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Flame recognition based on video image is an important method for fire detection. In order to improve the accuracy of flame recognition and the applicability of complex scenes, the flame color model was improved on the basis of RGB and HSI color space models, and the flame color model with adaptive threshold values was proposed for different background spaces, which could be adapted to the extraction of suspected flame areas in different environments. The flame has motion characteristics during combustion. ViBe(Visual Background Extractor) algorithm can quickly identify moving objects, but it cannot detect moving objects quickly when the first frame of the image contains moving objects. In this paper, an improved ViBe algorithm is proposed. Frame difference method is used to build the background model through the difference of the first two frames. The method of combining three frame difference and VIBE algorithm can reduce the influence of noise. The hole in the target graph is solved through image morphology processing. Experiments show that the algorithm can identify the flame region accurately and quickly.

A bipolar triangular wave current pulse inverter for shallow TEM survey is described. It can generate a peak current more than 10A and the PRF of the bipolar current pulse is between 1Hz and 10kHz. The proposed inverter contains a high voltage source circuit for the rising edge and a Zener diodes circuit with constant voltage clamping for the falling edge. Measurement results are presented, which show the high quality triangular wave current pulse with linear rising edge and rapidly turnoff falling edge.

As a new learning framework, Multi-Instance learning is labeled recently and has successfully found application in vision classification. A novel Multi-instance bag generating method is presented in this paper on basis of Gaussian Mixed Model. The generated GMM model composes not only color but also the locally stable unchangeable components. It is frequently named as MI bag by researchers. Besides, another method called Agglomerative Information Bottleneck clustering is applied to replace the MIL problem with the help of single-instance learning ones. Meanwhile, single-instance classifiers are employed for classification. Finally, ensemble learning is adopted to strengthen classifiers’ generalization ability of RBM (Restricted Boltzmann Machine) as the base classifier. On the basis of large-scale datasets, this method is tested and the corresponding result shows that our method provides high accuracy and good performance for image annotation, feature matching and example-based objectclassification.

According to the problem that in what scope can subway engineering influence the prices of peripheral real estate, this paper summarized the problems in similar research presented, and put forward that the influence is taken by factors of person, and the influence can be studied by the probability of choosing subway. Different from other similar research, based on the analysis of the factors which can influence people choose subway or not, this paper constructs the logistic model. Testing the model by using the research data of Beijing, this paper get the list on which we know in what scope can subway engineering influence the surrounding real estate prices by adjusting the logistic model variable X4. Finally, discussed the model applicability and in different cities to application.

Faced the seriously unreasonable value distribution of residential engineering, how to study on the industrial value chain of residential engineering systematically and how to guide the reasonable value distribution effectively has become very urgent. The evaluation index system of value distribution is constructed. The value distribution calculation model is built, which is named Entropy-Fuzzy comprehensive evaluation model by using entropy and fuzzy comprehensive evaluation method. Furthermore, according to the market research data, the reasonable value distribution is discussed in order to provide a reference of comparative study on the value distribution of residential engineering for each city. The result implicates that the order of the reasonable value distribution is the construction value, the marketing value, the planning and design value, the investment analysis value, the service value, and the fund value, the land value.

This paper uses finite element method to obtain the three-dimensional temperature field of laser-induced transient thermal grating (TTG) for two-layered structure of diamond film on ZnSe substrate. The numerical results indicate that unique two-times heating process is gradually experienced in the area between two adjacent grating stripes. However, there is a little change for the temperature field along the depth direction for the diamond film due to its great thermal conductivity. It further finds that the thickness of the diamond film has a significant influence on the temperature field in diamond/ZnSe system. The results are useful for the application of laser-induced TTG technique in film/substrate system.

This paper presents a video-tracking system composed of two cameras. One camera acts for producing an in-focus image of the object and the other one ensures an extended vision field under monitoring. Such a system scheme can achieve an excellent tracking performance, especially under various unfavorable conditions. A projection algorithm is used for the calculation of the displacement of the moving object. As a result, the computational cost is reduced greatly. In order that the tracking action of the system persists even if the object is sheltered or its acceleration is larger than a specified threshold, a dedicated tracking algorithm on the basis of the α-β filtering is designed. Experiments show that the algorithm is efficient and the system works very well.

