• Title/Summary/Keyword: SACS program

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Investigation of the Design Wave Forces for Ear-Do Ocean Research Station I: Three Dimensional Hydraulic Model Tests (이어도 종합해양과학기지에 대한 설계파력의 검토 I: 삼차원 수리모형실험)

  • 전인식;심재설;최성진
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.12 no.4
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    • pp.157-167
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    • 2000
  • Korea Ocean Research and Development Institute performed the basic design of the Ear-Do Ocean Research Station in 1998. The design wave was taken to be the deep water wave which was obtained through wave hindcasting procedure. Wave forces acting on the structure were calculated by Morison formula utilizing the stream function theory of 5th. order. In the present study, a three dimensional hydraulic model testing was undertaken to investigate the validity of the basic design, measuring wave propagation over the Ear-Do, horizontal wave forces and air gaps. The measured forces were all compared by the corresponding values calculated by SACS program based on th design on the design wave. The results showed that in the three deep water wave directions (SSW, S, SE) the measured wave farces appeared less than the SACS calculated. But in the NNW wave direction, the measured forces generally exceeded the calculated values and showed a peculiar pattern very similar to the case that waves are superimposed by an unidirectional current. It was also found that the measured air gap underneath the structure appeared less than the values taken in the basic design for all wave directions.

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Comparison of stress analysis tools for ocean vertical pile under environmental loads (해양 수직 파일(Vertical Pile)에 작용하는 환경 하중하의 응력 해석 기법 비교)

  • 조철희;김병환;김두홍
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2001.04a
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    • pp.121-127
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    • 2001
  • To investigate the stability and integrity of offshore structures, it is necessary to estimates the significant ocean environmental loadings. They include hydrostatic pressure, wind, wave, current, tide, ice, earthquake, temperature, marine growth and scouring. Waves are of major importance among them because of the large forces acting on submerged parts of the structure caused by accompanying water motions. For the comparison of stress and deflection analysis tools, a vertical pile is applied under environmental loads. The analysis is concerned with SACS(Structural Analysis Computer System), ANSYS and C program. SACS and C program have nearly the same results but not ANSYS. This study shows the comparison of results obtained from 3 different approaches.

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Deep-learning-based gestational sac detection in ultrasound images using modified YOLOv7-E6E model

  • Tae-kyeong Kim;Jin Soo Kim;Hyun-chong Cho
    • Journal of Animal Science and Technology
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    • v.65 no.3
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    • pp.627-637
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    • 2023
  • As the population and income levels rise, meat consumption steadily increases annually. However, the number of farms and farmers producing meat decrease during the same period, reducing meat sufficiency. Information and Communications Technology (ICT) has begun to be applied to reduce labor and production costs of livestock farms and improve productivity. This technology can be used for rapid pregnancy diagnosis of sows; the location and size of the gestation sacs of sows are directly related to the productivity of the farm. In this study, a system proposes to determine the number of gestation sacs of sows from ultrasound images. The system used the YOLOv7-E6E model, changing the activation function from sigmoid-weighted linear unit (SiLU) to a multi-activation function (SiLU + Mish). Also, the upsampling method was modified from nearest to bicubic to improve performance. The model trained with the original model using the original data achieved mean average precision of 86.3%. When the proposed multi-activation function, upsampling, and AutoAugment were applied, the performance improved by 0.3%, 0.9%, and 0.9%, respectively. When all three proposed methods were simultaneously applied, a significant performance improvement of 3.5% to 89.8% was achieved.

