• Title/Summary/Keyword: ordinary stress

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Local Buckling and Inelastic Behaviour of 800 MPa High-Strength Steel Beams (800MPa급 고강도강 보 부재의 국부좌굴 및 비탄성 거동)

  • Lee, Cheol-Ho;Han, Kyu-Hong;Kim, Dae-Kyung;Park, Chang-Hee;Kim, Jin-Ho;Lee, Seung-Eun;Ha, Tae-Hyu
    • Journal of Korean Society of Steel Construction
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    • v.24 no.4
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    • pp.479-490
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    • 2012
  • Flexural tests on full-scale H-shaped beams, built up from high-strength steels (HSB800 and HSA800) with a nominal tensile strength of 800 MPa, was carried out to study the effect of flange slenderness of high-strength steel on flexural strength and rotation capacity. The primary objective was to investigate the appropriateness of extrapolating current stability criteria (originally developed for ordinary steel) to high-strength steel. The performance of high-strength steel specimens was very satisfactory from the strength, but not from the rotation capacity, perspective. The inferior rotation capacity of high-strength steel beams was shown to be directly attributable to the absence of a distinct yield plateau and the high yield ratio of the material. Residual stress measurements reconfirmed that the magnitude of the residual stress is almost independent of the yield stress of the base metal.

Mechanical Properties of Hwangtoh-Based Alkali-Activated Concrete

  • Yang, Keun-Hyeok;Hwang, Hey-Zoo;Lee, Seol
    • Architectural research
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    • v.11 no.1
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    • pp.25-33
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    • 2009
  • This study presents the testing of 15 hwangtoh-based cementless concrete mixes to explore the significance and limitations of the development of eco-friendly concrete without carbon dioxide emissions while maintaining various beneficial effects. Hwangtoh, which is a kind of kaolin, was incorporated with inorganic materials, such as calcium hydroxide, to produce a cement-less binder. The main variables investigated were the water-to-binder ratio and fine aggregate-to-total aggregate ratio to ascertain the reliable mixing design of hwangtoh-based cementless concrete. The variation of slump with elapsed time was recorded in fresh concrete specimens. Mechanical properties of hardened concrete were also measured: including compressive strength gain, splitting tensile strength, moduli of rupture and elasticity, stress-strain relationship, and bond resistance. In addition, mechanical properties of hwangtoh-based cement-less concrete were compared with those of ordinary portland cement (OPC) concrete and predictions obtained from the design equations specified in ACI 318-05 and CEB-FIP for OPC concrete, wherever possible. Test results show that the mechanical properties of hwangtoh-based concrete were significantly influenced by the water-to-binder ratio and to less extend by fine aggregate-to-total aggregate ratio. The moduli of rupture and elasticity of hwangtoh-based concrete were generally lower than those of OPC concrete. In addition, the stress-strain and bond stress-slip relationships measured from hwangtoh-based concrete showed little agreement with the design model specified in CEB-FIP. However, the measured moduli of rupture and elasticity, and bond strength were higher than those given in ACI 318-05 and CEB-FIP. Overall, the test results suggest that the hwangtoh-based concrete shows highly effective performance and great potential as an environmental-friendly building material.

A Clinical study on the Sasang Constitution and Obesity (사상체질(四象體質)과 비만(肥滿)에 관한 임상적(臨床的) 연구(硏究))

