• 제목/요약/키워드: Dual-frequency

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WLAN/WiMAX 시스템에 적용 가능한 변형된 원형 링 안테나 설계와 제작 (Design and Manufacture of Modified Circular Ring antenna for WLAN/WiMAX Applications)

  • 임대수;윤중한
    • 한국정보통신학회논문지
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    • 제18권2호
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    • pp.268-275
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    • 2014
  • 본 논문에서는 WLAN/WiMAX시스템에 적용 가능한 삼중 대역을 갖는 변형된 원형 링 안테나를 설계 및 제작 하였다. 제안된 안테나는 원형 링 모양의 평면형 모노폴 설계를 기본으로 원형 링 내부의 십자형 스터브의 구조와 변형된 급전선로, 그리고 접지면의 사각 슬롯으로 구성함으로서 삼중대역 특성을 갖도록 설계하였다. 최적화된 파라메타를 얻기 위해 상용 툴(HFSS)을 사용하여 시뮬레이션 하였으며 안테나 성능에 민감하게 작용하는 파라메타를 찾아내서 최적화된 수치를 얻었다. 얻어진 최적화된 수치를 사용하여 제안된 안테나를 제작하였다. 시뮬레이션 결과와 측정결과가 어느 정도 일치하고 있는 데이터를 얻었으며 -10dB 임피던스 대역폭을 기준으로 WLAN/WiMAX 대역을 동시에 만족하고 있음을 확인하였다. 그리고 WLAN/WiMAX 대역에서 이득과 방사패턴의 특성을 얻었다.

성인(成人) 여성(女性)의 브래지어 치수규격설정(置數規格設定)에 관(關)한 연구(硏究) (A Study on the Establishment of Brassiere Sizing System for Adult Women)

  • 박은미;손희순
    • 패션비즈니스
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    • 제4권1호
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    • pp.45-58
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    • 2000
  • The purpose of this study is to provide for the basic data useful to the development of a quality bassiere featuring a good wearing feeling, to investigate the characteristics of breast shapes by age and suggest a brassiere sizing system for woman. For this purpose, the subjects of anthropometry were 220 women aged between 20 and 59. The anthropometric measurements were analyzed by various statistical methods mean, standard deviation, F-test, Duncan-test, Factor analysis, frequency. The results of this study can be summarized as follows; 1. According to the increase of age, the items of height were decreased and items of width, depth, circumference and length were increased, being obeser and breast point were drooped. So volume and bottom area of breast of 40 50's women were larger than 20 30's women and breast point width of 40 50's women was being wider by increase of the interior of breast. 2. From analyzing the effect of brassiere wearing, it was found that brassiere reformed the breast shape with the breast volume transferred from exterior part to interior part and the bottom area of breast diminished, so brassiere can have the breast location of adult woman up and the breast point width being centered 3. It was found that there was no direct linear relationships between under bust girth and cup size from analysis of breast measurements. Therefore those 2 factors(under bust girth and cup size) was brought into basic item of brassiere sizing system. From the dual distribution table whose intervals had been decided by KS K-0070(1999), it was picked out 12 sizes which had more than 4% of appearance for suggesting brassiere size chart. The sizing system covers 76.36% of all subjects and supply reference measurements relevant to brassiere manufacturing.

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무선인터넷기반의 DGPS를 이용한 동체의 자세결정 성능평가 (Error Assessment of Attitude Determination Using Wireless Internet-Based DGPS)

