bluuebunny/crossref_metadata_2025 huggingface dataset:
Risk Reduction in Natural Disaster Management through Information Systems
Authors: Schryen Guido , Wex Felix
Published: May 2015

Natural disasters, including earthquakes, Tsunamis, floods, hurricanes, and volcanic eruptions, have caused tremendous harm and continue to threaten millions of humans and various infrastructure capabilities each year. In their efforts to take countermeasures against the threats posed by future natural disasters, the United Nations formulated the “Hyogo Framework for Action”, which aims at assessing and reducing risk. This framework and a global review of disaster reduction initiatives of the United Nations acknowledge the need for information systems research contributions in addressing major challenges of natural disaster management. In this paper, the authors provide a review of the literature with regard to how information systems research has addressed risk assessment and reduction in natural disaster management. Based on the review the authors identify research gaps that are centered around the need for acquiring general knowledge on how to design IS artifacts for risk assessment and reduction. In order to close these gaps in further research, the authors develop a research agenda that follows the IS design science paradigm.
The Impact of Traffic Information Acquisition on the Traffic Conditions of the Athens Greater Area
Authors: Tsirimpa Athena , Polydoropoulou Amalia
Published: May 2015

The main objective of this article is to gain fundamental understanding on the effect of real time information acquisition, on the traffic conditions of the Athens greater area. Activity scheduling is a dynamic process, where individuals often need to modify their schedule, as a result of new insights. Research so far hasn't analyzed the effect of traffic information acquisition, in activity scheduling, although several studies have been conducted to capture the factors that influence the rescheduling of activities. An integrated latent variable model has been estimated, that predicts the probability of rescheduling activities as a function of flexibility, mode choice constraints and travel information. The analysis of the results indicates that one of the biggest impacts of traffic information acquisition is reflected in the rescheduling of activities. Therefore, traffic information not only can significantly improve the travel experience of individuals but may directly affect the performance of the transportation system.
Project Risk Management
Authors: Karlsen Jan Terje , Folke-Olsen Odin , Torvatn Tim
Published: May 2015

This study is about project risk management tools. The aim has been to identify which tools have the greatest potential for contribution to risk management processes in the Norwegian oil and gas industry, and which factors contribute to efficient risk management. Empirical data from the Norwegian industry have been gathered using a questionnaire. The results revealed strong relationships between project system complexity, average tool score and risk management contribution. Furthermore, the results of the analysis show that some of the previous recommendations of tools for project risk management may have been based on a restricted set of determinants. On the other hand, similarities are also found with previous research in terms of the highest ranked tools based on perceived contribution to the risk management performance. Compared to the previous findings, this study indicates that a new measure for project management performance is needed, and that the recommendation of tools based on the risk management contribution index may be flawed. Nevertheless, it is concluded that several of the recommended tools are of great value across industries.
Passenger Train Delay Classification
Authors: Yaghini Masoud , Sanai Maryam Setayesh , Sadrabady Hossein Amin
Published: May 2015

One of the most popular data mining areas, which estimate future trends of data, is classification. This research is dedicated to predict Iranian passenger train delay with high accuracy over Iranian railway network. A hybrid method based on neuro-fuzzy inference system and Two-step clustering is used for this purpose. The results indicate that the hybrid method is superior over the other common classification methods. The result can be used by train dispatcher to accurate schedule trains to diminish train delay average.
Simulation-Based Scheduling of Waterway Projects Using a Parallel Genetic Algorithm
Authors: Yang Ning , Wang Shiaaulir , Schonfeld Paul
Published: May 2015

A Parallel Genetic Algorithm (PGA) is used for a simulation-based optimization of waterway project schedules. This PGA is designed to distribute a Genetic Algorithm application over multiple processors in order to speed up the solution search procedure for a very large combinational problem. The proposed PGA is based on a global parallel model, which is also called a master-slave model. A Message-Passing Interface (MPI) is used in developing the parallel computing program. A case study is presented, whose results show how the adaption of a simulation-based optimization algorithm to parallel computing can greatly reduce computation time. Additional techniques which are found to further improve the PGA performance include: (1) choosing an appropriate task distribution method, (2) distributing simulation replications instead of different solutions, (3) avoiding the simulation of duplicate solutions, (4) avoiding running multiple simulations simultaneously in shared-memory processors, and (5) avoiding using multiple processors which belong to different clusters (physical sub-networks).
Methodology for Risk Assessment and Costs Associated with Risk Occurrence in E-Government Projects
Authors: Vrček Neven , Peharda Petra , Munđar Dušan
Published: May 2015

The main purpose of this chapter is to emphasize the problem of e-government project risks and to introduce a methodology for risk assessment and calculation of costs associated with risk occurrence in e-government projects based on Bayesian networks. The proposed methodology presents a new approach to the assessment of risks and costs related to e-government project risks. As such, it facilitates the holistic decision making procedure for project managers. The application of Bayesian networks in the context of risks and risk related costs reduces the level of uncertainty in e-government projects and provides a graphical structure of risks and corresponding costs. Finally, the sensitivity analysis has also been integrated into the methodology and its results can have a significant impact on the overall project management quality.
Proactive Security Protection of Critical Infrastructure
Authors: Bailey Bill , Doleman Robert
Published: May 2015

