General Construction Research Articles

Covariance models for multivariate random fields resulting from pseudo cross-variograms

So far, the pseudo cross-variogram is primarily used as a tool for the structural analysis of multivariate random fields. Mainly applying recent theoretical results on the pseudo cross-variogram, we use it as a cornerstone in the construction of valid covariance models for multivariate random fields. In particular, we extend known univariate constructions to the multivariate case, and generalize existing multivariate models. Furthermore, we provide a general construction principle for conditionally negative definite matrix-valued kernels, which we use to reinterpret previous modeling proposals.

Industrialized house building productivity growth

PurposeThe purpose of this paper is to understand if and how industrialized house building (IHB) could support productivity developments for housebuilding on project and industry levels. The take is that fragmentation of construction is one explanation for the lack of productivity growth, and that IHB could be an integrating method of overcoming horizontal and vertical fragmentation.Design/methodology/approachSinge-factor productivity measures are calculated based on data reported by IHB companies and compared to official produced and published research data. The survey covers the years 2013–2020 for IHB companies building multi-storey houses in timber. Generalization is sought through descriptive statistics by contrasting the data samples to the used means to control vertical and horizontal fragmentation formulated as three theoretical propositions.FindingsAccording to the results, IHB in timber is on average more productive than conventional housebuilding at the company level, project level, in absolute and in growth terms over the eight-year period. On the company level, the labour productivity was on average 10% higher for IHB compared to general construction and positioned between general construction and general manufacturing. On the project level, IHB displayed an average cost productivity growth of 19% for an employed prefabrication degree of about 45%.Originality/valueEmpirical evidence is presented quantifying so far perceived advantages of IHB. By providing analysis of actual cost and project data derived from IHB companies, the article quantifies previous research that IHB is not only about prefabrication. The observed positive productivity growth in relation to the employed prefabrication degree indicates that off-site production is not a sufficient mean for reaching high productivity and productivity growth. Instead, the capabilities to integrate the operative logic of conventional housebuilding together with logic of IHB platform development and use is a probable explanation of the observed positive productivity growth.

Wildcarded identity-based ring signatures based on linearly homomorphic signatures

In identity-based ring signatures (IBRS) (Zhang and Kim, 2002), a binary string ID∈{0,1}L for L∈N, representing a unique information about a signer (e.g., e-mail address, telephone number), is associated with a secret-key. Its owner can anonymously signs a message under a set of IDs called ring including the signer’s ID. Wildcarded IBRS (WIBRS) (Ishizaka&Kiyomoto, ISC’20) is a generalization of IBRS, in which the ring consists of wildcarded IDs. The signer correctly signs iff her ID matches at least one of the wildcarded IDs. To the best of our knowledge, the only one known WIBRS scheme adaptively secure under standard assumptions is obtained as an instantiation of the attribute-based signatures scheme by Sakai et al. (PKC’16). It has signatures of length O(kL) and secret-keys of (constant) length O(1), where k denotes cardinality of the ring. In this paper, we propose a generic WIBRS construction, built by linearly homomorphic signatures and non-interactive witness-indistinguishable proof. We instantiate it to obtain a concrete WIBRS scheme secure under standard assumptions, whose length of signatures (resp. secret-keys) O(k+L) (resp. O(L)).

Enhancing station level Direct-Demand models with Multi-Scalar accessibility indicators

Direct-demand models (DDM) are increasingly being used for a diversity of transit research and practice purposes. Yet few station-level DDM studies have explored the use of composite indicators of metropolitan accessibility in predicting demand. After all, provision of access to metropolitan destinations is one of the main goals of rapid-transit systems. Furthermore, to this author’s knowledge no study has explored potential interactions with local-level accessibility indicators that are typically included in station level transit DDMs. This study explores these possibilities and uses Los Angeles multimodal rapid-transit network as a representative case study of a system that operates in a dispersed agglomeration where multiple sub-centers are linked. Multi-level generalized linear models were implemented where key predictors, including stations' metropolitan- and a local-accessibility indicators are regressed onto average weekday boardings. Furthermore, more general accessibility constructs were developed via EFA and implemented in models; and parameters non-stationarity was assessed via geographically weighted regressions. Results indicate that nodal metropolitan accessibility is a significant predictor of patronage in LA’s rapid-transit network, and that its interaction with local-accessibility amplifies boardings and improves DDM models’ explanatory power. More general constructs of accessibility at metropolitan and local-scale were derived via EFA and these resulted in a more parsimonious model with equal predictive power. Land-use and transit planners would benefit from including an accessibility lens in their DDM modeling. Practical applications of these type of models include TOD scenario planning, comparative route alignment studies, system expansion studies, and for didactic purposes given the ability of accessibility measures to capture land-use/transportation interactions.

