bluuebunny/crossref_metadata_2025 huggingface dataset:
Three-dimensional measurement of a particle field using phase retrieval digital holography
Authors: Ling Hangjian
Published: March 2020

Digital inline holography (DIH) has long been used to measure the three-dimensional (3D) distribution of micrometer particles in suspensions. However, DIH experiences a virtual image problem that limits the particle density and the placement of the hologram plane relative to the sample volume. Here, we apply virtual-image-free phase retrieval digital holography (PRDH) to detect opaque particles in 3D volumes that exceed

2000

p
a
r
t
i
c
l
e
s

/

m
m

3

. PRDH is based on recording two holograms whose planes are displaced along the optical axis, and then reconstructing the complete optical waves estimated by the iterative phase retrieval algorithm. Both numerical and experimental tests are performed, and results show that PRDH recovers the original 3D particle distributions even when the hologram planes are within the particle suspensions. Moreover, compared to single-hologram-based DIH, PRDH is proved to have better particle detection qualities. The uncertainty in the localization of particle centers is reduced to less than one particle diameter.
Automatic protocol for quantifying the vasoconstriction in blood vessel images
Authors: Xu Xuelin , Lin Lisheng , Li Buhong
Published: March 2020

Vascular targeted photodynamic therapy (V-PDT) has been successfully
utilized for various vascular-related diseases. To optimize the PDT
dose and treatment protocols for clinical treatments and to elucidate
the biological mechanisms for V-PDT, blood vessels in the dorsal
skin-fold window chamber (DSWC) of nude mice are often chosen to
perform in vivo studies. In this study, a new
automatic protocol to quantify the vasoconstriction of blood vessels
in the DSWC model is proposed, which focused on tracking the pixels of
blood vessels in pre- V-PDT images that disappear after V-PDT. The
disappearing pixels indicate that the blood vessels were constricted,
and thus, the vasoconstriction image for pixel distribution can be
constructed. For this, the image of the circular region of interest
was automatically extracted using the Hough transform. In addition,
the U-Net model is employed to segment the image, and the speeded-up
robust features algorithm to automatically register the segmented pre-
and post- V-PDT images. The vasoconstriction of blood vessels in the
DSWC model after V-PDT is directly quantified, which can avoid by the
potential of generating new capillaries. The accuracy, sensitivity and
specificity of the U-Net model for image segmentation are
90.64%, 80.12% and 92.83%, respectively. A
significant difference in vasoconstriction between a control and a
V-PDT group was observed. This new automatic protocol is well suitable
for quantifying vasoconstriction in blood vessel image, which holds
the potential application in V-PDT studies.
Metasurface homogenization based on contravariant tensor averaging in smooth field approximation
Authors: Edee Kofi
Published: March 2020

The homogenization of the transverse parameters of metasurfaces is introduced through the concept of covariant permittivity tensor averaging. The proposed scheme is based on a covariant form of Maxwell’s equations written in the matched coordinates system. Therefore, the average characteristics of the periodic structure take into account not only all of the physical boundary conditions, but also the geometrical details of the periodic structure that affect the electromagnetic field propagation. The proposed method is successfully applied to analyze the extraordinary optical transmission through a thick layer subwavelength periodic annular slit array.
Impact of the tilted magnetic field on the propagation of oblique waves in the plasma superlattice
Authors: Iakushev Denis , Lopez-Aguayo Servando
Published: March 2020

In its most general statement, we consider the problem of the impact of the external magnetic field on photonic properties of the superlattice comprising dielectric and conducting layers: the direction of the wave propagation as well as the direction of the external magnetic field are assumed to be arbitrary. We show that even a relatively weak external magnetic field can drastically alter the photonic spectrum of the superlattice, since within the photonic gaps there emerge photonic bands making the superlattice transparent for incident radiation. We demonstrate that the spectral width of photonic bands can be effectively controlled by rotation of the static external magnetic field.
Enhanced nanoplasmonic heating in standoff sensing of explosive residues with infrared reflection-absorption spectroscopy
Authors: Simin Nicholas , Park Yangkyu , Lee Dongkyu , Thundat Thomas , Kim Seonghwan
Published: March 2020

Various standoff sensing techniques employing optical spectroscopy have been developed to address challenges in safely identifying trace amounts of explosives at a distance. A flexible anodic aluminum oxide (AAO) microcantilever and a high-power quantum cascade laser utilized as the infrared (IR) source are used for standoff IR reflection-absorption spectroscopy to detect explosive residues on a metal surface. Standoff sensing of trinitrotoluene (TNT) is demonstrated by exploiting the high thermomechanical sensitivity of a bimetallic AAO microcantilever. Moreover, sputtering gold onto the fabricated AAO nanowells generates a strong scattering and absorption of IR light in the wavelength range of 5.18 µm to 5.85 µm resulting in enhanced nanoplasmonic heating. Utilizing the IR absorption enhancement in this wavelength range, the plasmonic AAO cantilever could detect TNT molecules 7 times better than could the bimetallic AAO cantilever.
Broad-bandwidth high-temporal-contrast carrier-envelope-phase-stabilized laser seed for 100  PW lasers
Authors: Shao Beijie , Li Yanyan , Peng Yujie , Wang Pengfei , Qian Junyu , Leng Yuxin , Li Ruxin
Published: March 2020

