• Title/Summary/Keyword: Development of port

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Analysis of Confidence Interval of Design Wave Height Estimated Using a Finite Number of Data (한정된 자료로 추정한 설계파고의 신뢰구간 분석)

  • Jeong, Weon-Mu;Cho, Hong-Yeon;Kim, Gunwoo
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.25 no.4
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    • pp.191-199
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    • 2013
  • It is estimated and analyzed that the design wave height and the confidence interval (hereafter CI) according to the return period using the fourteen-year wave data obtained at Pusan New Port. The functions used in the extreme value analysis are the Gumbel function, the Weibull function, and the Kernel function. The CI of the estimated wave heights was predicted using one of the Monte-Carlo simulation methods, the Bootstrap method. The analysis results of the estimated CI of the design wave height indicate that over 150 years of data is necessary in order to satisfy an approximately ${\pm}$10% CI. Also, estimating the number of practically possible data to be around 25~50, the allowable error was found to be approximately ${\pm}$16~22% for Type I PDF and ${\pm}$18~24% for Type III PDF. Whereas, the Kernel distribution method, a typical non-parametric method, shows that the CI of the method is below 40% in comparison with the CI of the other methods and the estimated design wave height is 1.2~1.6 m lower than that of the other methods.

A Study on Development of Mobile LNG Yard Tractor Refueling Standards (이동식 LNG 야드트랙터 충전 기준 개발 연구)

  • Ryou, Young-don;Yu, Chul-hee;Koo, Bon-deuk;Lee, Dong-won
    • Journal of the Korean Institute of Gas
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    • v.22 no.6
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    • pp.59-64
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    • 2018
  • As part of measures to reduce fine dust, the government is promoting a project to convert the fuel of Yard Tractors(YT, tractors operated at ports), from diesel to LNG (Liquefied Natural Gas). While a port having a small number of yard tractors, it is not proper to construct a stationary LNG fueling station and supply LNG to YT due to a problem of BOG (Boil off gas) generation. Therefore, it is necessary to make a regulation and a standard on mobile LNG YT refueling station installation and inspection as an alternative. In this study, we have investigated domestic and foreign mobile LNG refueling cases and refueling standards, including the USA and Europe. In addition, we have suggested the risk reduction method according to the cause after investigation of the cause of LNG accidents. And last, based on the proposed risk reduction measures, we have proposed an amendment to the Regulation of the Urban Gas Business Law in Korea. The proposed mobile LNG YT refueling amendment of the Regulation includes ; maintenance of the safety distance from the protection facility, installation of an interlock device to prevent refueling in places other than the authorized place, installation of the identification system through biometrics, separation of the tank lorry and tow vehicle before refueling, checking the wheel fixed status of tank lorry before refueling, construction of the impounding area, safety measures before, during and after refueling, etc. The safety standards proposed in this study could be used as a reference in establishing standards for mobile LNG vehicle refueling in the near future.

Estimation of Net Flux of Water Mass and Tidal Prism at a Tidal Entrance through Bottom Tracking with ADCP (단면 유속관측을 통한 조석 유입구에서의 단면통과 유량 및 조량 산정)

  • Yang, Su-Hyun;Kim, Yong-Muk;Hwang, Kyu-Nam
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.28 no.3
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    • pp.160-170
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    • 2016
  • In this study, the bottom tracking observation in the tidal entrance within Mokpo coast is performed using ADCP in order to estimate net flux of water mass and tidal prism. First of all, observed rawdata was conducted coordinate rotation considering rotation of the cross-section in order to derive the predominant velocity component. And observed rawdata is converted into Sigma coordinate with normalization and blank zone data near the water surface and bottom is interpolated using von-Karman equation. Net flux of water mass is calculated quantitively from the interpolated data, calculated results show that these represent well characteristic of ebb superiority at Mokpo coast as well as change of net flux of water mass with tide. Also, by complementing the definition of tidal prism proposed in past studies, the definition of tidal prism including tidal condition was re-established. Based on the new definition, tidal prism at a tidal entrance using bottom tracking data with ADCP is estimated quantitively for the first time domestically. The results are compared with those for results of previous study, calculated results were in good agreement with previous studies.

The Origin-Destination analysis of KORUS trade volume using spatial information (공간정보를 활용한 한-미 교역액의 기종점 분석)

  • Kang, Hyo-Won
    • International Commerce and Information Review
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    • v.18 no.3
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    • pp.47-72
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    • 2016
  • The Government of Korea has always focused on developing and maintaining a surplus on the balance of payments as a successful trade policy. The focus should now be on spatial information hiding, revealing patterns in trade activities that enable viewing trade in a more sophisticated manner. This study utilizes trade statistical data such as the United States-South Korea imports and exports from 2003 to 2015 officially released by the two countries. It allows us to analyze and extract the spatial information pertaining to the origin, transit, and destination. First, in the case of export data to the United States, the origin of the trade goods has expanded and decentralized from the metropolitan area. With regard to transit, in 2003, most of the exported goods were shipped by ocean vessels and arrived at the ports on the western coast of the United States. However, trade patterns have changed over the 12-year period and now more of that trade has moved to the southern ports of the United States. In terms of destination, California and Texas were importing goods from South Korea. With the development of the automotive industry in Georgia and Alabama, these two states also imported huge volumes of automobile parts. Second, in case of import data, most imported goods from the United States originated from California and Texas. In this case, 40% of goods were shipped by air freight and arrived at the Incheon-Seoul International Airport; most ocean freight was handled at the Port of Busan. The purpose of this study is to decompose the spatial information from the trade statistics data between Korea and the United States and to depict visualized bilateral trade structure by origin, transit, and destination.

