• 제목/요약/키워드: highly efficient

검색결과 2,182건 처리시간 0.056초

재구성 가능한 고성능 센서 운영체제를 위한 소프트웨어 아키텍처 설계 (A Software Architecture for Highly Reconfigurable Sensor Operating Systems)

  • 김태환;김희철
    • 대한임베디드공학회논문지
    • /
    • 제2권4호
    • /
    • pp.242-250
    • /
    • 2007
  • Wireless sensor networks are subject to highly heterogeneous system requirements in terms of their functionality and performance due to their broad application areas. Though the heterogeneity hinders the opportunity of developing a single universal platform for sensor networks, efforts to provide uniform, inter-operable and scalable ones for sensor networks are still essential for the growth of the industry as well as their technological advance. As a part of our work to develop such a robust platform, this paper presents the software architecture for sensor nodes with focus on our sensor node operating system and its configuration methodology. Addressing principle issues in its design space which includes programming, execution, task scheduling and software layer models, our architecture is highly reconfigurable with respect to system resources and functional requirements and also highly efficient in supporting multi-threading under small system resources.

  • PDF

Preparation of Highly Cross-Linked, Monodisperse Poly(methyl methacrylate) Microspheres by Dispersion Polymerization; Part II. Semi-continuous Processes

  • Lee, Ki-Chang;Lee, Sang-Yun
    • Macromolecular Research
    • /
    • 제16권4호
    • /
    • pp.293-302
    • /
    • 2008
  • In our previous publication, the problem of particle deformation and coagulation at the nucleation stage in the presence of cross-linker was intensely studied by seeded batch dispersion polymerization of methyl methacrylate (MMA). In the present work, highly cross-linked, monodisperse PMMA particles were prepared under various reaction conditions by seeded semi-continuous process. Monodisperse, $6.5{\mu}m$-diameter PMMA particles containing up to 8 wt% of DVB or EGDMA were successfully made by seeded semi-continuous process and multi-semi-continuous addition process, respectively. Therefore, this study shows that seeded semi-continuous process is more effective and efficient to prepare highly cross-linked, monodisperse particles than non-seeded and seeded batch processes.

Gold-Catalyzed Cycloisomerization of (2-Alkynyl-1-cycloalkenyl)methanols to Highly Substituted Furans

  • Oh, Chang-Ho;Yi, Hyun-Jik;Lee, Kyu-Hwan
    • Bulletin of the Korean Chemical Society
    • /
    • 제31권3호
    • /
    • pp.683-688
    • /
    • 2010
  • A new and efficient Au-catalyzed alkoxycyclization of conjugated enynols offers a general entry to a wide range of highly substituted furans in good to excellent yields. These furans were subjected to diethyl acetylenedicarcoxylate to afford the interesting cycloadducts in good to excellent yields.

A Post-stratified Estimation in Multivariate Stratified Sampling Surveys

  • Park, Jinwoo
    • Communications for Statistical Applications and Methods
    • /
    • 제6권3호
    • /
    • pp.755-760
    • /
    • 1999
  • In multivariate stratified sampling surveys it is general to use a few stratification variables which are highly correlated with the important variables at design stage. But there might be some secondary study variables which are not so highly correlated with those stratification variables. In that case it is not efficient to use the same type of estimator due to the secondary variables as the one base on the important variables. A post-stratified estimation is proposed to increase the efficiency of the estimator with existence of secondary variables. The proposed method is illustrated with a set of fishery household population survey data.

  • PDF

Lanthanide-Cored Supramolecular Systems with Highly Efficient Light-Harvesting Dendritic Arrays towards Tomorrow′s Information Technology

  • Kim, Hwan-Kyu;Roh, Soo-Gyun;Hong, Kyong-Soo;Ka, Jae-Won;Baek, Nam-Seob;Oh, Jae-Buem;Nah, Min-Kook;Cha, Yun-Hui;Jin Ko
    • Macromolecular Research
    • /
    • 제11권3호
    • /
    • pp.133-145
    • /
    • 2003
  • We have developed novel lanthanide-cored supramolecular systems with highly efficient light-harvesting dendritic arrays for integrated planar waveguide-typed amplifiers. Er$^{3+}$ ions were encapsulated by the supramolecular ligands, such as porphyrins and macrobicyclics. The supramolecular ligands have been designed and synthesized to provide enough coordination sites for the formation of stable Er(III)-chelated complexes. For getting a higher optical amplification gain, also, the energy levels of the supramolecular ligands were tailored to maintain the effective energy transfer process from supramolecular ligands to erbium(III) ions. Furthermore, to maximize the light-harvesting effect, new aryl ether-functionalized dendrons as photon antennas have been incorporated into lanthanide-cored supramolecular systems. In this paper, molecular design, synthesis and luminescent properties of novel lanthanide-cored integrated supramolecular systems with highly efficient light-harvesting dendritic arrays will be discussed.d.

