Search results for: natural boundary condition
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 10150

Search results for: natural boundary condition

5110 Accurate Algorithm for Selecting Ground Motions Satisfying Code Criteria

Authors: S. J. Ha, S. J. Baik, T. O. Kim, S. W. Han

Abstract:

For computing the seismic responses of structures, current seismic design provisions permit response history analyses (RHA) that can be used without limitations in height, seismic design category, and building irregularity. In order to obtain accurate seismic responses using RHA, it is important to use adequate input ground motions. Current seismic design provisions provide criteria for selecting ground motions. In this study, the accurate and computationally efficient algorithm is proposed for accurately selecting ground motions that satisfy the requirements specified in current seismic design provisions. The accuracy of the proposed algorithm is verified using single-degree-of-freedom systems with various natural periods and yield strengths. This study shows that the mean seismic responses obtained from RHA with seven and ten ground motions selected using the proposed algorithm produce errors within 20% and 13%, respectively.

Keywords: algorithm, ground motion, response history analysis, selection

Procedia PDF Downloads 277
5109 Fear of Covid-19 a Major Contributing Factor to Insomnia in General Iranian Population

Authors: Amin Nakhostin-Ansari, Samaneh Akbarour, Khosro Sadeghniiat Haghighi, Zahra Banafsheh Alemohammad, Farnaz Etesam, Arezu Najafi, Mahnaz Khalafehnilsaz

Abstract:

Introduction: The outbreak of coronavirus disease has considerably burdened the healthcare system in Iran. This study aimed to evaluate the characteristics of insomnia experienced by the general Iranian population during the COVID-19 pandemic. Method: A scale(FCV-19) was used for Fear of COVID-19, Insomnia Severity Index (ISI), Patient Health Questionnaire-2 (PHQ-2), and Generalized Anxiety Disorder Scale-2 (GAD-2) for detailed characterization of insomnia and its patterns Results: In total, 675 people with insomnia with the mean age of 40.28 years (SD=11.15) participated in this study. Prevalence of difficulty initiating sleep (DIS), difficulty maintaining sleep (DMS), and early morning awakening (EMA) were 91.4%, 86.7%, and 77%, respectively. DIS, DMS, and EMA were more common in people with depression and anxiety. FCV-19 score was higher in those with more severe types of DIS, DMS, and EMA (P<0.001). FCV-19 was a risk factor for all patterns of insomnia (OR=1.19, 1.12, 1.02 for DIS, DMS, and EMA, respectively). Conclusion: fear of COVID-19 is a major factor to insomnia patterns. Investigation of COVID-19 fear in people with insomnia and the addition of attributed relieving or management strategies to conventional management of insomnia are reasonable approaches to improve the sleep condition of people in the pandemic.

Keywords: insomnia, difficulty maintaining sleep, COVID-19, Coronavirus

Procedia PDF Downloads 153
5108 Influence of Roofing Material on Indoor Thermal Comfort of Bamboo House

Authors: Thet Su Hlaing, Shoichi Kojima

Abstract:

The growing desire for better indoor thermal performance with moderate energy consumption is becoming an issue for challenging today’s built environment. Studies related to the effective way of enhancing indoor thermal comfort had been done by approaching in numerous ways. Few studies have been focused on the correlation between building material and indoor thermal comfort of vernacular house. This paper analyzes the thermal comfort conditions of Bamboo House, mostly located in a hot and humid region. Depending on the roofing material, how the indoor environment varies will be observed through monitoring indoor and outdoor comfort measurement of Bamboo house as well as occupants’ preferable comfort condition. The result revealed that the indigenous roofing material mostly influences the indoor thermal environment by performing to have less effect from the outdoor temperature. It can keep the room cool with moderate thermal comfort, especially in the early morning and night, in the summertime without mechanical device assistance. After analyzing the performance of roofing material, which effect on indoor thermal comfort for 24 hours, it can be efficiently managed the time for availing mechanical cooling devices and make it supply only the necessary period of a day, which will lead to a partially reduce energy consumption.

Keywords: bamboo house, hot and humid climate, indoor thermal comfort, local indigenous roofing material

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5107 Shear Buckling of a Large Pultruded Composite I-Section under Asymmetric Loading

Authors: Jin Y. Park, Jeong Wan Lee

Abstract:

An experimental and analytical research on shear buckling of a comparably large polymer composite I-section is presented. It is known that shear buckling load of a large span composite beam is difficult to determine experimentally. In order to sensitively detect shear buckling of the tested I-section, twenty strain rosettes and eight displacement sensors were applied and attached on the web and flange surfaces. The tested specimen was a pultruded composite beam made of vinylester resin, E-glass, carbon fibers and micro-fillers. Various coupon tests were performed before the shear buckling test to obtain fundamental material properties of the I-section. An asymmetric four-point bending loading scheme was utilized for the shear test. The loading scheme resulted a high shear and almost zeros moment condition at the center of the web panel. The shear buckling load was successfully determined after analyzing the obtained test data from strain rosettes and displacement sensors. An analytical approach was also performed to verify the experimental results and to support the discussed experimental program.

