• Title/Summary/Keyword: 이종 전원

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Pulmonary Infarction Associated with Fracture of Right Clavicle and Multiple Ribs (우측 쇄골 및 늑골골절과 동반된 폐경식 1례)

  • 김수성;이종임
    • Journal of Chest Surgery
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    • v.30 no.9
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    • pp.941-944
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    • 1997
  • Pulmonary infarction is rarely diagnosed with certainty except at postmortem examination. Part of this uncertainty is because of the inability to distinguish between hemorrhage, congestive a electasis, and necrosis clinically and radiographically. The pathogenesis of pulmonary infarction is poorly understood. It is dif%cult to induce pulmonary infarction in animals by ligation of the arterial supply to the lung. Many factors seem to be important in its pathogenesis, in addition to congestive heart failure, malignant tumor, thrombophlebitis, chronic obstructive lung disease, nephrotic syndrome, and postopeiative state. However, pulmonary infarction have not been reported in association with chest trauma. We report a case of pulmonary infarction associated with fractures of right clavicle and multiple ribs. A 45-year-old male had admitted due to right chest pain and dyspnea, which developed after right chest trauma occurred at about 3 weeks ago. He was treated at local clinics under the diagnosis of fractures of right clavicle and ribs until the admission. Chest CT disclosed a huge mass with central low density in right upper lobe, and small masses were also seen on both l ng fields. Open lung biopsy resulted in negativity for the malignancy. Clinical symptoms and radiological findings were not improved by conservative treatment. Right upper lobectomy was done eventually. The final diagnosis was pulmonary infarction. And, the patient has been well after operation.

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Design and Fabrication of X-Band 50 W Pulsed SSPA Using Pulse Modulation and Power Supply Switching Method (펄스 변조 및 전원 스위칭 방법을 혼용한 X-대역 50 W Pulsed SSPA 설계 및 제작)

  • Kim, Hyo-Jong;Yoon, Myoung-Han;Chang, Pil-Sik;Kim, Wan-Sik;Lee, Jong-Wook
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.22 no.4
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    • pp.440-446
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    • 2011
  • In this paper, a X-band 50 W pulsed solid state power amplifier(SSPA) is designed and fabricated for radar systems. The SSPA consists of a driver amplifier, a high power amplifier, and a pulse modulator. The high power stage employes four 25 W GaAs FET to deliver 50 W at X-band. To meet the stringent target specification for the SSPA, we used a new hybrid pulse switching method, which combine the advantage of pulse modulation and bias switching method. The fabricated SSPA shows a power gain of 44.2 dB, an output power of 50 W over a 1.12 GHz bandwidth. Also, pulse droop < 1 dB meet the design goals and a rise/fall time is less than 12.45 ns. Fabricated X-band pulsed SSPA size is compact with overall size of $150{\times}105{\times}30\;mm^3$.

A Design of Voltage Controlled Oscillator and High Speed 1/4 Frequency Divider using 65nm CMOS Process (65nm CMOS 공정을 이용한 전압제어발진기와 고속 4분주기의 설계)

  • Lee, Jongsuk;Moon, Yong
    • Journal of the Institute of Electronics and Information Engineers
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    • v.51 no.11
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    • pp.107-113
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    • 2014
  • A VCO (Voltage Controlled Oscillator) and a divide-by-4 high speed frequency divider are implemented using 65nm CMOS technology for 60GHz wireless communication system. The mm-wave VCO was designed by NMOS cross-coupled LC type using current source. The architecture of the divide-by-4 high speed frequency divider is differential ILFD (Injection Locking Frequency Divider) with varactor to control frequency range. The frequency divider also uses current sources to get good phase noise characteristics. The measured results show that the VCO has 64.36~67.68GHz tuning range and the frequency divider divides the VCO output by 4 exactly. The high output power of 5.47~5.97dBm from the frequency divider is measured. The phase noise of the VCO including the frequency divider are -77.17dBc/Hz at 1MHz and -110.83dBc/Hz at 10MHz offset frequency. The power consumption including VCO is 38.4mW with 1.2V supply voltage.

