bluuebunny/crossref_metadata_2025 huggingface dataset:
A RETROFIT METHOD FOR OLD PRECAST PANEL BUILDING
Authors: Yamamoto Haruyuki , Altangerel Ankhtuya , Huang He
Published: March 2020

This study is devoted to the development of improved methods and computer programs for predicting the seismic performance of existing precast panel structures. It is necessary to establish an experimental investigation as well as to develop a more detailed analysis and design procedures related to seismic design considerations for existing precast panel structures. The nonlinear behavior of precast panel buildings depends on the panel contact zones and this feature should be incorporated into the analytical models for the elasto-plastic nonlinear analysis. This study presents a newly designed finite element program developed on Fortran software for the nonlinear analysis of typical precast panel buildings. With the aid of this finite element program, eight different analytical models were designed and performed to simulate the nonlinear behaviors of panel contact zones under lateral loading. The analytical models were composed of four control models without any retrofitting and four models retrofitted using a steel bolted plates at the both horizontal and vertical joints between associated panels. A two-dimensional elasto-plastic nonlinear analysis with pushover method was performed on the analytical models, to obtain lateral force and displacement relationship. The simulation results illustrate the comparisons of lateral force-displacement curves for both the non-retrofitted and the retrofitted models. It was observed that all the retrofitted models showed a significant increase in strength and ductility.
TENSILE CHARACTERIZATION OF TEXTILE REINFORCED MORTAR
Authors: Younis Adel , Ebead Usama , Shrestha Kshitij
Published: March 2020

Textile reinforced mortar (TRM) is a composite material consisting of dry fibers embedded in a cementitious matrix, commonly used for strengthening masonry and concrete structures. In general, tensile characterization is required to identify the TRM mechanical properties, which are considered the key parameters needed for the structural design of strengthening systems. This paper presents the results of an experimental study conducted to investigate the tensile properties of TRM. In this effort, a total of 15 TRM coupons of 410 mm in length, 50 mm in width, and 10 mm in thickness were tested under uniaxial tensile load with clevis-type anchors. Three different types of textile materials were considered: carbon, glass, and polyparaphenylene benzobisoxazole (PBO). As for the study results, a common shape of the TRM tensile constitutive law was observed. Moreover, the average mechanical properties were listed for each type of TRM. Finally, the results and considerations presented in this work can enrich the literature with background data, which are beneficial for future applications of TRM systems in structural rehabilitation and repair.
DEFORMATION AND ULTIMATE STRENGTH OF R/C ARCH UNDER ASYMMETRIC LOAD
Authors: Hara Takashi
Published: March 2020

In this paper, the structural behavior of R/C arch was investigated by use of the finite element method considering combined geometric and material nonlinearities. Also, the experimental analyses were conducted based on the numerical results. The deep and shallow arches were adopted as the model. The arches were pin supported at both ends and were subjected to asymmetric concentrate loads in vertical direction. The deformation and the load bearing characteristics were investigated from the load-deflection behavior and the crack propagation patterns. From both numerical and experimental analyses, the load bearing behavior and the ultimate strength of R/C arches were in good agreement.
VIBRATIONAL PROPERTIES OF EARLY SHOWA PERIOD BILLBOARD ARCHITECTURE FOR RENOVATING DENSELY BUILT-UP WOODEN HOUSE AREAS
Authors: Takiyama Noriko , Hara Kohei , Sanuki Ryo , Matsumoto Masumi , Gondo Tomoyuki , Aoki Shigeru
Published: March 2020

We report the progress of our research on buildings and their surroundings for disaster prevention in Chuo-3, Ota City, which is an area in Tokyo, Japan with densely built-up wooden house areas. In a previous paper, we reported the results of an exhaustive survey of 383 buildings and roads in the northwest area of Chuo-3. As a continuation, in this paper, we present findings from an exhaustive survey of 426 buildings and microtremor measurements on the ground in a more widespread area. As a result, we found evidence of early Showa period billboard architecture. We subsequently measured the dimensions of the billboard architecture and surveyed the materials of the walls, roofs, windows, etc. Furthermore, we constructed a standard billboard architectural model and conducted eigenvalue analysis to evaluate their respective vibrational properties, such as the natural frequency and vibrational mode. Lastly, sensitivity analyses were conducted on the floor rigidity or materials of the walls.
HEAVYLIFTING OPERATIONS FOR THE ASSEMBLY OF A 150 M LONG SIMPLY SUPPORTED BRIDGE DECK
Authors: Marti Juan J. , Martinez Javier , Salamanca Jose L. , Salamanca Salvador , Delicado Alvaro , Saenz Alvaro , Espinosa de los Monteros Fernando
Published: March 2020