We demonstrate in this Letter the generation of carrier-envelope-phase (CEP)-stabilized laser pulses at 910 nm with simultaneously high-temporal-contrast, broad spectral bandwidths and few-cycle pulse durations. Through combining the techniques of cascaded optical parametric amplification (OPA) and second-harmonic generation (SHG) in the laser setup, a pulse temporal contrast as high as

>

10

12

has been obtained at the laser output. During the OPA and SHG processes, both the pulse chirp and gain bandwidth are perfectly optimized, leading to the generation of 170 µJ pulses with

>

200

n
m

bandwidth and

∼

15

f
s

pulse duration. Moreover, the CEP of the laser is stabilized passively to a noise level of less than 340 mrad. This high-quality pulsed light source, as the seed laser of the deuterated potassium dihydrogen phosphate (DKDP)-based 100 PW system, will be integrated into the Station of Extreme Light facility in the near future.
Embodied reflection – exploring creative routes to teaching reflective practice within dance training
Authors: Petsilas Phaedra , Leigh Jennifer , Brown Nicole , Blackburn Catriona
Published: March 2020

This article draws from a collaboration between Rambert School of Dance, University of Kent, University College London Institute of Education and an anthropological filmmaker. Together we took a creative and embodied approach to teaching reflective practice within a conservatoire to second-year dance students. In this article, we explore where this somatically inspired pedagogy sits within dance training. We discuss the nature of reflection for dance training, and in particular consider embodied reflective practice. Finally we offer effective methodologies for drawing out and capturing embodied practice.
Imaging methods of the parathyroid glands in primary hyperparathyroidism. Literature review
Authors: Slashchuk Konstantin Y. , Degtyarev Michail V. , Rumyantsev Pavel O. , Troshina Ekaterina A. , Melnichenko Galina A.
Published: March 2020

Primary hyperparathyroidism (PHPT) is a common endocrine disease that occurs with multiple profiles in which no classical manifestation. Diagnosis revolves around routine measurement of serum calcium and parathyroid hormone more than in half cases. The understanding of clinical presentation, epidemiology and management tactics of patients with hyperparathyroidism has significantly changed by virtue of the use of biochemical calcium screening.
The successful diagnosis and treatment are possible with the cooperation of a multidisciplinary team of endocrinologist, endocrine surgeon, radiologist, nuclear medicine physician and pathomorphologist.
The only radical method of treatment is the surgical removal of abnormal parathyroid glands. In this regard, there is necessary to improve the parathyroid glands imaging algorithms.
Early treatment of hyperparathyroidism allows to avoid severe damage to the bones, kidneys, heart, other organs, improving the quality of life and reducing the incidence of disability.
For a systematic literature review, more than 100 articles published from 2000 to the present time were used, on following resources: PubMed, Embase, SciSearch, Scopus, Cochrane Databases, Research Gate, Google Scholar. Including recommendations from the American Association of Endocrinologists and Endocrine Surgeons (AACE/AAES), European Society of Nuclear Medicine (EANM), European Society ofEndocrinologists (ESE), Russian Association of Endocrinologists (RAE) and several other organizations.
The main goal of this review is to summarize and present relevant information and a new look on preoperative imaging techniques, methods of intraoperative navigation, surgery, control quality of treatment in patients with primary hyperparathyroidism.
A pesquisa em sala de aula como prática pedagógica emergente para a qualidade do ensino superior
Authors: Reschke Maria Janine Dalpiaz , Garcia Juliana Bittencourt
Published: March 2020

Este estudo objetivou compreender como docentes, que se envolvem no projeto “Mostra de Pesquisa em Sala de Aula”, em uma universidade comunitária no sul do Brasil, buscam estratégias para utilizar a investigação como princípio educativo e inovador em sala de aula. Para sua realização foi feito um levantamento das experiências apresentadas na Mostra de Pesquisa de 2010 até 2017. Para tal, foram analisados os textos apresentados com a descrição da experiência, observando o número de professores envolvidos, a natureza dos trabalhos e a participação dos estudantes. A motivação dos professores envolvidos na Mostra também foi objeto de interesse.  Entre eles há os que realizam investigações de forma sistemática e contínua, pertencentes a áreas acadêmicas distintas, com reconhecida competência docente. Foram realizadas entrevistas semi estruturadas com quinze professores, através de contato on line. A análise dos dados indicam que há fatores comuns que impactam as experiências, envolvendo a qualificação do professor, o compromisso social da universidade, o ensino relacionado com cotidiano, a capacidade de aprender a ensinar na prática social. Um destaque especial revela que os saberes da pesquisa estão presentes nas representações dos docentes quando manifestam sua compreensão da qualidade no ensino de graduação, encaminhando a perspectiva da indissociabilidade como referente da educação superior.
APPLICATION OF INNOVATIVE MATERIALS IN PRECAST CONCRETE STRUCTURES
Authors: Holschemacher Klaus
Published: March 2020

