• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2007.10a
• /
• pp.209-214
• /
• 2007

This study is concerned with working hardening of bending operation on hydroforming parts. Generally, hydroforming parts having the complicated shape of the automobile, require a 3-dimentional bending operation. This operation involves several variations in the tube which are the thickness, the mechanical characteristics, the hardness, the circumference etc., on original tube. So, we study those variations and the affect on the hydroforming operation and hydroforming parts. We used two methods, one of which was computer simulation and the other the actual test in the plant.

• Nuclear Engineering and Technology
• /
• v.35 no.4
• /
• pp.261-273
• /
• 2003

The characteristics of the recirculation operation of LMR which are different from the conventional plants such as PWR and fossil fuel plants were investigated using a computer code TSGS developed in this study. For simulating the transient behavior of the steam generation system, a water level control algorithm utilizing digital control hardware features was introduced. By investigation, the function of the recirculation operation was defined, the major features of the operation were found. Also good performance of the level control algorithm was confirmed.

• International Journal of Advanced Culture Technology
• /
• v.10 no.4
• /
• pp.487-498
• /
• 2022

This study aims to determine the importance of each factor considered when operating a rotorcraft in a city. After identifying factors that could affect urban air mobility, we reviewed the influencing factors by applying an analytic hierarchy process (AHP). Level 1 classifies the essential factors of the urban operation of rotorcraft in nominal and off-nominal situations. The factors corresponding to the characteristics of each were composed of lower levels, such as Levels 2 and 3. Using this, the importance of influencing factors was analyzed and the most important factors were determined. The most influential factors of the urban operation of rotorcraft included engine failure, fire situations, and vehicle safety. Accordingly, an environment that can guarantee safe operation by considering the most influential factors in advance in an actual operation stage must be constructed.

• Proceedings of the KIEE Conference
• /
• 2002.07b
• /
• pp.1100-1102
• /
• 2002

In this paper, resonant characteri-sties of the asymmetrical soft switching half bridge converter is analyzed. The operation principle for proposed converter is explained in steady-state and its operation characteristics by switching frequency is presented with experimental result. Experimental results carried out on a system prototype are included in this paper.

• Proceedings of the KIEE Conference
• /
• 1995.07c
• /
• pp.1271-1274
• /
• 1995

In this paper, design feature and operation characteristics of compact Ruby laser for plasma diagonostics are described. A linear Xe flashlamp and a single elliptical cavity are adopted as optical pumping system. With charging energy of 484J, the maximum output energy of 170mJ, laser pulse width $110{\mu}s$, and slope efficiency 0.09% were obtained. If Q-switch system is added to this laser, we suppose this laser will be quite enough for diagonizing plasma.

• ETRI Journal
• /
• v.31 no.5
• /
• pp.506-509
• /
• 2009

A novel design of a compact square-ring slot microstrip antenna for achieving circular polarization (CP) operation is proposed and experimentally studied. By using an arrow-shaped slot structure as a radiating element, the resonant frequency of the proposed antenna is significantly lowered, which can lead to a large size reduction for fixed frequency operation. The CP radiation characteristics are achieved by loading with proper asymmetry, which can be placed diagonally. A prototype of the proposed design is implemented and its performance is measured. Measured results show that radiation patterns with good CP characteristics are obtained at the resonant frequency.

• Journal of the Korea Safety Management & Science
• /
• v.5 no.1
• /
• pp.1-12
• /
• 2003

In this paper, computer simulation was used for researching into the estimate of flash over result from compartment fire and the characteristics operation of sprinkler RTI. Computing simulation, we analyzed and verified the path of the flame in compartment fire and the adaptation of sprinkler system concerned with sprinkler RTI.

• Journal of the Korean Institute of Telematics and Electronics B
• /
• v.29B no.1
• /
• pp.67-75
• /
• 1992

A new method of driving the PDP(Plasma Display Panel) was proposed and its characteristics were investigated. Applying high frequency non-discharge pulses to an auxiliary anode resulted an increased region of stable operation, decreased delay time and increased light intensity. It is suggested that PDP with DPM (Double Pulse Memory) drive technique improves the delay time, luminance, region of stable operation and luminous efficacy compared to PDP with PPM(Planar Pulse Memory) drive technique developed by NHK Lab. in Japan.

• Proceedings of the KIEE Conference
• /
• 2003.07b
• /
• pp.1157-1159
• /
• 2003

In this paper, resonant characteristics of the asymmetrical soft switching half bridge converter is analyzed. The operation principle for proposed converter is explained in steady-state and its operation characteristics by switching frequency is presented with experimental result. Experimental results carried out on a system prototype are included in this paper.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.15 no.1
• /
• pp.38-48
• /
• 2007

this paper analyses how much acceleration and deceleration of urban rail vehicle should be applied and how to choose an operation mode to minimize energy consumption when train runs between stations within the fixed operation time. The decided operation pattern satisfying the minimum energy consumption becomes a target trajectory and a basis for the controller design criteria. To make this goal it grasps the characteristics of urban rail vehicle, realize operation energy model of urban rail vehicle and verity the accuracy of embodied model the Matlab simulation with the same operation result of real route. It searches for operation pattern to minimize operation energy by changing the acceleration and deceleration on the imaginative route and proposes operation pattern minimizing energy consumption by applying real operation data between stations of Seoul Metropolitan Subway Line 6.