• 제목/요약/키워드: K-EDS

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SR 컨버터 기반 25[kW]급 DC 계통연계 태양광 PCS 개발 (Development of Series Resonant Converter Based DC Utility Interactive PCS for 25[kW] PV System)

  • 윤여영;김홍성;정재기
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2010년도 추계학술대회
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    • pp.202-204
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    • 2010
  • 본 논문은 DC 급전시스템에 적용 가능한 25[kW]급 계통연계 태양광 PCS 개발에 관한 것이다. 전력 회로는 넓은 범위의 입력 전압대에서 출력 전류가 조절 가능 하도록 Fixed Frequency Series Resonant Converter(SR Converter)로 구성하였으며, 스위칭 손실을 극소화 시킬 수 있는 ZVZCS 동작을 구현 하였으며, PWM 기법으로는 위상 천이 방식을 사용하였다. 제안한 DC 계통 연계형 태양광 PCS 시스템 동작에 대한 P-sim 시뮬레이션을 수행하였으며, 25[kW] Prototype을 제작하여 시뮬레이션 결과와 비교 실험을 수행하였다

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저진공 분위기 전기방전소결에 의해 제조된 다공성 Ti-6Al-4V 임플란트의 표면특성 연구 (Surface Characteristics of Porous Ti-6Al-4V Implants Fabricated by Electro-Discharge-Sintering in a Low Vacuum Atmosphere)

  • 현창용;허재근;이원희
    • 한국재료학회지
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    • 제16권3호
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    • pp.178-182
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    • 2006
  • A single electro-discharge-sintering (EDS) pulse (1.0 kJ/0.7 g), from a $300{\mu}F$ capacitor, was applied to atomized spherical Ti-6Al-4V powder in a low vacuum to produce porous-surfaced implant compacts. A solid core surrounded by a porous layer was formed by a discharge in the middle of the compact. XPS (X-ray photoelectron spectroscopy) was used to study the surface characteristics of the implant material. C, O, and Ti were the main constituents, with smaller amounts of Al, V, and N. The implant surface was lightly oxidized and was primarily in the form of $TiO_2$ with a small amount of metallic Ti. A lightly etched EDS implant sample showed the surface form of metallic Ti, indicating that EDS breaks down the oxide film of the as-received Ti-6Al-4V powder during the discharge process. The EDS Ti-6Al-4V implant surface also contained small amounts of aluminum oxide in addition to $TiO_2$. However, V detected in the EDS Ti-6Al-4V implant surface, did not contribute to the formation of the oxide film..

CAN기반 실시간 시스템을 위한 확장된 EDS 알고리즘 개발 (Development of an Extended EDS Algorithm for CAN-based Real-Time System)

  • 이병훈;김대원;김홍렬
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2001년도 하계학술대회 논문집 D
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    • pp.2369-2373
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    • 2001
  • Usually the static scheduling algorithms such as DMS (Deadline Monotonic Scheduling) or RMS(Rate Monotonic Scheduling) are used for CAN scheduling due to its ease with implementation. However, due to their inherently low utilization of network media, some dynamic scheduling approaches have been studied to enhance the utilization. In case of dynamic scheduling algorithms, two considerations are needed. The one is a priority inversion due to rough deadline encoding into stricted arbitration fields of CAN. The other is an arbitration delay due to the non-preemptive feature of CAN. In this paper, an extended algorithm is proposed from an existing EDS(Earliest Deadline Scheduling) approach of CAN scheduling algorithm haying a solution to the priority inversion. In the proposed algorithm, the available bandwidth of network media can be checked dynamically by all nodes. Through the algorithm, arbitration delay causing the miss of their deadline can be avoided in advance. Also non real-time messages can be processed with their bandwidth allocation. The proposed algorithm can achieve full network utilization and enhance aperiodic responsiveness, still guaranteeing the transmission of periodic messages.

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How Effective Are Radiation Reducing Gloves in C-arm Fluoroscopy-guided Pain Interventions?

