• Title/Summary/Keyword: form of vessel

Search Result 234, Processing Time 0.026 seconds

A Study on Flooding·Sinking Simulation for Cause Analysis of No. 501 Oryong Sinking Accident

  • Lee, Jae-Seok;Oh, Jai-Ho;Lee, Sang-Gab
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
    • /
    • 2018.11a
    • /
    • pp.241-247
    • /
    • 2018
  • Deep-sea fishing vessel No. 501 Oryong was fully flooded through its openings and sunk to the bottom of the sea due to the very rough sea weather on the way of evasion after a fishing operation in the Bearing Sea. As a result, many crew members died and/or were missing. In this study, a full-scale ship flooding and sinking simulation was conducted, and the sinking process was analyzed for the precise and scientific investigation of the sinking accident using a highly advanced Modeling & Simulation (M&S) system of the Fluid-Structure Interaction (FSI) analysis technique. To objectively secure the weather and sea states during the sinking accident in the Bering Sea, time-based wind and wave simulation at the region of the sinking accident was conducted and analyzed, and the weather and sea states were realized by simulating the irregular strong wave and wind spectrums. Simulation scenarios were developed and full-scale ship and fluid (air & seawater) modeling was performed for the flooding sinking simulation, by investigating the hull form, structural arrangement & weight distribution, and exterior inflow openings and interior flooding paths through its drawings, and by estimating the main tank capacities and their loading status. It was confirmed that the flooding and sinking accident was slightly different from a general capsize and sinking accident according to the simple loss of stability.

  • PDF

Nutrients and Individual Fatty Acids Intake Patterns in the Coronary Artery Disease Patients with Different Degrees of Stenosis (관상동맥질환자에서 병변의 협착정도에 따른 일반영양소 및 개별지방산의 섭취양상)

  • 김수연
    • Journal of Nutrition and Health
    • /
    • v.30 no.8
    • /
    • pp.976-986
    • /
    • 1997
  • Coronary artery disease (CAD) such as angina pectoris and myocardial infarction(MI) have been considered the major cause of death for decaddes . THeir incidence and prevalence are still increasing . Numerous studies have been done on the risk factor analysis of CAD in Western countries. Since the diet in Western countries is different from that in Korea it is difficult to assume that the Korean diet has the same effects as its western counterpeart on the development of CAD . THus the gudidelines for the Western CAD patients can no totally be applied to Koreans. This study was conducted to investigate the relationship between diet and CAD in Koreans. Subjects were comprised of patients admitted to the hospital for chest pain with poxxilbe CAD (men 129, women 65) . They were divided into the following three groups according to angiographic results ; angiogrphically normal coronary artery group (control), single vessel disease group(SVD) and multiple vessel disease group (MVD) . Intakes of dietary fatty acids and other nutrients were assessed by the semiquantitative food frequency method. Blood was also obtained from subjects for serum lipid analysis. Serum lipid profiles of men were clearly different form those of women. For men, serum choesterol levels (or LDL or LDL/HDL) seemed to be higher in the MVD group compared to the control and SVD groups, while TG level was significantly higher in the MVD group for women. Both men and women showed significantly higher caloric , fiber and vitamins C and A intakes in the MVD group than in the other two groups. Higher caloric intakes was due to higher intakes of carbohydrate and protein rather than fat intake. In terms of fatty acids intake, there were no significant differences among the three groups . Smoking seemed to have great effect on eating patterns in CAD patients. Smokers and ex-smokers showed significantly higher intakes of most nutrients including individual fatty acids that non-smokers. The results of stepwise regression showed that moderate alcohol intake decreases LDL levels and increases HDL levels and smoking seems to lowe HDL levels in CAD patients.

