• Journal of Engineering Education Research
• /
• v.11 no.1
• /
• pp.85-100
• /
• 2008

The purpose of this study is development of 'F1 in Schools Program' for elementary school student and validation of the program. Fifteen students were originally chosen from the W elementary school in Cheongju, Chungcheogbuk-Do. The children were tested on their understanding of science and 'F1 in Schools Program'. After developing the 'F1 in Schools Program', it was used in the classroom to evaluate applicability and to examine the responses from students, parents and schools. The program consists of 60 classes and the time of each class is 40 minutes. This study was conducted for 10 days from January 22nd, 2007 to February 2nd, 2007. CAD(Computer Aided Design), CFD(Computation Fluid Dynamics), CAM(Computer Aided manufacturing) and CNC Machine were used in this study and proved to be good materials for students in that they increased the students' participation and imagination. However, the children's cognitive and creative abilities as well as manuals written in English hampered the process. Most students, parents, schools seemed to be satisfied with use of the program. However, the schools showed that there was not enough understanding of the program as a whole. The processes with which students build and inspect using the $CO_2$Model Car not only improves the processing of the model but also enhanced the students scientific understanding related to the car speed.

• Transactions of the Korean hydrogen and new energy society
• /
• v.20 no.1
• /
• pp.9-21
• /
• 2009

As one of the alternative solution for energy and environmental issues such as climate change, energy security, oil price, etc., hydrogen energy has been getting so much attentions these days. This paper analyzed the $CO_2$ emission, costs, and energy consumptions when the hydrogen energy was introduced to transportation, specifically in Sedan sector using the energy system model, MARKAL. As results, 21.5% of $CO_2$ emission in 2040 could be reduced and additional 76 billion dollars will be needed in the high energy price scenario. The amount of energy saving mainly due to the replacement of existing car to hydrogen vehicle was 16% of the final energy consumption in 2040.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.10 no.5
• /
• pp.113-123
• /
• 2011

Recently, the global warming problem has arised around world, many nations has set up a various regulations for decreasing $CO_2$. In particular, $CO_2$ emissions reduction effect is very powerful in transport part, so there is a rising interest about development of green car, or electric vehicle in auto industry. For this reason, it is important to make a strategy for charging infra and forcast electric power demand, but it hasn't introduced about demand forecasting electric vehicle. Thus, this paper presents a demand forecasting for electric vehicles using choice based multigeneration diffusion model. In this paper, it estimates innovation coefficient, immitation coefficient in Bass model by using hybrid car market data and forecast electric vehicle market by year using potential demand market through SP(Stated Preference) experiment. Also, It facilitates more accurate demand forecasting electric vehicle market refelcting multigeneration diffusion model in accordance with attribute progress in development of electric vehicle. Through demand forecasting methodology in this paper, it can be utilized power supply and building a charging infra in the future.

• Korean System Dynamics Review
• /
• v.12 no.1
• /
• pp.75-87
• /
• 2011

Congestion problems can be approached from the viewpoint of system dynamics theory. The relationship between road capacity and congestion can be explained by the 'relative control' archetype among four system archetypes suggested by Wolstenholme. There is a balancing feedback loop between road capacity and road congestion. However, there is another balancing loop between road congestion and car traffic volume, which keeps disrupting the equilibrium of the former loop. A system dynamics model, which is based on a partial adjustment model of induced traffic in the literature, is built to simulate three road building scenarios: 'Expanding investment', 'Balancing investment' and 'Frozen road investment' scenarios. The 'Expanding investment' scenario manages to drop congestion levels by 9% over 30 years, however, causing much higher emissions of $CO_2$ than other scenarios. The trade-off relationship between congestion levels and environmental costs must be taken into consideration for road investment policies.

• IMMUNE NETWORK
• /
• v.7 no.4
• /
• pp.179-185
• /
• 2007

Background: Adenovirus (Ad) vectors have been widely used for many gene therapy applications because of their high transduction ability and broad tropism. However, their utility for cancer gene therapy is limited by their poor transduction into cancer cells lacking the primary receptor, coxsackievirus and adenovirus receptor (CAR). Methods: To achieve CAR-independent gene transfer via Ad, we pretreated Ad with 1,2-dioleoyl-3-trimethylammonium propane (DOTAP) and analyzed their transduction efficiency into cancer cells in vitro and in vivo comparing with the virus alone. Results: Treatment of DOTAP significantly increased adenoviral gene transfer in tumor cells in vitro. Moreover, DOTAP at an optimum dose $(10{\mu}g/ml)$ enhanced IL-12 transgene expression by fivefold in tumor, and twofold in serum after intratumoral injection of adenovirus expressing IL-12N220L (Ad/IL-12N220L). In addition, cotreatment of DOTAP decreased tumor growth rate in the Ad/IL-12N220L-transduced tumor model, finally leading to enhanced survival rate. Conclusion: Our results strongly suggest that DOTAP could be of great utility for improving adenovirus-mediated cancer gene therapy.

