• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 B
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• pp.800-802
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• 2004

When an accident is happen due to using a bad Wire Compressor, some public resentments are caused and It cause lawsuit for we. In case, we will undergo a colossal financial loss. in addition to, Guide to improve quality of operation by using the number of times of pressing and pressing pressure with cooperative private enterprise. And because of needs for Thermal, Electrical and Chemical factor analysis of connection point of sleeve, expect to try improving problems of wire presser whole our company. We expect that reduce fault and save cost by this process. Consequently, we will prevent power losing and black out due to line faults by expulsion of inferiority equipment and prevent heating and line fault. This is possible using Alarming and Auto Locking Wire Compressor that is improve on this study.

• 동력기계공학회지
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• 제13권5호
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• pp.95-102
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• 2009

A steam generator (boiler) in thermal power plants, consisting of more than 30,000 parts and components, can lead to the plant shutdown with damage to even the small part of the components; esp., like weld failures on boiler tubes. Consequently it is greatly demanded to improve the quality of the weld on the boiler tube for the stable operation of the power plants. Because of the feature of the welding, which is done past by melting the work pieces and adding a filler material that cools to become a strong coalescence, there is a great possibility that weld failures take place. As a result, it is regulated to make a non-destructive testing, like radiography test, to detect defects and flaws in the weld. The current film radiography test provides a lower image quality exceeding 2.0% of a basic quality level for a penetrameter, it is very likely to fail to detect micro defect. As a result, the prevention for the boiler tube failure has not been made effectively. In this study, computed radiography technology has been applied as a digital radiography test to the boiler tube weld, and Se-75 radiation source was used to improve the image quality, instead of Ir-192 source. As a result of this study, it is proven to save the time and cost for test and to enhance the quality level of penetrameter penetrating image, which enables to upgrade the quality of radiography test to the boiler tube weld.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 B
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• pp.704-706
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• 1996

This paper presents a new algorithm of unit commitment for optimal operation in power system. The proposed method developed algorithm that determined generators considering load variations at each stages. It has established forecast unit commitment over time horizon at first and next calculated quality cost of generators and then committed generator that has minimum quality cost at unit commitment schedule over time horizon. It is used that Objet-Oriented Programming for effective realization, and simple handling of complex program. The proposed method has applied at example system and the results has shown superior economics and computational requirement than the conventional method.

• 전기학회논문지P
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• 제61권1호
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• pp.41-46
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• 2012

Electrolytic power capacitors have been widely used in power conversion system such as inverter or UPS because of characteristics of large capacitance, high-voltage and low-cost. The electrolytic capacitor, which is most of the time affected by the aging effect, plays a very important role for the power-electronics system quality and reliability. Therefore it is important to diagnosis monitoring the condition of an electrolytic capacitor in real-time to predict the failure. In this paper, the on-line remote diagnosis monitoring system for UPS DC link electrolytic capacitors using low-cost single-chip zigbee communication modules is developed. To estimate the health status of the capacitor, the equivalent series resistor(ESR) of the component has to be determined. The capacitor ESR is estimated by using RMS computation using BPF modeling of DC link ripple voltage/current. Zigbee-based hardware experimental results show that the proposed remote capacitor diagnosis monitoring system can be applied to UPS successfully.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 E
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• pp.1608-1610
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• 1998

An oil-filled paper-insulated power cable and a XLPE-insulated power cable have been mainly applied as an extra-high-voltage underground power cable. But in recent the XLPE cable has been applied more widely than the OF cable, because of its advantages, such as the low-cost and simple installation. In general two types, molded and prefabricated, of straight joints are applied for the XLPE cables. For a tape-molded joint, one of molded joints, its electrical properties are excellent, but it has some disadvantages, such as a long working time. high skill of workers and the high cost of jointing equipments. For a prefabricated joint, developed and applied in Europe and Japan, its working time is short, its jointing procedures are simple, and its quality control is easy, but its prices are very high. In Korea the development of a compression-type PJ will be finished in the near future, and studies of its jointing techniques and equipments is actively going on. This paper describes the design and construction of the PJ, the jointing procedures and techniques for the PJ, and its future trends.

• 대한의생명과학회지
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• 제26권4호
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• pp.275-287
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• 2020

Since its introduction in the forensic field, quantitative PCR (qPCR) has played an essential role in DNA analysis. Quality of DNA should be evaluated before short tandem repeat (STR) profiling to obtain reliable results and reduce unnecessary costs. To this end, various human DNA quantification kits have been developed. Among these kits, the PowerQunat® System was designed not only to determine the total amount of human DNA and human male DNA from a forensic evidence item, but also to offer data about degradation of DNA samples. However, a crucial limitation of the PowerQunat® System is its high cost. Therefore, to minimize the cost of DNA quantification, we evaluated kit performance using a reduced volume of reagents (1/2-volume) using DNA samples of varying types and concentrations. Our results demonstrated that the low-volume method has almost comparable performance to the manufacturer's method for human DNA quantification, human male DNA quantification, and DNA degradation index. Furthermore, using a reduced volume of regents, it is possible to run 2 times more reactions per kit. We expect the proposed low-volume method to cut costs in half for laboratories dealing with large numbers of DNA samples.

