• Title/Summary/Keyword: Linear program

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Relationship Between Noise-Related Risk Perception, Knowledge, and the Use of Hearing Protection Devices Among Para Rubber Wood Sawmill Workers

  • Thepaksorn, Phayong;Siriwong, Wattasit;Neitzel, Richard L.;Somrongthong, Ratana;Techasrivichien, Teeranee
    • Safety and Health at Work
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    • v.9 no.1
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    • pp.25-29
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    • 2018
  • Background: The understanding of the relationship between risk perception, knowledge, and protective behaviors could play a major role in occupational risk control and management. Research exploring how workers perceive, recognize, and react to risks in different occupational settings is scarce in Thailand. The aim of this study was to assess the relationship of noise-related risk perceptions and knowledge to the use of hearing protective devices (HPDs) among sawmill workers in Thailand. Methods: Sawmill workers (n = 540) from four factories in Trang, Southern Thailand, participated in a questionnaire interview from December 2015 to January 2016. Descriptive statistics and linear regression models were used to explore the risk factors related to HPD use. Path diagram analysis was demonstrated and used to evaluate associations. Results: Risk perception was significantly correlated with HPD use (p < 0.01), HPD training (p = 0.01), and the number of years of work experience (p = 0.03). Sawmill workers were likely to use HPDs based on their risk perception and HPD training. However, HPD training was inversely correlated with age and the number of years of work experience. Conclusion: The study highlights the importance of risk perceptions and knowledge, and these factors should be emphasized in the design and implementation of any personal safety intervention program for sawmill workers.

The effects of Far-infrared on Type II collagen induced mouse and the relative cytokine computerize programming (Emphasis on TNF-a and IL-1b) (원적외선이 관절염 흰쥐 모델에 미치는 영향과 관련 싸이토카인 예측 프로그래밍)

  • Kim Jae Yoon;Kim Jin-Sang;Bae Sung Soo;Park Rae Joon
    • The Journal of Korean Physical Therapy
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    • v.15 no.1
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    • pp.38-60
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    • 2003
  • The purpose of this study was to observe the effects of Far-infrared on mice rheumatoid arthritis induced by type II collagen. The author peformed several experimental tests which were the hematoxylin-eosin tissue stain, the hind paw thickness, and ELSIA of cytokines(TNF-$\alpha$, IL-1$\beta$). On day 14 and 21, FIR-Tx. group decreased in synovial membrane thickness more than control II group FIR-Tx group decreased in hind paw thickness more than control II group. In the ELISA test of TNF-$\alpha$ concentration, control II group significantly increased in the concentration more than normal and FIR-Tx. group on day 7, 14, and 21. In the ELISA test of IL-$\beta$ concentration, FIR-Tx. group decreased in the concentration more than control II group on day 14 and 21. With J's Linear Function Data Process Program, researchers can get the estimated the concentration or the hind paw thickness from this experiment. The estimated results would be a good guide to therapists and researchers, planning Far-infrared application on the rheumatoid arthritis. These results indicated that far-infrared irradiating appeared to reduce the concentration of TNF-$\alpha$ and IL-1$\beta$ at mouse model of autoimmune arthritis. It would be considered that Far-infrared has an effect on relieving rheumatoid arthritis.

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Association between dietary flavanones intake and lipid profiles according to the presence of metabolic syndrome in Korean women with type 2 diabetes mellitus

  • Oh, Ji Soo;Kim, Hyesook;Vijayakumar, Aswathy;Kwon, Oran;Choi, Young Ju;Huh, Kap Bum;Chang, Namsoo
    • Nutrition Research and Practice
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    • v.10 no.1
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    • pp.67-73
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    • 2016
  • BACKGROUND/OBJECTIVES: This study was aimed at examining the association between dietary flavanones intake and lipid profiles according to the presence of metabolic syndrome (MetS) in Korean women with type 2 diabetes mellitus (T2DM). SUBJECTS/METHODS: A cross-sectional analysis was performed among 502 female T2DM patients (non-MetS group; n = 129, MetS group; n = 373) who were recruited from the Huh's Diabetes Clinic in Seoul, Korea between 2005 and 2011. The dietary intake was assessed by a validated semi-quantitative food frequency questionnaire (FFQ) and the data was analyzed using the Computer Aided Nutritional Analysis program (CAN-Pro) version 4.0 software. The intake of flavanones was estimated on the basis of the flavonoid database. RESULTS: In the multiple linear regression analysis after adjustment for confounding factors, daily flavanones intake was negatively associated with CVD risk factors such as total cholesterol, LDL-cholesterol, and apoB and apoB/apoA1 ratio only in the MetS group but not in the non-MetS group. Multiple logistic regression analysis revealed that the odds ratio for a higher apoB/apoA1 ratio above the median (${\geq}0.74$) was significantly low in the $4^{th}$ quartile compared to that in the $1^{st}$ quartile of dietary flavanones intake [OR: 0.477, 95% CI: 0.255-0.894, P for trend = 0.0377] in the MetS group. CONCLUSIONS: Dietary flavanones intake was inversely associated with the apoB/apoA1 ratio, suggesting a potential protective effect of flavanones against CVD in T2DM women with MetS.

