Search results for: load characteristics
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 9563

Search results for: load characteristics

8903 Development of Interaction Factors Charts for Piled Raft Foundation

Authors: Abdelazim Makki Ibrahim, Esamaldeen Ali

Abstract:

This study aims at analysing the load settlement behavior and predict the bearing capacity of piled raft foundation a series of finite element models with different foundation configurations and stiffness were established. Numerical modeling is used to study the behavior of the piled raft foundation due to the complexity of piles, raft, and soil interaction and also due to the lack of reliable analytical method that can predict the behavior of the piled raft foundation system. Simple analytical models are developed to predict the average settlement and the load sharing between the piles and the raft in piled raft foundation system. A simple example to demonstrate the applications of these charts is included.

Keywords: finite element, pile-raft foundation, method, PLAXIS software, settlement

Procedia PDF Downloads 551
8902 Socio-Economic Determinants of House Developments in Nigeria

Authors: Odunjo Oluronke Omolola, Okanlawon Simon Ayorinde

Abstract:

This study examines the relationship between house characteristics and socio-economic characteristics of developers in Ibadan, southwest, Nigeria. The research is borne out of the fact that social housing has not done much as a result of finance and housing poverty is on the increase in the country. Multistage random sampling was used in selecting 2,646 respondents in the area. The questionnaire forms the basic instrument for data collection and was administered to heads of households to collect information on socio-economic and demographic characteristics as well as characteristics of development. Both descriptive and inferential statistical analyses were employed in the presentation of the findings; MANOVA was used to analyse the relationship between house characteristics measured by wall materials (Y1-Yn) and socio-economic characteristics of developers measured by gender (X1), religion (X2), educational background (X3) and employment status (X4).The study found out that the bulk of the respondents (65.7%) were male, while 51.7% practiced Christianity. Also, 35.9% had HND/1st/Postgraduate degree, while 43.9% were self employed; Most households however, had membership size of 5 (26.9%). The significant wall material in the area was sandcrete block (71.2%) as opposed to mud (19.1%) and brick (0.6%). Multiple Analysis of Variance shows that there is a significant relationship between sandcrete block and each of gender (X1) and employment status (X3). The factor adduced to this is accessibility to cooperative societies which serve as the gravitational force of attraction for housing finance. The study suggests among others that, there should be re-invigoration of existing cooperative societies, while more should be established for the provision of housing finance.

Keywords: relationship, house development, developers, sandcrete block, cooperative societies

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8901 Analysis of Brushless DC Motor with Trapezoidal Back EMF Using Matlab

Authors: Taha Ahmed Husain

Abstract:

The dynamic characteristics such as speed and torque as well as voltages and currents of pwm brushless DC motor inverter are analyzed with a MATLAB model. The contribution of external load torque and friction torque is monitored. The switching function technique is adopted for the current control of the embedded three phase inverter that drives the brushless DC motor.In switching functions the power conversions circuits can be modeled according to their functions rather than circuit topologies. Therefore, it can achieve simplification of the overall power conversion functions. The trapezoidal type (back emf) is used in the model as ithas lower switching loss compared with sinusoidal type (back emf). Results show reliable time analysis for speed, torque, phase and line voltages and currents and the effect of current commutation is clearly observed.

Keywords: BLDC motor, brushless dc motors, pwm inverter, DC motor control, trapezoidal back emf, ripple torque in brushless DC motor

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8900 Management Practices in Holding Pens in Pig’s Slaughterhouses in the Valle De Aburrá, Antioquia and Animal Welfare

Authors: Natalia Uribe Corrales, Santiago Henao Villegas

Abstract:

Introduction: The management of pigs in the holding pens at the slaughterhouses is a key point to minimize levels of stress and fear, improve efficiency, maintain a good quality of meat and avoid economic losses. Holding pens should guarantee drinking water continuously, a minimum space of 1.2 m2/ animal; As well as an adequate management in the conduction of the animals towards stun. Objective: To characterize the management practices in holding pens in slaughterhouses in the Valle de Aburrá. Methods: A descriptive cross - sectional study was carried out in Valle de Aburrá benefit plants, which were authorized by National Institute for Food and Medicine Surveillance (INVIMA). Variables such as management mechanisms to the pens, time of housing, water supply, load density, vocalization, slips and falls of the animals in the pens and mechanism of conduction towards desensitization were analyzed. Results: 225 pigs were analyzed, finding that 35.6% were lowered with slaps from the trucks to the waiting pens; The lairage time was greater than 10 hours in 16% of the animals; 12.9% of pigs had no water permanently; 40.9% was subjected to a high load density, while 19.6% had a low load density. Regarding aspects of animal welfare, 37.3% presented high vocalizations; 29.3% and 14.2% presented slips or falls respectively. Regarding the mechanism of conduction towards desensitization, slapping was used in 56% and electrical prod in 4%. Conclusions: It is necessary to continue promoting the learning of the densities of load, since both high and low densities generate inconveniences in animal welfare, favoring the appearance of lesions and stress in the animals. Also, to promote the rule of permanent water in the pens and a time of housing less than 10 hours. In relation to the driving mechanisms, it is necessary to continue animal husbandry campaigns, encouraging the use of other alternatives such as boards or panels to assist the movement of pigs.

