Search results for: real time control

Authors: Jung-Woon Lee, Jung-Taek Kim, Jae-Chang Park, In-Koo Hwang, Sung-Pil Lyu

Abstract:

Computerized alarm systems have been applied increasingly to nuclear power plants. For existing plants, an add-on computer alarm system is often installed to the control rooms. Alarm avalanches during the plant transients are major problems with the alarm systems in nuclear power plants. Computerized alarm systems can process alarms to reduce the number of alarms during the plant transients. This paper describes various alarm processing methods, an alarm cause tracking function, and various alarm presentation schemes to show alarm information to the operators effectively which are considered during the development of several computerized alarm systems for Korean nuclear power plants and are found to be helpful to the operators.

Keywords: Alarm processing, Alarm presentation, Alarm causetracking, Alarm logic diagram computerization, Alarm patternrecognition.

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Authors: Heide Lukosch, Roy Van Bussel, Sebastiaan Meijer

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Serious games have proven to be a useful instrument to engage learners and increase motivation. Nevertheless, a broadly accepted, practical instructional design approach to serious games does not exist. In this paper, we introduce the use of an instructional design model that has not been applied to serious games yet, and has some advantages compared to other design approaches. We present the case of mechanics mechatronics education to illustrate the close match with timing and role of knowledge and information that the instructional design model prescribes and how this has been translated to a rigidly structured game design. The structured approach answers the learning needs of applicable knowledge within the target group. It combines advantages of simulations with strengths of entertainment games to foster learner-s motivation in the best possible way. A prototype of the game will be evaluated along a well-respected evaluation method within an advanced test setting including test and control group.

Keywords: Serious Gaming, Simulation, Complex Learning.

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Authors: Sharil Tumin, Sylvia Encheva

Abstract:

Centrally controlled authentication and authorization services can provide enterprise with an increase in security, more flexible access control solutions and an increased users' trust. By using redirections, users of all Web-based applications within an organization are authenticated at a single well known and secure Web site and using secure communication protocol. Users are first authenticated at the central server using their domain wide credentials before being redirected to a particular Web-based application. The central authentication server will then provide others with pertinence authorization related particulars and credentials of the authenticated user to the specific application. The trust between the clients and the server hosts is established by secure session keys exchange. Case- studies are provided to demonstrate the usefulness and flexibility of the proposed solution.

Keywords: Authentication, Authorization, Security, Protected Web-based Applications

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Authors: Sunil Dehipawala, Aregama Sirisumana, P. Schneider, G. Tremberger Jr, D. Lieberman, Todd Holden T. Cheung

Abstract:

The arsenic and iron environments in different growth stages have been studied with EXAFS and XANES using Brookhaven Synchrotron Light Source. Collard Greens plants were grown and tissue samples were harvested. The project studied the EXAFS and XANES of tissue samples using As and Fe K-edges. The Fe absorption and the Fourier transform bond length information were used as a control comparison. The Fourier transform of the XAFS data revealed the coexistence of As (III) and As (V) in the As bonding environment inside the studied plant tissue samples, although the soil only had As (III). The data suggests that Collard Greens has a novel pathway to handle arsenic absorption in soil.

Keywords: EXAFS, Fourier Transform, metalloproteins, XANES.

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Authors: Haga Elimam

Abstract:

This paper investigates the connotation, and some of the realistic implications, of the economic reform of health sector in under developed countries. The paper investigates the issues that economic reforms have to address, and the policy targets they are considered to accomplish. The work argues that the development of economic reform is not connected only with understanding the priorities and refining them, furthermore with reformation and restructuring the organizations through which health policies are employed. Considering various organizational values, that are likely to be regular to all economic reform programs, a regulatory approach to institutional reform is unsuitable. The paper further investigates the selection of economic reform that may as well influence via technical suggestions and analysis, but the verdict to continue, and the consequent success of execution, eventually depends on the progressive political sustainability. The paper concludes by giving examples of institutional reforms from various underdeveloped countries and includes recommendation of the responsibility and control of donor organizations.

Keywords: Economic Reform, Health Sector, underdeveloped Countries.

