Keizan, South Korea
Keizan, South Korea

Time filter

Source Type

Suh B.,University of California at Davis | Chang Y.H.,Induk University | Han S.B.,Induk University | Chung Y.J.,Daegu Future College
International Journal of Automotive Technology | Year: 2012

The plug-in hybrid electric bus (HEB) is designed to overcome the vulnerable driving range and performance limitations of a purely electric vehicle (EV) and have an improved fuel economy and lower exhaust emissions than those of a conventional bus and convention HEBs. The control strategy of the plug-in parallel HEB's complicated connected propulsion system is one of the most significant factors for achieving a higher fuel economy and lower exhaust emissions than those of the HEV. The proposed powertrain control strategy has flexibility in adapting to the battery's state of charge (SOC), exhaust emissions, classified driving patterns, driving conditions, and engine temperature. Simulation is required to model hybrid powertrain systems and test and develop powertrain control strategies for the plug-in parallel HEB. This paper describes the simulation analysis tools, powertrain components' models and modifications, simulation procedure, and simulation results. © 2012 The Korean Society of Automotive Engineers and Springer-Verlag Berlin Heidelberg.


Suh B.,University of California at Davis | Frank A.,University of California at Davis | Chung Y.J.,Daegu Future College | Lee E.Y.,Kunsan National University | And 2 more authors.
International Journal of Automotive Technology | Year: 2011

This research concerns the design of a powertrain system for a plug-in parallel diesel hybrid electric bus equipped with a continuously variable transmission (CVT) and presents a new design paradigm for the plug-in hybrid electric bus (HEB). The criteria and method for selecting and sizing powertrain components equipped in the plug-in HEB are presented. The plug-in HEB is designed to overcome the vulnerable limitations of driving range and performance of a purely electric vehicle (EV), and it is also designed to improve the fuel economy and exhaust emissions of conventional buses and conventional HEBs. Optimization of the control strategy for the complicated and interconnected propulsion system in the plug-in parallel HEB is one of the most significant factors for achieving higher fuel economy and lower exhaust emissions in the hybrid electric vehicle (HEV). In this research, the proposed control strategy was simulated to prove its validity using the ADVISOR (advanced vehicle simulator) analysis simulation tool. © 2011 The Korean Society of Automotive Engineers and Springer-Verlag Berlin Heidelberg.


Suh B.,University of California at Davis | Frank A.,University of California at Davis | Chung Y.J.,Daegu Future College | Lee E.Y.,Kunsan National University | And 2 more authors.
International Journal of Automotive Technology | Year: 2010

This research is the first to develop a design for a powertain system of a plug-in parallel diesel hybrid electric bus equipped with a continuously variable transmission (CVT) and presents a new design paradigm of the plug-in hybrid electric bus (HEB). The criteria and method for selecting and sizing powertrain components equipped in the plug-in HEB are presented. The plug-in HEB is designed to overcome the vulnerable limitations of driving range and performance of a purely electric vehicle (EV) and to improve fuel economy and exhaust emissions of conventional bus and conventional HEBs. The control strategy of the complicated connected propulsion system in the plug-in parallel HEB is one of the most significant factors in achieving higher fuel economy and lower exhaust emissions of the HEV. In this research, a new optimal control strategy concept is proposed against existing rule-based control strategies. The optimal powertrain control strategy is obtained through two steps of optimizations: tradeoff optimization for emission control and energy flow optimization based on the instantaneous optimization technique. The proposed powertrain control strategy has the flexibility to adapt to battery SOC, exhaust emission amount, classified driving pattern, driving condition, and engine temperature. The objective of the optimal control strategy is to optimize the fuel consumption, electricity use, and exhaust emissions proper to the performance targets. The proposed control strategy was simulated to prove its validity by using analysis simulation tool ADVISOR (advanced vehicle simulator). © 2010 The Korean Society of Automotive Engineers and Springer-Verlag Berlin Heidelberg.


Han S.B.,Induk University | Chang Y.H.,Induk University | Lee E.Y.,Kunsan National University | Chung Y.J.,Daegu Future College | Suh B.,University of California at Davis
International Journal of Automotive Technology | Year: 2010

Hybrids combine a combustion engine with an electric motor and battery. The two technologies can be combined to reduce fuel consumption and exhaust emissions. This paper presents the concept of hybrid electric vehicles (HEVs) applied to truck or van vehicles with diesel engines. The simulation results from the advanced vehicle simulator (ADVISOR) demonstrate that the required power may be properly shared between the internal combustion engine and electric motor. The simulation can also be used to prove that the technique is useful for improvements in driving performance; additionally, the technique is suitable for hybrid electric vehicles, allowing for good fuel economy and low emissions performance. © 2010 The Korean Society of Automotive Engineers and Springer-Verlag Berlin Heidelberg.


Choi G.H.,EROOM G and G Co. | Lee J.C.,Keimyung University | Kwon T.Y.,Keimyung University | Ha C.U.,Daedong Co. | And 4 more authors.
Journal of Mechanical Science and Technology | Year: 2010

A numerical model that utilizes Computational Fluid Dynamics (CFD) techniques is simulated for the analysis of a swirl chamber type diesel engine. This research also reveals the effects of swirl chamber passage hole geometry on the combustion characteristics of a swirl chamber type diesel engine depending on the shape, angle, and area of the jet passage. Turbulence kinetic energy is generated by compound effects of the pressure, heat release, NOx concentrations, and soot concentrations. Results show that combustion characteristics are affected by the passage hole areas and the passage hole inclination angles. © KSME & Springer 2009.


