• Title/Summary/Keyword: 공중

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Crytal Structure Study of Random Copolymers by CPMAS Solid-State NMR Spectrosecopy (고체상태에서의 CPMAS NMR분광법을 이용한 랜덤 공중합체의 결정구조 연구)

  • Yoo, Hee-Yeoul;Shim, Mi-Ja;Kim, Sang-Uk
    • Korean Journal of Materials Research
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    • v.3 no.4
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    • pp.344-351
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    • 1993
  • The crystal structunes of poly(ethylene terephthalate-eo-1, 4 cyciohexylene dimethylene terephthalate), P(ET CT), copolymers were studied by CPMAS solid state NMR spectroscopy. With the estimation of methylene resonance peaks, the bulkier CT component of the copolymer in the range of 0 20 mol% CT is excluded from the ET crystal lattice, whereas smaller ET component of the copolymer in the range of 66 100 mol% CT can be partially included into the CT crystal lattice. Those different crystallization behavior can be explained with the difference in chain bulkiness and crystal lattice dimension be tween two copolymer compurwnts.

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Development of a Diagnostic Module Based Maintenance Support Device for Fiber Optic Telecommunication Cable in Overhead Region (고소지역 작업현장에서 공중선 상태 진단 모듈 기반 정비 지원 장치 개발)

  • Kim, Hee-Chul
    • The Journal of the Korea institute of electronic communication sciences
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    • v.9 no.4
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    • pp.469-474
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    • 2014
  • Installed on telephone poles laid scrambling to monitor the status of the communication lines, and cost information can provid eadditional information tools to develop systems to support on-site monitoring. Aerial support for a maintenance monitoring module to apply an embedded system, and information processing applications manufactured. In this study, a comprehensive plan in accordance with the government's aerial maintenance work to prevent accidents spread support for the device to immediately take advantage of big cities and aerial maintenance business, Construction worker accused of bias and aims to improve efficiency of maintenance puts.

Development of Balloon-based Autonomous Airborne Robot-kit (풍선기반 자율형 공중로봇키트 개발)

  • Kim, Hyun-Sik
    • The Journal of the Korea institute of electronic communication sciences
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    • v.8 no.8
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    • pp.1213-1218
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    • 2013
  • Recently, although the need of marine robots such as the underwater robot, surface robot and airborne robot being raised in extreme areas, the basis is very deficient. Fortunately, as the need of the robot education is increasing, it is desirable to establish the R&D basis of marine robots and to train future talents through the development and diffusion of marine robot kits. However, in conventional case, there is no marine robot-kit based on the balloon, which has the abilities of the airborne locomotion and obstacle avoidance. To solve this problem, a balloon-based autonomous airborne robot-kit that has the ability of the obstacle avoidance with an infrared sensor, is developed. The test and evaluation results show the possibility of the real applications and the necessity of additional work.

Optimal Supersonic Air-Launching Rocket Design Using Multidisciplinary System Optimization Approach (다분야 최적화 기법을 이용한 공중발사 로켓 최적설계)

  • Choi, Young-Chang;Lee, Jae-Woo;ByUn, Yung-Hwan
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.33 no.12
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    • pp.26-32
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    • 2005
  • Compared with the conventional ground rocket launching, air-launching has many advantages. However, a comprehensive and integrated system design approach is required because the physical geometry of air launch vehicle is quite dependent on the installation limitation of the mother plane. The system design has been performed using two different approaches: the sequential optimization and the multidisciplinary feasible(MDF) optimization method. Analysis modules include mission analysis, staging, propulsion analysis, configuration, weight analysis, aerodynamics analysis and trajectory analysis. MDF optimization shows better results than the sequential optimization. As a result of system optimization, a supersonic air launching rocket with total mass of 1244.91kg, total length of 6.36m, outer diameter of 0.60m and the payload mass of 7.5kg has been successfully designed.

