• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.5
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• pp.15-21
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• 2008

It is generally known that the PRAT(Plysteer Residual Aligning Torque) is one of indicating a performance factors of a tire for assessing the vehicle pull, also tire pattern shape, which means lateral groove angle, is very important tire design factor in relation to the PRAT. Lateral grooves of tire pattern are widely divided into center and shoulder parts. So, this paper has studied the correlation between the PRAT and their lateral groove angles using FEM. Especially, the steady state rolling analysis among tire rolling analysis methods has been used for the PRAT performance study. Firstly, analysis result data have been compared with the experimental data to validate FE analysis for PRAT. Next, the PRAT due to the lateral groove angle about PCR(Passenger Car Radial) tire and SUV tire has been analyzed. The tendency of the PRAT due to the lateral groove angles can be used as a guide line for the tire design in relation to vehicle pull.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.2 s.179
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• pp.104-112
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• 2006

The influence of tire belt angle on the Plysteer Residual Aligning Torque(PRAT) and the cornering stiffness by the FEM has been studied. The PRAT is a performance factor of the tire about vehicle pull, and the cornering stiffness has relation to vehicle steering response of outdoor test. To validate FE model for analysis, simulation data for both the static stiffness(vertical, lateral) and the PRAT have been compared with the experimental data. In addition to the characteristics of the PRAT and the cornering stiffness due to the tire belt angle, rolling and cornering contact characteristics have been studied. The tendency of the PRAT and the cornering stiffness due to the belt angle can be used as a guide line for the tire design in relation to vehicle pull and vehicle steering response.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.1371-1375
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• 2005

The paper has analyzed the influence of tire design variable on the tire Force and Moment (F&M) characteristics, especially by the belt angle, the Plysteer Residual Aligning Torque (PRAT) which is considered as one of the causing factors for the vehicle pull. To validate the tire FE model, the tire stiffness and the PRAT which can be derived from the simulation data have been compared with the experimental data of test machine. In addition to PRAT characteristic, the tire stiffness and cornering characteristics due to the belt angle have been investigated. The effects of drum's curvature on the PRAT have been also investigated using the tire FE model and the usefulness of the current drum type F&M test machine can be confirmed.

• Plant Biotechnology Reports
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• v.3 no.4
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• pp.347-353
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• 2009

Procedures that induce microspore embryogenesis have been described for a range of Brassica species, but embryo yield remains low for a number of genotypes. We have carried out experiments with the microspores from a weakly responsive line of B. napus to determine the culture conditions that optimize their in vitro embryogenesis by treating them with effectors of ethylene synthesis and action. The results revealed that isolated microspores subjected to an initial heat stress in a medium supplemented with inhibitors of ethylene synthesis such as AVG and $CoCl_2$ exhibited significantly increased embryo yields. This suggested that regulatory effects are exerted by the ethylene produced by the isolated microspores on the early processes of gametogenesis. As a consequence, treatment of microspores with SAM, an ethylene synthesis precursor, or with the ethylene-releasing agent ethephon, led to decreases in embryo yield. A special response to ethylene during the early stages of microspore development was finally shown to occur through experiments where isolated microspores were treated for increasing periods of time with $CoCl_2$. Collectively, our data demonstrated that the induction of embryogenesis induced by heat stress can be enhanced by inhibitors of ethylene biosynthesis.

• Korean Journal of Computational Design and Engineering
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• v.16 no.6
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• pp.449-457
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• 2011

The productivity improvement is indispensible to shipbuilding industry for maintaining the world's No. 1. Simulation based production recently has been an issue as prat of efforts to high efficiency production and Korean shipyards requests simulation system tools specialized in a shipbuilding industry. IT convergence project between conventional shipbuilding industry and IT simulation technology has been carried out and integrated simulation framework was proposed as a way to overcome sporadic developments. The framework would provide reusability of kernels and modules and also ensure for expansibilities to other production simulations. The fact that production simulation system should reflect shipyard requirement would be most important. We suggest an analysis process of customer requirements and functional requirements for production simulations. It is partially based on concepts of software engineering and axiomatic design. The process is applied to a design of configuration for simulation framework.

• Journal of Engineering Education Research
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• v.17 no.3
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• pp.8-21
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• 2014

The increase of youth unemployment has delivered entire interests in career education by many institutes including universities Thereafter, the emphasis on career education makes the ability on career development be considered as one of the fundamental issues in a human life. There are many efforts to assist students for career exploring by universities, however, the findings through these researches have appeared to be insignificant. As a prat of the efforts to overcome these limitations, this study is to create the appropriate career exploring educational program for college students in engineering. In accordance with the objective of this study, the research was conducted with methodologies such as 1) literature reviews; 2) analysis on the career exploring ability and needs on the related programs focusing on 224 college students in engineering; 3) creation and development of the educational program for career exploring; 4) application of the developed program to twenty three number of college students; 5) result analysis after program implementation. The significant findings and a specific case delivered by this study expect to provide valuable contributions to prospective users who intent to involve in the related educational program.

• Proceedings of the ESK Conference
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• 1993.10a
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• pp.165-188
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• 1993

The study was to find out the current situation of supply and demand of apparel CAD systems in Korea. Also it was hoped to gather any valuable information about the curent usage of appared CAD systems for the development of the enhanced apparel CAD system. Three interviews were carried out for the study. The first interview with the importing agents was to find out the apparel CAD system's supplying situation. The second interview with the users of apparel CAD system was about the usage of the systems and related informations. The last interview was about the pattern making facilities, which was pointed out by the users to be the most inconvenient prat of apparel CAD systems. The results of the survey were:- 1. The supplu and demand of apparel CAD systems is increasing. 2. The education, training, maintenance of the system should be improved by the supplier. 3. Apparel CAD systems are used for various production systems in the apparel industry. 4. 100% of the systems are utilized for pattern input and 89% of the systems are utilized for marker making. Only 15% of the systems are utilized in pattern making process, which 80% of the users realize to be computerized. 5. The most serious barrier to the better usage of the system is the communication with the system in foreign language. This barrier could be lifted when Korean apparel CAD system is developed.

