Anomaly and damage detection is an important research topic in the field of structural health monitoring (SHM). It is in general difficult to establish a precise computational model and measure multiple dynamic loads for complex structures. Model-free identification methods using only response measurements are therefore highly desired. Based on second-order statistics blind separation (SOSBS), this study explores response-only blind excitation separation and structural feature extraction when the structure is subject to multiple periodic excitations. The proposed method proceeds with two steps: (i) a transformation to convert the measurement space to eigenspace with identity covariance matrix and compact the measurement dimension to independent source dimension; and (ii) joint diagonalization of covariances with various time shifts to determine the mixture features. Neither structural model nor measurement of excitations is required in this method, and the extracted mixture matrix representative of structural dynamic characteristics can be used for structural anomaly detection and damage diagnosis. Both numerical simulation of a 3-degree-of-freedom vibration system and experimental study of a 5-story physical structure are conducted to verify the proposed method.

The electric arcing for the railing system is examined in this paper. The key work is the pantograph-catenary systems that subject to high voltage, uneven contact and current, and contact point interruption. The high-power arcing affects the rolling stock seriously and contribute to the electromagnetic interference, life duration of the pantograph-catenary systems, safety, high current and voltage spike to the power components and other electrical systems. Present the model of this arcing us difficult to be examined as there are many unknown factors. The present work is to survey, review and examine the possible solution, modeling and its effect on the rolling stock. Moreover, the possible energy recovery from the arcing is an interesting development of the study.

In order to obtain the characteristic of the human impedance [1][2], A square wave electric signal is proposed to apply to the human beings. The peak current when a human is in initial contact of an electrical signal is examined. The use of square wave is a better method for human detection as it gives an exponential current that is unique as compared to another electrical appliance. The result provides a critical judgment for smart electric socket which could identify human being from another appliance. The whole research is based on the human model in the standard of IEC 479[3]. Considering the instant effect in the first charging moment by the step pulse, the human model is simplified to an RC circuit.

This paper is to discuss the examination of the arcing characteristics of railway system and its EMI implication; the electromagnetic induction of conductor's due to high frequency and high speed for railway system.

Current passing through conductor in free space of air generates magnetic field which could interfere with the other apparatus nearby or even interrupt it. Inversely, the electromagnetic sources could also be affected by reaction filed or field generated from else. Therefore, the equipment needs to be designed to both blocking and tolerating the electromagnetic radiation. The electromagnetic interference could be mitigated or minimized by many techniques like filtering, earthing, or shielding. Especially in high speed railway, enclosing dc and ac system, high power and lower power system into a limited area requires the equipment generates less electromagnetic Interference (EMI) and could perform against the interference by the other apparatus. Metal box shielding is a method when the circuit design alone cannot satisfy the requirement that the equipment could stand against the environmental EMI or emanating from the equipment. This paper presents a polymer bonded gridded box shielding method which is light, flexible, material saved and suitable for high and low frequency shielding by employing polymer material.

Spring stiffness is the key parameter of an active suspension consisting of an actuator and a mechanical spring. The effects of the spring stiffness on suspension performances are investigated comprehensively. A novel multi-objective optimization technique of the spring stiffness in automotive active suspension systems is developed in this study. The novel optimization objective is proposed as the compromise among the root-mean-square (RMS) vertical unsprung-mass-to-road-surface displacement, the RMS vertical acceleration of the sprung mass, the RMS vertical sprung-mass-to-unsprung-mass displacement, the RMS active force, and the vertical sprung-mass-to-unsprung-mass displacement at steady-state. Consequently, the drive safety, the ride comfort, the actuator's weight and volume, and the fail-safe performance are taken into account in the proposed optimization method. The simulated results have demonstrated that the presented method is viable and effective. Therefore, this paper offers a new and valuable method for the parameter optimization of automotive active suspension systems as well as rail vehicle.

