Abstract: Nowadays, the increasing applicability of internet of things (IoT) systems has changed the way that the world around is perceived. The massive interconnection of systems by means of sensing, processing and communication, allows multitude of data to be at our fingertips. In this way, countless advances have been made in different fields such as personal care, predictive maintenance in industry, quality control in production processes, security, and in everything imaginable. However, all these electronic systems have in common the need to be electrically powered. In this context, batteries and wires are the most commonly used solutions, but they are not a definitive solution in some applications, because of the attainability, the serviceability, or the performance requirements. Therefore, the need arises to look for other types of solutions based on energy harvesting and long-life electronics. Energy Harvesting can be defined as the action of capturing energy from the environment and store it for an instantaneous use or later use. Among the materials capable of harvesting energy from the environment, such as thermoelectrics, electromagnetics, photovoltaics or triboelectrics, the most suitable is the piezoelectric material. The phenomenon of piezoelectricity is one of the most powerful sources for energy harvesting, ranging from a few micro wats to hundreds of wats, depending on certain factors such as material type, geometry, excitation frequency, mechanical and electrical configurations, among others. In this research work, an exhaustive study is carried out on how different types of piezoelectric materials and electrical configurations influence the maximum power that a bimorph harvester is able to extract from mechanical vibrations. A series of experiments has been carried out in which the manufactured bimorph specimens are excited under fixed inertial vibrational conditions. In addition, in order to evaluate the dependence of the maximum transferred power, different load resistors are tested. In this way, the pure active power that achieves the maximum power transfer can be approximated. In this paper, we present the design of low-cost energy harvesting solutions based on piezoelectric smart materials with tunable frequency. The results obtained show the differences in energy extraction between the PZT materials studied and their electrical configurations. The aim of this work is to gain a better understanding of the behavior of piezoelectric materials, and the design process of bimorph PZT harvesters to optimize environmental energy extraction.
Abstract: Religion and Development relation is one of the most arguable phrases amongst politicians, philosophers, clerics, scientists, sociologists and even the public. The main objective of this research is to clarify the relations, contrasts and interactions between religion and the major types of development including social, political, economic and scientific developments, by focusing on Islam religion. A review of the literature was performed concerning religion and development relations and conflicts, by focusing on Islam religion and then the unprocessed tips of the review were characterized. Regarding clarification of the key points of the literature, three main sectors were considered in the research. The first sector of the research mainly focused on the philosophical views on religion, which were analyzed by main evaluation of three famous philosophers’ ideas: ‘Kant’, ‘Hegel’ and ‘Weber’, and then a critical discussion on Weber’s idea about Islam and development was applied. The second sector was specified to ‘Religion and Development’ and mainly discussed the role of religion in development through poverty reduction, the interconnection of religion, spirituality and social development, religious education effects on social development, and the relation of religion with political development. The third sector was specified to ‘Islam and Development’ and mainly discussed the Islamic golden age of science, major reasons of today’s backwardness (non-development) of most Islamic countries, and Quranic instructions regarding adaptability of Islam with development. The findings of the current research approved the research hypothesis as: ‘Religious instructions (included Islam) are not in conflict with development’, rather, it could have positive effects mainly on social development and it can pave the way for society to develop. Turkey was considered as a study model, as a successful developed Islamic country demonstrating the non-conflicting relation of Islam and development.
Abstract: Over 60% highly transparent quasi-solid-state dye-sensitized solar cells (DSSCs) with dimension of 50x50 cm2 were fabricated via inkjet printing process using nanocomposite inks as raw materials and tested under outdoor illumination conditions. The cells were electrically characterized, and their possible application to the shell of greenhouses was also examined. The panel design was in Z-interconnection, where the working electrode was inkjet printed on one conductive glass and the counter electrode on a second glass in a sandwich configuration. Silver current collective fingers were printed on the glasses to make the internal electrical connections. In that case, the adjacent cells were connected in series via silver fingers and finally insulated using a UV curing resin to protect them from the corrosive (I-/I3-) redox couple of the electrolyte.
