• Title/Summary/Keyword: Constraint Effects

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Hierarchical Leisure Constraints on Leisure Motivation and Participation among Security Agent

  • Kim, Kyong-Sik;Park, Young-Man
    • International Journal of Contents
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    • v.6 no.2
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    • pp.59-68
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    • 2010
  • This research looks close the effect of security agent's hierarchical leisure constraint on the leisure motivation and participation based on the Jackson's Model of the hierarchical leisure constraints. This research selected 420 people for sampling, designating security agents who work for security companies located in Seoul in 2009 at present as subjects by utilizing purposive sampling method, but the number of sampling used for ultimate analysis is 356. In this research, reliability analysis's and structural equation modeling's Maximum Likelihood method are used to prove the reliability and validity of questionnaire. By using these research method and procedures, the conclusion of this research is as following. First, intra-personal leisure constraint was affected by interpersonal, structural leisure constraint. Second, leisure motivation was affected negatively by leisure constraint. Third, leisure participation was affected positively by leisure motivation. Synthesizing all things referred above, leisure constraint was affected by inter-personal, structural leisure constraint, and in turn, leisure motivation and leisure participation were affected by its effects. It turned out that leisure motivation has a meaningful effect on leisure participation through leisure participation and adjusting process.

Evaluation of the Plastic Region Using Recrystallization Heat Treatment for Constraint Effect with STS 316L (STS 316L의 재결정 열처리법을 이용한 구속효과 평가)

  • Han, Min-Su;Jang, Seok-Ki
    • Journal of Advanced Marine Engineering and Technology
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    • v.33 no.4
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    • pp.539-544
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    • 2009
  • The constraint effect $A_2$ has to be evaluated within plastic region near crack tip front using opening displacement. Plastic boundary and stress or strain conditions in the vicinity of the crack tip using recrystallization heat treatment was represented. It was found that the plastic deformation boundary by recrystallization heat treatment method was the true strain of ${\epsilon}t$ = 0.05mm/mm. With the estimation of constraint effects $A_2$, the region of proper displacement measurement point near crack tip was between 0mm and 1mm distance toward direction of crack propagation, and was between 1mm to 3mm distance toward direction of load line.

Analysis of Cleavage Fracture Toughness of PCVN Specimens Based on a Scaling Model (PCVN 시편 파괴인성의 균열 깊이 영향에 대한 Scaling 모델 해석)

  • Park, Sang-Yun;Lee, Ho-Jin;Lee, Bong-Sang
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.33 no.4
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    • pp.409-416
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    • 2009
  • Standard procedures for a fracture toughness testing require very severe restrictions for the specimen geometry to eliminate a size effect on the measured properties. Therefore, the used standard fracture toughness data results in the integrity assessment being irrationally conservative. However, a realistic fracture in general structures, such as in nuclear power plants, may develop under the low constraint condition of a large scale yielding with a shallow surface crack. In this paper, cleavage fracture toughness tests have been made on side-grooved PCVN (precracked charpy V-notch) type specimens (10 by 10 by 55 mm) with various crack depths. The constraint effects on the crack depth ratios were evaluated quantitatively by the developed scaling method using the 3-D finite element method. After the fracture toughness correction from scaling model, the statistical size effects were also corrected according to the standard ASTM E 1921 procedure. The results were evaluated through a comparison with the $T_0$ of the standard CT specimen. The corrected $T_0$ for all of the PCVN specimens showed a good agreement to within $5.4^{\circ}C$ regardless of the crack depth, while the averaged PCVN $T_0$ was $13.4^{\circ}C$ higher than the real CT test results.

Development of Cleavage Fracture Toughness Locus Considering Constraint Effects

  • Chang, Yoon-Suk;Kim, Young-Jin;Ludwig Stumpfrock
    • Journal of Mechanical Science and Technology
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    • v.18 no.12
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    • pp.2158-2173
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    • 2004
  • In this paper, the higher order terms in the crack tip stress fields are investigated macroscopically for more realistic assessment of structural material behaviors. For reactor pressure vessel material of A533B ferritic steel, effects of crack size and temperature have been evaluated using 3-point SENB specimens through a series of finite element analyses, tensile tests and fracture toughness tests. The T-stress, Q-parameter and q-parameter as well as the K and J-integral are calculated and mutual relationships are investigated also. Based on the evaluation, it has proven that the effect of crack size from standard length (a/W=0.53) to shallow length (a/W=0.11) is remarkable whilst the effect of temperature from -20$^{\circ}C$ to -60$^{\circ}C$ is negligible. Finally, the cleavage fracture toughness loci as a function of the promising Q-parameter or q-parameter are developed using specific test results as well as finite element analysis results, which can be applicable for structural integrity evaluation considering constraint effects.

