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Article
Publication date: 5 June 2023

Huiyi Xu, Zhiming Gao, Yang Yang and Wenbin Hu

The purpose of this study is to ensure the safe use of carbon fiber composite pressure vessels in the nuclear industry environment.

Abstract

Purpose

The purpose of this study is to ensure the safe use of carbon fiber composite pressure vessels in the nuclear industry environment.

Design/methodology/approach

This study investigated the degradation behaviors of carbon fiber reinforced composite (CFRP) using the specific corrosive media HF solution, with a focus on the damage to the surface epoxy layer. The degradation behaviors of CFRP in HF solution were examined by electrochemical methods and surface characterization, using HCl, NaCl and NaF solution for comparison.

Findings

The results showed that the specimen in HF solution will have a value of |Z|0.01 Hz one order of magnitude lower, a substantially lower contact angle, more breakage of the surface epoxy and the stronger O─H peak and weaker C─O─C peak in the Fourier transform infrared spectrum, indicating severe hydrolytic damage to the surface epoxy.

Originality/value

The work focuses on the degradation damage to CFRP surface epoxy by specific corrosive media HF.

Details

Anti-Corrosion Methods and Materials, vol. 70 no. 4
Type: Research Article
ISSN: 0003-5599

Keywords

Article
Publication date: 26 April 2023

Rachel Worthington and Suzanne Wheeler

Hyperfocus (HF) is characterised by an intense state of concentration/focus. The purpose of this study is to explore in what ways HF has been found to contribute towards offending…

Abstract

Purpose

Hyperfocus (HF) is characterised by an intense state of concentration/focus. The purpose of this study is to explore in what ways HF has been found to contribute towards offending behaviour and what treatments have been found to be efficacious to reduce offending behaviour where HF was a contributing factor.

Design/methodology/approach

The systematic review was performed according to the recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. Papers were screened for quality appraisal and risk of bias. The initial search yielded 9,446 articles. Fifty-seven papers were deemed as meeting the inclusion criteria.

Findings

HF was noted to act as a vulnerability factor for aggression, sexual offending, radicalisation and stalking. HF was also observed in clients with psychopathy, autism, mental illness and those without a diagnosis. Thus, HF was not found to be offence or diagnosis specific. Furthermore, HF was found across males and females and adults and adolescents. The results identified themes in relation to the mechanisms by which HF may contribute to offending and suggested interventions for HF and offending.

Practical implications

Practitioners working with clients with HF currently lack evidence on the extent to which this contributes towards offending and recidivism and how HF could be addressed in interventions. Future research is needed to establish the role of HF in offending behaviour. Ideally, this should involve longitudinal data collection, retrospective analysis of data and sophisticated statistical analysis. This should also include exploration of the ways in which HF may be interconnected with offence risks/need factors which contribute towards offending. Research could inform the development of formal measurement tools for HF which are validated with norms for adult and adolescent offender samples. Practitioners should use case formulation to explore if HF represents a treatment need for clients they are working with.

Originality/value

This review noted that although HF has been postulated as being an important contributing factor to offending behaviour, few studies have tested this directly. From the limited studies available, HF was found to be relevant across different types of offences. HF was noted to contribute to offending due to neuropsychological mechanisms linked to executive functioning deficits and positive rewards associated with offending behaviour. Reasons for the lack of HF research are noted and recommendations for future research are discussed.

Details

The Journal of Forensic Practice, vol. 25 no. 3
Type: Research Article
ISSN: 2050-8794

Keywords

Article
Publication date: 13 April 2023

Mao-Lin Shi, Liye Lv and Lizhang Xu

Extreme support vector regression (ESVR) has been widely used in the design, analysis and optimization of engineering systems of its fast training speed and good computational…

Abstract

Purpose

Extreme support vector regression (ESVR) has been widely used in the design, analysis and optimization of engineering systems of its fast training speed and good computational ability. However, the ESVR model is only able to utilize one-fidelity information of engineering system. To solve this issue, this paper extends extreme support vector regression (ESVR) to a multi-fidelity surrogate (MFS) model which can make use of a few expensive but higher-fidelity (HF) samples and a lot of inaccurate but cheap low-fidelity (LF) samples, named ESVR-MFS.

Design/methodology/approach

In the ESVR-MFS model, a kernel matrix is designed to evaluate the relationship between the HF and LF samples. The root mean square error of HF samples is used as the training error metric, and the optimal hyper-parameters of the kernel matrix are obtained through a heuristic algorithm.

