bluuebunny/crossref_metadata_2025 huggingface dataset:
A case study on variability management in software product lines: identifying why real-life projects fail
Authors: Huysegoms Tom , Dedene Guido , Stumpe Frank , Snoeck Monique , Goderis Antoon
Published: March 2022

Economies of scale can be seen as some kind of “holy grail” in state of the art literature on the development of sets of related software systems. Software product line methods are often mentioned in this context, due to the variability management aspects they propose, in order to deal with sets of related software systems. They realize the sought-after reusability. Both variability management and software product lines already have a strong presence in theoretical research, but in real-life software product line projects trying to obtain economies of scale still tend to fall short of target. The objective of this paper is to study this gap between theory and reality through a case study in order to see why such gap exists, and to find a way to bridge this gap. Through analysis of the causes of failure identified by the stakeholders in the case study, the underlying problem, which is found to be located in the requirements engineering phase, is crystallized. The identification of a framework describing the problems will provide practitioners with a better focus for future endeavors in the field of software product lines, so that economies of scale can be achieved.
Project characteristics, project management software utilization and project performance: An impact analysis based on real project data
Authors: Pellerin Robert , Perrier Nathalie , Guillot Xavier , Léger Pierre-Majorique
Published: March 2022

Project management software packages are increasingly used by companies. These tools require a substantial financial investment, hence the importance of identifying the real contribution of project management software packages to the realization of projects. However, studies on the impacts of software packages on the performance of engineering project management are rare and mostly based on perceptions. The objective of this study is to investigate, from real project data, the level of utilization of a project management software package, developed by an engineering construction firm recognized internationally, and its link with project performance and project characteristics. Results stemming from non-parametric tests and correlation analyses show that the level of use of the software, and some of its subsystems, appears to be linked to project performance. Project duration also seems to be the most critical project characteristic.
Ladder to success – eliciting project managers’ perceptions of IS project success criteria
Authors: Pankratz Oleg , Basten Dirk
Published: March 2022

The traditional approach to assess information system (IS) project success is adherence to planning (ATP) – meeting budget, schedule, and requirements targets. Today, scholars agree that ATP is insufficient to adequately assess IS project success, but an agreed-on set of success criteria is still missing. Many works on this topic are based on theoretical considerations rather than empirical inquiries. We analyze practitioners’ subjective perspectives by investigating what criteria IS project managers consider relevant for IS project success assessment. We interview eleven experienced project managers in Germany, applying Repertory Grid and Laddering to minimize potential biases. Our results yield eight success criteria, indicating that criteria like process efficiency and stakeholder satisfaction must be considered in addition to ATP. Scholars can use our findings to apply the identified success criteria in future studies. Practitioners gain insights into the expert perspective on project success and might rethink the way of assessing success in their projects.
Best practice project management: an analysis of the front end of the innovation process in the medical technology industry
Authors: Giles Tracey , Cormican Kathryn
Published: March 2022

There are strong motivating factors for more effective project management practices at the front end of the innovation (FEI) process. Shrewd management of these pre-development activities has proven to be one of the greatest differentials for success. This study presents findings from an empirical case study analysis of a large organization operating in the medical technology industry in Ireland. We synthesized the literature to identify five critical success factors (CSFs) known to be effective in the successful management of the FEI process. From this analysis an instrument to assess best practices was developed. Data was collected from 66 engineers in the R&D discipline. The findings of the study show that the organization’s FEI phase aligns well with best practice. However, a difference between the level of agreement about the extent to which the critical success factors are in place in the organization and the level of importance placed on these practices emerged. This paper contributes to knowledge by (a) assessing the relative importance of critical success factors for the FEI in the medical technology industry, (b) examining whether these initiatives are implemented in practice and, if so, to what extent, and (c) providing a series of recommendations to help bridge the gap from theory to practice.
Managing enterprise information: meeting performance and conformance objectives in a changing information environment
Authors: Williams Susan P. , Hausmann Verena , Hardy Catherine A. , Schubert Petra
Published: March 2022

This paper presents the findings of an in-depth survey to examine the current status of enterprise information management (EIM) in organizations. The survey explores five key areas: drivers and capabilities of EIM; current status of EIM strategies; EIM content and technologies; EIM and compliance; and the changing role of the information professional. The survey reveals that the drivers for EIM cannot be simply reduced to a series of technical or organizational needs and that EIM is a complex sociotechnical phenomenon. A fine balance is required to achieve business performance objectives whilst at the same time also meeting conformance requirements. To date, few organizations have implemented enterprise-wide EIM strategies; however those who do have them are better able to keep track of, and achieve, performance objectives. In terms of technologies and content the landscape is complex with organizations focusing their efforts into managing and reducing this complexity. Finally information management work is changing; the survey reveals EIM as a multi-stakeholder activity requiring the combination of a wide range of professional groups, skills and knowledge. The survey findings provide the basis for further research investigations in supporting organization in their EIM initiatives.
Development and assessment of an instrument to measure equivocal situation and its causes in IS/IT project evaluation
Authors: Arviansyah Arviansyah , Spil Ton , Hillegersberg Jos van
Published: March 2022

