• Title/Summary/Keyword: Smith method

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Nonlinear Finite Element Analysis for Ultimate Hull Girder Strength of Container Ship (컨테이너선의 최종 종강도 평가를 위한 비선형 유한요소 해석의 적용)

  • Yeom, Cheol Wung;Moon, Jeong Woo;Nho, In Sik
    • Journal of the Society of Naval Architects of Korea
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    • v.52 no.4
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    • pp.349-355
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    • 2015
  • Through the recent accident, the checking of ultimate hull girder capacity for container ship should be needed. Smith’s method is well known as the only simplified method to access rapidly for ultimate hull girder capacity except very expensive nonlinear F.E approach. This simplified method, however, is admitted to apply only to bulker and tanker in accordance with Classification Rules up to now. The targets of this study are to verify effectiveness of the simplified method for container ship’s ultimate hull girder strength and to propose the safety factor considering the local bending in double bottom structures due to out of plane loads through the nonlinear F.E analyses. Two different sized ships and three loading conditions which are pure bending, homo-loading and one-bay empty condition were used for this study. Based on the F.E results, the present study showed that CSR’s simplified method is available for the ultimate hull girder strength of container ship and over 1.2 of safety factor should be applied to consider the local bending effect in double bottom structures due to out of plane loads such as sea pressure an cargo.

Comparison of Equilibrium Moisture Contents for Conventional Kiln Dried- and High Temperature Dried Softwood Lumber by Moisture Content Determination (관행열기건조(慣行熱氣乾操)와 고온건조(高溫乾燥) 침엽수재(針葉樹材)의 함수율(含水率) 측정법(測定法)에 의한 평형함수율(平衡含水率) 비교(比較))

  • Jung, Hee-Suk;Smith, William B.
    • Journal of the Korean Wood Science and Technology
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    • v.22 no.4
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    • pp.37-42
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    • 1994
  • The adsorption of water vapor and equilibrium moisture content(EMC) of the specimens for four softwood species dried by conventional- and high temperature method and equilibrated to 15% of the target EMC condition at 25$^{\circ}C$ were determined by oven drying method and with moisture meters. The amount of adsorption for high temperature dried red pine was significantly higher than that of conventional kiln dried wood, while those of eastern white pine, eastern hemlock and Norway spruce were not significantly different between drying methods. EMCs of these four species determined by oven drying method and with capacitive admittance moisture meter were not significantly different between drying methods. EMC of high temperature dried red pine determined with resistance moisture meter was significantly higher than that of conventional kiln dried wood. But EMCs of other species did not show significant difference between drying methods. EMCs of conventional and high-temperature dried wood determined with electronic moisture meters, especially in the case of the capacitive-admittance moisture meter measurement, were lower than that determined by oven drying method.

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Assessment of Ultimate Longitudinal Strength of a VLCC considering Kinematic Displacement Theory (기하학적 변위 이론을 적용한 VLCC 최종종강도 평가)

  • Choung, Joonmo;Nam, Ji-Myung;Tayyar, Gokhan Tansel;Yoon, Sung-Won;Lee, Kangsu
    • Journal of the Society of Naval Architects of Korea
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    • v.50 no.4
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    • pp.255-261
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    • 2013
  • This paper presents prediction of ultimate longitudinal strength of a VLCC, "Energy Concentration" for which many benchmark studies have been carried out, based on kinematic displacement method proposed by Tayyar and Bayraktarkatal (2012). Kinematic displacement theory provides semi-analytical solution of average compressive strengths for various kinds of stiffened panels. The accuracy of average compressive strengths obtained from formulas of CSR(common structural rules) for tankers and kinematic displacement method are discussed in the fore part of this paper. Hull girder ultimate strengths using Smith method are also compared for different average compressive strengths. By comparing them with other benchmark results, it is concluded that the new method provides lower bounds, because hull girder strengths under the sagging and hogging moment conditions approach nearly lower bounds.

