Search results for: optimal policy
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 6620

Search results for: optimal policy

5510 Study of Cavitation Phenomena Based on Flow Visualization Test in 3-Way Reversing Valve

Authors: Hyo Lim Kang, Tae An Kim, Seung Ho Han

Abstract:

A 3-way reversing valve has been used in automotive washing machines to remove remaining oil and dirt on machined engine and transmission blocks. It provides rapid and accurate changes of water flow direction without any precise control device. However, due to its complicated bottom-plug shape, a cavitation occurs in a wide range of the bottom-plug in a downstream. In this study, the cavitation index and POC (percent of cavitation) were used to evaluate quantitatively the cavitation phenomena occurring at the bottom-plug. An optimal shape design was carried out via parametric study for geometries of the bottom-plug, in which a simple CAE-model was used in order to avoid time-consuming CFD analysis and hard to achieve convergence. To verify the results of numerical analysis, a flow visualization test was carried out using a test specimen with a transparent acryl pipe according to ISA-RP75.23. The flow characteristics such as the cavitation occurring in the downstream were investigated by using a flow test equipment with valve and pump including a flow control system and high-speed camera.

Keywords: cavitation, flow visualization test, optimal shape design, percent of cavitation, reversing valve

Procedia PDF Downloads 287
5509 Enhancing Maritime Governance in Africa: Challenges of Maritime Policy Development in the East African Community

Authors: Christantus Begealawuh Nchongayi

Abstract:

As clearly stated in goal 14 of sustainable development goals, global oceans greatly contribute to making the earth habitable for mankind. This explains why ocean governance is an important global concern today. The emerging maritime security problems and the impact of climate change on African oceans, evidenced by tropical cyclones as seen recently in the Southern region of Africa, is also an indication that maritime governance and policymaking are important elements of peace and security in Africa. Within the last decade, there have been commendable efforts towards maritime governance and policymaking in Africa, although implementation of existing maritime policies is still lacking. This paper provides a snapshot of the overall state of the maritime policymaking process in Africa. It specifically explores the challenges facing policymakers in developing national and regional maritime security strategy in the East African Community. For methodology, the paper relied on primary and secondary data. Primary data was collected from informal discussions with policymakers and key policy-making bodies in Africa, and from a survey of public opinions. The study found that the Africa Integrated Maritime Strategy (2050 AIMS) is a recent template for regional and national maritime security policymaking in Africa and that although maritime security has in the past not been prioritized in the security agenda of the East African Community, developing and aligning a regional maritime security strategy to the 2050 AIMS will result to positive regional integration outcomes in East Africa.

Keywords: 2050 Africa integrated maritime strategy, east African community, maritime policy-making, maritime security

Procedia PDF Downloads 200
5508 Optimal Planning of Transmission Line Charging Mode During Black Start of a Hydroelectric Unit

Authors: Mohammad Reza Esmaili

Abstract:

After the occurrence of blackouts, the most important subject is how fast the electric service is restored. Power system restoration is an immensely complex issue and there should be a plan to be executed within the shortest time period. This plan has three main stages of black start, network reconfiguration and load restoration. In the black start stage, operators and experts may face several problems, for instance, the unsuccessful connection of the long high-voltage transmission line connected to the electrical source. In this situation, the generator may be tripped because of the unsuitable setting of its line charging mode or high absorbed reactive power. In order to solve this problem, the line charging process is defined as a nonlinear programming problem, and it is optimized by using GAMS software in this paper. The optimized process is performed on a grid that includes a 250 MW hydroelectric unit and a 400 KV transmission system. Simulations and field test results show the effectiveness of optimal planning.

Keywords: power system restoration, black start, line charging mode, nonlinear programming

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5507 Evaluating the Impact of Replacement Policies on the Cache Performance and Energy Consumption in Different Multicore Embedded Systems

Authors: Sajjad Rostami-Sani, Mojtaba Valinataj, Amir-Hossein Khojir-Angasi

Abstract:

The cache has an important role in the reduction of access delay between a processor and memory in high-performance embedded systems. In these systems, the energy consumption is one of the most important concerns, and it will become more important with smaller processor feature sizes and higher frequencies. Meanwhile, the cache system dissipates a significant portion of energy compared to the other components of a processor. There are some elements that can affect the energy consumption of the cache such as replacement policy and degree of associativity. Due to these points, it can be inferred that selecting an appropriate configuration for the cache is a crucial part of designing a system. In this paper, we investigate the effect of different cache replacement policies on both cache’s performance and energy consumption. Furthermore, the impact of different Instruction Set Architectures (ISAs) on cache’s performance and energy consumption has been investigated.

