• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.676-678
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• 2003

Recently, in according as rapid improvement of telecommunication markets and wireless internet technology, Location- Based Services (LBS) have been discussed as new 'Killer' application. The purpose of LBS is to determine location of user through mobile handset and to offer location information service to end-user. This paper has suggested an efficient transmission scheme of maps data as one of the important content services relating to data transmission of LBS in mobile environment. The basic system consists of three parts : (1) GIS (Geographic Information System) Server for storing, processing and handling map data, (2) Middleware Server for transmitting of map data by request of client, and (3) Client for requesting map data to Server and displaying them on handset. Also, in order to transmit map data, we are to expand WKB (Well Known Binary) in conformance to Simple Feature Specification of OGC (Open GIS Consortium), and increase efficiency of data transmission by developing trans mission data format to be able to transmit lightweight data and considering data compression technology.

• Journal of Power System Engineering
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• v.5 no.4
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• pp.90-96
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• 2001

In this study, a robust controller to control pressure in a pneumatic pressure vessel considering dynamic characteristics of pneumatic transmission line is proposed. Dynamic characteristics of transmission line using compressible fluid is changed by the flowing states of the fluid. So, if the fixed gain controller is designed based on a fixed model, the performance of the control system could be destabilized or degraded. The controller designed in this study is composed of two parts. The one is to reject modelling error based on the disturbance observer, the other is to obtain the control performance. The control results with the designed controller show that the robustness of the control system is achieved regardless of the change of the model of the transmission line. Therefore, the designed controller can be utilized for the performance improvement of the pressure control system using compressible fluid such as air and gas

• Proceedings of the KIEE Conference
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• 2002.11b
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• pp.375-377
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• 2002

In many parts of the world. the electricity industry is undergoing unprecedented changes. Hence, in order to reform the electricity industry readily and efficiently and minimize the confusion by these restructuring, it is required the systematic studies related to transmission pricing and transmission cost allocation issues. However, even now the basis of transmission cost allocation rate is not equipped so that the regulation body has determined the allocating rate under the common practice. In this paper it is demonstrated that the decision of transmission cost allocation rate is the regulation body's own right. For the analysis, game theory is applied to the procedure determining this rate and the competition to determine this rate between generators and distributors is modeled as the arbitration game.

• Journal of Ubiquitous Convergence Technology
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• v.1 no.1
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• pp.35-41
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• 2007

In mobile ad-hoc wireless networks, one of the most important challenging issues is how to conserve energy, maximizing the lifetime of route(networks) in the view points of both power and mobility of nodes. However, many transmission methods presented in the previous works can not satisfy these two objectives simultaneously. To obtain these two goals, in this paper we propose an architecture to support power saving transmission services with route stability in mobile ad-hoc wireless networks. The proposed architecture consists of two parts, the underlying route stability method to support route(network) lifetime and the power saving transmission methods. The performance evaluation of the proposed architecture is achieved via simulation and analysis.

• Journal of Welding and Joining
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• v.29 no.6
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• pp.45-48
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• 2011

In this research, laser welding of automotive transmission components was investigated to replace electron beam welding which is normally conducted under vacuum condition. Fiber laser welding was applied to the automotive transmission components - hub clutch and annulus gear. In the component welding, the laser welding parameters were optimized to eliminate spatters and the end crater. By applying laser welding to the transmission parts, the process time could be reduced up to 70% compared with the current electron beam welding process.

• Journal of the Semiconductor & Display Technology
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• v.18 no.1
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• pp.21-24
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• 2019

In this paper, 5.8GHz 25W microwave wireless power transmission system was developed. The transmission system is composed of a signal generator, a 1W drive amplifier, a 25W power amplifier, and a circularly polarized transmission antenna. The receiving system was fabricated with an integrated receiver that combines a circularly polarized receiving antenna, a pass band filter, and an RF-DC converter. And a multi-integrated receiver had twelve parts, including an integrated receiver. Under the conditions, voltage and current were measured for the system at 5cm intervals from a minimum distance of 5cm to a maximum distance of 80cm. The power was calculated for the system. The results of the system are shown in tables and graphs. The power decreases with distance, but the power does not drop sharply due to a multi-integrated receiver.

• International journal of advanced smart convergence
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• v.11 no.3
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• pp.215-221
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• 2022

In the manufacturing process of the bus treated as the commercial vehicle, after making the bare chassis which is the basic frame of the vehicle body, the part in which passengers ride is connected. In addition, the necessary parts such as the engine and transmission required for the operation of the bus are connected to the bare chassis. The element connecting the parts such as the boarding part of the passengers, the engine, the suspension and the transmission is the bracket. The device required for driving and operating the vehicle is mounted on the bare chassis using the bracket, which should ensure stability during bus operation. In this study, we were performed stress analysis to evaluate the stability of three types of brackets connecting the bare chassis of a new type of 30-seater bus in the development process and components required for driving and operation. The stress analysis should be preceded by the analysis of boundary conditions considering the loads applied to the brackets according to the material of the bracket to be analyzed and the driving type of the bus. The finite element model for structural analysis of brackets according to the driving type of the bus was used by Altair's Hypermesh 2017, and the solver used for structural analysis was Altair's Optistruct. The stress analysis was performed to present the safe and vulnerable parts of the three brackets.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.52 no.10
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• pp.602-609
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• 2003

This paper describes the fault location calculation using neuro-fuzzy systems in combined transmission lines with underground power cables. Neuro-fuzzy systems used in this paper are composed of two parts for fault section and fault location. First, neuro-fuzzy system discriminates the fault section between overhead and underground with normalized detail coefficient obtained by wavelet transform. Normalized detail coefficients of voltage and current in half cycle information are used for the inputs of neuro-fuzzy system. As the result of neuro-fuzzy system for fault section, impedance of selected fault section is calculated and it is used as the inputs of the neuro-fuzzy systems for fault location. Neuro-fuzzy systems for fault location also consist of two parts. One calculates the fault location of overhead, and the other does for underground. Fault section is completely classified and neuro-fuzzy system for fault location calculates the distance from the relaying point. Neuro-fuzzy systems proposed in this paper shows the excellent results of fault section and fault location.

• Tribology and Lubricants
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• v.40 no.1
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• pp.24-27
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• 2024

A monotype valve body for a dual clutch transmission has the potential to reduce costs, weight, and manufacturing time by modularizing various parts, including those of existing solenoid packs and valve bodies, into one through the application of super-precision die casting technology. However, this approach may lead to challenges such as reduced rigidity and increased interference due to modularization and compactness, impacting both product performance due to the reduced weight as well as durability and reliability. Unlike existing products, this approach requires a high-precision thin-wall block to avoid more complicated flow line formation, interference between flow lines, and leaks, as well as a strict quality requirement standard and precise inspections including detection of internal defects. To conduct precise inspections, we built an equivalent model corresponding to a driving distance of 300,000 km. Testing involved simulating actual road loads using a real vehicle and a chassis dynamometer in the FTP-75 mode (EPA Federal Test Procedure). The aim of the study was to establish a vehicle load-based part durability model for manufacturing a mono-type valve body and to develop fundamental technology for part weight reduction through preliminary design by introducing analytical weight reduction technology based on the derived results.

• Journal of Welding and Joining
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• v.28 no.3
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• pp.9-14
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• 2010