We have developed a high-resolution penetrating radar to measure glacial ice thickness. With an operating frequency band of 100–150 MHz, this radar can provide a range resolution of less than 2 m in ice. The radar is designed to measure ice sheet thickness up to 3000 m. The system uses pulse compression and coherent integration techniques to obtain a high processing gain. A high-speed Direct Digital Synthesizer (DDS) is used to generate a chirp with a very short pulse width to obtain a small blind zone. A dual-channel receiver with two different gains is used to obtain a very high dynamic range. In this paper, we provide a brief system description, and some experimental results which prove that the radar system is effective for ice thickness measurement.

The Ground Penetrating Radar (GPR) is a technique that utilizes the radio waves to map structure and features of objects buried in the ground. In this paper, we design a host control system (HCS) of GPR based on a maximum length binary sequence, abbreviation M-sequence, to implement the detecting of deep level objects on earth, and we realize the design of software and hardware for the HCS of GPR. Using single field-programmable logic array (FPGA) as the core, the HCS improves the flexibility of the system, reducing power consumption. Experiments show that the HCS can complete the tasks of generating transmitting, echo signals sampling, data transmission, controlling the work modes with parameters, meeting the design specifications requirements.

Since 2003, the Chinese government has strengthened controls on the real estate market. However, the academic circle has controversy on the policy effectiveness of real estate regulation. This paper adopts the data envelopment analysis (DEA) model to carry out system analysis to the effects of the real estate regulation policy during 2003–2008, and uses the statistical data to verify the conclusions. The results show that the real estate regulation of 2008 and 2006 was effective while other years were weak effective, the worst year of regulation performance was in 2007. The real estate regulation in this period is neither with no effectiveness as some public opinion in the early time, nor that with great success as claimed by some officials. These conclusions are helpful for using the instruments of real estate regulation policy in the future.

Risk management for general contract project is well experienced task, which must deal with much more qualitative factors that is easy influenced by individuals, so that the objectivity cannot be guaranteed. A novel method is proposed in order to overcome the shortcomings, which use the clustering analysis to evaluate bidding risk. An optimal objective function based clustering model is designed to explore the data collected from completed projects. Mixed scale is employed in clustering to handle qualitative and quantitative data without converting respectively. So the individual prejudice is eliminated from risk evaluate results and bidding decision making is supported. Moreover the quantitative results of risk estimate is good base for project cost reckoning quickly. An instance is carried out verifying proposed method validity.

Pulse decomposition has been proven to be efficient to analyze complicated signals and it is introduced into the photo-acoustic and thermo-acoustic tomography to eliminate reconstruction distortions caused by negative lobes. During image reconstruction, negative lobes bring errors in the estimation of acoustic pulse amplitude, which is closely related to the distribution of absorption coefficient. The negative lobe error degrades imaging quality seriously in limited-view conditions because it cannot be offset so well as in full-view conditions. Therefore, a pulse decomposition formula is provided with detailed deduction to eliminate the negative lobe error and is incorporated into the popular delay-and-sum method for better reconstructing the image without additional complicated computation. Numerical experiments show that the pulse decomposition improves the image quality obviously in the limited-view conditions, such as separating adjacent absorbers, discovering a small absorber despite disturbance from a big absorber nearby, etc.