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Effect the I-T curve and electrical characteristic of fuse elements by plated tin thickness (주석 도금 두께에 따른 퓨즈 가용체의 I-T 커브 및 전기적 특성의 영향)

  • Jin, Sang-Jun;Kim, Eun-Min;Youn, Jae-Seo;Lee, Ye-Ji;Noh, Seong-Yeo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.6
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    • pp.80-87
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    • 2018
  • In recent years, due to the spread of various renewable energy power sources and the pursuit of high efficiency and low-power consumption, not only trends in the electric power industry but also the consumption, control methods, and characteristics are diversified. However, in this diversified electric power industry, the fuse (which is the core part responsible for safety) has not developed significantly in classical operation mode, and thus, fires continue to occur. In this paper, the effects of low melting-point metal plating and high melting-point metal plating on operating characteristics and IT curve movement of the fuse are investigated in a cartridge fuse, which is a classic fuse manufacturing method. The effects of plating on the thickness of the fuse are investigated, and various operating characteristics of the fuse are implemented. In addition, it is suggested that the plating of the low melting-point metal moves the rated current line of the fuse to a low rating, and moves operating characteristics to characteristics of delay operation. It is possible to design various operating characteristics using this characteristic.

A Study on Magnitude Scaling Factors and Screening Limits of Liquefaction Potential Assessment in Moderate Earthquake Regions (중진지역에 적합한 액상화 평가 생략기준 및 지진규모 보정계수에 관한 연구)

  • Park Keun-Bo;Park Young-Geun;Choi Jae-Soon;Kim Soo-Il
    • Journal of the Korean Geotechnical Society
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    • v.20 no.7
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    • pp.127-140
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    • 2004
  • Conventional methods for the assessment of liquefaction potential were primarily for areas of severe earthquake zones (M=7.5) such as North America and Japan. Detailed earthquake related researches in Korea started in 1997, including development of the seismic design standards for port and harbour structures, which was later completed in 1999. Because most contents in the guidelines were quoted through literature reviews from North America and Japan, which are located in strong earthquake region, those are not proper in Korea, a moderate earthquake region. This requires further improvement of the present guidelines. Considering earthquake hazard data in Korea, use of laboratory tests based on irregular earthquake motion appears to be effective to reflect the dynamic characteristics of soil more realistically than those using simplified regular loading. In this study, cyclic triaxial tests using irregular earthquake motions are performed with different earthquake magnitudes, relative densities, and fines contents. Assessment of liquefaction potential in moderate earthquake regions is discussed based on various laboratory test results. Effects of these components on dynamic behavior of soils are discussed as well. From the test results, screening limits and magnitude scaling factors to determine the soil liquefaction resistance strength in seismic design were re-investigated and proposed using normalized maximum stress ratios under real irregular earthquake motions.

Effect of Lythrum salicaria Extract on Body Fat Reduction: A Protocol for a Randomized, Double-Blinded, Placebo-Controlled Clinical Trial (체지방 감소에 대한 털부처꽃 추출물의 효과: 무작위배정, 이중눈가림, 대조군 비교 인체적용시험 프로토콜)

  • Hye-Jin Park;In Heo;Yea-Jin Park;Hyo-Jin An;Su Shin;Yun-Yeop Cha
    • Journal of Korean Medicine for Obesity Research
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    • v.24 no.1
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    • pp.87-93
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    • 2024
  • Objectives: Obesity is a globally prevalent public health issue. Hence, there is a need for the development of safer and more effective anti-obesity drugs. Lythrum salicaria, a traditional medicinal herb used for centuries, has been reported to improve lipid metabolism and fat accumulation. It also has a low toxicity profile. Therefore, its potential as a functional ingredient in health functional foods needs to be evaluated. Methods: In this randomized, double-blind, placebo-controlled clinical trial, 90 participants will be randomly assigned to either the experimental or control group. Each subject will orally receive L. salicaria extract (1,350 mg/day) (500 mg L. salicaria+850 mg lactose as vehicle) or lactose (1,350 mg/day) as a hard capsule formula for 84 days (12 weeks). The primary outcome will be body fat mass (kg), which will be assessed using dual-energy x-ray absorptiometry (DXA) (performed only at visits 2 and 4). Secondary outcomes include body mass index, body weight, waist-to-hip ratio, body fat percentage (%) measured using DXA, lean body mass (kg) measured using DXA (assessed only at visits 2 and 4), lipids (total cholesterol, triglyceride, high-density lipoprotein cholesterol, and calculated low-density lipoprotein cholesterol), free fatty acid, high sensitivity C-reactive protein, adiponectin, and leptin. Conclusions: This protocol will be implemented after approval of Institutional Review Board of Pusan National University Korean Medicine Hospital (approval number: PNUKHIRB-2022-08-002) and registration with the Korean National Clinical Research Information Service (CRIS) (CRIS-KCT0008060). The results of this trial will provide potential of L. salicaria as a new anti-obesity functional food with fat-reducing effects and low toxicity.