  • 이홍식;임삼성;박준구
    • 한국측량학회지
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    • 제23권2호
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    • pp.101-108
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    • 2005
  • 관성항법시스템은 항체의 자세, 속도 및 위치정보를 획득하기 위하여 폭넓게 사용되어 왔다. 그러나 관성센서는 매우 고가이며, 무겁고, 시간이 경과함에 따라 센서의 오차가 누적되어 발산하게 되는 단점이 있다. 한편 GPS를 이용한 항법시스템은 오차의 누적이 없고, 위성의 가시성만 확보된다면 빠르게 항체의 속도, 위치정보를 획득할 수 있으며, GPS 안테나 배열을 이용하면, 항체의 자세요소도 계산이 가능하다. 본 연구에서는 중저가 GPS 수신기의 안테나 배열을 사용하여 항체의 위치측위 정확도 및 자세 정확도 모두를 개선시키기 위한 방법을 연구하였다. 중저가형의 GPS 수신기 안테나 배열을 사용한 자세 결정 방법은 기준과 보조 안테나 사이의 상대적인 벡터에 초점을 맞추었다. 기준 안테나의 위치는 의사거리 측위로 한 단독 측위가 사용되었기 때문에 미터 수준으로 결정된다. 또한 항체의 측위 정확도 향상을 위해, 무선 인터넷을 이용하여 실시간 차분 보정을 실시하였으며, 중저가의 2주파 GPS 수신기를 사용하였다. 본 연구의 결과는 측위에서 센티미터 수준의 정확도를, 자세결정에서 도 수준의 정확도를 가지는 것으로 나타났다.

Low Muscle Mass and Depressed Mood in Korean Adolescents: a Cross-Sectional Analysis of the Fourth and Fifth Korea National Health and Nutrition Examination Surveys

  • Moon, Ji Hyun;Kong, Mi Hee;Kim, Hyeon Ju
    • Journal of Korean Medical Science
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    • 제33권50호
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    • pp.320.1-320.8
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    • 2018
  • Background: Muscle mass and muscle function are related to depressed mood in studies of adults. Like adults, Korean students are highly likely to suffer from decreased muscle mass due to social conditions. In this study, we evaluated the muscle mass status of Korean adolescents and assess the effect of muscle on depressive mood. Methods: A total of 1,233 adolescent boys and girls participants from the Korea National Health and Nutrition Examination Survey were enrolled in our study. Participants underwent dual-energy X-ray absorptiometry for assessment of appendicular muscle mass and completed questionnaires regarding depressed mood, stress, suicidal ideations, and attempts. Results: There was no difference in depressive mood according to muscle mass among boys (P = 0.634); girls with decreased muscle mass had a greater tendency for depressed mood compared to girls with optimal muscle mass (P = 0.023). After adjusting for age, waist circumference-to-height ratio, smoking status, alcohol consumption, frequency of physical activity, self-reported obesity, weight-loss efforts, and monthly household income, girls with low muscle mass (LMM) were 2.60 times more at risk of developing depression than girls with normal muscle mass (95% confidence interval [CI], 1.05-6.49; P = 0.040). This trend was similar for girls with LMM with obesity (95% CI, 1.00-11.97; P = 0.049). Conclusion: Adolescent girls who have insufficient muscle mass are more likely to report depressed mood than girls who have ideal muscle mass. Interventions for maintaining proper muscle mass are required.

갱년기 변증 진단 도구 CaPSPI(Diagnostic System for Climacteric and Postmenopausal Syndrome Pattern Identification) 임상적용 결과 분석 연구 (Study on the Data Analysis of CaPSPI for clinical application, a Diagnostic System for Climacteric and Postmenopausal Syndrome Pattern Identification)

  • 박영희;이인선
    • 대한한방부인과학회지
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    • 제34권4호
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    • pp.78-96
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    • 2021
  • Objectives: It is a statistical study to examine the data of CaPSPI (Diagnostic System for Climacteric and Postmenopausal Syndrome Pattern Identification), developed for diagnosis of menopause disorders and to record the status of treatment of it. Methods: From November 1, 2020 to June 19, 2021, 36 cases of data of 33 respondents of the CaPSPI were analyzed. For the use of the basic data of the clinical menopausal disorder, we investigated frequency of menopausal symptoms and the difference between them depending on the period of menopause, and the presentation of usage prescriptions. And the diagnostic results for three kinds' diagnosis [for examination (D1), for treatment (D2), by doctors (D3)] were compared. The diagnostic consistency of D1 and D3 and the statistical significance between DT and disease elements (證素) was investigated. Results: 1. Hot flush was the highest in the symptom survey of the menopause that the subjects complained of, followed by insomnia. There was no significant difference in symptom expression according to menopausal period. 2. The diagnostic consistency of D1 and D2 showed significant diagnostic consistency only in liver depression, and the diagnostic consistency of D1 and D3 showed significant consistency in liver depression and Dual Deficiency of Heart and Spleen. 3. D3' diagnosis and disease elements had statistical significance for cases of P<0.1 was found to be related to the theory of oriental medicine. Conclusions: It is needed to continue to accumulate diagnosis and treatment results through CaPSPI in the future to strengthen the basis for patten identification and treatment of menopause disorders.

