• Title/Summary/Keyword: center loss

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Fabrication of HTS Microstrip Bandpass Filters using CeO$_2$ buffered YBCO Films grown on ${\alpha}\;Al_2O_3$ substrates (CeO$_2$ 버퍼막과 함께 ${\alpha}\;-Al_2O_3$ 기판 위에 성장된 YBCO 박막을 사용한 HTS Microscrp Bandpass filter의 제작)

  • Jung, Gu-Rak;Chu, Hyeong-Gon;Kang, Joon-Hee;Park, Sang-Jin;Sok, Jung-Hyeon;Lee, Eun-Hong
    • 한국초전도학회:학술대회논문집
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    • v.9
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    • pp.58-62
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    • 1999
  • We fabricated a new hairpin type HTS 2-pole microstrip Bandpass filter to operate at 5.8GHz. The fabrication method was pulsed laser deposition and YBCO films were deposited on ${\alpha}$-A1$_2O_3$ substrates with a CeO$_2$ thin layer as a buffer layer. We developed a new style hairpin type filter by using interdigitide innerpole. Compared to the saute size regular hairpin type filters, our filter had a lower center frequency, bandwidth and loss by an amount of 14.5%, 29.6%, 0.5488dB, respectively. The size of the filters were 13.7${\times}$3.3mm. We did simulations on the several types of band pass filters by using HFSS and serenade. We measured growth rate and Tc of YBCO films grown on CeO$_2$/ ${\alpha}$-A1$_2O_3$ substrates which were rotated while growing films.

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Diagnostic Imaging of Solitary Nodular Cecal Lymphoma in a Dog (맹장에 발생한 단일성 결절형 소화관 림프종의 영상 진단 증례)

  • Jung, Joo-Hyun;Kwon, Do-Hyoung;Lee, Seung-Hee;Chang, Jin-Hwa;Oh, Sun-Kyoung;Yoon, Jung-Hee;Choi, Min-Cheol
    • Journal of Veterinary Clinics
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    • v.26 no.1
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    • pp.81-85
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    • 2009
  • A spayed female, 8-year-old, maltese, weighing 1.84 kg with a history of acute severe vomiting, anorexia, depression for 2 day was referred. An abdominal mass was palpated with abdominal pain on physical examination. Radiographic findings included two soft tissue density masses in the mid-abdominal cavity and gas dilated colon. Ultrasonographs showed one heterogeneous hypoechoic round mass including intestinal wall. There were loss of normal wall layering and motility and absence of internal lumen of the intestinal wall. And another heterogeneous hyperechoic mass was identified to the medial side of the intestinal mass. Based on clinical signs, image findings, and the result of fine needle aspiration, intestinal obstruction due to alimentary lymphoma was diagnosed. On surgery, a cecal lymphoma and mesenteric lymphadenopathy were confirmed and the cecal mass was resected.

Traumatic Aortic Injury: Single-center Comparison of Open versus Endovascular Repair

  • Cho, Jun Woo;Kwon, Oh Choon;Lee, Sub;Jang, Jae Seok
    • Journal of Chest Surgery
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    • v.45 no.6
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    • pp.390-395
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    • 2012
  • Background: Conventional open repair is a suboptimal therapy for blunt traumatic aortic injury (BTAI) due to the high postoperative mortality and morbidity rates. Recent advances in the thoracic endovascular repair technique may improve outcomes so that it becomes an attractive therapeutic option. Materials and Methods: From August 2003 to March 2012, 21 patients (mean age, 45.81 years) with BTAI were admitted to our institution. Of these, 18 cases (open repair in 11 patients and endovascular repair in 7 patients) were retrospectively reviewed and the early perioperative results of the two groups were compared. Results: Although not statistically significant, there was a trend toward the reduction of mortality in the endovascular repair group (18.2% vs. 0%). There were no cases of paraplegia or endoleak. Statistically significant reductions in heparin dosage, blood loss, and transfusion amounts during the operations and in procedure duration were observed. Conclusion: Compared with open repair, endovascular repair can be performed with favorable mortality and morbidity rates. However, relatively younger patients who have acute aortic arch angulation and a small aortic diameter may be a therapeutic challenge. Improvements in graft design, delivery sheaths, and graft durability are the cornerstone of successful endovascular repair.

