• 제목/요약/키워드: Expansion Devices

검색결과 360건 처리시간 0.029초

반도체 패키지 EMC의 열물성 연구 (Thermophysical Properties of Epoxy Molding Compound for Microelectronic Packaging)

  • 이상현;도중광;송현훈
    • 반도체디스플레이기술학회지
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    • 제3권4호
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    • pp.33-37
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    • 2004
  • As the high speed and high integration of semiconductor devices and the generation of heat increases resulted in the effective heat dissipation influences on the performance and lifetime of semiconductor devices. The heat resistance or heat spread function of EMC(epoxy molding compound) which protects these devices became one of very important factors in the evaluation of semiconductor chips. Recently, silica, alumina, AlN(aluminum nitride) powders are widely used as the fillers of EMC. The filler loading in encapsulants was high up to about 80 vol%. A high loading of filler was improved low water absorption, low stress, high strength, better flowability and high thermal conductivity. In this study, the thermal properties were investigated through thermal, mechanical and microstructure. Thermophysical properties were investigated by laser flash and differential scanning calorimeter(DSC). For detailed inspection of materials, the samples were examined by SEM.

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다기능 주변기기에 대한 보호프로파일에 관한 연구 (A Study on Protection Profile for Multi-function Devices)

  • 이동범
    • 정보보호학회논문지
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    • 제25권5호
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    • pp.1257-1268
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    • 2015
  • 다기능 주변기기는 원래 이미지 처리 작업을 중심으로 수행하는 장치였지만 팩스 기능이 결합하여 전자화된 이미지 데이터를 전송하는 기능과 네트워크 기능이 추가되어 비약적으로 발전하였다. 또한, 다기능 주변기기는 인터넷 응용, 애플리케이션 확장, 원격 공유, 이미지 처리의 기능이 추가되었다. 하지만 다기능 주변기기는 네트워크 연결로 인한 위협으로 발생하는 데이터 노출 및 도청 등의 보안 취약점이 발생할 수 있다. 따라서 다기능 주변기기에 대한 평가 기준이 필요하지만, 현재는 다기능 주변기기에 대한 공통된 보호프로파일이 존재하지 않아서 제품에 대한 안전성을 평가하는데 구체적인 평가 기준을 적용하지 않아 평가 품질의 균일성을 유지하는 것이 어려웠다. 따라서 본 논문에서는 다기능 주변기기에 대한 위협을 분석하여 안전한 다기능 주변기기를 사용하기 위해서 공통평가기준을 기반으로 다기능 주변기기에 대한 보호프로파일을 개발하였다.

Development of RF Ion Source for Neutral Beam Injector in Fusion Devices

  • 장두희;박민;김선호;정승호
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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    • pp.550-551
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    • 2013
  • Large-area RF-driven ion source is being developed at Germany for the heating and current drive of ITER plasmas. Negative hydrogen (deuterium) ion sources are major components of neutral beam injection systems in future large-scale fusion experiments such as ITER and DEMO. RF ion sources for the production of positive hydrogen ions have been successfully developed at IPP (Max-Planck- Institute for Plasma Physics, Garching) for ASDEX-U and W7-AS neutral beam injection (NBI) systems. In recent, the first NBI system (NBI-1) has been developed successfully for the KSTAR. The first and second long-pulse ion sources (LPIS-1 and LPIS-2) of NBI-1 system consist of a magnetic bucket plasma generator with multi-pole cusp fields, filament heating structure, and a set of tetrode accelerators with circular apertures. There is a development plan of large-area RF ion source at KAERI to extract the positive ions, which can be used for the second NBI (NBI-2) system of KSTAR, and to extract the negative ions for future fusion devices such as ITER and K-DEMO. The large-area RF ion source consists of a driver region, including a helical antenna (6-turn copper tube with an outer diameter of 6 mm) and a discharge chamber (ceramic and/or quartz tubes with an inner diameter of 200 mm, a height of 150 mm, and a thickness of 8 mm), and an expansion region (magnetic bucket of prototype LPIS in the KAERI). RF power can be transferred up to 10 kW with a fixed frequency of 2 MHz through a matching circuit (auto- and manual-matching apparatus). Argon gas is commonly injected to the initial ignition of RF plasma discharge, and then hydrogen gas instead of argon gas is finally injected for the RF plasma sustainment. The uniformities of plasma density and electron temperature at the lowest area of expansion region (a distance of 300 mm from the driver region) are measured by using two electrostatic probes in the directions of short- and long-dimension of expansion region.

