• Title/Summary/Keyword: Draft Power

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Human Safety Assessment for a 4 × 8 Array Antenna Used for Wireless Power Transfer at 2.4 GHz (2.4 GHz의 무선전력전송에 사용되는 4 × 8 배열 안테나에 대한 인체안전성평가)

  • Ju, Young Jun;Kim, Jun Hee;Lee, Yu-ri;Gimm, Yoon-Myoung;Lim, Yong Seok
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2018.10a
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    • pp.338-341
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    • 2018
  • Wireless Power Transfer(WPT) of array antenna applied to beam-forming techniques enables highly efficient WPT when transmitters and receivers are not contacting and even when they are separated. However, this WPT method is possible to use only when human safety restriction by distance between the transmitters and the receivers is satisfied. In the paper, a $4{\times}8$ array antenna for 2.4 GHz is modeled by simulation, then electric field intensity and 10 gram average head SAR(Specific Absorption Rate) by distance away from the array antenna inputted 1 W of 2.4 GHz sinusoidal wave at each single antenna of the array antenna for 2.4 GHz were obtained. And they were compared with human safety restriction of draft of 2018 ICNIRP(International Commission on Non-Ionizing Radiation Protection) guidelines. As the result, power density of far field derived from the electric field intensity was $33.257W/m^2$, which satisfied with occupational human safety restriction but exceeded public's. In addition, the 10 gram average head SAR exceeded the human safety restriction.

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A Study on Effect of Recirculated Exhaust Gas upon Performance and Exhaust Emissions in a Power Plant Boiler with FGR System (FGR 시스템 동력 플랜트 보일러의 성능 및 배기 배출물에 미치는 재순환 배기의 영향에 관한 연구)

  • Bae, Myung-whan;Jung, Kwong-ho;Park, Sung-bum
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.40 no.4
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    • pp.263-273
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    • 2016
  • The effect of recirculated exhaust gas on performance and exhaust emissions with FGR rate are investigated by using a natural circulation, pressurized draft and water tube boiler with FGR system operating at several boiler loads and over fire air damper openings. The purpose of this study is to apply the FGR system to a power plant boiler for reducing $NO_x$ emissions. To activate the combustion, the OFA with 0 to 20% is supplied into the flame. When the suction damper of two stage combustion system installed in the upper side of wind box is opened by handling the lever between $0^{\circ}$ and $90^{\circ}$, also, the combustion air supplied to burner is changed. It is found that the fuel consumption rate per evaporation rate did not show an obvious tendency to increase or decrease with rising the FGR rate, and $NO_x$ emissions at the same OFA damper opening are decreased, as FGR rates are elevated and boiler loads are dropped. While a trace amount of soot is emitted without regard to the operation conditions of boiler load, OFA damper opening and FGR rate, because soot emissions are eliminated by the electrostatic precipitator with a collecting efficiency of 86.7%.

Determining Input Values for Dragging Anchor Assessments Using Regression Analysis (회귀분석을 이용한 주묘 위험성 평가 입력요소 결정에 관한 연구)

  • Kang, Byung-Sun;Jung, Chang-Hyun
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.27 no.6
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    • pp.822-831
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    • 2021
  • Although programs have been developed to evaluate the risk of dragging anchors, it is practically difficult for VTS(vessel traffic service) operators to calculate and evaluate these risks by obtaining input factors from anchored ships. Therefore, in this study, the gross tonnage (GT) that could be easily obtained from the ship by the VTS operators was set as an independent variable, and linear and nonlinear regression analyses were performed using the input factors as the dependent variables. From comparing the fit of the polynomial model (linear) and power series model (nonlinear), the power series model was evaluated to be more suitable for all input factors in the case of container ships and bulk carriers. However, in the case of tanker ships, the power supply model was suitable for the LBP(length between perpendiculars), width, and draft, and the polynomial model was evaluated to be more suitable for the front wind pressure area, weight of the anchor, equipment number, and height of the hawse pipe from the bottom of the ship. In addition, all other dependent variables, except for the front wind pressure area factor of the tanker ship, showed high degrees of fit with a coefficient of determination (R-squared value) of 0.7 or more. Therefore, among the input factors of the dragging anchor risk assessment program, all factors except the external force, seabed quality, water depth, and amount of anchor chain let out are automatically applied by the regression analysis model formula when only the GT of the ship is provided.