The Effect of PR Communication of Local Government through Social Media : Focusing on the Official Blog of Busan Metropolitan City, 'Cool Busan.' (소셜 미디어를 통한 지자체 PR 커뮤니케이션의 효과분석 : 부산광역시 블로그 '쿨부산'을 대상으로)

  • Sun, Hye-Jin
    • The Journal of the Korea Contents Association
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    • v.18 no.10
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    • pp.20-29
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    • 2018
  • This study investigated the effect of PR communication of local government on the relationship between the local government and the public and the image of the local government, focusing on the official blog of Busan Metropolitan City, 'Cool Busan.' It also examined the mediating role of organization-public relations. As a result, 'interactivity' and 'interest' among the characteristics of social media information have a statistically significant effect on organization-public relationship and municipal image. And balance' was found to affect the image of local government. In addition, the mediating role of the organization-public relations subfactors has been proved in the influence of the local government social media information characteristics on the local government image.

Analysis of Trifluoroacetyl group in PVA-polyvinyltrifluoroacetate Copolymer by the Pyrolysis Gas Chromatography (열분해 기체크로마토그래피를 이용한 PVA-polyvinyltrifluoroacetate 공중합체중의 trifluoroacetyl 기의 정량)

  • Chae, Hee-Ju;Jo, Seong-Mu;Lyu, Hark-Soo;Nakajima, Toshinari
    • Journal of the Korean Chemical Society
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    • v.31 no.3
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    • pp.287-291
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    • 1987
  • The composite mole fraction of monomers in PVA-PVFAc copolymer could be calculated from the analysis of trifluoroacetyl group by the pyrolysis gas chromatography without breaking of C-F bonds in polymer. A linearity between trifluoroacetyl peak areas in pyrogram and sample weights was obtained within the range below 3mg. The data of trifluoroacetyl contents derived from gas chromatogram of copolymers with various D.S. were in good agreement with results by the Specific Ionmeter.

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Preparation and Adhesive Properties of Acrylate Copolymer with Siloxane Group (실록산기를 함유한 아크릴 공중합체의 제조 및 점착특성)

  • Yoon, Keun-Byoung;Noh, Young-Joo;Lee, Dong-Ho
    • Applied Chemistry for Engineering
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    • v.18 no.2
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    • pp.121-125
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    • 2007
  • Siloxane monomer and oligomer were introduced to n-butyl acrylate and methyl methacrylate copolymer for improvement of water resistance and tactile sensation of acryl-type emulsion. Terpolymerimerization of n-butylacrylate, methyl methacrylate and siloxane monomer or oligomer was carried out in aqueous solution. The glass transition temperature (Tg) of terpolymer decreased with increasing siloxane monomer, however, the Tg of terpolymer increased with increasing siloxane oligomer due to the crosslinking of acrylated end group. The adhesion property and surface energy of the obtained terpolymer decreased with introducing siloxane monomer or oligomer in terpolymer. Decrement of tack and surface energy means the enhancement of water resistance and tactile sensation of the emulsion.

3D Visualization for Situational Awareness of Air Force Operations (공중작전 상황인식을 위한 3차원 가시화)

  • Kim Seong-Nam;Choi Jong-ln;Kim Chang-Hun;Lim Cheol-Su
    • Journal of KIISE:Computer Systems and Theory
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    • v.32 no.6
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    • pp.314-323
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    • 2005
  • This paper proposes a real-time 3D visualization system for situational awareness of Air force operations. This 3D system of situational awareness supports a high-level commander of Air force during the war game operations. These situation aware supporting data such as the aircraft track data of radar, aircraft schedule database, map and satellite image data are integrated into one structured data and those are visualized as 3D structure. By using an Out-of-Core method, we can visualize a 3D huge data in real-time in mobile notebook environment. The experiment shows several examples of 3D visualization supporting situation awareness for Air force operation.

