Search results for: Transmission Expansion Planning
1714 A Cooperative Transmission Scheme Using Two Sources Based On OFDM System
Authors: Bit-Na Kwon, Dong-Hyun Ha, Hyoung-Kyu Song
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In wireless communication, space-time block code (STBC), cyclic delay diversity (CDD) and space-time cyclic delay diversity (STCDD)are used as the spatial diversity schemes and have been widely studied for the reliablecommunication. If these schemes are used, the communication system can obtain the improved performance. However,the quality of the system is degraded when the distance between a source and a destination is distant in wireless communication system. In this paper, the cooperative transmission scheme using two sources is proposed and improves the performance of the wireless communication system.
Keywords: OFDM, Cooperative communication, CDD, STBC, STCDD.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 21211713 Simulated Annealing and Genetic Algorithm in Telecommunications Network Planning
Authors: Aleksandar Tsenov
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The main goal of this work is to propose a way for combined use of two nontraditional algorithms by solving topological problems on telecommunications concentrator networks. The algorithms suggested are the Simulated Annealing algorithm and the Genetic Algorithm. The Algorithm of Simulated Annealing unifies the well known local search algorithms. In addition - Simulated Annealing allows acceptation of moves in the search space witch lead to decisions with higher cost in order to attempt to overcome any local minima obtained. The Genetic Algorithm is a heuristic approach witch is being used in wide areas of optimization works. In the last years this approach is also widely implemented in Telecommunications Networks Planning. In order to solve less or more complex planning problem it is important to find the most appropriate parameters for initializing the function of the algorithm.Keywords: Concentrator network, genetic algorithm, simulated annealing, UCPL.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 17201712 Uniformity of Dose Distribution in Radiation Fields Surrounding the Spine using Film Dosimetry and Comparison with 3D Treatment Planning Software
Authors: Sadegh Masoudi , Vahid Fayaz , Hassan Zandi, Asieh Tavakol
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The overall penumbra is usually defined as the distance, p20–80, separating the 20% and 80% of the dose on the beam axis at the depth of interest. This overall penumbra accounts also for the fact that some photons emitted by the distal parts of the source are only partially attenuated by the collimator. Medulloblastoma is the most common type of childhood brain tumor and often spreads to the spine. Current guidelines call for surgery to remove as much of the tumor as possible, followed by radiation of the brain and spinal cord, and finally treatment with chemotherapy. The purpose of this paper was to present results on an Uniformity of dose distribution in radiation fields surrounding the spine using film dosimetry and comparison with 3D treatment planning software.Keywords: Absorbed Dose , Spine , Radiotherapy, 3D treatment planning software
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 18411711 Potential Field Functions for Motion Planning and Posture of the Standard 3-Trailer System
Authors: K. Raghuwaiya, S. Singh, B. Sharma, J. Vanualailai
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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 3-trailer systems 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. The effectiveness of the proposed control laws were demonstrated via simulations of two traffic scenarios.
Keywords: Artificial potential fields, 3-trailer systems, motion planning, posture, parking and collision-free trajectories.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 21271710 Production Planning and Scheduling and SME
Authors: M. Heck, H. Vettiger
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Small and medium-sized enterprises (SME) are the backbone of central Europe’s economies and have a significant contribution to the gross domestic product. Production planning and scheduling (PPS) is still a crucial element in manufacturing industries of the 21st century even though this area of research is more than a century old. The topic of PPS is well researched especially in the context of large enterprises in the manufacturing industry. However the implementation of PPS methodologies within SME is mostly unobserved. This work analyzes how PPS is implemented in SME with the geographical focus on Switzerland and its vicinity. Based on restricted resources compared to large enterprises, SME have to face different challenges. The real problem areas of selected enterprises in regards of PPS are identified and evaluated. For the identified real-life problem areas of SME clear and detailed recommendations are created, covering concepts and best practices and the efficient usage of PPS. Furthermore the economic and entrepreneurial value for companies is lined out and why the implementation of the introduced recommendations is advised.