Abstract: One possible approach for maintaining the security of communication systems relies on Physical Layer Security mechanisms. However, in wireless time division duplex systems, where uplink and downlink channels are reciprocal, the channel estimate procedure is exposed to attacks known as pilot contamination, with the aim of having an enhanced data signal sent to the malicious user. The Shifted 2-N-PSK method involves two random legitimate pilots in the training phase, each of which belongs to a constellation, shifted from the original N-PSK symbols by certain degrees. In this paper, legitimate pilots’ offset values and their influence on the detection capabilities of the Shifted 2-N-PSK method are investigated. As the implementation of the technique depends on the relation between the shift angles rather than their specific values, the optimal interconnection between the two legitimate constellations is investigated. The results show that no regularity exists in the relation between the pilot contamination attacks (PCA) detection probability and the choice of offset values. Therefore, an adversary who aims to obtain the exact offset values can only employ a brute-force attack but the large number of possible combinations for the shifted constellations makes such a type of attack difficult to successfully mount. For this reason, the number of optimal shift value pairs is also studied for both 100% and 98% probabilities of detecting pilot contamination attacks. Although the Shifted 2-N-PSK method has been broadly studied in different signal-to-noise ratio scenarios, in multi-cell systems the interference from the signals in other cells should be also taken into account. Therefore, the inter-cell interference impact on the performance of the method is investigated by means of a large number of simulations. The results show that the detection probability of the Shifted 2-N-PSK decreases inversely to the signal-to-interference-plus-noise ratio.
Abstract: The high prevalence of cardiovascular diseases has provoked a raising interest in the development of mathematical models in order to evaluate the cardiovascular function both under physiological and pathological conditions. In this paper, a physical model of the cardiovascular system with intrinsic regulation is presented and implemented by using the object-oriented Modelica simulation software tools. For this task, a multi-compartmental system previously validated with physiological data has been built, based on the interconnection of cardiovascular elements such as resistances, capacitances and pumping among others, by following an electrohydraulic analogy. The results obtained under both physiological and pathological scenarios provide an easy interpretative key to analyze the hemodynamic behavior of the patient. The described approach represents a valuable tool in the teaching of physiology for graduate medical and nursing students among others.
Abstract: This article presents the design of optimal automatic generation control (AGC) based on full state feedback control for a multi-area interconnected power system. An extra high voltage AC transmission line in parallel with a high voltage DC link is considered as an area interconnection between the areas. The optimal AGC are designed and implemented in the wake of 1% load perturbation in one of the areas and the system dynamic response plots for various system states are obtained to investigate the system dynamic performance. The pattern of closed-loop eigenvalues are also determined to analyze the system stability. From the investigations carried out in the work, it is revealed that the dynamic performance of the system under consideration has an appreciable improvement when a high voltage DC line is paralleled with an extra high voltage AC line as an interconnection between the areas. The investigation of closed-loop eigenvalues reveals that the system stability is ensured in all case studies carried out with the designed optimal AGC.
Abstract: Branch of modern mathematics, graphs represent instruments
for optimization and solving practical applications in
various fields such as economic networks, engineering, network optimization,
the geometry of social action, generally, complex systems
including contemporary urban problems (path or transport efficiencies,
biourbanism, & c.). In this paper is studied the interconnection
of some urban network, which can lead to a simulation problem of a
digraph through another digraph. The simulation is made univoc or
more general multivoc. The concepts of fragment and atom are very
useful in the study of connectivity in the digraph that is simulation
- including an alternative evaluation of k- connectivity. Rough set
approach in (bi)digraph which is proposed in premier in this paper
contribute to improved significantly the evaluation of k-connectivity.
This rough set approach is based on generalized rough sets - basic
facts are presented in this paper.