Keywords: animal welfare, quality of meat, swine, waiting pens

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8899 Rainstorm Characteristics over the Northeastern Region of Thailand: Weather Radar Analysis

Authors: P. Intaracharoen, P. Chantraket, C. Detyothin, S. Kirtsaeng

Abstract:

Radar reflectivity data from Phimai weather radar station of DRRAA (Department of Royal Rainmaking and Agricultural Aviation) were used to analyzed the rainstorm characteristics via Thunderstorm Identification Tracking Analysis and Nowcasting (TITAN) algorithm. The Phimai weather radar station was situated at Nakhon Ratchasima province, northeastern Thailand. The data from 277 days of rainstorm events occurring from May 2016 to May 2017 were used to investigate temporal distribution characteristics of convective individual rainclouds. The important storm properties, structures, and their behaviors were analyzed by 9 variables as storm number, storm duration, storm volume, storm area, storm top, storm base, storm speed, storm orientation, and maximum storm reflectivity. The rainstorm characteristics were also examined by separating the data into two periods as wet and dry season followed by an announcement of TMD (Thai Meteorological Department), under the influence of southwest monsoon (SWM) and northeast monsoon (NEM). According to the characteristics of rainstorm results, it can be seen that rainstorms during the SWM influence were found to be the most potential rainstorms over northeastern region of Thailand. The SWM rainstorms are larger number of the storm (404, 140 no./day), storm area (34.09, 26.79 km²) and storm volume (95.43, 66.97 km³) than NEM rainstorms, respectively. For the storm duration, the average individual storm duration during the SWM and NEM was found a minor difference in both periods (47.6, 48.38 min) and almost all storm duration in both periods were less than 3 hours. The storm velocity was not exceeding 15 km/hr (13.34 km/hr for SWM and 10.67 km/hr for NEM). For the rainstorm reflectivity, it was found a little difference between wet and dry season (43.08 dBz for SWM and 43.72 dBz for NEM). It assumed that rainstorms occurred in both seasons have same raindrop size.

Keywords: rainstorm characteristics, weather radar, TITAN, Northeastern Thailand

Procedia PDF Downloads 182
8898 The Capacity of Bolted and Screw Connections in Cold-Formed Steel Truss Structure through Analytical and Experimental Method

Authors: Slamet Setioboro, Rahutami Kusumaningsih, Prabowo Setiyawan, Danna Darmayadi

Abstract:

Designing of cold-formed steel capacity connections often based on the formula used for hot rolled steel. It makes the result of the actual capacity connection doesn’t accurate anymore. When the hot rolled steel receives the axial load pull, it will have different characteristics. As the result, there will be failure result when designing Truss structure made of hot rolled steel. This research aims to determine the capacity of actual cold-formed steel connections section which is loaded by the axial tensile force. It will test the appeal of the connection using bolt grafting tool and screw grafting tool. The variations of the test will be on the type of connection (single and double slap), the number of the connection tools and connection configuration. Bold and screw connections failure mode observed in this research are different each other. Failure mode of bolted connections includes sliding pivot plate, tearing at the plate and cutting of the bolt head. While the failure mode of screw connections includes tilting, hole-bearing, pull over and cutting the screw body out. This research was conducted using a laboratory test of HW2-600S Universal Testing Machine model with ASTM E8. It has done in the materials testing laboratory of Mechanical Engineering Department, Faculty of Engineering UNNES. The results obtained through the laboratory diversification towards theoretical calculations using the standards specified in ISO 7971-2013 Cold-Rolled Steel Structures. Based on the research, it can be concluded that the effective connection in receiving force strength is bolted connections neither single nor double plate. The method used is by applying 4 bolts through 2 parallel lines configuration. Furthermore, this connection deals with the consequences of holding the highest Pmaks, lowest failure risk and getting a little kind of mode of failure.

Keywords: axial load, cold-formed steel, capacity connections, bolted connections, screw connections

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8897 Economic Decision Making under Cognitive Load: The Role of Numeracy and Financial Literacy

Authors: Vânia Costa, Nuno De Sá Teixeira, Ana C. Santos, Eduardo Santos

Abstract:

Financial literacy and numeracy have been regarded as paramount for rational household decision making in the increasing complexity of financial markets. However, financial decisions are often made under sub-optimal circumstances, including cognitive overload. The present study aims to clarify how financial literacy and numeracy, taken as relevant expert knowledge for financial decision-making, modulate possible effects of cognitive load. Participants were required to perform a choice between a sure loss or a gambling pertaining a financial investment, either with or without a competing memory task. Two experiments were conducted varying only the content of the competing task. In the first, the financial choice task was made while maintaining on working memory a list of five random letters. In the second, cognitive load was based upon the retention of six random digits. In both experiments, one of the items in the list had to be recalled given its serial position. Outcomes of the first experiment revealed no significant main effect or interactions involving cognitive load manipulation and numeracy and financial literacy skills, strongly suggesting that retaining a list of random letters did not interfere with the cognitive abilities required for financial decision making. Conversely, and in the second experiment, a significant interaction between the competing mnesic task and level of financial literacy (but not numeracy) was found for the frequency of choice of a gambling option. Overall, and in the control condition, both participants with high financial literacy and high numeracy were more prone to choose the gambling option. However, and when under cognitive load, participants with high financial literacy were as likely as their illiterate counterparts to choose the gambling option. This outcome is interpreted as evidence that financial literacy prevents intuitive risk-aversion reasoning only under highly favourable conditions, as is the case when no other task is competing for cognitive resources. In contrast, participants with higher levels of numeracy were consistently more prone to choose the gambling option in both experimental conditions. These results are discussed in the light of the opposition between classical dual-process theories and fuzzy-trace theories for intuitive decision making, suggesting that while some instances of expertise (as numeracy) are prone to support easily accessible gist representations, other expert skills (as financial literacy) depend upon deliberative processes. It is furthermore suggested that this dissociation between types of expert knowledge might depend on the degree to which they are generalizable across disparate settings. Finally, applied implications of the present study are discussed with a focus on how it informs financial regulators and the importance and limits of promoting financial literacy and general numeracy.

Keywords: decision making, cognitive load, financial literacy, numeracy

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8896 Air Cargo Network Structure Characteristics and Robustness Analysis under the Belt and Road Area

Authors: Feng-jie Xie, Jian-hong Yan

Abstract:

Based on the complex network theory, we construct the air cargo network of the Belt and Road area, analyze its regional distribution and structural characteristics, measure the robustness of the network. The regional distribution results show that Southeast Asia and China have the most prominent development in the air cargo network of the Belt and Road area, Central Asia is the least developed. The structure characteristics found that the air cargo network has obvious small-world characteristics; the degree distribution has single-scale property; it shows a significant rich-club phenomenon simultaneously. The network robustness is measured by two attack strategies of degree and betweenness, but the betweenness of network nodes has a greater impact on network connectivity. And identified 24 key cities that have a large impact on the robustness of the network under the two attack strategies. Based on these results, recommendations are given to maintain the air cargo network connectivity in the Belt and Road area.

Keywords: air cargo, complex network, robustness, structure properties, The Belt and Road

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8895 Electrical Characteristics of SiON/GaAs MOS Capacitor with Various Passivations

Authors: Ming-Kwei Lee, Chih-Feng Yen

Abstract:

The electrical characteristics of liquid phase deposited silicon oxynitride film on ammonium sulfide treated p-type (100) gallium arsenide substrate were investigated. Hydrofluosilicic acid, ammonia and boric acid aqueous solutions were used as precursors. The electrical characteristics of silicon oxynitride film are much improved on gallium arsenide substrate with ammonium sulfide treatment. With post-metallization annealing, hydrogen ions can further passivate defects in SiON/GaAs film and interface. The leakage currents can reach 7.1 × 10-8 and 1.8 × 10-7 at ± 2 V. The dielectric constant and effective oxide charges are 5.6 and -5.3 × 1010 C/cm2, respectively. The hysteresis offset of hysteresis loop is merely 0.09 V.

Keywords: liquid phase deposition, SiON, GaAs, PMA, (NH4)2S

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8894 Quantification of Dowel-Concrete Interaction in Jointed Plain Concrete Pavements Using 3D Numerical Simulation

Authors: Lakshmana Ravi Raj Gali, K. Sridhar Reddy, M. Amaranatha Reddy

Abstract:

Load transfer between adjacent slabs of the jointed plain concrete pavement (JPCP) system is inevitable for long-lasting performance. Dowel bars are generally used to ensure sufficient degree of load transfer, in addition to the load transferred by aggregate interlock mechanism at the joints. Joint efficiency is the measure of joint quality, a major concern and therefore the dowel bar system should be designed and constructed well. The interaction between dowel bars and concrete that includes various parameters of dowel bar and concrete will explain the degree of joint efficiency. The present study focuses on the methodology of selecting contact stiffness, which quantifies dowel-concrete interaction. In addition, a parametric study which focuses on the effect of dowel diameter, dowel shape, the spacing between dowel bars, joint opening, the thickness of the slab, the elastic modulus of concrete, and concrete cover on contact stiffness was also performed. The results indicated that the thickness of the slab is most critical among various parameters to explain the joint efficiency. Further displacement equivalency method was proposed to find out the contact stiffness. The proposed methodology was validated with the available field surface deflection data collected by falling weight deflectometer (FWD).

