• Asian-Australasian Journal of Animal Sciences
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• v.14 no.11
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• pp.1616-1620
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• 2001

Two feeding trials were conducted to study the effects of different chelated copper and zinc compounds on the performance and fecal excretions of weanling pigs. In Exp. 1, 150 weanling pigs ($L{\times}Y{\times}D$, $12.30{\pm}2.07kg$) were randomly assigned to five dietary treatments: 170 ppm Cu from $CuSO_4$, 85 ppm Cu from Cu amino-chelate (CAC), 170 ppm Cu from CAC, 85 ppm Cu from Cu-Lysine (CL), and 170 ppm Cu from CL. In Exp. 2, 150 weanling pigs ($L{\times}Y{\times}D$, $12.52{\pm}1.80kg$) were randomly assigned to five dietary treatments: 120 ppm Zn from $ZnSO_4$, 60 ppm Zn from Zn-amino-chelate (ZAC), 120 ppm Zn from ZAC, 60 ppm Zn from Zn-Methionine (ZM), and 120 ppm Zn from ZM. In both experiments, pigs were randomly distributed to the treatments following a randomized complete block design on the basis of body weight as the blocking variable. Each experiment was conducted for 28 days. Blood and fecal samples were collected to determine mineral contents as affected by the dietary treatments. There was no difference (p>0.05) in ADG and ADFI among treatments, but F/G was improved (p<0.05) in pigs fed diet with 170 ppm CAC than 85 ppm CL but not different (p>0.05) to the control (170 ppm $CuSO_4$). Regardless of copper source, concentration of Cu in serum and feces were higher in pigs fed diet with 170 ppm Cu than pigs fed diet with 85 ppm Cu (Exp 1). In Exp 2 the ADG was higher (p<0.05) in pigs fed diet with 120 ppm ZM than in pigs fed diets with 120 ppm $ZnSO_4$ and 60 ppm ZAC and ZM. The serum zinc concentration was generally higher (p<0.05) in pigs fed diet with organic source than the control group ($ZnSO_4$). Also, there was a trend towards a decrease in fecal excretions of zinc when dietary zinc level was low. The efficacy of the two chelated copper and zinc sources is similar in terms of growth performance. The fecal excretions for Cu and Zn could be reduced in pigs fed low level of these minerals using organic sources.

• Polymer(Korea)
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• v.33 no.4
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• pp.377-383
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• 2009

Ionic polymer-metal composite (IPMC) actuator generates bending actuation via ion/water flux to the cathode side under an electric field. Polyelectrolytes in IPMC should possess high water-retention capability, proton conductivity, and Young's modulus. In this study. for endowing IPMCs with these properties, Nafion-alumina composite membranes containing $\alpha$- or $\gamma$-aluminas of $4{\sim}8$ wt% were prepared. Mechanical moduli of Nafion-alumina composite membranes were $7{\sim}3$ MPa higher than that of Nafion, with the slight decrease in proton conductivity. At DC 3 V. the actuation performance of the Nafion-$\alpha$-alumina (8 wt%)-IPMC was superior to that of the typical Nafion-IPMC. exhibiting 2.7 times the displacement with an enhanced blocking force. The enhanced actuation performance with the Nafion-$\alpha$-alumina composite membranes was attributed to the higher proton conductivity, the elevated ion/water flux, and the lower interfacial electric resistance of platinum electrodes and membrane, compared with those containing $\gamma$-alumina.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.3A
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• pp.129-139
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• 2003

CAC is a very important issue in CDMA system in order to protect the required QoS(quality of service) and increase the system's capacity. In this paper, we proposed and analyzed a call admission control scheme using multiple thresholds, which can provide quick processing time and better performance. There are two effective thresholds used to decide call admission. One is the number of active users, and the other is the signal to interference ratio(SIR). If the threshold of active users are lower than the low number of users threshold, we accept the new call without any other conditions. Otherwise, we check the current SIR to guarantee the quality of our service. System then accepts the new call when the SIR satisfies system requirement. Otherwise, the call will be rejected. Multiple threshold schemes are investigated and their performance is compared with the number of user and power based CAC's. simulation results are provided to evaluate the performance.

• Journal of the Korea Institute of Building Construction
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• v.10 no.2
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• pp.97-104
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• 2010

This study evaluated the energy efficiency of a windows system using built-in blinds, with regard to their insulation performance and their blocking of solar radiation. The study took advantage of the "Physibel Voltra" program as a physical simulation of heat transfer. To simulate the "Physibel Voltra" program, I practiced a mock-up test to determine heating quality and translation condition. I analyzed the propensity to annual energy consumption, the annual quantity of heat transfer, and the annual cooling and heating cost through a computer simulation for one general household in an apartment building. In the test, it was found that compared to a general windows system, a windows system with built-in blinds reduced the annual heat transfer by 10% in cooling states and by 11% in heating states when the blind was up. When the blind was down, the windows system with built-in blinds reduced the annual heat transfer by 25% in cooling states and 30% in heating states. When a windows system with built-in blinds is compared with a general windows system, the quantity of cooling and heating loads is reduced by 283.3kw in cooling states and 76.3kw in heating states. This leads to a reduction in the required cooling and heating energy of 359.6kw per house. It is thus judged that the use of a windows system with built-in blinds is advantageous in terms of reducing greenhouse gas emissions, because the annual TOE (tons of oil equivalent) per house is reduced by 0.078TOE, while $tCO_2$ is reduced by $0.16tCO_2$. In addition, compared with a general windows system, the cost of cooling and heating loads in the system reduces the annual cooling cost by 100,000won, and the annual heating cost by 50,000won. Ultimately, this means that cooling and heating loads are cut by 150,000won per year.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.12 no.3
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• pp.321-326
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• 2019

