• Title/Summary/Keyword: non-restrained

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Free Vibration Analysis of Thin-walled Curved Beams with Unsymmetric Cross-section (비대칭 단면을 갖는 박벽 곡선보의 자유진동 해석)

  • 김문영
    • Journal of the Earthquake Engineering Society of Korea
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    • v.3 no.1
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    • pp.41-54
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    • 1999
  • For free vibration of non-symmetric thin-walled circular arches including restrained warping effect, the elastic strain and kinetic energy is derived by introducing displacement fields of circular arches in which all displacement parameters are defined at the centroid axis. The cubic Hermitian polynomials are utilized as shape functions for development of the curved thin-walled beam element having eight degrees of freedom. Analytical solution for in-plane free vibration behaviors of simply supported thin-walled curved beams with monosymmetric cross-sections is newly derived. Also, a finite element formulation using two noded curved beams element is presented by evaluating elastic stiffness and mass matrices. In order to illustrate the accuracy and practical usefulness of this study, analytical and numerical solutions for free vibration of circular arches are presented and compared with solutions analyzed by the straight beam element and the ABAQUS's shell element.

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Compressive Behavior of H-section Brace Strengthened by Non-welded Cold-Formed Element (무용접 냉간성형 조립재로 보강한 H형강 가새의 압축거동)

  • Kim, Sun Hee;Kim, Do Bum;Choi, Sung Mo
    • Journal of Korean Society of Steel Construction
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    • v.27 no.2
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    • pp.169-180
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    • 2015
  • Recently, Seismic performance of the building built in the past is required to review, because the code for seismic design have been reinforced. In 2009, if the revised latest criteria of seismic design is applied, the majority the steel structure of the low-rise concentrically braced system is short of the seismic performance. Also, when the steel braces are subject to compressive load, which causes unstable behavior of the structure. In order to verify the compressive behavior of the reinforced braces, structural performance test was conducted with variables of slenderness ratio and the amount of reinforcement. Therefore, this study suggests restraining the bending buckling of slender H-shaped braces to resist compressive force. In order to verify the compressive behavior of the reinforced braces, structural performance test was conducted with variables of slenderness ratio and the amount of reinforcement.

Pressure loading, end- shortening and through- thickness shearing effects on geometrically nonlinear response of composite laminated plates using higher order finite strip method

  • Sherafat, Mohammad H.;Ghannadpour, Seyyed Amir M.;Ovesy, Hamid R.
    • Structural Engineering and Mechanics
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    • v.45 no.5
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    • pp.677-691
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    • 2013
  • A semi-analytical finite strip method is developed for analyzing the post-buckling behavior of rectangular composite laminated plates of arbitrary lay-up subjected to progressive end-shortening in their plane and to normal pressure loading. In this method, all the displacements are postulated by the appropriate harmonic shape functions in the longitudinal direction and polynomial interpolation functions in the transverse direction. Thin or thick plates are assumed and correspondingly the Classical Plate Theory (CPT) or Higher Order Plate Theory (HOPT) is applied. The in-plane transverse deflection is allowed at the loaded ends of the plate, whilst the same deflection at the unloaded edges is either allowed to occur or completely restrained. Geometric non-linearity is introduced in the strain-displacement equations in the manner of the von-Karman assumptions. The formulations of the finite strip methods are based on the concept of the principle of the minimum potential energy. The Newton-Raphson method is used to solve the non-linear equilibrium equations. A number of applications involving isotropic plates, symmetric and unsymmetric cross-ply laminates are described to investigate the through-thickness shearing effects as well as the effect of pressure loading, end-shortening and boundary conditions. The study of the results has revealed that the response of the composite laminated plates is particularly influenced by the application of the Higher Order Plate Theory (HOPT) and normal pressure loading. In the relatively thick plates, the HOPT results have more accuracy than CPT.