Keywords: contact stiffness, displacement equivalency method, Dowel-concrete interaction, joint behavior, 3D numerical simulation

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8893 Determination of Suitability Between Single Phase Induction Motor and Load

Authors: Nakarin Prempri

Abstract:

Single-phase induction motors are widely used in industry. Most manufacturing processes use capacitor-run single-phase induction motors to drive mechanical loads. The selection of a suitable motor for driving is important. The optimum operating range of the motor can help the motor operate efficiently. Thus, this paper presents an operating range analysis of capacitor-run single-phase induction motors and a determination of suitability between motor and mechanical loads. an observational study found that the optimum operating range of the motor can be used to determine the suitability between the motor and the mechanical load. Such considerations ensure that the motor uses no more current than necessary and operates efficiently.

Keywords: single phase induction motor, operating range, torque curve, efficiency curve

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8892 An Inverse Approach for Determining Creep Properties from a Miniature Thin Plate Specimen under Bending

Authors: Yang Zheng, Wei Sun

Abstract:

This paper describes a new approach which can be used to interpret the experimental creep deformation data obtained from miniaturized thin plate bending specimen test to the corresponding uniaxial data based on an inversed application of the reference stress method. The geometry of the thin plate is fully defined by the span of the support, l, the width, b, and the thickness, d. Firstly, analytical solutions for the steady-state, load-line creep deformation rate of the thin plates for a Norton’s power law under plane stress (b → 0) and plane strain (b → ∞) conditions were obtained, from which it can be seen that the load-line deformation rate of the thin plate under plane-stress conditions is much higher than that under the plane-strain conditions. Since analytical solution is not available for the plates with random b-values, finite element (FE) analyses are used to obtain the solutions. Based on the FE results obtained for various b/l ratios and creep exponent, n, as well as the analytical solutions under plane stress and plane strain conditions, an approximate, numerical solutions for the deformation rate are obtained by curve fitting. Using these solutions, a reference stress method is utilised to establish the conversion relationships between the applied load and the equivalent uniaxial stress and between the creep deformations of thin plate and the equivalent uniaxial creep strains. Finally, the accuracy of the empirical solution was assessed by using a set of “theoretical” experimental data.

Keywords: bending, creep, thin plate, materials engineering

Procedia PDF Downloads 465
8891 The Effects of Urban Public Spaces on Place Attachment in Large Cities: Examining Spatial Perception in Shenzhen’s Shekou Community as a Case Study

Authors: Xiaoxue Jin, Qiong Zhang

Abstract:

The rapid influx and ongoing flow of young migrants in large cities, alongside the emergence and evolution of new social media, have led to increased interpersonal alienation and weakened place attachment. In the interplay between individuals and space, urban public spaces play a pivotal role in meeting the multifaceted needs of individuals and fostering a sense of attachment. This article aims to investigate the relationship between the place characteristics of public spaces and individuals' needs and perceptions, with an aim to identify the factors influencing place attachment among the youth. This study is conducted in the Shekou community of Shenzhen, focusing on the youth residents to evaluate their place attachment levels and to analyze their perceptions of the place characteristics of selected public spaces. The influencing factors of public spaces on place attachment were sorted out through detailed data analysis. Research has found that rapid urbanization has led to spatial homogenization and spatial segregation caused by uneven resource distribution, which in turn diminishes the utilization of public spaces. The social characteristics of public spaces, such as the quality of social activities and spatial openness, are critical in forming place attachment. In this research, place characteristics impacting place attachment are categorized, aiming to reconstruct the characteristics of public space places and use them as a medium to explore the place attachment of young people, promote their independent creation and participation in public life, and enhance the dynamism between individuals and spaces.

Keywords: place attachment, place characteristics, public spaces, spatial perception

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8890 The Implementation of a Numerical Technique to Thermal Design of Fluidized Bed Cooler

Authors: Damiaa Saad Khudor

Abstract:

The paper describes an investigation for the thermal design of a fluidized bed cooler and prediction of heat transfer rate among the media categories. It is devoted to the thermal design of such equipment and their application in the industrial fields. It outlines the strategy for the fluidization heat transfer mode and its implementation in industry. The thermal design for fluidized bed cooler is used to furnish a complete design for a fluidized bed cooler of Sodium Bicarbonate. The total thermal load distribution between the air-solid and water-solid along the cooler is calculated according to the thermal equilibrium. The step by step technique was used to accomplish the thermal design of the fluidized bed cooler. It predicts the load, air, solid and water temperature along the trough. The thermal design for fluidized bed cooler revealed to the installation of a heat exchanger consists of (65) horizontal tubes with (33.4) mm diameter and (4) m length inside the bed trough.

Keywords: fluidization, powder technology, thermal design, heat exchangers

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8889 Dynamic Test and Numerical Analysis of Twin Tunnel

Authors: Changwon Kwak, Innjoon Park, Dongin Jang

Abstract:

Seismic load affects the behavior of underground structure like tunnel broadly. Seismic soil-structure interaction can play an important role in the dynamic behavior of tunnel. In this research, twin tunnel with flexible joint was physically modeled and the dynamic centrifuge test was performed to investigate seismic behavior of twin tunnel. Seismic waves have different frequency were exerted and the characteristics of response were obtained from the test. Test results demonstrated the amplification of peak acceleration in the longitudinal direction in seismic waves. The effect of the flexible joint was also verified. Additionally, 3-dimensional finite difference dynamic analysis was conducted and the analysis results exhibited good agreement with the test results.

