Theoretical Deductions Research Articles

Analysis of heterodyne detection in the frequency domain.

As opposed to previous works, our research on heterodyne detection is performed in the frequency domain. Based on the planar wave, it is pointed out that the current amplitude of a heterodyne signal is proportional to the spectrum value of the quantum efficiency function of a detector, and the frequency corresponding to the value is decided by the beam's incident angle. The spectrum of the quantum efficiency function has a low-pass characteristic, and its cut-off frequency is determined by the diameter of the photosensitive surface. Consequently, the strength of the heterodyne signal current depends on the position of a specific frequency in the passband. Our study method is extended to the arbitrary wave and proven to be still effective. According to our analyses, it is concluded that, in addition to the energy decline of interference field, the main cause of performance deterioration resulting from various influential factors can be generally explained as a spectrum mismatch between the interference field and the quantum efficiency function. Based on the Gaussian wave mode, the fact is illustrated by making theoretical deductions, in which the effects of the misaligned angle and beams' spot position offset are treated as examples. Our work provides the possibility of introducing frequency-domain theories into further studies on heterodyne detection.

Co-prime Sensing-Based Frequency Estimation Using Reduced Single-Tone Snapshots

In the paper, we propose a co-prime sensing-based frequency estimator by combining a simplified procedure of the Chinese remainder theorem and a phase-difference spectrum corrector. This estimator can accurately extract the frequency information from two adjacent snapshots after initialization. Some theoretical deductions and performance analysis are also presented. Numerical results show that the proposed estimator is robust to insufficient snapshots and noise.

Step‐down converter with wide voltage conversion ratio

A non-isolated dc–dc converter with a wide step-down voltage gain is presented, which combines one coupled inductor and two energy-transferring capacitors. The corresponding voltage conversion ratio is much lower than that of the traditional synchronously rectified buck converter, and the proposed converter can achieve an extremely low output voltage by adjusting the turns ratio and duty cycle. Furthermore, the proposed converter can achieve zero-voltage-switching turn-on, and the leakage inductance energy of the coupled inductor can be recycled to the capacitors, thereby causing the voltage spikes on some of the switches and all diodes to be quite low. In this study, theoretical deductions and experimental results are given to verify the feasibility and effectiveness of the proposed converter.

A Dual-Reduct Approach to Generate Core Rules

In this paper, we propose a Dual-Reduct method to generate core rules from original data sets for decision making. We rank the rules by rule usefulness after the step of first reduct. Then we take the useful rules as condition attribute and construct another new decision table. After the step of second reduct we generate core rules from the new constructed decision table. In our approach the generation process is straightforward and objective. At the same time, our approach can significantly reduce the number of rules comparing to the traditional generation approach because we adopt rule usefulness as a measure of core rules. We also provide theoretical proofs and deductions. Our approach is proved to be feasible and effective in a production security system.

Modeling the Dynamic Evolution of the Vehicular Ad Hoc Networks under the City Scenario

Nowadays, vehicular ad hoc network (VANET) has attracted more and more attention due to its various applications to improve the road traffic safety and efficiency. So there were plenty of exploration work and merit on the intervehicle communication, routing, and data forwarding, but it is not easy to design the efficient routing and data forwarding algorithm, because it is hard to understand the dynamic evolution of its network topology due to the fast movement of the vehicles in the network. While the network evolution structure is the key to design the optimal data forwarding strategy, hence, in this paper, we will analyze the dynamic evolution of topology characteristics based on the real data collected by the GPS devices installed on vehicles and then model the network evolution by the dynamic topology characteristics. In the end, we analyze and verify the efficiency of our model by theoretical deductions and simulations, and our model will be helpful to find more efficient routing algorithm and build the more trustable simulator of VANET.

The device characteristics of missing LDD implantation via nanoprobing techniques for localized failure analysis

In the recent years, localization of subtle defects has required device electrical data. Nanoprobing systems based on scanning electron microscopy (SEM) or atomic force microscopy (AFM) have become a significant tool for device measurement in failure analysis (FA) Labs. Failure Analysts can use electrical characteristics to isolate failure location in the metal–oxide–semiconductor field-effect-transistor (MOSFET). The missing lightly doped drain (LDD) implant is an example of a critical failure mechanism for the MOSFET and cell in the SRAM which is localized using nanoprobing. In this article, device data analysis and theoretical deductions are discussed related to missing LDD doping. Device data is used to propose a full set of characteristic for missing LDD. The simulation from a mature tool is able to support the electrical characteristics. The capability and challenge of the following physical FA to reveal the defect are also discussed.

