Projective Dimension Research Articles

ANALYSIS OF COST AND CASTING TIME WITH CONVENTIONAL AND PRECAST METHODS ON THE CITEREUP FLYOVER CONSTRUCTION PROJECT

The concrete manufacturing process, also known as casting, is the final stage that determines the success of a flyover construction project. The benchmark lies in the casting method which of course has a direct effect on resource efficiency, processing time, budget, and quality. Generally, the process of casting concrete in flyover construction projects in Indonesia uses the conventional method in which the process is carried out and cast in situ. However, the development of science and the paradigm of efficiency in the dimensions of flyover construction projects has given birth to a new method in which the concrete hardening process can be carried out elsewhere and made precast.The conventional method and the precast method are now the best alternative by taking into account aspects of cost, quality and time which are considered for efficiency in flyover construction projects. For this reason, the researchers analyzed the efficiency of the Citeureup flyover construction project using the concrete casting method used in the process

THE SMALL FINITISTIC DIMENSIONS OF COMMUTATIVE RINGS

Let R be a commutative ring with identity. The small finitistic dimension fPD(R) of R is defined to be the supremum of projective dimensions of R-modules with finite projective resolutions. In this paper, we characterize a ring R with fPD(R)≤n using finitely generated semiregular ideals, tilting modules, cotilting modules of cofinite type and vaguely associated prime ideals. As an application, we obtain that if R is a Noetherian ring, then fPD(R)=sup{grade(𝔪,R)|𝔪∈Max(R)} where grade(𝔪,R) is the grade of 𝔪 on R. We also show that a ring R satisfies fPD(R)≤1 if and only if R is a DW ring. As applications, we show that the small finitistic dimensions of strong Prüfer rings and LPVDs are at most one. Moreover, for any given n∈ℕ, we obtain a total ring of quotients R satisfying fPD(R)=n.

An Experimental Portuguese Social-Enterprise Project in Urban Agriculture: A Case Study on the Influence of the Interaction of Stakeholder Roles on Sustainable Governance

An experimental urban-agriculture (UA) project was started in 2018 with multiple stakeholders in Lisbon, Portugal. The project involved setting up an indoor vertical farm in a university building. Early on, there were promising outcomes across the environmental, social and economic pillars of sustainability. However, the project was closed in 2022. Here, we carried out an analysis of the sustainability-governance pillar that aimed to provide some understanding of why the project did not proceed. We used role-constellation mapping of the 27 stakeholder groups engaged. We also carried out force-field analysis of the stakeholders and their desirable or problematic interactions across seven factors of governance. Results showed that although the parties engaged represented various project aims and dimensions, there was a failure to establish a network of stakeholders consistently engaged in governance practices at the outset and in an ongoing way. Inadequate project culture and a lack of critical governance factors led to a failure in conveying a strong sense of ownership of the project to the stakeholders. This case study raises the need for future UA projects to invest in good governance structures, the promotion of dialogue between the parties, and a shared culture, in order to become sustainable.

Modules with finite reducing Gorenstein dimension

If M is a nonzero finitely generated module over a commutative Noetherian local ring R such that M has finite injective dimension and finite Gorenstein dimension, then it follows from a result of Holm that M has finite projective dimension, and hence a result of Foxby implies that R is Gorenstein. We prove that the same conclusion holds for certain nonzero finitely generated modules that have finite injective dimension and finite reducing Gorenstein dimension, where the reducing Gorenstein dimension is a finer invariant than the classical Gorenstein dimension, in general. Along the way, we also prove new results, independent of the reducing dimensions, concerning modules of finite Gorenstein dimension.

An Intelligent Recognition Method of a Short-Gap Arc in Aviation Cables Based on Feature Weight Enhancement

The cases of loose pin of electrical connectors and broken wire harnesses easily occur in aviation cables due to vibration and thus cause the short-gap arc fault. When the vibration frequency exceeds 30 Hz, the short-gap arc fast burning and extinguishing properties make the changes in time domain and frequency domain of fault signals weak, thus increasing the difficulty in the identification of such a fault. In this article, an arc recognition method based on weight enhancement (WE) and principal component analysis (PCA) is proposed to solve the identification problem of the short-gap arc fault caused by its unapparent frequency-domain characteristics. In the proposed method, the currents under different conditions were measured and analyzed based on the considerations of different vibration conditions and loads. The measured current signals were first decomposed with the empirical modal decomposition (EMD) method, and then, optimal intrinsic mode functions (IMFs) were selected based on the correlation coefficient and kurtosis index to reconstruct the signals with WE algorithm. The time-domain, frequency-domain, and sample entropy characteristics extracted from reconstructed signals were used to establish the 3-D eigenvectors with direct fusion algorithm. Finally, the short-gap arc fault was identified with a principal element analysis and dimension reduction method. The experimental results proved that WE could improve the selection of the optimal direction of PCA dimensional reduction projection and that the short-gap arc fault of aviation cables could be quickly and effectively identified with the proposed method.

