• Title/Summary/Keyword: initial effective stress

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Effect of K0-Consolidation in Behavior of Normally Consolidated Clay (정규압밀점토(正規壓密粘土)의 거동(擧動)에 미치는 K0-압밀효과(壓密効果))

  • Hong, Won Pyo
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.7 no.3
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    • pp.183-193
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    • 1987
  • After clay particles have been sedimented isotropically, the clay deposits have been consolidated under $K_0$-stress system. Therefore, in order to predict the behavior in-situ of normally consolidated clays, the effect of $K_0$-consolidation should be considered. A series of undrained and drained triaxial compression tests was performed on remolded specimens of clay consolidated under both $K_0$-and isotropic stress systems and the effect of $K_0$-consolidation was investigated. $K_0$-consolidation has much effect on the deviator stress, especially at initial deformation stage of consolidated-undrained tests, but has little effect on the principal effective stress ratio. Thus, the undrained strength behavior of $K_0$-consolidated samples can not be predicted from isotropically consolidated test data. However, the failure envelop, provided by the maximum principal effective stress ratio failure criterion, is unique and curved.

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Effects of a Yoga Program on School Stress of the Elementary School Children (요가 프로그램이 초등학생의 학교 스트레스에 미치는 효과)

  • Yang, Mi-Ae;Ahn, Ie-Hwan
    • The Korean Journal of Elementary Counseling
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    • v.9 no.2
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    • pp.175-193
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    • 2010
  • The aim of this study is to examine effects of a yoga program for children on school stress of the elementary school children. To achieve this goal, total 10 students out of 231 in 6 classes among the third graders in M elementary school in B city were selected as subjects for this study. After regular school hours, they participated in a children's yoga program for 16 times for 45 minutes per session in the course of 8 weeks. An ethnographic interview was conducted to identify the effects of the program. During the initial stage of the children's yoga program, the participants were interviewed preliminarily. An analysis of areas and an analysis of classifications were made based on the initial interview results, and an area classification table was drawn on the school stress perceived by the elementary school children. After the yoga program ended, a follow up interview was made to apply an analysis of components by comparing changes in the school stress level due to a yoga effect. A research report was written through a cycle of addition and supplement in which the previous data analysis was complemented and corrected by new findings of the study. As a result of the ethnographic interview to analyze the school stress perceived by the elementary school children, and an examination of the changes in the school stress level, the children's yoga program proved to be significantly effective in reducing the school stress. However there were limitations to a certain degree in stress reduction. Details of such findings in each sub-category are as follow. First, as a result of the initial interview analysis, the school stress was classified broadly into 4 categories of study stress, friendship stress, teacher stress, and school environment stress. Second, the study stress as the first category of the school stress was classified into 3 sub-categories of homework, class, and exam stresses. In spite of minor differences among 3 sub-categories, the stress was reduced in general. Third, the friendship stress as the second category of the school stress was also classified into 3 sub-categories of bullying, alienation, and performing one's duty. There were minor differences among sub-categories, however stress reduction also appeared with the exception of the performing one's duty category which had relatively little effect from the yoga program. Fourth, regarding the teacher stress as the third school stress, a classification was made into 3 sub-categories of preference, penalty, and teaching method. Minor differences among the 3 sub-categories notwithstanding, stress reduction appeared with the exception of the teaching method stress which had relatively little effect from the yoga program. Fifth, the school environment stress as the fourth category of the school stress was classified into 2 sub-categories of school meals and facilities. Minor differences between the 2 categories notwithstanding, stress reduction appeared with the facilities stress having relatively little effect.

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A Discrete Analysis of Dynamic Plastic Response of Beam-Columns (Beam-Column의 동적(動的) 역성(逆性) 응답(應答)에 관한 이산화(離散化) 해석(解析))

  • Sung-Hwan,Park;Chang-Doo,Jang
    • Bulletin of the Society of Naval Architects of Korea
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    • v.24 no.3
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    • pp.43-51
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    • 1987
  • In this paper, dynamic elastic, plastic response of beam-columns is analysed using discrete models. composed of rigid bars and springs. The equation of motion is formulated including the shear deformation effect, and the stress change of yielding points is calculated with various yielding criteria. The effect of initial axial force is considered by two ways: (1) including the effect in interaction curve only. (2) including the effect directly in the equation of motion in terms of initial stiffness method is also used in nonlinear interaction procedure. It is found that this model is very effective in analysing not only the plastic response but the elastic response, and present method is more efficient than Finite Element Method from the viewpoint of calculation time and accuracy.

