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On 13th November 2016, the Kaikoura region of New Zealand was struck by a major Mw7.8 earthquake. In this study, coseismic deformation field is derived from 1 Hz high-rate GPS observations based on the GAMIT track solution module, combining with PCA spatial filtering method firstly. Then the 5 s peak displacement of P-wave (Pd) and the peak ground displacement (PGD) are extracted from the real-time simulated kinematic displacements of the trackRTr module. Finally, the warning magnitude is calculated from the statistical regression model. Our results indicate that the duration time of the kinematic deformation is up to 2 min. The KAIK and HANM stations, which are closest to the epicenter, have secondary severe deformation. And the deformation amplitude of the north stations of the epicenter is larger than that of the south. The static coseismic deformation field from high-rate GPS observations shows the characteristics of the focal mechanism of strike-slip after thrust. In addition, the Pd warning magnitudes from different stations have a significant difference, with the maximum magnitude difference of Mw2.5. Considering the timeliness and reliability of the warning magnitude jointly, the warning magnitude from the four-station PGD joint warning method of reasonable spatial distribution can reach its initial stability (Mw7.56) at 23 s after the event, while final stability (Mw7.78) at 110 s, which is consistent with the USGS moment tensor magnitude (Mw7.8).

For large lifting body plane symmetric aircrafts, lateral maneuvering near the target may cause severe aerodynamic coupling between the lateral channels, possibly resulting in instability of the rolling channel. Aiming at this kind of coupling problem, the lateral system is decomposed based on the singular perturbation theory, and the cascade model of the inner and the outer loops is established. The outer loop is used as an example to design the sliding mode (SM) control law, and the stability of the closed-loop system is analyzed. The sliding mode disturbance observer (SMDO) is also employed to estimate and compensate for the coupling term and improves the robustness of the rolling channel against the lateral coupling. Simulation results show that the designed controller has good dynamic characteristics and anti-disturbance ability, improving the robustness and performance of the control system.

This letter presents a planar triple-band multiple- input-multiple-output (MIMO) antenna that meets GSM900/1800 and LTE2600 bands protocols. The antenna element contains three individual meander-line-type inverted-L radiators; the highest frequency band radiator is fed by a transmission line, while the other two utilize the proximity-coupling feeding mechanism driven by the highest band radiator. The MIMO antenna is incorporated with two symmetric triple-band antenna elements and two physical decoupling devices. The two antenna elements are closely spaced with 1/15 wavelength of the lowest band. The two decoupling devices, a T-shaped slot and a meandering microstrip-line resonator, are built for the highest and the lowest frequency bands, respectively. Meanwhile, a negligible mutual coupling effect in middle band is achieved by using a collinear-placed transverse meander-line pair in the MIMO antenna. The antenna prototype measurement results show good impedance matching with low mutual coupling effect. The calculated envelope correlation coefficient verifies the suitability of the proposed antenna for mobile wireless access applications.

Precision guided weapon is the main weapon in modern warfare. The precision guided weapon with photoelectric guidance has the advantages of strong resolution and high accuracy. It is widely used in the fields of sea-to-sea, air defense, anti-missile, space attack and defense. As optoelectronic guided weapons play an increasingly prominent role in modern warfare, their corresponding countermeasures are also constantly developing, which makes the combat environment more complex and requires them to continuously enhance adaptability to the increasingly complex battlefield environment. Based on the summary of the application of existing optical detection technologies such as infrared, visible light and laser semi-active in guided weapons, the shortcomings of the current technology in complex combat environments are analyzed, such as harsh natural weather, complex background and human interference. In view of the current development of multi-spectral detection, polarization imaging, laser three-dimensional imaging, quantum detection and other new technologies, the current research progress and results are introduced. It mainly includes multi-spectral multi-segment segmentation against true and false target camouflage recognition, polarization imaging against rain and fog, bad natural weather, laser three-dimensional imaging in the application of anti-complex background and penetration shielding and other research advantages and research progress. Finally, the problems in the application of the new detection technology and the key technologies that need to be broken through are systematically analyzed, and it is suggested that the guidance application of the new detection technology should be promoted through the joint attack of the basic technology and the application technology.

