• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.4 no.3
• /
• pp.242-247
• /
• 2003

This paper deals with an optimal design methodology for an automatic transmission lever using a genetic algorithm. A component of an automatic transmission lever has been designed sequentially in the industry, but the study presents a new design method to consider the design parameters of components simultaneously. A genetic algorithm approach is described to determine a set of design parameters for an automatic transmission lever. We have attempted to model the design problem with the objective of minimizing the angle variation of detent spring subject to constraints such as modulus of elasticity of steel, geometry of shift pipe. and stiffness of spring. The proposed method can give the better design alternative.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.4 no.2
• /
• pp.122-129
• /
• 2001

A characterization procedure for analyzing symmetric coupled MIS(Metal-Insulator-Semiconductor) transmission line is used the same procedure as a general single layer symmetric coupled line with perfect dielectric substrate from the extraction of the characteristic impedance and propagation constant for even- and odd-mode. In this paper, an analysis for a new substrate shielding symmetric coupled MIS structure consisting of grounded crossbar at the interface between Si and SiO2 layer using the Finite- Difference Time-Domain(FDTD) method is presented. In order to reduce the substrate effects on the transmission line characteristics, a shielding structure consisting of grounded crossbar lines over time-domain signal has been examined. Symmetric coupled MIS transmission line parameters for even- and odd-mode are investigated as the functions of frequency, and the extracted distributed frequency- dependent transmission line parameters and corresponding equivalent circuit parameters as well as quality factor for the new MIS crossbar embedded structure are also presented. It is shown that the quality factor of the symmetric coupled transmission line can be improved without significant change in the characteristic impedance and effective dielectric constant.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.7 no.3
• /
• pp.567-571
• /
• 2012

To design the long-haul optical communication system, we need to decide the type of optical fiber and optical amplifier, span length of optical amplifier, dispersion compensation method, optical signal power, etc. Therefore, we need to predict the performance of optical communication system when we change one of the system parameters. In this paper, we investigate the method of predicting the maximum transmission length of the designed optical communication system and finding the optimum optical signal power to obtain the maximum transmission length.

• Journal of the Institute of Electronics Engineers of Korea SC
• /
• v.49 no.3
• /
• pp.62-68
• /
• 2012

In this paper, we propose an efficient transmission scheme for flight data. It is important to reduce amount of flight data transmitted effectively for timely transmission in airplane that the safety is very importantly recognized. Thus, this paper shows the improved technique transmitting after compressing flight data by the lossless compression technique. Because the proposed method improves the transmission speed of the flight data effectively. The processing of flight data and handling can be easily performed in the time to be restricted. The simulation results show that the proposed scheme achieves 25% data transfer gain compared to the ARINC 429 based transmission method.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.31 no.9A
• /
• pp.878-883
• /
• 2006

New emerging wireless broadband internet can make many broadband multimedia services. The networked intelligent mobile robot service is one of the new services. In the networked robot control, both the on-line real-time control and the reliability of control data transmission are very important. Considering the real-time control and data reliability, an efficient transmission method based on UDP protocol is proposed. The proposed method allocates the priority to the robot control data and the transmission of the robot data at the base station is carried out in duplicate manner. NS-2 simulation results show that the proposed scheme has a very low packet delay and low packet errors.

• KEPCO Journal on Electric Power and Energy
• /
• v.1 no.1
• /
• pp.85-91
• /
• 2015

We investigated the structure of inductive coupler and its magnetic coupling to increase the transmission coefficient for power line communication. A Rogowski coil, which is an air-cored inductive coupler, and a magnetic cored coupler were fabricated to analyze the transmission coefficient for different coupler parameters. This paper proposes the impedance matching method using lumped elements and an impedance transformer to increase the transmission coefficient. In the experiment, the transmission coefficient of the proposed system was increased in both narrowband and broadband cases, and a trade-off between the transmission coefficient and the bandwidth was shown. This method will be useful for the further study of impedance matching with the load variation.

• Journal of Electrical Engineering and Technology
• /
• v.7 no.6
• /
• pp.814-823
• /
• 2012

Electric power transmission utilities make an effort to maximize profit by reducing their electricity supply and operation costs while maintaining their reliability. The development of maintenance strategies for aged components is one of the more effective ways to achieve this goal. The reliability centered approach is a key method in providing optimal maintenance strategies. It considers the tradeoffs between the upfront maintenance costs and the potential costs incurred by reliability losses. This paper discusses the application of the Particle Swarm Optimization (PSO) technique used to find the optimal maintenance strategy for a transmission component in order to achieve the minimum total expected cost composed of Generation Cost (GC), Maintenance Cost (MC), Repair Cost (RC) and Outage Cost (OC). Three components of a transmission system are considered: overhead lines, underground cables and insulators are considered. In regards to aged and aging component, a component state model that uses a modified Markov chain is proposed. A simulation has been performed on an IEEE 9-bus system. The results from this simulation are quite encouraging, and then the proposed approach will be useful in practical maintenance scheduling.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.18 no.12
• /
• pp.1262-1269
• /
• 2008

Though multilayered foam-panel structures have been widely used to reduce sound transmission in various fields, most of the previous works to design them were conducted by repeated analyses or experiments based on initially given configurations or sequences. Therefore, it was difficult to obtain an optimal sequence of multilayered foam-panel structure yielding superior sound isolation capability. In this work, we propose a new design method to sequence a multi-panel structure lined with a poroelastic material having maximized sound transmission loss. Being formulated as a one-dimensional topology optimization problem fur a given target frequency, the optimal sequencing of panel-poroelastic layers is systematically carried out in an iterative manner. In this method, a panel layer is expressed as a limiting case of a poroelastic layer to facilitate the optimization process. This means that main material properties of a poroelastic material are treated as interpolated functions of design variable. The designed sequences of panel-poroelastic multilayer were shown to be significantly affected by the target frequencies; more panels were obtained at higher target frequency. The sound transmission loss of the system was calculated by the transfer matrix derived from Biot's theory.

• Journal of Korea Multimedia Society
• /
• v.3 no.3
• /
• pp.234-240
• /
• 2000

In this paper, we propose the method in which a stream of multimedia data simultaneously transfers to the main memory and the multimedia processor from the network interface card using a conventional system bus. The proposed method can reduce the input/output time of multimedia data and improve the data stream in the system bus. Also, we compared the number of system bus accesses, bus cycles and data transmission time to the number of participants between the proposed method and the conventional methods in the multi-party video conference systems. The comparison results of performance anticipate that the number of bus accesses of the proposed method was reduced by 50%, and the total transmission time was reduced by 75% as much as the conventional method regardless of the relation of the participant numbers.

• Journal of Pharmaceutical Investigation
• /
• v.39 no.2
• /
• pp.93-95
• /
• 2009

To compare the water vapor transmission rate (WVTR) of PVA/Dextran blended hydrogel obtained by European Pharmacopiea (EP) and Japanese Industrial Standards 1099 (JIS) method, the hydrogels with various PVA/Dextran rates were prepared and their WVTR values were then checked. As dextran in the hydrogel was increased, the WVTR of hydrogel was increased. The WVTR of hydrogels were 660-1500 and $730-1900\;g/m^2$-day in EP and JIS method, respectively. There were no significant differences between the WVTRs of the hydrogels obtained by EP and those obtained by JIS method. Thus, JIS method was recommended as a WVTR method of hydrogel due to relatively simpler and shorter time.