Search results for: Virtual environment

Authors: S. H. J. Liu

Abstract:

This paper aims to explore the role of peer Corrective Feedback (CF) in improving written productions by English-as-a- foreign-language (EFL) learners who work together via Wikispaces. It attempted to determine the effect of peer CF on form accuracy in English, such as grammar and lexis. Thirty-four EFL learners at the tertiary level were randomly assigned into the experimental (with peer feedback) or the control (without peer feedback) group; each group was subdivided into small groups of two or three. This resulted in six and seven small groups in the experimental and control groups, respectively. In the experimental group, each learner played a role as an assessor (providing feedback to others), as well as an assessee (receiving feedback from others). Each participant was asked to compose his/her written work and revise it based on the feedback. In the control group, on the other hand, learners neither provided nor received feedback but composed and revised their written work on their own. Data collected from learners’ compositions and post-task interviews were analyzed and reported in this study. Following the completeness of three writing tasks, 10 participants were selected and interviewed individually regarding their perception of collaborative learning in the Computer-Mediated Communication (CMC) environment. Language aspects to be analyzed included lexis (e.g., appropriate use of words), verb tenses (e.g., present and past simple), prepositions (e.g., in, on, and between), nouns, and articles (e.g., a/an). Feedback types consisted of CF, affective, suggestive, and didactic. Frequencies of feedback types and the accuracy of the language aspects were calculated. The results first suggested that accurate items were found more in the experimental group than in the control group. Such results entail that those who worked collaboratively outperformed those who worked non-collaboratively on the accuracy of linguistic aspects. Furthermore, the first type of CF (e.g., corrections directly related to linguistic errors) was found to be the most frequently employed type, whereas affective and didactic were the least used by the experimental group. The results further indicated that most participants perceived that peer CF was helpful in improving the language accuracy, and they demonstrated a favorable attitude toward working with others in the CMC environment. Moreover, some participants stated that when they provided feedback to their peers, they tended to pay attention to linguistic errors in their peers’ work but overlook their own errors (e.g., past simple tense) when writing. Finally, L2 or FL teachers or practitioners are encouraged to employ CMC technologies to train their students to give each other feedback in writing to improve the accuracy of the language and to motivate them to attend to the language system.

Keywords: Peer corrective feedback, computer-mediated communication, second or foreign language learning, Wikispaces.

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Authors: Jiali Fu

Abstract:

Earthmoving operations are a major part of many construction projects. Because of the complexity and fast-changing environment of such operations, the planning and estimating are crucial on both planning and operational levels. This paper presents the framework ofa microscopic discrete-event simulation system for modeling earthmoving operations and conducting productivity estimations on an operational level.A prototype has been developed to demonstrate the applicability of the proposed framework, and this simulation system is presented via a case study based on an actual earthmoving project. The case study shows that the proposed simulation model is capable of evaluating alternative operating strategies and resource utilization at a very detailed level.

Keywords: Earthmoving operation, microscopic simulation, discrete-event simulation

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Authors: Jennifer Chen-Hua Min

Abstract:

The concept of self-efficacy refers to people’s beliefs in their ability to perform certain behaviors and cope with environmental demands. As such, self-efficacy plays a key role in linking ability to performance. Therefore, this study examines the relationships of self-efficacy, emotional intelligence (EI), and well-being among tour guides, who act as intermediaries between tourists and an unfamiliar environment and significantly influence tourists’ impressions of a destination. Structural equation modeling (SEM) is used to identify the relationships between these factors. The results found that self-efficacy is positively associated with EI and well-being, and a positive link was seen between EI and well-being. This study has practical implications, as the results can facilitate the development of interventions for enhancing tour guides’ EI and self-efficacy competencies, which will benefit them in terms of both enhanced achievements and improved psychological happiness and well-being.

Keywords: Self-efficacy, tour guides, tourism, emotional intelligence.

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Authors: Nikola Karanovic, Aleksandar Djuric

Abstract:

This paper introduces a method of calculating the quantities of construction materials and construction waste on site in city of Novi Sad. In buildings is about 40% of the total weight of materials that are in circulation in the world economic space. The best solution for this waste is to be stored at source, at the point of generation. There are several treatment options for this type of waste, reduction at source, reuse, recycling. Beside its negative effects on the environment, construction waste can be and resource. Novi Sad is divided in 16 single family resident zones and 10 multi family resident zones. For every zone of the city, quantities of used construction materials and construction waste were obtained. Rational use of natural resources is an essential factor in applying the principles of development with savings.

