• 한국소음진동공학회논문집
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• 제24권2호
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• pp.102-107
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• 2014

The engine excitation forces are considered as major vibration source for the forklift truck, especially in small class. Even though the current engine mounting system designs are acceptable for vibration isolation, the performance of the engine mounting system is still required for the tendency of light weight, higher power and driver's higher vibration requirement. In this paper vibration reduction technique of forklift engine which is supported on rubber mounts is presented. Based on the dynamic model of resilient engine mounting system, design evaluation program is established. The design optimization technique and evaluation method of system properties are discussed. Effects of optimal design are validated through comparison with test results.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2013년도 추계학술대회 논문집
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• pp.787-791
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• 2013

The engine excitation forces are considered as major vibration source for the forklift truck, especially in small class. Even though the current engine mounting system designs are acceptable for vibration isolation, the performance of the engine mounting system is still required for the tendency of light weight, higher power and driver's higher vibration requirement. In this paper vibration reduction technique of forklift engine which is supported on rubber mounts is presented. Based on the dynamic model of resilient engine mounting system, design evaluation program is established. The design optimization technique and evaluation method of system properties are discussed. Effects of optimal design are validated through comparison with test results.

• Computers and Concrete
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• 제32권4호
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• pp.351-363
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• 2023

Reducing the self-weight of reinforced concrete structures problem is discussed in this paper by using two types of self-weight reduction, the first is by using lightweight coarse aggregate (crushed brick) and the second is by using styropor block. Experimental and Numerical studies are conducted on (LWAC) lightweight aggregate reinforced concrete slabs, having styropor blocks with various sizes of blocks and the ratio of shear span to the effective depth (a/d). The experimental part included testing eleven lightweight concrete one-way simply supported slabs, comprising three as reference slabs (solid slabs) and eight as styropor block slabs (SBS) with a total reduction in cross-sectional area of (43.3% and 49.7%) were considered. The holes were formed by placing styropor at the ineffective concrete zones in resisting the tensile stresses. The length, width, and thickness of specimen dimensions were 1.1 m, 0.6 m, and 0.12 m respectively, except one specimen had a depth of 85 mm (which has a cross-sectional area equal to styropor block slab with a weight reduction of 49.7%). Two shear spans to effective depth ratios (a/d) of (3.125) for load case (A) and (a/d) of (2) for load case (B), (two-line monotonic loads) are considered. The test results showed under loading cases A and B (using minimum shear reinforcement and the reduction in cross-sectional area of styropor block slab by 29.1%) caused an increase in strength capacity by 60.4% and 54.6 % compared to the lightweight reference slab. Also, the best percentage of reduction in cross-sectional area is found to be 49.7%. Numerically, the computer program named (ANSYS) was used to study the behavior of these reinforced concrete slabs by using the finite element method. The results show acceptable agreement with the experimental test results. The average difference between experimental and numerical results is found to be (11.06%) in ultimate strength and (5.33%) in ultimate deflection.

• 전산구조공학
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• 제6권1호
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• pp.91-98
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• 1993

굴삭기 붐의 변위와 응력 제한조건에 대해 각 판의 두께를 설계변수로 선정하여 자중을 최소화 하였다. 변위와 응력 제한조건식을 구성하기 위해 붐을 판 복합 구조물로 모델링한 후 3절점 삼각형 판요소의 유한요소 해석 프로그램으로 해석하여 상용 구조해석 프로그램인 ANSYS결과와 비교 검토하였다. 유한요소 해석 결과로부터 구성된 변위와 응력 제한조건을 직접 미분법으로 민감도를 해석하고 차분결과를 기준으로 검토하였다. 최종적으로 민감도 해석 프로그램과 최적화 알고리즘을 결합하여 판의 최적설계 프로그램을 구성하고 균일응력의 외팔보 문제로써 해외 정확도를 검증하였다. 굴삭기 붐에 대한 자중 최소화를 수행한 결과, 붐의 반쪽 모델의 초기무게가 453kgf이었고 최적설계 결과가 331kgf로서 약 27%의 자중 감소 효과를 가져왔다.

