• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.2
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• pp.136-142
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• 2010

In this paper, the microstrip antenna for penta-band service is proposed. It is designed for a wide band characteristic based on a monopole line combined with a triangular patch structure which has two slits. Total antenna size is $35\;mm{\times}20\;mm$ and it was fabricated on FR-4 substrate($\varepsilon_r=4.4$) which has $35\;mm{\times}75\;mm{\times}1\;mm$ size and a microstrip line with impedance 50 ohm is used. Experimental result shows the impedance bandwidth($VSWR{\leq}3$) of the proposed antenna operated within GSM/DCS/USPCS/UMTS/Bluetooth frequency band. The resonance frequency of the proposed antenna is 0.92, 1.97, 2.45 GHz and the average gain is -2.18, -0.66, -0.58 dBi. Also, the radiation efficiency is 60, 85, 87%. The fabricated antenna is satisfied with the aimed impedance bandwidth ($VSWR{\leq}3$) in GSM/DCS/ USPCS/UMTS/Bluetooth frequency band.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.26 no.12A
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• pp.2000-2011
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• 2001

In this Paper, we convert conventional low speed(1x, 6x) DVD systems designed by analog PLL(Phase Locked Loop) into digital PLL to operate at high speed systems flexibly, and present optimal DPLL model in high speed(20x) DVD systems. Especially, we focused on the design of DPLL that can overcome channel effects such as bulk delay, sampling clock frequency offset and asymmetry phenomenon in high speed DVD systems. First, the modified Early-Late timing error detector as digital timing recovery scheme is proposed. And the four-sampled compensation algorithm using zero crossing point as asymmetry compensator is designed to achieve high speed operation and strong reliability. We show that the proposed timing recovery algorithm provides enhanced performances in jitter valiance and SNR margin by 4 times and 3dB respectively. Also, the new four-sampled zero crossing asymmetry compensation algorithm provides 34% improvement of jitter performance, 50% reduction of compensation time and 2.0dB gain of SNR compared with other algorithms. Finally, the proposed systems combined with asymmetry compensator and DPLL are shown to provide improved performance of about 0.4dB, 2dB over the existing schemes by BER evaluation.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.39 no.3
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• pp.140-149
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• 2002

This paper describes the characteristics of beam-tilting slot away waveguide antennas for mobile DBS reception. As a basic study of slotted waveguide array, design for 16 slot elements located on a broad-wall waveguide is considered. Design parameters such as slot length, space between each slot and cross slot angle of antennas with the beam-tilting characteristics are calculated by method of moments. Based on these results, the radiation waveguide antennas with 16-element $\times$16-array are designed and fabricated. The measured main beam direction angles of the fabricated antennas are 48$^{\circ}$to 50$^{\circ}$depending on the measured frequencies and it shows good agreement with prediction. The measured 3 dB beam width of elevation pattern is about 13$^{\circ}$, and the axial ratio and the gain measured at DBS band are observed 2.8 dB below and 24 dBi above, respectively. In order to evaluate a performance of the fabricated waveguide planar antenna, it is combined with the satellite tracking control system and the field performance test of antenna mounted on a mobile vehicle is carried out at highway. During the measurement, it was possible to watch television without a break signal in a driving vehicle and an excellent performance of the proposed antennas was demonstrated.

• Journal of Periodontal and Implant Science
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• v.46 no.6
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• pp.382-395
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• 2016

Purpose: Alendronate has been proposed as a local and systemic drug treatment used as an adjunct to scaling and root planing (SRP) for the treatment of periodontitis. However, its effectiveness has yet to be conclusively established. The purpose of the present meta-analysis was to assess the effectiveness of SRP with alendronate on periodontitis compared to SRP alone. Methods: Five electronic databases were used by 2 independent reviewers to identify relevant articles from the earliest records up to September 2016. Randomized controlled trials (RCTs) comparing SRP with alendronate to SRP with placebo in the treatment of periodontitis were included. The outcome measures were changes in bone defect fill, probing depth (PD), and clinical attachment level (CAL) from baseline to 6 months. A fixed-effect or random-effect model was used to pool the extracted data, as appropriate. Mean differences (MDs) with 95% confidence intervals (CIs) were calculated. Heterogeneity was assessed using the Cochrane ${\chi}^2$ and $I^2$ tests. Results: After the selection process, 8 articles were included in the meta-analysis. Compared with SRP alone, the adjunctive mean benefits of locally delivered alendronate were 38.25% for bone defect fill increase (95% CI=33.05%-43.45%; P<0.001; $I^2=94.0%$), 2.29 mm for PD reduction (95% CI=2.07-2.52 mm; P<0.001; $I^2=0.0%$) and 1.92 mm for CAL gain (95% CI=1.55-2.30 mm; P<0.001; $I^2=66.0%$). In addition, systemically administered alendronate with SRP significantly reduced PD by 0.36 mm (95% CI=0.18-0.55 mm; P<0.001; $I^2=0.0%$) and increased CAL by 0.39 mm (95% CI=0.11-0.68 mm; P=0.006; $I^2=6.0%$). Conclusions: The collective evidence regarding the adjunctive use of alendronate locally and systemically with SRP indicates that the combined treatment can improve the efficacy of non-surgical periodontal therapy on increasing CAL and bone defect fill and reducing PD. However, precautions must be exercised in interpreting these results, and multicenter studies evaluating this specific application should be carried out.

