• Title/Summary/Keyword: Sea environmental conditions

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A Study on the estimation of traffic congestion for Pyeongtaek·Dangjin port development (평택·당진항의 내항개발에 따른 교통혼잡도 평가에 관한 연구)

  • Gug Seung-Gi;Kim Se-Won;Kim Jung-Hoon
    • Journal of Navigation and Port Research
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    • v.29 no.6 s.102
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    • pp.481-485
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    • 2005
  • The port entry system of the inner harbor in Pyeongtaek${\cdot}$Dangjin was planned as lock-gate in 'Master plan project on port planning in Asan industry base(1990)‘, but was changed to tidal harbor in 'Project maintaining Master plan for comprehensive development of Pyeongtaek${\cdot}$Dangjin port(2001)'. Accordingly, southern sea bank constructed under the lower part of Seohae-bridge will be removed so that inbound/outbound vessels for the inner harbor can navigate at all times. However, in the view of the safety on passing through the lower of Seohae-bridge, navigating conditions for the inner harbor will be restricted in the single-way of 50,000 DWT vessel and the two-way of vessel less than 30,000 DWT Therefore, this study carried out the estimation of traffic congestion arising from these vessels with above restrictions q[ter supposing annual inbound/outbound vessel's numbers for loading and unloading cargo surveyed on the inner harbor.

Optimal Site Selection of Floating Offshore Wind Farm using Genetic Algorithm (유전 알고리즘을 활용한 부유식 해상풍력단지 최적위치 선정)

  • Lee, Jeong-Seok;Son, Woo-Ju;Lee, Bo-Kyeong;Cho, Ik-Soon
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.25 no.6
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    • pp.658-665
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    • 2019
  • Among the renewable energy resources, wind power is growing rapidly in terms of technological development and market share. Recently, onshore wind farm have been affected by limitations of terrestrial space and environmental problems. Consequently, installation sites have been moved to the sea, and the development of floating offshore wind farms that are installed at deep waters with more abundant wind conditions is actively underway. In the context of maritime traffic, the optimal site of offshore wind farms is required to minimize the interference between ships and wind turbines and to reduce the probability of accidents. In this study, genetic algorithm based AIS(Automatic Indentification System) data composed of genes and chromosomes has been used. The optimal site of floating offshore wind farm was selected by using 80 genes and by evaluating the fitness of genetic algorithm. Further, the final site was selected by aggregating the seasonal optimal site. During analysis, 11 optimal site were found, and it was verified that the final site selected usng the genetic algorithm was viable from the perspective of maritime traffic.

Overview of the KIOST-HYU Joint Experiment for Acoustic Propagation in Shallow Water Geological Environment (천해 지질환경에서의 음파전달 특성 연구를 위한 KIOST-한양대 공동실험 개요)

  • Cho, Sungho;Kang, Donhyug;Lee, Cheol-Ku;Jung, Seom-Kyu;Choi, Jee Woong;Oh, Suntaek
    • The Journal of the Acoustical Society of Korea
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    • v.34 no.6
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    • pp.411-422
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    • 2015
  • This paper presents an overview of the geological environment investigation and underwater acoustic measurements for the purpose of "Study on the Relationship between the Geological Environment and Acoustic Propagation in Shallow Water", which are jointly carried out by KIOST (Korea Institute of Ocean Science & Technology) and Hanyang University in the western shallow water off the Taean peninsula in the Yellow Sea in April-May 2013. The experimental site was made up of various sediment types and bedforms due to the strong tidal currents and coastal geomorphological characteristics. The geological characteristics of the study area were intensively investigated using multi-beam echo sounder, sub-bottom profiler, sparker system and grab sampler. Acoustic measurements with a wide range of research topics in a frequency range of 20~16,000 Hz: 1) low frequency sound propagation, 2) mid-frequency bottom loss, 3) spatial coherence analysis of ambient noise, and 4) mid- frequency bottom backscattering were performed using low- and mid-frequency sound sources and vertical line array. This paper summarizes the topics that motivated the experiment, methodologies of the acoustic measurements, and acoustic data analysis based on the measured geological characteristics, and describes summary results of the geological, meteorological, and oceanographic conditions found during the experiments.