Several Families of Binary Minimal Linear Codes From Two-to-One Functions

Minimal linear codes have important applications in secure communications, including in the framework of secret sharing schemes and secure multi-party computation. A lot of research have been carried out to derive codes with few weights (but more importantly, being minimal) using algebraic or geometric approaches. One of the main power and fructify algebraic methods is based on the design of those codes by employing functions over finite fields. K. Li, C. Li, T. Helleseth, and L. Qu have recently identified in [Binary linear codes with few weights from two-to-one functions, IEEE Trans. Inf. Theory, 2021] some binary linear codes with few weights from two classes of two-to-one functions. In this paper, our ultimate objective is to expand the class of codes derived from the paper of Li <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">et al</i> . by proposing larger classes of binary linear codes with few weights via generic constructions involving other known families of two-to-one functions over the finite field F <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2^<i>n</i></sub> of order 2 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><i>n</i></sup> . We succeed in constructing such codes, and we also completely determine their weight distributions. The linear codes presented in this paper differ in parameters from those known in the literature. Besides, some of them are optimal concerning the well-known Griesmer bound. Notably, we prove that our codes are either optimal or almost optimal with respect to the online Database of Grassl. We next observe that the derived binary linear codes also have the minimality property for most cases. We then describe the access structures of the secret-sharing schemes based on their dual codes. Finally, we solve two problems left open in the paper by Li <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">et al</i> . (more specifically, a complete solution to Problem 2 and a partial solution to Problem 1).

Design and construction of a compact, high-repetition-rate ultrafast electron diffraction instrument.

We present the design and performance of a compact ultrafast electron diffraction instrument. The diffractometer provides a means of examining time-resolved ultrafast dynamical properties of solids. The system's utilization is discussed in terms of instrument parameters and diffraction data from selected condensed matter samples. The difractometer's performance is highlighted in terms of detection sensitivity, instrumental temporal resolution, and the electron beam transverse coherence length. Following specific details of the construction, we present a practical discussion of parameters such as repetition rate and provide advice on general construction approaches for laboratory-based, keV ultrafast electron diffractometers. In addition, design guidance for constructing a compact electron gun source that is well-suited for studying diffraction from hard condensed matter is given. A unique data acquisition scheme, utilizing high laser repetition rates, is presented.

Integrable Degenerate varvec{mathcal {E}}-Models from 4d Chern–Simons Theory

We present a general construction of integrable degenerate mathcal {E}-models on a 2d manifold Sigma using the formalism of Costello and Yamazaki based on 4d Chern–Simons theory on Sigma times {mathbb {C}}{P}^1. We begin with a physically motivated review of the mathematical results of Benini et al. (Commun Math Phys 389(3):1417–1443, 2022. https://doi.org/10.1007/s00220-021-04304-7) where a unifying 2d action was obtained from 4d Chern–Simons theory which depends on a pair of 2d fields h and {mathcal {L}} on Sigma subject to a constraint and with {mathcal {L}} depending rationally on the complex coordinate on {mathbb {C}}{P}^1. When the meromorphic 1-form omega entering the action of 4d Chern–Simons theory is required to have a double pole at infinity, the constraint between h and {mathcal {L}} was solved in Lacroix and Vicedo (SIGMA 17:058, 2021. https://doi.org/10.3842/SIGMA.2021.058) to obtain integrable non-degenerate mathcal {E}-models. We extend the latter approach to the most general setting of an arbitrary 1-form omega and obtain integrable degenerate mathcal {E}-models. To illustrate the procedure, we reproduce two well-known examples of integrable degenerate mathcal {E}-models: the pseudo-dual of the principal chiral model and the bi-Yang-Baxter sigma -model.

Joint distribution of two local times for diffusion processes with the application to the construction of various conditioned processes

For a diffusion process X(t) of drift and of diffusion coefficient , we study the joint distribution of the two local times and at positions x = 0 and x = L, as well as the simpler statistics of their sum . Their asymptotic statistics for large time involves two very different cases: (i) when the diffusion process X(t) is transient, the two local times remain finite random variables and we analyze their limiting joint distribution; (ii) when the diffusion process X(t) is recurrent, we describe the large deviations properties of the two intensive local times and and of their intensive sum . These properties are then used to construct various conditioned processes satisfying certain constraints involving the two local times, thereby generalizing our previous work (Mazzolo and Monthus 2022 J. Stat. Mech. 103207) concerning the conditioning with respect to a single local time A(t). In particular for the infinite time horizon , we consider the conditioning towards the finite asymptotic values or , as well as the conditioning towards the intensive values or , that can be compared with the appropriate ‘canonical conditioning’ based on the generating function of the local times in the regime of large deviations. This general construction is then applied to the simplest case where the unconditioned diffusion is the Brownian motion of uniform drift µ.

