• Title/Summary/Keyword: Local behavior

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Local Buckling Behavior of Pultruded Structural Flexural Members (펄트루젼 구조용 휨부재의 국부좌굴 거동)

  • 정재호;윤순종
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2003.04a
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    • pp.147-151
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    • 2003
  • In this study, we discussed the local buckling behavior of pultruded structural flexural members. Previous works were briefly reviewed and the local buckling behavior of orthotropic box-shape flexural members was discussed. The simplified form of equation for finding the width ratio of plate element of box-shape flexural members in which all plate components buckle simultaneously was proposed and the macro flow-chart for finding local buckling strength of pultruded flexural members was also suggested. To establish the design guide line for the local buckling of pultruded flexural members, further studies need to be performed as follows; the simplified form of solutions for finding the minimum buckling coefficient of orthotropic plate with various loading and boundary conditions including rotationally restrained boundary conditions, the simplified form of equation for calculating the coefficient of restraint provided by the adjacent plate elements.

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Effect of vibration during local anesthesia administration on pain, anxiety, and behavior of pediatric patients aged 6-11 years: A crossover split-mouth study

  • Hegde, Kuthpady Manasa;Neeraja, R;Srinivasan, Ila;Murali Krishna, DR;Melwani, Anjana;Radhakrishna, Sreeraksha
    • Journal of Dental Anesthesia and Pain Medicine
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    • v.19 no.3
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    • pp.143-149
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    • 2019
  • Background: Uncooperative behavior of children due to dental anxiety may interfere with the effective delivery of dental care and compromise the quality of treatment provided. Injection of local anesthesia is one of the most anxiety-inducing stimuli in pediatric dentistry. This study aimed to compare the efficacy of a child-friendly device, having a combined effect of vibration and distraction, with the conventional method of injection on pain, anxiety, and behavior of pediatric patients aged 6-11 years. Methods: This randomized, crossover, split-mouth study included 30 children requiring a bilateral inferior alveolar nerve block. The children were equally divided into two groups: group 1, aged 6-8 and group 2, aged 9-11 years. All children were injected with anesthesia using the conventional and device method in two separate sessions. They were assessed for anxiety by measuring the pulse rate before and during the administration of local anesthesia. Behavior was assessed using Faces, Legs, Activity, Cry, Consolability (FLACC) scale, and the child's experience while receiving anesthesia was assessed using the Wong Bakers Pain Rating Scale. Results: Results showed that the children who received local anesthesia using the device method had a lower mean pulse rate, FLACC scores, and pain rating scores than those who received local anesthesia using the conventional method. Conclusion: The device method was more effective than the conventional method in managing pain, anxiety, and behavior of patients aged 6-11 years. The device is a cost effective, simple, and child-friendly product for administrating local anesthesia in pediatric patients.

A Study to Simulate Cell Voltage-Reversal Behavior Caused by Local Hydrogen Starvation in a Stack of Fuel Cell Vehicle (연료전지차 스택 내 국부적 수소 부족에 기인한 셀 역전압 거동 모사에 대한 연구)

  • Park, Ji Yeon;Im, Se Joon;Han, Kookil;Hong, Bo Ki
    • Transactions of the Korean hydrogen and new energy society
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    • v.24 no.4
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    • pp.311-319
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    • 2013
  • A clear understanding on cell voltage-reversal behavior due to local hydrogen starvation in a stack is of paramount importance to operate the fuel cell vehicle (FCV) stably since it affects significantly the cell performance and durability. In the present study, a novel experimental method to simulate the local cell voltage-reversal behavior caused by local hydrogen starvation, which typically occurs only one or several cells out of several hundred cells in a stack of FCV, has been proposed. Contrary to the conventional method of overall fuel starvation, the present method of local hydrogen starvation caused the local cell voltage-reversal behavior in a stack very well. Degradation of both membrane electrode assembly (i.e., pin-hole formation) and gas diffusion layer due to an excessive exothermic heat under voltage-reversal condition was also observed clearly.

