• Title/Summary/Keyword: Water Transportation

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A Study on the Maneuvering Area of Ship in Moving at Single Point Mooring (SPM 이안 선박의 조종영역에 관한 기초 연구)

  • Kim Jin-Soo;Jong Jae-Yong;Kim Kyung-Tae
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.11 no.2 s.23
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    • pp.19-25
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    • 2005
  • The work of VLCC SPM mainly is accomplished on the open sea. On the open sea as a result of meteorological condition and the ocean wave influence, When the weather condition is get bed, peremptorily moving to the safety place, bemuse of the gale and the billow, almost happened frequently, the pilot is unable to go on board and the tug is also unable to be used Now bemuse of the bad weather the VLCC SPM moving to the other safety place frequently happened in the ulsan port. the construction of new harbor, it constructed many break water around SPM. So that it is necessary to propose the new standard about how to maneuvering area actually. Now our country is at the blank stage about the establishment of SPM research Most of the situations refer to overseas standards. But these standards lack consistency and clarity. So when moving to the another safe place from SPM, we must Carry through the research and study on the ships using sailing through AIS Data We must put forward a new standard about maneuvering area of ships moving at SPM.

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A Study of Breakwater Layout on the Basis of Marine Traffic Flow (해상교통흐름을 고려한 방파제 형상 설계에 관한 연구)

  • Jung Jae-Yong;Park Young-Soo;Ko Jae-Yong
    • Proceedings of KOSOMES biannual meeting
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    • 2004.11a
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    • pp.57-62
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    • 2004
  • A mariner feels the ship-handling difficulty when the vessel onboard passes through breakwater. Until now, there is no a layout design of breakwater to take into account the ship-handling difficulty for the mariner. 11Us paper reproduced this situation which ship-handling is difficult by using marine traffic flow simulation, and it applied to Environmental Stress Model as the assessment model which is a quantitative model for evaluating the difficulty of ship-handling arising from restriction in maneuvering water areas and arising from traffic congestion The results are as follows. (1) The layout change of breakwater has little influence for reduction of ship-handling difficulty in the areas of vessel traffic volume. (2) In the situation of same breakwater width, difference of ship speed has an effect on decrease of ship-handling difficulty. (3) Expansion of breakwater width decreases ship-handling difficulty quantitatively.

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A Study on the Flow Characteristics around a Hull Form of Coast-Canal Going Pusher-Barge (연안-운하 연계수송용 푸셔-바지 선형주위의 유동특성에 관한 연구)

  • Kim, Sung-Yong;Lee, Young-Gill;Lee, Seung-Hee
    • Journal of the Society of Naval Architects of Korea
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    • v.38 no.1
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    • pp.9-26
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    • 2001
  • In this paper. the development of a pusher-barge hull form which enables the continuous transportation along the coast and canal is performed. For the design stage of the hull forms. these are developed for Kyungin canal which is will be drawn up as the next contribution project of the Korean government are adopted. The model tests for the designed ship are carried out in the Inha University Towing Tank and the numerical simulations are done with a finite difference method based on MAC scheme. At first, the experiments are performed with designed model ships from low speed to high speed including service speed(6knots) among the corresponding designed speed. Resistance characteristics of designed ships are compared with experimental results of other several pusher-barge hull shapes. Next, the numerical simulations are performed for three cases, that is pusher only, barge only and pusher-barge condition in the designed speed. Each calculations are carried out in deep and restricted water condition. The flow characteristics around hulls in the latter condition are compared with those in the former condition.

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An Experiment on Flow Simulation Depending on Opening Configuration of Weir Using a Numerical Model (수치모형을 이용한 보의 개방구성에 따른 흐름모의 실험)

  • Kang, Tae Un;Jang, Chang-Lae
    • Ecology and Resilient Infrastructure
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    • v.7 no.3
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    • pp.218-226
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    • 2020
  • This study investigated that the numerical experiment for analysis on free overtopping flow by a weir of levee type, as the first stage of the development of a numerical technique for prediction methodology based on a numerical model. Using 2-dimensional flow models, Nays2DH, we conducted numerical simulations based on existing experimental data to compare and verify the models. We firstly discussed the numerical reproducibility for the discontinued flow by weir shape, and calibrated the computational flow through preprocessing of channel bed. Further, we carried out and compared the simulations for prediction on the overtopping flow by the number of weir gates. As a result of simulations, we found that the maximum flow velocity of downstream of weir increases when the number of weir gates increases under the same cross sectional area of flow. Through such results, this study could present basic data for hydraulic research to consider the water flow and sediment transport depending on weir operation in the future work.