Project evaluations are vital for organizations to manage and balance the costs and benefits of their IS/IT investment. Despite the importance of project evaluations, equivocal situation may limit the effectiveness of an evaluation and hinder decision-makers in generating purposeful resolutions. There is a dearth of empirical studies with regard to equivocal situation, which this study addresses by developing and measuring a construct of an equivocal situation and its causes. The equivocal situation construct is derived from the notion of equivocality and its causes are extracted from the extant literature. The developed constructs are subjected to empirical validation through Partial Least Squares (PLS) analysis by employing the data collected from knowledge professionals in IS/IT project management. The developed instrument provides a firm foundation for future studies of equivocality in IS/IT project evaluation.
Use Cases and Collaboration Scenarios: how employees use socially-enabled Enterprise Collaboration Systems (ECS)
Authors: Schubert Petra , Glitsch Johannes H.
Published: March 2022

In recent years we have seen the emergence of a new type of collaboration software, the so-called “Enterprise Social Software”. The “social features” of this software type have stimulated a renewed interest in Enterprise Collaboration Systems (ECS). In this article we present findings from a longitudinal research project on the introduction and use of ECS in companies. We argue that ERP Systems and ECS are inherently different and that the process-paradigm that is common to ERP cannot be applied identically to ECS. To address this issue, we suggest the two concepts use case and collaboration scenario for the analysis and description of collaboration activity in companies. From the literature and 26 case studies we identified typical use cases and collaboration scenarios that can serve as blueprints for ECS introduction projects. The longitudinal objective of our research is to assist companies with their ECS initiatives and to provide them with a catalog of existing use cases and collaboration scenarios from various industry settings.
A qualitative study of success criteria in Norwegian agile software projects from suppliers’ perspective
Authors: Siddique Lubna , Hussein Bassam A.
Published: March 2022

This paper provides practical insights into the success criteria in agile projects in the Norwegian software industry. We conducted 32 interviews with practitioners working with agile projects. The findings revealed two fundamental differences that distinguish the perception of success in agile projects from that in projects that are based on the waterfall approach. Firstly, the evaluation is carried out on a regular basis after each increment. This regular and continuous measurement of success contributes several advantages, including greater commitment and involvement from the customer and a higher level of mutual trust between the supplier and the customer; and thus leads to better knowledge sharing and reduced task uncertainty. The reduction of task uncertainty provides more predictability about the direction of the project and better grounds for change control; not least, it allows room to consider multiple and subjective assessments by various stakeholders. Secondly, there is a stronger emphasis on customer satisfaction. Customer satisfaction is measured in terms of how quickly the customer obtains value from the project. The continuous assessment of success at the end of each iteration also has a significant, positive impact on the customer’s evaluation of the project outcome.
Issues for the long-term management of Social Business Documents
Authors: Hausmann Verena , Williams Susan P.
Published: March 2022

Social business documents are currently one of the fastest growing content types within organizations. As carriers of important business information they require systematic management to ensure their content is available, accurate and protected over the long-term. To achieve this requires a deep understanding of their structure, nature and use. In this paper we present the findings of a preliminary study of social business documents. The aim of the study is to understand how social business documents are structured and to identify the issues and challenges that surround their management. Through an analysis of social business documents in four different systems we identify and compare their structural components from a user perspective. From this cross document/cross system analysis we develop a conceptual model for social business documents and identify issues for their long-term management. Our findings also identify the need for more in-depth modeling for which we propose methods to assist in understanding the syntactic and semantic structure of social business documents and how these change over the life of a social business document.
Are PMOs really that momentous for public authorities?
Authors: Lundqvist Siw
Published: March 2022

Project management offices (PMOs) are frequently referred to as necessary, or even indispensable, for carrying out projects in multi-project settings, which often occur in public authorities’ Information Technology (IT) projects; particularly in times of today’s sweeping digitalization. Hence, this research studied Swedish public authorities and their IT departments’ use of PMOs; a survey was directed to IT project managers. Findings showed that even though PMOs are commonly described as significant, those that applied PMOs were fewer than those that did not. This research searched for correlations between the existence of PMOs and 88 variables that resulted in relatively few, mostly weak correlations. A hypothesis test did not show significant association between PMOs’ usage and project models’ usage. The research contributions are principally that PMOs do not appear to be that significant after all for Swedish public authorities, and to have reasonable expectations on PMOs. For practice, the implications foremost concern the importance of understanding conceivable pros and cons.
An assessment of business intelligence in public hospitals
Authors: Gaardboe Rikke , Sandalgaard Niels , Nyvang Tom
Published: March 2022

