Signal and Information Processing Methods for Embedded Robotic Tactile Sensing Systems

The human skin has several sensors with different properties and responses that are able to detect stimuli resulting from mechanical stimulations. Pressure sensors are the most important type of receptors for the exploration and manipulation of objects. In the last decades, smart tactile sensing based on different sensing techniques have been developed as their application in robotics and prosthetics is considered of huge interest, mainly driven by the prospect of autonomous and intelligent robots that can interact with the environment. However, regarding object properties estimation on robots, hardness detection is still a major limitation due to the lack of techniques to estimate it. Furthermore, finding processing methods that can interpret the measured information from multiple sensors and extract relevant information is a Challenging task. Moreover, embedding processing methods and machine learning algorithms in robotic applications to extract meaningful information such as object properties from tactile data is an ongoing challenge, which is controlled by the device constraints (power constraint, memory constraints, etc.), the computational complexity of the processing and machine learning algorithms, the application requirements (real-time operations, high prediction performance). In this dissertation, we focus on the design and implementation of pre-processing methods and machine learning algorithms to handle the aforementioned challenges for a tactile sensing system in robotic application. First, we propose a tactile sensing system for robotic application. Then we present efficient preprocessing and feature extraction methods for our tactile sensors. Then we propose a learning strategy to reduce the computational cost of our processing unit in object classification using sensorized Baxter robot. Finally, we present a real-time robotic tactile sensing system for hardness classification on a resource-constrained devices. The first study represents a further assessment of the sensing system that is based on the PVDF sensors and the interface electronics developed in our lab. In particular, first, it presents the development of a skin patch (multilayer structure) that allows us to use the sensors in several applications such as robotic hand/grippers. Second, it shows the characterization of the developed skin patch. Third, it validates the sensing system. Moreover, we designed a filter to remove noise and detect touch. The experimental assessment demonstrated that the developed skin patch and the interface electronics indeed can detect different touch patterns and stimulus waveforms. Moreover, the results of the experiments defined the frequency range of interest and the response of the system to realistic interactions with the sensing system to grasp and release events. In the next study, we presented an easy integration of our tactile sensing system into Baxter gripper. Computationally efficient pre-processing techniques were designed to filter the signal and extract relevant information from multiple sensor signals, in addition to feature extraction methods. These processing methods aim in turn to reduce also the computational complexity of machine learning algorithms utilized for object classification. The proposed system and processing strategy were evaluated on object classification application by integrating our system into the gripper and we collected data by grasping multiple objects. We further proposed a learning strategy to accomplish a trade-off between the generalization accuracy and the computational cost of the whole processing unit. The proposed pre-processing and feature extraction techniques together with the learning strategy have led to models with extremely low complexity and very high generalization accuracy. Moreover, the support vector machine achieved the best trade-off between accuracy and computational cost on tactile data from our sensors. Finally, we presented the development and implementation on the edge of a real–time tactile sensing system for hardness classification on Baxter robot based on machine and deep learning algorithms. We developed and implemented in plain C a set of functions that provide the fundamental layer functionalities of the Machine learning and Deep Learning models (ML and DL), along with the pre–processing methods to extract the features and normalize the data. The models can be deployed to any device that supports C code since it does not rely on any of the existing libraries. Shallow ML/DL algorithms for the deployment on resource–constrained devices are designed. To evaluate our work, we collected data by grasping objects of different hardness and shape. Two classification problems were addressed: 5 levels of hardness classified on the same objects’ shape, and 5 levels of hardness classified on two different objects’ shape. Furthermore, optimization techniques were employed. The models and pre–processing were implemented on a resource constrained device, where we assessed the performance of the system in terms of accuracy, memory footprint, time latency, and energy consumption. We achieved for both classification problems a real-time inference (< 0.08 ms), low power consumption (i.e., 3.35 μJ), extremely small models (i.e., 1576 Byte), and high accuracy (above 98%)

