Search results for: pattern construction
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 6227

Search results for: pattern construction

5057 Rheological and Morphological Properties of Investment Casting Pattern Material Based on Paraffin Wax Fortified with Linear Low-Density Polyethylene and Filled with Poly Methyl Methacrylate

Authors: Robert Kimutai Tewo, Hilary Limo Rutto, Tumisang Seodigeng

Abstract:

The rheological and morphological properties of paraffin wax, linear low-density polyethylene (LLDPE), and poly (methyl methacrylate) (PMMA) microbeads formulations were prepared via an extrusion process. The blends were characterized by rheometry, scanning electron microscopy (SEM), and Fourier transform infrared (FTIR) spectroscopy. The results indicated that the viscosity of the blends increased as compared to that of neat wax. SEM confirmed that LLDPE alters the wax crystal habit at higher concentrations. The rheological experimental data fitted with predicted data using the modified Krieger and Dougherty expression. The SEM micrograph of wax/LLDPE/PMMA revealed a near-perfect spherical nature for the filler particles in the wax/EVA polymer matrix. The FT-IR spectra show the deformation vibrations stretch of a long-chain aliphatic hydrocarbon (C-H) and also the presence of carbonyls absorption group denoted by -C=O- stretch.

Keywords: investment casting pattern, paraffin wax, LLDPE, PMMA, rheological properties, modified Krieger and Dougherty expression

Procedia PDF Downloads 154
5056 Construction Strategy of Urban Public Space in Driverless Era

Authors: Yang Ye, Hongfei Qiu, Yaqi Li

Abstract:

The planning and construction of traditional cities are oriented by cars, which leads to the problems of insufficient urban public space, fragmentation, and low utilization efficiency. With the development of driverless technology, the urban structure will change from the traditional single-core grid structure to the multi-core model. In terms of traffic organization, with the release of land for traffic facilities, public space will become more continuous and integrated with traffic space. In the context of driverless technology, urban public reconstruction is characterized by modularization and high efficiency, and its planning and layout features accord with points (service facilities), lines (smart lines), surfaces (activity centers). The public space of driverless urban roads will provide diversified urban public facilities and services. The intensive urban layout makes the commercial public space realize the functions of central activities and style display, respectively, in the interior (building atrium) and the exterior (building periphery). In addition to recreation function, urban green space can also utilize underground parking space to realize efficient dispatching of shared cars. The roads inside the residential community will be integrated into the urban landscape, providing conditions for the community public activity space with changing time sequence and improving the efficiency of space utilization. The intervention of driverless technology will change the thinking of traditional urban construction and turn it into a human-oriented one. As a result, urban public space will be richer, more connected, more efficient, and the urban space justice will be optimized. By summarizing the frontier research, this paper discusses the impact of unmanned driving on cities, especially urban public space, which is beneficial for landscape architects to cope with the future development and changes of the industry and provides a reference for the related research and practice.

Keywords: driverless, urban public space, construction strategy, urban design

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5055 An Index to Measure Transportation Sustainable Performance in Construction Projects

Authors: Sareh Rajabi, Taha Anjamrooz, Salwa Bheiry

Abstract:

The continuous increase in the world population, resource shortage and the warning of climate change cause various environmental and social issues to the world. Thus, sustainability concept is much needed nowadays. Organizations are progressively falling under strong worldwide pressure to integrate sustainability practices into their project decision-making development. Construction projects in the industry are amongst the most significant, since it is one of the biggest divisions and of main significance for the national economy and hence has a massive effect on the environment and society. So, it is important to discover approaches to incorporate sustainability into the management of those projects. This study presents a combined sustainability index of projects with sustainable transportation which has been formed as per a comprehensive literature review and survey study. Transportation systems enable the movement of goods and services worldwide, and it is leading to economic growth and creating jobs while creating negative impacts on the environment and society. This research is study to quantify the sustainability indicators, through 1) identifying the importance of sustainable transportation indicators that are based on the sustainable practices used for the construction projects and 2) measure the effectiveness of practices through these indicators on the three sustainable pillars. A total 26 sustainability indicators have been selected and grouped under each related sustainability pillars. A survey was used to collect the opinion about the sustainability indicators by a scoring system. A combined sustainability index considering three sustainable pillars can be helpful in evaluating the transportation sustainable practices of a project and making decisions regarding project selection. In addition to focus on the issue of financial resource allocation in a project selection, the decision-maker could take into account the sustainability as an important key in addition to the project’s return and risk. The purpose of this study is to measure the performance of transportation sustainability which allow companies to assess multiple projects selection. This is useful to decision makers to rank and focus more on future sustainable projects.

Keywords: sustainable transportation, transportation performances, sustainable indicators, sustainable construction practice, sustainability

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5054 Carbon Emission Reduction by Compact City Construction in Toyama, Japan

Authors: Benyan Jiang, Dawei Xia, Yong Li

Abstract:

Compact city construction is considered as an effective measure to reduce carbon emission in city lives. Toyama City started its compact city strategy in 2000 and was selected as a Japanese Environmental Model City in 2008 for its achievement. This paper takes Toyama as a study case, aiming to find how city polices affected people’s life styles and reduced carbon emission. The main materials used in this study are first-hand documents, like urban planning materials, government annual report and statistic data from transportation association. It is found that the main measures taken by Toyama City include the construction of light rail transit, increasing the frequency of buses, building park and ride parking lots. In addition to hardware facilities, it also offers flexible policies like passengers' coupons for the senior citizens and free use of parking lots by buying shopping vouchers. Besides, Toyama City encourages citizens to live within 500 meters of public transportation. People who buy an apartment near public transportation will receive 500,000 Japanese Yen. These measures have proven to their effects. Compared with 2005, in 2014, the transportation sector reduced emissions of 2.35 million tons of CO₂, 13.6%. This aspect is related to the increase in the number of cars in public transport and also related to fuel improvement.

