• Title/Summary/Keyword: Common structural rule

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A Comparative Study on the Prediction of Bow Flare Slamming load using CFD and Prescript Formula for the Container Ship

  • Seo, Dae-Won;Jeon, Gi-Young;Song, Kang-Hyun
    • Journal of Advanced Research in Ocean Engineering
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    • v.4 no.4
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    • pp.204-216
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    • 2018
  • A ship repeatedly face free surface under rough sea conditions owing to relative motion with wave encounter. The impact pressure is transferred to the hull structure and causes structural damage. In this study, the bow flare slamming load of a container ship is estimated using computations fluid dynamics (CFD) and prescript formula according to various classifications. It is found that the bow flare slamming load calculated by the formulas of the common structural rule and ABS tends to be similar to the CFD results.

Condition assessment of raking damaged bulk carriers under vertical bending moments

  • Kim, Do Kyun;Yub, Su Young;Choi, Han Suk
    • Structural Engineering and Mechanics
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    • v.46 no.5
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    • pp.629-644
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    • 2013
  • This paper concerns about the raking damages on the ultimate residual hull girder strength of bulk carriers by applying the modified R-D diagram (advanced method). The limited raking damage scenarios, based on the IMO's probability density function of grounding accidents, were carried out by using sampling technique. Recently, innovative method for the evaluation of the structural condition assessment, which covers the residual strength and damage index diagram (R-D diagram), was proposed by Paik et al. (2012). This concept is applied in the present study and modified R-D diagram, which can be considered vessel size effect, is then proposed. Four different types of bulk carrier structures, i.e., Handysize (37K), Supramax (57K), Kamsarmax (82K) and Capesize (181K) by Common Structural Rule (CSR), were applied to draw the general tendency. The ALPS/HULL, intelligent supersize finite element method, was employed for the ultimate longitudinal strength analysis. The obtained empirical formulas will be useful for the condition assessment of bulk carrier structures. It can also cover different sizes of the bulk carriers in terms of ultimate longitudinal strength. Important insights and findings with useful guidelines developed in this study are summarized.

Effect of corrosion on the ultimate strength of double hull oil tankers - Part II: hull girders

  • Kim, Do Kyun;Park, Dae Kyeom;Park, Dong Hee;Kim, Han Byul;Kim, Bong Ju;Seo, Jung Kwan;Paik, Jeom Kee
    • Structural Engineering and Mechanics
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    • v.42 no.4
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    • pp.531-549
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    • 2012
  • Numerous oil tanker losses have been reported and one of the possible causes of such casualties is caused by the structural failure of aging ship hulls in rough weather. In aging ships, corrosion and fatigue cracks are the two most important factors affecting structural safety and integrity. This research is about effect on hull girder ultimate strength behavior of double hull oil tanker according to corrosion after Part I: stiffened panel. Based on corrosion data of Part I (time-dependent corrosion wastage model and CSR corrosion model), when progressing corrosion of fourtypes of double hull oil tankers (VLCC, Suezmax, Aframax, and Panamax), the ultimate strength behavior of hull girder is compared and analyzed. In case of the ultimate strength behavior of hull girder, when occurring corrosion, the result under vertical and horizontal bending moment is analyzed. The effect of time-dependent corrosion wastage on the ultimate hull girder strength as well as the area, section modulus, and moment of inertia are also studied. The result of this research will be useful data to evaluate ultimate hull girder strength of corroded double hull oil tanker.