Nonlinear Analysis of RC Bridge Columns for Ductility Evaluation (철근콘크리트 교각의 연성도 평가를 위한 비선형해석)

  • 손혁수;이재훈
    • Journal of the Earthquake Engineering Society of Korea
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    • v.7 no.4
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    • pp.39-49
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    • 2003
  • This research is a part of a research program to develope a new design method for reinforced concrete bridge columns under axial load and cyclic lateral load. A nonlinear analytical method is proposed to obtain moment-curvature relationship and lateral load-displacement relationship. Various analytical models that contribute seismic behavior of reinforced concrete bridge columns are adopted and modified by comparing quasi-static test results of reinforced concrete columns with spirals of circular hoops. The analysis adopts confined concrete model, longitudinal reinforcement test result of reinforced concrete columns with spirals or circular hoops. The analysis adopts confined concrete model, etc. The results obtained using the propose analytical method agree well with test results and give conservative estimations particularly for deformation capacity and ductility.

Normalizing interval data and their use in AHP (구간데이터 정규화와 계층적 분석과정에의 활용)

  • Kim, Eun Young;Ahn, Byeong Seok
    • Journal of Intelligence and Information Systems
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    • v.22 no.2
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    • pp.1-11
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    • 2016
  • Entani and Tanaka (2007) presented a new approach for obtaining interval evaluations suitable for handling uncertain data. Above all, their approach is characterized by the normalization of interval data and thus the elimination of redundant bounds. Further, interval global weights in AHP are derived by using such normalized interval data. In this paper, we present a heuristic method for finding extreme points of interval data, which basically extends the method by Entani and Tanaka (2007), and also helps to obtain normalized interval data. In the second part of this paper, we show that the solutions to the linear program for interval global weights can be obtained by a simple inspection. In the meantime, the absolute dominance proposed by the authors is extended to pairwise dominance which makes it possible to identify at least more dominated alternatives under the same information.

Maternal Psychosocial Factors that Affect Breastfeeding Adaptation and Immune Substances in Human Milk (산모의 모유수유 적응과 모유 내 면역물질에 영향을 미치는 심리사회적 요인)

  • Kim, Eun Sook;Jeong, Mi Jo;Kim, Sue;Shin, Hyun-A;Lee, Hyang Kyu;Shin, Kayoung;Han, Jee Hee
    • Women's Health Nursing
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    • v.20 no.1
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    • pp.14-28
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    • 2014
  • Purpose: This study was to identify relationships of maternal psychosocial factors including mother's mood state, childcare stress, social support and sleep satisfaction with breastfeeding adaptation and immune substances in breast milk, especially secretory immunoglobulin A (sIgA) and transforming growth factor-beta 2 (TGF-${\beta}2$). Methods: Data were collected from 84 mothers who delivered full-term infants by natural childbirth. Structured questionnaires and breast milk were collected at 2~4 days and 6 weeks postpartum. Data were analyzed using descriptive statistics, Pearson's correlation, multiple linear regression, and generalized estimating equation (GEE). Results: Scores for the breastfeeding adaptation scale were significantly related with child care stress, mood state and social support. Mother's anger was positively correlated with the level of sIgA in colostrum (p<.01). Immune substances of breastmilk was significantly influenced by time for milk collection (p<.001) and the type of breastfeeding (sIgA, p<.001, TGF-${\beta}2$, p=.003). Regression analysis showed that breastfeeding adaptation could be explained 59.1% by the type of breastfeeding, childcare stress, the Profile of Mood States, emotional support and sleep quality (F=16.67, p<.001). Conclusion: The findings from this study provide important concepts of breastfeeding adaptation program and explanation of psychosocial factors by immune substances in breast milk. Future research, specially, bio-maker research on breast milk should focus on the ways to improve breastfeeding adaptation.

The Effects of Anxiety and Depression on Treatment Outcome of Social Skills Training in Adolescents with Autism Spectrum Disorder (청소년 자폐스펙트럼장애에서 사회기술훈련의 효과에 미치는 우울, 불안 증상의 영향)

  • Hong, Jung Kyung;Noh, Dong-Hyun;Oh, Miae;Kim, Ju-Hyun;Bong, Guiyoung;Yoo, Hee Jeong
    • Anxiety and mood
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    • v.14 no.2
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    • pp.99-105
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    • 2018
  • Objective : The purpose of this study was to investigate effects of depression and anxiety on treatment response of social skills training in adolescents with autism spectrum disorders (ASD). Methods : A total of 107 teenagers that participated in the Program for the Education and Enrichment of Relational Skills (PEERS$^{(R)}$) between 2011 and 2015 were analyzed using linear regression. Outcome measures used were the Korean version of Social Responsiveness Scale (SRS), the Test of Adolescent Social Skills Knowledge-Revised (TASSK-R), and the Korean version of Autism Diagnostic Observation Schedule (K-ADOS). Depression and anxiety were assessed by the Korean version of Child Depression Inventory (CDI), the Korean version of State and Trait Anxiety Inventory for Children (STAIC), and the Korean version of Child Behavior Checklist (K-CBCL). Results : As a result, depressive symptoms measured by CDI (p<0.05) and anxiety symptoms measured by STAIC (p<0.05) had significant influence on score change of social interaction domain of ADOS. It remained significant even after the baseline score was adjusted as covariates (p<0.05). Conclusion : We observed that pre-treatment anxiety and depressive symptoms of teenagers had significant effects on the treatment outcome of PEERS$^{(R)}$, especially in terms of face-to-face social interaction.