The belief that a static alarm system will safeguard critical infrastructure without additional support mechanisms is misplaced. This complacency is no longer satisfactory with the increase in worldwide threat levels and the potential social consequences. What is required is a more proactive, comprehensive security management process that adds to the ability to prevent, detect, deter, respond, and defeat potential harmful events and incidents. The model proposed here is proactive and grounded upon current operational procedures used by major companies in hostile and dangerous environments. By utilising a clearly defined comprehensive risk management tool, a more systematic security, threat, risk, and vulnerability assessment (STRVA), process can be developed. This process needs to identify deliberate targeting of assets through multiple intelligence gathering capabilities, plus defeat testing to probe existing security defences. The consequence approach to a potential breakthrough is at the essence of this methodology.
Meta-Modeling Based Secure Software Development Processes
Authors: Essafi Mehrez , Ben Ghezala Henda
Published: May 2015

This work suggests a multilevel support to software developers, who often lack knowledge and skills on how to proceed to develop secure software. In fact, developing software with such quality is a hard and complex task that involves many additional security-dedicated activities which are usually omitted in traditional software development lifecycles or integrated but not efficiently and appropriately deployed in some others. To federate all these software security-assurance activities in a structured way and provide the required guidelines for choosing and using them in a flexible development process, authors used meta-modeling techniques and dynamic process execution that consider developer's affinities and product's states. The proposed approach formalizes existing secure software development processes, allows integration of new ones, prevents ad-hoc executions and is supported by a tool to facilitate its deployment. A case study is given here to exemplify the proposed approach application and to illustrate some of its advantages.
ONTO-KMS-TEC
Authors: Robin C. R. Rene , Miriam D. Doreen Hepzibah , Uma G. V.
Published: May 2015

Knowledge management tools have been used in higher educational institutions for years to improve the effectiveness of teaching methodologies. Knowledge management in pedagogical includes processes of knowledge discovery, capture, storage, retrieval, sharing, and understanding. According to Pundt and Bishr, knowledge management aims at facilitating knowledge flow and utilization across every beneficeiary, such as faculty members and students. An ontology can be used to support knowledge retrieval, store, and sharing domain knowledge. The framework and the case studies described in this chapter detail how the knowledge of an engineering subject can be effectively retrieved, stored, and shared among the teachers and the students.
Communication Networks to Connect Moving Vehicles to Transportation Systems to Infrastructure
Authors: Kastell Kira
Published: May 2015

Communication in transportation systems not only involves the communication inside a vehicle, train, or airplane but it also includes the transfer of data to and from the transportation system or between devices belonging to that system. This will be done using different types of wireless communication. Therefore in this chapter, first, the fundamentals of mobile communication networks are shortly described. Thereafter, possible candidate networks are discussed. Their suitability for a certain transportation system can be evaluated taking into consideration the system's requirements. Among the most prominent are the influence of speed and mobility, data rate and bit error rate constraints, reliability of the system and on-going connections. As in most of the cases, there will be no single best wireless communication network to fulfil all requirements, and in this chapter also hybrid networks are discussed. These are networks consisting of different (wireless) access networks. The devices may use the best suited network for a given situation but also change to another network while continuing the on-going connection or data transfer. Here the design of the handover or relocation plays a critical role as well as localization.
QoS-Aware Chain-Based Data Aggregation in Cooperating Vehicular Communication Networks and Wireless Sensor Networks
Authors: Taghikhaki Zahra , Zhang Yang , Meratnia Nirvana , Havinga Paul J.M.
Published: May 2015

Vehicular Communication Networks (VCNs) and Wireless Sensor Networks (WSNs) are emerging types of networks, which have individually been extensively explored. However, their cooperation and exploring advantages offered by their integration are poorly explored. Such integration helps better investigate impacts of human mobility and transportation behaviors on safety and well-being of cities, their residents, their surrounding environments, and ecology. In this chapter, the authors propose a QoS-Aware Chain-based data Aggregation (QoS-ACA) technique for wireless sensor networks cooperating with vehicular communication networks, which fast, reliably, and energy efficiently aggregates sensor data and sends the aggregated value to the road side units. Ensuring quality of service parameters has been put forward as an essential consideration for wireless sensor networks, which are often deployed in unattended and open environments and are characterized by their limited resources. To this end, in-network data aggregation is an efficient solution to save energy and bandwidth and to provide meaningful information to end-users.
Holistic and Law Compatible IT Security Evaluation
Authors: Simić-Draws Daniela , Neumann Stephan , Kahlert Anna , Richter Philipp , Grimm Rüdiger , Volkamer Melanie , Roßnagel Alexander
Published: May 2015

Common Criteria and ISO 27001/IT-Grundschutz are well acknowledged evaluation standards for the security of IT systems and the organisation they are embedded in. These standards take a technical point of view. In legally sensitive areas, such as processing of personal information or online voting, compliance with the legal specifications is of high importance, however, for the users' trust in an IT system and thus for the success of this system. This article shows how standards for the evaluation of IT security may be integrated with the KORA approach for law compatible technology design to the benefit of both – increasing confidence IT systems and their conformity with the law on one hand and a concrete possibility for legal requirements to be integrated into technology design from the start. The soundness of this interdisciplinary work will be presented in an exemplary application to online voting.
Risk Analysis of Completion and Production Systems
Authors: Matanovic Davorin
Published: May 2015