Massive Thromboembolism Owing to the Left Ventricular Thrombus Associated with the Hypereosinophilic Syndrome

  • Kim, Ji Seong;Park, Samina;Kim, Hyung-Kwan;Jeon, Yun-Seok;Min, Seung-Kee;Hwang, Ho Young
    • Journal of Chest Surgery
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    • v.47 no.5
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    • pp.478-482
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    • 2014
  • A 39-year-old man presented with cough, chest discomfort, and weight loss. On the basis of the patient history and laboratory findings, he was diagnosed with the hypereosinophilic syndrome. Transthoracic echocardiography revealed a large thrombus in the left ventricle. Medical treatment with anticoagulation and immunosuppression was commenced immediately. Fourteen days after the initial diagnosis, the patient presented with acute pain in his right leg. Computed tomographic angiogram showed embolic occlusion of the infrarenal abdominal aorta and bilateral iliac (including common, external, and internal iliac) arteries. Emergent thromboembolectomy and left ventricular thrombectomy were performed. The postoperative course was uneventful, and the patient has undergone follow-up for 2 months without any evidence of recurrence of thromboembolism.

MANDIBULOTOMY, A SURGICAL APPROACH FOR ORAL CANCER: ITS COMPLICATIONS AND CONTRIBUTING FACTORS (구강암 절제를 위한 하악골이단술: 합병증과 기여인자)

  • Byun, Seong-Kyu;Choi, Eun-Chang;Park, Won-Se;Lee, Eui-Woong;Cha, In-Ho
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.26 no.4
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    • pp.422-426
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    • 2000
  • We reviewed 56 patients who received mandibulotomy at Yonsei medical center between 1989 and 1999. We also analysed the complications associated with mandibulotomy and its contributing factors. The complications occur in 16 patients(28.6%) and are classified into two categories; intraoperative and postperative complications. Nonunion was observed in 5 patients and osteoradionecrosis in 5. The patients who received preoperative radiation therapy were more tend to develop nonunion and osteoradionecrosis. This study suggests the benefits of mandibulotomy as a surgical approach to oral cancer: 1. Paramedian osteotomy was recommended for preservation of neurovascular bundle and ease of surgical access. 2. By using thin saw blade, reapproximation was improved with minimal bone loss. 3. osteotomy on anterior mandible which lies outside the usual portals of radiation therapy decreases the incidence of osteoradionecrosis.

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Evolutionary Feature of Spray Droplets Exiting from a Direct-Injection Type Thruster Nozzle-Orifice (직접분사방식 추력기 노즐오리피스로부터 발생하는 분무입자의 발달특성)

  • Kim, Jin-Seok;Jung, Hun;Kim, Jeong-Soo;Park, Jeong;Kim, Sung-Cho
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2009.05a
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    • pp.149-152
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    • 2009
  • Spray characteristic parameters such as droplet mean velocity, diameter, and volume flux are measured at various locations of spray in order to investigate the evolutionary feature of droplets exiting from a direct-injection type thruster nozzle-orifice. The experimental results indicate that the large droplets with high velocity at the center of upstream are broken-up into smaller droplets with low velocity due to their continuous momentum loss to surrounding air along with spray evolution toward downstream. Also it is found that the high volume flux expands its distribution in radial direction as a results of spray spreading and dispersion.

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Ultra-fast Detection and Differentiation of Mycoplasma haemofelis and Candidatus M. Haemominutum in Korean Feral Cats by Microchip Electrophoresis with Programmed Field Strength Gradients

