Closing the loop in appearance-guided omnidirectional visual odometry by using vocabulary trees

In this paper, we present a method that allows us to recover the trajectory of a vehicle purely from monocular omnidirectional images very accurately. The method uses a combination of appearance-guided structure from motion and loop closing. The appearance-guided monocular structure-from-motion scheme is used for initial motion estimation. Appearance information is used to correct the rotation estimates computed from feature points only. A place recognition scheme is employed for loop detection, which works with a visual word based approach. Loop closing is done by bundle adjustment minimizing the reprojection error of feature matches. The proposed method is successfully demonstrated on videos from an automotive platform. The experiments show that the use of appearance information leads to superior motion estimates compared to a purely feature based approach. And we demonstrate a working loop closing method which eliminates the residual drift errors of the motion estimation.     

Evaluation of negative energy Coulomb (Whittaker) functions

This paper describes a code for evaluating exponentially decaying negative energy Coulomb functions and their first derivatives with respect to the radial variable. The functions, which correspond to Whittaker functions of the second kind, are obtained to high accuracy for a wide range of parameters using recurrence techniques.

Program summary

Title of program: whittaker_wCatalog identifier: ADSZProgram summary URL:http://cpc.cs.qub.ac.uk/summaries/ADSZProgram obtainable from: CPC Program Library, Queen's University of Belfast, N. IrelandComputer: Cray T3E, Sun Ultra-5_10 sparc, Origin2000, Compaq EV67, IBM SP3, Toshiba 460CDTOperating systems under which the program has been tested: Windows NT4, Redhat Linux, SunOS 5.8Programming language used: Fortran 95Memory required to run with typical data: 500 KBNumber of bytes in distributed program, including test data, etc.: 39728Number of lines in distributed program, including test data, etc.: 2900Distribution format: tar gzip fileNature of physical problem: The closed-channel components of the asymptotic radial wave function corresponding to electron or positron scattering by atomic or molecular ions may be expressed in terms of negative energy Coulomb functions. The scattering observables are obtained from S or T matrices which in turn are obtained by matching the radial and asymptotic wavefunctions at a finite radial point. Recent large scale scattering calculations have required accurate values of the Coulomb functions at smaller ρ values and larger negative η values than previous work. The present program is designed to extend the range of parameters for which the function may be calculated.Method of solution: Recurrence relations, power series expansion, numerical quadrature.Restrictions on the complexity of the problem: The program has been tested for the parameter ranges: 0<ρ?1000, |η|?120 and 0?l?100. These ranges may, with appropriate scaling to avoid underflow and overflow, be extended.References: A. Sunderland, C.J. Noble, P.G. Burke, V.M. Burke, Comp. Phys. Commun. 145 (2002) 311.     

Analysis of large aeolian (wind-blown) bedforms using the Shuttle Radar Topography Mission (SRTM) digital elevation data

Dry land areas cover large parts of the land masses of Earth. Of these a large portion is mantled by aeolian (wind-blown) deposits and subjected to aeolian process, i.e., the transport of sand or dust by wind. One of the most prominent morphologies created by wind-driven deposits are dunes and in their larger form draas or mega dunes. These mega dunes tend to be widely spaced; very large; often forming a base on which smaller dunes form, producing a compound dune pattern.In February 2000 the Shuttle Radar Topography Mission, onboard the space shuttle Endeavour flew an interferometric radar system whose objective was to create a DEM of nearly all Earth land masses. In this paper DEM data from the C-band 90 m data set and the X-band 30 m data set were used to map and characterize the height and spacing of the large sand seas (Ergs) on Earth. Only the larger forms of dunes could be mapped reliably. The dune spacing and heights extracted from the SRTM DEMs tended to be in overall agreement with those reported in the literature. In a comparison between the X-band and the C-band data it was found that the X-band data are more sensitive to the smaller scale undulations on the compound dunes and better revealed the full height of the dunes.     