Keywords: energy consumption, replacement policy, instruction set architecture, multicore processor

Procedia PDF Downloads 142
5506 Optimal Design of a PV/Diesel Hybrid System for Decentralized Areas through Economic Criteria

Authors: David B. Tsuanyo, Didier Aussel, Yao Azoumah, Pierre Neveu

Abstract:

An innovative concept called “Flexy-Energy”is developing at 2iE. This concept aims to produce electricity at lower cost by smartly mix different available energies sources in accordance to the load profile of the region. With a higher solar irradiation and due to the fact that Diesel generator are massively used in sub-Saharan rural areas, PV/Diesel hybrid systems could be a good application of this concept and a good solution to electrify this region, provided they are reliable, cost effective and economically attractive to investors. Presentation of the developed approach is the aims of this paper. The PV/Diesel hybrid system designed consists to produce electricity and/or heat from a coupling between Diesel gensets and PV panels without batteries storage, while ensuring the substitution of gasoil by bio-fuels available in the area where the system will be installed. The optimal design of this system is based on his technical performances; the Life Cycle Cost (LCC) and Levelized Cost of Energy are developed and use as economic criteria. The Net Present Value (NPV), the internal rate of return (IRR) and the discounted payback (DPB) are also evaluated according to dual electricity pricing (in sunny and unsunny hours). The PV/Diesel hybrid system obtained is compared to the standalone Diesel gensets. The approach carried out in this paper has been applied to Siby village in Mali (Latitude 12 ° 23'N 8 ° 20'W) with 295 kWh as daily demand. This approach provides optimal physical characteristics (size of the components, number of component) and dynamical characteristics in real time (number of Diesel generator on, their load rate, fuel specific consumptions, and PV penetration rate) of the system. The system obtained is slightly cost effective; but could be improved with optimized tariffing strategies.

Keywords: investments criteria, optimization, PV hybrid, sizing, rural electrification

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5505 Inadequacy of Macronutrient and Micronutrient Intake in Children Aged 12-23 Months Old: An Urban Study in Central Jakarta, Indonesia

Authors: Dewi Fatmaningrum, Ade Wiradnyani

Abstract:

Background: Optimal feeding, include optimal micronutrient intake, becomes one of the ways to overcome the long-term consequences of undernutrition. Macronutrient and micronutrient intake were important for rapid growth and development of the children. Objectives: To assess macro and micronutrient intake of children aged 12-23 months old and nutrients inadequacy from intake of children aged 12-23 months old. Methods: This survey was a cross-sectional study, simple random sampling was performed to select respondents. Total sample of this study was 83 children aged 12-23 months old in Paseban Village, Senen Sub-district, Central Jakarta. The data was collected via interview and hemoglobin measurement of children. Results: The highest prevalence of inadequacy was iron intake (52.4%) compared to other micronutrients, 11.98% children had inadequate energy intake. There were 62.6% anemic children in the study area in which divided into anemic (37.3%) and severe anemic (25.3%). Conclusion: Micronutrient inadequacy occurred more frequently than macronutrient inadequacy in the study area. The higher the percentage of iron inadequacy gets, the higher the percentage of anemia among children is observed.

Keywords: micronutrient, macronutrient, children under five, urban setting

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5504 Towards Positive Identity Construction for Japanese Non-Native English Language Teachers

Authors: Yumi Okano

Abstract:

The low level of English proficiency among Japanese people has been a problem for a long time. Japanese non-native English language teachers, under social or ideological constraints, feel a gap between government policy and their language proficiency and cannot maintain high self-esteem. This paper focuses on current Japanese policies and the social context in which teachers are placed and examines the measures necessary for their positive identity formation from a macro-meso-micro perspective. Some suggestions for achieving this are: 1) Teachers should free themselves from the idea of native speakers and embrace local needs and accents, 2) Teachers should be involved in student discussions as facilitators and individuals so that they can be good role models for their students, and 3) Teachers should invest in their classrooms. 4) Guidelines and training should be provided to help teachers gain confidence. In addition to reducing the workload to make more time available, 5) expanding opportunities for investment outside the classroom into the real world is necessary.

Keywords: language teacher identity, native speakers, government policy, critical pedagogy, investment

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5503 Effectiveness of Multi-Business Core Development Policy in Tokyo Metropolitan Area

Authors: Takashi Nakamura

Abstract:

In the Tokyo metropolitan area, traffic congestion and long commute times are caused by overconcentration in the central area. To resolve these problems, a core business city development policy was adopted in 1988. The core business cities, which include Yokohama, Chiba, Saitama, Tachikawa, and others, have designated business facilities accumulation districts where assistance measures are applied. Focusing on Yokohama city, this study investigates the trends in the number of offices, employees, and commuters at 2001 and 2012 Economic Census, as well as the average commute time in the Tokyo metropolitan area from 2005 to 2015 Metropolitan Transportation Census. Surveys were administered in 2001 and 2012 Economic Census to participants who worked in Yokohama, according to their distribution in the city's 1,757 subregions. Four main findings emerged: (1) The number of offices increased in Yokohama when the number of offices decreased in the Tokyo metropolitan area overall. Additionally, the number of employees at Yokohama increased. (2) The number of commuters to Tokyo's central area increased from Saitama prefecture, Tokyo Tama area, and Tokyo central area. However, it decreased from other areas. (3) The average commute time in the Tokyo metropolitan area was 67.7 minutes in 2015, a slight decrease from 2005 and 2010. (4) The number of employees at business facilities accumulation districts in Yokohama city increased greatly.

