• Industrial Engineering and Management Systems
• /
• v.6 no.1
• /
• pp.40-48
• /
• 2007

This study investigated the optimum positions and warning foreperiod for auditory signals with an experiment on spatial stimulus-response (S-R) compatibility effects. The auditory signals were presented at the front-right, front-left, rear-right, and rear-left positions from the subjects, whose reaction times and accuracies at different spatial mapping conditions were examined. The results showed a significant spatial stimulus-response compatibility effect in which faster and more accurate responses were obtained in the transversely and longitudinally compatible condition while the worst performance was found when spatial stimulus-response compatibility did not exist in either orientation. It was also shown that the transverse compatibility effect was found significantly stronger than the longitudinal compatibility effect. The effect of signal position was found significant and post hoc test suggested that the emergent warning alarm should be placed on the front-right position for right-handed users. The warning foreperiod prior to the signal presentation was shown to influence reaction time and a warning foreperiod of 3 s is found optimal for the 2-choice auditory reaction task.

• Journal of the Korea Safety Management & Science
• /
• v.11 no.3
• /
• pp.217-226
• /
• 2009

The combustion reaction of polyvinylchloride(PVC) was investigated using a thermogravimetric technique under an air atmosphere condition at several heating rates from 10 to $50^{\circ}C$/min. To obtain information on the kinetic parameters, the dynamic thermogravimetric analysis curve and its derivative were analyzed by a variety of analytical methods such as Kissinger, Friedman, Chatterjee-Conrad, Ozawa and Coats-Redfern methods. The combustion reaction of PVC proceeded in two steps; the first step was caused by the dehydrochlorination process in PVC, and the second step by the combustion of polyene. The comparative works for the kinetic results obtained from various methods should be performed to determine the kinetic parameters, because there are tremendous differences in the calculated kinetic parameters depending upon the mathematical method taken in the analysis.

• Culinary science and hospitality research
• /
• v.18 no.4
• /
• pp.209-221
• /
• 2012

The purpose of this study is to apply molecular gastronomy and its spherification methodology to persimmon desserts. We prepared persimmon calcium alginate beads and investigated physical and sensory characteristics of beads according to the different concentration of calcium chloride(0.5, 0.75, 1.0%) and reaction time(2, 4, 6, 8, 10 min). Lightness and yellowness were decreased significantly as both calcium chloride concentration and reaction time increased. However, redness was increased significantly as the concentration of calcium chloride and reaction time increased. Hardness, springiness, chewiness, cohesiveness, and resilience except for adhesiveness tended to increase as the concentration of calcium chloride and reaction time increased. The thickness of beads also increased as the concentration of calcium chloride and reaction time increased. Quantitative descriptive analysis showed that voluminosity, springiness, hardness, chewiness, and residue tended to increase as the concentration of calcium chloride increased. Overall acceptability reached a peak at the persimmon bead containing 0.5% calcium chloride. The result of this study showed that the concentration of calcium chloride and reaction time influenced the overall characteristics of calcium alginate beads.

• Preventive Nutrition and Food Science
• /
• v.22 no.3
• /
• pp.211-215
• /
• 2017

The individual Maillard reactions of glucose, glucosamine, cyclohexylamine, and benzylamine were studied at a fixed temperature of $120^{\circ}C$ under different durations by monitoring the absorbance of the final products at 425 nm. Glucosamine was the most individually reactive compound, whereas the reactions of glucose, cyclohexylamine, and benzylamine were not significantly different from each other. Maillard reactions of reaction mixtures consisting of glucosaminecyclohexylamine, glucosamine-benzylamine, glucose-cyclohexylamine, and glucose-benzylamine were also studied using different concentration ratios under different durations at a fixed temperature of $120^{\circ}C$ and pH 9. Maillard reactions in the pairs involving glucosamine were observed to be more intense than those of the pairs involving glucose. Finally, with respect to the concentration ratios, it was observed that in most instances, optimal activity was realized, when the reaction mixtures were in the ratio of 1:1.

• Journal of the Korean Applied Science and Technology
• /
• v.33 no.3
• /
• pp.492-497
• /
• 2016

The intermediate product resulting from the radical degradation experiment of PCE and the atomic charge gained through Gaussian03W were compared against each other. The result was that the ratio of PCE radical degradation was almost 98% or higher after the 9 hr point in reaction time. The reaction speed constant was $0.16hr^{-1}$ and it followed the first reaction. We could see that at each location of the PCE molecule, dechlorination happened at a point where the negative atomic charge was the greatest. Moreover, the intermediate product of PCE radical degradation that was confirmed in the experiment and literature coincided exactly with the intermediate product in the atomic charge calculation. Therefore, when the atomic charge is calculated, the radical degradation pathway of the organic chlorine compound could be forecast.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.12 no.5
• /
• pp.2162-2176
• /
• 2018

Chemical reactions have an intricate relationship with the search for better-quality neighborhood solutions to optimization problems. A catalytic reaction for chemical reactions provides a clue and a framework to solve complicated optimization problems. The application of a catalytic reaction reveals new information hidden in the optimization problem and provides a non-intuitive perspective. This paper proposes a new simulated catalytic reaction method for search in optimization problems. In the experiments using this method, significantly improved results are obtained in almost all graphs tested by applying to a graph bisection problem, which is a representative problem of combinatorial optimization problems.

