• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.178.2-178
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• 2001

Today, many electronic devices and ECUs (Electronic Control Units) are used in the automotive body control systems. It becomes more common that these devices exchange data with others through an in-vehicle network. Automobile manufacturers concentrate their efforts on development of body control systems based on networks in order to save cost and to increase flexibility and safety. OSEK/VDX has been founded as a joint project in German and French automotive industry aiming at an industry standard for an open-ended architecture for distributed control units in vehicles OSEK/VDX consists of Communication (specification of data exchange within and between control units), Network Management specification of Configuration determination and monitoring and Operating System (specification of realtime executive for ECU software ...

• 제어로봇시스템학회:학술대회논문집
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• 1991.10a
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• pp.917-921
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• 1991

Hydraulic fitting impulse tester is equipment which produce impulse pressure waveform that specified foreign standard of SAE, JIS etc. Test conditions of SAE J1453 about waveform standard indicates frequency of 35-70 cycle/min, pressure of 560 bar, oil temperature of 93 .+-.3.deg. C etc. and required cycle is a million over. In additions, Test condition operated continuously equipment. This development item adopted new pattern method such as intensifier and rotary distributor is different from already established fitting impulse tester applied servo valve and high pressure direct directional control valve. Therefore, this development item which compares already established item is good reliability, low cost of manufacture and save of electric energy. especially, Domestic small and medium enterprise uses this tester because of economical cause. We develope appropriateness tester which conforms to demand of user.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.11 no.5
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• pp.99-103
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• 2012

Presently, A glass is widely used in telecommunication system, optoelectronic devices and micro electro mechanical systems. Micro drilling of glass using the laser can save processing cost and improve the accuracy. This paper experiments micro drilling using KrF excimer laser on the pyrex glass of $500{\mu}m$ thickness. We have experiment to find out optimum laser machining conditions of micro drilling of glass and ablation depth and influence by processing parameter suc'h pulse repetition rate, energy density and number of pulses. Pulse repetition rate don't influence ablation depth at the micro drilling of pyrex glass. Energy density influence micro drilling of parallelism and maximum thickness that can be drilled. Ablation depth is most influenced by number of pulses.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.20 no.1
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• pp.60-66
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• 2011

In this paper, the computer simulation analyzed the effective plastic strain and temperature behaviors. The quantitative analyses which proposed the effective mold design of S/CAM shaft was executed. The parameters of forging shape that affected on the optimize conditions that was calculated with simple equation were investigated. it is expected that the developed analysis model and design technique would greatly contribute to the drum brake optimal design considering effective plastic strain and temperature affected behaviors. This development could save more than 20% of production cost and reduced failure rate to more than 30%. By improving the life span of mold from 15,000 to 25,000, financial difficulty of company imposed on a mold manufacture could be overcome.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.335-340
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• 2001

We use so many plastic products in everyday. Because polymer materials have a lot of merits including low cost and easiness of forming, they are widely used in many manufacturing industries. Microcellular foaming process was developed at MIT in 1980's to save a quantity of materials and increase mechanical properties. The improvement of strength is very important factor in relation with the reduction of mass. So the first purpose of this research is to improve the strength of the microcellular foamed plastics as variation of glass-fiber's volume friction. Also the characteristic of filler such as glass-fiber was presented in a microcellular foaming process.

• Asia pacific journal of information systems
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• v.5 no.2
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• pp.131-142
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• 1995

In distributed database systems materialized views are useful to solve many problems caused by data replication. This paper deals with the problem of updating materialized views incluing join operations. We use a differential update which uses logs that record the change of base tables in certain periods. This method avoids locking of the base tables so that it makes the system more efficient. We update materialized views periodically to save the updating cost envolved. A screen test is applied to differential files to eliminate tuples that are irrelevant to any of the views being updated. Using these methods, a detailed procedure is addressed to refresh materialized views. Then we show that our update procedure performs better than a semijoin approach.

• Journal of Advanced Marine Engineering and Technology
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• v.24 no.3
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• pp.106-112
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• 2000

Since the oil crisis, we have been concerned about the energy saving techniques of electric generating systems. As a part of the effort to save energy, automatic electric load sharing device was developed. Usually, ship's electric generating system consists of two or three sets of generator. And, electric generating system is operated as single or parallel operation mode according to the demanded electric power. Therefore, it is important to investigate generators operating mode for the supply of required electric power in the ship in order to decrease the operating cost. So, this paper suggests the method to solve the optimal electric load distribution problem by dynamic programming. And, this thesis indicates that the proposed method is superior to the lagrange multiplier's method in obtaining optimal load distribution solution in the ship's electric generating system.

• International journal of advanced smart convergence
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• v.1 no.2
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• pp.12-15
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• 2012

Energy costs for operating and cooling computing resources in Cloud infrastructure have increased significantly up to the point where they would surpass the hardware purchasing costs. Thus, reducing the energy consumption can save a significant amount of management cost. One of major approach is removing hardware over-provisioning. In this paper, we propose a technique that facilitates power saving through reducing resource over provisioning based on virtualization technology. To this end, we use dynamic workload shaping to reschedule and redistribute job requests considering overall power consumption. In this paper, we present our approach to shape workloads dynamically and distribute them on virtual machines and physical machines through virtualization technology. We generated synthetic workload data and evaluated it in simulating and real implementation. Our simulated results demonstrate our approach outperforms to when not using no workload shaping methodology.

• Journal of the Korean Institute of Telematics and Electronics
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• v.27 no.6
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• pp.816-820
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• 1990

A Tx modulator of the AMPS cellular wireless communication has been implemented using the PLL synthesizer, of which is modified for multiple frequency output capability. The frequency range is in 825-845 MHz with the 666 channels of 30KHz channel spacing and its switching time is less than 40 msec. The purpose of this paper is to develope the PLL frequency synthesizer with the high speed pulse swallow prescaler in order to save power consumption and cost. The PLL frequency synthesizer is studied in this paper to apply the cellular communication modulator.

• Journal of the Korea Safety Management & Science
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• v.16 no.1
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• pp.139-146
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• 2014

As Crosby notes, the most companies spend 15 to 20% of their sales dollars on quality costs. Generally the most effective way to manage quality costs is to avoid having defects in the first place. In this paper we have studied about the repair(service) problem of domestic gas boiler within warranty period. We develop a system, which man could find the cause of the problem at an early stage and could devise a countermove to the problem under supposing that the service(repair) rate follows exponential distribution and the product is manufactured lot-for-lot continually. Using the developed early sensing system. it is expected to improve the reliability of the product, to save expenses of company and to improve customer's satisfaction. And the system will be expended to incorporate information technology, which can detect the repair rate automatically.