Position Of Window Research Articles

Controllable cavity linewidth narrowing via spontaneously generated coherence in a four level atomic system

A scheme for cavity linewidth narrowing in a four-level atomic system with spontaneously generated coherence is proposed. The atomic system consists of three closely spaced excited levels, which decay to one common ground level. In such a system, spontaneously generated coherence can result in the appearance of two narrow transparency windows accomplished by steep normal dispersion. When the medium is embedded in a ring cavity, two ultranarrow transmission peaks locating close to the position of the transparency windows can be obtained simultaneously. The cavity linewidth narrowing is owing to the quantum interference between the three decay channels and can be controlled by the frequency splitting of the excited levels, requiring no coupling lasers.

Global exponential stability of memristive neural networks with impulse time window and time-varying delays

A generalized model of memristive neural networks with time-varying delays and impulse time window is considered. By utilizing Lyapunov stability theory, we establish several sufficient conditions for global exponential stability and formulate a relationship between the exponential convergence rate and the impulse parameters including window position, window radius as well as impulse strength. Numerical example is also presented to verify the effectiveness of the theoretical results.

Performance Study of Novel Median Filter for Image De-Noising

Most common method of clearing image noise is through median filtration. Median smoothers discard outliers (or impulses) quite effectively at lower noise densities but, fail to provide adequate smoothing for heavily noised images for the simple reason that, in the conventional median filter approaches, each and every pixel of an image is filtered without concern about healthy pixels. To suppress this deficiency, in this paper, an improved median filter by the name Novel Median Filter (NMF) is proposed to enhance the effectiveness of the median filter at higher noise situations to provide a detail preserving de-noising of digital images. Proposed NMF algorithm is a 3-stage filter; first two stages are dedicated to selective switching median filtration in which noisy pixels are first detected and then the filtering operation is applied to restore their values with a valid (or a noise free) median computed for each 3×3 window position. Third level processing enables to remove any distortions present in the de-noised image. The proposed method, Novel Median Filter (NMF) is evaluated for its effectiveness in detail preserving de-noising capability on a large number of digital grey and color images affected with impulsive and non-impulsive noise in terms of objective and subjective quality measures. To better appraise the efficacy of the proposed method, Novel Median Filter (NMF), MATLAB simulation results in terms of peak signal to noise ratio (PSNR), mean square error (MSE) and the de-noised images are obtained and are compared with those obtained for a standard median filter (SMF) and its few variants and meaningful conclusions are derived. Detail preservation capability of the proposed filter has been demonstrated through experimentation on medical samples. General Terms Image Processing, Nonlinear Filter, Median Filtration.

Predicting building façade structures with multilinear Gaussian graphical models based on few observations

This paper presents a new approach for the prediction of substructures in building façades based on sparse observations. We automatically generate a small number of most likely hypotheses and provide probabilities for each of them. Probability density functions of model parameters which in most cases are non Gaussian and multimodal are learned from training data and approximated by Gaussian mixtures. Relations between model parameters are represented by non-linear constraints. For stochastic reasoning we design and apply a special kind of Bayesian networks which involves both discrete as well as continuous variables, a scenario which often suggests the use of approximate inference which however is infeasible in the face of a huge number of competing model hypotheses. In order to be able to scan huge model spaces avoiding the pitfalls of approximate reasoning and to exploit the potential of both observations and models, we combined Bayesian networks with constraint logic programs. We designed a method which breaks down the problem into a feasible number of subproblems for which exact inference can be applied. We illustrate our approach with building façades and demonstrate that particularly for buildings with strong symmetries number and position of windows can be deduced on the basis of ground plans alone.

풍력발전기 유성기어박스의 진동 변조 특성을 고려한 진동기반 고장 진단 기법 고찰

유성 기어박스의 진동기반 고장진단 기법은 조립 및 제작공차와 하중조건에 의해 결정되는 진동변조특성에 따라 성능을 달리하는 특성을 갖는다. 이 논문에서는 풍력발전기에 장착되어 있는 유성 기어박스의 고장을 효과적으로 진단하기 위해 진동 변조특성을 고려한 고장진단기법을 제안하고자 한다. 리샘플링된 진동신호에 대한 대역 필터링을 사용함으로써 유성기어박스의 진동 변조특성을 규명하고자 하였으며, 진동추출 윈도우함수의 최적위치를 선정하여 활용함으로써 가변적 진동 변조현상에서도 강건한 고장진단을 수행할 수 있도록 하였다. 제안된 고장진단기법의 검증을 위해 2kW 급 풍력발전기 테스트베드가 설계되었으며 기어 치 부분파손이 모사 제작되어 기어박스에 장착되었다.