In this paper, DeLone and McLean's information systems success model is empirically tested on 12 public hospitals in Denmark. The study aims to investigate the factors that contribute to business intelligence (BI) success. 1,352 BI endusers answered the questionnaire. A partial least square structural equation model was used to empirically test the model. We find that system quality is positively and significantly associated with use and user satisfaction, and that information quality is positively and significantly associated with user satisfaction. User satisfaction is positively and significantly related to individual impact. The other paths in the model are insignificant. Our findings also provide empirical support for the role of user satisfaction as a mechanism that mediates the relationship between information quality or system quality and individual impact. User satisfaction is not only a critical construct in the information systems success model but it also serves as a mediator. Generally, the model finds empirical support, as it has a good fit and predictive value.
Handling Missing Values in Information Systems Research: A Review of Methods and Assumptions
Authors: Peng Jiaxu , Hahn Jungpil , Huang Ke-Wei
Published: March 2022

Data have never been more essential to the success of decision making. However, data are often messy. A perennial data challenge is missing values, which frequently occur in real-world data, such as unreported data items in public firms’ financial statements and skipped product ratings from consumers. What is the influence of missing values and how should they be handled? Although we are in a big data era, missing values are not ignorable if data are missing for nonrandom reasons. In the case of product ratings, if only people who favor the product provide ratings while others put aside the product and do not respond, then even a simple mean estimation of the product rating would be significantly biased. Such bias challenges the validity of data analysis, and it cannot be eliminated simply by increasing the sample size of the data. To correct the bias arising from nonrandom missing values, it is necessary to examine and model what causes the missing values. We propose and demonstrate the superior performance of a Monte Carlo likelihood approach to correct the bias. Overall, we recommend well-designed data collection processes with documentation of the possible reasons for missing values, cautious adoption of missing value handling methods, and structured missing value reporting practices.
The Lived Experience of Mentally Disabled Persons Living in Group Homes
Authors: Choi Goya , Choi Eun Joung
Published: March 2022

Purpose: The purpose of this study was to explore the meaning and nature of the experience of mentally disabled persons living in group homes.Methods: Data were collected through individual in-depth interviews with six mentally disabled persons from April to October in 2017. The data were analyzed using hermeneutic phenomenological methodology based on four fundamental existential concepts: that lived space, lived body, lived time, and lived others.Results: Ten essential themes emerged: lived space-settle down in a strange environment, wish for my independent space in a daily routine; lived body-make a balance between soul and body, lead normal daily life by myself; lived time-rewrite my life; lived others-unapproachable relationship, meet my advocators.Conclusion: The meaning of living in group homes as mentally disabled persons was ‘living as an ordinary person’. This information would be useful in providing interventions to enable such people to return to the community.
A Systematic Review and Meta-analysis of Intervention Programs for Child Abuse Victims in Korea: Focused on Depression, Anxiety, Self-esteem, Problem Behavior, and Sociability
Authors: Sim Mi-Kyung , Kim Sinhyang
Published: March 2022

Purpose: The purpose of this study was to examine the effects of intervention studies for child abuse victims in Korea focused on depression, anxiety, self-esteem, problem behavior, and sociability.Methods: Published articles on intervention programs for abused children were investigated using the systematic review method. A total of 24 studies up to August 2021 were included in the final analysis using the Comprehensive Meta-Analysis (CMA) 2.2 program.Results: The differences in effects depending upon the year of publication, total sessions, group size, and time per session were statistically meaningful. The effect size of art therapy was found to be larger than that of traditional group therapy. The effect size of the overall interventions was 1.75, which was a high level in terms of Cohen’s criteria. Intervention programs showed significantly large effect sizes in sociability, problem behavior, and self-esteem. The effect of programs on anxiety and depression was not statistically meaningful.Conclusion: The results of this study are meaningful because they can be used as basic data for the development of intervention programs for abused children. Intervention programs for child abuse victims should continue to be developed and applied.
A Relação entre o Capitalismo no Pós Pandemia e os coletivos de cultura dos subúrbios cariocas
Authors: Soares Claudio Jorge , Reginensi Caterine
Published: March 2022