The new viaduct over the Cadiz Bay includes a removable deck to allow the navigation of large floating structures, higher than the 69 m clearance of the main cable-stayed span of the bridge. For this purpose, a 150 m long simply supported span was designed, which can be assembled and disassembled. The steel deck, weighing 4,000 metric tons, was completely manufactured onshore, the challenge being to move such a massive structure to its final position above the piers. It required for several heavylifting maneuvers, such as land transportation and load-out with two 6 x 28 axle lines of self-propelled modular transporters (SPMTs), sailing with a 100 m long barge and positioning the deck in-between the piers with a tight gap, a lifting with eight strand jacks 850 T capacity each and a final transversal shifting. The aim of this paper being to describe all the activities and the heavylifting equipment employed for the assembly of such a massive deck.
SERVICEABILITY OF LOW CREEP FLY ASH GEOPOLYMER CONCRETE BEAMS
Authors: Castel Arnaud , Foster Stephen , Gilbert Raymond Ian
Published: March 2020

In reinforced concrete construction, deflection control is an important performance criterion for their serviceability. The aim of the research described in this paper is to assess the deformation of cracked reinforced geopolymer concrete beams under long term service loading. The geopolymer binder is Portland cement free, using 85% of low calcium fly ash, 15% of GGBFS (Ground Granulated Blast Furnace Slag) and a sodium silicate/sodium hydroxide based activator. Firstly, geopolymer concrete drying shrinkage and creep were measured. Different curing conditions at elevated temperature were used. All experimental results are compared to predictions made using the Eurocode 2. Secondly, geopolymer concrete beams were subjected to short time bending tests leading to concrete cracking (pre-cracking tests). Beams were then stored under sustained loading for a period of four months. Both deflection and cracks were monitored versus time. Results show that, providing an appropriate heat curing regime, geopolymer concrete creep is much lower than that observed for OPC concrete and predicted by the Eurocode 2. As a result, the time-dependent deflection of geopolymer concrete beams measured after 4 months under sustained loading was always significantly lower than that of traditional OPC concrete beams. All results are showing that the crack widths of geopolymer concrete beams are significantly smaller than those expected for OPC concrete beams according to fib model code 2010 for both short and long terms tests. It is concluded that low calcium fly ash-based geopolymer concrete is a promising option for precast applications.
MOMENT AMPLIFICATION FACTOR OF BEAM-COLUMNS WITH INITIAL DEFLECTION
Authors: Utsunomiya Haruna , Haraguchi Masayuki , Kido Masae , Tsuda Keigo
Published: March 2020

In the design of slender steel beam-columns, the moment amplification factor is used to estimate the maximum bending moment. The formulas for evaluating the factor have been presented on the basis of the elastic or elastic-plastic analysis, however the initial deflection of beam-columns is not considered. This paper discusses the effect of initial deflection on the value of the moment amplification factor by performing the analytical work. The analytical model is a simply supported beam-column subjected to constant axial compressive force and end moments. First of all, the equilibrium differential equation which governs the problem is solved and the formula for calculating the bending moment is obtained. In the parametric study, magnitude of the initial deflection, the axial load ratio, the slenderness ratio and the end moment ratio are selected as the parameters. The effects of magnitude of the initial deflection and the end moment ratio on the moment amplification factor are discussed.
EFFECT OF STRAIN-STRESS RELATIONSHIP OF STEEL TUBE ON THE INITIAL STIFFNESS OF SQUARE CFT COLUMNS
Authors: Handa Ryo , Kido Masae , Liu Mao , Tsuda Keigo
Published: March 2020

The restoring force characteristic of a concrete filled steel tubular (CFT) column is modeled with three straight lines which show the relation of M-R. The initial stiffness is calculated by assuming that the steel and concrete portions are fully effective and materials are elastic. The first break point is the yield bending moment of the CFT column. The yield bending moment is defined by the bending moment when a part of the cross-section yield or the allowable strength for short-term loading obtained by the superposed strength method. It is supposed that the theoretical initial stiffness obtained by assuming that the whole cross section is effective is different from the real one. This study aims to clarify effects of strain-stress relation on the yield strength and allowable strength for short-term loading and the initial stiffness. Three types of stress-strain relations for steel are used, elastic-perfectly plastic model, Menegotto-Pinto's model and Morino's model. According to the analytical results, the difference between allowable strength and yield strength becomes larger as the axial load ratio, indexes Rh and k which are used in Menegotto-Pinto's model and Morino's model increase.
REHABILITATION OF BOX GIRDER BRIDGE
Authors: Alani Kawan , Ahmed Abdullah
Published: March 2020

A large pre-stress continuous box girder bridge consists of two separate parts, ten spans deck and eight spans deck. The bridge was subjected to multiple airstrikes, which caused several damages. The most serious are the complete destruction of four conductive spans in the ten spans deck, the movement of the remaining six spans longitudinally by about 1.25 m and transversely by about 0.1 m. Local damages occurred in other parts of the deck structure and minor damages in the piers and abutments. The deck structures were constructed by incremental launching method (ILM). Rehabilitation of the bridge included repair of the local damages, lifting and re-instatement the six spans, which weighs about 9,000 tons, to its original position, the constructing and launching of new box girder to substitute for missing spans, and finally connecting old and new spans effectively. This paper introduces briefly the re-instatement of the six spans, connection details between the old new structures, then assessing the efficiency of connection by analysis and load testing the connecting span.
ANALYSIS OF TIMBER COLUMN-GROUND SILL JOINTS REINFORCED WITH IMPROVED ARAMID FIBER SHEETS
Authors: Yamaguchi Akari , Chen Xinyan , Takiyama Noriko
Published: March 2020