Keywords: Toyama, compact city, public transportation, CO₂ reduction

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5053 Effects of Main Contractors’ Service Quality on Subcontractors’ Behaviours and Project Outcomes

Authors: Zhuoyuan Wang, Benson T. H. Lim, Imriyas Kamardeen

Abstract:

Effective service quality management has long been touted as a means of improving project and organisational performance. Particularly, in construction projects, main contractors are often seen as a broker between clients and subcontractors, and their service quality is thus associated with the overall project affinity and outcomes. While a considerable amount of research has focused on the aspect of clients-main contractors, very little research has been done to explore the effect of contractors’ service quality on subcontractors’ behaviours and so project outcomes. In addressing this gap, this study surveyed 97 subcontractors in the Chinese Construction industry and data was analysed using the Partial Least Square (PLS) Structural Equation Modelling (SEM) technique. The overall findings reveal that subcontractors categorised main contractors’ service quality into three dimensions: assurance; responsiveness; reliability and empathy. Of these, it is found that main contractors’ ‘assurance’ and ‘responsiveness’ positively influence subcontractors’ intention to engage in contractual behaviours. The results further show that the subcontractors’ intention to engage in organizational citizenship behaviours is associated with how flexible and committed the main contractors are in reliability and empathy. Collectively, both subcontractors’ contractual and organizational citizenship behaviours positively influence the overall project outcomes. In conclusion, the findings inform contractors different strategies towards managing and gaining subcontractors’ behaviour commitment in a socially connected, yet complex and uncertain, business environment.

Keywords: construction firms, organisational citizenship behaviour, service quality, social exchange theory

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5052 A Numerical Study of the Tidal Currents in the Persian Gulf and Oman Sea

Authors: Fatemeh Sadat Sharifi, A. A. Bidokhti, M. Ezam, F. Ahmadi Givi

Abstract:

This study focuses on the tidal oscillation and its speed to create a general pattern in seas. The purpose of the analysis is to find out the amplitude and phase for several important tidal components. Therefore, Regional Ocean Models (ROMS) was rendered to consider the correlation and accuracy of this pattern. Finding tidal harmonic components allows us to predict tide at this region. Better prediction of these tides, making standard platform, making suitable wave breakers, helping coastal building, navigation, fisheries, port management and tsunami research. Result shows a fair accuracy in the SSH. It reveals tidal currents are highest in Hormuz Strait and the narrow and shallow region between Kish Island. To investigate flow patterns of the region, the results of limited size model of FVCOM were utilized. Many features of the present day view of ocean circulation have some precedent in tidal and long- wave studies. Tidal waves are categorized to be among the long waves. So that tidal currents studies have indeed effects in subsequent studies of sea and ocean circulations.

Keywords: barotropic tide, FVCOM, numerical model, OTPS, ROMS

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5051 Comparative Study on the Effect of Compaction Energy and Moisture Content on the Strength Properties of Lateritic Soil

Authors: Ahmad Idris, O.A. Uche, Ado Y Abdulfatah

Abstract:

Lateritic soils are found in abundance and are the most common types of soils used in construction of roads and embankments in Nigeria. Strength properties of the soils depend on the amount of compaction applied and the amount of water available in the soil at the time of compaction. In this study, the influence of the compactive effort and that of the amount of water in the soil in the determination of the shear strength properties of lateritic soil was investigated. Lateritic soil sample was collected from an existing borrow pit in Kano, Nigeria and its basic characteristics were determined and the soil was classified according to AASHTO classification method. The soil was then compacted under various compactive efforts and at wide range of moisture contents. The maximum dry density (MDD) and optimum moisture content (OMC) at each compactive effort was determined. Unconfined undrained triaxial test was carried out to determine the shear strength properties of the soil under various conditions of moisture and energy. Preliminary results obtained indicated that the soil is an A-7-5 soil. The final results obtained shows that as the compaction energy is increased, both the cohesion and friction angle increased irrespective of the moisture content used in the compaction. However, when the amount of water in the soil was increased and compaction effort kept constant, only the cohesion of the soil increases while the friction angle shows no any pattern of variation. It was also found that the highest values for cohesion and friction angle were obtained when the soil was compacted at the highest energy and at OMC.

Keywords: laterite, OMC, compaction energy, moisture content

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5050 On Copular Constructions in Yemeni Arabic and the Cartography of Subjects

Authors: Ameen Alahdal

Abstract:

This paper investigates copular constructions in Raimi Yemeni Arabic (RYA). The aim of the paper is actually twofold. First it explores the types of copular constructions in Raimi Yemeni Arabic, a variety of Arabic that has not attracted a lot of attention. In this connection, the paper shows that RYA manifests ‘bare’, verbal and pronominal/PRON copular constructions, just like other varieties of Arabic and indeed other Semitic languages like Hebrew. The sentences below from RYA represent the three constructions, respectively. (1) a. nada Hilwah Nada pretty.3sf ‘Nada is pretty’ b. kan al-banat hina was the-girls here ‘The girls were here c. ali hu-l mudiir Ali he-the manager ‘Ali is the manager’ Interestingly, in addition to these common types of copular constructions, RYA seems to exhibit dual copula sentences, a construction that features both a pronominal copula and a verbal copula. Such a construction is attested neither in Standard Arabic nor in other modern varieties of Arabic such as Lebanese, Moroccan, Egyptian, Jordanian. Remarkably, dual copular sentences do not appear even in other dialects of Yemeni Arabic such as Sanaani, Adeni and Tehami. (2) is an example. (2) maha kan-ih mudarrisah maha was-she teacher.3sf ‘Maha was a teacehr’ Second, the paper considers the cartography of subject positions in copular constructions proposed by Shlonsky and Rizzi (2018). Different copular constructions seem to involve different subject positions (which might eventually correlate with different interpretations – not our concern in this paper). Here, it is argued that in a bare copular sentence, as in (1a), RYA might exploit two criterial subject positions (in Rizzi’s sense), in addition to the canonical Spec,TP position. Under mainstream minimalist assumption, a copular sentence is analyzed as a PredP. Thus, in addition to the PredP-related thematic subject position, a criterial subject position is posited outside of PredP. (3) below represents the cartography of subject positions in a bare copular construction. (3) [……..DP subj PredP DP Pred DP/AP/PP ] In PRON sentences, as exemplified in (1c), another two subject positions are postulated high in the clause, particularly above PolP. (4) illustrates the hierarchy of the subject positions in a PRON copular construction. The subject resides in Spec,SUBJ2P. (4) …DP SUBJ2 …DP SUBJ1 … Pol … DP subj PredP Another related phenomenon in RYA which sets it apart from other languages like Hebrew is that of negative bare copular construction. This construction involves a PRON, which is not found in its affirmative counterpart. PRON, however, is hosted neither by SUBJ20 nor by SUBJ10. Rather, PRON occurs below Neg0 (Pol0 in the hierarchy). This situation raises interesting issues for the hierarchy of subjects in copular constructions as well as to the syntax of the left periphery in general. With regard to what causes the subject to move, there are different potential triggers. For instance, movement of the subject at the base, i.e., out of PredP is triggered by a labeling failure. Other movements of the subject can be driven by a formal feature like EPP, or a criterial feature like [subj].

Keywords: Yemeni Arabic, copular constructions, cartography of subjects, labeling, criterial positions

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5049 Place, Female and Latino Identities in Kali Fajardo-Anstine’s Short Story Collection Sabrina and Corina

Authors: Jaroslav Kusnir

Abstract:

In her short story collection, Sabrina & Corina, Kali Fajardo-Anstine depicts mostly Latina characters of indigenous background living and travelling in the American West and the Southwest. In all the stories, place and the environment plays an important role in the construction of cultural identity of these characters that is influenced by their indigenous background, a specificity of the American West, its culture and environment, as well as a contemporary (modern) American culture, position of women and gender roles in a Latino community in the USA. This paper will analyze Fajardo-Anstine´s depiction of a specificity of place, especially of the American West and its role in a construction of Latino/a cultural identity in a modern American society as manifested especially in Fajardo-Anstine´s stories Any Further West and Sabrina & Corina. At the same time, the paper will point out Fajardo-Anstine´s construction of cultural identity of female characters and their gender roles in both Latino and a contemporary American societies. The research results show that the formation of Latina cultural identity is closely connected with both place, that is the American West and the Soutwest as well as with Latina and contemporary American cultures.

Keywords: American culture, american west, cultural identity, female identity, latina identity, place

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5048 Machine Learning Approach to Project Control Threshold Reliability Evaluation

Authors: Y. Kim, H. Lee, M. Park, B. Lee

Abstract:

Planning is understood as the determination of what has to be performed, how, in which sequence, when, what resources are needed, and their cost within the organization before execution. In most construction project, it is evident that the inherent nature of planning is dynamic, and initial planning is subject to be changed due to various uncertain conditions of construction project. Planners take a continuous revision process during the course of a project and until the very end of project. However, current practice lacks reliable, systematic tool for setting variance thresholds to determine when and what corrective actions to be taken. Rather it is heavily dependent on the level of experience and knowledge of the planner. Thus, this paper introduces a machine learning approach to evaluate project control threshold reliability incorporating project-specific data and presents a method to automate the process. The results have shown that the model improves the efficiency and accuracy of the monitoring process as an early warning.

Keywords: machine learning, project control, project progress monitoring, schedule

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5047 Review of Affected Parameters on Flexural Behavior of Hollow Concrete Beams Reinforced by Steel/GFRP Rebars

Authors: Shahrad Ebrahimzadeh

Abstract:

Nowadays, the main efforts of the researchers aim to constantly evolve new, optimized and efficient construction materials and methods related to reinforced concrete beams. Due to the fewer applied materials and offering a higher structural efficiency compared to solid concrete beams with the same concrete area, hollow reinforced concrete beams (HRCB) internally reinforced with steel rebars have been employed extensively for bridge structural members and high-rise buildings. Many experimental studies have been conducted to investigate the behavior of hollow beams subjected to bending loading and found that the structural performance of HRCBs is critically affected by many design parameters. While the proper design of the HRCBs demonstrated comparable behavior to solid sections, inappropriate design leads beams to be extremely prone to brittle failure. Another potential issue that needs to be further investigated is the replacement of steel bars with suitable materials due to their susceptibility to corrosion. Hence, to develop a reliable construction system, the application of GFRP bars as a non-corroding material has been utilized. Furthermore, this study aims to critically review the different design parameters that affect the flexural performance of the HRCBs and recognize the gaps of knowledge in the better design and more effective use of this construction system.

