5,915 research outputs found
In the name of status:Adolescent harmful social behavior as strategic self-regulation
Adolescent harmful social behavior is behavior that benefits the person that exhibits it but could harm (the interest of) another. The traditional perspective on adolescent harmful social behavior is that it is what happens when something goes wrong in the developmental process, classifying such behaviors as a self-regulation failure. Yet, theories drawing from evolution theory underscore the adaptiveness of harmful social behavior and argue that such behavior is enacted as a means to gain important resources for survival and reproduction; gaining a position of power This dissertation aims to examine whether adolescent harmful social behavior can indeed be strategic self-regulation, and formulated two questions: Can adolescent harmful social behavior be seen as strategic attempts to obtain social status? And how can we incorporate this status-pursuit perspective more into current interventions that aim to reduce harmful social behavior? To answer these questions, I conducted a meta-review, a meta-analysis, two experimental studies, and an individual participant data meta-analysis (IPDMA). Meta-review findings of this dissertation underscore that when engaging in particular behavior leads to the acquisition of important peer-status-related goals, harmful social behavior may also develop from adequate self-regulation. Empirical findings indicate that the prospect of status affordances can motivate adolescents to engage in harmful social behavior and that descriptive and injunctive peer norms can convey such status prospects effectively. IPDMA findings illustrate that we can reach more adolescent cooperation and collectivism than we are currently promoting via interventions. In this dissertation, I argue we can do this in two ways. One, teach adolescents how they can achieve status by behaving prosocially. And two, change peer norms that reward harmful social behavior with popularity
Posthuman Creative Styling can a creative writerâs style of writing be described as procedural?
This thesis is about creative styling â the styling a creative writer might use to make their writing
unique. It addresses the question as to whether such styling can be described as procedural. Creative
styling is part of the technique a creative writer uses when writing. It is how they make the text more
âlivelyâ by use of tips and tricks they have either learned or discovered. In essence these are rules, ones
the writer accrues over time by their practice. The thesis argues that the use and invention of these
rules can be set as procedures. and so describe creative styling as procedural.
The thesis follows from questioning why it is that machines or algorithms have, so far, been
incapable of producing creative writing which has value. Machine-written novels do not abound on
the bookshelves and writing styled by computers is, on the whole, dull in comparison to human-crafted
literature. It came about by thinking how it would be possible to reach a point where writing by people
and procedural writing are considered to have equal value. For this reason the thesis is set in a
posthuman context, where the differences between machines and people are erased.
The thesis uses practice to inform an original conceptual space model, based on quality dimensions
and dynamic-inter operation of spaces. This model gives an example of the procedures which a
posthuman creative writer uses when engaged in creative styling. It suggests an original formulation
for the conceptual blending of conceptual spaces, based on the casting of qualities from one space to
another. In support of and informing its arguments are ninety-nine examples of creative writing
practice which show the procedures by which style has been applied, created and assessed. It provides
a route forward for further joint research into both computational and human-coded creative writing
Constructing a profile for proactive career self-management in public higher education institutions in Ghana
Text in English with abstracts and keywords in English, isiXhosa, and isiZuluThe principal focus of this research study was to investigate the relationship among psychosocial career pre-occupation, social connectedness, and organisational commitment, and to determine whether an overall proactive career management profile can be constructed to inform career self-management practices in public higher education institutions (HEIs) in Ghana. Again, the research study intended to provide a background for testing hypotheses and theories as well as moderating the effect of socio-demographic characteristics (age, gender, marital status and job level) on the relationship between psychosocial career pre-occupations, social connectedness and organisational commitment.
A cross-sectional quantitative approach was conducted on a purposively selected sample of senior staff comprising academic and administrative staff (n = 288), from a single public higher educational institution in Ghana. The measuring instruments include a career pre-occupations inventory workplace friendship scale and an organisational commitment scale. Descriptive statistics (mean, standard deviation, skewness and kurtosis), bi-variate correlation analysis (Pearson product moment correlation coefficient), and inferential and multivariate statistics (SEM analysis, moderated regression analysis, ANOVAs and independent sample t-test) were used for the study.
Descriptive, bi-variate correlation and inferential statistics revealed that individual psychosocial career pre-occupations, social connectedness and organisational commitment can be used as elements within a proactive career self-management framework within the Ghanaian higher education institutions. The results of the moderated analysis showed that respondentsâ gender and job level moderated employeesâ level of psychosocial career pre-occupations in predicting organisational commitment. Furthermore, the test for significant mean differences revealed that gender, marital status and job level differed marginally in their psychosocial career pre-occupations, social connectedness and commitment to the organisation.