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Authors: Larysa Novak-Kalyayeva, Aleksander Kuczabski, Orystlava Sydorchuk, Nataliia Fersman, Tatyana Zemlinskaia

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The article presents the results of the creative analysis and comparison of trends in the development of the theory of public administration during the period from the second half of the 20^th to the beginning of the 21^st century. The process of conceptualization of the priorities of public administration in the dynamics of reforming was held under the influence of such factors as globalization, integration, information and technological changes and human rights is examined. The priorities of the social state in the concepts of the second half of the 20^th century are studied. Peculiar approaches to determining the priorities of public administration in the countries of "Soviet dictatorship" in Central and Eastern Europe in the same period are outlined. Particular attention is paid to the priorities of public administration regarding the interaction between public power and society and the development of conceptual foundations for the modern managerial process. There is a thought that the dynamics of the formation of concepts of the European governance is characterized by the sequence of priorities: from socio-economic and moral-ethical to organizational-procedural and non-hierarchical ones. The priorities of the "welfare state" were focused on the decent level of material wellbeing of population. At the same time, the conception of "minimal state" emphasized priorities of human responsibility for their own fate under the conditions of minimal state protection. Later on, the emphasis was placed on horizontal ties and redistribution of powers and competences of "effective state" with its developed procedures and limits of responsibility at all levels of government and in close cooperation with the civil society. The priorities of the contemporary period are concentrated on human rights in the concepts of "good governance" and all the following ones, which recognize the absolute priority of public administration with compliance, provision and protection of human rights. There is a proved point of view that civilizational changes taking place under the influence of information and technological imperatives also stipulate changes in priorities, redistribution of emphases and update principles of managerial concepts on the basis of publicity, transparency, departure from traditional forms of hierarchy and control in favor of interactivity and inter-sectoral interaction, decentralization and humanization of managerial processes. The necessity to permanently carry out the reorganization, by establishing the interaction between different participants of public power and social relations, to establish a balance between political forces and social interests on the basis of mutual trust and mutual understanding determines changes of social, political, economic and humanitarian paradigms of public administration and their theoretical comprehension. The further studies of theoretical foundations of modern public administration in interdisciplinary discourse in the context of ambiguous consequences of the globalizational and integrational processes of modern European state-building would be advisable. This is especially true during the period of political transformations and economic crises which are the characteristic of the contemporary Europe, especially for democratic transition countries.

Keywords: Concepts of public administration, democratic transition countries, human rights, the priorities of public administration, theory of public administration.

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Authors: Baki Koyuncu, Mehmet Güzel

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The kinematics of manipulators is a central problem in the automatic control of robot manipulators. Theoretical background for the analysis of the 5 Dof Lynx-6 educational Robot Arm kinematics is presented in this paper. The kinematics problem is defined as the transformation from the Cartesian space to the joint space and vice versa. The Denavit-Harbenterg (D-H) model of representation is used to model robot links and joints in this study. Both forward and inverse kinematics solutions for this educational manipulator are presented, An effective method is suggested to decrease multiple solutions in inverse kinematics. A visual software package, named MSG, is also developed for testing Motional Characteristics of the Lynx-6 Robot arm. The kinematics solutions of the software package were found to be identical with the robot arm-s physical motional behaviors.

Keywords: Lynx 6, robot arm, forward kinematics, inverse kinematics, software, DH parameters, 5 DOF , SSC-32 , simulator.

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Authors: Hadi Seyedarabi, Ali Aghagolzadeh, Sohrab Khanmohammadi

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Face and facial expressions play essential roles in interpersonal communication. Most of the current works on the facial expression recognition attempt to recognize a small set of the prototypic expressions such as happy, surprise, anger, sad, disgust and fear. However the most of the human emotions are communicated by changes in one or two of discrete features. In this paper, we develop a facial expressions synthesis system, based on the facial characteristic points (FCP's) tracking in the frontal image sequences. Selected FCP's are automatically tracked using a crosscorrelation based optical flow. The proposed synthesis system uses a simple deformable facial features model with a few set of control points that can be tracked in original facial image sequences.

Keywords: Deformable face model, facial animation, facialcharacteristic points, optical flow.

