• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.9
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• pp.940-946
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• 2010

In this paper, we proposed the internal antenna on PCB(Planar Circuit Board) for achieving WWAN(Wireless Wide Area Network) operation in the laptop computer. The proposed antenna has a metal structure instead of printed pattern on PCB to improve the antenna characteristics for GSM850/900 bands. Compared to PCB embedded antenna without metal structure, the proposed antenna occupies similar area of $74{\times}11{\times}0.5\;mm^3$ with before and the bandwidth of the proposed one for GSM850/900 bands is increased 13 MHz than before. Further we confirmed that the proposed antenna has higher radiation gain of -4.45~-2.29 dBi for GSM850/900 bands than PCB embedded antenna without metal structure.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.45 no.5
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• pp.523-526
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• 2012

This study evaluated the effects of the number of feeding days and feeding rate on the growth of growing-out flounder Paralichthys olivaceus. Three replicated groups of fish ($141{\pm}1.9g$) were hand-fed a commercial feed under different feeding regimes for 9 weeks. Fish in group 6F-1S were fed to satiation twice daily for 6 consecutive days and starved for 1 day. Fish in groups 4F-1S and 3F-1S were fed to satiation twice daily for 4 and 3 days, respectively, and starved for 1 day. Fish in group 6F-90% were fed a diet of 90% of 6F-1S twice daily for 6 consecutive days and starved for 1 day. The weight gain, feed efficiency and daily feed intake of the fish groups in 4F-1S and 3F-1S were not significantly different from those of group 6F-1S. The weight gain and feed efficiency of fish in group 6F-90% were not significantly different from those of group 6F-1S. The results of this study suggest that the growth of growing-out flounder fed to satiation twice daily for 4 or 3 days after starving 1 day was similar to that of fish fed to satiation for 6 days, and that the proper feeding rate for growth could be lowered to 90% of satiation without growth suppression.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.27 no.4
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• pp.342-349
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• 2016

We design a displaced-axis Gregorian dual antenna in the form of a metal reflectarray antenna for millimeter wave region, W-band. Unlike a reflectarray composed of printed patch antennas on a dielectric substrate, metallic rectangular waveguide unit-cells are proposed to avoid the loss of substrate and take an advantage of ease of typical metal machining fabrication. In this paper, the radiation characteristics of constructed metal reflectarray antennas show ultra high-gain antenna over 50 dBi at a target frequency in W-band. The experimental measurements are conducted in millimeter-wave compact range antenna measurement system.

• Korean Journal of Child Studies
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• v.21 no.3
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• pp.41-51
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• 2000

This study discusses the interpretation and application of a post modern perspective to child development knowledge and early childhood teacher education. The survey of literature focused on the post modern approach to child development knowledge and early childhood teacher education, research in the reassessment of child development knowledge as it is challenged by the post modern perspective, and deconstruction of both child development knowledge and early childhood teacher education. It was concluded that child development knowledge is necessary but insufficient to early childhood teacher education. In the post modern perspective, the movement toward fostering "reflective practitioners" and basic knowledge base is more significant. Therefore, the responsibility of academics is to walk the fine line between presenting a formal knowledge base so that students gain assumption to guide their thinking and practice, critiquing both theory and derived practices.

• Journal of the Korean Solar Energy Society
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• v.30 no.3
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• pp.47-54
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• 2010

Recently the researchers has been interested in the development of the high performance windows such as solar control window using automatic shading devices, air-flow window, selective coating window. In order to assess the energy performance of total fenestration system, the net energy gains or losses through the glazings and windows should be evaluated. It depends on the thermal transmittance (U-value) and the total solar energy transmittance (SHGC, g-value). This study aims to measure the solar heat gain coefficient according to the NFRC 201 standard test method. In results, we could find the result of different SHGC of the glazing system with a different slat angles. The SHGC in case of $90^{\circ}$ of internal slat angle with regard to the window surface is about 0.56, that in case of $45^{\circ}$ is about 0.49 and that in case of $0^{\circ}$ is about 0.33. Significant dependence on the solar radiation intensity and incident angle was found in comparison of the measured and simulated SHGC.