Optimized mix design of rapid-set lightweight-formed mortar for backfill (굴착복구용 속경성 경량기포 시멘트 모르타르의 최적 배합 도출을 위한 기초 물성 연구)

  • An, Ji-Hwan;Jeon, Sung-il
    • International Journal of Highway Engineering
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    • v.19 no.1
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    • pp.1-9
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    • 2017
  • PURPOSES : The objective of this study is to develop an optimized method of mix design for rapid-set lightweight-formed mortar mix. To achieve this objective, the workability, setting time, and compressive strength of mixes under various conditions of mix design were evaluated. METHODS : The water-bonder ratio, fly-ash substitution ratio, and forming agent injection amount were selected as design variables in the study. The fluidity, setting time, density, and strength of the mortar mix were considered as major evaluation criteria of the mixture, and were subsequently utilized to evaluate the characteristics of the mortar mix under various conditions. RESULTS : The observations made from the mix design process are as follows: 1) the air content and fluidity increase as the forming agent ratio and forming agent ratio increase, respectively; 2) the maximum air content is approximately 20%; 3) the accelerating agent decreases the fluidity of the mortar mix by 15% on average; 4) the forming agent injection ratio and fly-ash substitution ratio yield significant effects on the initial and final set times of the mortar mix; 5) as the forming agent injection ratio and fly-ash substitution ratio increase, the compressive strength of the mortar mix decreases; and 6) the 28-day compressive strengths of the forming agent injection ratio and fly-ash substitution ratio yield the most significant effects. CONCLUSIONS : It is concluded that the governing design variables for the rapid-set lightweight-formed mortar mix are the forming agent injection ratio and fly-ash substitution ratio.

Evaluation on Mechanical Properties of Polymer-Modified Warm-Mix Asphalt Mixtures for Monsoon Climate Regions (몬순기후형 중온 개질 아스팔트 혼합물의 역학적 물성 평가 연구)

  • Lee, Kanghun
    • International Journal of Highway Engineering
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    • v.19 no.5
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    • pp.131-141
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    • 2017
  • PURPOSES : The main distress of asphalt pavements in monsoon climate regions are caused by water damage and plastic deformation due to repeated rain season and increased heavy vehicle traffic volume. In this study, the mechanical properties of polymer-modified warm mix asphalt (PWMA) materials are evaluated to use in monsoon climate regions such as Indonesia. METHODS : Comprehensive laboratory tests are conducted to evaluate moisture resistance and permanent deformation resistance for three different asphalt mixtures such as the Indonesian conventional hot-mix asphalt (HMA) mixture, the polymer-modified asphalt mixture, and the polymer-modified warm mix asphalt (PWMA) mixture. Dynamic immersion test and indirect tensile strength ratio test are performed to evaluate moisture resistance. The wheel tracking test is performed to evaluate rutting resistance. Additionally, the Hamburg wheel tracking test is performed to evaluate rutting and moisture resistances simultaneously. RESULTS :The dynamic immersion test results indicate that the PWMA mixture shows the highest resistance to moisture. The indirect tensile strength ratio test indicates that TSR values of PWMA mixture, Indonesian PMA mixture, and Indonesian HMA mixture show 87.2%, 84.1%, and 67.9%, respectively. The wheel tracking test results indicate that the PWMA mixture is found to be more resistant to plastic deformation than the Indonesian PMA. The dynamic stability values are 2,739 times/mm and 3,150 times/mm, respectively. Moreover, the Hamburg wheel tracking test results indicate that PWMA mixture is more resistant to plastic deformation than Indonesian PMA and HMA mixtures. CONCLUSIONS :Based on limited laboratory test results, it is concluded that rutting resistance and moisture susceptibility of the PWMA mixture is superior to Indonesian HMA and Indonesian PMA mixtures. It is postulated that PWMA mixture would be suitable for climate and traffic conditions in Indonesia.

Evaluation of Status of Groundwater Quality Monitoring Network of Korea : Implications for Improvement (우리나라 지하수수질측정망 현황 평가 및 개선을 위한 고찰)

  • Park, Joung-Ku;Kim, Rak-Hyeon;Lee, Jin-Yong;Choi, Dong-Hyuk;Kim, Tae-Dong
    • Journal of Soil and Groundwater Environment
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    • v.12 no.6
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    • pp.92-99
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    • 2007
  • As of 2007, there are 2,499 groundwater quality monitoring stations in total in Korea. Among them,478 are operated by the MOCT (Ministry of Construction and Transportation) for the National Groundwater Network Program, 781 wells by the ME (Ministry of Environment) for monitoring of the area where imminent contamination is expected, and 1240 wells by the local governments for monitoring of other areas. Even though, water quality data obtained from those wells are being provided to the public since 1999, the information for the wells has not been appropriately informed. In this study, we assessed the wells that are being used for the national groundwater quality monitoring from the points of operation, location, and well configuration to provide suggestions for the improvement of the national groundwater quality monitoring.