Matching Network Design for Improving the Bandwidth of Microstrip Antenna (마이크로스트립 안테나의 대역폭 개선을 위한 정합회로설계)

  • 전성근;이종룡;이우재;이문수
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.9 no.3
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    • pp.305-316
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    • 1998
  • The impedance matching network with the simplfied real frequency technique (SRFT) is proposed as a method for bandwidth enhancement of microstrip antenna. The validity of the technique is based on the relative frequency insensitivity of the radiation pattern and gain characteristics as compared to the resonant behaviour of the input impedance. The most significant feature of this technique is that there is no need to find any analytical description of the antenna and generator, and it only utilizes directly real frequency generator and load data over the prescribed frequency band. Furthermore, it is not necessary to invent an analytic form of the system transfer function to assume a matching network topology in advance. In this paper, the transmission line model is used to investigate the rectangular microstrip antenna, and based on the Fano's bandwidth-enlargement theory, the SRFT is introduced to design the matching networks of microstrip antennas in order to obtain a constant gain over the frequency band of interest. Two representative microstrip antnnas with different structure are fabricated and tested. From these procedures, it is obtained that the proposed impedance matching networks of microstrip antenna improve the impedance bandwidth nearly three times compared to the antenna without them.

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Stable Standby-mode Implementation of Multi-output Power Supply using a New Load Current Estimation Technique with Linear Regulator (다중 출력 전원공급장치의 안정적 대기전력 구현을 위한 새로운 방식의 부하전류 측정기법 구현)

  • Lee, Jong-Hyun;Jung, An-Yeol;Kim, Dong-Joon;Park, Joung-Hu;Jeon, Hee-Jong
    • The Transactions of the Korean Institute of Power Electronics
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    • v.16 no.1
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    • pp.88-95
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    • 2011
  • In this paper, a new standby-mode control method for multiple output switching-mode power-supply is suggested, which uses the control signal of the feedback compensator of the inner loop in the linear voltage regulator located at the transformer secondary side, as the load current information. Conventional method has a problem that standby mode occurs depending only on the load condition of the main controller output, which makes the other secondary side output very inaccurate by burst mode operation. The proposed method detects all the load current information and operates in burst mode only when the all of them are light load condition. Minimum of the additional components are required for the implementation of the proposed method because the load information is obtained from the existing feedback circuit of the post-stage linear regulator. In this paper, the operating principles of the proposed standby-mode circuit are presented with an numerical analysis, and are verified by 25W hardware prototype implementation.

Battery Efficient Wireless Network Discovery Scheme for Inter-System Handover in Heterogeneous Wireless Networks (이종무선 네트워크 환경에서 네트워크 간 핸드오버를 위한 전력 효율적 무선 네트워크 탐지 기법)

  • Lee Bong-Ju;Kim Won-Ik;Song Pyeong-Jung;Shin Yeon-Seung
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.31 no.2A
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    • pp.128-137
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    • 2006
  • In this paper, we propose a wireless network discovery scheme which support effective device power management by employing battery efficient network scanning procedure. Multi-mode terminals need to discover other wireless systems, above all, to execute an inter-system handover in the environment of heterogeneous wireless networks. The existing methods introduced in some recent research reports have certain shortcomings, such as battery power consumption increased by frequent modem activation, or the multi-mode terminal's inability to promptly discover wireless system. We Propose a scheme in which multi-mode terminals more quickly and accurately discover other wireless systems than previous schemes, while consuming minimum power. It also proves that the scheme has better performance by comparing it with the existing schemes.

A Memory Mapping Technique to Reduce Data Retrieval Cost in the Storage Consisting of Multi Memories (다중 메모리로 구성된 저장장치에서 데이터 탐색 비용을 줄이기 위한 메모리 매핑 기법)

  • Hyun-Seob Lee
    • Journal of Internet of Things and Convergence
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    • v.9 no.1
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    • pp.19-24
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    • 2023
  • Recently, with the recent rapid development of memory technology, various types of memory are developed and are used to improve processing speed in data management systems. In particular, NAND flash memory is used as a main media for storing data in memory-based storage devices because it has a nonvolatile characteristic that it can maintain data even at the power off state. However, since the recently studied memory-based storage device consists of various types of memory such as MRAM and PRAM as well as NAND flash memory, research on memory management technology is needed to improve data processing performance and efficiency of media in a storage system composed of different types of memories. In this paper, we propose a memory mapping scheme thought technique for efficiently managing data in the storage device composed of various memories for data management. The proposed idea is a method of managing different memories using a single mapping table. This method can unify the address scheme of data and reduce the search cost of data stored in different memories for data tiering.

