드론, 최초에서 최고로

이성재 (사)방송기자연합회 2015 방송기자 Vol.25 No.-

고무강화 폴리스티렌과 유기화된 층상 실리케이트 나노복합재료의 합성 및 물성

이성재 수원대학교 산업기술연구소 2002 산업기술연구소논문집 Vol.17 No.-

Polymer/clay nanocomposites are potential materials with attractive properties such as improved stiffness, dimensional stability, barrier resistance, thermal stability and flame retardency. Many researches have focused on the property improvement of thermoplastics such as polystyrene with organically modified layered silicates, but open literatures have not been yet found on the rubber-toughened polystyrene by the author's knowledge. High impact polystyrene (HIPS) is known as the rubber-toughened polystyrene to improve the impact strength and toughness of glassy polystyrene. Current research issues of HIPS include high performance HIPS such as glossy, transparent, chemical-resistant, high strength and flame-retardant grades. Naturally, the introduction of clay would be one of good candidates to achieve these purposes. In this study, the preparation of HIPS/organically modified layered silicate nanocomposites by in situ polymerization is presented and the characterization techniques of the material are also discussed. Major attention will be focused on the dispersion of silicate layer and the change in rubber particle size affected by the clay loading.

韓國産 참나무科 樹種의 導管構造에 關한 硏究( II ) - 導管壁의 修飾構造 -

李成宰,李元用 강원대학교 산림과학연구소 1992 Journal of Forest Science Vol.8 No.-

시뮬레이션 분석 및 신뢰성 시험결과의 비교분석을 통한 피에조 센서의 피로강도 분석 및 예측

이성재,임성용,이영주,임홍우 한국신뢰성학회 2015 한국신뢰성학회 학술대회논문집 Vol.2015 No.5

국내·외적으로 지능형교통시스템(ITS) 시장이 확대됨으로써, 교통량조사시스템(AVC)의 보급이 증가하고 있으며, 데이터를 수집하는 센서부에는 피에조 필름을 이용한 피에조 센서가 사용되고 있다. 이러한 중요한 역할을 맞고 있는 피에조 센서의 외피를 구성하는 금속(동) 재질은 내부의 피에조 필름을 보호하고 기밀성을 유지하는 역할을 하고 있으며, 금속(동)의 파손은 피에조 센서의 심각한 고장을 초래 할 것이다. 본 논문에서는 피에조 센서의 외피를 구성하는 금속(동)의 단면형상을 분석하여, 시뮬레이션을 통한 구조해석 기법을 이용하여 피로강도를 분석하였으며, 반복하중내구시험을 통한 피로파괴 결과와 비교분석하였다. 또한, 비교분석의 결과를 바탕으로 제조공정에서 나타나는 다양한 형태의 단면 형상을 시뮬레이션을 통하여 구조해석을 함으로써 제조공정에서의 품질관리를 향상시키는데 기여할 것으로 예상된다.

음향방출 신호원의 위치추정 기법

이성재,김정석,강명창,정연식,정규동 한국공작기계학회 2003 한국공작기계학회 춘계학술대회논문집 Vol.2003 No.-

This study deals with the source location method of defect which can be occurred in structure. The existing methods was very difficult to be applied to predict it, because of using very complex numerical formula. The triangulation method which was proposed in this study can predict the source location predicted easily with small amount of data. Wave arrival time data can be directly converted into source-sensor distance is known. For this purpose, the propagation velocity was measured by Rayleigh wave, and the propagation behavior was analyzed. For the consideration of jointed part in structure, the source location method was applied to the welded workpieces. The signal propagation velocity was measured in welding part for the purpose of application to the part, and the revised algorithm of source location was proposed.

Numerical Simulations of Rotating Bondi Accretion Flows

이성재,류동수 한국물리학회 2004 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.45 No.3

We explore through numerical simulations the structure formed around a black hole as a consequence of supersonic Bondi accretion with a small, nite angular momentum. The structure accompanies an accretion shock, inside which the ow is subsonic and is dissipated by the viscosity. We assume the dissipated energy is stored as entropy rather than being radiated. Although it is generally known that such advection-dominated accretion ow, as well as Bondi accretion ow, is dynamically stable in one-dimension, our numerical simulations indicate that a structure that contains the two ows is globally unstable, resulting in an oscillation with a period of MBH=M sec. In this contribution, we describe brie y the nature of the oscillation, which may explain the low-frequency quasi-periodic oscillations with a frequency 0:1 Hz, observed in stellar mass black hole candidates.

