Engineering Commons^™

Bio-Inspired Method For Close-Proximity Operations On A Near-Earth Asteroid, Rene Alberto Valenzuela Najera

Open Access Theses & Dissertations

Space maneuvers in the vicinity of small celestial bodies and achieving a soft landing over the surface of small celestial bodies are essential movements to advance the status of exploration, collection of geographical data, measurement of physical properties among other on-orbit tasks. Before a spacecraft reaches hovering position over an asteroid in order to perform orbital tasks, close-proximity operations must be done. Since the movements of the spaceships depend on the acceleration forces provided by the thrusters and external disturbances forces, the correct planning of execution of the close-up trajectories on the celestial body orbit and trajectory to land on …

Synthesis And Characterization Of Material Systems For 3d Printed Smart Structures, Hilda Fontes

Open Access Theses & Dissertations

The silica hollow spheres have demonstrated excellent results in multiple applications such as light-weight composites, and optical applications as a glass coating. This material also exhibits excellent thermal, shock impact, and hydrophilic properties extremely useful for industrial applications. However, a controllable size of the particle is desired to further increase the number of applications of the silica hollow spheres.

This Thesis aims a method to fabricate silica hollow spheres in a single step with a controlled diameter size. A study was developed to demonstrate the particle size change when adjusting the molecular weight of the medium by using different alcohol …

Enhanced Gas Barrier Properties Of Graphene Oxide/Rubber Composites With Strong Interfaces Constructed By Graphene Oxide And Sulfur, Long Zheng, Stephen Jerrams, Zongchao Xu, Liqun Zhang, Li Liu, Shipeng Wen

Articles

Constructing strong interfacial interactions and complex filler networks is crucial to establishing high gas barrier properties in rubber composites. In this research, sulfur-graphene oxide (S-GO) hybrids were prepared by in situ growth of sulfur on the surfaces of GO sheets. The S-GO hybrids were also introduced into butadiene styrene rubber (SBR) using a green method of latex compounding. Results showed that sulfur could melt and spread on the surface of the GO during the crosslinking process at high temperatures. This process prevented the aggregation of GO and resulted in a fine dispersion of GO and complex filler networks in S-GO/SBR …

Enhanced Covalent Interface, Crosslinked Network And Gas Barrier Property Of Functionalized Graphene Oxide/Styrene-Butadiene Rubber Composites Triggered By Thiol-Ene Click Reaction, Long Zheng, Stephen Jerrams, Tian Su, Zongchao Xu, Liqun Zhang, Li Liu, Shipeng Wen

Articles

The high gas barrier property of a rubber composite is of great significance for reducing the exhaust gas emissions due to tire rolling resistance and hence the contribution this factor makes to environmental protection. Enhanced covalent interfaces and crosslinked networks are crucial to the gas barrier property of rubber composites. In this research, γ-mercaptopropyltriethoxysilane (MPS) modified GO (MGO)/styrene-butadiene rubber (SBR) composites were prepared by a synergetic strategy of latex compounding method and thiol-ene click reaction. It was found that the mercapto groups in MGO reacted with the vinyl groups in SBR molecules through thiol-ene click reaction during the crosslinking process …

An Examination Of The Role Of Spatial Ability In The Process Of Problem Solving In Chemical Engineering, Sheryl Sorby, Gavin Duffy, Norman Loney

Articles

Engineers often communicate with one another through drawings or sketches and understanding technical information through graphical representations is a skill necessary for engineering practice. Well-developed spatial skills are known to be important to understanding technical drawings and are therefore, important to success in engineering. Unfortunately, of all cognitive processes, spatial skills show robust gender differences, favouring males, which could contribute to the underrepresentation of women in engineering. In this research, we administered a test of spatial cognition to students enrolled in a common 3rd year course in chemical engineering . In a second session, students were given a set of …

Context-Aware System For Glycemic Control In Diabetic Patients Using Neural Networks, Owais Bhat, Dawood A. Khan

Turkish Journal of Electrical Engineering and Computer Sciences

Diabetic patients are quite hesitant in engaging in normal physiological activities due to difficulties associated with diabetes management. Over the last few decades, there have been advancements in the computational power of embedded systems and glucose sensing technologies. These advancements have attracted the attention of researchers around the globe developing automatic insulin delivery systems. In this paper, a method of closed-loop control of diabetes based on neural networks is proposed. These neural networks are used for making predictions based on the clinical data of a patient. A neural network feedback controller is also designed to provide a glycemic response by …

Automatic Characterization Of Copy Number Polymorphism Using High Throughput Sequencing, Can Alkan