Theoretically and empirically, the results advanced the career construction theory by empirically validating the core elements of career self-management. Practically, a recommendation was made to inform human resource (HR) managers and HR practitioners in public higher education institutions in Ghana and the consequences indicated in the study offer the opportunity to monitor and provide strategies and interventions for employees in their quest for career choices.Ugqaliselo oluphambili kolu phononongo lophando yayikukuphanda ubudlelwane phakathi komsebenzi wangaphambi kwekhondo ngokwesimo sengqondo nangokwezentlalo (psychosocial career pre-occupation), ukuziphatha, nokunxulumana kwezinto zokuziphatha nezentlalo (social connectedness), kunye nokuzibophelela kulungelelaniso /kucwangciso lombutho (organisational commitment), nokuqonda ukuba ingaba iprofayili yeendlela zokulawula ikhondo elisebenzayo elipheleleyo inokwakhelwa ukwazisa izenzo zekhondo lomsebenzi lokuzilawula kumaziko emfundo ephakamileyo karhulumente/oluntu (HEIs) eGhana.
Kwakhona , uphononongo lophando lwaluzimisele ukunikezela ngomhlaba osisiseko wokuvavanya ingcinga ethathwa njengeyinyaniso engekaqinisekiswa (hypothesis) neethiyori kwakunye nokumodereyitha impembelelo yeempawu zedemografi yoluntu, i-socio-demographic characteristics (iminyaka, isini, imeko yomtshato,kunye nenqanaba lomsebenzi) kubudlelwane phakathi kwemisebenzi yangaphambi kwekhondo nemeko yezengqondo nabantu (psychosocial career pre-occupations), unxulumano lwabantu kunye nokuzibophelela kumbutho (organizational commitment).
Inkqubo yophando ngokobungakanani enqamlezileyo ngokwamacandelo ahlukeneyo (cross sectional quantitative approach) yenziwe kwisampulu ekhethwe ngenjongo kujoliswe kubasebenzi abaphezulu/abadala ababandakanya izifundiswa nabasebenzi bezolawulo (n = 288), besuka kwiziko elinye loluntu lemfundo ephakamileyo eGhana. Izixhobo zokulinganisa zibandakanya uluhlu lwezinto kwisikali semisebenzi yangaphambi kwekhondo ubudlelwane kunye nokuzibophelela kumbutho kwindawo yokusebenzela. Iinkcukacha-manani ezichazayo (i-avareji, ukutenxa kumgangatho (standard deviation), ubugoso (skewness) kunye nomlinganiselo weenkcukacha-manani osetyenziselwa ukuchaza ukuhanjiswa kwedatha ephawulweyo malunga nentsingiselo (kurtosis), uhlalutyo lolungelelwaniso oluphindwe kabini kunye neenkcukacha-manani ezinokuthelelelekwa (i- Pearson product moment correlation coefficient), kunye neenkcukacha manani ezizintlobo-ntlobo ezininzi ezinokuthelekelelwa (uhlalutyo lwe-SEM, uhlalutyo oluhlehlayo olonganyelweyo/ olumodareyithiweyo, i-ANOVA kunye novavanyo oluzimeleyo lwe-t-test) zasetyenziswa kolu phando/phononongo. Inkcukacha-manani ezichazayo, ulungelelwaniso/unxulumaniso oluphindwe kabini kunye nezinokuthelekelelwa ezinentsingiselo zibonise ukuba imisebenzi yangaphambi kwekhondo,ngokwemeko yengqondo neyentlalo, unxulumano lwentlalo yoluntu kunye nokuzibophelela kumbutho kunokusetyenziswa njengezinto ezingaphakathi kwesakhelo solawulo esisebenzayo ngaphakathi kumaziko emfundo ephakamileyo yaseGhana.Iziphumo zohlalutyo olumodareyithiweyo zibonise ukuba isini sabaphenduli nenqanaba lomsebenzi samodareyitha inqanaba labasebenzi kwimisebenzi yangaphambi kwekhondo kwimeko yengqondo nezentlolontle ekuqikeleleni ukuzibophelela kumbutho. Ngaphaya koko, uvavanyo olubalulekileyo lweeyantlukwano lubonise ukuba isini, meko yomtshato kunye nenqanaba lomsebenzi lahlukile kancinci ngokwe-avareji kwimisebenzi yaphambi kwekhondo labo yengqondo nentlalontle, unxibelelwano lwentlalo kunye nokuzinikela embuthweni.