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Authors: Somchai Seviset, Lin Jian Qun

Abstract:

Amarindra-vinitchai-mahaisuraya Bhiman throne hall is one of the most significant throne halls in the grand palace in the Ratthanakosin city situated in Bangkok, Thailand. This is the first group of throne halls built in order to serve as a place for meetings, performing state affairs and royal duties until the present time. The structure and pattern of architectural design including the decoration and interior design of the throne hall obviously exhibits and convey the status of the king under the context of Thai society in the early period of Ratthanakosin era. According to the tradition of ruling the kingdom in absolute monarchy which had been in place since Ayutthaya era (A.D.1350-1767), the king was deemed as Deva Raja, the highest power and authority over the kingdom and as the greatest emperor of the universe (Chakkravatin). The architectural design adopted the concept of “Prasada" or Viman which served as the dwelling place of the gods and was presented in the form of “Thai traditional architecture" For the interior design of the throne hall, it had been adopted to be the heaven and the centre of the Universe in line with the cosmological beliefs of ancient people described in scripture Tribhumikatha (Tri Bhumi) written by Phra Maha Thamma Raja (Phraya Lithai) of the Sukhothai era (A.D.1347-1368). According to this belief, the throne hall had been designed to represent mount Meru, the central of the universe. On the top end of Mount Meru is situated the Viman and dwelling place of Indra who is the king of gods according to the idea of Deva Raja (the king god Avatar). At the same time, Indra also existed as the king of the universe simultaneously.

Keywords: Amarindra-vinitchai-mahaisuraya Bhiman throne hall, throne hall architecture, grand palace, Thai traditional architecture, Ratthanakosin era

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Authors: P. Suryakumari, P. Kantarao

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Optimal Power Flow (OPF) problem in electrical power system is considered as a static, non-linear, multi-objective or a single objective optimization problem. This paper presents an algorithm for solving the voltage stability objective reactive power dispatch problem in a power system .The proposed approach employs cat swarm optimization algorithm for optimal settings of RPD control variables. Generator terminal voltages, reactive power generation of the capacitor banks and tap changing transformer setting are taken as the optimization variables. CSO algorithm is tested on standard IEEE 30 bus system and the results are compared with other methods to prove the effectiveness of the new algorithm. As a result, the proposed method is the best for solving optimal reactive power dispatch problem.

Keywords: RPD problem, voltage stability enhancement, CSO algorithm.

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Authors: J. Kumchai, J. Z. Huang, C. Y. Lee, F. C. Chen, S. W. Chin

Abstract:

Cabbage seedlings grown in vitro were exposed to excess levels of heavy metals, including Cd, Mo, and Zn. High metal levels affected plant growth at cotyledonary stage. Seedlings under Cd, Mo, and Zn treatments could not produce root hairs and true leaves. Under stress conditions, seedlings accumulated a higher amount of anthocyanins in their cotyledons than those in the control. The pigments isolated from Cd and Zn stressed seedling cotyledons appeared as pink, while under Mo stress, was dark pink or purple. Moreover, excess Mo stress increased antioxidant enzyme activities of APX, CAT, SOD. These results suggest that, under excess Mo stress, the induced antioxidant enzyme activity of cabbage seedlings may function as a protective mechanism to shield the plants from toxicity and exacerbated growth.

Keywords: Anthocyanin, antioxidant enzyme activity, heavy metal, growth inhibition.

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Authors: Mofleh S. Awawdeh

Abstract:

Ten lactating multiparous Holstein cows were used in a cross-over design with two dietary treatments and 28-d periods (with 14 d as an adaptation) to study the effect of restaurant fat on milk production and composition. Each cow was offered 14.7 kg DM /d of the basal concentrate diet based on barley and corn (crude protein = 17.7%, neutral detergent fiber = 23.5%, and acid detergent fiber = 5.8% of dry matter) with free access to alfalfa. Dietary treatments were arranged as supplying each cow with 0 (CONTROL) or 150 g/day (RF) of restaurant fat. Supplemental RF did not significantly (P > 0.25) affect milk yield, composition, and composition yields, except for milk fat contents. Milk fat contents were depressed (P < 0.05) with supplemental RF. Our results indicate that RF could depress milk fat without affecting milk yield and that the depression in milk fat in response to RF precedes the depression in milk yield.

Keywords: Dairy Cows, Restaurant Fat, Lipids.