Keywords: 3-dimensional finite difference dynamic analysis, dynamic centrifuge test, flexible joint, seismic soil-structure interaction

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8888 Behavior of Composite Construction Precast Reactive Powder RC Girder and Ordinary RC Deck Slab

Authors: Nameer A. Alwash, Dunia A. Abd AlRadha, Arshed M. Aljanaby

Abstract:

This study present an experimental investigation of composite behavior for hybrid reinforced concrete slab on girder from locale material in Iraq, ordinary concrete, NC, in slab and reactive powder concrete in girder ,RPC, with steel fibers of different types(straight, hook, and mix between its), tested as simply supported span subjected under two point loading, also study effects on overall behavior such as the ultimate load, crack width and deflection. The result shows that the most suitable for production girder from RPC by using 2% micro straight steel fiber, in terms of ultimate strength and min crack width. Also the results shows that using RPC in girder of composite section increased ultimate load by 79% when compared with same section made of NC, and increased the shear strength which erased the effect of changing reinforcement in shear, and using RPC in girder and epoxy (in shear transfer between composite section) (meaning no stirrups) equivalent presence of shear reinforcement by 90% when compared with same section using Φ8@100 as shear reinforcement. And the result shows that changing the cross section girder shape of the composite section to inverted T, with same section area, increased the ultimate load by 5% when compared with same section of rectangular shape girder.

Keywords: reactive powder concrete, RPC, hybrid concrete, composite section, RC girder, RC slab, shear connecters, inverted T section, shear reinforcment, shear span over effective depth

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8887 The Effect of Grading Characteristics on the Shear Strength and Mechanical Behavior of Granular Classes of Sand-Silt

Authors: Youssouf Benmeriem

Abstract:

Shear strength of sandy soils has been considered as the important parameter to study the stability of different civil engineering structures when subjected to monotonic, cyclic and earthquake loading conditions. The proposed research investigated the effect of grading characteristics on the shear strength and mechanical behavior of granular classes of sands mixed with silt in loose and dense states (Dr = 15% and 90%). The laboratory investigation aimed at understanding the extent or degree at which shear strength of sand-silt mixture soil is affected by its gradation under static loading conditions. For the purpose of clarifying and evaluating the shear strength characteristics of sandy soils, a series of Casagrande shear box tests were carried out on different reconstituted samples of sand-silt mixtures with various gradations. The soil samples were tested under different normal stresses (100, 200 and 300 kPa). The results from this laboratory investigation were used to develop insight into the shear strength response of sand and sand-silt mixtures under monotonic loading conditions. The analysis of the obtained data revealed that the grading characteristics (D10, D50, Cu, ESR, and MGSR) have significant influence on the shear strength response. It was found that shear strength can be correlated to the grading characteristics for the sand-silt mixture. The effective size ratio (ESR) and mean grain size ratio (MGSR) appear as pertinent parameters to predict the shear strength response of the sand-silt mixtures for soil gradation under study.

Keywords: grading characteristics, granular classes of sands, mechanical behavior, sand-silt, shear strength

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8886 IACOP - Route Optimization in Wireless Networks Using Improved Ant Colony Optimization Protocol

Authors: S. Vasundra, D. Venkatesh

Abstract:

Wireless networks have gone through an extraordinary growth in the past few years, and will keep on playing a crucial role in future data communication. The present wireless networks aim to make communication possible anywhere and anytime. With the converging of mobile and wireless communications with Internet services, the boundary between mobile personal telecommunications and wireless computer networks is disappearing. Wireless networks of the next generation need the support of all the advances on new architectures, standards, and protocols. Since an ad hoc network may consist of a large number of mobile hosts, this imposes a significant challenge on the design of an effective and efficient routing protocol that can work well in an environment with frequent topological changes. This paper proposes improved ant colony optimization (IACO) technique. It also maintains load balancing in wireless networks. The simulation results show that the proposed IACO performs better than existing routing techniques.

Keywords: wireless networks, ant colony optimization, load balancing, architecture

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8885 A Study on Characteristics of Entrepreneur Spirit-Focus on Ventures

Authors: Do Jaesoo, Kim Kyoung Seok

Abstract:

Under the recent difficult economic conditions, a number of people are increasingly expecting fostering ventures as the breakthrough in economic recovery and thus more attention is socially paid to an entrepreneur spirit. However, even though the role of managers is very important for the success of a venture company, programs to cultivate their qualities and skills are quite insufficient. In recent years, programs to foster entrepreneurs and business men have proliferated, which are led mainly by national agencies, research institutions, and large corporations. However, these programs still remain at a tottering stage, since there is no accumulated knowledge in many aspects, including systemic know-how and education. Therefore, this study attempted to introduce the definition of the entrepreneur (founder’s) spirit and furthermore identify the characteristics required for entrepreneurs as the subject of management. It thus tried to examine how those characteristics have an influence on entrepreneurs as their successful conditions, and presented foreign cases after analyzing the entrepreneur spirit through case studies. The entrepreneur spirit and the venture management emerge as a new field in business administration and scholars have reported various theories. Further research activities and efforts for active exchanges are also needed thereof.