Ultrahigh Step-Down Converter

In this paper, an ultrahigh step-down converter is presented, which combines one coupled inductor and one energy-transferring capacitor. The corresponding voltage conversion ratio is much lower than that of the traditional synchronously rectified (SR) buck converter, and the proposed converter can achieve extremely low output voltage with an appropriate duty ratio. Moreover, there are three major merits in the proposed converter. One merit is that the voltage conversion ratio of the proposed converter is linear, thereby making control quite easy. Another merit is that if one of the switches fails or is abnormally controlled, a high voltage does not appear in the output terminal, so the output load can be protected. The other merit is that the proposed converter can be driven using the existing SR buck pulse-width modulation control integrated circuit. In this study, brief theoretical deductions and some experimental results are given to verify the feasibility and effectiveness of the proposed converter.

Line broadening interference for high-resolution nuclear magnetic resonance spectra under inhomogeneous magnetic fields.

Nuclear magnetic resonance spectroscopy serves as an important tool for analyzing chemicals and biological metabolites. However, its performance is subject to the magnetic-field homogeneity. Under inhomogeneous fields, peaks are broadened to overlap each other, introducing difficulties for assignments. Here, we propose a method termed as line broadening interference (LBI) to provide high-resolution information under inhomogeneous magnetic fields by employing certain gradients in the indirect dimension to interfere the magnetic-field inhomogeneity. The conventional spectral-line broadening is thus interfered to be non-diagonal, avoiding the overlapping among adjacent resonances. Furthermore, an inhomogeneity correction algorithm is developed based on pattern recognition to recover the high-resolution information from LBI spectra. Theoretical deductions are performed to offer systematic and detailed analyses on the proposed method. Moreover, experiments are conducted to prove the feasibility of the proposed method for yielding high-resolution spectra in inhomogeneous magnetic fields.

Vibroacoustic Comparisons and Acoustic Power Insulation Mechanisms of Multidirectional Stiffened Laminated Plates

Vibroacoustic characteristics of multidirectional stiffened laminated plates with or without compliant layers are explored in the wavenumber and spatial domains with the help of the two-dimensional continuous Fourier transform and discrete inverse fast Fourier transform. Implicit equations of motion for the arbitrary angle ply laminated plates are derived from the three-dimensional higher order and Reddy third order shear deformation plate theories. The expressions of acoustic power of the stiffened laminated plates with or without complaint layers are formulated in the wavenumber domain, which is a significant method to calculate acoustic power of the stiffened plates with multiple sets of cross stiffeners. Vibroacoustic comparisons of the stiffened laminated plates are made in terms of the transverse displacement spectra, forced responses, acoustic power, and input power according to the first order, Reddy third order, and three-dimensional higher order plate theories. Sound reduction profiles of compliant layers are further examined by the theoretical deductions. This study shows the feasibility and high efficiency of the first order and Reddy third order plate theories in the broad frequency range and allows a better understanding the principal mechanisms of acoustic power radiated from multidirectional stiffened laminated composite plates with compliant layers, which has not been adequately addressed in its companion paper. (Cao and Hua, 2012, “Sound Radiation From Shear Deformable Stiffened Laminated Plates With Multiple Compliant Layers,” ASME J. Vib. Acoust., 134(5), p. 051001.)

Stochastic stability of center difference predictive filter

In this paper, based on Stirling’׳s polynomial interpolation formula, the Second-order Central Difference Predictive Filter (CDPF2) is proposed for nonlinear estimation. To facilitate the new method, the algorithm flow of CDPF2 is given first. Then, the theoretical deductions demonstrate that the estimated accuracy of the model error and system state for the CDPF2 is higher than that of the conventional PF. In addition, the stochastic boundedness and the error behavior of CDPF2 is analyzed for general nonlinear systems in a stochastic framework. The theoretical analysis presents that the estimation error will remain bounded and the covariance will remain stable if the system׳s initial estimation error, disturbing noise terms and model error are small enough, which is the core part of the CDPF2 theory. All of the results have been demonstrated by numerical simulations for a nonlinear example system.

Temperature‐ and Atmosphere‐Dependent Defect Chemistry Model of SnO2 Nanocrystalline Film

By combining the concept of defect chemistry and the small‐polaron hopping conduction model, the present work takes an intensively considering of the electron conduction mechanism in the nonstoichiometric SnO2 nanocrystalline film. The temperature‐dependent and atmosphere‐dependent relationship between the electrical conductivity and the defect reaction is outlined. To investigate the influence of temperature and atmosphere on the electrical properties of the SnO2 nanocrystalline film, a temperature‐programmed system integrated with the high‐throughput screening platform of gas‐sensing materials (HTSP‐GM) is developed as the test tool in this work. With this platform, the temperature‐dependent conductivity of SnO2 nanocrystalline film in different atmosphere (dry air, nitrogen, and formaldehyde) was conducted. A good fit between the theoretical deductions and experimental results is achieved.