• Preventive Nutrition and Food Science
• /
• v.22 no.1
• /
• pp.37-44
• /
• 2017

Sulfur-containing amino acids play important roles in good flavor generation in Maillard reaction of non-enzymatic browning, so aqueous model systems of glucosamine and cysteine were studied to investigate the effects of reaction temperature, initial pH, reaction time, and concentration ratio of glucosamine and cysteine. Response surface methodology was applied to optimize the independent reaction parameters of cysteine and glucosamine in Maillard reaction. Box-Behnken factorial design was used with 30 runs of 16 factorial levels, 8 axial levels and 6 central levels. The degree of Maillard reaction was determined by reading absorption at 425 nm in a spectrophotometer and Hunter's L, a, and b values. ${\Delta}E$ was consequently set as the fifth response factor. In the statistical analyses, determination coefficients ($R^2$) for their absorbance, Hunter's L, a, b values, and ${\Delta}E$ were 0.94, 0.79, 0.73, 0.96, and 0.79, respectively, showing that the absorbance and Hunter's b value were good dependent variables for this model system. The optimum processing parameters were determined to yield glucosamine-cysteine Maillard reaction product with higher absorbance and higher colour change. The optimum estimated absorbance was achieved at the condition of initial pH 8.0, $111^{\circ}C$ reaction temperature, 2.47 h reaction time, and 1.30 concentration ratio. The optimum condition for colour change measured by Hunter's b value was 2.41 h reaction time, $114^{\circ}C$ reaction temperature, initial pH 8.3, and 1.26 concentration ratio. These results can provide the basic information for Maillard reaction of aqueous model system between glucosamine and cysteine.

• Journal of the Korea Safety Management & Science
• /
• v.15 no.3
• /
• pp.151-161
• /
• 2013

This paper proposes a strategic model of linkage between productivity metrics and financial accounting metrics to properly evaluate the financial effect of TPM activities and the business performance. This linkage strategy provides a connection tool for clear communication between factory-level and headquarters that the metrics proposed by this paper ultimately improves a quality of support from the management by receiving the factors required for productivity activities in the practical field. This factor includes such as equipment, raw materials and labors. Here, we propose that chain reaction models using break down structure of productivity metrics and financial metrics enhance the knowledge sharing of KPI (Key Performance Indicator) which generally tend to create oversimplified communication between management in headquarters and employees in the practical fields. The productivity metrics include OEE(Overall Equipment Effectiveness) of TPM (Total Productive Maintenance), OLE (Overall Labor Effectiveness) of PAC(Performance and Analysis and Control) activities, and OYE (Overall Yield Effectiveness) of TMM(Total Material Management) activities. The financial accounting metrics include ROE(Return on Equity), ROA(Return on Asset), and AVR(Added-Value Rate). The suggested chain reaction model selects the financial metrics as initial stage and branch down until final stage of productivity metrics. When demand exceeds supply, an ideal speed rate, the lean OEE strategy can be initially applied to reduce the gap between the demand and supply, then apply variable costing to estimate correct amount of operating profit. In addition, the paper presents a new type of model for linkage between financial accounting metrics including CAPEX(Capital Expenditure), OPEX(Operating Expenditure), EVA(Economic Added Value), DCL(Degree of Combined Leverage), and TPM productivity activities including AM(Autonomous Maintenance), PM(Preventive Maintenance), MP(Maintenance Prevention) and QM(Quality Maintenance). In order to support the evidence of proposed linkage strategy, a case analysis on 52 projects from national TPM contest from 2011 to 2012 is analyzed. The case presents the classification of CAPEX and OPEX activities from TPM, and proposes the correct implementation of financial effect for TPM projects.

• Culinary science and hospitality research
• /
• v.19 no.3
• /
• pp.173-193
• /
• 2013

This study was conducted to investigate the effects of servicescape factors(space, convenience, aesthetics, comfortableness, cleanliness), brand reputation and experiences factors(feel, think, act, relate) on emotional and cognitive reactions of visitors to Korean restaurants. It also investigated the relationship between emotional and cognitive reactions and brand loyalty. A total of 353 questionnaires were analyzed using the factor analysis, a reliability test, and structural equation modeling analysis. The results revealed that space, aesthetics and comfortableness were positively related to emotional reaction, and convenience and cleanliness were related to cognitive reaction. This study also found that brand reputation was positively related to emotional and cognitive reactions. Moreover, it was found that think was positively related to emotional reaction, and feel, think, act and relate were positively related to cognitive reaction. Finally, cognitive reaction was positively related to loyalty. Therefore, Korean restaurant marketers should introduce or strengthen servicescape, brand reputation and experiences, which increases brand attitude or loyalty.

• The Korean Journal of Food And Nutrition
• /
• v.24 no.4
• /
• pp.670-679
• /
• 2011

This study investigated the hotel buffet restaurant's service quality, emotional reaction of customer, recommendation intention, and defection intention. The survey was conducted from January 3 to February 7 in 2011, and 400 respondents were used in the data analysis. As a results of this study, the hotel buffet restaurant's service quality was classified by the interaction, outcome, and physical environment quality. The emotional reaction of hotel buffet restaurant's customer was classified by the positive and negative emotion. The all factors of hotel buffet restaurant's service quality had a positive impact on positive emotion, while it had a negative impact on negative emotion. The positive emotion reaction of hotel buffet restaurant's customer had a positive impact on the recommendation intention, while the negative emotion had a negative impact on the recommendation intention. And the negative emotion had a positive impact on the defection intention in hotel buffet restaurants. In addition, there were partially differences in the service quality and emotional reaction by general characteristics. There were significant differences in the recommendation intention by marriage status and monthly income. Therefore, the hotel buffet restaurants have to design a strategy of service for increasing customer's positive emotion and recommendation intention.