A variety of definitions are available through the literature, but the universal one is in defining the well completion as the optimal path for the reservoir fluids to be produced. That means to achieve a desired production with minimal costs. Wells represent the greatest part of expenditure when developing the reservoir. For a long period of time it was defined to be simple, reliable, and safe with enough flexibility to allow future operations. Nowadays, so called “intelligent completions” appear to give more financial benefits, flexibility, and control. The reliability of system components is essential for long-lasting production. In addition, the differences according to natural flowing well risk and artificial lift are given.
Teaching Case for Addressing Risks with Strategies in an International Airport Project
Authors: Paulose Daly
Published: May 2015

This is a case applying risk management, project management, and business strategy theories. The center piece is a successful build-own-operate (BOO) international airport mega-project completed in south-west India. This case study was applied for teaching a university senior-level course in business strategy. The paper explains the risk management framework, expected monetary value (EMV) calculation, and how the theoretical models can be applied to the BOO project. It then presents worked-out solutions to selected EMV problems.
Traffic Safety Implications of Travel Demand Management Policies
Authors: Pirdavani Ali , Bellemans Tom , Brijs Tom , Kochan Bruno , Wets Geert
Published: May 2015

Travel Demand Management (TDM) consists of a variety of policy measures that affect the transportation system's effectiveness by changing travel behavior. Although the primary objective to implement such TDM strategies is not to improve traffic safety, their impact on traffic safety should not be neglected. The main purpose of this study is to investigate differences in the traffic safety consequences of two TDM scenarios: a fuel-cost increase scenario (i.e. increasing the fuel price by 20%) and a teleworking scenario (i.e. 5% of the working population engages in teleworking). Since TDM strategies are usually conducted at a geographically aggregated level, crash prediction models that are used to evaluate such strategies should also be developed at an aggregate level. Moreover, given that crash occurrences are often spatially heterogeneous and are affected by many spatial variables, the existence of spatial correlation in the data is also examined. The results indicate the necessity of accounting for the spatial correlation when developing crash prediction models. Therefore, Zonal Crash Prediction Models (ZCPMs) within the geographically weighted generalized linear modeling framework are developed to incorporate the spatial variations in association between the Number Of Crashes (NOCs) (including fatal, severe, and slight injury crashes recorded between 2004 and 2007) and a set of explanatory variables. Different exposure, network, and socio-demographic variables of 2200 traffic analysis zones in Flanders, Belgium, are considered as predictors of crashes. An activity-based transportation model is adopted to produce exposure metrics. This enables a more detailed and reliable assessment while TDM strategies are inherently modeled in the activity-based models. In this chapter, several ZCPMs with different severity levels and crash types are developed to predict the NOCs. The results show considerable traffic safety benefits of conducting both TDM scenarios at an average level. However, there are certain differences when considering changes in NOCs by different crash types.
Risk Analysis in the Process of Hydraulic Fracturing
Authors: Kolin Sonja Koščak , Čikeš Marin
Published: May 2015

This chapter focuses on risk to the environment from hydraulic fracturing operations, starting with transport of materials and ending when the well is routed to the production facilities. The initial assumption for the fracturing risk analysis is that the well is new and was constructed correctly so that all producible formations are securely isolated behind the barriers of casing and competent cement. The justification for this assumption is that the vast majority of fracturing is the first major stimulation in a well and occurs immediately after completing a new well. Although many well development problems are blamed on fracturing, there are only excluded problems that are real and worthy of the discussion to help define boundaries of the fracturing risk (King, 2012).
Applying the Safety and Environmental Risk and Reliability Model (SERM) for Malaysian Langat River Collision Aversion
Authors: Olanrewaju Oladokun Sulaiman , Kader Ab Saman Ab
Published: May 2015

Collision accident remains a big threat to coastal water transportation operation. Occurrence of a collision event exposes vessel owners and operators as well as the public to risk. The nature of the threat can be worrisome; it may lead to loss of life, damage to the environment, disruption of operation, and injuries. This makes hybrid analysis of accident frequency and consequence for risk quantification of accident scenarios through stochastic tools very imperative for reliable design and exercise of technocrat stewardship of safety and safeguard of the environmental. The study involves a predictive model for collision risk and mitigation option for aversion of collision incident. Accident frequency and consequence are obtained using probability tools. Validity of the result is checked with reliability tools. Findings of the study were checked with subsystem and uncertainty risk-contributing factors in order to arrive at a sustainable decision support for collision aversion for inland water transportation. This chapter discusses the result and validation of implementation of the Safety and Environmental Risk and Reliability Model (SERM) for aversion of collision accident for vessel navigating for inland waterways.
General Approach to Risk Analysis
Authors: Matanovic Davorin
Published: May 2015