Privacy by design in systems for assisted living, personalised care, and wellbeing: A stakeholder analysis.

Privacy by design within a system for assisted living, personalised care, and wellbeing is crucial to protect users from misuse of the data collected about their health. Especially if the information is collected through audio-video devices, the question is even more delicate due to the nature of these data. In addition to guaranteeing a high level of privacy, it is necessary to reassure end users about the correct use of these streams. The evolution of data analysis techniques began to take on an important role and increasingly defined characteristics in recent years. The purpose of this paper is twofold: on the one hand, it presents a state of the art about privacy in European Active Healthy Ageing/Active Healthy Ageing projects, with a focus on those related to audio and video processing. On the other hand, it proposes a methodology, developed in the context of the European project PlatfromUptake.eu, to identify clusters of stakeholders and application dimensions (technical, contextual, and business), define their characteristics, and show how privacy constraints affect them. From this study, we then generated a Strengths, Weaknesses, Opportunities, and Threats analysis in which we aim to identify the critical features connected to the selection and involvement of relevant stakeholders for the success of a project. Applying this type of methodology to the initial stages of a project allows understanding of which privacy issues could be related to the various stakeholder groups and which problems can then affect the correct development of the project. The idea is, therefore, to suggest a privacy-by-design approach according to the categories of stakeholders and project dimensions. The analysis will cover technical aspects, legislative and policies-related aspects also regarding the point of view of the municipalities, and aspects related to the acceptance and, therefore, to the perception of the safety of these technologies by the final end users.

Dimensionality reduction method based on multiple feature-space collaborative discriminative projection for rotor fault diagnosis

At present, the trend for complex and intelligent rotating machinery and equipment, which generate a large amount of high-dimensional and nonlinear fault monitoring data that is difficult to handle, is becoming more and more apparent. This makes the traditional dimensionality reduction algorithms based on point-to-point metrics or a small number of graph-embedding structures lose their utility. To solve this problem, a multiple feature-space collaborative discriminative projection (MFSCDP) algorithm for rotor fault data set dimensionality reduction is proposed. The algorithm first improves the projection metric from sample point to feature space into the median metric in order to achieve the effect of weakening the extrapolation error of the algorithm, and based on this, we propose a sample point-to-point guided nearest-neighbor feature space selection method to improve the construction efficiency of the feature space embedding graph. Then, we use Relief F to indirectly construct the reduced dimensional projection matrix with multiple feature space of collaboration. Finally, the proposed MFSCDP algorithm is used for the dimensionality reduction process of a rotor fault data set. The algorithm’s performance was verified using experimental information from rotor failure simulations of two different structural types. The results show that the algorithm can reduce the difficulty of fault classification and improve the accuracy of identification.

Generalized local duality, canonical modules, and prescribed bound on projective dimension

We present various approaches to J. Herzog's theory of generalized local cohomology and explore its main aspects, e.g., (non-)vanishing results as well as a general local duality theorem which extends, to a much broader class of rings, previous results by Herzog-Zamani and Suzuki. As an application, we establish a prescribed upper bound for the projective dimension of a module satisfying suitable cohomological conditions, and we derive some freeness criteria and questions of Auslander-Reiten type. Along the way, we prove a new characterization of Cohen-Macaulay modules which truly relies on generalized local cohomology, and in addition we introduce and study a generalization of the notion of canonical module.