Keywords: design parameters, experimental investigations, hollow reinforced concrete beams, steel, GFRP, flexural strength

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5046 Combining the Noble Values of Traditional Architecture on Modern Architecture

Authors: Dwi Retno Sri Ambarwati

Abstract:

Recently, the traditional architecture were getting lost, replaced by modern architecture. The existence of many traditional houses often changing the function and change the values in an effort to adjust to the modern lifestyle, whereas the spiritual background of traditional architectural design is very specific and be the basis for consideration in the construction of the building, both in terms of determining the location of the building, the direction toward building, the spatial pattern and organization of space, zoning, hierarchical space, building form, ornamentation, the selection of building materials, and so on. The changes in function and form will transformed the spiritual values contained in it, because the architecture affects human behavior and reflects the culture. The traditional architecture views the architecture as a concept that has different tendencies in terms of orientation, shape, and attitude toward nature that tends to harmony with the social environment and local culture. The concept of the spirit of place made the architecture looks familiar, not arrogant and give a positive value to the surrounding environment. Every culture has a traditional architecture that full of spiritual values, although in the simplest form. Humans can learn about human values and local wisdom through the positive values that contained in traditional architecture, the desire to balance themselves with nature and the environment, not overbearing, strict adherence to the prevailing norms, openness in public life and intimacy family life that form a harmonious in life. The great and the wise value of traditional architecture should be revived in modern architecture that tends to ignore the spiritual values and more concerned with the functional and aesthetic pleasure, by combining the noble values of traditional architecture into modern architecture.

Keywords: architecture, combining noble values, local wisdom, traditional architecture

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5045 Climate Change Impact Due to Timber Product Imports in the UK

Authors: Juan A. Ferriz-Papi, Allan L. Nantel, Talib E. Butt

Abstract:

Buildings are thought to consume about 50% of the total energy in the UK. The use stage in a building life cycle has the largest energy consumption, although different assessments are showing that the construction can equal several years of maintenance and operations. The selection of materials with lower embodied energy is very important to reduce this consumption. For this reason, timber is one adequate material due to its low embodied energy and the capacity to be used as carbon storage. The use of timber in the construction industry is very significant. Sawn wood, for example, is one of the top 5 construction materials consumed in the UK according to National Statistics. Embodied energy for building products considers the energy consumed in extraction and production stages. However, it is not the same consideration if this product is produced locally as when considering the resource produced further afield. Transport is a very relevant matter that profoundly influences in the results of embodied energy. The case of timber use in the UK is important because the balance between imports and exports is far negative, industry consuming more imported timber than produced. Nearly 80% of sawn softwood used in construction is imported. The imports-exports deficit for sawn wood accounted for more than 180 million pounds during the first four-month period of 2016. More than 85% of these imports come from Europe (83% from the EU). The aim of this study is to analyze climate change impact due to transport for timber products consumed in the UK. An approximate estimation of energy consumed and carbon emissions are calculated considering the timber product’s import origin. The results are compared to the total consumption of each product, estimating the impact of transport on the final embodied energy and carbon emissions. The analysis of these results can help deduce that one big challenge for climate change is the reduction of external dependency, with the associated improvement of internal production of timber products. A study of different types of timber products produced in the UK and abroad is developed to understand the possibilities for this country to improve sustainability and self-management. Reuse and recycle possibilities are also considered.

Keywords: embodied energy, climate change, CO2 emissions, timber, transport

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5044 The Impact of Shifting Trading Pattern from Long-Haul to Short-Sea to the Car Carriers’ Freight Revenues

Authors: Tianyu Wang, Nikita Karandikar

Abstract:

The uncertainty around cost, safety, and feasibility of the decarbonized shipping fuels has made it increasingly complex for the shipping companies to set pricing strategies and forecast their freight revenues going forward. The increase in the green fuel surcharges will ultimately influence the automobile’s consumer prices. The auto shipping demand (ton-miles) has been gradually shifting from long-haul to short-sea trade over the past years following the relocation of the original equipment manufacturer (OEM) manufacturing to regions such as South America and Southeast Asia. The objective of this paper is twofold: 1) to investigate the car-carriers freight revenue development over the years when the trade pattern is gradually shifting towards short-sea exports 2) to empirically identify the quantitative impact of such trade pattern shifting to mainly freight rate, but also vessel size, fleet size as well as Green House Gas (GHG) emission in Roll on-Roll Off (Ro-Ro) shipping. In this paper, a model of analyzing and forecasting ton-miles and freight revenues for the trade routes of AS-NA (Asia to North America), EU-NA (Europe to North America), and SA-NA (South America to North America) is established by deploying Automatic Identification System (AIS) data and the financial results of a selected car carrier company. More specifically, Wallenius Wilhelmsen Logistics (WALWIL), the Norwegian Ro-Ro carrier listed on Oslo Stock Exchange, is selected as the case study company in this paper. AIS-based ton-mile datasets of WALWIL vessels that are sailing into North America region from three different origins (Asia, Europe, and South America), together with WALWIL’s quarterly freight revenues as reported in trade segments, will be investigated and compared for the past five years (2018-2022). Furthermore, ordinary‐least‐square (OLS) regression is utilized to construct the ton-mile demand and freight revenue forecasting. The determinants of trade pattern shifting, such as import tariffs following the China-US trade war and fuel prices following the 0.1% Emission Control Areas (ECA) zone requirement after IMO2020 will be set as key variable inputs to the machine learning model. The model will be tested on another newly listed Norwegian Car Carrier, Hoegh Autoliner, to forecast its 2022 financial results and to validate the accuracy based on its actual results. GHG emissions on the three routes will be compared and discussed based on a constant emission per mile assumption and voyage distances. Our findings will provide important insights about 1) the trade-off evaluation between revenue reduction and energy saving with the new ton-mile pattern and 2) how the trade flow shifting would influence the future need for the vessel and fleet size.

Keywords: AIS, automobile exports, maritime big data, trade flows

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5043 GIS Mapping of Sheep Population and Distribution Pattern in the Derived Savannah of Nigeria

Authors: Sosina Adedayo O., Babyemi Olaniyi J.

