Blockchain for secured IoT and D2D applications over 5G cellular networks : a thesis by publications presented in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Computer and Electronics Engineering, Massey University, Albany, New Zealand

Author's Declaration: "In accordance with Sensors, SpringerOpen, and IEEE’s copyright policy, this thesis contains the accepted and published version of each manuscript as the final version. Consequently, the content is identical to the published versions."The Internet of things (IoT) is in continuous development with ever-growing popularity. It brings significant benefits through enabling humans and the physical world to interact using various technologies from small sensors to cloud computing. IoT devices and networks are appealing targets of various cyber attacks and can be hampered by malicious intervening attackers if the IoT is not appropriately protected. However, IoT security and privacy remain a major challenge due to characteristics of the IoT, such as heterogeneity, scalability, nature of the data, and operation in open environments. Moreover, many existing cloud-based solutions for IoT security rely on central remote servers over vulnerable Internet connections. The decentralized and distributed nature of blockchain technology has attracted significant attention as a suitable solution to tackle the security and privacy concerns of the IoT and device-to-device (D2D) communication. This thesis explores the possible adoption of blockchain technology to address the security and privacy challenges of the IoT under the 5G cellular system. This thesis makes four novel contributions. First, a Multi-layer Blockchain Security (MBS) model is proposed to protect IoT networks while simplifying the implementation of blockchain technology. The concept of clustering is utilized to facilitate multi-layer architecture deployment and increase scalability. The K-unknown clusters are formed within the IoT network by applying a hybrid Evolutionary Computation Algorithm using Simulated Annealing (SA) and Genetic Algorithms (GA) to structure the overlay nodes. The open-source Hyperledger Fabric (HLF) Blockchain platform is deployed for the proposed model development. Base stations adopt a global blockchain approach to communicate with each other securely. The quantitative arguments demonstrate that the proposed clustering algorithm performs well when compared to the earlier reported methods. The proposed lightweight blockchain model is also better suited to balance network latency and throughput compared to a traditional global blockchain. Next, a model is proposed to integrate IoT systems and blockchain by implementing the permissioned blockchain Hyperledger Fabric. The security of the edge computing devices is provided by employing a local authentication process. A lightweight mutual authentication and authorization solution is proposed to ensure the security of tiny IoT devices within the ecosystem. In addition, the proposed model provides traceability for the data generated by the IoT devices. The performance of the proposed model is validated with practical implementation by measuring performance metrics such as transaction throughput and latency, resource consumption, and network use. The results indicate that the proposed platform with the HLF implementation is promising for the security of resource-constrained IoT devices and is scalable for deployment in various IoT scenarios. Despite the increasing development of blockchain platforms, there is still no comprehensive method for adopting blockchain technology on IoT systems due to the blockchain's limited capability to process substantial transaction requests from a massive number of IoT devices. The Fabric comprises various components such as smart contracts, peers, endorsers, validators, committers, and Orderers. A comprehensive empirical model is proposed that measures HLF's performance and identifies potential performance bottlenecks to better meet blockchain-based IoT applications' requirements. The implementation of HLF on distributed large-scale IoT systems is proposed. The performance of the HLF is evaluated in terms of throughput, latency, network sizes, scalability, and the number of peers serviceable by the platform. The experimental results demonstrate that the proposed framework can provide a detailed and real-time performance evaluation of blockchain systems for large-scale IoT applications. The diversity and the sheer increase in the number of connected IoT devices have brought significant concerns about storing and protecting the large IoT data volume. Dependencies of the centralized server solution impose significant trust issues and make it vulnerable to security risks. A layer-based distributed data storage design and implementation of a blockchain-enabled large-scale IoT system is proposed to mitigate these challenges by using the HLF platform for distributed ledger solutions. The need for a centralized server and third-party auditor is eliminated by leveraging HLF peers who perform transaction verification and records audits in a big data system with the help of blockchain technology. The HLF blockchain facilitates storing the lightweight verification tags on the blockchain ledger. In contrast, the actual metadata is stored in the off-chain big data system to reduce the communication overheads and enhance data integrity. Finally, experiments are conducted to evaluate the performance of the proposed scheme in terms of throughput, latency, communication, and computation costs. The results indicate the feasibility of the proposed solution to retrieve and store the provenance of large-scale IoT data within the big data ecosystem using the HLF blockchain

Transport and fate of Escherichia coli and somatic bacteriophages in the saturated zone (moraine soil) in a 6 m long column)