An analysis of Characteristics of Heavy Rainfall Events over Yeongdong Region Associated with Tropopause Folding (대류권계면 접힘에 의한 영동지방 집중호우사례의 특성분석)

  • Lee, Hye-Young;Ko, Hye-Young;Kim, Kyung-Eak;Yoon, Ill-Hee
    • Journal of the Korean earth science society
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    • v.31 no.4
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    • pp.354-369
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    • 2010
  • The synoptic and kinematic characteristics of a heavy rainfall that occurred in Gangneung region on 22 to 24 October 2006 were investigated using weather maps, infrared images, AWS observation data and NCEP global final analyses data. The total amount of rainfall observed in the region for the period was 316.5 mm, and the instanteneous maximum wind speed was $63.7m\;s^{-1}$. According to the analysis of weather maps, before the starting of the heavy rainfall, an extratropical low pressure system was developed in the middle region of the Korean Peninsula, and an inverted trough was formed in the northern region of the peninsula. In addition, a jet stream on the upper charts of 300 hPa was located over the Yellow Sea and the southern boundary of the peninsula. A cutoff low in the cyclonic shear side of the upper jet streak, which was linked to an anomaly of isentropic potential vorticity, was developed over the northwestern part of the peninsula. And there are analyzed potential vorticity and wind, time-height cross section of potential vorticity, vertical air motion, maximums of the divergence and convergence and vertical distribution of potential temperature in Gangneung region. The analyzed results of the synoptic conditions and kinematic processes strongly suggest that the tropopause folding made a significant role of initializing the heavy rainfall.

A Study on the estimation of traffic congestion for Pyeongtaek (Asan) port development (평택(아산)항 개발에 따른 교통혼잡도 평가에 관한 연구)

  • Kuk, Seung-Gi;Kim, Se-Won;Kim, Jeong-Hoon
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • v.29 no.1
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    • pp.191-195
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    • 2005
  • The port entry system of the inner harbor in Pyeongtaek (Asan) was planned as lock-gate in 'Master plan project on port planning in Asan industry base(1990)', but was changed to tidal harbor in 'Project maintaining Master Plan for comprehensive development of Pyeongtaek (Asan) port(2001)'. Accordingly, southern sea bank constructed under the lower part of Seohae-bridge will be removed so that inbound/outbound vessels for the inner harbor can navigate at all times. However, in the view of the safety on passing through the lower of Seohae-bridge, navigating conditions for the inner harbor will be restricted in the single-way of 50,000 DWT vessel and the two-day of vessel less than 30,000 DWT. Therefore, this study carried out the estimation of traffic congestion arising from these vessels with above restrictions after supposing annual inbound/outboubd vessel's numbers for loading and unloading cargo surveyed on the inner harbor.

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Synoptic Climatic Patterns for Winter Extreme Low Temperature Events in the Republic of Korea (우리나라 겨울철 극한저온현상 발생 시 종관 기후 패턴)

  • Choi, Gwangyong;Kim, Junsu
    • Journal of the Korean Geographical Society
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    • v.50 no.1
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    • pp.1-21
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    • 2015
  • The present study aims to characterize the synoptic climatic patterns of winter extreme low temperature events occurred in different regions of Korea based on daily temperature data observed at 61 weather stations under the supervision of the Korea Meteorological Administation and NCEP/NCAR reanalysis I data for the recent 40 years (1973~2012) period. Analyses of daily maximum and minimum temperatures below 10th percentile thresholds show that high frequencies of winter extreme low temperature events appear across the entire regions of Korea or in either the western or eastern half region divided by major mountain ridges at the 2~7 dayintervals particularly in the first half of the winter period (before mid-January). Composite analyses of surface synoptic climatic data including sea level pressure and wind vector reveal that 13 regional types of winter extreme low temperature events in Korea are closely associated with the relative location and intensity of both the Siberian high pressure and the Aleutian low pressure systems as well as major mountain ridges. Investigations of mid-troposphere (500 hPa) synoptic climatic charts demonstrate that the blocking-like upper troposphere low pressure system advecting the cold air from the Arctic toward the Korean Peninsula may provide favorable synoptic conditions for the outbreaks of winter extreme low temperature events in Korea. These results indicate that the monitoring of synoptic scale climatic systems in East Asia including the Siberian high pressure system, the Aleutian low pressure system and upper level blocking system is critical to the improvement of the predictability of winter extreme low temperature events in Korea.

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Simulating Bacterial Dispersion from Coastal Sewage Outfalls Using the QUICKEST Scheme (QUICKEST법을 사용한 연안해역에서 박테리아 확산의 수치모의)

  • Kang Yun Ho;Lee Moon Ock
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.2 no.2
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    • pp.20-30
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    • 1999
  • To improve water quality particularly for sea bathers along the Fylde coastal zone near Blackpool, North West England, waste water from a sewage outfall is studied using a mathematical model. The explicit second order accurate central scheme and the third order accurate QUICKEST scheme are used to represent the diffusion terms and the advection terms of the advective-diffusion equation, respectively. Hydrodynamic model is run for a coarse and fine grid, of 1km and 200m, respectively, obtaining good agreement with measured data. Water quality model is then used to predict faecal coliform levels in the region for four different scenarios, including discharges from: - (i) Fleetwood outfall, (ii)River Ribble for summer condition, (iii)River Ribble for winter condition, and (iv)combined sewer overflows for the Blackpool and Fleetwood communities. Main findings from the simulations are:- (i) Fleetwood outfall has a negligible impact on the beaches with respect to pathogen levels; (ii) Discharge from River Ribble for both summer and winter conditions is predicted in the range of coliform levels 10 -500 counts/100ml along the beach at Lytham St. Annes; and (iii) The CSO effluent discharges are predicted not to advect out into offshore by stronger tidal currents.