  • PDF

A Study on the Manoeuvrability as Function of Stern Hull Form in Shallow Water (선미형상을 고려한 천수역에서의 조종성능에 관한 연구)

  • Lee, Sungwook
    • Journal of the Korean Society of Marine Environment & Safety
    • /
    • v.21 no.5
    • /
    • pp.552-557
    • /
    • 2015
  • A numerical simulation studies were performed to investigate a manoeuvring characteristics as function of stern hull form with the mathematical model. In order to consider the effect of the stern hull form and obtain the manoeuvring characteristics, a parameter($C_{wa}$) which is aft. water plane area coefficient is modified. Because modifying $C_{wa}$(${\pm}2%$) means that the stern hull form is modified to V-type or U-type, the numerical simulation was performed with this modified $C_{wa}$. A changing trend for the manoeuvring characteristics not only in deep water but also in shallow water such as directional stability, turning and zig-zag was investigated and presented as the results. Present study showed that the manoeuvrability in shallow water largely changed when the draught and water depth ratio(=d/H) become 0.5, and the stern hull form can affect to the manoeuvrability of a vessel navigating in restricted water depth. In addition, it showed that approaching the stern hull to U-type makes the advance and tactical diameter of turning motion large and the overshoot angle of zig-zag motions small. Otherwise, it showed approaching the stern hull form to V-type makes the advance and tactical diameter of turning motion small and the overshoot angle of zig-zag motions large in the present study.

Scleral Diagnostic System Implementation with Color and Blood Vessel Sign Pattern Code Generations (컬러와 혈관징후패턴 코드 생성에 의한 공막진단시스템 구현)

  • Ryu, Kwang Ryol
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.18 no.12
    • /
    • pp.3029-3034
    • /
    • 2014
  • The paper describes the scleral diagnostic system implementation for human eyes by using the scleral color code and vessels sign pattern code generations. The system is based on the high performance DSP image signal processor, programmable gain control for preprocessing and RISC SD frames storage. RGB image signals are optimized by PGC, the edge image is detected form the gray image converted. The processing algorithms are executed by scleral color code generation and scleral vessels sign pattern code creation for discriminating and matching. The scleral symptomatic color code is generated by YCbCr values at memory map tolerated and the vessel sign pattern code is created by digitizing the 24 clock and 13 ring zones, overlay matching and tolerances. The experimental results for performance are that the system runs 40ms, and the color and pattern for diagnostic errors are around 20% and 24% on average. The system and technique enable a scleral diagnosis with subdividing the patterns and patient database.

Inhibitory Effect of Chlorine Dioxide Using Reactive Oxygen Species Against Heart Contraction of the Indianmeal Moth, Plodia interpunctella (이산화염소의 활성산소 발생에 따른 화랑곡나방 심장박동 억제 효과)

  • Kim, Chul-young;Kwon, Hyeok;Kim, Wook;Kim, Yonggyun
    • Korean journal of applied entomology
    • /
    • v.56 no.2
    • /
    • pp.147-152
    • /
    • 2017
  • Heart contraction is essential for insect hemolymph circulation, in which various physiological changes need control of the heart contraction. Thus, interruption of heartbeats intimidate insect survival. Chlorine dioxide induces release of reactive oxygen species (ROS), which has been regarded as the main insecticidal agent. This study analyzed the effect of chlorine dioxide on heartbeats of the Indianmeal moth, Plodia interpunctella. The larvae have the dorsal vessel on the medial dorsal region in a form of an extending tube from the first thorax to 10th abdominal segment. Dorsal vessel contraction was noticeable between 3rd and 10th abdominal segments, where five heart chambers were observed. Average heartbeat rate was 118.6 beats per min at $25^{\circ}C$. However, the heartbeats varied with ambient temperature. Injection of chlorine dioxide to hemocoel suppressed the heartbeats in a dose-dependent manner. The suppressive effect of chlorine dioxide also increased with exposure time to gas form of the chemical at 100 ppm. However, vitamin E (an antioxidant against ROS) treatment significantly rescued the larvae treated with chlorine dioxide in the heart contraction activity. These results suggest that chlorine dioxide negatively influences on the heart contraction of P. interpunctella via its production of ROS.