Construction industry contributes essentially to Germany’s gross domestic product (GDP). In 2015 construction investments amounted around 300 billion Euro corresponding to a share of 10% of total GDP. Because of the essential importance of construction industry there are many activities aiming on reduction of construction costs and improvement of durability and sustainability. Recent tendencies in precast concrete industry include application of innovative materials like self-compacting concrete, fiber reinforced concrete, textile reinforced concrete, carbon concrete composite and strain hardening cementitious materials. The report describes the material developments and first applications for precast concrete members. By the application of non-metallic reinforcement, such as carbon meshes and carbon bars, there is no corrosion risk for the reinforcement resulting in an essentially lower concrete cover and depth of structural members. However, the use of carbon reinforcement requires new design concepts and new construction methods. By solving these problems there is a big chance for precast concrete industry to enhance their market share.
INNOVATION SCENARIOS FOR THE TECHNOLOGICAL DESIGN OF THE OPERATING SUITE: DESIGN CRITERIA AND METHODS
Authors: Di Sivo Michele , De Paolis Valentina
Published: March 2020

Today the operating suite is considered, together with the diagnostic unit, the functional area that is more subject to profound changes, resulting in an increased technological complexity. The road paved by the new approaches to care and illness imply that the coming years will be characterized by a profound and radical change of the medical-scientific knowledge and even more so of the diagnostic and therapeutic methodologies. This paper analyses the characteristics of existing healthcare facilities, with respect to the needs created by the new role of the hospital, as well as the impacts on the more complex and rapidly changing sectors. The identification of the problems and the definition of the number of needs will allow to outline the strategies to adopt for the design of a modern operating suite, defining the basic requirements for an optimum supply of the service. The objective will be to define useful design criteria and methods to favour the inclusion process of innovative factors, so that the building unit can promptly respond to any evolution of needs, overcoming the now consolidated spatial and functional obsolescence that has characterized it lately.
DAMAGE MODES AND FAILURE MECHANISM OF 160,000 m3 LNG OUTER CONCRETE TANK UNDER IMPACT LOADING
Authors: Zhai Ximei , Zhao Xinyu , Li Xinrui
Published: March 2020

In order to investigate the damage models and failure mechanism of the outer concrete tank of the liquefied natural gas (LNG) storage tank under impact loading, the finite element (FE) model of the outer concrete tank of 160,000 m3 LNG storage tank for an actual LNG project and a cylindrical impactor are established based on ANSYS/LSDYNA FE analysis software platform. Through the result comparison of the numerical simulation and an impact perforation test of reinforced concrete slabs subjected to projectile with high speed, the accuracy of the numerical simulation method and material model proposed from this paper are verified. The dynamic response of the concrete dome for LNG outer concrete tank structures under impact loading is studied. Based on response rules and failure phenomena of the dome for LNG outer concrete storage tank subject to impact loading, three damage modes are defined, and the failure mechanism for each mode is revealed from the view point of energy.
STRUCTURAL DESIGN AND ANALYSIS OF HIGH-RISE BUILDING USING ULTRA-LIGHTWEIGHT FLOOR SYSTEM
Authors: Hajjaj Rashad , Alhimeidi Abdulaziz , Sabbagh Mohamed , Alatallah Abdallah , Ahmed Danish , Asiz Andi , Ayadat Tahar , Salman Alaa , Ouda Omar K. M.
Published: March 2020

The main objective of this paper is to study feasibility of using ultra-lightweight (ULW) slab as an alternative design solution for floor component used in high-rise buildings. The main method is numerical case study by comparing the structural performances of 60-storey building in which floor component designed using one type of ULW called cross laminated timber (CLT) relative to floor component designed using conventional reinforced concrete (RC) slab using ETABS. The structural performances were compared between the two types of floor system including: total drift, inter-story drift, and base reaction which results in smaller frame sections and less reactions for the foundation demands by using ultra-lightweight (ULW). Additional survey to assess the awareness level of the public and engineering professionals about general high-rise building demand and new alternative building materials such as timber and its potential application in Saudi Arabia was also conducted.
EVALUATION OF APPLIED REMEDIATION WORKS ON HISTORICAL MASONRY WALL EXPOSED TO LONG-TERM DETERIORATION
Authors: Fořt Jan , Pavlík Zbyšek , Balík Lukáš , Černý Robert
Published: March 2020

The exposure of massive historical masonry walls to varying climatic conditions represents a crucial factor for long-term damage related to moisture and soluble salts increase. Moisture movement in the porous structure of massive historical masonry wall driven by capillary forces is usually connected with transport of salt solutions, which can be responsible for a severe damage. Because of missing damp-proof insulation layers, the moisture ingress carrying soluble salt from the ground especially during winter periods is not prevented from. This study is aimed on the evaluation of the effect of commonly used restoration works on the conservation of an exposed building. The influence of applied precautions was continuously monitored by time-domain reflectometry probes in various depths and heights of the studied masonry wall located in the basement of a residential house in Prague, Czech Republic. Based on the obtained results, taking into account also the influence of indoor and outdoor temperature and relative humidity variations monitored by combined temperature/relative humidity sensors, the wall drying process and the success of applied methods is analyzed.
WIND LOAD PREDICTION OF LARGE-SPAN DRY COAL SHEDS BASED ON GRNN AND ITS APPLICATION
Authors: Sun Ying , Yang Lin , Wu Yue
Published: March 2020