Geometric shape measurement and its application in bridge construction based on UAV and terrestrial laser scanner

Oblique photography and laser scanning techniques are increasingly being used to measure the geometric shapes of structures. Optimizing the flight path of unmanned aerial vehicles (UAVs) in data acquisition can make the collected image data more complete with muti-view details and improve the utilization of image data in 3D reconstruction. This paper proposed a convenient UAV flight planning approach for oblique photography based on feature waypoints along with an efficient framework for automatically extracting bridge alignment from point cloud data. The application on an under-construction long multi-span girder bridge demonstrated the effectiveness of the optimized UAV flight planning method for collecting multi-view bridge images and the superiority of the rebuilt 3D model compared to commonly used flight strategies. Taking the total station data as references, the errors of the bridge alignment obtained from the point cloud collected by the frequently adopted terrestrial laser scanners (TLS) and UAV devices, respectively, achieve 4.41 mm and 10.97 mm in 142 m measured length. The analysis of the original and eliminated-slope bridge alignments illustrates the potential for using the suggested method in general large-scale bridge constructions.

A general construction of regular complete permutation polynomials

A general construction of regular complete permutation polynomials

Strong quantum nonlocality without entanglement in an n -partite system with even n

In multipartite systems, great progress has been made recently on the study of strong quantum nonlocality without entanglement. However, the existence of orthogonal product sets with strong quantum nonlocality in even party systems remains unknown. Here the even number is greater than four. In this paper, we successfully construct strongly nonlocal orthogonal product sets in $n$-partite systems for all even $n$, which answers the open questions given by Halder et al. [\href{https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.122.040403} {Phys. Rev. Lett \textbf{122}, 040403 (2019)}] and Yuan et al. [\href{https://journals.aps.org/pra/abstract/10.1103/PhysRevA.102.042228} {Phys. Rev. A \textbf{102}, 042228 (2020)}] for any possible even party systems. Thus, we find general construction of strongly nonlocal orthogonal product sets in space $\otimes_{i=1}^{n}\mathcal{C}^{d_{i}}$ ($n,d_{i}\geq 3$) and show that there do exist incomplete orthogonal product bases that can be strongly nonlocal in any possible $n$-partite systems for all even $n$. Our newly constructed orthogonal product sets are asymmetric. We analyze the differences and connections between these sets and the known orthogonal product sets in odd party systems. In addition, we present a local state discrimination protocol for our sets by using additional entangled resource. When at least two subsystems have dimensions greater than three, the protocol consumes less entanglement than teleportation-based protocol. Strongly nonlocal set implies that the information cannot be completely accessed as long as it does not happen that all parties are together. As an application, we connect our sets with local information hiding in multipartite system.

‘I’d best take out life insurance, then.’ Conceptualisations of risk and uncertainty in primary care consultations, and implications for shared decision-making

The main objective of this study is to gain knowledge about interactional factors that support and obstruct mutual risk-assessments and shared decision-making (SDM) in clinical consultations. Through a narrative analysis of verbatim transcripts of 28 naturally occurring consultations performed in English National Health Service practices, we explore the ways in which patients and general practitioners conceptualise, construct and negotiate risks related to diagnostic tests and medical treatments. Consultations were sampled from a corpus of 212 consultation transcripts from the One in a Million: Primary care consultations archive on the basis that they contained the word ‘risk(s)’. Most sampled cases relate to cardiovascular conditions and cancer. Drawing on a social constructionist perspective and the relational theory of risk, we found that while GPs talked about mathematical-probabilistic population risk, patients expressed their own experiences of possible future dangers, conceptualised through words like ‘worried’, ‘scared’ and ‘concerned’. Risk objects, defined here as entities to which harmful consequences are conceptually attached, were constructed differently by patients and GPs, especially in relation to cardiovascular risks. Their different rationalities sometimes obstructed any form of mutual risk-assessments. The relational theory of risk proved to be a useful theoretical frame for exploring layers and configurations of risk constructions among patients and clinicians, and for capturing interactional factors that support and obstruct mutual risk-assessments and SDM. For patients to be able to engage in genuine dialogues and make informed decisions about their care, it is paramount for patients and doctors to co-construct patients’ health-risks during clinical encounters.

