• 제목/요약/키워드: 2D heterogeneous

검색결과 219건 처리시간 0.027초

증발디젤분무의 공간적 구조해석에 관한 기초 연구 (Basic Study on the Spatial Structure Analysis of the Evaporative Diesel Spray)

  • 염정국
    • 동력기계공학회지
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    • 제14권3호
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    • pp.5-12
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    • 2010
  • The purpose of this study is to analyze heterogeneous distribution of branch-like structure at downstream region of inner spray. The previous many studies about diesel spray structure have yet stayed in the analysis of 2-D structure, and there are very few of informations which are concerned with 3-D analysis of the structure. The heterogeneous distribution of droplets in inner spray affects the mixture formation of diesel spray, and also the combustion characteristics of the diesel engines. Therefore, in order to investigate 3-D structure of evaporative spray the laser beam of 2-D plane was used in this study. Liquid fuel was injected from a single-hole nozzle (l/d=5) into a constant-volume vessel under high pressure and temperature in order to visualize the spray phenomena. The incident laser beam was offset on the central axis. From the images analysis taken by offset of laser beam, we examine formation mechanism of heterogeneous distribution by vortex flow at the downstream of the diesel spray. As the experimental results, the branch-like structure formed heterogeneous distribution of the droplets consists of high concentration of vapor phase in the periphery of droplets and spray tip of branch-like structure. Also the 3-D spatial structure of the evaporative diesel spray can be verified by images obtained from 2-D measurement methods.

3-D Hetero-Integration Technologies for Multifunctional Convergence Systems

  • 이강욱
    • 마이크로전자및패키징학회지
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    • 제22권2호
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    • pp.11-19
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    • 2015
  • Since CMOS device scaling has stalled, three-dimensional (3-D) integration allows extending Moore's law to ever high density, higher functionality, higher performance, and more diversed materials and devices to be integrated with lower cost. 3-D integration has many benefits such as increased multi-functionality, increased performance, increased data bandwidth, reduced power, small form factor, reduced packaging volume, because it vertically stacks multiple materials, technologies, and functional components such as processor, memory, sensors, logic, analog, and power ICs into one stacked chip. Anticipated applications start with memory, handheld devices, and high-performance computers and especially extend to multifunctional convengence systems such as cloud networking for internet of things, exascale computing for big data server, electrical vehicle system for future automotive, radioactivity safety system, energy harvesting system and, wireless implantable medical system by flexible heterogeneous integrations involving CMOS, MEMS, sensors and photonic circuits. However, heterogeneous integration of different functional devices has many technical challenges owing to various types of size, thickness, and substrate of different functional devices, because they were fabricated by different technologies. This paper describes new 3-D heterogeneous integration technologies of chip self-assembling stacking and 3-D heterogeneous opto-electronics integration, backside TSV fabrication developed by Tohoku University for multifunctional convergence systems. The paper introduce a high speed sensing, highly parallel processing image sensor system comprising a 3-D stacked image sensor with extremely fast signal sensing and processing speed and a 3-D stacked microprocessor with a self-test and self-repair function for autonomous driving assist fabricated by 3-D heterogeneous integration technologies.

클라우드 서비스 기반 이기종간의 데이터 공유 기법 (Data Sharing Technique between Heterogeneous based on Cloud Service)

  • 서정희;박흥복
    • 한국정보통신학회논문지
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    • 제22권3호
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    • pp.391-398
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    • 2018
  • 일반적인 이기종 디지털 장치들간의 데이터 공유는 다양한 인터페이스로 인해 많은 문제를 야기시킨다. 이런 문제를 해결하기 위해서 본 논문은 서로 다른 장치들간의 통신을 지원하는 D2D 통신을 사용하여 클라우드 서비스와 모바일을 결합한 이기종간의 데이터 공유를 제안한다. 제안된 기법은 데이터 동기화를 수행하기 위해 서버에 집중되는 부하를 줄이는 프로세스로 수행되며, 장치들간의 데이터 복제로 인한 지연을 최소화하기 위해 청크 리스트에 수정된 부분만을 복사하여 데이터 쓰기 속도에 기여하기 위한 기술을 채택하고, 데이터 공유를 위한 동기화로 소모되는 네트워크 대역폭을 최소화하기 위해서 모바일 환경과 결합한 클라우드 서비스 모델을 구현한다. 따라서 서로 다른 공간의 데이터를 효율적으로 공유하고 데이터의 무결성과 지연을 최소화할 수 있다.