• 품질경영학회지
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• 제16권1호
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• pp.1-7
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• 1988

The most important element upon the quality of family glass products is the color of glass, which is the first object of consumers concern in purchasing. Therefore, colorless and transparent color tone can level up the additional value of the products. But we have produced the glass products in a large quantity by using the automatic tank brazier, chronic problem has been left over the color tone. By compounding and analizing the management techniques applied by peculiar technique and design of experiments pertinently, and by adjusting the decoloring composition ratio, we can contribute to improvement of color tone as well as to the cost reduction by diminishing the unnecessary decoloring agent. Intangible effect was the securing the superiority of quality home and abroad with the improvement of color tone and was taking a triangular position the factors influencing the glass decoloring which had been an unexhausted field. Tangible effect was the reduction of decoloring cost by diminishing the unnecessary oxidant. We registered the optimal composition ratio condition which was searched by applicating the design of experiments. To maintain good color tone, we manage the degree of purity, the most important thing among the items of color tone, continuously by control chart and it has maintained steady state now.

• 제어로봇시스템학회논문지
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• 제14권1호
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• pp.36-41
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• 2008

Cooling tower is an important equipment of the cooling systems for large buildings like factory and department store. Water used for cooling in cooling tower is reused continuously. If the water is polluted, corrosion and scale can happen at equipments and pipes. In order to prevent this problem, it is necessary to control the water quality using chemicals. To control the water quality, an automatic control system is designed, fabricated, and experimented. The control system is based on an imbedded microcontroller. Relays are used for power driving, an LCD and LED for display, and RS485 for remote data acquisition. Monitoring program is also developed for easy man-machine interface and extraction of data stored in the imbedded processor and EEPROM. The control system calculates amounts of chemicals necessary using sensor data and injects the chemicals into the cooling tower on proper time. The developed water quality control system is expected to reduce cost of maintenance and extend the lifetime of the cooling systems with low cost.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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• pp.433-433
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• 2013

Graphene, $sp^2$-hybridized 2-Dimension carbon material, has drawn enormous attention due to its desirable performance of excellent properties. Graphene can be applied for many electronic devices such as field-effect transistors (FETs), touch screen, solar cells. Furthermore, indium tin oxide (ITO) is commercially used and sets the standard for transparent electrode. However, ITO has certain limitations, such as increasing cost due to indium scarcity, instability in acid and basic environments, high surface roughness and brittle. Due to those reasons, graphene will be a perfect substitute as a transparent electrode. We report the graphene synthesized by inductive coupled plasma enhanced chemical vapor deposition (ICP-PECVD) process on Cu substrate. The growth was carried out using low temperature at $400^{\circ}C$ rather than typical chemical vapor deposition (CVD) process at $1,000^{\circ}C$ The low-temperature process has advantage of low cost and also low melting point materials will be available to synthesize graphene as substrate, but the drawback is low quality. To improve the quality, the factor affect the quality of graphene was be investigated by changing the plasma power, the flow rate of precursors, the scenario of precursors. Then, graphene film's quality was investigated with Raman spectroscopy and sheet resistance and optical emission spectroscopy.

• Journal of Power Electronics
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• 제15권4호
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• pp.1093-1104
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• 2015

A standard repetitive controller (RC) is theoretically able to replace a bank of resonant controllers in harmonic signals tracking applications. However, the traditional RC has some drawbacks such as a poor dynamic response and a complex structure to compensate grid frequency deviations for an effective unified power quality conditioner (UPQC) control scheme. In order to solve these problems, an improved RC with an outstanding dynamic response and a simplified grid frequency adaptive scheme is proposed for UPQC control systems in this paper. The control strategy developed for the UPQC has delay time, i.e., one-sixth of a fundamental period (T_p/6), repetitive controllers. As a result, the UPQC system can provide a fast dynamic response along with good compensation performance under both nonlinear and unbalanced loads. Furthermore, to guarantee the excellent performance of the UPQC under grid frequency deviations, a grid frequency adaptive scheme was developed for the RC using a simple first order Padé's approximation. When compared with other approaches, the proposed control method is simpler in structure and requires little computing time. Moreover, the entire control strategy can be easily implemented with a low-cost DSP. The effectiveness of the proposed control method is verified through various experimental tests.