This paper explores the use of wavelet transform-based methods for ITS data compression. A methodology for structuring data and applying wavelet transform-based algorithms is proposed. The methodology provides the option of controlling the compression ratio at the cost of an acceptable distortion, visualizing data at different detail levels. With proper database management, this methodology will also allow faster data access without fully decompressing them. Given a high correlation of traffic data and knowing that the image data are compressed very well due to the inherent correlation of image pixels, the idea here is to restructure the traffic data, such that efficient image compression methods underlying modern image compression standards can be used. Three data structures are discussed: 1-D, 2-D, and 3-D. For a 1-D arrangement, different wavelets and decomposition levels were tested and analyzed for distortion levels in the data after decompression. The 2-D and 3-D data arrangements were compressed using embedded zero-tree wavelet and set partitioning in hierarchical trees algorithms, which are well-proved algorithms for compressing image data. A case study was performed using the traffic flow data from freeways in Las Vegas, Nevada. As could be expected, the compression ratio under the 3-D scheme has shown the best results. The 2-D and 3-D approaches yielded a 91% and 95.2% reduction ratios, respectively.

In the past few years, unmanned aerial vehicles (UAVs) have become a primary airborne platform for hyperspectral imager for studies on precision agriculture, defence, and the environment. The ‘push‐broom’ type of hyperspectral sensors require moving vehicle, and transmission and analysis of hyperspectral data by means of a UAV's high‐mobility channel is challenging. While high bandwidth of hyperspectral imaging justify using orthogonal frequency division multiplexing (OFDM) for data transmission, the high speed of UAVs imposes intercarrier interference (ICI) on the transmitted OFDM signal because of the Doppler shift. This study proposes a technique for channel estimation and equalisation in order to compensate the ICI. This technique uses a complete channel matrix estimation in the frequency domain in contrast to conventional methods that only use diagonal elements when recovering the data. In order to evaluate the received data using this technique, a classification framework was designed that took into consideration both spectral and spatial information. In order to verify the robustness of the proposed model, the system was analysed using a Pavia Center hyperspectral dataset, and evaluated against speeds of 50 and 500 m/s. By using this method, improvement in both data transmission and the analysis was achieved.

To perform the inspection of cargo containers the radioscopic screening is performed by switching between 6 and 9 MeV of boundary energies as rapidly as 200 times per second and measuring the penetration levels in the contents of cargo. This technology facilitates the material identification via the analyses of the ratios of signals obtained at nominal and dual energies, which are 6 and 9 MeV, respectively. The techniques are developed for (a) visualizing the contents to produce an image suitable for fast inspection by a human operator, and for (b) prompting the custom personnel about the location of suspicious objects. Specifically, nuclear materials are of interest. The experiments have been conducted with Linatron K9 device designed by Varian Security and Inspection Products. The capabilities are demonstrated for detection of objects of interests for the steel shields of 10 inches of thickness.

Key goals of call admission control in the next generations of wireless networks are the efficient use of the limited wireless resource and the enhanced quality of service (QoS). Knowing that blocking of handoff calls is less desirable than blocking of new calls and the latter inevitably leads to the reduced resource utilization, we propose in this paper a new call admission control for balancing this tradeoff. It is based on the sub-rating strategy (SRS) implemented in conjunction with unidirectional call overflow in hierarchical cellular networks (HCN). With SRS, an occupied full-rate channel is halved to service a call in progress and a handoff call in parallel. Theoretical models based on 1-D Markov process for a microcell and 2-D Markov chain for macrocell analyses are developed to evaluate the performance of the proposed scheme. We compare the results with that obtained by Shan in W.H. Shan and P.Z. Fan, (2003). The experimental results certify higher performance in terms of the forced termination probability. Additionally, we evaluate the voice degradation quality due to subrating.

In current Personal Communication Service (PCS) Networks, such as Global Systems for Mobile Communications (GSM), the always-update (AU) strategy is used to keep track of mobile terminals (MTs) within the network. However, future PCS networks, like Universal Mobile Telecommunication System (UMTS) envision larger number of MTs and smaller cells. This will cause frequent updating of locations, hence the increase of the signaling load. A proper location management scheme is crucial for the system effectiveness. In this paper, we present a dynamic location management scheme with personalized location areas (PLA). The proposed technology takes into account both the movement behavior of the individual users in the system and the system parameters. To analyze the location management cost, we model the network after a continuous time Markov chain. The PLAs are then dynamically defined for each MT such that the location management cost is minimized. The problem of dynamic planning of PLAs is proved to be NP-complete. Due to the high computational complexity of the problem, we search for an approximate solution using a simulated annealing (SA) algorithm. Simulation results show that the proposed dynamic location management scheme always outperforms the AU mechanism. Also the PLAs designed by the SA algorithm offer a lower signaling cost compared to that obtained using the heuristic algorithm.

An algorithm, which performs connected components detection in the course of decoding ITU-T (former CCITT) facsimile Group 3/4, i.e., MH/MR/MMR compressed images is presented. New definitions of mode color and a new transition element are introduced that allow MR/MMR codes to analyze and derive information about connection of black runs in two adjacent scan lines in the course of decoding. The experiments on the standard set of eight CCITT documents have shown that, on the average, the complexity of direct processing of MR/MMR codes is lower by a factor of 20 and 2.5 than that for raster images and MH codes processing respectively. Data structures for image vector description are discussed.