Photoacoustic imaging is a hybrid imaging technique based on the photoacoustic effect. As a non-invasive and non-ionizing modality, photoacoustic imaging takes the both merits of the conventional acoustic imaging and optical imaging. Firstly, the contrast of photoacoustic imaging primarily depends on the optical absorption. The unique optical spectra of atoms and molecules makes optical methods to be a widely used modality to probe the molecular and chemical information of biological tissue. Therefore, photoacoustic imaging has its inherent advantage in high-contrast functional and physiological imaging of biological tissue, as well as the optical imaging method. Secondly, photoacoustic imaging has the high spatial resolution in deep tissue in comparison with the pure optical imaging method. Since the strongly optical scattering in biological tissue, pure optical imaging method is difficult to obtain the high-resolution image in the tissue deeper than ～1 mm. Whereas, acoustic wave suffers much less from scattering than optical wave, the acoustic scattering coefficient is about 2-3 orders of magnitude less than the optical scattering coefficient. Photoacoustic imaging can achieve a fine resolution in deep tissue, which equivalent to 1/200 of the imaging depth. Thirdly, non-ionizing radiation used for photoacoustic imaging is much safer than X-ray. Moreover, the low-temperature rises make photoacoustic imaging be safely used in live tissue. A laser-induced temperature rise of 1 mK yields an initial pressure of ～800 Pa in soft tissue. Such a sound pressure level has reached the sensitivities of typical ultrasonic transducers. Fourthly, photoacoustic imaging has the ability of extracting multiple contrasts, including biochemical parameter, biomechanical parameter, blood velocity distribution, tissue temperature, and microstructure information. Photoacoustic imaging can capture more specific and reliable information about the tissue structure, function, metabolism, molecule, and gene. As a result, photoacoustic imaging has become one of the fastest growing biomedical imaging techniques in the past decade.#br#In this review, we will explain photoacoustic effect and the principle of photoacoustic imaging. Then, we introduce the two classical photoacoustic imaging schemes, including photoacoustic tomography and photoacoustic microscopy. Their main specifications, such as resolution, are also preflents. We review the ability of photoacoustic imaging in extracting multiple contrasts and discuss their biomedicine applications. In addition, we also introduce the remarkable breakthroughs in super-resolution photoacoustic imaging. Finally, we look the further development and the limitations of photoacoustic imaging.

The electric field enhancement properties of an active gold nanoshell with gain material inside have been investigated by using Mie theory. As the gain coefficient of the inner core increases to a critical value, a super-resonance appears in the active gold nanoshell, and enormous enhancements of the electric fields can be found near the surface of the particle. With increasing shell thickness, the critical value of the gain coefficient for the super-resonance of the active gold nanoshell first decreases and then increases, and the corresponding surface enhanced Raman scattering (SERS) enhancement factor (G factor) also first increases and then decreases. The optimized active gold nanoshell can be obtained with an extremely high SERS G factor of the order of 1019–1020. Such an optimized active gold nanoshell possesses a high-efficiency SERS effect and may be useful for single-molecule detection.

In this paper, a modified nonlinear chirp scaling (MNLCS) algorithm for air-borne ice radar data is proposed. The spatial geometry based on the two-layer medium is analyzed for the studying of MNLCS. The algorithm can compensate the refraction effects and the propagation velocity changes in different mediums automatically, and can improve the focusing feature of the scatters. According to the model of echo signal, the phase compensation factors and realized steps of the algorithm are given. Numerical experiments are executed. The experimental results show the effectiveness of the proposed algorithm.

In this paper, we investigate the effects of the relative size and arrangement of a virtual transducer on the image quality in limited-view photoacoustic tomography. A virtual transducer refers to the acoustic scatterers used to reflect photoacoustic waves and improve the images reconstructed from incomplete PA signal. Size and spatial arrangement determine the performance of the virtual transducer. In this study, the scatterers utilized as virtual transducers are arranged in different manners, such as on a straight line or on an arc line. We find that virtual transducers with a big distributing angle can provide more significant image improvement than with a small distributing angle, which is similar to the true transducers. We also change the size of virtual transducer and study its influence on image quality. It is found that the bigger scatterers provide better images than the smaller ones. Especially, when the size of scatterers is reduced to the wavelength of photoacoustic wave, the image quality observably decreases, owing to the strong diffraction effect. Thus, it is suggested that the size of the acoustical scatterers should be much larger than the photoacoustic wavelength. The simulations are conducted, and the results could be helpful for the application and further study of virtual transducer theory in limited-view photoacoustic tomography.