High-performance aramid fiber sheets are a new class of composite materials made up of weaved polyamide fibers. In this study, the seismic performance and failure behavior of timber column-ground sill joints reinforced with aramid fiber sheets were investigated. In a past study, we conducted bending tests under cyclic loading for three column-ground sill specimens. After reinforcing the specimens with aramid fiber sheets, the joint strength improved but was dependent on the method of attaching the sheet. It was found that the compression zone of the aramid fiber-reinforced plastic layer broke at the joint boundary. In this paper, we proposed an improvement in the method of attaching the fiber sheet to the joint. On the compression zone at the boundary of the joint, resin was not pasted onto the aramid fiber, the fiber was not cured, and the plastic layer was not formed. Therefore, we could solve some problems and control the failure of column-ground sill joints.
STAND-ALONE EDUCATIONAL CENTER
Authors: Al Shali Rashid , Qadir Ghulam , El Naffar Asalah , Hittini Batoul , Obaid Aisha , Rida Hind
Published: March 2020

The world is suffering from the worse refugee crises since World War II as Syria alone has 7.6 million. Out of which 85,000 people (December 2015) are living at Al Zaatari camp located in Jordan near to Jerusalem. A need to design and build a sustainable self-sufficient educational center for the school children was felt. A district wise study and site analysis was performed using geographical information and climate analysis computer tool, Climate Consultant 6.0 to figure out important factors like quantity of ground water, rainfall intensity, solar radiation and sun path at the site. Integrating different sustainable active and passive strategies for energy generation developed building plan. The model was simulated using annual whole building energy modeling software (Safeira â„¢), Photovoltaics can produce 50% of the required energy, natural ventilation and geothermal heat pump can reduce the annual energy consumption by 9.28% and 2% respectively, if used in months in which they are more useful whereas the remaining energy can be covered by wind turbines. With skylights, enough daylight was provided (unlit areas were reduced to 10%) and providing natural ventilation as well. It was concluded that a Stand-Alone refugee center for Syrian refugees at Al Zatari camp is possible and could well be constructed if proper support from international community is provided.
PREVALENCE AND VALUE OF BUILDING INFORMATION MODELING USES IN CONSTRUCTION
Authors: Leicht Robert M. , Niu Miaomiao , Messner John I.
Published: March 2020

Despite the growth in interest and rapid technological development of Building Information Modeling tools and processes, the adoption of modeling uses to advance construction tasks in the field have been slow in adoption. A list of 30 modeling uses for construction are presented, based upon previous research that develops a taxonomy of modeling uses for construction specific tasks. This research presents survey responses from over 250 industry practitioners regarding the status of industry adoption, perceived value, and level of difficulty to implement for a list of 30 modeling uses specific to construction. Findings highlight the differing perspectives by industry sector and role. In addition to the providing insights into the status of adoption, the paper will introduce the concept of methods as a key differentiator of construction modeling uses that influence their adoption and value in support of construction tasks.
OPTIMIZING GREEN-BUILDING PROJECT DELIVERY: COMPARATIVE ANALYSIS OF DESIGN-BID-BUILD AND DESIGN-BUILD DELIVERY METHODS USING CASE STUDIES
Authors: Orsi Alessandro , Pellicer Eugenio , Guillen Guillamon Ignacio
Published: March 2020

The development of a green-building project following a specific reference standard, such as LEED or BREEAM, brings new conditions and restrains for all subjects involved in the process. Within this scope, project management plays a key role for the optimization of the design-project development. This research develops a comparative analysis between the design processes of two case-study projects from the project management perspective, taking into consideration all the activities that negatively affected the project design development. The first project design was developed following the so-called "design-bid-build" process with the fragmentation of the process where each subject and technician involved worked independently from the others. The second project design was developed following a "turn-key" philosophy using a completely integrated process. A new methodology was created in order to analyze the project and evaluate the effects of detected project-management issues under three different points of view: costs, time and building sustainability. Such issues were identified by researchers on the basis of the Lean-definition of "waste". The results showed that process integration affects considerably the cost, schedule and sustainability level of the project design and vice versa, the accuracy of the project management tasks affect the sustainability features of the final building design.
STRENGTHENING OF RC BEAMS SUBJECTED TO CYCLIC LOAD USING ULTRA HIGH-PERFORMANCE STRAIN HARDENING CEMENTITIOUS COMPOSITES
Authors: Khalil Abd El-Hakim , Etman Emad , Atta Ahmed , Essam Mohamed
Published: March 2020