Abstract: The aim of non-profit organizations (NPO) is to provide services and goods for its clientele, with profit being a minor objective. By having this definition as the basic purpose of doing business, it is obvious that the goal of an organisation is to serve several bottom lines and not only the financial one. This approach is underpinned by the non-distribution constraint which means that NPO are allowed to make profits to a certain extent, but not to distribute them. The advantage is that there are no single shareholders who might have an interest in the prosperity of the organisation: there is no pie to divide. The gained profits remain within the organisation and will be reinvested in purposeful projects. Good governance is mandatory to support the aim of NPOs. Looking for a measure of good governance the principals of corporate governance (CG) will come in mind. The purpose of CG is direction and control, and in the field of NPO, CG is enlarged to consider the relationship to all important stakeholders who have an impact on the organisation. The recognition of more relevant parties than the shareholder is the link to corporate social responsibility (CSR). It supports a broader view of the bottom line: It is no longer enough to know how profits are used but rather how they are made. Besides, CSR addresses the responsibility of organisations for their impact on society. When transferring the concept of CSR to the non-profit area it will become obvious that CSR with its distinctive features will match the aims of NPOs. As a consequence, NPOs who apply CG apply also CSR to a certain extent. The research is designed as a comprehensive theoretical and empirical analysis. First, the investigation focuses on the theoretical basis of both concepts. Second, the similarities and differences are outlined and as a result the interconnection of both concepts will show up. The contribution of this research is manifold: The interconnection of both concepts when applied to NPOs has not got any attention in science yet. CSR and governance as integrated concept provides a lot of advantages for NPOs compared to for-profit organisations which are in a steady justification to show the impact they might have on the society. NPOs, however, integrate economic and social aspects as starting point. For NPOs CG is not a mere concept of compliance but rather an enhanced concept integrating a lot of aspects of CSR. There is no “either-nor” between the concepts for NPOs.
Abstract: In this paper, CYME Distribution software has been used to assess the impacts of solar Photovoltaic (PV) distributed generation (DG) plant on the Electricity Company of Ghana (ECG) 33 kV sub-transmission network at different PV penetration levels. As ECG begins to encourage DG PV interconnections within its network, there has been the need to assess the impacts on the sub-transmission losses and voltage contribution. In Tema, a city in Accra - Ghana, ECG has a 33 kV sub-transmission network made up of 20 No. 33 kV buses that was modeled. Three different locations were chosen: The source bus, a bus along the sub-transmission radial network and a bus at the tail end to determine the optimal location for DG PV interconnection. The optimal location was determined based on sub-transmission technical losses and voltage impact. PV capacities at different penetration levels were modeled at each location and simulations performed to determine the optimal PV penetration level. Interconnection at a bus along (or in the middle of) the sub-transmission network offered the highest benefits at an optimal PV penetration level of 80%. At that location, the maximum voltage improvement of 0.789% on the neighboring 33 kV buses and maximum loss reduction of 6.033% over the base case scenario were recorded. Hence, the optimal location for DG PV integration within the 33 kV sub-transmission utility network is at a bus along the sub-transmission radial network.
Abstract: Greek islands’ interconnection (IC) with larger power systems, such as the mainland grid, is a crucial issue that has attracted a lot of interest; however, the recent economic recession that the country undergoes together with the highly capital intensive nature of this kind of projects have stalled or sifted the development of many of those on a more long-term basis. On the other hand, most of Greek islands are still heavily dependent on the lengthy and costly supply chain of oil imports whilst the majority of them exhibit excellent potential for wind energy (WE) applications. In this respect, the main purpose of the present work is to investigate −through a parametric study which varies both in wind farm (WF) and submarine IC capacities− the impact of large-scale WE development on the IC of the third in size island of Greece (Lesbos) with the mainland system. The energy and economic performance of the system is simulated over a 25-year evaluation period assuming two possible scenarios, i.e. S(a): without the contribution of the local Thermal Power Plant (TPP) and S(b): the TPP is maintained to ensure electrification of the island. The economic feasibility of the two options is investigated in terms of determining their Levelized Cost of Energy (LCOE) including also a sensitivity analysis on the worst/reference/best Cases. According to the results, Lesbos island IC presents considerable economic interest for covering part of island’s future electrification needs with WE having a vital role in this challenging venture.