Turkish Journal of Electrical Engineering and Computer Sciences

Genome structural variation, broadly defined as alterations longer than 50 bp, are important sources for genetic variation among humans, including those that cause complex diseases such as autism, developmental delay, and schizophrenia. Although there has been considerable progress in characterizing structural variation since the beginnings of the 1000 Genomes Project, one form of structural variation called segmental duplications (SDs) remained largely understudied in large cohorts. This is mostly because SDs cannot be accurately discovered using the alignment files generated with standard read mapping tools. Instead, they can only be found when multiple map locations are considered. There is still a …

A Power And Area Efficient Approximate Carry Skip Adder For Error Resilient Applications, Sujit Patel, Bharat Garg, Shireesh Kumar Rai

Turkish Journal of Electrical Engineering and Computer Sciences

The compute-intensive multimedia applications on portable devices require power and area efficient arithmetic units. The adder is a prime building block of these arithmetic units and limits the overall performance. Therefore, this paper analyzes the logic operations of the state-of-the-art adders and presents a novel low complexity adder segment with new carry prediction logic by removing the redundant logic and sharing the common operations. Further, a new power and area efficient approximate carry skip (PAEA-CSK) adder is proposed using the novel adder segment. The effectiveness of the proposed PAEA-CSK adder is evaluated and compared over the existing adders by implementing …

Rule Extraction And Performance Estimation By Using Variable Neighborhoodsearch For Solar Power Plant In Konya, Yusuf Uzun, Muci̇z Özcan

Turkish Journal of Electrical Engineering and Computer Sciences

The use of renewable energy sources in the production of electricity has become inevitable in order to reduce the greenhouse gases left in the atmosphere that cause the Earth to warm up. Although countries on a national basis have implemented a number of policies to support electricity generated from renewable energy sources, investments to produce electricity without a license on a local basis are not desirable. Those who want to invest medium and small scale for the most reason expect that this work will be supported by real data. Although the electricity generated by renewable investments is generated by simulation …

Robust Optimal Operation Of Smart Distribution Grids With Renewable Basedgenerators, Omid Zare, Sadjad Galvani, Murtaza Farsadi

Turkish Journal of Electrical Engineering and Computer Sciences

Modern distribution systems are equipped with various distributed energy resources (DERs) because of the importance of local generation. These distribution systems encounter more and more uncertainties because of the ever-increasing use of renewable energies. Other sources of uncertainty, such as load variation and system components? failure, will intensify the unpredictable nature of modern distribution systems. Integrating energy storage systems into distribution grids can play a role as a flexible bidirectional source to accommodate issues from constantly varying loads and renewable resources. The overall functionality of these modern distribution systems is enhanced using communication and computational abilities in smart grid frameworks. …

Lattice-Reduction Aided Multiple-Symbol Differential Detection In Two-Way Relay Transmission, Chanfei Wang, Minghua Cao

Turkish Journal of Electrical Engineering and Computer Sciences

Multiple-symbol differential detection (MSDD) algorithms are proposed in two-way relay transmission (TWRT). Firstly, generalized likelihood ratio test based MSDD (GLRT-MSDD) is proposed in TWRT. Unfortunately, as the number of observation windows increases, the computational complexity of GLRT-MSDD increases exponentially. Hence, this detection in TWRT constitutes a challenging problem. Moreover, we find a way to reformulate the GLRTMSDD model and additionally propose a lattice-reduction aided MSDD (LR-MSDD) model. Performance analysis and simulations show that the proposed LR-MSDD provides bit-error rate performance close to that of GLRT-MSDD with lower complexity in TWRT.

Emulation Of Burst-Based Adaptive Link Rates In Netfpga Towards Green Networking, Shahul Hamead H, Mirnalinee Tt, Kavi Priya D

Turkish Journal of Electrical Engineering and Computer Sciences

In recent times, energy consumption in communication media has been increasing drastically. In the literature, energy-saving techniques that enable network devices to enter sleep state or limit the data rate have been proposed to reduce energy costs. In our earlier work, we proposed an energy-saving technique called burst-based adaptive link rate (BBALR), the simulation of which assures increased energy savings. In this paper, we have emulated the hardware implementation of BBALR and compared its performance with the outputs of other prominent energy-saving policies based on dynamic link rate adaption. The energy savings are mapped from the measured sleep time and …

Assessment Of Environmental Factors Affecting Software Reliability: A Survey Study, Alper Özcan, Çağatay Çatal, Cengi̇z Toğay, Bedi̇r Teki̇nerdoğan, Emrah Dönmez