We investigate the effect of a metallic electrode on the ability for poly[2-methoxy-5-(2'-ethylhexyloxy)-1,4-phenylene vinylene] (MEH-PPV) film to undergo amplified spontaneous emission (ASE). The threshold of the device with Ag cladding is about 10 times greater than that of a metal-free device, but metal such as Al completely shuts off ASE. The ASE recurs when a thin spacer layer, such as a few nanometers of SiO2, is introduced between the MEH-PPV film and the Al cladding. Compared with the Cu or Al electrode, the Ag cladding is most suited to serve as an electrode with its low optical loss due to its high work-function and reflectivity.

The local electric field components of the elliptical gold nanotube are calculated based on the finite difference time domain (FDTD) method. It is find that when the wavelength of the incident light is just at a resonant wavelength, the local field enhancement of the gold nanotube reaches a maximum. The increase of the semiminor axis of the ellipse makes the distribution of the local field change from a distribution that is high in both sides and low in the middle part of the nanotube into a distribution that is uniform around the tube. With the increase of the angle between the incident polarization and the semimajor axis, the local electric field components increase rapidly. The increases of the dielectric constants for both the core and the embedding medium cause the local field around the nanotube to decrease.

The optical properties and electronic structure of marokite-type CaMn2O4 are investigated by using UV-vis spectroscopy and the local-spin-density approximation plus the Hubbard-U (LSDA+U) method. Four absorption bands are observed at 638 nm (1.94 eV), 512 nm (2.42 eV), 377 nm (3.29 eV) and 248nm (5.00eV), which are ascribed to the charge transfer transitions O2p↑→Mn3d eg↑, O2p↓→Mn3d eg↑, Mn3d eg↑→Mn3d t2g↓ and O2p↑→Mn3d t2g↓, respectively. We further use CaMn2O4 as a photocatalyst to decompose an azo-dye acid orange 7 (AO7) under irradiation of visible light and find that the decomposition ratio of AO7 reaches 15.9% under the irradiation of visible light for two hours.

In this work, performance enhancements of amplified spontaneous emission (ASE) from poly[2-methoxy-5-(2'-ethyl-hexyloxy)-1, 4-phenylene vinylene] (MEH-PPV) have been achieved via solvent vapour treatment. Correlations between the morphology of the film and the optical performance of polymer-based ASE are investigated. The active layers are characterised by atomic force microscopy and optical absorption. The results show that the solvent-vapour treatment can induce the MEH-PPV self-organisation into an ordered structure with a smooth surface, leading to enhanced optical gain. Thus the solvent-vapour treatment is a good method for improving the optical properties of the MEH-PPV.

The Ag-doping effects on TiO2 nanoparticles are investigated by means of x-ray diffraction (XRD) and Raman scattering spectroscopy. XRD and Raman results indicate that Ag-doping stabilizes the rutile phase in TiO2. We find an Ag-doping induced lattice expansion in both anatase and rutile phases. The Ag-doping has different influences on the lattice distortion for anatase and rutile phases, that is, the c/a-value for the anatase phase decreases with 0.5% Ag-doping and then increases with 1% Ag-doping while that for the rutile phase shows a gradual increase with increasing Ag-doping. We have ascribed the different variations of lattice distortion due to Ag-doping to the change of interfacial interaction between the anatase and rutile phases induced by different Ag con centrations.

A novel composite waveguide is proposed to improve the directional emission of phononic crystal waveguide by introducing a point defect array. The finite element simulations indicate that the point defects attached to the output surface of phononic crystal waveguide produce resonant modes, which act as secondary radiation sources. The interferences of sound wave radiated from these radiation sources and waveguide can enhance the normal radiation intensity by 161.21% and reduce the half-power angular width by 85.35%. In addition, when the number of the point defects is large enough, the directivity approaches a steady value. The investigation provides a new method to improve the directional emission of phononic crystal waveguide.