Keywords: Central Europe, PPS, Production Planning, SME.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 21771709 Study on Scheduling of the Planning Method Using the Web-based Visualization System in a Shipbuilding Block Assembly Shop
Authors: A. Eui Koog Ahn, B. Gi-Nam Wang, C. Sang C. Park
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Higher productivity and less cost in the ship manufacturing process are required to maintain the international competitiveness of morden manufacturing industries. In shipbuilding, however, the Engineering To Order (ETO) production method and production process is very difficult. Thus, designs change frequently. In accordance with production, planning should be set up according to scene changes. Therefore, fixed production planning is very difficult. Thus, a scheduler must first make sketchy plans, then change the plans based on the work progress and modifications. Thus, data sharing in a shipbuilding block assembly shop is very important. In this paper, we proposed to scheduling method applicable to the shipbuilding industry and decision making support system through web based visualization system.Keywords: Shipbuilding, Monitoring, Block assembly shop, Visualization
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 20631708 Optimization of Real Time Measured Data Transmission, Given the Amount of Data Transmitted
Authors: Michal Kopcek, Tomas Skulavik, Michal Kebisek, Gabriela Krizanova
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The operation of nuclear power plants involves continuous monitoring of the environment in their area. This monitoring is performed using a complex data acquisition system, which collects status information about the system itself and values of many important physical variables e.g. temperature, humidity, dose rate etc. This paper describes a proposal and optimization of communication that takes place in teledosimetric system between the central control server responsible for the data processing and storing and the decentralized measuring stations, which are measuring the physical variables. Analyzes of ongoing communication were performed and consequently the optimization of the system architecture and communication was done.
Keywords: Communication protocol, transmission optimization, data acquisition.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 18191707 Evaluation of the Energy Consumption per Bit inBENES Optical Packet Switch
Authors: V. Eramo, E. Miucci, A. Cianfrani, A. Germoni, M. Listanti
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We evaluate the average energy consumption per bit in Optical Packet Switches equipped with BENES switching fabric realized in Semiconductor Optical Amplifier (SOA) technology. We also study the impact that the Amplifier Spontaneous Emission (ASE) noise generated by a transmission system has on the power consumption of the BENES switches due to the gain saturation of the SOAs used to realize the switching fabric. As a matter of example for 32×32 switches supporting 64 wavelengths and offered traffic equal to 0,8, the average energy consumption per bit is 2, 34 · 10-1 nJ/bit and increases if ASE noise introduced by the transmission systems is increased.Keywords: Benes, Amplifier Spontaneous Emission Noise, EnergyConsumption, Optical Packet Switch.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 13901706 Development of an Efficient CVT using Electromecanical System
Authors: A. A. Shafie, M. H. Ali
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Continuously variable transmission (CVT) is a type of automatic transmission that can change the gear ratio to any arbitrary setting within the limits. The most common type of CVT operates on a pulley system that allows an infinite variability between highest and lowest gears with no discrete steps. However, the current CVT system with hydraulic actuation method suffers from the power loss. It needs continuous force for the pulley to clamp the belt and hold the torque resulting in large amount of energy consumption. This study focused on the development of an electromechanical actuated control CVT to eliminate the problem that faced by the existing CVT. It is conducted with several steps; computing and selecting the appropriate sizing for stroke length, lead screw system and etc. From the visual observation it was found that the CVT system of this research is satisfactory.Keywords: CVT, Hydraulic Actuator, Discrete shifts, Electromechanical system, Lead screws.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 22231705 Effect of Different BER Performance Comparison of MAP and ML Detection
Authors: Naveed Ur Rehman, Rehan Jamil, Irfan Jamil
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In this paper, we regard as a coded transmission over a frequency-selective channel. We plan to study analytically the convergence of the turbo-detector using a maximum a posteriori (MAP) equalizer and a MAP decoder. We demonstrate that the densities of the maximum likelihood (ML) exchanged during the iterations are e-symmetric and output-symmetric. Under the Gaussian approximation, this property allows to execute a one-dimensional scrutiny of the turbo-detector. By deriving the analytical terminology of the ML distributions under the Gaussian approximation, we confirm that the bit error rate (BER) performance of the turbo-detector converges to the BER performance of the coded additive white Gaussian noise (AWGN) channel at high signal to noise ratio (SNR), for any frequency selective channel.