There exists a steady-state error in the closed-loop system output with some conventional linear active rejection control approaches when the pitch channel control variable of the near space vehicle is the angle of attack. In this study, a cascaded linear active disturbance rejection control approach based on the cascaded control idea is proposed. Both the inner-loop controller and the outer-loop controller are designed by the linear active disturbance rejection control method. The inner-loop is built by angular rate feedback to improve dynamic performance of the closed-loop system, and the outer-loop is built by angle of attack feedback to remove the undesired steady-state error. The approach is employed to a hypersonic near space vehicle autopilot. The numerical simulations show that the proposed approach preserves the performances on time domain and frequency domain as good as those of the conventional active disturbance rejection control approaches, and it has the better performances on disturbance rejection and angle of attack command tracking accuracy than those of some previous active disturbance rejection control approaches.

The angular rate is the derivative of pitch angle other than the derivative of angle of attack, there determinately exists a steady-state error in the closed-loop system output with the linear active rejection control in the case that the control variable is the angle of attack. In this study, an unbiased linear active disturbance rejection control approach based on two-loop control is proposed. The internal-loop is built by angular rate feedback to improve the damping, and the external-loop is built by angle of attack feedback to realize the system output accurately reproducing the reference input. Furthermore, a linear active disturbance rej ection control is applied for the external-loop controller design. The approach is employed to a hypersonic near space vehicle autopilot. The numerical simulations show that the proposed approach preserves the performance on frequency domain as good as that of the conventional active disturbance rejection control approach, the steady-state error of the closed-loop system is well removed, and the angle of attack command is tracked with better accuracy than that of some previous active disturbance rejection control approaches.

This paper presents a compact dual-band MIMO antenna that is compatible to the IEEE 802.11n wireless LAN standards. The MIMO antenna contains two tree-type elements placed back to back with distance of one-sixth wavelength of 2.4GHz; the element in the MIMO antenna is structured with a two-branch tree-type planar inverted-L monopoles, the lengths in both branches are set to the electrical quarter-wavelength of the frequency bands of 5.2GHz and 2.4GHz respectively. The MIMO antenna characterized by small size, low mutual coupling effect and nearly omni-directional coverage in radiation pattern make it entirely applicable to the mobile wireless network applications. The measurement results of the fabricated MIMO antenna demonstrate the success of the suggested design topologies.

Few investigation interests have been focused on anti-windup design under Active Disturbance Rejection Control scheme. In this study, an anti-windup compensation strategy under ADRC scheme is proposed. The strategy is also a special case of the unified framework for anti-windup compensation. By feeding the actual plant input into the extended state observer, the extended state is correctly estimated while actuator saturation emerges, then the adequate controller output is accordingly produced to alleviate the adverse influence of actuator saturation on closed-loop dynamics. The approach is applied to a hypersonic near space vehicle pitch-axis autopilot design with fin-deflection saturation, the capability and effectiveness of the proposed approach is demonstrated by the results.

The angular rate is the derivative of pitch angle other than the derivative of angle of attack, there determinately exists a steady-state error in the closed-loop system output in the case that the control variable is the angle of attack. In this study, A linear compensation term is introduced into the extended state observer, and an unbiased linear active disturbance rejection control approach is proposed. The approach is employed to a hypersonic near space vehicle autopilot. The numeral simulations show that the proposed approach preserves the performance on frequency domain as good as that of the conventional active disturbance rejection control approach, furthermore, the steady-error of the closed system is removed simultaneously, and the angle of attack command is tracked with better accuracy than that of some previous active disturbance rejection control approaches.

This paper presents a compact self-decoupling dual band MIMO antenna that meets wireless local area network communication standards. The self-decoupling is taken place by purposely using a folded loop-shape element in the MIMO antenna. Furthermore, the feeding point of the element antenna is deliberately selected so as to produce both the two desired frequency bands. The whole loop structure is constructed to produce the lower frequency band while a portion of the loop is resonant to the higher frequency band. The MIMO antenna contains two folded loop-shape elements situated back-to-back with a closed inter-element distance of one-tenth wavelength of the lower band. The novelty of this MIMO antenna is attributed to the achievement of good isolation without using any other supplementary decoupling mechanisms. In addition, the properties of small in size, simple in structure, nearly omni-directional in radiation pattern with moderate radiation gain make the proposed MIMO antenna fully compatible and fairly attractive to the wireless and internet network applications.