Newer developments on self-modeling curve resolution implementing equality and unimodality constraints

Analytical self-modeling curve resolution (SMCR) methods resolve data sets to a range of feasible solutions using only non-negative constraints. The Lawton–Sylvestre method was the first direct method to analyze a two-component system. It was generalized as a Borgen plot for determining the feasible regions in three-component systems. It seems that a geometrical view is required for considering curve resolution methods, because the complicated (only algebraic) conceptions caused a stop in the general study of Borgen’s work for 20 years. Rajkó and István revised and elucidated the principles of existing theory in SMCR methods and subsequently introduced computational geometry tools for developing an algorithm to draw Borgen plots in three-component systems. These developments are theoretical inventions and the formulations are not always able to be given in close form or regularized formalism, especially for geometric descriptions, that is why several algorithms should have been developed and provided for even the theoretical deductions and determinations. In this study, analytical SMCR methods are revised and described using simple concepts. The details of a drawing algorithm for a developmental type of Borgen plot are given. Additionally, for the first time in the literature, equality and unimodality constraints are successfully implemented in the Lawton–Sylvestre method. To this end, a new state-of-the-art procedure is proposed to impose equality constraint in Borgen plots. Two- and three-component HPLC-DAD data set were simulated and analyzed by the new analytical curve resolution methods with and without additional constraints. Detailed descriptions and explanations are given based on the obtained abstract spaces.

Zwischen religiöser Ideologie und religiösem Fundamentalismus

Abstract According to a wide-spread opinion, protestant ethics is based on its Christian understanding of reality. Hence the task of protestant ethics is seen in the deduction and justification of moral judgments about ethically controversial questions from premises of the Christian faith. The present contribution offers an in-depth critique of this predominant view. Its assumption is that this concept is based on a wrong understanding of both moral and religion. Either one is connected to the presence of reality (»Wirklichkeitspräsenz«); thus the relation between the two has to be determined within the horizon of the presence of reality instead of theoretical deductions and constructs.

An Empirical Study on the Effectiveness of Automated Test Case Generation Techniques

The advent of automated test case generation has helped to reduce the laborious task of generating test cases manually and is prominent in the software testing field of research and as a result, several techniques have been developed to aid the generation of test cases automatically. However, some major currently used automated test case generation techniques have not been empirically evaluated to ascertain their performances as many assumptions on technique performances are based on theoretical deductions. In this paper, we perform experiment on two major automated test case generation techniques (Concolic test case generation technique and the Combinatorial test case generation technique) and evaluate based on selected metrics (number of test cases generated, complexities of the selected programs, the percentage of test coverage and performance score). The results from the experiment show that the Combinatorial technique performed better than the Concolic technique. Hence, the Combinatorial test case generation technique was found to be more effective than the Concolic test case generation technique based on the selected metrics.

Alfred Russel Wallace and the destruction of island life: the Iguana tragedy

The Galápagos Islands (Ecuador) are usually associated with the explorations and theoretical deductions of Charles Robert Darwin (1809-1882), but Alfred Russel Wallace (1823-1913) also investigated these islands and published several reports on the living world of this unique archipelago. In contrast to Darwin, Wallace described the destruction of natural ecosystems by humans and foresaw the resulting extinction of species. Here, we outline two case studies pertinent to Wallace's prediction. First, we summarize the behavior of the predator-naive marine iguanas (Amblyrhynchus cristatus) on the Galápagos Islands, which are threatened by feral dogs and cats imported by humans. We also describe the unique life cycle of the spiny-tailed iguana (Ctenosaura bakeri) from the island of Utila (Honduras), a rare species whose populations are declining because of habitat destructions. In contrast to these threatened, endemic island species, the Green iguana (Iguana iguana) is still widely distributed, although, as a result of de-forestation, in some areas of South America local populations have disappeared. We conclude that Wallace was correct in his prediction that, because of human activities, numerous species of animals and plants will be driven to extinction, notably on islands.