Ultra High-Performance Strain Hardening Cementitious Composites (UHP-SHCC) is a composite material comprising a cement-based matrix and short fibers with outstanding mechanical and protective performance having advantages as large strain capacity as well as high compressive and tensile strength, which is useful for strengthening or repair concrete members. In the present study, five specimens were tested experimentally, one as a control and four strengthened with 40 mm thickness of UHP-SHCC layer attached from tension side with variable reinforcement ratios embedded in strengthening layer. Cyclic loading was applied to all specimens. The test results showed the importance of reinforcing the UHP-SHCC to eliminate the observed early strain localization and to gain adequate dissipated energy under cyclic loading. It is also proved that using an unreinforced UHP-SHCC layer for strengthening may lead to a brittle failure especially in case of cyclic load.
TRANSFORMING INTO A KNOWLEDGE-BASED SOCIETY: EXAMINING THE ROLES OF HIGHER EDUCATION INSTITUTIONS
Authors: Aliu John , Aigbavboa Clinton
Published: March 2020

More than ever, the Nigerian construction industry requires construction professionals who are responsive to economic, technical, social and environmental change and can fit into the world of work. Apart from possessing the requisite non-academic skills, construction graduates need to be abreast with the dynamics of the construction industry to contribute meaningfully to its activities. Thus, the roles of Higher Education Institutions (HEIs) have become more critical in skill creation and impartation as students of today are to be adequately prepared to take up industry responsibilities in various roles. In building a knowledge-based society, the level of construction pedagogy in HEIs is key in the economic development of any nation. This paper identifies the various roles HEIs play in improving the level of construction pedagogy delivered to future construction professionals. An extant review of literatures was conducted from databases such as Springer, Scopus, ASC conference proceedings amongst others. Findings from this study revealed that that government alone cannot provide the resources needed to provide qualitative higher education, and advocates for other sources of dealing with these challenges. Hence, the findings of this paper provide a basis for HEIs in Nigeria to get involved in improved teaching, training and research as these actions are key in contributing to the success of the construction industry as well as transforming Nigeria into a knowledge-based society.
A VALIDATION OF A RE-EQUILIBRIUM DECISION SUPPORT SYSTEM FOR PPP CONTRACTS
Authors: Shalaby Amira , Hassanein Amr , Hannoura Atter
Published: March 2020

A re-equilibrium model was developed which ensures that the rights of the Public Private Partnership (PPP) project stakeholders are preserved during renegotiation and minimizes the chances of disputes. The model develops the typical renegotiation scenarios which include: increasing the service charges, increasing the concession period, or paying a lump sum amount to the party of concern in order to maintain a fixed rate of return and keep the return on equity constant. Moreover, a decision support system was developed with the aid of Microsoft Excel 2013, Visual Basic for Applications (VBA) programming language, and the Precision Tree 5.5 for Excel addin, in order to facilitate the process of selecting the optimum scenario which maximizes the satisfaction of both parties (the private sector and the public sector). In this paper, data is obtained from a case study of a wastewater treatment plant in Egypt, and applied to the proposed model. The results obtained from the model are close to the ones obtained from the Independent Financial Expert (IFE) of the wastewater treatment plant project. This verifies and validates the objectives of the model.
DEALING WITH WEATHER-RELATED CLAIMS IN CONSTRUCTION CONTRACTS: A NEW APPROACH
Authors: Ballesteros-Pérez Pablo , Kabiri Shabnam , Smith Stefan T. , Hughes Will
Published: March 2020

Project execution is often delayed by extreme and unforeseen weather conditions. This is because extreme weather usually causes work disruption, waste of resources, significant project delays and, eventually, financial losses for both the contractor and the project owner. Construction contracts generally include weather-related clauses addressing when, and to what extent, the responsibilities and consequences of adverse weather are to be shared or compensated. However, setting clear and objective limits for abnormal weather is problematic, starting with the lack of agreement about which weather conditions can be considered as "normal" or "average”. Research on the influence of weather on construction productivity is scarce and underdeveloped. Therefore, practitioners cannot count on sound methods to mediate in and evaluate weather-related contract disputes. In these situations, claims are likely to arise and escalate. A stochastic model for objectively evaluating the weather influence during the execution stage is proposed. This model allows actual weather to be compared to historical data in a way that provides an objective assessment of the extent to which the adverse weather was (or not) exceptional. A case study of a fictional project is used to show its implementation. This is the first tool of its kind to address this concern with a straightforward, holistic and quantitative approach.
DUCTILITY ENHANCEMENT OF RC BEAMS STRENGTHENED WITH STRAIN HARDENING CEMENTITIOUS COMPOSITES
Authors: Khalil Abd El-Hakim , Etman Emad , Atta Ahmed , Essam Mohamed
Published: March 2020