• 한국엔터테인먼트산업학회논문지
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• 제14권7호
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• pp.469-476
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• 2020

본 연구는 등받이 유무에 따른 하지 운동프로그램이 허리통증이 있는 대학생에게 미치는 영향을 알아 보기 위해 균형능력, KODI, VAS 검사를 이용하였다. 광주광역시 소재 K대학교 학생 32명을 대상으로 4주간 탄력밴드를 이용한 하지 운동프로그램을 진행하였으며 등받이의 유무에 따른 집단 별 16명씩 무작위로 선정하여 진행하였다. 균형능력과 KODI 점수에서는 집단과 시간에 의한 상호작용이 없는 것으로 나타난 반면 VAS 점수에서는 집단과 시간에 의한 상호작용이 나타났다. 또한 두 집단 모두 중재 후에 균형능력, KODI, VAS 점수에서 유의하게 증가하였다. 따라서 등받이 유무와 상관없이 의자에 앉아서 시행하는 하지운동 프로그램이 오랜시간 앉아서 생활하며 허리통증이 있는 학생과 직장인에게 일상에서 쉽게 할 수 있는 운동 프로그램으로 적용하는 것이 필요할 것으로 생각된다.

• 한국농공학회지
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• 제37권E호
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• pp.31-39
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• 1995

Weight minimization for the steel bridge girders using an approximation based optimization technique is presented. To accomplish this, an optimization oriented finite element program is used to achieve continuous weight reduction until the optimum is reached. To reduce computational cost, approximation techniques are adopted during the optimization process. Constraint deletion as well as intermediate design variables and responses are also used for higher qualitv of approximations and for a better convergence rate. Both the reliability and the effectiveness of the underlying optimization method are reviewed.

• 한국식생활문화학회지
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• 제23권6호
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• pp.820-833
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• 2008

The study analyzed the body shape perception, weight control attitude, nutrition knowledge, and dietary habits of 529 high school students in Jeju surveyed from January 14-18, 2008 according to students' body shape satisfaction, with the aim of providing basic nutritional education data to aid in appropriate weight control for high school students. The data were analyzed by descriptive analysis, T-test, Chi-square test, ANOVA, and Pearson's correlation coefficients, using the SPSS Win 12.0 program. The body mass index (BMI) of subjects was in the normal range. With regard to weight distribution, 59.4% of subjects showed normal weight and girls were significantly more underweight than boys. More girls considered themselves to be fatter than boys and tended to be increasingly dissatisfied with their body shape. Both boys and girls were more interested in weight control for obesity and were significantly less satisfied with their body shape. Efforts at weight control and reduction had occurred significantly more often for girls than for boys. Dietary attitude scores were significantly higher in girls than boys. BMI positively correlated to weight control concern and nutrition knowledge positively correlated to dietary attitude. BMI negatively correlated to the body shape satisfaction, which in turn negatively correlated to food ingestion disorders. Therefore, it is necessary to develop a systematic nutrition educational program that can induce changes in dietary behavior and increase accurate perception and satisfaction of body shape.

• Safety and Health at Work
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• 제8권1호
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• pp.89-93
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• 2017

Background: Rates of overweight and obese Australians are high and continue to rise, putting a large proportion of the population at risk of chronic illness. Examining characteristics associated with preference for a work-based weight-loss program will enable employers to better target programs to increase enrolment and benefit employees' health and fitness for work. Methods: A cross-sectional survey was undertaken at two Australian mining sites. The survey collected information on employee demographics, health characteristics, work characteristics, stages of behavior change, and preference for workplace assistance with reaching a healthy weight. Results: A total of 897 employees participated; 73.7% were male, and 68% had a body mass index in the overweight or obese range. Employees at risk of developing obesity-related chronic illnesses (based on high body mass index) were more likely to report preference for weight management assistance than lower risk employees. This indicates that, even in the absence of workplace promotion for weight management, some at risk employees want workplace assistance. Employees who were not aware of a need to change their current nutrition or physical activity behaviors were less likely to seek assistance. This indicates that practitioners need to communicate the negative effects of excess weight and promote the benefits of a healthy lifestyle to increase the likelihood of weight management. Conclusion: Weight management programs should provide information, motivation. and trouble-shooting assistance to meet the needs of at-risk mining employees, including those who are attempting to change and maintain behaviors to achieve a healthy weight and be suitably fit for work.