Kim H.-Y.,Seoul Regional Korea Food and Drug Administration | Oh S.-W.,Seoul Regional Korea Food and Drug Administration | Chung S.-Y.,Seoul Regional Korea Food and Drug Administration | Choi S.-H.,Seoul Regional Korea Food and Drug Administration | And 8 more authors.
Korean Journal of Food Science and Technology | Year: 2011

This study was carried out to examine microbiological contamination of ready-to-eat products and to propose a draft-standard and specifications according to food types. RTE foods were classified into 6 groups including fish products, meat products, breads, rices, salads, and fresh cut foods. The prevalence rates of pathogens detected from all samples were compared among food categories. The pH ranges for all RTE samples were between 3.8 and 7.3. Total aerobic cell counts ranged from 2 to 6 log CFU/g. Bread, rice and fresh-cut foods showed significantly higher counts, which ranged above 4.0 log CFU/g among the samples. Two kinds of rice were above the level of the KFDA Food Code standard for Eschrichia coli. The prevalence rate of E. coli in the rice was 6.7%. For Staphylococcus aureus, one fish product and one bread-product had levels above 2 log CFU/g. Bacillus cereus counts for all samples were below the level of 3 log CFU/g. Listeria monocytogenes was not detected in the samples. Therefore, these data suggest that the primary microbial hazard factors for ready-to-eat foods and risk assessments should focus on E. coli, S. aureus, and B. cereus. © The Korean Society of Food Science and Technology.


Bai S.-E.,Yeungnam University | Shim J.-S.,Yeungnam University | Lee C.-H.,Yeungnam University | Bai C.-H.,Yeungnam University | Shin K.-Y.,Daegu Future College
Japanese Journal of Applied Physics | Year: 2014

In this study, experiments on liquid transfer were performed to observe the change of the surface contact angle with respect to the process speed. The liquid transfer ratio from the experiments was compared with that from numerical simulation for low speed ranges. While the surface contact angle on the lower plate was almost constant in the experiment regardless of operating speed, the surface contact angle on the upper plate was found to be significantly changed during the process at the low speed ranges. This resulted in a reduction of the transfer ratio. By applying the timedependent values of contact angle to the numerical simulation model, the transfer ratio showed better agreement with the experimental results. The dynamic effect of surface contact angle should be considered as an additional variable, especially for the analysis of liquid transfer in a low speed printing process. © 2014 The Japan Society of Applied Physics.


Yun S.-C.,Daegu Future College | Kim J.-W.,Yeungnam University
Metals and Materials International | Year: 2010

In the manufacture of high-quality welds or pipeline, a full-penetration weld has to be made along the weld joint. Therefore, root-pass welding is very important, and its conditions have to be selected carefully. In this study, an experimental method for the selection of optimal welding conditions is proposed for gas tungsten arc (GTA) pulse welding in the root pass which is done along the V-grooved butt-weld joint. This method uses response surface analysis in which the width and height of back bead are chosen as quality variables of the weld. The overall desirability function, which is the combined desirability function for the two quality variables, is used as the objective function to obtain the optimal welding conditions. In our experiments, the target values of back bead width and height are 4 mm and zero, respectively, for a V-grooved butt- weld joint of a 7-mm-thick steel plate. The optimal welding conditions could determine the back bead profile (bead width and height) as 4.012 mm and 0.02 mm. From a series of welding tests, it was revealed that a uniform and full-penetration weld bead can be obtained by adopting the optimal welding conditions determined according to the proposed method. © KIM and Springer.


Leem I.,Daegu Future College | Wu M.,Yeungnam University | Kim C.,Daegu Future College
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2012

TDMA-based MAC protocols have been discussed in WSNs for their energy-efficient performance. Clustering is an effective method for achieving good energy efficiency and flexible scalability, and is often combined with TDMA-based schemes to reduce the cost of idle listening. But conventional TDMA protocols focus on effective intra-cluster communications. The methods don't consider collisions occurring among inter-clusters in WSNs that is extensible to hundreds of thousands of nodes. This paper proposes a TDMA based MAC protocol and a resource allocation algorithm for avoiding inter-cluster collisions among clusters. © 2012 Springer-Verlag.


PubMed | Daegu Future College
Type: Journal Article | Journal: Toxicological research | Year: 2013

To evaluate the whitening effect of black tea water extract (BT), BT was topically applied to artificially hyperpigmented spots on the back skins of brown guinea-pigs (weight: 450~500 g) induced by 1,500 mJ/ cm(2) of ultraviolet B (UVB) irradiation. The test compounds of 30 l were applied twice a day, six days a week, for four weeks. The artificially hyperpigmented spots were divided into 5 groups: control (UVB + saline, C), vehicle control [UVB + propylene glycol: ethanol: water (5 : 3 : 2), VC], positive control (UVB + 2% hydroquinone, PC), experimental 1 (UVB + 1% BT), experimental 2 (UVB + 2% BT). After 4-week application, the spots were removed by biopsy punch under anesthetic condition and used as specimens for the histological examination. The total polyphenol and flavonoid contents of BT were 104 and 91 mg/g, respectively. The electron-donating ability of BT revealed a dose-dependent response, showing the excellent capacities of 86% at 800 g/ml. The artificially hyperpigmented spots treated with the PC and BT were obviously lightened compared to the C and VC groups. At the fourth week, the melanin indices for the PC and BT groups were significantly lower (p < 0.00l) than those of the C and VC groups. In histological examination, PC and BT groups were significantly reduced in the melanin pigmentation, the proliferation of melanocytes and the synthesis of melanosomes compared to the C and VC groups. It is found that BT inhibits the proliferation of melanocytes and synthesis of melanosomes in vivo using brown guinea pigs, thereby showing a definite skin whitening effect.

Loading Daegu Future College collaborators
Loading Daegu Future College collaborators