The distribution and fluctuation of wind load on large-span dry coal sheds are complicated. Wind load on typical shape of roofs can be sometimes determined based on the wind tunnel tests carried out on roofs of similar shape. To expand the application scope of the test data, Generalized Regression Neural Network (GRNN) is introduced. The prediction models on large-span dry coal are given, where the wind load is expressed by eight parameters: mean, RMS, skewness, kurtosis of wind pressure coefficients, three auto-spectral parameters (including descendent slope in high frequency range, peak reduced spectrum and reduced peak frequency) and coherence exponent for cross-spectra. Cross validation and trails are carried out to determine the parameter in the GRNN model. Further, the wind load prediction is applied on a dry coal shed shell. The wind-induced responses are calculated and compared with the results of wind tunnel tests, with extremely close result. Therefore, it can be concluded that GRNN is feasible in predicting wind load on roof structures.
AUTOMATION OF A STEEL WALL FRAMING ASSEMBLY
Authors: Tamayo Edgar , Bardwell Michael , Qureshi Ahmed , Al-Hussein Mohamed
Published: March 2020

Modular construction has become increasingly popular in North America in recent years. In this emerging paradigm of building construction, building components are manufactured off site and then transported to the construction site for assembly. In Canada, automated modular steel structure fabrication is in high demand. Offsite manufacturing of steel wall frames for residential and commercial buildings provides timesaving and improvement of working conditions and morale that translates to improved productivity and safety performance. This paper demonstrates the feasibility of efficiently fabricating steel wall frames for offsite modular construction using automated assembly controlled by a Programmable Logic Controller (PLC) and connected in a cost-effective and efficient electrical installation and centralized communication by Fieldbus technology. In particular, this paper describes the control strategy used to automate a steel wall framing assembly that incorporates a PLC and Fieldbus technology.
TECHNICAL-ECONOMIC RESEARCH FOR PASSIVE BUILDINGS FOUNDATION
Authors: Miniotaite Ruta
Published: March 2020

The Energy Performance of Buildings Directive (EPBD) per the 2010 directive of the European Parliament requires all new public buildings to become near-zero energy buildings by 2019 and will be extended to all new buildings by 2021. A passive house is something more than just an energy-saving house. This concept involves sustainable, high-quality, valuable, healthy and durable construction. Foundation is one of the most essential elements of a house. The type of foundation for a private house is selected considering many factors. The article examines technological and structural solutions for passive buildings foundation. The technical-economic comparison of the main structures of a passive house revealed that it is cheaper to install an adequately designed concrete slab foundation than to build strip or pile foundation and the floor separately. The comparison of the main envelope elements efficiency by multiple-criteria evaluation methods showed that it is economically feasible to install concrete slab on ground foundation.
AN INVESTIGATION OF PERSON-TASK-TECHNOLOGY INTERACTION AND ICT ADOPTION IN CONSTRUCTION
Authors: Hua Yuanyuan , Liu Anita M. M.
Published: March 2020

Information and communication technology (ICT) has been identified as key to enhancing information processing in construction. However, the use of ICT is not always effective due to individuals’ resistance to use the ICT. Effective technology use is the interaction of three elements: the competencies and motivations of users, the nature and purpose of technology, and the characteristics of tasks. This research positions task requirements at the center of person-task-technology interaction. Both individuals’ capability and technology’s functionality need to fit task requirements. The aim of this research is to explore the influence of task-technology fit and person-task fit on individuals’ ICT adoption behavior. This research extends the traditional task-technology fit model by combing it with the construct of person-task fit from person-environment fit theory. The research model proposes that both individuals’ capability and technology’s functionality to carry out the task are crucial in ICT adoption. ICT managers should not overlook human factors during ICT implementation.
STUDY ON MECHANISM OF ROCK FALL AT TUNNEL CUTTING FACE AFTER BLASTING
Authors: Sato Fumi , Kikkawa Naotaka , Hiraoka Nobutaka , Itoh Kazuya , Suemasa Naoaki
Published: March 2020

There are around 10 casualties due to rock-fall at cutting face annually in conventional tunnel construction in Japan. As from the analysis conducted on the cases involving such casualties, workers were either killed or seriously injured when they works in front of or near the cutting face. For the purpose of evaluating the mechanism of rock fall at tunnel cutting face, this paper performed experimental tests which involved blasting to excavate a model ground of tunnel cutting face, and then analyzed the stress state which is in the cutting face by using Discrete Element Method (DEM) simulation. Based on the results, the tensile stresses remained even when the action of gas expansion due to blasting has completed. Therefore, it is suggested that rock falls might be induced because of the residual tensile stresses. The tensile stresses would gradually open small cracks between rocks and then rocks may suddenly fall after sufficient crack opening due to gravity.
THE IMPORTANCE OF LOCAL FACTORS FOR INVENTORY ANALYSIS
Authors: Karaman Öztaş Saniye , Tanaçan Leyla
Published: March 2020