ASSESSMENT OF NEIGHBORHOOD VITALITY IN DOHA

Well-functioning urban environments are good causes of societies living healthily and happily. The performance of the public realm plays an important role, in this regard, where societies are in direct contact with their physical environment. Urban environments should be created in which economic prosperity, social cohesion, and citizenship occur. The concept of urban vitality achieves this through being concerned with the socio-cultural, experiential, and spatial dimensions of the urban environment. On the scale of intimate communities, vitality plays a significant role in encouraging behaviours, social interactions, in the neighbourhood. Three domains are studied to define urban vitality: the society, its activities, and its physical environment. Considering the local context of the thesis, the rapid growth of vehicle-oriented neighbourhoods in Doha is leading to a decline in their degree of vitality. In many cases, this leads to a lower quality of urban life and a decline in the vitality of the city. Therefore, this thesis aims to assess the degree of neighbourhood vitality in Doha in order to recommend actions for areas of improvements. Study neighbourhoods are selected based on their geographical location within Doha and filtered by the average population density. Fereej Bin Mahmoud (downtown), Al-Thumama (suburban), and Al-Dafna (waterfront) neighbourhoods were selected. The assessment is approached through establishing a neighbourhood vitality index which was aggregated from the individual scores of socio-cultural, experiential, and spatial dimensions of neighbourhood vitality. This approach is supported by three data collection tools: questionnaire survey, observations, and semi-structured interviews. A total of ninety questionnaires were collected from residents, along with six neighbourhood observations, during morning and evening hours to study the functionality of the public realm. Results of the vitality index calculations showed that downtown and suburban neighbourhoods were indexed as moderately vital, whereas waterfront neighbourhoods were indexed as vital. Results of the analysis showed that three main factors should be considered to enhance the degree of vitality in neighbourhoods: culture, climate, and context. Planning and design approaches should consider these factors to create well-functioning public realms through accessible streets and shaded, green public spaces

Lateral column lengthening augmented by medial split tibialis posterior tendon advancement for the treatment of symptomatic flexible flatfeet

Background: Management of Idiopathic flexible pes planus (IFPP) is debatable. Surgery is rarely indicated for flexible flatfoot. The goal of the surgery should be always to treat symptomatic patients and not to alter the shape of the foot. There are numerous options for surgical treatment in children and adolescents including subtalar arthroereisis or osteotomy with or without soft tissue procedures.Methods: Between June 2013 to December 2017, twenty eight feet in sixteen patients (9 boys, 7 girls) were included in this study. Twelve cases were operated bilaterally, three in the right foot and one in the left side. The mean age of the patients was 8.36±1.704 years (6-12 years). Calcaneal lengthening osteotomy was done with an oscillating saw about 1.5 cm proximal to the calcaneocuboid joint. Usually, 8-10 mm autologous bone graft from iliac crest was sufficient and fixed by K wires. Half of the tibialis posterior tendon after splitting with a periosteal flap from the navicular was then advanced distally until clinical restoration of the medial arch was then performed.Results: Radiographic analysis revealed significant improvements in talo-first metatarsal, calcaneal pitch, talocalcaneal angles in lateral radiographs, and talo-first metatarsal and talonavicular coverage angles in AP radiographs. All patients were evaluated at final follow-up visits. Preoperative mean AOFAS score increased significantly from 64.04±8.867 (range: 50 to75) to 94.11±3.765 (90-100).Conclusions: It is concluded that Evans calcaneal lengthening osteotomy augmented by spilt tibialis posterior tendon advancement is an excellent procedure in the management of IFPP

Trans-Sense: Real Time Transportation Schedule Estimation Using Smart Phones

Developing countries suffer from traffic congestion, poorly planned road/rail networks, and lack of access to public transportation facilities. This context results in an increase in fuel consumption, pollution level, monetary losses, massive delays, and less productivity. On the other hand, it has a negative impact on the commuters feelings and moods. Availability of real-time transit information - by providing public transportation vehicles locations using GPS devices - helps in estimating a passenger's waiting time and addressing the above issues. However, such solution is expensive for developing countries. This paper aims at designing and implementing a crowd-sourced mobile phones-based solution to estimate the expected waiting time of a passenger in public transit systems, the prediction of the remaining time to get on/off a vehicle, and to construct a real time public transit schedule. Trans-Sense has been evaluated using real data collected for over 800 hours, on a daily basis, by different Android phones, and using different light rail transit lines at different time spans. The results show that Trans-Sense can achieve an average recall and precision of 95.35% and 90.1%, respectively, in discriminating lightrail stations. Moreover, the empirical distributions governing the different time delays affecting a passenger's total trip time enable predicting the right time of arrival of a passenger to her destination with an accuracy of 91.81%.In addition, the system estimates the stations dimensions with an accuracy of 95.71%.Comment: 8 pages, 11 figures

Ankle reconstruction in type II fibular hemimelia

Ankle reconstruction prior to limb lengthening for was performed in 13 patients with fibular hemimelia with complete radiological absence of the fibula (type II). There were different degrees of absence of metatarsal rays. The hindfoot deformity was a heel valgus in 12 patients and equinovarus in 1 patient. The patients’ ages ranged from 9 to 26 months. Excision of the fibular anlage was performed with lateral subtalar and ankle soft tissue releases to restore the ankle and subtalar joint relationships. In all cases, the fibular anlage ended distally in a cartilaginous lateral malleolar remnant that was fused to the talus in two patients. This fibular remnant was advanced distally and fixed to the tibia with 2 Kirschner wires to recreate an ankle mortise. The period of follow-up ranged from 12 to 38 months. All patients had a stable ankle without tendency to valgus deformity or subluxation. The ankle range of movement was a mean of 27.3° plantarflexion (25–30) and 18° dorsiflexion (15–20). Reconstruction of the ankle in type II fibular hemimelia using advancement of the cartilaginous lateral malleolar remnant has produced encouraging results in the short-term but longer follow-up is needed

