Search results for: Air transport chain
396 Influence of Noise on the Inference of Dynamic Bayesian Networks from Short Time Series
Authors: Frank Emmert Streib, Matthias Dehmer, Gökhan H. Bakır, Max Mühlhauser
Abstract:
In this paper we investigate the influence of external noise on the inference of network structures. The purpose of our simulations is to gain insights in the experimental design of microarray experiments to infer, e.g., transcription regulatory networks from microarray experiments. Here external noise means, that the dynamics of the system under investigation, e.g., temporal changes of mRNA concentration, is affected by measurement errors. Additionally to external noise another problem occurs in the context of microarray experiments. Practically, it is not possible to monitor the mRNA concentration over an arbitrary long time period as demanded by the statistical methods used to learn the underlying network structure. For this reason, we use only short time series to make our simulations more biologically plausible.Keywords: Dynamic Bayesian networks, structure learning, gene networks, Markov chain Monte Carlo, microarray data.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1611395 Graft Copolymerization of Methyl Methacrylate onto Cellulose in Homogeneous Medium – Effect of Solvent and Initiator
Authors: B. Tosh, C. R. Routray
Abstract:
Homogeneous graft copolymerization of methyl methacrylate (MMA) onto cellulose was carried out in N, N – dimethyl acetamide/LiCl (DMAc/LiCl) and dimethyl sulfoxide/ paraformaldehyde (DMSO/PF) solvent system taking ceric ammonium nitrate (CAN), benzoyl peroxide (BPO) and tin (II)-2-ethyl hexanoate [Sn(Oct)2] as initiators. Different grafting parameters like graft yield (GY), grafting efficiency (GE) and total conversion of monomer to polymer (TC) were evaluated at different reaction conditions of temperature, time, and variation of the amount of monomer and initiator. The viscosity average molecular weight of grafted PMMA and number of grafts per cellulose chain were also calculated. The products were characterized by FT-IR and 1H-NMR analyses and possible reaction mechanisms were deduced. Thermal degradation of the grafted products was also studied by thermo-gravimetric analysis (TG) and differential thermo-gravimetry (DTG).
Keywords: Grafting, grafting efficiency, homogeneous medium, methyl methacrylate.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 3184394 Payment Problems, Cash Flow and Profitability of Construction Project: A System Dynamics Model
Authors: Wenhua Hou, Xing Liu, Deqiang Chen
Abstract:
The ubiquitous payment problems within construction industry of China are notoriously hard to be resolved, thus lead to a series of impacts to the industry chain. Among of them, the most direct result is affecting the normal operation of contractors negatively. A wealth of research has already discussed reasons of the payment problems by introducing a number of possible improvement strategies. But the causalities of these problems are still far from harsh reality. In this paper, the authors propose a model for cash flow system of construction projects by introducing System Dynamics techniques to explore causal facets of the payment problem. The effects of payment arrears on both cash flow and profitability of project are simulated into four scenarios by using data from real projects. Simulating results show visible clues to help contractors quantitatively determining the consequences for the construction project that arise from payment delay.Keywords: payment problems, cash flow, profitability, system dynamics.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2740393 Estimation of the External Force for a Co-Manipulation Task Using the Drive Chain Robot
Authors: Sylvain Devie, Pierre-Philippe Robet, Yannick Aoustin, Maxime Gautier
Abstract:
The aim of this paper is to show that the observation of the external effort and the sensor-less control of a system is limited by the mechanical system. First, the model of a one-joint robot with a prismatic joint is presented. Based on this model, two different procedures were performed in order to identify the mechanical parameters of the system and observe the external effort applied on it. Experiments have proven that the accuracy of the force observer, based on the DC motor current, is limited by the mechanics of the robot. The sensor-less control will be limited by the accuracy in estimation of the mechanical parameters and by the maximum static friction force, that is the minimum force which can be observed in this case. The consequence of this limitation is that industrial robots without specific design are not well adapted to perform sensor-less precision tasks. Finally, an efficient control law is presented for high effort applications.Keywords: Control, Identification, Robot, Co-manipulation, Sensor-less.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 639392 Research of the Factors Affecting the Administrative Capacity of Enterprises in the Logistic Sector of Bulgaria
Authors: R. Kenova, K. Anguelov, R. Nikolova
Abstract:
The human factor plays a major role in boosting the competitive capacity of logistic enterprises. This is of particular importance when it comes to logistic companies. On the one hand they should be strictly compliant with legislation; on the other hand, they should be competitive in terms of pricing and of delivery timelines. Moreover, their policies should allow them to be as flexible as possible. All these circumstances are reason for very serious challenges for the qualification, motivation and experience of the human resources, working in logistic companies or in logistic departments of trade and industrial enterprises. The geographic place of Bulgaria puts it in position of a country with some specific competitive advantages in the goods transport from Europe to Asia and back. Along with it, there is a number of logistic companies, that operate in this sphere in Bulgaria. In the current paper, the authors aim to establish the condition of the administrative capacity and human resources in the logistic companies and logistic departments of trade and industrial companies in Bulgaria in order to propose some guidelines for improving of their effectiveness. Due to independent empirical research, conducted in Bulgarian logistic, trade and industrial enterprises, the authors investigate both the impact degree and the interdependence of various factors that characterize the administrative capacity. The study is conducted with a prepared questionnaire, in format of direct interview with the respondents. The volume of the poll is 50 respondents, representatives of: general managers of industrial or trade enterprises; logistic managers of industrial or trade enterprises; general managers of forwarding companies – either with own or with hired transport; experts from Bulgarian association of logistics; logistic lobbyist and scientists of the relevant area. The data are gathered for 3 months, then arranged by a specialized software program and analyzed by preset criteria. Based on the results of this methodological toolbox, it can be claimed that there is a correlation between the individual criteria. Also, a commitment between the administrative capacity and other factors that determine the competitiveness of the studied companies is established. In this paper, the authors present results of the empirical research that concerns the number and the workload in the logistic departments of the enterprises. Also, what is commented is the experience, related to logistic processes management and human resources competence. Moreover, the overload level of the logistic specialists is analyzed as one of the main threats for making mistakes and losing clients. The paper stands behind the thesis that there is indispensability of forming an effective and efficient administrative capacity, based on the number, qualification, experience and motivation of the staff in the logistic companies. The paper ends with recommendations about the qualification and experience of the specialists in logistic departments; providing effective and efficient administrative capacity in the logistic departments; interdependence of the human factor and the other factors that influence the enterprise competitiveness.
Keywords: Administrative capacity, human resources, logistic competitiveness, staff qualification.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 615391 Application of Whole Genome Amplification Technique for Genotype Analysis of Bovine Embryos
Authors: S. Moghaddaszadeh-Ahrabi, S. Farajnia, Gh. Rahimi-Mianji, A. Nejati-Javaremi
Abstract:
In recent years, there has been an increasing interest toward the use of bovine genotyped embryos for commercial embryo transfer programs. Biopsy of a few cells in morulla stage is essential for preimplantation genetic diagnosis (PGD). Low amount of DNA have limited performing the several molecular analyses within PGD analyses. Whole genome amplification (WGA) promises to eliminate this problem. We evaluated the possibility and performance of an improved primer extension preamplification (I-PEP) method with a range of starting bovine genomic DNA from 1-8 cells into the WGA reaction. We optimized a short and simple I-PEP (ssI-PEP) procedure (~3h). This optimized WGA method was assessed by 6 loci specific polymerase chain reactions (PCRs), included restriction fragments length polymorphism (RFLP). Optimized WGA procedure possesses enough sensitivity for molecular genetic analyses through the few input cells. This is a new era for generating characterized bovine embryos in preimplantation stage.Keywords: Whole genome amplification (WGA), Genotyping, Bovine, Preimplantation genetic diagnosis (PGD)
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1669390 Directed Approach and Resolution of Practical Cases as a Motivation Tool for Self-Learning and Cooperation
Authors: B. Montero, M. Rico, A. Ares, R. Bouza
Abstract:
The development of competences and practical capacities of students is getting an important incidence into the guidelines of the European Higher Education Area (EHEA). The methodology applied in this work is based on the education through directed resolution of practical cases. All cases are related to professional tasks that the students will have to develop in their future career. The method is intended to form the necessary competences of students of the Marine Engineering and Maritime Transport Degree in the matter of “Physics". The experience was applied in the course of 2011/2012. Students were grouped, and a practical task was assigned to them, that should be developed and solved within the team. The aim was to realize students learning by three ways: their own knowledge, the contribution of their teammates and the teacher's direction. The results of the evaluation were compared with those obtained previously by the traditional teaching method.Keywords: Cooperation, Marine Engineering, Self-learning skills.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1903389 A Numerical Study of the Interaction between Residual Stress Profiles Induced by Quasi-Static Plastification
Authors: G. F. Guimarães, A. R. de Faria, R. R. Rego, A. L. R. D’Oliveira
Abstract:
One of the most relevant phenomena in manufacturing is the residual stress state development through the manufacturing chain. In most cases, the residual stresses have their origin in the heterogenous plastification produced by the processes. Although a few manufacturing processes have been successfully approached by numerical modeling, there is still lack of understanding on how these processes' interactions will affect the final stress state. The objective of this work is to analyze the effect of the grinding procedure on the residual stress state generated by a quasi-static indentation. The model consists in a simplified approach of shot peening, modeling four cases with variations in indenter size and force. This model was validated through topography, measured by optical 3D focus-variation. The indentation model configured with two loads was then exposed to two grinding procedures and the result was analyzed. It was observed that the grinding procedure will have a significant effect on the stress state.
Keywords: plasticity, residual stress, finite element method, manufacturing
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 437388 Convective Interactions and Heat Transfer in a Czochralski Melt with a Model Phase Boundary of Two Different Shapes
Authors: R. Faiez, M. Mashhoudi, F. Najafi
Abstract:
Implicit in most large-scale numerical analyses of the crystal growth from the melt is the assumption that the shape and position of the phase boundary are determined by the transport phenomena coupled strongly to the melt hydrodynamics. In the present numerical study, the interface shape-effect on the convective interactions in a Czochralski oxide melt is described. It was demonstrated that thermocapillary flow affects inversely the phase boundaries of distinct shapes. The inhomogenity of heat flux and the location of the stagnation point at the crystallization front were investigated. The forced convection effect on the point displacement at the boundary found to be much stronger for the flat plate interface compared to the cone-shaped one with and without the Marangoni flow.
Keywords: Computer simulation, fluid flow, interface shape, thermocapillary effect.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2146387 Signal Driven Sampling and Filtering a Promising Approach for Time Varying Signals Processing
Authors: Saeed Mian Qaisar, Laurent Fesquet, Marc Renaudin
Abstract:
The mobile systems are powered by batteries. Reducing the system power consumption is a key to increase its autonomy. It is known that mostly the systems are dealing with time varying signals. Thus, we aim to achieve power efficiency by smartly adapting the system processing activity in accordance with the input signal local characteristics. It is done by completely rethinking the processing chain, by adopting signal driven sampling and processing. In this context, a signal driven filtering technique, based on the level crossing sampling is devised. It adapts the sampling frequency and the filter order by analysing the input signal local variations. Thus, it correlates the processing activity with the signal variations. It leads towards a drastic computational gain of the proposed technique compared to the classical one.Keywords: Level Crossing Sampling, Activity Selection, Adaptive Rate Filtering, Computational Complexity.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1361386 Spatial Time Series Models for Rice and Cassava Yields Based On Bayesian Linear Mixed Models
Authors: Panudet Saengseedam, Nanthachai Kantanantha
Abstract:
This paper proposes a linear mixed model (LMM) with spatial effects to forecast rice and cassava yields in Thailand at the same time. A multivariate conditional autoregressive (MCAR) model is assumed to present the spatial effects. A Bayesian method is used for parameter estimation via Gibbs sampling Markov Chain Monte Carlo (MCMC). The model is applied to the rice and cassava yields monthly data which have been extracted from the Office of Agricultural Economics, Ministry of Agriculture and Cooperatives of Thailand. The results show that the proposed model has better performance in most provinces in both fitting part and validation part compared to the simple exponential smoothing and conditional auto regressive models (CAR) from our previous study.