고압 배터리 팩의 임피던스 스펙트럼 측정용 휴대용 임피던스 분광기 (A Portable Impedance Spectroscopy Instrument for the Measurement of the Impedance Spectrum of High Voltage Battery Pack)

  • 굴 라힘;최우진
    • 전력전자학회논문지
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    • 제26권3호
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    • pp.192-198
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    • 2021
  • The battery's State of Health (SOH) is a critical parameter in the process of battery use, as it represents the Remaining Useful Life (RUL) of the battery. Electrochemical Impedance Spectroscopy (EIS) is a widely used technique in observing the state of the battery. The measured impedance at certain frequencies can be used to evaluate the state of the battery, as it is intimately tied to the underlying chemical reactions. In this work, a low-cost portable EIS instrument is developed on the basis of the ARM Cortex-M4 Microcontroller Unit (MCU) for measuring the impedance spectrum of Li-ion battery packs. The MCU uses a built-in DAC module to generate the sinusoidal sweep perturbation signal. Moreover, it performs the dual-channel acquisition of voltage and current signals, calculates impedance using a Digital Lock-in Amplifier (DLA), and transmits the result to a PC. By using LabVIEW, an interface was developed with the real-time display of the EIS information. The developed instrument was suitable for measuring the impedance spectrum of the battery pack up to 1000 V. The measurement frequency range of the instrument was from 1 hz to 1 Khz. Then, to prove the performance of the developed system, the impedance of a Samsung SM3 battery pack and a Bexel pouch module were measured and compared with those obtained by the commercial instrument.

Effect of Cross-legged Sitting Posture on Joint Range of Motion: Correlation with Musculoskeletal Symptoms and Facial Asymmetry

  • Shin, Yeong hui
    • The Journal of Korean Physical Therapy
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    • 제34권5호
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    • pp.255-266
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    • 2022
  • Purpose: This study sought to study the effects of cross-legged sitting posture on joint motion. It also examined the correlation between the changes in the joint range of motion, musculoskeletal symptoms, and facial asymmetry. Methods: The Acumar Digital Inclinometer (Lafayette Instrument Company, USA) was used to measure the range of motion (ROM). We measured the flexion and extension of the cervical, thoracic, and lumbar spine using a dual inclinometer, and measured the ROM of the shoulder and hip joint with a single inclinometer. The Likert scale questionnaire was used to investigate musculoskeletal symptoms and facial asymmetry. Results: The data analysis was performed using the Jamovi version 1.6.23 statistical software. After confirming the normality of the ROM with descriptive statistics, it was compared with the normal ROM through a one-sample t-test. Correlation matrix analysis was performed to confirm the association between facial asymmetry and musculoskeletal symptoms. The result of the one-sample t-test showed a significant increase in the thoracic spine extension and right and left hip external rotation (p<0.001***), while most other joints were restricted. As per the frequency analysis, facial asymmetry was found to be 81.70%. Conclusion: The independent variable, namely cross-legged sitting posture led to an increase in ROM. The study also suggests that facial asymmetry and musculoskeletal symptoms could occur. Therefore, to prevent the increase and limitation of ROM and to prevent the occurrence of facial asymmetry and musculoskeletal symptoms, it is suggested that the usual cross-legged sitting posture should be avoided.