Ultra High-Performance Strain Hardening Cementitious Composites (UHP-SHCC) is a newly developed construction material, has large advantages on large strain capacity as well as high compressive and tensile strength, which is useful for strengthening or repair concrete members. An important obstacle needs to be studied, is the strain localization occurs in the UHP-SHCC strengthening layer around the substrate concrete cracks, which severely limits the ductility of the strengthened beam. In the present study, five specimens were tested experimentally, one as a control and four strengthened with variable reinforcement ratios embedded in the strengthening layer. The recorded tests showed that it is sufficient to use 1.2% additional reinforcement ratio embedded in the strengthening layer for beams strengthened with UHP-SHCC to eliminate the observed early strain localization and to gain adequate ductility. Another important conclusion is the strengthening of RC structures using an unreinforced UHP-SHCC layer may lead to a brittle failure.
EXPLORING BARRIERS IN IMPLEMENTING BUILDING INFORMATION MODELING: A PRELIMINARY STUDY
Authors: Bekr Ghanim A.
Published: March 2020

This study involves with Building Information Modeling (BIM) and exploring the reasons behind the slow speed of implementing this method in the construction industry in developing countries in general and Jordan in specific. The aim of the research was achieved through a survey which considered 15 barrier factors and 13 driving factors. The study revealed that the level of BIM implementation in construction projects is generally low. In addition, the significant barriers affecting the adoption of BIM are lack of qualified staff to operate the software, difficulty learning BIM, the existing system fulfils the need, resistance to change and uncertainties concerning return on investment of BIM. Also, the study pointed out the most important factors that could help implementing BIM in the Jordanian construction industry. These are providing BIM training program, introducing BIM in the university curriculum and providing the efforts by the government to push implementation of BIM in their projects. Finally, the paper presented some recommendations if followed the level of (BIM) implementation in this country may be improved.
SPATIAL REGRESSION ANALYSIS FOR MODELING THE SPATIAL VARIATION IN HIGHWAY CONSTRUCTION COSTS
Authors: Baek Minsoo , Ashuri Baabak
Published: March 2020

Price volatility in wages, materials, and equipment has a significant impact on highway construction costs. As the construction market and economy have experienced dynamic changes in prices, the price volatility becomes less predictable. In addition, various levels of the price volatility in different market locations aggravate the prediction. Thus, in developing highway construction costs, transportation agencies should consider geographical location of construction projects and market conditions of the locations. Transportation agencies face significant uncertainties in price volatility across different geographical locations. This volatility may not be uniformly distributed across different geographical locations due to changes in the availability of local contractors, materials, equipment, and labor. The objective of this research is to develop statistical models that are capable to explain spatial variations in submitted unit prices for asphalt line items in highway projects considering local market condition factors. Historical bid data used in this research consist of resurfacing and widening projects let in the state of Georgia, the United States, between 2008 and 2015. The methodology of this research is a spatial regression analysis to explain the spatial variation in the submitted unit prices for asphalt line items. The findings of this research indicate that volatility in submitted bid prices is not uniformly distributed across different geographical locations within the same transportation agency. The contribution to the body of knowledge of this research is an improved understanding of the role of local construction market and macroeconomic conditions to explain geographic variability in construction costs.
USING EYE MOVEMENTS TO IDENTIFY HAZARDS MISSED BY AT-RISK WORKERS
Authors: Hasanzadeh Sogand , Esmaeili Behzad , Dodd Michael D. , Pellicer Eugenio
Published: March 2020

Identifying hazardous situations is a complex and multidimensional cognitive process that requires the proper allocation of workers’ attention. Eye-tracking technologies provide a viable option for studying construction workers’ attentional allocation and for linking attention to their hazard-identification capabilities. The objective of the study is to use eye-movement measures to determine which types of hazards construction workers miss, ignore, or perceive to be insignificant. In order to achieve this goal, 31 construction workers participated in a controlled laboratory experiment in which they searched for hazards in images of 35 real construction-site scenarios while a head-mounted EyeLink II tracked their eye movements. The results showed differences in the participants’ attentional distributions and that the hazard identification of workers with low and high hazard-identification skills stems from the types of hazard—not the number of hazards—within the scenarios. Further investigation on five images revealed that at-risk workers dwelt on imminent danger (e.g., workers in dangerous areas) rather than spreading their attentional efforts searching for sources of non-obvious hazards, including electrical hazards, housekeeping hazards and fall-protection-system-related hazards. The results of this experiment can thus support personalized safety training that targets at-risk workers.
PRESERVING TRADITIONAL CONSTRUCTION TECHNIQUES AND MATERIALS AS AN ANSWER TO FUTURE ENERGY-FUEL CRISIS
Authors: Villacis Enrique , Rodriguez Maria Lorena , Ayarza Cynthia
Published: March 2020

Once a highly skilled and experienced professor told us: the future of architecture is in its handcraft past. We were not able to completely understand him at that time. Looking forward to the future where architecture and engineering professionals will perform facing energy fuel crisis and global warming, an endogenous approach, working with what is available, may be a subsistence tool. Preserving and further development of traditional construction materials, methods and techniques now has become a must, not form the cultural heritage stand point but as a survival instrument. In this paper we will analyze three different roofing systems, two of them ancestral techniques; toquilla leaf roof and straw thatch roofs, using them in real contemporary construction circumstances by incorporating them into the professional life through real construction projects and the educational system through Con lo que hay, a design-build class room in architectural school in Ecuador, facing them with conventional zinc metal roofing. This study will show the impact of recovering these techniques and materials within the academic, the professional, scientific development and on the local economies.
AN ASSET MANAGEMENT FRAMEWORK FOR RAMP METERING SYSTEMS AND ADAPTIVE TRAFFIC CONTROL SYSTEMS
Authors: He Song , Salem Ossama , Salman Baris
Published: March 2020

