Improving Throughput and Predictability of High-volume Business Processes Through Embedded Modeling

Being faster is good. Being predictable is better. A faithful model of a system, loaded to reflect the system\u27s current state, can then be used to look into the future and predict performance. Building faithful models of processes with high degrees of uncertainty can be very challenging, especially where this uncertainty exists in terms of processing times, queuing behavior and re-work rates. Within the context of an electronic, multi-tiered workflow management system (WFMS) the author builds such a model to endogenously quote due dates. A WFMS that manages business objects can be recast as a flexible flow shop in which the stations that a job (representing the business object) passes through are known and the jobs in the stations queues at any point are known. All of the other parameters associated with the flow shop, including job processing times per station, and station queuing behavior are uncertain though there is a significant body of past performance data that might be brought to bear. The objective, in this environment, is to meet the delivery date promised when the job is accepted. To attack the problem the author develops a novel heuristic algorithm for decomposing the WFMS\u27s event logs exposing non-standard queuing behavior, develops a new simulation component to implement that behavior, and assembles a prototypical system to automate the required historical analysis and allow for on-demand due date quoting through the use of embedded discrete event simulation modeling. To attack the problem the author develops a novel heuristic algorithm for decomposing the WFMS\u27s event logs exposing non-standard queuing behavior, develops a new simulation component to implement that behavior, and assembles a prototypical system to automate the required historical analysis and allow for on-demand due date quoting through the use of embedded discrete event simulation modeling. The developed software components are flexible enough to allow for both the analysis of past performance in conjunction with the WFMS\u27s event logs, and on-demand analysis of new jobs entering the system. Using the proportion of jobs completed within the predicted interval as the measure of effectiveness, the author validates the performance of the system over six months of historical data and during live operations with both samples achieving the 90% service level targeted

The Industrial Village Energy Approach: A Cost-Effective Approach To Balance Interests and Collaboratively Harness Onsite Solar Energy

While the residential sector has seen a strong and rapid uptake of photovoltaic panels on rooftops in the last decade, especially in Australia, the uptake has been much slower on commercial and industrial roofs. This research focuses on how commercial and industrial precincts can transition to cost-effective long-term solar energy generation in a manner that creates multiple benefits. The outcome is a new approach that benefits the energy customers, the embedded utility and the environment

Network Layer Aspects of Permissionless Blockchains

Permissionless blockchains reach decentralized consensus without requiring pre-established identities or trusted third parties, thus enabling applications such as cryptocurrencies and smart contracts. Consensus is agreed on data that is generated by the application and transmitted by the system’s (peer-to-peer) network layer. While many attacks on the network layer were discussed so far, there is no systematic approach that brings together known attacks, the requirements, and the design space of the network layer. In this paper, we survey attacks on the network layer of permissionless blockchains, and derive five requirements: performance, low cost of participation, anonymity, DoS resistance, and topology hiding. Furthermore, we survey the design space of the network layer and qualitatively show the effect of each design decisions on the fulfillment of the requirements. Finally, we pick two aspects of the design space, in-band peer discovery and relay delay, and demonstrate possible directions of future research by quantitatively analyzing and optimizing simplified scenarios. We show that while most design decisions imply certain tradeoffs, there is a lack of models that analyze and formalize these tradeoffs. Such models could aid the design of the network layer of permissionless blockchains. One reason for the lack of models is the deliberately limited observability of deployed blockchains. We emphasize that simulation based approaches cope with these limitations and are suited for the analysis of the network layer of permissionless blockchains

Beyond Just Money Transactions: Redesigning Digital Peer-to-Peer Payments for Social Connections

