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Chen Y.-L.,National Central University | Cheng L.-C.,Soochow University of Taiwan
Decision Support Systems | Year: 2010

The group ranking problem is used to construct coherent aggregate results from preference data provided by decision makers. Although there have been different input formats used to represent user preferences, they share a common weakness, that the input mode is static. In other words, users must provide all the preference data at one time. To overcome this weakness, we propose a framework which allows users to provide partial and/or incomplete preference data at multiple times. Since this is a complicated issue, we specifically focus on a particular aspect as a first attempt at this framework. Accordingly, we reexamine a variant of the group ranking problem, the maximum consensus mining problem, which will give the longest ranking lists of alternatives that agree with the majority and disagree only with the minority, under the dynamic input mode assumption. An algorithm is developed to determine the maximum consensus sequences from the users' partial ranking data. Finally, extensive experiments are carried out using synthetic data sets. The results indicate that the proposed method is computationally efficient, and can effectively identify consensus among all users. © 2009 Elsevier B.V. All rights reserved. Source

Lu S.-I.,Soochow University of Taiwan
Chemical Physics Letters | Year: 2013

Density functional theory has been used to calculate the μ·β(-2ν;ν,ν,0) on a series of solution-phase hydrazones. Using the experimental and MP2(Full) calculated data as references, the qualitative trend of the Hartree-Fock, M06-HF and range-separated hybrids have been examined. Our results propose methods with long-range corrections, and without short-range exact exchange, are capable of qualitatively predicting the nonlinear optical responses of the hydrazones when reliable geometries have been provided. The same conclusion can also be applied to solution-phase push-pull phenylpolyenes. © 2013 Elsevier B.V. All rights reserved. Source

Kuo Y.-C.,Soochow University of Taiwan
Computer Networks | Year: 2010

The asynchronous PS (Power-Saving) unicast protocol was designed for two PS wireless hosts to transmit the unicast message in the ad hoc network even their clocks are asynchronous. However, as regard to transmit a multicast message among more than two PS hosts, the protocol could not guarantee that all PS hosts can wake up at the same time. Some PS hosts may be in the PS mode when the multicast message is transmitted. Thus, the multicast message should be retransmitted again and again until all PS hosts receive the message. It will increase the energy consumption and the usage of the bandwidth. In this paper, we propose quorum-based PS multicast protocols for PS hosts to transmit multicast messages in the asynchronous ad hoc network. In those protocols, PS hosts use quorums to indicate their wakeup patterns. We introduce the rotation m-closure property to guarantee that m different quorums have the intersection even quorums are rotated due to asynchronous clocks. Thus, m PS hosts adopting m quorums satisfying the rotation m-closure property could wake up simultaneously and receive the multicast message even their clocks are asynchronous. We propose two quorum systems named the uniform k-arbiter and the CRT (Chinese Remainder Theorem) quorum system, which satisfy the rotation m-closure property. As shown in our analysis results, our quorum-based PS multicast protocols adopting those quorum systems can save more energy to transmit multicast messages. © 2010 Elsevier B.V. All rights reserved. Source

The dynamic second-order hyperpolarizability from the third-harmonic generation experiment, 〈γ〉 (-3ωωωω), of 59 solution-phase organic molecules has been theoretically calculated and compared with available experimental data. The DFT/6-311+G(2d,p)//(CAM-)B3LYP/6-31G(2df,p) level of theory with the polarizable continuum model was employed to evaluate the static second-order hyperpolarizability. The theoretical static values were then corrected to dynamic estimates of 〈γ〉 (-3ωωωω) by employing a two-level approximation (Chen et al. in J Chem Phys 101(7):5860-5864, 1994). Calculated results showed that for the property of interest, the range-separated hybrids provided more accurate and consistent estimate than the global hybrids and the CAMB3LYP optimized geometry delivered more accurate estimate than the B3LYP optimized geometry. © Springer-Verlag Berlin Heidelberg 2013. Source

Leong M.-I.,Instituto para os Assuntos Civicos e Municipais IACM | Fuh M.-R.,Soochow University of Taiwan | Huang S.-D.,National Tsing Hua University
Journal of Chromatography A | Year: 2014

Dispersive liquid-liquid microextraction (DLLME) and other dispersion liquid-phase microextraction (LPME) methods have been developed since the first DLLME method was reported in 2006. DLLME is simple, rapid, and affords high enrichment factor, this is due to the large contact surface area of the extraction solvent. DLLME is a method suitable for the extraction in many different water samples, but it requires using chlorinated solvents. In recent years, interest in DLLME or dispersion LPME has been focused on the use of low-toxicity solvents and more conveniently practical procedures. This review examines some of the most interesting developments in the past few years. In the first section, DLLME methods are separated in two categories: DLLME with low-density extraction solvent and DLLME with high-density extraction solvent. Besides these methods, many novel special devices for collecting low-density extraction solvent are also mentioned. In addition, various dispersion techniques with LPME, including manual shaking, air-assisted LPME (aspirating and injecting the extraction mixture by syringe), ultrasound-assisted emulsification, vortex-assisted emulsification, surfactant-assisted emulsification, and microwave-assisted emulsification are described. Besides the above methods, combinations of DLLME with other extraction techniques (solid-phase extraction, stir bar sorptive extraction, molecularly imprinted matrix solid-phase dispersion and supercritical fluid extraction) are introduced. The combination of nanotechnique with DLLME is also introduced. Furthermore, this review illustrates the application of DLLME or dispersion LPME methods to separate and preconcentrate various organic analytes, inorganic analytes, and samples. © 2014 Elsevier B.V. Source

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