The feasibility of hydrogen production from distillers grains substrate, an industrial cellulosic waste, was investigated. A substrate concentration of 80 g/L gave the maximum production at 50 °C and pH of 6.0 using sewage sludge. Four controllable factors with three levels: seed sludge (two sewage sludges and cow dung), temperature (40, 50, and 60 °C), pH (6, 7 and 8) and seed pretreatment (none, heat, and acid) were selected in Taguchi experimental design to optimize fermentation conditions. The peak hydrogen and ethanol productions were found with heat-treated cow dung seed, substrate concentration 80 g/L, 50 °C and pH 6. The peak hydrogen production rate and hydrogen yield were 7.9 mmol H2/L/d and 0.40 mmol H2/g-COD respectively whereas the peak ethanol production was 3050 mg COD/L and rate 0.22 g EtOH/L/d. A total bioenergy yield of 41 J/g substrate was obtained which was 21% and 79% from hydrogen and ethanol respectively.

Biohydrogen production from untreated rice straw using different heat-treated sludge, initial cultivation pH, substrate concentration and particle size was evaluated at 55 °C. The peak hydrogen production yield of 24.8 mL/g TS was obtained with rice straw concentration 90 g TS/L, particle size

The effect of effluent recycle on hydrogen production in an anaerobic continuous stirred tank reactor (CSTR) was investigated. The CSTR was fed on sucrose (20 g chemical oxygen demand (COD)/L) and at hydraulic retention time (HRT) of 12 h. The pH and temperature were regulated around 6.7 and 35 °C, respectively. The effluent was then recycled at recycle ratios of 0, 0.2, 0.4, 0.6, 0.8 and 1.0. When the recycle ratios increased, the volatile suspended solid (VSS) concentration also increased with a peak of 14.2% at the recycle ratio 0.4 compared with the VSS 3.52 g/L without effluent recycle. However, a drastic drop in hydrogen production performance was observed with increased recycle ratio. The strategy of increasing organic loading rate by increasing the substrate concentration and shorting the HRT was then applied keeping a recycle ratio of 0.2. VSS concentration increased with increasing substrate concentration but as the HRT was shortened from 12 h to 2 h stepwise, VSS concentration increased first and then decreased at HRT 8 h. The maximal hydrogen production was obtained at sucrose concentration of 20 g COD/L and HRT 6 h (organic loading rate (OLR) 66.7 g COD/L-d) with recycle ratio 0.2. The hydrogen yield, hydrogen production rate and specific hydrogen production rate values also peaked at the same conditions (sucrose 20 g COD/L and HRT 6 h) with 3.88 mol H 2 /mol sucrose, 807 mmol H 2 /L-d and 244.3 mmol H 2 /g VSS-d, respectively. This study showed peak hydrogen production performance at OLR 66.7 g COD/L-d in the recycled continuous anaerobic biohydrogen production system by controlling HRT. Thus, effluent recycling at the optimum ratio along with optimum HRT and substrate concentration can maximize the hydrogen production performance in an anaerobic biohydrogen production system.

This paper presents an improved H∞ guidance law with the terminal impact angle constraint for homing missiles. By regarding target maneuvers as exogenous disturbances, the missile guidance problem is formulated as a nonlinear disturbance attenuation control problem. Furthermore, by introducing the Lyapunov stability criteria into guidance dynamics, not only the small miss distance and the specified impact angle are obtained, but also the H∞ attenuation level and the stability of the closed-loop system are guaranteed. The numerical simulation shows that the proposed method has the effectiveness and the robustness for homing missiles against both non-maneuvering targets and maneuvering targets.