Abstract:

The location, population, and distribution pattern of sheep are severe challenges to agribusiness investment and policy formulation in the livestock industry. There is a significant disconnect between farmers' needs and the policy framework towards ameliorating the sheep production constraints. Information on the population, production, and distribution pattern of sheep remains very scanty. A multi-stage sampling technique was used to elicit information from 180 purposively selected respondents from the study area comprised of Oluyole, Ona-ara, Akinyele, Egbeda, Ido and Ibarapa East LGA. The Global Positioning Systems (GPS) of the farmers' location (distribution), and average sheep herd size (Total Livestock Unit, TLU) (population) were recorded, taking the longitude and latitude of the locations in question. The recorded GPS data of the study area were transferred into the ARC-GIS. The ARC-GIS software processed the data using the ARC-GIS model 10.0. Sheep production and distribution (TLU) ranged from 4.1 (Oluyole) to 25.0 (Ibarapa East), with Oluyole, Akinyele, Ona-ara and Egbeda having TLU of 5, 7, 8 and 20, respectively. The herd sizes were classified as less than 8 (smallholders), 9-25 (medium), 26-50 (large), and above 50 (commercial). The majority (45%) of farmers were smallholders. The FR CP (%) ranged from 5.81±0.26 (cassava leaf) to 24.91±0.91 (Amaranthus spinosus), NDF (%) ranged from 22.38±4.43 (Amaranthus spinosus) to 67.96 ± 2.58 (Althemanthe dedentata) while ME ranged from 7.88±0.24 (Althemanthe dedentata) to 10.68±0.18 (cassava leaf). The smallholders’ sheep farmers were the majority, evenly distributed across rural areas due to the availability of abundant feed resources (crop residues, tree crops, shrubs, natural pastures, and feed ingredients) coupled with a large expanse of land in the study area. Most feed resources available were below sheep protein requirement level, hence supplementation is necessary for productivity. Bio-informatics can provide relevant information for sheep production for policy framework and intervention strategies.

Keywords: sheep enterprise, agribusiness investment, policy, bio-informatics, ecological zone

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5042 Management Strategies for Risk Events in Construction Industries during Economic Situation and COVID-19 Pandemic in Nigeria

Authors: Ezeabasili Chibuike Patrick

Abstract:

The complex situation of construction industries in Nigeria and the risk of failures involved includes cost overrun, time overrun, Corruption, Government influence, Subcontractor challenges, Political influence and Instability, Cultural differences, Human resources deficiencies, cash flow Challenges, foreign exchange issues, inadequate design, Safety, low productivity, late payment, Quality control issues, project management issues, Environmental issues, Force majeure Competition amongst others has made the industry prone to risk and failures. Good project management remains effective in improving decision-making, which minimizes these risk events. This study was done to address these project risks and good decision-making to avert them. A mixed-method approach to research was used to do this study. Data collected by questionnaires and interviews on thirty-two (32) construction professionals was used in analyses to aid the knowledge and management of risks that were identified. The study revealed that there is no good risk management expertise in Nigeria. Also, that the economic/political situation and the recent COVID-19 pandemic has added to the risk and poor management strategies. The contingency theory and cost has therefore surfaced to be the most strategic management method used to reduce these risk issues and they seem to be very effective.

Keywords: strategies, risk management, contingency theory, Nigeria

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5041 Measuring Development through Extreme Observations: An Archetypal Analysis Approach to Index Construction

Authors: Claudeline D. Cellan

Abstract:

Development is multifaceted, and efforts to hasten growth in all these facets have been gaining traction in recent years. Thus, producing a composite index that is reflective of these multidimensional impacts captures the interests of policymakers. The problem lies in going through a mixture of theoretical, methodological and empirical decisions and complexities which, when done carelessly, can lead to inconsistent and unreliable results. This study looks into index computation from a different and less complex perspective. Borrowing the idea of archetypes or ‘pure types’, archetypal analysis looks for points in the convex hull of the multivariate data set that captures as much information in the data as possible. The archetypes or 'pure types' are estimated such that they are convex combinations of all the observations, which in turn are convex combinations of the archetypes. This ensures that the archetypes are realistically observable, therefore achievable. In the sense of composite indices, we look for the best among these archetypes and use this as a benchmark for index computation. Its straightforward and simplistic approach does away with aggregation and substitutability problems which are commonly encountered in index computation. As an example of the application of archetypal analysis in index construction, the country data for the Human Development Index (HDI 2017) of the United Nations Development Programme (UNDP) is used. The goal of this exercise is not to replicate the result of the UNDP-computed HDI, but to illustrate the usability of archetypal analysis in index construction. Here best is defined in the context of life, education and gross national income sub-indices. Results show that the HDI from the archetypal analysis has a linear relationship with the UNDP-computed HDI.

Keywords: archetypes, composite index, convex combination, development

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5040 Investigation of the Speckle Pattern Effect for Displacement Assessments by Digital Image Correlation

Authors: Salim Çalışkan, Hakan Akyüz

Abstract:

Digital image correlation has been accustomed as a versatile and efficient method for measuring displacements on the article surfaces by comparing reference subsets in undeformed images with the define target subset in the distorted image. The theoretical model points out that the accuracy of the digital image correlation displacement data can be exactly anticipated based on the divergence of the image noise and the sum of the squares of the subset intensity gradients. The digital image correlation procedure locates each subset of the original image in the distorted image. The software then determines the displacement values of the centers of the subassemblies, providing the complete displacement measures. In this paper, the effect of the speckle distribution and its effect on displacements measured out plane displacement data as a function of the size of the subset was investigated. Nine groups of speckle patterns were used in this study: samples are sprayed randomly by pre-manufactured patterns of three different hole diameters, each with three coverage ratios, on a computer numerical control punch press. The resulting displacement values, referenced at the center of the subset, are evaluated based on the average of the displacements of the pixel’s interior the subset.