Este artigo tem por objetivo apresentar os efeitos da distribuição desigual dos investimentos públicos e privados e seus efeitos nefastos na Cultura dos Subúrbios Cariocas durante a pandemia de Covid19. Ancorado em pesquisas realizadas a partir das redes sociais, da vasta oferta de informações das mídias sociais, conjugado com material de pesquisa de campo colhido antes da pandemia. O artigo também visa apresentar as fragilidades expostas pelo capitalismo como sistema produtor de bem-estar social. Para isso, apresentaremos uma análise comparativa do desenvolvimento capitalista no Brasil, sob a perspectiva cultural. Mas, para que a análise tenha um fio lógico, é necessário apresentar o conjunto de acontecimentos históricos que levaram a economia da Cidade do Rio de Janeiro e da Região Metropolitana ao estágio de estagnação atual, trazendo consequências para os investimentos em políticas públicas mais robustas. Essa retrospectiva começa com a adoção da cultura como instrumento de desenvolvimento e de afirmação nacional, assim como a perda da liderança por parte da Cidade do Rio de Janeiro como principal polo de desenvolvimento industrial do país para São Paulo, a perda da capitalidade e seus efeitos econômicos, a ditadura militar, a redemocratização e a crise econômica dos anos 1980, e, por fim, as mudanças na estrutura produtiva da indústria.
O BRINCAR DO QUINTAL E DO TERREIRO: Possibilidades da BNCC para a ERER na educação infantil
Authors: França Débora Magalhães
Published: March 2022

Este artigo trata-se de uma reflexão acerca da educação antirracista e tem por objetivo propor possibilidades de ações que relacionem os campos de experiências da Base Nacional Comum Curricular para educação infantil (BNCC) e a Educação para as Relações Étnico-raciais (ERER). Partiremos de um recorte etário que compreende a fase entre os 4 anos e os 5 anos e 11 meses, identificados na BNCC como crianças pequenas. A metodologia empregada foi a de análise documental da Base Nacional Comum Curricular para a educação infantil e dos apontamentos das Leis 10.639/03 e 11.645/08 para o ensino de História e Cultura Afro-brasileira e indígena na educação básica. Também foram consultados os registros e experiências docente vivenciados pela autora em turmas de educação infantil, onde atua desde o ano de 2019, na rede municipal de Niterói. Concluiu-se que a articulação entre os campos de experiências da BNCC para a educação infantil e o ensino das relações étnico raciais não só é possível como de extrema relevância na implementação de uma educação antirracista.
SOCIEDADE E EDUCAÇÃO NO GOVERNO BOLSONARO: ANULAÇÃO DE DIREITOS UNIVERSAIS, DESUMANIZAÇÃO E VIOLÊNCIA.
Authors: Frigotto Gaudêncio
Published: March 2022

O texto apresentado trata-se de um artigo de opinião.
What you need to know about: arterial cerebrovascular syndromes caused by static or dynamic musculoskeletal compression
Authors: Karabacak Mert , Ozkara Burak B , Ozaydin Burak , Baskaya Mustafa K
Published: March 2022

Compressive syndromes of the cervical arteries caused by musculoskeletal structures include bow hunter's syndrome, beauty parlour stroke syndrome, carotid compression by the hyoid bone, carotid compression by the digastric muscle and Eagle syndrome. They are a rare but increasingly recognised group of syndromes, so a high level of suspicion is needed so the diagnosis is not missed. The diagnosis is typically based on a combination of clinical history and advanced imaging investigations. Compression of the arteries may be static (only provoked by compression) or dynamic (exaggerated by movement), and this should be considered when selecting imaging studies. Symptoms resulting from vertebrobasilar insufficiency or ischaemia of areas supplied by the internal carotid artery are caused by compression of the vertebral artery and the internal carotid artery respectively. Surgical procedures are the preferred treatment for most of these syndromes.
Beating the bias in AI-based biometrics
Authors: Psychoula Ismini
Published: March 2022

OneSpan research scientist Ismini Psychoula outlines the many types of bias that can exist in face and other biometric systems – and how to counter them.
An analysis of the polyphonic Georgian folk song “Maqruli” performed by Machakheli Seniors’ Ensemble
Authors: Şahin Damla , Demirel Temel Sernaz
Published: March 2022