Bathymetry Change Investigation of the 2011 Tohoku Earthquake

  • Kim, Kwang Bae;Lee, Chang Kyung
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.33 no.3
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    • pp.181-192
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    • 2015
  • Bathymetry change due to the 2011 Tohoku (M9.0) earthquake was investigated through satellite altimetry-derived free-air gravity anomalies (SAFAGA) and shipborne measurements. The earthquake occurred at the plate boundaries near the northeastern coast of Japan, where the oceanic plate subducts beneath the continental plate along deep-sea trench. Data analyzed in this study include SAFAGA from Scripps Institution of Oceanography (SIO), shipborne bathymetry (SB) from the U.S. National Geophysical Data Center (NGDC) and the Japan Agency for Marine-Earth-Science And Technology (JAMSTEC). To estimate the bathymetry change, a reference bathymetry before the earthquake was predicted by gravity-geologic method (GGM) and Smith & Sandwell’s (SAS) method. In comparison with the bathymetry models before the earthquake, GGM bathymetry model generated by a tuning density contrast of 17.04 g/cm3 by downward continuation method was selected because it shows better bathymetry in the short wavelength below about 6 km. From the results, remarkable bathymetry change of about ±50 m was found on the west side of the Japan Trench caused by the earthquake.

HPLC Analysis and Screening of Standard Compound on Cibotii Rhizoma for Standardization of GCSB-5 Preparation (생약복합제 GCSB-5의 품질 표준화를 위한 구척의 지표성분 탐색 및 HPLC 분석)

  • Cha, Bae-Cheon;Lee, Eun-Hee
    • Korean Journal of Pharmacognosy
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    • v.41 no.1
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    • pp.48-53
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    • 2010
  • GCSB-5 preparation is a purified extract from a mixture of 6 medicinal plants(Acanthopanacis Cortex, Achyranthis Radix, Saposhnikoviae Radix, Cibotii Rhizoma, Glycine Semen Nigra, Eucommiae Cortex) that have been widely used for the treatment of various bone disorders. The aim of this study was to investigate HPLC analysis method and screening of standard compound on Cibotii Rhizoma for quality standardization of a medicinal crude drug GCSB-5. Onitin-4-O-$\beta$-D-glucopyranoside was isolated from Cibotii Rhizoma as the standard compound and identified on the basis of spectroscopic data such as NMR. HPLC analysis method for the determination of onitin-4-O-$\beta$-D-glucopyranoside was established for the quality control of the medicinal plants of Cibotii Rhizoma species, GCSB-5 raw material and GCSB-5 preparation. And validation of HPLC analysis methods were conformed for verification of HPLC methods by check to specificity, linearity, intra-day precision, inter-day precision and accuracy following ICH guideline.

Rejection Scheme of Nearest Neighbor Classifier for Diagnosis of Rotating Machine Fault (회전 기계 고장 진단을 위한 최근접 이웃 분류기의 기각 전략)

  • Choe, Yeong-Il;Park, Gwang-Ho;Gi, Chang-Du
    • Journal of the Korean Society for Precision Engineering
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    • v.19 no.3
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    • pp.52-58
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    • 2002
  • The purpose of condition monitoring and fault diagnosis is to detect faults occurring in machinery in order to improve the level of safety in plants and reduce operational and maintenance costs. The recognition performance is important not only to gain a high recognition rate bur a1so to minimize the diagnosis failures error rate by using off effective rejection module. We examined the problem of performance evaluation for the rejection scheme considering the accuracy of individual c1asses in order to increase the recognition performance. We use the Smith's method among the previous studies related to rejection method. Nearest neighbor classifier is used for classifying the machine conditions from the vibration signals. The experiment results for the performance evaluation of rejection show the modified optimum rejection method is superior to others.