Keywords: digital image correlation, speckle pattern, experimental mechanics, tensile test, aluminum alloy

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5039 Improving Forecasting Demand for Maintenance Spare Parts: Case Study

Authors: Abdulaziz Afandi

Abstract:

Minimizing the inventory cost, optimizing the inventory quantities, and increasing system operational availability are the main motivations to enhance forecasting demand of spare parts in a major power utility company in Medina. This paper reports in an effort made to optimize the orders quantities of spare parts by improving the method of forecasting the demand. The study focuses on equipment that has frequent spare parts purchase orders with uncertain demand. The pattern of the demand considers a lumpy pattern which makes conventional forecasting methods less effective. A comparison was made by benchmarking various methods of forecasting based on experts’ criteria to select the most suitable method for the case study. Three actual data sets were used to make the forecast in this case study. Two neural networks (NN) approaches were utilized and compared, namely long short-term memory (LSTM) and multilayer perceptron (MLP). The results as expected, showed that the NN models gave better results than traditional forecasting method (judgmental method). In addition, the LSTM model had a higher predictive accuracy than the MLP model.

Keywords: neural network, LSTM, MLP, forecasting demand, inventory management

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5038 A Study on Fire Safety Standards through Case Study of Performance Based Design

Authors: Kyung Hoon Park, Hyung Jun Kim, Jong Wook Song

Abstract:

Super-tall building, large-scale and multi-purpose underground spaces reflect changes in construction trend. As current laws and codes such as Fire Services Act and construction codes are not enough to secure the fire safety of those structures and spaces, it is required to provide systemic supplement for performance-based design to establish or revise laws and technical standards to cope with the changes flexibly. In this study, the performance-based design standards of structures designed in Korea are compared with specification based design standards in an attempt to find the ways to establish fire safety standards for structures in Korea.

Keywords: performance based design, specification based design, fire safety design, life safety

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5037 A Comprehensive Finite Element Model for Incremental Launching of Bridges: Optimizing Construction and Design

Authors: Mohammad Bagher Anvari, Arman Shojaei

Abstract:

Incremental launching, a widely adopted bridge erection technique, offers numerous advantages for bridge designers. However, accurately simulating and modeling the dynamic behavior of the bridge during each step of the launching process proves to be tedious and time-consuming. The perpetual variation of internal forces within the deck during construction stages adds complexity, exacerbated further by considerations of other load cases, such as support settlements and temperature effects. As a result, there is an urgent need for a reliable, simple, economical, and fast algorithmic solution to model bridge construction stages effectively. This paper presents a novel Finite Element (FE) model that focuses on studying the static behavior of bridges during the launching process. Additionally, a simple method is introduced to normalize all quantities in the problem. The new FE model overcomes the limitations of previous models, enabling the simulation of all stages of launching, which conventional models fail to achieve due to underlying assumptions. By leveraging the results obtained from the new FE model, this study proposes solutions to improve the accuracy of conventional models, particularly for the initial stages of bridge construction that have been neglected in previous research. The research highlights the critical role played by the first span of the bridge during the initial stages, a factor often overlooked in existing studies. Furthermore, a new and simplified model termed the "semi-infinite beam" model, is developed to address this oversight. By utilizing this model alongside a simple optimization approach, optimal values for launching nose specifications are derived. The practical applications of this study extend to optimizing the nose-deck system of incrementally launched bridges, providing valuable insights for practical usage. In conclusion, this paper introduces a comprehensive Finite Element model for studying the static behavior of bridges during incremental launching. The proposed model addresses limitations found in previous approaches and offers practical solutions to enhance accuracy. The study emphasizes the importance of considering the initial stages and introduces the "semi-infinite beam" model. Through the developed model and optimization approach, optimal specifications for launching nose configurations are determined. This research holds significant practical implications and contributes to the optimization of incrementally launched bridges, benefiting both the construction industry and bridge designers.

Keywords: incremental launching, bridge construction, finite element model, optimization

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5036 Investigating the Motion of a Viscous Droplet in Natural Convection Using the Level Set Method

Authors: Isadora Bugarin, Taygoara F. de Oliveira

Abstract:

Binary fluids and emulsions, in general, are present in a vast range of industrial, medical, and scientific applications, showing complex behaviors responsible for defining the flow dynamics and the system operation. However, the literature describing those highlighted fluids in non-isothermal models is currently still limited. The present work brings a detailed investigation on droplet migration due to natural convection in square enclosure, aiming to clarify the effects of drop viscosity on the flow dynamics by showing how distinct viscosity ratios (droplet/ambient fluid) influence the drop motion and the final movement pattern kept on stationary regimes. The analysis was taken by observing distinct combinations of Rayleigh number, drop initial position, and viscosity ratios. The Navier-Stokes and Energy equations were solved considering the Boussinesq approximation in a laminar flow using the finite differences method combined with the Level Set method for binary flow solution. Previous results collected by the authors showed that the Rayleigh number and the drop initial position affect drastically the motion pattern of the droplet. For Ra ≥ 10⁴, two very marked behaviors were observed accordingly with the initial position: the drop can travel either a helical path towards the center or a cyclic circular path resulting in a closed cycle on the stationary regime. The variation of viscosity ratio showed a significant alteration of pattern, exposing a large influence on the droplet path, capable of modifying the flow’s behavior. Analyses on viscosity effects on the flow’s unsteady Nusselt number were also performed. Among the relevant contributions proposed in this work is the potential use of the flow initial conditions as a mechanism to control the droplet migration inside the enclosure.