  • Kim, Ah Na;Chang, Young Jae;Cheon, Bo Kyung;Kim, Jae Hun
    • The Korean Journal of Pain
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    • 제27권2호
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    • pp.145-151
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    • 2014
  • Background: The physician's hands are close to the X-ray field in C-arm fluoroscopy-guided pain interventions. We prospectively investigated the radiation attenuation of Proguard RR-2 gloves. Methods: In 100 cases, the effective doses (EDs) of two dosimeters without a radiation-reducing glove were collected. EDs from the two dosimeters-one dosimeter wrapped with a glove and the other dosimeter without a glove-were also measured at the side of the table (Group 1, 140 cases) and at a location 20 cm away from the side of the table (Group 2, 120 cases). Mean differences such as age, height, weight, radiation absorbed dose (RAD), exposure time, ED, and ratio of EDs were analyzed. Results: In the EDs of two dosimeters without gloves, there were no significant differences ($39.0{\pm}36.3{\mu}Sv$ vs. $38.8{\pm}36.4{\mu}Sv$) (P = 0.578). The RAD ($192.0{\pm}182.0radcm^2$) in Group 2 was higher than that ($132.3{\pm}103.5radcm^2$) in Group 1 (P = 0.002). The ED ($33.3{\pm}30.9{\mu}Sv$) of the dosimeter without a glove in Group 1 was higher than that ($12.3{\pm}8.8{\mu}Sv$) in Group 2 (P < 0.001). The ED ($24.4{\pm}22.4{\mu}Sv$) of the dosimeter wrapped with a glove in Group 1 was higher than that ($9.2{\pm}6.8{\mu}Sv$) in Group 2 (P < 0.001). No significant differences were noted in the ratio of EDs ($73.5{\pm}6.7%$ vs. $74.2{\pm}9.3%$, P = 0.469) between Group 1 and Group 2. Conclusions: Proguard RR-2 gloves have a radiation attenuation effect of 25.8-26.5%. The radiation attenuation is not significantly different by intensity of scatter radiation or the different RADs of C-arm fluoroscopy.

Unified Identification for Event Driven Service in User-Centric Environments

  • Lee, Soong-Hee;Kim, Dong-Il;Jeon, Hyung-Goo;Jang, Jong-Wook
    • Journal of information and communication convergence engineering
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    • 제9권2호
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    • pp.177-182
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    • 2011
  • Considerations for user-centric environments are regarded as essential for the successful deployment of convergence services in BcN. Event driven service (EDS) is regarded as a typical convergence service converging different functions of multiple service providers to support user-centric environments. This paper first describes the deployment model and service scenario of EDS, a convergence service for user-centric environments in BcN. The user-centric environments stimulates the unified identifier management, namely unified identification (U-ID), to enable users to be provided convergence services without awareness of multiple providers. Then the designed structure and implementation results are given.

초고속 자기부상열차를 위한 초전도 반발식 자기부상 특성 해석 (Analysis on Superconducting Electrodynamic Suspension for Very High Speed Maglev)

  • 배덕권;이종민;조한욱;한형석
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2009년도 춘계학술대회 논문집 에너지변화시스템부문
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    • pp.198-200
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    • 2009
  • This paper presents the numerical simulation results on the moving type electrodynamic suspension (EDS) simulator. Superconducting EDS system is generated by the interaction between the magnetic field made by the induced the eddy current in the ground conductor and the moving magnetic field made by onboard superconducting magnet. The levitation force of EDS system, which is proportional to the strength of the moving magnetic field, becomes saturated according to the increase of the velocity Especially, the levitation force is influenced by the structure of HTS magnet and ground conductor. The 3-D numerical analysis with FEM was used to find the distribution of the magnetic field, the optimal coil structure, and the calculation of the levitation force.