Updates on the treatment of adhesive capsulitis with hydraulic distension

  • Jang Hyuk, Cho
    • Journal of Yeungnam Medical Science
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    • v.38 no.1
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    • pp.19-26
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    • 2021
  • Adhesive capsulitis of the shoulder joint is a common disease characterized by pain at the insertional area of the deltoid muscle and decreased range of motion. The pathophysiological process involves fibrous inflammation of the capsule and intraarticular adhesion of synovial folds leading to capsular thickening and contracture. Regarding the multidirectional limitation of motion, a limitation in external rotation is especially prominent, which is related to not only global fibrosis but also to a localized tightness of the anterior capsule. Ultrasound and magnetic resonance imaging studies can be applied to rule out other structural lesions in the diagnosis of adhesive capsulitis. Hydraulic distension of the shoulder joint capsule provides pain relief and an immediate improvement in range of motion by directly expanding the capsule along with the infusion of steroids. However, the optimal technique for hydraulic distension is still a matter of controversy, with regards to the infusion volume and rupture of the capsule. By monitoring the real-time pressure-volume profile during hydraulic distension, the largest possible fluid volume can be infused without rupturing the capsule. The improvement in clinical outcomes is shown to be greater in capsule-preserved hydraulic distension than in capsule-ruptured distension. Moreover, repeated distension is possible, which provides additional clinical improvement. Capsule-preserved hydraulic distension with maximal volume is suggested to be an efficacious treatment option for persistent adhesive capsulitis.

Numerical nonlinear bending analysis of FG-GPLRC plates with arbitrary shape including cutout

  • Reza, Ansari;Ramtin, Hassani;Yousef, Gholami;Hessam, Rouhi
    • Structural Engineering and Mechanics
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    • v.85 no.2
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    • pp.147-161
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    • 2023
  • Based on the ideas of variational differential quadrature (VDQ) and finite element method (FEM), a numerical approach named as VDQFEM is applied herein to study the large deformations of plate-type structures under static loading with arbitrary shape hole made of functionally graded graphene platelet-reinforced composite (FG-GPLRC) in the context of higher-order shear deformation theory (HSDT). The material properties of composite are approximated based upon the modified Halpin-Tsai model and rule of mixture. Furthermore, various FG distribution patterns are considered along the thickness direction of plate for GPLs. Using novel vector/matrix relations, the governing equations are derived through a variational approach. The matricized formulation can be efficiently employed in the coding process of numerical methods. In VDQFEM, the space domain of structure is first transformed into a number of finite elements. Then, the VDQ discretization technique is implemented within each element. As the last step, the assemblage procedure is performed to derive the set of governing equations which is solved via the pseudo arc-length continuation algorithm. Also, since HSDT is used herein, the mixed formulation approach is proposed to accommodate the continuity of first-order derivatives on the common boundaries of elements. Rectangular and circular plates under various boundary conditions with circular/rectangular/elliptical cutout are selected to generate the numerical results. In the numerical examples, the effects of geometrical properties and reinforcement with GPL on the nonlinear maximum deflection-transverse load amplitude curve are studied.

A study on hull girder shear strength in bulk carriers for CSR and Harmonized CSR (CSR-BC와 Harmonized CSR-BC의 선체 전단 응력에 대한 비교 고찰)

  • Park, Jong Min;Lee, Kyu Ho;Lee, Sang Bok;Shin, Sung-Kwang
    • Special Issue of the Society of Naval Architects of Korea
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    • 2015.09a
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    • pp.46-49
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    • 2015
  • Common Structural Rules (CSR) about bulk carriers and double-hull oil tankers of International Association of Classification Societies (IACS) has been applied to ships contracted for construction since April 2006. By unifying each society's rules, the difference of opinion in the between shipyard and ship owners, classification was reduced, and CSR has been evaluated by rules the safety structure more enhanced. However, The CSR about the bulk carriers and double hull oil tankers, important design content standards, such as the local scantling calculation, static/dynamic load case and corrosion margin and etc., are different. Therefore in order to combine the CSR, the Harmonized CSR for bulk carriers and double hull oil tankers (H-CSR) was issued on 1, January, 2014, and will be apply to ships contracted for construction after 1st July 2015. It is necessary to verify the H-CSR to optimize the structural arrangement because effective date is not far off. In this study, we compared the impact by rule change for the hull girder shear strength of bulk carriers between CSR and H-CSR in respect of the yielding and buckling strength.