Keywords: Bayesian method, Linear mixed model, Multivariate conditional autoregressive model, Spatial time series.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2247385 Use Cuticular Hydrocarbons as Chemotaxonomic of The Pamphagidae Pamphagus elephas (Insecta, Orthoptera) of Algeria
Authors: M. Bounechada, F. Benia, M. Aiouaz, S. Bouharati, N. Djirar, H. Benamrani
Abstract:
The cuticular hydrocarbons of Pamphagus elephas (Orthoptera: Pamphagidae) has been analysed by gas chromatography and by combined gas chromatograph-mass spectrometry. The following hydrocarbon classes have been identified in insect cuticular hydrocarbons are: n-alkanes and methylalkanes comprising Monomethyl-, dimethyl-and trimethylalkanes. Sexual dimorphism is observed in long chain alkanes (C24-C36) present on male and female. The cuticulars hydrocarbons of P.elephas ranged from 24 to 36 carbons and incluted n-alkanes, Dimethylalkanes and Trimethylalkanes. nalkanes represented by (C24-C36,72,7% on male and 79,2% on female), internally branched Monomethylalkanes identified were (C25, C30-C32,C35-C37;11% on male and 9,4% on female), Dimethylalkanes detected are (C31-C32, C36; 2,2% on male and 2,06% on female) and Trimethylalkanes detected are (C32, C36; 3,1% on male and 4, 97 on female). Larvae male and female (stage 7) showed the same quality of n-alkanes observed in adults. However a difference quantity is noted.Keywords: Cuticular hydrocarbons, Gas chromatography, Mass spectrometry, Pamphagus elephas, , Sexual dimorphism
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1724384 Value for Money in Investment Projects
Authors: Jan Ceselsky
Abstract:
Construction and reconstruction of settlements and individual municipalities, environmental management and the creation, deployment of the forces of production and building transport and technical equipment requires a large expenditure of material and human resources. That is why the economic aspects of the majority decision in these planes built in the foreground and are often decisive. Thereby but more serious is that the economic aspects of the settlement, the creation and function remain in their whole, unprocessed, and cannot speak of a set of individual techniques and methods traditional indicators and experiments with new approaches. This is true both at the level of the national economy, and in their own urban designs. Still a few remain identified specific economic shaping patterns of settlement and the less it is possible to speak of their control. Also practical assessing economics of specific solutions are often used non-apt indicators in addition to economics usually identifies with the lowest acquisition cost or high-intensity land use with little regard for functional efficiency and little studied much higher operating and maintenance costs".Keywords: Investment, municipal engineering, value for money.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1721383 Estimation of Attenuation and Phase Delay in Driving Voltage Waveform of an Ultra-High-Speed Image Sensor by Dimensional Analysis
Authors: V. T. S. Dao, T. G. Etoh, C. Vo Le, H. D. Nguyen, K. Takehara, T. Akino, K. Nishi
Abstract:
We present an explicit expression to estimate driving voltage attenuation through RC networks representation of an ultrahigh- speed image sensor. Elmore delay metric for a fundamental RC chain is employed as the first-order approximation. By application of dimensional analysis to SPICE simulation data, we found a simple expression that significantly improves the accuracy of the approximation. Estimation error of the resultant expression for uniform RC networks is less than 2%. Similarly, another simple closed-form model to estimate 50 % delay through fundamental RC networks is also derived with sufficient accuracy. The framework of this analysis can be extended to address delay or attenuation issues of other VLSI structures.