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New economical and simple device for intraoperative expansion on small and medium sized soft tissue defects

  • Lee, Jun Won;Park, Seong Hoon;Lee, Seong Joo;Kim, Seong Hwan;Jeong, Hii Sun;Suh, In Suck
    • 대한두개안면성형외과학회지
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    • 제19권3호
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    • pp.235-239
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    • 2018
  • Intraoperative expansion has been used to cover small to large defects without disadvantages of the conventional tissue expanders. Various materials, for example, expanders and Foley catheters are being used. We introduce a new, convenient and economical device immediately available in the operating room, according to the defect size for intraoperative expansion, with latex gloves or balloons. The retrospective study was done with 20 patients who presented with skin and soft tissue defects. During the operation, expansion was done with latex gloves or balloons inflated with saline through an intravenous line and a three-way stopcock. After the inflation, the glove was removed and skin was covered with expanded tissue. A careful decision was made regarding the inflation volume and placement of the expander according to the defect size. There were no postoperative complications. The skin contracture and tension was minimal with a texture similar to the adjacent tissue. The new intraoperative expansion devices with latex gloves and balloons were cheap and made easily right in the operation room. The reconstruction of small to large sized skin defects can be done successfully, functionally and aesthetically without using expensive commercial materials.

Comparison of the effects of rapid maxillary expansion and alternate rapid maxillary expansion and constriction protocols followed by facemask therapy

  • Ozbilen, Elvan Onem;Yilmaz, Hanife Nuray;Kucukkeles, Nazan
    • 대한치과교정학회지
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    • 제49권1호
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    • pp.49-58
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    • 2019
  • Objective: The aim of this retrospective study was to evaluate and compare the changes in the pharyngeal airway (PA), maxillary sinus volume, and skeletal parameters after rapid maxillary expansion (RME) and alternate rapid maxillary expansion and constriction (Alt-RAMEC) followed by facemask (FM) therapy. Methods: The records of 40 patients with skeletal Class III malocclusion due to maxillary retrognathism were collected, and the patients were assigned into two groups. The first group comprised 8 male and 12 female patients (mean age, $10.0{\pm}1.1years$) treated using RME/FM for an average of 10 months. The second group comprised 10 male and 10 female patients (mean age, $9.64{\pm}1.3years$) treated using Alt-RAMEC/FM for an average of 12 months. Cone-beam computed tomography images acquired before (T0) and after treatment (T1) were evaluated. Results: Regarding the skeletal effects, significant differences between the groups were the increase in ANS-HRP (perpendicular distance of ANS to the horizontal reference plane, 0.99 mm, p <0.05) in the Alt-RAMEC/FM group and the decrease in PP-SN (palatal plane to Sella-Nasion plane, $0.93^{\circ}$, p < 0.05) in the RME/FM group. Maxillary sinus volumes increased significantly in both the groups, and the increase was statistically significantly higher in the Alt-RAMEC/FM group. Although no significant intergroup differences were observed in PA volumes, both lower ($1,011.19mm^3$) and total ($1,601.21mm^3$), PA volume increased significantly in the Alt-RAMEC/FM group. Conclusions: The different expansion devices and protocols used with FM therapy do not seem to affect the forward movement of the maxilla and PA volumes. In contrast, the increase in maxillary sinus volume was greater in the Alt-RAMEC/FM protocol.

국내 미약 무선국 기술기준 개선방안 (Reforming Method for the Technical Regulations of Extremely Low Power Devices)

  • 강건환;오세준;이재천;박덕규
    • 한국전자파학회:학술대회논문집
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    • 한국전자파학회 2005년도 종합학술발표회 논문집 Vol.15 No.1
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    • pp.391-396
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    • 2005
  • 본 연구에서는 미약무선국의 전계강도(기술기준)에 대한 현재 각국의 동향과 그 기준치를 연구 분석하고, 파악함과 동시에, 또한, 전자파적합등록에서 제시하고 있는 각국의 전계강도 기준치와 연계하여 이에 적합한 국내의 비허가 무선기기(미약무선기기)의 실질적인 도입 가능한 전계강도의 기준치를 제시함을 목적으로 한다. 여기에서 제시한 전계강도 허용치를 바탕으로, 미약무선기기의 보급과 발전에 기여할 것으로 예상되며 국내통신시장은 물론 국제통신시장에서 경쟁력을 갖출 수 있을 것으로 예상된다.