Transportation systems management and operations (TSM&O) strategies such as adaptive traffic control systems (ATCSs) and ramp metering systems (RMSs) can be utilized to exploit existing transporting capacity instead of undertaking costly new construction projects. This paper presents an asset management framework for TSM&O components used in ATCSs and RMSs including signal heads, controllers, detectors, supporting structures, and communication lines to support the decision making processes of transportation agencies. ATCS and RMS overall condition ratings and importance indices are the two parameters that contribute to prioritization of these TSM&O applications. A fuzzy logic approach is used to combine these two major components. Inspection guidelines and published cost databases are primary data sources, while economic (agency), social (traveler), and environmental benefits that would be lost in case of failures are considered in developing procedures to determine the importance indices. This asset management framework allows transportation agencies to identify ATCS and RMS deployments with high risk considering both the condition levels and benefits provided by these deployments, and hence constitutes a highly important step towards development of risk management and mitigation plans featuring appropriate maintenance, repair and rehabilitation (MRR) strategies. Future research can integrate additional TSM&O components into the asset management framework, and the boundary of benefits considered in determining the importance indices can be expanded.
INNOVATIVE IMPLICIT FINITE DIFFERENCE SOLUTION TO TIME RATE OF SETTLEMENT IN CLAY
Authors: Al-Khafaji Amir W.
Published: March 2020

The primary consolidation process in clay involves changes in excess pore water pressure (EPWP) with time. The changes in the EPWP are related to permeability, void ratio, and boundary conditions. Closed-form solutions for simple initial EPWP have been published. Such solutions include simplifying assumptions and limited to few impractical initial EPWP distributions. Generally, the initial EPWP encountered in practice is complex, in which case, numerical methods are used. The finite differences and the finite element methods are the primary tools employed in the analysis of settlement behavior of fine-grained soils. Unfortunately, these methods suffer from three main problems: (1) they require evaluation of EPWP vectors at each time increment which results in a large number of calculations; (2) roundoff errors at each time increment; and (3) the solution for a given initial EPWP distribution is achieved at a predetermined integer time increment. An innovative explicit finite difference model is proposed that will permit any initial EPWP distribution, substantially reduces the number of calculations and roundoff errors.
WIND PRESSURE DISTRIBUTION ON NORTH-LIGHT INDUSTRIAL BUILDING ROOF STUDY
Authors: Verma Astha , Ahuja Ashok Kumar
Published: March 2020

Present paper describes details of the experimental study carried out on the models of industrial building with north-light roof in order to generate the information about wind pressure distribution on it. The models are tested in a closed circuit boundary layer wind tunnel to measure values of wind pressures on roof surface. Four cases namely one, two, three and four spans are considered. The side of Perspex sheet model in case of multi-span study places plywood models. Wind is made to hit the models at 13 wind incidence angles from 0° to 180° at an interval of 15°. Values of mean wind pressure coefficients are evaluated from the measured values of wind pressures and contours are plotted.
NON-CRACKING TECHNIQUES FOR GROUTING
Authors: Todorov Miroslav
Published: March 2020

Techniques for improving the ground base have been used since ancient times. The need of the geotechnical engineer to use zones with weak (cracked or high porosity) soil poses new, increasingly complicated problems. The solutions must consider requirements for the materials used and restrictions over the invasion. The use of natural (inorganic) materials is an approach resulting from the low speed of the change of the properties. The insignificant effect of the environment on the properties of the materials to be grouted is unquestionable. Here we should consider a number of factors connected with the anthropogenic conditions. An important aspect in the choice of materials is the expected positive changes in the structure and properties of the natural materials-improvement of soil skeleton structure, preservation of the migration of water, filling saturation, decreasing the consolidation deformability and others. The use of techniques for grouting with relatively small influence over the structure and properties of the natural materials requires certain basic mechanical parameters. Here we should pay attention to the scale of the interventions as a whole, the effect of which is considerably smaller than in usual techniques for different deep foundations. Another important aspect of these techniques is the economic effect, which creates conditions for a number of optimizations concerning the use of small-scale resources, by-products (colloidal clay, flay ash, lime, gypsum), small quantities of waste products, short periods for realization and others.
EFFECTS OF RESIDUAL RUST ON STRENGTH RECOVERY OF CORRODED STEEL PLATE REPAIRED WITH PATCH PLATE
Authors: Ogami Hiroshi , Fujii Katashi , Yokota Ryuichi , Kawano Makoto , Horii Hisakazu
Published: March 2020