Keywords: Dimensional Analysis, Elmore model, RC network, Signal Attenuation, Ultra-High-Speed Image Sensor.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1424382 DEA ANN Approach in Supplier Evaluation System
Authors: Dilek Özdemir, Gül Tekin Temur
Abstract:
In Supply Chain Management (SCM), strengthening partnerships with suppliers is a significant factor for enhancing competitiveness. Hence, firms increasingly emphasize supplier evaluation processes. Supplier evaluation systems are basically developed in terms of criteria such as quality, cost, delivery, and flexibility. Because there are many variables to be analyzed, this process becomes hard to execute and needs expertise. On this account, this study aims to develop an expert system on supplier evaluation process by designing Artificial Neural Network (ANN) that is supported with Data Envelopment Analysis (DEA). The methods are applied on the data of 24 suppliers, which have longterm relationships with a medium sized company from German Iron and Steel Industry. The data of suppliers consists of variables such as material quality (MQ), discount of amount (DOA), discount of cash (DOC), payment term (PT), delivery time (DT) and annual revenue (AR). Meanwhile, the efficiency that is generated by using DEA is added to the supplier evaluation system in order to use them as system outputs.
Keywords: Artificial Neural Network (ANN), DataEnvelopment Analysis (DEA), Supplier Evaluation System.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2153381 Electromagnetic Assessment of Submarine Power Cable Degradation Using Finite Element Method and Sensitivity Analysis
Authors: N. Boutra, N. Ravot, J. Benoit, O. Picon
Abstract:
Submarine power cables used for offshore wind farms electric energy distribution and transmission are subject to numerous threats. Some of the risks are associated with transport, installation and operating in harsh marine environment. This paper describes the feasibility of an electromagnetic low frequency sensing technique for submarine power cable failure prediction. The impact of a structural damage shape and material variability on the induced electric field is evaluated. The analysis is performed by modeling the cable using the finite element method, we use sensitivity analysis in order to identify the main damage characteristics affecting electric field variation. Lastly, we discuss the results obtained.Keywords: Electromagnetism, defect, finite element method, sensitivity analysis, submarine power cables.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1092380 Architecture for Smart Cities’ Sustainable Modular Houses
Authors: Khaled Elbehiery, Hussam Elbehiery
Abstract:
Smart cities are a framework of technologies along with sustainable infrastructure to provide their citizens an improved quality of life, safer environment, affordability, and more, which in turn helps with the society's economic growth. The proposed research will focus on the primary building block of the smart city; the infrastructure of the house itself. The traditional method of building houses has been, for a long time, nothing but a costly manufacturing process, and consequently, buying a house becomes not an option for everyone anymore. The smart cities' Modular Houses are not using traditional building construction materials; the design reduces the common lengthy construction times and associated high costs. The Modular Houses are technological homes, low-cost and customizable based on a family's requirements. In addition, the Modular Houses are environmentally friendly and healthy enough to assist with the pandemic situation.
Keywords: Smart cities, modular houses, single-unit property, multi-unit property, mobility features, chain-supply, livable environment, carbon footprint.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 318379 Port Governance Model by International Freight Forwarders’ Point of View: A Study at Port of Santos - Brazil
Authors: Guilherme B. B. Vieira, Rafael M. da Silva, Eliana T. P. Senna, Luiz A. S. Senna, Francisco J. Kliemann Neto
Abstract:
Due to the importance of ports to trade and economic development of the regions in which they are inserted, in recent decades the number of studies devoted to this subject has increased. Part of these studies considers the ports as business agglomerations and focuses on port governance. This is an important approach since the port performance is the result of activities performed by actors belonging to the port-logistics chain, which need to be properly coordinated. This coordination takes place through a port governance model. Given this context, this study aims to analyze the governance model of the port of Santos from the perspective of port customers. To do this, a closed-ended questionnaire based on a conceptual model that considers the key dimensions associated with port governance was applied to the international freight forwarders that operate in the port. The results show the applicability of the considered model and highlight improvement opportunities to be implemented at the port of Santos.