A Novel Feature Extraction Approach Using Window Function Capturing and QPSO-SVM for Enhancing Electronic Nose Performance.

In this paper, a novel feature extraction approach which can be referred to as moving window function capturing (MWFC) has been proposed to analyze signals of an electronic nose (E-nose) used for detecting types of infectious pathogens in rat wounds. Meanwhile, a quantum-behaved particle swarm optimization (QPSO) algorithm is implemented in conjunction with support vector machine (SVM) for realizing a synchronization optimization of the sensor array and SVM model parameters. The results prove the efficacy of the proposed method for E-nose feature extraction, which can lead to a higher classification accuracy rate compared to other established techniques. Meanwhile it is interesting to note that different classification results can be obtained by changing the types, widths or positions of windows. By selecting the optimum window function for the sensor response, the performance of an E-nose can be enhanced.

The early design stage of a building envelope: Multi-objective search through heating, cooling and lighting energy performance analysis

The majority of decisions in the building design process are taken in the early design stage. This delicate phase presents the greatest opportunity to obtain high performance buildings, but pertinent performance information is needed for designers to be able to deal with multidisciplinary and contrasting objectives. In the present work, an integrative approach for the early stages of building design is proposed to obtain detailed information on energy efficient envelope configurations. By means of genetic algorithms, a multi-objective search was performed with the aim of minimising the energy need for heating, cooling and lighting of a case study. The investigation was carried out for an open space office building by varying number, position, shape and type of windows and the thickness of the masonry walls. The search was performed through an implementation of the NSGA-II algorithm, which was made capable of exchanging information with the EnergyPlus building energy simulation tool. The analyses were conducted both in absence and in presence of an urban context in the climates of Palermo, Torino, Frankfurt and Oslo. In addition, a preliminary analysis on the Pareto front solutions was performed to investigate the statistical variation of the values assumed by the input variables in all the non-dominated solutions. For the analysed case study, results highlighted a small overall Window-to-Wall Ratio (WWR) of the building in all locations. Pareto front solutions were characterised by low WWR values especially in east, west and north exposed facades. The area of the south facing windows was higher compared to the other orientations and characterised by a higher variability.

QoS-Aware Downlink Cooperation for Cell-Edge and Handoff Users

In this paper, we present a quality-of-service (QoS)-aware cooperative downlink scheduling approach for cell-edge and handoff users that offers more reliability and higher effective capacity. The cooperation (handoff) region is defined for active handoff users between two adjacent base stations (BSs) as a function of the user QoS requirements and network load. In addition, the proposed technique inherently acquires intercell interference (ICI) coordination by adjusting the position and size of the cooperation window suitably. Numerical results are presented showing reliability, user QoS and capacity gain performance, and the region for cooperative scheduling in a coded communication scenario. Our analysis indicates that cooperation provides relatively less gain in effective capacity, i.e., up to about 40% with respect to noncooperative handoff, when the QoS requirement is loose. On the other hand, when the QoS requirement is more stringent, the effective capacity gain can increase up to nearly 100%. Additionally, we show that, while for applications with a loose QoS requirement the cooperation window size is small, i.e., nearly 1% of the total area of the BSs participating in cooperation, it increases quite significantly, i.e., up to nearly 25%, for the applications with stringent QoS. Although the outage performance of the proposed approach is poorer than the joint transmission mode of a cooperative multipoint scheme in lightly loaded networks, its effective capacity is significantly higher under varying network traffic load and QoS constraints.

A More Efficient Driving Method for a Spherical Superconducting Rotor

A spherical superconducting rotor is spinning at low temperature of 4.2 K. The electromagnetic field generated by the stator coils engenders driving torque on the superconducting rotor through the window on the window side wall. The driving torque at different rotation position was calculated by using finite element analysis (FEA). The results show that the driving torque is changed periodically when the rotor rotates every one quarter revolution. Based on the calculation results, this paper describes an approach to design higher efficient driving method which reduces the number of the window position patterns from eight to four and adds more driving ranges to increase driving toque. As a results, the value of driving acceleration of the rotor using this improved driving method is increased 4.58% compared with the original method with the driving current of 50 A. The rotation experiment is performed. It will be helpful to improve the acceleration efficiency of the spherical superconducting rotor.