Financial activities, such as the exchange of money between individuals, have long been considered a crucial aspect of how people build and maintain their interpersonal relationships (i.e., a strong, deep, or close association/acquaintance between two or more people) with individuals they know because money is a sensitive social construct. In particular, over the past decade, how to conduct, manage, and experience money exchanges and processes between individuals has been dramatically transformed due to the increasing popularity of digital peer-to-peer (P2P) payment services (i.e., performing one to one online money transactions via a digital device). In this sense, digital P2P payments have shown the potential to affect how people pay and interact with each other regarding money, an important impact factor on various forms of interpersonal relationships, by facilitating direct money transactions between individuals through computer-mediated channels. Therefore, this dissertation research is motivated to leverage a sociotechnical approach to conduct an in-depth investigation of the nuanced human experiences of personal money exchanges mediated by digital P2P payments between people who know each other and the unique role of digital P2P payments in shaping these individuals\u27 social connections with each other online and offline. In doing so, this dissertation research aims to (i) reveal and elaborate the multidimensional influences of digital P2P payments on interpersonal relationships between people who already know each other in terms of both experiences of money exchanges and everyday social interactions; ii) advance our knowledge and understanding of how digital P2P payments systems can be redesigned to better support people\u27s social connections with individuals they know; and iii) envision the future landscape of digital P2P payments in our increasingly networked digital society. This dissertation research involves four studies. Grounded in 158 social media posts and 8 interviews, Study 1 explores how people perceive the increasing trend of integrating digital P2P payments with social media services (e.g., Facebook Messenger payment) and why they decide not to use this service in their daily lives. Study 2 reports findings of a qualitative study of 31 in-depth semi-structured interviews to investigate the influences of using digital P2P payments on people\u27s offline interpersonal relationships. Study 3 reports results of a large-scale anonymous online survey with 218 valid responses to measure the specific immediate social consequences and lasting impacts of using digital P2P payments on people\u27s interpersonal relationships. Study 4 adopts the research through design (RtD) approach with a specific emphasis on participatory design activities to both elicit and qualitatively investigate user needs and user-generated design solutions for digital P2P payment services that can better support people\u27s social connections. This dissertation research thus contributes to innovating financial technologies in the perspective of Human-Computer Interaction and Human-Centered Computing by better understanding new and more complicated social phenomena and dynamics emerging in today\u27s digital economy. First, this dissertation research offers one of the first empirical evidence to unpack and explicate the multidimensional influences of digital P2P payments on both financial experiences/processes and everyday social connections between known contacts, which is understudied in prior scholarship. In doing so, we provide new perspectives on today\u27s technology-mediated financial life and shed light on the intertwining financial and social relationships through technology. These insights also help re-conceptualize computer-mediated interpersonal relationships in today\u27s networked society. Second, we identify and further reflect on user-generated design recommendations and develop prototypes that highlight the importance of taking the interplay of financial and social engagement, in addition to security and privacy, into consideration when redesigning digital P2P payments platforms. Through this RtD approach, we thus rethink and envision the future landscape of digital P2P payments where such technologies can be designed, developed, and used in a more comfortable, innovative, and emotionally satisfactory way. As we are entering a post COVID-19 pandemic age, there is an increasing interest to make digital financial technologies not only secure but also more human-centered, interaction-centric, and culturally sensitive, which can be used to better support and maintain human connections through daily financial activities with or without face-to-face interaction. Therefore, in a broader sense, this dissertation research on the social values of digital P2P payments also contributes to building a more robust and inclusive digital economy in today\u27s changing society

Regulatory Pathways for Smart Grid Development in China

Energy Policy, Economics and Management; Energy Technology; Environmental Law/Policy/Ecojustic

A secure client / server interface protocol for the electricity prepayment vending industry