Broadly accepted methodology that is implemented in the oil industry when dealing with risks includes as the first step the identification of possible hazards. That is done by gathering information about degree of risk according to working procedures, processes, and individuals involved in the operation of the process. That is the first step in risk management, an iterative process that must lead to the use of proper measurements in the way of protecting people, facilities and environment. The analysis is done based on the combination of probability and severity of undesirable events, and the final consequences. Explanation of basic terms, their interdependence, dilemmas, and methods of risk analysis are introduced. Each method is shortly described with main anteriority and shortcomings. Differences between quantitative methods, qualitative methods, and hybrid methods (the combination of qualitative-quantitative or semi-quantitative methods) are elaborated. The impact, occurrence, and the consequences are at the end compared to risk acceptance criteria concept. The ALARP (As Low as Reasonably Practicable) framework is explained with some observation on the quality and acceptance in petroleum industry. Finally, the human impact on the risk and consequences is analyzed.
The Integrative Time-Dependent Modeling of the Reliability and Failure of the Causes of Drivers' Error Leading to Road Accidents
Authors: Hojjati-Emami Khashayar , Dhillon Balbir S. , Jenab Kouroush
Published: May 2015

Nowadays, the human error is usually identified as the conclusive cause of investigations in road accidents. The human although is the person in control of vehicle until the moment of crash but it has to be understood that the human is under continued impact by various factors including road environment, vehicle and human's state, abilities and conduct. The current advances in design of vehicle and roads have been intended to provide drivers with extra comfort with less physical and mental efforts, whereas the fatigue imposed on driver is just being transformed from over-load fatigue to under-load fatigue and boredom. A representational model to illustrate the relationships between design and condition of vehicle and road as well as driver's condition and state on fatigue and the human error leading to accidents has been developed. Thereafter, the stochastic mathematical models based on time-dependent failure rates were developed to make prediction on the road transportation reliability and failure probabilities due to each cause (vehicle, road environment, human due to fatigue, and human due to non fatigue factors). Furthermore, the supportive assessment methodology and models to assess and predict the failure rates of driver due to each category of causes were developed and proposed.
Lost Circulation
Authors: Gaurina-Medjimurec Nediljka , Pasic Borivoje
Published: May 2015

Lost circulation is defined as the uncontrolled flow of mud into a thief zone and presents one of the major risks associated with drilling. The complete prevention of lost circulation is impossible, but limiting circulation loss is possible if certain precautions are taken. Failure to minimize lost circulation can greatly increase the cost of drilling, as well as the risk of well loss. The risk of drilling a well in areas known to contain potential zones of lost circulation such as fractured, cavernous, or high permeability formations is a key factor in making a decision to approve or cancel a drilling project. The successful management of lost circulation should include identification of potential loss zones, optimization of drilling hydraulics, and remedial measures when lost circulation occures.
Landslides
Authors: Arbanas Snježana Mihalić , Arbanas Željko
Published: May 2015

Landslide research is an interdisciplinary field that primarily encompasses scientists from geomorphology, engineering geology, and geotechnical engineering in collaboration with researchers from such fields as geodesy, hydrogeology, geophysics, and many others. This chapter is intended as a resource for researchers interested in landslide engineering and landslide science to acquire a summarized review of research subjects and the state-of-the-art literature. A wide range of landslide topics are presented in the following sections: landslide mapping, landslide investigation, landslide monitoring, landslide hazard and risk assessment, and landslide stabilization and remediation measures. The results of landslide studies have practical applications to society via the avoidance, prevention, and mitigation of landslide hazards and risks. Landslide avoidance and prevention are the primary interests for land-use policies based on landslide mapping, followed by the prediction of landslide processes and their consequences. Landslide mitigation includes the development of engineering technologies for landslide investigation, monitoring, and remediation.
Effects of Temperature on I-V Characteristics of InAs/GaAs Quantum-Dot Solar Cells
Authors: Sriphan Saichon , Kiravittaya Suwit , Thainoi Supachok , Panyakaew Somsak
Published: May 2015

The current-voltage (I-V) characteristics of quantum-dot (QD) solar cells under illumination at various temperatures are presented. Stacked of high-density self-assembled InAs/GaAs QDs were incorporated into the Schottky-barrier-type solar cell structure. The I-V characteristics reveal that both short-circuit current and open-circuit voltage of the QD solar cell reduce when the measurement temperature increases. This result is unexpected and inconsistent with a basic solar cell theory where the temperature is believed to cause the enhancement of the short-circuit current. By considering the solar-cell circuit model, we can explain the obtained I-V curves by a high series resistance of the cell structure. Theoretical exclusion of the series resistance shows a substantial improvement of solar cell fill factor and efficiency. This work therefore suggests that reduction of series resistance by properly doping of the epitaxial layers can improve these devices.
Development of Chemical Sensor Array for Rice Aroma Detection
Authors: Lorwongtragool Panida , Kerdcharoen Teerakiat
Published: May 2015

