1,721,162 research outputs found
Dielectric resonator antenna for dual-band PCS/IMT-2000
No full textA novel broadband and small dielectric resonator antenna has been investigated experimentally and numerically. A bandwidth of 25% has been achieved, and an omni-directional radiation pattern obtained. These features make such antennas highly suitable for application to mobile handsets
Small chip dielectric antenna for bluetooth application
No full textThis paper proposes the design of a small chip-type dielectric antenna using the advanced meander line technique, so that the radiation metals are formed on the bottom face of a ceramic dielectric (8 X 4 X 1.5 mm(3), alumina) and on both faces of the substrate (thickness 1.0 mm, FR4). The performance of the proposed antenna mode, which remarkably reduced the size, shows good agreement between measured and computed results The measured results show that this antenna has 11.2% bandwidth (2.35-2.63 GHz \S11\ < - 10 dB) and 2.3-dBi maximum radiation gain, respectively. (C) 2003 Wiley Periodicals, Inc
Interannual variations in net community production in the North Pacific Ocean
No full textAccurate estimation of net community production (NCP) in the ocean and its interannual variations is important for determining the future trend for carbon dioxide concentrations in the atmosphere and thus for understanding the global carbon cycle and climate change. We used large data sets obtained from the North Pacific Ocean of seawater pCO comprising approximately 940,000 data (obtained from 2003 to 2017; Surface Ocean CO Atlas version 2019), which are 2 orders of magnitude greater than the dissolved inorganic carbon (DIC) data set; this enabled accurate resolution of the seasonal evolution of pCO in the North Pacific Ocean. In particular, the combination of this data set with a surface alkalinity data set (Lee et al., 2006) and the established thermodynamic model for the seawater carbonate system should enable the seasonal evolution of DIC in the North Pacific from 2003 to 2017 to be accurately resolved. Our results based on direct observations showed considerable interannual variability in NCP in the North Pacific. Such large interannual variability appeared to be associated with large-scale climatic variability in the North Pacific basin.1
Beyond the Usefulness and Ease of Use : Extending the TAM for a World - Wide - Web Context
No full textEase of use and usefulness are believed to be fundamental in determining the acceptance and use of various, corporate ITs. These beliefs, however, may not explain the users behavior towards newly emerging ITs, such as the World-Wide-Web (WWW). In this study, we introduce playfulness as a new factor that reflects the users intrinsic belief in WWW acceptance. Using it as an intrinsic motivation factor, we extend and empirically validate the Technology Acceptance Model (TAM) for the WWW context
Extending the TAM for a World-Wide-Web context
No full textEase of use and usefulness are believed to be fundamental in determining the acceptance and use of various, corporate ITs. These beliefs, however, may not explain the user's behavior toward newly emerging ITs, such as the World-Wide-Web (WWW). In this study, we introduce playfulness as a new factor that reflects the user's intrinsic belief in WWW acceptance. Using it as an intrinsic motivation factor, we extend and empirically validate the Technology Acceptance Model (TAM) for the WWW context. (C), 2001 Elsevier Science B.V. All rights reserved
Extending the technology acceptance model for the World-Wide-Web context: Playfulness as a sailent belief
No full textThis article is confirmed to be submitted through the review and edition of the Korean Operations Research and Management Science Society. Please enter the title (Journal/Proceedings), volume, number, and pages properly when citing the article
Impacts of Anthropogenic Nitrogen on Ocean Nitrogen System in the Yellow and East China Seas
No full textIncrease in anthropogenic emissions of reactive nitrogen from China, Korea, and Japan, and its subsequent addition, via riverine input and atmospheric deposition, to the East China and Yellow Seas has led to an unprecedented increase in the nitrate (N) concentration of the upper ocean, without the proportional increase in phosphorous (P). The disproportional addition of anthropogenic N that persisting the past 4 decades has progressively driven the extensive regions of the East China and Yellow Seas from being N-limited to being Plimited. Our results provide unique observational evidence pointing to a nutrient regime changeover (i.e. N limitation to P limitation), largely driven by anthropogenic N inputs, in extensive areas of East China and Yellow Seas. The changeover in nutrient regime transformed the study area to the new condition in which the frequency of dinoflagellate bloom began to surpass over that of diatom bloom and dinoflagellate is known to better enable the acquisition of P (both inorganic and organic forms).1
Increasing input of anthropogenic nitrogen drives the East China and Yellow Seas to Phosphorus limitation
No full textIncrease in anthropogenic emissions of reactive nitrogen from China, Korea, and Japan, and its subsequent addition, via riverine input and atmospheric deposition, to the East China and Yellow Seas has led to an unprecedented increase in the nitrate (N) concentration of the upper ocean, without the proportional increase in phosphorous(P). The disproportional addition of anthropogenic N that persisting the past 4 decades has progressively driven the extensive regions of the East China and Yellow Seas from being N-limited to being P-limited. In 1980s, P limited area was small and mostly confined to the coastal areas near the mouth of Changjiang River, whereas the rest of East China and Yellow Seas remained severely deficit in N relative to P. After 1990s onward, the P-limited waters have rapidly expanded to the downstream of the Changjiang River, including the southern and eastern coastal waters of Korea. The areas located outside of downstream of Changjiang River remains still being N-limited relative to P but the magnitude of N deficiency has been less severe over time. Our results provide unique observational evidence pointing to a nutrient regime shift (i.e. N limitation transiting to P limitation), largely driven by anthropogenic N inputs, in extensive areas of East China and Yellow Seas in the vicinity of the largest source of anthropogenic N (northeastern Asian continent).1
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