• Title/Summary/Keyword: EBG

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Removing the Resonance due to the Power-Bus Structure using EBG Inductive Sheets (유도성 주기 대역 저지구조를 이용한 적층구조 전원공급면의 불요공진 억제)

  • Kahng, Sung-Tek;Kim, Hyeong-Seok;Jang, Gun-Ho;Lim, Dong-Jin
    • 한국정보통신설비학회:학술대회논문집
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    • 2009.08a
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    • pp.138-140
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    • 2009
  • This paper investigates a method to remove the undesirable resonance of the rectangular power-bus structure(PBS) using an inductive layer. The equivalent surface impedance of the proposed loading is calculated for characterizing the proposed EBG geometry. The effects of the strips and the immediate surroundings are illustrated by a number of numerical experiments.

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Design and SAR Analysis of Wearable Antenna on Various Parts of Human Body, Using Conventional and Artificial Ground Planes

  • Ali, Usman;Ullah, Sadiq;Khan, Jalal;Shafi, Muhammad;Kamal, Babar;Basir, Abdul;Flint, James A;Seager, Rob D.
    • Journal of Electrical Engineering and Technology
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    • v.12 no.1
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    • pp.317-328
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    • 2017
  • This paper presents design and specific absorption rate analysis of a 2.4 GHz wearable patch antenna on a conventional and electromagnetic bandgap (EBG) ground planes, under normal and bent conditions. Wearable materials are used in the design of the antenna and EBG surfaces. A woven fabric (Zelt) is used as a conductive material and a 3 mm thicker Wash Cotton is used as a substrate. The dielectric constant and tangent loss of the substrate are 1.51 and 0.02 respectively. The volume of the proposed antenna is $113{\times}96.4{\times}3mm^3$. The metamaterial surface is used as a high impedance surface which shields the body from the hazards of electromagnetic radiations to reduce the Specific Absorption Rate (SAR). For on-body analysis a three layer model (containing skin, fats and muscles) of human arm is used. Antenna employing the EBG ground plane gives safe value of SAR (i.e. 1.77W/kg<2W/kg), when worn on human arm. This value is obtained using the safe limit of 2 W/kg, averaged over 10g of tissue, specified by the International Commission of Non Ionization Radiation Protection (ICNIRP). The SAR is reduced by 83.82 % as compare to the conventional antenna (8.16 W/kg>2W/kg). The efficiency of the EBG based antenna is improved from 52 to 74 %, relative to the conventional counterpart. The proposed antenna can be used in wearable electronics and smart clothing.

Nutritional Quality of Breakfast among Korean School-Aged Children and Adolescents Depending on Eating Together as a Family: Based on the Data from the 2013-2014 Korea National Health and Nutrition Survey (가족 동반여부에 따른 학령기 아동 및 청소년 아침식사의 질: 2013-2014년 국민건강영양조사자료를 바탕으로)

  • Hong, Jeongmin;Kim, Meeyoung;Yoon, Jihyun;Kim, So-young
    • Journal of the Korean Society of Food Culture
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    • v.34 no.4
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    • pp.378-388
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    • 2019
  • This study aimed to assess the nutritional quality of breakfast among Korean school-aged children and adolescents depending on eating together as a family, based on the 2013-2014 Korea National Health and Nutrition Survey. One day 24-hour recall data of 1,831 children and adolescents aged from 6 to 17 years were collected. The nutritional quality of breakfast was analyzed and compared between Family Breakfast Group (FBG, n=1,410) and Eating-alone Breakfast Group (EBG, n=421). The results showed that age, family structure, number of family members, and frequency of breakfast were associated with eating breakfast as a family. The calorie intake from breakfast explained 19% and 16% of the daily intake for FBG and EBG, respectively. The percentages of children and adolescents consuming Vitamin A, Vitamin $B_1$, Vitamin $B_2$, Vitamin C, Niacin, and Iron less than 1/4 of the Estimated Average Requirements were significantly lower in FBG than in EBG. The average numbers of serving for "Grains" and "Vegetables" food groups and the average Dietary Diversity Score were significantly higher in FBG than in EBG. Overall, the results indicated that eating breakfast as a family is positively associated with nutritional quality of breakfast among Korean school-aged children and adolescents.