Keywords: core business city development policy, commute time, number of employees, Yokohama city, distribution of employees

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5502 Innovation Policy and Development of Creative Industries: Case Study of Lithuanian Animation Industry

Authors: Tomas Mitkus, Vaida Nedzinskaitė-Mitkė

Abstract:

The objective of this study is to identify and explore how adequate is modern innovation support mechanism to developed creative industries. We argue that current development and support strategy for creative industries, although acknowledge high correlation between innovation and creativity, do not seek to improve conditions to promote systematic innovation development in the creative sector. Using the Lithuanian animation industry as a case study, this paper will examine innovation contribution to creativity and, for that matter, the competitiveness of animation enterprises. This paper proposes insights that contribute to theoretical and practical discussions on how creative profile companies build national and international competitiveness through innovations. The conclusions suggest that development of creative industries could greatly benefit if policymakers would implement tools that would encourage creative profile enterprises to invest in to development of innovation at a constant rate.

Keywords: creative industries, innovation policy, innovation, management

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5501 Achieving Quality of Life and Sustainability in Mexican Cities, the Case of the Housing Complex “Villa del Campo”, Tijuana, Mexico

Authors: María de los Ángeles Zárate López, Juan Antonio Pitones Rubio

Abstract:

Quality of life and sustainability in cities are among the most important challenges faced by designers, city planners and urban managers. The Mexican city of Tijuana has a particular dynamic in its demographics which has been accelerated by its border city condition, putting to the test the ability from authorities to provide the population with the necessary services to aspire for a deserving quality of life. In the recent story of Tijuana, we found that the housing policy and the solutions presented by private housing developers have not met the best living conditions for end users by far, thereby adding issues to current social problems which impact the whole metropolitan area, including damage to the natural environment. Therefore this research presents the case study about the situation of a suburban housing development near Tijuana named “Villa del Campo” and exposes the problems of this specific project (originally labelled as a “sustainable” proposal) demonstrating that, once built, the place does not reflect the quality of life that it promised as a project. Currently, this housing development has a number of problematic issues such as the faulty operating conditions of public utilities and serious cases of crime inside the neighborhood. There is no intention to only expose the negative side of this case study, but to explore some alternatives which could help solving the most serious problems at the place, considering possible architectural and landscape interventions within the housing complex to help achieve the optimal conditions of livability and sustainability required by their inhabitants.

Keywords: suburban, housing, quality of life, sustainability, Tijuana, demographics

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5500 A GIS Based Composite Land Degradation Assessment and Mapping of Tarkwa Mining Area

Authors: Bernard Kumi-Boateng, Kofi Bonsu

Abstract:

The clearing of vegetation in the Tarkwa Mining Area (TMA) for the purposes of mining, lumbering and development of settlement for the increasing population has caused a large scale denudation of the forest cover and erosion of the top soil thereby degrading the agriculture land. It is, therefore, essential to know the current status of land degradation in TMA so as to facilitate land conservation policy-making. The types of degradation, the extents of the degradations and their various degrees were combined to develop a composite land degradation index to assess the current status of land degradation in TMA using GIS based techniques. The assessment revealed that the most significant types of degradation in TMA were open pit and quarry mining; urbanisation and other construction projects; and surface scraping during land clearing. It was found that 21.62 % of the total area of TMA (353.07 km2) had high degradation index rating. It is recommended that decision makers use this assessment as a reference point for future initiatives that will be taken in order to develop land conservation policy.

Keywords: degradation, GIS, land, mining

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5499 Optimal Perturbation in an Impulsively Blocked Channel Flow

Authors: Avinash Nayak, Debopam Das

Abstract:

The current work implements the variational principle to find the optimum initial perturbation that provides maximum growth in an impulsively blocked channel flow. The conventional method for studying temporal stability has always been through modal analysis. In most of the transient flows, this modal analysis is still followed with the quasi-steady assumption, i.e. change in base flow is much slower compared to perturbation growth rate. There are other studies where transient analysis on time dependent flows is done by formulating the growth of perturbation as an initial value problem. But the perturbation growth is sensitive to the initial condition. This study intends to find the initial perturbation that provides the maximum growth at a later time. Here, the expression of base flow for blocked channel is derived and the formulation is based on the two dimensional perturbation with stream function representing the perturbation quantity. Hence, the governing equation becomes the Orr-Sommerfeld equation. In the current context, the cost functional is defined as the ratio of disturbance energy at a terminal time 'T' to the initial energy, i.e. G(T) = ||q(T)||2/||q(0)||2 where q is the perturbation and ||.|| defines the norm chosen. The above cost functional needs to be maximized against the initial perturbation distribution. It is achieved with the constraint that perturbation follows the basic governing equation, i.e. Orr-Sommerfeld equation. The corresponding adjoint equation is derived and is solved along with the basic governing equation in an iterative manner to provide the initial spatial shape of the perturbation that provides the maximum growth G (T). The growth rate is plotted against time showing the development of perturbation which achieves an asymptotic shape. The effects of various parameters, e.g. Reynolds number, are studied in the process. Thus, the study emphasizes on the usage of optimal perturbation and its growth to understand the stability characteristics of time dependent flows. The assumption of quasi-steady analysis can be verified against these results for the transient flows like impulsive blocked channel flow.