Turkish Journal of Electrical Engineering and Computer Sciences

Currently, many systems depend on software, and software reliability as such has become one of the key challenges. Several studies have been carried out that focus on the impact of external environmental factors that impact software reliability. These studies, however, were all carried out in the same geographical context. Given the rapid developments in software engineering, this study aims to identify and reinvestigate the environmental factors that impact software reliability by also considering a different context. The environmental factors that have an impact on software reliability as reported in earlier studies have been analyzed and synthesized. Subsequently, a survey study …

Improving Performance Of Indoor Localization Using Compressive Sensing Andnormal Hedge Algorithm, Saeid Hassanhosseini, Mohammad Reza Taban, Jamshid Abouei, Arash Mohammadi

Turkish Journal of Electrical Engineering and Computer Sciences

Accurate indoor localization technologies are currently in high demand in wireless sensor networks, which strongly drive the development of various wireless applications including healthcare monitoring, patient tracking and endoscopic capsule localization. The precise position determination requires exact estimation of the time varying characteristics of wireless channels. In this paper, we address this issue and propose a three-phased scheme, which employs an optimal single stage TDOA/FDOA/AOA indoor localization based on spatial sparsity. The first contribution is to formulate the received unknown signals from the emitter as a compressive sensing problem. Then, we solve an $\ell_1$ minimization problem to localize the emitter's …

Optimal Svc Allocation In Power Systems Using Lightning Attachment Procedureoptimization, Ayman Awad, Salah Kamel, Heba Youssef, Francisco Jurado

Turkish Journal of Electrical Engineering and Computer Sciences

Flexible AC transmission systems (FACTS) technology is widely adopted and utilized to maintain the performance of power systems. However, the improvements of power system performance achieved by FACTS devices depend on the right sizing and allocation of such devices. For technical and economic considerations, a FACTS device's location and size should be selected very carefully in order to maximize its benefits to the power system. In this paper, the sizing and location of a static VAR compensator (SVC) are optimally determined using a new optimization technique called lightning attachment procedure optimization (LAPO). The optimal allocation of the SVC is determined …

Fiber Optic Chemical Sensors For Water Testing By Using Fiber Loop Ringdown Spectroscopy Technique, Mali̇k Kaya

Turkish Journal of Electrical Engineering and Computer Sciences

Real-time response, low cost, sensitive and easy setup fiber optic chemical sensors were fabricated by etching a part of single mode fiber in hydrofluoric (HF) acid solution and tested in different water samples such as tap water, DI water, salty and sugar water with different concentrations to record ringdown time (RDT) differences between media due to refractive index differences by employing the fiber loop ringdown (FLRD) spectroscopy technique. Baseline stability of 0.63 % and the minimum detectable RDT of $5.05$ $\mu$s for this kind of fiber optic chemical sensors were obtained. Fabricated sensors were coated with N,N-Diethyl-p-phenylenediamine for the first …

Prominent Quality Attributes Of Crisis Software Systems: A Literature Review, Ahmet Ari̇f Aydin

Turkish Journal of Electrical Engineering and Computer Sciences

Developing software systems to meet user-demanded functionality is critical. Achieving the design goals by providing the needed functionality is a necessary task, and it is about figuring out a proper set of quality attributes and implementing each one by reflecting a complete set of quality attributes. This study presents popular quality attributes of crisis software systems by conducting a literature review. Each crisis software system has been studied by concentrating on crisis management phases where the system is used, design purposes, and the data processing style. The findings of this research shed light on the crisis software development process by …

A Mechanism Of Qos Differentiation Based On Offset Time And Adjusted Burstlength In Obs Networks, Viet Minh Nhat Vo, Trung Duc Pham, Thanh Chuong Dang, Van Hoa Le

Turkish Journal of Electrical Engineering and Computer Sciences

Quality of service (QoS) differentiation is an integral component of any networking system, particularly, with the current and future great diversity of users? applications and their manifold requirements. In optical burst switching (OBS) networks, there are two approaches for QoS differentiation: one is based on offset time and the other is based on burst length. This paper presents a mechanism of QoS differentiation based on both offset time and burst length, in which the offset times are calculated to achieve a complete isolation of data loss between priority classes and the burst length is adaptively adjusted according to the feedbacked …

Diagnosis Of Speed Sensor Faults In An Induction Machine Based On A Robustadaptive Super-Twisting Observer, Mohammed Zakaria Kari, Abdelkader Mechernene, Sidi Mohammed Meliani, Ibrahim Guenoune