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The Economic Growth of Korea Since 1990 : Contributing Factors from Demand and Supply Sides (1990년대 이후 한국경제의 성장: 수요 및 공급 측 요인의 문제)

  • Hur, Seok-Kyun
    • KDI Journal of Economic Policy
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    • v.31 no.1
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    • pp.169-206
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    • 2009
  • This study stems from a question, "How should we understand the pattern of the Korean economy after the 1990s?" Among various analytic methods applicable, this study chooses a Structural Vector Autoregression (SVAR) with long-run restrictions, identifies diverse impacts that gave rise to the current status of the Korean economy, and differentiates relative contributions of those impacts. To that end, SVAR is applied to four economic models; Blanchard and Quah (1989)'s 2-variable model, its 3-variable extensions, and the two other New Keynesian type linear models modified from Stock and Watson (2002). Especially, the latter two models are devised to reflect the recent transitions in the determination of foreign exchange rate (from a fixed rate regime to a flexible rate one) as well as the monetary policy rule (from aggregate targeting to inflation targeting). When organizing the assumed results in the form of impulse response and forecasting error variance decomposition, two common denominators are found as follows. First, changes in the rate of economic growth are mainly attributable to the impact on productivity, and such trend has grown strong since the 2000s, which indicates that Korea's economic growth since the 2000s has been closely associated with its potential growth rate. Second, the magnitude or consistency of impact responses tends to have subsided since the 2000s. Given Korea's high dependence on trade, it is possible that low interest rates, low inflation, steady growth, and the economic emergence of China as a world player have helped secure capital and demand for export and import, which therefore might reduced the impact of each sector on overall economic status. Despite the fact that a diverse mixture of models and impacts has been used for analysis, always two common findings are observed in the result. Therefore, it can be concluded that the decreased rate of economic growth of Korea since 2000 appears to be on the same track as the decrease in Korea's potential growth rate. The contents of this paper are constructed as follows: The second section observes the recent trend of the economic development of Korea and related Korean articles, which might help in clearly defining the scope and analytic methodology of this study. The third section provides an analysis model to be used in this study, which is Structural VAR as mentioned above. Variables used, estimation equations, and identification conditions of impacts are explained. The fourth section reports estimation results derived by the previously introduced model, and the fifth section concludes.

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A Study on the Strength Evaluation Method of Plate Structures with Penetration-holes (관통구를 갖는 판구조물의 강도평가 방법에 관한 연구)

  • Kim, Ul-Nyeon;Jang, Jun-Tae
    • Journal of the Society of Naval Architects of Korea
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    • v.54 no.6
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    • pp.476-484
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    • 2017
  • The purpose of this paper is to verify the structural integrity of a region with numerous penetration-holes in offshore structures such as semi-submersible rig and FPSO. In order to effectively check the yielding and buckling strength of plate members with penetration-holes, a screening analysis program was developed with the FE analysis tool to generate fine meshed model using the theoretical and analysis methods. When a hole is appeared in the plate structure members, the flow of stress is altered such that concentrations of stress form near the hole. Stress concentrations are of concern during both preliminary and detail design and need to be addressed from the perspectives of strength. To configure the geometrical shape, very fine meshed FE analysis is needed as the most accurate method. However, this method is practically impossible to apply for the strength verifications for all perforated plates. In this paper, screening analysis method was introduced to reduce analysis tasks prior to detailed FE analysis. This method is applied to not only the peak stress calculation combined stress concentration factor with nominal stress but also nominal equivalent stress calculation considering cutout effects. The areas investigated by very fine meshed analysis were to be chosen through screening analysis without any reinforcements for penetration-holes. If screening analysis results did not satisfy the acceptance criteria, direct FE analysis method as the 2nd step approach were applied with one of the coarse meshed model considering hole or with the very fine meshed model considering the hole shape and size. In order to effectively perform the local fine meshed analysis, automatic model generating program was developed based on the MSC/PATRAN which is pre-post FE analysis program. Buckling strength was also evaluated by Common Structure Rule (CSR) adopted by IACS as the stress obtained from very fine meshed FE analysis. Due to development of the screening analysis program and automatic FE modeling program, it was able to reduce the design periods and structural analysis costs.