Keywords: Construction materials, Construction waste, Novi Sad, Recycling

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Authors: John M. Ikome, Martha E. Ikome, Therese Van Wyk

Abstract:

Productivity optimization of a company can significantly increase the company’s output and productivity which can be in the form of corrective actions of ineffective activities, process simplification, and reduction of variations, responsiveness, and reduction of set-up-time which are all under the classification of waste within the manufacturing environment. Deriving a means to eliminate a number of these issues has a key importance for manufacturing organization. This paper focused on a number of industrial engineering techniques which include a cause and effect diagram, to identify and optimize the method or systems being used. Based on our results, it shows that there are a number of variations within the production processes that can significantly disrupt the expected output.

Keywords: Optimization, fishbone diagram, productivity.

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Authors: Vesna Bosilj Vuksic, Mirjana Pejic Bach

Abstract:

Business process management (BPM) has become widely accepted within business community as a means for improving business performance. However, it is of the highest importance to incorporate BPM as part of the curriculum at the university level education in order to achieve the appropriate acceptance of the method. Goal of the paper is to determine the current state of education in business process management (BPM) at the Croatian universities and abroad. It investigates the applied forms of instruction and teaching methods and gives several proposals for BPM courses improvement. Since majority of undergraduate and postgraduate students have limited understanding of business processes and lack of any practical experience, there is a need for introducing new teaching approaches. Therefore, we offer some suggestions for further improvement, among which the introduction of simulation games environment in BPM education is strongly recommended.

Keywords: business process management, simulation games, education

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Authors: G. Shruthi, Purohit Shrinivasacharya

Abstract:

The biggest problem in cloud is securing an outsourcing data. A cloud environment cannot be considered to be trusted. It becomes more challenging when outsourced data sources are managed by multiple outsourcers with different access rights. Several methods have been proposed to protect data confidentiality against the cloud service provider to support fine-grained data access control. We propose a method with combined Cipher Text Policy Attribute-based Encryption (CP-ABE) and Timed-release encryption (TRE) secure method to control medical data storage in public cloud.

Keywords: Attribute, encryption, security, trapdoor.

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Authors: Teodora Bakardjieva, Galya Gercheva

Abstract:

In this paper an open agent-based modular framework for personalized and adaptive curriculum generation in e-learning environment is proposed. Agent-based approaches offer several potential advantages over alternative approaches. Agent-based systems exhibit high levels of flexibility and robustness in dynamic or unpredictable environments by virtue of their intrinsic autonomy. The presented framework enables integration of different types of expert agents, various kinds of learning objects and user modeling techniques. It creates possibilities for adaptive e-learning process. The KM e-learning system is in a process of implementation in Varna Free University and will be used for supporting the educational process at the University.

Keywords: agents, e-Learning, knowledge management, knowledge sharing, artificial intelligence

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Authors: Burja C., Burja V.

Abstract:

For Romania, the fulfilment of the obligations undertaken as a member state of the European Union in accordance with the Treaty of Accession requires the effective implementation of sustainable development principles and practices, this being the only reasonable development option, which adequately draws in on the economic, social and environment resources. Achieving this objective is based on a profound analysis of the realities in the Romanian economy, which will reflect the existent situation and the action directions for the future. The paper presents an analysis of the Romanian economic performances compared to the EU economy, based on the sustainable value (SV) model. The analysis highlighted the considerable gap between Romania and the EU regarding the sustainable capitalization of resources, the provided information being useful to justify strategic development decisions at a micro and macro levels.

Keywords: Sustainable value, sustainable development, opportunity cost, economic performance.

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Authors: A. Mallick

Abstract:

The tensile properties of Mg-3%Al nanocrystalline alloys were investigated at different test environment. Bulk nanocrystalline samples of these alloy was successfully prepared by mechanical alloying (MA) followed by cold compaction, sintering, and hot extrusion process. The crystal size of the consolidated milled sample was calculated by X-Ray line profile analysis. The deformation mechanism and microstructural characteristic at different test condition was discussed extensively. At room temperature, relatively lower value of activation volume (AV) and higher value of strain rate sensitivity (SRS) suggests that new rate controlling mechanism accommodating plastic flow in the present nanocrystalline sample. The deformation behavior and the microstructural character of the present samples were discussed in details.

Keywords: Nanocrystalline, tensile properties, temperature effect.