Keywords: strain sensor, displacement sensor, shear buckling, polymer composite I-section, asymmetric loading

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5106 Analysis and Modeling of Vibratory Signals Based on LMD for Rolling Bearing Fault Diagnosis

Authors: Toufik Bensana, Slimane Mekhilef, Kamel Tadjine

Abstract:

The use of vibration analysis has been established as the most common and reliable method of analysis in the field of condition monitoring and diagnostics of rotating machinery. Rolling bearings cover a broad range of rotary machines and plays a crucial role in the modern manufacturing industry. Unfortunately, the vibration signals collected from a faulty bearing are generally non-stationary, nonlinear and with strong noise interference, so it is essential to obtain the fault features correctly. In this paper, a novel numerical analysis method based on local mean decomposition (LMD) is proposed. LMD decompose the signal into a series of product functions (PFs), each of which is the product of an envelope signal and a purely frequency modulated FM signal. The envelope of a PF is the instantaneous amplitude (IA) and the derivative of the unwrapped phase of a purely flat frequency demodulated (FM) signal is the IF. After that, the fault characteristic frequency of the roller bearing can be extracted by performing spectrum analysis to the instantaneous amplitude of PF component containing dominant fault information. the results show the effectiveness of the proposed technique in fault detection and diagnosis of rolling element bearing.

Keywords: fault diagnosis, local mean decomposition, rolling element bearing, vibration analysis

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5105 Rheological Properties of Polysulfone-Sepiolite Nanocomposites

Authors: Nilay Tanrıver, Birgül Benli, Nilgün Kızılcan

Abstract:

Polysulfone (PSU) is a specialty engineering polymer having various industrial applications. PSU is especially used in waste water treatment membranes due to its good mechanical properties, structural and chemical stability. But it is a hydrophobic material and therefore its surface aim to pollute easily. In order to resolve this problem and extend the properties of membrane, PSU surface is rendered hydrophilic by addition of the sepiolite nanofibers. Sepiolite is one of the natural clays, which is a hydrate magnesium silicate fiber, also one of the well known layered clays of the montmorillonites where has several unique channels and pores within. It has also moisture durability, strength and low price. Sepiolite channels give great capacity of absorption and good surface properties. In this study, nanocomposites of commercial PSU and Sepiolite were prepared by solvent mixing method. Different organic solvents and their mixtures were used. Rheological characteristics of PSU-Sepiolite solvent mixtures were analyzed, the solubility of nanocomposite content in those mixtures were studied.

Keywords: nanocomposite, polysulfone, rheology, sepiolite, solution mixing

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5104 Ways for the Development of the Audit Quality Control System through the Analysis of Ongoing Problems, Experience and Challenges: Example of the Republic of Georgia

Authors: Levan Sabauri

Abstract:

Audit is an independent inspection of the financial statement of the audited person and expresses the opinion of an auditor on the reliability of this statement. The auditor’s activity (auditor’s service) is realized by auditing organizations, individual auditors in connection to conduction of an audit and rendering of audit accompanying services. The profession of auditor means a high level of responsibility for rendered service. Results of decisions made by information users depend on the quality of the auditor’s conclusion. Owners, investors, creditors, and society rely on the opinion of the auditor under the condition that inspection was conducted with good quality. Therefore, the existence of the well-functioning audit quality control system for the administering of the audit is an important issue. An efficient audit quality control system is a substantial challenge that many countries face worldwide, especially those states where these systems are being formed within the respective reform program. The presented article reflects on the best practices of the leading countries, the assumptions and recommendations for the financial accounting, reporting and audit; current reforms in Georgia are made based on this comparative analysis.

Keywords: audit quality control, audit program, financial statement, perspective analysis

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5103 A Review of Test Protocols for Assessing Coating Performance of Water Ballast Tank Coatings

Authors: Emmanuel A. Oriaifo, Noel Perera, Alan Guy, Pak. S. Leung, Kian T. Tan

Abstract:

Concerns on corrosion and effective coating protection of double hull tankers and bulk carriers in service have been raised especially in water ballast tanks (WBTs). Test protocols/methodologies specifically that which is incorporated in the International Maritime Organisation (IMO), Performance Standard for Protective Coatings for Dedicated Sea Water ballast tanks (PSPC) are being used to assess and evaluate the performance of the coatings for type approval prior to their application in WBTs. However, some of the type approved coatings may be applied as very thick films to less than ideally prepared steel substrates in the WBT. As such films experience hygrothermal cycling from operating and environmental conditions, they become embrittled which may ultimately result in cracking. This embrittlement of the coatings is identified as an undesirable feature in the PSPC but is not mentioned in the test protocols within it. There is therefore renewed industrial research aimed at understanding this issue in order to eliminate cracking and achieve the intended coating lifespan of 15 years in good condition. This paper will critically review test protocols currently used for assessing and evaluating coating performance, particularly the IMO PSPC.

Keywords: corrosion test, hygrothermal cycling, coating test protocols, water ballast tanks

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5102 Insights of Interaction Studies between HSP-60, HSP-70 Proteins and HSF-1 in Bubalus bubalis

Authors: Ravinder Singh, C Rajesh, Saroj Badhan, Shailendra Mishra, Ranjit Singh Kataria

Abstract:

Heat shock protein 60 and 70 are crucial chaperones that guide appropriate folding of denatured proteins under heat stress conditions. HSP60 and HSP70 provide assistance in correct folding of a multitude of denatured proteins. The heat shock factors are the family of some transcription factors which controls the regulation of gene expression of proteins involved in folding of damaged or improper folded proteins during stress conditions. Under normal condition heat shock proteins bind with HSF-1 and act as its repressor as well as aids in maintaining the HSF-1’s nonactive and monomeric confirmation. The experimental protein structure for all these proteins in Bubalus bubalis is not known till date. Therefore computational approach was explored to identify three-dimensional structure analysis of all these proteins. In this study, an extensive in silico analysis has been performed including sequence comparison among species to comparative modeling of Bubalus bubalis HSP60, HSP70 and HSF-1 protein. The stereochemical properties of proteins were assessed by utilizing several scrutiny bioinformatics tools to ensure model accuracy. Further docking approach was used to study interactions between Heat shock proteins and HSF-1.

