• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.10 no.7
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• pp.998-1009
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• 1999

In this paper, a microstrip aperture-patch antenna and a microstrip ring antenna, which have single microstrip line feeding systems for the circular polarization, are designed, and experimental results are presented at X-band. The microstrip aperture-patch antenna is characterized by its wide operating frequency range, and the microstrip ring antenna is suitable for a basic radiator in the large array antenna due to its small size. Several design parameters for these antennas are considered and analyzed to improve antenna characteristics such as VSWR bandwidth and axial ratio. Initially, the sizes of the aperture and ring radiator are determined on a basis of the cavity model, then shapes of the patch within the aperture and the inner stub of the ring are optimized using Ensemble software. Measurement results show that the aperture-patch antenna has 25% of VSWR bandwidth and 1.2dB of axial ratio at the boresight, and the ring antenna has 6.7% of VSWR bandwidth and 1.6dB of axial ratio at the boresight.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.5
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• pp.1270-1276
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• 2010

In this paper, Quad-Band small antenna for GSM850, GSM900, DCS1800, DCS1900 is designed and fabricated. The antenna achieved the size reduction of over 67.9 % than the conventional PIFA(Planar Inverted-F Antenna) by using a MD(Magneto-Dielectric) material. A simple feeding microstrip line is used to feed the antenna from a $50{\Omega}$ coaxial line, which is capacitively coupled to the grounded patch structure for broadband characteristics. The impedance bandwidth the proposed antenna shows good results as broadband characteristics of 1341 MHz (801 ~ 2142 MHz) in VSWR < 3 (${\leq}\;-6\;dB$) and the gain is -6.67 ~ 4.25 dBi in the operating frequency.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.6
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• pp.984-989
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• 2008

In this paper, we will design a 800MHz broadband antenna after a problem of the narrow bandwidth is improved. This multiple band antenna unifies the CDMA(Code Division Multiple Access), GSM(Global System for Mobile Telecommunication) and TRS(Trunked Radio System) band in the UHF band, and then it is possible at the shore base station or repeater as the commercial use. It used the duplex resonance effect it had the L-shared feeding structure which adds the U-slot. And it improved profit using stack structure. It was measured that the frequency bandwidth of the designed antenna which is planed $792{\sim}1040MHz$ with 248MHz(33%). And the antenna gain is 9.4dBi, 3dB beam width $60^{\circ}$ in radiation pattern.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.3
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• pp.395-400
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• 2021

In this paper, the wideband patch antenna is simulated and manufactured for the wireless LAN of 5GHz band that is defined in IEEE 802.11a. In the 802.11a, 200 channels of 675MHz are defined. Therefore, the bandwidth is needed more than 12.3%. For the wideband characteristics, low dielectric constant is realized with the multi-layer of 2 teflon substrates and the air dielectric layer and the feeding method of the coupled-line is used. Optimized wideband patch antenna is simulated with the return loss of 38.99dB at the center frequency of 5.43GHz and the bandwidth of 12.9%. The gain of manufactured patch antenna is 4.38, 4.52, and 5.12dBi at the channel number of 46, 56, and 153, respectively.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.6
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• pp.740-747
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• 2019

In this paper, an antenna applicable to WLAN and WiMAX frequency bands is designed, fabricated, and measured. The proposed antenna is designed to have two branch strip line in the patch plane and a rectangular slit in the ground plane based on microstrip feeding for triple band characteristics and added a vertical strip in the ground plane to enhance impedance bandwidth characteristics. The proposed antenna is designed on a substrate with a relative permittivity of 4.4, a thickness of 1.0 mm, and has a size of $18.0mm(W1){\times}37.3mm$ (L4+L5+L7). From the fabricated and measured results, impedance bandwidths of 480 MHz (2.32 to 2.80 GHz) for 2.4/2.5 GHz band, 810 MHz (3.22 to 4.03 GHz) for 3.5 GHz band, and 1,820 MHz (5.05 to 6.87 GHz) for 5.0 GHz band were obtained based on the impedance bandwidth. Measured 3D pattern and gains are displayed.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.22 no.1
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• pp.63-71
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• 2019

Purpose: The aim of this study was to identify the minimally meaningful dosage of inulin leading to a prebiotic effect in Indonesian infants. Methods: In a randomized controlled double-blinded, parallel, 3-arm intervention study, 164 healthy formula-fed infants aged 3 to 5 months first obtained formula-A (without inulin) during a 4-week adaptation period. Subsequently, 142 subjects were subjected to a 4-week feeding period by administering either formula-A (no inulin), formula-B (0.2 g/100 mL inulin) or formula-C (0.4 g/100 mL inulin). The primary outcome parameter was %-bifidobacteria in faecal samples determined using quantitative polymerase chain reaction analyses. Secondary outcome parameters were faecal %-lactobacilli, pH and stool frequency, and consistency. Growth and tolerance/adverse effects were recorded as safety parameters. Results: Typical %-bifidobacteria and %-lactobacilli at the end of the adaptation period in the study population were 14% and 2%, respectively. For faecal pH, significant differences between formula groups A vs. C and A vs. B were found at the end of the intervention period. Testing for differences in faecal %-bifidobacteria and %-lactobacilli between groups was hampered by non-normal data set distributions; no statistically significant differences were obtained. Comparisons within groups revealed that only in formula group C, all the three relevant parameters exhibited a significant effect with an increase in faecal %-bifidobacteria and %-lactobacilli and a decrease in pH. Conclusion: A consistent prebiotic effect along with a decrease in pH and increase in %-bifidobacteria and %-lactobacilli was found only in the group administered 0.4 g inulin/100 mL.