Antipodal Structuralization Strategy of Character Appearing in : Based on Psychological Functions of MBTI Personality Types Theory (<배가본드>에 나타난 캐릭터의 대척적 구조화 전략: MBTI 성격유형론의 심리기능에 근거하여)

  • Yang, Se-Hyeok;Kim, Dae-Gwon
    • Cartoon and Animation Studies
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    • s.31
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    • pp.117-152
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    • 2013
  • is a comics that the original Yoshokawa Eiji's novel . Since the series started in 1998, it's epic that records the 54 million or more copies of the cumulative sales volume to 1.7 million unit volume average in the book, 34 are currently up to volume has been published. proceeds with narratives in a way of following naturally the personality of a character based on the rule of an author, which is 'people should be described as what they are'. Accordingly it features very unique characterizing. This study focused on the fact that numerous characters in maintain a structural balance through the establishment of a character composition in an antipodal relationship although those characters have strong personalities. In order to analyze the relationship of such characters, the study utilized as an analytic frame MBTI personality types theory which is a psychology test tool. First, the study inferred personality patterns as the temperamental characteristics of MBTI, and tried to analyze the antipodal character composition based on the combination of cognition and judgment which are assumably the most important functions. From this, the study was able to discover the following three structures applied to those characters. (1) The antipodism between Musasi, the main character and Kojiro, a mirror character becomes central to the work, (2) The antipodal relationship between their fosterers and the character playing the mentor's role extends the character attribute of Musasi and Kojiro. (3) The Yoshioka family was also established in the antipodal composition as a role of exchanging influences with Musasi and Kojiro. Through this, the study reached a conclusion that in the pairs of characters in contrast were established as if to reach a dialectic synthesis. As such, the antipodal structuralization of the character composition shown in is deemed to differentiate the inner sides of numerous unique characters; thereby make it possible to describe their inner sides in-depth. Finally, the following common context is found: works in the field of successful comics and animation in terms of criticism and performance are focused on characters. It is probably because their consumers are relatively very interested in those characters as the characters in comics or animation become differentiated from those of novels or movies. Subsequently, it is expected that the analyzed results of characterizing can be referred to during the production of contents by preparing the results as database.

Development and Validation of Classroom Problem Behavior Scale - Elementary School Version(CPBS-E) (초등학생 문제행동선별척도: 교사용(CPBS-E)의 개발과 타당화)

  • Song, Wonyoung;Chang, Eun Jin;Choi, Gayoung;Choi, Jae Gwang;ChoBlair, Kwang-Sun;Won, Sung-Doo;Han, Miryeung
    • Korean Journal of School Psychology
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    • v.16 no.3
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    • pp.433-451
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    • 2019
  • This study aimed to develop and validate the Classroom Problem Behavior Scale - Elementary School Version (CPBS-E) measure which is unique to classroom problem behavior exhibited by Korean elementary school students. The focus was on developing a universal screening instrument designed to identify and provide intervention to students who are at-risk for severe social-emotional and behavioral problems. Items were initially drawn from the literature, interviews with elementary school teachers, common office discipline referral measures used in U.S. elementary schools, penalty point systems used in Korean schools, 'Green Mileage', and the Inventory of Emotional and Behavioral Traits. The content validity of the initially developed items was assessed by six classroom and subject teachers, which resulted in the development of a preliminary scale consisting of 63 two-dimensional items (i.e., Within Classroom Problem Behavior and Outside of Classroom Problem Behavior), each of which consisted of 3 to 4 factors. The Within Classroom Problem Behavior dimension consisted of 4 subscales (not being prepared for class, class disruption, aggression, and withdrawn) and the Outside of Classroom Problem Behavior dimension consisted of 3 subscales (rule-violation, aggression, and withdrawn). The CPBS-E was pilot tested on a sample of 154 elementary school students, which resulted in reducing the scale to 23 items. Following the scale revision, the CPBS-E was validated on a sample population of 209 elementary school students. The validation results indicated that the two-dimensional CPBS-E scale of classroom problem behavior was a reliable and valid measure. The test-retest reliability was stable at above .80 in most of the subscales. The CPBS-E measure demonstrated high internal consistency of .76-.94. In examining the criterion validity, the scale's correlation with the Teacher Observation of Classroom Adaptation-Checklist (TOCA-C) was high and the aggression and withdrawn subscales of the CPBS-E demonstrated high correlations with externalization and internalization, respectively, of the Child Behavior Checklist - Teacher Report Form CBCL-TRF). In addition, the factor structure of the CPBS-E scale was examined using the structural equation model and found to be acceptable. The results are discussed in relation to implications, contributions to the field, and limitations.