Mycobacterium avium subsp. avium infection in a lineolated parakeet (Bolborhynchus lineola)

  • Lee, So-Young;Yoo, Jong-Hyun;Yoon, Jang-Won;Kim, Dae-Young;Cho, Ho-Seong;Park, Chul;Park, Hee-Myung
    • Korean Journal of Veterinary Research
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    • v.50 no.1
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    • pp.59-62
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    • 2010
  • A 2-year-old lineolated parakeet (Bolborhynchus lineola) was presented with abdominal distention and respiratory distress for two months. The bird was poorly fleshed and the liver was enlarged on coelomic palpation. Plain and contrast radiographic examinations exhibited hepatomegaly and distended intestinal loop, which compromised the air sacs. Multifocal hyperechogenecity was observed in the liver on ultrasonography. Postmortem gross examination revealed hepatomegaly with numerous pinpoint tan foci in the hepatic parenchyma and distended small intestine filled with adult ascarids. Microscopically, granulomatous hepatitis and enteritis infected by intrahistiocytic acid-fast bacilli were evident. Polymerase chain reaction indicated that the acid-fast bacilli were Mycobacterium avium subsp. avium.

Seasonal Variation in the Abundance of the Demersal Copepod Pseudodiaptomus sp. (Calanoida, Pseudodiaptomidae) in the Seomjin River Estuary, Southern Korea

  • Park Eun Ok;Suh Hae-Lip;Soh Ho Young
    • Korean Journal of Environmental Biology
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    • v.23 no.4
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    • pp.367-373
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    • 2005
  • We conducted a year-long survey in 2000 to examine seasonal fluctuations in the abundance of the demersal copepod Pseudodiaptomus sp., the dominant copepod in the Seomjin River estuary, where the spring tide strongly affects changes in salinity gradients. Pseudodiaptomus sp. was found throughout the year in the entire range of salinities measured, but most individuals appeared at oligohaline conditions below 5.0 psu, and less than $2\%$ were observed in polyhaline conditions above 18.0 psu. The peak abundance occurred during autumn in oligohaline waters, and the density was relatively low during the rainy season in summer. In spring and autumn, copepodites were most abundant in oligohaline waters, although they were also fairly abundant in mesohaline conditions $(5\~18\;psu)$. Females with egg sacs appeared in oligo- and mesohaline waters during spring and autumn but were seldom found in polyhaline conditions throughout the year. Our results indicate that, despite the strong physical influence of the tide, Pseudodiaptomus sp. can manipulate its position to remain at its preferred salinity. We also found that spawning mainly occurred in oligohaline waters twice a year.

Spectral Fatigue Analysis for Topside Structure of Offshore Floating Vessel

  • Kim, Dae-Ho;Ahn, Jae-Woo;Park, Sung-Gun;Jun, Seock-Hee;Oh, Yeong-Tae
    • Journal of Advanced Research in Ocean Engineering
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    • v.1 no.4
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    • pp.239-251
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    • 2015
  • In this study, a spectral fatigue analysis was performed for the topside structure of an offshore floating vessel. The topside structure was idealized using beam elements in the SACS program. The fatigue analysis was carried out considering the wave and wind loads separately. For the wave-induced fatigue damage calculation, motion RAOs calculated from a direct wave load analysis and regular waves with different periods and unit wave heights were utilized. Then, the member end force transfer functions were generated covering all the loading conditions. Stress response transfer functions at each joint were produced using the specified SCFs and member end force transfer functions. fatigue damages were calculated using the obtained stress ranges, S-N curve, wave spectrum, heading probability of each loading condition, and their corresponding occurrences in the wave scatter diagrams. For the wind induced fatigue damage calculation, a dynamic wind spectral fatigue analysis was performed. First, a dynamic natural frequency analysis was performed to generate the structural dynamic characteristics, including the eigenvalues (natural frequencies), eigenvectors (mode shapes), and mass matrix. To adequately represent the dynamic characteristic of the structure, the number of modes was appropriately determined in the lateral direction. Second, a wind spectral fatigue analysis was performed using the mode shapes and mass data obtained from the previous results. In this analysis, the Weibull distribution of the wind speed occurrence, occurrence probability in each direction, damping coefficient, S-N curves, and SCF of each joint were defined and used. In particular, the wind fatigue damages were calculated under the assumption that the stress ranges followed a Rayleigh distribution. The total fatigue damages were calculated from the combination with wind and wave fatigue damages according to the DNV rule.

