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Open Access
Article
Publication date: 30 March 2023

Guilherme Duarte, Ana M.A. Neves and António Ramos Silva

The goal of this work is to create a computational finite element model to perform thermoelastic stress analysis (TSA) with the usage of a non-ideal load frequency, containing the…

Abstract

Purpose

The goal of this work is to create a computational finite element model to perform thermoelastic stress analysis (TSA) with the usage of a non-ideal load frequency, containing the effects of the material thermal properties.

Design/methodology/approach

Throughout this document, the methodology of the model is presented first, followed by the procedure and results. The last part is reserved to results, discussion and conclusions.

Findings

This work had the main goal to create a model to perform TSA with the usage of non-ideal loading frequencies, considering the materials’ thermal properties. Loading frequencies out of the ideal range were applied and the model showed capable of good results. The created model reproduced acceptably the TSA, with the desired conditions.

Originality/value

This work creates a model to perform TSA with the usage of non-ideal loading frequencies, considering the materials’ thermal properties.

Details

International Journal of Structural Integrity, vol. 14 no. 3
Type: Research Article
ISSN: 1757-9864

Keywords

Open Access
Article
Publication date: 31 May 2006

Yu Kyung Kim

The Korean securities and derivatives markets, which offer such internationally renowned products as KOSPI 200 futures and options, along with proliferation of such derivative…

7

Abstract

The Korean securities and derivatives markets, which offer such internationally renowned products as KOSPI 200 futures and options, along with proliferation of such derivative securities as ELS have offered an opportunity for investors to manage risk and select investment products for all different future prospects. However, if the market was to face with a shock in the magnitude of, for instance, the Black Monday of October 1987, possibly the market may trap into total confusion as the increased demand for portfolio insurance could enlarge the volatility of both cash and derivatives markets‘

In this paper we estimate the amount of settlement fund required in the Korean securities and derivatives markets via stress testing if the market falls into an extreme case of vulnerability. The required settlement fund was estimated using two step procedures. Firstly, we estimate market risk applying three different approaches, namely, 99% VaR. EVT and the historical time periods when the market exhibited extreme volatility. We found that from six member companies to as many as 16 companies could face settlement failures, which are represented by having the operating-income-to-capital ratio of less than 100%.

Secondly‘ after estimating each company's settlement amount and summing them to forecast the aggregate amount of settlement fund, it was found that at maximum 350 billion won was required for settlement fund. However, as OTC products become more popular in the near future, the required settlement fund will be larger. Especially if the CCP takes over the OTC market in terms of settlement and clearing, it is expected that the emergency settlement requirement will even become larger.

Details

Journal of Derivatives and Quantitative Studies, vol. 14 no. 1
Type: Research Article
ISSN: 2713-6647

Keywords

Open Access
Book part
Publication date: 1 October 2018

Abstract

Details

Social Media Use in Crisis and Risk Communication
Type: Book
ISBN: 978-1-78756-269-1

Open Access
Book part
Publication date: 4 June 2021

Eva PenzeyMoog and Danielle C. Slakoff

The reality of domestic violence does not disappear when people enter the digital world, as abusers may use technology to stalk, exploit, and control their victims. In this…

Abstract

The reality of domestic violence does not disappear when people enter the digital world, as abusers may use technology to stalk, exploit, and control their victims. In this chapter, we discuss three unique types of technological abuse: (1) financial abuse via banking websites and apps; (2) abuse via smart home devices (i.e., “Internet of Things” abuse); and (3) stalking via geo-location or GPS. We also argue pregnancy and wellness apps provide an opportunity for meaningful intervention for pregnant victims of domestic violence.

While there is no way to ensure users' safety in all situations, we argue thoughtful considerations while designing and building digital products can result in meaningful contributions to victims' safety. This chapter concludes with PenzeyMoog's (2020) “Framework for Inclusive Safety,” which is a roadmap for building technology that increases the safety of domestic violence survivors. This framework includes three key points: (1) the importance of educating technologists about domestic violence; (2) the importance of identifying possible abuse situations and designing against them; and (3) identifying user interactions that might signal abuse and offering safe interventions.

Details

The Emerald International Handbook of Technology-Facilitated Violence and Abuse
Type: Book
ISBN: 978-1-83982-849-2

Keywords

Open Access
Article
Publication date: 5 November 2018

Wei Wei Liu, Berdy Weng and Scott Chen

The Kirkendall void had been a well-known issue for long-term reliability of semiconductor interconnects; while even the KVs exist at the interfaces of Cu and Sn, it may still be…

1477

Abstract

Purpose

The Kirkendall void had been a well-known issue for long-term reliability of semiconductor interconnects; while even the KVs exist at the interfaces of Cu and Sn, it may still be able to pass the condition of unbias long-term reliability testing, especially for 2,000 cycles of temperature cycling test and 2,000 h of high temperature storage. A large number of KVs were observed after 200 cycles of temperature cycling test at the intermetallic Cu3Sn layer which locate between the intermetallic Cu6Sn5 and Cu layers. These kinds of voids will grow proportional with the aging time at the initial stage. This paper aims to compare various IMC thickness as a function of stress test, the Cu3Sn and Cu6Sn5 do affected seriously by heat, but Ni3Sn4 is not affected by heat or moisture.