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A Study on the Influence of English Vowel Pronunciation Training on Word Initial Stop Pronunciation of Korean English Learners (영어 모음 발음 교육이 한국인 학습자의 어두 폐쇄음 발화에 미치는 영향에 대한 연구)

  • Km, Ji-Eun
    • Phonetics and Speech Sciences
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    • v.5 no.3
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    • pp.31-38
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    • 2013
  • This study investigated the influence of English vowel pronunciation training to English word-initial stop pronunciation. For that purpose, VOT values of English stops produced by twenty Korean English learners(five Youngnam dialect male speakers, five Youngnam dialect female speakers, five Kangwon dialect male speakers, and five Kangwon dialect female speakers) were measured using the Speech Analyzer and their post-training production was compared with their pre-training production. The result shows that post-training VOT values of voiced stops became closer to those of native English speakers in all four groups. Hence, it can be inferred that vowel pronunciation training is effective for correcting pronunciation of voiced vowels by analyzing the change of the quality of following vowels(especially low vowels) and the degree of giving stress.

EFFECT ON EXPLANATION OF PATHOGENESIS AND STRESS MANAGEMENT AS PRIMARY CARE OF TMJ DISORDER (악관절 장애의 1차 처치로서 병인설명과 스트레스 관리의 효과)

  • Yoo, Jae-Ha;Kang, Sang-Hoon;Baek, Sung-Hum;You, Tae-Min;Kim, Jong-Bae
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.28 no.5
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    • pp.358-363
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    • 2002
  • Purpose : Authors attempted to evaluate the effect on explanation of pathogenesis and stress management as the initial care of temporomandibular disorders. Materials and methods : The materials were 634 patients with temporomandibular disorder, who had been referred to our Department of Dentistry, Wonju Christian Hospital during recent 5 years. We examined about clinical aspects of temporomandibular disorders, such as, major signs of temporomandibular joint disorder, life environment and habits, radiological findings of temporomandibular joint and electromyography of masseter muscle. The patients were treated by explanation of TMJ pathogenesis and stress management. After that, the patient were evaluated about the effect in third week. Results : The result was more favorable (96.5% success rate) without intolerable signs of temporomandibular joint disorder. Conclusion : The explanation of TMJ pathogenesis and stress management were thought as the very effective care in management of patients with temporomandibular disorder.

The Effect of Snoezelen and Computerized Cognitive Rehabilitation(Rehacom) on Improvement of Cognitive Function (스노젤렌과 전산화 인지재활 프로그램(Rehacom)이 인지기능 향상에 미치는 영향)

  • Song, Minok;Kim, Moungjin;You, Youngmin;Lee, Hyangjin;Yang, Giung
    • Journal of The Korean Society of Integrative Medicine
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    • v.1 no.3
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    • pp.79-95
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    • 2013
  • Purpose : This study aims to investigate the effect of the Snoezelen and Rehacom programs on improvement of attention and memory, and the effect of the Snoezelen program on stress reduction. Method : This study was targeted at 11 subjects in the Snoezelen experimental group, 11 subjects in the Rehacom group and 11 subjects in the non-experimental group. As the initial evaluation, all the subjects took electroencephalography. Then, the Snoezelen group and Rehacom group did Snoezelen training and Rehacom training, respectively total 12 times(for 20 minutes twice per week for six weeks), but no training was applied to the control group. Three weeks after the training, the interim was carried out, and four weeks after the training, the final evaluation was carried out. Results : Subjects' attention increased to $58.15{\pm}4.96$ from $43.75{\pm}4.69$ during the Snoezelen training, and increased to $49.85{\pm}1.91$ from $43.28{\pm}2.71$ during the Rehacom training, which means the Snoezelen training was more effective in improving attention(P<0.05). Subjects' memory increased to $56.14{\pm}1.26$ from $43.19{\pm}3.46$ during the Snoezelen training, and increased to $50.94{\pm}4.0$ from $43.07{\pm}2.58$ during the Rehacom training. This also implies that the Snoezelen training was more effective in improving memory(P<0.05). Conclusion : Though both of the Snoezelen training and Rehacom training improved attention and memory, the Snoezelen program was more effective, and it also influenced stress resistance and physical arousal.