Reference Intervals from Hospital-Based Data for Hematologic and Serum Chemistry Values in Dogs (병원자료에 근거한 혈액 및 혈액화학 검사항목의 참고구간 설정)

  • Kwon, Young-Wook;Pak, Son-Il
    • Journal of Veterinary Clinics
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    • v.27 no.1
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    • pp.66-70
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    • 2010
  • Reference interval is critical for interpreting laboratory results, monitoring response to therapy and predicting the prognosis of the patients in clinical settings. The aim of the present study was to update established reference intervals for routine hematologic and serum chemistry values for a population of clinically healthy dogs (range, 1-8 years) seen in an animal hospital. Blood was obtained by venipuncture while animals were physically restrained, and samples were analyzed for 9 chemistries on MS9-5H (Melot Schloesing Lab, France) and 6 hematology on Vet Test 8008 (IDEXX, USA). Data from 105 dogs (52 males and 53 females) for hematology and 113 dogs (37 males and 76 females) for chemistry were used to determine reference intervals using the parametric, nonparametric and bootstrap methods. Prior to analysis, all parameters were tested for normal distribution using Anderson-Darling criterion. Of the 9 biochemical analytes, alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase, creatinine, total protein, and glucose concentrations did not fit normal distribution for both original and transformed data. All but eosinophil count satisfied normal distribution for either original or transformed data. Parametric method can be used for original cholesterol concentrations, RBC, WBC, and neutrophil counts. This technique can also be used for power-transformed values of blood urea nitrogen concentrations and for logarithm of lymphocyte and monocyte counts. Non-parametric or bootstrap method was the preferred choice for the remaining 7 biochemical parameters and eosinophil count as they did not follow normal distributions. All three statistical techniques performed in similar reference intervals. When establishing reference intervals for clinical laboratory data, it is essential to assess the distribution of the original data to increase the accuracy of the interval, and non-parametric or bootstrap methods are of alternative for the data that do not fit normal distribution.

Free Vibration Analysis of Non-symmetric Thin-Walled Curved Beams with Shear Deformation (전단변형을 고려한 비대칭 박벽 곡선보의 자유진동해석)

  • Kim, Nam-Il;Kim, Moon-Young;Cheol, Min-Byoung
    • Journal of the Earthquake Engineering Society of Korea
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    • v.7 no.4
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    • pp.1-13
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    • 2003
  • For spatial free vibration of non-symmetric thin-walled curved beams with shear deformation, an improved formulation is proposed in the present study. The elastic strain and the kinetic energies are first derived by considering constant curvature and shear deformation effects due to shear forces and restrained warping torsion. Next equilibrium equations and force-deformation relations are obtained using a stationary condition of total potential energy. And the finite element procedures are developed by using isoparametric curved beam element with arbitray thin-walled sections. Particularly not only shear deformation and thickness-curvature effects on vibration behaviors of curved beams but also mode transition and crossover phenomena with change in curvatures of beams are parametrically investigated. In order to illustrate the accuracy and the reliability of this study, various numerical solutions for spatial free vibration are compared with results by available references and ABAQUS's shell element.

Seismic Performance Evaluation and Retrofit of a 2-Story Steel Building Using a Fragility Contour Method (취약성 등고선을 이용한 비내진 2층 철골조 건축물에 대한 내진성능 평가와 보강)

  • Shin, Ji-Uk;Lee, Ki-Hak;Jeong, Seong-Hoon
    • Journal of the Earthquake Engineering Society of Korea
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    • v.16 no.2
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    • pp.47-60
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    • 2012
  • Based on the Korean Building Standard Law, a building less than 3-stories and $1000m^2$ in area is defined as a small-level building and, as a result, this type of building has been excluded from the requirement to comply with seismic design. In order to prevent the loss of life and property under earthquake loadings, the small-scale building should satisfy the seismic performance specified in the current code through a seismic retrofit. In this study, a seismic retrofit scheme of a Buckling-Restrained Knee Brace (BRKB) was developed for non-seismic 2-story steel buildings, including small-scale buildings, using a fragility contour method. In order to develop an effective retrofit scheme of the BRKB for the building, a total of 75 BRKB analytical models were used to achieve the desired performance levels and analyzed using the fragility contour method. The seismic performance of the retrofitted building was evaluated in terms of the weight of the developed BRKB systems. This study shows that the fragility contour method can be used for rapid evaluation and is an effective tool for structural engineers.