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Authors: R. Boondao, A. J. Hurst, J. I. Sheard

Abstract:

In the globalized e-learning environment, students coming from different cultures and countries have different characteristics and require different support designed for their approaches to study and learning styles. This paper explores the ways in which cultural background influences students- approaches to study and learning styles. Participants in the study consisted of 131 eastern students and 54 western students from an Australian university. The students were tested using the Study Process Questionnaire (SPQ) for assessing their approaches to study and the Index of Learning Styles Questionnaire (ILS) for assessing their learning styles. The results of the study led to a set of principles being proposed to guide personalization of e-learning system design on the basis of cultural differences.

Keywords: Approaches to study, Cultural influences, Learningstyles, Personalization, e-learning system.

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Authors: N. Bhalaji, A. R. Sivaramkrishnan, Sinchan Banerjee, V. Sundar, A. Shanmugam

Abstract:

Nodes in mobile Ad Hoc Network (MANET) do not rely on a central infrastructure but relay packets originated by other nodes. Mobile ad hoc networks can work properly only if the participating nodes collaborate in routing and forwarding. For individual nodes it might be advantageous not to collaborate, though. In this conceptual paper we propose a new approach based on relationship among the nodes which makes them to cooperate in an Adhoc environment. The trust unit is used to calculate the trust values of each node in the network. The calculated trust values are being used by the relationship estimator to determine the relationship status of nodes. The proposed enhanced protocol was compared with the standard DSR protocol and the results are analyzed using the network simulator-2.

Keywords: Reliable Routing, DSR, Grudger, Adhoc network.

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Authors: Mohammad Javad Mollakazemi, Farhad Asadi

Abstract:

In this paper a real-time obstacle avoidance approach for both autonomous and non-autonomous dynamical systems (DS) is presented. In this approach the original dynamics of the controller which allow us to determine safety margin can be modulated. Different common types of DS increase the robot’s reactiveness in the face of uncertainty in the localization of the obstacle especially when robot moves very fast in changeable complex environments. The method is validated by simulation and influence of different autonomous and non-autonomous DS such as important characteristics of limit cycles and unstable DS. Furthermore, the position of different obstacles in complex environment is explained. Finally, the verification of avoidance trajectories is described through different parameters such as safety factor.

Keywords: Limit cycles, Nonlinear dynamical system, Real time obstacle avoidance.

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Authors: M.R. Osman, F. Abas, M.S. Noh, A. Mohamad Suffian, O. Ilhamah, H.Z. Zarir, A.B. Wahida, P. Noor Faradila, M.F. Siti Atiqah

Abstract:

Safety Health and Environment Code of Practice (SHE COP) was developed to help road transportation operators to manage its operation in a systematic and safe manner. A study was conducted to determine the effectiveness of SHE COP implementation during non-OPS period. The objective of the study is to evaluate the implementations of SHE COP among bus operators during wee hour operations. The data was collected by completing a set of checklist after observing the activities during pre departure, during the trip, and upon arrival. The results show that there are seven widely practiced SHE COP elements. 22% of the buses have average speed exceeding the maximum permissible speed on the highways (90 km/h), with 13% of the buses were travelling at the speed of more than 100 km/h. The statistical analysis shows that there is only one significant association which relates speeding with prior presence of enforcement officers.

Keywords: Safety practices, speeding, wee hour.

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Authors: Yingxin He, Kyouichi Tatsuno

Abstract:

In this paper, we propose an architecture for easily constructing a robot controller. The architecture is a multi-agent system which has eight agents: the Man-machine interface, Task planner, Task teaching editor, Motion planner, Arm controller, Vehicle controller, Vision system and CG display. The controller has three databases: the Task knowledge database, the Robot database and the Environment database. Based on this controller architecture, we are constructing an experimental power distribution line maintenance robot system and are doing the experiment for the maintenance tasks, for example, “Bolt insertion task".

Keywords: Robot controller, Software library, Maintenance robot, Robot language, Agent system.

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Authors: Weichang Du

Abstract:

This paper proposes a new of cloud computing for individual computer users to share applications in distributed communities, called community-based personal cloud computing (CPCC). The paper also presents a prototype design and implementation of CPCC. The users of CPCC are able to share their computing applications with other users of the community. Any member of the community is able to execute remote applications shared by other members. The remote applications behave in the same way as their local counterparts, allowing the user to enter input, receive output as well as providing the access to the local data of the user. CPCC provides a peer-to-peer (P2P) environment where each peer provides applications which can be used by the other peers that are connected CPCC.