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Authors: Xindong An, Kai Gu

Abstract:

Urban intensification is regarded as the prevalent strategy in many cities of the world to ease the pressures of urban sprawl and deliver sustainable development through increasing the density of built form and activities. However, within the context of intensive development, planning and design control measures that help to maintain and promote the character of existing residential environments have been slow to develop. This causes the possible loss of the character of an area that makes a place unique and distinctive. The purpose of this paper is to explore the way of identifying the character of an urban area for the planning of urban landscape in the implementation of intensification. By employing the theory of urban morphology, the concept of morphological region is used for the analysis and characterisation of the spatial structure of the urban landscape in terms of ground plans, building types, and building and land utilisation. The morphological mapping of the character of urban landscape is suggested, which lays a foundation for more sensitive planning of urban landscape changes.

Keywords: Character areas, urban intensification, urban morphology, urban landscape.

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Authors: İnci M. Erhan

Abstract:

A numerical method for solving the time-independent Schrödinger equation of a particle moving freely in a three-dimensional axisymmetric region is developed. The boundary of the region is defined by an arbitrary analytic function. The method uses a coordinate transformation and an expansion in eigenfunctions. The effectiveness is checked and confirmed by applying the method to a particular example, which is a prolate spheroid.

Keywords: Bessel functions, Eigenfunction expansion, Quantum billiard, Schrödinger equation, Spherical harmonics

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Authors: Debabrata Pradhan, Dong J. Kim, Jong G. Ahn, Seoung W. Lee

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Spent petroleum catalyst from Korean petrochemical industry contains trace amount of metals such as Ni, V and Mo. Therefore an attempt was made to recover those trace metal using bioleaching process. Different leaching parameters such as Fe(II) concentration, pulp density, pH, temperature and particle size of spent catalyst particle were studied to evaluate their effects on the leaching efficiency. All the three metal ions like Ni, V and Mo followed dual kinetics, i.e., initial faster followed by slower rate. The percentage of leaching efficiency of Ni and V were higher than Mo. The leaching process followed a diffusion controlled model and the product layer was observed to be impervious due to formation of ammonium jarosite (NH4)Fe3(SO4)2(OH)6. In addition, the lower leaching efficiency of Mo was observed due to a hydrophobic coating of elemental sulfur over Mo matrix in the spent catalyst.

Keywords: Bioleaching, diffusion control, shrinking core, spentpetroleum catalyst.

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Authors: Prakash Singh

Abstract:

Many schools throughout the world are facing constant pressure to cope with the violence and drug abuse of learners who show little or no respect for acceptable and desirable social norms. These delinquent learners tend to harbour feelings of being beyond reproach because they strongly believe that it is well within their rights to engage in violent and destructive behaviour. Knives, guns, and other weapons appear to be more readily used by them on the school premises than before. It is known that learners smoke, drink alcohol, and use drugs during school hours, hence, their ability to concentrate, work, and learn, is affected. They become violent and display disruptive behaviour in their classrooms as well as on the school premises, and this atrocious behaviour makes it possible for drug dealers and gangsters to gain access onto the school premises. The primary purpose of this exploratory quantitative study was therefore to establish how tobephobia (TBP), caused by school violence and drug abuse, affects teaching and learning in schools. The findings of this study affirmed that poor discipline resulted in producing poor quality education. Most of the teachers in this study agreed that educating learners who consumed alcohol and other drugs on the school premises resulted in them suffering from TBP. These learners are frequently abusive and disrespectful, and resort to violence to seek attention. As a result, teachers feel extremely demotivated and suffer from high levels of anxiety and stress. The word TBP will surely be regarded as a blessing by many teachers throughout the world because finally, there is a word that will make people sit up and listen to their problems that cause real fear and anxiety in schools.

Keywords: Aims and objectives of quality education, Debilitating effects of tobephobia, Fear of failure associated with education, learners’ violent behaviour and drug abuse.