THE POTENTIAL OF SPECULAR REFLECTIONS FOR FAÇADE IMAGE ANALYSIS

Abstract. Several approaches for window detection have been proposed in recent years, which all use the window size, shape or position within the façade as characteristics for the detection. In this paper another property of windows is proposed for their detection: Windows are made of glass, so they tend to specularly reflect sun light, while the surrounding wall diffusely reflects it. To this end, colour values in multiple views are analysed to detect specular reflections. In the experiments, walls often show a high homogeneity of small colour differences, and many windows are clearly visible in the form of colour differences. Nevertheless, it is difficult to segment windows from the façade if there is no prior knowledge about the intensity of the scene’s illumination. Promising results are obtained if the façade lies in the shadow, e.g., of another building or a tree.

Effects of window position in vertical direction on wind driven natural cross ventilation

Natural ventilation system can be considered as one of the zero energy building systems. The comfort of occupants can be achieved if the buildings are designed in favourable and satisfactory ambient conditions. The replacement of any mechanical ventilation system may not only save the electric cost but also contribute to the reduction of the pollutants that are generated during the electricity production stages. The effects of window position in vertical direction on the wind driven natural (WDN) cross ventilation of a full scale building has been investigated using the computational fluid dynamics (CFD) technique after validating the numerical methodology through a satisfactory comparison with an experimental work when RNG κ-ε has been chosen to resolve the turbulence phenomenon. The numerical results have been completely analysed and it is found that ventilation performance is significantly influenced by the vertical window position.

Experimental Study of Automated Car Power Window with "Preset" Position

In today's automotive industry, many features are added in power window system. For instance, Anti Trap System, with immediate reversal of the window in the event of entrapment. Thus, it gives full and reliable protection for children's hand, neck and any obstacles as well. The aim of this paper is to develop an innovative mechanism to enable the user to control the degree of opening power window position with preset position. This experiment involved design and development of PIC program, electronic circuit design and modification on existing power window mechanism. In this experiment, microcontroller PIC16F877A is applied as a medium to achieve the goal. Generally, it will control the degree opening window whenever the user or motorist required, plus anti-entrapment features on window lifting control system. Therefore the user will be able to open and close the power window within the selected position and feel free while maneuvering their vehicles.

Coarse Symbol Timing Synchronization Improved Algorithm for CMMB Mobile TV

There are some multipath and frequency offset in wireless transmission environment, in order to determine the correct starting position of each OFDM symbol, CMMB system must achieve accurate symbol synchronization for send- ing and receiving data, making FFT data transform window position in receiver consistent with IFFT window position in sender. This paper combined the specific frame structure of CMMB standard protocol, analyzed some influences of sym- bol synchronization timing errors in system, discussed the traditional ML (Maximum Likelihood) algorithm, the non data aided algorithm and the reverse conjugate symmetry direct algorithm, and based on the characteristics of these algorithm, proposed a coarse symbol timing synchronization improved algorithm according to CMMB mobile TV, the feasibility of this algorithm is verified in AWGN and multipath channel. Simulation results show that the performance of improved al- gorithm is better, there is no multi-peak of ML algorithm, and don't worry about appearing lat roof phenomenon like no data aided algorithm, and it also eliminates adjacent peak interference of the reverse conjugate symmetry direct algorithm, this algorithm is not limited by SNR, even in bad multipath channel condition, the approximate starting position of sym- bol can be estimated.

Photosynthesis-dependent formation of convoluted plasma membrane domains in Chara internodal cells is independent of chloroplast position.