Development of the Vertical Ladder using a High-Strength Aluminium Alloys (6082-T6) (고강도 알루미늄 합금을 적용한 수직 사다리 개발 연구)

  • Kim, Jae-hyeong;Seo, Kwang-Cheol;Park, Joo-Shin
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.26 no.6
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    • pp.698-705
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    • 2020
  • In this study, an improved aluminum alloy (6082-T6) was used to develop a unique model of an aluminum ladder for usage in offshore plant. The structural strength design was carried out in accordance with international standards such as ISO, NORSOK Austria Standard. Load combination was performed to satisfy all conditions. The structural safety of the designed model was verified using SACS, an analysis program for offshore plants based on the Finite elements method. The analysis results confirmed that both stress and deflection were satisfied within the acceptance criteria. The developed model can be applied used in various fields in the near future as it meets all the necessary criteria and is lightweight and has improved productivity.

Design comparison of Fixed Offshore Structures Designed by WSD and LRFD Methods (허용응력설계법 및 하중저항계수설계법에 의한 고정식 해양구조물 설계결과 비교 )

  • Bae-Keun Jeong;Doo-Yong Cho
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.27 no.2
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    • pp.42-49
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    • 2023
  • When designing fixed jacket structures, overseas design standards are applied due to the absence of domestic design methods. Although the US API standards are mainly applied, API RP 2A suggests two design methods: the allowable stress design method (WSD) and the load resistance coefficient method (LRFD), and is applied according to the designer's judgment. In this study, the stress ratio of the two design methods was reviewed and compared using SACS, an analysis program dedicated to marine structures, for fixed marine structures actually installed on the domestic coast. As a result of the review, it was found that the LRFD design method showed a greater stress ratio for extreme load analysis and transportation analysis, and the WSD design method showed a greater stress ratio for loading and lifting. Therefore, when applying the design method, it is considered appropriate to select the final design method considering safety and economic feasibility after conducting an applicability review for the two design methods.

Gintonin absorption in intestinal model systems

  • Lee, Byung-Hwan;Choi, Sun-Hye;Kim, Hyeon-Joong;Park, Sang-Deuk;Rhim, Hyewhon;Kim, Hyoung-Chun;Hwang, Sung-Hee;Nah, Seung-Yeol
    • Journal of Ginseng Research
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    • v.42 no.1
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    • pp.35-41
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    • 2018
  • Background: Recently, we identified a novel ginseng-derived lysophosphatidic acid receptor ligand, called gintonin. We showed that gintonin induces $[Ca^{2+}]i$ transient-mediated morphological changes, proliferation, and migration in cells expressing lysophosphatidic acid receptors and that oral administration of gintonin exhibits anti-Alzheimer disease effects in model mice. However, little is known about the intestinal absorption of gintonin. The aim of this study was to investigate gintonin absorption using two model systems. Methods: Gintonin membrane permeation was examined using a parallel artificial membrane permeation assay, and gintonin absorption was evaluated in a mouse everted intestinal sac model. Results: The parallel artificial membrane permeation assay showed that gintonin could permeate an artificial membrane in a dose-dependent manner. In the everted sac model, gintonin absorption increased with incubation time (from 0 min to 60 min), followed by a decrease in absorption. Gintonin absorption into everted sacs was also dose dependent, with a nonlinear correlation between gintonin absorption and concentration at 0.1-3 mg/mL and saturation at 3-5 mg/mL. Gintonin absorption was inhibited by the Rho kinase inhibitor Y-27632 and the sodiumeglucose transporter inhibitor phloridzin. Moreover, lipid extraction with methanol also attenuated gintonin absorption, suggesting the importance of the lipid portion of gintonin in absorption. This result shows that gintonin might be absorbed through passive diffusion, paracellular, and active transport pathways. Conclusion: The present study shows that gintonin could be absorbed in the intestine through transcellular and paracellular diffusion, and active transport. In addition, the lipid component of gintonin might play a key role in its intestinal absorption.