Songs performed by Machakheli Seniors Ensemble have survived from past to present through oral tradition. In this study, the polyphonic vocal style of Machakheli Seniors Ensemble that is transferred to younger generations through master–apprentice relationship was analysed. In this study, the polyphonic vocal style of Machakheli Seniors Ensemble that is transferred to younger generations through master – apprentice relationship was analysed over the song “Maqruli” performed by the ensemble. In addition to the musical terms and concepts of general music theory, Georgian folk music employs various traditional terms. Basic terms such as Modzakhili, Meore Khma, Bani functionally determine the mission of the voice in Georgian language and its function within the musical structure. The song “Maqruli” performed by Machakheli Seniors Ensemble was analysed through these terms and also a descriptive linguistic analysis in terms of syllabic meter, rhyme and thematic integrity was conducted. As a result of the literature review conducted, no written source conveying the vocal performance practices of Machakheli Seniors Ensemble was found. The aim of this study was to analyse the existing performance practices of Machakheli Seniors Ensemble both technically and historically. In this article, qualitative data collection methods such as observation, interview and document analysis were used. It may be predicted that more researches are to be conducted on the subject in the future. Machakheli Seniors Ensemble should be given a range of priorities in order for the them to transfers the songs voiced by Machakheli Seniors Ensemble and the polyphonic vocal tradition. It is anticipated that it will be appropriate, with the support of associations and municipalities in the region, to create a training model in which choirs will be formed and they will be regularly trained on the polyphonic singing tradition by the members of Machakheli Seniors Ensemble in order to ensure its continuity. It is essential for educational materials to include cultural values and singing tradition of Machakheli Valley for intergenerational transfer. Socio-culturally evaluating the region of Machakheli Valley that straddles the border of Turkey and Georgia, researchers may conduct studies in context of the shared and diverging musical practices of the two countries.
Coping with COVID-19 Isolation in Kerala, India: A Qualitative Analysis
Authors:   Department of Psychology, University of Kerala, India, Jabbar Jasseer , Dharmarajan Shibu ,   Graduate programs of counseling psychology, Assumption University of Thailand, Ramachandran Athira P. ,   Department of Psychology, University of Kerala, India, Jasseer Alisha ,   Department of psychology, Calicut University, India
Published: March 2022

COVID-19 has had a negative impact on all areas of human life. Populations both directly and indirectly affected faced similar challenges to a certain extent. This article explores the emergent attitudes and healthcare practices of COVID-19-affected people during the period of their isolation after positive infection, following a qualitative research design. A total of ten participants from Malappuram District, Kerala State, India were selected for the study by the convenience sampling method. Semi-structured telephone interviews were conducted to understand their emergent attitudes and health care practices. The results show that the attitudes and vulnerabilities of the individual during quarantine, environmental factors, and access and availability of resources, are the individual and social factors leading to major psychological impacts on participants during COVID-19 quarantines. Coping strategies and healthcare practices, mental health related practices, social connectivity, socioeconomic status and social support are individual and social factors that helped participants to overcome negative psychological impacts. Keywords: Emergent attitudes, Healthcare practices, COVID-19 survivors
Tibial cortex transverse transport accelerates wound healing via enhanced angiogenesis and immunomodulation
Authors: Yang Yongkang , Li Yucong , Pan Qi , Bai Shanshan , Wang Haixing , Pan Xiao-hua , Ling Ka-Kin , Li Gang
Published: March 2022

Aims

Treatment for delayed wound healing resulting from peripheral vascular diseases and diabetic foot ulcers remains a challenge. A novel surgical technique named ‘tibial cortex transverse transport’ (TTT) has been developed for treating peripheral ischaemia, with encouraging clinical effects. However, its underlying mechanisms remain unclear. In the present study, we explored the potential biological mechanisms of TTT surgery using various techniques in a rat TTT animal model.

Methods

A novel rat model of TTT was established with a designed external fixator, and effects on wound healing were investigated. Laser speckle perfusion imaging, vessel perfusion, histology, and immunohistochemistry were used to evaluate the wound healing processes.

Results

Gross and histological examinations showed that TTT technique accelerated wound closure and enhanced the quality of the newly formed skin tissues. In the TTT group, haematoxylin and eosin (H&E) staining demonstrated a better epidermis and dermis recovery, while immunohistochemical staining showed that TTT technique promoted local collagen deposition. The TTT technique also benefited to angiogenesis and immunomodulation. In the TTT group, blood flow in the wound area was higher than that of other groups according to laser speckle imaging with more blood vessels observed. Enhanced neovascularization was seen in the TTT group with double immune-labelling of CD31 and α-Smooth Muscle Actin (α-SMA). The number of M2 macrophages at the wound site in the TTT group was also increased.

Conclusion

The TTT technique accelerated wound healing through enhanced angiogenesis and immunomodulation. Cite this article: Bone Joint Res 2022;11(4):189–199.
Loss to patient-reported outcome measure follow-up after hip arthroplasty and knee arthroplasty
Authors: Ross Lauren A. , O'Rourke Sara C. , Toland Gemma , MacDonald Deborah J. , Clement Nick D. , Scott Chloe E. H.
Published: March 2022

Aims

The aim of this study was to determine satisfaction rates after hip and knee arthroplasty in patients who did not respond to postoperative patient-reported outcome measures (PROMs), characteristics of non-responders, and contact preferences to maximize response rates.

Methods

A prospective cohort study of patients planned to undergo hip arthroplasty (n = 713) and knee arthroplasty (n = 737) at a UK university teaching hospital who had completed preoperative PROMs questionnaires, including the EuroQol five-dimension health-related quality of life score, and Oxford Hip Score (OHS) and Oxford Knee Score (OKS). Follow-up questionnaires were sent by post at one year, including satisfaction scoring. Attempts were made to contact patients who did not initially respond. Univariate, logistic regression, and receiver operator curve analysis was performed.

