• 제목/요약/키워드: strength effect

검색결과 11,667건 처리시간 0.038초

Perceived Employment Instability Effect on Psychological Well-being and Job Satisfaction: Resilience and Character Strength as Mediator

  • Yang, Hoe-Chang;Sun, Il-Suck;Park, Soo-Hong
    • Asian Journal of Business Environment
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    • 제5권4호
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    • pp.29-35
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    • 2015
  • Purpose - This study intended to identify how resilience and character strength among employees are influenced by employment instability and the negative impact it could have on job satisfaction and psychological wellbeing. Research design, data, and methodology - This study hypothesizes that employment instability will have a negative effect on resilience and character strength, but resilience and character strength will have a positive effect on job satisfaction and psychological wellbeing. A total of 150 valid questionnaires were collected and utilized for analysis. Results - Employment instability was found to have a negative impact not only on job satisfaction and psychological wellbeing but also on employee resilience and character strength. Conclusion - The results suggest that along with the necessity for a strategic approach at the corporate level, enterprises should also acknowledge employee failures and support them in job situations. They should create a positive work environment and a structure of empowerment, interesting jobs, and a positive organizational culture to build various systems and the ability to enhance self-esteem and stamina in order to reinforce character strength.

Temperature and humidity effects on behavior of grouts

  • Farzampour, Alireza
    • Advances in concrete construction
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    • 제5권6호
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    • pp.659-669
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    • 2017
  • Grouts compared to other material sources, could be highly sensitive to cold weather conditions, especially when the compressive strength is the matter of concern. Grout as one the substantial residential building material used in retaining walls, rebar fixation, sidewalks is in need of deeper investigation, especially in extreme weather condition. In this article, compressive strength development of four different commercial grouts at three temperatures and two humidity rates are evaluated. This experiment is aimed to assess the grout strength development over time and overall compressive strength when the material is cast at low temperatures. Results represent that reducing the curing temperature about 15 degrees could result in 20% reduction in ultimate strength; however, decreasing the humidity percentage by 50% could lead to 10% reduction in ultimate strength. The maturity test results represented the effect of various temperatures and humidity rates on maturity of the grouts. Additionally, the freeze-thaw cycle's effect on the grouts is conducted to investigate the durability factor. The results show that the lower temperatures could be significantly influential on the behavior of grouts compared to lower humidity rates. It is indicated that the maturity test could not be valid and precise in harsh temperature conditions.

Effect of Strength Training Combined with Blood Flow Restriction Exercise on Leg Muscle Thickness in Children with Cerebral Palsy

  • Mun, Dal-Ju;Park, Jae-Cheol
    • PNF and Movement
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    • 제19권3호
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    • pp.441-449
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    • 2021
  • Purpose: The purpose of this study was to investigate the effect of strength training combined with blood flow restriction on leg muscle thickness in children with cerebral palsy. Methods: Nineteen children with cerebral palsy, aged between five and 10 years of age, living in area N, were recruited. Ten participants were classified into a blood flow restriction group and nine into a strength exercise group. The experimental group performed strength training using a blood flow restriction cuff on the leg, and the control group performed strength training without blood flow restriction. A paired t-test was performed to confirm intragroup changes before and after five weeks of the experiment, and an independent t-test was performed to confirm intergroup changes, and the significance level was α=0.05. Results: The rectus femoris, gastrocnemius and gluteus medius muscles showed significant differences in the groups after five weeks (p<0.05). There was a significant difference between the groups in the rectus femoris and gastrocnemius after five weeks (p<0.05). Conclusion: As a result of this study, it was found that strength training combined with blood flow restriction had a positive effect on the changes in leg muscle thickness in children with cerebral palsy. This suggests the possibility of using it in the future as basic data for strength training methods and blood flow restriction exercises for children with cerebral palsy.

Evaluation of Strength Properties for Bolted Connections with Lumber from Small Diameter Logs

  • Park, Joo-Saeng;Park, Chun-Young;Chun, Su-Kyoung;Lee, Jun-Jae
    • Journal of the Korean Wood Science and Technology
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    • 제30권3호
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    • pp.59-65
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    • 2002
  • EYM (European Yield Model), which was adopted in NDS (National Design Specification for wood construction), has been used in Korea without any verification of the analysis of bolted wood connections. In the case of applying lumber from domestic small diameter logs, however, there are some problems with the direct application of EYM ; 1) relatively low dowel bearing strength and dimensional stability due to a large amount of immature wood, 2) effect of MC (moisture contents) on the dowel bearing strength of wood and the yield load of a bolted connection. To evaluate the strength properties of bolted connections with lumber from domestic small diameter logs, effect of MC on the dowel bearing strength of wood was investigated and double shear bolted connection tests were performed. As the MC of wood increased, the dowel bearing strength was linearly reduced, even under 19% MC, which showed that adjustment, not considered in NDS, was required. Double shear bolted connection tests indicated that effect of MC on yield load should be considered in order to determine design value.

