SNR-Based OLSR Routing Protocol for Wireless Mesh Networks

Wireless Mesh Networks (WMNs) consist of a collection of mobile and fixed nodes that form a network. Nodes are capable of communicating with each other either with infrastructure, or infrastructureless, or in a hybrid mode. The major advantages of WMNs over the other wireless networks are the low-cost, self organization, self configuration, last mile internet solution, scalability, and reliability. These advantages have attracted the researcher over the last five years. WMNs technology is gaining an increased attention from the Institute of Electrical and Electronics Engineers (IEEE) community. This led the IEEE organization to emerge a special working group (IEEE 802.11s) in charge of the issues deriving from a completely wireless distribution system used to interconnect different Basic Service Sets (BSSs) through secure and performing links. In a multi-hop networks, like WMN, one of the main factors that influences the performance is the routing protocol. Generally speaking, routing protocols can be classified based-on the routing metric to 1) hop count-based routing protocols, like Adhoc on demand distance vector (AODV) where the optimum path is defined as the path that goes through the minimum number of nodes, 2) the link quality-based routing protocols, like OLSR where some metrics such as the bandwidth and the packet error rate are considered to define the optimum path to the destination. In this work the performances of a three commonly used routing protocols are compared. The main goal of this stag is to study the influence of different routing protocols in WMNs. The comparison is conducted with two scenarios of networks; a high mobility network and a low mobility network. (Open network) OPNET 11.5 modeler is used to build the WMNs. The performance of the network and the routing protocols has been studied in means of network throughput, End-to-End delay, routing protocol overhead and the mobility. The obtained results show that the Optimized link state routing protocol (OLSR) has the highestthroughput overDSR andAODVrouting protocols in WMNs. The unpredictable behavior of the wireless medium in WMNs environment demands the need for a routing protocol that is aware of the link conditions. Unfortunately the routing protocols used such as AODV and Dynamic source routing (DSR) are hop count-based; where the routing algorithm uses the number of nodes to determine the optimum path to the destination. In the second stage of this work a new routing technique for WMNs based-on Signal to noise ratio (SNR) as a new metric for OLSR routing protocol, is developed. The new metric has been implemented on the OLSR routing protocol module using OPNET simulator. The modified OLSR routing protocol is implemented in the comparison scenarios. The obtained results show that, when SNR is used as a routing metric in the OLSR routing protocol, the OLSR is getting the significantly higher network throughput over the DSR and AODV routing protocols. In the same time, the modified OLSR implemented with the SNR metric is showing a high improvement over the OLSR with the traditional hop-count metric. This thesis also studies the affect of different amounts of mobility in WMNs performance. VI

Adaptive Heuristic Methods for the Continuous p-Centre Location Problems

This research studies the p-centre problem in the continuous space. This problem is particularly useful in locating emergency facilities, such as fire-fighting stations, police stations and hospitals where it is aimed to minimise the worst-case response time. This problem can be divided into a single facility minmax location problem (1-centre) and multi-facility minmax location problem (p-centre). The solution of the 1-centre location problem can be found optimally in polynomial time by using the well known Elzinga-Hearn algorithm for both the weighted and the unweighted case. The objective of the p-centre problem is to locate p facilities (p>1) so as to minimise the radius of the largest circle. However, in this case, we cannot always guarantee optimality as the problem is known to be NP hard. The aim of the research is to develop and analyse powerful meta-heuristics including the hybridisation of exact methods and heuristics to solve this global optimisation problem. To our knowledge this is the first study that meta-heuristics are developed for this problem. In addition larger instances previously used in the literature are tested .This is achieved by designing an efficient variable neighbourhood search, adapting a powerful perturbation method and extending a newly developed reformulation local search. Large instances are used to evaluate our approaches with promising results

The Prognostic Significance of the Depth of Cervical Stromal Invasion in Women with FIGO Stage II Uterine Endometrioid Carcinoma