Infiltrasjon med utslipp av forurensing avløpsvann kan utgjør en fare for spredning av mikroorganismer og dermed føre til forurensing av jord, vann og miljøet. Avløpsvannets negative egenskaper avhengige av avløpsvannets innhold av avløpsvannets innhold av mikroorganismer og avstanden til nærmeste vannresipient Det ble utført renneforsøk. Forsøksrennen var 6 meter lang, hadde en bredde på 0.4 meter og en dybde på 0,5meter. Renneforsøket ble utført for å undersøke skjebnen og transport av bakteriofag St 28B og bakterier som funksjon av oppholdstid og transportavstand i mettetsone og i morenejord. I tillegg ble det klorid (NaCl) anvendt som en konservativ sporstoff for å bestemme transportegenskaper. Fire log10 av S.t 28 ble fjernet ved adsorpsjon og inaktivering i løpet av 20 dager oppholdstid, under en transport avstand på 5 meter. Den totale fjerning med hensyn til E. coli var over 5 log10 og under en transport avstand på 5 meter og en oppholdstid i løpet av 20 dager. Størst fjerning oppnås de første meterne av transportstrekningen. Etter bare 0.5 meter ble fjernet omtrent 3 log10 for E.coli. Som var 1.6 log10 lavere enn fjerning av S.t 28B dette gjør at en kan si at bakteriofager er et bedre indikator enn E.coli for fjerning av virus Inaktivering eksperimenter ble utført for tre forskjellige temperaturer i området fra 4 til 20 Oppbevaringsmetode av virusprøver Resultatet av utførte forsøket viser at den faktiske reduksjonen av virusprøver som ble frosset ned i perioden var mye større enn et en kunne tenke seg. Det ser ut at reduksjonen bakteriofaget var i initialfasen større enn reduksjonen over tid av bakteriofager og betydelig større enn inaktiveringseffekt.Groundwater acts as a recipient for supplying of infiltrating water passing through the unsaturated zone. Accurate knowledge of the processes that control the fate and transport of viruses in saturating zone therefore it is necessary to assess the pollution potential and designing setback distances for water production wells / water sources Column of Plexiglas experiments in a 6 m long× 0.2 m2 (0.5x0.4) meter column were performed to investigate the fate and transport of bacteriophage S.t 28B and bacteria as a function of distance and residence for the saturated zone in moraine soil after the graywater soil infiltration systems. In addition, chloride (Cl) was used as a conservative tracer to determine transport characteristics. Inactivation experiments were performed for three different temperatures ranging from 4to 20◦C and for Storage Method of water samples Four log10 of S.t 28 was removed by adsorption and inactivation during 20 days residence time, during a transport distance of 5 meters. The total removal with respect to E.coli was over five log10 and during a transport distance of 5 meters and a residence time during 20 days. The greatest removal is achieved the first few meters of transport after only 0.5 meters was removed about 3log10 for E.coli. Which was 1.6 log10 lower than removal of S.t 28B The result of the experiment performed shows that the actual reduction of samples that were frozen during the period was much larger than one could imagine. It appears that the reduction of bacteriophage was in the initial phase greater than the reduction over time of bacteriophages and considerably larger than inactivation.M-V

The Clinical Efficacy of Infrared Photocoagulation Versus Closed Hemorrhoidectomy in Treatment of Hemorrhoid

Introduction: Infrared photocoagulation (IRC) was introduced as a mainstay procedure for treatment of hemorrhoids. The present study aimed to compare the clinical efficacy of IRC compared to closed hemorrhoidectomy.Methods: Forty patients suffering grade-3 hemorrhoid that referred to the surgery clinic at Imam Hossein hospital in Tehran in 2013 were randomly assigned to groups treated with the IRC modality or Ferguson’s closed hemorrhoidectomy method. The patients in the 2 groups were followed-up for the first 24 hours after surgery and 8 weeks later. Postoperative pain was assessed using visual analogue scale (VAS) at three time points of 24 hours, 2 weeks and 8 weeks after operation.Results: Regarding bleeding, its overall prevalence was 5.0% in the IRC group and 30.0% in the hemorrhoidectomy group, which was significantly less prevalent in the IRC group. Notably, the IRC group had a lower mean postoperative pain score compared to the hemorrhoidectomy group. Time of return to work was significantly shorter in the IRC group; no difference was found in the mean duration of hospital stay, and recurrence rate across 2 groups.Conclusion: IRC procedure is safer than closed hemorrhoidectomy with lower postoperative pain severity, less secondary bleeding, and leads to earlier return to work in patients with hemorrhoid

Success Rate and Time for Bypassing the Fractured Segments of Four NiTi Rotary Instruments