Ngokwethiyori nangobungqina, iziphumo ziqhubele phambili ithiyori yolwakhiwo lwekhondo lomsebenzi ngokuqinisekisa ngobuchule izinto ezingundoqo zokuzilawula kwekhondo lomsebenzi.Ngokwenene, kwenziwa isindululo sokwazisa abaphathi bezabasebenzi neengcali ze-HR kumaziko emfundo ephakamileyo yoluntu eGhana kwaye iziphumo ezibonakaliswe kuphononongo zinika ithuba lokubeka esweni nokubonelela ngezicwangciso-qhinga nongenelelo ngoncedo kubaqeshwa kwiphulo labo lokukhetha amakhondo omsebenzi.Lesi sifundo socwaningo sasigxile kakhulu ekuphenyeni ngobudlelwano phakathi kokucabanga ngomkhakha womsebenzi komuntu, ukuxhumana nabantu, ukuzibophezela komuntu emsebenzini, kanye nokunquma ukuthi iphrofayili yokukwazi ukuzilawula ngokuzenzela ekukhetheni umkhakha womsebenzi kungahlelwa yini ngendlela yokuthi kudlale indima ekuzilawuleleni maqondana nomkhakha womsebenzi ezikhungweni zezemfundo ephakeme zomphakathi (ama-HEI) eGhana. Kanti futhi, isifundo socwaningo sihlose ukunikeza umlando maqondana nokuhlola imicabango kanye nemibono yezinjulalwazi kanjalo nokulinganisa umphumela wezici zokuhleleka kwabantu emphakathini (iminyaka yobudala, ubulili, isimo somshado kanye nezinga lomsebenzi) ebudlelwaneni phakathi kokucabanga ngomkhakha womsebenzi komuntu, ukuxhumana nabantu, kanye nokuzibophezela emsebenzini.
Kwalandelwa indlela yokubheka isibalo samaqoqo abantu emphakathini ngokukhetha ngokuqaphela isampula labasebenzi abasezikhundleni eziphezulu elibandakanya abasebenza ngezemfundo kanye nezokuphatha (n = 288), esikhungweni sezemfundo ephakeme somphakathi esisodwa eGhana. Amathuluzi okukala afaka kuwo isilinganiso sobungane basemsebenzini ekukhetheni ezinhlobeni zemikhakha ecatshangwayo kanye nesilinganiso maqondana nokuzibophezela kwabantu emsebenzini. Kulolu cwaningo kwasetshenziswa izibalo ezichazayo (okujwayelekile, ukuphambuka okuvamile, ukungalingani kanye nobukhali), ukuhlaziywa kokuhlobana okukhona phakathi kwezinombolo ezimbili (isilinganiso sokuxhumana kwezinombolo ezimbili ngokukaPearson), kanye nezibalo eziveza izimbangela nezibalo ezahlukahlukene (ukuhlaziywa kwe-SEM, ukuhlaziywa kokubuyelamuva okulingene, ama-ANOVA kanye nesampula elizimele lokuhlola).