Gold nanoparticles immobilized onto melamine-formaldehyde microspheres as catalyst for the reduction of 4-nitrophenol

이성재,장영욱 한국고분자학회 2017 한국고분자학회 학술대회 연구논문 초록집 Vol.42 No.1

GRATING COUPLER FOR THIN FILM WAVEGUIDE

이성재,송재원,신상영 대한전자공학회 1981 대한전자공학회 학술대회 Vol.1981 No.1

발화이론과 화용론에 관한 연구

이성재 부산대학교 사범대학 1990 교사교육연구 Vol.21 No.-

On constate que les travaux de pragmatique linguistique, d'analyse du dialogue et du discours font e´clater le domaine de la linguistique et interessent de plus en plus tous les proble`mes concerne´s par les proble`mes d'emploi du langage en communication. C'est pour ca qu'on a esquisse´ les courants des pragmatiques. Selon les diverses traditions, les pragmatiques contemporaines se distinguent par leurs methodologies. On a essage´ de saisir les courants de pense´e et d'analyse dont les me´thodologies des the´oriciens les plus influence´s ont contribue´ a` la pragmatique (aux pragmatiques). Benveniste a contribue´ a` jeter les bases d'une the´orie linguistique de l'e´nonciation et a` de´crire les proce´de´s linguistiques qui permettent la conversion de la langue en discours, son appropriation par le sujet parlant et l'inscription dans l'enonce de l'enonciateur et de l'e´nonciataire. Austin e´laborait les bases de la pragmatique par l'e´tude systematique de la relation singne-utilisateur. Selon lui, en accomplissant un acte illocutoire, le locuteur s'assigne un certain ro^le et assigne corre´lativement a` l'auditeur un ro^le comple´mentaire. Le ro^le social endosse par le locuteru est re´alise institutionnellement. Austin a montre´ que le langage est une sorte de vaste institution, comportant une panoplie des ro^les conventionnels correspondant a` la gamme des actes de discours socialement reconnus. Avec Austin, la pragmatique est reintegree dans le champ des etudes proprement linguistiques. Ducrot developpe les e´tudes de pragmatique linguistique, dont lorigine est a `situer principlament dans les travaux d'Austin sur les e´nonce´s performatifs et les actes illocutoires d'une part et de Benveniste sur le discours et l'e´nonciation. A la base de cette aproche linguistique, on trouve l'ide´e majeure que la langue ne fonctionnent pas comme un syste`me de signes, un code, dont chacun des termes recevrait sa valeur des diffe´rences ou oppositions qu'il entretient avec les autres e´le´ments de syste`me. Ducrot, en suivant Benveniste, fait au contraire l'hypothse que le sens d'un e´nonce´ fait obligatoirement re´fe´rence a` son e´nonciation, ou en d'autres termes, qu'il est sui-re´fe´rentiel. Pour lui, l'e´tude du idscours devient une etude du discours ide´al. Selon Ducrot, les actes illocutoires, la pre´supposition et les indicateurs pragmatiques sont compris conventionnellement dans la langue, il les ve´rifie par la valeur argumentative et la loi du discours. Searle regroupe les categories des actes illocutoires d'Austin. La reflexion sur les actes de langage est nee d'une opposition radicale aux conceptions vericonditionnelles de la signification en philosoophie du langage, insistant sur le fait que les actes des communication langagie`re visent la re´alisation d'actes sociaux(les actes illocutoires). La proble´matique des actes illocutoires s'est de´finie principalement comme des conditions ne´cessaires et suffisantes a` la re´alisation appropriee des actions langagie`res et des conditions ge´ne´rales garantissant la reconnaissance des intentions illocutoires dans la communication. La pragmatique conversationnelle vise la modelisation du dialogue. Le mode`le d'analyse va permette d'une part de mettre a` jour des faits conversationnels perinents qu'il n'aurait pas e´te´ possible de de´couvrir sans son utilisation, et d'autre part d'ouvrir des perspectives interessantes quant a` la description lingusitique du francais. La fonction d'anayse conversationnelle reside dans sa capacite´ a` de´crire des structures conversationnelles differentes permettant d'expliquer des comportements diffe´rencies chez les interlocuteurs. L'esquisse ci-dessus permet de comprendre que dans le domaine de la se´mantique, avec l'extension de la notion de convention, sont introduits les e´le´ments pragmatiques. Cela veut dire que le domaine de la se´muntique etend sans cesse.

수지이동성형의 충전공정 해석을 위한 모델링 및 모사

李聖載 水原大學校 1997 論文集 Vol.15 No.-

The filling processes of resin transfer molding for the manufacturing of polymer composite materials were numerically analyzed by the use of the finite difference method based on boundary fitted coordinate systems. Composite grids with dynamic moving meshes were particularly suitable for irregular geometries and multiple domains. Along the pseudo-boundaries interfacing composite grids, rigorous control volume scheme was implemented for the mass conservation. Several tests were performed for the complex mold composed of double gates and stiffeners including variable gap thicknesses and permeabilities. Numerical results demonstrated the applicability of dynamic moving mesh scheme with composite grids in achieving accurate modeling of the flow front without interpolation or double grid scheme that were common in fixed mesh schemes.