Keywords: venture, entrepreneur, entrepreneur (founder’s) spirit, characteristics of entrepreneur spirit

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8884 Fuzzy Logic Driven PID Controller for PWM Based Buck Converter

Authors: Bandreddy Anand Babu, Mandadi Srinivasa Rao, Chintala Pradeep Reddy

Abstract:

The main theme of this paper is to design fuzzy logic Proportional Integral Derivative controller for controlling of Pulse Width Modulator (PWM) based DCDC buck converter in continuous conduction mode of operation and comparing the results of FPID and ANFIS. Simulation is done to fuzzy the given input variables and membership functions of input values, creating the interference rules linking the input and output variables and after then defuzzfies the output variables. Fuzzy logic is simple for nonlinear models like buck converter. Fuzzy logic based PID controller technique is to control, nonlinear plants like buck converters in switching variables of power electronics. The characteristics of FPID are in terms of rise time, settling time, rise time, steady state errors for different inputs and load disturbances.

Keywords: fuzzy logic, PID controller, DC-DC buck converter, pulse width modulation

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8883 Hybrid Approach for Controlling Inductive Load Fed by a Multicellular Converter by Using the Petri Nets

Authors: I. Bentchikou, A. Tlemcani, F. Boudjema, D. Boukhetala, N. Ould Cherchali

Abstract:

In this paper, hybrid approach is proposed to regulate the voltages of the floating capacitor multicell inverter and the current in the load. This structure makes it possible to ensure the distribution of the voltage stresses on the various low-voltage semiconductor components connected in series. And as the problem and to keep a constant voltage across the capacitors. Thus, it is necessary to ensure a distribution balanced voltages at the terminals of floating capacitors thanks to Algorithm develop for this, using the Petri nets. So we consider a three-cell converter represented as a hybrid system with eight modes of operation. The operating modes of the system are governed by the control reference voltage and a reference current. Finally, we present the results of the simulation with MATLAB/SIMULINK to illustrate the performances of this approach.

Keywords: hybrid control, floating condensers, multicellular converter, petri nets

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8882 Preliminary Analysis for Oil and Gas Geological Characteristics and Exploration Prospects of Doseo Basin in Central Africa

Authors: Haiqiang Song, Huiqing Liu

Abstract:

The Doseo basin in Chad, Central Africa is one of the most important oil and gas blocks in the world. However, the low degree of oil and gas exploration and the lack of relevant geological data restrict the understanding and resource evaluation of the basin. To further develop the Doseo basin efficiently, it is urgent to deeply analyze the source rock characteristics and hydrocarbon generation potential of the Doseo basin. Based on seismic and drilling data in recent years, this paper systematically evaluates the geochemical characteristics of source rocks and their generated oils in Doseo Basin, explores the development, distribution, and evolution characteristics of source rocks, and evaluates the exploration potential of Doseo Basin according to the hydrocarbon enrichment law. The results show that the Lower Cretaceous Baliemian and Apudian source rocks in Doseo Basin are well developed, with high organic matter abundance (average TOC≥3%) and good organic matter types (type I~II), which are the main development layers of source rocks, but the organic matter maturity is generally low (Ro of the drilled source rocks is mainly between 0.4%~0.8%). The planar structure also shows that the main hydrocarbon accumulation mode in Doseo sag is the forward tectonic reservoirs such as near source anticlines and faulted noses. Finally, it is estimated that the accumulative resources of the main source rocks in the Doseo Basin are about 4.33× 108T in Apudite and Balim terrace layers. The results of this study will help guide the next step of oil and gas exploration, which is expected to drive the next step of oil and gas development.

Keywords: Doseo basin, lower cretaceous, source rock characteristics, developmental characteristics, hydrocarbon generation potential

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8881 Reliability Based Optimal Design of Laterally Loaded Pile with Limited Residual Strain Energy Capacity

Authors: M. Movahedi Rad

Abstract:

In this study, a general approach to the reliability based limit analysis of laterally loaded piles is presented. In engineering practice, the uncertainties play a very important role. The aim of this study is to evaluate the lateral load capacity of free head and fixed-head long pile when the plastic limit analysis is considered. In addition to the plastic limit analysis to control the plastic behaviour of the structure, uncertain bound on the complementary strain energy of the residual forces is also applied. This bound has a significant effect for the load parameter. The solution to reliability-based problems is obtained by a computer program which is governed by the reliability index calculation.

