http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Rheo- compocasting 법에 의한 SiC 입자분산 복합재료의 마모특성에 관한 연구
곽현만,최창옥 ( Hyun Man Kwak,Chang Ock Choi ) 한국주조공학회 1993 한국주조공학회지 Vol.13 No.3
N/A Microstructure, hardness and wear characteristics of SiC_P/Al-6.5wt%Si-1.7wt%Mg alloy composites fabricated by the method of rheo-compocasting and hot pressing are investigated in this study. The dispersion of SiC particles in the composites is homogeneous and the hardness improves as additional amount increases. The wear amount of the matrix metal increases highly as wear rates increase, for the wear mechanism changes from adhesive wear to melt wear, and the matrix metal was coated on the surface of revolving disc and its weight increases. In the 5vol% composites, Fe is adhered on the surface of specimen by the projection of the dispersed hard SiC particles which have net-work structure and the coating layer is about 300㎛. But in the composite more than 20vol%, the wear amount of composite decreases because the SiC particles which have superior hardness, wear resistance and heat resistance properties resist wear, the abrasive wear turn out predominant wear mechanism and so the wear amount of revolving disc increases.
Rheo-compocasting 및 Hot Pressing 에 의하여 제조한 Al-Si-Mg / Al2O3 단섬유강화 복합재료의 조직 및 인장특성
곽현만,이학주 ( Hyun Man Kwak,Hag Ju Lee ) 한국주조공학회 1993 한국주조공학회지 Vol.13 No.6
N/A Aluminum alloy matrix composites reinforced with various amounts of Al₂O₃ short fibers have been produced by rheo-compocasting accompanied by hot pressing. When composites reinforced with fibers are produced by rheo-compocasting, S-L process is the most effective method for homogeneous dispersion of fibers. A sound composites with the improved orientation(3 dimension→2 dimension) of the fibers and increased volume fraction of them have been fabricated through the hot pressing of the casted composites. Fibers are broken down when rheo-compocasting, hot pressing, and T_6 treating. Among them fibers are broken down most heavily in the hot pressing. And even in the case of the composite reinforced with 30vol% fibers, which showed the hardest fiber break down, aspect ratio(11.6) is higher than critical aspect ratio(10.7). The fiber strengthening effect in the composites has showed up to 573K. As the test temperature increases to the range of 573K, the effect has been higher. The fracture of composites is controlled by fiber from room temperature to 473K, but the fracture of composites is controlled by interface between fiber and matrix alloy above 473K.
딥러닝 기반 객체 인식을 활용한 퍼스널 모빌리티 안전 보조 시스템 개발
곽현서,김민영,전지용,정은혜,김주엽,현소담,정진우 한국정보통신학회 2021 한국정보통신학회논문지 Vol.25 No.3
Recently, the demand for the use of personal mobility vehicles, such as an electric kickboard, is increasing explosively because of its high portability and usability. However, the number of traffic accidents caused by personal mobility vehicles has also increased rapidly in recent years. To address the issues regarding the driver’s safety, we propose a novel approach that can monitor context information around personal mobility vehicles using deep learning-based object detection and smartphone captured videos. In the proposed framework, a smartphone is attached to a personal mobility device and a front or rear view is recorded to detect an approaching object that may affect the driver's safety. Through the detection results using YOLOv5 model, we report the preliminary results and validated the feasibility of the proposed approach.
A Review of Research on Social Network Services Using the New Media Evolutionary Model
곽현,이호근 한국정보화진흥원 2011 정보화정책 Vol.18 No.3
The purpose of this paper is to indicate possible future research directions for social network services(SNS) by reviewing past and recent trends in SNS studies. The framework used for the analysis is the New Media Evolutionary Model(NMEM) proposed by Wimmer and Dominick, a four-phase system for research on new media development. Although early forms of SNS emerged in the late 1990s, most research in this field has been published in the past five years. We searched for SNS-related articles published from 2006 to August 2011 from academic journal archives in information systems, communication, marketing, and other fields, and classified them according to the NMEM to analyze the current state of SNS research. Researchers in this field have so far focused on the first two phases of the model(the media itself and use of the media), but little research has been conducted on the third(effects of the media) and fourth phases(improvements in the media). Although SNS research is still in its early stages, we suggest the need for more studies on the effects of SNS and how it can be improved. Very few studies test existing theories or build new theories related to SNS. Thus, a more rigorous approach towards SNS research is warranted, and future research should focus on theory building and testing.
곽현,이호근 한국정보화진흥원 2014 정보화정책 Vol.21 No.4
Crowd-funding platforms, which enable to collect funds from individuals, have recently gainedgrowing interests around the world. This study intends to provide future research directions for thecrowd-funding by reviewing past research works. For this purpose, two research themes are selected - (1)motivations to participate in crowd-funding and (2) critical success factors for the project funding. Themotivations are analyzed from both perspectives of fund demanders and suppliers. The critical success factors areinvestigated by using four dimensions: fund demanders, fund suppliers, relationships between demanders andsuppliers, and project characteristics. Using the implications found from the past research, this paper offersfuture research issues necessary for the growth of crowd-funding platforms. 최근 국내외에서 다수의 대중으로부터 자금을 모아 투자하는 크라우드펀딩 플랫폼에 대한 관심이 높아지고 있다. 본 연구에서는 크라우드펀딩 분야의 연구동향을 분석하여 향후 이 분야의 새로운 연구방향을 제시하고자 한다. 이를 위해 크라우드펀딩에 관련된 연구주제를 참여동기와 성공요인의 두 가지로 구분하여 분석하였다. 이용자의 참여동기에 관한연구는 자금 수요자 및 자금 공급자의 동기로 나누어서 살펴보았으며, 크라우드펀딩의 성공요인에 대한 연구는 자금 수요자 특성요인, 자금 공급자 특성요인, 수요자와 공급자간 관계의 특성요인, 그리고 프로젝트의 특성요인 등으로 구분하였다. 본 연구는기존 연구가 가지는 함의를 살펴봄으로써 향후 크라우드펀딩 분야의 연구방향을 제시하고 있다.