• Asian-Australasian Journal of Animal Sciences
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• v.21 no.2
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• pp.262-269
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• 2008

The aim of this study was to determine the effects of breeder age and stocking density on performance, carcass characteristics and some stress parameters (H-L ratio, serum glucose, cholesterol and triglyceride levels, tonic immobility test (TI), antibody production, relative asymmetry (RA) and external appearances). This experiment was carried out with 705 one-day old male broiler chicks (Ross 308) obtained from three different ages of broiler breeder (32, 48 and 61 wks). Each age group was randomly divided into two stocking density groups (11.9 and 17.5 broilers per $m^2$) with 5 replications per group. The experimental period was 6 weeks. Broilers from 32 wk-old breeders had lower initial weight (p<0.001), body weight gain of the first 3 week of rearing (p<0.01), the percentage of abdominal fat (p<0.001) and serum cholesterol level (p<0.01); higher percentage of gizzard (p<0.01) and longer TI duration (p<0.001) than those from 48 and 61 wk-old breeders. Broilers reared at 17.5 b/m2 had lower final BW, body weight gain, feed consumption, feather condition and foot health (p<0.001), higher percentage of heart, H-L ratio, serum glucose and cholesterol levels (p<0.001), and longer TI durations (p<0.001). There were no significant interactions in examined parameters except for feed to gain ratio between breeder age and stocking density.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.10 no.1
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• pp.109-121
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• 1999

In this paper, HF band LPDA(Log-periodic Dipole Antenna) and MLPDA(Modified Log-periodic Dipole Antenna) above lossy grounds were analyzed using moment method by considering the practical media parameter of lossy grounds, not assuming free space or perfect ground approximation. The radiation pattern and gain of LPDA and MLPDA as functions of frequency, antenna height from ground, and antenna tilt angle are presented, and the lossy ground effect on antennas characteristics are described. MLPDA was found to exhibit a smaller variation for gain and radiation pattern and a higher maximum beam direction relative to LPDA. It was shown that media parameter of lossy grounds and antenna height have a direct influence on the antenna gain of both LPDA and MLPDA.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1371-1374
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• 2004

The control system design of 2-DOF for SISO process by root locus technique is not complicated and efficiently. It can design the control system to have the transient and steady state responses, and do not adjust the gain of process controller later. However, due to control system design for MIMO process, by root locus technique, there is not exact method. This paper is presents the control system design method for Quadruple-Tank Process, by using root locus technique for the structure of 2-DOF control system. The design procedures are first decentralized then using the relative gain array, and finally 2-DOF controller design is applied.

• Journal of Communications and Networks
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• v.16 no.1
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• pp.56-66
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• 2014

We propose a novel opportunistic access scheme for cognitive radios in an interweave cognitive system, that considers the channel gain as well as the predicted idle channel probability (primary user occupancy: Busy/idle). In contrast to previous work where a cognitive user vacates a channel only when that channel becomes busy, the proposed scheme requires the cognitive user to switch to the channel with the next highest idle probability if the current channel's gain is below a certain threshold. We derive the threshold values that maximize the long term throughput for various primary user transition probabilities and cognitive user's relative movement.

• Journal of the Korean Graphic Arts Communication Society
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• v.23 no.1
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• pp.53-63
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• 2005

The quality of the print can be specified through the quality of the coloring, the reproduction of fine structures and the range of tone values. Also, package printed quality are controlled by this points. In this paper, densitometry method was used for printed quality. By densitometry we can get the print density and the parameters of each conditions that characterize halftone printing, such as dot gain and relative printing contrast. Also, we have proposed the optimizes range of the parameters such as density, dot gain etc. to the package printed printability control.

