• Journal of the Korean Society of Hazard Mitigation
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• v.2 no.2 s.5
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• pp.61-72
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• 2002

The optimum fiber and asphalt binder contents were decided on the base of the Mashall mix design method. To compare the mechanical characteristics between the conventional(dense-graded 20) and the fiber-reinforced mixtures, indirect tension tests were conducted under three temperatures(5, 20, 60$^{\circ}C$). In particular, the wheel tracking tests were performed to evaluate the rutting resistances of the mixtures. Test results showed that the indirect tensile strength of fiber-reinforced asphalt concrete was higher than that of conventional one. The toughness of fiber-reinforced mixture was 1.27 to 1.97 times higher than that of conventional one, depending upon the temperature. In addition, the results of wheel tracking tests and the retained indirect splitting tension tests conducted at $60^{\circ}C$ revealed that the resistance to permanent deformation of fiber-reinforced mixture was stronger than that of the conventional one.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.515-519
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• 2011

Structural tests for the mixing head of a 75tonf class thrust chamber were performed to verify structural stability. The mixing head of a thrust chamber is loaded by high pressure with regeneratively cooled fuel and cryogenic liquid oxygen(LOx) as well as it transfers thrust load generated by liquid rocket engine. Therefore structural stability of mixing head is a very important factor to work without any plastic deformation or structural failure. In this study, two mixing heads were manufactured using different welding methods, Tungsten Inert Gas(TIG) welding and Electron Beam Welding(EBW) and evaluated a structural stability. The results of structural tests showed that the mixing head assembled by EBW can withstand the applied design load without any structural failures and be structurally more stable than that of TIG welding.

• Journal of Pharmaceutical Investigation
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• v.35 no.5
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• pp.355-360
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• 2005

The purpose of the present study was to evaluate the bioequivalence of two cetirizine HCl tablets, Zyrtec tablet (UCB Pharm. Co., Ltd. Korea, reference product) and Zyrix tablet (Kukje Pharm. Co., Ltd., Korea, test product), according to the guidelines of Korea Food and Drug Administration (KFDA). After adding an internal standard (diazepam), plasma samples were extracted using 1 mL of dichloromethane. Compounds extracted were analyzed by reverse-phase HPLC with ultra-violet detector. This method for determination cetirizine is proved accurate and reproducible with a limit of quantitation of 10 ng/mL in male plasma. Twenty-four healthy male Korean volunteers received each medicine at the cetirizine HCl dose of 10 mg in a $2{\times}2$ crossover study. There was a one-week wash out period between the doses. Plasma concentrations of cetirizine were monitored for over a period of 24 hr after the administration. AUC (the area under the plasma concentration-time curve) was calculated by the linear trapezoidal rule. $C_{max}$ (maximum plasma drug concentration) and $T_{max}$ (time to reach $C_{max}$) were compiled from the plasma concentration-time data. Analysis of variance was carried out using logarithmically transformed AUC and $C_{max}$. No significant sequence effect was found for all of the bioavailability parameters indicating that the crossover design was properly performed. The 90% confidence intervals for the log transformed data were acceptable range of log 0.8 to log 1.25 $(e.g.,\;log\;0.93-log\;1.08\;for\;AUC_{0-t},\;log\;0.91-log\;1.08\;for\;AUC_{0-{\infty}}\;and\;log\;1.01-log\;1.11\;for\;C_{max})$. The major parameters, AUC and $C_{max}$ met the criteria of KFDA for bioequivalence indicating that Zyrix tablet is bioequivalent to Zyrtec tablet.

• The Journal of the Korea Contents Association
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• v.10 no.6
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• pp.312-322
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• 2010

The aim of this study is to find the effect of action learning on the problem solving process of nursing students during the clinical practice of nursing management. A total of 99 senior nursing students participated in this study. Data was collected from May 2006 to October 2007 and statistical analysis for paired t-test was performed on the data using SPSS/WIN 14.0. The results of the data show that there was a significant increase in the problem solving process for nursing students after the implementation of action learning(t=-4.718, p=.000). In the problem solving process, there was a significant increase in definition of problem(t=-4.123, p=.004), design of problem solution(t=-2.973, p=.002), execution of problem solution(t=-3.264, p=.000) and investigation of problem solving(t=-3.677, p=.000). The only exception in the problem solving process was detection of problem(t=-1.858, p=.066). Therefore, action learning provides nursing students a new alternative for improving the problem solving process and clinical adaptability after graduating from nursing school.