Gas sensor array based on polymer/multi-walled carbon nanotubes (polymer/MWCNTs) composites prepared by screen printing technique was examined for rice aroma detection. The sensor array consists of two sets of three different sensors, i.e., MWCNTs dispersed in the matrix of poly (2-Acrylamido-2-methyl-1-propanesulfonic acid-co-acrylonitrile (S1-S2), polyvinyl alcohol (S3-S4) and poly (styreneco-maleic acid) partial isobutyl/methyl mixed ester (S5-S6). Sample temperature, which is one of the important parameters, has been found to influence the releasing rate of the volatiles from rice grain when needed to operate on the electronic nose system. In this case, the fabricated sensor array installed within a lab-made electronic nose system with optimum sample temperature at 70°C could provide rapid and best responses to the volatiles released from the milled rice sample. Moreover, the responsive signals could be recovered to original state as well within four minutes by only purging with fresh air at room temperature. Based on the principal component analysis (PCA) pattern recognition, it was shown that the electronic nose can discriminate six rice samples based on the content of aroma.
Effect of pH and Temperature on Physical Properties of Zinc Aluminate Based Nanostructure Synthesized via Co-Precipitation Method
Authors: Mekprasart Wanichaya , Worasawat Suchada , Pecharapa Wisanu
Published: May 2015

Zinc aluminate (ZnAl2O4) nanopowders were synthesized by co-precipitation method using zinc chloride and aluminum chloride as starting precursors. The crucial preparation factors including pH and calcination temperature were varied and their influence on relevant physical properties of the product is investigated. Structural properties of as-synthesized nanoparticles were investigated by X-ray diffraction, scanning electron microscope and Raman spectroscopy. XRD results suggested that ZnAl2O4 in spinel structure with high crystallinity could be obtained by this process after calcination beyond specific temperature. Meanwhile, SEM images revealed that surface morphologies and structure of ZnAl2O4 were in spherical structure with average size of few hundred nanometer range at high pH condition. Raman result indicated the correlated chemical bonding relating to the formation of ZnAl2O4 structure.
Different Photoresponses for Positive and Negative Biases of CuPc/C60 Heterojunction Nanostructures
Authors: Juagwon Theerasak , Subannajui Kittitat , Osotchan Tanakorn
Published: May 2015

Photoresponse characteristic from efficient exciton dissociated heterojunction based on copper phthalocyanine (CuPc) and fullerene (C60) layers was observed the different spectrum responses under positive and negative biases. The nanostructures of CuPc and C60 thin films were fabricated between transparent indium tin oxide (ITO) and aluminum (Al) electrodes. The 100 nm thick of CuPc and C60 layers were deposited on patterned ITO glass substrates by thermal evaporation with quartz thickness monitor. Photoresponses of the fabricated devices were investigated by current measuring as a function of wavelength in range of 400 to 700 nm. Measured current in Al/C60/CuPc/ITO structure when applied negative voltage to ITO electrode is higher than that of positive voltage case. Under monochromatic light, the photoresponse characteristic of Al/C60/CuPc/ITO structure under negative bias shows dominate response current peak at around 450 nm and double peaks in range of 500-700 nm originated from C60 and CuPc layers, respectively. These two response characteristics can be described by the combination of responses from Al/C60/ITO and Al/CuPc/ITO structures. The response current characteristics of Al/C60/ITO and Al/CuPc/ITO structures also agree with the optical absorptions of C60 and CuPc layers, respectively. By applying positive bias to Al/C60/CuPc/ITO structure, the photoresponse characteristic has only one peak at about 450 nm that is similar to the response in Al/C60/ITO structure only. This indicates that under positive bias, the photocurrent only from C60 layer can be observed.
Electrical Contact Properties of Micro-Injection Molded Polypropylene/CNT/CB-Composites on Metallic Electrodes
Authors: Heinrich Michael , Decker Ricardo , Schaufuss Joerg , Troeltzsch Juergen , Mehner Jan , Kroll Lothar
Published: May 2015

The investigations carried out under this work dealing with a new field of application for large-scale production of electric contacting processes for micro-electro-mechanical systems (MEMS) using the micro-injection molding technology. The focus of this article is the analysis of process-related influential factors of micro-injection molding that determines both the electrical resistivity and the flowability of polymer nanocomposites filled with carbon nanotubes (CNT) and carbon black (CB). For that, the viscosity and the electrical conductivity as a function of different CNT-and CB-contents and their combination were investigated in a manufacturing study for Polypropylene. The results of the investigations answered questions regarding material science and technical processes. By this, optimal rheological properties for formation of micro injection molded conductive patterns with high aspect ratios on the one side and with the best possible conductivity of the nanocomposites on the other side can be set.
Diode Parameters of Mesa Structural n-Type Nanocrystalline FeSi2/p-Type Si Heterojunctions Prepared by Lift-Off Photolithography
Authors: Promros Nathaporn , Funasaki Suguru , Takahara Motoki , Iwasaki Ryūhei , Shaban Mahmoud , Yoshitake Tsuyoshi
Published: May 2015