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Internet-of-Things Based Approach for Monitoring Pharmaceutical Cold Chain (사물인터넷을 이용한 의약품 콜드체인 관리 시스템)

  • Chandra, Abel Avitesh;Back, Jong Sang;Lee, Seong Ro
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.39C no.9
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    • pp.828-840
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    • 2014
  • There is a new evolution in technological advancement taking place called the Internet of Things (IoT). The IoT enables physical world objects in our surroundings to be connected to the Internet. For this idea to come to life, two architectures are required: the Sensing Entity in the environment which collects data and connects to the cloud and the Cloud Service that hosts the data. In particular, the combination of wireless sensor network for sensing and cloud computing for managing sensor data is becoming a popular intervention for the IoT era. The pharmaceutical cold chain requires controlled environmental conditions for the sensitive products in order for them to maintain their potency and fit for consumption. The monitoring of distribution process is the only assurance that a process has been successfully validated. The distribution process is so critical that anomaly at any point will result in the process being no longer valid. Taking the cold chain monitoring to IoT and using its benefits and power will result in better management and product handling in the cold chain. In this paper, Arduino based wireless sensor network for storage and logistics (land and sea) is presented and integrated with Xively cloud service to offer a real-time and innovative solution for pharmaceutical cold chain monitoring.

Development of the Pre-treatment Technology for LNG-FPSO (LNG-FPSO용 천연가스 전처리 기술 개발)

  • Jee, Hyun-Woo;Lee, Sun-Keun;Jung, Je-Ho;Min, Kwang-Joon;Kim, Mi-Jin
    • Plant Journal
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    • v.9 no.3
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    • pp.38-42
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    • 2013
  • Submarine gas fields have focused because of the increasing fuel cost, the environmental regulations, and the safety & NIMBY problems. LNG-FPSO which is available for acid gas removal, recovery of the condensate & LPG and Liquefaction in topside process is one of high technology offshore structures. On the other hands, it is necessary to verify the pre-treatment efficiency by the ship motion and to apply to the design for LNG-FPSO. This study is to develop the pre-treatment technology for LNG-FPSO as taking account to the process efficiency by ship motion effects and the area optimization. Based on the simulation results, it founds that hybrid process shows the low circulate rate, the low heat duty and the small size of column dimensions compared to typical amine process. It will be verified the process efficiency in the various conditions by sea states as performing the 6-DOF motion test and CFD simulation.

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Comparison of Biomass Productivity of the Microalgae, Tetraselmis sp. KCTC12236BP, in Polyvinyl Chloride Marine Photobioreactor and High Density Polyethylene Marine Photobioreactor (폴리비닐클로라이드 해양광생물반응기와 고밀도 폴리에틸렌 해양광생물반응기에서 미세조류, Tetraselmis sp. KCTC12236BP의 생산성 비교)

  • Jung, Seung-Gyun;Kim, Su-Kwon;Bun, Moon-Sup;Cho, Yonghee;Shin, Dong-Woo;Kim, Z-Hun;Lim, Sang-Min;Lee, Choul-Gyun
    • Journal of Marine Bioscience and Biotechnology
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    • v.8 no.1
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    • pp.18-23
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    • 2016
  • It is important to design photobioreactor by cheap material for economical microalgal biomass production. In this study, two types of marine photobioreactors (MPBR), made by either polyvinyl chloride (MPBR-PVC) or high density poly ethylene (MPBR-HDPE), are used and performance of these were compared. Tetraselmis sp. KCTC 12236BP is a green marine alga that isolated from Ganghwa Island, Korea, and the strain was used for marine cultivations using MPBR-PVC and MPBR-HDPE. The cultivations were performed three times in the spring season of 2012 using MPBR-PVC and of 2013 using MPBR-HDPE in the coastal area of Young Heung Island. As the results, MPBR-PVC shows higher biomass productivities than MPBR-HDPE, due to its high light transmittance. In the cultivations using MPBR-PVC, the average sea water temperature was $11.5^{\circ}C$ during the first experiment and $16.5^{\circ}C$ during the second and third experiments. Average light intensities during three times for experiments were 407.5, 268.1 and $273.0{\mu}{\cdot}E{\cdot}m^{-2}{\cdot}s^{-1}$, respectively. The maximum fresh cell weight and average biomass productivity were $1.2g{\cdot}L^{-1}$ and $0.12g{\cdot}L^{-1}{\cdot}day^{-1}$. These results showed that Tetraselmis sp. KCTC12236BP were adapted well with the environmental conditions from ocean, and grow in the MPBR-PVC and MPBR-HDPE.