• Transactions of the Korean Society of Mechanical Engineers A
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• v.28 no.5
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• pp.554-562
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• 2004

An empirical relationship between parameters from SP curves and tensile properties has been systematically investigated by experimental tests and FEM simulations. A series of SP and tensile tests were performed. SP tests were also simulated by FE analysis with various tensile properties. It was found that the yield loads(Py) and the maximum loads( $P_{MAX}$) in SP curves were linearly related with the yield strength($\sigma$$_{o}$) and the tensile strength($\sigma$$_{UTS}$), respectively. The yield loads defined from the intersection point of two lines tangent to the elastic bending region and plastic bending region showed better relation to the yield strength than those from offset line. The maximum loads in SP curves showing plastic instability region was linearly related with the tensile strengths. The slope of SP curves in simulation results had a close correlation with the hardening coefficient and hardening strength as well.l.l.l.

• Structural Engineering and Mechanics
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• v.82 no.6
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• pp.757-770
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• 2022

For the design of flexural and shear crack control for reinforced concrete (RC) beams related to serviceability and reparability ensuring, eight simply-supported normal-strength reinforced concrete (NSRC) beam specimens are tested and the existing high-strength reinforced concrete (HSRC) experimental data are included in the investigation of this work. According to the investigation results of flexural and shear cracks, this works modifies the existing design formulas to determine the spacing of the tensile reinforcement for the flexural crack control of a HSRC/NSRC beam design. Additionally, for a specified shear crack width of 0.4 mm, the allowable stresses of the shear reinforcement are also identified. For the serviceability and reparability ensuring of HSRC/NSRC beams, this works proposes the relationship curves between the maximum flexural width and allowable stress of the tensile reinforcement, and the relationship curves between the shear crack width and allowable shear force that can be used to do the crack width control directly.

• International Journal of Korean Welding Society
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• v.3 no.2
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• pp.24-28
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• 2003

This study was aimed to evaluate the quality of flash welded joints and optimize the welding process for flash butt welding of 780MPa grade high strength steel. And then the relationship between the welding process variables and the joint quality would be established. The effect of process variables between flashing and upsetting process was elucidated. Microstructure observation of the joint indicated that the decarburized band was mainly changed with upsetting process. Width of HAZ was also related to the upsetting conditions rather than the flashing conditions. Generally maximum hardness at HAZ was correlated with Ceq of steel and the empirical relationship was obtained to estimate the HAZ properties. Tensile elongation at the joint was usually decreased with increasing the initial clamping distance. Investigation of fracture surface after tensile and bending tests reveal that the origin of cracking at the joint was oxide inclusions composed of $SiO_2$, MnO, $Al_2O_3$, and/or FeO. The amount of inclusions was dependent on the composition ratio of Mn/Si in steel. If this ratio was above 4, the amount of inclusions was low and then the resistance to cracking at the joint was enough to maintain the joint performance. It was obtained that the flashing process influenced the conditions for the energy input to establish uniform or non­uniform molten layer, while the upsetting conditions influenced the joint strength. Heat input variable during flashing process was also discussed with the joint properties.

• Structural Engineering and Mechanics
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• v.45 no.6
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• pp.837-851
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• 2013

In construction industry, strength is a primary criterion in selecting a concrete for a particular application. The concrete used for construction gains strength over a long period of time after pouring the concrete. The characteristic strength of concrete is defined as the compressive strength of a sample that has been aged for 28 days. Neither waiting for 28 days for such a test would serve the rapidity of construction, nor would neglecting it serve the quality control process on concrete in large construction sites. Therefore, rapid and reliable prediction of the strength of concrete would be of great significance. On this backdrop, the method is proposed to establish a predictive relationship between properties and proportions of ingredients of concrete, compaction factor, weight of concrete cubes and strength of concrete whereby the strength of concrete can be predicted at early age. Multiple regression analysis was carried out for predicting the compressive strength of concrete containing Portland Pozolana cement using statistical analysis for the concrete data obtained from the experimental work done in this study. The multiple linear regression models yielded fairly good correlation coefficient for the prediction of compressive strength for 7, 28 and 40 days curing. The results indicate that the proposed regression models are effectively capable of evaluating the compressive strength of the concrete containing Portaland Pozolana Cement. The derived formulas are very simple, straightforward and provide an effective analysis tool accessible to practicing engineers.

• Journal of Preventive Medicine and Public Health
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• v.45 no.6
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• pp.381-386
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• 2012

Objectives: To investigate the link between cigarette smoking and muscle strength in Japanese men. Methods: We used data on 4249 Japanese men, aged $43.3{\pm}13.9$ years, in this cross-sectional investigation study. Grip strength and leg strength were measured as indicators of overall muscle strength. Meanwhile, subjects' cigarette smoking habits were recorded by trained medical staff. The effect of cigarette smoking on muscle strength was evaluated. Results: A total of 1618 men (38.1%) were smokers and 1481 men (34.9%) exercised regularly. Significant differences in muscle strength were noted between men with and without a Brinkman index of 400 or greater, after adjusting for age. After adjusting for age, height, body weight and exercise habits, associations between the Brinkman index and leg strength and the ratio of leg strength to body weight were attenuated. Conclusions: Cigarette smoking might be negatively associated with muscle strength, especially grip strength in Japanese men.