Keywords: binary fluids, droplet motion, level set method, natural convection, viscosity

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5035 Association of Work Pattern with the Well-Being and Happiness: Evidence from Married Women Working in Delhi, India

Authors: Kanchan Negi

Abstract:

Background: Modern work culture has driven demands for people to work long hours and weekends and take work to home at times. Research on the health effects of these exhaustive temporal work patterns is scant or contradictory. This study examines the relationship between work patterns and well-being (including happiness) in a sample of working women. Method: Primary data of 360 currently married women working in the education, health, banking and IT sector in Delhi, India, were analysed. Logistic regression was used to estimate physical and psychological well-being and happiness across work characteristics. Results: Relative to 35–40 hours/week, working longer related to poor well-being (ß=0.75, 95% CI 0.12 to 1.39). Compared with not working weekends, working most or all weekends is related to poor physical (ß=0.34, 95% CI 0.08 to 0.61) and psychological well-being (ß=0.50, 95% CI 0.20 to 0.79). Rigid work patterns (ß=0.17, 95% CI −0.09 to 0.42) are also related to poor well-being. Conclusion: Decreased well-being and unhappiness are significantly linked to strenuous and rigid work patterns, suggesting that modern work culture may contribute to poor well-being. Flexible timings, compensatory holidays, work-from-home, and daycare facilities for young ones must be welcomed by companies to ease the dual burden of homemakers and career makers.

Keywords: happiness, well-being, work pattern, working women

Procedia PDF Downloads 173
5034 Computational Fluid Dynamics Simulation of Reservoir for Dwell Time Prediction

Authors: Nitin Dewangan, Nitin Kattula, Megha Anawat

Abstract:

Hydraulic reservoir is the key component in the mobile construction vehicles; most of the off-road earth moving construction machinery requires bigger side hydraulic reservoirs. Their reservoir construction is very much non-uniform and designers used such design to utilize the space available under the vehicle. There is no way to find out the space utilization of the reservoir by oil and validity of design except virtual simulation. Computational fluid dynamics (CFD) helps to predict the reservoir space utilization by vortex mapping, path line plots and dwell time prediction to make sure the design is valid and efficient for the vehicle. The dwell time acceptance criteria for effective reservoir design is 15 seconds. The paper will describe the hydraulic reservoir simulation which is carried out using CFD tool acuSolve using automated mesh strategy. The free surface flow and moving reference mesh is used to define the oil flow level inside the reservoir. The first baseline design is not able to meet the acceptance criteria, i.e., dwell time below 15 seconds because the oil entry and exit ports were very close. CFD is used to redefine the port locations for the reservoir so that oil dwell time increases in the reservoir. CFD also proposed baffle design the effective space utilization. The final design proposed through CFD analysis is used for physical validation on the machine.

Keywords: reservoir, turbulence model, transient model, level set, free-surface flow, moving frame of reference

Procedia PDF Downloads 137
5033 Embodied Energy in Concrete and Structural Masonry on Typical Brazilian Buildings

Authors: Marco A. S. González, Marlova P. Kulakowski, Luciano G. Breitenbach, Felipe Kirch

Abstract:

The AEC sector has an expressive environmental responsibility. Actually, most building materials have severe environmental impacts along their production cycle. Professionals enrolled in building design may choice the materials and techniques with less impact among the viable options. This work presents a study about embodied energy in materials of two typical Brazilian constructive alternatives. The construction options considered are reinforced concrete structure and structural masonry. The study was developed for the region of São Leopoldo, southern Brazil. Results indicated that the energy embodied in these two constructive systems is approximately 1.72 GJ•m-2 and 1.26 GJ•m-2, respectively. It may be concluded that the embodied energy is lower in the structural masonry system, with a reduction around to 1/4 in relation to the traditional option. The results can be used to help design decisions.

Keywords: civil construction, sustainability, embodied energy, Brazil

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5032 Value for Money in Investment Projects

Authors: Jan Ceselsky

Abstract:

Construction and reconstruction of settlements and individual municipalities, environmental management and the creation, deployment of the forces of production and building transport and technical equipment requires a large expenditure of material and human resources. That is why the economic aspects of the majority decision in these planes built in the foreground and are often decisive. Thereby but more serious is that the economic aspects of the settlement, the creation and function remain in their whole, unprocessed, and can not speak of a set of individual techniques and methods traditional indicators and experiments with new approaches. This is true both at the level of the national economy, and in their own urban designs. Still a few remain identified specific economic shaping patterns of settlement and the less it is possible to speak of their control. Also practical assessing economics of specific solutions are often used non-apt indicators in addition to economics usually identifies with the lowest acquisition cost or high-intensity land use with little regard for functional efficiency and little studied much higher operating and maintenance costs.

Keywords: investment, municipal engineering, value for money, construction

Procedia PDF Downloads 276
5031 Structure-Constructivism in the Philosophy of Mathematics

Authors: Jeansou Moun

Abstract:

This study argues that constructivism and structuralism, which have been the two important schools of mathematical philosophy since the mid-19th century, can and should be synthesized into structure-constructivism. In fact, the philosophy of mathematics is divided into more than ten schools depending on the point of view. However, the biggest trend is Platonism which claims that mathematical objects are "abstract entities" that exists independently of the human mind and material objects. Its opposite is constructivism. According to the latter, mathematical objects are products of the construction of the human mind. However, whether the basis of the construction is a logical device, a symbolic system, or an empirical perception, it is subdivided into logicism, formalism, and intuitionism. However, these three schools themselves are further subdivided into various variants, and among them, structuralism, which emerged in the mid-20th century, is receiving the most attention. On the other hand, structuralism which emphasizes structure instead of individual objects, is divided into non-eliminative structuralism, which supports the a priori of structure, and non-eliminative structuralism, which rejects any abstract entity. In this context, it is believed that the structure itself is not an a priori entity but a result of the construction of the cognitive subject and that no object has ever been given to us in its full meaning from the outset. In other words, concepts are progressively structured through a dialectical cycle between sensory perception, imagination (abstraction), concepts, judgments, and reasoning. Symbols are needed for formal operation. However, without concrete manipulation, the formal operation cannot have any meaning. However, when formal structurization is achieved, the reality (object) itself is also newly structured. This is the "structure-constructivism".