• Journal of Biosystems Engineering
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• v.24 no.5
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• pp.425-430
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• 1999

Complex environmental control systems were developed, which control properly the pig's environment in windowless pig-housing based on the thermoregulatory behaviors of pigs and concentrations of noxious gases (CO2 and NH3). The this study was conducted to assess the performance of complex environmental control systems by raising weaned piglets and growing pigs under different seasonal conditions. Average daily gain of pigs in the experimental pig-housing was slightly higher than that of pigs in the conventional pig-housing. Average daily gain was not significantly different in winter and spring(P＞0.05), but was significantly different in summer(P＜0.05). Feed conversion rate of pigs in the experimental pig-housing was smaller than that of pigs in the conventional pig-housing. Feed conversion rate was not significantly different in environment for weaned piglets and growing pigs resulted in the improved daily gain, feed conversion rate, and carcass quality of the finishing pigs. These results showed that the performance of the complex environmental control systems in windowless pig-housing was excellent for weaned piglets and growing pigs.

• Asian-Australasian Journal of Animal Sciences
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• v.11 no.1
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• pp.17-20
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• 1998

Sixteen local sheep (8 male + 8 female) of about six months old with average live weight 10.78 $({\pm}1.11)$ kg were allocated into four treatments. The treatments (T) are : $T_0$ = Restricted grazing without concentrate; $T_1$, $T_2$ and $T_3$ = Grazing + 100, 200 and 300 g concentrate per sheep daily. Live weight of grazing (7.30 hrs daily) sheep was recorded in each week. The uncastrated male sheep were slaughtered for carcass and non-carcass parameters. Statistically significant (p < 0.05) differences were observed in live weight gain (g/day) among the treatments ($T_0=15.71$; $T_1=22.66$; $T_2 =32.66$ and $T_3=40.47$). The dressing % were : ($T_0=32.75$, $T_1=38.50$, $T_2=36.90 $ and $T_3=37.75$). The warm carcass weight represented 37.21% of live weight. Significant (p < 0.01) correlation were observed for live weight with carcass weight (r = 0.99) and dressing % (r = 0.88). Concentrate supplement increase live weight gain in sheep on grazing. Live weight is a good indicator to assess carcass characteristics.

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.8
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• pp.1192-1199
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• 1999

Two cultivars of subterranean clover (Trifolium subterraneum L.), "Dinninup" and "Seaton Park" were sown at Shenton Park Field Station, Western Australia, in May 1992 and 1993. The characteristics of Dinninup related to animal production were compared with Seaton Park under grazing conditions with herbage utilization efficiencies of 60% in 1992 and 65% in 1993. The results showed that Dinninup and Seaton Park had similar dry matter digestibility (77-78%) and dry matter production (1,290 kg/ha in 1992; 930 kg/ha in 1993) before flowering initiation even though Dinninup had more (p<0.05) branches, leaves and petioles per plant. After flowering, the herbage on offer of Dinninup was higher (p<0.05) and dry matter digestibility was lower (p<0.05) than that of Seaton Park while the sward structure was similar for both cultivars. The variation in nutritive value among plant parts increased with maturation. Leaf was more digestible than stem and petiole with a higher nitrogen content, and stem had the lowest dry matter digesitibility and nitrogen content in late of the season. Sheep did not show any preference for Seaton Park over Dinninup. The predicted bodyweight gain of sheep grazing pure Seaton Park and Dinninup swards using Grazfed software indicated that sheep grazing Dinninup were predicted to have a similar bodyweight gain in early growing stage and a significantly lower gain after flowering compared with those grazing Seaton Park.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.10
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• pp.1329-1334
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• 2011

The Hinai-dori is a breed of chicken native to Akita Prefecture, Japan. An $F_2$ resource population produced by crossing low- and high-growth lines of the Hinai-dori breed was analyzed to detect quantitative trait loci (QTL) for growth traits. Highly significant QTLs for body weight at 10 and 14 weeks of age and average daily gain between 4 and 10 weeks and between 10 and 14 weeks of age were accordingly mapped in a common region between ADL0198 and ABR0287 on chromosome 1 and between MCW0240 and ABR0622 on chromosome 4, respectively. A significant QTL for body weight at 4 weeks of age and a significant QTL for average daily gain between 0 and 4 weeks of age were mapped for the first time to the same region flanking ABR0204 and ABR0284 on chromosome 1. These QTLs are good candidates for application in the development of marker-assisted selection strategies for increasing growth efficiencies in the Hinai-dori breed and native breeds of chickens in Asia.

• Journal of the Korean Society of Propulsion Engineers
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• v.20 no.1
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• pp.28-36
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• 2016

Theoretical model of a variable thrust solid rocket motor with a pintle nozzle was derived. For the chamber pressure control, classical model linearization and proportional-intergral controller was used. And then two types of gain scheduling controller were suggested to imporve controller performance for the non-linear propulsion model. Considering characteristics of systems, control gains were scheduled by chamber pressure or free volume. Step responses of each controllers were compared. As a result, the proper control algorithm about characteristics of variable thrust rocket motor was suggested.