Keywords: MAP, ML, SNR, Decoder, BER, Coded transmission.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 22551704 Universities Strategic Evaluation Using Balanced Scorecard
Authors: M. D. Nayeri, M. M. Mashhadi, K. Mohajeri
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Defining strategic position of the organizations within the industry environment is one of the basic and most important phases of strategic planning to which extent that one of the fundamental schools of strategic planning is the strategic positioning school. In today-s knowledge-based economy and dynamic environment, it is essential for universities as the centers of education, knowledge creation and knowledge worker evolvement. Till now, variant models with different approaches to strategic positioning are deployed in defining the strategic position within the various industries. Balanced Scorecard as one of the powerful models for strategic positioning, analyzes all aspects of the organization evenly. In this paper with the consideration of BSC strength in strategic evaluation, it is used for analyzing the environmental position of the best-s Iranian Business Schools. The results could be used in developing strategic plans for these schools as well as other Iranian Management and Business Schools.Keywords: Strategic planning, Strategic position, Balancedscorecard, Higher education institutions.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 44411703 Evaluation of Power Consumption of Spanke Optical Packet Switch
Authors: V. Eramo, E. Miucci, A. Cianfrani, A. Germoni, M. Listanti
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The power consumption of an Optical Packet Switch equipped with SOA technology based Spanke switching fabric is evaluated. Sophisticated analytical models are introduced to evaluate the power consumption versus the offered traffic, the main switch parameters, and the used device characteristics. The impact of Amplifier Spontaneous Emission (ASE) noise generated by a transmission system on the power consumption is investigated. As a matter of example for 32×32 switches supporting 64 wavelengths and offered traffic equal to 0,8, the average energy consumption per bit is 5, 07 · 10-2 nJ/bit and increases if ASE noise introduced by the transmission systems is increased.Keywords: Spanke, Amplifier Spontaneous Emission Noise, Power Consumption, Optical Packet Switch.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 14071702 A Model for Analyzing the Startup Dynamics of a Belt Transmission Driven by a DC Motor
Authors: Giovanni Incerti
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In this paper the vibration of a synchronous belt drive during start-up is analyzed and discussed. Besides considering the belt elasticity, the model here proposed also takes into consideration the electromagnetic response of the DC motor. The solution of the motion equations is obtained by means of the modal analysis in state space, which allows to obtain the decoupling of all equations, without introducing the hypothesis of proportional damping. The mathematical model of the transmission and the solution algorithms have been implemented within a computing software that allows the user to simulate the dynamics of the system and to evaluate the effects due to the elasticity of the belt branches and to the electromagnetic behavior of the DC motor. In order to show the details of the calculation procedure, the paper presents a case study developed with the aid of the above-mentioned software.
Keywords: Belt drive, Vibrations, Startup, DC motor.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 30981701 Parametric Study of a Vapor Compression Refrigeration Cycle Using a Two-Phase Constant Area Ejector
Authors: E. Elgendy
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There are several ways of improving the performance of a vapor compression refrigeration cycle. Use of an ejector as expansion device is one of the alternative ways. The present paper aims at evaluate the performance improvement of a vapor compression refrigeration cycle under a wide range of operating conditions. A numerical model is developed and a parametric study of important parameters such as condensation (30-50°C) and evaporation temperatures (-20-5°C), nozzle and diffuser efficiencies (0.75-0.95), subcooling and superheating degrees (0-15K) are investigated. The model verification gives a good agreement with the literature data. The simulation results revealed that condensation temperature has the highest effect (129%) on the performance improvement ratio while superheating has the lowest one (6.2%). Among ejector efficiencies, the diffuser efficiency has a significant effect on the COP of ejector expansion refrigeration cycle. The COP improvement percentage decreases from 10.9% to 4.6% as subcooling degrees increases by 15K.
