Leak localisation in urban water supply system : a literature synopsis on model based methodologies

Abstract: In water supply systems (WSS), water loss is inex- orable, nevertheless, the volume of these losses differ from one WSS to the other. Because of its association with financial losses, environmental concern and most importantly saving of the water resource, advanced computing tools and methodologies have been developed for sustainable management of water resource through leak localisation. Over the years, several research studies have been conducted proposing different methodologies for leak localisation in WSS. Amongst the previous methodology used, a model-based approach is cost-effective. Thus, this paper presents a literature synopsis on the model-based approach to localising leaks in WSS. We categorise the model-based approach under orifice discharge modelling, pressure measurement and leak sensitivity analysis, water audit and minimum night flow analysis, leak signature analysis, and optimisation approach. Numerous research studies in this category are discussed therein. Also, technical challenges and research gaps for further studies are introduced

IoT-based smart water network management challenges and future trend

Abstract: In recent years, internet of things (IoT)-based tech- nology has been deployed to different areas of water supply system. This is in line with the Smart Water Network Manage- ment (SWNM) initiative, that aims to propose a methodology to improve operational performance and monitoring of water supply systems. In the smart water network management applications, IoT-based technology is facing quite a few challenges. In this paper, we present IoT’s applications for monitoring the water supply network with emphasis on its application to water quality and leakage monitoring. In these applications, the technical challenges of IoT-based technology are also discussed. Finally, future research directions in this domain are also highlighted, which may be useful for further studies

Assessment of encryption and decryption schemes for secure data transmission in healthcare systems

Abstract: In the biomedical research community, transmitting a patient medical record via wireless means to an administrative centre or other medical centres is increasingly common. However, due to the open nature of wireless media, the security of such a system is a major concern, so, it is desirable to have a reliable security scheme. Amidst the numerous methods used to secure medical data, encryption schemes are becoming more popular due to their performance and relative simplicity. In this study, the performance of some data encryption and decryption schemes used to secure medical data is evaluated. These schemes are Blowfish, DES, AES, RC4, RSA, ECC, CBE, MTLM and CEC. The performance of these schemes was assessed through their execution time, throughput, average data rate and information entropy. For this performance assessment, some medical data were used for this task. The results showed that the performance of CBE, MTLM and CEC was better. CBE and MTLM offer a secure way to encrypt data with a significant reduction in the execution time. Moreover, if some of these schemes were combined to form a hybrid system, an enhancement in the security of medical data over wireless communication networks is guaranteed

Impact of Pressure-Driven Demand on Background Leakage Estimation in Water Supply Networks

Increasing water demand due to urbanization creates a need to develop schemes for managing water supply networks (WSNs). In recent years, hydraulic modeling of WSNs has been used to assess the state of networks in terms of leakage analysis and pressure control. These models are based on demand-driven modeling (DDM) analysis and pressure-driven modeling (PDM) analysis. The former assumes that the nodal demand is fulfilled consistently regardless of the nodal pressure head. The latter appraises the demand as a function of the available pressure head at the nodes. In a previous paper by Adedeji et al. (2017), an algorithm was presented for background leakage detection and estimation in WSNs. The results demonstrated that the algorithm allows the detection of critical pipes and the indication of the nodes where such critical pipes are located for possible pressure control. However, such an algorithm assumes a demand-driven condition of WSNs. In this paper, a pressure-driven modeling is integrated into the developed algorithm with emphasis on its impact on the background leakage estimate. The results obtained are compared to the demand-driven analysis using two WSNs as case studies. The results presented, which consider pipe and node levels, demonstrate that the reliance of the nodal demand on the available pressure head at the node influences the magnitude of the background leakage flow. It is conceived that this investigation might be crucial for the background leakage estimation while considering WSNs operating under pressure-deficient conditions. In this paper, the solution time for both simulation scenarios is also presented

Cyber-Physical Systems for Water Supply Network Management: Basics, Challenges, and Roadmap