Keywords: Bubalus bubalis, comparative modelling, docking, heat shock protein

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5101 The Spanish Didactic Book 'El Calculo Y La Medida en El Primer Grado De La Escuela Decroly' (1934): A Look at the Mathematical Knowledge

Authors: Juliana Chiarini Balbino Fernandes

Abstract:

This article aims to investigate the Spanish didactic book, entitled ‘El Calculo y La Medida en El Primer Grado de La Escuela Decroly’, written by Dr. O. Decroly and A. Hamaide, published in Madrid, in the year 1934. In addition to analyzing how mathematical knowledge is present in the proposed Centers of Interest. The textbooks, in addition to pedagogical tools, reflect a certain moment in society and allow the analysis of the theoretical-methodological proposal that can be implemented by the teacher. The study proposed here will be carried out by the lens of Cultural History, supported by Roger Chartier (1991) and by the concepts on textbooks, based on Alain Choppin (2004). The textbook selected for this study exposes a program of ideas associated with the method of Centers of Interest and arithmetic is linked to these interests. In the first courses (six to eight years), most centers can be considered to correspond to occasional calls, as they take advantage of events that arise spontaneously to work with observation, measurement, association and expression exercises. The program of ideas associated with Centers of Interest addresses the biological and social aspects of children, as long as they can express their needs for activities and games, satisfying the natural curiosity. Still, the program of associated ideas offers occasions for problems whose data are taken in observation exercises and concrete expressions (manuals, drawings). In the method applied at the school of L'Ermitage, school created by Decroly in Belgium in 1907, observation, is the basis of each center of interest. It offers the chance to compare and measure. To observe is more than to perceive; it is also to establish relations between the graded aspects of the same object, to seek relations between different intensities; is to verify successions, special and temporary relationships; is to make comparisons, to notice differences and similarities in block or datable (analysis), is to establish a bridge between the world and the thought. To make the observation more precise, it is important to compare, measure, and resort to considered objects as natural units of measure. Measurement and calculation are, therefore, quite naturally subject to observation. Thus, it is possible to make the child enter into the interest in the calculation, linking it to the observation. It was observed that the Centers of Interest, according to Decroly, should respond to the concerns and attend to the motivations of the students and the teaching of arithmetical must obey a logical seriation, considering the interest and the experience of the children. The teaching of arithmetical should not be limited to the schedule, it should cover every quantitative aspect that arises in the other disciplines. The feeling of unity is established in observation, association and expression, which coordinate a whole program of cultural activities, concentrating it around a central idea.

Keywords: didactic book, centers of interest, mathematical knowledge, primary education

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5100 Contribution of Soluble Microbial Products on Dissolved Organic Nitrogen in Wastewater Effluent from Moving Bed Biofilm Reactor

Authors: Boonsiri Dandumrongsin, Halis Simsek, Chaiwat Rongsayamanont

Abstract:

Dissolved organic nitrogen (DON) is known as one of the persistence nitrogenous pollutant being originated from secondary treated effluent of municipal sewage treatment plant. However, effect of key system operating condition on the fate and behavior of residual DON in the treated effluent is still not known. This study aims to investigate effect of organic loading rate (OLR) on the residual level of DON in the biofilm reactor effluent. Synthetic municipal wastewater was fed into moving bed biofilm reactors at OLR of 1.6x10-3 and 3.2x10-3 kg SCOD/m3-d. The results showed higher organic removal efficiency was found in the reactor operating at higher OLR. However, DON was observed at higher value in the effluent of the higher OLR reactor than that of the lower OLR reactor evidencing a clear influence of OLR on the residual DON level in the treated effluent of the biofilm reactors. It is possible that the lower DON being observed in the reactor at lower OLR is likely to be a result of providing the microbe with the additional period for utilizing the refractory DON molecules during operation at lower organic loading. All the experiments were repeated using raw wastewaters and similar trend was obtained.

Keywords: dissolved organic nitrogen, hydraulic retention time, moving bed biofilm reactor, soluble microbial products

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5099 Reinforced Concrete, Problems and Solutions: A Literature Review

Authors: Omar Alhamad, Waleed Eid

Abstract:

Reinforced concrete is a concrete lined with steel so that the materials work together in the resistance forces. Reinforcement rods or mesh are used for tensile, shear, and sometimes intense pressure in a concrete structure. Reinforced concrete is subject to many natural problems or industrial errors. The result of these problems is that it reduces the efficiency of the reinforced concrete or its usefulness. Some of these problems are cracks, earthquakes, high temperatures or fires, as well as corrosion of reinforced iron inside reinforced concrete. There are also factors of ancient buildings or monuments that require some techniques to preserve them. This research presents some general information about reinforced concrete, the pros and cons of reinforced concrete, and then presents a series of literary studies of some of the late published researches on the subject of reinforced concrete and how to preserve it, propose solutions or treatments for the treatment of reinforced concrete problems, raise efficiency and quality for a longer period. These studies have provided advanced and modern methods and techniques in the field of reinforced concrete.

