• 산업경영시스템학회지
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• 제30권2호
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• pp.44-50
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• 2007

This paper deals with the problem of scheduling jobs and rate-modifying activities on parallel machines. A rate-modifying activity is an activity that changes the production rate of equipment such as maintenance and readjustment. If a job is scheduled after the rate-modifying activity, then the processing time varies depending on the modifying rate of the activity. In this study, we extend the single machine problem to parallel machines problem and propose algorithms is to schedule the rate-modifying activities and jobs to minimize the makespan on parallel machines which is NP-hard. We propose a branch and bound algorithm with three lower bounds to solve medium size problems optimally. Also we develop three heuristics, Modified Longest Processing Time, Modified MULTIFIT and Modified COMBINE algorithms to solve large size problems. The test results show that branch and bound algorithm finds the optimal solution in a reasonable time for medium size problems (up to 15 jobs and 5 machines). For large size problem, Modified COMBINE and Modified MULTIFIT algorithms outperform Modified LPT algorithm in terms of solution quality.

• 경영과학
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• 제30권1호
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• pp.15-24
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• 2013

We consider the single machine scheduling problem with a rate-modifying activity and time-dependent deterioration after the activity. The class of scheduling problems with rate-modifying activities and the class of scheduling problems with time-dependent processing times have been studied independently. However, the integration of these classes is motivated by human operators of tasks who has fatigue while carrying out the operation of a series of tasks. This situation is also applicable to machines that experience performance degradation over time due to mal-position or mal-alignment of jobs, abrasion of tools, and scraps of operations, etc. In this study, the integration of the two classes of scheduling problems is considered. We present a mathematical model to determine job-sequence and a position of a rate-modifying activity for the integration problem. Since the model is difficult to solve as the size of real problem being very large, we propose genetic algorithms. The performance of the algorithms are compared with optimal solutions with various problems.

• Industrial Engineering and Management Systems
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• 제10권4호
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• pp.247-254
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• 2011

In this paper, we study a single-machine scheduling problem with deteriorating processing time of jobs and multiple rate-modifying activities which reset deteriorated processing time to the original processing time. In this situation, the objective function is to minimize total completion time. First, we formulate an integer programming model. Since the model is difficult to solve as the size of real problem being very large, we design an improved genetic algorithm called adaptive genetic algorithm (AGA) with spontaneously adjusting crossover and mutation rate depending upon the status of current population. Finally, we conduct some computational experiments to evaluate the performance of AGA with the conventional GAs with various combinations of crossover and mutation rates.

• 산업경영시스템학회지
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• 제37권3호
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• pp.43-50
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• 2014

In this paper, we deal with a single machine scheduling problems integrating with step deterioration effect and a rate-modifying activity (RMA). The scheduling problem assumes that the machine may have a single RMA and each job has the processing time of a job with deterioration is a step function of the gap between recent RMA and starting time of the job and a deteriorating date that is individual to all jobs. Based on the two scheduling phenomena, we simultaneously determine the schedule of step deteriorating jobs and the position of the RMA to minimize the makespan. To solve the problem, we propose a hybrid typed genetic algorithm compared with conventional GAs.

• PNF and Movement
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• 제22권2호
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• pp.243-255
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• 2024

Purpose: Although foot muscle imbalance has been confirmed in patients with hallux valgus deformity, there is insufficient information on how corrective taping affects muscle activity and contraction rate of the foot muscles. The purpose of this study was to confirm the effectiveness of Mulligan taping as a treatment method for hallux valgus deformity by examining changes in muscle activity and contraction rate when Mulligan taping with inelastic tape was applied to these patients. Methods: Thirty-two patients with hallux valgus deformity were randomly divided into two groups, experimental and control. In the experimental group, Mulligan taping with inelastic tape was applied to correct the hallux valgus angle of the big toe, and in the control group, placebo taping was performed in which inelastic tape was applied in a straight line without modifying the angle of the big toe. Muscle activity and muscle contraction rate were measured before and after the intervention, and changes were compared and analyzed. Results: In the experimental group where Mulligan taping was applied, the muscle activity and muscle contraction rate of the abductor hallucis muscle significantly increased after the intervention (P < 0.05). On the other hand, the muscle activity and muscle contraction rate of the adductor hallucis muscle and tibialis posterior muscle significantly decreased (P < 0.05). There was no significant difference in muscle activity and muscle contraction rate in the control group, where placebo taping was applied (P > 0.05). Conclusion: Mulligan taping significantly changed muscle activity and contraction rates compared to placebo taping. By correcting the position of the big toe, the activity and contraction rate of the abductor hallucis muscle increased, while the activity and contraction rate of the adductor hallucis muscle and tibialis posterior muscle decreased. Therefore, Mulligan taping is considered an intervention that can prevent symptom worsening and enhance foot function by improving muscle imbalance in patients with hallux valgus deformity.

