• Proceedings of the Korean Institute of Building Construction Conference
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• 2020.06a
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• pp.23-24
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• 2020

In this study, the concrete compressive strength estimation system Concrete IoT Management System (hereinafter referred to as CIMS) was developed, and CIMS was applied to domestic field structure slabs and wall concrete to check whether CIMS is practically available and to estimate the accuracy of the initial strength estimation of concrete. As a result, it shows a very high correlation when the compressive strength of the specimen for structural management is compared with the estimated strength of CIMS in terms of integrated temperature, and it is expected to be gradually applied to domestic construction sites in the future.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2020.06a
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• pp.25-26
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• 2020

In this study, by applying the concrete compressive strength estimation system Concrete IoT Management System (hereinafter referred to as CIMS) to the concrete slab concrete in the domestic field, the purpose of this study is to confirm the practical use of CIMS and to verify the accuracy of estimating the initial strength of concrete. As a result, it shows a high correlation when the compressive strength and CIMS estimated strength of the specimen for structural management are converted and compared with the integrated temperature. However, in order to determine a more accurate experimental constant, it is necessary to consider the results up to 28 days.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.11a
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• pp.131-132
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• 2021

According to the domestic specification, the curing of the specimen for strength management used to determine the time of the mold deformity of the structure concrete in early spring and early autumn is cured in the field structure condition. However, when the seal curing is performed in the field, the temperature of the specimen is very low compared to the temperature of the actual structure, so the strength of the structure concrete predicted based on the strength of the specimen is much undervalued than the actual one, which causes the mold to be deformed. Therefore, this study analyzed the temperature history and compressive strength characteristics of the specimen for strength management through other sealing curing at 5℃ and concrete of the actual structure, and presented the most suitable curing method.

• Journal of muscle and joint health
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• v.21 no.2
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• pp.114-124
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• 2014

Purpose: The purpose of this study was to explore the effects of the 8-weeks back pain management program (consisted of exercise and education for back pain) in patients with chronic low back pain. Methods: A total of 20 subjects who visited the pain clinic in a university hospital were randomly assigned either to a experimental or a control group. Ten subjects in the experimental group carried out the back pain management program for 8 weeks, and 10 in the control group did not. Results: After the back pain management program, back pain and disability were significantly reduced, and back pain management behavior and back muscle strength were significantly increased in the experimental group. However, radiating pain and flexibility were not significantly changed after the back pain management program. Conclusion: Findings of this study indicated that the 8-weeks back pain management program had favorable effects on back pain, degree of disability, back pain management behavior, and back muscle strength in patients with chronic low back pain. Future research needs to examine the optimal intensity and frequency of back muscle strengthen exercise, and the lasting effects of education for back pain.

• Journal of the Korean Society of Safety
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• v.31 no.1
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• pp.81-86
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• 2016

The WMSDs are known to occur more in upper extremity than lower extremity, and such a ratio is increasing each year. The motions or repeated work requiring excessive strength beyond worker's maximum grip strength were known as a major cause of the WMSDs in upper extremity. To prevent the WMSDs in upper extremity, research on the grip strength characteristics analysis of field workers that can be used as basic data for work design and manual tool design is needed. The purpose of this study is to identify various variables affecting grip strength and is to find out the impacts of grip strength on WMSDs. This research measured the grip strength of 327 field workers at Heavy Industries, and also conducted a questionnaire survey on individual characteristics and job characteristics. As a result of analyzing grip strength, the grip strength was statistically significant (P<0.1) according to the body surface area (BSA) of the research subjects. The differences between percentile groups of grip strength were statistically significant (P<0.1) according to pain levels of hand/wrist/finger and arm/elbow. The comparison results between the average grip strength of Korean adult males and the average grip strength of the survey-targeted heavy industry workers show that the average grip strength of the heavy industry workers was higher by 9.75 kg. This study analyzed relationship between grip strength and the pain levels of hand/wrist/finger and arm/elbow, and compared the findings in this study with those of existing preceding studies. Also, this research comparatively analyzed the grip strength of Korean adult males and survey-targeted heavy industry workers. The findings of this study can be used as useful data for ergonomic work design and manual tool design to prevent WMSDs at industrial worksites, given that almost no data on the grip strength of workers in the industrial sites are found in Korea.