• Steel and Composite Structures
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• v.52 no.1
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• pp.1-14
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• 2024

This paper introduces a system allows for seismic isolation of the pallet from the rack in the down-aisle direction, occupies minimal vertical space (5 cm) and ±7.5 cm of deformation range. A conceptual model of the isolation system is presented, leading to a constitutive equation governing its behavior. A first experimental campaign studying the response of the isolation system's components was conducted to calibrate the parameters of its constitutive equation. A second experimental campaign evaluated the response of the isolation system with mass placed on it, subjected to cyclic loading. The results of this second campaign were compared with the numerical predictions using the pre-calibrated constitutive equation, allowing a double-blind validation of the constitutive equation of the isolation system. Finally, a numerical evaluation of the isolation system subjected to a synthetic earthquake of one component. This evaluation allowed verifying attributes of the proposed isolation system, such as its self-centering capacity and its effectiveness in reducing the absolute acceleration of the isolated mass and the shear load transmitted to the supporting beams of the rack.

• Proceedings of the Korean Society of Food Science and Nutrition Conference
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• 2004.11a
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• pp.65-70
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• 2004

Modulation of biotransformation enzymes is one mechanism by which a diet high in fruits and vegetable may influence cancer risk. Inhibition of cytochrome P450s (CYP) and concomitant induction of conjugating enzymes are hypothesized to reduce the impact of carcinogens in humans. Thus, exposure to types and amounts of phytochemicals may influence disease risk. Like other xenobiotics, many classes of phytochemicals are rapodly conjugated with glutathione, glucuronide, and sulfate moieties and excreted in urine and bile. In humans, circulating phytochemical levels very widely among individuals even in response to controlled dietary interventions. Polymorphisms in biotransformation enzymes, such as the glutathione S-transferases (GST), UDP-glucuronosyltransferases (UGT), and sulfotransferases (SULT), may ocntribute to the variability in phytochemical clearance and efficacy; polymorphic enzymes with lower enzyme activity prolong the half-lives of phytochmicals in vivo. Isothiocyanates (ITC) in cruciferous vegetables are catalyzed by the four major human GSTs: however reaction velocities of the enzymes differ greatly. In some observational studies of cancer, polymorphisms in the GSTMI and GSTTI genes that result in complete lack of GSTM1-1 protein, respectively, confer greater protection from cruciferous vegetable in individuals with these genotypes. Similarly, we have shown in a controlled dietary trial that levels of GST-alpha-induced by ITC-are higher in GSTMI-null individuals exposed to cruciferous vegetablse. The selectivity of glucuronosyl conjugation of flavonoids is dependent both on flavonoid structure as well as on the UGI isozyme involved in its conjuagtion. The effects of UGI polymorphisms on flavonoid clearnace have not been examind; but polymorphisms affect glucuronidation of several drugs. Given the strong interest in the chemopreventive effects of flavonoids, systematic evaluation of these polymorphic UGTs and flavonoid pharmacokinetics are warranted. Overall, these studies suggest that for phytochemicals that are metabolized by, and affect activity of, biotransformation enzymes, interactions between genetic polymorphisms in the enzymes and intake of the compounds should be considered in studies of cancer risk. Genetic polymorphisms in biotransformation enzymes may account in prat for individual variation in metabolism of a wide range of phytochemicals and their ultimate impact on health.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.7
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• pp.916-923
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• 2010

We report nutritional physiology and non-specific immune responses of vitamin E in parrot fish for the first time. This study aimed to investigate the essentiality and requirements in diets based on growth performances, non-specific immune responses and a challenge test against Vibrio angullarum. Six casein-gelatin based semi-purified diets were formulated to contain six graded levels of DL-${\alpha}$-tocopheryl acetate (${\alpha}$-TA) at 0, 25, 50, 75, 100 and 500 mg/kg diet (designated as E0, E25, E50, E75, E100 and E500, respectively) and fed to triplicate groups of juvenile parrot fish for 12 weeks. The analyzed dietary concentrations of vitamin E were 0, 38, 53, 87, 119 and 538 mg/kg diet for E0, E25, E50, E75, E100 and E500, respectively. At the end of the feeding trial, growth performance and feed utilization of fish fed the E25 were significantly higher compared to that of fish fed the other diets. Liver ${\alpha}$-tocopherol concentration was significantly increased with an increase in dietary ${\alpha}$-TA in a dose dependent manner. No apparent clinical signs of vitamin E deficiency and mortality were observed in fish fed the basal diet for 12 weeks. Among the immune responses assayed, phagocytic (NBT assay) and myeloperoxidase activities were significantly increased with increment of dietary ${\alpha}$-TA levels. During the challenge test with V. anguillarum, E75, E100, and E500 diets resulted in higher survivals than E0, E25 and E50 diets. The findings of this study suggest that parrot fish require exogenous vitamin E and the optimum dietary level could be approximately 38 mg ${\alpha}$-TA/kg diet for normal growth and physiology. Dietary ${\alpha}$-TA concentration over 500 mg/kg could be required to enhance the nonspecific immune responses and improve the resistance of juvenile parrot fish against V. anguillarum.