• Nutrition Research and Practice
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• 제11권4호
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• pp.319-326
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• 2017

BACKGROUND/OBJECTIVE: Effective weight reduction remains a challenge throughout the world as the prevalence of obesity and its consequences are increasing. This study aimed to determine the effects of an individualized nutrition counseling program (IC) matched with a transtheoretical model (TTM) for overweight and obese subjects. SUBJECTS/METHODS: Fifty overweight and obese subjects aged 19-60 years with a body mass index ${\geq}23kg/m^2$ were enrolled in the weight reduction study. They were randomized into two groups: Intervention group received an IC matched with a TTM; control group received an educational handbook. Body weight (BW), body fat (BF), waist circumference (WC), waist to height ratio (WHtR), stages of change (SOC), processes of change (POC), food intake, and physical activity (PA) were assessed at baseline and at 4, 8, and 12 weeks after program initiation in both groups. All data were analyzed by intention-to-treat, using SPSS software for hypothesis testing. RESULTS: Forty-five female subjects were included in the 12-week trial at Ramkhamhaeng Hospital, Bangkok, Thailand. The results showed significant weight loss ($1.98{\pm}1.75kg$; 3% loss of initial weight) in the intervention group at 12 weeks, compared to a $0.17{\pm}1.67kg$ loss in the control group. There were significant differences between intervention and control groups in BF mass ($-1.68{\pm}1.78$, $-0.04{\pm}1.62kg$); percentage BF ($-1.54{\pm}2.11$, $0.08{\pm}2.05$); WC ($-5.35{\pm}3.84$, $0.13{\pm}3.23cm$); WHtR ($-0.0336{\pm}0.02$, $-0.0004{\pm}0.02$), and energy consumption ($-405.09{\pm}431.31$, $-74.92{\pm}499.54kcal/day$) in the intervention and control groups, respectively. Intragroup SOC was improved in both groups. The POC for the weight management action (WMA) process was significantly different with POC scores increasing by $16.00{\pm}11.73$ and $7.74{\pm}14.97$ in the intervention and the control groups, respectively. PA level did not change in either group. CONCLUSIONS: The IC matched with a TTM resulted in reductions in BW, BF, and WC, thus reducing likely health risks by decreasing energy intake and inducing positive behavior changes while enhancing the WMA process.

• Journal of Nutrition and Health
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• 제40권7호
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• pp.630-638
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• 2007

This study was performed to examine the combined effects of L-carnitine and isoflavone supplementation on weight reduction and body fat distribution in overweight women. Overweight/obese women (body mass index > $23kg/m^2$) who were not diagnosed any type of diseases were included in this study and sixty subjects ($41.1{\pm}1.5$ years, $25.9{\pm}0.3kg/m^2)$ were randomly assigned to a placebo (n=30) or a supplement group (n=30, L-carnitine 300 mg+isoflavone 40 mg/day). We measured anthropometric parameters, abdominal fat distribution by computerizd tomography and blood components before and after the 12 week intervention period. After the 12 weeks of supplementation, subjects in L-carnitine and isoflavone supplement group showed a significant reduction of body weight (p < 0.001), body fat % (p < 0.05), and waist to hip ratio (p < 0.01) whereas placebo group did not show any changes. In a CT-scanned results, total fat area at L4 level was significantly reduced by 8.1% (p < 0.01) with the reduction of visceral fat area (-11.1%, p < 0.001) and subcutaneous fat area (-7.0%, p < 0.05) in the supplement group. The supplementation of L-carnitine and isoflavone showed the significant improvement of HDL-C (p < 0.01) and apoB (p < 0.05) concentrations, however, change values in those markers were not significant compared with those of the placebo group. In addition, a significant increase of adiponectin level (p<0.001) was observed in the supplement group after the intervention. The result of present study demonstrated that supplementation of 300 mg L-carnitine and 40 mg isoflavone per day fur 12 weeks can give beneficial effects on weight reduction and visceral fat accumulation. These potential antiobesity supplement can produce more favorable effects when combined with lifestyle modification.