• Journal of the Ergonomics Society of Korea
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• v.32 no.4
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• pp.405-411
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• 2013

Objective: Product design process without considering the strength of the user can cause the excessive burden on musculoskeletal system of human body. Since the muscle strength will vary depending on the body posture, the design of product should consider the characteristics of body posture. This study was performed to investigate the effects of forearm postures on the push and pull strength. Background: Overexerted force has been identified to cause musculoskeletal disorders. It is important to know the push and pull strength exerted by human when designing so that exerted force does not exceed the safety limits. Method: Maximum isometric push and pull strength of left, right and both hands were measured according to forearm postures with pronation, neutral and supination. For the study, 66 male and 30 female undergraduate students were participated as subjects. All subjects were normal and healthy with no clinical history. Results: The results showed that the push strength of male and female were 93.3% and 85.4% of pull strength. It showed that the strength of one-hand was 72.1~81.0% of the strength of two-hands, and the strength of left hand was 93.1~95.8% of the strength of right hand. The strength of female was 62% of the one of male. It was found that the strength with pronation $90^{\circ}$ was reduced up to 20% compared to the strength with neutral posture. Conclusion: Push and pull strength of male and female were reduced when forearm was rotated extremely. Application: The results of this study will be used for the prevention of work related musculoskeletal disorders and design of industrial equipment.

• Journal of Korean Society for Quality Management
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• v.25 no.1
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• pp.193-203
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• 1997

In this paper, we obtain some a, pp.oximate confidence intervals for the reliability of the stress-strength model when the stress and strength each depend on some explanatory variables, respectively. Also we compare the confidence intervals via Monte Carlo simulation.

• Management & Information Systems Review
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• v.32 no.4
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• pp.225-254
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• 2013

This research tries to examine the effect of brand experience in service marketing perspective for generalized application. The analysis was held with customers who recently visited in retail stores by using SPSS18K and Smart PLS 2.0. The study verified the structural equation model hypothesizing the relationship among brand experience, relationship quality, and relationship strength. According to the result of this study, four brand experience factors have positive effect on the relationship quality. In detail, the effect of sensory experience was strongest. Furthermore, the effect of relationship quality on relationship strength also significant as prior researches addressed. The research has several marketing implication on brand experience management and customer relationship management. For service firms, customers' perception of positive brand experience can generate the tangible and intangible performance in the relationship marketing perspectives.

• Journal of Family Resource Management and Policy Review
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• v.16 no.3
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• pp.53-65
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• 2012

This study analyzes the relation between family strength, self-efficacy and career maturity of college students. The results from the study are based on surveys, using a questionnaire method, undertaken by students from the Jeonnam area. Data was analyzed using the SPSS 19.0 program and the statistics used for analysis were t-Test, ANOVA, Correlation and Regression. The study found the following results. First, the family strength of the subjects was above average. Second, family strength, self-efficacy, and career maturity showed differences in terms of gender, major satisfaction, career counselling and major area. Third, the correlation among family strength, self-efficacy, and career maturity were observed positively in almost all sub-categories. Forth, the effects of family strength on self-efficacy and career maturity were significant. Based on these results, it is suggested that family strength should be enhanced to improve self-efficacy and career maturity of college students.

• Journal of Korean Society for Quality Management
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• v.48 no.2
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• pp.257-267
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• 2020

Purpose: The purpose of this study is to define guideline for fiber-glass-resin-putty repairing method for submarine GFRP by comparing structural strength between normal GFRP and putty repaired GFRP. Methods: GFRP specimen tensile and flexural tests are conducted in accordance with ASTM D3039/3039M-17 and ASTM D790 Procedure A. The collected data was analysed whether satisfies its structural strength criteria. Furthermore, It is analysed to find dominant reason of structural strength changes. Results: The result of the study is as follows; flexural strength of GFRP is satisfied strength criteria for all test cases, but tensile strength is not satisfied its criteria for some cases which over 2 mm depth of surface damage. Conclusion: The fiberglass-resin-putty repairing method should be applied to under 2 mm depth of damage which is not affecting to roving fiber layer destruction in GREP laminate.