Currently, a majority of existing algorithms for sparse optimization problems are based on regularization framework. The main goal of these algorithms is to recover a sparse solution with k non-zero components(called ...
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Heavy metals are considered to be hazardous pollutants with toxic effects on plant and/or human health. Different techniques and methods (e.g., AAS, ICP-MS, ICP-OES) have been utilized for trace metals determination i...
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ISBN:
(纸本)9781622762088
Heavy metals are considered to be hazardous pollutants with toxic effects on plant and/or human health. Different techniques and methods (e.g., AAS, ICP-MS, ICP-OES) have been utilized for trace metals determination in the lab.ratory, but they are characterized by high costs, complex operation and long time consuming. The demand of rapid on-site screening and assessment of agricultural land contaminate induced by heavy metal is highly desirable. This paper reported a fast, inexpensive electrochemical analysis method for the simultaneous determination of cadmium (Cd) and lead (Pb) in soil samples. A simplified soil extraction procedure, using 0.11 molL-1 acetic acid and a 1 h ultrasonic agitation, had been used to fulfill the requirements of field-based screening usage. A disposable sensor, incorporating a three-electrode configuration (working electrode, reference electrode and counter electrode), had been fabricated by low cost screen-printing technology. The surface of graphite carbon working electrode was judiciously modified by multiwalled carbon nanotubes(MWCNTs)/Nafion/bismuth coating. Coupled with the portable electrochemical instrument, trace detection of heavy metal ions had been carried out by square wave anodic stripping voltammetry (SWASV) technique. The electrode exhibited good sensibility and stability in the electrochemical measurement. Linear responses were obtained in the range from 1 to 80 μgL-1 for both the metal ions at a preconcentration time of 180s, with detection limits of 0.5 μgL-1 for Cd(II) and 0.8 μgL -1 for Pb(II), respectively. The relative standard deviation is 1.9% and 2.3% for 20 μgL-1 each of Cd(II) and Pb(II). Soil samples were assayed by the proposed process and compared against standard ICP-MS analysis, the results showed good agreement between methods.
Measuring word similarities is a fundamental issue in NLP, while the measuring procedure is always aided by dictionaries or corpus. However, when figurative or metaphor usages are considered, the situation becomes mor...
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Video streaming over mesh networks operates under stringent network resource constraints, with a large number of video sessions competing for limited network resources. In this work, we aim to establish so-called reso...
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Spectrum auctions have been proposed as an effective approach to fairly and efficiently trade the scarce spectrum resource among wireless users. The most significant challenge of the auction design to provide economic...
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Spectrum auctions have been proposed as an effective approach to fairly and efficiently trade the scarce spectrum resource among wireless users. The most significant challenge of the auction design to provide economic robustness, particularly truthfulness, under the local-dependent interference constraints. However, existing designs either do not consider spectrum reuse or are based on the impractical assumption that each user requests at most one channel. In this paper, we address this problem by proposing DOTA, a DOuble Truthful Auction for dynamic spectrum access. DOTA is economic-robust in terms of truthfulness, individual rationality, and no-deficit. It achieves improved utilization by exploiting spectrum reuse as well as dealing with the interference constraints. Moreover, DOTA minimizes the network transaction overhead and provides flexible channel bidding including range bidding and strict bidding.
Advances in mobile networking and information processing technologies have triggered vehicular ad hoc networks (VANETs) for traffic safety and value-added applications. Most efforts have been made to address the secur...
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Geometric constraint problem is equivalent to the problem of solving a set of nonlinear equations substantially. The constraint problem can be transformed to an optimization n problem. We can solve the problem with Ge...
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Data collected from mobile phones have potential knowledge to provide with important behavior patterns of individuals. In this paper, we present approaches to discovering personal mobility and characteristics based on...
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Group Search Optimizer (GSO) has been shown to yield good performance for solving various optimization problems. However, it tends to suffer from premature convergence when solving complex problems. At the same time, ...
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This paper discusses period properties of some linear maps which are employed in various applications such as image encryption, public key cryptography and watermarking. Conditions for the bijectiveness of such maps a...
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This paper discusses period properties of some linear maps which are employed in various applications such as image encryption, public key cryptography and watermarking. Conditions for the bijectiveness of such maps and the existence of a period are presented. Period structure is also given. Then, the recurrence equation theory is adopted to address the period distribution problem. Finally, a framework to solve the problem is proposed with a demonstration of its effectiveness and efficiency into some applications.
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