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EDS (Energy Dispersive Spectrometry)를 이용한 Mineral Trioxide Aggregate와 3종의 포틀랜드 시멘트의 성분비교에 관한 연구 (Analysis of Chemical Constitutions of MTA and 3 Portland Cements)

  • 장석우;배광식
    • 구강회복응용과학지
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    • 제23권1호
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    • pp.79-84
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    • 2007
  • Mineral Trioxide Aggregate(MTA) has been used in Endodontic treatment successfully for more than 10 years. But the high cost of MTA limits its use in endodontics in Korea. Recently many studies have been done to compare MTA and Portland cements. To investigate the chemical constitutions of MTA (Proroot MTA, Tulsa Dental), Gray Portland cement (Lafarge Halla cement), White Portland cement(Union corp), and fast setting cement (SSangyong cement), we performed SEM(scanning electron microscope)(S4700, Hitachi) examination and EDS(Energy dispersive spectrometry)(emax, Horiba) analysis. SEM examination and EDS analysis were committed to and performed in SNU DRI (Seoul National University Dental Research Institute). We found that particles of MTA were relatively round, uniform in size, and compactly packed compared to Portland cements. Chemical constitutions of MTA, GPC, WPC and FSC were similar. It was shown that MTA contains much BiO2 . MTA and WPC showed less heavy metals such as Fe and Mg compared to GPC and FSC. FSC showed remarkably high aluminum content.

나로호(KSLV-I) 비행상태 감시를 위한 우주센터 원격수신자료전시시스템 구축과 운용 (Development and Operation of EDS for Monitoring KSLV-I Flight Status in Space Center)

  • 최경준;김정석;최용태
    • 한국컴퓨터정보학회:학술대회논문집
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    • 한국컴퓨터정보학회 2016년도 제54차 하계학술대회논문집 24권2호
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    • pp.29-32
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    • 2016
  • 본 논문에서는 나로호(KSLV-I) 비행상태의 실시간 감시를 목적으로 국내에서는 처음 개발된 우주센터 원격수신자료전시시스템(EDS)의 구축과 운용을 소개한다. EDS는 우주센터 발사통제시스템의 주요 시스템 중 하나이고 그 역할은 위성발사체의 비행에 중대한 영향을 주는 주요정보(QLM)와 궤적정보(TSPI)를 수신하여 실시간으로 처리함으로써 탑재 서브시스템별 전문가들이 위성발사체의 비행 상태를 감시할 수 있도록 지원하는 것이다. EDS는 3회에 걸친 나로호 비행시험에서 그 역할에 따라 매회 8대가 운영되었으며 임무를 성공적으로 수행하였다. 본 시스템을 기반으로 추후 발전된 형태의 한국형발사체(KSLV-II) 비행상태의 실시간 감시시스템의 구축이 가능할 것으로 예상된다.

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Ehlers-Danlos syndrome 환아의 맹출장애 : 증례보고 (DENTAL MANAGEMENT ASSOCIATED WITH ERUPTION DISORDERS IN A PATIENT WITH EHLERS-DANLOS SYNDROME : A CASE REPORT)

  • 진달래;김종철;이상훈;김정욱;김영재;현홍근;신터전;장기택
    • 대한장애인치과학회지
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    • 제8권2호
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    • pp.127-133
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    • 2012
  • EDS는 관절의 과운동성, 피부의 과신장, 조직 약화 등을 임상적 특징으로 하는 유전 질환이다. 피부, 골격, 근육, 인대, 점막, 혈관 등을 구성하는 교원질의 합성 과정과 관련된 유전자의 결함으로 결합조직이 비정상적으로 변하므로 신체 전반에 걸쳐 그 증상이 나타난다. 구강 영역에서도 교원 질과 관련된 조직에 영향을 받게 된다. 구강 점막, 치주 조직, 측두하악관절 및 치아 경조직에 문제가 발생할 수 있으므로, 총체적이고 정기적인 구강관리가 이루어져야 한다. 이번 증례와 같이 EDS에 의해 치아의 맹출 장애가 발생하고, 치은비대, 유착, 매복, 선천적 결손치, 부정교합 등이 관찰되는 경우에도 구강 위생 관리와 함께 장기적인 계획 하에 맹출 관리 및 치료가 요구된다. EDS 환아의 치과 치료시에는 질환의 원인과 전신적 특징에 대한 이해를 바탕으로, 비정상적 교원질 대사에 의해 약화된 점막과 치주조직, 지혈 관리, 반흔 형성 및 측두하악관절에 대한 종합적인 고려와 지속적인 관리가 필요하다.