Keywords: blocked channel flow, calculus of variation, hydrodynamic stability, optimal perturbation

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5498 Multiloop Fractional Order PID Controller Tuned Using Cuckoo Algorithm for Two Interacting Conical Tank Process

Authors: U. Sabura Banu, S. K. Lakshmanaprabu

Abstract:

The improvement of meta-heuristic algorithm encourages control engineer to design an optimal controller for industrial process. Most real-world industrial processes are non-linear multivariable process with high interaction. Even in sub-process unit, thousands of loops are available mostly interacting in nature. Optimal controller design for such process are still challenging task. Closed loop controller design by multiloop PID involves a tedious procedure by performing interaction study and then PID auto-tuning the loop with higher interaction. Finally, detuning the controller to accommodate the effects of the other process variables. Fractional order PID controllers are replacing integer order PID controllers recently. Design of Multiloop Fractional Order (MFO) PID controller is still more complicated. Cuckoo algorithm, a swarm intelligence technique is used to optimally tune the MFO PID controller with easiness minimizing Integral Time Absolute Error. The closed loop performance is tested under servo, regulatory and servo-regulatory conditions.

Keywords: Cuckoo algorithm, mutliloop fractional order PID controller, two Interacting conical tank process

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5497 A Multicriteria Mathematical Programming Model for Farm Planning in Greece

Authors: Basil Manos, Parthena Chatzinikolaou, Fedra Kiomourtzi

Abstract:

This paper presents a Multicriteria Mathematical Programming model for farm planning and sustainable optimization of agricultural production. The model can be used as a tool for the analysis and simulation of agricultural production plans, as well as for the study of impacts of various measures of Common Agriculture Policy in the member states of European Union. The model can achieve the optimum production plan of a farm or an agricultural region combining in one utility function different conflicting criteria as the maximization of gross margin and the minimization of fertilizers used, under a set of constraints for land, labor, available capital, Common Agricultural Policy etc. The proposed model was applied to the region of Larisa in central Greece. The optimum production plan achieves a greater gross return, a less fertilizers use, and a less irrigated water use than the existent production plan.

Keywords: sustainable optimization, multicriteria analysis, agricultural production, farm planning

Procedia PDF Downloads 589
5496 The Impact of Informal Care on Health Behavior among Older People with Chronic Diseases: A Study in China Using Propensity Score Matching

Authors: Hong Wu, Naiji Lu

Abstract:

Improvement of health behavior among people with chronic diseases is vital for increasing longevity and enhancing quality of life. This paper researched the causal effects of informal care on the compliance with doctor’s health advices – smoking control, dietetic regulation, weight control and keep exercising – among older people with chronic diseases in China, which is facing the challenge of aging. We addressed the selection bias by using propensity score matching in the estimation process. We used the 2011-2012 national baseline data of the China Health and Retirement Longitudinal Study. Our results showed informal care can help improve health behavior of older people. First, informal care improved the compliance of smoking controls: whether smoke, frequency of smoking, and the time lag between wake up and the first cigarette was all lower for these older people with informal care; Second, for dietetic regulation, older people with informal care had more meals every day than older people without informal care; Third, three variables: BMI, whether gain weight and whether lose weight were used to measure the outcome of weight control. There were no significant difference between group with informal care and that without for BMI and the possibility of losing weight. Older people with informal care had lower possibility of gain weight than that without; Last, for the advice of keeping exercising, informal care increased the probability of walking exercise, however, the difference between groups for moderate and vigorous exercise were not significant. Our results indicate policy makers who aim to decrease accidents should take informal care to elders into account and provide an appropriate policy to meet the demand of informal care. Our birth policy and postponed retirement policy may decrease the informal caregiving hours, so adjustments of these policies are important and urgent to meet the current situation of aged tendency of population. In addition, government could give more support to develop organizations to provide formal care, such as nursing home. We infer that formal care is also useful for health behavior improvements.

Keywords: chronic diseases, compliance, CHARLS, health advice, informal care, older people, propensity score matching

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5495 A Construction Scheduling Model by Applying Pedestrian and Vehicle Simulation

Authors: Akhmad F. K. Khitam, Yi Tai, Hsin-Yun Lee

Abstract:

In the modern research of construction management, the goals of scheduling are not only to finish the project within the limited duration, but also to improve the impact of people and environment. Especially for the impact to the pedestrian and vehicles, the considerable social cost should be estimated in the total performance of a construction project. However, the site environment has many differences between projects. These interactions affect the requirement and goal of scheduling. It is difficult for schedule planners to quantify these interactions. Therefore, this study use 3D dynamic simulation technology to plan the schedule of the construction engineering projects that affect the current space users (i.e., the pedestrians and vehicles). The proposed model can help the project manager find out the optimal schedule to minimize the inconvenience brought to the space users. Besides, a roadwork project and a building renovation project were analyzed for the practical situation of engineering and operations. Then this study integrates the proper optimization algorithms and computer technology to establish a decision support model. The proposed model can generate a near-optimal schedule solution for project planners.

Keywords: scheduling, simulation, optimization, pedestrian and vehicle behavior

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5494 A Security Cloud Storage Scheme Based Accountable Key-Policy Attribute-Based Encryption without Key Escrow

Authors: Ming Lun Wang, Yan Wang, Ning Ruo Sun

Abstract:

With the development of cloud computing, more and more users start to utilize the cloud storage service. However, there exist some issues: 1) cloud server steals the shared data, 2) sharers collude with the cloud server to steal the shared data, 3) cloud server tampers the shared data, 4) sharers and key generation center (KGC) conspire to steal the shared data. In this paper, we use advanced encryption standard (AES), hash algorithms, and accountable key-policy attribute-based encryption without key escrow (WOKE-AKP-ABE) to build a security cloud storage scheme. Moreover, the data are encrypted to protect the privacy. We use hash algorithms to prevent the cloud server from tampering the data uploaded to the cloud. Analysis results show that this scheme can resist conspired attacks.

