• Proceedings of the KIEE Conference
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• 1988.07a
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• pp.335-338
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• 1988

A numerical method is presented for the scattering by the perfectly conducting cylinder with arbitrary cross sections. The relevant integral equation considered by the E-field formulation is solved by method of moments, and thereby the surface current induced as well as the radar cross section of the scatterer are numerically computed to specify the scattering nature of the scatterer. Two separate methods, one with point matching and the other Galerkin's method, are considered to make cross checks to the results obtained. Taking two half pulses suggested to expand the surface current shows savings in computation time and accurate solutions for the corners on the scatterer.

• Korean Journal of Poultry Science
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• v.40 no.1
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• pp.41-47
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• 2013

This work was carried out to investigate performance and carcass yield of large-type broiler females at different stocking densities. Chicks (n = 492; 1-day-old; female; Arbor Acre broiler) were reared for six weeks (starter, 0~1 wk; earlier, 1~3 wk; finisher, 3~6 wk) and randomly divided into 3 treatments (4 replications/treatment, 36, 41 or 46 birds/replication). Treatments were T1 (10.9 birds/$m^2$), T2 (12.4 birds/$m^2$) and T3 (13.9 birds/$m^2$) by the stocking densities. Research indexes were livability, body weight, body weight gain, feed intake, feed conversion ratio, production efficiency factor, carcass yield and primal cuts ratio (wing, leg, back, breast and neck). Livability (%) was 90% or more for all treatments, but there was no significant difference on weekly livability (%). Body weight of T3 treatment were the lowest at 3 wk and body weight gain, feed intake, and feed conversion ratio were the lowest at 2~3 wk (P<0.05). Production efficiency factors of T1, T2 and T3 were 331.0, 340.8 and 336.0, respectively, and there was no significant difference among treatments. Leg meat ratio of T2 treatment was higher compared to other treatments at the age of 4 wk (P<0.05). Carcass yield of T1 treatment was the highest as 76.2% at the age of 5 wk (P<0.05). However, there was no significant difference on carcass ratio and partial meat ratio among treatments at the age of 6 wk. This result may provide the standard data of different stocking densities for heavy female broilers.

• Korean Journal of Organic Agriculture
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• v.31 no.4
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• pp.453-460
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• 2023

This study was conducted to confirm the growth performance of Hanwoo steers according to the crude protein and calcium levels and their effects on carcass characteristics. The experiment consisted of a total of 4 groups: HPHC (CP 15%, Ca 1.2%), HPLC (CP 15%, Ca 0.6%), LPHC (CP 12.5%, Ca 1.2%), LPLC (CP 12.5%, Ca 0.6%). In the feeding trial, Hanwoo steers (650.8±16.27 kg, n = 32, 24 months of age) were divided into four feeding groups (n = 8 each) with the same initial body weight. Animals were fed with each rice straw and concentrate (1:9) until the late fattening stage. Growth performance was measured by daily weight gain, feed conversion rate, and final weight. Carcass characteristics were measured carcass weight, loin area, back-fat thickness and marbling score. There was no significant difference in growth performance and carcass characteristics among the treatment groups. However, the ratio of meat quality grade 1⁺ or higher was 76% in LPLC, which was higher than other treatments (HPHC, 63%; HPLC, 63% and LPHC, 50%). Therefore, reducing crude protein in the feed did not affect growth and carcass characteristics. In addition, calcium control in the late fattening stage did not affect growth performance. In LPLC, the ratio of meat quality 1⁺ or higher was the highest, so additional research on calcium control in feed is thought to be necessary. However, there was no significant difference in the relationship between protein and calcium levels in feed in all study results, so the influence of the two factors on each other is thought to be low.

