Advanced property valuation techniques and valuation accuracy: Deciphering the artificial neural network technique

Property valuation end-users generally rely on property value opinion provided by valuers in making informed real estate investment decisions. However, the inaccuracy of valuation estimates could be attributed to the adoption of inappropriate property valuation methods and such inaccurate estimates could mislead real estate investors and stakeholders. This could result in individual loss and national loss due to the importance of the real estate sector to the national economy. Therefore, this study aims to examine the application of advanced property valuation techniques with special emphasis on the artificial neural network (ANN) technique in estimating accurate property values. A detailed review of the literature on issues involved in property valuation was conducted. The issues presented in this paper include the origin of ANN, its strength and weaknesses in comparison with other valuation approaches, its application both in theory and in practice, requirements for application in property valuation, valuers' response to its adoption, amongst others. It was found that the ANN technique could produce on the average accurate and reliable estimates but has not been widely adopted in practice. Thereafter, the challenges ahead in bridging the gap between theory and practice of the application of artificial intelligence (AI) techniques were discussed. In addition, the strategies of facilitating this paradigm shift to achieve a global sustainable property valuation practice are presented in this paper

Critical Factors Affecting the Safety Communication of Ethnic Minority Construction Workers

Ethnic minority workers (EMWs) or migrant workers continue to be confronted with communication problems, which can have serious effects on safety outcomes. This study aims to help improve construction industry EMW safety communication by uncovering and analyzing the criticality, underlying constructs, and explanatory power of the influencing factors involved. A mixed research design was employed by combining a literature review, semistructured interviews, and a questionnaire survey. Following the identification of an initial set of safety communication factors (SCFs) and a questionnaire designed and administered to EMWs in the Hong Kong and Australian construction industry, a total of 134 valid responses were analyzed through mean scoring, factor analysis, and importance-explanation analysis. Eighteen critical EMW SCFs are identified and categorized into three groups of worker-related SCFs, manager-related SCFs, and organization-related SCFs. A set of 36 SCFs identified cannot only be used to examine the relative importance of EMW SCFs, but can also be adopted to capture the critical SCFs for both local and ethnic minority construction workers in other countries. Narrowing a wide range of SCFs for EMWs provides stakeholders with the insights needed to the key contributory factors of safety communication, which in turn has a positive impact on safety performance. Despite this study being conducted in Hong Kong and Australia, its findings can also be used as a reference for other countries where EMWs are employed (e.g., the US, the UK, Canada, the Middle East, Malaysia, Singapore, and South Africa). Practical Applications Safety communication is a major safety challenge for EMWs and effective safety communication leads to improved safety performance and decreased injuries and fatalities. This research provides extra information on the key issues of safety communication that associated stakeholders need to address for EMWs to help them understand and mitigate the main safety communication barriers. This study suggests that apart from some measures (e.g., language courses, understandable safety training and safety materials, and bilingual translators) that have been taken for improving EMW safety communication in many countries, governments and employers are recommended to adopt multifaceted strategies manipulating worker-, manager-, and organization-related SCFs that would be more effective than a single measure. The critical roles of managers and organizations in promoting EMW safety communication are also emphasized in this study. Future efforts to improve or develop programs or interventions for EMW safety communication can benefit from this study by referring to the critical SCFs to include each aspect of safety communication. Furthermore, the identified critical SCFs will also help industry practitioners diagnose deficiencies in EMW safety management practices.</p

Prepotential and Instanton Corrections in N=2 Supersymmetric SU(N_1)xSU(N_2) Yang Mills Theories

In this paper we analyse the non-hyperelliptic Seiberg-Witten curves derived from M-theory that encode the low energy solution of N=2 supersymmetric theories with product gauge groups. We consider the case of a SU(N_1)xSU(N_2) gauge theory with a hypermultiplet in the bifundamental representation together with matter in the fundamental representations of SU(N_1) and SU(N_2). By means of the Riemann bilinear relations that hold on the Riemann surface defined by the Seiberg--Witten curve, we compute the logarithmic derivative of the prepotential with respect to the quantum scales of both gauge groups. As an application we develop a method to compute recursively the instanton corrections to the prepotential in a straightforward way. We present explicit formulas for up to third order on both quantum scales. Furthermore, we extend those results to SU(N) gauge theories with a matter hypermultiplet in the symmetric and antisymmetric representation. We also present some non-trivial checks of our results.Comment: 21 pages, 2 figures, minor changes and references adde

Development of a building sustainability assessment method (BSAM) for developing countries in sub-Saharan Africa

The consideration of the regional context in the development of green building rating systems is well established in the extant literature, and this informs the development of a sustainability assessment method for sub-Saharan Africa. Hence, a multi-expert consultation method was carried out in Nigeria which is the largest economy in the region. This was performed via a structured questionnaire survey and interview approaches to identify the key sustainability assessment criteria, assign score-weights to the various criteria, and establish the certification grading system of buildings. The developed Building Sustainability Assessment Method (BSAM) scheme and its weighted criteria were validated using two existing building case studies. The established BSAM scheme was compared to six widely used green building rating systems. The comparative analysis reveals that the score-weights and priorities of the BSAM scheme were remarkably different from the existing rating systems. The study findings also show the increasing focus on the indoor environmental quality and energy criteria by all the rating systems. The developed BSAM scheme, meanwhile, has adequately considered the three main pillars of sustainable development unlike the existing green rating tools. Hence, it is expected for the proposed BSAM scheme to promote greener buildings and enhance sustainable urban development in the region