Izibalo ezichazayo, eziveza ukuhlobana phakathi kwezinombolo ezimbili kanye nezibalo eziveza izimbangela ziveze ukuthi ukucabanga ngomkhakha womsebenzi komuntu ngamunye, ukuxhumana nabantu nokuzibophezela emsebenzini kungasetshenziswa njengezinto ezikhona ohlakeni lokukwazi ukuzilawula ngokuzenzela ekukhetheni umkhakha ezikhungweni zezemfundo ephakeme zaseGhana. Imiphumela yokuhlaziywa okulingene yakhombisa ukuthi ubulili bababambiqhaza kanye nezinga labo ngokwezikhundla zomsebenzi kuhambisana nezinga abasebenzi abacabanga ngalo nomkhakha womsebenzi ekuqageleni indlela abazozibophezela ngayo emsebenzini. Ngaphezu kwalokho, ukuhlolwa komehluko omkhulu ojwayelekile kwaveza ukuthi ubulili, isimo somshado kanye nezinga ngokwesikhundla somsebenzi kwahluka kakhulu nendlela abacabanga ngayo ngomkhakha womsebenzi, ukuxhumana nabantu nokuzibophezela emsebenzini. Ngokombono wenjulalwazi nocwaningo olufakazelwe, imiphumela ithuthukise umbono wenjulalwazi wokuhlela umkhakha womsebenzi okuqinisekiswe ngokocwaningo olufakazelwe izinto ezinqala zokuzilawulela umkhakha womsebenzi. Ekusebenzeni, kwenziwa izincomo zokufundisa abaphathi babasebenzi (ba-HR) kanye nabasebenza ngezabasebenzi (ngezakwa-HR) ezikhungweni zezemfundo ephakeme zomphakathi eGhana, kanti nemiphumela evezwe ocwaningweni inikeza ithuba lokuqapha nokuhlinzeka amasu kanye nokungenelela kwabasebenzi ekwenzeni kwabo izinqumo zomsebenzi.Business ManagementPh. D. (Business Management
Heterogeneous Federated Learning: State-of-the-art and Research Challenges
Federated learning (FL) has drawn increasing attention owing to its potential
use in large-scale industrial applications. Existing federated learning works
mainly focus on model homogeneous settings. However, practical federated
learning typically faces the heterogeneity of data distributions, model
architectures, network environments, and hardware devices among participant
clients. Heterogeneous Federated Learning (HFL) is much more challenging, and
corresponding solutions are diverse and complex. Therefore, a systematic survey
on this topic about the research challenges and state-of-the-art is essential.
In this survey, we firstly summarize the various research challenges in HFL
from five aspects: statistical heterogeneity, model heterogeneity,
communication heterogeneity, device heterogeneity, and additional challenges.
In addition, recent advances in HFL are reviewed and a new taxonomy of existing
HFL methods is proposed with an in-depth analysis of their pros and cons. We
classify existing methods from three different levels according to the HFL
procedure: data-level, model-level, and server-level. Finally, several critical
and promising future research directions in HFL are discussed, which may
facilitate further developments in this field. A periodically updated
collection on HFL is available at https://github.com/marswhu/HFL_Survey.Comment: 42 pages, 11 figures, and 4 table
Consensus Algorithms of Distributed Ledger Technology -- A Comprehensive Analysis
The most essential component of every Distributed Ledger Technology (DLT) is
the Consensus Algorithm (CA), which enables users to reach a consensus in a
decentralized and distributed manner. Numerous CA exist, but their viability
for particular applications varies, making their trade-offs a crucial factor to
consider when implementing DLT in a specific field. This article provided a
comprehensive analysis of the various consensus algorithms used in distributed
ledger technologies (DLT) and blockchain networks. We cover an extensive array
of thirty consensus algorithms. Eleven attributes including hardware
requirements, pre-trust level, tolerance level, and more, were used to generate
a series of comparison tables evaluating these consensus algorithms. In
addition, we discuss DLT classifications, the categories of certain consensus
algorithms, and provide examples of authentication-focused and
data-storage-focused DLTs. In addition, we analyze the pros and cons of
particular consensus algorithms, such as Nominated Proof of Stake (NPoS),
Bonded Proof of Stake (BPoS), and Avalanche. In conclusion, we discuss the
applicability of these consensus algorithms to various Cyber Physical System
(CPS) use cases, including supply chain management, intelligent transportation
systems, and smart healthcare.Comment: 50 pages, 20 figure
Exploring Text Mining and Analytics for Applications in Public Security: An in-depth dive into a systematic literature review
Text mining and related analytics emerge as a technological approach to support human activities in extracting useful knowledge through texts in several formats. From a managerial point of view, it can help organizations in planning and decision-making processes, providing information that was not previously evident through textual materials produced internally or even externally. In this context, within the public/governmental scope, public security agencies are great beneficiaries of the tools associated with text mining, in several aspects, from applications in the criminal area to the collection of people's opinions and sentiments about the actions taken to promote their welfare. This article reports details of a systematic literature review focused on identifying the main areas of text mining application in public security, the most recurrent technological tools, and future research directions. The searches covered four major article bases (Scopus, Web of Science, IEEE Xplore, and ACM Digital Library), selecting 194 materials published between 2014 and the first half of 2021, among journals, conferences, and book chapters. There were several findings concerning the targets of the literature review, as presented in the results of this article
How to Collaborate and Not Just Coexist: An Explanatory Sequential Mixed Methods Study on the Impact of a Physician and Nurse Interprofessional Education Program on the Development of Early Career Pediatrician Communication Skills and Collaborative Behaviors Once in Practice
Healthcare organizations are challenged to build and develop interprofessional (IP) teams capable of delivering effective patient care (Tang et al., 2018). Historically, these multiple professional roles are not formally educated together but are all expected to work in unison once they enter practice (El-Hanafy, 2018). This lack of relational foundation has led to age-old conflict between the physician and nurse roles on the care team (Stein et al., 1990). This conflict has been attributed to a lack of role definition or an overemphasis on hierarchical structures, poor communication, and the inability of physicians to collaboratively work with their nurse counterparts (Crawford et al., 2012). These barriers can lead to ineffective patient care planning and management, decreased work satisfaction, and workplace tension between essential roles (Wang et al., 2018). The problem is that no standard curriculum currently exists in the literature that is being actively used in U.S. based graduate medical education programs that uniformly places importance on IP collaboration between nurses and physicians, yet there is an identified need in the clinical care setting (Allenbaugh et al., 2019; Looman et al., 2020, Wang et al., 2018).