Water supply systems are dynamic in nature, owing to the effect of climate change and consumer demand uncertainties. The operation of such a system must be managed effectively to meet up with the uncertainties, thus posing a key challenge. Unfortunately, previous information and communication technology (ICT) solutions could not provide the necessary support for applications to deal with the dynamics of the changing physical environment. Nevertheless, tremendous growth in technology offers better possibilities to enhance water supply systems’ operations. As a result, development in technology in sensing and instrumentation, communication and networking, computing and control is now jointly integrated with water supply system infrastructures to enhance the water system operations. One such technological paradigm shift is the cyber-physical system (CPS). In this paper, we present the concept of the CPS in the water system context and investigate the CPS applications to water supply system monitoring. Also, the various applications of CPSs and the application domain requirements are outlined. More importantly, research studies on its application to water system monitoring are scrutinized. As such, key challenges sounding the applications in WSSs are identified. We then outline the areas of improvement for further studies

Improved Image Encryption for Real-Time Application over Wireless Communication Networks using Hybrid Cryptography Technique

Advances in communication networks have enabled organization to send confidential data such as digital images over wireless networks. However, the broadcast nature of wireless communication channel has made it vulnerable to attack from eavesdroppers. We have developed a hybrid cryptography technique, and we present its application to digital images as a means of improving the security of digital image for transmission over wireless communication networks. The hybrid technique uses a combination of a symmetric (Data Encryption Standard) and asymmetric (Rivest Shamir Adleman) cryptographic algorithms to secure data to be transmitted between different nodes of a wireless network. Three different image samples of type jpeg, png and jpg were tested using this technique. The results obtained showed that the hybrid system encrypt the images with minimal simulation time, and high throughput. More importantly, there is no relation or information between the original images and their encrypted form, according to Shannon’s definition of perfect security, thereby making the system much more secure

Mutual Coupling Effect and Reduction Method with Modified Electromagnetic Band Gap in UWB MIMO Antenna

In this paper, an effective technique for mutual coupling (MC) reduction between antenna elements of two multiple input multiple output (MIMO) microstrip patch antennas operating in the ultra-wide band (UWB) between 3.1 and 13.5 GHz is presented. The antenna array separation was kept at 44 mm for investigation, and the isolation was achieved through a modified electromagnetic band gap (MEBG) decoupling structure. The MEBG is embedded behind the radiating elements connected to the ground plane. HFSSv15 software was used to design and simulate the antenna. The effectiveness of the antenna and the MC reduction method was examined with and without the MEBG structure. The results revealed that the MC between the MIMO antenna elements was minimized when the MEBG structure was introduced. An MC of about −23 dB was obtained over the entire UWB frequency spectrum. This is more than a 10 dB improvement over the reference antenna (without the MEBG structure). Without limiting the effectiveness of the antenna when the MEBG structure was introduced, the results of the envelope correlation coefficient (ECC) gave the antenna a satisfactory diversity performance. The MEBG UWB MIMO antenna has an ECC less than 0.09 with a wide bandwidth. In addition, the total gain and the Voltage Standing Ware Ratio (VSWR) results were analyzed, which show that the performance of the antenna was not degraded while reducing the MC effect between the MIMO antenna elements

Leakage Detection and Estimation Algorithm for Loss Reduction in Water Piping Networks

Water loss through leaking pipes constitutes a major challenge to the operational service of water utilities. In recent years, increasing concern about the financial loss and environmental pollution caused by leaking pipes has been driving the development of efficient algorithms for detecting leakage in water piping networks. Water distribution networks (WDNs) are disperse in nature with numerous number of nodes and branches. Consequently, identifying the segment(s) of the network and the exact leaking pipelines connected to this segment(s) where higher background leakage outflow occurs is a challenging task. Background leakage concerns the outflow from small cracks or deteriorated joints. In addition, because they are diffuse flow, they are not characterised by quick pressure drop and are not detectable by measuring instruments. Consequently, they go unreported for a long period of time posing a threat to water loss volume. Most of the existing research focuses on the detection and localisation of burst type leakages which are characterised by a sudden pressure drop. In this work, an algorithm for detecting and estimating background leakage in water distribution networks is presented. The algorithm integrates a leakage model into a classical WDN hydraulic model for solving the network leakage flows. The applicability of the developed algorithm is demonstrated on two different water networks. The results of the tested networks are discussed and the solutions obtained show the benefits of the proposed algorithm. A noteworthy evidence is that the algorithm permits the detection of critical segments or pipes of the network experiencing higher leakage outflow and indicates the probable pipes of the network where pressure control can be performed. However, the possible position of pressure control elements along such critical pipes will be addressed in future work