A Hybrid Tendency of Contemporary Landscape Design (현대조경설계의 하이브리드적 경향)

  • Jang Il-Young;Kim Jin-Seon
    • Journal of the Korean Institute of Landscape Architecture
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    • v.34 no.2 s.115
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    • pp.80-98
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    • 2006
  • This study originated from following questions. What can we understand the conception of deconstruction, which has been the core idea of new discourses developed in various ways since modernism? How can this question be interpreted in landscape design? What is the conceptional frame of integration the prominent hybrid post-genre movements and phenomena? The frame can be epitomized with the deconstruction phenomenon. 'Deconstruction' is the core conception appeared in late or post-modern ages in the embodiment of modernity and can be viewed as an integrating or a hybrid phenomenon between areas or genres in formative arts. Therefore, the author regards the hybrid movements widely witnessed in the post contemporary formative arts as one of the most important indicators of de-constructive signs. It is safe to say that the phenomenon of this integration or hybridism, of course, does not threaten the identity of landscape design but serves as an opportunity to extend the areas of landscape design. One of the consequences of this integration or hybridism is the voluntary participation of users who have been alienated in the production of the meanings of design works and hybrid landscape design with the hybridization of genres that is characterized with transformation in forms. This view is based on the distinction between hybridization of interactions between the designer (the subject) and the user (the object), and hybridization of synesthesia. Generally speaking, this is an act of destroying boundaries of the daily life and arts. At the same time, it corresponds to vanishing of modern aesthetics and emerging of post-contemporary aesthetics which is a new aesthetic category like sublimeness. This types of landscape design tries to restore humans' sensibility and perceptions restrained by rationality and recognition in previous approach and to express non-materialistic characteristics with precaution against excessive materialism in the modern era. In light of these backgrounds, the study aims to suggest the hybrid concept and to explorer a new landscape design approach with this concept, in order to change the design structure from 'completed' or 'closed' toward 'opened' and to understand the characteristics of interactions between users and designs. This new approach is expected to create an open-space integrating complexity and dynamics of users. At the same time, it emphasizes senses of user' body with synesthesia and non-determination. The focus is placed on user participation and sublimity rather than on aesthetic beauty, which kind of experience is called simulacre. By attaching importance to user participation, the work got free from the material characteristics, and acceptance from the old practice of simple perception and contemplation. The boundaries between the subject and object and the beautiful and ordinary, from the perspective of this approach, are vanished. Now everything ordinary can become an artistic work. Western dichotomy and discrimination is not effective any more. And there is 'de-construction' where there is perfect equality between ordinary daily life and beautiful arts. Thus today's landscape design pays attention to the user and uses newly perceived sensitivity by pursing obscure and unfamiliar things rather than aesthetic beauty. Space is accordingly defined to take place accidentally as happening and event, not as volume of shape. It's the true way to express spatiality of landscape design. That's an attempt to reject conventional concepts about forms and space, which served as the basis for landscape design, and to search for new things.

Body Image, Eating Problems and Dietary Intakes among Female College Students in Urban Area of Korea (일부 도시지역 여대생들의 신체상과 섭식 장애 및 영양 섭취 양상)

  • 박혜순;이현옥;승정자
    • Korean Journal of Community Nutrition
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    • v.2 no.4
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    • pp.505-514
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    • 1997
  • Concern about body weight among young females is too much, so distorted body image and restrained eating are serious problems among Korean young females. A society preoccupied with thinness give a psychological burden to women, this burden may have adverse effects on health physically and psychologically. We tried this study to investigate body image, eating problems, and dietary intakes among female college students in urban areas of Korea. We satisfactorily surveyed using their body weight, desired weight dieting, binge eating, and night eating by self-questionnaires with 500 female college students. We evaluated their dietary intakes by semi-quantitative food frequency questionnaires to assess their usual intakes. After removing incomplete data, we analyzed 469 data by SAS 6.10. The 469 women aged 21.1 years. Their mean height, weight, and BMI were 161.4cm, 52.5kg, and 20.2kg/$m^2$ respectively. Though the frequency of obesity was only 2.6$\%$, the frequency of dissatisfaction with their body weight was 84.7$\%$. Female college students desired their hight, weight, and BMI to be 165.8cm, 48.2kg, and 17.5kg/$m^2$, respectively. The frequency of binge eating and night eating were 20.7$\%$and 6.8$\%$. The odds ratios for binge eating and night eating were 10.9(95$\%$ CI : 2.6-15.1) and 6.0(95% CI : 1.8-14.8) in the group satisfied with their body weight compared with the dissatisfied group. The odds ratios for binge eating and night eating were 2.6(95% CI : 1.6-4.4) and 2.4(95% CI : 1.1-5.4) in the dieting group compared with the non-dieting group. The mean caloric intake was 1, 840kacl and percent intakes of carbohydrate, protein, and fat wee 57.2$\%$, 16.3$\%$, and 24.0$\%$, respectively. The dieting group showed deficient intakes of protein and calcium significantly compared with the non-dieting group showed deficient intakes of protein and calcium significantly compared with the non-dieting group. Almost all women college students in urban area had dissatisfaction with their body shape, and desired severe undrerweight. The frequency of binge eating and night eating increased according to dissatisfaction with body weight, diet, and distortion of body image. Dieting has adverse effect on the intakes of essential nutrients. Educations is needed to correct distorted body image, and bad eating habits in young females, and marked preoccupation with thinness among women should then be reduced. (Korean J Community Nutrition2(4) : 505-514, 1997)

