• The Transactions of the Korean Institute of Electrical Engineers D
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• v.54 no.11
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• pp.669-672
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• 2005

An algorithm detecting abrupt and gradual shot boundaries is proposed in this Paper. The conventional methods detect abrupt shot boundaries well, but do not show good performance on gradual shot boundaries. The proposed method Is based on the fact that the difference of the characteristic between frames is large when the shot conversion occurs. And the Proposed method detects abrupt and gradual shot boundaries with one algorithm. Moreover, it detects not only position where gradual shot conversion occurs, but also the exact duration where gradual shot conversion occurs.

• Proceedings of the KIEE Conference
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• 2002.11d
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• pp.320-322
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• 2002

The paper presents an electrical model of a grid-connected wind energy conversion system (WECS) with a variable speed drive, a fixed pitch angle, a synchronous generator as a wind generator and AC-DC-AC conversion scheme for simulating dynamic behaviors and performance responding to varying wind speed input. The electric output of the WECS is controlled by the AC-DC-AC conversion scheme, the objective of which is to capture the maximum active power under varying wind conditions and to keep the voltage of WECS terminal bus at a specific level. Aerodynamic models are used to incorporate the power characteristics to wind speed. The modeling and simulation of the WECS are realized on PSCAD/EMTDC environment.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.3
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• pp.520-525
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• 2016

In this paper, Characteristic of power conversion unit of a railway vehicles according to contact loss in feeding system that applied impedance of rigid conductor is analyzed. It applied impedance of rigid bar in modeling of electric railway system. Railway vehicles are performed of modeling based on the performance of the electric railway vehicle. Effects of the contact loss in the power conversion unit were analyzed via main transformer of railway vehicle, the input and output voltage characteristics of the converter through contact loss was generated after linking the vehicle with feeding system.

• The Journal of Korea Robotics Society
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• v.18 no.1
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• pp.122-126
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• 2023

An unexpected occlusion in a real life, not in a laboratory, can be more fatal to neural networks than expected. In addition, it is virtually impossible to create a network that learns all the environmental changes as well as occlusions. Therefore, we propose an alternative approach in which the architecture and number of parameters remain unchanged while adapting to occlusion circumstances. Learning method with the term Conversion Learning classifies them more robustly by converting the weights from various occlusion situations. The experiments on MNIST dataset showed a 3.07 [%p] performance improvement over the baseline CNN model in a situation where most objects are occluded and unknowing what occlusion will appear in advance. The experimental results suggest that Conversion Learning is an efficient method to respond to environmental changes such as occluded images.

• Nuclear Engineering and Technology
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• v.56 no.6
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• pp.2404-2411
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• 2024

The GEOUNED code is specifically designed to convert CAD models, defined using the B-rep approach, into MC radiation transport models, defined using the CSG approach, and vice versa from MC to CAD. This code incorporates standard features commonly found in conversion tools, including decomposition, conversion, and automatic void generation. Additionally, it introduces innovative features, mainly in the automatic void generation part, which are described in this article. GEOUNED has demonstrated successful application in highly detailed 3D models used in fusion neutronics, which are known for their complex geometries, particularly those utilized in ITER. The article includes examples showcasing GEOUNED's performance in these challenging models, as well as custom applications that highlight its flexibility in addressing non-standard problems. The code is open-source and utilizes Open CASCADE as the geometry engine, with FreeCAD serving as the Python API.

• Journal of Korea Multimedia Society
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• v.10 no.1
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• pp.49-57
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• 2007

Recently, CMOS RF integration has been widely explored in the wireless communication area to save cost, power, and chip area. The direct conversion architecture, rather than a more conventional super-het-erodyne, has been an attractive choice for single-chip integration because of its many advantages. However, the direct conversion architecture has several fundamental problems to solve in achieving performance comparable to a super-heterodyne counterpart. In this paper, we describe a programmable filter for mobile communication terminals using a direct conversion architecture. The proposed filter can be implemented with the active-RC filter and programmed to meet the requirements of different communication standards, including GSM, DECT and WCDMA. The filter can be tuned to select a detail frequency by changing the gate voltage of the MOS resistors. The gain of the proposed architecture can be programmed from 27dB to 72dB using the filter gain and VGA in 3dB steps.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.857-860
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• 2005

We reported 94 GHz, low conversion loss, and high isolation single balanced active-gate mixer based on 70 nm gate length InGaAs/InAlAs metamorphic high electron mobility transistors (MHEMTs). This mixer showed that the conversion loss and isolation characteristics were 2.5 ${\sim}$ 2.8 dB and under -30 dB, respectively, in the range of 93.65 ${\sim}$ 94.25 GHz. The low conversion loss of the mixer is mainly attributed to the high-performance of the MHEMTs exhibiting a maximum drain current density of 607 mA/mm, a extrinsic transconductance of 1015 mS/mm, a current gain cutoff frequency ($f_t$) of 330 GHz, and a maximum oscillation frequency ($f_{max}$) of 425 GHz. High isolation characteristics are due to hybrid ring coupler which adopted dielectric-supported air-gapped microstrip line (DAML) structure using surface micromachined technology. To our knowledge, these results are the best performance demonstrated from 94 GHz single balanced mixer utilizing GaAs-based HEMTs in terms of conversion loss as well as isolation characteristics.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.7
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• pp.1008-1013
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• 2001