In this paper, the main conductive and radiative electromagnetic sources are introduced especially for low frequency electromagnetic sources. Systematic and equipment view of electromagnetic field in the normal operation are simulated and analyzed by Maxwell and HFSS based on FEM. This paper provides an overview of the low frequency conductive and radiative EMI and EMC for the high speed railway.

Due to higher specific power density, longer life time and safer operation, super-capacitors (ultra-capacitors or electric double layer capacitors) are being considered in applications of electric vehicles (EVs). This study deals with design of light electric vehicles or even rail vehicle powered by full or partial pure super-capacitors (SCs). The simulation model of the electric vehicles powered by super-capacitors is proposed for predicting the EV performances of acceleration and travelled distance. The design objectives of a case are presented. Moreover, the development of the super-capacitor pack consisting of body-integrated SC modules is discussed. Simulated results demonstrate that the objective of the designed light EV powered by body-integrated super-capacitor pack is achieved.

All-electric intelligent anti-lock braking system (ABS) is a new technology to be developed and applied in the Electric Vehicles(EVs). It could completely replace the traditional mechanical brake as well as hybrid ABS system which is not suitable for electric vehicles. Thus it greatly improves the reaction speed, shorten the braking time, and is more easily to be integrated in the electric vehicle central control unit. It improves the braking performance by optimizing the coefficient of tire adhesion to the ground to in order obtain Maximum braking force. This paper examines an integrated controller of the ABS using Simulink/Stateflow module of Matlab, which consists of a traditional continuous PID and logic limits controller based on finite state machine theory. The two controllers regulate slip ratio and deceleration simultaneously, which can effectively optimize the braking characteristics and further improve the safety of ABS. The ABS parameters including Vehicle velocity, wheel rotational speed, braking displacement, pressure state and slip ratio are investigated to reveal the performance of ABS. This method is simple and suitable for all electric ABS. More importantly, it could solve braking problem under complex road condition and a sudden change of road condition. Quarter-car system is studied for the concept such that the proposed controller can effectively shorten braking distance and duration and also enhance the stability of ABS and has potential to applied to all electric vehicle

The paper presents the investigation of the electromagnetic interference for the traction system in a high speed railway (HSR). Tt is important to study the characteristic of the transformer, converter and power cable for HSR. Traction transformer as the one of the first equipment on board traction system for connection to pantograph, and plays a key role in the electromagnetic investigation. In this paper, the characteristic of the transformer is studied to further provide information for investigation of electromagnetic interference.

This paper investigates characteristics of copper foil conductor for 50 kHz high frequency AC power distribution. Characterization includes parameter estimation, power loss analysis and electro-magnetic field simulation using FEM software. Experiments have been conducted to obtain parameters for the double layer copper foil transmission line. Further, a model for the high frequency AC transmission line is proposed based on the obtained experimental results

This paper selects indexes such as climate inclination rate, anomaly, cumulative anomaly and 5 a moving average to study the climate change of Shiyang River from 1951 to 2005. It discusses the characteristics and laws of the variation of meteorological factors. The results show that in the past 50 years, the overall performance rainfall in the basin is a downward trend. 1962 was a turning point for the reduction of the rainfall in the upstream. But there was a significant increase in the midstream and the downstream since the 1990s. The region has a warmer temperature since 1987, 1997 and 1987 respectively for the upstream, the midstream and the downstream. The temperature surged in particular in 2000. The wind velocity in the upstream significantly increased in the 20th century. That in the midstream registered a fluctuation for every decade. 1984 marked the decrease of wind velocity in the downstream. As for the humidity, the mid-1950s to mid-1960s were the period with the most obvious reduction, while in the late 1990s, the humidity significantly reduced in the midstream. The humidity remained low between 1999 and 2005. With the construction of Shiyang River Protection Project in recent years, the drought has been eased in the midstream and the downstream and the situation is expected to improve gradually.