Keywords: applications, cloud computing, services, software.

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Authors: Somayeh Farzin, Hossein Teimoori Nezhad

Abstract:

Procurement is an important component in the field of operating resource management and e-procurement is the golden key to optimizing the supply chains system. Global firms are optimistic on the level of savings that can be achieved through full implementation of e-procurement strategies. E-procurement is an Internet-based business process for obtaining materials and services and managing their inflow into the organization. In this paper, the subjects of supply chains and e-procurement and its benefits to organizations have been studied. Also, e-procurement in construction and its drivers and barriers have been discussed and a framework of supplier selection in an e-procurement environment has been demonstrated. This paper also has addressed critical success factors in adopting e-procurement in supply chains.

Keywords: E-Procurement, Supply Chain, Benefits, Construction, Drivers, Barriers, Supplier Selection, CFSs.

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Authors: Elsayed A. Habib Elamir

Abstract:

In social network analysis the mean nodal degree and density of the graph can be considered as a measure of the activity of all actors in the network and this is an important property of a graph and for making comparisons among networks. Since subjects in a family or organization are subject to common environment factors, it is prime interest to study the association between responses. Therefore, we study the distribution of the mean nodal degree and density of the graph under correlated binary units. The cross product ratio is used to capture the intra-units association among subjects. Computer program and an application are given to show the benefits of the method.

Keywords: Correlated Binary data, cross product ratio, densityof the graph, multiplicative binomial distribution.

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Authors: Son Tung Pham, William Prince

Abstract:

The objective of this work was to examine the changes in non destructive properties caused by carbonation of CEM II mortar. Samples of CEM II mortar were prepared and subjected to accelerated carbonation at 20°C, 65% relative humidity and 20% CO2 concentration. We examined the evolutions of the gas permeability, the thermal conductivity, the thermal diffusivity, the volume of the solid phase by helium pycnometry, the longitudinal and transverse ultrasonic velocities. The principal contribution of this work is that, apart of the gas permeability, changes in other non destructive properties have never been studied during the carbonation of cement materials. These properties are important in predicting/measuring the durability of reinforced concrete in CO2 environment. The carbonation depth and the porosity accessible to water were also reported in order to explain comprehensively the changes in non destructive parameters.

Keywords: Carbonation, cement mortar, longitudinal and transverse ultrasonic velocities, non destructive tests.

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Authors: Sarah Odofin, Zhiwei Gao, Sun Kai

Abstract:

Operations, maintenance and reliability of wind turbines have received much attention over the years due to the rapid expansion of wind farms. This paper explores early fault diagnosis technique for a 5MW wind turbine system subjected to multiple faults, where genetic optimization algorithm is employed to make the residual sensitive to the faults, but robust against disturbances. The proposed technique has a potential to reduce the downtime mostly caused by the breakdown of components and exploit the productivity consistency by providing timely fault alarms. Simulation results show the effectiveness of the robust fault detection methods used under Matlab/Simulink/Gatool environment.

Keywords: Disturbance robustness, fault monitoring and detection, genetic algorithm and observer technique.

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Authors: Shirong Li, Xueping Xiang

Abstract:

Construction site safety in China has aroused comprehensive concern all over the world. It is imperative to investigate the main causes of poor construction site safety. This paper divides all the causes into four aspects, namely the factors of workers, object, environment and management and sets up the accident causes element system based on Delphi Method. This is followed by the application of structural equation modeling to examine the importance of each aspect of causes from the standpoints of different roles related to the construction respectively. The results indicate that all the four aspects of factors are in need of improvement, and different roles have different ideas considering the priority of those factors. The paper has instructive significance for the practitioners to take measures to improve construction site safety in China accordingly.

Keywords: construction site safety, Delphi Method, structuralequation modeling, different perspective.

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Authors: Ulrich Berger, Yuliya Lebedynska, Veronica Vargas

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The right information at the right time influences the enterprise and technical success. Sharing knowledge among members of a big organization may be a complex activity. And as long as the knowledge is not shared, can not be exploited by the organization. There are some mechanisms which can originate knowledge sharing. It is intended, in this paper, to trigger these mechanisms by using semantic nets. Moreover, the intersection and overlapping of terms and sub-terms, as well as their relationships will be described through the mereology science for the whole knowledge sharing system. It is proposed a knowledge system to supply to operators with the right information about a specific process and possible risks, e.g. at the assembly process, at the right time in an automated manufacturing environment, such as at the automotive industry.