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LncRNA CRNDE Promotes the Progression of B-cell Precursor Acute Lymphoblastic Leukemia by Targeting the miR-345-5p/CREB Axis

  • Wang, Weimin;Wu, Feifei;Ma, Ping;Gan, Silin;Li, Xue;Chen, Li;Sun, Ling;Sun, Hui;Jiang, Zhongxing;Guo, Feng
    • Molecules and Cells
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    • v.43 no.8
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    • pp.718-727
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    • 2020
  • The imbalance between the proliferation and apoptosis of B-cell precursors is an important contributor to the pathogenesis of B-cell precursor acute lymphoblastic leukemia (BCP-ALL), while its specific regulatory mechanism remains perplexing. This study aimed to expound the underlying mechanism of the proliferation and apoptosis of BCP-ALL cells from the perspective of non-coding RNA. In this study, long non-coding RNA colorectal neoplasia differentially expressed (LncRNA CRNDE) was upregulated in the bone marrow of BCP-ALL patients and BCP-ALL cell lines (NALM-6 and RS4;11). Functionally, LncRNA CRNDE knockdown restrained cell proliferation and boosted cell apoptosis in NALM-6 and RS4;11 cells. The subsequent investigation confirmed that LncRNA CRNDE bound to miR-345-5p and negatively regulated miR-345-5p expression. The overexpression of miR-345-5p suppressed cell proliferation and boosted cell apoptosis in NALM-6 and RS4;11 cells. Further experiments revealed that miR-345-5p downregulated cyclic AMP response element-binding protein (CREB) expression by targeting its mRNA directly. CREB overexpression reversed the effect of miR-345-5p mimic on cell proliferation and apoptosis in NALM-6 and RS4;11 cells. Finally, in vivo experiments showed that LncRNA CRNDE knockdown prolonged the survival of mice xenotransplanted with NALM-6 cells. In conclusion, LncRNA CRNDE upregulated CREB expression by suppressing miR-345-5p, thus promoting cell proliferation and reducing cell apoptosis in BCP-ALL.

Journal of Body Mass Index, Body Shape Dissatisfaction, Eating Behavior (대학생의 체질량지수(BMI:Body Mass Index), 체형 불만족도와 식이행동에 관한 연구)

  • Shin, Mee-Kyung
    • Journal of Convergence for Information Technology
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    • v.9 no.12
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    • pp.98-103
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    • 2019
  • The purpose of this study was to identify the correlation and level of Body Mass Index, Body Shape Dissatisfaction, Eating Behavior in college students. Methods: A total of 383 students were asked. The survey was analyzed by SPSS Win 21.0 program. 293 were female students and most of the students were normal in BMI(58.2%), and underweight students were the next(14.9%). There were positive correlation between body shape non satisfication and eating behavior and BMI(r=.587, p=.000; r=.174, p=.001), and negative correlation between body shape non satisfication and age and sleeping time. According to BMI the body shape non satisfication was different in normal and 1 stage obesity students. and 2 stage obesity and under weight students (F=2.993, p=.019;F=2.993, p=.109). As a result of this study, students with body mass index overweight have low body satisfaction, so it is necessary to educate the right dietary exercise therapy for weight management. And even underweight groups should be mediated so that they undergo normal diet behaviors, rather than restrained dietary behaviors, to maintain health.