Shyh-Kang Jeng

EEG-Based Emotion Recognition in Music Listening

Ongoing brain activity can be recorded as electroen-cephalograph (EEG) to discover the links between emotional states and brain activity. This study applied machine-learning algorithms to categorize EEG dynamics according to subject self-reported emotional states during music listening. A framework was proposed to optimize EEG-based emotion recognition by systematically 1) seeking emotion-specific EEG features and 2) exploring the efficacy of the classifiers. Support vector machine was employed to classify four emotional states (joy, anger, sadness, and pleasure) and obtained an averaged classification accuracy of 82.29% ± 3.06% across 26 subjects. Further, this study identified 30 subject-independent features that were most relevant to emotional processing across subjects and explored the feasibility of using fewer electrodes to characterize the EEG dynamics during music listening. The identified features were primarily derived from electrodes placed near the frontal and the parietal lobes, consistent with many of the findings in the literature. This study might lead to a practical system for noninvasive assessment of the emotional states in practical or clinical applications.

Planar miniature tapered-slot-fed annular slot antennas for ultrawide-band radios

A novel planar tapered-slot-fed annular slot antenna is proposed in this paper. The antenna utilizes a unique tapered-slot feeding structure and simultaneously possesses ultrawide bandwidth, almost uniform radiation patterns, and low profile. It is, hence, adequate for ultrawide-band (UWB) applications. By means of a normalized antenna transfer function, both frequency domain and time domain characteristics of the antenna are carefully investigated. Two measures, the uniformity related to the radiation patterns and the fidelity associated with the transient behaviors, are used to quantitatively describe the performance of an antenna over such an ultrawide bandwidth. Effects of varying the antennas geometric parameters on the performance are then investigated. Finally, the influence of minimizing the antenna dimension is discussed at the end of the paper.

An SBR/image approach for radio wave propagation in indoor environments with metallic furniture

In this paper, we propose a deterministic approach to model the radio wave propagation channels in complex indoor environments. This technique applies the modified shooting-and-bouncing-ray (SBR) method to find the equivalent sources (images) for each launched ray tube. In addition, the first-order wedge diffraction from furniture is included and the diffracted rays also can be attributed to the corresponding images. By summing the contributions of all these images coherently, we can obtain the total received field at a receiver. Besides, the vector-effective height (VEH) of an antenna is introduced to consider the polarization coupling effect resulting from multiple reflection inside the rooms. We verify this approach by comparing the numerical results in three canonical examples where closed-form solutions exist. The good agreement indicates that our method can provide a good approximation of high-frequency radio propagation inside rooms where multiple reflection is dominant. Work reported in this paper has shown that the propagation loss in indoor environments varies considerably according to furniture and polarizations.

Compact Switched-Beam Antenna Employing a Four-Element Slot Antenna Array for Digital Home Applications

In this paper a compact switched-beam antenna is proposed. The antenna is composed of a four-element antenna array based on L-shaped quarter-wavelength slot antenna elements. Such an antenna element is a planar structure and presents a directional radiation pattern in the azimuth plane. Its maximum radiation direction is toward near the direction of the open end of the slot. As a result, the open ends of the four slot antennas are arranged toward 0, pi/2, pi, and 3pi/2 , respectively. The statuses of these antennas are controlled by some diodes. Consequently, by carefully controlling the diodes, an antenna with several switchable patterns can be achieved. To prove the concept, a 2.4-2.5 GHz switched-beam antenna for WLAN applications is designed and implemented. Its size is 52 mm in square. The antenna possesses eight directional patterns and many nearly omnidirectional patterns in the azimuth plane. The experiment results fully demonstrate the performance of the proposed design. The envelope correlations and the characteristics of the designed antenna are also discussed. Due to the compact size and low manufacture cost, such a design can be a promising solution for digital home applications to overcome multipath problems and increase the transmission data rate.

A printed dipole antenna with tapered slot feed for ultrawide-band applications

In this paper a planar antenna is studied for ultrawide-band (UWB) applications. This antenna consists of a wide-band tapered-slot feeding structure, curved radiators and a parasitic element. It is a modification of the conventional dual exponential tapered slot antenna and can be viewed as a printed dipole antenna with tapered slot feed. The design guideline is introduced, and the antenna parameters including return loss, radiation patterns and gain are investigated. To demonstrate the applicability of the proposed antenna to UWB applications, the transfer functions of a transmitting-receiving system with a pair of identical antennas are measured. Transient waveforms as the transmitting-receiving system being excited by a simulated pulse are discussed at the end of this paper.