Keywords: cloud storage security, sharing storage, attributes, Hash algorithm

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5493 Optimal Tamping for Railway Tracks, Reducing Railway Maintenance Expenditures by the Use of Integer Programming

Authors: Rui Li, Min Wen, Kim Bang Salling

Abstract:

For the modern railways, maintenance is critical for ensuring safety, train punctuality and overall capacity utilization. The cost of railway maintenance in Europe is high, on average between 30,000 – 100,000 Euros per kilometer per year. In order to reduce such maintenance expenditures, this paper presents a mixed 0-1 linear mathematical model designed to optimize the predictive railway tamping activities for ballast track in the planning horizon of three to four years. The objective function is to minimize the tamping machine actual costs. The approach of the research is using the simple dynamic model for modelling condition-based tamping process and the solution method for finding optimal condition-based tamping schedule. Seven technical and practical aspects are taken into account to schedule tamping: (1) track degradation of the standard deviation of the longitudinal level over time; (2) track geometrical alignment; (3) track quality thresholds based on the train speed limits; (4) the dependency of the track quality recovery on the track quality after tamping operation; (5) Tamping machine operation practices (6) tamping budgets and (7) differentiating the open track from the station sections. A Danish railway track between Odense and Fredericia with 42.6 km of length is applied for a time period of three and four years in the proposed maintenance model. The generated tamping schedule is reasonable and robust. Based on the result from the Danish railway corridor, the total costs can be reduced significantly (50%) than the previous model which is based on optimizing the number of tamping. The different maintenance strategies have been discussed in the paper. The analysis from the results obtained from the model also shows a longer period of predictive tamping planning has more optimal scheduling of maintenance actions than continuous short term preventive maintenance, namely yearly condition-based planning.

Keywords: integer programming, railway tamping, predictive maintenance model, preventive condition-based maintenance

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5492 A Case Study on Performance of Isolated Bridges under Near-Fault Ground Motion

Authors: Daniele Losanno, H. A. Hadad, Giorgio Serino

Abstract:

This paper presents a numerical investigation on the seismic performance of a benchmark bridge with different optimal isolation systems under near fault ground motion. Usually, very large displacements make seismic isolation an unfeasible solution due to boundary conditions, especially in case of existing bridges or high risk seismic regions. Hence, near-fault ground motions are most likely to affect either structures with long natural period range like isolated structures or structures sensitive to velocity content such as viscously damped structures. The work is aimed at analyzing the seismic performance of a three-span continuous bridge designed with different isolation systems having different levels of damping. The case study was analyzed in different configurations including: (a) simply supported, (b) isolated with lead rubber bearings (LRBs), (c) isolated with rubber isolators and 10% classical damping (HDLRBs), and (d) isolated with rubber isolators and 70% supplemental damping ratio. Case (d) represents an alternative control strategy that combines the effect of seismic isolation with additional supplemental damping trying to take advantages from both solutions. The bridge is modeled in SAP2000 and solved by time history direct-integration analyses under a set of six recorded near-fault ground motions. In addition to this, a set of analysis under Italian code provided seismic action is also conducted, in order to evaluate the effectiveness of the suggested optimal control strategies under far field seismic action. Results of the analysis demonstrated that an isolated bridge equipped with HDLRBs and a total equivalent damping ratio of 70% represents a very effective design solution for both mitigation of displacement demand at the isolation level and base shear reduction in the piers also in case of near fault ground motion.

Keywords: isolated bridges, near-fault motion, seismic response, supplemental damping, optimal design

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5491 Optimization of Structures with Mixed Integer Non-linear Programming (MINLP)

Authors: Stojan Kravanja, Andrej Ivanič, Tomaž Žula

Abstract:

This contribution focuses on structural optimization in civil engineering using mixed integer non-linear programming (MINLP). MINLP is characterized as a versatile method that can handle both continuous and discrete optimization variables simultaneously. Continuous variables are used to optimize parameters such as dimensions, stresses, masses, or costs, while discrete variables represent binary decisions to determine the presence or absence of structural elements within a structure while also calculating discrete materials and standard sections. The optimization process is divided into three main steps. First, a mechanical superstructure with a variety of different topology-, material- and dimensional alternatives. Next, a MINLP model is formulated to encapsulate the optimization problem. Finally, an optimal solution is searched in the direction of the defined objective function while respecting the structural constraints. The economic or mass objective function of the material and labor costs of a structure is subjected to the constraints known from structural analysis. These constraints include equations for the calculation of internal forces and deflections, as well as equations for the dimensioning of structural components (in accordance with the Eurocode standards). Given the complex, non-convex and highly non-linear nature of optimization problems in civil engineering, the Modified Outer-Approximation/Equality-Relaxation (OA/ER) algorithm is applied. This algorithm alternately solves subproblems of non-linear programming (NLP) and main problems of mixed-integer linear programming (MILP), in this way gradually refines the solution space up to the optimal solution. The NLP corresponds to the continuous optimization of parameters (with fixed topology, discrete materials and standard dimensions, all determined in the previous MILP), while the MILP involves a global approximation to the superstructure of alternatives, where a new topology, materials, standard dimensions are determined. The optimization of a convex problem is stopped when the MILP solution becomes better than the best NLP solution. Otherwise, it is terminated when the NLP solution can no longer be improved. While the OA/ER algorithm, like all other algorithms, does not guarantee global optimality due to the presence of non-convex functions, various modifications, including convexity tests, are implemented in OA/ER to mitigate these difficulties. The effectiveness of the proposed MINLP approach is demonstrated by its application to various structural optimization tasks, such as mass optimization of steel buildings, cost optimization of timber halls, composite floor systems, etc. Special optimization models have been developed for the optimization of these structures. The MINLP optimizations, facilitated by the user-friendly software package MIPSYN, provide insights into a mass or cost-optimal solutions, optimal structural topologies, optimal material and standard cross-section choices, confirming MINLP as a valuable method for the optimization of structures in civil engineering.

Keywords: MINLP, mixed-integer non-linear programming, optimization, structures

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5490 A Proposed Optimized and Efficient Intrusion Detection System for Wireless Sensor Network

Authors: Abdulaziz Alsadhan, Naveed Khan

Abstract:

In recent years intrusions on computer network are the major security threat. Hence, it is important to impede such intrusions. The hindrance of such intrusions entirely relies on its detection, which is primary concern of any security tool like Intrusion Detection System (IDS). Therefore, it is imperative to accurately detect network attack. Numerous intrusion detection techniques are available but the main issue is their performance. The performance of IDS can be improved by increasing the accurate detection rate and reducing false positive. The existing intrusion detection techniques have the limitation of usage of raw data set for classification. The classifier may get jumble due to redundancy, which results incorrect classification. To minimize this problem, Principle Component Analysis (PCA), Linear Discriminant Analysis (LDA), and Local Binary Pattern (LBP) can be applied to transform raw features into principle features space and select the features based on their sensitivity. Eigen values can be used to determine the sensitivity. To further classify, the selected features greedy search, back elimination, and Particle Swarm Optimization (PSO) can be used to obtain a subset of features with optimal sensitivity and highest discriminatory power. These optimal feature subset used to perform classification. For classification purpose, Support Vector Machine (SVM) and Multilayer Perceptron (MLP) used due to its proven ability in classification. The Knowledge Discovery and Data mining (KDD’99) cup dataset was considered as a benchmark for evaluating security detection mechanisms. The proposed approach can provide an optimal intrusion detection mechanism that outperforms the existing approaches and has the capability to minimize the number of features and maximize the detection rates.

Keywords: Particle Swarm Optimization (PSO), Principle Component Analysis (PCA), Linear Discriminant Analysis (LDA), Local Binary Pattern (LBP), Support Vector Machine (SVM), Multilayer Perceptron (MLP)

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5489 Synthesis of Balanced 3-RRR Planar Parallel Manipulators

Authors: Arakelian Vigen, Geng Jing, Le Baron Jean-Paul

Abstract:

The paper deals with the design of parallel manipulators with balanced inertia forces and moments. The balancing of the resultant of the inertia forces of 3-RRR planar parallel manipulators is carried out through mass redistribution and centre of mass acceleration minimization. The proposed balancing technique is achieved in two steps: at first, optimal redistribution of the masses of input links is accomplished, which ensures the similarity of the end-effector trajectory and the manipulator’s common centre of mass trajectory, then, optimal trajectory planning of the end-effector by 'bang-bang' profile is reached. In such a way, the minimization of the magnitude of the acceleration of the centre of mass of the manipulator brings about a minimization of shaking force. To minimize the resultant of the inertia moments (shaking moment), the active balancing via inertia flywheel is applied. However, in this case, the active balancing is quite different from previous applications because it provides only a partial cancellation of the shaking moment due to the incomplete balancing of shaking force.

Keywords: dynamic balancing, inertia force minimization, inertia moment minimization, 3-RRR planar parallel manipulator

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5488 Missing Narratives and Their Potential Impact on Resettlement Strategies

Authors: Natina Roberts, Hanhee Lee

Abstract:

The existing and emerging refugee research reports unfavorable resettlement outcomes in multiple domains. The proposed paper highlights trends in refugee research in which empirical studies investigate resettlement of former refugees from individual and culturally homogeneous perspectives. The proposed paper then aims to examine the reality of the lived experience of resettlement from family and cross-cultural viewpoints. Proponents for this focus include the United Nations High Commissioner for Refugees (UNHCR). The UNHCR is responsible for leading resettlement efforts for refugees through the durable solutions of repatriation, local integration and resettlement. Life experiences with refugee families, and a report of literary findings on former refugee resettlement from various cultural backgrounds – that highlight similarities and differences among various ethnic groups, will be discussed. The proposed paper is expected to frame underrepresented refugee perspectives, and review policy implications in healthcare, education, and public support systems.