Purpose/Objective(s): To explore the prognostic significance of the depth of cervical stromal invasion (CSI) on survival endpoints in women with FIGO stage II uterine endometrioid adenocarcinoma. Materials/Methods: A total of 117 patients were included in this retrospective review. Between 1990 and 2021, all patients with FIGO stage II endometrial cancer (EC) underwent hysterectomy and oophorectomy at our institution, with or without lymph node dissection. Patients with synchronous ovarian or breast cancer, as well as those who had undergone adjuvant systemic chemotherapy for EC, were excluded from the study. Pathologic slides were retrieved for these patients and were reviewed by a gynecologic pathologist to determine stromal thickness and the depth of CSI. The depth of CSI was then measured as a percentage of invasion (% CSI) and used in the analysis as a continuous or dichotomous variable (\u3c 50% vs \u3e = 50%). Patients\u27 demographics, pathologic, and treatment characteristics were analyzed using univariate and multivariate analysis to calculate recurrence-free (RFS) and disease-specific (DSS) rates. Results: The median age for the study cohort was 65 years (range, 34–96), and the median follow-up was 131 months (range, 9–334). A total of 90 patients (77%) had lymph node dissection, with a median of 8 examined lymph nodes (range 0-18). Adjuvant radiation therapy (RT) with pelvic or vaginal cuff HDR brachytherapy, or a combination of the two, was completed in 92 patients (79 percent). The median % CSI was 27% (range, 1-100) with 68% of patients having ≥ 50% CSI. While there was a trend for a worse 5-year RFS and DSS for women with ≥ 50% CSI (69% vs. 83%, p = 0.093) and (78% vs. 91%, p = 0.034), respectively, the depth of CSI was not statistically significant as an independent predictor of 5-year RFS, DSS, or OS. The depth of CSI was not associated with a difference in the recurrence pattern (vaginal cuff, pelvic, paraaortic, or distant). In multivariate analysis, FIGO grade was the only predictor of 5-year OS. FIGO grade and the presence of lympho-vascular space invasion (LVSI) were independent predictors of 5-year RFS and DSS. Conclusion: Deep cervical stromal invasion does not appear to be an independent predictive factor for survival endpoints in women with stage II uterine endometroid cancer, according to our findings. The presence of LVSI and tumor grade were both independent predictors of recurrence-free and disease-specific survival. Pooled data analysis may be needed to validate our study findings

SNR-Based OLSR Routing Protocol for Wireless Mesh Networks

Wireless Mesh Networks (WMNs) consist of a collection of mobile and fixed nodes that form a network. Nodes are capable of communicating with each other either with infrastructure, or infrastructureless, or in a hybrid mode. The major advantages of WMNs over the other wireless networks are the low-cost, self organization, self configuration, last mile internet solution, scalability, and reliability. These advantages have attracted the researcher over the last five years. WMNs technology is gaining an increased attention from the Institute of Electrical and Electronics Engineers (IEEE) community. This led the IEEE organization to emerge a special working group (IEEE 802.11s) in charge of the issues deriving from a completely wireless distribution system used to interconnect different Basic Service Sets (BSSs) through secure and performing links. In a multi-hop networks, like WMN, one of the main factors that influences the performance is the routing protocol. Generally speaking, routing protocols can be classified based-on the routing metric to 1) hop count-based routing protocols, like Adhoc on demand distance vector (AODV) where the optimum path is defined as the path that goes through the minimum number of nodes, 2) the link quality-based routing protocols, like OLSR where some metrics such as the bandwidth and the packet error rate are considered to define the optimum path to the destination. In this work the performances of a three commonly used routing protocols are compared. The main goal of this stag is to study the influence of different routing protocols in WMNs. The comparison is conducted with two scenarios of networks; a high mobility network and a low mobility network. (Open network) OPNET 11.5 modeler is used to build the WMNs. The performance of the network and the routing protocols has been studied in means of network throughput, End-to-End delay, routing protocol overhead and the mobility. The obtained results show that the Optimized link state routing protocol (OLSR) has the highestthroughput overDSR andAODVrouting protocols in WMNs. The unpredictable behavior of the wireless medium in WMNs environment demands the need for a routing protocol that is aware of the link conditions. Unfortunately the routing protocols used such as AODV and Dynamic source routing (DSR) are hop count-based; where the routing algorithm uses the number of nodes to determine the optimum path to the destination. In the second stage of this work a new routing technique for WMNs based-on Signal to noise ratio (SNR) as a new metric for OLSR routing protocol, is developed. The new metric has been implemented on the OLSR routing protocol module using OPNET simulator. The modified OLSR routing protocol is implemented in the comparison scenarios. The obtained results show that, when SNR is used as a routing metric in the OLSR routing protocol, the OLSR is getting the significantly higher network throughput over the DSR and AODV routing protocols. In the same time, the modified OLSR implemented with the SNR metric is showing a high improvement over the OLSR with the traditional hop-count metric. This thesis also studies the affect of different amounts of mobility in WMNs performance. VI

A new fair marker algorithm for DiffServ networks

Internet Engineering Task Force (IETF) has proposed many new technologies to cover the new real time applications which have become very important in today's Internet demands. One such technology is Differentiated Services (DiffServ). DiffServ routers provide Per Hop Behaviors (PHBs) to aggregate traffic for different level of services. There is an unfairness problem that occur in a DiffServ networks. In this paper an improved version of the time sliding window three color marker is proposed and analyzed. The proposed algorithm is based on the adaptability concept of changing the constant value in the previous version of the algorithm (ItswTCM), in other words, changing the limit for the constant value without affecting the simplicity of the algorithm. The paper design and implement the algorithm with extensive simulations using NS-2 simulator to compare the proposed algorithm with previous algorithms. Results show that our new marker performs better than previous algorithms such as srTCM, trTCM, tswWTCM and ItswTCM in terms of fairness and number of yellow packets injected to the network in proportion to the committed rate

