• 제목/요약/키워드: Field-enhanced

검색결과 1,500건 처리시간 0.036초

MARCO${\cdot}$COMBINE 프로젝트의 조사 연구 (A Survey on the MARCO and COMBINE projects)

  • 오석문;홍순흠
    • 한국철도학회:학술대회논문집
    • /
    • 한국철도학회 2003년도 춘계학술대회 논문집
    • /
    • pp.263-271
    • /
    • 2003
  • In this paper, we presents the results of the leading 2 European projects in the real-time train conflict dection and resolution field. One is MARCO(Multi-level Advanced Railways Conflicts Resolution and Operation Control) and the other is COMBINE(enhanced COntrol center for a Moving Block sigNaling systeEm) project. From the results of the survey, we derive the basic principles in order to use in the similar project of Korea Nation Railway.

  • PDF

오염지반의 동전기 정화 (Electrokinetic Remediation of Contaminated Soils)

  • 김수삼
    • 한국지반공학회:학술대회논문집
    • /
    • 한국지반공학회 2002년도 봄 학술발표회 논문집
    • /
    • pp.3-38
    • /
    • 2002
  • This paper presents a general review of the literature on electrokinetic (EK) remediation of contaminated soil. Lab-scale tests were investigated and contaminant transport mechanism were examined. And also major factors affecting to the EK process were discussed. Enhanced techniques as a method to solve the problems that frequently occurred during traditional EK process were examined. And last, field implemented case and commercially applied case were described.

  • PDF

GERAN에서의 향상된 셀 재탐색에 관한 연구 (A Study on Enhanced Cell Reselection algorithm on GERAN)

  • 표상훈;함형민;송주석
    • 한국정보처리학회:학술대회논문집
    • /
    • 한국정보처리학회 2009년도 춘계학술발표대회
    • /
    • pp.1330-1331
    • /
    • 2009
  • 본 연구에서는 GERAN (GSM EDGE Radio Access Network) 망에서 다양한 무선환경에 따른 셀 재탐색을 연구하였으며, 시계열분석을 통하여 재탐색 이후의 RSS (Received Signal Strength)를 예측하여 개선된 재탐색 알고리즘을 연구하였다. Field 데이터를 통해 제안된 알고리즘을 분석하였으며, 이를 통하여 다양한 조건에 적합한 기법을 제안코저 한다.

Fabrication of field emitters using a filtration-taping-transfer method

  • Song, Ye-Nan;Shin, Dong-Hoon;Sun, Yuning;Shin, Ji-Hong;Lee, Cheol-Jin
    • 한국진공학회:학술대회논문집
    • /
    • 한국진공학회 2011년도 제40회 동계학술대회 초록집
    • /
    • pp.466-466
    • /
    • 2011
  • There have been several methods to fabricate carbon nanotube (CNT) emitters, which include as-grown, spraying, screen-printing, electrophoresis and bonding methods. Unfortunately, these techniques generally suffer from two main problems. One is a weak mechanical adhesion between CNTs and the cathode. The as-grown, spraying and electrophoresis methods show a weak mechanical adhesion between CNTs and the cathodes, which induces CNT emitters pulled out under a high electric field. The other is a severe degradation of the CNT tip due to organic binders used in the fabrication process. The screen-printing method which is widely used to fabricate CNT emitters generally shows a critical degradation of CNT emitters caused by the organic binder. Such kinds of problems induce a short lifetime of the CNT field emitters which may limit their practical applications. Therefore, a robust CNT emitter which has the strong mechanical adhesion and no degradation is still a great challenge. Here, we introduce a simple and effective technique for fabrication of CNT field emitter, namely filtration-taping-transfer method. The CNT emitters fabricated by the filtration-taping-transfer method show the low turn-on electric fields, the high emission current, good uniformity and good stability. The enhanced emission performance of the CNT emitters is mainly attributed to high emission sites on the emitter area, and to good ohmic contact and strong mechanical adhesion between the emitters and cathodes. The CNT emitters using a simple and effective fabrication method can be applied for various field emission applications such as field emission displays, lamps, e-beam sources, and x-ray sources. The detail fabrication process will be covered at the poster.

