• Transactions of the Korean Society of Automotive Engineers
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• v.9 no.4
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• pp.85-91
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• 2001

LPG has been well known as a clean alternative fuel for vehicles. As a fundamental study on liquid phase LPG injection (hereafter LPLI) system application to heavy-duty engine, engine output and combustion performance were investigated with various operating conditions using a single cylinder engine equipped with the LPLI system. Experimental results revealed that no problems were occurred in application of the LPG fuel to heavy-duty engine, and that volumetric efficiency and engine output, by 10% approximately, were increased with the LPLI system. It was resulted from the decrease of the intake manifold temperature through liquid phase LPG fuel injection. These results provided an advantage in the decrease of the exhaust gas temperature, in the control of knocking phenomena, spark timing and compression ratio. The LPLI engine could normally operated under $\lambda$=1.5 or EGR 30% condition. The optimized swirl ratio for the heavy duty LPG engine was found around R_s$ = 2.0.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2004.03a
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• pp.789-794
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• 2004

The pressure sensitive paint (PSP) technique has been well established in external flow field. However, there are still unresolved issues in internal flow field. This work was focused on the application to unsteady pressure measurement of fan flow field. The PSP measurement system was established and the image processing software was developed. First, the performance of PSP was investigated at the static cell. Then the unsteady PSP measurement was carried out at fan test facility. PSP data images were acquired from the suction and pressure surface of stator vanes. Pressure distributions on the surface of the stator vane were detected non-intrusively. The issues of image acquisition and image processing were clarified through the practical PSP application to fan flow field.

• Plant Resources
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• v.1 no.1
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• pp.53-59
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• 1998

Laboratory experiments for the removal efficiency of heavy metals in land application of sludge, the accumulation and translocation of heavy metals in x plants after transplanting, and the responses of Minari growth with different ratio of land application of sludge were conducted to determine the potential ability of bioremediation with Minari plants. The removal rate and translocation of copper. zinc. lead. and cadmium in soil and plants were compared after transplanting the Minari plants to soil treated with different ratio of sludge. The removal efficiency of heavy metals in soil incorporated with sludge was different with application ratio, but increased with growing periods of Minari plants. The removal efficiency of Cu, Zn, Pb, and Cd ranged from 67 to 74% from 51% to 63%, from 37% to 71%. and from 15% to 25% after 45 days of transplanting. respectively. The amount removed the copper value. 65.9 mg/kg, observed to be highest in soil incorporated 3% sludge after 45 days. The translocation of Cu. Zn. Pb. and Cd from shoots to roots ranged from 18 to 53%, from 17 to 32%, from 14 to 49%, and from 23 to 38% over growing periods. respectively. In plant responses it appeared to be inhibited the plant growth in the treatment compared with the control at early stage of growth. However, the fresh weights of Minari plant increased from 12.5 to 62.5% in the sludge application after 45 days relative to the control. Therefore the Minari might play a useful role in bioremediation of Cu, Zn, Pb, and Cd in the land application of sludge.

• Proceedings of the KIPE Conference
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• 2003.07a
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• pp.430-433
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• 2003

IGBTS are widely used for the industrial inverters in the mid power range at low voltage (440V$\~$660V) application. Advantageous features of the device are simple gate drive and high speed switching capability. Due to these advantages the application of IGBTS is enlarging into the high power application. However, to increase the power handling capacity at lower input voltage level, the current rating in each bridge arm must be enlarged. Therefore the parallel operation of IGBT devices is essentially needed. This paper describes the feasible parallel structures of the power circuit for the mid & the high power inverters and introduces the important design condition for the parallel operation of IGBT devices. To verify feasibility of the IGBT parallel operation, the feature of several IGBT devices (EUPEC, SEMIKRON's IGBT) are investigated and the power stacks are implemented and tested with these devices. The experimental results show the good characteristics for the parallel operation of IGBTS.