Image denoising methods based on block matching are founded on the experimental observations that neighboring patches or blocks in images retain similar features with each other, and have been proved to show superior performance in denoising different kinds of noise. The methods, however, take into account only neighboring blocks in searching for similar blocks, and ignore the characteristic features of the reference block itself. Consequently, denoising performance is negatively affected when outliers of the Gaussian distribution are included in the reference block which is to be denoised. In this paper, we propose an expanded block matching method in which noisy images are first decomposed into a number of bit-planes, then the range of true signals are estimated based on the distribution of pixels on the bit-planes, and finally outliers are replaced by the neighboring pixels belonging to the estimated range. In this way, the advantages of the conventional Gaussian filter can be added to the blocking matching method. We tested the proposed method through extensive experiments with well known test-bed images, and observed that performance gain can be achieved by the proposed method.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.7B
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• pp.433-439
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• 2005

In this paper, we propose a Flow Based Waiting Time Priority (FB-WTP) scheduler that supports the proportional delay differentiated services between classes. Existing scheduling algorithms utilize the configuration of scheduler, which is operated as class unit, applied to wired network. However, FB-WTP scheduler is operated as flow unit and can take advantage of multi-flow diversity effect in time-varying channel state environment. As a result, FB-WTP improves the average queueing delay on each class as well as supporting the average queueing delay ratio between classes. It also solves the HOL packet blocking problem implicitly. Simulation results show that FB-WTP scheduler has better system queueing delay performance than Look-ahead Waiting Time Priority (LWTP) scheduler and supports the larger queueing delay ratio between classes that network operator set.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.45 no.2
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• pp.8-17
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• 2008

This paper proposes a robust license plate extraction method from images taken under unconstrained environments. Utilization of the color and the edge information in complementary fashion makes the proposed method deal with not only various lighting conditions, hilt blocking artifacts frequently observed in compressed images. Computational complexity is significantly reduced by applying Hough transform to estimate the skew angle, and subsequent do-skewing procedure only to the candidate regions. The true plate region is determined from the candidates under examination using clues including the aspect ratio, the number of zero crossings from vertical scan lines, and the number of connected components. The performance of the proposed method is evaluated using compressed images collected under various realistic circumstances. The experimental results show 94.9% of correct license plate extraction rate.

• Journal of Computational Design and Engineering
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• v.1 no.3
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• pp.173-186
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• 2014

The failure of a subsea production plant could induce fatal hazards and enormous loss to human lives, environments, and properties. Thus, for securing integrated design safety, core source technologies include subsea system integration that has high safety and reliability and a technique for the subsea flow assurance of subsea production plant and subsea pipeline network fluids. The evaluation of subsea flow assurance needs to be performed considering the performance of a subsea production plant, reservoir production characteristics, and the flow characteristics of multiphase fluids. A subsea production plant is installed in the deep sea, and thus is exposed to a high-pressure/ low-temperature environment. Accordingly, hydrates could be formed inside a subsea production plant or within a subsea pipeline network. These hydrates could induce serious damages by blocking the flow of subsea fluids. In this study, a simulation technology, which can visualize the system configuration of subsea production processes and can simulate stable flow of fluids, was introduced. Most existing subsea simulations have performed the analysis of dynamic behaviors for the installation of subsea facilities or the flow analysis of multiphase flow within pipes. The above studies occupy extensive research areas of the subsea field. In this study, with the goal of simulating the configuration of an entire deep sea production system compared to existing studies, a DES-based simulation technology, which can logically simulate oil production processes in the deep sea, was analyzed, and an implementation example of a simplified case was introduced.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.39 no.12
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• pp.529-538
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• 2002

Conventional method to reduce the handoff call blocking probability(PBH) in mobile communication system is to reserve a predetermined number of channels only for handoff calls. To determine the number of reserved channels, an optimization problem, which is generally computationally heavily involved, must be solved. In this Paper, we propose a call admission control (CAC) scheme that can be used to reduce the PBH without reserving channels in advance. For this, we define a new measure, gain, which depends on the state of the system upon the arrival of a new call. The proposed CAC decision rule relies on the gain computed when a new call arrives. SRN, an extended stochastic Petri nets, provides compact modeling facilities for system analysis can be calculated performance index by appropriate reward to the model. In this Paper, we develop SRN models which can perform the CAC with gain. The SRN models are 2 level hierarchical models. The upper layer models are the structure state model representing the CAC and channel allocation methods considering QoS with multimedia traffic The lower layer model Is to compute the gain under the state of the upper layer models.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.10
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• pp.895-903
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• 2016

Spaceborne imaging sensors require periodic calibrations using an on-board calibration device for an image quality of observation satellites. The on-board calibration device consists of a blackbody to provide uniform radiance temperatures and calibration mechanism with a function of stow and deploy to target the blackbody during the calibration. Among these devices, the calibration mechanism is required to implement a fail-safe function to prevent blocking of the main optical path when the mechanism stops at a certain position during on-orbit calibration. In addition, structural safety of the mechanical driving part of the mechanism within the launch environment must be guaranteed. In this study, we proposed a deploy/stow-type calibration mechanism that provides launch-lock and fail-safe function. The effectiveness of the functionality of the proposed mechanism was validated through functional test using engineering model.