• Title/Summary/Keyword: Stress-dependency

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Video image analysis algorithms with happy emotion tree (영상 이미지 행복 감성 트리를 이용한 분석 알고리즘)

  • Lee, Yean-Ran;Lim, Young-Hwan
    • Cartoon and Animation Studies
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    • s.33
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    • pp.403-423
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    • 2013
  • Video images of emotional happiness or unhappiness, stress or emotional division of tranquility in the form of a tree is evaluated by weighting. Representative evaluation of the video image brightness contrast sensitivity ratings 1 car happy, unhappy or nervous, calm and refined with two car dependency, sensitivity to visual images are separated. Emotion Recognition of four compared to the numerical data is measured by brightness. OpenCV implementation through evaluation graph the stress intensity contrast, tranquility, happiness, unhappiness with changes in the value of four, separated by sensitivity to computing. Contrast sensitivity of computing the brightness according to the input value 'unhappy' to 'happy' or 'stress' to 'calm' the emotional changes are implemented. Emotion computing the regularity of the image to calculate the sensitivity localized computing system can be controlled according to the emotion of the contrast value of the brightness changes are implemented. The future direction of industry on the application of emotion recognition will play a positive role.

Anisotropy in Strength and Deformation Properties of a Variety of Sands by Plane Strain Compression Tests(Part III) -Shear Deformation Characteristics- (평면변형률압축시험에 의한 각종 모래의 강도.변형특성의 이방성(III) -전단변형 특성-)

  • 박춘식;황성춘;장정욱
    • Journal of the Korean Geotechnical Society
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    • v.16 no.4
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    • pp.95-105
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    • 2000
  • Anisotropy of stiffiness, from extremely small strains to post-failure strains, of isotropically consolidated air-pulviated sands in plane strain compression was studied by using the newly developed instrumentation for small strain measurements. Seven types of sand of the world-wide origins were tested, which have been extensively used for research purposes. Stress-strain relationships for a wide range of strain from about 0.0001% to 10% were obtained with measuring axial and lateral strains locally free from the effects of bedding and membrane penetration errors at the specimen boundaries. It was found that the maximum shear modulus Gmax was irrespective of the angle $\delta$of the $\sigma$1 direction relative to the bedding plane. However, the normalized Gmax was varied with the types of sand. Furthermore, the dependency of the strain and stress level on the stiffness increased as decreased.

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Anisotropy in Strength and Deformation Properties of a Variety of Sands by Plane Strain Compression Tests(Part II) -Deformation Characteristics at Extremely Small Strain Level (평면변형률압축시험에 의한 각종 모래의 강도.변형특성의 이방성(II)-미소변형률에서의 변형특성 이방성)

  • 박춘식;장정욱
    • Geotechnical Engineering
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    • v.14 no.4
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    • pp.33-46
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    • 1998
  • Anisotropy of stiffness, from extremely small strains to post-failure strains, of isotropically consolidated air-pluviated sands in plane strain compression was studied by using the newly developed instrumentation for small strain measurements. Seven types of sand of the world-wide origins were tested, which have been extensively used for research purposes. Stress-strain at the specimen boundaries. It was found that the maximum Young's modulus $E_{max}$ was irrespective of the angle $\delta$ of the $\delta_1$ direction relative to the bedding plane. However, the normalized$ E_{max}$ was varied with the types of sand. Furthermore, the dependency of the strain and stress level on the stiffness was increased as $\delta$ decreased.

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Location-dependent Reliability of Solder Interconnection on Printed Circuit Board in Random Vibration Environment (랜덤진동환경에서 솔더접합부의 인쇄회로기판내 위치에 따른 내구수명 변화 연구)

  • Han, Changwoon
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.38 no.1
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    • pp.45-50
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    • 2014
  • A vibration test coupon is prepared with nine plastic ball grid array packages on a printed circuit board using SnPb solders, and a random vibration test is conducted on the coupon. Life data from the test are analyzed, and it is shown that over the board, life data is location-dependent. For investigating this location dependency, a finite element model is developed and the equivalent stresses, which are defined based on the stress response functions at each node, are investigated. It is shown that one of the corner solder balls has the maximum equivalent stress at a package during the test. Finally, it is demonstrated that the maximum equivalent stress and durability life are inversely proportional.