• The Journal of Korean Institute of Information Technology
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• v.16 no.11
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• pp.77-84
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• 2018

In this paper, the circular polarization microstrip patch antenna using the T-junction power divider is proposed. The operating frequency of the proposed antenna is ISM band of 2.4GHz and the circular polarization is induced by feeding a phase difference of $90^{\circ}$ in two edges. The structure of the antenna consists of a general patch and a T-junction power divider. Furthermore, to optimize the proposed antenna, it is analyzed the reflection coefficient, the axial ration and the radiation pattern. The impedance bandwidth of the antenna is observed to be 40MHz within a range of 2.39 to 2.43GHz, similarly, the axial ratio bandwidth is observed having the bandwidth of about 12MHz in 2.398 to 2.410GHz range. The radiation pattern of the antenna is seen to be right circular polarization. Furthermore, the gain of the antenna is observed to be 2.04 and 3.4dBic at XZ and YZ-plane, respectively.

• Korean Journal of Poultry Science
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• v.46 no.3
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• pp.155-160
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• 2019

The Korean Hanhyup broiler has commercialized native meat-type chicken. This study aimed to determine the effects of two types of litter material-sawdust and rice husk, and gender on the Korean Hanhyup broiler. Chicks (n=416) were randomly assigned in a $2{\times}2$ factorial design by type of litter material and gender. The behavior of chicken's was monitored continuously for 12 hours during the $1^{st}$ through $8^{th}$ week of age. The time spent on standing, sitting, and walking and the frequency of drinking, feeding, preening, dust bathing, flapping, and aggressive pecking, and pecking of chicken's behavior were recorded. The behavior of chickens during the starter (1 to 4 weeks) and finisher period (5 to 8 weeks) was compared to observe the changes upon maturity. Our results indicate that litter material type and gender have no effect on the behavior of chickens. However, aggressive pecking and pecking caused increment in the rice husk as compared to sawdust (P<0.05). Sawdust as litter material for bedding was found to be better than rice husk with respect to Korean Hanhyup broiler behavior.

• Korean journal of applied entomology
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• v.60 no.1
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• pp.105-114
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• 2021

Ground-dwelling arthropods are important components in apple orchard providing beneficial ecological services of predation and decomposition as well as herbivory. Groundcovers are managed differentially in organic and conventional apple orchards influencing ground-dwelling arthropod assemblages. We conducted 3-year studies to assess the effects of orchard management relative to weed management on the abundance and diversity of ground-dwelling arthropods using pitfall trapping. Most arthropods were classified as higher taxonomical groups and functional feeding guilds, while carabid beetles were classified into species level. Coleoptera was the dominating taxon of all ground-dwelling arthropods. Abundance of herbivores and predators was significantly higher in organic apple orchards than conventional ones. Higher abundance and diversity of carabid beetles were found in organic orchards than in conventional orchards. The abundance of Araneae, Coleoptera, or carabid beetles was negatively correlated to weed management frequency. It was found that ground-dwelling arthropods were more influenced by weed management practices than the farming systems.

• Archives of Craniofacial Surgery
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• v.22 no.1
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• pp.33-37
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• 2021

Background: Children with cleft lip and/or palate can be undernourished due to feeding difficulties after birth. A vicious cycle ensues where malnutrition and low body weight precludes the child from having the corrective surgery, in the absence of which the child fails to gain weight. This study aimed to identify the proportion of malnutrition, including the deficiency of major micronutrients, namely iron, folate and vitamin B12, in children with cleft lip and/or palate and thus help in finding out what nutritional interventions can improve the scenario for these children. Methods: All children less than 5 years with cleft lip and/or cleft palate attending our institute were included. On their first visit, following were recorded: demographic data, assessment of malnutrition, investigations: complete blood count and peripheral blood film examination; serum albumin, ferritin, iron, folate, and vitamin B12 levels. Results: Eighty-one children with cleft lip and/or palate were included. Mean age was 25.37±21.49 months (range, 3-60 months). In 53% of children suffered from moderate to severe wasting, according to World Health Organization (WHO) classification. Iron deficiency state was found in 91.6% of children. In 35.80% of children had vitamin B12 deficiency and 23.45% had folate deficiency. No correlation was found between iron deficiency and the type of deformity. Conclusion: Iron deficiency state is almost universally present in children with cleft lip and palate. Thus, iron and folic acid supplementation should be given at first contact to improve iron reserve and hematological parameters for optimum and safe surgery.