Keywords: reinforced concrete, treatment, concrete, corrosion, seismic, cracks

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5098 Identifying Confirmed Resemblances in Problem-Solving Engineering, Both in the Past and Present

Authors: Colin Schmidt, Adrien Lecossier, Pascal Crubleau, Simon Richir

Abstract:

Introduction:The widespread availability of artificial intelligence, exemplified by Generative Pre-trained Transformers (GPT) relying on large language models (LLM), has caused a seismic shift in the realm of knowledge. Everyone now has the capacity to swiftly learn how these models can either serve them well or not. Today, conversational AI like ChatGPT is grounded in neural transformer models, a significant advance in natural language processing facilitated by the emergence of renowned LLMs constructed using neural transformer architecture. Inventiveness of an LLM : OpenAI's GPT-3 stands as a premier LLM, capable of handling a broad spectrum of natural language processing tasks without requiring fine-tuning, reliably producing text that reads as if authored by humans. However, even with an understanding of how LLMs respond to questions asked, there may be lurking behind OpenAI’s seemingly endless responses an inventive model yet to be uncovered. There may be some unforeseen reasoning emerging from the interconnection of neural networks here. Just as a Soviet researcher in the 1940s questioned the existence of Common factors in inventions, enabling an Under standing of how and according to what principles humans create them, it is equally legitimate today to explore whether solutions provided by LLMs to complex problems also share common denominators. Theory of Inventive Problem Solving (TRIZ) : We will revisit some fundamentals of TRIZ and how Genrich ALTSHULLER was inspired by the idea that inventions and innovations are essential means to solve societal problems. It's crucial to note that traditional problem-solving methods often fall short in discovering innovative solutions. The design team is frequently hampered by psychological barriers stemming from confinement within a highly specialized knowledge domain that is difficult to question. We presume ChatGPT Utilizes TRIZ 40. Hence, the objective of this research is to decipher the inventive model of LLMs, particularly that of ChatGPT, through a comparative study. This will enhance the efficiency of sustainable innovation processes and shed light on how the construction of a solution to a complex problem was devised. Description of the Experimental Protocol : To confirm or reject our main hypothesis that is to determine whether ChatGPT uses TRIZ, we will follow a stringent protocol that we will detail, drawing on insights from a panel of two TRIZ experts. Conclusion and Future Directions : In this endeavor, we sought to comprehend how an LLM like GPT addresses complex challenges. Our goal was to analyze the inventive model of responses provided by an LLM, specifically ChatGPT, by comparing it to an existing standard model: TRIZ 40. Of course, problem solving is our main focus in our endeavours.

Keywords: artificial intelligence, Triz, ChatGPT, inventiveness, problem-solving

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5097 Application of Soft Sets to Non-Associative Rings

Authors: Inayatur Rehman

Abstract:

Molodtstove developed the theory of soft sets which can be seen as an effective tool to deal with uncertainties. Since the introduction of this concept, the application of soft sets has been restricted to associative algebraic structures (groups, semi groups, associative rings, semi-rings etc.). Acceptably, though the study of soft sets, where the base set of parameters is a commutative structure, has attracted the attention of many researchers for more than one decade. But on the other hand there are many sets which are naturally endowed by two compatible binary operations forming a non-associative ring and we may dig out examples which investigate a non-associative structure in the context of soft sets. Thus it seems natural to apply the concept of soft sets to non-commutative and non-associative structures. In present paper, we make a new approach to apply Molodtsoves notion of soft sets to LA-ring (a class of non-associative ring). We extend the study of soft commutative rings from theoretical aspect.

Keywords: soft sets, LA-rings, soft LA-rings, soft ideals, soft prime ideals, idealistic soft LA-rings, LA-ring homomorphism

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5096 Mouthing Patterns in Indian Sign Language

Authors: Neha Kulshreshtha

Abstract:

This paper examines the patterns of 'Mouthing', a non-manual marker, and its distribution in Indian Sign Language (ISL). Linguistic research in Indian Sign Language is an emerging field where much is needed to be done. The little research which has happened focuses on the structure of ISL in terms of physical or manual markers, therefore a study of mouthing patterns would give an insight into the distribution of this particular non-manual marker. Data has been collected with the help of native ISL users through various techniques in which natural signs can be captured, for example, storytelling, informal conversations etc. The aim of the study is to find out the various situations where mouthing is used. Sometimes, the mouthing is not actually the articulation of the word as spoken in the local languages. The paper aims to find out whether the mouthing patterns in ISL are influenced by any local language or they are independent of any influence from the local language or both. Mouthing patterns have been studied in many sign languages and an investigation into ISL will reveal whether it falls in pattern with the other sign languages.

Keywords: Indian sign language, mouthing, non-manual marker, spoken language influence

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5095 Enabling the Physical Elements of a Pedestrian Friendly District around a Rail Station for Supporting Transit Oriented Development

Authors: Dyah Titisari Widyastuti

Abstract:

Rail-station area development that is based on the concept of TOD (Transit Oriented Development) is principally oriented to pedestrian accessibility for daily mobility. The aim of this research is elaborating how far the existing physical elements of a rail-station district could facilitate pedestrian mobility and establish a pedestrian friendly district toward implementation of a TOD concept. This research was conducted through some steps: (i) mapping the rail-station area pedestrian sidewalk and pedestrian network as well as activity nodes and transit nodes, (ii) assessing the level of pedestrian sidewalk connectivity joining trip origin and destination. The research area coverage in this case is limited to walking distance of the rail station (around 500 meters or 10-15 minutes walking). The findings of this research on the current condition of the street and pedestrian sidewalk network and connectivity, show good preference for the foot modal share (more than 50%) is achieved. Nevertheless, it depends on the distance from the trip origin to destination.