Codimension-2 defects and higher symmetries in (3+1)D topological phases

(3+1)D topological phases of matter can host a broad class of non-trivial topological defects of codimension-1, 2, and 3, of which the well-known point charges and flux loops are special cases. The complete algebraic structure of these defects defines a higher category, and can be viewed as an emergent higher symmetry. This plays a crucial role both in the classification of phases of matter and the possible fault-tolerant logical operations in topological quantum error-correcting codes. In this paper, we study several examples of such higher codimension defects from distinct perspectives. We mainly study a class of invertible codimension-2 topological defects, which we refer to as twist strings. We provide a number of general constructions for twist strings, in terms of gauging lower dimensional invertible phases, layer constructions, and condensation defects. We study some special examples in the context of \mathbb{Z}_2ℤ2 gauge theory with fermionic charges, in \mathbb{Z}_2 \times \mathbb{Z}_2ℤ2×ℤ2 gauge theory with bosonic charges, and also in non-Abelian discrete gauge theories based on dihedral (D_nDn) and alternating (A_6A6) groups. The intersection between twist strings and Abelian flux loops sources Abelian point charges, which defines an H^4H4 cohomology class that characterizes part of an underlying 3-group symmetry of the topological order. The equations involving background gauge fields for the 3-group symmetry have been explicitly written down for various cases. We also study examples of twist strings interacting with non-Abelian flux loops (defining part of a non-invertible higher symmetry), examples of non-invertible codimension-2 defects, and examples of the interplay of codimension-2 defects with codimension-1 defects. We also find an example of geometric, not fully topological, twist strings in (3+1)D A_6A6 gauge theory.

Multi-criteria decision analysis for optimum selection of different construction bricks

Theis research aims to analyse a solar dryer based geopolymer bricks and compare it with other types of bricks available in the market. In recent days, some research studies are carried out related to construction bricks, apart from solar dried geopolymer bricks, which are sustainable construction materials. In this study, we analysed and compared the qualities of burnt clay bricks, concrete bricks, hollow blocks, bio-bricks, and geopolymer bricks. Multi-criteria analysis is utilised with the results obtained through the compressive test, water absorption test, thermal conductivity test, Scanning Electron Microscope (SEM) analysis, cost comparison, and VIKOR's matrix test data. To evaluate the experimental and analytical data and to select the best brick for the decision-makers, the ranking system developed by VlseKriterijumska Optimizacija I Kompromisno Resenje (VIKOR) is used in this investigation. This study also compares the test results of brick used in general construction with geopolymer solar-dried brick, which performs better than clay bricks, cement bricks, Bio-bricks, and Eco-friendly bricks. Results concluded that the eco-friendly cement bricks have good strength, shape and texture and 16% water absorption. Cement bricks are the most ecologically friendly and found as a sustainable product since they are available at the lowest embodied energy of 1.49 MJ/kg and emit the lowest embodied greenhouse gas of 0.162 kg of CO2 when compared to conventional bricks.

INSTITUTIONS OF CIVIL SOCIETY IN SYSTEM OF PROVIDING STATE FINANCIAL SECURITY

It was determined that in modern conditions the most destructive threats for the economic and financial systems of Ukraine are such threats as the shadowing of economic activity and, as a result, money laundering. The author's vision of the general construction of the system for ensuring the economic security of the state is proposed, according to which the subjects of economic security carry out balanced actions and measures in relation to the objects of economic security in response to threats to the economic security of the state, the occurrence of which has a negative impact. Such interaction between subjects and objects takes place in accordance with the system-forming factor, which is the realization of national interests in order to maintain such a state of the State's economy, which is characterized by balance, resistance to negative factors, the ability to ensure efficient functioning of the economy and economic growth. It was determined that the main threats to economic security at the current stage are the shadow economy, organized crime, corruption, capital flight abroad, raiding, and criminal bankruptcies. The importance of considering civil society institutions as full-fledged subjects of the system of ensuring the economic security of the state is substantiated. It was determined that the main threats to such a component of the state's economic security as financial, to which civil society institutions are related, are political corruption and the shadowing of the finances of civil society institutions. The role of civil society institutions as subjects of the system of ensuring the economic security of the state is revealed in the following two roles: those that carry out measures to eliminate, counter and reduce the consequences of the main threats; such that can act as tools for the implementation of criminal actions.

