• Asian-Australasian Journal of Animal Sciences
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• v.33 no.5
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• pp.753-762
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• 2020

Objective: The aim of the present study was to determine the effect of supplementing pasture-finished steers with corn silage on the expression level of the calpain system proteins and beef tenderization. Methods: Thirty Braford steers grazing on summer pasture were used for the study. For 120 days fifteen animals were supplemented with corn silage at 1% of body weight per head per day (Suppl) whereas the remaining 15 steers only received pasture (Contr). Carcass and meat traits were evaluated and compared between groups. Gene expression and activities of proteases (calpain 1 and calpain 2) and inhibitor (calpastatin) were measured using real-time polymerase chain reaction and casein zymography. Results: Carcass and meat traits were significantly different between feeding systems. Supplemented steers showed higher hot carcass weight (p<0.01), fat content (p = 0.02), and Warner-Bratzler shear force (p = 0.03). Furthermore, the control group showed higher protease:inhibitor ratios, at mRNA (p = 0.01) and protein levels (p<0.10). Warner-Bratzler shear force and mRNA calpains:calpastatin ratio were associated in both feeding systems (p<0.01). Conclusion: Based on the results obtained in the study, beef tenderness differences among finishing strategies could be modulated through differential expression of the calpain system proteins.

• Animal Bioscience
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• v.34 no.7
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• pp.1193-1201
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• 2021

Objective: According to market demand, meat duck breeding mainly includes 2 breeding directions: lean Pekin duck (LPD) and fat Pekin duck (FPD). The aim of the present study was to compare carcass and meat quality traits between 2 strains, and to provide basic data for guidelines of processing and meat quality improvement. Methods: A total of 62 female Pekin ducks (32 LPDs and 30 FPDs) were slaughtered at the age of 42 days. The live body weight and carcass traits were measured and calculated. Physical properties of breast muscle were determined by texture analyzer and muscle fibers were measured by paraffin sections. The content of inosine monophosphate (IMP), intramuscular fat (IMF) and fatty acids composition were measured by high-performance liquid chromatography, Soxhlet extraction method and automated gas chromatography respectively. Results: The results showed that the bodyweight of LPDs was higher than that of FPDs. FPDs were significantly higher than LPDs in subcutaneous fat thickness, subcutaneous fat weight, subcutaneous fat percentage, abdominal fat percentage and abdominal fat shear force (p<0.01). LPDs were significantly higher than FPDs in breast muscle thickness, breast muscle weight, breast muscle rate and breast muscle shear force (p<0.01). The muscle fiber average area and fiber diameter of LPDs were significantly higher than those of FPDs (p<0.01). The muscle fiber density of LPDs was significantly lower than that of FPDs (p<0.01). The IMF of LPDs in the breast muscle was significantly higher than that in the FPDs (p<0.01). There was no significant difference between the 2 strains in IMP content (p>0.05). The polyunsaturated fatty acid content of LPDs was significantly higher than that of FPDs (p<0.01), and FPDs had higher saturated fatty acid and monounsaturated fatty acid levels (p<0.05). Conclusion: Long-term breeding work resulted in vast differences between the two strains Pekin ducks. This study provides a reference for differences between LPD and FPD that manifest as a result of long-term selection.

• 한국사회정책
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• v.25 no.1
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• pp.195-229
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• 2018

This study has examined how the welfare system has changed as it has passed through the most controversial period in Korean modern history. The welfare system has changed in a way that adapts to the need for export-led economic growth. Industrialization centered on light industry, which started in the mid-1960s, absorbed the labor force that existed in the rural areas and commodified them, thereby creating a momentum for Korean society to get out of poverty. However, the public de-commodification, ie social security system, adapted to the commodification of the labor force has been institutionalized only in a very limited area and people. Indeed, the de-commodification system was confined to the area directly linked to the reproduction of the labor force. Even so, the target was very limited in the abundance of labor in rural areas. Compulsory medical insurance was rejected because of corporate burden, and industrial accidents insurance was introduced centering on large-scale workplaces. As the Korean economy began to move from the light industry to the heavy industry in the 1970s, the commodificated labor force changed from a low skilled labor force to a skilled male labor force. It is at this time that dual structures have begun to be created between workers employed in export-oriented large enterprises and workers employed in domestic-oriented SMEs. Therefore, the system of de-commodification that supports the reproduction of labor power in response to social risks has also been institutionalized centering on large-scale workplaces.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.21 no.3
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• pp.493-501
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• 2012

