El Mehdi Ismaili Alaoui, Laboratory of Computer Networks and Systems Faculty of Sciences, Moulay Ismail University Meknes-Morocco
Motion estimation is a signal-matching technique. It is a key component of target tracking, medical imaging, video compression, and many other systems. This paper presents a four new estimators for frame-to-frame image motion estimation. The estimators of interest are the ROTH impulse response, the smoothed coherence transform (SCOT), the maximum likelihood (ML) and the Wiener estimators. These are all referred to as Generalized Cross-Correlation (GCC)-estimators. These estimators are based on the cross-correlation of the received images and various weighting functions are used to prefilter the received images before cross-correlation. Since the estimators and weighting functions are similar to those used in the time delay estimation . As the performances of the GCC-estimators are considerably degraded by the signal-to-noise ratio (SNR) level, this factor has been taken as a prime factor in benchmarking the different GCC-estimators. For robust motion estimation it has been found that the GCC-Wiener is particularly suited to this purpose. The accuracy of the estimators is also discussed.
Motion estimation, Motion vector field, Whitening function, Noisy image sequences, GCC-estimators
Hao Yuan, Guo Yu, Yifan Ma, Jieneng Chen, Xiongda Chen, Tongji University, China
Traditional methods for simulating the flow of people includes the Cellular Automaton, artificial potential field, and so on. This paper seeks out to refine the traditional Cellular Automaton and combines it with the adapted Ant Colony model as well as the Artificial Potential Field to simulate the evacuation process within large buildings. This research work includes applying the model to the Louvre to get an estimation of the total evacuation time within one floor, and after systematic analysis, identifying the bottlenecks alongside the evacuation routes. This proves the applicability and flexibility of the model.
Evacuation Simulation Model, Cellular Automaton, Artificial Potential Field, Ant Colony, Large Complex Buildings.
Hamid Khemissa1 and Mourad Oussala2, 1Computer Systems Laboratory, Faculty of Electronics and Informatics, Computer Science Institute, USTHB: University of Science and Technology Houari Boumediene, Algiers; Algeria and 2Laboratoire des Sciences du Numérique de Nantes (LS2N), Faculty of sciences, Nantes University, France
The need for adaptive guidance systems is now recognized for all software development processes. The new needs generated by the mobility context for software development led these guidance systems to both quality and ability adaptation to the possible variations of the development context. This paper deals with the adaptive guidance quality to satisfy the developer’s guidance needs. We propose a quality model to the adaptive guidance. This model offers a more detailed description of the quality factors of guidance service adaptation. This description aims to assess the quality level of each guidance adaptation factor and therefore the evaluation of the adaptive quality guidance services.
Quality model, Guidance System Quality, Adaptive Guidance, Plasticity.
Ahmed Saidi1, Omar Nouali2 And Abdelouahab Amira3, 1, 2, 3Department Of Computer Security, Research Center For Scientific And Technical Information, Algiers, Algeria and 1, 3Faculty Of Exact Sciences, Universite De Bejaia, 06000 Bejaia, Algeria
Nowadays, IOT (Internet Of Things) devices are everywhere and are used in many domains including ehealth, smart-cities, vehicular networks, .. etc. Users use IOT devices like smartphones to access and share data anytime and from anywhere. However, the usage of such devices also introduces many security issues, including in data sharing. For this reason, security mechanisms such as ABE (AttributeBased Encryption) have been introduced in IOT environments to secure data sharing. Nevertheless, Ciphertext-Policy ABE (CP-ABE) is rather resource intensive both in the encryption and the decryption processes. This makes it unadapted for IOT environments where the devices have limited computing resources and low energy. In addition, in CP-ABE, the privacy of the access policy is not assured because it is sent in clear text along with the cipher-text. To overcome these issues, we propose a new approach based on CP-ABE which uses fog devices to reduce the bandwidth, and partially delegates data decryption to these fog devices. It also ensures the privacy of the access policy by adding false attributes to the access policy. We also discuss the security properties and the complexity of our approach. We show that our approach ensures the confidentiality of the data and the privacy of the access policy. The complexity is also improved when compared with existing approaches.
Fog Computing, Access Control, Attribute based Encryption, Decryption Outsourcing