Barriers to the Integration of BIM and Sustainability Practices in Construction Projects: A Delphi Survey of International Experts

The built environment faces numerous challenges in its quest to be more productive and sustainable, and to the adoption of a smart and creative process of carrying out the various operations. This study aims to investigate the profound barriers faced by construction stakeholders in their attempts to integrate BIM and sustainability practices in the construction processes. A two-round Delphi survey formed the basis of aggregating consensus among the expert panel based on a set of 38 factors derived via content analysis of previous research studies. Descriptive and inferential tests were employed for data analysis, and the results validated using the interrater agreement analysis. The three key barriers by descending order of significance are industry's resistance to change from traditional working practices, an extended period of adapting to innovative technologies and the lack of understanding of the processes and workflows required for BIM and sustainability. Deductions were also made based on the comparative analysis of the expert groups. The findings will advance the implementation of BIM and sustainability practices in construction projects and enable project stakeholders to focus on addressing the critical challenges discussed in this study

Dynamics of Viscous Dissipative Plane Symmetric Gravitational Collapse

We present dynamical description of gravitational collapse in view of Misner and Sharp's formalism. Matter under consideration is a complicated fluid consistent with plane symmetry which we assume to undergo dissipation in the form of heat flow, radiation, shear and bulk viscosity. Junction conditions are studied for a general spacetime in the interior and Vaidya spacetime in the exterior regions. Dynamical equations are obtained and coupled with causal transport equations derived in context of M$\ddot{u}$ller Israel Stewart theory. The role of dissipative quantities over collapse is investigated.Comment: 17 pages, accepted for publication in Gen. Relativ. Gra

Crosstalk between hepatocyte growth factor and integrin signaling pathways

Most types of normal cells require integrin-mediated attachment to extracellular matrix to be able to respond to growth factor stimulation for proliferation and survival. Therefore, a consensus that integrins are close collaborators with growth factors in signal transduction has gradually emerged. Some integrins and growth factor receptors appear to be normally in relatively close proximity, which can be induced to form complexes upon cell adhesion or growth factor stimulation. Moreover, since integrins and growth factor receptors share many common elements in their signaling pathways, it is clear that there are many opportunities for integrin signals to modulate growth factor signals and vice versa. Increasing evidence indicates that integrins can crosstalk with receptor tyrosine kinases in a cell- and integrin-type-dependent manner through a variety of specific mechanisms. This review is intended specifically for summarizing recent progress uncovering how the hepatocyte growth factor receptor c-Met coordinates with integrins to transmit signals

Space-time inhomogeneity, anisotropy and gravitational collapse

We investigate the evolution of non-adiabatic collapse of a shear-free spherically symmetric stellar configuration with anisotropic stresses accompanied with radial heat flux. The collapse begins from a curvature singularity with infinite mass and size on an inhomogeneous space-time background. The collapse is found to proceed without formation of an even horizon to singularity when the collapsing configuration radiates all its mass energy. The impact of inhomogeneity on various parameters of the collapsing stellar configuration is examined in some specific space-time backgrounds.Comment: To appear in Gen. Relativ. Gra

Phosphorylation of focal adhesion kinase on tyrosine 194 by Met leads to its activation through relief of autoinhibition

Focal adhesion kinase (FAK) has a crucial role in integration of signals from integrins and growth factor receptors. In this study, we demonstrate that growth factor receptors including hepatocyte growth factor receptor Met, epidermal growth factor receptor, and platelet-derived growth factor receptor directly phosphorylate FAK on Tyr194 in the FERM domain (band 4.1 and ezrin/radixin/moesin homology domain). Upon binding to Met or phosphoinositides, FAK may undergo conformational changes, which renders Tyr194 accessible for phosphorylation. Substitution of Tyr194 with Phe significantly suppresses the activation of FAK by Met. In contrast, substitution of Tyr194 with Glu (Y194E substitution) leads to constitutive activation of FAK. The phosphorylation of FAK on Tyr194 may cause conformational changes in the FERM domain, which disrupts the intramolecular inhibitory interaction between the FERM and kinase domains of FAK. Moreover, substitution of the basic residues in the (216)KAKTLRK(222) patch in the FERM domain with Ala antagonizes the effect of the Y194E substitution on FAK activation, thus suggesting that the interactions between the phosphorylated Tyr194 and the basic resides in the (216)KAKTLRK(222) patch may allow FAK to be activated through relief of its autoinhibition. Collectively, this study provides the first example to explain how FAK is activated by receptor tyrosine kinases. Oncogene (2011) 30, 153-166; doi:10.1038/onc.2010.398; published online 30 August 201