A Study on the Local Buckling Collapse Behavior of an Aluminum Square Tube Beam under a Bending Load (굽힘하중을 받는 알루미늄 사각관 보의 국부적 좌굴붕괴 거동에 관한 연구)

  • Lee, Sung-Hyuk;Choi, Nak-Sam
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.27 no.12
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    • pp.2011-2018
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    • 2003
  • To analyze the bending collapse behavior of an aluminum square tube beam under a bending load, a finite element simulation for the four-point bending test has been performed. Using an aluminum tube beam specimen partly inserted with two steel bars, the local buckling deformation near the center of the tube beam was induced. The maximum bending load and the bending collapse behavior obtained from the numerical simulation were in good agreement with experimental results. Using a combination of the four-point bending test and its finite element simulation, analysis of the local buckling and the accompanied bending collapse behavior of aluminum tube beam could be quantitative accomplished.

Evaluation of Local Damage of SC Wall using Local Collision Simulation (국부충돌해석에 의한 SC벽체의 국부손상 평가)

  • Woo, Dong In;Chung, Chul Hun
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.35 no.2
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    • pp.265-274
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    • 2015
  • The structural safety of nuclear power plant against impact from aircraft crash has been performed so far in two viewpoints such as local behavior and global behavior, and the local behavior has been evaluated using local damage evaluation formulas suggested based on the results of experimental data of RC (Reinforcement Concrete) wall. However, few data have been collected from recent research to evaluate the local behavior and damage of SC (Steel plate reinforced Concrete) wall, which is recently applied to the newly designed nuclear power plant. In this study, local damages of SC wall and RC wall against an idealized aircraft engine projectile impact are evaluated through FE simulation analyses with various wall thicknesses and steel ratio. Through analysis of local collision simulation results of SC and RC wall, the penetration depth of SC wall and RC wall are compared.

Local ratcheting behavior in notched 1045 steel plates

  • Kolasangiani, K.;Farhangdoost, K.;Shariati, M.;Varvani-Farahani, A.
    • Steel and Composite Structures
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    • v.28 no.1
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    • pp.1-11
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    • 2018
  • In this paper, local ratcheting behavior of 1045 steel plates with circular cutout was investigated. Experimental tests were carried out by a Zwick/Roell HB 100 servo hydraulic machine. In order to measure the local strain at notch root, a data acquisition system with strain gauge was used. Various notch diameters and distances of strain gauges mounted from the notch root were found influential in the magnitude of local ratcheting strain. It was found that the local maximum principal stress plays a crucial role in increasing the local plastic deformation. Numerical simulation was done by ABAQUS software using nonlinear isotropic/kinematic hardening model. Material parameters of hardening model were attained from several stabilized cycles of flat specimens subjected to symmetric strain cycles. The nonlinear kinematic hardening model along with the Neuber's rule was employed to assess local ratcheting at the notch root of steel plates. The results of the numerical simulations agreed closely with those measured values in this study. Both ratcheting progress and mean stress relaxation occurred simultaneously at the notch root.

Fracture Behavior of Welded Pipes with Local Wall Thinning (감육을 가지는 배관 용접부의 파괴거동)

  • Ahn, Seok-Hwan;Nam, Ki-Woo;Jeong, Jeong-Hwan;Kim, Yong-Un
    • Proceedings of the KSME Conference
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    • 2003.04a
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    • pp.90-95
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    • 2003
  • Fracture behaviors of pipes with local wall thinning are very important for the integrity of nuclear power plant. In pipes of energy plants, sometimes, the local wall thinning may result from severe erosion-corrosion (E/C) damage. However, the effects of local wall thinning on strength and fracture behaviors of piping system were not well studied. In this paper, the monotonic bending tests were performed of full-scale welded and unwelded carbon steel pipes with local wall thinning. A monotonic bending load was applied to straight pipe specimens by four-point loading at ambient temperature without internal pressure. The observed failure modes were divided into four types; ovalization, crack initiation/growth after ovalization, local buckling and crack initiation/growth after local buckling. Also, the strengths of welded and unwelded piping system with local wall thinning were evaluated.