Results

At one year, 667 hip patients (93.5%) and 685 knee patients (92.9%) had undergone surgery and were alive. No response was received from 151/667 hip patients (22.6%), 83 (55.0%) of whom were ultimately contacted); or from 108/685 knee patients (15.8%), 91 (84.3%) of whom were ultimately contacted. There was no difference in satisfaction after arthroplasty between initial non-responders and responders for hips (74/81 satisfied vs 476/516 satisfied; p = 0.847) or knees (81/93 satisfied vs 470/561 satisfied; p = 0.480). Initial non-response and persistent non-response was associated with younger age, higher BMIs, and worse preoperative PROMs for both hip and knee patients (p < 0.050). Being in employment was associated with persistent non-response for hip patients (p = 0.047). Multivariate analysis demonstrated that younger age (p < 0.038), higher BMI (p = 0.018), and poorer preoperative OHS (p = 0.031) were independently associated with persistent non-response to hip PROMs. No independent associations were identified for knees. Using a threshold of > 66.4 years predicted a preference for contact by post (area under the curve 0.723 (95% confidence interval (CI) 0.647 to 0.799; p < 0.001, though this CI crosses the 0.7 limit considered reliable).

Conclusion

The majority of initial non-responders were ultimately contactable with effort. Satisfaction rates were not inferior in patients who did not initially respond to PROMs. Cite this article: Bone Jt Open 2022;3(4):275–283.
‘The golden way is to be friends with the world and to regard the whole human family as one’
Authors: Crean St John
Published: March 2022

Our editor reflects on the current state of the world and how we must aim to move forward as one.
‘Never become so much of an expert that you stop gaining expertise’
Authors: Crean StJohn
Published: March 2022

Our Editor-in-chief reflects on the 50th issue of the FDJ and the future of dentistry. With a comment from the FDS Dean, Matthew Garrett.
Measures of illuminant-induced metameric mismatch: theory, comparative analysis, and implications for application
Authors: Esposito Tony , Royer Michael P. , Houser Kevin W.
Published: March 2022

Illuminant-induced metameric mismatch is an important consideration in the specification of light sources for some architectural environments, yet there is currently no standardized performance measure. The goal of this work was to evaluate two recent research proposals: the metameric uncertainty index (Rt) and the metamer mismatching color rendering index (MMCRI). To compare the relative performance of these two measures, 100,000 spectral power distributions were generated with 3, 4, 5, 6, and 7 Gaussian spectral components and spectral widths varying from 1 nm (monochromatic) to 100 nm. Both measures generally agree with the theory that broadband radiation should cause less metameric mismatch than narrowband radiation. The two measures have relatively better agreement for broadband SPDs and relatively worse agreement for narrower spectra. Despite some similarities, non-parametric statistical tests suggest that Rt and MMCRI are significantly different quantifications of illuminant-induced metameric mismatch (p < 0.0001 for all comparisons). Characteristics of the MMCRI computation that are potentially problematic for applied lighting were observed.
Deep learning-based ballistocardiography reconstruction algorithm on the optical fiber sensor
Authors: Chen Shuyang , Tan Fengze , Lyu Weimin , Luo Huaijian , Yu Jianxun , Qu Jiaqi , Yu Changyuan
Published: March 2022

Ballistocardiography (BCG) is a vibration signal related to cardiac activity, which can be obtained in a non-invasive way by optical fiber sensors. In this paper, we propose a modified generative adversarial network (GAN) to reconstruct BCG signals by solving signal fading problems in a Mach-Zehnder interferometer (MZI). Based on this algorithm, additional modulators and demodulators are not needed in the MZI, which reduces the cost and hardware complexity. The correlation between reconstructed BCG and reference BCG is 0.952 in test data. To further test the model performance, we collect special BCG signals including sinus arrhythmia data and post-exercise cardiac activities data, and analyze the reconstructed results. In conclusion, a BCG reconstruction algorithm is presented to solve the signal fading problem in the optical fiber interferometer innovatively, which greatly simplifies the BCG monitoring system.
Self-referenced electro-optic response measurement of dual-parallel Mach-Zehnder modulators employing single-tone level control and low-frequency bias swing
Authors: Xu Ying , Wang Mengke , He Yutong , Gu Chaoyu , Zhang Zhiyao , Zhang Yali , Zhang Shangjian , Liu Yong
Published: March 2022