• 한국미생물·생명공학회지
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• 제22권6호
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• pp.636-642
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• 1994

Essential amino acids involving in the catalytic mechanism of the $\beta$-D-xylosidase of Bacillus stearothermophilus were determined by chemical modification studies. Among various che- mical modifiers tested N-bromosuccinimide (NBS), $\rho$-hydroxymercurybenzoate (PHMB), N-ethylma- leimide, 1-[3-(di-ethylamino)-propyl]$-3-ethylcarbodi-imide (EDC), and Woodward's Reagent K(WRK)inactivated the enzyme, resulting in the residual activity of less than 20%. WRK reduced the enzyme activity by modifying carboxylic amino acids, and the inactivation reacion proceeded in the form of pseudo-first-order kinetics. The double-lagarithmic plot of the observed pseudo-first- order rate constant against the modifier concentration yielded a reaction order of 2, indicating that two carboxylic amino acids were essential for the enzyme activity. The $\beta$-D-xylosidase was also inactivated by N-ethylmaleimide which specifically modified a cysteine residue with a reaction order of 1, implying that one cysteine residue was important for the enzyme activity. Xylobiose protected the enzyme against inactivation by WRK and N-ethylmaleimide, revealing that carboxylic amino acids and a cysteine residue were present at the substrate-binding site of the enzyme molecule.

• BMB Reports
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• 제33권2호
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• pp.172-178
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• 2000

The lipoxygenase was purified 35 fold to homogeneity from the Korean red potato by an ammonium sulfate precipitation and DEAE-cellulose column chromatography. The simple purification method is useful for the preparation of pure lipoxygenase. The molecular weight of the enzyme was estimated to be 38,000 by SDS-polyacrylamide gel electrophoreses and Sepharose 6B column chromatography. The purified enzyme with 2 M $(NH_4)_2SO_4$ in a potassium phosphate buffer, pH 7.0, was very stable for 5 months at $-20^{\circ}C$. Because the purified lipoxygenase is very stable, it could be useful for the screening of a lipoxygenase inhibitor. The optimal pH and temperature for lipoxygenase purified from the red potato were found to be pH 9.0. and $30^{\circ}C$, respectively. The Km and Vmax values for linoleic acid of the lipoxygenase purified from the red potato were $48\;{\mu}M$ and $0.03\;{\mu}M$ per minute per milligram of protein, respectively. The enzyme was insensitive to the metal chelating agents tested (2 mM KCN, 1 and 10mM EDTA, and 1 mM $NaN_3$), but was inhibited by several divalent cations, such as $Cu^{++}$, $Co^{++}$ and $Ni^{++}$. The essential amino acids that were involved in the catalytic mechanism of the 5-lipoxygenase from the Korean red potato were determined by chemical modification studies. The catalytic activity of lipoxygenase from the red potato was seriously reduced after treatment with a diethylpyrocarbonate (DEPC) modifying histidine residue and Woodward's reagent (WRK) modifying aspartic/glutamic acid. The inactivation reaction of DEPC (WRK) processed in the form of pseudo-first-order kinetics. The double-logarithmic plot of the observed pseudo-first-order rate constant against the modifier concentration yielded a reaction order 2, indicating that two histidine residues (carboxylic acids) were essential for the lipoxygenase activity from the red potato. The linoleic acid protected the enzyme against inactivation by DEPC(WRK), revealing that histidine and carboxylic amino acids residues were present at the substrate binding site of the enzyme molecules.