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Authors: Sandro Bartolini, Alessandro Mecocci, Alessio Medaglini

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The growing popularity of systems based on Unmanned Aerial Vehicles (UAVs) is highlighting their vulnerability particularly in relation to the positioning system used. Typically, UAV architectures use the civilian GPS which is exposed to a number of different attacks, such as jamming or spoofing. This is why it is important to develop alternative methodologies to accurately estimate the actual UAV position without relying on GPS measurements only. In this paper we propose a position estimate method for UAVs based on monocular visual odometry. We have developed a flight control system capable of keeping track of the entire trajectory travelled, with a reduced dependency on the availability of GPS signal. Moreover, the simplicity of the developed solution makes it applicable to a wide range of commercial drones. The final goal is to allow for safer flights in all conditions, even under cyber-attacks trying to deceive the drone.

Keywords: Visual odometry, autonomous UAV, position measurement, autonomous outdoor flight.

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Authors: L. Ramirez, E. Guillén, J. Sánchez

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Some of the main goals about telecare such as monitoring, treatment, telediagnostic are deployed with the integration of applications with specific appliances. In order to achieve a coherent model to integrate software, hardware, and healthcare systems, different telehealth models with Internet of Things (IoT), cloud computing, artificial intelligence, etc. have been implemented, and their advantages are still under analysis. In this paper, we propose an integrated model based on IoT architecture and cloud computing telehealth center. Analytics module is presented as a solution to control an ideal diagnostic about some diseases. Specific features are then compared with the recently deployed conventional models in telemedicine. The main advantage of this model is the availability of controlling the security and privacy about patient information and the optimization on processing and acquiring clinical parameters according to technical characteristics.

Keywords: Analytics, telemedicine, internet of things, cloud computing.

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Authors: Paul Dallyn, Ashraf El-Hamalawi, Alessandro Palmeri, Bob Knight

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In order to better understand the long term implications of the grout wear failure mode in large-diameter plainsided grouted connections, a numerical model has been developed and calibrated that can take advantage of existing operational plant data to predict the wear accumulation for the actual load conditions experienced over a given period, thus limiting the requirement for expensive monitoring systems. This model has been derived and calibrated based on site structural condition monitoring (SCM) data and supervisory control and data acquisition systems (SCADA) data for two operational wind turbine generator substructures afflicted with this challenge, along with experimentally derived wear rates.

Keywords: Grouted Connection, Numerical Model, Offshore Structure, Wear, Wind Energy.

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Authors: Jing Hang Choo, Soon Nyean Cheong, Yee Lien Lee, Sze Hou Teh

Abstract:

The advancement of smartphones, wireless networking and Near Field Communication (NFC) technology have opened up a new approach to indoor navigation. Although NFC technology has been used to support electronic commerce, access control, and ticketing, there is a lack of research work on building NFC-based indoor navigation system for smartphone users. This paper presents an indoor interactive navigation system (named I2Navi) based on NFC technology for users to navigate within a building with ease using their smartphones. The I2Navi system has been implemented at the Faculty of Engineering (FOE), Multimedia University (MMU) to enable students, parents, visitors who own NFC-enabled Android smartphones to navigate themselves within the faculty. An evaluation is carried out and the results show positive response to the proposed indoor navigation system using NFC and smartphone technologies.

Keywords: Near Field Communication, indoor navigation system, smartphones.

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Authors: M. Nekri, A. Khelladi

Abstract:

The world wide web network is a network with a complex topology, the main properties of which are the distribution of degrees in power law, A low clustering coefficient and a weak average distance. Modeling the web as a graph allows locating the information in little time and consequently offering a help in the construction of the research engine. Here, we present a model based on the already existing probabilistic graphs with all the aforesaid characteristics. This work will consist in studying the web in order to know its structuring thus it will enable us to modelize it more easily and propose a possible algorithm for its exploration.

Keywords: Clustering coefficient, preferential attachment, small world, Web community.

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Authors: Fatima Zohra Bissaad, Farid Bounaceur, Nassima Behidj, Nadjiba Chebouti, Fatma Halouane, Bahia Doumandji-Mitiche

Abstract:

Effect of Beauveria bassiana and Metarhizium anisopliae var. acridum on the 5^th instar nymphs of Schistocerca gregaria was studied in the laboratory. Infection by these both entomopathogenic fungi caused reduction in the hemolymph total protein. The average amounts of total proteins were 2.3, 2.07, 2.09 µg/100 ml of haemolymph in the control and M. anisopliae var. acridum, and B. bassiana based-treatments, respectively. Three types of haemocytes were recognized and identified as prohaemocytes, plasmatocytes and granulocytes. The treatment caused significant reduction in the total haemocyte count and in each haemocyte type on the 9^th day after its application.