  • Kim, Eun-Youn;Kim, Jong-Won
    • Journal of Sasang Constitutional Medicine
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    • v.16 no.1
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    • pp.100-111
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    • 2004
  • Objectives To study on the relation between Sasang constitution and obesity and that of obese patient's clinical symptom. Methods The subjects were 129 female patients to visit to diet. The subjects were 129 female patients to diet who answered questionnaire QSCC II and were diagnosed by the Sasang constitution from May to December in 2001 at Nara oriental medical clinic. Results 1. Of obese patients 79.1% were Taeumin, 11.6% Soeumin, and 9.3% Soyangin. 2. A relation of a grade of obesity and Sasang constitution. 2-1) 45.8% of the obese patients were high level obesity who had over 35% of body fat. Out of these people, 91.5% were Taeumin. 2-2) 40.3% of the obese patients weight hip ratio was between 0.84 to 0.89 and 84.6% of these people were proved to be Taeumin. 2-3) 39.2% of the people who had a minimum weight hip ratio of 0.90 were significantly Taeumin, 6.7% Soeumin and 16.6% Soyangin. 2-4) 65.7% of Taeumin were obese patients. 3. Obesity treatment with constitution. 3-1) 59.8% of Taeumin were Pyo-zng patients. 3-2) As treatment periods tended to increase, Taeumin and Soeumin patients showed a large decling of body fat, whereas Soeumin patients showed the opposite reaction. 3-3) The weight hip ratio was led by Taeumin with 0.03 and then came Soeumin and Soyangin with a 0.02 ratio. As treatment was taken into process longer Taeumin patients showed a great progress in decreasing their weight hip ratios. 4. Costitutional related symptom with Obesity. 4-1) Taeumin was followed by Soyangin and then Soeumin in family history. 4-2) Soeumin was followed by Taeumin, then Soyangin when complain of physical fatigue was taken into consideration. 4-3) The ordinary exercise was led by Soyangin, Taeumin then Soeumin. 4-4) People who receive stress turned out to be 72.9% much higher than the people who don't. 4-5) Overeating due to stress was found in 83.3% of Soyangin.

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The Influence of 'Qi Energy Healing' On Control of Autonomic Nervous System (기치유가 자율신경계의 조절능력에 미치는 영향)

  • Hong, Seung-Hui;Oh, Pyung-Il;Lee, Han-Chun;Lee, Mi-Ja
    • The Journal of the Korea institute of electronic communication sciences
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    • v.8 no.7
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    • pp.1093-1101
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    • 2013
  • This paper demonstrates that 'Qi Energy Healing' effects on elevation of capabilities in regards with the autonomic nervous system which prevents from the stress. Nineteen participants were assigned into 'Qi Energy Healing' and the 'Ordinary Relaxation' condition. Participants were examined to see the difference of frequency domain analysis, heart rate tachogram, physical resistance through the heart rate variability. The 'Qi Energy Healing' is significantly more likely to influence on reducing and diminishing the stress. 'Qi Energy Healing' treatment showed clear distinction on 6 fact. Our findings established the link between effectiveness of 'Qi Energy Healing' and the autonomic nervous system.

Statistical analysis of life pattern and functional cosmetics awareness (생활형태와 기능성화장품 인지도에 대한 통계적 분석)

  • Shin, Jae-Kyoung
    • Journal of the Korean Data and Information Science Society
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    • v.25 no.6
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    • pp.1273-1281
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    • 2014
  • As a variety of industrial technology advances with various materials developed, cosmetics industry in general is witnessing many kinds of new cosmetic products. At the same time, Cosmetics Act becomes effective, and cosmetics ingredient labeling is implemented. Concerns with life pattern such as life management, biorhythm, right posture, and stress symptoms are on the increase in order to seek high-quality life as well. These life patterns are closely connected not only with life quality and health but with skin management, and thus this paper conducts a survey on the connection between functional cosmetics awareness and life pattern. Results show that out of 16 questions concerning cosmetics awareness, responses to question number 3, 5, 6 and 11 have relevant differences among colleges. Furthermore, the results of cross analysis with life pattern show that there are relevant differences between the year of responses and stress symptoms and between the year of responses and right posture. Lastly, it is shown that answers to questions regarding gender and biorhythm, gender and right posture, and gender and stress symptoms are relevantly different. Further research is needed to reveal the differences between college students and ordinary people at large.