Using WorldView-2 bands and indices to predict bronze bug (Thaumastocoris peregrinus) damage in plantation forests

Thaumastocoris peregrinus is an insect that causes significant damage to Eucalyptus plantations internationally. This bug inhibits the photosynthetic ability of the tree, resulting in stunted growth and even death of severely infested trees. This study uses high spatial resolution satellite imagery (WorldView-2 sensor data), with unique band settings for the prediction of T. peregrinus damage in plantation forests using partial least squares (PLS) regression. The PLS models developed from the WorldView-2 sensor bands and indices were inverted to map the severity of the damage caused by the pest. The WorldView-2 sensor bands and indices predicted T. peregrinus damage with an R ² value of 0.65 and a root mean square error (RMSE) of 3.62% on an independent test data set. The red-edge and near-infrared bands of the WorldView-2 sensor and pigment-specific indices and red-edge indices were identified as significant bands by variable importance scores for the prediction of T. peregrinus damage. This study demonstrates the potential of WorldView-2 sensor data in successfully predicting T. peregrinus damage using PLS regression and identifies important spectral variables for the prediction of forest damage in plantation forests.     

Analysis of JERS-1 (Fuyo-1) SAR data for vegetation discrimination in northwestern Brazil using the semivariogram textural classifier (STC)

Classification of JERS-1 (Fuyo-1) SAR data from the northwestern portion of Brazil was performed using the semivariogram textural classifier (STC). This is a deterministic, supervised classifier which provides the option of combining textural and radiometric information. Textural information is expressed by the semivariogram function; radiometric information is conveyed by the mean digital number (DN) value. Results have shown that STC allows vegetation units and water bodies to be discriminated and tentatively mapped, suggesting that this is a promising approach for environmental monitoring of rainforest regions using SAR data.     

Reducing the negative effects of sales promotions in supply chains using genetic algorithms

This paper considers the detrimental effect of promotions on the supply chain (SC), one of the main causes of the bullwhip effect. A genetic algorithm (GA) is proposed to reduce these negative effects. In order to validate the GA, it is used to determine the optimal ordering policy in an online version of the MIT beer distribution game. Subsequently, the GA is applied in a number of experiments involving deterministic and random demand and lead times combined with sales promotions. It is shown how GAs can be used to dampen the impact of the bullwhip effect and can be used to assist supply managers in predicting reorder quantities along the supply chain.     

Analysis of ambulatory colonic motility records using a BBC(B) microcomputer

Colonic motility has been monitored using a pressure sensitive radiotelemetry capsule and portable receiving equipment in ambulatory subjects. Data from 24 hour recordings were stored on miniature cassette tape and subsequently replayed on a standard unit interfaced to a BBC B microcomputer. The computer program provides a semi-automated analysis and calculates a motility index allowing objective quantitative measurements to be made which can be rapidly and accurately presented. This method of analysis has been shown to be resistant to interobserver bias and in comparison with the analysis of analogue paper traces shown to be reproducible.     

使用基于SVM的否定概率和法的图像标注

在基于内容的图像检索中,建立图像底层视觉特征与高层语义的联系是个难题.对此提出了一种为图像提供语义标签的标注方法.先建立小规模图像库为训练集,库中每个图像标有单一的语义标签,再利用其底层特征,以SVM为子分类器,“否定概率和”法为合成方法构建基于成对耦合方式（PWC）的多类分类器,并对未标注的图像进行分类,结果以N维标注向量表示,实验表明,与一对多方式（OPC）的多类分类器及使用概率和法的PWC相比,“否定概率和”法性能更好.     

Analysis of the spatial distribution of net primary productivity across Corsica (France) using the echelon approach

One of the main directions of research for ecologists studying the Earth as a global system is the search for quantitative methods for mapping and monitoring broad-scale patterns of net primary productivity (NPP). While all monitoring activities have a spatial context to a varying degree, the monitoring of NPP patterns requires an objective, criterion-based method for characterizing the spatial distribution of areas that are high or low in NPP relative to their surroundings. In this Letter, we apply a topology-based methodology called the 'echelon approach' to characterize the spatial structure of the remotely sensed NPP spatial structure across the island of Corsica (France) using a coarse-grained grid consisting of annually integrated Normalized Difference Vegetation Index (NDVI) values. Results show that the echelon approach provides a new perspective to objectively characterize the structural complexity of a tessellated surface variable for environmental monitoring purposes.     