Rheological Properties of Rehydrated Suspensions of Freeze Dried Kochujang Powders (동결건조 분말고추장의 재수화시 리올로지 특성)

  • Kim, Suk-Shin;Chang, Kyu-Seob;Yoon, Han-Kyo;Lee, Sang-Kyu;Lee, Shin-Young
    • Korean Journal of Food Science and Technology
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    • v.19 no.2
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    • pp.81-88
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    • 1987
  • Rheological properties of rehydrated suspensions of two kinds of freeze dried Kochujang powders, processed at different freezing rates, were compared with raw Kochujang using Brookfield wide-gap rotational viscometer at $25^{\circ}C-60^{\circ}C$. Shear rates ranged from $0.1965\;sec^{-1}$ to $1.9650\;sec^{-1}$ and solid content ranged from 47% to 56%. Rehydrated suspensions of quickly frozen Kochujang powder and slowly frozen Kochujang powder, and raw Kochujang exhibited pseudoplastic behaviors with yield stress and presented thixotropic properties which followed the second-order kinetic behavior proposed by Tiu. Suspensions of Kochujang powders exhibited considerably higher decaying rates than raw Kochujang. The dependency of the equilibrium structure parameter on the shear rate was weak, and there were no significant differences among the values of structure parameters of three samples. The temperature dependency of the apparent viscosity of Kochujang suspension was fully expressed by Arrhenius equation and activation energies of suspensions of quickly frozen Kochujang powder and slowly frozen Kochujang powder, and raw Kochujang were 2.21, 2.18, and 2.32 Kcal/g.mole respectively. Consistency indices of three samples increased with solid content and decreased with temperature. Flow behavior indices of three samples showed no considerable dependency on the temperature and solid content. There were no significant differences in the rheological properties between two Kochujang powders.

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Restorative Effects of Natural Landscape on University Students' Stress Reduction and Cognitive Enhancement (대학생들의 스트레스 해소와 인지향상에 미치는 자연경관의 치유효과)

  • Yi, Young Kyoung
    • Journal of the Korean Institute of Landscape Architecture
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    • v.43 no.6
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    • pp.127-137
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    • 2015
  • Recent research has shown that university students experience severe stress and depleted directed attention due to study, social relationships, and economic dependency. Based on the stress reduction theory and the attention restoration theory, this study aims to investigate the effects of natural landscape on university students' stress and cognitive performance through a wide array of measurements including GSR(galvanic skin responsse), IBI(interbeat interval), ZIPERS(Zucherman Inventory of Personal Reactions), and mental arithmetic test. The restorative effects of natural landscape were compared with those of urban landscape. 128 university students participated in the study, and the data of 120 students was analyzed. The results showed that natural landscape was more restorative in relieving psychological stress and in enhancing cognitive performance than urban landscape, which evidenced the restorative effects of natural landscape. Therefore, it could be proposed that natural landscaping of the university campus contributes to students' stress reduction and cognitive enhancement. But such effects were not found in the two physiological measures(both GSR and IBI). Moreover, it was analyzed that urban landscape had a more beneficial effect than natural landscape for IBI, which might resulted from the participants' characteristics and the study landscape. Specifically, the young age span of the participants(average 23.8 years old) and the very natural setting of the university where they were enrolled might lead to the conflicting results in physiological measures. Also, the urban landscape used in the study had a sense of "scope", which is one of the Kaplan and Kaplan's restorative characteristics. Based on this opinion, it was suggested that future study should investigate the impact of the landscape type and contents as well as the participants' characteristics on the restorative effects of natural landscape.

Joining of $\textrm{ZrO}_2$/Na $\beta$"-Alumina to $\alpha$-Alumina using Aluminoborate Glass Sealant (Aluminoborate계 유리질을 사용한 $\textrm{ZrO}_2$/Na $\beta$"-알루미나 복합재와 $\alpha$-알루미나간의 접합)

  • Park, Sang-Myeon;Choe, Gi-Yong;Park, Jeong-Yong;Kim, Gyeong-Heum
    • Korean Journal of Materials Research
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    • v.9 no.1
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    • pp.35-41
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    • 1999
  • In this study we investigated the effects of process variables on the bond strength, and its dependency upon the interfacial chemistry when the joined $ZrO_2$ toughened $Na\beta$"-alumina to $\alpha$-alumina using B$_2$$O_3$-$SiO_2$-Al$_2$$O_3$-CaO glass sealant. We observed that bond strength is mainly determined by the strength of the glass, which, in turn, depends on the glass composition established after joining reaction. Joining at $950^{\circ}C$ for 15min yielded the highest average bond strength of 66MPa. Different types of interfacial reaction seem to occur at each interface. After joining at $950^{\circ}C$ for 15min we found that Ca and Si diffuse much deeper(~15$\mu\textrm{m}$) into the $\beta$"-alumina composite than into the $\alpha$-alumina(<1$\mu\textrm{m}$) as a result of ion exchange reaction and more effective grain boundary diffusion. Thermal expansion coefficient of the glass was found to have changed more closely to those of the $\beta$"-alumina composite and $\alpha$-alumina, which put the glass under a slight compressive stress.ressive stress.