Findings

A number of numerical problems and three engineering problems are used to compare the ESVR-MFS model with the single-fidelity ESVR model and two benchmark MFS models. The results show that the ESVR-MFS model exhibits competitive performance in both numerical cases and practical cases tested in this work.

Practical implications

The proposed approach exhibits great capability for practical multi-fidelity engineering design problems.

Originality/value

A MFS model is proposed based on ESVR, which can make full use of the advantages of both HF data and LF data to achieve optimal results at same or lower cost.

Details

Engineering Computations, vol. 40 no. 2
Type: Research Article
ISSN: 0264-4401

Keywords

Article
Publication date: 2 August 2022

Regina Ngozi Ugbaja, Beno Okechukwu Onunkwor, Emmanuel Ifeanyichukwu Ugwor, Kunle Ogungbemi, Anuoluwapo Adewole, Michael Ayobami Olowoyeye, David Arowojolu, Olamide Yewande Adeleke and Victory Chukwudalu Ugbaja

This study aims to scrutinize the efficacy of chitosan (CT) on cardio-lipotoxic responses elicited by a high-fat diet (HF).

Abstract

Purpose

This study aims to scrutinize the efficacy of chitosan (CT) on cardio-lipotoxic responses elicited by a high-fat diet (HF).

Design/methodology/approach

Thirty-six male Wistar rats were distributed across six groups (n = 6): normal diet (ND), HF, ND-5%CT, HF-1%CT, HF-3%CT and HF-5%CT, for seven weeks. Blood and cardiac tissues were processed for biochemical, immunohistochemical and histopathological analyses.

Findings

Ingestion of HF induced hyperlipidaemia and lipid accumulation, leading to increased body and heart weight by 70.5% (p < 0.0001) and 124% (p = 0.0021), respectively, compared to ND-groups. Cardiac damage markers (creatine kinase, lactate dehydrogenase and malondialdehyde) were higher in the HF-group compared to control rats. Also, atherogenic and coronary risk indices were significantly elevated by 155% (p = 0.0044) and 174% (p = 0.0008), respectively, compared to control rats. Rats fed HF had significantly reduced cardiac antioxidants (superoxide dismutase, catalase and glutathione peroxidase) and elevated expression of NF-κB-p65 and p53 (p < 0.0001) in the cardiac tissues. Histology revealed lipid inclusions in the cardiac tissues of HF-groups. CT (1%–5%) prevented hyperlipidaemia, lipid accumulation, oxidative stress and cardiac damage in HF-fed rats, while greatly improving the histology of the cardiac tissues in HF-fed rats in a dose-dependent manner.

Originality/value

To the best of the authors’ knowledge, this is the first report of the effects of CT against cardio-lipotoxicity elicited by HF diet ingestion. The findings suggest that CT may present a safe therapeutic alternative for managing complications arising from cardio-lipotoxicity.

Details

Nutrition & Food Science , vol. 53 no. 3
Type: Research Article
ISSN: 0034-6659

Keywords

Article
Publication date: 17 February 2023

Nahid Zehra and Udai Bhan Singh

The objective of this systematic literature review (SLR) is to explore the current state of research in the field of household finance (HF). This study aims to summarize the…

Abstract

Purpose

The objective of this systematic literature review (SLR) is to explore the current state of research in the field of household finance (HF). This study aims to summarize the existing research to highlight the importance of household finance in a nation’s economy. By exploring all conceptual and applied implications of HF, this study projects directions for future research to develop a comprehensive understanding of the subject.

Design/methodology/approach

This SLR is based on 112 articles published in peer-reviewed journals between 2006 and 2020 (Table 3). The methodology comprises five steps, namely, formulation of research questions, identification of studies, their selection and evaluation, analyses and syntheses and presentation of results.

Findings

The findings of this study show that studies on HF are gradually increasing worldwide with the USA registering the highest number of published research on the topic during the period under scrutiny. Notwithstanding the increasing attention and research on HF, empirical research in emerging economies is lagging. Additionally, this study finds that HF structure presents a perfect setting to understand how households compose their financial portfolio, make financial decisions and what factors influence their decisions.

Research limitations/implications

This study is an SLR – an accurate and accepted method of reviewing available literature on a selected subject. However, the selection of inclusion and exclusion criteria depends on the researchers’ rationale which might lead to research bias. This should be considered an inherent limitation of SLR.