Keywords: accessibility of daily mobility, pedestrian-friendly district, rail-station district, transit oriented development

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5094 A Priori, Transcendental and Naturalistic Argument: Three Defense Strategies for Realism

Authors: SanXi Wu

Abstract:

A priori argument is a kind of reductio ad absurdum provided by Colin McGinn on the premise of accepting the basic rules of Dummett. The core part of the theory is to analyze the three joint positions besides realism and make them invalid, thus proving the rationality of the stance of realism. However, this argument strategy is vulnerable to skepticism because it delays the skeptical problem. In addition to McGinn, John Searle offers a linguistic transcendental argument strategy, which regards realism as the comprehensible condition that all normal activities of understanding must assume, while skepticism does not enjoy the same status. However, Searle's transcendental argument does not solve the problem of the relationship between realist presupposition and representational presupposition. Strawson, Hume, Reid, Wittgenstein, and others provide a naturalistic argument for realism. In this argument, realism is either a priori commitment from nature, or our second nature, or even a background belief that is fundamentally immovable. The key to this argument is to provide a quietistic treatment that ultimately invalidates our anti-realist myths. In comparison, the naturalistic argument is a more promising one. In this paper, methods of theoretical analysis and comparative research are used in order to demonstrate that in the face of skepticism, McGinn's a priori strategy and Searle's transcendental strategy are untenable, while Strawson and others' naturalistic strategy may resist the pressure of skepticism and make realism possible.

Keywords: a priori argument, transcendental argument, naturalism, realism, skepticism

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5093 Service Information Integration Platform as Decision Making Tools for the Service Industry Supply Chain-Indonesia Service Integration Project

Authors: Haikal Achmad Thaha, Pujo Laksono, Dhamma Nibbana Putra

Abstract:

Customer service is one of the core interest in a service sector of a company, whether as the core business or as service part of the operation. Most of the time, the people and the previous research in service industry is focused on finding the best business model solution for the service sector, usually to decide between total in house customer service, outsourcing, or something in between. Conventionally, to take this decision is some important part of the management job, and this is a process that usually takes some time and staff effort, meanwhile market condition and overall company needs may change and cause loss of income and temporary disturbance in the companies operation . However, in this paper we have offer a new concept model to assist decision making process in service industry. This model will featured information platform as central tool to integrate service industry operation. The result is service information model which would ideally increase response time and effectivity of the decision making. it will also help service industry in switching the service solution system quickly through machine learning when the companies growth and the service solution needed are changing.

Keywords: service industry, customer service, machine learning, decision making, information platform

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5092 Aspects Concerning the Use of Recycled Concrete Aggregates

Authors: Ion Robu, Claudiu Mazilu, Radu Deju

Abstract:

Natural aggregates (gravel and crushed) are essential non-renewable resources which are used for infrastructure works and civil engineering. In European Union member states from Southeast Europe, it is estimated that the construction industry will grow by 4.2% thereafter complicating aggregate supply management. In addition, a significant additional problem that can be associated to the aggregates industry is wasting potential resources through waste dumping of inert waste, especially waste from construction and demolition activities. In 2012, in Romania, less than 10% of construction and demolition waste (including concrete) are valorized, while the European Union requires that by 2020 this proportion should be at least 70% (Directive 2008/98/EC on waste, transposed into Romanian legislation by Law 211/2011). Depending on the efficiency of waste processing and the quality of recycled aggregate concrete (RCA) obtained, poor quality aggregate can be used as foundation material for roads and at the high quality for new concrete on construction. To obtain good quality concrete using recycled aggregate is necessary to meet the minimum requirements defined by the rules for the manufacture of concrete with natural aggregate. Properties of recycled aggregate (density, granulosity, granule shape, water absorption, weight loss to Los Angeles test, attached mortar content etc.) are the basis for concrete quality; also establishing appropriate proportions between components and the concrete production methods are extremely important for its quality. This paper presents a study on the use of recycled aggregates, from a concrete of specified class, to acquire new cement concrete with different percentages of recycled aggregates. To achieve recycled aggregates several batches of concrete class C16/20, C25/30 and C35/45 were made, the compositions calculation being made according NE012/2007 CP012/2007. Tests for producing recycled aggregate was carried out using concrete samples of the established three classes after 28 days of storage under the above conditions. Cubes with 150mm side were crushed in a first stage with a jaw crusher Liebherr type set at 50 mm nominally. The resulting material was separated by sieving on granulometric sorts and 10-50 sort was used for preliminary tests of crushing in the second stage with a jaw crusher BB 200 Retsch model, respectively a hammer crusher Buffalo Shuttle WA-12-H model. It was highlighted the influence of the type of crusher used to obtain recycled aggregates on granulometry and granule shape and the influence of the attached mortar on the density, water absorption, behavior to the Los Angeles test etc. The proportion of attached mortar was determined and correlated with provenance concrete class of the recycled aggregates and their granulometric sort. The aim to characterize the recycled aggregates is their valorification in new concrete used in construction. In this regard have been made a series of concrete in which the recycled aggregate content was varied from 0 to 100%. The new concrete were characterized by point of view of the change in the density and compressive strength with the proportion of recycled aggregates. It has been shown that an increase in recycled aggregate content not necessarily mean a reduction in compressive strength, quality of the aggregate having a decisive role.