Life Cycle Inventory (LCI) is an important phase of Life Cycle Assessment (LCA) that provides information on environmental impact assessment of products throughout their life cycle. Local factors have an effect that can influence the results of an LCI. Many developed countries established their own databases for inventory analysis thus eliminating the issues related with locality. In some of LCA studies, data of similar systems or technologies are considered into inventory calculations. However, there might be mistakes in the inventory analysis results because of the differences between the real system and the system used as a source. Environmental impact assessment is an important selection criterion in the construction sector with different kinds of materials. Turkey has lack of environmental data and is one of the developing countries which has not yet generated a database for the construction materials. In this study, it was aimed to discuss the importance of local factors for LCI. Therefore, environmental information taken from Environmental Product Declaration (EPD) of the ceramic tiles manufactured in different geographical context were compared. It was pointed out the urgency of local inventory data and concluded that the gaps may be minimized with industry involvement.
SPALL REPAIR USING A 3D PRINTER AND EPOXY RESIN ADHESIVE
Authors: Yeon Jaeheum , Kang Julian
Published: March 2020

The spall repair sequence currently used is as follows. The damage is removed from the area with heavy equipment and fresh concrete is poured into the cleaned section. A curing compound is then applied to the patch to prevent drying shrinkage or to absorb water. But this spall repair method requires a great deal of equipment and time. During the repair process, adjacent roads must be closed in order to secure a working space, often resulting in traffic congestion. According to a report by the US Department of Transportation, the depreciation can be up to $20,000 a day due to traffic jams. The depreciation can easily reach up to $140,000 when a road is blocked for seven days to repair a spall. The objective of this research is to see if 3D printing technology can be used to repair spall damage on a concrete pavement. More specifically, this study, using a simple finite element method, investigates whether the bond line thickness will have an influence on shear strength development when an adhesive layer is present between the spall and the 3D printed concrete segment. In addition, this study proposes a modified test method of ASTM C882 to experimentally investigate the influence of bond line thickness of epoxy-resin adhesive on shear strength when the glue applied to a concrete adherend.
EXPERIMENTAL STUDY OF STILLING BASIN MODELS
Authors: Tiwari Hari Lal , Singh Kamal
Published: March 2020

Stilling basins with appurtenances can be used effectively in dissipating the excessive energy downstream of hydraulic structure like spillway, sluices, pipe outlets etc. Experimental investigation leading to the development of new stilling basin model design for pipe outlet with different appurtenances is reported in this paper. On the basis of present study, newly stilling basin design has been compared with USBR VI model. The new models were tested in a rectangular shaped pipe outlet for three Froude numbers, namely Fr = 1.85, 2.85, and 3.85 in comparison to USBR VI stilling basin model recommended for the pipe outlets. The scour pattern was measured for each test run and flow pattern was also observed. The performance of the basin was compared by Performance number (PN) as criteria to evaluate the performance of model, using same sand base material and test run time for all the tested models. After test runs, it is found that, for a given Froude number range, the performance of new stilling basin model is improved and also the length of the newly developed basin is reduced as compared to USBR VI stilling basin for a given flow conditions.
SUITABILITY OF RED MUD IN SUBGRADE USING RBI GRADE 81
Authors: Singh Kamal , Tiwari Hari Lal
Published: March 2020

The waste generated by aluminum industry is known as bauxite residue or red mud. By nature, the red mud is toxic which creates problem for disposal. Due to the alkaline nature it is unsuitable for construction and vegetation. Every year more or less 75 million tons of red mud is generated worldwide. RBI grade 81 is a powdered cementitious stabilizer. It improves the engineering properties of several types of soils. This paper presents investigation carried out for better understanding on effect of RBI Grade 81 on red mud properties to be used in subgrades. It is found that with optimum dose of RBI grade 81 as 4%, liquid limit decreases and plastic limit increase. MDD values decrease slightly but the CBR value of the red mud increase with addition of RBI grade 81.
DESIRED VERSUS REALIZED BENEFITS OF ALTERNATIVE CONTRACTING METHODS ON EXTREME VALUE HIGHWAY PROJECTS
Authors: Alleman Douglas , Antoine Arthur , Papajohn Dean , Molenaar Keith
Published: March 2020