Cohen–Macaulay Noetherian algebras

Let (R,m) be a d-dimensional commutative complete Noetherian local ring and Λ be a Noetherian R-algebra. Motivated by the notion of Cohen–Macaulay Artin algebras of Auslander and Reiten, we say that Λ is Cohen–Macaulay if there is a finitely generated Λ-bimodule ω that is maximal Cohen–Macaulay over R such that the adjoint pair of functors (ω⊗Λ′−,HomΛ′(ω,−)) induces quasi-inverse equivalences between the full subcategories of finitely generated Λ′-modules consisting of modules of finite projective dimension, P∞(Λ′), and the modules of finite injective dimension, I∞(Λ′), whenever Λ′=Λ,Λop. It is proved that such a module ω is unique, up to isomorphism, as a Λ′-module. It is also shown that Λ is a Cohen–Macaulay algebra if and only if there is a semidualizing Λ-bimodule ω of finite injective dimension and P∞(Λ′) and I∞(Λ′) are contained in the Auslander and Bass classes, respectively. We prove that Cohen–Macaulayness behaves well under reduction modulo system of parameters of R. Indeed, it will be observed that if Λ is a Cohen–Macaulay algebra, then for any system of parameters x=x1,…,xd of R, the Artin algebra Λ∕xΛ is Cohen–Macaulay as well. Assume that ω is a semidualizing Λ-bimodule of finite injective dimension that is maximal Cohen–Macaulay as an R-module. It will turn out that Λ being a Cohen–Macaulay algebra is equivalent to saying that the pair (CM(Λ′),I∞(Λ′)) forms a hereditary complete cotorsion theory and the pair (CM(Λ′op),P∞(Λ′)) forms a Tor-torsion theory, where CM(Λ′) is the class of all finitely generated Λ′-modules admitting a right resolution by modules in addω. Finally, it is shown that Cohen–Macaulayness ascends from R to RΓ and RQ, where Γ is a finite group and Q is a finite acyclic quiver.

Sustainability indicators to achieve a circular economy: A case study of renewable energy and plastic waste recycling corporate social responsibility (CSR) projects in Thailand

To promote their public image, a growing number of companies have adopted corporate social responsibility (CSR) projects that benefit various social interests. As such, it is imperative to audit the social, environmental, and economic dimensions of CSR projects for their sustainable development. This paper presents an assessment of three CSR projects undertaken by the energy industry (renewable energy) and commercial sector (plastic waste recycling) in Thailand to transition towards the circular economy (CE) business model. A set of CE indicators were selected from the World Business Council for Sustainable Development: WBCSD 2018 European Commission 2018, and British Standard Institution 2017 and compared with the sustainability indicators listed in the ISO 26000:2010 (referenced in the Global Reporting Initiative (GRI): G4 Guidelines). These indicators were established to assess the readiness of companies to implement sustainable CSR projects. The assessment results showed that the CSR projects in the case study were conducive to the CE model, as most of the CE concepts evaluated by the performance indicators were already in place. This study aimed to support the implementation of CSR projects that contribute to adopting a CE business model and determine key performance indicators (KPIs) to measure and monitor CSR projects in terms of their CE concepts. The sustainability KPIs proposed in this study can serve as a set of guidelines to drive CE strategy adoption and allow for the identification of sustainable CSR projects that can simultaneously offer more value creation and satisfaction for all stakeholders, including society and the companies, while reducing environmental impacts. This paper integrates CSR into a CE approach that results in business sustainability and contributes to Sustainability Development Goal (SDG) targets.

How effective has the low-carbon city pilot policy been as an environmental intervention in curbing pollution? Evidence from Chinese industrial enterprises

In response to China's burgeoning environmental pollution, since 2010, Chinese policymakers have implemented a low-carbon city pilot policy (LCCP) and expanded the pilot project's dimension since then. An accurate evaluation of the consequences of this environmental intervention is vital for the further promotion and extension of this pilot project. In this milieu, we develop a framework to put credibility on this newly intervened policy by harnessing robust econometric approaches. To achieve this objective, we garner integrated data from 2006 to 2014, sourced from two distinct databases: the Chinese Industrial Enterprise database and the China Enterprise Pollution Emissions database. This paper deploys a time-varying Difference in Difference (DID) approach to scrutinize the influence of LCCP on China's emissions reduction agenda from a micro-perspective. The findings reveal that: (1) LCCP significantly reduces enterprise pollution by promoting eco-friendly technologies and innovation capacity; (2) LCCP promotes healthy urbanization and restores the urban ecosystem by abating emissions intensities significantly (i.e., for every one percentage point increase in LCCP, firm-level emissions plummet by 1.87%); (3) LCCP efficacy in controlling emissions varies in terms of ownership, type and location of the firms (i.e., LCCP policy is more efficacious in controlling emissions if the firm is foreign or private-owned if it is a capital and technology-intensive high polluting firm and if the firm is located in eastern and western zones of the country). The findings are robust after replacing the explained variables, changing the estimation method, excluding the interference of outliers, considering the lagged term, and excluding other policy interference. Based on the findings, this study touts the Chinese Government's LCCP policy by providing firm-level theoretical support and empirical evidence for China to boost the revamping strategy of carbon-neutral cities. Therefore, the benefits of pilot cities should be further harnessed to guide enterprises in low-carbon pilot cities so that they can engage in cleaner production activities and achieve green transformation through policy preferences and other incentives. Further policy suggestions have been made in the relevant section.