Establishment of Konjac Manufacturing Process and Optimum Storage Conditions at Room Temperature (곤약의 제조공정 및 최적 저장조건 확립)

  • Lee, Nan-Hee;Choi, Ung-Kyu
    • Journal of Food Hygiene and Safety
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    • v.35 no.2
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    • pp.183-188
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    • 2020
  • The manufacturing process for konjac jelly is largely divided into the three processes of powder manufacturing, a coagulation and finishing. It was found that the number of aerobic bacteria in konjac jelly decreases as the concentration of coagulation agent and soaking liquid increases. The temperature of the water has no significant effect. When the concentration of coagulation agent was maintained at 1.0%, the tensile strength was also maintained without significant change for up to 10 months. When the concentration was kept below 0.8%, however, the tensile strength showed a tendency to sharply decrease. After fixing the coagulant concentration to 1.0%, the effect by the soaking liquid was confirmed. At all concentrations of soaking, it was found that both tensile strength and bacterial numbers are unchanged until 10 months of storage.

Development of the Sentiment Indicators of Housing Welfare (주거복지지표 개발에 관한 연구 II - 수요자 측면의 주거복지체감지표와 지수를 중심으로 -)

  • Jee, Eun-Young;Eun, Nan-Soon;Hong, Hyung-Ock
    • Journal of the Korean housing association
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    • v.19 no.5
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    • pp.85-92
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    • 2008
  • The aim of this research is to develop the sentiment indicators of housing welfare for evaluating housing welfare policies conducted by the Korean government. The methods of this research are used by analysis of related documents, FGI (Focus Group Interview), and survey. The survey was made by experts and consumers. To analyze the survey, this research also uses confirmatory factor analysis by SPSS (Statistical Package for the Social Science) program, AHP (Analytical Hierarchy Process) by Expert Choice program, frequency, average, percentages, Factor analysis etc. As a result of this research, selected housing welfare indicators are settled as follows: In the housing welfare aspect, 11 indicators in the department of 'Housing Satisfaction' and 11 indicators in the department of 'Community Satisfaction' (22 in total) are suggested. The indicators are 1) Water Supply and Distribution Equipment 2) Heating equipment 3) the size of the exclusive residential area 4) the number of rooms 5) Ventilation and Lighting 6) Sound Insulation (Indoor Noise) 7) Air Pollution/Odor 8) House Deposit 9) Rent Paid 10) Maintenance (Dwelling) Cost 11) The length of Occupation 12) Proximity to Welfare Facilities 13) Educational Environment 14) Convenience of Facilities (shops, hospitals etc.) 15) Convenience of Transportation and Commuting 16) Distance from Workplace 17) Landscape and Green Space (Tree, Flowers, Grass etc.) 18) Vandalism (Destruction Behavior, graffiti etc.) 19) Privacy 20) Noise in Public Places (Drinking, Loudly Talking etc.) 21) Safety from Crime 22) Safety from a Disaster. As of 2007, the housing welfare sentiment index is measured by the survey of 1,000 inhabitants in the public housing, which shows 3.51.

Effect of Dietary Supplementation of the Combination of Gallic and Linoleic Acid in Thigh Meat of Broilers

  • Lee, Kyung-Haeng;Jung, Samooel;Kim, Hyun-Joo;Kim, Il-Suk;Lee, Jun-Heon;Jo, Cheorun
    • Asian-Australasian Journal of Animal Sciences
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    • v.25 no.11
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    • pp.1641-1648
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    • 2012
  • This study was performed to investigate the combined effect of dietary supplementation of gallic and linoleic acid (GL) on the antioxidative effect and quality of thigh meat from broilers. Broilers received 3 dietary treatments: i) commercial finisher diet (control), ii) 0.5% GL (gallic:linoleic acid = 1 M:1 M), and iii) 1.0% GL during the 22 to 36 d. The pH value of broiler thigh meat was increased by GL supplementation. Water holding capacity of the thigh meat was enhanced by the 1.0% dietary GL supplementation. Antioxidative effect (total phenolic content, DPPH radical scavenging activity, $ABTS^+$ reducing activity, reducing power, and TBARS value) in the thigh from the broilers improved significantly with 1.0% GL. Linoleic acid and docosahexaenoic acids were higher in the broilers fed both levels of dietary GL. However, volatile basic nitrogen content and microbiological quality was not shown to be different between control and treated group. Results indicate that 1.0% dietary supplementation of GL can improve the antioxidant activity of broiler thigh meat and may enhance the meat quality.