Keywords: refugee, cross-cultural, families, resettlement policy

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5487 Rural Women in Serbia: Key Challenges in Enjoyment of Economic and Social Rights

Authors: Mirjana Dokmanovic

Abstract:

In recent years, the disadvantaged and marginalised position of rural women in the Republic of Serbia has been recognised in a number of national strategies and policy papers. A number of measures have been adopted by the government aimed at economic empowerment of rural women and eliminating barriers to accessing decision making and economic and social opportunities. However, their implementation pace is still slow. The aim of the paper is to indicate the necessity of a comprehensive policy approach to eliminating discrimination against rural women that would include policy and financial commitments for enhancing agricultural and rural development as a whole, instead of taking fragmented measures targeting consequences instead of causes. The paper introduces main findings of the study of challenges, constraints, and opportunities of rural women in Serbia to enjoy their economic and social rights. The research methodology included the desk research and the qualitative analysis of the available data, statistics, policy papers, studies, and reports produced by the government, ministries and other governmental bodies, independent human rights bodies, and civil society organizations (CSOs). The findings of the study reveal that rural women are at great risk of poverty, particularly in remote areas, and when getting old or widowed. Young rural women working in agriculture are also in unfavorable position, as they do not have opportunities to enjoy their rights during pregnancy and maternity leave, childcare leave and leave due to the special care of a child. The study indicates that the main causes of their unfavorable position are related to the prevalent patriarchal surrounding and economic and social underdevelopment of rural areas in Serbia. Gender inequalities have been particularly present in accessing land and property rights, inheritance, education, social protection, healthcare, and decision making. Women living in the rural areas are exposed at high risk of discrimination in all spheres of public and private life that undermine their enjoyment of basic economic, social and cultural rights. The vulnerability of rural women to discrimination increases in cases of the intersectionality of other grounds of discrimination, such as disability, ethnicity, age, health condition and sexual discrimination. If they are victims of domestic violence, their experience lack of access to shelters and protection services. Despite the State’s recognition of the marginalized position of rural women, there is still a lack of a comprehensive policy approach to improving the economic and social position of rural women.

Keywords: agricultural and rural development, care economy, discrimination against women, economic and social rights, feminization of poverty, Republic of Serbia, rural women

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5486 Recovery of Chromium(III) from Tannery Wastewater by Nanoparticles and Whiskers of Chitosan

Authors: El Montassir Dahmane, Nadia Eladlani, Aziz Ouahrouch, Mohammed Rhazi, Moha Taourirte

Abstract:

The present study was aimed to approximate the optimal conditions to chromium recovery from wastewater by nanoparticles and whiskers of chitosan. Chitosan with an average molecular weight of 63 kDa and a 96% deacetylation degree was prepared according to our previous study. Chromium recovery is influenced by different parameters. In our search, we determined the appropriate range of pH to form chitosan–Cr(III), nanoparticles Cr(III), and whiskers– Cr(III) complex. We studied also the influence of chromium concentration and the nature of chitosan-based materials on the complexation process. Our main aim is to approximate the optimal conditions to remove chromium(III) from the tanning bath, recuperated from tannery wastewater of Marrakech in Morocco. A Perkin Elmer optima 2000 Inductively Coupled Plasma- Optical Emission Spectrometer (ICP-OES), was used to determine the quantity of chromium persistent in tannery wastewater after complexation phenomenon. To the best of our knowledge, this is the first report interested in the optimal conditions for chromium recovery from wastewater by nanoparticles and whiskers of chitosan. From our research, we found that in chromium solution, the appropriate range of pH to form complex is between 5.6 and 6.7. Also, the complexation of Cr(III) is depending on the nature of complexing ligand and chromium concentration. The obtained results reveal that nanoparticles present an excellent adsorption capacity regardless of chromium concentration. In addition, after a critical chromium concentration (250 mg/l), our ligand becomes saturated, that requires an increase of ligand mass for increasing chromium concentration in order to have a better adsorption capacity. Hence, in the same conditions, we used chitosan, its nanoparticles, whiskers, and chitosan based films to remove Cr(III) from tannery wastewater. The pH of this effluent was around 6, and its chromium concentration was 300 mg/l. The results expose that the sequence of complexing ligand in the effluent is the same in chromium solution, determined via our previous study. However, the adsorbed quantity is less due to the presence of other metallic ions in tannery wastewater. We conclude that the best complexing ligand-based chitosan is chitosan nanoaprticles whether it’s in chromium solution or in tannery wastewater. Nanoparticles are the best complexing ligand after 24 h of contact nanoparticles can remove 70% of chromium from this tannery wastewater.

Keywords: nanoparticles, whiskers, chitosan, chromium

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5485 Optimal Allocation of Distributed Generation Sources for Loss Reduction and Voltage Profile Improvement by Using Particle Swarm Optimization

Authors: Muhammad Zaheer Babar, Amer Kashif, Muhammad Rizwan Javed

Abstract:

Nowadays distributed generation integration is best way to overcome the increasing load demand. Optimal allocation of distributed generation plays a vital role in reducing system losses and improves voltage profile. In this paper, a Meta heuristic technique is proposed for allocation of DG in order to reduce power losses and improve voltage profile. The proposed technique is based on Multi Objective Particle Swarm optimization. Fewer control parameters are needed in this algorithm. Modification is made in search space of PSO. The effectiveness of proposed technique is tested on IEEE 33 bus test system. Single DG as well as multiple DG scenario is adopted for proposed method. Proposed method is more effective as compared to other Meta heuristic techniques and gives better results regarding system losses and voltage profile.