Highway agencies choose alternative contracting methods (ACMs) to for a wide variety of reasons, primarily their potential for superior cost and schedule performance. Most literature focuses on these two factors by analyzing aggregate datasets covering a wide-ranging contract values. These analyses create two voids that this paper attempts to explore: (1) ACMs provide a wide variety of benefits, which cost and schedule performance alone do not identify; and (2) projects of differing contract values benefit differently. This paper investigates the selection criteria for ACMs and why US agencies chose ACMs for projects at the extreme ends of the cost spectrum (defined as projects at the upper and lower 10th percentiles for each delivery method) and what benefits are realized, above and beyond cost and schedule performance. These findings are presented through a survey of 291 US projects, interviews of sixteen US agency representatives, literature review, agency ACM manual content analysis.
CALCULATION OF “NORMAL” CONSTRUCTION TIME FOR BUILDING CONSTRUCTION PROJECTS WHILST CONSIDERING UNCERTAINTIES
Authors: Hofstadler Christian
Published: March 2020

Construction time has a major influence both on the cost-efficient execution of construction works and on the overall project outcome achieved by the client. Clients would do themselves a disservice if they specified short or extremely short construction periods for their projects. The same applies to time made available for project preparation, particularly for the design and tender stages. Any project that is poorly planned, tendered, and executed under time pressure will adversely affect actual construction work but also the building’s use and possible reuse. Cost, time and quality targets are at risk due to the resulting disruptions to the construction process. Productivity is adversely affected not only by unduly short but also exceedingly long construction times. Short or very short construction times have a major influence on the efficient and effective utilization of production factors, including elementary (workforce, materials, equipment and machinery) and discretionary factors (project manager, site manager, technicians, etc.). This paper outlines the basic correlation between construction time, labor consumption rates and productivity as well as construction cost. Furthermore, it sets out to determine the influence of construction time on costing and, consequently, on the construction process. A practical example demonstrates how normal construction time can be calculated for reinforced concrete works based on uncertain input parameters. In addition, the benefits of specifying normal construction time for clients and contractors are outlined.
INFLUENCE OF BASEBOARD HEIGHT ON WIND FORCE OF SCAFFOLDS AT BUILDING EDGE
Authors: Takahashi Hiroki , Ohdo Katsutoshi , Ohgaki Kazuo
Published: March 2020

When scaffolds are installed in construction sites, their resistance against wind force needs to be calculated. Japanese design guidelines require a specific scaffold resistance against wind force, but such rules and regulations are applicable solely to old-style scaffolds. A number of risks are inherent in the existing guidelines. First, new-style scaffolds are used in construction sites without practitioners knowing whether the design guidelines are appropriate for modern building components. Second, scaffolds are set near buildings, but workers are unaware of the effect of the wind force at the building edge. Finally, conventional designs feature the use of baseboards as scaffold components. While considering the aforementioned issues, a wind tunnel test was carried out as part of this study to examine the wind force exerted on scaffolds erected near a building edge. The parameters used in the test were baseboard height and the distance from the building edge. From the results, when the distances between the building’s center and the scaffold’s center are 180 mm, the wind force is high. Additionally, when the baseboard height is 130 mm, the wind force is high. This study examined the correction number for the wind force coefficient of scaffolds with baseboards that were positioned at building edge. Whenever the scaffolds were set near the building edge, we needed to revise the wind force coefficient of the scaffolds.
AN OVERVIEW OF THE LOCATION OF AIRPORTS USING GEOGRAPHIC INFORMATION SYSTEM
Authors: Honarmand Mehrdad , Beiranvand Mohammad , Bashash Sina , Ghaderi Ali
Published: March 2020

A geographic information system (GIS) is a system designed to capture, store, manipulate, analyze, manage, and present spatial or geographic data. The acronym GIS is sometimes used for geographic information science (GIS science) to refer to the academic discipline that studies geographic information systems and is a large domain within the broader academic discipline of geoinformatics. GIS can provide the airport management staff with visual pavement information and powerful analysis tool. Meanwhile, the spatial information managed by GIS can ensure the accumulation of valid attribute data of airport. Based on the principle and general implementation process of GIS and the characteristics of airport pavement management, this paper describes the implementation process of GIS in Airport planning and design. To organize the spatial entities effectively, some layers are set according to the characteristics of spatial entities. The spatial database is established, and then the function design of the GIS software is presented including map exploring, map locating, spatial query, rendering style of map and output of map. Finally, in this paper, an overview of locating airports using GIS studied.
ANALYSIS OF EMPIRICAL COMPRESSION INDEX EQUATIONS USING THE VOID RATIO
Authors: Al-Khafaji Amir , Maillacheruvu Krishnanand , Jacobs Robert
Published: March 2020

A new technique to assess the reliability of published compression index equations in terms of soil void ratio is presented. Several published equations pertaining to different soil types are examined in terms of accuracy and applicability. The new technique employs regression analysis to examine a substantial number of published compression data objectively. The traditional bias inherent in the selection of the number of data points and the range of void ratios for a given regression equation is eliminated. This was made possible by creating ranges for the compression index irrespective of the data set involved. This technique revealed that a strong correlation exists between the slopes and intercepts of all published equations. The slopes and intercepts of the newly developed regression equations were used to compare several well know published equations to assess accuracy and applicability. The proposed technique permits the examination of the authenticity of any published empirical equations relating to the compression index of clay to void ratio.
FULL-SCALE MODEL TEST FOR PREDICTING COLLAPSE USING INVERSE OF VELOCITY OF SLOPE SURFACE DURING EXCAVATION
Authors: Hiraoka Nobutaka , Kikkawa Naotaka , Sasahara Katsuo , Itoh Kazuya
Published: March 2020

