• Title/Summary/Keyword: risk strength

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Prediction Model for the Risk of Scapular Winging in Young Women Based on the Decision Tree

  • Gwak, Gyeong-tae;Ahn, Sun-hee;Kim, Jun-hee;Weon, Young-soo;Kwon, Oh-yun
    • Physical Therapy Korea
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    • v.27 no.2
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    • pp.140-148
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    • 2020
  • Background: Scapular winging (SW) could be caused by tightness or weakness of the periscapular muscles. Although data mining techniques are useful in classifying or predicting risk of musculoskeletal disorder, predictive models for risk of musculoskeletal disorder using the results of clinical test or quantitative data are scarce. Objects: This study aimed to (1) investigate the difference between young women with and without SW, (2) establish a predictive model for presence of SW, and (3) determine the cutoff value of each variable for predicting the risk of SW using the decision tree method. Methods: Fifty young female subjects participated in this study. To classify the presence of SW as the outcome variable, scapular protractor strength, elbow flexor strength, shoulder internal rotation, and whether the scapula is in the dominant or nondominant side were determined. Results: The classification tree selected scapular protractor strength, shoulder internal rotation range of motion, and whether the scapula is in the dominant or nondominant side as predictor variables. The classification tree model correctly classified 78.79% (p = 0.02) of the training data set. The accuracy obtained by the classification tree on the test data set was 82.35% (p = 0.04). Conclusion: The classification tree showed acceptable accuracy (82.35%) and high specificity (95.65%) but low sensitivity (54.55%). Based on the predictive model in this study, we suggested that 20% of body weight in scapular protractor strength is a meaningful cutoff value for presence of SW.

Risk Factors and Methods in Balance Assessment Associated with Fall in Older Adults (노인의 낙상과 연관된 위험요소와 균형 측정 방법)

  • Lee, Yun-Kyung;Bae, Sung-Soo
    • Journal of the Korean Society of Physical Medicine
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    • v.2 no.1
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    • pp.73-84
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    • 2007
  • Purpose : The purpose of this study was to determine risk factors and methods in balance assessment associated with fall in older adults. Methods : This article describes many of the tools that can be used to evaluate the physical parameters associated with fall risk in older adults. Results : Composite ratings of performance(Tinetti balance assessment, Guralnik test battery, Berg balance scale, modified-physical performance test) measures the score compounding the balance measure to determine fall risk. Static balance instruments are composed of FICSIT-4 that measures the ability of maintaining foot positions and CTSIB that measures postural stability. Dynamic balance instrument is composed of functional reach test. To measure walking velocity and mobility, 8-foot up-and-go test and walking around two cones are used. We can use 1-RM and to measure muscular strength, isokinetic dynamometery, and 30-second chair stand to measure lower extremity muscle strength. Conclusion : The described instruments are easy to use and widespread. To select and use these tool kits carefully is considered to be helpful in identifying those who are most likely to fall. The final part of the article includes a brief discussion of the potential role of exercise training interventions to improve these physical parameters and prevent falls.

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A Modified Metric of FMEA for Risk Evaluation Based on ASIL of Safety System (ASIL에 기초하여 수정된 안전시스템 FMEA 위험평가척도)

  • Baek, Myoung-Sig;Jang, Hyeon Ae;Kwon, Hyuck Moo
    • Journal of Korean Society for Quality Management
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    • v.42 no.4
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    • pp.543-562
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    • 2014
  • Purpose: The purpose of this study is to suggest a modified approach that compensates some shortcomings of RPN with relevant strength of ASIL for Safety System and suggests systematic and logical approach for FMEA. Methods: By comparing the objectives, determination procedures, and key conceptual differences of RPN and ASIL, a refined method of risk evaluation and a new risk metric are devised. Results: While the traditional FMEA provides only rough evaluation of relative risk for each failure, the proposed method compensates its shortcomings with relevant strength of ASIL and provides a more logical and practical procedure of risk evaluation. Conclusion: The new metric RPM provides not only a comparative priority rank but also the degree of physical seriousness. Besides, it may have even more benefits for various applications if the severity can be expressed as mone tary amount of losses.

