• Title/Summary/Keyword: Ro-Ro

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Whirling Vibration Analysis & Measurement of the propulsion shafting system of l000P Ro-Ro Ferry (1000인승 대형 Ro-Ro Ferry 의 축계 whirling 진동 해석 및 계측/분석)

  • Kwon, Hyuk;Han, Sung-Yong;Um, Jae-Kwang
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2001.05a
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    • pp.143-148
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    • 2001
  • Relatively high rotating speed propulsion shafting system of the large Ro-Ro Ferry has a greate risk of the resonance of the whirling vibration within the operating speed range. Therefore, it is necessary to control the whirling vibration characteristics of the shafting system in the initial design stage so as not to be resonant with the blade number order excitation in the normal operating speed range. The results of the whirling vibration analysis for l000P Ro-Ro Ferry with SHI's in-house program and the measured results during the sea trial are introduced. Additionally the outline of the program and the calculation method of the major properties are presented.

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A Noise Control of a Ro-Ro Passenger Ferry (대형 Ro-Ro Ferry의 방음 설계)

  • 김동해;박종현
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2003.05a
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    • pp.738-741
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    • 2003
  • In general, the essential requirement for cruisers or car ferries is the reduction in noise to ensure high quality and comfort. Recently, the Ro-Ro Passengers Ferry (ROPAX) was built in Hyundai Heavy Industries. In order to minimize the noise levels, careful attention have to De paid by the special committee of experts from the initial design stage to the sea trial. Proper countermeasures, considering the characteristics of sources and receiver spaces, were applied from the noise prediction and various experiment results. Finally, this ship was successfully delivered with excellent noise properties. This paper describes the procedure of noise analysis, the countermeasures of noise control, and the measurement results of the sea trial. Onboard noise analysis had been carried out by statistical energy analysis program and outdoor noise prediction program based on ISO9614. The prediction results are in good agreements with the measurement results. The technology to minimize the noise levels for cruisers or car ferries has been established throughout the construction of this ship.

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The culture of in vitro matured and fertilized bovine oocytes in rabbit oviduct (체외성숙 및 체외수정유래 소 수정란의 토끼난관내 배양에 관한 연구)

  • Chung, Hye-ok;Hwang, Woo-suk;Jo, Choong-ho;Lee, Byeong-chun
    • Korean Journal of Veterinary Research
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    • v.33 no.1
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    • pp.179-188
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    • 1993
  • The developmental capacity of bovine oocytes under three different culture systems was investigated in this experiment ; One was culture in TCM199 with bovine oviductal epithelial cells(BOEC) for in vitro culture, another was culture in TCM199 with BOEC for 2 days and then transfer of 4~8cell embryos to rabbit oviduct(RO) and the other was transfer of 1 or 2cell embryos to RO for in vivo culture. And the other concern of this experiment was to investigate the effect of culture period and transfer site on recovery. Immature bovine oocytes were cultured in TCM199 with granulosa cells for 22-24hrs and then fertilized in vitro using frozen-thawed semen treated with BO-caffine and BO-BSA. Fifteen to 18hrs after in vitro fertilization oocytes were cultured in TCM199 with BOEC or transferred to RO for 5 days. The rate of development to the morula or blastocyst was higher in transfer of 1 or 2cell embryos to RO(23.1%) than culture in TCM199 with BOEC(11.7%). But, there was no difference between transfer of 1 or 2cell embryos and transfer of 4~8cell embryos to RO(12.8%). Recovery under different culture periods in RO was significantly higher in 90~95hrs(70.1%) than 122~125hrs(50.9%, p<0.05) and recovery significantly increased when oocytes were transferred deeper in RO(2.5cm>, 47.7% ; 2.5~4.5cm, 63.9% ; 4.5cm<, 77.3%, p<0.05). The results show that transfer of 1 or 2cell embryos to RO is an effective means of supporting the further development of in vitro matured and fertilized bovine oocytes than culture in TCM199 with BOEC or transfer of 4~8cell embryos to RO, and recovery from RO increases when oocytes are transferred deeper and incubated shorter in RO.