• Journal of Korean Society for Atmospheric Environment
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• v.23 no.5
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• pp.547-556
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• 2007

The release, sampling and analytical methods have been developed and tested for perfluorocarbons (PFCs) atmospheric tracers in order to gain insight into the atmospheric transport and dispersion over the urban conditions of Seoul, Korea. Although PFCs tracer experiments provide unique opportunities to test local and urban scale of transport and dispersion, no previous experiment with PFCs has been conducted in Korea. PMCH and PDCH were chosen as targeted tracers in our study due to their extreme low ambient concentrations and great sensitivities among various PFCs. For PFCs release system, a set of micro-metering pump, electronic balance, vaporizing furnace and high speed blower was constructed for precise and accurate release of tracers. The precision of released rate by this system was estimated to be 1%. Samplings of PFCs were carried out by fabricated portable air samplers with micro pumps and rotameters into glass tubes packed with 150 mg of Carboxen-569. The uncertainty of these sampling system was maintained below 14%. PMCH and PDCH were quantified in GC/ECD with preconditioned injection system to eliminate the interference compounds using traps and subsequent catalytic conversion system prior to column separation. Three intensive field test were undertaken during the springtime of 2002 to 2004 in eastern part of Seoul. Daily background samples were collected to characterize the background levels of PMCH and PDCH prior to their release. The observed background concentrations of PMCH ranged from 3.5 to 10.1 fL/L and varied randomly in location and time in this study. Its mean and standard variation of background concentration ($6.8{\pm}1.9\;fL/L$) are higher than those ($3.2{\sim}5.8\;fL/L$) of other historic tracer studies. Identified uncertainty for background PMCH was $1.7{\sim}2.0\;fL/L$ using this analytical system. Combined relative uncertainty in determining the tracer's concentrations was estimated as 17%. However, its background concentrations and uncertainty in concentration determination were found to be low and stable enough for tracer study.

• Asian-Australasian Journal of Animal Sciences
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• v.5 no.2
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• pp.261-266
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• 1992

Yearling replacement heifers were used in a two-year study at the Fort Stanton Experimental Ranch near Capitan, New Mexico, USA to compare frequency (once versus three times weekly) of feeding a cottonseed cake supplement. The study involved periods of 130 days (January 4 through May 14) in 1985, and 146 days (December 4 through April 29) in 1986. In each year, supplemental periods were just before the breeding season (natural breeding in multiple-sire groups) that lasted for 75 days during first year and 60 days during second year. During the first year, all (83) heifers (Angus $\times$ Hereford) were supplemented at a level equivalent to 45 kg/head daily and during second year, all (69) heifers (Angus $\times$ Hereford, Hereford) were fed at a level equivalent to .68 kg/head daily. In the first year, heifers were sorted by initial weight into two replications, i.e., those weighing under 223 kg were placed in replicate 1 and those weighing over 223 kg were placed in replicate 2. During the second year, heifers were sorted by breed into two replications, i.e., Angus $\times$ Hereford heifers were placed in replicate 1 and Hereford heifers in replicate 2. Each year, half of the heifers in each replication were supplemented once weekly and the other half three time weekly. Weight gains of heifers were similar for the two treatments over both years of study. During the first year, weight gains for heifers supplemented once or thrice weekly (.23 vs .21 kg daily, respectively) did not differ (p>.05) and the same trend for the second year (.15 vs .16 kg daily, respectively) was observed. Similarly, breeding performance was consistent with weight gains and no difference (p>.05) between treatments was observed either year. Lower conception rates during the second tear of study (92 vs 72% for years 1 and 2, respectively) were due mainly to involvement of Hereford heifers that had an average weight of 232 kg at the start of breeding season and conception rate of 54% (averaged across both supplemental treatments). Based on the combined results of both trials, frequency of supplementation did not affect growth rate of yearling heifers nor did it influence their subsequent conception rate.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.10
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• pp.2223-2231
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• 2015

In this paper, we propose a built-in antenna for wireless USB dongle which has a modified structure from the existing planar monopole antenna. The proposed antenna implemented a dual-band characteristic by inserting Strip1, Strip2, Strip3 into the monopole structure combined with 'n' shape and feeded 50-Ω using coaxial cable. The antenna is designed on an FR-4 substrate of which the dielectric constant is 4.6, and its overall size is 10 mm × 50 mm × 1mm. Based on the measurement results of the return loss, it was confirmed to satisfy the dual band resonance characteristics of 740 MHz (2.3 ~ 2.7 GHz) and 1,200 MHz (5.15 ~ 5.825 GHz) by -10 dB. In addition, we obtain the omni-directional radiation pattern measurements in the operating frequency bands, and the maximum gain of the proposed antenna has 2.26~3.81 dBi in the 2.4 GHz band and 2.21~5.79 dBi. in the 5.5 GHz band, respectively.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.3
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• pp.394-400
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• 2004