Predicting the onset of slope failure or rock falls is important for occupational safety because they kill approximately ten to 20 workers every year in Japan. Approximately half of such victims are from slope failure during slope excavation and construction. In order to predict the time of slope failure during an excavation, a full-scale model slope was built, and the displacement of the slope surface was monitored during slope excavation. The surface displacement rapidly increased with the elapsed time after the excavation, and the relationship between the displacement and elapsed time included an exponential function just before collapse. Based on the results, by computing the inverse of the velocity of the slope surface displacement obtained in ten-second intervals, a warning signal can be provided five min before collapse.
ECONOMIC SCORING FORMULAE IN MULTI-ATTRIBUTE CONSTRUCTION AUCTIONS
Authors: Ballesteros-Perez Pablo , Pellicer Eugenio , Gonzalez-Cruz Mª Carmen
Published: March 2020

Public tendering implies the free concurrence and competition of bidding companies that certify their solvency, so that those companies proposing the most attractive bid, both technically and economically, are awarded the contracts and carry them out according to the same terms and conditions that they proposed. Generally, there is high competition in public tendering, both concerning the number of bidders (constantly increasing), as well as the profit margin (constantly decreasing). On the other side, handling the procurement process, there is a contracting authority that spends public money while trying to fulfill a particular socio-economic objective. This paper will take the contracting authority's (auctioneer's) point of view which is in charge of devising and implementing the awarding criteria, as well as choosing the best bidder. Particularly, this paper will focus on some aspects of the Economic Scoring Formula (ESF) design. The ESF constitutes a set of mathematical expressions that transform the economic bids submitted by the bidders into scores, so that, eventually, the bidders can be ranked and the best one selected. We will conclude that, despite apparently simple, how ESF are configured eventually have profound consequences on bidding behavior and some bidding results, like a higher or lower bid dispersion.
EFFECT OF CURING TEMPERATURE ON THE PROPERTIES OF 100% CLAY-BASED GEOPOLYMER CONCRETE
Authors: Rahman Muhammad Mukhlesur , Law David w. , Patnaikuni Indubhushan
Published: March 2020

Substantial researches have already been carried out on alkali-activated binders for the production of geopolymer concrete but studies on clay-based geopolymer concrete is still insufficient. The aim of this paper is to identify the effect of curing temperature on the properties of 100% clay-based geopolymer concrete. Clay pre-treated at 80°C and 120°C for 24 hours were selected as the source binder material. Four Activator Modulus (AM); 1.0, 1.25, 1.5 and 1.75 for each of two Sodium Oxide (Na2O) dosages of 10% and 15% were selected as the activator material for this investigation. X-ray diffraction (XRF) was applied to characterize the clay material. Specimens were cured at 80°C and 120°C for 24 hours. Specimens were tested under compression at seven, 14, 28 and 40 days. Specimens cured at 80°C took a longer duration (>28 days) to achieve structural integrity while the specimens cured at 120°C achieved structural integrity within seven days. Compressive strength of specimens prepared with AM of 1.0 for both of the Na2O dosage of 10% and 15% exhibited superior performance to other AMs investigated.
The impact of the truck loads on the braking efficiency assessment
Authors: Šarkan Branislav , Jaśkiewicz Marek , Kiktová Monika
Published: March 2020

The paper deals with possibilities of assessment of braking efficiency during evaluation of braking system at technical inspection of trucks in conditions of the Slovak Republic. The braking efficiency of the vehicle is evaluated by measuring the braking forces at the roller brake tester. The magnitude of these forces also depends on the loads of the measured vehicle. The paper analyses the results of the practical tests of the braking efficiency measurement of a truck of category N3 and of a vehicle combination consisting of vehicles of category N3 and O4. The analysed vehicle combination was gradually loaded in four different ways and a special situation was the measurement of the braking efficiency of the tractor itself. The instantaneous load on each axle was recorded with portable axle weights. The braking efficiency evaluation was carried out in accordance with the valid methodology, which allows the application of the direct evaluation method, the method of linear extrapolation, the method of the reference braking forces and the indicative evaluation. A vehicle with the same braking system may be assessed as roadworthy or not roadworthy. This is due to the application of different methods of evaluating the braking efficiency and different way of loads at the loading area.
General Application of Multiple Criteria Decision Making Methods for Finding the Optimal Solution in City Logistics
Authors: Hanzl Jiří
Published: March 2020