Improved analytical method for adhesive stresses in plated beam: Effect of shear deformation

  • Guenaneche, B.;Benyoucef, S.;Tounsi, A.;Adda Bedia, E.A.
    • Advances in concrete construction
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    • v.7 no.3
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    • pp.151-166
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    • 2019
  • This paper introduces a new efficient analytical method, based on shear deformations obtained with 2D elasticity theory approach, to perform an explicit closed-form solution for calculation the interfacial shear and normal stresses in plated RC beam. The materials of plate, necessary for the reinforcement of the beam, are in general made with fiber reinforced polymers (Carbon or Glass) or steel. The experimental tests showed that at the ends of the plate, high shear and normal stresses are developed, consequently a debonding phenomenon at this position produce a sudden failure of the soffit plate. The interfacial stresses play a significant role in understanding this premature debonding failure of such repaired structures. In order to efficiently model the calculation of the interfacial stresses we have integrated the effect of shear deformations using the equilibrium equations of the elasticity. The approach of this method includes stress-strain and strain-displacement relationships for the adhesive and adherends. The use of the stresses continuity conditions at interfaces between the adhesive and adherents, results pair of second-order and fourth-order coupled ordinary differential equations. The analytical solution for this coupled differential equations give new explicit closed-form solution including shear deformations effects. This new solution is indented for applications of all plated beam. Finally, numerical results obtained with this method are in agreement of the existing solutions and the experimental results.

Case Studies on Preparing a Business Plan for the Foundation of Food Service Business and Analysis of Investing Economy. (외식사업 신규창업을 위한 사업계획서 작성방법 사례와 투자경제성 분석에 관한 연구)

  • 홍기운
    • Culinary science and hospitality research
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    • v.3
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    • pp.385-421
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    • 1997
  • This study was performed as placing stress on business plan preparation and investing economy analysis centered to cases upon presenting the premises of study for new foundation of food service business. The summarized results are as follows: 1. In the aspect of carrying out process of practical project, establishing the promotion strategy, the facility project program, the menu program, the facility and furniture program, organization & manning schedule, the business operation schedule, review of all laws & provisions and the allout promotion schedule in order were deployed. 2. Analysis of investing economy for review of profitability 1) In case of investment, excluding 600million for the real setate lease among the total investment of 1billion, it was required by 161, 235, 000 for interior project, 161, 110, 000 for facility & equipment, 19, 235, 000 for fittings, 27, 600, 000 for menu plate & uniform, 27, 600, 000 for furniture, 13, 800, 000 for sign article. 2) In case of loss & profit presumed the annual turnover is to be 1, 115, 856, 000 the contigent profit(before tax) is to be 148, 966, 000 which is 13.3% in comparson to the sales amount and the net profit(after tax) for this term s to be 104, 276, 000 which is 9.3% against the sales and the profitable ratio to the equity investment( 500 million) is 20.9% and it satisfies 20% of the premises of study. 3) In case of the payback period will be approximately two(2) years which indicated within three(3) years that is standard of new project evaluation term of ordinary enterprise. 4) In case of internal rate of return it will be 21.5% which is favorable profitability as taking into account of 15% that is standard of new project evaluation by ordinary enterprise based on general downtown money interest. That the investing value of Happy Day profitability is hinted as it is sufficient enough as the case under this study based upon such results and considered that securing supremacy is competitive power in case of commitment will be possible.