  • PDF

A novel preparation of polyaniline in presence electric and magnetic fields

  • Hosseini, Seyed Hossein;Gohari, S. Jamal
    • Advances in materials Research
    • /
    • 제2권4호
    • /
    • pp.209-219
    • /
    • 2013
  • We have described primary studies on conductivity and molecular weight of polyaniline separately in the electric and magnetic fields when it is used in a field effect experimental configuration. We report further studies on doped in-situ deposited polyaniline. First we have chemically synthesized polyaniline by ammonium peroxodisulfate in acidic aques and organic solutions at different times. Then we measured mass and conductivity and obtained the best time of polymerizations. In continue, we repeated these reactions separately under different electric and magnetic fields in constant time and measured mass and conductivity. The polyaniline is characterized by gel permeation chromatography (GPC), UV-Visible spectroscopy and electrical conductivity. High molecular weight polyanilines are synthesized under electric field, $M_w$ = 520000-680000 g/mol, with $M_w/M_n$ = 2-2.5. The UV-Visible spectra of polyanilines oxidized by ammonium peroxodisulfate and protonated with dodecylbenzenesulfonic acid (PANi-DBSA), in N-methylpyrolidone (NMP), show a smeared polaron peak shifted into the visible. Electrical conductivity of polyanilines has been studied by four-probe method. The conductivity of the films of emeraldine protonated by DBSA cast from NMP are higher than 500 and 25 S/cm under 10 KV/m of potential) electric field and 0.1 T magnetic field, respectively. It shows an enhanced resistance to ageing too. By the next steps, we carried chemical polymerization at the best electric and magnetic fields at different times. Finally, resulted in finding the best time and amount of the fields. The longer polymerization time and the higher magnetic field can lead to degradation of polyaniline films and decrease conductivity and molecular mass.

PLM 기반의 국방 형상관리 정보체계 구축 사례연구 (A Study of Implementation of Defense Configuration Management System based on PLM)

  • 임채오
    • 한국CDE학회논문집
    • /
    • 제13권4호
    • /
    • pp.305-313
    • /
    • 2008
  • A configuration management system was implemented by applying PLM to the defense field. The PLM system has recently been incorporated in a wide range of industries, and it has allowed for improvements in work productivity and expansion of related services by comprehensively managing and securing connection regarding configuration information in the defense field. Implementations include acquisition of configuration related information and reinforcement of BOM-oriented configuration management function, securing compatibility among 3D drawings of different agencies, improvement of drawing and document management functions, comprehensive systematic configuration management focused on product structure, strengthened configuration control functions, a management system according to the work flow and life cycle functions, an integrated configuration management system of 3D model CAD resources and an enhanced management system. This paper covers a case study reviewing the implementation of a PLM-based configuration management information system and its results, so that the information can be made available to other agencies and companies seeking to apply PLM in their organizations.

Preparation of Porous Nanostructures Controlled by Electrospray

  • Nguyen, Dung The;Nah, In Wook;Kim, Kyo-Seon
    • Korean Chemical Engineering Research
    • /
    • 제53권5호
    • /
    • pp.627-631
    • /
    • 2015
  • Various solid structures were prepared by electrospray technique. In this process, liquid flows out from a capillary nozzle under a high electrical potential and is subjected to an electric field, which causes elongation of the meniscus to form a jet. In our study, by controlling the amount of polyvinyl pyrrolydone in precursor solution, the jet either disrupted into droplets for the formation of spherical particles or was stretched in the electric field for the formation of fibers. During the electrospray process, the ethanol solvent was evaporated and induced the solidification of precursors, forming solid particles. The evaporation of ethanol solvent also enhanced the mass transport of solutes from the inner core to the solid shell, which facilitated fabrication of porous and hollow structure. The network structures were also prepared by heating the collector.

Fabrication of High Break-down Voltage MIM Capacitors for IPD Applications

  • Wang, Cong;Kim, Nam-Young
    • 한국전기전자재료학회:학술대회논문집
    • /
    • 한국전기전자재료학회 2009년도 추계학술대회 논문집
    • /
    • pp.241-241
    • /
    • 2009
  • For the Radio Frequency Integrated Passive Device (RFIPD) application, we have successfully developed and characterized high break-down voltage metal-insulator-metal (MIM) capacitors with 2,000 ${\AA}$ plasma-enhanced chemical vapor deposition (PECVD) silicon nitride which deposited with $SiH_4/NH_3$ gas mixing rate, working pressure, and RF power of PECVD at $250^{\circ}C$ chamber temperature. At the PECVD process condition of gas mixing rate (0.957), working pressure (0.9 Torr), and RF power (60 W), the AFM RMS value of about 2,000 ${\AA}$ silicon nitride on the bottom metal was the lowest of 0.862 nm and break-down electric field was the highest of about 8.0 MV/cm with the capacitance density of 326.5 $pF/mm^2$.

  • PDF

Low Spin-Casting Solution Temperatures Enhance the Molecular Ordering in Polythiophene Films

  • Lee, Wi Hyoung;Lee, Hwa Sung;Park, Yeong Don
    • Bulletin of the Korean Chemical Society
    • /
    • 제35권5호
    • /
    • pp.1491-1494
    • /
    • 2014
  • High-crystallinity poly(3-hexylthiophene) (P3HT) thin films were prepared by aging the precursor solutions, prepared using a good solvent, chloroform, at low temperatures prior to spin-casting. Lower solution temperatures significantly improved the molecular ordering in the spin-cast P3HT films and, therefore, the electrical properties of field-effect transistors prepared using these films. Solution cooling enhanced the electrical properties by shifting the P3HT configuration equilibrium away from random coils and toward more ordered aggregates. At room temperature, the P3HT molecules were completely solvated in chloroform and adopted a random coil conformation. Upon cooling, however, the chloroform poorly solvated the P3HT molecules, favoring the formation of ordered P3HT aggregates, which then yielded more highly crystalline molecular ordering in the P3HT thin films produced from the solution.