This paper presents a kind of CPW-fed Pentagon-type multi-band planar monopole antenna. It provides an integrated wideband operating frequency band coverage from 900MHz of GSM to 10.6GHz UWB applications. This is the desirable antenna characteristic that is suitable for modern integrated mobile broadband wireless radio access applications. The proposed antenna was fabricated in practice with the FR4 print circuit board having 1.6 mm substrate thickness and dielectric constant of 4.4, tangent loss constant of 0.02. The measurement results show the success of the proposed planar monopole antenna. The detailed antenna design parameters are given in this paper. The characteristics of this type antenna, wide in bandwidth, low in profile, light in weight and small in size and single layer fabrication can be beneficial in the future integration with other microwave circuit of wireless systems.

In this paper, we apply the two-time Green's function method, and provide a simple way to study the magnetic properties of one-dimensional spin-(S,s) Heisenberg ferromagnets. The magnetic susceptibility and correlation functions are obtained by using the Tyablikov decoupling approximation. Our results show that the magnetic susceptibility and correlation length are a monotonically decreasing function of temperature regardless of the mixed spins. It is found that in the case of S=s, our results of one-dimensional mixed-spin model is reduced to be those of the isotropic ferromagnetic Heisenberg chain in the whole temperature region. Our results for the susceptibility are in agreement with those obtained by other theoretical approaches.

This paper reports the periodic power variation of the pulse-train in a passively mode-locked soliton fiber ring laser. It can obtain either the uniform or nonuniform pulse-train output by simply rotating the polarization controllers. The experimental results show that the pulse-train nonuniformity is caused by the interaction between the nonuniform polarization states of the soliton pulses and the passive polarizer in the cavity.

A novel controller, which is called fuzzy sliding mode controller and employs the classical topology, is presented. This paper considers the pitch channel controller design process based on a static-unstable flexible vehicle and proves the system equilibrium state at the origin is stable by using Lyapunov stability analysis method. The fixed point simulation is carried out to check the response characteristics in time domain and the property of tracking command signal. The simulation results show the robustness of the controller.

Usually the missile attitude control process in a large flight envelope has strong time-varying and nonlinear characteristics, so the controller parameter is difficultly scheduled with conventional PID control approach. In this study a linear active disturbance rejection control approach based on reduced-order linear extended state observer is proposed. The approach is employed to the attitude controller for a supersonic missile in attack with high angle. It is not hard to determine the proposed controller parameter, and the numeral simulations show that the presented approach has a very good capability on tracking attitude command.

A compact multiband planar monopole antenna is presented in this paper. The operating frequency bands of the proposed antenna cover the multiple wireless access protocols of GSM (880-960MHz), DCS (1710-1880MHz), WiMAX (3.23.6GHz), WLAN and Bluetooth (2.4GHz), and WLAN (5.15.35GHz). The antenna is constructed by two distinct monopoles which are individually located at the opposite side of the substrate; a broadband meander-line monopole is structured to create the triple lower frequency bands, on the other hand, a tree-type monopole is built not only to produce the dual higher frequency bands, but also to act as a proximity-coupled feed for the meander-line resonator. The antenna together with several attractive characteristics, such as small in size, broad in operating frequency band and omni-directional in radiation pattern, makes itself particularly suitable to the integrated mobile wireless access applications. The measurement results demonstrate the success of the antenna design approach.

In order to obtain the full advantages of modern mobile MIMO wireless access communication, a compact and low mutual coupling antenna array is essential. Hence, this paper presents a compact dual band two element MIMO antenna operating in the 2.4GHz and 5.2GHz bands for mobile wireless LAN application. The dual-band antenna element is structured with a planar two-branch inverted-L tree-type monopole, where, the two collinear inverted-L radiators have been purposely organized such that a squeezed element radiation pattern is obtainable. The MIMO antenna is then incorporated with two tree-type monopoles and a simple narrow band isolator to achieve an excellent mutual coupling performance. Besides, the characteristics of small size and nearly omnidirectional coverage in array radiation pattern make the proposed MIMO antenna entirely compatible with the mobile wireless network applications. The measurement results of the fabricated antenna array demonstrate the success of the suggested design topology.