압전형 가속도계의 설계, 제작 및 보정 I

  • 이종원;구경회
    • Journal of the KSME
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    • v.29 no.2
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    • pp.175-183
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    • 1989
  • 오늘날 널리 연구되고 있고 공학자들에게 많은 관심을 끌고있는 압전 세라믹(ceramic)을 이용 하여 자연계에서 일어나는 각종 진동현상을 측정하고 해석하기 위한 센서(sensor)의 설계, 제작은 이미 선진국에서도 보편화된지 오래이다. 특히 압전형 가속도계(piezo type accelerometer)는 진동의 절대 측정에 가장 유용한 센서로 널리 알려져 있다. (1) 아주 넓은 사용 주파수 범위 (2) 넓은 동적범위(dynamic range)에 걸친 뛰어난 선형성(linearity) (3) 측정된 가속도 신호를 전기적으로 적분하여 속도와 변위에 대한 자료 제공 용이 (4) 높은 정확성 (5) 자발 전(self-generating)이므로 외부 전원 공급이 불필요 (6) 수명과 뛰어난 내구성 (7) 작은 크기와 가벼운 무게 등이다. 현재 기계 구조물 진동 측정에 이용되고 있는 스트레인 게이지 형(strain gage-type)의 가속도계는 감도가 좋고 저주파 진동 측정에는 편리한 반면 충격이나 높은 주파수 전동 측정에는 적합하지 않으며 내부 구조가 다소 복잡하다(2). 반면에 압전형 가 속도계는 압전 소자와 관성 질량의 조합 설계로서 저주파 진동 측정에 적합한 고감도의 가속도 계와, 감도는 떨어지나 아주 높은 주파수 범위의 진동까지 측정이 가능한 가속도계를 손쉽게 설계, 제작할 수 있다. 본 글에서는 선진국에 비해 낙후된 국내의 센서 설계, 제작 기술을 고 양시키고자 최근 한국과학기술원에서 시도된 압전형 가속도계의 개발 연구 사례를 중심으로 설계 및 제작시 고려 사항과 보정 문제를 소개하고자 한다.

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A New Modular 3-phase AC-DC Flyback Converter for Telecommunication (새로운 통신전원용 3상 AC-DC Flyback 컨버터)

  • Lee, Jong-Pil;Choi, Ju-Yeop;Song, Joong-Ho;Choy, Ick;Kim, Taek-Yong;Yoon, Tae-Woong
    • The Transactions of the Korean Institute of Power Electronics
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    • v.4 no.2
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    • pp.159-165
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    • 1999
  • Three-phase AC-DC flyback converter with high power factor correction and tight regulation is presented in this p paper. The advantage of the proposed converter does not require expensive high voltage and high cun‘ent devices that a are normally needed in popular boost type 3-phase converter. In this paper the detailed small signal analysis of the m modular 3-phase AC-DC flyback converter is provided for control purposes and also experimental results are included t to confirm the validity of the analysis.

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Operation of Tricuspid Valve Endocarditis with Pulmonary Infarction - Lobectomy with Open Heart Surgery (폐경색을 동반한 삼천판막 심내막염의 수술치험 -폐엽 절제술과 개심술의 동시 수술-)

  • 김성완;김덕실;조준용;전상훈;이응배;장봉현;이종태;김규태
    • Journal of Chest Surgery
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    • v.36 no.10
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    • pp.776-779
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    • 2003
  • An eight-year-old boy was referred to our hospital with cough and high fever. His past medical history included a small sized ventricular septal defect (VSD) at birth. Transthoracic echocardiography disclosed a 10 x 6 mm vegetation on tricuspid valve, a small VSD and the moderate tricuspid valve insufficiency were found. Blood cultures grew methicillin-resistant staphylococcus aureus. Despite proper antibiotic therapy, fever was not controlled and his course was complicated by pulmonary infarction. The patient simultaneously underwent pulmonary resection and open heart surgery. Through the median sternotomy we performed open thrombectomy and lobectomy (right lower lobe) at first, and then vegetectomy, tricuspid valve repair, and direct closure of VSD were done under cardiopulmonary bypass.