• Journal of Animal Science and Technology
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• v.58 no.12
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• pp.41.1-41.7
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• 2016

Background: Over two decades of observations in the field in South East Asia and Hawai'i suggest that majority of the commercial dairy herds are of black hair coat. Hence a simple study to determine the accuracy of the observation was conducted with two large dairy herds in Hawaii in the mid-1990s. Methods: A retrospective study on longevity of Holstein cattle in the tropics was conducted using DairyComp-305 lactation information coupled with phenotypic evaluation of hair coat color in two large dairy farms. Cows were classified into 3 groups: a) black (B, >90%); b) black/white (BW, 50:50) and c) white (W, >90%). Cows with other hair coat distribution were excluded from the study. In farm A, 211 out of 970 cows were identified having 4 or more lactations. In farm B, 690 out of 1,350 cows were identified with 2 or more lactations for the study. Results: The regression analyses and the Wilcoxon-Log-rank test for survival probability showed that Holstein cattle with 90% black hair coat had greater longevity compared to Holstein cattle with 90% white hair coat. Conclusions: This study suggests that longevity of Holstein cattle in tropical regions was influenced by hair coat color and characteristics.

• Proceedings of the KIPE Conference
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• 2004.07a
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• pp.144-146
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• 2004

This paper presents experimental operation with utility invertactive 3kW photovoltaic generation system. And that describe configuration of utility interactive photovoltaic system which power supply for Demonstration experiment. The status of photovoltaic generation system comp-onents and interconnection and safety equipment will be summarized. This paper discusses property operation state which system endure division of power for demonstration experiment.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.5B no.4
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• pp.392-398
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• 2005

This paper presents technologies that have strategic importance in future motor drives. The underlying strategic issue for motor drives is maintaining cost while increasing certain dimensions of functionality. The dimensions of functionality which should increase include reliability and added value features such as providing continuous energy optimization, providing sensing of the driven system suitable for application specific diagnostic purposes, and providing continuously optimal thermal utilization of the capability of the drive. This paper will address each of these issues and discuss the technology status for each case, with a focus on research needed to fully deliver the needed functionality.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.3B no.2
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• pp.97-102
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• 2003

In this paper, a recurrent artificial neural network (RNN) based self-tuning speed controller is proposed for the high-performance drives of induction motors. The RNN provides a nonlinear modeling of a motor drive system and could provide the controller with information regarding the load variation system noise, and parameter variation of the induction motor through the on-line estimated weights of the corresponding RNN. Thus, the proposed self-tuning controller can change the gains of the controller according to system conditions. The gain is composed with the weights of the RNN. For the on-line estimation of the RNN weights, an extended Kalman filter (EKF) algorithm is used. A self-tuning controller is designed that is adequate for the speed control of the induction motor The availability of the proposed controller is verified through MATLAB simulations and is compared with the conventional PI controller.

• Proceedings of the KIPE Conference
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• 2005.07a
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• pp.734-736
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• 2005

This paper presents experimental operation with utility invertactive 3kW photovoltaic generation system. And that describe configuration of utility interactive photovoltaic system which power supply for Demonstration experiment. The status of photovoltaic generation system comp-onents and interconnection and safety equipment will be summarized. This paper discusses property operation state which system endure division of power for demonstration experiment.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.6
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• pp.573-582
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• 2021

In this study, a series of processes for evaluating the effective protection against barriers that should be equipped in institutions that perform reliability tests on high-risk ammunition, such as high-explosive ammunition, were introduced. The impact that high-explosive bombs can have on personnel includes damage to the eardrum and lungs caused by explosion overpressure and penetrating wounds that can be received by fragments generated simultaneously with the explosion. Therefore, a high-explosive with COMP B explosives as its contents were set up, and an explosion protection theory investigation to calculate the degree of damage, numerical calculations and simulations were performed to verify the protection power. A numerical calculation revealed the maximum explosion overpressure on the protective wall when the high-explosive exploded and the penetration force of the fragment against a 50 mm-thick protective wall to be 77.74 kPa and 41.34 mm, respectively. In the simulation verification using AUTODYN, the maximum explosion overpressures affecting the firewall and personnel were 56.68 kPa and 18.175 kPa, respectively, and the penetration of fragments was 35.56 mm. This figure is lower than the human damage limit, and it was judged that the protective power of the barrier would be effective.