Analyzing the Weight of Assessment Criteria in Korea Green Building Certification System - Focused on Certification Standards for Multi-unit Apartment Projects - (국내 친환경 건축물 인증제도 평가항목의 중요도 분석 - 공동주택 인증심사기준 중심으로 -)

  • Choi, Yeo-Jin;Lhee, Sang-Choon
    • KIEAE Journal
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    • v.12 no.1
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    • pp.83-90
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    • 2012
  • Over the world, social demands and concerns of energy and resource depletions and environmental conservation have resulted in many researches and applications on sustainable development and construction. In order to support these demands and concerns, international green building certification systems such as LEED(Leadership in Energy and Environmental Design) and BREEAM(Building Research Establishment Environmental Assessment Method) were developed. In Korea, the green building certification system was introduced in 2000 and widely applied to all types of new buildings in order to induce the diffusion of sustainable buildings on May, 2010. This paper investigates the importance of assessment criteria on multi-unit apartment projects among certification rating systems using the AHP(Analytic Hierarchy Process) method and suggests a new direction on certification assessment standards. For applying the AHP method, the survey of staffs in green building certification consulting companies and architectural design companies was conducted via e-mail. As a result, criteria like energy, indoor environment, land use, pollution control, and ecological environment among 9 main ones turned out important on assessing green building certification at multi-unit apartment projects, while criteria like water resource, transportation, maintenance management, and material and resource did relatively unimportant.

A Study on the Inverse Emulsion Polymerization of Anionic Arcrylamide and Acrylic Acid (음이온성 아크릴아미드와 아크릴산의 역유화 중합에 관한 연구)

  • Lee, Ki-Chang;Choi, Hee-Chun;Choi, Bong-Jong;Lee, Kwang-Il
    • Journal of the Korean Applied Science and Technology
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    • v.6 no.1
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    • pp.1-7
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    • 1989
  • To developed new process for obtaining maximum molecular weight of anionic acrylamide and acrylic acid copolymer by inverse emulsion polymerization. Concentration of initiator, reducing agent, surfactant and mole ratio of acrylamide-acrylic acid were studied for the process. Semi-batch processes with method of redox, control of reaction temperature, feeding method of monomer and reaction time, was suitable for maximum molecular weight of P(AMAC) from this process obtained $3.09\;{\time}\;10^6({\bar{M}}n.)$ and $4.41\;{\time}\;10^6({\bar{M}}w.)$ in molecular weight measured by the intrinsic viscosity method. inverse emulsion polymerization mechanism of P(AMAC) does not followed the Smith-Ewart and Medvedev theory, but selected for concentration of initiator, reducing agent, surfactant, water solubility of monomer.

Probabilistic Approach to Predicting Residual Longitudinal Strength of Damaged Double HullVLCC

  • Huynh, Van-Vu;Lee, Seung-Hyun;Cho, Sang-Rai
    • Journal of Ocean Engineering and Technology
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    • v.25 no.3
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    • pp.1-10
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    • 2011
  • This paper estimates the residual longitudinal strength of a damaged double hull VLCC (Very Large Crude Carrier) under combined vertical and horizontal bending moments using Smith's method. The damage estimated in this study occurred due to collision or grounding accidents. The effects of the randomness of the yield stress, plate thickness, extent of damage, and the combination of these three parameters on the ultimate hull girder strength were investigated. Random variables were generated by a Monte Carlo simulation and applied to the double hull VLCC described by the ISSC (International Ship and Offshore Structures Congress) 2000 report.

LINEAR AND NON-LINEAR LOOP-TRANSVERSAL CODES IN ERROR-CORRECTION AND GRAPH DOMINATION

  • Dagli, Mehmet;Im, Bokhee;Smith, Jonathan D.H.
    • Bulletin of the Korean Mathematical Society
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    • v.57 no.2
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    • pp.295-309
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    • 2020
  • Loop transversal codes take an alternative approach to the theory of error-correcting codes, placing emphasis on the set of errors that are to be corrected. Hitherto, the loop transversal code method has been restricted to linear codes. The goal of the current paper is to extend the conceptual framework of loop transversal codes to admit nonlinear codes. We present a natural example of this nonlinearity among perfect single-error correcting codes that exhibit efficient domination in a circulant graph, and contrast it with linear codes in a similar context.