이질적인 협업환경을 위한 시공간적 계위를 이용한 스테레오 비디오 압축 (Stereo Video Coding with Spatio-Temporal Scalability for Heterogeneous Collaboration Environments)

  • 오세찬;이영호;우운택
    • 한국정보과학회논문지:소프트웨어및응용
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    • 제31권9호
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    • pp.1150-1160
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    • 2004
  • 본 논문에서는 MPEG-2에서 정의한 시공간적 계위를 확장하여 enhanced Access Grid (e-AG) 상의 서로 다른 디스플레이 시스템 및 네트워크 환경을 가진 수신 단말의 효율적인 디스플레이를 위한 새로운 3차원 영상의 부호화 방법을 제안한다. 제안된 부호화기는 3차원 영상에 대해서 시공간적 기본 해상도 및 고 해상도의 영상을 표현 가능하도록 여러 계층의 비트 열을 생성한다. 생성된 비트 열은 수신 단말의 네트워크 환경 및 처리속도, 디스플레이 환경에 따라 다른 시공간적 해상포론 표현할 수 있도록 선택적으로 전송된다. 제안된 시공간적 계위를 이용한 3차원 영상 부호화기는 이질적인 분산환경에서의 효율적인 3차원 비디오 전송 서비스에 활용 가능하다.

5,7-Diaryl-4,4-dimethyl-4,5,6,7-tetrahydropyridino [3,4-d]-1,2,3-selenadiazoles의 손쉬운 One-pot 합성 (A Facile Entry for One-pot Synthesis of 5,7-Diaryl-4,4-dimethyl-4,5,6,7-tetrahydropyridino[3,4-d]-1,2,3-selenadiazoles)

  • Gopalakrishnan, M.;Thanusu, J.;Kanagarajan, V.
    • 대한화학회지
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    • 제52권1호
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    • pp.47-51
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    • 2008
  • 조사 아래 불균일촉매 NaHSO4.SiO2의 존재하에서 5,7-diaryl-4,4-dimethyl-4,5,6,7-tetrahydropyridino [3,4-d]-1,2,3-selenadiazoles의 one-pot.

Reduction of the Retransmission Delay for Heterogeneous Devices in Dynamic Opportunistic Device-to-device Network

  • Chen, Sixuan;Zou, Weixia;Liu, Xuefeng;Zhao, Yang;Zhou, Zheng
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제12권10호
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    • pp.4662-4677
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    • 2018
  • The dynamic opportunistic device-to-device (DO-D2D) network will frequently emerge in the fifth generation (5G) wireless communication due to high-density and fast-moving mobile devices. In order to improve the Quality of Experience (QoE) of users with different computing capacity devices in the DO-D2D network, in this paper, we focus on the study of how to reduce the packets retransmission delay and satisfy heterogeneous devices. To select as many devices as possible to transmit simultaneously without interference, the concurrent transmitters-selecting algorithm is firstly put forward. It jointly considers the number of packets successfully received by each device and the device's connectivity. Then, to satisfy different devices' demands while primarily ensuring the base-layer packets successfully received by all the devices, the layer-cooperation instantly decodable network coding is presented, which is used to select transmission packets combination for each transmitter. Simulation results illustrate that there is an appreciable retransmission delay gain especially in the poor channel quality network compared to the traditional base-station (BS) retransmission algorithm. In addition, our proposed algorithms perform well to satisfy the different demands of users with heterogeneous devices.