Optimization of a Defected Ground Structure to Improve Electromagnetic Bandgap Performance

  • Kwon, Manseok;Kim, Myunghoi;Kam, Dong Gun
    • Journal of electromagnetic engineering and science
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    • v.14 no.4
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    • pp.346-348
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    • 2014
  • A dispersion analysis is performed to estimate the stopband characteristics of electromagnetic bandgap (EBG) structures with defected ground structures (DGS) of various shapes. Design guidelines are suggested for both elliptical and rectangular DGS patterns that result in a maximum stopband bandwidth for a given perforation area. This method provides a basis for numerical optimization techniques that can be used in synthesizing DGS shapes to meet bandgap requirements and layout constraints.

An Antenna & RF System for Fly-away Satcom Terminal Application on Ka-band (Ka대역 위성통신용 fly-away 터미널 안테나 & RF 시스템 설계)

  • Park, Byungjun;Kim, Chunwon;Yoon, Wonsang;Lee, SeongJae
    • Journal of the Korea Institute of Military Science and Technology
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    • v.17 no.4
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    • pp.485-491
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    • 2014
  • An Antenna & RF system for a fly-away satcom terminal application on ka-band is presented in this paper. The Fly-away satellite terminal can be moved and operated by two person and adapt automatic satellite tracking system in order to decrease the tracking time. Additionally, for low-power consumption, compact size and light-weight, a dual reflector antenna is constructed using dual-offset gregorian antenna structure. For minimize weight, the reflector of the antenna is made of Magnesium. For low-power consumption and light-weight, the pHEMT MMIC compound devices is utilized. The Electronic Band-Gap(EBG) Low-Pass Filter(LPF) is designed for harmonic rejection. In the receiving part, Low-Noise Block converter(LNB) structure is designed for compact and lightweight. In this paper, fly-away satcom terminal with low-power consumption, compact size and light-weight is described with antenna system and RF system performances. Through the experimentation, fly-away terminal's EIRP is more than 50dBW, G/T is more than $17dB/^{\circ}K$.

Nutrient requirements and evaluation of equations to predict chemical body composition of dairy crossbred steers

  • Silva, Flavia Adriane de Sales;Valadares Filho, Sebastiao de Campos;Silva, Luiz Fernando Costa e;Fernandes, Jaqueline Goncalves;Lage, Bruno Correa;Chizzotti, Mario Luiz;Felix, Tara Louise
    • Animal Bioscience
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    • v.34 no.4
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    • pp.558-566
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    • 2021
  • Objective: Objectives were to estimate energy and protein requirements of dairy crossbred steers, as well as to evaluate equations previously described in the literature (HH46 and CS16) to predict the carcass and empty body chemical composition of crossbred dairy cattle. Methods: Thirty-three Holstein×Zebu steers, aged 19±1 months old, with an initial shrunk body weight (BW) of 324±7.7 kg, were randomly divided into three groups: reference group (n = 5), maintenance level (1.17% BW; n = 4), and the remaining 24 steers were randomly allocated to 1 of 4 treatments. Treatments were: intake restricted to 85% of ad libitum feed intake for either 0, 28, 42, or 84 d of an 84-d finishing period. Results: The net energy and the metabolizable protein requirements for maintenance were 0.083 Mcal/EBW0.75/d and 4.40 g/EBW0.75, respectively. The net energy (NEG) and protein (NPG) requirements for growth can be estimated with the following equations: NEG (Mcal/kg EBG) = $0.2973_{({\pm}0.1212)}{\times}EBW^{0.4336_{({\pm}0.1002)}$ and NPG (g/d) = 183.6(±22.5333)×EBG-2.0693(±4.7254)×RE, where EBW, empty BW; EBG, empty body gain; and RE, retained energy. Crude protein (CP) and ether extract (EE) chemical contents in carcass, and all the chemical components in the empty body were precisely and accurately estimated by CS16 equations. However, water content in carcass was better predicted by HH46 equation. Conclusion: The equations proposed in this study can be used for estimating the energy and protein requirements of crossbred dairy steers. The CS16 equations were the best estimator for CP and EE chemical contents in carcass, and all chemical components in the empty body of crossbred dairy steers, whereas water in carcass was better estimated using the HH46 equations.