Keywords: Port Governance, Model, Port of Santos, Customers’ Perception.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2168378 Identification of Aquatic and Semi aquatic Birds of Sattarkhan Lake (East Azerbaijan- Iran)
Authors: Mahbobeh Hajirostamloo
Abstract:
Aquatic and semi aquatic birds as a group are suited to feed and breed in environments in which water forms a fundamental part. These birds are biological indicator in aquatic environment, because these birds belong to the top level of food chain in aquatic ecosystems. There are 61 species in 14 families of aquatic and semi aquatic birds in Iran. The birds of the Sattarkhan Lake belong to 16 species in 8 families which include 26.2 percent of total Aquatic and semi aquatic bird species and 57% of Aquatic and semi aquatic bird's family of Iran. Study was carried out monthly at Sattarkhan Lake show the existence of Phalacrocorax carbo, Ardea cinerea, Egretta alba, Egretta garzetta, Bubulcus ibis, Botaurus stellaris, Sterna hirundo, Chlidonias leucopterus, Larus minutus, Larus argentatus, Larus ridibunbus, Alcedo atthis, Ciconia ciconia, Plegadis falcinellus, Circus aeruginosus, Corvus frugilegusKeywords: Aquatic bird, Sattarkhan Lake, Identification, Iran
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1730377 The Benefit of Green Logistics to Organization
Authors: Wijittra Srisorn
Abstract:
This research studied about green logistics and the expected benefit that organization gotten when adapted to green logistics also the organization concerned about the important activity in green logistics to apply in implementation from study was found that the benefit of green logistics that organization was gotten by logistics management which was the increased efficiency process of management the product from producer to customer all of reduce production cost, increased value added save energy and prevented environment together From study was found that the organization had green logistics to apply in logistics activities in supply chain since downstream till upstream to prevent environment as follow 1). Purchasing process, trade facilitation enhance such as linking of information technology during business to business (B2B business). 2). Productions process improved by business logistics improvement 3). Warehouse management process such as recycled packaging, moving goods in to warehouse, transportation goods and inside receiving and delivery products plan.
Keywords: Green Logistics, Trade Facilitation, Business Logistics Improvement, Double handling.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 9720376 Assessing Organizational Resilience Capacity to Flooding: Index Development and Application to Greek Small and Medium-Sized Enterprises
Authors: A. Skouloudis, K. Evangelinos, W. Leal-Filho, P. Vouros, I. Nikolaou, T. Tsalis
Abstract:
In this study a composite index of factors linked to the resilience capacity of small and medium-sized enterprises (SMEs) to flooding is proposed and tested. A sample of SMEs located in flood-prone areas (n = 391) was administered a structured questionnaire pertaining to cognitive, managerial and contextual factors that affect the ability to prepare, withstand, and recover from flooding events. Through the proposed index, a bottom-up, self-assessment approach is set forth that could assist in standardizing such assessments with an overarching aim of reducing the vulnerability of SMEs to floods. This is achieved by examining critical internal and external parameters affecting SMEs’ resilience capacity which is particularly important taking into account the limited resources these enterprises tend to have at their disposal and that they can generate single points of failure in dense supply chain networks.
Keywords: Floods, SMEs, organizational resilience capacity, index development, Greece.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 471375 Analysis of a WDM System for Tanzania
Authors: Shaban Pazi, Chris Chatwin, Rupert Young, Philip Birch
Abstract:
Internet infrastructures in most places of the world have been supported by the advancement of optical fiber technology, most notably wavelength division multiplexing (WDM) system. Optical technology by means of WDM system has revolutionized long distance data transport and has resulted in high data capacity, cost reductions, extremely low bit error rate, and operational simplification of the overall Internet infrastructure. This paper analyses and compares the system impairments, which occur at data transmission rates of 2.5Gb/s and 10 Gb/s per wavelength channel in our proposed optical WDM system for Internet infrastructure in Tanzania. The results show that the data transmission rate of 2.5 Gb/s has minimum system impairments compared with a rate of 10 Gb/s per wavelength channel, and achieves a sufficient system performance to provide a good Internet access service.Keywords: Internet infrastructure, WDM system, standard single mode fibers, system impairments.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1662374 Effect of Sand Particle Transportation in Oil and Gas Pipeline Erosion
Authors: Christopher Deekia Nwimae, Nigel Simms, Liyun Lao
Abstract:
Erosion in a pipe bends caused by particles is a major concern in the oil and gas fields and might cause breakdown to production equipment. This work investigates the effect of sand particle transport in an elbow using computational fluid dynamics (CFD) approach. Two-way coupled Euler-Lagrange and discrete phase model is employed to calculate the air/solid particle flow in the elbow. Generic erosion model in Ansys fluent and three particle rebound models are used to predict the erosion rate on the 90° elbows. The model result is compared with experimental data from the open literature validating the CFD-based predictions which reveals that due to the sand particles impinging on the wall of the elbow at high velocity, a point on the pipe elbow were observed to have started turning red due to velocity increase and the maximum erosion locations occur at 48°.