Keywords: recycled concrete aggregate, characteristics, recycled aggregate concrete, properties

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5091 The Effect of Land Cover on Movement of Vehicles in the Terrain

Authors: Krisstalova Dana, Mazal Jan

Abstract:

This article deals with geographical conditions in terrain and their effect on the movement of vehicles, their effect on speed and safety of movement of people and vehicles. Finding of the optimal routes outside the communication is studied in the army environment, but it occur in civilian as well, primarily in crisis situation, or by the provision of assistance when natural disasters such as floods, fires, storms etc., have happened. These movements require the optimization of routes when effects of geographical factors should be included. The most important factor is the surface of a terrain. It is based on several geographical factors as are slopes, soil conditions, micro-relief, a type of surface and meteorological conditions. Their mutual impact has been given by coefficient of deceleration. This coefficient can be used for the commander`s decision. New approaches and methods of terrain testing, mathematical computing, mathematical statistics or cartometric investigation are necessary parts of this evaluation.

Keywords: movement in a terrain, geographical factors, surface of a field, mathematical evaluation, optimization and searching paths

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5090 A 3-Dimensional Memory-Based Model for Planning Working Postures Reaching Specific Area with Postural Constraints

Authors: Minho Lee, Donghyun Back, Jaemoon Jung, Woojin Park

Abstract:

The current 3-dimensional (3D) posture prediction models commonly provide only a few optimal postures to achieve a specific objective. The problem with such models is that they are incapable of rapidly providing several optimal posture candidates according to various situations. In order to solve this problem, this paper presents a 3D memory-based posture planning (3D MBPP) model, which is a new digital human model that can analyze the feasible postures in 3D space for reaching tasks that have postural constraints and specific reaching space. The 3D MBPP model can be applied to the types of works that are done with constrained working postures and have specific reaching space. The examples of such works include driving an excavator, driving automobiles, painting buildings, working at an office, pitching/batting, and boxing. For these types of works, a limited amount of space is required to store all of the feasible postures, as the hand reaches boundary can be determined prior to perform the task. This prevents computation time from increasing exponentially, which has been one of the major drawbacks of memory-based posture planning model in 3D space. This paper validates the utility of 3D MBPP model using a practical example of analyzing baseball batting posture. In baseball, batters swing with both feet fixed to the ground. This motion is appropriate for use with the 3D MBPP model since the player must try to hit the ball when the ball is located inside the strike zone (a limited area) in a constrained posture. The results from the analysis showed that the stored and the optimal postures vary depending on the ball’s flying path, the hitting location, the batter’s body size, and the batting objective. These results can be used to establish the optimal postural strategies for achieving the batting objective and performing effective hitting. The 3D MBPP model can also be applied to various domains to determine the optimal postural strategies and improve worker comfort.

Keywords: baseball, memory-based, posture prediction, reaching area, 3D digital human models

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5089 Analysis Rotor Bearing System Dynamic Interaction with Bearing Supports

Authors: V. T. Ngo, D. M. Xie

Abstract:

Frequently, in the design of machines, some of parameters that directly affect the rotor dynamics of the machines are not accurately known. In particular, bearing stiffness support is one such parameter. One of the most basic principles to grasp in rotor dynamics is the influence of the bearing stiffness on the critical speeds and mode shapes associated with a rotor-bearing system. Taking a rig shafting as an example, this paper studies the lateral vibration of the rotor with multi-degree-of-freedom by using Finite Element Method (FEM). The FEM model is created and the eigenvalues and eigenvectors are calculated and analyzed to find natural frequencies, critical speeds, mode shapes. Then critical speeds and mode shapes are analyzed by set bearing stiffness changes. The model permitted to identify the critical speeds and bearings that have an important influence on the vibration behavior.

Keywords: lateral vibration, finite element method, rig shafting, critical speed

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5088 The Projections of Urban Climate Change Using Conformal Cubic Atmospheric Model in Bali, Indonesia

Authors: Laras Tursilowati, Bambang Siswanto

Abstract:

Urban climate change has short- and long-term implications for decision-makers in urban development. The problem for this important metropolitan regional of population and economic value is that there is very little usable information on climate change. Research about urban climate change has been carried out in Bali Indonesia by using Conformal Cubic Atmospheric Model (CCAM) that runs with Representative Concentration Pathway (RCP)4.5. The history data means average data from 1975 to 2005, climate projections with RCP4.5 scenario means average data from 2006 to 2099, and anomaly (urban climate change) is RCP4.5 minus history. The results are the history of temperature between 22.5-27.5 OC, and RCP4.5 between 25.5-29.5 OC. The temperature anomalies can be seen in most of northern Bali that increased by about 1.6 to 2.9 OC. There is a reduced humidity tendency (drier) in most parts of Bali, especially the northern part of Bali, while a small portion in the south increase moisture (wetter). The comfort index of Bali region in history is still relatively comfortable (20-26 OC), but on the condition RCP4.5 there is no comfortable area with index more than 26 OC (hot and dry). This research is expected to be useful to help the government make good urban planning.