Study on the Selection of Optimal Operation Position Using AI Techniques (인공지능 기법에 의한 최적 운항자세 선정에 관한 연구)

  • Dong-Woo Park
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.29 no.6
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    • pp.681-687
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    • 2023
  • The selection technique for optimal operation position selection technique is used to present the initial bow and stern draft with minimum resistance, for achievingthat is, the optimal fuel consumption efficiency at a given operating displacement and speed. The main purpose of this studypaper is to develop a program to select the optimal operating position with maximum energy efficiency under given operating conditions based on the effective power data of the target ship. This program was written as a Python-based GUI (Graphic User Interface) usingbased on artificial intelligence techniques sucho that ship owners could easily use the GUIit. In the process, tThe introduction of the target ship, the collection of effective power data through computational fluid dynamics (CFD), the learning method of the effective power model using deep learning, and the program for presenting the optimal operation position using the deep neural network (DNN) model were specifically explained. Ships are loaded and unloaded for each operation, which changes the cargo load and changes the displacement. The shipowners wants to know the optimal operating position with minimum resistance, that is, maximum energy efficiency, according to the given speed of each displacement. The developed GUI can be installed on the ship's tablet PC and application and used to determineselect the optimal operating position.

Semisubmersible platforms with Steel Catenary Risers for Western Australia and Gulf of Mexico

  • Zou, Jun
    • Ocean Systems Engineering
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    • v.2 no.2
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    • pp.99-113
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    • 2012
  • Steel Catenary Risers (SCR) are the simplest and often the most economic solution compared to other riser types such as flexible pipe, riser towers, top tensioned risers, etc. The top of a SCR is connected to the host platform riser porch. The other end of the SCR connects to flowlines from subsea wells. The riser touchdown point (TDP), which is the location along the riser where contact with the sea floor first occurs, exhibits complex behaviors and often results in compression and fatigue related issues. Heave dynamic responses of semisubmersibles in extreme and operating sea states are crucial for feasibility of SCR application. Recent full field measurement results of a deep draft semisubmersible in Hurricane Gustav displayed the considerable discrepancies in heave responses characteristics between the measured and the simulated results. The adequacy and accuracy of the simulated results from recognized commercial software should be examined. This finding raised the awareness of shortcomings of current commercial software and potential risk in mega investment loss and environmental pollutions due to SCR failures. One main objective of this paper is to attempt to assess the importance and necessity of accounting for viscous effects during design and analysis by employing indicator of viscous parameter. Since viscous effects increase with nearly third power of significant wave height, thus newly increased metocean criteria per API in central Gulf of Mexico (GoM) and even more severe environmental conditions in Western Australia (WA) call for fundamental enhancements of the existing analysis tools to ensure reliable and robust design. Furthermore, another aim of this paper is to address the impacts of metocean criteria and design philosophy on semisubmersible hull sizing in WA and GoM.

The Revision Guideline of Interim Measures of Protection under UNCITRAL Model Law on International Commercial Arbitration (UNCITRAL 모델중재법상 임시적 보호처분의 개정방향)

  • Lee Kang-Bin
    • Journal of Arbitration Studies
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    • v.14 no.2
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    • pp.73-106
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    • 2004
  • The UNCITRAL Arbitration Working Group began its deliberations on the topic of interim measures of protection at its thirty-second session (Vienna, 21-30 March 2000), when the Working Group expressed general support for a legal regime governing enforcement of interim measures of protection ordered by the arbitral tribunal. Also the Working Group took a preliminary analysis of whether there was a need for a uniform rule on court-ordered interim measures of protection in support of arbitration. The Working Group agreed, at its thirty-third session (Vienna, 20 November-1 December 2000), that the proposed new article to the UNCITRAL Model Law on International Commercial Arbitration on enforcement of interim measures of protection (tentatively numbered article 17 bis) should include an obligation on courts to enforce interim measures if prescribed conditions were met. At its thirty-fourth session (New York, 21 May-1 Jun 2001), in addition to continuing its review of draft article 17 bis, the Working Group proceeded to consider a text revising article 17 of the UNCITRAL Model Law, which defined the scope of an arbitral tribunal's power to order interim measures and included an additional provision on the granting of interim measures on an ex parte basis. Discussions in relation to revised drafts of article 17 and 17 bis of the UNCITRAL Model Law have continued at the fortieth session ( New York, 23-27 February 2004). Article 17 of the UNCITRAL Model Law provides that the arbitral tribunal may order any party to take such interim measure of protection as the arbitral tribunal may consider necessary in respect to the subject matter of the dispute. However it may be noted that the article does not deal with enforcement of such measures.

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Regulation of Unfair Contract Terms in English Law (영법상 불공정계약조항의 구제)

  • Lee, Byung-Mun
    • THE INTERNATIONAL COMMERCE & LAW REVIEW
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    • v.21
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    • pp.3-37
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    • 2003
  • English law accepts the basic principle of freedom of contract that the parties should be free to agree on any terms that they like unless their agreement is illegal or otherwise contrary to public policy because it infringes some public interest. On the other hand, it has been limited for hundreds of years on the basis that certain contract terms, particularly in standard form, may alter a distribution of risks that the customer would reasonably intended. The alteration may often result from his simple ignorance caused by either lack of opportunity to become aware of clauses or inability to understand their full potential implications. In addition, it may also result from disparity in bargaining power which does not allow the customer to look after their own interests even if he is fully aware of the unacceptable clauses. In response to this problem, English law has employed both judicial and statutory intervention techniques to control unfair contract terms. This study describes and analyzes in detail how English law regulates such terms, particularly, in standard form, in order to provide legal advice to our sellers residing either in UK or in Korea who plan to enter into UK markets. It also attempts to explore any problem in the existing double legislations of UCTA and UTCCR and put forward future direction of English law in light of the Draft Unfair Terms Bill which was currently proposed by the Law Commissioners. The main concern of this paper will be confined to some of the various aspects of both judicial and statutory control of unfair contract terms in English law which may draw our attention in terms of domestic or international business sales.