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Wastewater Recycling from Electroless Printed Circuit Board Plating Process Using Membranes (분리막을 이용한 무전해 PCB 도금 폐수의 재활용)

  • 이동훈;김래현;정건용
    • Membrane Journal
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    • v.13 no.1
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    • pp.9-19
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    • 2003
  • Membrane process was investigated to recover process water and valuable gold from washing water of electroless PCB plating processes. The filtration experiments were carried out using not only a RO membrane test cell to determine suitable membrane for washing water but also spiral wound membrane modules of nanofiltration and reverse osmosis for scale-up. At first, RO-TL(tap water, low pressure), RO-BL(brackish water, low pressure) and RO-normal(for water purifier) sheet membranes made by Saehan Co. were tested, and the performance of RO-TL membrane showed most suitable f3r recovery of soft etching, catalyst and Ni washing waters. As a result of RO test cell, the experiments for scale-up were carried out using RO-TL modules far water purifier at 7bar and $25^{\circ}C $The permeate flux fur Au washing water was about 30 LMH, but Au rejection was less than 80%. The permeate fluxes for Pd, Ni and soft etching washing water were about 22, 17 and 10 LMH, respectively. The Pd, Ni and Cu rejections showed more than 85, 97 and 98% respectively. The nanofiltration module for water purifier was introduced to recover Au selectively from Au, Ni and Cu ions in Au washing water. Most of Ni and Cu ions in the feed washing water were removed, and only Au ion was existed 81.9% in the permeate. Furthermore, Au ion in the permeate was concentrated and recovered by RO-TL membrane module. Finally, Au was also able to recover effectively by using 4 inch diameter spiral wound modules of NF and RO-TL membranes, in series.

A Study on the Improvement of Rules of Origin in the Korea Foreign Trade Act in the Global Trade Circumstances (국제무역환경 변화에 따른 대외무역법 원산지제도의 개선방안에 관한 연구)

  • Park, Kwang-So;Lee, Byung-Mun;Oh, Won-Suk
    • THE INTERNATIONAL COMMERCE & LAW REVIEW
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    • v.41
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    • pp.267-292
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    • 2009
  • It is a right time to improve the Korea Foreign Trade Act(KFTA) as a fundamental law on Rules of Origin(RoO) in the global trade circumstances which are summarized FTA and WTO. The KFTA's RoO constitutes the labelling system of the Country of Origin, the criterion of it, the issuing of certificate of origin and the punishing offender mainly around the importing goods. This study has focused on the problems of KFTA's RoO at the macro and practical level, and proposed the programs to improve the KFTA's RoO about importing, exporting and domestic production goods. KFTA need to create a purpose clause to protect consumers and industries also, and has to be located a general and top position in the RoO of Korea. In the concrete, the labelling system of the Country of Origin has to set limited in the point of minimum necessity view. The criterion of the Country of Origin also has to improve the wholly obtained criterion, the changing in tariff classification criterion, value added criterion and processing operation criterion to harmonize WTO Rules of Origin and FTA Rules of Origin. The punishment ceiling against offender has to raise to guarantee the effectiveness of RoO.

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Verification of Silt Density Index (SDI) as a fouling index for reverse osmosis (RO) feed water (역삼투 공정 파울링 지표로서 SDI(Silt Density Index)의 적합성 검증)

  • Kim, Su-Han;Kim, Chung-H.;Kang, Suk-H.;Lee, Won-T.;Lim, Jae-L.
    • Journal of Korean Society of Water and Wastewater
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    • v.25 no.4
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    • pp.489-495
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    • 2011
  • Silt Density Index (SDI) has been used as a fouling index for reverse osmosis (RO) processes for decades. In order to decrease RO fouling, feed water should meet SDI standard, which was used to select a proper pretreatment system for RO processes. However, SDI is supposed to be sensitive only to particles larger than 0.45 ${\mu}m$ in terms of diameters while nanoparticles and dissolved organic matter can be potent foulants for RO processes. Our study started from the suspected performance of SDI as a RO fouling index. SDI data from pilot plants located world wide including South Korea were collected and analyzed. Suspended partcle concentration (i.e., turbidity and particle counts), and dissolved organic matter concentration (i.e., dissolved orgnaic carbon (DOC) concentration) data were also collected and compared to SDI values of same water samples. We found that SDI values were not only affected by suspended particle concentration but also by dissolved organic matter concentration. Therefore SDI can be used as a reasonable fouling index for RO feed water because the main foulants for RO processes are suspended particle and dissolved organic matter.