The Effects of Modified Constraint-Induced Movement Therapy and Bilateral Arm Training on the Upper Extremity Performance of Individuals with Chronic Hemiparetic Stroke (수정된 강제-유도운동치료와 양측성 상지훈련이 만성 뇌졸중 환자의 상지 수행 능력에 미치는 영향)

  • Yang, Sung-Hwa;Lee, Wan-Hee;Lee, Kyoung-Suk
    • The Journal of Korean Physical Therapy
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    • v.23 no.5
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    • pp.65-72
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    • 2011
  • Purpose: The intention of this study was to investigate the effects of modified constraint-induced movement therapy (mCIMT) with bilateral arm training (BAT) on the motor performance and daily activity performance of individuals with chronic hemiparetic stroke. Methods: Sixteen subjects one year after stroke participated in this study with a control group; the pretest-posttest method was used. The subjects were randomly allocated into two groups: combination of bilateral arm training and modified constraint-induced movement therapy (n=8), and modified constraint-induced movement therapy (n=8). The mCIMT group received therapy for 90 minutes in 3 sessions per week over a period of 4 weeks. The patients receiving a combination of mCIMT and BAT were treated for the same period and frequency. The results were evaluated using the Fugl-Meyer Assessment, Action Research Arm Test (ARAT), and Motor Activity Log-Amount of Use, and Quality of Movement (MAL-AOU, QOM) assessment tools. Results: The Fugl-Meyer Assessment showed that hand and wrist performance improved significantly more in the mCIMT group than in the Combination group (p<0.05). Result from the ARAT assessment showed greater scores for gross movement in the combined group than in the mCIMT group (p<0.05). The MAL-AOU showed that there was greater improvement in the combined group than in the mCIMT group (p<0.05). Conclusion: The forced use of the more affected side can be important for the enhancement of upper extremity performance for chronic hemiparetic stroke patients during their daily activities.

The Effects of Action Observation Combined with Modified Constraint-induced Movement Therapy on Upper-extremity Function of Subacute Stroke Patients with Moderate Impairment -A Single-blinded Randomized Controlled Trial-

  • Bang, Dae-Hyouk;Lee, Soon-Hyun
    • PNF and Movement
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    • v.18 no.1
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    • pp.23-34
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    • 2020
  • Purpose: To explore the effects of action observation combined with modified constraint-induced movement therapy on upper-extremity function and the activities of daily living in subacute stroke patients. Methods: Twenty-four subacute stroke patients were randomly assigned to the experimental group or the control group (n = 12 each). Both groups received therapy based on motor learning concepts, including repetitive and task-specific practice. The experimental group watched video clips for 10 minutes related to tasks performed during modified constraint-induced movement therapy while the control group watched videos unrelated to upper-extremity movement. These programs were performed for 40 minutes a day five times a week for four weeks. Their scores on the Fugl-Meyer assessment of upper extremities (FMA-UE), the action research arm test (ARAT), a motor activity log (amount of use [AOU] and quality of movement [QOM]), and the modified Barthel index (MBI) were recorded. Results: In both groups, all variables were significantly different between the pre-test and post-test periods (p < 0.05). The post-test variables were significantly different within each group (p < 0.05). In the experimental group, the changes between pre-test and post-test scores in the FMA-UE (14.39 ± 4.31 versus 6.31 ± 4.63), the ARAT (16.00 ± 4.73 versus 11.46 ± 3.73), MAL-AOU (1.57 ± 0.15 versus 1.18 ± 0.28), and MBI (27.54 ± 4.65 versus 18.08 ± 8.52) were significantly higher than those of the control group (p < 0.05). Conclusion: These findings suggest that action observation combined with modified constraint-induced movement therapy may be a beneficial rehabilitation option to improve upper-extremity function in subacute stroke patients with moderate impairment.

A study on the determination of the number of mobility cluster (적정 이동군집수 결정에 관한 연구)

  • ;Ham, Sung Hun
    • Journal of the Korean Geographical Society
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    • v.30 no.2
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    • pp.120-131
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    • 1995
  • To analyze mobility patterns, this study used three Constraint (Capability Constraint, Coupling Constraint, Authority Constraint) models which were proposed in Dr. Hagerstrand's Time-space theory. This paper shows that three constraint models have some effects upon mobility by age. In this study, Capability Constraint means a certain special constraint that is what we can't do during proceeding basic natural urges like sleep, fare, etc. Coupling constraint is a physical one. Each person limits the action range for staying on a special place in special time. For instance, students have to stay in school so that they have mobility constraints. Authority Constraint is a social one. When we use urban facilities or traffic, we may be controlled by mobility sphere by an agreement or a social position. It is social agreement that the opening hour of a store, the time table of mass-transportation and a social positional control that the personal income, the standard of education. In this study it has been in a process of determination of the cluster number that degree of influences a social constraint to mobility. Considering the mobility constraint of characteristics of space divides urban and rural, people in urban area have higher mobility rate than in rural area. Resuets of determination of the cluster, show similar mobility pattern. People in urban area are connected verity of mobility which related to urban space structures with determination of cluste-number. That is to say, mobility patterns can be changed by space charactcristics. Constraints by sex and age are also social constraints and they are influenced by mobility patterns. For instance, females at the age of twenties have similar mobility pattern to the same age male but they have sudden changes after thirty's age. Male entertains a similar pattern without restriction of age. That is to say, management by sex as a social constraint affects mobility. To establish more realistic traffie policy, mobility formation should be reflected to the space in a view of social-behavioral science. To embody this, some problems should be investigated as follows. 1. As a problem of methodology, if sufficient samples ensured, we could subdivide clusters and could open up a new method of analyzing the mobility clusters by using the neuro-network. 2. Extracting actions connected with mobility and finding life cycle which is classified by daily cluste-characteristics, suitable counterproposal could be presented to the traific policy.