Abstract: Connected vehicles are one of the promising technologies for future Intelligent Transportation Systems (ITS). A connected vehicle system is essentially a set of vehicles communicating through a network to exchange their information with each other and the infrastructure. Although this interconnection of the vehicles can be potentially beneficial in creating an efficient, sustainable, and green transportation system, a set of safety and reliability challenges come out with this technology. The first challenge arises from the information loss due to unreliable communication network which affects the control/management system of the individual vehicles and the overall system. Such scenario may lead to degraded or even unsafe operation which could be potentially catastrophic. Secondly, faulty sensors and actuators can affect the individual vehicle’s safe operation and in turn will create a potentially unsafe node in the vehicular network. Further, sending that faulty sensor information to other vehicles and failure in actuators may significantly affect the safe operation of the overall vehicular network. Therefore, it is of utmost importance to take these issues into consideration while designing the control/management algorithms of the individual vehicles as a part of connected vehicle system. In this paper, we consider a connected vehicle system under Co-operative Adaptive Cruise Control (CACC) and propose a fault diagnosis scheme that deals with these aforementioned challenges. Specifically, the conventional CACC algorithm is modified by adding a Kalman filter-based estimation algorithm to suppress the effect of lost information under unreliable network. Further, a sliding mode observer-based algorithm is used to improve the sensor reliability under faults. The effectiveness of the overall diagnostic scheme is verified via simulation studies.
Abstract: In this paper, a thorough review about dual-cubes, DCn,
the related studies and their variations are given. DCn was introduced
to be a network which retains the pleasing properties of hypercube Qn
but has a much smaller diameter. In fact, it is so constructed that the
number of vertices of DCn is equal to the number of vertices of Q2n
+1. However, each vertex in DCn is adjacent to n + 1 neighbors and
so DCn has (n + 1) × 2^2n edges in total, which is roughly half the
number of edges of Q2n+1. In addition, the diameter of any DCn is 2n
+2, which is of the same order of that of Q2n+1. For selfcompleteness,
basic definitions, construction rules and symbols are
provided. We chronicle the results, where eleven significant theorems
are presented, and include some open problems at the end.
Abstract: Although, reliability is an important attribute of quality, especially for mission critical systems, yet, there does not exist any versatile model even today for the reliability assessment of component-based software. The existing Black Box models are found to make various assumptions which may not always be realistic and may be quite contrary to the actual behaviour of software. They focus on observing the manner in which the system behaves without considering the structure of the system, the components composing the system, their interconnections, dependencies, usage frequencies, etc.As a result, the entropy (uncertainty) in assessment using these models is much high.Though, there are some models based on operation profile yet sometimes it becomes extremely difficult to obtain the exact operation profile concerned with a given operation. This paper discusses the drawbacks, deficiencies and limitations of Black Box approaches from the perspective of various authors and finally proposes a conceptual model for the reliability assessment of software.
Abstract: On the basis of comparative analysis of alternative “development scenarios” for electricity generation, the main objective of the present study is to investigate the techno-economic viability of high wind energy (WE) use at the local (island) level. An integrated theoretical model is developed based on first principles assuming two main possible scenarios for covering future electrification needs of a medium–sized Greek island, i.e. Lesbos. The first scenario (S1), assumes that the island will keep using oil products as the main source for electricity generation. The second scenario (S2) involves the interconnection of the island with the mainland grid to satisfy part of the electricity demand, while remarkable WE penetration is also achieved. The economic feasibility of the above solutions is investigated in terms of determining their Levelized Cost of Energy (LCOE) for the time-period 2020-2045, including also a sensitivity analysis on the worst/reference/best Cases. According to the results obtained, interconnection of Lesbos Island with the mainland grid (S2) presents considerable economic interest in comparison to autonomous development (S1) with WE having a prominent role to this effect.