The Case Study on Risk Assessment and Probability of Failure for Port Structure Reinforced by DCM Method (심층혼합처리공법이 적용된 항만 구조물의 파괴확률과 위험도 평가에 관한 사례 연구)

  • Kim, Byung Il;Park, Eon Sang
    • Journal of the Korean Geosynthetics Society
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    • v.17 no.4
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    • pp.53-64
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    • 2018
  • In this study, the evaluation to probability of failure for risk assessment of port structures on DCM reinforced soils, where stability and risk assessment are increasing in importance, was performed. As a random variables affecting the risk of DCM improved ground, the design strength, superposition (overlap) of construction, strength of the natural ground, internal friction angle and unit weight of the modified ground were selected and applied to the risk assessment. In addition, the failure probability for the entire system under ordinary conditions and under earthquake conditions were analyzed. As a result, it was found that the highest coefficient of variation in the random variable for the risk assessment of the DCM improved ground is the design strength, but this does not have a great influence on the safety factor, ie, the risk of the system. The main risk factor for the failure probability of the system for the DCM reinforced soils was evaluated as horizontal sliding in case of external stability and compression failure in case of internal stability both at ordinary condition and earthquake condition. In addition, the failure probability for ordinary horizontal sliding is higher than that for earthquake failure, and the failure probability for ordinary compression failure is lower than that for earthquake failure. The ordinary failure probability of the entire system is similar to the failure probability on earthquake condition, but in this case, the risk of earthquake is somewhat higher.

Effect of Nordic Walking on Depression and Physical Function in the Elderly with High-Risk of Depression

  • An, Tae-Geun;Lee, Han-Suk;Park, Sun-Wook;Seon, Hee-Chang
    • Journal of the Korean Society of Physical Medicine
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    • v.15 no.4
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    • pp.11-20
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    • 2020
  • PURPOSE: This study examined the effects of Nordic walking on depression and the physical function of elderly patients with a high risk of depression. METHODS: This study was a blinded randomized allocation study; 32 elderly were assigned to a Nordic walking group (n = 17), consisting of 60 min Nordic walking (including warming up 5 min, warming down 5 min, and Nordic walking 50 min) two days per week for 12 weeks and general leisure group (n = 15), consisting of 60 min leisure program community center. The pre and post 12-week program, depression test, muscle strength (including grip test, and 30sec sit to stand), and balance (including Functional Reach test, and One Leg Standing test) were measured. A Mann-Whitney U test was used to compare within the group, and a Wilcoxon signed-rank test was used to compare between the groups. RESULTS: After 12 weeks, only the Nordic walking group showed significant improvement in depression, muscle strength, and balance (p < .05). In the general leisure group, however, the left grip strength and Functional Reach Test (FRT) showed a significant decrease. The Nordic walking program was better than the general leisure group, and a significant difference was observed in depression, muscle strength, and balance between the two groups (p < .05). CONCLUSION: Nordic walking was effective for the elderly with a high risk of depression. Therefore, Nordic walking may be an option for preventing elderly mental disorders and functional improvement.

Risk Assessment of Drought for Regional Upland Soil According to RCP8.5 Scenario Using Soil Moisture Evaluation Model (AFKE 0.5)

  • Seo, Myung-Chul;Cho, Hyeon-Suk;Seong, Ki-Yeong;Kim, Min-Tae;Park, Tae-Seon;Kang, Hang-Won;Shin, Kook-Sik
    • Korean Journal of Soil Science and Fertilizer
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    • v.46 no.6
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    • pp.434-444
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    • 2013
  • In order to evaluate drought risk at upland according to climate change scenario (RCP8.5), we have carried out the simulation using agricultural water balance estimation model, called AFKAE0.5, at 66 weather station sites in 2020, 2046, 2050, 2084, and 2090. Total Drought Risk Index between the first month (f) and last month (l) (TDRI(f/l)) and maximum continuous drought risk index (MCDRI(f/l)) were defined as the index for analyzing pattern and strength of drought simulated by the model. Based on distribution maps of MCDRI (1/12), drought strength was predicted to be most severe in 2084 for all regions. Some regions showed severe risk of drought meaning over 20 days of MCDRI (1/12) in the other years, while MCDRI (1/12) in other regions did not reach 5 days. Even though maximum value of TDRI (1/12) in 2090 was greater than in 2050, more severe drought risk in 2050 than in 2090 was predicted based on MCDRI (4/6). It implies that drought risk should be assessed for each crop with its own growing season.

How User-Generated Content Characteristics Influence the Impulsive Consumption: Moderating Effect of Tie Strength (사용자 제작 콘텐츠 특성이 충동구매에 미치는 영향: 유대강도의 조절효과를 중심으로)

  • Weiyi Luo;Young-Chan Lee
    • Knowledge Management Research
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    • v.23 no.4
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    • pp.275-294
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    • 2022
  • In recent years, with the continuous integrative development of e-commerce and social media, social commerce, as a trust-centered social transaction mode, has become an important performance form of e-commerce. The good experience of online community and abundant user-generated content (UGC) attract more and more users and businesses to participate in the community contribution. In this context, the cost of accessing information is continuously decreasing, which not only makes the purchase process more concise and efficient, but also greatly increases the possibility of consumers' impulsive consumption. However, there are very few empirical studies on the internal influencing mechanism of consumers' impulsive consumption based on the characteristics of UGC for social commerce. In view of this, based on S-O-R model, this study constructs a model of consumers' impulsive consumption in the context of social commerce from the characteristics of UGC, with perceived risk as the mediating variable and tie strength as the moderating variable. The results show that content authenticity, content usefulness, and content valence of UGC have significant negative impacts on consumers' risk perception in the process of purchase decision-making, and consumers' perceived risk has a significant negative impact on consumers' impulsive consumption. Meanwhile, the tie strength between UGC producer and UGC receiver plays a moderating role between content usefulness and perceived risk, as well as between perceived risk and impulsive consumption. Finally, combined with the above findings, this study provides effective suggestions for relevant participants in social commerce in terms of business management.

