Mathematical Programming Formulations for the Collapsed k-Core Problem

In social network analysis, the size of the k-core, i.e., the maximal induced subgraph of the network with minimum degree at least k, is frequently adopted as a typical metric to evaluate the cohesiveness of a community. We address the Collapsed k-Core Problem, which seeks to find a subset of $b$ users, namely the most critical users of the network, the removal of which results in the smallest possible k-core. For the first time, both the problem of finding the k-core of a network and the Collapsed k-Core Problem are formulated using mathematical programming. On the one hand, we model the Collapsed k-Core Problem as a natural deletion-round-indexed Integer Linear formulation. On the other hand, we provide two bilevel programs for the problem, which differ in the way in which the k-core identification problem is formulated at the lower level. The first bilevel formulation is reformulated as a single-level sparse model, exploiting a Benders-like decomposition approach. To derive the second bilevel model, we provide a linear formulation for finding the k-core and use it to state the lower-level problem. We then dualize the lower level and obtain a compact Mixed-Integer Nonlinear single-level problem reformulation. We additionally derive a combinatorial lower bound on the value of the optimal solution and describe some pre-processing procedures and valid inequalities for the three formulations. The performance of the proposed formulations is compared on a set of benchmarking instances with the existing state-of-the-art solver for mixed-integer bilevel problems proposed in (Fischetti et al., A New General-Purpose Algorithm for Mixed-Integer Bilevel Linear Programs, Operations Research 65(6), 2017)

Creative Strategies to Recover Urban Land in Disuse

[eng] Industrial land in disuse is a dual carrier of crisis and revitalization of mining cities facing decline. On the one hand, it is an object that carries urban crisis, which has many negative effects on the urban environment, economy, and society. On the other hand, it has the advantage of reuse and can be transformed into a positive factor for urban revival. The main starting point of this research is to explore the value of industrial wastelands and their reuse to promote China's mining cities out of their difficulties. The existing research on industrial lands in disuse lacks a holistic and systematic view and has insufficient knowledge of overall value of industrial lands in disuse and inadequate refining of their core values. This has led to a series of problems such as "islanding" renewal, "destructive" protection, and convergence of appearance. On account of these problems, this research applies landscape genetic theory to the conservation and renewal of industrial lands in disuse by using literature research, field survey, typology, comparative study, and systematic analysis, and analyzes the regular characteristics of industrial land in disuse clusters in China in time and space, so as to explore a more effective way for the deep excavation and scientific expression of the value of industrial lands in disuse. This research is highly interdisciplinary and exploratory. The main research contents and academic contributions: 1. The research introduces the concept of genes in biogenetics, based on the principles of "base pairing" and "DNA sequence combination" in the storage and transmission of genetic information. And based on the typology and the epistemology that interprets anthropology and the methodological basis of designing language and semiotics, we have constructed a landscape genetic theory structure with a landscape gene structure system and landscape genetic atlas as the core. 2. This research unravels the mining cities in China as the research background, clarifies the definition, classification, regional distribution, and spatial structure of mining cities, discusses the characteristics and laws of the formation and development of mining cities, and summarizes the problems and countermeasures. Then, the concept of industrial land in disuse is proposed. Its causes are analyzed and classified, and the main problems in the protection and renewal of industrial lands in disuse in China are analyzed. 3. Based on the evaluation of the value of industrial lands in disuse and their morphological and structural laws, the "unit-piece-chain-domain" landscape genetic structure system is proposed, so that any complex industrial land in disuse group can be quickly decomposed and combined under the guidance of this system. Based on this structure system, coupling mining city spaces, industrial land in disuse groups, and green space, the effective way for transformation and characteristics shaping of mining city and high-quality human living environment construction is explored. 4. This research proposes a conservation method and creative strategy for industrial land in disuse based on the genetic behavior of landscape genes. In the gene replication stage, it focuses on the protection of the authenticity and integrity of the landscape genes of industrial wasteland. In the gene translation stage, it focuses on the benign recombination and functional grafting of the landscape genes of industrial land in disuse. Three creative strategies of recombination and grafting are proposed: landscape genetic juxtaposition, landscape genetic translation, and landscape genetic symbiosis. The space of industrial land in disuse, which is contradictory and conflicting due to cultural heterogeneity and spatial and temporal differences, is reconstructed to create a landscape with regional characteristics. Huangshi City is a representative mining city in China, with a large number and many types of industrial wastelands, which has temporal continuity and spatial integrity. Based on the evaluation of the value of industrial wastelands in Huangshi City, using landscape gene theory, this research constructs the landscape gene structure system of "unit-piece-chain-domain", and builds the spatial layout of coupling urban space, industrial land in disuse clusters, and green space. Taking Tonglvshan landscape gene piece and Hanyeping Railway landscape gene chain as examples, this research maps the landscape gene atlas. Based on the landscape gene atlas and genetic behavior, protection of authenticity and integrity, recombination, and grafting measures are proposed to revitalize industrial land in disuse