A self-referenced method is proposed to characterize the electro-optic frequency response of dual-parallel Mach-Zehnder modulators (DPMZMs) based on single-tone level control and low-frequency bias swing. The single-tone driving signal and the low-frequency bias signal of the DPMZM mix with each other after photodetection, and a low-frequency beat note is generated in the electrical domain. The functional relationship between the desired low-frequency amplitude and the single-tone driving level is investigated and established, from which the modulation depth and half-wave voltage are extracted with the help of regression analysis. We experimentally demonstrate the feasibility of the proposed method and compare it with the conventional ones to check the consistency. The self-referenced method features single-tone modulation and low-frequency detection for measuring high-speed DPMZMs, which avoids the use of a broadband photodetector (PD) and the influence of the uneven response of the PD.
Ultrafast all-optical phase switching enabled by epsilon-near-zero materials in silicon
Authors: Navarro-Arenas Juan , Parra Jorge , Sanchis Pablo
Published: March 2022

Transparent conducting oxides (TCOs) have emerged as both particularly appealing epsilon-near-zero (ENZ) materials and remarkable candidates for the design and fabrication of active silicon nanophotonic devices. However, the leverage of TCO’s ultrafast nonlinearities requires precise control of the intricate physical mechanisms that take place upon excitation. Here we investigate such behavior for ultrafast all-optical phase switching in hybrid TCO-silicon waveguides through numerical simulation. The model is driven from the framework of intraband-transition-induced optical nonlinearity. Transient evolution is studied with a phenomenological two-temperature model. Our results reveal the best compromise between energy consumption, insertion losses and phase change per unit length for enabling ultrafast switching times below 100 fs and compact active lengths in the order of several micrometers.
Realization of ultrawide-angle high transmission and its applications in 5G millimeter-wave communications
Authors: Zhang Zhe , Che Zhiyuan , Chen Jingguang , Zeng Jianping , Huang Hao , Guan Fang , Shi Lei , Liu Xiaohan , Zi Jian
Published: March 2022

By using single-layer metasurfaces, we realized ultrawide-angle high-transmission in the millimeter-wave band, which allowed more than 98% transmission of dual-polarized electromagnetic waves for almost all incident angles. The multipolar expansion method was used to analyze and verify the condition of the generalized Kerker effect at the corresponding reflected angles. Using quartz glass substrates with the same metallic periodic structures, electromagnetic windows are proposed that can improve any-directed 5G millimeter-wave communication signals from outdoor to indoor environments. The proposed interpretations can connect the Kerker effect with actual applications and enable the design of easy-to-integrate all-angle Kerker effect metasurface devices.
Wide-viewing holographic stereogram based on self-interference incoherent digital holography
Authors: Kim Youngrok , Hong Keehoon , Yeom Han-Ju , Choi KiHong , Park Joongki , Min Sung-Wook
Published: March 2022

We propose a holographic stereogram synthesis method which uses holograms that are optically captured by self-interference incoherent digital holography (SIDH) based on a geometric phase lens. SIDH is a promising solution for hologram acquisition under low-coherence lighting condition. A mechanical scanning system is constructed to acquire multiple perspective holograms. Numerical simulations and experimental analyses conducted using high-resolution diffractive optical element demonstrate that the proposed method can produce a wide-viewing hologram which can realize realistic 3D scenarios with depth cues such as accommodation and motion parallax. The future objectives include the implementation of a multiple-camera system for holographic videos.
Dual-band terahertz all-silicon metasurface with giant chirality for frequency-undifferentiated near-field imaging
Authors: Li Fuyu , Li Yuanxun , Tang Tingting , Liao Yulong , Lu Yongcheng , Liu Xinyan , Wen Qiye
Published: March 2022

Chiral metasurfaces are widely used in imaging and biosensing due to their powerful light field control capabilities. Most of the work is devoted to achieving the goals of chirality enhancement and tunability, but lacks consideration of design complexity, loss, cost, and multi-band operation. In order to alleviate this situation, we propose a pair of dual-frequency giant chiral structures based on all-silicon, which can achieve excellent and opposite spin-selective transmission around 1.09 THz and 1.65 THz. The giant chirality derives from the in-plane electric and magnetic dipole moments excited in different degrees. Theoretically, the maximum circular dichroism at the two frequencies are both as high as 0.34, and the coverage bandwidths of the two giant chirality are 85.5 GHz and 41.4 GHz, respectively. The experimental results are in good agreement with the simulation results. Based on the dual-band giant chiral patterns, the terahertz near-field imaging of different Chinese character images is demonstrated at two frequencies. The frequency-undifferentiated characteristics, good intensity contrast and three-dimensional imaging information are shown by the results. This work provides new ideas for the design of terahertz devices with simple structure and multi-functions, which are expected to be applied in the field of terahertz imaging or multi-channel communication.
Single longitudinal mode lasing near the exceptional point in a fiber laser using a tunable isolator
Authors: Zhang Jianing , Guo Jun , Wang Haotian , Tang Dingyuan , Shen Deyuan
Published: March 2022

