
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    • 2022
  • Purpose: We would like to identify the appropriate size of stores in the commercial district suitable for the era of low growth. In addition, it is intended to present alternatives to prevent gentrification along with measures to revitalize commercial districts according to the selection of appropriate stores. Research design, data and methodology: The importance and commercial district usage patterns were identified through surveys by consumers and sellers. the demand and size of the commercial area were calculated based on the floating population and resident registration population. In addition, based on this, through metric analysis, the importance of the business district activation plan and what important matters can prevent gentrification were analyzed. Result: In this the study, 555 stores are currently operating in the target area, but it is seen as a commercial district with a scale that can operate 136 stores and 938 stores. In addition, it was analyzed that the Commercial Lease Protection Act needs to be strengthened to prevent gentrification. Conclusions: Due to the nature of small and medium-sized cities in Korea, commercial districts that have once lost their resilience must take much effort to find vitality. It is believed that local commercial districts will have resilience when diagnosis and recovery measures are adequately presented.