Keywords: reliability, laterally loaded pile, residual strain energy, probability, limit analysis

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8880 COVID-19, Employee Perspectives, and the Shifting Nature of Work

Authors: Jonathan H. Westover, Maureen S. Andrade, Angela Schill, Jeff Peterson, Samuel Choi

Abstract:

The purpose of this research is to understand employee perspectives on their work characteristics and conditions, particularly related to the COVID-19 pandemic and the future of work. Working conditions impact job satisfaction. People tend to measure job satisfaction by comparing aspects of the job they have with those they want. Job satisfaction is related to the value that one places on specific aspects of a job, such as autonomy, pay and benefits, challenge, growth, or meaningful work, and the degree to which such elements are present. The value one places on these various job characteristics may differ based on gender, age, personality, occupation, context, or other factors. This study will examine various job characteristics and working conditions with an emphasis on COVID-19 to determine how managers and leaders and better support and develop their employees.

Keywords: COVID-19, employee perspectives nature of work, future of work

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8879 Control Algorithm Design of Single-Phase Inverter For ZnO Breakdown Characteristics Tests

Authors: Kashif Habib, Zeeshan Ayyub

Abstract:

ZnO voltage dependent resistor was widely used as components of the electrical system for over-voltage protection. It has a wide application prospect in superconducting energy-removal, generator de-excitation, overvoltage protection of electrical & electronics equipment. At present, the research for the application of ZnO voltage dependent resistor stop, it uses just in the field of its nonlinear voltage current characteristic and overvoltage protection areas. There is no further study over the over-voltage breakdown characteristics, such as the combustion phenomena and the measure of the voltage/current when it breakdown, and the affect to its surrounding equipment. It is also a blind spot in its application. So, when we do the feature test of ZnO voltage dependent resistor, we need to design a reasonable test power supply, making the terminal voltage keep for sine wave, simulating the real use of PF voltage in power supply conditions. We put forward the solutions of using inverter to generate a controllable power. The paper mainly focuses on the breakdown characteristic test power supply of nonlinear ZnO voltage dependent resistor. According to the current mature switching power supply technology, we proposed power control system using the inverter as the core. The power mainly realize the sin-voltage output on the condition of three-phase PF-AC input, and 3 control modes (RMS, Peak, Average) of the current output. We choose TMS320F2812M as the control part of the hardware platform. It is used to convert the power from three-phase to a controlled single-phase sin-voltage through a rectifier, filter, and inverter. Design controller produce SPWM, to get the controlled voltage source via appropriate multi-loop control strategy, while execute data acquisition and display, system protection, start logic control, etc. The TMS320F2812M is able to complete the multi-loop control quickly and can be a good completion of the inverter output control.

Keywords: ZnO, multi-loop control, SPWM, non-linear load

Procedia PDF Downloads 315
8878 Effects of Ground Motion Characteristics on Damage of RC Buildings: A Detailed Investiagation

Authors: Mohamed Elassaly

Abstract:

The damage status of RC buildings is greatly influenced by the characteristics of the imposed ground motion. Peak Ground Acceleration and frequency contents are considered the main two factors that affect ground motion characteristics; hence, affecting the seismic response of RC structures and consequently their damage state. A detailed investigation on the combined effects of these two factors on damage assessment of RC buildings, is carried out. Twenty one earthquake records are analyzed and arranged into three groups, according to their frequency contents. These records are used in an investigation to define the expected damage state that would be attained by RC buildings, if subjected to varying ground motion characteristics. The damage assessment is conducted through examining drift ratios and damage indices of the overall structure and the significant structural components of RC building. Base and story shear of RC building model, are also investigated, for cases when the model is subjected to the chosen twenty one earthquake records. Nonlinear dynamic analyses are performed on a 2-dimensional model of a 12-story R.C. building.

Keywords: damage, frequency content, ground motion, PGA, RC building, seismic

Procedia PDF Downloads 398
8877 Reproductive Behavior of Caspian Red Deer (Cervus Elaphus Maral) in Wildlife Refuge of Semeskande, Sari

Authors: Behrang Ekrami, Amin Tamadon

Abstract:

Caspian red deer or maral (Cervus elaphus maral) is a ruminant from the family of Cervidae. Maintenance and protection of maral requires knowing the behavioral, physiological, environmental characteristics and factors harmful to this species. In this article, reproductive and behavioral traits of this species in both sexes are presented based on observations and the available records of protected deer in Wildlife Refuge of Semeskande, Sari (one of the sites that preserve the maral in the Free Zones of Hyrcanian forest) from 2006 to 2011. Hart characteristics including sexual behavior, apparent changes during reproductive season and reproductive physiology; and hind characteristics including of ovulation, reproductive cycle, mating, pregnancy and parturition, have been evaluated. Identification of maral reproductive characteristics in Wildlife Refuge of Semeskande, Sari is one of the most important information requirements to preserve and breed this species and will open up new routes for performing new methods of reproduction of this species in Iran wildlife parks or other refuge areas.