The aim of this paper is to familiarize the reader with the general application of MCDM methods on a specific example of City Logistics in order to find the optimal solution for operation of the territory. In its introductory part, methods used for quantitative evaluation of variant solutions are briefly described, and then the so-called Forces Decision Matrix Method (FDMM) including the determination of criteria weights using pairwise comparison of variants according to individual criteria on the specific example is applied. In the final part of the paper, the advantages and disadvantages of using this method for more complex tasks with multiple variant solutions based on the results of the practical example are evaluated and the so-called Saaty’s method based on the quantitative pair-wise comparison to partially eliminate differences in the mutual evaluation of weights and criteria is mentioned.
The Role of Affect in the Development of Entrepreneurial Intentions
Authors: Pérez-Fernández Héctor , Delgado-García Juan Bautista , Martín-Cruz Natalia , Rodríguez-Escudero Ana Isabel
Published: March 2020

Advances on the study of entrepreneurial intention among students from universities motivate to further investigate the factors behind this intention. In this paper, we focus on the effect of affective traits (positive and negative) on the entrepreneurial intention antecedents proposed by Ajzen’s theory of planned behavior drawing on the arguments of affect priming. Using a sample of 597 students from Spain, we use structural equation model to test our hypotheses. Our results show that positive affective traits have a positive impact on the attitude toward entrepreneurship (ATE), perceived behavioral control of entrepreneurship (PBC), and social norms toward entrepreneurship (SN). Negative affective traits negatively influence ATE and SN, but not PBC. In addition, using a K-means clustering analysis and an analysis of variance, our study further explores how different affective personalities relate to a particular level of entrepreneurial intention. Our results contribute to understand of the psychological processes that influence entrepreneurial intention. Overall, our research contributes to the literature on affect and entrepreneurial cognition by evaluating the interaction of affect and the cognitive antecedents of entrepreneurial intention.
Solving subset sum with small space – Handling cryptanalytic Big Data
Authors: May Alexander
Published: March 2020

Big Data applications are characterized by processing an amount of data too huge to be stored. Cryptographic protocols are by construction supposed to define huge data spaces that cannot be handled by any attacker. Nevertheless, the task of protocol cryptanalysis is to properly select cryptographic parameter lengths that guarantee both efficiency and security. This requires to break cryptographic protocols and their underlying hardness assumptions for mid-sized parameters. But even for mid-sized parameters cryptographic search spaces are way too huge to be stored. This asks for technical solutions that traverse the search space without storing elements. As an appealingly simple example, we address the subset sum problem which lies at the heart of many modern cryptographic protocols designed to offer security even against quantum computers. In the subset sum problem, one obtains integers

a

1

,
…
,

a

n

{a_{1}},\dots ,{a_{n}}

and an integer target t, and has to find a subset of the

a

i

{a_{i}}

’s that exactly sums to t. A trivial memory-less algorithm tests for all

2

n

{2^{n}}

subsets, whether their sum equals t. It may come as a surprise that there exist memory-less algorithms significantly faster than

2

n

{2^{n}}

. We give a survey on recent memory-less techniques, that apply but are not limited to the subset sum problem. We start by describing a general collision finding technique that was introduced in 1994 in the seminal work of van Oorschot and Wiener. Applied to subset sum the van Oorschot-Wiener technique leads to a

2

0.75
n

{2^{0.75n}}

-algorithm. This was improved in 2011 by Becker, Coron and Joux to

2

0.72
n

{2^{0.72n}}

using the representation technique. Recently, Esser and May presented a memory-less algorithm achieving

2

0.65
n

{2^{0.65n}}

using two-layered collision finding. These running times have to be compared to the optimal

2

0.5
n

{2^{0.5n}}

lower bound for collision finding algorithms.
An inverse problem of triple-thickness parameters determination for thermal protective clothing with Stephan–Boltzmann interface conditions
Authors: Li Tingyue , Kabanikhin Sergey , Nakamura Gen , Wang Faming , Xu Dinghua
Published: March 2020

A seven-layers parabolic model with Stephan–Boltzmann interface conditions and Robin boundary conditions is mathematically formulated to describe the heat transfer process in environment-three layers clothing-air gap-body system.
Based on this model, the solution to the corresponding inverse problem of simultaneous determination of triple fabric layers thickness is given in this paper, which satisfies the thermal safety requirements of human skin.
By implementing a stable finite difference scheme, the thermal burn injuries on the skin of the body can be predicted.
Then a kind of stochastic method, named as particle swarm optimization (PSO) algorithm, is developed to numerically solve the inverse problem.
Numerical results indicate that the formulation of the model and proposed algorithm for solving the corresponding inverse problem are effective.
Hence, the results in this paper will provide scientific supports for designing and manufacturing thermal protective clothing (TPC).
New Filbert and Lilbert matrices with asymmetric entries
Authors: Bozdağ Hacer , Kiliç Emrah , Akkus Ilker
Published: March 2020

In this paper, two new analogues of the Hilbert matrix with four-parameters have been introduced. Explicit formulæ are derived for the LU-decompositions and their inverses, and the inverse matrices of these analogue matrices.
Sequences of positive homoclinic solutions to difference equations with variable exponent
Authors: Stegliński Robert , Nockowska-Rosiak Magdalena
Published: March 2020

We study the existence of infinitely many positive homoclinic solutions to a second-order difference equation on integers withpk-Laplacian. To achieve our goal we use the critical point theory and the general variational principle of Ricceri.