Intermediate dimensions of infinitely generated attractors

We study the dimension theory of limit sets of iterated function systems consisting of a countably infinite number of contractions. Our primary focus is on the intermediate dimensions: a family of dimensions depending on a parameter θ ∈ [ 0 , 1 ] \theta \in [0,1] which interpolate between the Hausdorff and box dimensions. Our main results are in the case when all the contractions are conformal. Under a natural separation condition we prove that the intermediate dimensions of the limit set are the maximum of the Hausdorff dimension of the limit set and the intermediate dimensions of the set of fixed points of the contractions. This builds on work of Mauldin and Urbański concerning the Hausdorff and upper box dimension. We give several (often counter-intuitive) applications of our work to dimensions of projections, fractional Brownian images, and general Hölder images. These applications apply to well-studied examples such as sets of numbers which have real or complex continued fraction expansions with restricted entries. We also obtain several results without assuming conformality or any separation conditions. We prove general upper bounds for the Hausdorff, box and intermediate dimensions of infinitely generated attractors in terms of a topological pressure function. We also show that the limit set of a ‘generic’ infinite iterated function system has box and intermediate dimensions equal to the ambient spatial dimension, where ‘generic’ can refer to any one of (i) full measure; (ii) prevalent; or (iii) comeagre.

Semi-automatic extraction of dangerous rock blocks from jointed rock exposures based on a discontinuity trace map

Using a rock slope surface model generated from unmanned aerial vehicle (UAV) digital photogrammetry, this study develops a new semi-automatic dangerous rock blocks extraction approach. It consists of four steps: (1) three dimensional trace map extraction and projection; (2) convex polygon searching using a depth-first search algorithm and a sign consistency test; (3) true block formation analysis based on the geometric topology; and (4) block removability, failure mode and stability analyses using the edge vector, active resultant vector and limit equilibrium method, respectively. Compared with existing block identification methods, the proposed approach considers the contribution of line-type discontinuities on block formation and integrates geometric and mechanical modelling processes in one program. This approach is suitable for rockfall sources quantitative assessment. The locations, geometric parameters, and stability results of all identified blocks can be automatically obtained, and these could provide a reference for rockfall hazard assessment. The proposed approach is applied to a railway bridge case in China, and the corresponding rockfall hazard is evaluated. At the end of this paper, the joint sets related to block formation, uncertainties of block shapes, and discontinuity size effect are discussed.

Story thinking for technology foresight

This article explores how skills and knowledge from the field of science fiction and fantasy (SFF) creative writing can be applied in technology foresight, especially for workshops with transdisciplinary research teams. The practical model introduced here, Story Thinking, builds upon and complements existing models for combining elements of storytelling with foresight, and highlights the contributions of writing practitioners. It offers four benefits for transdisciplinary teams: (1) it provides effective and straightforward techniques to inhabit possible futures (2) it encourages researchers to empathise with the humans who may have an impact on the uses of new technology; (3) it allows these researchers to envision plausible, possible and preferable chains of cause and effect; and (4) it works to engage researchers across disciplines in a shared vision, developing affinities to see them through the complex dimensions of large research projects. This article offers a rationale and background for this model, articulates it as it currently stands, and analyses a case study emerging from an ongoing collaboration with the University of Queensland and the Australian Defence Forces (ADF).