Post-Earthquake Home Reconstruction in the Surrounding Hills of Kathmandu Valley, Nepal, PRP 200

In April of 2015, a 7.6 magnitude earthquake struck the Kathmandu Valley at the center of Nepal. Within the following year, Kathmandu was struck by a 7.3 magnitude earthquake and multiple aftershocks. The initial earthquake caused the deaths of 8,856 people, injured 22,309, and affected eight million more. Many agencies around the world came together to fund reconstruction efforts as part of a Nepal and a Multi-Donor Trust Fund (MDTF). The MDTF conducted an Earthquake Housing Damage and Characteristics Survey (EHDC) which led to the creation of Nepal Rural Housing Reconstruction Program (NRHRP), which sought to reconstruct earthquake-resistant homes. The NRHRP developed a homeowner-driven grant process and established the National Reconstruction Authority (NRA) to distribute housing reconstruction grants to families. Those grants were to be paid out via three tranches, each after the completion of a specific construction phase. During 2017, an international collaborative effort began among four parties: Hiroshima University (HU); Tribhuvan University (TU); Nepal’s Alternative Energy Promotion Center (AEPC); and the Lyndon B. Johnson School of Public Affairs (LBJ) of the University of Texas at Austin (UT). The team investigated the challenges and opportunities for reconstruction of homes in rural areas damaged by the 2015 earthquake in and around the hinterland of Kathmandu Valley, Nepal. Within the context of a university course, students began by studying alternative building technologies (ABTs) being implemented in Nepal by local nongovernmental organizations (NGOs). When project members visited Nepal in March 2017, they interviewed rural residents to identify barriers to home reconstruction. During a field study, the students also met with local governmental officials and NGO representatives. This report describes students’ field investigation in Nepal, background research on alternative building technologies (ABTs) for home reconstruction, and recommendations developed from consultation with stakeholders and technical advisors. The first chapter starts with the earthquake and its associated damage and describes the response of the Government of Nepal (GON) and the international community in forming the MDTF, the NRHRP, and the NRA. The second chapter discusses different alternative building technologies (ABTs) considered by the GON, including bamboo, hempcrete, rammed earth, Compressed Stabilized Earth Brick (CSEB), earthbags, and modified conventional housing. Each section describes the type of building style, its construction, materials and labor required, estimates of construction time (if available), costs, and a brief section on comparative advantages and disadvantages. The third chapter describes the 2017 field study in Nepal, included the locations of the field study and interviews and discussions with local NGOs, the governmental agencies, and local residents. The research group sought to learn whether a lack of affordable and appropriate building methods could explain why many villagers still live in temporary shelters. Village residents discussed barriers to housing reconstruction unrelated to the type of home being built. The final chapter presents conclusions from 2017 field study observations of the three villages. Researchers found four common barriers to reconstruction: the cost of transportation and materials; insufficient reconstruction incentives; grant processes with many procedural barriers to funding; and the need for consistent interaction of the community with governmental agencies. One suggestion is to evaluate the home reconstruction program to assess its procedures and outcomes. A second suggestion is for Nepal to enhance the number and authority of mobile teams of professionals to assist villagers seeking to reconstruct homes.Public Affair

