Energy-Aware and Secure Task Offloading for Multi-Tier Edge-Cloud Computing Systems.

Nowadays, Unmanned Aerial Vehicle (UAV) devices and their services and applications are gaining popularity and attracting considerable attention in different fields of our daily life. Nevertheless, most of these applications and services require more powerful computational resources and energy, and their limited battery capacity and processing power make it difficult to run them on a single device. Edge-Cloud Computing (ECC) is emerging as a new paradigm to cope with the challenges of these applications, which moves computing resources to the edge of the network and remote cloud, thereby alleviating the overhead through task offloading. Even though ECC offers substantial benefits for these devices, the limited bandwidth condition in the case of simultaneous offloading via the same channel with increasing data transmission of these applications has not been adequately addressed. Moreover, protecting the data through transmission remains a significant concern that still needs to be addressed. Therefore, in this paper, to bypass the limited bandwidth and address the potential security threats challenge, a new compression, security, and energy-aware task offloading framework is proposed for the ECC system environment. Specifically, we first introduce an efficient layer of compression to smartly reduce the transmission data over the channel. In addition, to address the security issue, a new layer of security based on an Advanced Encryption Standard (AES) cryptographic technique is presented to protect offloaded and sensitive data from different vulnerabilities. Subsequently, task offloading, data compression, and security are jointly formulated as a mixed integer problem whose objective is to reduce the overall energy of the system under latency constraints. Finally, simulation results reveal that our model is scalable and can cause a significant reduction in energy consumption (i.e., 19%, 18%, 21%, 14.5%, 13.1% and 12%) with respect to other benchmarks (i.e., local, edge, cloud and further benchmark models).

Influence of Surface Type with Coffee Immersion on Surface Topography and Optical and Mechanical Properties of Selected Ceramic Materials.

BACKGROUND The aim of this study was to assess and compare the effect of surface type (glazed or polished) with coffee immersion and aging on surface topography (Ra), optical properties (TP, OP), and mechanical properties (fracture forces and modes) of zirconia-reinforced lithium silicate (Vita Suprinity), hybrid polymer-infiltrated-feldspathic ceramic network material (Vita Enamic), and leucite-containing feldspathic glass (Vitablocs® Mark II) made by computer-aided design and computer-aided manufactured (CAD/CAM) ceramic materials. MATERIAL AND METHODS Fifty-four specimens were assembled out of the above 3 CAD/CAMs ceramic materials. Each group was divided into glazed or polished surfaces, having 9 specimens of every type and stained in coffee for 15 days. Ra and color of specimens in the form of TP and OP were recorded before and after immersion in staining material. Fracture forces and modes were analyzed after the 90-day aging. Data were analyzed using ANOVA, then post hoc analysis and Bonferroni tests. RESULTS Our study found significant differences in Ra, TP, and Op before and after coffee immersion between glazed and polished specimens, with higher values in the polished surfaces among the 3 ceramic materials. The highest values of fracture resistance were noted in Vita Suprinity, and Vita Enamic had the lowest values, without significant differences among groups. CONCLUSIONS Most of the TP and OP values were in acceptable clinical range, and Vita Suprinity had superior TP than the other groups. Reparable fracture types were observed in Vita Suprinity, whereas semi-reparable and non-reparable were predominant in other groups.

Clinical and Radiographical Measurements of Supraeruption and Occlusal Interferences in Unopposed Posterior Teeth.

AIMS AND OBJECTIVES: This study compared the supraeruption of teeth for study casts (SCs) and panoramic radiographs (PRs) and its relation to tooth type, arch, facial sides, presence of occlusal interferences, and type of tooth movements. MATERIALS AND METHODS: A total of 65 patients with their SCs and PRs were recruited. Supraerupted tooth type, arches, sides involved, and the presence of occlusal interferences were recorded. The SCs for supraerupted teeth were photographed, and supraeruption from PRs was recorded from the patients' files. The values were transferred to a software program and assessed. RESULTS: The highest frequency was observed among the younger-age group and molars in both arches. Working side (WS) and retruded cuspal position (RCP) interferences were recorded the highest. Supraeruption values of 0.7-1.2 mm accounted for 47.5% (38) of the total. Tilting and tipping of teeth were the highest, followed by buccolingual displacement. Kappa tests showed good intraexaminer reliability and Bland-Altman plot showed 95% confidence interval band. CONCLUSIONS: No significant differences were observed in the supraeruption values between the type of tooth among different subgroups of SCs and PRs. Significant differences were recorded between the types and sites of teeth, with a higher ratio observed in molar teeth, mandibular arch, and young age group. RCP and WS were the most recorded occlusal interferences and buccolingual displacement, and tilting and tipping were the most noticeable occlusal tooth movements. CLINICAL SIGNIFICANCE: Diagnosis and measurements of supraeruption are essential, useful, and significant steps before treatments for replacement of missing tooth/teeth as well as corrections of occlusal interferences during different mandibular movements.