A Study on the Mixture Formation Process of Evaporating Diesel Spray by Offset Incidence Laser Beam

  • Yeom, Jeong-Kuk;Kang, Byung-Mu;Lee, Myung-Jun;Chung, Sung-Sik;Ha, Jong-Yul;Hajime Fujimoto
    • Journal of Mechanical Science and Technology
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    • 제16권12호
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    • pp.1702-1709
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    • 2002
  • This paper analyzes heterogeneous distribution of branch-like structure at the downstream region of the spray. The liquid and vapor phase of the spray are obtained using a 35㎜ still camera and CCD camera in order to investigate spray structure of evaporating diesel spray. There have been many studies conducted on diesel spray structure but have yet only focused on the analyses of 2-D structure. There are a few information which is concerned with 3-D structure analysis of evaporating spray. The heterogeneous distribution of droplets in inner spray affects the mixture formation of diesel spray and the combustion characteristics of the diesel engines. In this study, the laser beam of 2-D plane was used in order to investigate 3-D structure of evaporating spray The incident laser beam was offset on the central axis of the spray. From the analysis of images taken by offset laser beam, we will examine the formation mechanism of heterogeneous distribution of the diesel spray by vortex flow at the downstream of the spray. The images of liquid and vapor phase of free spray are simultaneously taken through an exciplex fluorescence method. Through this, the branch-like structure consisting of heterogeneous distribution of the droplets forms high concentrated vapor phase at the periphery of droplets and at the spray tip.

Clean and Efficient Synthesis of Furfural From Xylose by Microwave-Assisted Biphasic System using Bio-Based Heterogeneous Acid Catalysts

  • Vo, Anh Thi Hoang;Lee, Hong-shik;Kim, Sangyong;Cho, Jin Ku
    • 청정기술
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    • 제22권4호
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    • pp.250-257
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    • 2016
  • As an attempt to replacing petroleum-based chemicals with bio-based ones, synthesis of furfural from biomass-derived xylose attracts much attention in recent days. Conventionally, furfural from xylose has been produced via the utilization of highly corrosive, toxic, and environmentally unfriendly mineral acids such as sulfuric acid or hydrochloric acid. In this study, microwave-assisted biphasic reaction process in the presence of novel bio-based heterogeneous acid catalysts was developed for the eco-benign and effective synthesis of furfural from xylose. The microwave was irradiated for reaction acceleration and a biphasic system consisting of $H_2O$ : MIBK (1 : 2) was designed for continuous extraction of furfural into the organic phase in order to reduce the undesired side products formed by decomposition/condensation/oligomerization in the acidic aqueous phase. Moreover, sulfonated amorphous carbonaceous materials were prepared from wood powder, the most abundant lignocellulosic biomass. The prepared catalysts were characterized by FT-IR, XPS, BET, elemental analysis and they were used as bio-based heterogeneous acid catalysts for the dehydration of xylose into furfural more effectively. For further optimization, the effect of temperature, reaction time, water/organic solvent ratio, and substrate/catalyst ratio on the xylose conversion and furfural yield were investigated and 100% conversion of xylose and 74% yield of furfural was achieved within 5 h at $180^{\circ}C$. The bio-based heterogeneous acid catalysts could be used three times without any significant loss of activity. This greener protocol provides highly selective conversion of xylose to furfural as well as facile isolation of product and bio-based heterogeneous acid catalysts can alternate the environmentally-burdened mineral acids.

A 3-D Genetic Algorithm for Finding the Number of Vehicles in VRPTW

  • Paik, Si-Hyun;Ko, Young-Min;Kim, Nae-Heon
    • 산업경영시스템학회지
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    • 제22권53호
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    • pp.37-44
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    • 1999
  • The problem to be studied here is the minimization of the total travel distance and the number of vehicles used for delivering goods to customers. Vehicle routes must also satisfy a variety of constraints such as fixed vehicle capacity, allowed operating time. Genetic algorithm to solve the VRPTW with heterogeneous fleet is presented. The chromosome of the proposed GA in this study has the 3-dimension. We propose GA that has the cubic-chromosome for VRPTW with heterogeneous fleet. The newly suggested ‘Cubic-GA (or 3-D GA)’ in this paper means the 2-D GA with GLS(Genetic Local Search) algorithms and is quite flexible. To evaluate the performance of the algorithm, we apply it to the Solomon's VRPTW instances. It produces a set of good routes and the reasonable number of vehicles.

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