• Transactions of The Korea Fluid Power Systems Society
• /
• v.7 no.2
• /
• pp.7-12
• /
• 2010

In these days, the researches about hybrid and fuel cell electric vehicles are actively performed due to the environmental contamination and resource exhaust. Specially, the technology of regenerative braking, converting heat energy to electric energy, is one of the most effective technologies to improve fuel economy. This paper developed a regenerative braking control algorithm that is considered vehicle stability. The vehicle has a inline motor at front drive shaft and has a EHB(Electo-hydraulic Brake) system. The control logic and regenerative braking control algorithm are analyzed by MATLAB/Simulink. The vehicle model is carried out by CarSim and the driving simulation is performed by using co-simulation of CarSim and MATLAB/Simulink. From the simulation results, a regenerative braking control algorithm is verified to improve the vehicle stability as well as fuel economy.

• Design & Manufacturing
• /
• v.16 no.2
• /
• pp.46-52
• /
• 2022

As the consumer market in the eco-friendly vehicle industry grows, the demand for water pump in a electric car parts market. This study intend to propose a mathematical model that can verify the effect of improving thermal properties when a non-conductive cooling filler liquid is introduced into an electric vehicle water pump. Also, the pros and cons of the immersion cooling method and future development way were suggested by analyzing the cooling characteristics using on the derived analysis solution. Thermal characteristics analysis of electric water pump applied with non-conductive filler liquid was carried out, and the diffusion boundary condition in the motor body and the boundary condition the inside pump were expressed as a geometric model. As a result of analyzing the temperature change for the heat source of the natural convection method and the heat conduction method, the natural convection method has difficulty in dissipating heat because no decrease in temperature due to heat release was found even after 300 sec. Also, it can be seen that the heat dissipation effect was obtained even though the non-conductive filling liquid was applied at the 120 sec and 180 sec in the heat conduction method. It has proposed to minimize thermal embrittlement and lower motor torque by injecting a non-conductive filler liquid into the motor body and designing a partition wall thickness of 2.5 mm or less.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.21 no.6
• /
• pp.729-736
• /
• 2015

In this paper, It was performed to optimize for the deck's structural design of a double ended car ferry ship respect to Goal-Driven Optimization (GDO). It was examined for the strength and deformation of the deck and determined to save economic cost the optimal point. The deck thickness based on the Design of Experiments (DOE) and response surface method was increased to 110%. and can improve the deck's strength and stiffness. By performing the regression analysis respect to the result, we propose the optimal regression model formula as a third degree polynomial regression models. The coefficient of determination $R^2$ was about 0.98 and reliability could be obtained.

• Proceedings of the KSR Conference
• /
• 2007.05a
• /
• pp.1807-1813
• /
• 2007

The study aims at analyzing an underground station refuge model using EXODUS, one of the refuge simulation programs. The model for simulation is the Daegu Subway (Joongang-ro station). The details of the accident are referred to as the simulation condition the refuge time of traveling from the $3^{rd}$ basement platform to the $1^{st}$ basement is mainly calculated, with passengers numbering 1,000 including 329 at car 1079, 320 at car 1080, and 360 who are not on board. Reference data is used to set up the position of passengers. CFAST fire simulator is also used, and a fast curve among the $t^2$ growth curves, selected as fire growth scenario. The zone is divided into a total of 24 including 18 at the $3^{rd}$ basement platform and 6 at the $2^{nd}$ basement the $1^{st}$ basement is excluded in the fire simulation, however.

• International Journal of Automotive Technology
• /
• v.2 no.2
• /
• pp.53-62
• /
• 2001

The combination of physical models of an advanced engine control system was proposed to obtain sophisticated combustion control in ultra-lean combustion, including homogeneous compression-ignition and activated radical combustion with a light load and in stoichiometric mixture combustion with a full load. Physical models of intake, combustion and engine thermodynamics were incorporated, in which the effects of residual gas from prior cycles on intake air mass and combustion were taken into consideration. The combined control of compression ignition at a light load and sparit ignition at full load for a high compession ratio engine was investigated using simulations. The control strategies of the variable valve timing and the intake pressure were clarified to keep auto-ignition at a light load and prevent knock at a full load.