The characean green alga Chara australis forms complex plasma membrane convolutions called charasomes when exposed to light. Charasomes are involved in local acidification of the surrounding medium which facilitates carbon uptake required for photosynthesis. They have hitherto been only described in the internodal cells and in close contact with the stationary chloroplasts. Here, we show that charasomes are not only present in the internodal cells of the main axis, side branches, and branchlets but that the plasma membranes of chloroplast-containing nodal cells, protonemata, and rhizoids are also able to invaginate into complex domains. Removal of chloroplasts by local irradiation with intense light revealed that charasomes can develop at chloroplast-free “windows” and that the resulting pH banding pattern is independent of chloroplast or window position. Charasomes were not detected along cell walls containing functional plasmodesmata. However, charasomes formed next to a smooth wound wall which was deposited onto the plasmodesmata-containing wall when the neighboring cell was damaged. In contrast, charasomes were rarely found at uneven, bulged wound walls which protrude into the streaming endoplasm and which were induced by ligation or puncturing. The results of this study show that charasome formation, although dependent on photosynthesis, does not require intimate contact with chloroplasts. Our data suggest further that the presence of plasmodesmata inhibits charasome formation and/or that exposure to the outer medium is a prerequisite for charasome formation. Finally, we hypothesize that the absence of charasomes at bulged wound walls is due to the disturbance of uniform laminar mass streaming.Electronic supplementary materialThe online version of this article (doi:10.1007/s00709-014-0742-9) contains supplementary material, which is available to authorized users.

A new signal processing algorithm of pulsed infrared thermography

A new signal processing algorithm combining Markov and principal component analysis (PCA) algorithm, which was named as Markov–PCA algorithm, was proposed to process the pulsed infrared thermography. First, the image sequence was reconstructed using Markov algorithm, then the original complex data dimensionality was reduced using PCA algorithm, which can remove the noise and redundancy of the infrared image sequences, and thus improve the detectability of defects. Results show that both the starting frame position and size of analysis window has an obvious effect on the processing results of Markov–PCA algorithm. And the proposed Markov–PCA algorithm improves the signal to noise ratio (SNR) of feature images more significantly than the commonly used PPT algorithm.

Glyoxal retrieval from the Ozone Monitoring Instrument

Abstract. We present an algorithm for the retrieval of glyoxal from backscattered solar radiation, and apply it to spectra measured by the Ozone Monitoring Instrument (OMI). The algorithm is based on direct spectrum fitting, and adopts a two-step fitting routine to account for liquid water absorption. Previous studies have shown that glyoxal retrieval algorithms are highly sensitive to the position of the spectral fit window. This dependence was systematically tested on real and simulated OMI spectra. We find that a combination of errors resulting from uncertainties in reference cross sections and spectral features associated with the Ring effect are consistent with the fit-window dependence observed in real spectra. This implies an optimal fitting window of 435–461 nm, consistent with previous satellite glyoxal retrievals. The results from the retrieval of simulated spectra also support previous findings that have suggested that glyoxal is sensitive to NO2 cross-section temperature. The retrieval window limits of the liquid water retrieval are also tested. A retrieval window 385–470 nm reduces interference with strong spectral features associated with sand. We show that cross-track dependent offsets (stripes) present in OMI can be corrected using offsets derived from retrieved slant columns over the Sahara, and apply the correction to OMI data. Average glyoxal columns are on average lower than those of previous studies likely owing to the choice of reference sector for offset correction. OMI VCDs (vertical column densities)are lower compared to other satellites over the tropics and Asia during the monsoon season, suggesting that the new retrieval is less sensitive to water vapour abundance. Consequently we do not see significant glyoxal enhancements over tropical oceans. OMI-derived glyoxal-to-formaldehyde ratios over biogenic and anthropogenic source regions are consistent with surface observations.

Water Hazard Detection for Intelligent Vehicle Based on Vision Information

Water hazard is one of the most dangerous obstacles for unmanned vehicle to travel in off-road environment. The vision information for water hazard body includes relatively high brightness, low saturation and smooth texture. In this paper, static image and sequence image are captured by CCD. Color and texture information extracted from image pixels would be utilized to form a feature matrix to train the SVM classifier. While, with the assistance of RBF kernel function, low-dimensional sample space is projected to high-dimensional space. Based on large amount of experiments, RBF kernel function parameters are optimized by using grid method. The optimized RBF kernel function parameters are proved satisfactory when detecting in the static water image. Notice that there is certain relationship between target position and its scale for the adjacent frame. SURF feature detection and matching method can be used to match feature point between adjacent frames in image sequences. The searching window size and position in new frame could be updated in time, which allows to detect water hazard in a relatively small region. Water obstacle tracking experiment with patents proved the satisfactory performance of the SURF method in this paper.