• Journal of Advanced Navigation Technology
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• v.12 no.5
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• pp.420-428
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• 2008

In this paper, Stack structure patch antenna has been designed and fabricated for wireless LAN applications. The patch and ground plane were used by PEC metal. It was 0.05 [mm] thick. In order to broaden the bandwidth of the antenna and improve of gain, the stack structured antenna with probe feed. The measured input return loss showed less than -10 [dB] at the broadband from 5100 to 6140 [MHz]. It's measured bandwidth was 1040 MHz. The gain of antenna in the E-plane and H-plane was 13 dBi and 3 dB beam width was $40^{\circ}$.

• Journal of Advanced Navigation Technology
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• v.16 no.4
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• pp.635-640
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• 2012

In this paper, The TE (Transverse Electric) scattering problems by a perfectly conducting strip grating over a grounded two dielectric layers are analyzed by applying the conductive boundary condition and the FGMM (Fourier-Galerkin Moment Method) known as a numerical procedure, then the induced surface current density is expanded in a series of the multiplication of the unknown coefficient and the exponential function as a simple function. Generally, the reflected power gets increased according as the relative permittivity ${\epsilon}_{r2}$ and the thickness of dielectric layer $t_2$ of the region-2 in the presented structure gets increased, respectively. The sharp variations of the reflected power are due to resonance effects were previously called wood's anomaly, the numerical results show in good agreement with those of the existing papers.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.5
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• pp.1-5
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• 2010

This paper deals with a method to measure the thickness of scale-layer, iron oxide formed on the surface of the rolling steel, using a dielectric lens antenna. The dielectric lens antenna has an independent characteristic with the frequency in the X-band and changes the spherical wave radiated from a horn antenna into a plane wave at the focusing point. Using this concept, we regard a scale-layer on the rolling steel as a dielectric-PEC(Perfect Electric Conductor) layer and apply a theoretical analysis of the normal-incident plane wave. To reduce the phase error arising from the use of the dielectric lens antenna, this paper utilizes a regression process algorithm. In comparison with the conventional iteration algorithm, the present algorithm led to a unique solution for the thickness of the scale-layer.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.3
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• pp.197-201
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• 2017

The demand for electric power is increasing every year in Korea. All the systems adopted at power stations in order to generate and transmit electric power should operate in perfect condition or reliability. The device for transmitting the generated high-voltage electric power is 6 kV CV single core cables. The manufacturing companies of the cables makes an official announcement that the operating lifetime of their cables is about 30years. But from the moment of operation the deterioration precesses of worsening the characteristics of cables starts. Since the reliability for the status of installed cables in deterioration has not been diagnosed, the cables can be broken at any unexpected moments. In order to prevent the abrupt cable accident by systematically monitoring the cable status, we have invented the first device in Korea. We have installed our device at Korea Western Power Co. Ltd. in order to diagnose the live cables. In this paper, we present our research results of measured temperatures of inner conductor and surface and the compared results of those data with other cable company. We also show that our results agree with those made by other company.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.4 no.4
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• pp.334-340
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• 2003

This study was conducted to evaluate the effects of dietary herbal extracts mixture on the growth rate. carcass traits and serological changes in finishing pigs. For the Exp 1, eighty Duroc(Yorkshir(Landrace pigs(81.58$\pm$3.20kg average initial body weight) were used in a 45 day experiment. Dietary treatments included 1) NC(negative control; antibiotics-free diet), 2) PC(positive control; NC diet added 0.1% of chlortetracycline), 3) NCM(NC diet added 0.1% of herbal plant mixture) and 4) PCM(PC diet added 0.1% of herbal plant mixture). Through the entire experimental period, ADG of pigs fed NCM and PCM diets was greater(P<0.08) than that of pigs fed NC diet. There was interaction of ADG(P<0.01) in pigs fed NC diet with herbal plant mixture compared to pigs fed PC diet with herbal plant mixture. ADFI and G/F tended to increase in PC and NCM treatments. However, there were not significantly differences among the treatments. Total protein of serum was improved by supplementation of the herbal plant mixture in NC diet(P<0.04). For the Exp 2. one hundred Duroc(Yorkshir(Landrace pigs(77.36$\pm$2.01kg average initial body weight) were used in a 28 day experiment. Dietary treatments included 1) NC(negative control; antibiotics-free diet), 2) PC(positive control; NC diet added 0.1% of chlortetracycline), 3) PM0.1(NC diet added 0.1% of herbal plant mixture) and 4) PM0.2(NC diet added 0.2% of herbal plant mixture). Through the entire experimental period, ADG tended to increase in PC treatment. However, there was not significantly difference among the treatments. Carcass weight in NC was higher than other treatments(P<0.06). Backfat thickness was higher in pigs fed PC than other treatments. However, there was not significantly difference among the treatments. A grade appearances of carcass tended to increase in pigs fed PM(P<0.09). In conclusion, the results of the experiments suggest that pigs fed PM could be a beneficial growth performance and serogical immunity for finishing pigs.