Introduction: The aim of this in vitro study was to compare the success rate and time required for bypassing the fractured segments of four different nickel-titanium (NiTi) rotary systems. Methods and Materials: This study was conducted on the mesiobuccal canals of 60 mandibular molars with fully-formed apices. Fifteen Flex Master, K3, RaCe and Hero Shaper instruments with 0.04 taper and tip size of #30 and 25 mm in length, were obtained. These instruments were notched at a point 3 mm from the tip of the instrument and were driven into the canals using a handpiece until the instruments fractured and became lodged therein. In the next step, an endodontist tried to bypass the fractured segment using K-files. The number of bypassed samples and the time required for bypassing of each sample were recorded. The Chi-square test was used to compare the bypassing rate among the experimental groups. One-way analysis of variance followed by Tukey’s post hoc test was conducted to compare the time taken for bypassing of the fractured fragments. Results: One instrument in Flex Master group and two broken segments in each of the K3 and Hero groups were not bypassed. All of the samples in RaCe group were bypassed. No significant difference was found among four tested groups regarding rate of bypassing (P=0.738). The time taken to bypass fragments in the Hero group was significantly more than in those of K3 (P=0.047) and RaCe (P=0.024). Conclusion: Under the limitations of this study, design features of rotary files can influence the time needed to bypass separated fragments.Keywords: Instrument Fracture; Instrument Separation; File Fracture; Fractured Instrument; NiTi Rotary File; Root Canal Treatmen

Rare presentation of pancreatic schwannoma: a case report

<p>Abstract</p> <p>Introduction</p> <p>Schwannoma is a rare tumor among pancreatic neoplasms. Schwannomas vary in size, and most of them are cystic, mimicking pancreatic cystic lesions. Generally, a definitive diagnosis is made at the time of histological analysis. The mainstay treatment is surgical resection.</p> <p>Case presentation</p> <p>We report an unusual presentation of pancreatic schwannoma with abdominal pain and several episodes of cholangitis in a 54-year-old Caucasian (Iranian) man. The condition was not diagnosed pre-operatively and Whipple's procedure was performed.</p> <p>Conclusion</p> <p>Pancreatic schwannoma is an important clinical entity to include in the differential diagnosis of pancreatic lesions. Pre-operative diagnosis is difficult but computed tomographic findings may be helpful. The tumor may also have atypical and rare presentations, such as cholangitis and weight loss. For benign tumors, simple enucleation is usually adequate, whereas malignant tumors require standard oncological resection.</p

Ultrasound-guided Placement of Permanent Hemodialysis Catheters Compared to the Traditional Blind Method

Background: Central venous hemodialysis catheters are one of the most common vascular accesses for patients suffering from end-stage kidney disease. The application of ultrasound-guided placement of permanent hemodialysis catheters is highly recommended by the new guidelines because of its advantages over the traditional blind methods.Methods: In this prospective study, the samples comprised patients (N=80) referred to a vascular surgery clinic by their nephrologist or elective vascular surgery consultations and asking for the placement of permanent hemodialysis catheters in Imam Hossain Hospital (A referral hospital complex center in, Tehran, Iran) during 2014 to 2015. The patients were randomly divided into two groups (n=40); one of the groups underwent the placement of catheters with the guidance of Doppler ultrasound and the other with the traditional blind method. Then, the data were analyzed by SPSS V. 21 software.Results: There was statistically significant fewer attempts for successful placement (Z= -2.725, P=0.006), less insertion failure (Chi-Square=9.600, P=0.002), fewer failures with the first attempt (Chi-square=9.600, P=0.002), and less total placement time (t=1.379, df=69.549, P=0.172) in the sonography-guided group compared to the blind method. Furthermore, there was no significant difference in venous cannulation time and complications such as pneumothorax, neck hematoma, and carotid puncture between the two groups. Moreover, the patients had significantly greater satisfaction with the sonography-guided method (Z=-4.306, P=0.0001).Conclusion: According to this study, it might be beneficial to use ultrasound as the first method of permanent hemodialysis catheters insertion and patients would be more satisfied with this approach as well. In addition, learning the blind method is recommended to the practitioners because of the possibility of lacking ultrasound in an emergency

Evaluation of Early Removal of Urinary Catheter after Rectal Cancer Surgery

Background: It is a common practice to catheterize the bladder during major surgical procedure and leave the catheter in situ to avoid post-operative urinary complications such as retention or incontinence. Catheter removal on post-operative day 5 is a routine, and it causes some urinary problems and longer hospital stay. The objective of this study was to evaluate the effect of early removal of urinary catheter on the 1st day after rectal cancer surgery, on the rate of urinary complications.Methods: This quasi-experimental study was approved by the Ethics Committee of Shahid Beheshti University of Medical Sciences, Iran. 80 patients with rectal cancer underwent surgery at Imam Hossein Hospital from 2015 to 2016, were recruited with planned early removal of urinary catheter after surgery. Personal and disease information was recorded in all patients after obtaining the informed consent. Urinary complications were checked by the surgical resident after the operation.Results: Mean age of participants was 56.64 ± 14.90 (range: 22-84 years). From these patients 46 (57.5%) were male, and 34 (42.5%) were female. Two cases (2.5%) were manifested urinary problems in men. One of them reported urinary retention and the other one had hematuria. Both patients were in Stage III of rectal cancer and had laparoscopic surgery. Urinary incontinence was not reported in any patients.Conclusions: In patients who undergoing rectal cancer surgery, urinary catheter can be removed on the 1st post-operative day without any significant increase in urinary complications