Preparation and characterization of fluorinated poly(arylene ether sulfone) block copolymers for fuel cell applications (고분자 연료전지용 불소계 poly(arylene ether sulfone) 블록 공중합체 전해질막의 합성 및 특성연구)

  • Yoo, Min-Chul;Chang, Bong-Jun;Kim, Jeong-Hoon;Lee, Soo-Bok;Lee, Yong-Taek
    • New & Renewable Energy
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    • v.2 no.4 s.8
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    • pp.46-55
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    • 2006
  • 본 연구는 불소그룹을 함유한 술폰화된 아릴렌에테르계 블록 공중합체 고분자 전해질막의 제조 및 연료전지 특성에 관한 것이다. 이러한 불소그룹을 함유한 술폰화된 아랄렌에테르계 블록 공중합체를 제조하기 위하여 양말단에 불소계 비닐기를 가지면서, 고분자 전환시 상온에서 술폰화 가능한 biphenyl계 단량체와 술폰화가 불가능한 sulfonyl계 단량체를 각각 합성하였다. Biphenyl계 단량체로 부터 올리고머를 합성한 후 sulfonyl계 단량체와 열적 고리화 부가중합을 하여 다양한 몰조성을 갖는 일련의 perfluorocyclobutane(PFCB)기를 포함하는 블록 공중합체를 제조하였다. 제조된 블록 공중합체를 상온에서 술폰화제인 chlorosulfonic acid(CSA)를 이용하여 후술폰화시켜 강산 이온기인 sulfonic acid를 biphenyl계 올리고머 부분에 선택적으로 도입하였다. 이렇게 제조된 술폰화된 고분자를 제막한 후 연료전지 특성을 Nafion-115와 비교하였다. 술폰화가 되는 올리고머 블록의 비율 증가에 따라 이온교환능력 (IEC)이 증가하였고 , 그에 따른 팽윤도 역시 증가하는 것을 보였다. 술폰화된 고분자들은 건조 및 습윤 상태에서도 기계적 강도가 우수하였다. 최적화된 술폰화 블록 고분자(S-2) 를 대상으로 membrane electrolyte assembly(MEA) 를 제조하여 연료전지 초기성능을 측정한 결과 Nafion-112와 유사한 전기화학적 성능을 나타내었다.

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Self-Assembly Monolayers 처리 공정이 블록 공중합체를 이용한 나노패턴 제조에 미치는 영향

  • Hwang, Yeong-Hyeon;Gwon, Sun-Muk;Kim, Yeong-Hwan;Jo, Won-Ju;Kim, Yong-Tae
    • Proceedings of the Korean Vacuum Society Conference
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    • 2011.02a
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    • pp.339-339
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    • 2011
  • 기존의 광학리소그래피방법으로는 나노크기의 패턴을 형성하는데에 있어서 많은 제약이 있으며, 사실상 수십나노크기의 패턴을 형성하는데에는 전자빔리소그래피등 새로운 패턴형성 방법이 요구되고 있다. 블록 공중합체를 이용한 나노 패턴은 서로 다른 화학적 구조를 가지는 고분자들이 공유결합으로 연결되어 있는 분자구조를 이용하여, 하나의 분자 내에 서로 다른 블록들이 상분리를 일으키려는 것과 동시에 이들의 공유결합으로 인해 그 정도가 제한되는 것을 이용하여 라멜라, 실린더, 구 등의 주기적으로 배열된 형태의 구조물을 형성하는 패터닝 기술이다. 블록 공중합체를 이용한 나노크기의 패턴 형성은 열역학적으로 안정적인 구조이며, 대면적으로 구현 할 수 있어서 차세대 소자제작을 위한 제작기술로 많은 관심을 가지고 있다. 하지만 블록공중합체를 이용한 나노패턴 기술은 선행적으로 나노구조체를 결함이 없고, 원하는 형태로 제작 할 수 있는 공정의 확립이 필요하다. 따라서 본 연구에서는, 이러한 블록 공중합체을 이용한 나노패턴을 제조하는 공정에서, 폴리스틸렌과 실리콘 산화물 박막과의 표면반응을 막기 위한 Self-Assembly Monolayers (SAMs) 처리 공정이 패턴 형성에 미치는 영향을 알아보기 위하여 MPTS의 농도 및 처리시간을 변화시켰다. 나노패턴을 분석, 확인하기 위하여 Atomic Force Microscopic (AFM)과 Field Emission Scanning Electron Microscope (FESEM)을 이용하였다.

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