Analysis and Experiment on the Tape Spring Hinges for CubeSat Missions (큐브위성 임무를 위한 테이프 스프링 힌지의 비선형 거동 분석 및 실험)

  • Yoo, JeongUk;Im, Byeong-Uk;Shin, SangJoon
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.47 no.10
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    • pp.712-719
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    • 2019
  • This paper explores an implementation of finite element analysis and experiment in the design process of a tape spring hinge used for various CubeSat missions. Tape spring hinges consist of short-length hardened-steel strips with one-sided curvature, and thus the behavior is subject to large deformation with unpredicted non-linearity. Precise dimensions of a commercial tape spring are traced by the use of high-resolution digital camera, and thin-shell FEM analysis is conducted using ABAQUS program. Based on the rotation-moment analysis suggested in previous studies, parametric analysis is conducted by adjusting the contributing factors such as strip thickness and the subtended angle of the cross section. Finally the behaviors are investigated by both analytical and non-linear finite element methods, and the results are compared with the simple measurements. Further studies suggest a possible application in dynamic characteristics of hinges during CubeSat operations.

Influence of Predominant Periods of Seismic Waves on a High-rise Building in SSI Dynamic Analyses with the Complete System Model (연속체 모델에 기초한 SSI 동적해석 시 지진파 탁월주기가 초고층 건물에 미치는 영향)

  • You, Kwangho;Kim, Juhyong;Kim, Seungjin
    • Journal of the Korean GEO-environmental Society
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    • v.20 no.12
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    • pp.5-14
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    • 2019
  • Recently in Korea, researches on seismic analyses for high-rise buildings in a large city have been increasing because earthquakes have occurred. However, the ground conditions are not included in most of seismic researches and analyses on a high-rise building. Also the influence of the predominant period of a seismic wave is not considered in reality. Therefore, in this study, the influence of the predominant period of a seismic wave on the dynamic behavior of high-rise buildings was analyzed based on the complete system model which can consider the grounds. For this purpose, 2D dynamic analyses based on a linear time history analysis were performed using MIDAS GTS NX, a finite-element based program. Dynamic behavior was analyzed in terms of horizontal displacements, drift ratios, bending stresses, and building weak zones. As a result, in overall, the dynamic response of a high-rise building become bigger as the predominant period of a seismic wave become longer. It was also found that the predominant period had a greater influence than other parameters, ground conditions and peak ground acceleration.

Ultrasonic characterization of exhumed cast iron water pipes

  • Groves, Paul;Cascante, Giovanni;Knight, Mark
    • Smart Structures and Systems
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    • v.7 no.4
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    • pp.241-262
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    • 2011
  • Cast iron pipe has been used as a water distribution technology in North America since the early nineteenth century. The first cast iron pipes were made of grey cast iron which was succeeded by ductile iron as a pipe material in the 1940s. These different iron alloys have significantly different microstructures which give rise to distinct mechanical properties. Insight into the non-destructive structural condition assessment of aging pipes can be advantageous in developing mitigation strategies for pipe failures. This paper examines the relationship between the small-strain and large-strain properties of exhumed cast iron water pipes. Nondestructive and destructive testing programs were performed on eight pipes varying in age from 40 to 130 years. The experimental program included microstructure evaluation and ultrasonic, tensile, and flexural testing. New applications of frequency domain analysis techniques including Fourier and wavelet transforms of ultrasonic pulse velocity measurements are presented. A low correlation between wave propagation and large-strain measurements was observed. However, the wave velocities were consistently different between ductile and grey cast iron pipes (14% to 18% difference); the ductile iron pipes showed the smaller variation in wave velocities. Thus, the variation of elastic properties for ductile iron was not enough to define a linear correlation because all the measurements were practically concentrated in single cluster of points. The cross-sectional areas of the specimens tested varied as a result of minor manufacturing defects and levels of corrosion. These variations affect the large strain testing results; but, surface defects have limited effect on wave velocities and may also contribute to the low correlations observed. Lamb waves are typically not considered in the evaluation of ultrasonic pulse velocity. However, Lamb waves were found to contribute significantly to the frequency content of the ultrasonic signals possibly resulting in the poor correlations observed. Therefore, correlations between wave velocities and large strain properties obtained using specimens manufactured in the laboratory must be used with caution in the condition assessment of aged water pipes especially for grey cast iron pipes.