Free-running 4D whole-heart self-navigated golden angle MRI: Initial results.

To test the hypothesis that both coronary anatomy and ventricular function can be assessed simultaneously using a single four-dimensional (4D) acquisition. A free-running 4D whole-heart self-navigated acquisition incorporating a golden angle radial trajectory was implemented and tested in vivo in nine healthy adult human subjects. Coronary magnetic resonance angiography (MRA) datasets with retrospective selection of acquisition window width and position were extracted and quantitatively compared with baseline self-navigated electrocardiography (ECG) -triggered coronary MRA. From the 4D datasets, the left-ventricular end-systolic, end-diastolic volumes (ESV & EDV) and ejection fraction (EF) were computed and compared with values obtained from conventional 2D cine images. The 4D datasets enabled dynamic assessment of the whole heart with isotropic spatial resolution of 1.15 mm(3). Coronary artery image quality was very similar to that of the ECG-triggered baseline scan despite some SNR penalty. A good agreement between 4D and 2D cine imaging was found for EDV, ESV, and EF. The hypothesis that both coronary anatomy and ventricular function can be assessed simultaneously in vivo has been tested positive. Retrospective and flexible acquisition window selection allows to best visualize each coronary segment at its individual time point of quiescence.

A data-mining approach to discover patterns of window opening and closing behavior in offices

Understanding the relationship between occupant behaviors and building energy consumption is one of the most effective ways to bridge the gap between predicted and actual energy consumption in buildings. However effective methodologies to remove the impact of other variables on building energy consumption and isolate the leverage of the human factor precisely are still poorly investigated. Moreover, the effectiveness of statistical and data mining approaches in finding meaningful correlations in data is largely undiscussed in literature. This study develops a framework combining statistical analysis with two data-mining techniques, cluster analysis and association rules mining, to identify valid window operational patterns in measured data. Analyses are performed on a data set with measured indoor and outdoor physical parameters and human interaction with operable windows in 16 offices. Logistic regression was first used to identify factors influencing window opening and closing behavior. Clustering procedures were employed to obtain distinct behavioral patterns, including motivational, opening duration, interactivity and window position patterns. Finally the clustered patterns constituted a base for association rules segmenting the window opening behaviors into two archetypal office user profiles for which different natural ventilation strategies as well as robust building design recommendations that may be appropriate. Moreover, discerned working user profiles represent more accurate input to building energy modeling programs, to investigate the impacts of typical window opening behavior scenarios on energy use, thermal comfort and productivity in office buildings.

Computed tomographic assessment of the causal factors of unsuccessful medialization thyroplasty

Conclusion: The present results demonstrate that a small implant size, undercorrection of the vocal fold, antero-posterior implant malposition, and the use of expanded polytetrafluoroethylene (ePTFE) are the primary factors that cause a poor outcome of medialization thyroplasty (MT). Objectives: To assess the postoperative laryngeal condition using computed tomography (CT) in patients with unilateral vocal fold paralysis who underwent MT alone, and to identify the primary causal factors in terms of the surgical procedures that affect the outcomes of MT. Methods: Twenty-two patients who underwent MT alone were divided into two groups based on either the maximal phonation time or the perceived vocal breathiness. Two laryngologists assessed the postoperative laryngeal CT images during sustained vowel phonation and judged whether there were abnormalities of the arytenoid cartilage position, window position, implant size, and implant position, as well as the degree of correction of the vocal fold. As implant material, a silicone block, ePTFE, and hydroxyapatite had been inserted in 2, 9, and 11 patients, respectively. Comparisons of the prevalence of abnormalities in the abovementioned factors between the different outcomes and between the types of material used for the implant were performed. Results: Twelve patients with a poor outcome and 10 with a good outcome showed 36 and 18 abnormal findings identified by either of the two laryngologists, respectively. In the poor outcome group, a smaller implant size and undercorrection of the vocal fold showed both high kappa values and a significantly higher prevalence than those in the good outcome group (p < 0.001 and p < 0.05), respectively. The comparison between material types demonstrated that the sheet-like material (ePTFE) group exhibited a significantly higher prevalence of undercorrection than the block-like material group (p < 0.05).