Keywords: caspian red deer, reproduction, behavior, Iran

Procedia PDF Downloads 469
8876 DSF Elements in High-Rise Timber Buildings

Authors: Miroslav Premrov, Andrej Štrukelj, Erika Kozem Šilih

Abstract:

The utilization of prefabricated timber-wall elements with double glazing, called as double-skin façade element (DSF), represents an innovative structural approach in the context of new high-rise timber construction, simultaneously combining sustainable solutions with improved energy efficiency and living quality. In addition to the minimum energy needs of buildings, the design of modern buildings is also increasingly focused on the optimal indoor comfort, in particular on sufficient natural light indoors. An optimally energy-designed building with an optimal layout of glazed areas around the building envelope represents a great potential in modern timber construction. Usually, all these transparent façade elements, because of energy benefits, are primary asymmetrical oriented and if they are considered as non-resisting against a horizontal load impact, a strong torsion effects in the building can appear. The problem of structural stability against a strong horizontal load impact of such modern timber buildings especially increase in a case of high-rise structures where additional bracing elements have to be used. In such a case, special diagonal bracing systems or other bracing solutions with common timber wall elements have to be incorporated into the structure of the building to satisfy all prescribed resisting requirements given by the standards. However, all such structural solutions are usually not environmentally friendly and also not contribute to an improved living comfort, or they are not accepted by the architects at all. Consequently, it is a special need to develop innovative load-bearing timber-glass wall elements which are in the same time environmentally friendly, can increase internal comfort in the building, but are also load-bearing. The new developed load-bearing DSF elements can be a good answer on all these requirements. Timber-glass façade elements DSF wall elements consist of two transparent layers, thermal-insulated three-layered glass pane on the internal side and an additional single-layered glass pane on the external side of the wall. The both panes are separated by an air channel which can be of any dimensions and can have a significant influence on the thermal insulation or acoustic response of such a wall element. Most already published studies on DSF elements primarily deal only with energy and LCA solutions and do not address any structural problems. In previous studies according to experimental analysis and mathematical modeling it was already presented a possible benefit of such load-bearing DSF elements, especially comparing with previously developed load-bearing single-skin timber wall elements, but they were not applicate yet in any high-rise timber structure. Therefore, in the presented study specially selected 10-storey prefabricated timber building constructed in a cross-laminated timber (CLT) structural wall system is analyzed using the developed DSF elements in a sense to increase a structural lateral stability of the whole building. The results evidently highlight the importance the load-bearing DSF elements, as their incorporation can have a significant impact on the overall behavior of the structure through their influence on the stiffness properties. Taking these considerations into account is crucial to ensure compliance with seismic design codes and to improve the structural resilience of high-rise timber buildings.

Keywords: glass, high-rise buildings, numerical analysis, timber

Procedia PDF Downloads 34
8875 Analysis of Stacked SCR-Based ESD Protection Circuit with Low Trigger Voltage and Latch-Up Immunity

Authors: Jun-Geol Park, Kyoung-Il Do, Min-Ju Kwon, Kyung-Hyun Park, Yong-Seo Koo

Abstract:

In this paper, we proposed the SCR (Silicon Controlled Rectifier)-based ESD (Electrostatic Discharge) protection circuit for latch-up immunity. The proposed circuit has a lower trigger voltage and a higher holding voltage characteristic by using the zener diode structure. These characteristics prevent latch-up problem in normal operating conditions. The proposed circuit was analyzed to figure out the electrical characteristics by the variations of design parameters D1, D2 and stack technology to obtain the n-fold electrical characteristics. The simulations are accomplished by using the Synopsys TCAD simulator. When using the stack technology, 2-stack has the holding voltage of 6.9V and 3-stack has the holding voltage of 10.9V.

Keywords: ESD, SCR, trigger voltage, holding voltage

Procedia PDF Downloads 517
8874 A Case Study of Building Behavior Damaged during 26th Oct, 2015 Earthquake in Northern Areas of Pakistan

Authors: Rahmat Ali, Amjad Naseer, Abid A. Shah

Abstract:

This paper is an attempt to presents the performance of building observed during 26th Oct, 2015 earthquake in District Swat and Shangla region. Most of the buildings in the earthquake hit areas were built with Rubble stone masonry, dress Stone Masonry, brick masonry with and without RC column, Brick masonry with RC beams and column, Block Masonry with and without RC column. It was found that most of the buildings were built without proper supervision and without following any codes. A majority of load bearing masonry walls were highly affected during the earthquake. The load bearing walls built with rubble stone masonry were collapsed resulting huge damages and loss of property and life. Load bearing bricks masonry walls were also affected in most of the region. In some residential buildings the bricks were crushed in a single brick walls. Severe cracks were also found in double brick masonry walls. In RC frame structure beams and columns were also seriously affected. A majority of building structures were non-engineered. Some buildings designed by unskilled local consultants were also affected during the earthquake. Several architectural and structural mistakes were also found in various buildings designed by local consultant. It was found that the structures were collapsed prematurely either because of unskillful labor and using substandard materials or avoiding delicate repair, maintenance, and health monitoring activities because of lack of available sophisticated technology in our country.

Keywords: cracks, collapse, earthquake, masonry, repair

Procedia PDF Downloads 486