SALAM: A SCALABLE ANCHOR-FREE LOCALIZATION ALGORITHM FOR WIRELESS SENSOR NETWORKS

In this dissertation, we present SALAM, a scalable anchor-free protocol for localization in wireless sensor networks. SALAM can determine the positions of sensor nodes without any infrastructure support. We assume that each node has the capability to estimate distances to its corresponding neighbors, that are within its transmission range. SALAM allows to trade the accuracy of the estimated position against node transmission range and/or computational power. The application layer can choose from a whole range of different options, to estimate the sensor node's positions with different accuracy while conserving battery power. Scalability is achieved by dividing the network into overlapping multi-hop clusters each with its own cluster head node. Each cluster head is responsible for building a local relative map corresponding to its cluster using intra-cluster node's range measurements. To obtain the global relative topology of the network, the cluster head nodes collaboratively combine their local maps using simple matrix transformations. In order for two cluster heads to perform a matrix transformation, there must be at least three boundary nodes that belongs to both clusters (i.e. the two clusters are overlapping with degree 3). We formulate the overlapping multi-hop clustering problem and present a randomized distributed heuristic algorithm for solving the problem. We evaluate the performance of the proposed algorithm through analytical analysis and simulation. A major problem with multi-hop relative location estimation is the error accumulated in the node position as it becomes multi-hop away from the cluster head node. We analyze different sources of error and develop techniques to avoid these errors. We also show how the local coordinate system (LCS) affects the accuracy and propose different heuristics to select the LCS. Simulation results show that SALAM achieves precise localization of sensors. We show that our approach is scalable in terms of communication overhead regardless of the network size. In addition, we capture the impact of different parameters on the accuracy of the estimated node's positions. The results also show that SALAM is able to achieve accuracy better than the current ad-hoc localization algorithms

THE ROLE OF CORPORATE GOVERNANCE IN ACHIEVING ACCOUNTING INFORMATION QUALITY (FIELD STUDY IN THE MISHRAQ SULFUR STATE CO.)

Under the new worldwide changes that were produced by the economic data and technological revolution, corporate governance considered as one of the modern terms. Its importance increased in the business sector because it plays a role in managing any company, and protecting the shareholders’ rights. There are several thoughts on the importance of corporate governance. Some thought that corporate governance is important in the public sector because it influence the economy. Others thought corporate governance is very important in the privet sector. The importance of the term, corporate governance, increased in all institutions and in all advanced and emerging economies in the last few decades especially after the economic and financial crisis that many countries underwent. These crisis affected the global financial market; such as, the crisis in Southeast Asia in 1997. Moreover, many major international companies especially the American companies collapsed in Fall 2008 because they used complex accounting methods in order to hide their loses and manipulate the rights of people; such as, shareholders, lenders, suppliers, and even the civil society. Hence, the governance became one of the important topics that are applied in both privet and public companies. The reason many shareholders lost their trust in the financial market is that companies’ managers and auditors concealed the financial and accounting statements that are applied in all kind of companies. Mistrust was created in the financial reports, and it increased anytime one of the huge companies stumbled. Therefore, this study shows the overlapping and reciprocal relationship between corporate governance and the accounting information quality. Apparently, the accounting information is affected by the rules and mechanisms of governance, and applying it means increasing the trustworthy of the accounting information that are included in financial statements that were prepared for all interested parts

Liquid-liquid extraction technique for purification of Egyptian WET process phosphoric acid

High grade phosphoric acid can be obtained using liquid-liquid extraction technique. Different organic solvents were investigated, separately or in mixture, viz. butanol, hexanol, octanol and a mixture of tributylphosphate plus butanol. Among these solvents, n-octanol proved to be the most efficient and selective. The effects of organic solvent concentration, organic/aqueous (O/A) phase ratio, temperature, shaking time and phosphoric acid concentration on P2O5 extraction were studied. The temperature has a slight positive effect and the extraction was enhanced by increasing P2O5 and octanol concentrations and with the increase of organic/aqueous phase ratio. The McCabe Thiele extraction equilibrium curve showed that an overall extraction yield of more than 80% could be reached over three stages from aqueous solutions. Scrubbing and stripping were also investigated. Scrubbing of the loaded organic acid was done using pure phosphoric acid while stripping of H3PO4 was successfully performed using doubly di stilled water (DDW). For 9.2 M H3PO4, 99.90% of iron, 97.99% of fluoride and 99.99% of manganese were removed whereas complete removal of copper, cadmium and zinc was attained