Mesa structural n-type nanocrystalline-FeSi2/p-type Si heterojunctions were successfully fabricated by a lift-off technique combined with a photolithography process. Their current-voltage characteristics were measured at low temperatures range from 300 K down to 60 K. We estimated their diode parameters such as ideality factor, barrier height and series resistance based on the thermionic emission theory and Cheung’s method. From the estimation by the thermionic emission theory, the obtained results show an increase of ideality factor and a decrease of barrier height at low temperatures. The estimation by Cheung’s method shows that the values of ideality factor and barrier height are in agreement with those obtained from the thermionic emission theory. The obtained series resistances from dV/d (lnJ)-J and H(J)-J plots, which are approximately equal to each others, are increased at low temperatures.
Frequency Bandwidth Adjustment by Precision Post-Processing for a 0.78–0.95 THz Band SIS Mixer
Authors: Miyachi Akihira , Kojima Takafumi , Fujii Yasunori , Takeda Masanori , Uzawa Yoshinori , Kroug Matthias , Noguchi Takashi
Published: May 2015

In this study, we demonstrate a method for adjusting the frequency bandwidth of a Superconductor-insulator-superconductor (SIS) mixer device by controlling its thickness after microfabrication. We estimate the relationship between SIS mixer device thickness and frequency bandwidth using electromagnetic (EM) simulation. We propose an optimal method for the precision polishing of the back side of the device. We evaluate the noise temperature and measure the frequency bandwidth of SIS mixer devices with different thicknesses. This study presents the adjustment of the frequency bandwidth of a device through controlling its thickness after microfabrication. This technique may improve the yield of SIS mixer device mass production and support the construction of receivers for ultra-high frequencies such as Atacama Large Millimeter/Submillimeter Array (ALMA) Band 10.
Impact Response Measurement of Contact Lenses
Authors: Watanabe Kazuhide , Miyashita Naoki , Bin Du Hong , Irisa Kyohei , Takita Akihiro , Yamaguchi Takao , Carcasona Edwin , Mitatha Somsak , Fujii Yusaku
Published: May 2015

Impact response of contact lenses is measured using the Levitation Mass Method (LMM). In the LMM, a small mass collides with contact lenses and the impact force is measured with high accuracy as the inertial force of the moving part. A pneumatic linear bearing is used to achieve linear motion with sufficiently small friction acting on the moving part. Hysteresis loop and consumed energy as mechanical characteristics of contact lenses are also calculated.
Enhancement of Optical Transmittance of Polymer-Dispersed Liquid Crystal Cells
Authors: Syazwani Intan , Haruyama Moriyoshi , Hachisuka Hiroki , Sha Gicho , Kada Wataru , Sasaki Tomoyuki , Miura Kenta , Hanaizumi Osamu
Published: May 2015

Enhancement of optical transmittance of polymer-dispersed liquid crystal (PDLC) cells was investigated by introducing a modification into the substrates. Surface treatment by rubbing was performed on both network-type and droplet-type PDLCs to investigate the effect on the optical transmittance of the cells. Differences in the transmittance of the PDLC in the polymer matrix were observed by introducing rubbing effect on network-type PDLC but not on droplet-type PDLC. These phenomena might be used to distinguish the application field of both types of PDLC cells by enhancing optical transmittance and scattering properties.
Long Range Ordering of 5-nm-Sized Dot Arrays with a Pitch of <10 nm along EB-Drawn Guide Lines Using PS-PDMS Self-Assembly
Authors: Zhang Hui , Huda Miftakhul , Liu Jing , Zhang Yu Long , Jin Tao , Hosaka Sumio , Yin You
Published: May 2015

We demonstrate the possibility of forming long-range-ordered self-assembled nanodot arrays with dots size of 5 nm and pitches of 10×7.5 nm2using guide line templates and low molecular weight (MW) (4,700–1,200 g/mol) poly (styrene)-poly (dimethylsiloxane) (PS-PDMS) for application in ultrahigh density patterned media. The self-assembled PDMS nanodots are controlled in a long range by varying the heights and gaps of the guide lines. Adopting the 14-nm-high resist guide lines with suitable gaps, the 5-nm-sized and 10×7.5 nm2-pitched self-assembled nanodots were ordered in maximum 7 dot arrays with long-range order. The experimental results demonstrate that the method is possible for achieving patterned media with magnetic recording densities of 8.6 Tbit/in.2using low MW PS-PDMS and slim guide lines.
Magnetic Compton and Bragg Scattering Studies of Disordered Pd0.80Co0.20 Alloy
Authors: Ito Masahisa , Suzuki Kosuke , Sakurai Hiroshi , Yamaki Ryutaro , Sato Ayako , Itou Masayoshi , Sakurai Yoshiharu
Published: May 2015

We have applied two kinds of experimental methods using elliptically polarized synchrotron X-rays, magnetic Compton and Bragg scattering experiments, to a single crystal of a disordered Pd0.80Co0.20 alloy, and have measured magnetic Compton profiles and magnetic form factors, respectively. The result of the Compton scattering experiment has shown that the electronic structure of Pd0.80Co0.20 is similar to that of Pd0.72Co0.28, and the spin moment has been evaluated. The result of the Bragg scattering experiment has reinforced that of the previous experiment [M. Ito et al.: Mater. Sci. Forum Vol. 459 (2011), p. 3.], and the spin moment estimated by the magnetic Bragg scattering has reproduced that by the magnetic Compton scattering. These results show that the joint study of the magnetic Compton and Bragg scattering provides a tool for investigating the magnetic property of alloys.
Poling Effects in Melt-Spun PVDF Bicomponent Fibres
Authors: Glauß Benjamin , Jux Maximilian , Walter Stephan , Kubicka Marcus , Seide Gunnar , Wierach Peter , Gries Thomas , Roth Georg
Published: May 2015