Design/methodology/approach

The package is the design in the flip chip-chip scale package with bumping process and assembly. The package was put in reliability stress test that followed AEC-Q100 automotive criteria and recorded the IMC growing morphology.

Findings

The Cu6Sn5 intermetallic compound is the most sensitive to continuous heat which grows from 3 to 10 µm at high temperature storage 2,000 h testing, and the second is Cu3Sn IMC. Cu6Sn5 IMC will convert to Cu3Sn IMC at initial stage, and then Kirkendall void will be found at the interface of Cu and Cu3Sn IMC, which has quality concerning issue if the void’s density grows up. The first phase to form and grow into observable thickness for Ni and lead-free interface is Ni3Sn4 IMC, and the thickness has little relationship to the environmental stress, as no IMC thickness variation between TCT, uHAST and HTSL stress test. The more the Sn exists, the thicker Ni3Sn4 IMC will be derived from this experimental finding compare the Cu/Ni/SnAg cell and Ni/SnAg cell.

Research limitations/implications

The research found that FCCSP can pass automotive criteria that follow AEC-Q100, which give the confidence for upgrading the package type with higher efficiency and complexities of the pin design.

Practical implications

This result will impact to the future automotive package, how to choose the best package methodology and what is the way to do the package. The authors can understand the tolerance for the kind of flip chip package, and the bump structure is then applied for high-end technology.

Originality/value

The overall three kinds of bump structures, Cu/Ni/SnAg, Cu/SnAg and Ni/SnAg, were taken into consideration, and the IMC growing morphology had been recorded. Also, the IMC had changed during the environmental stress, and KV formation was reserved.

Details

PSU Research Review, vol. 3 no. 1
Type: Research Article
ISSN: 2399-1747

Keywords

Open Access
Article
Publication date: 4 December 2017

Stefan Holmström, Frits De Haan, Ulrich Führer, Rami Pohja and Jaromir Janousek

There are a number of different approaches for calculating creep-fatigue (CF) damage for design, such as the French nuclear code RCC-MRx, the American ASME III NH and the British…

1227

Abstract

Purpose

There are a number of different approaches for calculating creep-fatigue (CF) damage for design, such as the French nuclear code RCC-MRx, the American ASME III NH and the British R5 assessment code. To acquire estimates for the CF damage, that are not overly conservative, both the cyclic material softening/hardening and the potential changes in relaxation behavior have to be considered. The data presented here and models are an initial glimpse of the ongoing European FP7 project MATISSE effort to model the softening and relaxation behavior of Grade 91 steel under CF loading. The resulting models are used for calculating the relaxed stress at arbitrary location in the material cyclic softening curve. The initial test results show that softening of the material is not always detrimental. The initial model development and the pre-assessment of the MATISSE data show that the relaxed stress can be robustly predicted with hold time, strain range and the cyclic life fraction as the main input parameters. The paper aims to discuss these issues.

Design/methodology/approach

Engineering models have been developed for predicting cyclic softening and relaxation for Gr. 91 steel at 550 and 600°C.

Findings

A simple engineering model can adequately predict the low cycle fatigue (LCF) and CF softening rates of Gr. 91 steel. Also a simple relaxation model was successfully defined for predicting relaxed stress of both virgin and cyclically softened material.

Research limitations/implications

The data are not yet complete and the models will be updated when the complete set of data in the MATISSE project is available.

Practical implications

The models described can be used for predicting P91 material softening in an arbitrary location (n/Nf0) of the LCF and CF cyclic life. Also the relaxed stress in the softened material can be estimated.

Originality/value

The models are simple in nature but are able to estimate both material softening and relaxation in arbitrary location of the softening curve. This is the first time the Wilshire methodology has been applied on cyclic relaxation data.

Details

International Journal of Structural Integrity, vol. 8 no. 6
Type: Research Article
ISSN: 1757-9864

Keywords

Open Access
Article
Publication date: 6 November 2018

Pasquale Caponnetto, Rosanna Magro, Lucio Inguscio and Maria Concetta Cannella

Emergency room have particularly stressful work situations. Emergency room personnel cope with stressors on a daily basis. These stressors can be risks factor for burn out and for…

2642

Abstract

Emergency room have particularly stressful work situations. Emergency room personnel cope with stressors on a daily basis. These stressors can be risks factor for burn out and for reduced quality of life and work motivation. Emergency room staff of one of ASP 3 CT urban hospital in Acireale, Italy participated to stress management program by autogenic training twice a month for 16 weeks. This program were prepared based on existing research and studies, and were conducted by clinical psychologists. We found that the mean value in pre-test is significantly different from mean value in post-test for: Perceived Stress Scale PPS (t=7.72 with 27 df and P<0.001); Euro Quality for life (t=-14,13 with 27 df and P<0.001); Work motivation assessed by Visual Analogue scale VAS (t=-4.52 with 27 df and P<0.001). In the Maslach Burnout Inventory, the mean value is significantly different for emotional exhaustion sub-scale (t=5.64 with 27 with 27 df and P<0.001) and for depersonalization subscale (t=6.67 with 27 df and P<0.001). No significant difference was observed for the personal accomplishment sub-scale. This research suggests that psychological interventions with emergency room staff are effective. Our study showed effectiveness of an auto-genic and stress management training in improvement of quality of life, work motivation, burn-out and stress perceptions for emergency department team.