A rotational force generator for molten metal is developed using a linear motor design technology. Also, the developed device is applied to reproduce aluminum scraps and easy to control the rotate, stop, and forward and reverse rotation of molten metal. In addition, the developed device improves the melting speed and reproduction rate about 250 (%) and 96-99 (%), respectively, compared to the conventional handmade methods. Because it generates almost no dusts, it can improve working environments in a factory. Also, it has no losses in energy because it directly melts scraps. The device generates small amounts of the loss in refractory materials and aluminum caused by its oxidation because the molten metal is continuously rotated in which the loss and oxidized aluminum are the problems in the conventional melting and holding furnaces. Thus, it is possible to extend the life of furnaces and to produce high quality aluminum products.

• Journal of the Korean Regional Science Association
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• v.6 no.1
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• pp.11-38
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• 1990

The purpose of this thesis is, first to present the spatial division of labor in Korea and its mechanism, and second, to elucidate the organic integral relation between local labor market and local community by studing the mechanism that the spatial division of labor is projected into the individual lacal labor marker, and reproduction of labor force process in this local labor market. According to this purpose, the theoretical frame of this analysis is done, the positive analysis is made and Kumi is choosed as its analysis case area. The main data is from 'Survey Report on Manufacturing Idustry Wage Conditions' published by Minimum Wage Council, Ministry of Labour and from the questionnaires and interview on textile industry and electric electronics industry firms in Kumi Export Industrial Estate. The following are the results of this study. 1. The mechanism of spatial division of labor in Korea, seen through the employment structure index, is accelerating the regional discrimination by fixing the regional hierarchisation between Seoul (or Seoul Metropolitan Area as expanded Seoul) and other areas. But it is also developing highly the regional employment structure at the level of technical division of labor, since the spatial division of labor in Korea is leaded by large firms and influenced by the policy for regional development. 2. Local labor market is formed in Kumi area and its delimitation is Kumi city. The employment structure of Kumi local labor market is occupying lower hierarchy division at management hierachical level and occupying upper hierarchy division at the level of technical division of labor, and brand plants of large firs are determinating and dominating this emplogment structure. These bdranch plants of large firs are forming more favorable and stabel labor marker than locally controlled ploants in Kumi local labor market. But the reproduction of labor force process in Kumi local labor market is not fully carried out and leaked into central city, therefore Kumi is now becoming an unstable local community, suffering from large movement of population. This is because Kumi local labor market is found not for itself, but by the state policy and externally controlled plants of large firms, and therefore no potentiality to control and to absorb the exterior influences is built in Kumi local labor market. 3. The case firms A, B have spatial division of labor between decision-making function and production function, and between upper management hierachical labor force and lower management hierachical labor force in internal labor market.

• Journal of the Korean Society for Precision Engineering
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• v.32 no.10
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• pp.885-890
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• 2015

Walking on split-belt treadmill has been applied to study walking disabilities, such as osteoarthritis (OA), to show asymmetric walking characteristics. In this study, we compared asymmetric walking in OA patients with healthy subjects under split-belt conditions and examined the reproduction of walking asymmetry in OA. Seven OA patients were instructed to walk at four frequencies, while four healthy subjects walked on a treadmill with tied-belt and split-belt conditions. To compare walking asymmetries, kinetic and kinematic measurements were made using force-plates and motion capture cameras, and subsequently center of mass (CoM) velocity, mechanical work and potential energy were calculated. Horizontal velocity change during split-belt walking of healthy subjects was similar to OA patients. Difference of mechanical work during single support phase occurred due to fall of CoM in fast belt. OA walking asymmetry could be reproduced by reducing differences of belt speeds to prevent rapid fall of CoM.