This research shows the successful functionalisation of bicomponent fibres, consisting of a conductive polypropylene (PP) core, doped with carbon nanotubes (CNT) and a piezoelectric sheath (polyvinylidene fluoride, PVDF) by draw winding and poling. These steps lead to the usability of the PVDF’s piezoelectric capabilities. The PP/CNT constitutes the fibre core that is conductive due to a percolation CNT network. The PVDF sheath’s piezoelectric effect is based on the formation of β phase crystals (all-trans conformation), caused by draw-winding of the fibres. This β phase eventually has to be poled for the uniform alignment of polymer chains. The material’s behaviour in high electric field is analysed recording the poling voltage during the poling process. The outcome is hysteresis curves for different β phase contents, which verify a successful material poling.
New Porous Nanocomposite Materials for Electrochemical Power Sources
Authors: Markova Ivania , Milanova Valentina , Petrov Tihomir , Denev Ivan , Chauvet Olivier
Published: May 2015

Intermetallic (Cu-Sn) nanoparticles are synthesized through a borohydride reduction with NaBH4 in a mixture of aqueous solutions of CuCl2.2H2O and SnCl2.2H2O at mass ratio Cu:Sn = 3:2 applying a template technique with a support such as carbon foam. The ratio is chosen in accordance with the Cu-Sn binary system phase diagram. The reductive precipitation is carried out at room temperature and atmospheric pressure. Porous nanocomposites are obtained and studied by scanning and transmission electron microscopy (SEM/TEM), and X-ray diffraction (XRD) analysis. The electrochemical behavior of the synthesized Cu-Sn alloy and the C-based composites (С-foam/Cu-Sn alloy) as positive electrodes is also investigated in a Li-ion battery) using a computer controlled laboratory cycling equipment BA500 Series Battery Analyzer.
Polymeric Artificial Muscles are Linear Faradaic Motors
Authors: Valero Laura L. , Otero Toribio Fernandez , Martinez Jose Gabriel
Published: May 2015

Engineers, physicists and robot designers use to consider polymeric bilayer actuators (or artificial muscles) as low reliable devices for soft tools or soft robotic developments. Here we present the mechanical (movement rate and position) characterization of a polypyrrole/tape bilayer bending actuator. The polypyrrole film was synthesized in presence of dodecyl-benzene-sulphonate (DBS-) and ClO4- anions: it exchanges cations during subsequent oxidation/reduction reactions. The angular rate of the movement results a linear function of the applied current and the described angle is a linear function of the consumed charge. The correlation coefficients overcame 0.99: electro-chemo-mechanical polymeric motors are full reliable for technological applications. The electrochemical model explaining the relationships between charge, film volume variation, mechanical work, force and displacement, strain and stress is also presented.
Electronic State and Piezoresistivity Analysis of Zinc Oxide Nanowires for Force Sensing Devices
Authors: Nakamura Koichi
Published: May 2015

The piezoresistivity for force sensing in wurtzite-ZnO nanowires with [0001] orientation has been simulated on the basis of the first-principles calculations of model structures. According to the difference in wall structure, our devised nanowire models can be divided into three groups by their conductivities; no band-gap conducting models, direct band-gap semiconducting models, and indirect band-gap semiconducting models. The strain responses to carrier conductivity of n-or p-doped semiconducting wurtzite-ZnO[0001] nanowire models were calculated using band carrier densities and their corresponding effective masses derived from the one-dimensional band diagram by our original procedure for a small amount of carrier occupation. The conductivities of p-type direct band-gap models change drastically due to longitudinal uniaxial strain in the simulation: the longitudinal piezoresistance coefficient is 120 × 10–11 Pa–1 for p-type (ZnO)24 nanowire model with 1% compressive strain at room temperature.
Ferroelectric Properties and Internal Friction in Doped PZT Ceramics
Authors: Bochenek Dariusz , Niemiec Przemysław , Zachariasz Radosław , Skulski Ryszard
Published: May 2015

Multicomponent PZT-type solid solution with composition: Pb0.975Ba0.01Ca0.01Sr0.005 (Zr0.52Ti0.48)O3+1.4wt.%Bi2O3+0.3wt.%GeO obtained by hot uniaxial pressing method is described in this paper. There are presented the results of studies of structural, dielectric and internal friction of obtained multicomponent PZT-type ceramics. It has been stated that the dielectric anomalies and internal friction anomalies are observed in similar temperature ranges. Obtained PZT-type ceramics have high value of the dielectric permittivity and low dielectric losses. The high temperature of phase transition and high value of electric permittivity allow considering this material as a base for low frequency and high temperature electromechanical transducers.
Real-Time Analysis of Chemotactic Motion of Euglena Cells Confined in a Microchip Toxicity Sensor
Authors: Ozasa Kazunari , Lee Jee Soo , Song Simon , Maeda Mizuo
Published: May 2015