This experiment was conducted to determine the effects of enzyme supplementation on the performance of 80 growing-finishing pigs (26.2 kg) fed diets containing either soybean or canola meal. Barley-based diets formulated using either soybean meal or canola meal were fed with or without enzyme (Allzyme Vegpro, Alltech Biotechnology Centre). Eight castrates and twelve gilts were fed each diet. Digestibility of dry matter, crude protein and gross energy was 8.0 (p=0.0001), 7.9 (p=0.0005) and 7.9 (p=0.0003) percent lower for pigs fed diets containing canola meal compared with soybean meal. Enzyme supplementation had no effect on nutrient digestibility (p>0.05). There was a significant interaction between protein source and enzyme for all three nutrients. Over the entire experimental period (26.2 to 77.9 kg), pigs fed canola meal consumed 9.4% less feed (p=0.001), gained weight 20.4% slower (p=0.001) and had a 12.9% poorer feed conversion (p=0.001) than pigs fed soybean meal. Weight gain, feed intake and feed conversion were unaffected by enzyme addition (p>0.05). Castrates gained weight 11.4% faster (p=0.001), consumed 9.3% more feed (p=0.001) and had a 2.6% better feed conversion (p=0.026) than gilts. There was a significant interaction between protein source and sex of pig for feed conversion. Pigs fed diets based on canola meal had a significantly lower carcass value index (p=0.01), lower lean yield (p=0.007) and lower lean depth over the loin (p=0.001) than pigs fed diets based on soybean meal. Enzyme addition significantly increased lean depth over the loin (p=0.01). There was a significant interaction between protein source and enzyme for carcass value index (p=0.04), estimated lean yield (p=0.05) and fat depth over the loin (p=0.05). These results confirm previous studies which have demonstrated poorer pig performance when canola meal completely replaces soybean meal in diets fed to growing-finishing pigs. In addition, the results provide little justification for the inclusion of the Vegpro enzyme in diets fed to pigs of this weight range.

• Korean Journal of Organic Agriculture
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• v.12 no.1
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• pp.81-92
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• 2004

The effect of feeding extracts from rhus trees on performance of broiler were performed to investigate development of natural antibiotic in process of broilers production. A total of 320 broiler chicks at 7 day of age were fed the commercial diet and water, water containing 0 ppm (control), 300 ppm (T1), 600 ppm (T2) and 1000 ppm (T3) of extracts from rims trees for 7 weeks. The body weight gain and feed conversion ratio were improvement by feeding extracts from rims trees at 7 to 21 days of age (P<0.05), but amount of feed intake and mortality were not different among the four group. When 21 to 35 days of age, body weight gain, amount of feed intake, feed conversion ratio and mortality were almost same results when 7 to 21days of age, but it was not significantly different. When 35 to 49 days of age, body weight gain in T1 and T3 group was significantly improvement than control group (P<0.05), also feed conversion ratio was improve by feeding extracts from rhus trees. There was a decrease in the microflora population of both E coli. and salmonella in the cecum contents and feaces in broilers by feeding extracts from rhus trees. Emission of ammonia and VFA gas from excreta were significantly decreased at 5 to 10 days of storaged period (P<0.05). The digestibility of dry matter, crude fat, and crude ash of feed were tend to increased in broiler feeding extracts from rims trees. Digestibility of crude protein of feed in broiler three treatmental groups was significantly improved (P<0.05) as compared with those in control group. These results indicated that the feeding extracts from rhus trees of 300 to 1000 ppm of broiler production were improvement in th6 body weight gain, feed conversion ratio, and mortality due to increasing nutrients digestibility from feed, decreasing of microflora population of both E coll. and salmonella in the cecum contents and feaces, decreasing emission of ammonia and VFA gas from excreta.

• Journal of the Korean Applied Science and Technology
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• v.33 no.1
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• pp.100-109
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• 2016

In this study, the NO oxidation using dry oxidant produced by catalytic $H_2O_2$ conversion was conducted. It was shown that Mn-based $Fe_2O_3$ support catalyst has the best performance in the catalytic $H_2O_2$ conversion and its combined-NO oxidation. The reaction characteristics of NO oxidation was investigated by the various operation conditions such as $H_2O_2$ amount, oxidation temperature and space velocity. As a results, the oxidation efficiency of NO greatly depends on the oxidation reaction temperature, $H_2O_2$ amount and space velocity. The performance of NO oxidation was increased with increasing the oxidation temperature and $H_2O_2$ amount. Also, the performance of NO oxidation was decreased with increasing the space velocity.