Development of Medium Size High Speed Ro-Pax Vessel (고속 중형 Ro-Pax선의 개발)

  • 이건호;김진현;장학수;주영렬;전호환
    • Journal of the Society of Naval Architects of Korea
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    • v.41 no.1
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    • pp.64-69
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    • 2004
  • In recent years, Medium size high speed Ro-Pax vessel has appeared at European sea and especially Agean sea is a center of operating in this type of Ro-Pax. This vessel operates its high Froude number range and requires higher engine power due to considerably increased resistance in comparing to large Ro-Pax in high speed range. SHI has investigated this kind of high speed Ro-Pax in accordance with market requirements and developed more advanced vessel to meet the future market needs. Process of hull form development, model test results and design of general arrangement results are introduced in this paper.

Stability of Ro/Ro Ship due to Deck Inflow (갑판타입수의 유입에 따른 Ro/Ro선 안정성 연구)

  • Bong K. Woo;Young S. Kwon;Chul. H. Jo;Hyun W. Seo;Ihn S. Na;Kim, Doo H.
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2001.05a
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    • pp.70-75
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    • 2001
  • Intensive experimental investigations were carried out to provide information of the effects of inflow on the rolling characteristics and stability of ships, which becomes great concern in relation to ship's capsizing. A series of systematic experiments have been performed considering the effects cf combined motion of roll-heave-sway and relevant parameters, such as roll angle and period, tank water height etc. To accommodate this type of experiments with 3-degree of freedom of motion, a bench tester has been developed and verified using existing data. Also, theoretical application of anti-roll tank has been incorporated to support the process of investigation. A model of Ro-Ro ships is used in the present study as this type of vessels, as well as fishing vessels, with large open decks, can loose stability rapidly when there is inflow on the decks.

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Comparison of Image Compression Performance based on RoI Extraction Methods for Machines Vision (RoI 추출 방법에 따른 기계를 위한 영상 압축 성능 비교)

  • Lee, Yegi;Kim, Shin;Yoon, Kyoungro
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2022.06a
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    • pp.146-149
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    • 2022
  • 기존 RDO(Rate Distortion Optimization) 기반 압축 방식은 압축 성능에 초점을 두기 때문에 영상 내 인지 특성이 무시될 수 있다. 따라서 RoI(Region of Interest)을 기반으로 압축률을 조절하는 연구가 고안[1, 2, 3, 4] 되었으며, HVS(Human Visual System) 관점에서 영상 내 중요한 부분에 대해 더 높은 품질로 영상을 압축하는 연구가 대부분이다. 최근 인공지능 기술이 발전함에 따라 지능형 영상 분석에 대한 수요가 증가하고 있으며, 이에 따라 머신 비전을 위한 영상 부호화 및 효율적인 전송에 대한 필요성이 대두되고 있다. 본 논문에서는 VVC(Versatile Video Coding)의 dQP(delta Quantization Parameter)를 활용하여 RoI(Region of Interest) 기반압축 방법을 제안하고, 두가지의 RoI 추출 방식을 소개한다. Detectron2 Faster R-CNN X101-FPN [5]의 첫번째 탐지기를 통해 후보 영역 기반 RoI 을 추출하고, 두번째 탐지기를 통해 객체 기반 RoI 을 추출하여, 영상 내 객체 부분과 비객체 부분으로 나누어 서로 다른 압축률로 압축을 수행하였으며, 이에 따른 성능을 비교하고자 한다.

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