Turkish Journal of Electrical Engineering and Computer Sciences

The present paper aims to determine a robust sensor fault-tolerant controller based on fuzzy logic using a robust adaptive super-twisting observer for the control of an induction machine and an inverter set by a state estimation method. The speed sensor is considered in the present case. The modular structure of the fault-tolerant control (FTC) scheme allows integrating this sensor within the existing closed-loop system, and the observer can therefore be designed independently. This article presents a new method to develop a fuzzy decision system that provides faulttolerant control. This paper also aims at detecting the mechanical speed sensor faults. The …

Sdma-Based Distributed Device Discovery For D2d Communication, Muddasir Rahim, Muhammad Awais Javed, Ahmad Naseem Alvi

Turkish Journal of Electrical Engineering and Computer Sciences

Device-to-device (D2D) communication is an important technique to improve capacity of future wireless networks. Cellular communications, internet of things and intelligent transport systems are key areas that could benefit from reduced end-to-end delay provided by D2D communication. Efficient device discovery is an important precondition to enable D2D communication. In this paper, we propose a space division multiple access (SDMA)-based distributed device discovery protocol in which user equipments (UEs) periodically transmit discovery beacons to each other. The proposed protocol reduces contention in the discovery beacons by allocating resource blocks to the UEs based on their location. Simulations results show that the …

A New Grid Partitioning Technology For Location Privacy Protection, Yue Sun, Lei Zhang, Jing Li, Zhen Zhang

Turkish Journal of Electrical Engineering and Computer Sciences

Nowadays, the location-based service (LBS) has become an essential part of convenient service in people's daily life. However, the untrusted LBS servers can store lots of information about the user, such as the user's identity, location, and destination. Then the information can be used as background knowledge and combined with the query frequency of the user to launch the inference attack to obtain user's privacy. In most of the existing schemes, the author considers the algorithm of virtual location selection from the historical location of the user. However, the LBS server can infer the user's location information on the historical …

Simultaneous Measurement Of Displacement And Temperature Based On Two Cascaded Balloon-Like Bent Fibre Structures, Ke Tian, Ruoning Wang, Meng Zhang, Xiafan Wang, Xin Wang, Guoyong Jin, Elfed Lewis, Gerald Farrell, Pengfei Wang

Articles

A low-cost optical fibre sensor based on two cascaded balloon-like bent fibre (BBF) structures for simultaneous displacement and temperature measurement is reported. The sensor is fabricated by cascading two balloon-like bent single-mode fibres (SMFs) which with different bending radii, generating two separate interference dips within a limited wavelength range. The wavelength of the two interference dips exhibits different responses to external displacement and temperature variations, hence simultaneous measurement of displacement and temperature is realized. Experimental results show that the proposed optical fibre sensor achieves a displacement sensitivity of −318.8 pm/μm and a temperature sensitivity of 47.4 pm/°C. Taking advantage of …

Saperi: Approaching Gender Gap Using Spatial Ability Training Week In High-School Context, Maria Giulia Ballatore, Gavin Duffy, Sheryl Sorby, Anita Tabacco

Articles

Maria Giulia Ballatore, Gavin Duffy, Sheryl Sorby, and Anita Tabacco. 2020. SAperI: approaching gender gap using Spatial Ability training week in high-school context. In Eighth International Conference on Technological Ecosystems for Enhancing Multiculturality (TEEM’20), October 21–23, 2020, Salamanca, Spain. ACM, New York, NY, USA, 7 pages. https://doi.org/10.1145/3434780.3436577

Color Variation Of The Up-Conversion Luminescence In Er3+-Yb3+Co-Doped Lead Germanate Glasses And Microsphere Integrated Devices, Meng Zhang, Ke Tian, Shunbin Wang, Libo Yuan, Gerald Farrell, Elfed Lewis, Pengfei Wang

Articles

Abstract—Lead germanate glass samples co-doped with different Er3+/Yb3+ concentrations were prepared and the color variation of the up-conversion emissions in these glasses was observed using a 980 nm laser pump. A practical optical integrated device based on Er3+ -Yb3+ co-doped lead germanate glass microsphere and a special fiber structure, consisting of single mode fiber (SMF), multimode fiber (MMF) and a suspended tricore hollow fiber (STCHF) is described. As the pump light is coupled into the microsphere from the cores suspended inside the STCHF, the microsphere fixed in the air hole of the STCHF is excited and the up-conversion emissions are …

Investigation On The Polarization Dependence Of An Angled Polished Multimode Fibre Structure, Ruoning Wang, Ke Tian, Meng Zhang, Yuxuan Jiang, Libo Yuan, Guoyong Jin, Gerald Farrell, Elfed Lewis, Pengfei Wang