History of Construction Cultures Volume 1

History of Construction Cultures Volume 1 contains papers presented at the 7ICCH – Seventh International Congress on Construction History, held at the Lisbon School of Architecture, Portugal, from 12 to 16 July, 2021. The conference has been organized by the Lisbon School of Architecture (FAUL), NOVA School of Social Sciences and Humanities, the Portuguese Society for Construction History Studies and the University of the Azores. The contributions cover the wide interdisciplinary spectrum of Construction History and consist on the most recent advances in theory and practical case studies analysis, following themes such as: - epistemological issues; - building actors; - building materials; - building machines, tools and equipment; - construction processes; - building services and techniques ; -structural theory and analysis ; - political, social and economic aspects; - knowledge transfer and cultural translation of construction cultures. Furthermore, papers presented at thematic sessions aim at covering important problematics, historical periods and different regions of the globe, opening new directions for Construction History research. We are what we build and how we build; thus, the study of Construction History is now more than ever at the centre of current debates as to the shape of a sustainable future for humankind. Therefore, History of Construction Cultures is a critical and indispensable work to expand our understanding of the ways in which everyday building activities have been perceived and experienced in different cultures, from ancient times to our century and all over the world

Proceedings of the 8th International Conference on Civil Engineering

This open access book is a collection of accepted papers from the 8th International Conference on Civil Engineering (ICCE2021). Researchers and engineers have discussed and presented around three major topics, i.e., construction and structural mechanics, building materials, and transportation and traffic. The content provide new ideas and practical experiences for both scientists and professionals

Julia 2010: The caretaker election

This book provides a comprehensive coverage of one of Australia’s most historic elections, which produced a hung parliament and a carefully crafted minority government that remains a heartbeat away from collapse, as well as Australia’s first elected woman Prime Minister and the Australian Greens’ first lower house Member of Parliament. The volume considers the key contextual and possibly determining factors, such as: the role of leadership and ideology in the campaign; the importance of state and regional factors (was there evidence of the two or three speed economy at work?); and the role of policy areas and issues, including the environment, immigration, religion, gender and industrial relations. Contributors utilise a wide range of sources and approaches to provide comprehensive insights into the campaign. This volume notably includes the perspectives of the major political groupings, the ALP, the Coalition and the Greens; and the data from the Australian Election Survey. Finally we conclude with a detailed analysis of those 17 days that it took to construct a minority party government

From Valuable Resource to Valued Person: Ontologies of Human Resource Management

This thesis examines the conceptualisations of those who do the work of organisations as evidenced in human resource management (HRM) scholarship. It contrasts three perspectives in the HRM discourse: strategic, humanistic and personalistic, and distinguishes the world-views and philosophies within them. The four papers in the thesis address these perspectives and indicate implications for HRM theory, research and practice. The primary research question is ‘how is the person conceptualised in the HRM discourse?’ which is answered by affirming that such conceptualisation has varied throughout the HRM tradition wherein the ‘human’ in HRM is regarded as both a valuable resource and a valued person. The ontology of those who do the work of organisations is analysed and it is argued that they are not merely assets but persons within communities of persons. To support this argument, the thesis employs the philosophy of Jacques Maritain (1882– 1973) whose themes of integral humanism, the person, and the common good are employed to examine selected HRM literature. The researcher seeks to join other scholars in advocating that organisations are not the only beneficiaries of employee efforts and that a multi-stakeholder approach needs to be taken in the HRM discourse which recognises employee, community, societal and environmental outcomes. It is suggested that the well-being of those who do the work of organisations is core to the HRM agenda. The manner in which those who do the work of organisation are being conceptualised and framed is significant for HRM scholars and practitioners. The utility, dignity and human flourishing of those who contribute to organisational outcomes are highlighted

BRIDGE: The Heritage of Connecting Places and Cultures, Conference Proceedings

Official Conference Proceedings for the international conference BRIDGE: The Heritage of Connecting Places and Cultures (6-10 July 2017, Ironbridge Gorge World Heritage Site, UK) Organised by the Ironbridge International Institute for Cultural Heritage, University of Birmingham, and the Ironbridge Gorge Museum Trust

Proceedings of the 8th International Conference on Civil Engineering

This open access book is a collection of accepted papers from the 8th International Conference on Civil Engineering (ICCE2021). Researchers and engineers have discussed and presented around three major topics, i.e., construction and structural mechanics, building materials, and transportation and traffic. The content provide new ideas and practical experiences for both scientists and professionals