Keywords: philosophy of mathematics, platonism, logicism, formalism, constructivism, structuralism, structure-constructivism

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5030 Construction of a Fusion Gene Carrying E10A and K5 with 2A Peptide-Linked by Using Overlap Extension PCR

Authors: Tiancheng Lan

Abstract:

E10A is a kind of replication-defective adenovirus which carries the human endostatin gene to inhibit the growth of tumors. Kringle 5(K5) has almost the same function as angiostatin to also inhibit the growth of tumors since they are all the byproduct of the proteolytic cleavage of plasminogen. Tumor size increasing can be suppressed because both of the endostatin and K5 can restrain the angiogenesis process. Therefore, in order to improve the treatment effect on tumor, 2A peptide is used to construct a fusion gene carrying both E10A and K5. Using 2A peptide is an ideal strategy when a fusion gene is expressed because it can avoid many problems during the expression of more than one kind of protein. The overlap extension PCR is also used to connect 2A peptide with E10A and K5. The final construction of fusion gene E10A-2A-K5 can provide a possible new method of the anti-angiogenesis treatment with a better expression performance.

Keywords: E10A, Kringle 5, 2A peptide, overlap extension PCR

Procedia PDF Downloads 137
5029 Feasibility Study on the Application of Waste Materials for Production of Sustainable Asphalt Mixtures

Authors: Farzaneh Tahmoorian, Bijan Samali, John Yeaman

Abstract:

Road networks are expanding all over the world during the past few decades to meet the increasing freight volumes created by the population growth and industrial development. At the same time, the rate of generation of solid wastes in the society is increasing with the population growth, technological development, and changes in the lifestyle of people. Thus, the management of solid wastes has become an acute problem. Accordingly, there is a need for greater efficiency in the construction and maintenance of road networks, in reducing the overall cost, especially the utilization of natural materials such as aggregates. An efficient means to reduce construction and maintenance costs of road networks is to replace natural (virgin) materials by secondary, recycled materials. Recycling will also help to reduce pressure on landfills and demand for extraction of natural virgin materials thus ensuring sustainability. Application of solid wastes in asphalt layer reduces not only environmental issues associated with waste disposal but also the demand for virgin materials which will subsequently result in sustainability. Therefore, this research aims to investigate the feasibility of the application of some of the waste materials such as glass, construction and demolition wastes, etc. as alternative materials in pavement construction, particularly flexible pavements. To this end, various combination of different waste materials in certain percentages is considered in designing the asphalt mixture. One of the goals of this research is to determine the optimum percentage of all these materials in the mixture. This is done through a series of tests to evaluate the volumetric properties and resilient modulus of the mixture. The information and data collected from these tests are used to select the adequate samples for further assessment through advanced tests such as triaxial dynamic test and fatigue test, in order to investigate the asphalt mixture resistance to permanent deformation and also cracking. This paper presents the results of these investigations on the application of waste materials in asphalt mixture for production of a sustainable asphalt mix.

Keywords: asphalt, glass, pavement, recycled aggregate, sustainability

Procedia PDF Downloads 223
5028 Optimizing Pavement Construction Procedures in the Southern Desert of Libya

Authors: Khlifa El Atrash, Gabriel Assaf

Abstract:

Libya uses a volumetric analysis in designing asphalt mixtures, which can also be upgraded in hot, arid weather. However, in order to be effective, it should include many important aspects which are materials, environment, and method of construction. However, the quality of some roads was below a satisfactory level. This paper examines the factors that contribute to low quality of road performance in Libya. To evaluate these factors, a questionnaire survey and a laboratory comparative study were performed for a few mixes under-represented of temperature and traffic load. In laboratory, rutting test conducted on two different asphalt mixture, these mixes included, an asphalt concrete mix using local aggregate and asphalt binder B(60/70) at the optimum Marshall asphalt content, another mixes designed using Superpave design procedure with the same materials and performance asphalt binder grade PG (70-10). In the survey, the questionnaire was distributed to 55 engineers and specialists in this field. The interview was conducted to a few others, and the factors that were leading to poor performance of asphalt roads were listed as; 1) Owner Experience and technical staff 2) Asphalt characteristics 3) Updating and development of Asphalt Mix Design methods 4) Lack of data collection by authorization Agency 5) Construction and compaction process 6) Mentoring and controlling mixing procedure. Considering and improving these factors will play an important role to improve the pavement performances, longer service life, and lower maintenance costs. This research summarized some recommendations for making asphalt mixtures used in hot, dry areas. Such asphalt mixtures should use asphalt binder which is less affected by pavement temperature change and traffic load. The properties of the mixture, such as durability, deformation, air voids, and performance, largely depend on the type of materials, environment, and mixing method. These properties, in turn, affect the pavement performance.

Keywords: volumetric analysis, pavement performances, hot climate, traffic load, pavement temperature, asphalt mixture, environment, design and construction

Procedia PDF Downloads 249