In the process of fabrication of polymer photovoltaic (PV) devices, poly (3, 4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT:PSS) thin film, acting as an anode buffer layer, is spin-coated under the action of an electric field. The PV devices with a PEDOT:PSS layer spin-coated under the action of a static electric field exhibit improved short-circuit current density (Jsc) and power conversion efficiency (PCE). The investigation of morphology shows that the appropriate intensity of the electric field can increase the roughness of the surface of the PEDOT:PSS layer, which results in improved contact between the anode and hole transport layer and thus enhances the Jsc of the devices. Chemical analysis is also provided by x-ray photoelectron spectroscopy (XPS) spectra.

In this study, numerical experiments are carried out to quantitatively investigate the effects of limited-view scanning on the resolution of photoacoustic tomography. An empirical formula is provided to approach our numerical results.The results of the study are helpful for the design of scanning trajectory and the evaluation of reconstruction.

Since welded seams of pressure vessels are generally rather narrow, for the longitudinal weld the general formulas based on the technique of stereoscopic radiography can be directiy applied for determining the location of the point defect. But for circular weld, owing to that films during photo-taking are curved ones whereas they are to be made flate during observation and measurement on a 3–dimensional detector, so some further equations must be established to satisfy the relations between the stereographic curevd films and the assumed flate films and thereby to determine the spatial point location for the defects in pressure vessels. With these epuations and by surveying of the point image of defects, coordinates ZA, XA and YA can be determined and hence the real position of defects in vessels. Ascertainment of point location of defects is the background for the dimensional location and quantitative analysis of defects. Once ascertained, such geometric parameters as depth of defects, height of defects themselves, their orientation, size and spacing can all be determined consequently.

We present a systematic study on the extraordinary resonant scattering in imperfect acoustic cloak by means of acoustic scattering theory. Analysis results demonstrate that the resonances are inevitable due to the perturbation to the ideal cloak, and specific resonance modes are excited by specific order waves. The strength of resonance is determined by the magnitude of perturbation and each order wave's sensitivity to the perturbation. Further studies reveal the unique scattering characters of different resonance modes.

The performance of TiO2 nanotubes in bulk heterojunction of poly (2-methoxy-5-(2'-ethylhexyloxy)-1, 4-phenylenevinylene) (MEH-PPV)/TiO2 nanotubes is investigated. The transport properties are studied by using the time-of-fight technique (TOF). The carrier mobilities of both holes and electrons are not improved for the MEH-PPV:TiO2 composites compared with the pristine MEH-PPV. However, photoluminescence under the influence of the electric field indicates that the dissociation of excitons in the MEH-PPV:TiO2 composites, which is facilitated by photoinduced charge transfer, only requires a smaller electric field.

The travelling properties of laser-generated surface acoustic wave with broad bandwidth, which propagated on a sample with surface defects, have been investigated in theory. The numerical results of theoretical models with different defects indicate that the surface defects worked as low-pass filter for the travelling surface acoustic waves. The cut-off frequency of low-pass filter is linearly related to the depth of the defect, and decreased against the increasing depth of the defect. The amplitude of the travelling surface acoustic wave is seriously attenuated with increasing width of surface defect. The numerical results provide a theoretical basis for quantitative detection of the surface defects.

Aimed at the deficiency of the traditional PERT method in the risk assessment for engineering project progress, this paper has improved PERT method, so as to make it more suitable for engineering project risk assessment of spliced network. Firstly, in calculating project activity duration, it adopts response management theory and introduces double-buffering zone, so that the calculated project activity duration is more approximate to the realistic one. Meanwhile, the paper takes advantage of equivalent-weight probability method to revise the main path, so that the calculated project duration is more suitable for the realistic situation. Finally, the paper has further demonstrated the feasibility of the method by an engineering project case study.

This paper analyzes risks of the engineering project construction-agent system from other risks of other engineering projects, applies entropy measurement method to assess risks of a project of construction-agent system and analyses the result. The result shows that entropy measurement provides a simple and more objective method of analysis for risk of the engineering project management mode of construction-agent system.