A Study on Reinforced Concrete Beams with Perforation (철근콘크리트 유공보에 관한 연구)

  • Park, Kyong-Ho
    • Journal of Industrial Technology
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    • v.21 no.A
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    • pp.7-14
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    • 2001
  • In building structure, the story height can be minimized by providing openings in beams which serves for the utility equipments passing through. The dead space in false ceiling thus put to economical use in the form of a substantial reduction in materials and construction cost. In the case of steel structure, there is no critical risk in the structural strength because of reinforcing methods of stiffness and steel plate but in the case of reinforced concrete structure, proper provision should be made in designing these openings, otherwise there is a risk that these opening will possibly weaken the structural strength of the building frame to a critical degree. In this paper, for the numerical analysis of the reinforced concrete beams with circular opening in the web, expecting stress concentration of the circular opening, reinforcing methods were studied. Twenty test pieces with each different reinforcing methods were tested and their resisting forces were defined. From the numerical analysis and test results, the followings were founded;(1)high shear stress distributed around the openings reduce the shearing strength, (2)from the numerical analysis, the maximum tensile stress occurred at opening nodes 1,7, these phenomena were agreed with the test results, (3)reinforcing method around openings have to carried out for stopping diagonal cracks, and (4)both, by steel plate, and wire mesh, are effective reinforcing methods.

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Probabilistic Model of Service Life to Evaluate Damage Tolerance of Composite Structure (복합재 항공구조물의 손상허용평가를 위한 운항수명의 확률적 모델)

  • A.스튜어트;A.우샤코프;심재열;황인희
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2000.11a
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    • pp.245-248
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    • 2000
  • Modern aircraft composite structures are designed using a damage tolerance philosophy. This design philosophy envisions sufficient strength and structural integrity of the aircraft to sustain major damage and to avoid catastrophic failure. The only reasonable way to treat on the same basis all the conditions and uncertainties participating in the design of damage tolerant composite aircraft structures is to use the probability-based approach. Therefore, the model has been developed to assess the probability of structural failure (POSF) and associated risk taking into account the random mechanical loads, random temperature-humidity conditions, conditions causing damages, as well as structural strength variations due to intrinsic strength scatter, manufacturing defects, operational damages, temperature-humidity conditions. The model enables engineers to establish the relationship between static/residual strength safety margins, production quality control requirements, in-service inspection resolution and criteria, and POSF. This make possible to estimate the cost associated with the mentioned factors and to use this cost as overall criterion. The methodology has been programmed into software.

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Effects of Tai Chi Exercise on Physical Fitness, Bone Mineral Density, and Fracture Risk in Institutionalized Elderly (저강도 타이치 운동이 시설거주노인의 체력, 골밀도 및 골절위험도에 미치는 효과)

  • Kim, Hyun-Li;So, Hee-Young;Song, Rha-Yun
    • Journal of Korean Academy of Fundamentals of Nursing
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    • v.17 no.3
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    • pp.334-342
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    • 2010
  • Purpose: The purpose of this study was to examine the effects of Tai Chi exercise on flexibility, balance, walking ability, muscle strength, bone mineral density, and fracture risk in institutionalized elders. Method: A quasi-experimental pretest-posttest design with a nonequivalent comparison group was utilized, and 53 older adults living in one institution were recruited and assigned to one of two groups, experimental group (18) or comparison (20). Both groups completed posttest measures at 6 months. There was a 31% rate of dropouts. Tai Chi exercise was provided twice a week for 24 weeks. Outcome measurements were conducted by a physiotherapist at a university hospital health promotion center who did not know the group assignment. Results: At 6 months, the experimental group had significantly greater grip strength(t=2.12, p=.04), back muscle strength (t=2.42, p=.02), balance (t=5.31, p<001), and flexibility (t=3.57, p<.001). They also showed significantly greater bone mineral density of lumbar spine and femur, and reduced fracture risk. Conclusion: Tai Chi exercise was safely and effectively used with institutionalized elders for 6 months and significantly improved physical fitness, bone mineral density along with a reduction in fracture risk. Whether Tai Chi exercise would lead to prevention of fall episodes and fall related fractures in this population will require further study.