Abstract: This paper presents the results of a study on the
influence of varying percentages of rock bridges along a basal surface
defining a biplanar failure mode. A pseudo-coupled-hydromechanical
brittle fracture analysis is adopted using the state-of-the-art code
Slope Model. Model results show that rock bridge failure is strongly
influenced by the incorporation of groundwater pressures. The
models show that groundwater pressure can promote total failure of a
5% rock bridge along the basal surface. Once the percentage of the
rock bridges increases to 10 and 15%, although, the rock bridges are
broken, full interconnection of the surface defining the basal surface
of the biplanar mode does not occur. Increased damage is caused
when the rock bridge is located at the daylighting end of the basal
surface in proximity to the blast damage zone. As expected, some
cracking damage is experienced in the blast damage zone, where
properties representing a good quality controlled damage blast
technique were assumed. Model results indicate the potential increase
of permeability towards the blast damage zone.
Abstract: At the present work, highly transparent strip type
quasi-solid state dye-sensitized solar cells (DSSCs) were fabricated
through inkjet printing using nanocomposite TiO2 inks as raw
materials and tested under outdoor illumination conditions. The cells,
which can be considered as the structural units of large area modules,
were fully characterized electrically and electrochemically and after
the evaluation of the received results a large area DSSC module was
manufactured. The module design was a sandwich Z-interconnection
where the working electrode is deposited on one conductive glass and
the counter electrode on a second glass. Silver current collective
fingers were printed on the conductive glasses to make the internal
electrical connections and the adjacent cells were connected in series
and finally insulated using a UV curing resin to protect them from the
corrosive (I-/I3-) redox couple of the electrolyte. Finally, outdoor tests
were carried out to the fabricated dye-sensitized solar module and its
performance data were collected and assessed.
Abstract: Mobile Adhoc Networks (MANETs) are
infrastructure-less, dynamic network of collections of wireless mobile
nodes communicating with each other without any centralized
authority. A MANET is a mobile device of interconnections through
wireless links, forming a dynamic topology. Routing protocols have a
big role in data transmission across a network. Routing protocols,
two major classifications are unipath and multipath. This study
evaluates performance of an on-demand multipath routing protocol
named Adhoc On-demand Multipath Distance Vector routing
(AOMDV). This study proposes Energy Aware AOMDV (EAAOMDV)
an extension of AOMDV which decreases energy
consumed on a route.
Abstract: Floorplanning plays a vital role in the physical design
process of Very Large Scale Integrated (VLSI) chips. It is an
essential design step to estimate the chip area prior to the optimized
placement of digital blocks and their interconnections. Since VLSI
floorplanning is an NP-hard problem, many optimization techniques
were adopted in the literature. In this work, a music-inspired
Harmony Search (HS) algorithm is used for the fixed die outline
constrained floorplanning, with the aim of reducing the total chip
area. HS draws inspiration from the musical improvisation process of
searching for a perfect state of harmony. Initially, B*-tree is used to
generate the primary floorplan for the given rectangular hard
modules and then HS algorithm is applied to obtain an optimal
solution for the efficient floorplan. The experimental results of the
HS algorithm are obtained for the MCNC benchmark circuits.
Abstract: By textile science incorporating with electronic
industry, developed textile products start to take part in different
areas such as industry, military, space, medical etc. for health,
protection, defense, communication and automation. Electronic
textiles (e-textiles) are fabrics that contain electronics and
interconnections with them. In this study, two types of base yarns
(cotton and acrylic) and three types of conductive steel yarns with
different linear resistance values (14Ω/m, 30Ω/m, 70Ω/m) were used
to investigate the effect of base yarn type and linear resistance of
conductive yarns on thermal behavior of e-textile structures. Thermal
behavior of samples was examined by thermal camera.
Abstract: Object-oriented modeling is spreading in current
simulation of physiological systems through the use of the individual
components of the model and its interconnections to define the
underlying dynamic equations. In this paper we describe the use of
both the SIMSCAPE and MODELICA simulation environments in
the object-oriented modeling of the closed loop cardiovascular
system. The performance of the controlled system was analyzed by
simulation in light of the existing hypothesis and validation tests
previously performed with physiological data. The described
approach represents a valuable tool in the teaching of physiology for
graduate medical students.