위성 SAR 탑재체용 파형발생수신모듈 설계 및 제작 (Design and Implementation of CTM for SAR Payload)

  • 김동식;김현철;유경덕;허전;우재춘;이상규;이현철;유상범
    • 한국항공우주학회지
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    • 제50권2호
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    • pp.119-125
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    • 2022
  • 본 논문에서는 500kg급 중형위성에 탑재를 목표로 개발한 C-밴드 영상 레이다용 파형발생수신모듈의 설계, 제작 및 시험 결과를 제시한다. 파형발생수신모듈은 약 500km의 고도에서 해상도 10m 기준 120km의 관측 폭을 만족할 수 있도록 50MHz 대역의 2개 주파수를 동시 운용하는 이중주파수 스캔 방식을 적용할 수 있도록 설계하였다. 제작된 파형발생수신모듈은 우주환경을 고려하여 방사성 내성이 고려된 RTG4 FPGA를 적용하였으며, 병렬 직접합성방식(PDDS)을 적용하여 메모리 맵 방식 대비 작은 메모리 용량으로 첩 신호를 생성할 수 있도록 구현하였다. 시험결과 주파수 순도가 높은 첩 파형을 안정적으로 생성하였으며, 수신 신호에 대해 디지털 하향 변환 후 확인 결과 목표한 IRF (Impulse Response Function) 성능을 확인할 수 있었다.

Investigation of the Factors Affecting Bone Mineral Density in Children with Celiac Disease

  • Dehghani, Seyed Mohsen;Ilkhanipour, Homa;Samipour, Leila;Niknam, Ramin;Shahramian, Iraj;Parooie, Fateme;Salarzaei, Morteza;Tahani, Masoud
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • 제25권2호
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    • pp.138-146
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    • 2022
  • Purpose: Children with celiac disease (CD) are at an increased risk of low bone mineral density (BMD) owing to malabsorption of fat-soluble vitamins, inflammation, and malnutrition. This study aimed to determine the prevalence and risk factors for low BMD in Iranian children with CD. Methods: This prospective cohort study examined 149 Iranian children with CD between 2011 and 2018 at Zabol University of Medical Sciences. BMD was measured using dual-energy X-ray absorptiometry. Demographic, clinical, and laboratory data were collected from patients' medical records. Logistic regression analysis was performed to identify the factors associated with low areal BMD (BMD-Z <-2) in the lumbar spine and femoral neck. Descriptive data were analyzed using the mean, standard deviation, and relative frequency. Data were analyzed using the chi-square test, t-test, and analysis of variance. Results: Of the 149 children with CD, 27.5% had osteoporosis. The mean body mass index (BMI) Z score was -1.28±1.2. Lower BMI was associated with a higher likelihood of BMD-Z (odds ratio 2.17; p≤0.05). Conclusion: Overall, the findings of this study showed that there was no correlation among Marsh classification, presence of specific human leukocyte antigens, and low BMD in Iranian children with CD. BMI can be a predictor of bone density in children with CD and may be applied clinically in early screenings to evaluate the bone health status in these children.

New therapeutic approach with extracellular vesicles from stem cells for interstitial cystitis/bladder pain syndrome

  • Dayem, Ahmed Abdal;Song, Kwonwoo;Lee, Soobin;Kim, Aram;Cho, Ssang-Goo
    • BMB Reports
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    • 제55권5호
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    • pp.205-212
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    • 2022
  • Interstitial cystitis/bladder pain syndrome (IC/BPS) is a debilitating chronic disorder characterized by suprapubic pain and urinary symptoms such as urgency, nocturia, and frequency. The prevalence of IC/BPS is increasing as diagnostic criteria become more comprehensive. Conventional pharmacotherapy against IC/BPS has shown suboptimal effects, and consequently, patients with end-stage IC/BPS are subjected to surgery. The novel treatment strategies should have two main functions, anti-inflammatory action and the regeneration of glycosaminoglycan and urothelium layers. Stem cell therapy has been shown to have dual functions. Mesenchymal stem cells (MSCs) are a promising therapeutic option for IC/BPS, but they come with several shortcomings, such as immune activation and tumorigenicity. MSC-derived extracellular vesicles (MSC-EVs) hold numerous therapeutic cargos and are thus a viable cell-free therapeutic option. In this review, we provide a brief overview of IC/BPS pathophysiology and limitations of the MSC-based therapies. Then we provide a detailed explanation and discussion of therapeutic applications of EVs in IC/BPS as well as the possible mechanisms. We believe our review will give an insight into the strengths and drawbacks of EV-mediated IC/BPS therapy and will provide a basis for further development.