타설 직후의 동해가 콘크리트의 압축강도에 미치는 효과 (The Effect of Early Frost Damage after Placement on Compressive Strength of Concrete)

  • 이윤;김진근;이성태
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2001년도 가을 학술발표회 논문집
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    • pp.1199-1202
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    • 2001
  • The objective of this study is to examine the effect of frost damage immediately after placement on compressive strength of concrete. Obviously frost damage produced under low curing temperature at early ages causes the loss of compressive strength of concrete. In order to find the degrees of the loss of compressive strength, compressive strength tests was peformed at 7 and 28-day ages on concrete specimen with various curing temperature history. The results from the tests showed that the loss of compressive strength relative to concrete cured under isothermal temperature at $20^{\circ}C$ was generally from 20 to 50% for 7-day ages and below 20% for 28 day ages. Considering the serious loss of compressive strength over 50% for some cases, careful attention may be needed to placing of concrete under low atmospheric temperature.

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강섬유가 고강도 SFRC의 압축강도에 미치는 영향 (the Effect of Steel Fiber on the Compressive Strength of High Strength Steel Fiber Reinforced Cementitious Composites)

  • 강수태;박정준;고경택;김성욱;이장화
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2004년도 춘계 학술발표회 제16권1호
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    • pp.308-311
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    • 2004
  • Many researchers have reported that adding steel fiber to concrete improved its tensile and flexural strength significantly, but relatively few studies have been made on the compressive behavior of SFRC(steel fiber reinforced concrete). It is still less in case of high strength SFRC. The main objective of this research is to examine the effect of adding steel fiber on the compressive strength of high strength SFRC using fiber reinforcing index$(RI,\;V_f(l/d))$. It was found from the study that compressive strength was noticeably increased in proportion to RI.

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플라이 애쉬 치환율에 따른 저열 포틀랜드 시멘트 콘크리트의 고강도 영역에서의 강도발현 특성 (Strength Development of Low Heat Portland Cement Concrete according of Substitution of Fly-ash in High Strength Range)

  • 김태홍;하재담;엄태선;이종열;권영호
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2005년도 추계 학술발표회 제17권2호
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    • pp.603-606
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    • 2005
  • Strength development of low heat portland cement(Type IV) concrete according of addition of fly-ash in high strength range is tested. In this study strength development according to water-binder ratio, strength development according to age, effect of fly ash are tested. This study tests effect of low heat portland cement in high strength range concrete and provide guide line concrete mix design for later study and construction.

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실존 콘크리트 구조체의 코어 강도에 관한 연구 (A Study on the Strength of Concrete Core in Existing Structures)

  • 배영미;김민수;권영웅
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2005년도 추계 학술발표회 제17권2호
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    • pp.611-614
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    • 2005
  • This study concerns the strength of concrete cores drilled from existing structures. The test factors are core size, drilled position of core, concrete age and concrete strength. The test results are as follows; (1) Under the filled condition of curing, concrete strength for three years are larger than that of 28 days by $15\~20\%$ (2) According to the core size effect from diameter of 75mm to 150mm , the variation of core strength are by $8\~18\%$ (3) According to the wall height of 1m, the strength of lower point of wall is than larger that of the upper point by $5\~20\%$. (4) In Accessing the core strength of concrete as a basis, the effect of core size and drilling position should be considered.

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작업 요인이 push-pull strength와 근육 동원 패턴에 미치는 영향 (Effect of various work factors on push-pull strength and muscle recruitment pattern)

  • 심정훈;이상도
    • 산업경영시스템학회지
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    • 제25권4호
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    • pp.46-53
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    • 2002
  • Push-pull strength has been found to be associated with various work factors such as height, distance, repetition, duration, posture and individual factors. Therefore, this study was performed to investigate the effect of various work factors on push-pull strength and muscle recruitment pattern. Work factors were consisted of grip height(elbow, shoulder), grip distance(100%, 50%, and 25% of maximum grip distance) and shoulder angle(neutral($90^{\cire}$), and abduction($45^{\cire}$, $0^{\cire}$)) during sitting work. The results showed that the normalized strength and EMG value were higher at the elbow height than the shoulder height, and increased with grip distance and shoulder adduction. The results of ANOVA showed that there was significant difference on muscle recruitment patterns among the task conditions. Therefore, it is necessary to consider work factors as well as strength to prevent workers from work-related injuries.

유기섬유의 열적 특성이 고강도 콘크리트 폭열에 미치는 영향 (The Effect of Thermal Characteristic of Organic Fibres on the Spalling of High Strength Concrete)

  • 박찬규;이승훈;김규동;손유신
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2005년도 봄학술 발표회 논문집(II)
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    • pp.37-40
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    • 2005
  • Recently, in order to reduce the spalling of high strength concrete under fire, the addition of organic fibres to high strength concrete has been investigated. In this study, the effect of thermal characteristic of organic fibres on the spalling of high strength concrete was experimantally investigated. Two types of fibre, polypropylene(PP) and polyvinyl alcohol(PVA) fibres, were selected, and the strength level of concrete was correnponding to the design strength of 80MPa. As a result, it appears that when the remaining ratios(by weight) of fibre at 300$^{circ}C$ and 350$^{circ}C$ are less than 80$\%$ and 50$\%$, respectively, the spalling of high strength concrete is prevented.

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