Highly Efficient Red Emissive Heteroleptic Cyclometalated Iridium(III) Complexes Bearing Two Substituted 2-Phenylquinoxaline and One 2-Pyrazinecarboxylic Acid

  • Sengottuvelan, Nallathambi;Yun, Seong-Jae;Kim, Dae-Young;Hwang, In-Hye;Kang, Sung Kwon;Kim, Young-Inn
    • Bulletin of the Korean Chemical Society
    • /
    • 제34권1호
    • /
    • pp.167-173
    • /
    • 2013
  • A series of highly efficient red phosphorescent heteroleptic iridium(III) complexes 1-6 containing two cyclometalating 2-(2,4-substitued phenyl)quinoxaline ligands and one chromophoric ancillary ligand were synthesized: (pqx)$_2Ir$(mprz) (1), (dmpqx)$_2Ir$(mprz) (2), (dfpqx)$_2Ir$(mprz) (3), (pqx)$_2Ir$(prz) (4), (dmpqx)$_2Ir$(prz) (5), (dfpqx)$_2Ir$(prz) (6), where pqx = 2-phenylquinoxaline, dfpqx = 2-(2,4-diflourophenyl)quinoxaline, dmpqx = 2-(2,4-dimethoxyphenyl)quinoxaline, prz = 2-pyrazinecarboxylate and mprz = 5-methyl-2-pyrazinecarboxylate. The absorption, emission, electrochemical and thermal properties of the complexes were evaluated for potential applications to organic light-emitting diodes (OLEDs). The structure of complex 2 was also determined by single-crystal X-ray diffraction analysis. Complex 2 exhibited distorted octahedral geometry around the iridium metal ion, for which 2-(2,4-dimethoxyphenyl)quinoxaline N atoms and C atoms of orthometalated phenyl groups are located at the mutual trans and cis-positions, respectively. The emission spectra of the complexes are governed largely by the nature of the cyclometalating ligand, and the phosphorescent peak wavelengths can be tuned from 588 to 630 nm with high quantum efficiencies of 0.64 to 0.86. Cyclic voltammetry revealed irreversible metal-centered oxidation with potentials in the range of 1.16 to 1.89 V as well as two quasi-reversible reduction waves with potentials ranging from -0.94 to -1.54 V due to the sequential addition of two electrons to the more electron-accepting heterocyclic portion of two distinctive cyclometalated C^N ligands.

A Simple and Efficient One-Pot Three-Component Synthesis of Propargylamines Using Bismuth (III) Chloride

  • Teimouri, Abbas;Chermahini, Alireza Najafi;Narimani, M.
    • Bulletin of the Korean Chemical Society
    • /
    • 제33권5호
    • /
    • pp.1556-1560
    • /
    • 2012
  • A simple highly versatile and efficient method has been developed for the three-component coupling of aldehydes, amines and alkynes to prepare propargylamines, in the presence of a catalytic amount of $BiCl_3$. The advantages of methods are high yield, mild reaction conditions, no environmental pollution and easy work up procedure.

The development of the highly efficient Circular Nozzle Source by using a study on the flux distributions of nozzle type thermal evaporation sources

  • Kim, Sung-Moon;Jeong, Kwang-Ho
    • 한국정보디스플레이학회:학술대회논문집
    • /
    • 한국정보디스플레이학회 2008년도 International Meeting on Information Display
    • /
    • pp.1171-1174
    • /
    • 2008
  • We studied the properties of vapor flux distributions of nozzle shaped thermal evaporation sources and the factors, which can change the flux distributions such as nozzle structure. We used a simulation and experiment methods for this study. By using the results of our study, we improved the Circular Nozzle Source, which can make uniform thin films without substrate rotation, into more efficient source.

  • PDF