Closed loop control design for the sense mode of micromachined vibratory gyroscopes

This paper presents a novel design method of force rebalance control for the sense mode of micromachined vibratory gyroscopes. Specific theoretical deductions are performed to identify a precise linear model of the open loop system of the sense mode, which is crucial for the PI controller design. The frequency responses obtained by experimental tests agree well with those calculated with the theoretical model, indicating the accuracy of the theoretical analyses. Experimental results demonstrate that the bandwidth of the closed loop is extended to 94.8 Hz from 2.3 Hz in the open loop and the quadrature signal is suppressed by about 64 dBV in the closed loop system. The overshoot and stable time in the step response of the closed loop system are measured to be about 15% and 35 ms, respectively. The mode-splitting gyroscope with the closed loop controlled sense mode achieves a scale factor of 41.0 mV/deg/s with nonlinearity of 0.09% and asymmetry of 1%, and a bias instability of 4.0 °/h with angle random walk of 0.171 deg/h1/2.

Nano-displacement measurement based on virtual pinhole confocal method

A virtual pinhole confocal system based on charge-coupled device (CCD) detection and image processing techniques is built to measure axial displacement with 10 nm resolution, preeminent flexibility and excellent robustness when facing spot drifting. Axial displacement of the sample surface is determined by capturing the confocal laser spot using a CCD detector and quantifying the energy collected by programmable virtual pinholes. Experiments indicate an applicable measuring range of 1000 nm (Gaussian fitting r = 0.9902) with a highly linear range of 500 nm (linear fitting r = 0.9993). A concentric subtraction algorithm is introduced to further enhance resolution. Factors affecting measuring precision, sensitivity and signal-to-noise ratio are discussed using theoretical deductions and diffraction simulations. The virtual pinhole technique has promising applications in surface profiling and confocal imaging applications which require easily-customizable pinhole configurations.

Theoretical and experimental studies on isotachophoresis in multi-moving chelation boundary system formed with metal ions and EDTA

In this paper, a general mode and theory of moving chelation boundary based isotachophoresis (MCB-based ITP), together with the concept of decisive metal ion (DMI) having the maximum complexation constant (lg Kmax) with the chelator, were developed from a multi-MCB (mMCB) system. The theoretical deductions were: (i) the reaction boundary velocities in the mMCB system at steady state were equal to each other, resulting in a novel MCB-based ITP separation of metal ions; (ii) the boundary directions and velocities in the system were controlled by the fluxes of chelator and DMI, rather than other metal ions; and (iii) a controllable stacking of metal ions could be simultaneously achieved in the developed system. To demonstrate the deductions, a series of experiments were conducted by using model chelator of EDTA and metal ions of Cu(II) and Co(II) due to characteristic colors of blue [Cu-EDTA](2-) and pink [Co-EDTA](2-) complexes. The experiments demonstrated the correctness of theoretical deductions, indicating the validity of the developed model and theory of ITP. These findings provide guidance for the development of MRB-based ITP separation and stacking of metal ions in biological sample matrix and heavy metal ions in environmental samples.

On structure and bonding of lanthanoid trifluorides LnF3 (Ln = La to Lu)

The trends in the series of lanthanoid (lanthanide) trifluoride molecules LnF3 (Ln = La to Lu) are governed by the valence-active Ln(4f,5d,5p,6s) shells. The series is investigated by quasi-relativistic density functional theory at both the scalar and spin-orbit-coupled levels. Integrating many of the previous experimental and theoretical deductions, we obtain the following comprehensive picture: (1) The comparatively small Ln-F bond length contraction of 14 pm from La to Lu is rather smooth but weakly modulated by spin-orbit coupling. (2) From La to Lu the floppy structure becomes more quasi-planar. (3) The heterolytic LnF bond energies (⅓LnF3→⅓Ln(3+) + F(-)) at the spin-orbit averaged level increase smoothly from 15.3 to 16.3 eV for La to Lu, only the 'divalent' lanthanoids Eu and Yb are outliers with 0.2 eV higher bond energies. (4) The homolytic LnF bond energies (⅓LnF3→⅓Ln + F) however show an overall W-shaped double-periodicity with maxima for LaF3, GdF3 and LuF3, decreasing from La to Eu and from Gd to Yb, the large individual variations being caused by different spin-orbit coupling and Coulomb interaction effects in Ln(0) and LnF3. (5) The Ln-F interaction is basically ionic (increasing with decreasing ionic radii) with some dative Ln(3+)← F(-) bonding. (6) The latter is of the Ln(5d)-F(2p) type with a rather constant bond order from La to Lu, with small Ln(5p) and very small Ln(4f) semi-core contributions decreasing from La to Lu. All these trends are rationalized.

Concerns with attempts by neuroeconomics to answer the philosophical question “Is it rational to donate money for charity?”

GENERAL COMMENTARY article Front. Psychol., 30 August 2013Sec. Theoretical and Philosophical Psychology Volume 4 - 2013 | https://doi.org/10.3389/fpsyg.2013.00585