Keywords: Beauveria bassiana, haemolymph picture, haemolymph protein, Metarhizium anisopliae var. acridum, Schistocerca gregaria.

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Authors: S. Abdourraziq, R. El Bachtiri

Abstract:

The use of solar energy as a source for pumping water is one of the promising areas in the photovoltaic (PV) application. The energy of photovoltaic pumping systems (PVPS) can be widely improved by employing an MPPT algorithm. This will lead consequently to maximize the electrical motor speed of the system. This paper presents a modified incremental conductance (IncCond) MPPT algorithm with direct control method applied to a standalone PV pumping system. The influence of the algorithm parameters on system behavior is investigated and compared with the traditional (INC) method. The studied system consists of a PV panel, a DC-DC boost converter, and a PMDC motor-pump. The simulation of the system by MATLAB-SIMULINK is carried out. Simulation results found are satisfactory.

Keywords: Photovoltaic pumping system (PVPS), incremental conductance (INC), MPPT algorithm, boost converter.

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Authors: D. Karimi, M.J. Nategh

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One of the main concerns about parallel mechanisms is the presence of singular points within their workspaces. In singular positions the mechanism gains or loses one or several degrees of freedom. It is impossible to control the mechanism in singular positions. Therefore, these positions have to be avoided. This is a vital need especially in computer controlled machine tools designed and manufactured on the basis of parallel mechanisms. This need has to be taken into consideration when selecting design parameters. A prerequisite to this is a thorough knowledge about the effect of design parameters and constraints on singularity. In this paper, quality condition index was introduced as a criterion for evaluating singularities of different configurations of a hexapod mechanism obtainable by different design parameters. It was illustrated that this method can effectively be employed to obtain the optimum configuration of hexapod mechanism with the aim of avoiding singularity within the workspace. This method was then employed to design the hexapod table of a CNC milling machine.

Keywords: Hexapod, Machine Tool, Singularity, Workspace.

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Authors: Masoume Amirkhani, Kambiz Mashayekhi, Maurizio Lambardi

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Agropyron cristatum L. Gaertn. is a native grass of semiarid region in Iran which is quit resistant to cool and drought climate and withstand heavy grazing. This species has close phylogenetic relationship with Triticum and Hordeum. In this research, the effect of seven different concentrations of growth regulator 2,4-D on callus production and somatic embryogenesis of A. cristatum was investigated on Murashige and Skoog medium. The results showed that the rate of callus, embryo and neomorph were highest in 1 mg L-1 2,4-D. Callus production was increased in 1 mg L-1 2,4-D but dramatically decreased at 5.5 and 9 mg L-1 2,4-D. The somatic embryos were observed at 1 and 4 mg L-1 2,4-D but matured embryos and plantlet were only occurred at 1 mg L-1 2,4-D. There were significant differences between 1 mg L-1 2,4-D and other treatments for producing globular and torpedo embryos, plantlet, rooted callus and number of roots (p<0.05) and there was not any callus production and embryogenesis in control treatment without growth regulator.

Keywords: 2, 4-D, callus production, somatic embryogenesis, Agropyron cristatum.

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Authors: Ming Cong, Yinghua Wu, Dong Liu, Haiying Wen, Junfa Yu

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In order to improve control performance and eliminate steady, a coupling compensation for 6-DOF parallel robot is presented. Taking dynamic load Tank Simulator as the research object, this paper analyzes the coupling of 6-DOC parallel robot considering the degree of freedom of the 6-DOF parallel manipulator. The coupling angle and coupling velocity are derived based on inverse kinematics model. It uses the mechanism-model combined method which takes practical moving track that considering the performance of motion controller and motor as its input to make the study. Experimental results show that the coupling compensation improves motion stability as well as accuracy. Besides, it decreases the dither amplitude of dynamic load Tank Simulator.