• Journal of Families and Better Life
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• v.25 no.3 s.87
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• pp.25-44
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• 2007

The purpose of this study was to classify the financial strategies and investigate major determinants of the financial performance in elderly households. This study used the data of 4,577households with all ages and 1,255 elderly households were from the Korean Labor and Income Panel Study(2000, 2003). The data were analyzed by various statistical methods such as frequency, mean-test, Duncan's multiple range test, k-mean cluster analysis and regression. The major findings were as follows: First, the classified household financial strategy types were Residual(44.3%), Financial Assets(24.0%), Informal Institutional(19.7%), Diversified Portfolio(7.6%), Real Estate(4.5%). Second, the criteria of classification of the financial strategies were relative, not absolute. Third, elderly households that employed a financial assets had the greatest financial performance (62,320,000 won net gain). Households with all ages that employed a diversified portfolio strategy had the greatest financial performance (98,360,000 won net gain). Forth, the determinants of the financial performance were significantly different according to the types of financial strategy.

• International Journal of Aeronautical and Space Sciences
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• v.8 no.1
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• pp.129-139
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• 2007

In this paper, attitude control laws for simultaneous pointing of multiple spacecrafts are considered under a formation flying scenario. The basic approach lies in adaptive feedback gains using relative attitude information or maneuver time approximation for coordinated attitude control. Each control law is targeted to balancing mean motion or to correcting system response to the slowest satellite. The control gain adaptation is constructed by two approaches. The first one is using variable damping gain to manipulate speed of a fast system response, and the second one uses alternate natural frequency of the system under control. The validity and stability of the proposed approaches are examined analytically and tested through numerical simulations.

• Journal of the Optical Society of Korea
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• v.14 no.4
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• pp.298-304
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• 2010

The pair-induced quenching (PIQ) effect in a highly doped bismuth oxide-based erbium-doped fiber amplifier (EDFA) was theoretically and experimentally investigated. In the theoretical investigation, the bismuth oxide-based EDFA was modeled as a 6-level amplifier system that incorporated clustering-induced concentration quenching, cooperative up-conversion, pump excited state absorption (ESA), and signal ESA. The relative number of paired ions in a highly doped bismuth oxide EDF was estimated to be ~6.02%, determined by a comparison between the theoretical and the experimentally measured gain values. The impacts of the PIQ on the gain and the noise figure were also investigated.

• Journal of Institute of Control, Robotics and Systems
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• v.7 no.4
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• pp.295-303
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• 2001

The demand for steam generators is increasing in industrial systems in which the design strategy should be implemented for safe and efficient operation of steam generators. It is, however, difficult to design a controller by the conventional method because of the nonlinear dynamics of the steam generator and influences by the set value of disturbance. This paper presents an automatic parameter optimization technique for a multivariable fuzzy controller using evolutionary strategy, At first, we use the steady state information such as a steady state gain matrix(SSGM) and a relative gain matrix(RGM). We can obtain much information on the control inputs and the outputs of the boiler-turbine system from the matrices. In order to determine the structure of the controller by using RGM and SSGM, the fuzzy rules are trained by evolutionary strategy. The good performance of the proposed multivariable fuzzy controller is verified through simulations.

• YAKHAK HOEJI
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• v.43 no.1
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• pp.48-54
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• 1999

Effects of zinc chloride (Zn) on the immune responses of lipopolysaccharide (LPS) were studied by using ICR mice. Mice were divided into 4 groups (10 mice/group), and Zn was given to the mice with i.p. injection at 0.3 mg/kg 5 times a week for 14 days, and 1 hr after Zn administration, LPS was given with i.p. injection at 5 mg/kg twice a week. Mice were immunized and challenged with sheep red blood cells (SRBC). Immunobiological responses were evaluated by humoral, cellular and nonspecific immunity. LPS treatment significantly increased the relative weights of spleen and thymus, hemagglutination titer (HA) and proliferation of splenocytes compared with those in controls, but significantly decreased the body weight gain. Zn treatment significantly increased proliferation of splenocytes and circulating leukocytes compared with those in controls. Combination of Zn and LPS significantly decreased the body weight gain and proliferation of splenocytes compared with those in controls. Combination of Zn and LPS significantly decreased HA and proliferation of splenocytes than in LPS alone. These findings indicate that zinc lowered the humoral immune responses of LPS.