To investigate the efficacy of alternatives to antibiotics, the present study was conducted to compare the effects of antibiotic, lactic acid, a blend of commercial essential oils (EOs) and EOs in combination with lactic acid on growth performance and the functional activity of the gut in broiler chickens. A total of 168 broiler chickens were given the basal diet supplemented with 10 ppm colistin (T1), 0.1% lactic acid (T2), 25 ppm EOs (T3), 25 ppm EOs+0.1% lactic acid (T4), 50 ppm EOs (T5) or 50 ppm EOs+0.1% lactic acid (T6) in the period 3 to 35 days of age. As a result, the broiler chickens assigned to T4 group throughout the experimental period had apparently (p<0.05) greater body weight and total gain than these assigned to T1, T2, T3 and T5 groups. However, there was no difference in growth performance among the birds fed the diets supplemented with antibiotic (T1), lactic acid (T2) and EOs (T3 and T5) alone. The weights of digestive organs and the number of lactobacilli and E. coli in the lower ileum were not affected by dietary treatments. Total trypsin activity was significantly (p<0.05) greater in T4 than T1, T2, T3 and T5 groups. Total and specific pancreatic $\alpha$-amylase activities were significantly (p<0.05) enhanced in the broiler chickens fed T4 diet compared with these fed T1, T2 and T3 diets. However, there were no differences in growth performance and digestive enzyme activities including pancreatic trypsin and $\alpha$-amylase between T4 and T6 groups fed the diets supplemented with either low or high EOs levels in combination of lactic acid. In conclusion, a blend of commercial EOs combined with lactic acid showed significant increases in digestive enzyme activities of the pancreas and intestinal mucosa, leading to increase in growth performance.

• Fisheries and Aquatic Sciences
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• v.13 no.4
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• pp.294-299
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• 2010

The effects of dietary nutrient composition on compensatory growth of grower olive flounder (Paralichthys olivaceus) under different feeding regimes at suboptimal temperature were determined. Four hundred five fish weighing 271.2 g were distributed into 27 300 L flow-through tanks (15 fish per tank). Nine treatments were prepared in triplicate: fish were hand-fed with control (C) diet for 12 weeks (12WF-C); four groups of fish were starved for 1 week and then fed C, high-protein (HP), high-lipid (HL), or combined high-protein and high-lipid (HPL) diets for 11 weeks; these groups are referred to as 11WF-C, 11WF-HP, 11WF-HL, and 11WF-HPL, respectively. Four other groups of fish were starved for 2 weeks and then fed C, HP, HL, and HPL diets for 10 weeks; these groups are referred to as 10WF-C, 10WF-HP, 10WF-HL, and 10WF-HPL, respectively. Weight gain and specific growth rate of fish from 12WF-C group were greater than those of fish from 11WF-C, 11WF-HP, 11WF-HL, 10WF-C, 10WFHP, and 10WF-HL groups, but not different from those of fish from 11WF-HPL and 10WF-HPL groups. Feed-efficiency ratio of fish from 12WF-C, 11WF-HP, 11WF-HPL, 10WF-HL, and 10WF-HPL groups was higher than that of fish in 11WF-C, 11WF-HL, 10WF-C, and 10WF-HP groups. The results of this study demonstrated that grower olive flounder subjected to 1- or 2-week feed deprivation were able to achieve full compensatory growth at suboptimal temperature only when fed HPL diet.

• Journal of the Korean Solar Energy Society
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• v.32 no.4
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• pp.24-33
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• 2012

Recently, finishing materials at spandrel area, a part of curtain-wall system, are gradually forced to improve thermal insulation performance in order to enhance the building energy efficiency. Also, Building Integrated Photovoltaics(BIPV) systems have been installed in the exterior side of the spandrel area, which is generally composed of windows. Those BIPVs aim to achieve high building energy efficiency and supply the electricity to building. However, if transparent BIPV module is combined with high insulated spandrel, it would reduce the PV efficiency for two major reasons. First, temperature in the air space, located between window layer and finishing layer of the spandrel area, can significantly increase by solar heat gain, because the space has a few air density relative to other spaces in building. Secondly, PV has a characteristics of decreased Voltage(Voc and Vmp) with the increased temperature on the PV cell. For these reasons, this research analyzed a direct interrelation between PV Cell temperature and electricity generation performance under different insulation conditions in the spandrel area. The different insulation conditions under consideration are 1) high insulated spandrel(HIS) 2) low insulated spandrel(LIS) 3) PV stand alone on the ground(SAG). As a result, in case of 1) HIS, PV temperature was increased and thus electricity generation efficiency was decreased more than other cases. To be specific, each cases' maximum temperature indicated that 1) HIS is $83.8^{\circ}C$, 2) LIS is $74.2^{\circ}C$, and 3) SAG is $66.3^{\circ}C$. Also, each cases yield electricity generation like that 1) HIS is 913.3kWh/kWp, 2) LIS is 942.8kWh/kWp, and 3) SAG is 981.3kWh/kWp. These result showed that it is needed for us to seek to the way how the PV Cell temperature would be decreased.