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Stress concentrations around a circular hole in an infinite plate of arbitrary thickness

  • Dai, Longchao;Wang, Xinwei;Liu, Feng
    • Structural Engineering and Mechanics
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    • v.34 no.2
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    • pp.143-157
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    • 2010
  • This paper presents theoretical solutions for the three-dimensional (3D) stress field in an infinite isotropic elastic plate containing a through-the-thickness circular hole subjected to far-field in-plane loads by using Kane and Mindlin's assumption. The dangerous position, where the premature fracture or failure of the plate will take place, the expressions of the tangential stress at the surface of the hole and the out-of-plane stress constraint factor are found in a concise, explicit form. Based on the present theoretical solutions, a comprehensive analysis is performed on the deviated degree of the in-plane stresses from the related plane stress solutions, stress concentration and out-of-plane constraint, and the emphasis has been placed on the effects of the plate thickness, Poisson's ratio and the far-field in-plane loads on the stress field. The analytical solution shows that the effects of the plate thickness and Poisson's ratio on the deviation of the 3D in-plane stress components is obvious and could not be ignored, although their effects on distributions of the in-plane stress components are slight, and that the effect of the far-field in-plane loads is just on the contrary of that of the above two. When only the shear stress is loaded at far field, the stress concentration factor reach its peak value about 8.9% higher than that of the plane stress solutions, and the out-of-plane stress constraint factor can reach 1 at the surface of the hole and is the biggest among all cases considered.

Two-Parameter Characterization for the Resistance Curves of Ductile Crack Growth (연선균열성장 저항곡선에 대한 2매개변수의 특성)

  • X.K.Zhu
    • Journal of Advanced Marine Engineering and Technology
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    • v.23 no.4
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    • pp.488-503
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    • 1999
  • The present paper considers the constraint effect on J-R curves under the two-parameter $J-A_2$ controlled crack growth within a certain amount of crack extension. Since the parameter $A_2$ in $J-A_2$ three-term solution is independent of applied loading under fully plasticity or large-scale defor-mation $A_2$ is a proper constraint parameter uring crack extension. Both J and $A_2$ are used to char-acterize the resistance curves of ductile crack growth using J as the loading level and $A_2$ are used to char-acterize the resistance curves of ductile crack growth using J as the loading level and A2 as a con-straint parameter. Approach of the constraint-corrected J-R curve is proposed and a procedure of transferring the J-R curves determined from standard ASTM procedure to non-standard speci-mens or real cracked structures is outlined. The test data(e.g. initiation toughness JIC and tearing modulus $T_R$) of Joyce and Link(Engineer-ing Fracture Mechanics 1997, 57(4) : 431-446) for single-edge notched bend[SENB] specimen with from shallow to deep cracks is employed to demonstrate the efficiency of the present approach. The variation of $J_{IC}$ and $T_R$ with the constraint parameter $A_2$ is obtained and a con-straint-corrected J-R curves is constructed for the test material of HY80 steel. Comparisons show that the predicted J-R curves can very well match with the experimental data for both deep and shallow cracked specimens over a reasonably large amount of crack extension. Finally the present constraint-corrected J-R curve is used to predict the crack growth resistance curves for different fracture specimens. over a reasonably large amount of crack extension. Finally the present constraint-corrected J-R curve is used to predict the crack growth resistance curves for different fracture specimens. The constraint effects of specimen types and specimen sizes on the J-R curves can be easily obtained from the constrain-corrected J-R curves.

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The effects of perceived father's rearing attitude on leisure satisfaction and leisure constraint in middle school students: the mediating effects of self-efficacy (중학생이 지각한 아버지의 애정-합리적 설명형 양육태도가 여가만족 및 여가제약에 미치는 영향 : 자기효능감의 매개효과를 중심으로)

  • Jung, In-Kyung;Kim, Jung-Hyun
    • Journal of Korean Home Economics Education Association
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    • v.27 no.2
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    • pp.77-93
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    • 2015
  • The purpose of this study was to investigate the mediating effects of self-efficacy on the relationship between perceived father's rearing attitude and leisure satisfaction/leisure constraint in junior high school students. A survey was conducted using a convenient sample drawn from 448 students from eleven junior high school in Seoul area. Data were analyzed using SPSS 20.0 program. The results showed that students who perceived their father's rearing attitude as affection-rational explanation performed more of out-door leisure activity with their family. Perceived father's rearing attitude and self-efficacy was positively related with leisure satisfaction but negatively related with leisure constraint. In addition, self-efficacy partially mediated the relationship between perceived father's rearing attitude and leisure satisfaction/leisure constraint. These results suggest the leisure activity could be increased by father's rearing attitude through improving self-efficacy. Therefore, to improve the leisure activity through increase of leisure satisfaction and decrease of leisure constraint, father should raise their children in love and help to grow their self-efficacy.

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