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새로운 공정을 이용한 AIN 체적 탄성파 소자의 제작 및 다양한 금속 전극막에 따른 주파수 응답 특성 분석 (Fabrication of AIN-based FBAR Devices by Using a Novel Process and Characterization of Their Frequency Response Characteristics in terms of Various Electrode Metals)

  • 김보현;박창균;박진석
    • 전기학회논문지
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    • 제56권5호
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    • pp.915-920
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    • 2007
  • AIN-based film bulk acoustic resonator (FBAR) devices which adopt a membrane-type configuration such as Mo/AIN/bottom-metal/Si are fabricated by employing a novel process. The proposed resonator structure does not require any supporting layer above the substrate, which leads to the reduction in energy loss of the resonators. For all the FBAR devices, the frequency response characteristics are measured and the device parameters, such as return loss and input impedance, are extracted from the frequency responses, and analyzed in terms of the various metals such as Al. Cu, Mo, W used in the bottom-electrode. The mass-loading effect caused by the used bottom-electrode metals is found to be the main reason for the difference revealed in the measured characteristics of the fabricated FBAH devices. The results obtained in this study also show that the degree of match in lattice constant and thermal expansion coefficient hetween piezoelectric layers and electrode metals is crucial to determine the device performance of FEAR.

RESTful 기반의 Android - PC간 동영상 이어보기 구현 (Implementation of a Continuous Playing Schemes on Android - PC Environment Based On RESTful)

  • 김정길
    • 한국위성정보통신학회논문지
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    • 제8권4호
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    • pp.70-74
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    • 2013
  • 최근 모바일 디바이스 보급의 확산으로 다양한 기종의 디바이스를 다수 보유중인 사용자의 수가 지속적으로 증가하고 있는 추세이다. 이에 따라 하나의 미디어 콘텐츠를 사용자가 보유한 다양한 기기에서 서로 공유해야 할 필요성이 증가하고 있으며, 이는 연결성, 이동성, 통합성 기반의 N-screen 서비스의 확대를 가지고 왔다. N-screen 서비스는 하나의 미디어 콘텐츠를 공유하여 사용자가 보유한 다양한 디바이스에서 서로 이어보기가 가능하게끔 서비스를 제공한다. 그러나 N-screen 서비스들은 서비스 제공 사업자의 전용 플랫폼에서 시행되는 문제점을 가지고 있다. 따라서 본 논문은 개방형 서비스 플랫폼에서의 이어보기 기능의 설계를 위하여 시험적으로 이어보기 기능을 제공하는 RESTful 기반의 이어보기 기능 제공이 가능한 프로토타입 프로그램을 개발하였으며 동작검증은 Android - PC간 시행하였다.

DLNA Protocol Inspection Tool for Compatibility Analysis

  • Park, Se-Ho;Park, Yong-Suk;Seo, Jeong-Wook;Choi, Jun-Rim
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제8권6호
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    • pp.2104-2117
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    • 2014
  • The propagation of smart devices and the rapid expansion of wireless mobile networks have increased the need for ubiquitous device connectivity and contents access. DLNA is currently being used as the de facto standard for connectivity of consumer devices in the digital home. The guidelines provided by DLNA are intended to facilitate device and contents discovery, management, sharing and distribution. However, consumer experience with DLNA has been rather poor and usability not up to speed. Different problems and issues in limited compatibility have been reported due to manufacturer customizations. Such compatibility issues are often difficult to identify by average consumers who are not savvy in information communications and multimedia technology. In this paper, the design and implementation of a DLNA protocol inspection tool is presented for compatibility analysis among DLNA certified devices. The tool monitors the home network and performs analysis of the underlying protocols used by DLNA. The tool can be used for diagnostics and troubleshooting, enabling the user to identify compatibility issues between devices or problems in the network.

화재사례 및 재현실험을 통한 온도조절장치 고장 및 오동작으로 인한 전자제품 화재 메커니즘 분석 (A Study on the Analysis of Fire Mechanisms in Electronic Products due to Failure and Malfunction of Thermostats Through Fire Cases and Reproduction Experiments)

  • 이정일;임종화
    • 대한안전경영과학회지
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    • 제26권1호
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    • pp.31-38
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    • 2024
  • In this paper, as there are many cases of fires occurring due to the failure or inoperability of the thermostat of electronic products, the purpose is to test and analyze the risks and probabilities through fire cases and reproduction experiments, and suggest countermeasures. Among electronic products, water purifiers are composed of a refrigerant system with a compressor to make cold water, a heating device to make hot water, and an electric device used as an energy source. Due to the nature of the water purifier manufacturing, these devices are subject to a lot of moisture and dust. etc. exist in large quantities and use electrical energy, so there is a possibility of fire due to short circuit in the wire, electrical abnormal overheating (tracking phenomenon) in the thermostat, electronic board, starting relay, etc., and overheating of the heating device (Band Heater). there is. Therefore, in order to prevent fires from these devices, a system to remove foreign substances inside the water purifier is necessary, the use of heat-resistant (fire-resistant) wires for electrical devices is essential, and the use of non-combustible materials (semi-combustible materials) for each part is necessary to prevent fire. The risk must be eliminated through prevention and combustion expansion prevention devices.