In Japan, there have been found a lot of corrosion damages recently in steel bridges aged for fifty or more years. If the strength of a steel structure is decreased by serious corrosion damages, the structure must be repaired to ensure its safety. In order to supplement the strength loss of a steel member with local corrosion, steel plate bonding method is often adopted, where the corroded area is covered with steel plate bonded by adhesive. In this case, surface preparation is the most important issue to bond the cover plates completely. In this method, surface preparation is the most important issue to bond the cover plates completely. However, it is quite difficult to completely remove rust and wastes in the fieldwork of surface preparation. Thus, this paper presents recovery effect of local corroded steel plate by steel plate bonding method when rust is not completely removed. Specimens are rectangular steel plates with irregular surface which imitated local corrosion in the center of plate. Then rust is also imitated rather than actual one to quantitatively evaluate the recovery effect. Axial tensile tests were conducted for these specimens repaired with patch plate. Then, the size of patch plate and amount of rust were changed and investigated how these differences affect the peeling off of the patch plate.
Design of River Tour Boat’s Hull For Taman Nasional Tanjung Puting, Central Borneo
Authors: Utama Danu , Nasirudin Ahmad , Iqbal Muhammad
Published: March 2020

Tanjung Puting National Park is a natural wildlife park with a positively increasing trend in the number of visitors. The transportation which is utilized in Sekonyer river is ‘klotok’ boat, a traditional tour boat modified from a fishing boat. The design of a fiberglass-based tour boat is needed to accommodate the limitation of Kalimantan’s logs, which become the main structural components of klotok and to comply with the technical characteristic of the river. The purpose of this study is to obtain the optimum main dimensions of the fiberglass-based tour boat and its hull form design. The method performed to obtain the main dimension of the boat is non-linear optimization with the help of solver in Microsoft Excel software. The process of boat’s hull design is done by line distortion approach where the shape of a reference boat’s hull is conformed to a particular size and hydrodynamical coefficients, which are obtained from the optimization process. The result of optimization process is the main dimension of the boat (Lpp = 12.23 m, B = 2.70 m, H = 1.14 m, T = 0.80 m and Cb = 0.55). By conducting a series of calculations, the obtained value of the total boat’s resistance worths 2,427 N. Therefore, the number of boat’s power needed is less than the power of existing boats. The boat’s hull also complies with technical requirements and regulations, which are freeboard and intact stability.
Estimation of Effective Wave Slope Coefficient of Ships with Large Breadth and Draught Ratio
Authors: Paroka Daeng , Muhammad Andi Haris , Rahman Sabaruddin
Published: March 2020

One of parameters to estimate heel angle of a ship in beam seas is effective wave slope coefficient. In the weather criterion of IMO, the effective wave slope coefficient is determined as function of ratio between distance of center of gravity from the sea surface and the ship draught. The others methods could be used to estimate the effective wave slope coefficient are simplified strip theory and model experiment. A ship with shallow draught and large vertical center of gravity can have an effective wave slope coefficient larger than 1.0 if the coefficient is calculated by using the formulae of weather criterion. Therefore, an alternative method to estimate the coefficient is necessary when it is applied to ships with geometry characteristics different with those used to develop the formulae. This research conducts to estimate the effective wave slope coefficient using three different methods, namely the formulae of weather criterion, the simplified strip theory and model experiment. Results of the three methods may provide enough evidence about suitable method to estimate the effective wave slope coefficient of ships with breadth and draught ratio larger than 3.5 like the Indonesian ro-ro ferries. Results and discussion show that the effective wave slope coefficient obtained by using the formulae of weather criterion is larger compared to that obtained by using the simplified strip theory and the model experiment. Here, the result of simplified strip theory for wave frequency the same as the roll natural frequency of subject ship is similar with the result of model experiment. This results show that the simplified strip theory can be used as an alternative method to determine the effective wave slope of a ship with breadth and draught ratio larger than 3.5 if the result of model experiment does not available.
Modelling of the system “driver - automation - autonomous vehicle - road”
Authors: Koralewski Grzegorz
Published: March 2020

The work presents a simulation model of a “driver–automation–autonomous vehicles–road” system which is the basis for synthesis of automatic gear shift control system. The mathematical description makes use of physical quantities which characterise driving torque transformation from the combustion engine to the car driven wheels. The basic components of the model are algorithms for the driver’s action logic in controlling motion velocity, logic of gear shift control functioning regarding direction and moment of switching, for determining right-hand side of differential equations and for motion quality indicators. The model is realised in a form of an application software package, comprising sub-programmes for input data, for computerised motion simulation of cars with mechanical and hydro-mechanical – automatically controlled – transmission systems and for models of characteristic car routes.
Decomposition rank of approximately subhomogeneous C*-algebras
Authors: Elliott George A. , Niu Zhuang , Santiago Luis , Tikuisis Aaron
Published: March 2020

It is shown that every Jiang–Su stable approximately subhomogeneous

C
*

{{\mathrm{C}^{*}}}

-algebra has finite decomposition rank.
This settles a key direction of the Toms–Winter conjecture for simple approximately subhomogeneous

