• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2022년도 봄 학술논문 발표대회
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• pp.186-187
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• 2022

The purpose of this study was to give fluidizing properties to non-sirtered cement made using by-products that can replace Portland cement by using a fluidizing agent. Blast furnace slag, C-type fly ash, and F-type fly ash were used for non-sirtered cement, and sand was used for aggregate. The amount of fluidizing agent used was fixed at 1%, and the water-cement ratio (W/C) was different by setting the binder blending ratio of the non-sintered cement differently, and the fluidity test and flow were compared. As a result of the experiment, when the flow standard was 170mm when the fluidizing agent was used, the fluidizing properties were shown at an average water-cement ratio (W/C) of 36%. Through this study, it was confirmed that the fluidizing properties appeared when the fluidizing agent was used in non-sintered cement.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 학술대회 논문집 정보 및 제어부문
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• pp.358-360
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• 2004

The digital images contain a significant amount of redundancy and require a large amount of data for their storage and transmission. Therefore, the image compression is necessary to treat digital images efficiently. The goal of image compression is to reduce the number of bits required for their representation. The image compression can reduce the size of image data using contractive mapping of original image. Among the compression methods, the mapping is affine transformation to find the block(called range block) which is the most similar to the original image. In this paper, we applied the neural network(SOM) in encoding. In order to improve the performance of image compression, we intend to reduce the similarities and unnecesaries comparing with the originals in the codebook. In standard image coding, the affine transform is performed with eight isometries that used to approximate domain blocks to range blocks.

• 한국자동차공학회논문집
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• 제3권3호
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• pp.9-18
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• 1995

The substitution of conventional fuel oil by alternative fuels is of immense interest due to liquid oil shortage and requirements of emission control standard. Among the alternative fuels, natural gas may be the most rational fuel, because of its widespread resource and clean est burning. Meanwhile, engine simulation is of great importance in engine development. Hence a zero-dimensional combustion model was developed for dual-fuel system. Natural gas was injected directly into the cylinder and small amount of distillate was used to provide the ignition kernel for natural gas burning. The intake air and exhaust gas flow was modeled by filling and emptying method. Although the single zone approach has an inherent limitation, the model showed promise as a predictive tool for engine performance. Its simulation was also made to see how the engine performance was influenced by the fuel injection timings and amount of each fuel.

• 조명전기설비학회논문지
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• 제21권4호
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• pp.28-35
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• 2007

In this paper, a study was made of the technology used to measure the remaining amount of energy in secondary cells, for which demand is ever increasing. First, the standard data were stored for measurement of the remaining energy and a compare/analysis algorithm was developed. Next, hardware was designed and a prototype that can display the SOC(State Of Charge) through an LCD displayinstrument was created. The small size of the prototype allows it to be portable and its performance is within ${\pm}4$[%].

• 동력기계공학회지
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• 제14권1호
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• pp.34-39
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• 2010

A side by side refrigerator is popularly used one among electric home appliances according to the rise of the customer's living standard. But the frost problem in freezing compartment comes out whenever we develop the high quality refrigerator. In this research, internal flow simulation and temperature measurement were carried out by using CFD and T-type thermocouple respectively in order to understand freezing mechanism. It was revealed that the amount of frost beneath the 1st and 2nd shelves is approximately 40% of total frost and the cause of frost generation is due to bad circulation of low speed cold flow. Using this analysis, the shapes of outlets under shelves are modified. So, the amount of frost in this modified model decreases 6% comparing to original one.

• 농촌계획
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• 제14권1호
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• pp.43-50
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• 2008

The dichotomous-choice contingent valuation method is applied to estimate the landscape value of Jeju mandarin(orchard). A distribution-free approach, Turnbull empirical distribution model, is employed to solve negative willingness to pay and truncation problems. The data used are collected from the interviews with tourist about willingness-to-pay at the various donation amount levels of Jeju mandarin(orchard)'s landscape value. The evaluation result is shown that the average amount of willingness to pay for the Jeju mandarin's landscape value is 12,926 won per person with standard deviation of 1,874.7 won/person. When the number of Jeju visitors is considered, the economic value of Jeju mandarin's landscape rises every year(2005:64.89 billion won, 2011: 84.43 billion won). The average economic value of Jeju mandarin's landscape are estimated 59.65 billion won during 2000-2005 and 76.88 billion won during 2006-2011, respectively.

• 농촌계획
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• 제13권4호
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• pp.1-8
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• 2007

The dichotomous-choice contingent valuation method is applied to estimate the landscape value of Jeju Island's stonewall fencing farming land. A distribution-free approach, Turnbull empirical distribution model, is employed to solve negative willingness to pay and truncation problems. The data used are collected from the interviews with tourist about willingness-to-pay at the various donation amount levels of Jeju stonewall's landscape value. The evaluation result is shown that the average amount of willingness to pay for the Jeju stonewall fencing farming land is 3,001 won per meter with standard deviation of 511.0 won/m.

• 한국연초학회지
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• 제23권1호
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• pp.77-81
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• 2001

This study was conducted to determine menthol migration from the tobacco to the filter and the change in percentage of menthol in pack for different mentholated cigarettes. Methanol was used to extract menthol from tobacco, filter and foil. A known weight of internal standard was added to each extract and then the extracts were analyzed by gas chromatography. After 4 days, 95% of the menthol applied to the foil was delivered into the tobacco and filter, but in case of menthol applied to the tobacco, the percentage of menthol that migrated from the tobacco to the filter was below 10%. After 100 days, 30-45% of the menthol in the tobacco had migrated into the filter. The amount of menthol in the pack decreased after 20 days of storage, however, the remaining menthol in cigarette treated with 0.30% propylene glycol was higher in amount than that with 0.12% propylene glycol In analysis on menthol transfer to mainstream smoke, the most efficient sample was the cigarette with menthol applied to the foil rather than to the tobacco.

• ETRI Journal
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• 제24권1호
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• pp.23-30
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• 2002

MPEG-7 Visual Standard specifies a set of descriptors that can be used to measure similarity in images or video. Among them, the Edge Histogram Descriptor describes edge distribution with a histogram based on local edge distribution in an image. Since the Edge Histogram Descriptor recommended for the MPEG-7 standard represents only local edge distribution in the image, the matching performance for image retrieval may not be satisfactory. This paper proposes the use of global and semi-local edge histograms generated directly from the local histogram bins to increase the matching performance. Then, the global, semi-global, and local histograms of images are combined to measure the image similarity and are compared with the MPEG-7 descriptor of the local-only histogram. Since we exploit the absolute location of the edge in the image as well as its global composition, the proposed matching method can retrieve semantically similar images. Experiments on MPEG-7 test images show that the proposed method yields better retrieval performance by an amount of 0.04 in ANMRR, which shows a significant difference in visual inspection.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.1426-1431
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• 2011

A study on the standardization of design fire HRR(heat release rate) curve was conducted for various railcar from the fire simulation or the fire tests. These standard curves are listed on the tunnel fire safety manual which will be used for the QRA(quantitative risk analysis) process of the long railway tunnels. The design fire curve is based with four simple factor representing the key of fire curve characteristics. Flashover time, maximum HRR and burn out time are the key factors of the design fire curve. Specially total heat release is decided by the burnable material amount in the car.