This explanatory sequential mixed methods study aimed to determine the impact that participation in an interprofessional education (IPE) program had on graduatesâ perceptions of collaborative behaviors and effective communication skills once in practice by answering the following research questions: Is there a difference in the participantsâ perceived abilities across the six domains as they recall them on the Interprofessional Collaborative Competency Attainment Survey (revised; ICCASr) pre and post-assessment? Is there a difference between factor outcomes on the ICCASr pre/posttest between nursesâ and physiciansâ professional roles? Is there a correlation between posttest factors for each participant group (nurses and physicians)? How do nurses and physicians describe their communication and collaboration with each other after participation in the program? The quantitative questions were answered using the ICCASr and the qualitative question was answered using open-ended survey questions and interviews.
This mixed methods explanatory sequential design was divided into two distinct phases. Phase 1 involved the collection and analyses of quantitative data via the ICCASr and Phase 2 used qualitative methods derived from open-ended questions and a semi-structured interview. In Phase 1, quantitative data were gained by distributing the ICCASr to 53 graduates from an IPE program, representing the first three cohorts with a return of 22 responses. The ICCASr underwent paired t-tests, independent t-tests, and correlational statistics that were calculated to determine if there was a difference in the participantsâ perceived abilities across the six designated domains: communication, roles and responsibilities, conflict management/resolution, team functioning, collaboration, and collaborative patient-family centered approach pre and postintervention. In Phase 2, qualitative data were collected using responses from the open-ended questions on the ICCASr to reveal how the program impacted the participantsâ perceived abilities to communicate and collaborate postintervention to offer better patient care. These initial data led to the development of 12 semi-structured interview questions. Virtual interviews were conducted with eight survey participants who volunteered to share their experiences. The qualitative data utilized multilevel descriptive, holistic, and In Vivo coding for analysis to locate significant themes from the position of the participantsâ own experiences in relation to the overall study aim.
The ICCASr survey results showed a statistically significant difference in participantsâ perceptions on all areas of the IP domains from pre to postintervention. There was no significant correlation between patient-family centered approach associated with conflict management/resolution or communication or team functioning associated with communication for the nurse role. The results of the descriptive statistics and comparative and correlation analyses supported the focused interview questions. The qualitative data generated four essential thematic interpretations as to the interventionâs impact: foundational deficits, construction of perspectives, development of relationship and organizational influence. Each essential theme was influenced through the discovery of categorizing data obtained from the participantsâ narratives. The quantitative results were supported by qualitative insights, allowing for a more robust picture from the perspective of the learner as to how the intervention impacted their learning and why this type of programming is important. Using a mixed methods study design and sequential process aimed to determine perceptional behavior change and gain a deeper understanding of how participation in one institutionâs early intervention program impacted communication skills and nurseâphysician collaborative relationships.