We developed the real-time analysis of chemotactic motion of microbial cells (Euglena gracilis), for on-chip cytotoxicity sensing for environmental chemical substances. TheEuglenacells were confined in a closed-type micro-aquarium in a PDMS microchip, and their movements were taken by a CMOS video camera. When 1.5%-H2O2was introduced into a microchannel running aside of the micro-aquarium, the H2O2molecules permeated into the micro-aquarium by diffusion through porous PDMS wall, and the cells fell into continuous rotation instead of single step turning and/or straightforward swimming. Such an abnormal swimming behavior is the result of metabolic disturbing effects evoked by radical oxygen species released from H2O2. In order to sensing the metabolic disturbing effects, we achieved real-time categorization of the swimming traces into straightforward swimming or continuous rotation; firstly the swimming traces in the video image were sectioned into squares, and then the aspect ratio and filling factor for each square were calculated. High aspect ratio or small filling factor corresponded to straightforward swimming, whereas low aspect ratio and high filling factor to continuous rotation. This motion analysis enables to measure the metabolic disturbing effects on swimmingEuglenacells quantitatively, which is important to detect unidentified toxic substances in environments.
Improvement of Magnetic Force Microscope Performance by Tuning the Coating Material of Sensor Tip
Authors: Futamoto Masaaki , Ohtake Mitsuru
Published: May 2015

Effects of magnetic material, coating thickness, and tip radius on the magnetic force microscope (MFM) spatial resolution and the switching field have been investigated. MFM tips are prepared by coating soft and hard magnetic materials on non-magnetic Si-base tips. MFM spatial resolutions better than 8 nm are obtained by optimizing the coating layer thickness at around 20 nm on the Si tips with top radius of 3 – 5 nm. The switching field can be increased greater than 1 kOe by coating a high-Ku magnetic material and by increasing the coating thickness. The tips are successfully applied to the observations of magnetic thin films which include magnetization structures less than 20 nm in length.
An Efficient RADFET Sensors Model Using Artificial Neural Network (ANN)
Authors: Meddour Fayçal , Dibi Zohir , Kouda Souhil , Djeffal Fayçal
Published: May 2015

In this work, a new approach is proposed to design the neutron angle and fluence radiation sensor. It is based on an Artificial Neural Network (ANN) model which has the advantage of efficient nonlinear mapping in addition to noise tolerance. This model allows us to obtain the angle and the fluence radiation from the drain source current, the drain source voltage, the gate source voltage and the temperature parameters. The obtained results are nearly closed to the experimental results in the literature.
Co/Cu/Co Pseudo Spin-Valve System Prepared by Magnetron Sputtering with Different Argon Pressure
Authors: Svalov A.V. , Sorokin A.N. , Savin P.A. , García-Arribas Alfredo , Fernández A. , Vas’kovskiy V.O. , Kurlyandskaya G.V.
Published: May 2015

Thin Co films were fabricated by DC magnetron sputtering. The effect of argon pressure on the microstructure, surface morphology and magnetic properties of the samples was systematically studied. It was found that with the increase of argon pressure, the sharpness of the crystalline texture of the samples declines, the roughness of film surfaces and the coercivity of the films increase. Based on these results, a Co/Cu/Co pseudo spin-valve system was designed and the corresponding structures were fabricated. The difference in coercivity of magnetic layers was obtained by deposition of the Co layers at different Ar pressures. Change of the resistance of this trilayer is induced at a moderate field by the spin rotation in the soft layer with lower coercivity.
Correlation of Cooling Conditions with the Shape of Hysteresis Loops in Air Cooled and Quenched Axis Shaft
Authors: Tsoutsias Angelos
Published: May 2015

The present paper investigates the utilization of the magnetic hysteresis loops for the nondestructive characterization of annealed axis shaft samples. The resulting magnetic properties were further evaluated by examining the microstructure of the annealed samples by using scanning electron microscopy.
Microstructural Evaluation of Annealed Low-Alloy Carbon Steels with the Magnetic Barkhausen Noise
Authors: Kanellopoulos Nikolaos Philopimin
Published: May 2015

The present paper investigates the utilization of the MBN method for the nondestructive characterization of annealed AISI 4130 steel samples. The resulting magnetic properties were further evaluated by examining the microstructure of the annealed samples by using scanning electron microscopy.
Correlation of the Barkhausen Noise with Metallurgical and Mechanical Characteristics of Welded Low Carbon Steel
Authors: Vourna Polykseni , Ktena Aphrodite , Hristoforou Evangelos
Published: May 2015

The influence of Electron Beam welding technique on the microstructure, mechanical and magnetic properties of low carbon steels was presented and evaluated. Samples with dimensions of 12 cm x 6 cm x 1.5 mm were prepared from stock plate, installed on the welding table and welded at welding speeds and pulsed currents following a predesigned protocol. In order to examine the influence of welding on the magnetizing behavior of low carbon steel, magnetic Barkhausen noise were conducted on the surface of the welded samples. The results were further evaluated by examining the microstructure and mechanical properties of the welded samples by using scanning electron microscopy and micro-hardness measurements, respectively.