• Imaging Science in Dentistry
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• v.35 no.3
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• pp.167-173
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• 2005

Purpose : To investigate the relationship between three-dimensional (3D) bone imaging parameters and trabecular strength in the mandible. Materials and Methods : Bone specimens were obtained from the mandibles of five male pigs weighing around 110 kg each. Of those, 43 samples were selected for 3D analysis and measured by micro-computed tomography. The five morphometric parameters were trabecular thickness (Tb.Th), bone specific surface (BS/BV), percent bone volume (BV/TV), structure model index (SMI) and degree of anisotropy (DA). Through destructive mechanical testing, strength parameters were obtained. Results : BV/TV, SMI, BS/BV, and Tb.Th showed significant correlations with strength parameters. DA did not show any correlation with the other parameters. In multiple linear regression analysis, BV/TV alone explained $43\%$ of the variance in Young's modulus. By stepwise inclusion of SMI, the variance in the Young's modulus was better explained up to $52\%$. Conclusions : Predicting trabecular strength in the mandible through architectural analysis would be possible. Further study is needed to establish the tendency and variety of trabecular architecture and strength according to the locations within the mandible.

• Journal of Korean Medicine Rehabilitation
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• v.27 no.1
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• pp.37-51
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• 2017

Objectives This study was designed to identify the effect of acupuncture combined with wooden neck pillow self-exercise program (WSP). Methods 25 eligible subjects with chronic neck pain were recruited from September 2015 to August 2016. Subjects were treated by acupuncture twice a week for 4 weeks, also were educated WSP and exercised every day for 4 weeks. They were assessed using PI-NRS, NDI and the maximum muscle strength of deep cervical flexor muscles (DCF) before and after treatment. Also the Cobb's angle (C1-C7), Ishihara index, Park method were assessed for evaluating the radiographical changes. Variables were compared using paired t-test. And correlates analysis was used for analyzing relationship between differentials in the maximum muscle strength of DCF and differentials in cervical spine curvature measurement methods. Results Among the 25 subjects, 4 subjects were lost to follow-up or excluded in accordance with the criteria. Significant differences on NRS, NDI and the maximum muscle strength of DCF were seen after treatment (p<0.001). In radiological finding, cervical spine curvature measurement methods were significantly increased (p<0.001, p<0.05, p<0.05). Differentials in the maximum muscle strength of DCF significantly correlates to differentials in Ishihara index (R=0.479, p<0.05). Conclusions Acupuncture combined with WSP may decrease neck pain intensity and associated disability, and also increase the muscle strength of DCF and cervical lordosis, in patients with chronic neck pain. Especially, Improving the muscle strength of DCF has a relationship with improving Ishihara index. However, due to the design of this study, this treatment can not be compared with other treatments. Future randomized project should be needed.

• Journal of Korean Physical Therapy Science
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• v.10 no.2
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• pp.208-215
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• 2003

This study measured body composition and muscular strength, to examine their relationship, using the Bioelectrical Impedance (IB) method and biodex system3, respectively, in 44 healthy male(20) and female(24) university students. 1. Muscular strength of the upper extremities correlated significantly with fat-free mass(FFM) with $r=.604{\sim}.630$ and intracellular fluid(ICF) with $r=.672{\sim}.668$ in males and FFM with $r=.416{\sim}.552$, ICF with $r=.432{\sim}.564$ and extracellular fluid(ECF) with $r=.429{\sim}.463$ in females. 2. Muscular strength of the lower extremities correlated significantly with FFM with $r=.522{\sim}.785$, ICF with $r=.501{\sim}.739$ and ECF with $r=.498{\sim}.796$ in males and FFM with $r=.642{\sim}.660$, ICF with $r=.627{\sim}.671$ and ECF with $r=.572{\sim}.623$ in females. 3. Muscular strength of the trunk correlated with FFM with $r=.595$, ICF with $r=.627$, ECF with $r=.448$ in males, but did not correlate significantly with body composition in females. These results suggest that total body water(TBW) and ICF may be factors directly associated with muscular strength as well as physical fitness.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.25 no.4
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• pp.191-199
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• 1989

Research on the acoustic properties of fish has been carried out by a number of scientific workers from the earliest days of applying acoustic techniques to fish biomass estimates. This paper describes measurements of the target strength of Cyprinus Carpio, which measurements made at 50KHz in the experimental water tank. The results obtained are as follows: 1. The target strength(dB) of the fish has a directivity pattern quite similar to that of a transducer. The maximum value of target strength(dB) is obtained when the fish is insonified to its head-tail axis either from the dorsal or from the ventral side. 2. Empirical relationship between target strength(dB) and body length(cm) of the fish can be estimated as TS=20 Log L-65.4 where TS is the target strength of the fish and L is the body length of the fish. 3. The relationship between target strength(dB) and body weight(g) of the fish can be estimated as TS=6.7 Log W-53.7 where W is body weight of the fish.

• Journal of Family Resource Management and Policy Review
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• v.17 no.2
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• pp.19-35
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• 2013

The purpose of this study is to analyze the effective factors that influence subjective cognition, conflict degree of work-family balance, and cognition of family strength according to general characteristic factors, working environmental factors, and home environmental factors, as well as analyze the relationships among subjective cognition, conflict degree, and cognition of family strength. The main data source for analysis in this study is the Second National Survey of Korean Families by the Ministry of Gender Equality and Family in 2010. The survey includes the analysis of 419 respondents who have a dual income and live with their wife. The collected data are analyzed using SPSS 19.0. The results of the study are as follows. First, subjective cognition of work-family balance is influenced by satisfaction of work, division of housework, and care of family. Second, the conflict degree of work-family balance is influenced by age, working week, and satisfaction with work. Third, the relationship between subjective cognition and conflict degree of work-family balance is a negative correlation. The relationship between subjective cognition of work-family balance and cognition of family strength is a positive correlation but the difference between conflict degree of work-family balance and cognition of family strength is not significant. Finally, for the married men, the working environmental factor is a significant factor for the work-family balance. And the higher the satisfaction of work and division of domestic work, the greater is the balance between work and family. This suggests that they also have a higher cognition of family strength.