Articles

An angled polished multimode (APM) fibre structure is described for the first time, to the best our knowledge, and its polarization dependence is investigated theoretically and experimentally. Two angled planes are established in the multimode fibre (MMF) section of a single-mode-multimode-single-mode (SMS) fibre structure using the fibre side-polishing technique, forming the APM fibre structure. This designed circular asymmetric geometry induces different propagation characteristics for the TE and TM modes within the MMF. Simulated and experimental results both show that this difference is enhanced as the polishing angle increases, and a maximum extinction ratio (ER) of the spectrum of 13 dB …

Queueing-Inventory Models For A Two-Vendor System With Positive Service Times, Srinivas Chakravarthy, Khizer Hayat

Industrial & Manufacturing Engineering Publications

Queueing-inventory systems wherein the demands are processed with random service times have been getting a lot of attention recently. In such systems, each demand needs one or more inventory items and needs positive processing times. The inventory is generally replenished using -type policy and the lead times are assumed to be random. In this paper we introduce the concept of multiple vendors who will be responsible for the replenishment of inventory. Under the assumptions of a two-vendor system wherein the demands occurring according to a Markovian arrival process, the service times to be of phase type, and the lead times …

Understandings Of "Global Responsibility’ Expressed By Civil Engineers Working In London, Shannon Chance, Inez Direito, J. Mitchell

Conference papers

This paper discusses the term ‘global responsibility’, how it emerged and why, and analysis of interview data collected from nine civil engineers working in London regarding their understandings of the term. Professional Bodies often take the lead in envisioning change, by identifying the direction their professionals should take to help address society’s evolving needs and aspirations. Often, such Bodies charge academia with addressing society’s evolving needs through research, outreach, and preparing the next generation of professionals. In the UK, leaders in civil engineering have pressed for individual and collective action to facilitate sustainable development and decrease occurrence of corruption. Nevertheless, …

Daylight: What Makes The Difference?, M. Knoop, O. Stefani, B. Bueno, B. Matusiak, R. Hobday, A. Wirz-Justice, K. Martiny, T. Tandermann, N. Zemmouri, S. Appelt, Brian Norton

Articles

Light is necessary for vision; it enables us to sense and perceive our surroundings and in many direct and indirect ways, via eye and skin, affects our physiological and psychological health. The use of light in built environments has comfort, behavioural, economic and environmental consequences. Daylight has many particular benefits including excellent visual performance, permitting good eyesight, effective entrainment of the circadian systemas well as a number of acute non-image forming effects and the important role of vitamin D production. Some human responses to daylight seem to be well defined whilst others require more research to be adequately understood. This …

Comparison Of Hybridizing Options For Solar Heat, Biomass And Heat Storage For Electricity Generation In Spain, Cm Iftekhar Hussain, Brian Norton, Aidan Duffy

Articles

Diurnal and seasonal variations of direct solar energy circumscribe locations suitable for sole use of concentrated solar power for electricity generation, whereas to generate electricity at night and during winter months, biomass systems can be used that incur fuel expenditures and may encounter fuel supply discontinuities. Combining solar heat, biomass conversion and heat storage in a hybrid electricity generation plant may overcome the limitations of sole use of any one of these energy sources in specific geographic and/or economic conditions. In this work standalone biomass, hybrid concentrated solar power-biomass and hybrid concentrated solar power-biomass-thermal energy storage power generation systems are …

Crystal-Field Engineering Of Ultrabroadband Mid-Infrared Emission In Co2+-Doped Nano-Chalcogenide Glass Composites, Xiasong Lu, Runan Zhang, Yindong Zhang, Shaoqian Zhang, Jing Ren, Lukas Strizik, Thomas Wagner, Gerald Farrell, Pengfei Wang

Articles

unable and ultrabroadband mid-infrared (MIR) emissions in the range of 2.5–4.5 μm are firstly reported from Co2+-doped nano-chalcogenide (ChG) glass composites. The composites embedded with a variety of binary (ZnS, CdS, ZnSe) and ternary (ZnCdS, ZnSSe) ChG nanocrystals (NCs) can be readily obtained by a simple one-step thermal annealing method. They are highly transparent in the near- and mid-infrared wavelength region. Low-cost and commercially available Er3+-doped fiber lasers can be used as the excitation source. By crystal-field engineering of the embedded NCs through cation- or anion-substitution, the emission properties of Co2+ including its emission peak wavelength and bandwidth can be …