• Journal of IKEEE
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• v.2 no.2 s.3
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• pp.185-193
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• 1998

Fractal-based monochrome image coding method can be easily applied for color image compression by splitting the color image into different primary spectral channels such as RGB, YIQ or $YC_bC_r$, and encoding each channel independently According to this method, it needs to repeat the fractal coding for each channel, so it have the problem of encoding time. In this paper, a fractal-based coder for color still image is proposed which features the enhancement of compression rate and the reduction of coding time. As the result of the experiment where the proposed algorithm is applied far color images, the compression rate is enhanced by 28 : 1 above with average PSNR value $28{\sim}29[dB]$, do not lossless encoding process using JPEG. And the encoding time is reduced by maximum 11.5 %.

• Journal of the Korea Institute of Military Science and Technology
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• v.14 no.5
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• pp.932-940
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• 2011

This study describes computational simulation results in 2-dimensional and 3-dimensional space concerning large scale gap test(LSGT) by using commercial hydrocode such as AUTODYN and LS-DYNA to analyze the detonation phenomenons of high explosives. To consider the possibilities of LSGT simulation, we used Lee - Tarver reaction rate model of PBX-9404 and Comp-B which were implemented AUTODYN's material library. Also we have tried the diverse numerical schemes such as Lagrangian, Eulerian and ALE(Arbitary Lagrangian Eulerian), SPH(Smoothed Particle Hydrodynamics) in LSGT simulations. After LSGT simulations, we compared the simulation results with published results to verify the LSGT simulations. According to the LSGT simulations, we have concluded as follows. In 2-dimensional and 3-dimensional space, Lagrangian solver provided the most reliable results based on analysis time and accuracy. When using two hydrocodes in 2-dimensional space, the simulation results are almost same except one explosive model. We have verified the modeling method and simulation results of the LSGT by using the commenrcial hydrocode in this study.

• The Korea Journal of Herbology
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• v.37 no.5
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• pp.27-35
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• 2022

Objectives : 3-Acetyl-11-keto-𝛽-boswellic acid (AKBA) is a major active compound in Boswellia serrata. We investigated the arthritic changes following AKBA administration in monosodium iodoacetate (MIA)-induced osteoarthritis rats. Methods : All rats were randomly divided into five groups: Normal, Control, INDO (indomethacin 2 mg/kg treated), AKBA30 (AKBA 30 mg/kg treated), and AKBA60 (AKBA 60 mg/kg treated); drugs were given 2 weeks before MIA injection. For all groups except the normal group, 50 µL of sterile saline with MIA (80 mg/mL) was injected into the right knee joint 2 weeks after drug administration. The drug administration was continued for 4 weeks from 1 week after osteoarthritis induction. The histomorphological changes of knee joint cartilage were observed by H&E staining. Also, the levels of glycosaminoglycan (GAG), cartilage oligomeric matrix protein (COMP), 5-lipoxygenase (5-LOX), 5-LOX-activating protein (FLAP), and leukotriene B₄ (LTB₄) in the knee joint were determined by the ELISA kits. The expressions of mitogen-activated protein kinases (MAPKs), inflammatory cytokines, and matrix metalloproteinases (MMPs) in knee joint were detected by Western blot. Results : Data show that levels of 5-LOX, FLAP, LTB4, and COMP were downregulated significantly in the AKBA treated groups when compared to those in the Control group. On the other hand, GAG levels were significantly elevated. As a result of Western blot, the AKBA-treated groups significantly inhibited phosphorylation of MAPKs. In addition, significant downregulation of the expression of inflammatory cytokines and MMPs was found in the AKBA-treated groups. Conclusion : Our findings suggest that administration of AKBA could exert better chondroprotective and anti-inflammatory effects for MIA-induced osteoarthritis rats.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.39 no.2
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• pp.153-159
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• 2015

In this study, a 2-W micro-gas turbine engine was designed using micro-electro-mechanical systems (MEMS) technology, and analytical and experimental investigations of its potential under actual combustion conditions were performed. An ultra-micro-gas turbine contains a turbo-charger, combustor, and generator. A compressor, turbine blade, and generator coil were manufactured using MEMS technology. The shaft was supported by a precision computer numerical control machined air bearing, and a permanent magnet was attached to the end of the shaft for generation. An analysis found that the cooling effect of the air bearing and compressor was sufficient to cover the combustor heat, which was verified in an actual experiment.