• Journal of Korea Entertainment Industry Association
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• v.14 no.7
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• pp.501-509
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• 2020

The purpose of this study was to provide basic information about the analysis of the changes in problem behavior, sleep quality and quality of life of the people with intellectual disability through the application of the heavy work activities. This study subjects were 10 people with intellectual disability and they participated in the this activities for 12 weeks. Through the application of heavy work activities, Korean-Adaptive Behavior Scale was used to analyze the changes in problem behavior, sleep quality assessment was used to analyze the changes in sleep quality and satisfaction with life scale was used to analyze the changes in quality of life. As the results, the decrease of problem behavior, the improvement of sleep quality and quality of life were showed. Heavy work activities should be act to decrease the problem behavior, improve sleep quality and quality of life of the study subjects. Thus, heavy work activities should be considered to apply for the people with intellectual disability.

• Korean Journal of Environmental Agriculture
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• v.17 no.2
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• pp.170-173
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• 1998

This study was conducted to investigate the effect of municipal sludge application on the change of physico-chemical properties and contents of heavy metals in soils. The application of the sludge resulted in increasing the content of total nitrogen, available phosphate,exchangeable K, Ca, Mg, and the soil porosity and permeability but soil hardness was reduce. It is clear that application of municipal sewage sludge would not due to increase in the heavy metals content in soil because of the lower concentration of heavy metal in the sludge. Totally it is evident that municipal sewage sludge application should play an important role in improving soil physico-chemical properties.

• Special Issue of the Society of Naval Architects of Korea
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• 2006.09a
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• pp.23-33
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• 2006

Generally wave buoy and visual observation are used to measure sea waves. But the wave buoy cannot be applicable for the ship moving in deep sea. So the visual observation has been used for it. But it has several defects and limitation related to environmental condition and observer. To overcome this problem, various wave measurement systems have been suggested. Recently, the wave measurement systems using nautical X-band radar have been developed and extended its application area. In this report, we introduce the wave measurement system, WaveFinder, developed by authors. The system was calibrated and verified with the measurement results of wave buoy. The system was adopted to measure wave condition during sea trials. The system will be a device to support safe navigation in ship's voyage.

• Communications for Statistical Applications and Methods
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• v.28 no.1
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• pp.1-19
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• 2021

Heavy tailed distributions are useful for modeling actuarial and financial risk management problems. Actuaries often search for finding distributions that provide the best fit to heavy tailed data sets. In the present work, we introduce a new class of heavy tailed distributions of a special sub-model of the proposed family, called a new extended alpha power transformed Weibull distribution, useful for modeling heavy tailed data sets. Mathematical properties along with certain characterizations of the proposed distribution are presented. Maximum likelihood estimates of the model parameters are obtained. A simulation study is provided to evaluate the performance of the maximum likelihood estimators. Actuarial measures such as Value at Risk and Tail Value at Risk are also calculated. Further, a simulation study based on the actuarial measures is done. Finally, an application of the proposed model to a heavy tailed data set is presented. The proposed distribution is compared with some well-known (i) two-parameter models, (ii) three-parameter models and (iii) four-parameter models.

• Proceedings of the KIEE Conference
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• summer
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• pp.590-593
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• 2004

This paper presents recent trends on the on-line monitoring and diagnostic systems for oil-immersed transformers. Specially, our system on YeoSu thermal power plant is introduced for high sensitivity and accuracy of ours. It is combined with communication networks to provide an on-line remote monitoring system. Several alarm criteria are formulated to enable a superimposed monitoring system to perform decisive action. The reasons for monitoring the condition and maintaining the health of electrical apparatus were discussed. The experience at the fields and the criteria for the judgment are also discussed in detail.

• Korean Journal of Environmental Agriculture
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• v.17 no.2
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• pp.150-155
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• 1998

To investigate effects of organic matter application on heavy metal uptake of infant rice seeding, the various amount of organic matter(peat and $Bio-com^{(R)}$)was applied on Cd or Cu treated nursery bed soil. No growth difference was observed up to 20mg/kg of Cu treatment. Above 20mg/kg of Cu treatment, the seeding height and top dry weight were decreased but the Cu uptake by seeding was increased with increasing Cu treatment level. The mat formation was poor above 20mg/kg of Cu treatment, however, the seeding peat application level. All peat treatment resulted better mat formation than control. The seeding height and top dry increasing Cd treatment level. The mat formation was not effected by either Cd treatment level or organic matter sources. The effect of peat and $Bio-com{(R)}$ application on Cd uptake by infant rice seeding was not observed at all Cd treatments level.