Analysis of optical cavities in the presence of negative refractive index materials

We introduce the ABCD matrix for negative refractive materials (NRM) and investigate the optical properties of (NRM), according to the matrix method. The propagation of a Gaussian beam inside a NRM slab is also investigated. It is demonstrated that for n = −1, the waist of the transmitted Gaussian beam is the same as the waist of incident beam, which leads in the perfect lens. Further the optical resonator in the presence of NRM is studied and the stable condition is introduced. The article is published in the original.     

Purification of a droplet using negative dielectrophoresis traps in digital microfluidics

The development of techniques for manipulating particles and integrating them into the digital microfluidic (DMF) devices has been the subject of several studies in recent years. This paper presents a dielectrophoretic-based method that uses triangular traps to manipulate particles and purify a droplet in DMF platforms. Numerical and experimental studies are conducted to show the effectiveness of the proposed trap geometry which is also compatible with the other operators in the DMF platform. The triangular trap geometry is used to move the polystyrene particles to one side of the trap using negative dielectrophoresis (nDEP). The droplet is then split into two smaller droplets with very low and high concentrations of particles using the electrowetting on dielectric technique. The average velocity of the particles (as they move along the trap) as a function of the vertex angle of the triangular trap and the gap between the top and bottom plate is examined. It is observed that the vertex angle of the trap plays more important role on the motion of the particles than the gap. Thus, to enhance the motion of the particles and minimize the effect of splitting on the purification process, the vertex angle and the slope of the side arms of the triangular trap are modified based on the results of the numerical model simulating the dielectrophoretic force on the particle. The enhanced geometry is fabricated and tested experimentally to show the effectiveness and ease-of-use of the proposed technique in purifying (or concentrating) a droplet in DMF. The results show that using the proposed nDEP electrode geometry purification (or concentration) can be performed with the efficiency of 90 %.     

Verification of the Multistream Protocol (MSP) using COSPAN

This article presents the verification of several key properties of the MultiStream Protocol (MSP), a new feature-rich transport protocol. The verification was performed using the Coordination Specification Analyzer (COSPAN). The verification of this protocol presented many challenges due to the complexity of the protocol and its implementation architecture     

Analysis of vegetation recovery surrounding a restored wetland using the normalized difference infrared index (NDII) and normalized difference vegetation index (NDVI)

Watershed restoration efforts seek to rejuvenate vegetation, biological diversity, and land productivity at Cienega San Bernardino, an important wetland in southeastern Arizona and northern Sonora, Mexico. Rock detention and earthen berm structures were built on the Cienega San Bernardino over the course of four decades, beginning in 1984 and continuing to the present. Previous research findings show that restoration supports and even increases vegetation health despite ongoing drought conditions in this arid watershed. However, the extent of restoration impacts is still unknown despite qualitative observations of improvement in surrounding vegetation amount and vigor. We analyzed spatial and temporal trends in vegetation greenness and soil moisture by applying the normalized difference vegetation index (NDVI) and normalized difference infrared index (NDII) to one dry summer season Landsat path/row from 1984 to 2016. The study area was divided into zones and spectral data for each zone was analyzed and compared with precipitation record using statistical measures including linear regression, Mann–Kendall test, and linear correlation. NDVI and NDII performed differently due to the presence of continued grazing and the effects of grazing on canopy cover; NDVI was better able to track changes in vegetation in areas without grazing while NDII was better at tracking changes in areas with continued grazing. Restoration impacts display higher greenness and vegetation water content levels, greater increases in greenness and water content through time, and a decoupling of vegetation greenness and water content from spring precipitation when compared to control sites in nearby tributary and upland areas. Our results confirm the potential of erosion control structures to affect areas up to 5 km downstream of restoration sites over time and to affect 1 km upstream of the sites.     