Tension and impact behaviors of new type fiber reinforced concrete

  • Deng, Zongcai;Li, Jianhui
    • Computers and Concrete
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    • v.4 no.1
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    • pp.19-32
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    • 2007
  • This paper is concentrated on the behaviors of five different types of fiber reinforced concrete (FRC) in uniaxial tension and flexural impact. The complete stress-strain responses in tension were acquired through a systematic experimental program. It was found that the tensile peak strains of concrete with micro polyethylene (PEF) fiber are about 18-31% higher than that of matrix concrete, those for composite with macro polypropylene fiber is 40-83% higher than that of steel fiber reinforced concrete (SFRC). The fracture energy of composites with micro-fiber is 23-67% higher than that of matrix concrete; this for macro polypropylene fiber and steel fiber FRCs are about 150-210% and 270-320% larger than that of plain concrete respectively. Micro-fiber is more effective than macro-fiber for initial crack impact resistance; however, the failure impact resistance of macro-fiber is significantly larger than that of microfiber, especially macro-polypropylene-fiber.

Statistic Pattern Analysis of HFPD According to Applied Stress (인가 스트레스에 따른 HFPD의 통계적 패턴해석)

  • Kim, Duck-Keun;Lee, Eun-Suk;Jung, Young-Ill;Lim, Jang-Seub;Kim, Tae-Sung
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.05a
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    • pp.18-22
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    • 2000
  • The partial discharge testing is widely used in insulation property measurement because it gives low stress to high voltage equipment which is undertaken tests. Therefore it is very useful method compare to previous destructive methods and effective diagnosis method in power transformer that requires live-line diagnosis. But partial discharges have very complex characteristics of discharge pattern so it is required continuous research to development of precise analysis method. In recent, the study of partial discharge is carrying out discover of initial defect of power equipment through condition diagnosis and system development of degradation diagnosis using HFPD(High Frequency Partial Discharge) detection. In this study, simulated transformer is manufactured and HFPD occurred from transformer is measured with broad band antenna in real time, the degradation grade of transformer is analyzed through produced patterns in simulated transformer according to applied voltages.

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Deformation and Stress Distribution of Discontinuous Precast Concrete Track Slab : I. Initial and Temperature Deformation (불연속 프리캐스트 콘크리트궤도 슬래브의 변형과 응력 분포 : I. 초기 및 온도 변형)

  • Lee, Dong Hoon;Kim, Ki Hyun;Jang, Seung Yup;Zi, Goangseup
    • Journal of the Korean Society for Railway
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    • v.20 no.5
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    • pp.625-636
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    • 2017
  • This study looked into the behavior of precast concrete track due to temperature variation and initial track deformation and examined the effect of initial deformation and deformation caused by temperature gradient on the stress distribution of slab under train load. In this paper, one of two papers in a series, a finite element analysis model for calculating deformation and stress of precast concrete track was proposed; the temperature distribution and displacements measured at the precast concrete track in the field were compared with the analytical results. The results show that the slab always curled up due to initial deformation; by comparing the measured displacements with the displacements calculated by taking measured temperatures at each depth as input, the effective built-in temperature (EBITD), the temperature difference between the top and bottom of the slab corresponding to the initial deformation, can be estimated. If EBITD is relevantly assumed, the calculated displacements correlate well with the measured ones.

Size-effect of fracture parameters for crack propagation in concrete: a comparative study

  • Kumar, Shailendra;Barai, S.V.
    • Computers and Concrete
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    • v.9 no.1
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    • pp.1-19
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    • 2012
  • The size-effect study of various fracture parameters obtained from two parameter fracture model, effective crack model, double-K fracture model and double-G fracture model is presented in the paper. Fictitious crack model (FCM) for three-point bend test geometry for cracked concrete beam of laboratory size range 100-400 mm is developed and the different fracture parameters from size effect model, effective crack model, double-K fracture model and double-G fracture model are evaluated using the input data obtained from FCM. In addition, the fracture parameters of two parameter fracture model are obtained using the mathematical coefficients available in literature. From the study it is concluded that the fracture parameters obtained from various nonlinear fracture models including the double-K and double-G fracture models are influenced by the specimen size. These fracture parameters maintain some definite interrelationship depending upon the specimen size and relative size of initial notch length.