GENERIC LINES IN PROJECTIVE SPACE AND THE KOSZUL PROPERTY

AbstractIn this paper, we study the Koszul property of the homogeneous coordinate ring of a generic collection of lines in $\mathbb {P}^n$ and the homogeneous coordinate ring of a collection of lines in general linear position in $\mathbb {P}^n.$ We show that if $\mathcal {M}$ is a collection of m lines in general linear position in $\mathbb {P}^n$ with $2m \leq n+1$ and R is the coordinate ring of $\mathcal {M},$ then R is Koszul. Furthermore, if $\mathcal {M}$ is a generic collection of m lines in $\mathbb {P}^n$ and R is the coordinate ring of $\mathcal {M}$ with m even and $m +1\leq n$ or m is odd and $m +2\leq n,$ then R is Koszul. Lastly, we show that if $\mathcal {M}$ is a generic collection of m lines such that $$ \begin{align*} m> \frac{1}{72}\left(3(n^2+10n+13)+\sqrt{3(n-1)^3(3n+5)}\right),\end{align*} $$ then R is not Koszul. We give a complete characterization of the Koszul property of the coordinate ring of a generic collection of lines for $n \leq 6$ or $m \leq 6$ . We also determine the Castelnuovo–Mumford regularity of the coordinate ring for a generic collection of lines and the projective dimension of the coordinate ring of collection of lines in general linear position.

A network analysis for providing insights into national R&D budget allocation and investment planning

A network analysis for providing insights into national R&D budget allocation and investment planning

Translocal Implications of the Green Belt and Road Initiative: The China-Pakistan Economic Corridor Case

Since its inception in 2013, the Belt and Road Initiative (BRI) has been surrounded by doubts and fears. Some were confirmed, and some were dismissed, because they were groundless or due to adjustments. One of the most critical adjustments was the environmental dimension in the BRI projects, reflecting China’s internal environmental concerns. The enactment of the constitutional rule pursuing ecological civilization can translate to increasing environmental security within the investments in the recipient countries. The hypothesis in the study is that adopting the green BRI incorporates the ecological civilization concept, which refers to a myriad of transnational efforts by China to increase environmental security within its partners. In addition, it includes a constructivist perspective that considers ideational factors that do not happen at the level of the current neoliberal international institutions. Finally, this paper deploys the content analysis technique to seek sufficient empirical evidence to confirm the hypothesis and point out new research directions and limitations.

Relative finitistic projective and injective dimensions

Relative finitistic projective and injective dimensions

Some algebraic invariants of the edge ideals of perfect $ [h, d] $-ary trees and some unicyclic graphs

<abstract><p>This article is mainly concerned with computations of some algebraic invariants of quotient rings of edge ideals of perfect $ [h, d] $-ary trees and unicyclic graphs. We compute exact values of depth and Stanley depth and consequently projective dimension for above mentioned quotient rings, except for the one special case of unicyclic graph for which best possible bounds of Stanley depth are given.</p></abstract>

특수체육 전공 교사의 행위 주체성(Teacher Agency) 탐색

Objectives This study explores how the teacher agency of adapted physical education teachers is expressed in their subject, and what contextual factors affect the teacher agency in various special education settings.
 Methods A qualitative case study method was used for six adapted physical education teachers working at special education sites in various regions. Educational data of research participants were collected through in-depth interviews. Data analysis was conducted inductively by harnessing Priestley et al.’s (2015) ecological perspective as a theoretical framework.
 Results Adapted physical education teachers proactively practiced physical education when they understood the context of the situation and formed their own firm belief, while endeavouring to teach their subject consistently in any environment. The manifestation of teacher agency was promoted when the belief and values of physical education formed from teachers’ previous life experience matched with any one of the cultural, structural, and social contexts. In addition, factors that facilitated the manifestation of teacher agency include the school culture that is permissive for major subjects, the support from fellow teachers and important people, and the proper physical environment for physical education classes. On the other hand, barriers to the manifestation of teacher agency were the discourse taking adapted physical education as an integrated subject and stressing individualised education for students subject to special education as opposed to school curriculum, on-site atmosphere that does not recognise adapted physical education, the absence of physical environment support, limited emphasis on their role as special teachers, and lack of reflection on their major subject. In addition, despite the agreement between the repetitive and evaluative dimensions, fear of the projective dimensions also acted as a barrier.
 Conclusions Based on the findings, this study suggested the possibility that adapted physical education teachers proactively manifest teacher agency, the need for incumbent teacher education for adapted physical education, and the atmosphere to recognise special education as a school curriculum and institutional measures to improve this.