A scheduling strategy in the manufacture of printed circuit boards (PCBs) using Surface Mount Technology (SMT)

A scheduling strategy for a company that manufacturers printed circuit boards is presented. This firm makes on an average over 70 different ceramic boards in a month to customer specification using Surface Mount Technology. These hybrid circuit boards are made to order. Therefore, the objective in the scheduling strategy is to minimize the number of tardy jobs and minimize the makespan.     

ANN-based 3D part search with different levels of detail (LOD) in negative feature decomposition

Duplicate designs consume a large amount of enterprise resources during product development. Automatic search for similar parts is an effective solution for design reuse. Previous studies have only concerned similarity assessment based on complete 3D models, which may produce unsatisfactory result in practice. This paper proposes a novel scheme which incorporates the concept of LOD (levels of detail) into 3D part search. The scheme allows searching with different LOD variants created from the negative feature tree (NFT) of a solid model. A back-propagation artificial neural network is established to combine the D2-based similarity evaluation at each level of NFT. A human cognition model (HCM) is obtained by training the network with a set of data generated from a human experiment of similarity ranking. Search examples based on HCM show that the proposed scheme provides a practical tool for retrieval of similar part models.     

Cognitive and psychological predictors of the negative outcomes associated with playing MMOGs (massively multiplayer online games)

This study integrates research on problematic Internet use to explore the cognitive and psychological predictors of negative consequences associated with playing massively multiplayer online games (MMOGs). Participants recruited from online discussion boards completed self-report measures on their online game-related cognitions and psychological condition, social skills, psychological well-being, and negative life outcomes associated with game playing. The results demonstrated the important roles that psychological dependency and deficient self-regulation play in negative consequences associated with online gaming. The results also indicated that psychological dependency on MMOGs was predicted by cognitive preference for a virtual life—a construct that is negatively related to social control skills.     

波长调制光谱（WMS）谐波信号分析与仿真

概述了采用波长调制光谱（WMS）技术进行痕量气体浓度测量的基本原理,对强度调制和频率调制结合的信号（IM-FM）模型进行了理论描述,对谐波信号随归一化调制振幅变化和信号对称性进行了重点分析以说明强度调制的影响。利用MATLAB软件,对甲烷在6046.9647cm-1处的吸收线进行仿真,以验证理论分析的正确性。     

Glacial cover mapping (1987-1996) of the Cordillera Blanca (Peru) using satellite imagery

Multitemporal glacier area mapping is a key element in accurately determining fresh water reserves, as well as providing an indicator of climate change.In Peru, the first glacier inventory was based on visual interpretation of aerial photos, requiring several years of effort. Landsat Thematic Mapper satellite imagery, on the other hand, provides an increasingly employed alternative for the monitoring of changes in glacier area and in other glaciological parameters.By means of Normalized Difference Snow Index (NDSI) computations on TM images, an estimate of the glacierized area in Cordillera Blanca (Peru) was carried out for 1987 (643±63 km²) and 1996 (600±61 km²). Compared to an estimate of 721 km² in 1970, it can be concluded that the glacier area has retreated in this massif by more than 15% in 25 years.     

聚羟基脂肪酸酯(PHAs)不同比例组成的定量分析

利用傅里叶变换红外光谱法（ＦＴＩＲ）和计算机辅助解析法对于聚羟基脂肪酸脂（ＰＨＡｓ）共聚物中不同比例组成进行了定量的研究。通过去卷积和曲线拟合,得到了羟基丁酸与羟基己酸共聚物「Ｐ（ＨＢ－ｃｏ－ｘＨＨ）」中,单在己酸（ＨＨ）的含量,结果表明,此含量与已知的加入量吻合,则可用此方法对于未知呈的共聚物进行预测。