  • Kumar, Kailasa S.;Lee, Hee-Gu;Yoo, Dong-Jin;Kang, Seong-Ho
    • Bulletin of the Korean Chemical Society
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    • v.29 no.1
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    • pp.153-158
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    • 2008
  • A microchip-based capillary gel electrophoresis (MCGE) technique was developed for the ultra-fast detection and differentiation of Candidatus Mycoplasma haemominutum (Candidatus M. haemominutum, California strain) and Mycoplasma haemofelis (M. haemofelis, Ohio strain) in Korean feral cats through the application of programmed field strength gradients (PFSG) in a conventional glass double-T microchip. The effects of the poly (ethyleneoxide) (PEO) concentration and electric field strength on the separation of DNA fragments were investigated. The PCR-amplified products of Candidatus M. haemominutum (202-bp) and M. haemofelis (273-bp) were analyzed by MCGE within 75 s under a constant applied electric field of 117.6 V/cm and a sieving matrix of 0.3% PEO (Mr 8 000 000). When the PFSG was applied, MCGE analysis generated results 6.8-times faster without any loss of resolution or reproducibility. The MCGE-PFSG technique was also applied to eleven samples selected randomly from 33 positive samples. The samples were detected and differentiated within 11 s. The analysis time of the MCGE-PFSG technique was approximately 980-times faster than that using conventional slab gel electrophoresis.

Study on the Array type antenna of 2×2 (2×2 배열 구조 안테나 특성 연구)

  • Park, Yong-Wook
    • The Journal of the Korea institute of electronic communication sciences
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    • v.12 no.4
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    • pp.549-554
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    • 2017
  • In this paper, we studied the design and fabrication of $2{\times}2$ microstrip array antenna at around 5 GHz band.. To improve of frequency properties of antenna, feed microstrip patch antenna was simulated by HFSS(High Frequency Structure Simulator). A $2{\times}2$ array antenna was designed and fabricated by photolithograph on an FR4 substrate (dielectric constant of 4.4 and thickness of 1.6 mm). The fabricated $2{\times}2$ array antenna showed a center frequency, the minimum return loss and bandwidth were 5.3 GHz, -24dB, and 390MHz, respectively.

A Study of Andropause Symptoms and Life Satisfaction among Middle-aged Men (중년 남성의 갱년기 증상과 삶의 만족도에 관한 연구)

  • Lee, Young-Joo;Kim, Jung-Hee
    • Research in Community and Public Health Nursing
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    • v.16 no.2
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    • pp.186-195
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    • 2005
  • Purpose: This study aims to understand andropause symptoms and life satisfaction among middle-aged Korean men. Method: The subjects were selected among men in their middle age who visited one of two university hospitals or a convalescent center in Seoul. Korea. Eight items were used to measure their andropause symptoms. Life Satisfaction Index-Z was used to measure life satisfaction. Results: Major symptoms related andropause. in the order of frequency, include memory loss, muscle weakness. powerlessness and impotence. Among the subjects. 62.5% smoked and 70% drank alcohol. and life satisfaction was generally moderate in the participants. Current smokers and alcohol drinkers reported a low level of life satisfaction. Diabetic patients and subjects who had powerlessness and hot flashes of andropause symptoms experienced a low level of life satisfaction. Muscle weakness was more frequent in current smokers, and powerlessness more in alcohol drinkers. Conclusion: This study's findings indicate that and ropause is one of major health concerns among middle-aged men. It reminds us of the smoking and alcohol drinking issues among middle-aged men. These findings show the necessity to improve strategies for nursing intervention in andropause symptoms and health risk behaviors.

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A Micromachined Tunable Bandpass Filter Using RF MEMS Switch (RF MEMS 스위치를 이용한 주파수 가변 대역 통과 필터)

  • Kim Jong-Man;Park Jae-Hyoung;Kim Jung-Mu;Lee Sang-Hyo;Baek Chang-Wook;Kwon Young-Woo;Kim Yong-Kweon
    • 한국정보통신설비학회:학술대회논문집
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    • 2004.08a
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    • pp.11-14
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    • 2004
  • In this paper, a novel tunable bandpass filter using tunable series inductors and MEMS switches for wireless LAN applications was proposed. The proposed tunable filter was fabricated using a micromachining technology and performances of the fabricated filter were estimated. The filter consists of spiral inductors, MIM capacitors and direct-contact type MEMS switches, and its frequency tunability is achieved by changing the inductance that is induced by ON/OFF actuations of the MEMS switches. The actuation voltage of the MEMS switches was 58 V, and the measured center frequencies were 2.55 GHz and 5.1 GHz, respectively. The passband insertion loss and 3-dB bandwidth were 4.2 dB and 22.5 % at 2.55 GHz, and 5.2 dB and 23.5 % at 5.1 GHz, respectively.

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