Nurses' Knowledge and Performance for the Prevention of Intravascular Catheter-related Infections according to the Strength of Recommendations of Evidence based Guidelines (정맥관 감염예방 근거중심 가이드라인의 권고강도 별 간호사의 지식 및 수행정도)

  • Ryu, Se-Ang;Kim, Yun-Hee;Jang, Keum-Seong;Chung, Kyung-Hee;Choi, Ja-Yun;Yang, Jin-Ju;Park, Soon-Joo
    • Korean Journal of Adult Nursing
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    • v.24 no.5
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    • pp.546-555
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    • 2012
  • Purpose: The objective of this study was to examine the relationships between nurses' knowledge and performance for the prevention of intravascular catheter-related infections (ICRI) according to the strength of recommendations in evidence based guidelines (EBG). Methods: The total participants were 144 nurses working for medical surgical unit and intensive care unit. Data were collected from July 12 to July 30, 2010 and analyzed by one way ANOVA and Pearson's correlation analysis. Results: The knowledge and performance mean scores were $0.80{\pm}0.17$ and $3.04{\pm}0.31$ for peripheral venous catheter (PVC) management, and $0.83{\pm}0.17$ and $3.00{\pm}0.30$ for central venous catheter (CVC) management respectively. The items of category IA had the highest knowledge score (F=44.70, p<.001) and the items of category II had the highest performance score (F=47.09, p<.001) in PVC management, while the items of category IA had the highest knowledge (F=20.04, p<.001) and performance scores (F=18.20, p<.001) in CVC management. Knowledge and performance scores were significantly correlated in CVC management (r=.24, p=.004), but not in PVC management (r=.03, p=.753). Conclusion: EBG for the prevention of ICRI was not fully implemented in clinical settings. These findings emphasize that clinical professions need to develope strategies to enhance nursing practices with evidence based guideline.

Fatty acid profiles and flavour-related compounds of retorted Korean ginseng chicken soup (Samgyetang) affected by pre-treated black garlic extract

  • Barido, Farouq Heidar;Utama, Dicky Tri;Kim, Yeong Jong;Lee, Sung Ki
    • Animal Bioscience
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    • v.35 no.7
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    • pp.1080-1090
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    • 2022
  • Objective: This study aimed to characterize the effect of pre-treated black garlic (BG) extracts addition into retorted Korean ginseng chicken soup (Samgyetang) on the fatty acid composition and flavour-related indexes. Methods: Four different treatments; Samgyetang made with a 5% (w/w) addition of garlic (G), fresh BG (FBG), oven-dried BG (DBG), or encapsulated BG (EBG) extracts were developed and compared to negative control (NC) without any extract addition. Prepared samples were cooked via retorting at 121.1℃, 1.5 kgf/cm2 for 1 h. Results: The BG treated samples were higher in C18:3n3 and C18:2n6 fatty acids, with thrombogenic index was 18% to 20% lower than the NC. EBG yielded the highest umami-related nucleotides (5'-guanosine monophosphate and 5'-inosine monophosphate) and modified some free amino acid (alyne, phenylalanine and leucine) thus possessed the highest equivalent umami concentration among samples. Some individual aldehydes (pentanal, hexanal, and heptanal) were lower, while furans and volatile sulfur compounds were higher than the NC and G treatment group, indicating a potential suppression of unpleasant flavour alongwith the intensificiation of favourable flavour from the addition of BG extracts into retorted Samgyetang. Conclusion: Taken together, the synergistic results of this study indicate that incorportating suitable pre-treatment of BG extract could be of critical importance for the development of the retorted Samgyetang with improved flavour and functionalities.

A study for pattern recognition of partial discharge in Extra High Voltage cable on the site (Neural Network를 이용한 초고압 실선로에서의 부분방전 패턴인식 연구)

  • Kim, Young-Hong;Kim, Choong-Sik;Kim, Jung-Yoon
    • Proceedings of the KIEE Conference
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    • 2008.05a
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    • pp.145-146
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    • 2008
  • 초고압 케이블에서 발생하는 부분방전을 측정하기 위해 다양한 방법들이 연구 개발되어왔다. 최근에는 초고압 케이블의 설치 후 시행하는 준공시험에 있어 부분방전 측정을 필수적으로 할 만큼 부분방전 진단기술의 중요성이 부각되고 있는 실정이며, 디지털 측정기술을 통한 부분방전자동측정 기술이 많이 제안되고 있다. 특히, 비전문가들만으로도 진단 및 감시가 가능하도록 하는 자동 패턴 분류에 대한 다양한 연구에 활발히 보고되고 있다. 본 논문에서는 초고압 케이블에서 발생되는 결함을 내부, 외부, 노이즈의 세 가지로 분류하고 PRPD(Phase Resolved Partial Discharge) 형태로 모의된 실험데이터와 현장에서 축적된 데이터를 선별하여 다양한 통계치를 추출하였고, 결함별 구분이 용이하지 않은 통계치를 제외한 값들을 Neural Network 방법으로 학습시켰다. 학습된 가중치 값을 LabView로 작성된 프로그램에 사용하여 변전소 내 EBG에서 검출한 부분방전 측정 결과에 적용하였다.

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