Keywords: Numerical modeling, R134a, Two phase ejector, Vapor compression refrigeration system.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 58071700 Bactericidal Properties of Carbohydrate-Stabilized Platinum Oxide Nanoparticles
Authors: Saeed Rezaei-Zarchi
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Platinum oxide nanoparticles were prepared by a simple hydrothermal route and chemical reduction using carbohydrates (Fructose and sucrose) as the reducing and stabilizing agents. The crystallite size of these nanoparticles was evaluated from X-ray diffraction (XRD), atomic force microscopy (AFM) and transmission electron microscopy (TEM) and was found to be 10 nm as shown in figure 1, which is the demonstration of EM bright field and transmission electron microscopy. The effect of carbohydrates on the morphology of the nanoparticles was studied using TEM (Figure 1). The nanoparticles (100 μg/ml) were administered to the Pseudomonas Stutzeri and Lactobacillus cultures and the incubation was done at 35 oC for 24 hours. The nanocomposites exhibited interesting inhibitory as well as bactericidal activity against P. Stutzeri and and Lactobacillus species. Incorporation of nanoparticles also increased the thermal stability of the carbohydrates.Keywords: Platinum oxide, P. Stutzeri, Lactobacillus, bactericidal effect.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 21121699 The Influence of the Commons Structure Modification on the Active Power Losses Allocation
Authors: O. Pop, C. Barbulescu, M. Nemes, St. Kilyeni
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The tracing methods determine the contribution the power system sources have in their supplying. These methods can be used to assess the transmission prices, but also to recover the transmission fixed cost. In this paper is presented the influence of the modification of commons structure has on the specific price of transfer and on active power losses. The authors propose a power losses allocation method, based on Kirschen-s method. The system operator must make use of a few basic principles about allocation. The only necessary information is the power flows on system branches and the modifications applied to power system buses. In order to illustrate this method, the 25-bus test system is used, elaborated within the Electrical Power Engineering Department, from Timisoara, Romania.Keywords: Power systems, P-U bus, P-Q bus, loss allocation, traceability methods.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 15241698 Peakwise Smoothing of Data Models using Wavelets
Authors: D Sudheer Reddy, N Gopal Reddy, P V Radhadevi, J Saibaba, Geeta Varadan
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Smoothing or filtering of data is first preprocessing step for noise suppression in many applications involving data analysis. Moving average is the most popular method of smoothing the data, generalization of this led to the development of Savitzky-Golay filter. Many window smoothing methods were developed by convolving the data with different window functions for different applications; most widely used window functions are Gaussian or Kaiser. Function approximation of the data by polynomial regression or Fourier expansion or wavelet expansion also gives a smoothed data. Wavelets also smooth the data to great extent by thresholding the wavelet coefficients. Almost all smoothing methods destroys the peaks and flatten them when the support of the window is increased. In certain applications it is desirable to retain peaks while smoothing the data as much as possible. In this paper we present a methodology called as peak-wise smoothing that will smooth the data to any desired level without losing the major peak features.Keywords: smoothing, moving average, peakwise smoothing, spatialdensity models, planar shape models, wavelets.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 17491697 Risk Based Maintenance Planning for Loading Equipment in Underground Hard Rock Mine: Case Study
Authors: Sidharth Talan, Devendra Kumar Yadav, Yuvraj Singh Rajput, Subhajit Bhattacharjee
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Mining industry is known for its appetite to spend sizeable capital on mine equipment. However, in the current scenario, the mining industry is challenged by daunting factors of non-uniform geological conditions, uneven ore grade, uncontrollable and volatile mineral commodity prices and the ever increasing quest to optimize the capital and operational costs. Thus, the role of equipment reliability and maintenance planning inherits a significant role in augmenting the equipment availability for the operation and in turn boosting the mine productivity. This paper presents the Risk Based Maintenance (RBM) planning conducted on mine loading equipment namely Load Haul Dumpers (LHDs) at Vedanta Resources Ltd subsidiary Hindustan Zinc Limited operated Sindesar Khurd Mines, an underground zinc and lead mine situated in Dariba, Rajasthan, India. The mining equipment at the location is maintained by the Original Equipment Manufacturers (OEMs) namely Sandvik and Atlas Copco, who carry out the maintenance and inspection operations for the equipment. Based on the downtime data extracted for the equipment fleet over the period of 6 months spanning from 1st January 2017 until 30th June 2017, it was revealed that significant contribution of three downtime issues related to namely Engine, Hydraulics, and Transmission to be common among all the loading equipment fleet and substantiated by Pareto Analysis. Further scrutiny through Bubble Matrix Analysis of the given factors revealed the major influence of selective factors namely Overheating, No Load Taken (NTL) issues, Gear Changing issues and Hose Puncture and leakage issues. Utilizing the equipment wise analysis of all the downtime factors obtained, spares consumed, and the alarm logs extracted from the machines, technical design changes in the equipment and pre shift critical alarms checklist were proposed for the equipment maintenance. The given analysis is beneficial to allow OEMs or mine management to focus on the critical issues hampering the reliability of mine equipment and design necessary maintenance strategies to mitigate them.
