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Speech emotion recognition is a challenging task in natural language processing. It relies heavily on the effectiveness of speech features and acoustic models. However, existing acoustic models may not handle speech emotion recognition efficiently for their built-in limitations. In this work, a novel deep-learning acoustic model called attention-based skip convolution bi-directional long short-term memory, abbreviated as SCBAMM, is proposed to recognize speech emotion. It has eight hidden layers, namely, two dense layers, convolutional layer, skip layer, mask layer, Bi-LSTM layer, attention layer, and pooling layer. SCBAMM makes better use of spatiotemporal information and captures emotion-related features more effectively. In addition, it solves the problems of gradient exploding and gradient vanishing in deep learning to some extent. On the databases EMO-DB and CASIA, the proposed model SCBAMM achieves an accuracy rate of 94.58% and 72.50%, respectively. As far as we know, compared with peer models, this is the best accuracy rate.

Photonic integrated circuits enable energy efficient and compact technologies for modern information communications. Here, we explore semiconductor epitaxial quantum dots lasers on silicon and demonstrate their high suitability for addressing the important issues associated to photonic integration on silicon.

Soft robotic pneumatic grippers have been shown to be versatile, robust to impacts, and safe for use on delicate objects. One type, fluidic elastomer grippers, are characterized by fingers with an inextensible gripping surface backed by extensible pneumatic chambers; when inflated, this mismatch in extensibility results in the finger curling. However, one drawback of these simple fingers is that they have one preprogrammed grasp, usually a simple constant-curvature wrap. While well-suited for finger-sized round objects, they do not grasp flat or small objects well. Here, we present an adaptable tri-stable soft robotic finger that can form either a pinch or wrap grasp based on the shape of the grasped object. We enable this by incorporating two bi-stable springs into the inextensible layer. The three stable positions are: i) open (unpressurized), ii) pinch (with only the proximal section bending), and iii) wrap (with the entire finger bending). We present a simple model of the behavior of our finger and experimental results verifying the model. Further, we apply forces and moments to grasped objects, and show that the tri-stable finger increases the grasping performance when compared to a control gripper with equal gripping force. Our work presents a novel design modification that is unobtrusive, simple, and passive. Our introduction of inexpensive programmable hardware advances the versatility and adaptability of soft grippers.

This work investigates the reflection sensitivity of a hybrid III-V on silicon narrow line semiconductor laser based on a high quality factor grating. Experimental results reveal a floor-free operation under optical feedback hence indicating that such lasers can function without optical isolators.

InAs/GaAs quantum dot (QD) lasers monolithically grown on Ge or Si are a promising method to achieve low cost, large scale, and high yield optical sources for photonic integrated circuits [1]. This work shows that a free-running Ge-based QD laser can output periodic pulse oscillations with one, two and three periods, without incorporating saturable absorber or employing any external perturbations [2,3]. The QD laser under study was epitaxially grown on a 4-inch Ge-wafer by the gas-source molecular beam epitaxy, and the active region consists of five stacked dot-in-well layers [4]. The wafer was fabricated into a ridge-waveguide laser with a ridge width of 4.0 μm and a cavity length of 4.4 mm. The laser shows a lasing threshold of 60 mA at 20 °C, and the lasing peak is at 1213 nm. Figure 1(a) shows that the relative intensity noise (RIN) of the Ge-based laser pumped at 80 mA exhibits a common resonance with continuous-wave output. However, the resonance of the laser pumped at 160 mA does not become overdamped, but evolves into pulse oscillations with a high and sharp peak. Figure 1(b) shows the resonance frequency and the damping factor extracted from the RIN spectra. The resonance frequency increases with the pump current from 0.4 GHz at 80 mA up to 1.1 GHz at 170 mA, whereas the damping factor declines from 4.0 GHz down to 0.03 GHz. The damping reduction confirms the onset of peculiar pulsing dynamics for pump currents above 140 mA.

The nonlinear dynamics of InAs/GaAs quantum dot lasers emitting exclusively on single lasing states, either ground or excited state, is investigated. While a laser emitting on the ground state is of importance for the development of isolator-free transmitters, lasers emitting on the excited states are essential for chaos-based applications, microwave photonics, and self-pulsating devices.

We investigate the interplay between linewidth and $\alpha$ -factor in quantum dot lasers using experimental data and a minimal quantum dot laser rate equation model. The rebroadening of the laser linewidth found experimentally at high injection currents is explained by analytical means and traced back to nonlinear scattering processes. Important differences of the pump current dependent linewidth evolution of quantum dot lasers are highlighted especially if compared to conventional laser devices. Furthermore, we provide a scheme to extract the amplitude-phase coupling as well as effective carrier scattering rates with standard characterization techniques, i.e., linewidth, light versus injected pump current and modulation response measurements.

Non-linear properties of quantum-dot and quantum-dash lasers under dual-mode optical injection are investigated experimentally, showing higher nonlinearity of quantum-dash lasers. Frequency response measurements show equal 3 dB modulation bandwidth of 8 GHz.

Based on the general syllable structure, a syllable’s component letters should be expanded orderly into the series of basic consonant, prefix consonant, head consonant… and the second suffix consonant. If there is no letter in a syllable’s particular position, a special character, whose collation element is less than that of any Tibetan letter, should be used in the corresponding position of the expanded series. Thus, we have a character series that is canonically equivalent to the Tibetan syllable. Furthermore, a syllable’s collation element series could be developed by introducing each character's collation element and each syllable could be collated correctly with its collation element series. However, for the sake of memory saving, a syllable’s collation element series is compressed with the Run-Length algorithm and the final compression ratio reaches 4:1.

The manipulation of microvolumes of chemical and biological samples by means of electrical and magnetic cases has been the important issues in microfluidics and lab-on-chip research fields. In this paper, a novel micro-device which could be used for manipulation and analysis of micro-volume fluid drops based on magneticphoresis was fabricated by our newly introduced method named micro-wire molding and withdrawing technique and the thermal effects caused by joule heat in such simple microdevice were preliminary investigated, some implications towards DNA microdroplet manipulation and analysis experiments in such microdevice were also prospected and discussed.