High frequency power distribution already has a numerous applications in electric vehicle, renewable energy microgird, and telecommunication system. In order to propel high frequency power distribution into larger power grade, an effective ac arc protection scheme is significant for safety and reliability. However, almost all of the studies of arc fault are focused on dc or low frequency ac (LFAC). This paper presents protection scheme and examines electrical characteristics for high frequency arc fault. Meanwhile, high frequency breaker is examined with ZCS feature, and residual current devices (RCD) design is explored for high frequency power distribution as well. First, the location of arc fault detector (AFD) and interrupting devices (ID) is studied from system level; and the single phase arc grounding fault is analyzed for high frequency sinusoidal waveforms. Second, zero-current-switching (ZCS) feature of high frequency breaker is discussed from monitor circuit and breaker circuit. Third, trigger deficiency of high frequency RCD is demonstrated and corresponding solution is examined. Lastly, the simulation results further testify the effectiveness of theoretical analysis.

The history of the centralized and distributed power system is introduced far away from the power system being first built by Edison, which started the first confrontation between ac and dc power system. Although ac power system has dominated for a long century because of easy transmission and some other benefits, dc power system has still gave some good performances and attracted more attention during the past three decades. This paper will discuss the current developing stage of dc distributed power system by the following contents: the basic structure and characteristics; the benefits of the dc distribution system; the development of current techniques adopted in DPS and its analysis of protection and system interaction. In additional, the comparisons between dc and ac distributed power system are presented in detail, and finally, the challenge in future is also summarized.

A method using gel permeation chromatography (GPC) combined with solid-phase extraction (SPE) cleanup followed by gas chromatography–mass spectrometry (GC-MS) has been established for quantitative determination of 69 pesticide residues in coffee. Based on an appraisal of the characteristics of GC-MS, validation experiments were conducted for 69 pesticides. In the method, 2.0 g samples were mixed with 5 ml water and 1 g sodium chloride and extracted with 5 ml of ethyl acetate by blender homogenization, centrifugation, and filtration. Evaporation was conducted and the sample was injected into a 250 mm × 10 mm S-X3 GPC column, with ethyl acetate–n-hexane (1:2 v/v) as the mobile phase at a flow rate of 3 ml/min. The 4–15 min fraction was collected for the SPE cleanup, which was Envi-Carb SPE cartridge coupled with NH2-LC SPE cartridge with acetone–ethyl acetate (2:5 v/v) as the eluted solvent. The eluents were collected and then evaporated to dryness, which was redissolved in 0.5 ml ethyl acetate for GC-MS analysis. For the 69 pesticides determined by GC-MS, the portions collected from GPC were concentrated to 0.5 ml and exchanged with 5 ml n-hexane. In the linear range of each pesticide, the correlation coefficient was R 2 ≥ 0.99. At the low, medium, and high fortification levels of 0.05–1.0 mg/kg, recoveries fell within 60–120%. The relative standard deviation was between 1.3% and 22.3% for all 69 pesticides. The limits of detection for the method were 10 μg/kg to 150 μg/kg, depending on each pesticide.

Two new diterpenoid acids, pinusenocarp ( 1 ) and pinusenoid ( 2 ), were isolated from the pine cone of Pinus koraiensis . All the compounds were characterized on the basis of spectral analysis, viz. 1 H NMR, 13 C NMR, IR, UV, ESI-MS, and elemental analysis.

The essential oil of an endemic species, Pinus armandii, gathered from China, was extracted by hydrodistillation and solid phase micro-extraction (SPME). The oils have been studied by GC and GC-MS. A total of 57 compounds have been identified in the pine cone oil extracted by hydrodistillation, the principal components being alpha-pinene (20.92%) and D-limonene (15.78%), beta-pinene (4.91%) and transpinocarveol (4.76%), while the oil extracted by SPME showed alpha-pinene (41.59%), D-limonene (17.8%), beta-caryophllene (11.02%) and beta-pinene (7.54%) as the principal components. SPME extracts indicated that alpha-pinene and beta-caryophllene were in greater concentration in the head space vapours than in the oil. The antioxidant activity of the oils from P. armandii was evaluated using the DPPH. This is the first report describing the essential oil composition and antioxidant activity of this species.