Keywords: Bubble matrix analysis, LHDs, OEMs, pareto chart analysis, spares consumption matrix, critical alarms checklist.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 10891696 A Prediction-Based Reversible Watermarking for MRI Images
Authors: Nuha Omran Abokhdair, Azizah Bt Abdul Manaf
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Reversible watermarking is a special branch of image watermarking, that is able to recover the original image after extracting the watermark from the image. In this paper, an adaptive prediction-based reversible watermarking scheme is presented, in order to increase the payload capacity of MRI medical images. The scheme divides the image into two parts, Region of Interest (ROI) and Region of Non-Interest (RONI). Two bits are embedded in each embeddable pixel of RONI and one bit is embedded in each embeddable pixel of ROI. The experimental results demonstrate that the proposed scheme is able to achieve high embedding capacity. This is mainly caused by two reasons. First, the pixels that were excluded from data embedding due to overflow/underflow are used for data embedding. Second, large location map that need to be added to watermark data as overhead is eliminated and thus lower data embedding capacity is prevented. Moreover, the scheme provides good visual quality to the watermarked image.
Keywords: Medical image watermarking, reversible watermarking, Difference Expansion, Prediction-Error Expansion.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 19151695 Urban Intensification and the Character of Urban Landscape: A Morphological Perspective
Authors: Xindong An, Kai Gu
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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.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 11431694 Effect of Aging Condition on Semisolid Cast 2024 Aluminum Alloy
Authors: Wisutmethangoon S., Pannaray S., Plookphol T., Wannasin J.
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2024 Aluminum alloy was squeezed cast by the Gas Induced Semi Solid (GISS) process. Effect of artificial aging on microstructure and mechanical properties of this alloy was studied in the present work. The solutionized specimens were aged hardened at temperatures of 175°C, 200°C, and 225°C under various time durations. The highest hardness of about 77.7 HRE was attained from specimen aged at the temperature of 175°C for 36h. Upon investigation the microstructure by using transmission electron microscopy (TEM), the S’ phase was mainly attributed to the strengthening effect in the aged alloy. The apparent activation energy for precipitation hardening of the alloy was calculated as 133,805 J/mol.
Keywords: 2024 aluminum alloy, Gas induced semi solid, T6 heat treatment, Aged hardening, Transmission electron microscopy.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 30111693 A Traditional Settlement in a Modernized City: Yanbu, Saudi Arabia
Authors: Hisham Mortada
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Transition in the urban configuration of Arab cities has never been as radical and visible as it has been since the turn of the last century. The emergence of new cities near historical settlements of Arabia has spawned a series of developments in and around the old city precincts. New developments are based on advanced technology and conform to globally prevalent standards of city planning, superseding the vernacular arrangements based on traditional norms that guided so-called ‘city planning’. Evidence to this fact are the extant Arab buildings present at the urban core of modern cities, which inform us about intricate spatial organization. Organization that subscribed to multiple norms such as, satisfying gender segregation and socialization, economic sustainability, and ensuring security and environmental coherence etc., within settlement compounds. Several participating factors achieved harmony in such an inclusive city—an organization that was challenged and apparently replaced by the new planning order in the face of growing needs of globalized, economy-centric and high-tech models of development. Communities found it difficult to acclimatize with the new western planning models that were implemented at a very large scale throughout the Kingdom, which later experienced spatial re-structuring to suit users’ needs. A closer look the ancient city of Yanbu, now flanked with such new developments, allows us to differentiate and track the beginnings of this unprecedented transition in settlement formations. This paper aims to elaborate the Arabian context offered to both the ‘traditional’ and ‘modern’ planning approaches, in order to understand challenges and solutions offered by both at different times. In the process it will also establish the inconsistencies and conflicts that arose with the shift in planning paradigm, from traditional-'cultural norms’, to modern-'physical planning', in the Arabian context. Thus, by distinguishing the two divergent planning philosophies, their impact of the Arabian morphology, relevance to lifestyle and suitability to the biophysical environment, it concludes with a perspective on sustainability particularly for in case of Yanbu.Keywords: Yanbu, traditional architecture, Hijaz, coral building, Saudi Arabia.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 16031692 MaxMin Share Based Medium Access for Attaining Fairness and Channel Utilization in Mobile Adhoc Networks