Practical implications

By synthesizing the contents of extant literature, this study presents important insights into HF. This study underlines the most discussed topics in the domain and identifies potential investigation areas. This study gives the knowledge of leading articles, authors and journals and informs scholars and academicians about the areas that need further investigation by portraying the complete picture of the subject in a systematic manner. Further, this study highlights that households make suboptimal financial decisions that affect their financial well-being. To reduce the adverse impacts of these decisions, policymakers and financial institutions must take steps to improve households’ use of formal financial markets. Household decisions can be reformed by enhancing consumers’ knowledge about financial products and services. Furthermore, households can be served better by offering customization in traditional financial products.

Originality/value

This study synthesizes the main findings of selected literature on HF. The expansion of studies on HF has generated the need to review the existing literature in a systematic manner. To the researchers’ best knowledge, this SLR is the first thorough study of available articles in the HF domain. This study presents the scope of future research by highlighting numerous aspects and functions of HF.

Details

Qualitative Research in Financial Markets, vol. 15 no. 5
Type: Research Article
ISSN: 1755-4179

Keywords

Article
Publication date: 15 June 2015

Daniel K. Malone, Susan E. Collins and Seema L. Clifasefi

Chronic homelessness is a serious public health issue that places a strain on health-care and criminal justice systems. Typical housing models place requirements on chronically…

Abstract

Purpose

Chronic homelessness is a serious public health issue that places a strain on health-care and criminal justice systems. Typical housing models place requirements on chronically homeless individuals that are often experienced as insurmountable barriers to housing. Housing First (HF) models attempt to more effectively reach this population, and an emerging version of this is the single-site HF approach introduced by Seattle’s DESC. Single-site HF entails the provision of immediate, permanent, low-barrier supportive housing to chronically homeless individuals within a single building. The paper aims to discuss these issues.

Design/methodology/approach

In this case report, the authors use DESC’s 1811 Eastlake, a well-known and well-researched application of the single-site HF approach, as an example to describe single-site HF, enumerate its underlying principles, and provide a strong evidence base for its replication.

Findings

The paper provides information and insight into elements of a successful single-site HF program and what it looks like in practice.

Research limitations/implications

1811 Eastlake is one specific application of the single-site HF approach focused specifically on chronically homeless individuals with severe alcohol problems who are the highest utilizers of publicly funded services. Due to the specific nature of the population, the findings presented may lack generalizability. Therefore, researchers are encouraged to continue evaluating the outcomes of single-site HF programs on alcohol use, mental health and quality of life outcomes for all populations receiving single-site HF.

Practical implications

The accumulating research and clinical evidence have indicated that HF is key to engaging and housing chronically homeless individuals.

Social implications

These ongoing efforts stand to decrease the burden of chronic homelessness for affected individuals, their families, communities and society-at-large.

Originality/value

Many housing providers look to DESC’s 1811 as a model program. This paper fulfills an identified need to describe a successful model of single-site HF for purposes of replication.

Details

Housing, Care and Support, vol. 18 no. 2
Type: Research Article
ISSN: 1460-8790

Keywords

Article
Publication date: 6 May 2022

Chengshan Li and Huachao Dong

Variable-fidelity optimization (VFO) frameworks generally aim at taking full advantage of high-fidelity (HF) and low-fidelity (LF) models to solve computationally expensive…

Abstract

Purpose

Variable-fidelity optimization (VFO) frameworks generally aim at taking full advantage of high-fidelity (HF) and low-fidelity (LF) models to solve computationally expensive problems. The purpose of this paper is to develop a novel modified trust-region assisted variable-fidelity optimization (MTR-VFO) framework that can improve the optimization efficiency for computationally expensive engineering design problems.

Design/methodology/approach

Though the LF model is rough and inaccurate, it probably contains the gradient information and trend of the computationally expensive HF model. In the proposed framework, the extreme locations of the LF kriging model are firstly utilized to enhance the HF kriging model, and then a modified trust-region (MTR) method is presented for efficient local search. The proposed MTR-VFO framework is verified through comparison with three typical methods on some benchmark problems, and it is also applied to optimize the configuration of underwater tandem wings.

Findings

The results indicate that the proposed MTR-VFO framework is more effective than some existing typical methods and it has the potential of solving computationally expensive problems more efficiently.

Originality/value

The extreme locations of LF models are utilized to improve the accuracy of HF models and a MTR method is first proposed for local search without utilizing HF gradient. Besides, a novel MTR-VFO framework is presented which is verified to be more effective than some existing typical methods and shows great potential of solving computationally expensive problems effectively.