Inhibitory Effect of Chloroform Extract of Marine Algae Hizikia Fusifomis on Angiogenesis (Hizikia fusiformis 클로로포름 추출물의 in vitro 및 in vivo 혈관신생 억제 연구)

  • Myeong-Eun Jegal;Yu-Seon Han;Shi-Young Park;Ji-Hyeok Lee;Eui-Yeun Yi;Yung-Jin Kim
    • Journal of Life Science
    • /
    • v.34 no.6
    • /
    • pp.399-407
    • /
    • 2024
  • Angiogenesis is the process by which new blood vessels form from existing blood vessels. This phenomenon occurs during growth, healing, and menstrual cycle changes. Angiogenesis is a complex and multifaceted process that is important for the continued growth of primary tumors, metastasis promotion, the support of metastatic tumors, and cancer progression. Impaired angiogenesis can lead to cancer, autoimmune diseases, rheumatoid arthritis, cardiovascular disease, and delayed wound healing. Currently, there are only a handful of effective antiangiogenic drugs. Recent studies have shown that natural marine products exhibit antiangiogenic effects. In a previous study, we reported that the hexane extract of H. fusiformis (HFH) could inhibit the development of new blood vessels both in vitro and in vivo. The aim of this study was to describe the inhibitory effect of chloroform extracts of H. fusiformis on angiogenesis. To investigate how chloroform extract prevents blood vessel growth, we examined its effects on HUVEC, including cell migration, invasion, and tube formation. In a mouse Matrigel plug assay, H. fusiformis chloroform extract (HFC) also inhibited angiogenesis in vivo. Certain proteins associated with blood vessel growth were reduced after HFC treatment. These proteins include vascular endothelial growth factor (VEGF), mitogen-activated protein kinase (MAPK)/extracellular signal transduction kinase, and serine/threonine kinase 1 (AKT). These studies have shown that the chloroform extract of H. fusiformis can inhibit blood vessel growth both in vitro and in vivo.

Sliding Mode Control with Super-Twisting Algorithm for Surge Oscillation of Mooring Vessel System (슈퍼트위스팅 슬라이딩모드를 이용한 선박계류시스템의 동적제어)

  • Lee, Sang-Do;Lee, Bo-Kyeong;You, Sam-Sang
    • Journal of the Korean Society of Marine Environment & Safety
    • /
    • v.24 no.7
    • /
    • pp.953-959
    • /
    • 2018
  • This paper deals with controlling surge oscillations of a mooring vessel system under large external disturbances such as wind, waves and currents. A control synthesis based on Sliding Mode Control (SMC) with a Super-Twisting Algorithm (STA) has been applied to suppress nonlinear surge oscillations of a two-point mooring system. Despite the advantages of robustness against parameter uncertainties and disturbances for SMC, chattering is the main drawback for implementing sliding mode controllers. First-order SMC shows convergence within the desired level of accuracy, in which chattering is the main obstacle related to the destructive phenomenon. Alternatively, STA completely eliminates chattering phenomenon with high accuracy even for large disturbances. SMC based on STA is an effective tool for the motion control of a nonlinear mooring system because it avoids the chattering problems of a first-order sliding mode controller. In addition, the error trajectories of controlled mooring systems implemented by means of STA form in the bounded region. Finally, the control gain effect of STA can be observed in sliding surface and position trajectory errors.