• Smart Structures and Systems
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• v.26 no.3
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• pp.373-390
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• 2020

Hybrid simulation (HS) is a versatile tool for structural performance evaluation under dynamic loads. Although real structural responses are often multiple-directional owing to an eccentric mass/stiffness of the structure and/or excitations not along structural major axes, few HS in this field takes into account structural responses in multiple directions. Multi-directional loading is more challenging than uni-directional loading as there is a nonlinear transformation between actuator and specimen coordinate systems, increasing the difficulty of suppressing loading error. Moreover, redundant actuators may exist in multi-directional hybrid simulations of large-scale structures, which requires the loading strategy to contain ineffective loading of multiple actuators. To address these issues, lately a new strategy was conceived for accurate reproduction of desired displacements in bi-directional hybrid simulations (BHS), which is characterized in two features, i.e., iterative displacement command updating based on the Jacobian matrix considering nonlinear geometric relationships, and force-based control for compensating ineffective forces of redundant actuators. This paper performs performance validation and application of this new mixed loading strategy. In particular, virtual BHS considering linear and nonlinear specimen models, and the diversity of actuator properties were carried out. A validation test was implemented with a steel frame specimen. A real application of this strategy to BHS on a full-scale 2-story frame specimen was performed. Studies showed that this strategy exhibited excellent tracking performance for the measured displacements of the control point and remarkable compensation for ineffective forces of the redundant actuator. This strategy was demonstrated to be capable of accurately and effectively reproducing the desired displacements in large-scale BHS.

• Computers and Concrete
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• v.4 no.5
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• pp.331-346
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• 2007

A computer program was developed to analyze the non-linear, cyclic flexural performance of reinforced concrete structural members under various types of loading paths including non-sequential variations in axial load. This performance is significantly affected by the loading history. Different monotonic material models as well as hysteresis rules for confined and unconfined concrete and steel, some developed and calibrated against test results on material samples, were implemented in a fiber-based moment-curvature and in turn force-deflection analysis. One of the assumptions on curvature distribution along the member was based on a method developed to address the variation of the plastic hinge length as a result of loading pattern. Functionality of the program was verified by reproduction of analytical results obtained by others for several cases, and accuracy of the analytical process and the implemented models were evaluated against the experimental results from large-scale reinforced concrete columns tested under the analyzed loading cases. While the program can be used to predict the response of a member under a certain loading pattern, it can also be used to examine various analytical models and methods or refine a custom material model against test data.

• Physical Therapy Korea
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• v.6 no.3
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• pp.22-37
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• 1999

It was recently reported that exercise-induced fatigue is related to joint position sense although some controversy remains. The purposes of this study were to examine the effect on the accuracy of reproducing the knee angles after a fatiguing isokinetic quadriceps exercise at four different levels (10%, 30%, 50%, and 70% of maximal force) and to find the optimal exercise level without causing knee joint proprioception impairment. Forty healthy women, ages 19 to 27, were randomly assigned to four experimental groups. Before and after the exercise, accuracy of positioning with respect to auditory feedback for specific angles was estimated by calculating the mean errors between specific angles and reproduction angles. Fatigue was measured by EMG signals displayed by a frequency spectrum analysis during the quadriceps exercise. Results showed that there was no significant difference in accuracy of the knee joint positioning sense following the exercises in group 1, group 2, and group 3 (10%, 30%, and 50% of maximal force, respectively); the exception being group 4 (70%). Fatigue level was significantly increased in group 4 but there were no significant increases of fatigue level in group 1, group 2, or group 3. The results concluded that the optimal exercise level to acquire the therapeutic exercise effectiveness without position sense impairment was at 50% of maximal force. Further studies using large sample size and patient groups with poor knee joint proprioception would be needed to confirm this conclusion and to clarify the possibility of clinical applications.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.8 no.1
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• pp.67-73
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• 1999

This paper presents resizing design optimization method by utilizing genetic algorithm(GA), which consists of three basic operators : reproduction, crossover and mutation. The fitness and penalty function for resizing optimization problem are defined, and the flowchart of the developed computer program along with the descriptions of each modules is presented. Also, modelling for flexible-body dynamic analysis is presented. The model is composed of bodies, joints, and force elements such as translational spring-damper-actuator. The design objects si to determine the wall thickness for minimum weight under dynamic displacement constraint.