Keywords: coupling compensation, screw theory, parallel robot, mechanism-model combined motion

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Authors: I. Kurashvili, A. Sichinava, G. Bokuchava, G. Darsavelidze

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Si-Ge solid solutions (bulk poly- and mono-crystalline samples, thin films) are characterized by high perspectives for application in semiconductor devices, in particular, optoelectronics and microelectronics. From this point of view, complex studying of structural state of the defects and structural-sensitive physical properties of Si-Ge solid solutions depending on the contents of Si and Ge components is very important. Present work deals with the investigations of microstructure, microhardness, internal friction and shear modulus of Si1-xGex(x≤0,02) bulk monocrystals conducted at room temperature. Si-Ge bulk crystals were obtained by Czochralski method in [111] crystallographic direction. Investigated monocrystalline Si-Ge samples are characterized by p-type conductivity and carriers’ concentration 5.1014-1.1015cm-3. Microhardness was studied on Dynamic Ultra Micro hardness Tester DUH-201S with Berkovich indenter. Investigate samples are characterized with 0,5x0,5x(10-15)mm3 sizes, oriented along [111] direction at torsion oscillations ≈1Hz, multistage changing of internal friction and shear modulus has been revealed in an interval of strain amplitude of 10-5-5.10-3. Critical values of strain amplitude have been determined at which hysteretic changes of inelastic characteristics and microplasticity are observed. The critical strain amplitude and elasticity limit values are also determined. Dynamic mechanical characteristics decreasing trend is shown with increasing Ge content in Si-Ge solid solutions. Observed changes are discussed from the point of view of interaction of various dislocations with point defects and their complexes in a real structure of Si-Ge solid solutions.

Keywords: Internal friction, microhardness, relaxation processes, shear modulus, Si-Ge.

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Authors: Samantha E. Booth, Andrew D. Deacon, Nichola J. Coleman

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A study has been carried out to determine the effect of coating two commercial glass-ionomer cements in either petroleum jelly or wax. After coating, specimens were stored in water for 24 or 168 hours, then the coating removed and the surface examined. Coating in wax was found to increase the surface hardness significantly compared with the uncoated control, whereas coating the specimens in petroleum jelly led to only a slight increase in surface hardness. Coating in wax led to no detectable ion release after either 24 or 168 hours, though there was some ion release after the coating had been removed and the specimens exposed to water for a further 24 hours. This shows that soluble species remained in these specimens. Overall, this study confirms the idea that immature glass-ionomers should be protected from early exposure to moisture, and that the protection offered by petroleum jelly is only modest.

Keywords: Coating, Glass-Ionomer Cements, Ion Release, Surface Hardness, Wax.

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Authors: Ketevan Kokrashvili, Rusudan Kutateladze, Nino Pailodze

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Importance of management of legal entities under private law of which especially corporate management, as well as looking for ways of its improvement and perfection has become especially relevant in the twenty-first century, which was greatly contributed to by the global economic crisis. Some states have adopted Corporate Governance Codes; the European Union has set to work on a series of directives the main purpose of which is an improvement of corporate governance, provision of greater transparency and implementation of an effective control mechanism. This process is not yet completed, and various problematic issues associated with management of legal persons are still being debated among practitioner experts and scholars. Georgia is not an exception in this regard. The article discusses the legislative gaps, and in some cases, discrepancies having arisen in legal relationships under private law and having caused many practical problems. This especially applies to the management of capital companies.

Keywords: Business entities, corporate management, public capital management, collective norms, existing problems, legal discrepancies.

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Authors: R. Kokilavani, K. Gurusamy, K. Arumugasamy

Abstract:

Protective effect of ethanolic extract of polyherbal formulation (PHF) was studied on carbon tetrachloride induced liver damage on carbon tetrachloride induced liver damage. Treatment of rats with 250mg /kg body weight of ethanolic extract of PHF protected rats against carbon tetrachloride liver injury by significant lowerering 5’ nucleotidase (5’NT), Gamma Glutamyl transferase (GGT), Glutamate dehdyrogenasse (GDH) and Succinate Dehydrogenase (SDH) levels compared to control. Normalization in these enzyme levels indicates strong hepatoprotective property of PHF extract.

Keywords: Carbon tetrachloride, ethanolic, hepatoprotective, polyherbal formulation.

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