At the conclusion of the study, it was determined that the ICCASr was an effective assessment tool in identifying perceived changes in behavior as it relates to IP programming even years after an intervention. The statistical improvement identified between pre and post-learning surveys supports the effectiveness of this specific program to provide IPE knowledge long term. The themes that emerged from the interviews provided an in-depth look at how this specific program impacted the participants and revealed areas needing attention when developing future IPE programs, such as moving away from modules and simulation. There was a comprehensive belief that the deficit in IPE training in formal healthcare education created the most significant barrier to providing team care. IPE interventions should fill these gaps by providing the necessary job-related soft skills to ensure the positive collaboration between roles in the clinical care setting. Intervention activities should provide a pathway for participants to reflect on their own paradigms as they learn to see the âotherâ as a human instead of a role, which has not previously been role modeled but will change practice approaches immensely. Having a well-developed early career intervention will improve IP relationships immediately but also provide transferable skills to teach others as providers advance their careers. Finally, to truly support IPE education in the clinical care setting, there must be organizational support to maintain positive relationships and build trust among employees. Mixed methods designs are a novel approach to healthcare education research and provide a deeper dive into the lived experience and shared meaning of learners. The results of this study are meaningful for healthcare education as no other study has assessed the impact of a longitudinal IPE intervention between physicians-in-training and nurses. This study supports the importance of developing a standard IPE curriculum using interactive, relationship-driven activities as a meaningful and necessary part of training to preventatively reduce conflict and proactively develop effective IP communication and collaboration skills to meet healthcare organization and patient needs once in practice
Design and Real-World Evaluation of Dependable Wireless Cyber-Physical Systems
The ongoing effort for an efficient, sustainable, and automated interaction between humans, machines, and our environment will make cyber-physical systems (CPS) an integral part of the industry and our daily lives. At their core, CPS integrate computing elements, communication networks, and physical processes that are monitored and controlled through sensors and actuators. New and innovative applications become possible by extending or replacing static and expensive cable-based communication infrastructures with wireless technology. The flexibility of wireless CPS is a key enabler for many envisioned scenarios, such as intelligent factories, smart farming, personalized healthcare systems, autonomous search and rescue, and smart cities.
High dependability, efficiency, and adaptivity requirements complement the demand for wireless and low-cost solutions in such applications. For instance, industrial and medical systems should work reliably and predictably with performance guarantees, even if parts of the system fail. Because emerging CPS will feature mobile and battery-driven devices that can execute various tasks, the systems must also quickly adapt to frequently changing conditions. Moreover, as applications become ever more sophisticated, featuring compact embedded devices that are deployed densely and at scale, efficient designs are indispensable to achieve desired operational lifetimes and satisfy high bandwidth demands.
Meeting these partly conflicting requirements, however, is challenging due to imperfections of wireless communication and resource constraints along several dimensions, for example, computing, memory, and power constraints of the devices. More precisely, frequent and correlated message losses paired with very limited bandwidth and varying delays for the message exchange significantly complicate the control design. In addition, since communication ranges are limited, messages must be relayed over multiple hops to cover larger distances, such as an entire factory. Although the resulting mesh networks are more robust against interference, efficient communication is a major challenge as wireless imperfections get amplified, and significant coordination effort is needed, especially if the networks are dynamic.
CPS combine various research disciplines, which are often investigated in isolation, ignoring their complex interaction. However, to address this interaction and build trust in the proposed solutions, evaluating CPS using real physical systems and wireless networks paired with formal guarantees of a systemâs end-to-end behavior is necessary. Existing works that take this step can only satisfy a few of the abovementioned requirements. Most notably, multi-hop communication has only been used to control slow physical processes while providing no guarantees. One of the reasons is that the current communication protocols are not suited for dynamic multi-hop networks.
This thesis closes the gap between existing works and the diverse needs of emerging wireless CPS. The contributions address different research directions and are split into two parts. In the first part, we specifically address the shortcomings of existing communication protocols and make the following contributions to provide a solid networking foundation:
⢠We present Mixer, a communication primitive for the reliable many-to-all message exchange in dynamic wireless multi-hop networks. Mixer runs on resource-constrained low-power embedded devices and combines synchronous transmissions and network coding for a highly scalable and topology-agnostic message exchange. As a result, it supports mobile nodes and can serve any possible traffic patterns, for example, to efficiently realize distributed control, as required by emerging CPS applications.
⢠We present Butler, a lightweight and distributed synchronization mechanism with formally guaranteed correctness properties to improve the dependability of synchronous transmissions-based protocols. These protocols require precise time synchronization provided by a specific node. Upon failure of this node, the entire network cannot communicate. Butler removes this single point of failure by quickly synchronizing all nodes in the network without affecting the protocolsâ performance.