Parity time symmetry breaking was obtained in a specially designed fiber ring laser with a homemade tunable isolator in the cavity. The dynamic evolution of the cavity eigenmodes around the exceptional point (EP) was further experimentally studied. We showed that operating the laser near the EP can facilitate single longitudinal mode lasing. A single-frequency fiber laser with a linewidth of 163 Hz was first, to the best of our knowledge, demonstrated near the EP of the cavity without using any filter with a narrow bandwidth.
Quartic Kerr cavity combs: bright and dark solitons
Authors: Parra-Rivas Pedro , Hetzel Sabrina , Kartashov Yaroslav V. , de Córdoba Pedro Fernández , Alberto Conejero J. , Aceves Alejandro , Milián Carles
Published: March 2022

We theoretically investigate the dynamics, bifurcation structure, and stability of localized states in Kerr cavities driven at the pure fourth-order dispersion point. Both the normal and anomalous group velocity dispersion regimes are analyzed, highlighting the main differences from the standard second-order dispersion case. In the anomalous regime, single and multi-peak localized states exist and are stable over a much wider region of the parameter space. In the normal dispersion regime, stable narrow bright solitons exist. Some of our findings can be understood using a new, to the best of our knowledge, scenario reported here for the spatial eigenvalues, which imposes oscillatory tails to all localized states.
Interplay of sidewall damage and light extraction efficiency of micro-LEDs
Authors: Park Jeong-Hwan , Pristovsek Markus , Cai Wentao , Cheong Heajeong , Kumabe Takeru , Lee Dong-Seon , Seong Tae-Yeon , Amano Hiroshi
Published: March 2022

This Letter describes the impact of shape on micro light-emitting diodes (µLEDs), analyzing 400 µm2 area µLEDs with various mesa shapes (circular, square, and stripes). Appropriate external quantum efficiency (EQE) can yield internal quantum efficiency (IQE) which decreases with increasing peripheral length of the mesas. However, light extraction efficiency (ηe) increased with increasing mesa periphery. We introduce analysis of Jpeak (the current at peak EQE) since it is proportional to the non-radiative recombination. Etching the sidewalls using tetramethylammonium hydroxide (TMAH) increased the peak EQE and decreased the sidewall dependency of Jpeak. Quantitatively, the TMAH etching reduced non-radiative surface recombination by a factor of four. Hence, shrinking µLEDs needs an understanding of the relationship between non-radiative recombination and ηe, where analyzing Jpeak can offer new insights.
Atomic layer deposition of conformal anti-reflective coatings on complex 3D printed micro-optical systems
Authors: Ristok Simon , Flad Philipp , Giessen Harald
Published: March 2022

3D printing of micro-optics has recently become a very powerful fabrication method for sub-millimeter sized optics. Miniature optical systems and entire optical instruments such as endoscopes have become possible with this technique. 3D printed complex micro-optical systems are printed in one single process, rather than being assembled. This precludes anti-reflection coating of the individual lenses before assembly by conventional coating methods such as sputtering or directed plasma etching, as voids between the individual lenses cannot be reached by a directed coating beam. We solve this issue by conformal low-temperature thermal atomic layer deposition (ALD) which is compatible with the low glass transition temperature of the utilized 3D printed polymer materials. Utilizing 4-layer designs, we decrease the broadband reflectivity of coated flat substrates in the visible to below 1%. We characterize and investigate the properties of the coatings based on transmission measurements through coated and uncoated 3D printed test samples as well as through a double-lens imaging system. We find that the reflectivity is significantly reduced and conversely the transmission is enhanced, which is of particular interest for low-light applications. Furthermore, the physical durability and resistance against humidity uptake should also be improved.
Modulation instability and highly sensitive optical fiber biosensor
Authors: Madani S. A. , Bahrami M. , Rostami A.
Published: March 2022

The modulation instability (MI) is one of the interesting nonlinear phenomena which is used as a sensing mechanism. The performance of this mechanism is based on the shift of generated sidebands when the effective refractive index of the sensor is changed. The use of the MI process as a biosensing mechanism has capabilities such as high sensitivity, label-free and selective operation. In this paper, the novel optical fiber structures are proposed as lab-on-a-chip biosensors. In the proposed biosensors, capturing target biomolecules is achieved by immobilizing a capture layer. Consequently, after attaching the target layer the effective refractive index and the total dispersion of the structure are changed. As a result, the MI gain profile is changed and the generated sidebands (Stokes and anti-Stokes) around pump frequency are shifted. We demonstrate that the maximum sensitivity of these proposed sensors is 34.88 nm/nm. Moreover, the nonlinear material which is used in these biosensors is semiconductor doped glass (CS 3-68). This material due to the high nonlinear refractive index is an appropriate candidate to realize the MI process at low pump power. The used laser is a conventional laser 1550 nm with a power of 100 mW. The maximum length of the proposed biosensors is 0.199 cm which can realize the concept of lab-on-a-chip biosensors.