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Plasticity and Fracture Behaviors of Marine Structural Steel, Part V: Effects of Strain Rate and Temperature (조선 해양 구조물용 강재의 소성 및 파단 특성 V: 온도 의존성을 고려한 변형률 속도에 관한 실험적 연구)

  • Choung, Joon-Mo;Im, Sung-Woo;Kim, Kyung-Su
    • Journal of Ocean Engineering and Technology
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    • v.25 no.3
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    • pp.73-84
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    • 2011
  • This is the fifth in a series of companion papers dealing with the dynamic hardening properties of various marine structural steels at intermediate strain rates. Five steps of strain rate levels (0.001, 1, 10, 100, 200/s) and three steps of temperature levels (LT ($-40^{\circ}C$), RT, and HT ($200^{\circ}C$)) were taken into account for the dynamic tensile tests of three types of marine structural steels: API 2W50 and Classifications EH36 and DH36. The total number of specimens was 180 pieces. It was seen that the effects of dynamic hardening became clearer at LT than at RT. Dynamic strain aging accompanying serrated flow stress curves was also observed from high temperature tests for all kinds of steels. The dynamic hardening factors (DHFs) at the two temperature levels of LT and RT were derived at the three plastic strain levels of 0.05, 0.10, 0.15 from dynamic tensile tests. Meanwhile, no DHFs were found for the high temperature tests because a slight negative strain rate dependency due to dynamic strain aging had occurred. A new formulation to determine material constant D in a Cowper-Symonds constitutive equation is provided as a function of the plastic strain rate, as well as the plastic strain level. The proposed formula is verified by comparing with test flow stress curves, not only at intermediate strain rate ranges but also at high strain rate ranges.

A Study on Hydro-mechanical Behaviors of Rock Joints using Rotary Shear Testing Apparatus (회전식 전단시험기를 이용한 암석절리의 수리-역학적 거동에 관한 연구)

  • 천대성;이희석;이정인
    • Tunnel and Underground Space
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    • v.9 no.4
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    • pp.328-336
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    • 1999
  • To characterize the hydro-mechanical behavior of a rock joint, a rotary shear testing apparatus was devised in this study. Shear stress was driven by twisting the end of a sample in the rotary shear testing apparatus. The test results show that the rotary shear test underestimates the peak shear strength of a rock joint. The torque is known as a function of the radial distance from the axis of rotation, resulting in the radial variation of the shear stress. Fluid flow through rock joints is mainly dependent on the Joint roughness, contact area, initial aperture. To examine the dependency, the relationship between the hydraulic and the mechanical apertures for shear-flow was established by measuring the initial aperture. It shows that the mechanical aperture and the hydraulic aperture increase linearly with the dilatancy. The difference between the hydraulic and mechanical apertures describes the deviation from the behavior predicted by the parallel plate model.

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Three-dimensional FE analysis of headed stud anchors exposed to fire

  • Ozbolt, Josko;Koxar, Ivica;Eligehausen, Rolf;Periskic, Goran
    • Computers and Concrete
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    • v.2 no.4
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    • pp.249-266
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    • 2005
  • In the present paper a transient three-dimensional thermo-mechanical model for concrete is presented. For given boundary conditions, temperature distribution is calculated by employing a three-dimensional transient thermal finite element analysis. Thermal properties of concrete are assumed to be constant and independent of the stress-strain distribution. In the thermo-mechanical model for concrete the total strain tensor is decomposed into pure mechanical strain, free thermal strain and load induced thermal strain. The mechanical strain is calculated by using temperature dependent microplane model for concrete (O$\check{z}$bolt, et al. 2001). The dependency of the macroscopic concrete properties (Young's modulus, tensile and compressive strengths and fracture energy) on temperature is based on the available experimental database. The stress independent free thermal strain is calculated according to the proposal of Nielsen, et al. (2001). The load induced thermal strain is obtained by employing the biparabolic model, which was recently proposed by Nielsen, et al. (2004). It is assumed that the total load induced thermal strain is irrecoverable, i.e., creep component is neglected. The model is implemented into a three-dimensional FE code. The performance of headed stud anchors exposed to fire was studied. Three-dimensional transient thermal FE analysis was carried out for three embedment depths and for four thermal loading histories. The results of the analysis show that the resistance of anchors can be significantly reduced if they are exposed to fire. The largest reduction of the load capacity was obtained for anchors with relatively small embedment depths. The numerical results agree well with the available experimental evidence.