Details

Mental Illness, vol. 10 no. 2
Type: Research Article
ISSN: 2036-7465

Keywords

Open Access
Book part
Publication date: 1 October 2018

Jenny Lindholm, Klas Backholm and Joachim Högväg

Technical solutions can be important when key communicators take on the task of making sense of social media flows during crises. However, to provide situation awareness during…

Abstract

Technical solutions can be important when key communicators take on the task of making sense of social media flows during crises. However, to provide situation awareness during high-stress assignments, usability problems must be identified and corrected. In usability studies, where researchers investigate the user-friendliness of a product, several types of data gathering methods can be combined. Methods may include subjective (surveys and observations) and psychophysiological (e.g. skin conductance and eye tracking) data collection. This chapter mainly focuses on how the latter type can provide detailed clues about user-friendliness. Results from two studies are summarised. The tool tested is intended to help communicators and journalists with monitoring and handling social media content during times of crises.

Details

Social Media Use in Crisis and Risk Communication
Type: Book
ISBN: 978-1-78756-269-1

Keywords

Open Access
Article
Publication date: 8 July 2022

Choiwai Maggie Chak, Lara Carminati and Celeste P.M. Wilderom

Combining the goal-setting and job demands-resources (JD-R) theories, we examine how two project resources, collaborative project leadership and financial project resources…

2013

Abstract

Purpose

Combining the goal-setting and job demands-resources (JD-R) theories, we examine how two project resources, collaborative project leadership and financial project resources, enhance high project performance in community-academic health partnerships.

Design/methodology/approach

With a sequential explanatory mixed-method research design, data were collected through a survey (N = 318) and semi-structured interviews (N = 21). A hypothesised three-path mediation model was tested using structural equation modelling with bootstrapping. Qualitative data were examined using thematic analysis.

Findings

Project workers’ hope, goal-commitment and -stress: (1) fully mediate the hypothesised relationship between highly collaborative project leadership and high project performance; and (2) partially mediate the relationship between financial project resources and high project performance. The qualitative data corroborate and deepen these findings, revealing the crucial role of hope as a cognitive-motivational facilitator in project workers’ ability to cope with challenges.

Practical implications

Project leaders should promote project workers’ goal commitment, reduce their goal stress and boost project performance by securing financial project resources or reinforcing workers’ hope, e.g. by fostering collaborative project leadership.

Originality/value

The findings contribute to the project management and JD-R literature by considering the joint effects of project workers’ hope and two commonly studied project resources (collaborative project leadership and financial project resources) on high project performance. Moreover, we demonstrate the importance of the goal-setting and JD-R theories for understanding complex health-promotion projects connecting academic to community work.

Details

International Journal of Productivity and Performance Management, vol. 72 no. 10
Type: Research Article
ISSN: 1741-0401

Keywords

Open Access
Article
Publication date: 28 March 2022

Eoin Whelan, Willie Golden and Monideepa Tarafdar

Social networking sites (SNS) are heavily used by university students for personal and academic purposes. Despite their benefits, using SNS can generate stress for many people…

5111

Abstract

Purpose

Social networking sites (SNS) are heavily used by university students for personal and academic purposes. Despite their benefits, using SNS can generate stress for many people. SNS stressors have been associated with numerous maladaptive outcomes. The objective in this study is to investigate when and how SNS use damages student achievement and psychological wellbeing.

Design/methodology/approach

Combining the theoretical perspectives from technostress and the strength model of self-control, this study theoretically develops and empirically tests the pathways which explain how and when SNS stressors harm student achievement and psychological wellbeing. The authors test the research model through a two-wave survey of 220 SNS using university students.

Findings

The study extends existing research by showing that it is through the process of diminishing self-control over SNS use that SNS stressors inhibit achievement and wellbeing outcomes. The study also finds that the high use of SNS for academic purposes enhances the effect of SNS stressors on deficient SNS self-control.

Originality/value

This study further opens up the black box of the social media technostress phenomenon by documenting and validating novel processes (i.e. deficient self-control) and conditions (i.e. enhanced academic use) on which the negative impacts of SNS stressors depend.

Details

Internet Research, vol. 32 no. 7
Type: Research Article
ISSN: 1066-2243

Keywords

1 – 10 of over 3000