C
*

{{\mathrm{C}^{*}}}

-algebras.
A key step in the proof is that subhomogeneous

C
*

{{\mathrm{C}^{*}}}

-algebras are locally approximated by a certain class of more tractable subhomogeneous algebras, namely a non-commutative generalization of the class of cell complexes.
The result is applied, in combination with other recent results, to show classifiability of crossed product

C
*

{{\mathrm{C}^{*}}}

-algebras associated to minimal homeomorphisms with mean dimension zero.
An Ultra-compact Plasmonic Modulator Using Elasto-optic Effect and Resonance Phenomena
Authors: Vaidya Tanvi , Chauhan Diksha , Mola Genene Tessema , Dwivedi Ram Prakash
Published: March 2020

We theoretically demonstrate an ultra-compact plasmonic modulator and switch of sub-micron size using elasto-optic effect with quite acceptable modulation ratio. The device is based on metal-dielectric-metal waveguide structure and uses resonance phenomena. The modulation mechanism originates by electrically changing thickness of dielectric layer made of elasto-optic material, which changes the effective refractive index of propagating optical mode. All the results are obtained using FEM simulation software. The seamless integration of optical beam modulation bears significant potential towards broadband, compact and efficient communication links and circuits.
Rough sets based on fuzzy ideals in distributive lattices
Authors: Yang Yongwei , Zhu Kuanyun , Xin Xiaolong
Published: March 2020

In this paper, we present a rough set model based on fuzzy ideals of distributive lattices. In fact, we consider a distributive lattice as a universal set and we apply the concept of a fuzzy ideal for definitions of the lower and upper approximations in a distributive lattice. A novel congruence relation induced by a fuzzy ideal of a distributive lattice is introduced. Moreover, we study the special properties of rough sets which can be constructed by means of the congruence relations determined by fuzzy ideals in distributive lattices. Finally, the properties of the generalized rough sets with respect to fuzzy ideals in distributive lattices are also investigated.
New fixed point results inbv(s)-metric spaces
Authors: Došenović Tatjana , Kadelburg Zoran , D. Mitrović Zoran , Radenović Stojan
Published: March 2020

Z. D. Mitrović and S. Radenović introduced in [The Banach and Reich contractions inbv(s)-metric spaces, J. Fixed Point Theory Appl.19(2017), 3087–3095] a new class of generalized metric spaces and proved some fixed point theorems in this framework. The purpose of this paper is to consider other kinds of contractive mappings inbv(s)-metric spaces, and show how the work in the new settings differs from the one in standard metric andb-metric spaces. Examples show the usefulness of the obtained results.
Equibiaxially stretchable colorless and transparent polyimides for flexible display substrates
Authors: Chang Jin-Hae
Published: March 2020

4,4′-(4,4′-isopropylidenediphenoxy)bis(phthalic anhydride) (BPADA) was reacted with three structurally different diamines to produce poly(amic acid)s, which were then imidized to produce colorless and transparent polyimide (CPI) films through stepwise thermal cyclization. The three amines used to synthesize CPI based on BPADA are: bis(3-aminophenyl)sulfone (APS),p-xylyenediamine (p-XDA), and bis[4-(3-aminophenoxy)-phenyl] sulfone (m-BAPS). The obtained CPI films were almost colorless and exhibited excellent optical transparencies. The solubility of the CPI films in various solvents was investigated, and all the CPI films were found to be soluble in common solvents such as chloroform, dichloromethane,N,N’-dimethyl acetamide, and pyridine. The thermo-optical properties and oxygen transmission rates (O2TRs) of the CPI films were examined for various biaxial stretching ratios in the range of 100–150%, and their properties were compared. When the stretching ratio changed from 100 to 150%, the glass transition temperature and yellow index did not show any significant change; however, the O2TR decreased for all CPI films.
A new numerical method for 1-D backward stochastic differential equations without using conditional expectations
Authors: Sghir Aissa , Hadiri Sokaina
Published: March 2020

In this paper, we propose a new numerical method for 1-D
backward stochastic differential equations (BSDEs for
short) without using
conditional expectations. The approximations of the solutions
are obtained as solutions of a backward linear
system generated by the terminal conditions. Our idea is inspired
from the extended Kalman filter to non-linear system models by using
a linear approximation around deterministic nominal reference
trajectories.
Lebesgue structure of asymmetric Bernoulli convolution based on Jacobsthal–Lucas sequence
Authors: Pratsiovytyi Mykola , Makarchuk Oleg , Karvatsky Dmytro
Published: March 2020

We study the problem of deepening the Jessen–Wintner theorem for asymmetric Bernoulli convolutions.
In particular, we investigate the Lebesgue structure of a random incomplete sum of series, whose terms are reciprocal to Jacobsthal–Lucas numbers.
Dossiê "Intolerâncias, preconceitos e racismos na Era Moderna: entre permanências e rupturas"
Authors: Martins Natália Ribeiro , Malacco Felipe Silveira de Oliveira
Published: March 2020

Apresentação do Dossiê "Intolerâncias, preconceitos e racismos na Era Moderna: entre permanências e rupturas" - Vol. 4, nº 6