Authors: P. Priakanth, P. Thangaraj
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Due to the complex network architecture, the mobile adhoc network-s multihop feature gives additional problems to the users. When the traffic load at each node gets increased, the additional contention due its traffic pattern might cause the nodes which are close to destination to starve the nodes more away from the destination and also the capacity of network is unable to satisfy the total user-s demand which results in an unfairness problem. In this paper, we propose to create an algorithm to compute the optimal MAC-layer bandwidth assigned to each flow in the network. The bottleneck links contention area determines the fair time share which is necessary to calculate the maximum allowed transmission rate used by each flow. To completely utilize the network resources, we compute two optimal rates namely, the maximum fair share and minimum fair share. We use the maximum fair share achieved in order to limit the input rate of those flows which crosses the bottleneck links contention area when the flows that are not allocated to the optimal transmission rate and calculate the following highest fair share. Through simulation results, we show that the proposed protocol achieves improved fair share and throughput with reduced delay.Keywords: MAC-layer, MANETs, Multihop, optimal rate, Transmission.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 15071691 Solid Waste Characterization and Recycling Potential in Hawassa University, Ethiopia
Authors: Hunachew B. Mengesha, Biruck Y. Dessalegn
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Owing to the dramatic expansion of universities in Ethiopia, understanding the composition and nature of solid waste at the source of generation plays an important role in designing a program for an integrated waste management program. In this study, we report the quantity, quality and recycling potential of the waste generated in the three campuses of the Hawassa University, Southern Ethiopia. A total of 3.5 tons of waste was generated per day in the three campuses of the university. More than 95% of the waste constituents were with potential to be recovered. It was a lesson from the study that there was no source reduction, recycling, composting, proper land filling or incineration practices in-place. The considerably high waste generation associated with the expansion of educational programs in the university appears worthwhile requiring implementation of programs for an integrated solid waste management to minimize health risk to humans and reduce environmental implications as a result of improper handling and disposal of wastes.
Keywords: Hawassa University, integrated solid waste management, solid waste generation.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 41421690 A Short Survey of Integrating Urban Agriculture and Environmental Planning
Authors: Rayeheh Khatami, Toktam Hanaei, Mohammad Reza Mansouri Daneshvar
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The growth of the agricultural sector is known as an essential way to achieve development goals in developing countries. Urban agriculture is a way to reduce the vulnerability of urban populations of the world toward global environmental change. It is a sustainable and efficient system to respond to the environmental, social and economic needs of the city, which leads to urban sustainability. Today, many local and national governments are developing urban agriculture as an effective tool in responding to challenges such as poverty, food security, and environmental problems. In this study, we follow a perspective based on urban agriculture literature in order to indicate the urban agriculture’s benefits in environmental planning strategies in non-western countries like Iran. The methodological approach adopted is based on qualitative approach and documentary studies. A total of 35 articles (mixed quantitative and qualitative methods studies) were studied in final analysis, which are published in relevant journals that focus on this subject. Studies show the wide range of positive benefits of urban agriculture on food security, nutrition outcomes, health outcomes, environmental outcomes, and social capital. However, there was no definitive conclusion about the negative effects of urban agriculture. This paper provides a conceptual and theoretical basis to know about urban agriculture and its roles in environmental planning, and also conclude the benefits of urban agriculture for researchers, practitioners, and policymakers who seek to create spaces in cities for implementation urban agriculture in future.