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Relationship Between Dietary Consciousness of Housewives and Their Attitude of Households - in Puchon City - (부천 지역 주부의 식문화 의식과 가사행동과의 관계)

  • Koh, Kyung-Hee
    • Journal of the Korean Society of Food Culture
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    • v.14 no.3
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    • pp.211-224
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    • 1999
  • The purpose of this study was to investigate the understanding of dietary consciousness and define the relationship of housewife attitude of middle class residence in Puchon city. Questionnaires were collected 282 housewives in Puchon city. Data were analysed with SAS software package for F-test and Duncan's multiple range test. The main findings of the research were as follows: The food related perchasing place was supermarket(91%), ordinary market(77%), department store(68%), special store(58%), common purchase(37%), convenience store(22%) and communication marketing(13%). The clothing perchasing place showed in the order of department store(71%), special store(65%), ordinary market(52%), common purchase(23%), supermarket(18%), convenience store(15%) and communication marketing(10%). Dietary cosciousness of housewife on foods, clothing, and housing related items was significantly different, specially 20's housewife was concerned about foods and 30's housewife was housing(p<0.05). The behavior consciousness of housewife was significantly different between age, education level, family type and income(p<0.05). Highly educated housewife showed a tendency to spend money and times for food related fields, and to buy clothes in a department store for breaking stress(p<0.05). However, low education level and extended family type housewife got more conservative consciousness on traditional fermented food making(p<0.05). Most of young housewife answered that the making of bread, cookies, soybean paste soup, children clothes and handicraft led to positive consciousness(p<0.05). Especially high life satisfaction housewife preferred to make a dosirak(lunch box), dinner, children clothes and handicraft(p<0.05).

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Free Vibrations of Tapered Timoshenko Beam by using 4th Order Ordinary Differential Equation (4계 상미분방정식에 의한 변단면 Timoshenko 보의 자유진동)

  • Lee, Byoung-Koo;Park, Kwang-Kyou;Lee, Tae-Eun
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.25 no.3
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    • pp.185-194
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    • 2012
  • This paper deals with free vibrations of the tapered Timoshenko beam in which both the rotatory inertia and shear deformation are included. The cross section of the tapered beam is chosen as the rectangular cross section whose depth is constant but breadth is varied with the parabolic function. The fourth order ordinary differential equation with respect the vertical deflection governing free vibrations of such beam is derived based on the Timoshenko beam theory. This governing equation is solved for determining the natural frequencies corresponding with their mode shapes. In the numerical examples, three end constraints of the hinged-hinged, hinged-clamped and clamped-clamped ends are considered. The effects of various beam parameters on natural frequencies are extensively discussed. The mode shapes of both the deflections and stress resultants are presented, in which the composing rates due to bending rotation and shear deformation are determined.

Experimental and numerical studies of concrete bridge decks using ultra high-performance concrete and reinforced concrete

  • Shemirani, Alireza Bagher
    • Computers and Concrete
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    • v.29 no.6
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    • pp.407-418
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    • 2022
  • This paper numerically investigates the effect of changes in the mechanical properties (displacement, strain, and stress) of the ultra-high-performance concrete (UHPC) without rebar and the reinforced concrete (RC) using steel re-bars. This reinforced concrete is mostly used in the concrete bridge decks. A mixture of sand, gravel, cement, water, steel fiber, superplasticizer, and micro silica was used to fabricate UHPC specimens. The extended finite element method as used in the ABAQUS software is applied for considering the mechanical properties of UHPC, RC, and ordinary concrete specimens. To calibrate the ABAQUS, some experimental tests have been carried out in the laboratory to measure the direct tensile strength of UHPC by the compressive-to-tensile load converting (CTLC) device. This device contains a concrete specimen and is mounted on a universal tensile testing apparatus. In the experiments, three types of mixed concrete were used for UHPC specimens. The tensile strength of these specimens ranges from 9.24 to 11.4 MPa, which is relatively high compared with ordinary concrete specimens, which have a tensile strength ranging from 2 to 5 MPa. In the experimental tests, the UHPC specimen of size 150×60×190 mm with a central hole of 75 mm (in diameter)×60 mm (in thickness) was specially made in the laboratory, and its direct tensile strength was measured by the CTLC device. However, the numerical simulation results for the tensile strength and failure mechanism of the UHPC were very close to those measured experimentally. From comparing the numerical and experimental results obtained in this study, it has been concluded that UHPC can be effectively used for bridge decks.