New Measurements and Corner-Guidance for Curve Matching with Probabilistic Relaxation

Reliable curve matching is a difficult yet important problem in many vision-based applications including image-based modeling. We describe in this paper two aspects of our research in this area: a new algorithm for curve matching (including lines) within a probabilistic relaxation framework, and an approach of incorporating previously matched points/corners to guide curve matching. We propose similarity-invariant unary and binary measurements suitable for curves, and introduce an additional measurement to model the uncertainty of the binary measurements. The uncertainty measure is proven to be very important in computing the matching support from neighboring matches. We also show how to use a set of previously matched points/corners to guide the curve matching. The role of the corner guidance is explicitly modeled by a set of unary measurements and a similarity function under the same relaxation framework. Preprocessing techniques contributing to the success of our curve matching techniques are also developed and discussed. Experiments with complex real scenes show that the rate of correct matching is higher than 98%.     

有限域上椭圆曲线 Jacobian 群求阶算法综述与比较

关于椭圆曲线密码体制（ECC）的研究,如今无论是 ECC 理论还是 ECC 的标准化、产业化都趋于成熟。在 ECC 的设计中,安全椭圆曲线的选取是 ECC 实现的基石,也是其安全性的重要保证。目前,随机选取法是最好的安全椭圆曲线选取方法,其核心思想是对随机生成的椭圆曲线计算其 Jacobian 群的阶。文章主要介绍了几类经典的计算椭圆曲线 Jacobian群阶的算法：Schoof 算法、SEA 算法、Satoh 算法、AGM 算法。在详细介绍 Schoof 算法的基础上,提出了其基于离散对数问题的改进算法：袋鼠算法和大步小步（BSGS）算法的改进方法,并用实验结果说明加速后的算法得到了提升。针对 SEA 算法,文章也提出了其 BSGS 改进算法并通过实例分析比较了原 SEA 算法与 BSGS 改进算法的实现效率。针对 Satoh 算法、AGM算法,文章介绍了算法的理论依据和具体实现,并通过实例分析比较了其优劣性和适用情况。     

Level Set Curve Matching and Particle Image Velocimetry for Resolving Chemistry and Turbulence Interactions in Propagating Flames

We present an imaging, image processing, and image analysis framework for facilitating the separation of flow and chemistry effects on local flame front structures. Image data of combustion processes are obtained by a novel technique that combines simultaneous measurements of distribution evolutions of OH radicals and of instantaneous velocity fields in turbulent flames. High-speed planar laser induced fluorescence (PLIF) of OH radicals is used to track the response of the flame front to the turbulent flow field. Instantaneous velocity field measurements are simultaneously performed using particle image velocimetry (PIV). Image analysis methods are developed to process the experimentally captured data for the quantitative study of turbulence/chemistry interactions. The flame image sequences are smoothed using nonlinear diffusion filtering and flame boundary contours are automatically segmented using active contour models. OH image sequences are analyzed using a curve matching algorithm that incorporates level sets and geodesic path computation to track the propagation of curves representing successive flame contours within a sequence. This makes it possible to calculate local flame front velocities, which are strongly affected by turbulence/chemistry interactions. Since the PIV data resolves the turbulent flow field, the combined technique allows a more detailed investigation of turbulent flame phenomena.     

Elliptic Curve Cryptography; Applications,challenges, recent advances,and future trends: A comprehensive survey

Elliptic Curve (EC) is the most recent and advanced technique of Elliptic Curve Cryptography (ECC). EC is often used to improve the security of open communication networks and to let specific persons with confirmed identities into the Modern Digital Era (MDE). Users of MDE make use of many technologies, such as social media, the cloud, and the IoT industry, among others. No matter what tool the users are using, the whole environment has to be able to keep their security and privacy preserved.The study of cryptography is required because unsecure networks make data transmission and the transfer of information susceptible to data theft and attack via an open channel. This makes it necessary to learn cryptography. The art of encrypting documents and communications using keys in such a way that only the individuals who are intended to receive them are able to decode and process them is referred to as cryptography. A digital signature, cryptographic data integrity, and authentication method all rely on the address of the receiver and the sender in addition to mathematical operations to find the signature. During the process of signature and verification, the solution that was presented is compared with the technique that is currently being used by ECDSA in order to illustrate the differences that exist between the two processes.This comprehensive survey of EC seeks to thoroughly investigate many scientific concepts, state-of-the-art, and innovative methodologies and implementations. This work will be useful for academics, who are interested in further analysis. Use and development of EC based schemes for cloud computing, e-health, and e-voting, is more secure as compared to RSA, and Diffie–Hellman schemes. In this comprehensive study, we claim that the adoption of EC methods in distributed computing and asynchronous networking provides significant benefits in distributed computing and interdependent networking.     

Objective and subjective assessments of lighting in a hospital setting: implications for health,safety and performance

A field study was conducted to evaluate the illumination levels, to examine the effect of lighting conditions (including lighting characteristics and disturbances) on employee satisfaction, job performance, safety and health, and to compare the employees' perception of lighting level with actual illuminance levels in a hospital setting using both questionnaire and physical illuminance measurements. The illumination levels varied across different locations within the hospital and were lower than standards for 52.2% of the workplaces surveyed. Most respondents indicated that at least one of the four lighting characteristics (i.e. light level, type of light sources, light colour and use of daylight) was inappropriate, and that at least one of the three lighting disturbances (i.e. flickering lights, glare and unwanted shadows) was a major disturbance to them. The employees' perceptions of illuminance generally reflected the actual illuminance levels. The more appropriate maintenance or installation of lighting fixtures was rated as the most appropriate for improving lighting. The findings suggest that environmental ergonomics should be given a more prominent role in hospital building and workplace design to support safer healthcare facilities (for staff and potentially for patients).

Practitioner Summary: Good lighting is essential to improve employee performance, health and safety. The findings suggest that quantitative physical measurements should be supplemented by qualitative subjective assessments to provide a more holistic approach where specific details about the lighting condition in each working environment are incorporated from the workers' perspective.