Keywords: CCAM, comfort index, IPCC AR5, temperature, urban climate change

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5087 Characteristics of Cumulative Distribution Function of Grown Crack Size at Specified Fatigue Crack Propagation Life under Different Maximum Fatigue Loads in AZ31

Authors: Seon Soon Choi

Abstract:

Magnesium alloy has been widely used in structure such as an automobile. It is necessary to consider probabilistic characteristics of a structural material because a fatigue behavior of a structure has a randomness and uncertainty. The purpose of this study is to find the characteristics of the cumulative distribution function (CDF) of the grown crack size at a specified fatigue crack propagation life and to investigate a statistical crack propagation in magnesium alloys. The statistical fatigue data of the grown crack size are obtained through the fatigue crack propagation (FCP) tests under different maximum fatigue load conditions conducted on the replicated specimens of magnesium alloys. The 3-parameter Weibull distribution is used to find the CDF of grown crack size. The CDF of grown crack size in case of larger maximum fatigue load has longer tail in below 10 percent and above 90 percent. The fatigue failure occurs easily as the tail of CDF of grown crack size becomes long. The fatigue behavior under the larger maximum fatigue load condition shows more rapid propagation and failure mode.

Keywords: cumulative distribution function, fatigue crack propagation, grown crack size, magnesium alloys, maximum fatigue load

Procedia PDF Downloads 274
5086 The Modern Era in the Cricket World: How Far Have We Really Come?

Authors: Habib Noorbhai

Abstract:

History of Cricket: Cricket has a known history spanning from the 16th century till present, with international matches having been played since 1844. The game of cricket arrived in Australia as soon as colonization began in 1788. Cricketers started playing on turf wickets in the late 1800’s and dimensions for both the boundary and pitch later became assimilated. As the years evolved, cricket bats and balls, protective equipment, playing surfaces and the three formats of the game adapted to the playing conditions and laws of cricket. Business of Cricket: During the late 1900's, the shorter version of the game (T20) was introduced in order to attract the crowds to stadiums and television viewers for broadcasting rights. One could argue if this was merely a business venture or a platform for enhancing the performance of cricketers. Between the 16th and 20th century, cricket was a common sport played for passion and pure enjoyment. Industries saw a potential in diversified business ventures in the game (as well as other sports played globally) and cricket subsequently became a career for players, administrators and coaches, the media, health professionals, managers and the corporate world. Pros and Cons of Cricket Developments: At present, the game has significantly gained from the use of technology, sports sciences and varied mechanisms to optimize the performances and forecast frameworks for injury prevention in cricket players. Unfortunately, these had not been utilized in the earlier times of cricket and it would prove interesting to observe how the greats of the game would have benefited with such developments. Cricketers in the 21st century are faced with many overwhelming commitments. One of these is playing cricket for 11 months in a year, making it more than 250 days away from home and their families. As the demand of player contracts increase, the supply of commitment and performances from players increase. Way Forward and Future Implications: The questions are: Are such disadvantages contributing to the overload and injury risks of players? How far have we really come in the cricketing world or has everything since the game’s inception become institutionalized with a business model? These are the fundamental questions which need to be addressed and legislation, policies and ethical considerations need to be drafted and implemented. These will ensure that there is equilibrium of effective transitions and management of not only the players, but also the credibility of the wonderful game.

Keywords: enterprising business of cricket, technology, legislation, credibility

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5085 The Role of College Teachers’ in Identifying Attention Deficit Hyperactivity Disorder in Students

Authors: Hargunjeet Shergill, Palwinder Singh

Abstract:

The present paper analyzes the lack of teachers' awareness and knowledge regarding the Attention Deficit Hyperactivity Disorder in the college students. Attention deficit hyperactivity disorder causes individuals to consistently display extreme inattention, impulsivity and in many cases hyperactivity as a result of the physiological differences of the brain. Teachers have a formative influence on their students and can play a key role in identifying and supporting students with Attention Deficit/Hyperactivity Disorder (ADHD). Despite the pervasiveness and salience of this disorder, educators at college continue to labor under a number of misconceptions about the nature of ADHD. In order to fulfill this important role, it is imperative for teachers to have explicit knowledge about this disorder. ADHD in college students remains the most under-recognized and undertreated mental health condition. The overall aim of this study is to investigate teachers’ knowledge and misconceptions of ADHD with a particular focus on recognition, assessment and management of ADHD in adult college students. It designed to assess the college teachers' knowledge, opinions, and experience related to the diagnosis of attention-deficit/hyperactivity disorder (ADHD) and by maintaining open lines of communication with the students and understanding some key elements that can affect students’ overall growth and ability. The discussion focuses on the value of the role of teachers and their relationship with each college student dealing with ADHD.

Keywords: attention deficit hyperactivity disorder, development of ADHD, diagnostic criteria, role of teachers

Procedia PDF Downloads 196
5084 Its about Cortana, Microsoft’s Virtual Assistant

Authors: Aya Idriss, Esraa Othman, Lujain Malak

Abstract:

Artificial intelligence is the emulation of human intelligence processes by machines, particularly computer systems that act logically. Some of the specific applications of AI include natural language processing, speech recognition, and machine vision. Cortana is a virtual assistant and she’s an example of an AI Application. Microsoft made it possible for this app to be accessed not only on laptops and PCs but can be downloaded on mobile phones and used as a virtual assistant which was a huge success. Cortana can offer a lot apart from the basic orders such as setting alarms and marking the calendar. Its capabilities spread past that, for example, it provides us with listening to music and podcasts on the go, managing my to-do list and emails, connecting with my contacts hands-free by simply just telling the virtual assistant to call somebody, gives me instant answers and so on. A questionnaire was sent online to numerous friends and family members to perform the study, which is critical in evaluating Cortana's recognition capacity and the majority of the answers were in favor of Cortana’s capabilities. The results of the questionnaire assisted us in determining the level of Cortana's skills.