• 농업과학연구
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• 제41권4호
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• pp.265-274
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• 2014

Physiological characteristics of two Korean golden kiwifruit cultivars, 'Halla Gold' and 'Haehyang', were compared to determine the storage potential of fruit. The soluble solid levels of the fruit were 8.9 and 6.9 oBrix in 'Halla Gold' and 'Haehyang' at harvest, respectively but increased up to 15.4 in 'Halla Gold' and 17.5 oBrix in 'Haehyang' after 2 months of storage. Major sugars were fructose and glucose, and sucrose content was relatively low regardless of cultivar. The edible quality of 'Haehyang' was better than 'Halla Gold' because of higher amount of sugars. Firmness of the fruits gradually decreased as the increase of storage period in 'Halla Gold' in both flesh and core tissue. Th firmness loss of 'Haehyang' fruit was faster in the first 2 months and then became slow. After 75 days of storage, the firmness of 'Haehyang' fruit was only 5.2% at harvest. Core tissue was soften enough to eat at ripe stage. Wall modifying enzyme activities including xylanase, ${\alpha}$-L-arabinofuranosi-dase and ${\beta}$-galactosidase were consistently higher in 'Haehyang' and the activity of pectate lyase was more increased than 'Halla Gold' after 2 months of storage. Respiration rate of 'Haehyang' was higher than 'Halla Gold' and further increased after 2 months of storage. Weight loss was much higher in 'Haehyang' which showed higher rate of the firmness loss. The storage potential of golden kiwifruit was estimated to be about 2 months for 'Haehyang' and 3 months for 'Halla Gold' when determined on the basis of the fruit firmness.

• Bulletin of the Korean Chemical Society
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• 제30권3호
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• pp.675-678
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• 2009

$Fe_2O_3,\;Ag_2O,\;CaWO_4$ and $Gd_2O_2S$:Tb loaded on titanium dioxide photocatalysts (P25, Degussa) were prepared by a calcination. Their composite films containing water-born polyurethane used as a material for immobilization were obtained by spray coating technique. The photocatalytic activity of the titanium dioxide films was characterized by decrease of UV-vis absorption spectra for methylene blue and gas chromatography for photocatalytic decomposition of formaldehyde diluted in water. It was shown that the $Gd_2O_2S$:Tb modified titanium dioxide films had good photocatalytic properties and followed the first-order kinetic model with regard to photocatalytic decoloration of methylene blue. Especially in formaldehyde photodegradation experiment, decrease rate of concentration of the titanium dioxide films with $Gd_2O_2S$:Tb modifying was about 35% larger than that of the unloaded titanium dioxide film.

• 보건교육건강증진학회지
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• 제21권2호
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• pp.35-54
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• 2004

This study was intended to provide basic data of nutrition education to a prevention of obesity and living patterns of elementary school students. Through the measurment of the actual obesity rate of children for students who were in the fifth and sixth grades of elementary school as well as their mothers, and by analyzing obesity-related factors. Children have started to have the characteristics obesity and obesity problems. 1. There were total 234 children including 133 boys (56.8％) and 101 girls (43.2％) for the study. There were 80 children in the fifth grade (34.2％) and 154 children in the sixth grade (65.8％). 2. Among the subjects 20.1％ were obese. By gender, the obesity rate of boys (27.1％) was higher than that of girls (l0.9％)(p＜0.01). By grade, children in the fifth grade (26.3％) had higher obesity rate than children in the sixth grade (l6.9％)(p＜0.05). 3. In terms of the educational level of parents, the obesity rate of children of parents who received university and／or higher education was 27.5％ (p＜0.05). 44.1％ of parents answered ‘I almost never give snack’s’(p＜0.01). 4. There was 32.8％ for an irregular quantity of meal. There was no obese child who under-ate (p＜0.05). In terms of impulse eating, ‘I eat.’ and ‘I don't eat.’ were 24.4％ and 25.9％ respectively. The obesity rate of the case of ‘I eat only food I like.’ was 10.6％ (p＜0.05). In terms of the obesity rate based on the daily average meal frequency, there was the highest rate of 26.1％ for I average meal frequency per day, 13.0％ for 2 daily average meal frequency, and 7.4％ for over 3 average meal frequency per day (p＜0.05). For a degree of a physical activity, the group of active physical activity (p＜0.05) and the group which liked the physical exercise showed a lower obesity rate (p＜0.001). The obesity rate of children who had regular exercise was 11.8％. It was lower than the obesity rate (24.8％) of children who didn't exercise (p＜0.01). The higher exercise frequency per week was, the lower the obesity rate was(p＜0.01). In terms of the exercise time, there was 8.3％ for over 60 minutes and 28.9％ for less 15 minutes. The group which had the long exercise time showed a lower obesity rate(p＜0.05). As the result, the education for obesity must enable students to recognize the warning signs for obesity and control their own weight with proper living patterns, by modifying behaviors considering the degree of obesity. Obesity must be controlled by the prevention and education connected with the family for all students as one of the school health programs. There must be also the development of a program through individual consultation considering the degree of obesity.