Experimental verification of the linear and non-linear versions of a panel code

  • Grigoropoulos, G.J.;Katsikis, C.;Chalkias, D.S.
    • International Journal of Naval Architecture and Ocean Engineering
    • /
    • v.3 no.1
    • /
    • pp.27-36
    • /
    • 2011
  • In the proposed paper numerical calculations are carried out using two versions of a three-dimensional, timedomain panel method developed by the group of Prof. P. Sclavounos at MIT, i.e. the linear code SWAN2, enabling optionally the use of the instantaneous non-linear Froude-Krylov and hydrostatic forces and the fully non-linear SWAN4. The analytical results are compared with experimental results for three hull forms with increasing geometrical complexity, the Series 60, a reefer vessel with stern bulb and a modern fast ROPAX hull form with hollow bottom in the stern region. The details of the geometrical modeling of the hull forms are discussed. In addition, since SWAN4 does not support transom sterns, only the two versions of SWAN2 were evaluated over experimental results for the parent hull form of the NTUA double-chine, wide-transom, high-speed monohull series. The effect of speed on the numerical predictions was investigated. It is concluded that both versions of SWAN2 the linear and the one with the non-linear Froude-Krylov and hydrostatic forces provide a more robust tool for prediction of the dynamic response of the vessels than the non-linear SWAN4 code. In general, their results are close to what was expected on the basis of experience. Furthermore, the use of the option of non-linear Froude-Krylov and hydrostatic forces is beneficial for the accuracy of the predictions. The content of the paper is based on the Diploma thesis of the second author, supervised by the first one and further refined by the third one.

Improvement in Resistance Performance of a Medium-Sized Passenger Ship with Variation of Bulbous Bow Shape (중형 여객선의 저항성능 향상을 위한 선수벌브의 형상 개선 연구)

  • Yu, Jin-Won;Lee, Young-Gill;Lee, Seung-Hee
    • Journal of the Society of Naval Architects of Korea
    • /
    • v.51 no.4
    • /
    • pp.334-341
    • /
    • 2014
  • Due to the rise of international oil prices, with the continued increase of vessel operating costs, profitability has gradually deteriorated in the some case of South Korea ferry shipping. Therefore, it is necessary to improve the resistance performance of passenger ship. Goose neck bulb can be one of the methods to improve the resistance performance of passenger ship. Goose neck bulb has been applied to passenger ships operated in Europe and large cruise line. But there is no application example in the passenger ship to be operated on a regular basis in the sea near Korea. It is needed to provide reference data that can be applied efficiently goose neck bulb on the medium-sized passenger ships. This study, intended for the medium-sized passenger ship operated short international routes, presents the design of the hull form that goose neck bulb has been applied. And the resistance performance of the designed hull confirmed by numerical simulation. The numerical simulation is performed while changing the local shape of the goose neck depending on the bulb parameters. This study finds bulb parameters and their range that can affect the resistance performance. Thus, it is possible to provide a foundation to develop the optimal design technique and regression analysis on the resistance performance and goose neck bulb.

Remodeling of tuna purse seiner for improving fishing performance (조업성능 향상을 위한 선망선 개선)

  • Hong, Jin-Keun;Kang, Il-Kwon;Jeong, Seong-Jae
    • Journal of the Korean Society of Fisheries and Ocean Technology
    • /
    • v.47 no.4
    • /
    • pp.435-442
    • /
    • 2011
  • In an attempt to respond to the increase in international oil prices and reduce operating expenses, ship remodeling was carried out on a 740ton class tuna purse seiner. To strengthen the competitiveness of the fisheries industry by improving vessel performance, a bulbous bow was newly equipped. The slipway and rudder area were also lengthened and enlarged with the propeller and main engine remained unchanged. To reduce the hull resistance, a circle type bulbous bow was attached on the hull behind bow thruster and thus the cost for exchanging electrical equipment for bow thruster was reduced. The new rudder area was expanded 15% more than the old one within the extent that the existing mechanical control part and rudder stock were not changed. To prevent fishing net damage and stabilize wake field, slipway was lengthened to the optimal position. All of the new design of remodeling parts went through the model tests in towing tank and CWC. Besides resistance test, all of necessary model test results were delivered for hydrodynamic character for the modified ship. The maneuvering simulation to verify that the remodeled ship satisfies the IMO rules was performed in both zigzag and turning tests. The estimated resistance with new bulbous bow and lengthened stern was reduced by 4.8% in the 2-dimensional analysis and 17.4% in the 3-dimensional analysis in comparison of conventional ship. The average reduction of resistance was estimated about 10%. Maneuvering character of modified hull form was found to satisfy all regulations under IMO. The remodeling of tuna purse seiner can not only improve fishing performance but also contribute to reduction of operating cost by saving energy for the fisheries industry.