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Association between health financial capacity of local governments and health behaviors of local residents: a cross-sectional study (지방자치단체의 보건재정역량과 지역주민의 건강행태 간 관련성에 대한 단면조사연구)

  • Miyong Yon
    • Korean Journal of Community Nutrition
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    • v.28 no.2
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    • pp.95-103
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    • 2023
  • Objectives: The budget gap in the health sector of local governments affects the supply of health services, which can cause the health gap. This study classified local governments according to their financial characteristics, such as local financial independence and health budget level. It analyzed the health behaviors and disease prevalence of local residents to examine the effect of local government financial investment on the health of local residents. Methods: To classify types according to the financial characteristics of local governments, financial independence and the health budget data for 17 local governments were collected from the local fiscal yearbook of the Ministry of Public Administration and Security. The prevalence of chronic diseases and healthy behavior was compared using the 16,333 data of adults between the ages of 30 and 65 years among the original data of the National Health and Nutrition Examination Survey (2016-2020). Results: Cluster analysis was used to classify local governments into five clusters according to the health financial capacity type. A comparison of the prevalence of local residents by cluster revealed a similar prevalence of hypertension, diabetes, and hypercholesterolemia. On the other hand, the obesity rate (P < 0.01), high-risk drinking rate (P < 0.01), aerobic physical activity rate (P < 0.001), and healthy eating practice rate (P < 0.001) were significantly different. In addition, an analysis of the odds ratio based on the Seoul area revealed a higher risk of health behavior of non-Seoul residents. Conclusions: It is necessary to review the universal health promotion project budget considering the degree of regional financial vulnerability from the viewpoint of health equity to narrow the health gap among regions.

Fracture Behavior Evalustion of Pipes with Local Wall Thinning (감육배관의 파괴거동 평가)

  • Ahn, S.H.;Nam, K.W.;Kim, S.J.;Kim, H.S.;Kim, J.H.;Do, J.Y.
    • Proceedings of the KSME Conference
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    • 2001.11a
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    • pp.61-66
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    • 2001
  • Fracture behaviors of pipes with local wall thinning is very important for the integrity of nuclear power plant. In pipes of energy plants, sometimes, the local wall thinning may result from severe drosion-corrosion damage. However, effect of local wall thinning on strength and fracture behaviors of piping system were not well studied. In this paper, the monotonic bending tests were performed of full-scale carbon steel pipes with local wall thinning. A monotonic bending load was applied to straight pipe specimens by four-point loading at ambient temperature without internal pressure. From the tests, fracture behaviors and fracture strength of locally thinned pipe were manifested systematically. The observed failure modes were divided into four types; ovalization, ovalization+cracking, local buckling and local buckling+cracking. Also, maximum load was successfully evaluated.

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Intraoperative Caring Behavior and Anxiety as Perceived by Patients Undergoing Spinal Surgery under Local Anesthesia (국소마취에 의한 척추수술 환자가 지각한 수술 중 돌봄과 불안정도)

  • Ha, Jung Suck;Lee, Eun Nam
    • Journal of muscle and joint health
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    • v.22 no.2
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    • pp.96-104
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    • 2015
  • Purpose: The purpose of this study was to identify the relationship between intraoperative level of caring and anxiety among patients who underwent spinal surgery under local anesthesia. Methods: The study participants included 162 patients who had spinal surgery under local anesthesia at a general hospital in B metropolitan city between July 20 and September 20, 2014. To measure the caring behaviors of patients under local anesthesia, we used the Caring Behavior Measurement, and state anxiety was measured by the State Trait Anxiety Inventory. The collected data were analyzed using a SAS program. The differences in anxiety levels based on participants' characteristics were analyzed with t-test and an analysis of variance. The correlation between levels of caring and anxiety was tested with Pearson's correlation coefficient. Results: Education and caring levels showed significant relationship with the anxiety level of patients with spinal surgery under local anesthesia. Conclusion: To decrease the level of anxiety in patients undergoing spinal surgery under local anesthesia, it is necessary to educate and train operating nurses about the intra-operative caring behavior.