• Korean Journal of Poultry Science
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• v.39 no.1
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• pp.45-52
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• 2012

This study was carried out to investigate the growth performance and the carcass ratio of meat-type Korean Native Ducks. Four hundred twenty Korean Native Ducks' chicks were selected and divided into four treatments (7 replications/ treatment, 15 birds/replication) by strains (A and B) and gender(male and female) with $2{\times}2$ fractal factors. There was no significant difference between A and B on the body weight at 2, 4, 6, and 8 weeks old (P>0.05). However, body weight of female was higher at 2 weeks old than male while that of male was higher at the 8 weeks old (P<0.01). Daily feed intake of male was higher compared to female during 6~8 weeks (P<0.05). On weekly body weight gain, there was no significant difference between strains, but gained body weight of male was higher until 2 weeks old while that of female was higher during 6~8 weeks (P<0.01). On the live body weight and carcass weight by strains and genders, B strain was higher than A strains at the 8 weeks of age (P<0.01). Carcass yield was the highest at 8 weeks of age in both strains (P<0.05). These results may provided the basic data on growth performance and carcass ratio of meat-type Korean Native Ducks.

• Journal of Animal Science and Technology
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• v.48 no.6
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• pp.819-826
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• 2006

The objective of the present study was to investigate the effect of dietary supplementation of cultured wild-ginseng powder or its fermented culture byproduct on growth performance, blood parameters, carcass and meat quality in finishing pigs. The animals used in the experiment were a total of 36 Landrace×Yorkshire and weighted 65.81±2.02kg. The experimental diets were basis diet, 2.5% wild-ginseng fermented culture byproduct of B. subtilis replaced lupin in basis diet and 0.2% cultured wild-ginseng powder replaced lupin in basis diet to CON, T1 and T2 for 60 days, respectively. The pigs were allotted at 4 pigs per pen with three replicate pens per treatment by completely randomized design. In growth performance, ADG was not significantly different between treatments. ADFI was significantly lower (P<0.05) in T1 and T2 than in CON. Feed/Gain was not different between treatments. In plasma's biochemical composition, total protein was significantly higher (P<0.05) in T1 than in CON. Blood urea nitrogen was not different between treatments. Glucose and albumin were significantly higher (P<0.05) in T1 than in other treatments. Calcium was significantly higher (P<0.05) in T1 than in CON. Inorganic phosphate was significantly higher in T1 than in other treatments. In plasma's lipid composition, triglyceride was significantly higher (P<0.05) in T1 than in other treatments. Total cholesterol was not different between treatments. HDL cholesterol was significantly higher (P<0.05) in T1 than in other treatments. In carcass and meat quality, carcass weight, dressing precent, meat precent and back-fat thickness were not significantly different between treatments. Moisture and crude fat were also not significantly different between treatments. The results indicate that growth performance, carcass and meat quality were not affected but plasma's biochemical and/or lipid composition were affected when replaced with wild-ginseng fermented culture byproduct of B. subtilis and cultured wild-ginseng. Our research indicates that wild-ginseng fermented culture byproduct of B. subtilis and cultured wild-ginseng powder were able to using with pig's diet in finishing period.