Formulating a Conceptual Model of Wisdom Based on Islamic Sources: Grounded Theory

The present study tried to achieve a conceptual model of wisdom and examine its validating through three methods of linguistic semantics, grounded theory, and survey descriptive method. By reviewing the concept of wisdom in the fields of vocabulary and psychology, 23 primary concepts related to wisdom were identified in Islamic sources. After analyzing content validity, nineteen concepts were left out of 23 concepts. In the phase of collecting the documents, there were 2149 data resulted from seeking the data related to nineteen concepts which were screened in the two stages of book weakness and the lack of conceptual relevance. It resulted in omitting 1039 documents and leaving 1110 Islamic data as well as twelve concepts for modeling. These concepts, including reason (Aghl), intellect (Hekmat), distinction (Tamiz), knowledge (Marefat), science (Elm), mental processing (Pardazesh Zehni), understanding (Fahm), insight (Basirat), acumen (Ferasat), perspicacity (Kiasat), Fiqh, ingenuity (Fetanat), and sagacity (Zekavat), were analyzed using grounded theory in the four stages. By the judgmental sampling, 1276 primary open codes, 344 centralized open codes, 84 axial codes, and 19 core categories were identified. The proportionality among the core categories and comparing them with the documents showed that Islamic wisdom consists of ten conceptual elements, including knowledge (Danesh), distinction (Tamiz), mental processing (Pardazesh Zehni), control (Mahar), certainty in action (Etghan dar Amal), perspicacity (Kiasat), acumen (Ferasat), insight (Basirat), Fiqh, and cleverness (Tizfahmi). These elements were analyzed by eleven experts and Content Validity Index (CVI). In addition, the experts confirmed the validity of elements

Evaluation of type 2 Diabetes Mellitus Risk in Patients with post Trauma Splenectomy

Introduction: Recent studies suggest that the spleen has an important role as a source of multipotent stem cells and precursors of beta cells of pancreas islets. In addition, increased risk of developing hyperglycemia was reported in patients who underwent splenectomy due to trauma in long-term follow up. Therefore, there might be an association between splenectomy and an increased risk of type 2 diabetes mellitus. In this study, we evaluated the risk of type 2 diabetes and its risk factors including hyperglycemia, dyslipidemia, obesity and hypertension in trauma patients with splenectomy. Materials and methods: In this study, 221 patients who underwent splenectomy surgery due to trauma in the surgical ward of Imam Hossein Hospital 5 to 10 years ago were selected. Those with a history of diabetes, cancer, hyperthyroidism, Cushing's syndrome, pancreatitis, renal failure, and cirrhosis were excluded from the study. Then fasting plasma glucose, hemoglobin A1c (HbA1c), triglyceride, cholesterol and high density lipoprotein (HDL), body mass index and blood pressure have been evaluated in 90 patients who had had a history of splenectomy due to trauma from 2007, July 23 to 2012, July 22. Results: The results indicate that none of these patients has diabetes, 14.4 percent are in pre-diabetic stage, 56.6 percent has dyslipidemia, 57.7 percent has obesity and 20 percent has hypertension. Conclusion: The results of this study suggest that splenectomy does not increase the risk of type 2 diabetes. Prevalence of diabetes risk factors was approximately the same with those of Tehran population

Urban Growth Prediction Using Cellular Automata Markov: A Case Study Using Sulaimaniya City in the Kurdistan Region of North Iraq

Many cities in the Kurdistan Region have witnessed a rapid change in land use during the last two decades. Geographic information systems (GIS) and remote sensing have been broadly utilized to monitor and detect urban growth prediction. In this paper, three Landsat TM 5 and one Landsat 8 of Sulaimaniya city were used to identify and develop an urban growth map for 1991, 1998, 2006 and 2014. A supervised classification approach was applied; in order to predict urban growth, the Markov chain and CA-Markov models were used. The result demonstrates that validation of CA-Markov to forecast 2006 land cover map is ineffective in reasonably predicting land coverage for this time period; however this model had significant validation for the year 2014 and also has a good forecast power for 2024. Keywords Land Use Change/Cover, Urban Growth Prediction, Supervised Classification, Markov Chain, CA-Markov, Validation