• Journal of Korea Multimedia Society
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• v.12 no.2
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• pp.290-299
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• 2009

Evolutionary Artificial Neural Networks (EANNs) has been highly effective in Artificial Intelligence (AI) and in training NPCs in video games. When EANNs is applied to design game NPCs' smart AI which can make the game more interesting, there always comes two important problems: the more complex situation NPCs are in, the more complex structure of neural networks needed which leads to large operation cost. In this paper, the Dynamic State Evolutionary Neural Networks (DSENNs) is proposed based on EANNs which deletes or fixes the connection of the neurons to reduce the operation cost in evolution and evaluation process. Darwin Platform is chosen as our test bed to show its efficiency: Darwin offers the competitive team game playing behaviors by teams of virtual football game players.

• Journal of Distribution Science
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• v.18 no.3
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• pp.87-97
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• 2020

Purpose: The aim of this study is to understand the internal and external responses that consumers experience when they are exposed to an innovative system in retail stores. This study considered the SST(Self-Service Technology) system in a retail setting as a type of functional environmental stimuli and selected a smart shopping cart as an example of SST system. The influences of functional environmental stimuli on consumers' emotional, cognitive, and behavioral responses were examined by applying S-O-R model. In addition, this study attempted to extend the traditional S-O-R model by (a) incorporating personal characteristics variables such as time pressure and perceived crowding and (b) considering not only emotional but also cognitive aspects of consumers' internal responses. Research Design, Data, and Methodology: This study used a video-scenario technique. Participants watched a video about grocery shopping situations using a smart shopping cart and responded to their emotional, cognitive, and behavioral responses. An online survey was conducted using Amazon's Mechanical Turk (N = 185). All participants were US consumers over 20 years old and had been shopping at the grocery store in the last month. Data were analyzed through structural equations modeling with AMOS 20. Results: Test results showed that consumers who perceived higher levels of time pressure and perceived crowding in usual shopping situations were more likely to evaluate the SST system favorably. The results showed that personal characteristics have a significant impact on consumers' evaluation of functional environmental stimuli in retail setting. As consumers evaluated the SST system favorably, they experienced more positive affect and less negative affect during their shopping behaviors. Positive affect led to good service quality inference, which further increased patronize intention. However, negative affect did not show a significant impact on service quality inference, but only on patronize intention. Conclusions: This study attempted to investigate the influence of SST system by extending the traditional S-O-R model. This study classified the SST system as functional environmental stimulus of retail stores and analyzed the effect of stimulus on consumers' internal and external responses. The results of this study showed that the introduction of innovative SST can serve as an effective store differentiation strategy in an increasingly competitive retail environment.

• Journal of Nutrition and Health
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• v.14 no.4
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• pp.209-219
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• 1981

To evaluate long-term metabolic response of free-living Korean subjects consuming local sources adequately or slightly below habitual intake. Subjects, six male medical students aged 23-25 years were free-living, but consumed diets in the metabolic unit. They were healthy as determined from medical laborarory tests. They belong to the Korean middle-class. Temperature of outdoor during study were ranged between -2 to $26^{\circ}C$, whereas the indoor were $18-22^{\circ}C$. Animal protein ranged between 25-30% of total calorie. The three meals and a vitamin supplement to meet recommendation were given daily. Three 50day periods following the design were used to test the protein-energy adequacy of the diet. Urinary nitrogen excretion was measured daily. Fecal samples were pooled for the last 5 days of each week. Nitrogen balance was computed using 5mg N/Kg skin and miscellaneous losses. Body weight was measured daily. The study was covered on 126 metabolic observations weekly. Body weight changes were relatively stable with the energy intake of 37-44Kca1/kg, and N-balances were also relatively stable, but it was influenced by physical and or mental stress somehow. It could be assumed that the mean protein and energy requirement were $190{\pm}10mg$ N/Kg with $41{\pm}2$ Kcal/kg, and the mean digestibility of protein was 81% on these subjects with the experimental conditions. The protein requirement, however, could be cut down somewhat with some limited increaing of energy intake under parameters of N-balance and maintaining body weight. It was also observed a tendency of the requirement were getting smaller with the increase of body size.