This paper presents a compact dual band two element MIMO array covering the 2.4GHz and 5.2GHz bands for the modern mobile wireless LAN applications. The dual band antenna element is structured as a two-branch tree-type inverted-L monopole, where, the two collinear inverted-L radiators have been purposely organized such that an oblique element radiation pattern is obtainable. The MIMO array is then incorporated with two tree-type monopoles and a simple narrow band isolator to achieve an excellent mutual coupling performance. Besides, the characteristics of small size and nearly omnidirectional array radiation pattern make the proposed MIMO array entirely compatible with the mobile wireless network applications. The measurement results of the prototype antenna array demonstrate the success of the suggested design topology.

This paper presents a compact planar monopole antenna that covers the operating frequency bands of GSM (880-960MHz), DCS (1710-1880MHz), WiMAX (3.2-3.6GHz), WLAN and Bluetooth (2.4GHz), and WLAN (5.1-5.35GHz). The proposed antenna is incorporated with two distinct monopoles, a tree-type and a shaped meander-line type monopole, situated on the opposite side of the substrate; the shaped meander-line type monopole is tuned to create the triple lower frequency bands, on the other hand, the tree-type monopole is built not only to produce the two higher frequency bands, but also to act as a proximity coupling feed for the meander-line resonator. The noticeable originalities exhibited in this proposed antenna include the handiwork of shaped multiband meander-line monopole and the use of broadband proximity coupling mechanism. Both of them enable us to simply the tuning process of the broadband matched network and to reduce the antenna size as well. The proposed antenna accompanied with several attractive characteristics makes itself particularly suitable to the modern integrated mobile wireless access applications.

A self-starting, passively mode-locked all-fibre ring laser based on the homemade Er3+/Yb3+codoped phosphate glass fibre is reported. Dual-pump sources were used to achieve the mode-locked operation in the experiment. The fundamental mode-locked pulse repetition rate is 10.67 MHz. The pulse duration, assumed as the fit of hyperbolic secant pulse shape, is 5.82ps. We also observe the multi-pulse output of the fibre laser.

This paper presents a kind of CPW-Fed Multi-Broadband Monopole Antenna, which provides an integrated operating bandwidth coverage from 900MHz of GSM, WLANs up to 10.6GHz of UWB. This is the antenna particularly desirable for modern integrated mobile broadband wireless radio access applications. The property of wide range in multiple broadband appeared in the proposed antenna has been created judiciously by using a folded-line loaded monopole with an edge-coupling mechanism. The measurement result shows the success of this novel design approach.

This study applied a pilot-scale trickle-bed air biofilter (TBAB) system for treating waste gas emitted from the breather vent of a vertical fixed roof storage tank containing p-xylene (p-X) liquid. The volatile organic compound (VOC) concentration of the waste gas was related to ambient temperature as well as solar radiation, peaking at above 6300 ppmv of p-X and 25000 ppmv of total hydrocarbons during the hours of 8 AM to 3 PM. When the activated carbon adsorber was employed as a VOC buffer, the peak waste gas VOC concentration was significantly reduced resulting in a stably and efficiently performing TBAB system. The pressure drop appeared to be low, reflecting that the TBAB system could be employed in the prolonged operation with a low running penalty. These advantages suggest that the TBAB system is a cost-effective treatment technology for VOC emission from a fixed roof storage tank.

A cross-dipole antenna surrounded by four pins is used as a radiating element for a finite-element phased array. To achieve near-hemispherical radiation coverage and high gain under the consideration of mutual coupling effects, a method using genetic algorithms to optimize the design parameters of a cross-dipole antenna is presented. A method of moment code performs the task of evaluating each of the antenna designs generated by the genetic algorithm (GA) during the optimization process. To illustrate the capabilities of this approach, the numerical results are compared to the measured ones, showing excellent agreement in the comparison.

The paper presents a new technique for synthesizing the radiation pattern of an active linear phased array. The approach taken in the paper is to integrate the power response of the array over a spatial region of interest and force it to less than or equal to the desirable value. The closed form equation of the objective function is derived such that a numerical technique based on gradient search can be used to optimize the far-field patterns in a fast and efficient manner.