Electricity prepayment systems have been successfully implemented by South Africa’s national electricity utility (Eskom) and local municipalities for more than 17 years. The prepayment vending sub-system is a critical component of prepayment systems. It provides convenient locations for customers to purchase electricity. It predominantly operates in an “offline” mode, however, electricity utilities are now opting for systems that operate in an “online” mode. “Online” mode of operation or online vending is when a prepayment token is requested from a centralised server that is remote from the client at the actual point of sale (POS). The token is only generated by the server and transferred to the POS client, once the transaction, the POS client and the payment mechanism has been authenticated and authorised. The connection between the POS client and the server is a standard computer network channel (like Internet, direct dial-up link, X.25, GPRS, etc) The lack of online vending system standardisation was a concern and significant risk for utilities, as they faced the problem of being locked into proprietary online vending systems. Thus the South African prepayment industry, lead by Eskom, initiated a project to develop an industry specification for online vending systems. The first critical project task was a current state analysis of the South African prepayment industry, technology and specifications. The prepayment industry is built around the Standard Transfer Specification (STS). STS has become the de-facto industry standard to securely transfer electricity credit from a Point of Sale (POS) to the prepaid meter. STS is supported by several “offline” vending system specifications. The current state analysis was followed by the requirements analysis phase. The requirements analysis confirmed the need for a standard interface protocol specification rather than a full systems specification. The interface specification focuses on the protocol between a vending client and vending server and does not specify the client and server application layer functionality and performance requirements. This approach encourages innovation and competitiveness amongst client and server suppliers while ensuring interoperability between these systems. The online vending protocol design was implemented using the web services framework and therefore appropriately named, XMLVend. The protocol development phase was an iterative process with two major releases, XMLVend 1.22 and XMLVend 2.1. XMLVend 2.1 is the current version of the protocol. XMLVend 2.1 addressed the shortcomings identified in XMLVend 1.22, updated the existing use cases and added several new use cases. It was also modelled as a unified modelling language (UML) interface or contract for prepayment vending services. Therefore, clients using the XMLVend interface are able to request services from any service provider (server) that implements the XMLVend interface. The UML modelled interface and use case message pairs were mapped to Web Service Definition Language (WSDL) and schema (XSD) definitions respectively. XMLVend 2.1 is a secure and open web service based protocol that facilitates prepayment vending functionality between a single logical vending server and ‘n’ number of clients. It has become a key enabler for utilities to implement standardised, secure, interoperable and flexible online vending systems. AFRIKAANS : Voorafbetaalde elektrisiteitstelsels is suksesvol deur Suid-Afrika se nasionale elektrisiteitsverskaffer (Eskom) en plaaslike munisipaliteite geïmplementeer vir meer as 17 jaar. Die Voorafbetaal verkoop-subsisteem is 'n esensiële komponent van voorafbetaal elektrisiteitstelsels. Dit laat gebruikers toe om elektrisiteit te koop by ‘n verskeidenheid van verkooppunte. In die verlede het hierdie stelsels meestal bestaan as alleenstaande verkooppunte maar elektrisiteitsverskaffers is besig om hulle stelsels te verander om in n aanlyn modus te werk. Aanlyn verkoop is wanneer 'n voorafbetaalkoepon versoek word vanaf ‘n sentrale bediener wat vêr verwydered is van die kliënt se verkooppunt. Die koepon word slegs gegenereer deur die bediener en gestuur aan die kliënt nadat die transaksie, die kliënt self, en die betaling meganisme, gemagtig is. Die koppeling tussen verkooppuntkliënt en die bediener is ‘n standaard kommunikasie kanaal, (byvoorbeeld; Internettoegang, direkte inbel skakel, X.25 en “GPRS”) Die gebrek aan 'n standaard vir aanlynverkoopstelsels was 'n bekommernis en beduidende risiko vir elektrisiteitsverskaffers, aangesien hulle ‘n probleem ondervind dat hulle ingeperk sal word tot ‘n eksklusiewe ontwerp vir so ‘n aanlynverkoopstelsel. Dus het die Suid Afrikaanse voorafbetaal industrie, gelei deur Eskom, 'n projek begin om 'n industriespesifikasie te ontwikkel vir aanlyn verkoopstelsels. Die eerste kritiese projek taak was 'n analise van die huidige stand van die Suid-Afrikaanse vooruitbetaling industrie, die tegnologie en spesifikasies. Die voorafbetaal sektor is gebou rondom die Standaard Oordrag Spesifikasie, bekend as “Standard Transfer Specification” (STS). STS word algemeen aanvaar as die industrie standaard vir die oordrag van elektrisiteit krediet vanaf 'n Verkooppunt na die voorafbetaalmeter. STS word ondersteun deur verskeie alleenstaande verkoopstelsel spesifikasies. Die analise vir die huidige status was opgevolg deur ‘n studie van die vereistes vir so ‘n stelsel. Die vereistes analise het die behoefte bevestig vir 'n standaard koppelvlak protokol spesifikasie, eerder as 'n nuwe spesifikasie vir ‘n volledige oorafbetaalstelsel. Dit bepaal alleenlik die protokol koppelvlak tussen 'n voorafbetaalkliënt en die bediener. Dit spesifiseer nie die program vlak funksionaliteit of prestasie vereistes, vir die kliënt en bediener nie. Hierdie benadering bevorder innovasie en mededingendheid onder kliënt- en bediener-verskaffers, terwyl dit nog steeds verseker dat die stelsels wedersyds aanpasbaar bly. Die aanlyn verkoopprotokol ontwerp is geïmplementeer met die webdienste raamwerk en staan bekend as XMLVend. Die protokol vir die ontwikkeling fase was 'n iteratiewe proses met die twee groot weergawes, XMLVend 1.22 en XMLVend 2.1. Die huidige weergawe van die protokol - XMLVend 2.1, adresseer die tekortkominge wat geïdentifiseer is met XMLVend 1.22, terwyl dit ook die bestaande gebruiksgevalle opdatteer en verskeie nuwe gebruiksgevalle byvoeg. Dit was ook geskoei as 'n verenigde modelleringtaal (UML) koppelvlak, of 'n kontrak, vir die voorafbetaal verkoopsdienste. Kliënte is daarom in staat om, met behulp van die XMLVend koppelvlak, dienste te versoek van enige diensverskaffer wat die XMLVend koppelvlak ondersteun. Die UML gemodelleerde koppelvlak- en gebruiksgevalle- boodskappare was gemodeleer in die Web Dienste Definisie Taal (WSDL) en skema (XSD) definisies onderskeidelik. XMLVend 2.1 is 'n sekure en oop webdienste-gebaseerde protokol wat dit moontlik maak om voorafbetaalfunksies te fasilliteer tussen 'n enkele logiese verkoopbediener en 'x' aantal kliënte. Dit het 'n sleutelrol aangeneem vir verskaffers om ‘n gestandaardiseerde, veilige, wedersyds-aanpasbare en buigsame aanlyn verkoopstelsels moontlik te maak. CopyrightDissertation (MSc)--University of Pretoria, 2010.Electrical, Electronic and Computer Engineeringunrestricte