Antimicrobial Effect of Extract of Glycyrrhiza uralensis on Methicillin-Resistant Staphylococcus aureus (감초 추출물이 항생제 내성균주의 항균활성에 미치는 영향)

  • Lee, Ji-Won;Ji, Young-Ju;Yu, Mi-Hee;Im, Hyo-Gwon;HwangBo, Mi-Hyang;Lee, In-Seon
    • Korean Journal of Food Science and Technology
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    • v.37 no.3
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    • pp.456-464
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    • 2005
  • Antimicrobial drug-resistance is natural response to antimicrobial stress based on selection, which weakens chemotherapy effect. Introduction of large numbers of chemotherapeutic agents to clinical practice has generated strains of microorganisms that survive and multiply in vivo with high-drug concentrations. Methicillin-resistant Staphylococcus aureus (MRSA), bacteria found in normal daily life, can be easily ingested through milk vegetables, and meats, etc. MRSA emerged in many port of the world, increasing complex clinical problems. Therefore, new agents are needed to treat MRSA. Glycyrrhiza uralensis was extracted using 80% MeOH to investigate its antimicrobial activity against MRSA stains KCCM 11812, 40510, and 40512 through bacterial measurement, disc diffusion, and O.D. methods, MIC values, MRSA gene expression investigation, and scanning electron microscope observation. Results revealed MecA, Mecl, MecRI, and FemA were the most highly manifested MRSA genes. Methanolic extract of G. uralensis significantly inhibited MRSA and thus could be used in development of antibacteria.

Hydraulic Conductivity and Strength Characteristics of Self Recovering Sustainable Liner (SRSL) as a Landfill Final Cover (SRSL 매립지 최종 복토층의 투수 및 강도 특성)

  • Kwon, Oh-Jung;Lee, Ju-Hyung;Cho, Wan-Jei;Jung, Young-Hoon
    • Journal of the Korean Geotechnical Society
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    • v.27 no.12
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    • pp.5-15
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    • 2011
  • Conventional designs of landfill covers use geosynthetics such as geomembrane and GCL, and clay liners to lower the permeability of final covers of landfill sites. However, differential settlement and the variation of temperature or humidity in landfill sites cause the development of cracks or structural damage inside the final cover. This study examined the application of a Self Recovering Sustainable Liner (SRSL) as an alternative landfill final cover material. SRSL consists of double layers, which have chemicals, can generate precipitates filling the pores of the layers by chemical reaction. The interface material forms an impermeable layer and in case of internal cracks, the reactants of the two layers migrate towards the crack and heal it by forming another liner. In this study the applicability of SRSL material for landfill final cover was examined by performing flexible wall permeameter tests to prove that the hydraulic conductivity is lower than the regulations and unconfined compression tests to judge whether the strength satisfies the restriction for the landfill final cover. Furthermore, the environmental impacts on the permeability and strength were evaluated. The experimental results show that the SRSL has lower hydraulic conductivity and higher strength than the regulations and is little influenced by climatic changes such as wet/dry or freeze/thaw process.

Analysis of the Wave Spectral Shape Parameters for the Definition of Swell Waves (너울성파랑 정의를 위한 파랑스펙트럼의 형상모수 특성 분석)

  • Ahn, Kyungmo;Chun, Hwusub;Jeong, Weon Mu;Park, Deungdae;Kang, Tae-Soon;Hong, Sung-Jin
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.25 no.6
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    • pp.394-404
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    • 2013
  • In the present study, the characteristics of spectral peakedness parameter $Q_p$, bandwidth parameter ${\varepsilon}$, and spectral width parameter ${\nu}$ were analyzed as a first step to define the swell waves quantitatively. For the analysis, the joint probability density function of significant wave heights and peak periods were newly developed. The MCMC(Markov Chain Monte Carlo) simulations have been performed to generate the significant wave heights and peak periods from the developed probability density functions. Applying the simulated significant wave heights and peak periods to the theoretical wave spectrum models, the spectral shapes parameters were obtained and analyzed. Among the spectral shape parameters, only the spectral peakedness parameter $Q_p$, is shown to be independent with the significant wave height and peak wave period. It also best represents the peakedness of the spectral shape, and henceforth $Q_p$ should be used to define the swell waves with a wave period. For the field verification of the results, wave data obtained from Hupo port and Ulleungdo were analyzed and results showed the same trend with the MCMC simulation results.