• Journal of the Korean Society for Railway
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• v.11 no.1
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• pp.54-60
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• 2008

In the trackbed design using elastic multilayer model, the stress-dependent resilient modulus $(E_R)$ is an important input parameter, that is, reflects substructure performance under repeated traffic loading. However, the evaluation method for resilient modulus using repeated loading triaxial test is not fully developed for practical purpose, because of costly equipment and the significantly fluctuated values depending on the testing equipment and laboratory personnel. The this study, the paper will present an indirect method to estimate the resilient modulus using dynamic properties. The resilient modulus of crushed stone, which is the typical material of sub-ballast, was calculated with the measured dynamic properties and the range of stress level of the sub-ballast, and approximated with the power model combined with bulk and deviatoric stresses. The resilient modulus of coarse grained material decreases with increasing deviatoric stress at a confining pressure, and increases with increasing bulk stress. Sandy soil (SM classified from Unified Soil Classification System) of subgrade was also evaluated and best fitted with the power model of deviatoric stress only.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.40 no.1
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• pp.1-10
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• 2017

The difficulties in opening and closing a sport utility vehicle (SUV) tailgate is important aspect of JD (James David) power's Initial Quality Survey (IQS) assessment, and affective quality has a big impact on the the success of thesedays products. The purpose of this study is to evaluate the perceived difficulty and satisfaction of customers by the opening and closing of the tailgate and to grasp the relationship between them and the opening and closing reaction force. The mechanical force required to open and close 42 domestic and overseas SUV tailgates was measured with the help of an auto company. In the experiment, 100 male drivers in their 20s to 50s evaluated perceived difficulty and satisfaction with opening and closing the tailgate. The results of the analysis showed that perceived difficulty and satisfaction were statistically different depending on the vehicle, but did not depend on the personal characteristics of the participants. The perceived difficulty and satisfaction regression model of tailgate opening and closing was developed by mechanical force variables and had a relatively high adjusted $R^2$ ranging from 0.62 to 0.73. The models showed that the the initial close and open force, the difference between initial and maximum close force and the difference between initial and auto-fall angle should be small for the low perceived exertion and high satisfaction. In addition, the correlation analysis between IQS score of tailages and perceived difficulty and satisfaction showed that the IQS scores were more related to the perceived difficulty and satisfaction of closing than those of opening. The results of the study will be helpful to design and test mechanical open and close structure of SUV tailgates.

• Proceedings of the KWS Conference
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• 2002.10a
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• pp.661-667
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• 2002

Welding-induced buckling distortion is one of the most problematic concerns in both design and fabrication of welded thin-plate structures. This paper deals with experimental and numerical results of the welding-induced longitudinal and/or buckling distortion occurring in welding of 6mm-thick AH36 high strength steel plates. Effects of the heat input and the plate size on the distortion were experimentally evaluated for square plates. Bead-on-plate welding was performed with the submerged arc welding process along the middle line of plate specimens. Experimental results showed that the longitudinal distortion made a single curvature in the plate, and the distortion magnitude along the weld centerline was proportional to the heat input and the plate size. The experimental results were used to examine the validity of the numerical simulation procedure for welding-induced distortion where the longitudinal distortion mode and magnitude were numerically quantified. Three-dimensional, large deformation, welding simulations were performed for selected weld models. Numerical results of the distortion mode and magnitude were in a good agreement with experimental ones. Depending on the presence of halting the distortion growth during the cooling cycle of welding, the condition discriminating buckling distortion from longitudinal distortion was established. Eigenvalue analyses were performed to check the buckling instability of tested plates with different sizes subjected to different heat inputs. The perturbation load pattern for the analysis was extracted from longitudinal inherent strain distributions. Critical buckling curve from the eigenvalue analyses revealed that the buckling instability is manifested when plate size or heat input increases.