Keywords: Urban agriculture, environmental planning, urban planning, literature.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 23061689 An Intelligent Optimization Model for Multi-objective Order Allocation Planning
Authors: W. K. Wong, Z. X. Guo, P.Y. Mok
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This paper presents a multi-objective order allocation planning problem with the consideration of various real-world production features. A novel hybrid intelligent optimization model, integrating a multi-objective memetic optimization process, a Monte Carlo simulation technique and a heuristic pruning technique, is proposed to handle this problem. Experiments based on industrial data are conducted to validate the proposed model. Results show that (1) the proposed model can effectively solve the investigated problem by providing effective production decision-making solutions, which outperformsan NSGA-II-based optimization process and an industrial method.Keywords: Multi-objective order allocation planning, Pareto optimization, Memetic algorithm, Mento Carlo simulation
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 16381688 Stroma-Providing Activity of Adipose Derived Mesenchymal Stromal Cells in Tissue-Related O2 Microenvironment
Authors: P. I. Bobyleva, E. R. Andreeva, I. V. Andrianova, E. V. Maslova, L.B. Buravkova
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This work studied the ability of adipose tissue-derived mesenchymal stromal cells (MSCs) to form stroma for expansion of cord blood hematopoietic cells. We showed that 72-hour interaction of MSCs with cord blood mononuclear cells (MNCs) in vitro at atmospheric (20%) and low (5%) O2 conditions increased the expression of ICAM-1, HCAM (at the beginning of interaction) on MSCs. Viability of MSCs and MNCs were maintained at high level. Adhesion of MNCs to MSCs was faster at 20% O2. MSCs promoted the proliferation of adhered MNCs to form the suspension containing great number of hematopoietic colony-forming units, and this effect was more pronounced at 5% O2. Thus, adipose-derived MSCs supplied sufficient stromal support to cord blood MNCs both at 20% and 5% О2, providing their adhesion with further expansion of new generation of different hematopoietic lineages.
Keywords: Hematopoietic stem and progenitor cells, mesenchymal stromal cells, tissue-related oxygen.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 17441687 Urban Flood Control and Management - An Integrated Approach
Authors: Ranjan Sarukkalige, Joseph Sanjaya Ma
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Flood management is one of the important fields in urban storm water management. Floods are influenced by the increase of huge storm event, or improper planning of the area. This study mainly provides the flood protection in four stages; planning, flood event, responses and evaluation. However it is most effective then flood protection is considered in planning/design and evaluation stages since both stages represent the land development of the area. Structural adjustments are often more reliable than nonstructural adjustments in providing flood protection, however structural adjustments are constrained by numerous factors such as political constraints and cost. Therefore it is important to balance both adjustments with the situation. The technical decisions provided will have to be approved by the higher-ups who have the power to decide on the final solution. Costs however, are the biggest factor in determining the final decision. Therefore this study recommends flood protection system should have been integrated and enforces more in the early stages (planning and design) as part of the storm water management plan. Factors influencing the technical decisions provided should be reduced as low as possible to avoid a reduction in the expected performance of the proposed adjustments.Keywords: Urban Flood, flood protection, water management, storm water, cost,
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 15211686 Modeling of a Novel Dual-Belt Continuously Variable Transmission for Automobiles
Authors: Y. Q. Chen, P. K. Wong, Z. C. Xie, H. W. Wu, K. U. Chan, J., L. Huang
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It is believed that continuously variable transmission (CVT) will dominate the automotive transmissions in the future. The most popular design is Van Doorne-s CVT with single metal pushing V-belt. However, it is only applicable to low power passenger cars because its major limitation is low torque capacity. Therefore, this research studies a novel dual-belt CVT system to overcome the limitation of traditional single-belt CVT, such that it can be applicable to the heavy-duty vehicles. This paper presents the mathematical model of the design and its experimental verification. Experimental and simulated results show that the model developed is valid and the proposed dual-belt CVT can really overcome the traditional limitation of single-belt Van Doorne-s CVT.
Keywords: Analytical model, CVT, Dual belts, Torque capacity.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 21441685 Teacher Professionalisation and Career Commitment
Authors: Fauziah Noordin, Rahmah Mohd Rashid, Rohani Ghani, Rasimah Aripin, , Zabani Darus
Abstract:
Overall, the findings of the present study suggest that teachers have low to moderate levels of professionalisation, high level of career identity and moderate levels of career resilience, and career planning. From the T-tests and F-tests conducted, it was found that gender has a significant impact on career identity whereas age and marital status have significant impact on career planning and also on career identity. The results indicate that there is a higher possibility of male teachers to leave the teaching profession than the female teachers. The result of the T-test on career identity in relation to gender supports this deduction in which female teachers have significantly higher career identity than their male counterparts. Marital status was also found to have a significant impact on career identity.Keywords: Professionalisation, career identity, career resilience, career planning
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