Keywords: artificial intelligence, Cortana, AI, abstract

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5083 Design of Residential Geothermal Cooling System in Kuwait

Authors: Tebah KH A AlFouzan, Meznah Dahlous Ali Alkreebani, Fatemah Salem Dekheel Alrasheedi, Hanadi Bandar Rughayan AlNomas, Muneerah Mohammad Sulaiman ALOjairi

Abstract:

Article spotlights the heat transfer process based beneath the earth’s surface. The process starts by exchanging the heat found in the building as fluid in the pipes absorbs it, then transports it down the soil consuming cool temperature exchange, recirculating, and rebounding to deliver cool air. This system is a renewable energy that is reliable and sustainable. The analysis showed the disposal of fossil fuels, energy preservation, 400% efficiency, long lifespan, and lower maintenance. Investigation displays the system’s types of design, whether open or closed loop and piping layout. Finally, the geothermal cooling study presents the challenges of creating a prototype in Kuwait, as constraints are applicable due to geography.

Keywords: cooling system, engineering, geothermal cooling, natural ventilation, renewable energy

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5082 Effect of Piston and its Weight on the Performance of a Gun Tunnel via Computational Fluid Dynamics

Authors: A. A. Ahmadi, A. R. Pishevar, M. Nili

Abstract:

As the test gas in a gun tunnel is non-isentropically compressed and heated by a light weight piston. Here, first consideration is the optimum piston weight. Although various aspects of the influence of piston weight on gun tunnel performance have been studied, it is not possible to decide from the existing literature what piston weight is required for optimum performance in various conditions. The technique whereby the piston is rapidly brought to rest at the end of the gun tunnel barrel, and the resulted peak pressure is equal in magnitude to the final equilibrium pressure, is called the equilibrium piston technique. The equilibrium piston technique was developed to estimate the equilibrium piston mass; but this technique cannot give an appropriate estimate for the optimum piston weight. In the present work, a gun tunnel with diameter of 3 in. is described and its performance is investigated numerically to obtain the effect of piston and its weight. Numerical results in the present work are in very good agreement with experimental results. Significant influence of the existence of a piston is shown by comparing the gun tunnel results with results of a conventional shock tunnel in the same dimension and same initial condition. In gun tunnel, an increase of around 250% in running time is gained relative to shock tunnel. Also, Numerical results show that equilibrium piston technique is not a good way to estimate suitable piston weight and there will be a lighter piston which can increase running time of the gun tunnel around 60%.

Keywords: gun tunnel, hypersonic flow, piston, shock tunnel

Procedia PDF Downloads 360
5081 Removal of Heavy Metals by Ultrafiltration Assisted with Chitosan or Carboxy-Methyl Cellulose

Authors: Boukary Lam, Sebastien Deon, Patrick Fievet, Nadia Crini, Gregorio Crini

Abstract:

Treatment of heavy metal-contaminated industrial wastewater has become a major challenge over the last decades. Conventional processes for the treatment of metal-containing effluents do not always simultaneously satisfy both legislative and economic criteria. In this context, coupling of processes can then be a promising alternative to the conventional approaches used by industry. The polymer-assisted ultrafiltration (PAUF) process is one of these coupling processes. Its principle is based on a sequence of steps with reaction (e.g., complexation) between metal ions and a polymer and a step involving the rejection of the formed species by means of a UF membrane. Unlike free ions, which can cross the UF membrane due to their small size, the polymer/ion species, the size of which is larger than pore size, are rejected. The PAUF process was deeply investigated herein in the case of removal of nickel ions by adding chitosan and carboxymethyl cellulose (CMC). Experiments were conducted with synthetic solutions containing 1 to 100 ppm of nickel ions with or without the presence of NaCl (0.05 to 0.2 M), and an industrial discharge water (containing several metal ions) with and without polymer. Chitosan with a molecular weight of 1.8×105 g mol⁻¹ and a degree of acetylation close to 15% was used. CMC with a degree of substitution of 0.7 and a molecular weight of 9×105 g mol⁻¹ was employed. Filtration experiments were performed under cross-flow conditions with a filtration cell equipped with a polyamide thin film composite flat-sheet membrane (3.5 kDa). Without the step of polymer addition, it was found that nickel rejection decreases from 80 to 0% with increasing metal ion concentration and salt concentration. This behavior agrees qualitatively with the Donnan exclusion principle: the increase in the electrolyte concentration screens the electrostatic interaction between ions and the membrane fixed the charge, which decreases their rejection. It was shown that addition of a sufficient amount of polymer (greater than 10⁻² M of monomer unit) can offset this decrease and allow good metal removal. However, the permeation flux was found to be somewhat reduced due to the increase in osmotic pressure and viscosity. It was also highlighted that the increase in pH (from 3 to 9) has a strong influence on removal performances: the higher pH value, the better removal performance. The two polymers have shown similar performance enhancement at natural pH. However, chitosan has proved more efficient in slightly basic conditions (above its pKa) whereas CMC has demonstrated very weak rejection performances when pH is below its pKa. In terms of metal rejection, chitosan is thus probably the better option for basic or strongly acid (pH < 4) conditions. Nevertheless, CMC should probably be preferred to chitosan in natural conditions (5 < pH < 8) since its impact on the permeation flux is less significant. Finally, ultrafiltration of an industrial discharge water has shown that the increase in metal ion rejection induced by the polymer addition is very low due to the competing phenomenon between the various ions present in the complex mixture.

Keywords: carboxymethyl cellulose, chitosan, heavy metals, nickel ion, polymer-assisted ultrafiltration

Procedia PDF Downloads 148