In the second part, we focus on the challenges of integrating communication and various control concepts using classical time-triggered and modern event-based approaches. Based on the design, implementation, and evaluation of the proposed solutions using real systems and networks, we make the following contributions, which in many ways push the boundaries of previous approaches:
⢠We are the first to demonstrate and evaluate fast feedback control over low-power wireless multi-hop networks. Essential for this achievement is a novel co-design and integration of communication and control. Our wireless embedded platform tames the imperfections impairing control, for example, message loss and varying delays, and considers the resulting key properties in the control design. Furthermore, the careful orchestration of control and communication tasks enables real-time operation and makes our system amenable to an end-to-end analysis. Due to this, we can provably guarantee closed-loop stability for physical processes with linear time-invariant dynamics.
⢠We propose control-guided communication, a novel co-design for distributed self-triggered control over wireless multi-hop networks. Self-triggered control can save energy by transmitting data only when needed. However, there are no solutions that bring those savings to multi-hop networks and that can reallocate freed-up resources, for example, to other agents. Our control system informs the communication system of its transmission demands ahead of time so that communication resources can be allocated accordingly. Thus, we can transfer the energy savings from the control to the communication side and achieve an end-to-end benefit.
⢠We present a novel co-design of distributed control and wireless communication that resolves overload situations in which the communication demand exceeds the available bandwidth. As systems scale up, featuring more agents and higher bandwidth demands, the available bandwidth will be quickly exceeded, resulting in overload. While event-triggered control and self-triggered control approaches reduce the communication demand on average, they cannot prevent that potentially all agents want to communicate simultaneously. We address this limitation by dynamically allocating the available bandwidth to the agents with the highest need. Thus, we can formally prove that our co-design guarantees closed-loop stability for physical systems with stochastic linear time-invariant dynamics.:Abstract
Acknowledgements
List of Abbreviations
List of Figures
List of Tables
1 Introduction
1.1 Motivation
1.2 Application Requirements
1.3 Challenges
1.4 State of the Art
1.5 Contributions and Road Map
2 Mixer: Efficient Many-to-All Broadcast in Dynamic Wireless Mesh Networks
2.1 Introduction
2.2 Overview
2.3 Design
2.4 Implementation
2.5 Evaluation
2.6 Discussion
2.7 Related Work
3 Butler: Increasing the Availability of Low-Power Wireless Communication Protocols
3.1 Introduction
3.2 Motivation and Background
3.3 Design
3.4 Analysis
3.5 Implementation
3.6 Evaluation
3.7 Related Work
4 Feedback Control Goes Wireless: Guaranteed Stability over Low-Power Multi-Hop Networks
4.1 Introduction
4.2 Related Work
4.3 Problem Setting and Approach
4.4 Wireless Embedded System Design
4.5 Control Design and Analysis
4.6 Experimental Evaluation
4.A Control Details
5 Control-Guided Communication: Efficient Resource Arbitration and Allocation in Multi-Hop Wireless Control Systems
5.1 Introduction
5.2 Problem Setting
5.3 Co-Design Approach
5.4 Wireless Communication System Design
5.5 Self-Triggered Control Design
5.6 Experimental Evaluation
6 Scaling Beyond Bandwidth Limitations: Wireless Control With Stability Guarantees Under Overload
6.1 Introduction
6.2 Problem and Related Work
6.3 Overview of Co-Design Approach
6.4 Predictive Triggering and Control System
6.5 Adaptive Communication System
6.6 Integration and Stability Analysis
6.7 Testbed Experiments
6.A Proof of Theorem 4
6.B Usage of the Network Bandwidth for Control
7 Conclusion and Outlook
7.1 Contributions
7.2 Future Directions
Bibliography
List of Publication
Comparing the production of a formula with the development of L2 competence
This pilot study investigates the production of a formula with the development of L2 competence over proficiency levels of a spoken learner corpus. The results show that the formula
in beginner production data is likely being recalled holistically from learnersâ phonological
memory rather than generated online, identifiable by virtue of its fluent production in absence
of any other surface structure evidence of the formulaâs syntactic properties. As learnersâ L2
competence increases, the formula becomes sensitive to modifications which show structural
conformity at each proficiency level. The transparency between the formulaâs modification
and learnersâ corresponding L2 surface structure realisations suggest that it is the independent
development of L2 competence which integrates the formula into compositional language,
and ultimately drives the SLA process forward
- âŚ