Details

Engineering Computations, vol. 39 no. 7
Type: Research Article
ISSN: 0264-4401

Keywords

Article
Publication date: 1 February 2001

Gene Fliedner

In order to provide the appropriate demand forecast information given various managerial levels and functional disciplines within organizations, reliance on family‐based…

3168

Abstract

In order to provide the appropriate demand forecast information given various managerial levels and functional disciplines within organizations, reliance on family‐based forecasting is increasing. The family‐based approach, sometimes referred to as hierarchical forecasting (HF), is based on a strategy of aggregating items into families. HF systems are capable of providing forecasts for items and their respective families. The objectives of HF systems, include improved forecast performance and a reduction in the overall forecasting burden. To date, several studies have offered practical guidelines for the structural design of HF systems. The primary purpose of this paper is to summarize these guidelines. First, an explanation of the HF process is provided. In this explanation, important system parameters and strategic choices, which allow for the custom configuration of HF systems are identified. Second, the relevant family‐based forecast research is reviewed. The important issues addressed and the conclusions presented in this research are identified. Third, practical guidelines regarding the use of a HF approach that have been reported in the research literature are clearly delineated. With much still unknown regarding the performance impact of various system parameter and strategic process choices, the paper concludes with suggestions for future research.

Details

Industrial Management & Data Systems, vol. 101 no. 1
Type: Research Article
ISSN: 0263-5577

Keywords

Article
Publication date: 5 August 2019

Tao Wang, Zhanli Liu, Yue Gao, Xuan Ye and Zhuo Zhuang

The interaction between hydraulic fracture (HF) and natural fracture (NF) in naturally fractured rocks is critical for hydraulic fracturing. This paper aims to focus on…

167

Abstract

Purpose

The interaction between hydraulic fracture (HF) and natural fracture (NF) in naturally fractured rocks is critical for hydraulic fracturing. This paper aims to focus on investigating the development of tensile and shear debonding zone on the NF caused by the stresses produced by HF, and the influence of NF’s debonding behavior on the interaction between HF and NF.

Design/methodology/approach

Theoretically, tensile and shear debonding modes of NF are considered, two dimensionless parameters are proposed to characterize the difficulty of tensile and shear failure of NF, respectively. Numerically, a finite element model combining the extended finite element method and cohesive zone method (CZM) is proposed to study NF’s debonding behavior and its influence on the interaction between HF and NF.

Findings

Both theoretical analysis and numerical simulation show the existence of two debonding modes. The numerical results also show that the HF can cross, offset or propagate along the NFs depending on the parameters’ value, resulting in different fracture network and stimulated reservoir volume. When they are large, the NF’s debonding area is small, HF tends to cross the NF and the fracture network is simple; when they are small, the NF’s debonding area is large, HF will propagate along the NF. In addition, HF is easier to propagate along with NF under tensile debonding mode while it is easier to pass through NF under shear debonding mode.

Originality/value

The theoretical and numerical considerations are taken into account in the influence of the debonding of NFs on the interaction between HFs and NFs and the influence on the formation of the fracture network.

Details

Engineering Computations, vol. 36 no. 8
Type: Research Article
ISSN: 0264-4401

Keywords

Article
Publication date: 13 September 2021

Geraldina Silveyra, Lucía Rodríguez-Aceves, Humberto Charles-Leija and José Manuel Saiz-Álvarez

This study aims to propose a causal relationship between the level of students’ human flourishing (HF) and their entrepreneurial intention (EI) and the mediation role of…

Abstract

Purpose

This study aims to propose a causal relationship between the level of students’ human flourishing (HF) and their entrepreneurial intention (EI) and the mediation role of entrepreneurial self-efficacy (ESE).

Design/methodology/approach

The study uses a sample of 5,035 first-year university students who graduated from 950 different upper secondary schools in Mexico and abroad. Data were analysed using structural equation modelling.

Findings

The results reveal that HF increases EI and ESE; ESE positively impacts EI; and the student’s ESE partially mediates the HF-EI relationship.

Practical implications

These findings may improve educational strategies in upper secondary schools and higher education institutions’ management programmes to impact graduates’ HF and EI. To the knowledge, the authors are the first to measure how HF in upper secondary school graduates contributes to increasing their EI.

Social implications

Recommendations are made to increase Latin American students’ HF and EI.

Originality/value

The authors propose an inverse relationship between HF and EI, as HF can be enhanced in upper secondary education to boost EI later in students’ lives.

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