Keywords: Distributed generation (DG), Multi Objective Particle Swarm Optimization (MOPSO), particle swarm optimization (PSO), IEEE standard Test System

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5484 Modelling and Optimisation of Floating Drum Biogas Reactor

Authors: L. Rakesh, T. Y. Heblekar

Abstract:

This study entails the development and optimization of a mathematical model for a floating drum biogas reactor from first principles using thermal and empirical considerations. The model was derived on the basis of mass conservation, lumped mass heat transfer formulations and empirical biogas formation laws. The treatment leads to a system of coupled nonlinear ordinary differential equations whose solution mapped four-time independent controllable parameters to five output variables which adequately serve to describe the reactor performance. These equations were solved numerically using fourth order Runge-Kutta method for a range of input parameter values. Using the data so obtained an Artificial Neural Network with a single hidden layer was trained using Levenberg-Marquardt Damped Least Squares (DLS) algorithm. This network was then fine-tuned for optimal mapping by varying hidden layer size. This fast forward model was then employed as a health score generator in the Bacterial Foraging Optimization code. The optimal operating state of the simplified Biogas reactor was thus obtained.

Keywords: biogas, floating drum reactor, neural network model, optimization

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5483 Numerical and Comparative Analysis between Two Composite Plates Notched in Different Shapes and Repaired by Composite

Authors: Amari Khaoula, Berrahou Mohamed

Abstract:

The topic of our article revolves around a numerical and comparative analysis between two notched Boron/epoxy plates that are U-shaped and the other V-shaped, cracked, and repaired by a rectangular patch of the same composite material; the finite element method was used for the analytical study and comparison of the results obtained for determining the optimal shape of notch which will give a longer life to the repair. In this context, we studied the variation of the stress intensity factor, the evolution of the damaged area, and the calculation of the ratio of the damaged area according to the crack length and the concentration of the Von Mises stresses as a function of the lengths of the paths. According to the results obtained, we conclude that the notch plate U is the optimal one than notch plate V because it has lower values either for the stress intensity factor (SIF), damaged area ratio (Dᵣ), or the Von Mises stresses.

Keywords: the notch U, the notch V, the finite element method FEM, comparison, rectangular patch, composite, stress intensity factor, damaged area ratio, Von Mises stresses

Procedia PDF Downloads 88
5482 Reflecting Socio-Political Needs in Education Policy-Making: An Exploratory Study of Vietnam's Key Education Reforms (1945-2017)

Authors: Linh Tong

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This paper aims to contribute to the understanding of key education reforms in Vietnam from 1945 to 2017, which reflects an evolution of socio-political needs of the Socialist Republic of Vietnam throughout this period. It explores the contextual conditions, motivations and ambitions influencing the formation of the education reforms in Vietnam. It also looks, from an applied practical perspective, at the influence of politics on education policy-making. The research methodology includes a content analysis of curriculum designs proposed by the Ministry of Education and Training, relevant resolutions and executive orders passed by the National Assembly and the Prime Minister, as well as interviews with experts and key stakeholders. The results point to a particular configuration of factors which have been inspiring the shape and substance of these reforms and which have most certainly influenced their implementation. This configuration evolves from the immediate needs to erase illiteracy and cultivate socialist economic model at the beginning of Vietnam’s independence in 1945-1975, to a renewed urge to adopt market-oriented economy in 1986 and cautiously communicate with the outside world until 2000s, and to currently a demonstrated desire to fully integrate into the global economy and tackle with rising concerns about national security (the South China Sea Dispute), environmental sustainability, construction of a knowledge economy, and a rule-of-law society. Overall, the paper attempts to map Vietnam’s socio-political needs with the changing sets of goals and expected outcomes in teaching and learning methodologies and practices as introduced in Vietnamese key education reforms.

Keywords: curriculum development, knowledge society, national security, politics of education policy-making, Vietnam's education reforms

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5481 Defence Diplomacy and Collective Security in Africa: Case of Rwanda Defence Forces

Authors: Emmanuel Mugiraneza

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Rwanda uses defence diplomacy to pursue international collective security through different mechanisms. This paper shows that with an intent of promoting international collective security, Rwanda has constituted its defense diplomacy policy in three standpoints. First, Rwanda has formed strategic cooperation alliances with state actors, regional and international Organizations that enables her to participate in and promote international collective peace, security and cooperation. Secondary, Rwanda uses defence diplomacy to foster cooperation in to pre-empt, minimize and neutralize potential triggers that would lead to the outbreak of international conflict. Thirdly, Rwanda implements defence diplomacy policy strategy through internationally recognized operational and tactical standards while dispelling hostilities, assisting the friendly nation’s forces and or building and maintaining public confidence and trust in the areas where Rwanda Defence Force deploys for peacekeeping missions in Sudan, South Sudan, Central African Republic and Mozambique for a counterterrorism mission.

Keywords: defence diplomacy, collective security, Rwanda, Peacekeeping

Procedia PDF Downloads 104