Energy efficient anti-collision algorithm for the RFID networks

Energy efficiency is crucial for radio frequency identification (RFID) systems as the readers are often battery operated. The main source of the energy wastage is the collision which happens when tags access the communication medium at the same time. Thus, an efficient anti-collision protocol could minimize the energy wastage and prolong the lifetime of the RFID systems. In this regard, EPCGlobal-Class1-Generation2 (EPC-C1G2) protocol is currently being used in the commercial RFID readers to provide fast tag identification through efficient collision arbitration using the Q algorithm. However, this protocol requires a lot of control message overheads for its operation. Thus, a reinforcement learning based anti-collision protocol (RL-DFSA) is proposed to provide better time system efficiency while being energy efficient through the minimization of control message overheads. The proposed RL-DFSA was evaluated through extensive simulations and compared with the variants of EPC-Class 1 Generation 2 algorithms that are currently being used in the commercial readers. The results show conclusively that the proposed RL-DFSA performs identically to the very efficient EPC-C1G2 protocol in terms of time system efficiency but readily outperforms the compared protocol in the number of control message overhead required for the operation

Recurrence Risk Stratification for Women with FIGO Stage I Uterine Endometrioid Carcinoma Who Underwent Surgical Lymph Node Evaluation

Purpose/Objective(s): To estimate the recurrence risk based on the number of prognostic factors in women with FIGO stage I uterine endometrioid carcinoma (EC) in a large cohort of patients who underwent surgical staging including surgical lymph node evaluation (SLNE) and were managed with no adjuvant therapy. Materials/Methods: We queried our in-house prospectively maintained uterine cancer database for patients with FIGO stage I EC underwent surgical staging including SLNE between 1/1990-12/2020. Patients with synchronous ovarian and breast cancer diagnosis were excluded as well as those who received adjuvant therapy of any form. Patient\u27s demographics and pathologic variables were analyzed. We used multivariate analysis (MVA) with Stepwise Model Selection to determine risk factors for 5-year recurrence-free survival (RFS). Study population was then stratified based on the number of risk factors identified (0, 1 or 2). The resultant groups were compared for RFS, disease-specific survival (DSS) and overall survival (OS) using log-rank test and Kaplan-Meier curves. Additionally, independent predictors of DSS and overall OS were estimated. Results: 706 patients were identified who met our inclusion criteria with a median age of 60 years (range, 30-93) and a median follow-up of 120 months. All patients had at least pelvic SLNE with a median number of examined lymph node (LN) of 8 (range, 1-66): 66 patients (11%) had a sentinel LN sampling and 43% had paraaortic SLNE. 639 patients (91%) were stage IA and lymphovascular space invasion (LVSI) was detected in 6% (n=41). Recurrence was diagnosed in 44 patients (6%). Independent predictors of 5-year RFS include age ≥ 60 years (p=0.038), grade 2 vs. 1 (p=0.003), and grade 3 vs 1 (p\u3c0.001). 5-year RFS for group-0 (age \u3c 60 years and grade 1) was 98% vs. 92% for group-1 (either: age ≥ 60 years or grade 2/3) vs 84% for group-2 (both: age ≥ 60 years and grade 2/3), respectively (p\u3c0.001). 5- year DSS for the three groups was (100% vs 98% vs 95%, p=0.012) and 5-year OS was (98% vs 90% vs 81%, p\u3c0.001), respectively. On MVA, stage IB vs IA was deterministic for DSS (p=0.02); whereas age ≥ 60 years (p\u3c0.001) and grade 3 vs grade 1 (p=0.004) were predictors for worse OS. Conclusion: In patients with stage I endometrioid carcinoma who had surgical staging including SLNE and no adjuvant therapy, only age ≥ 60 years and high tumor grade were independent predictors of cancer recurrence and hence can be used to quantify individualized recurrence risk. Surprisingly, LVSI was not an independent prognostic factor in this study cohort with SLNE

Banana residue could be a viable rice straw alternative for Pleurotus mushroom production

Purpose Oyster mushroom (Pleurotus ostreatus) is becoming more popular as an efficient biotechnological procedure for upcycling agricultural by-products into valuable human food. This study looked into the possibility of employing banana residue (BR) and sorghum stalks (SS) as localized feasible rice straw (RS) substitutes for cultivating P. ostreatus. This has the potential to improve the livelihoods of rural agricultural communities in Egypt, as well as those in other parts of the world.Method For two successive trials, three sole substrates (BR, SS, and RS) and six various combinations of SS and BR each with rice straw at 1:1, 1:2, and 2:1 ratio were tested. Agronomic features, antioxidant capacity, and crude protein contents of mushroom basidiocarps were measured.  The chemical profile of the three raw and spent sole substrates was also studied.Results The sole BR substrate was superior to both RS and SS in terms of basidiocarps yield and both exterior (average cap weight, diameter, and thickness) and interior (crude protein and total antioxidant activity, phenols and flavonoids contents) quality attributes. The yield of basidiocarps developed on the sole SS substrate was far lower than that of the other substrates. It is worth mentioning that, BR tended to contain high initial potassium, phosphorus, cellulose, and total carbohydrates concentration.Conclusion Sole BR could entirely substitute sole RS as a substrate for the production of Pleurotus ostreatus