A general construction of permutation polynomials of [formula omitted

Let r be a positive integer, h(X)∈Fq2[X], and μq+1 be the subgroup of order q+1 of Fq2⁎. It is well known that Xrh(Xq−1) permutes Fq2 if and only if gcd(r,q−1)=1 and Xrh(X)q−1 permutes μq+1. There are many ad hoc constructions of permutation polynomials of Fq2 of this type such that h(X)q−1 induces monomial functions on the cosets of a subgroup of μq+1. We give a general construction that can generate, through an algorithm, all permutation polynomials of Fq2 with this property, including many which are not known previously. The construction is illustrated explicitly for permutation binomials and trinomials.

A General Condition of Structural Distinguisher

AbstractThis paper proposes a general construction method for structural distinguishers, based on the recently proposed ‘multiple-of-n property’ of a subspace trail. The multiple-of-n property refers to the fact that by appropriate choices of difference for a number of input pairs, it is possible to make sure that the number of times that the difference of the resulting output pairs lie in a particular subspace is always a multiple of n. We weaken the condition for constructing the structural distinguisher from the exact subspace trail to the general subspace trail and this general condition is applied to the SPN cryptographic algorithm, allowing a six-round structural distinguisher to be obtained for the first time. In this way, the best six-round Midori-64 distinguisher is constructed, with its data complexity being identical to Midori’s five-round structural distinguisher. We also applied this new condition to the SKINNY algorithm, extending its structural distinguisher from five to six rounds.

Experimental analysis of Wellbore cement-steel bond mechanics and characterization

Portland cement is commonly used in everything from general construction to fluid barriers in environmental and petroleum structures. Wellbore integrity finite element models have shown that the bond strength between cement to steel is a weak point, but the failure mechanism is not well understood. Bond strength of cement to steel has been modeled using traction separation law which includes the bond strength, critical energy, and contact stiffness associated with the bond. However, experimental measurements only focus on the bond strength resulting in an incomplete analysis of the failure. A novel experimental methodology was developed to measure the tensile bond strength, critical energy, and contact stiffness of neat cement to steel bonds cured at atmospheric conditions for two days. Strain rates of 0.1 mm/min, 1.0 mm/min, and 10 mm/min were tested. The results showed that the 0.1 mm/min strain rate is too slow for bond testing since two of the bonding parameters experience relaxation during testing and result in low values. The 1.0 and 10 mm/min strain rates do not have statistical significance with respect to the bonding parameters. From the direct tensile tests of neat cement to steel, the bond strength is 0.61 MPa, the critical energy is 204.2 J/m2, and the contact stiffness is 1.00 E+09 N/m3.

General Construction of Ultrathick Sulfur Cathode for High‐Energy‐Density Lithium–Sulfur Battery

Lithium–sulfur battery has high theoretical energy density (2600 Wh kg−1) and specific capacity (1675 mAh g−1), which is the research hotspot of next‐generation high‐energy‐density energy storage systems. In order to make the actual energy density of the battery closer to the theoretical value, it is necessary to increase the proportion of active substances as much as possible, but this will lead to the increase of the thickness of the electrode and affect the transport of ions inside the electrode. A new NH4HCO3 template to help solve the above problem is proposed. A large number of efficient ion transport channels are generated in ultrathick cathodes. The discharge capacity of the primary button battery reaches 1500 mAh g−1 at the rate of 0.005C. Meanwhile, the actual gravimetric and volumetric energy density of the primary pouch cell are 645 Wh kg−1 and 952 Wh L−1. The special cathode structure makes it easier for the electrolyte to penetrate the thick cathode, and makes the ion transport faster, which is the reason for the excellent performance of the battery. The work provides an effective way to improve the performance of high‐loaded sulfur cathode, enabling the commercialization of high‐specific energy Li–S batteries.

Method for clearance of contaminated buildings in Korea research reactor 1 and 2

The objective of this study was the establishment of clearance method that can ensure radiological safety and reasonably minimize radioactive waste when demolishing contaminated buildings at KRR-1&2. By reviewing Korean and international laws related to decommissioning, the method for clearance of contaminated buildings presented in this study is to first decontaminate the building and then conduct a radiological safety assessment, such as measuring residual radioactivity, to determine whether the radiation dose criteria for clearance are satisfied. The measurement results meet the radiation dose criteria, the contaminated buildings are regarded as clearance and can be converted into the general buildings. The demolition of the cleared buildings is carried out using conventional demolition methods. The waste generated during the demolition is classified as general construction waste and is disposed of according to relevant laws. The proposed method significantly optimized the number of samples analyzed and reduced the time and cost associated with the decommissioning. The established method will be applied to the ongoing decommissioning of contaminated buildings at KRR-1&2, and its application will be verified by regulatory bodies. The study suggests that this method could be used for the decommissioning of contaminated buildings at other Korean nuclear facilities in the future.© 2017 Elsevier Inc. All rights reserved.