Keywords: Erosion, prediction, elbow, computational fluid dynamics, CFD.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 499373 Designing a Multilingual Auction Website for Selling Agricultural Products
Authors: Popa Cosmin, Chiran Aurel
Abstract:
The study aimed to identify the logical structure of data and particularities of developing and testing a website designed for selling farm products through online auctions. The research is based on a short literature review in the field and exploratory trials of some successful models from other industries, in order to identify the advantages of using such tool, as well as the optimal structure and functionality of an auction portal. In the last part, the study focuses on the results of testing the website by the potential beneficiaries. Conclusions of the study underlines that the particularities of some agricultural products could raise difficulties in the process of selling them through online auctions, but the use of such system it is perceived to bring significant improvements in the supply chain. The results of scientific investigations require a more detailed study regarding the importance of using quality standards for agricultural products sold via online auction, the impact that implementation of an online payment system could have on trade with agricultural products and problems which could arise in using the website in different countries.Keywords: E-commerce, online auctions, marketing.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 3599372 Challenges and Opportunities of E-Procurement in the Construction Industry
Authors: Mansur Hamma-adama, Abdul-Basit Sa’eed Ahmad
Abstract:
Construction Industry is evolving amid the fourth industrial revolution. Transportation, commerce, manufacturing and many other industries ripened the current technological advancement and are striving to utilise every development in the IT sector. The procurement of construction works is known to be very conventional and backward in the adoption of digitalisation. The construction industry's procurement and supply chain are blamed for the most inflated cost of construction projects, mainly attributed to a lack of transparency and trust between the industry stakeholders. This research explores the challenges of e-procurement adoption in the industry and identifies the potential opportunities for its usage. This investigation's data are acquired through interviews, and the data are analysed using qualitative content analysis. This study reveals compounding challenges (i.e., corruption and lack of commitment) that lead to the failure of such efforts in Nigeria and the potential prospects (i.e., transparency and efficiency). This study is essential in developing a more effective and transparent process of procurement so that the Nigerian construction industry is not be left behind in the fast-digitalising markets.
Keywords: Challenges, construction industry, corruption, e-procurement, Nigeria, opportunities.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 727371 Proteolytic Dedradation of Anchovy (Spolephorus spp.) Proteins by Halophilic Proteinase from Halobacillus sp. SR5-3
Authors: Sirilak Namwong , Wonnop Visessanguan, Soottawat Benjakul, Somboon Tanasupawat
Abstract:
The halophilic proteinase showed a maximal activity at 50°C and pH 9~10, in 20% NaCl and was highly stabilized by NaCl. It was able to hydrolyse natural actomyosin (NAM), collagen and anchovy protein. For NAM hydrolysis, the myosin heavy chain was completely digested by halophilic proteinase as evidenced by the lowest band intensity remaining, but partially hydrolysed actin. The SR5-3 proteinase was also capable hydrolyzing two major components of collagen, β- and α-compounds, effectively. The degree of hydrolysis (DH) of the halophilic proteinase and commercial proteinases (Novozyme, Neutrase, chymotrypsin and Flavourzyme) on the anchovy protein, were compared, and it was found that the proteinase showed a greater degree of hydrolysis towards anchovy protein than that from commercial proteinases. DH of halophilic proteinase was sharply enhanced according to the increase in the concentration of enzyme from 0.035 U to 0.105 U. The results warranting that the acceleration of the production of fish sauce with higher quality, may be achieved by adding of the halophilic proteinase from this bacterium.Keywords: Halophilic proteinase, Halobacillus sp. SR5-3, anchovy (Spolephorus spp.) proteins, fish sauce
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1572370 Land Use around Metro Stations: A Case Study
Authors: A. Roukouni, S. Basbas, M. Giannopoulou
Abstract:
Transport and land use are two systems that are mutually influenced. Their interaction is a complex process associated with continuous feedback. The paper examines the existing land use around an under construction metro station of the new metro network of Thessaloniki, Greece, through the use of field investigations, around the station-s predefined location. Moreover, except from the analytical land use recording, a sampling questionnaire survey is addressed to several selected enterprises of the study area. The survey aims to specify the characteristics of the enterprises, the trip patterns of their employees and clients, as well as the stated preferences towards the changes the new metro station is considered to bring to the area. The interpretation of the interrelationships among selected data from the questionnaire survey takes place using the method of Principal Components Analysis for Categorical Data. The followed methodology and the survey-s results contribute to the enrichment of the relevant bibliography concerning the way the creation of a new metro station can have an impact on the land use pattern of an area, by examining the situation before the operation of the station.Keywords: land use, metro station, questionnaire survey
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 3113369 Enzymatic Esterification of Carboxylic Acids and Higher Alcohols in Organic Medium
Authors: D.T. Mirzarakhmetova
Abstract:
The studying of enzymatic esterification of carboxylic acids and higher alcohols was performed by esterase Saccharomyces cerevisiae in water-organic medium. Investigation of the enzyme specificity to acetic substrates showed the best result with acetic acid in esterification reactions with ethanol whereas within other carboxylic acids the esterification decreased with acids: hexanoic > pentanoic > butyric > decanoic. In relation to higher alcohols C3-C5, esterification increased with alcohols propanol < butanol < amylol. Also it was determined that esterase was more specific to alcohols with branched chain such as isobutyl alcohol and isoamyl alcohol. Data obtained may have important practical implications, for example, for application of yeast esterase in producing various volatile esters as well as in enzymatic transformation of volatile acids and toxic fusel alcohols into volatile esters by providing the production of the high quality alcoholic beverages with redused content of higher alcohols as well as with improved degustational and hygienic properties.Keywords: enzymes in non-conventional media, esterification, higher alcohols, volatile esters, yeast esterase
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 3500368 Mean Velocity Modeling of Open-Channel Flow with Submerged Rigid Vegetation
Authors: M. Morri, A. Soualmia, P. Belleudy
Abstract:
Vegetation affects the mean and turbulent flow structure. It may increase flood risks and sediment transport. Therefore, it is important to develop analytical approaches for the bed shear stress on vegetated bed, to predict resistance caused by vegetation. In the recent years, experimental and numerical models have both been developed to model the effects of submerged vegetation on open-channel flow. In this paper, different analytic models are compared and tested using the criteria of deviation, to explore their capacity for predicting the mean velocity and select the suitable one that will be applied in real case of rivers. The comparison between the measured data in vegetated flume and simulated mean velocities indicated, a good performance, in the case of rigid vegetation, whereas, Huthoff model shows the best agreement with a high coefficient of determination (R2=80%) and the smallest error in the prediction of the average velocities.
Keywords: Analytic Models, Comparison, Mean Velocity, Vegetation.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2538367 A New Fuzzy Mathematical Model in Recycling Collection Networks: A Possibilistic Approach
Authors: B. Vahdani, R. Tavakkoli-Moghaddam, A. Baboli, S. M. Mousavi
Abstract:
Focusing on the environmental issues, including the reduction of scrap and consumer residuals, along with the benefiting from the economic value during the life cycle of goods/products leads the companies to have an important competitive approach. The aim of this paper is to present a new mixed nonlinear facility locationallocation model in recycling collection networks by considering multi-echelon, multi-suppliers, multi-collection centers and multifacilities in the recycling network. To make an appropriate decision in reality, demands, returns, capacities, costs and distances, are regarded uncertain in our model. For this purpose, a fuzzy mathematical programming-based possibilistic approach is introduced as a solution methodology from the recent literature to solve the proposed mixed-nonlinear programming model (MNLP). The computational experiments are provided to illustrate the applicability of the designed model in a supply chain environment and to help the decision makers to facilitate their analysis.
Keywords: Location-allocation model, recycling collection networks, fuzzy mathematical programming.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2098