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Hull-form optimization of KSUEZMAX to enhance resistance performance

  • Park, Jong-Heon;Choi, Jung-Eun;Chun, Ho-Hwan
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.7 no.1
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    • pp.100-114
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    • 2015
  • This paper deploys optimization techniques to obtain the optimum hull form of KSUEZMAX at the conditions of full-load draft and design speed. The processes have been carried out using a RaPID-HOP program. The bow and the stern hull-forms are optimized separately without altering neither, and the resulting versions of the two are then combined. Objective functions are the minimum values of wave-making and viscous pressure resistance coefficients for the bow and stern. Parametric modification functions for the bow hull-form variation are SAC shape, section shape (U-V type, DLWL type), bulb shape (bulb height and size); and those for the stern are SAC and section shape (U-V type, DLWL type). WAVIS version 1.3 code is used for the potential and the viscous-flow solver. Prior to the optimization, a parametric study has been conducted to observe the effects of design parameters on the objective functions. SQP has been applied for the optimization algorithm. The model tests have been conducted at a towing tank to evaluate the resistance performance of the optimized hull-form. It has been noted that the optimized hull-form brings 2.4% and 6.8% reduction in total and residual resistance coefficients compared to those of the original hull-form. The propulsive efficiency increases by 2.0% and the delivered power is reduced 3.7%, whereas the propeller rotating speed increases slightly by 0.41 rpm.

Environment Assessing for Airborne Radioactive Particulate Release-introduction of Methods in IAEA Safety Report Series No.19

  • Meng, Dan;Yang, Liu;Shen, Fu;Yang, Yi;Ma, Yinghao;Ma, Tao;Zhang, Zhilong;Fu, Cuiming
    • Journal of Radiation Protection and Research
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    • v.41 no.4
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    • pp.409-417
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    • 2016
  • Background: Airborne radioactive particulate in many important nuclear facilities (particularly nuclear power plants) will have a strong impact on the relative public dose if they are released into the corresponding environment traversing the stack or vents. The radiation protection researchers have regarded the relative environment assessing and estimation of public doses. And the model of assessing impact of discharges radioactive substance to the environment have been recommended by many international organizations (e.g. IAEA) with the nuclear energy safety and radiation protection. Materials and Methods: This paper introduced the generic models that were suggested by International Atomic Energy Agency (IAEA), for use in assessing the impact of discharges of radioactive substances to the environment (e.g. IAEA Safety Report Series No.19). Results and Discussion: The writers of this paper, based on the recommend methods, assessed the discharge limits in some airborne radioactive substances discharging standards. The reasons that IAEA method are introduced are mainly the following considerations: IAEA is one of international organizations with some authorities in the nuclear energy safety and radiation protection; and, more important, the recommend modes are operational methods rather than the methods having little operations such as that have used by some researchers. Conclusion: It is wish that the introduced methods in this paper can be referenced in draft or revise of the standards related to discharges of radioactive substances to the environment.

Development of a Factory Layout Design System using Leisure-Boat Building Process (레저보트 생산공정정보 기반의 공장 레이아웃 설계 시스템 개발)

  • Lee, Dong-Kun;Jeong, Yong-Kuk;Shin, Jong-Gye
    • Journal of the Society of Naval Architects of Korea
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    • v.50 no.1
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    • pp.14-24
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    • 2013
  • The marine leisure industry in Korea has been the focus of the power of economic growth and the creation of jobs in recent years. In this regard, many studies concerning marine leisure are on-going in various fields. In this paper, developed a layout system and algorithm can resolve the factory and facility layout problem. For a layout design of leisure-boat factories, the leisure-boat production process is analyzed in order to derive standard production space elements for the layout of the factory. Based on the results, a draft design of the factory layout is carried out based on the manpower planning data, as well as the characteristics and relationships of each process data. A layout design of this paper can be verified through a factory simulation solution and we suggest the verification method using a SBD(simulation based design) methodology. The layout system takes into account the user's accessibility and extendibility, so it is web-oriented and uses RIA (rich Internet Application) technology. Furthermore, the system and layout algorithm of this paper are verified with samples data that show the efficient factory arrangement and practical application method.