Keywords: Automated manufacturing, knowledge sharing, mereology, risk management, semantic net.

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Authors: K. Raghuwaiya, B. Sharma, J. Vanualailai

Abstract:

This paper presents a set of artificial potential field functions that improves upon, in general, the motion planning and posture control, with theoretically guaranteed point and posture stabilities, convergence and collision avoidance properties of the general3-trailer system in a priori known environment. We basically design and inject two new concepts; ghost walls and the distance optimization technique (DOT) to strengthen point and posture stabilities, in the sense of Lyapunov, of our dynamical model. This new combination of techniques emerges as a convenient mechanism for obtaining feasible orientations at the target positions with an overall reduction in the complexity of the navigation laws. Simulations are provided to demonstrate the effectiveness of the controls laws.

Keywords: Artificial potential fields, 3-trailer systems, motion planning, posture.

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Authors: Alicia Y. C. Tang, Rukaini Hj. Abdullah, Sharifuddin M. Zain

Abstract:

This paper discusses the development of a qualitative simulator (abbreviated QRiOM) for predicting the behaviour of organic chemical reactions. The simulation technique is based on the qualitative process theory (QPT) ontology. The modelling constructs of QPT embody notions of causality which can be used to explain the behaviour of a chemical system. The major theme of this work is that, in a qualitative simulation environment, students are able to articulate his/her knowledge through the inspection of explanations generated by software. The implementation languages are Java and Prolog. The software produces explanation in various forms that stresses on the causal theories in the chemical system which can be effectively used to support learning.

Keywords: Chemical reactions, explanation, qualitative processtheory, simulation

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Authors: Daniel Kliewe, Arno Kühn, Roman Dumitrescu, Jürgen Gausemeier

Abstract:

This paper examines the system protection for cyber-physical systems (CPS). CPS are particularly characterized by their networking system components. This means they are able to adapt to the needs of their users and its environment. With this ability, CPS have new, specific requirements on the protection against anti-counterfeiting, know-how loss and manipulation. They increase the requirements on system protection because piracy attacks can be more diverse, for example because of an increasing number of interfaces or through the networking abilities. The new requirements were identified and in a next step matched with existing protective measures. Due to the found gap the development of new protection measures has to be forced to close this gap. Moreover a comparison of the effectiveness between selected measures was realized and the first results are presented in this paper.

Keywords: Anti-counterfeiting, cyber physical systems, Intellectual property (IP) and knowledge management, system protection.

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Authors: Ana Paula Monte, Christiane Fontenete

Abstract:

As current business environment is demanding a constant adaptation of companies, the planning and strategic management should be an ongoing and natural process in all kind of organizations. The use of management and monitoring strategic performance tools such as the Balanced Scorecard (BSC) have been popular; even to Small and Medium-sized Enterprises. This paper aims to investigate whether the BSC is being used in monitoring the performance of small businesses, particularly in small fuel retailers companies, which are competing in co-branding; and if not, it aims to identify its strategic orientation in order to recommend a possible strategy map for those managers that are willing to adopt this model as an alternative to traditional ones for organizational performance evaluation, which often focus only on evaluation of the organizational financial performance.

Keywords: Balanced Scorecard, Performance Management and Evaluation, SMEs, Strategy Maps

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Authors: Srinivas Bathini, Duraichelvan Raju, Simona Badilescu, Muthukumaran Packirisamy

Abstract:

A bio-sensing method, based on the plasmonic property of gold nano-islands, has been developed for detection of exosomes in a clinical setting. The position of the gold plasmon band in the UV-Visible spectrum depends on the size and shape of gold nanoparticles as well as on the surrounding environment. By adsorbing various chemical entities, or binding them, the gold plasmon band will shift toward longer wavelengths and the shift is proportional to the concentration. Exosomes transport cargoes of molecules and genetic materials to proximal and distal cells. Presently, the standard method for their isolation and quantification from body fluids is by ultracentrifugation, not a practical method to be implemented in a clinical setting. Thus, a versatile and cutting-edge platform is required to selectively detect and isolate exosomes for further analysis at clinical level. The new sensing protocol, instead of antibodies, makes use of a specially synthesized polypeptide (Vn96), to capture and quantify the exosomes from different media, by binding the heat shock proteins from exosomes. The protocol has been established and optimized by using a glass substrate, in order to facilitate the next stage, namely the transfer of the protocol to a microfluidic environment. After each step of the protocol, the UV-Vis spectrum was recorded and the position of gold Localized Surface Plasmon Resonance (LSPR) band was measured. The sensing process was modelled, taking into account the characteristics of the nano-island structure, prepared by thermal convection and annealing. The optimal molar ratios of the most important chemical entities, involved in the detection of exosomes were calculated as well. Indeed, it was found that the results of the sensing process depend on the two major steps: the molar ratios of streptavidin to biotin-PEG-Vn96 and, the final step, the capture of exosomes by the biotin-PEG-Vn96 complex. The microfluidic device designed for sensing of exosomes consists of a glass substrate, sealed by a PDMS layer that contains the channel and a collecting chamber. In the device, the solutions of linker, cross-linker, etc., are pumped over the gold nano-islands and an Ocean Optics spectrometer is used to measure the position of the Au plasmon band at each step of the sensing. The experiments have shown that the shift of the Au LSPR band is proportional to the concentration of exosomes and, thereby, exosomes can be accurately quantified. An important advantage of the method is the ability to discriminate between exosomes having different origins.

Keywords: Exosomes, gold nano-islands, microfluidics, plasmonic biosensing.

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Authors: Jae Moon Lee

Abstract:

In general, algorithms to find continuous k-nearest neighbors have been researched on the location based services, monitoring periodically the moving objects such as vehicles and mobile phone. Those researches assume the environment that the number of query points is much less than that of moving objects and the query points are not moved but fixed. In gaming environments, this problem is when computing the next movement considering the neighbors such as flocking, crowd and robot simulations. In this case, every moving object becomes a query point so that the number of query point is same to that of moving objects and the query points are also moving. In this paper, we analyze the performance of the existing algorithms focused on location based services how they operate under gaming environments.

Keywords: Flocking behavior, heterogeneous agents, similarity, simulation.

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Authors: Eklas Hossain, Sheroz Khan, Ahad Ali

Abstract:

Power line communications may be used as a data communication channel in public and indoor distribution networks so that it does not require the installing of new cables. Industrial low voltage distribution network may be utilized for data transfer required by the on-line condition monitoring of electric motors. This paper presents a pilot distribution network for modeling low voltage power line as data transfer channel. The signal attenuation in communication channels in the pilot environment is presented and the analysis is done by varying the corresponding parameters for the signal attenuation.

Keywords: Data communication, indoor distribution networks, low voltage, power line.

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Authors: Isabel Brás, Artur Figueirinha, Bruno Esteves, Luísa P. Cruz-Lopes

Abstract:

The agriculture lignocellulosic by-products are receiving increased attention, namely in the search for filter materials that retain contaminants from water. These by-products, specifically almond and hazelnut shells are abundant in Portugal once almond and hazelnuts production is a local important activity. Hazelnut and almond shells have as main constituents lignin, cellulose and hemicelluloses, water soluble extractives and tannins. Along the adsorption of heavy metals from contaminated waters, water soluble compounds can leach from shells and have a negative impact in the environment. Usually, the chemical characterization of treated water by itself may not show environmental impact caused by the discharges when parameters obey to legal quality standards for water. Only biological systems can detect the toxic effects of the water constituents. Therefore, the evaluation of toxicity by biological tests is very important when deciding the suitability for safe water discharge or for irrigation applications.

The main purpose of the present work was to assess the potential impacts of waters after been treated for heavy metal removal by hazelnut and almond shells adsorption systems, with short term acute toxicity tests.

To conduct the study, water at pH 6 with 25 mg.L^-1 of lead, was treated with 10 g of shell per litre of wastewater, for 24 hours. This procedure was followed for each bark. Afterwards the water was collected for toxicological assays; namely bacterial resistance, seed germination, Lemna minor L. test and plant grow. The effect in isolated bacteria strains was determined by disc diffusion method and the germination index of seed was evaluated using lettuce, with temperature and humidity germination control for 7 days. For aquatic higher organism, Lemnas were used with 4 days contact time with shell solutions, in controlled light and temperature. For terrestrial higher plants, biomass production was evaluated after 14 days of tomato germination had occurred in soil, with controlled humidity, light and temperature.

Toxicity tests of water treated with shells revealed in some extent effects in the tested organisms, with the test assays showing a close behaviour as the control, leading to the conclusion that its further utilization may not be considered to create a serious risk to the environment.

Keywords: Acute toxicity tests, adsorption, lignocellulosic wastes, risk assessment.

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