Compact microstrip dual-band bandpass filters design using genetic-algorithm techniques

An optimization scheme based on hybrid-coded genetic-algorithm (GA) techniques is presented to design compact dual-band bandpass filters with microstrip lines. A representation scheme is proposed to represent an arbitrary microstrip circuit as a set of data structures. Each data structure in the set describes a simple two-port network with the corresponding connection method and electrical parameters. The optimization algorithm based on conventional GAs is then applied to simultaneously search for the appropriate circuit topology and the corresponding electrical parameters with dual-band characteristic. Two examples are designed and implemented to validate the proposed algorithm. In the first example, the 3-dB fractional bandwidth of the low and high bands is 35% and 17%, respectively. It has return losses larger than 10 dB from 2.14 to 2.96 and 5.14 to 6.06 GHz. In the second example, the 3-dB fractional bandwidth of the low and high bands is 9.9% and 7.9%, respectively. The return losses are larger than 10 dB from 3.37 to 3.64 and 5.27 to 5.62 GHz. The sizes of the proposed filters are nearly half as small as those of the filters presented before. All the studies are completed on a computer with a 2.4-GHz microprocessor, and the computing time of two examples is 6 and 3 min, respectively

Design of Matching Circuits for Microstrip Triplexers Based on Stepped-Impedance Resonators

New matching circuits for microstrip triplexers are proposed based on half-wavelength tapped-connected (or fed) stepped-impedance resonators. The stepped-impedance resonators play important roles for the matching circuits, either to serve as a through pass at the center frequency of a bandpass filter or to provide a short circuit at the center frequency of another bandpass filter. First, three tapped-connected stepped-impedance resonators together with suitable branch transmission lines are utilized to develop the matching circuits for a microstrip triplexer. The design procedure for these matching circuits is much simpler than that for the conventional triplexer structures due to the use of tapped-connected stepped-impedance resonators. Second, to reduce the number of stepped-impedance resonators and to improve the spurious resonances associated with the proposed matching circuits, modified matching circuits for the triplexer are also proposed. Agreement between measured and simulated results is observed and supports the usefulness of the design procedure

Scattering from a cavity-backed slit in a ground plane-TM case

Two-dimensional transverse electric wave scattering from a cavity-backed slit in a ground plane is analyzed by R.F. Harrington and J.R. Mautzs (1976) generalized network formulation. The admittance matrix of the cavity or arbitrary shape and medium is obtained by the finite-element method. A variational equation for the cavity problem is established and then discretized to a matrix equation. An efficient algorithm using the modified frontal-solution algorithm is developed to solve the matrix equation. The solution is manipulated to get the admittance matrix of the cavity. The computed admittance matrix is added to the radiation admittance matrix of the equivalent magnetic current on a ground plane and is used to solve for the equivalent magnetic current on the slit. Numerical results for trapezoidal and coated rectangular cavities are included. >

Support vector machine for EEG signal classification during listening to emotional music

An approach to recognize the emotion responses during multimedia presentation using the electroencephalogram (EEG) signals is proposed. The association between EEG signals and music-induced emotion responses was investigated in three factors, including: 1) the types of features, 2) the temporal resolutions of features, and 3) the components of EEG. The results showed that the spectrum power asymmetry index of EEG signal was a sensitive marker to reflect the brain activation related to emotion responses, especially for the low frequency bands of delta, theta and alpha components. Besides, the maximum classification accuracy was obtained around 92.73% by using support vector machine (SVM) based on 60 features derived from all EEG components with the feature temporal resolution of one second. As such, it will be able to provide key clues to develop EEG-inspired multimedia applications, in which multimedia contents could be offered interactively according to the userspsila immediate feedback.

On variational electromagnetics: Theory and application

A methodology to he named variational electromagnetics (VEM) is introduced for handling time-harmonic linear electromagnetic field problems. First a desired variational formulation is derived from a fundamental variational principle (FVP) and then is solved by the hybrid element method along with the frontal solution algorithm. The main advantages of such an approach are the unified derivation of variational equations for both interior and exterior field problems and their efficient numerical solution, especially for problems with inhomogeneons media. Also included is a numerical example in which the scattering from an inhomogeneously coated cylinder is analyzed.