A comparative study of the performance of concurrency control algorithms in a centralised database

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A Case Study of Cross-Cultural Complexities and Interpersonal Conflict Faced by Project Managers in Multicultural Software Development Project Teams

The problem of cross-cultural complexities is a hindrance to effective multicultural team leadership across many industries. Cultural differences among project team members cause conflict, misunderstanding, and poor project performance. The absence of competent leaders is a problem because business in the future will rely increasingly on the use of multicultural project teams. The purpose of this qualitative exploratory case study was to explore the challenges faced and the cultural competencies needed by project managers leading multicultural software development project teams to successfully manage and resolve cross-cultural interpersonal conflict amongst project team members. The researcher collected data using semi-structured interviews with the population of 12 project managers recruited from the Project Management Institute’s credentialed project management professionals LinkedIn group. Through a cross-case synthesis, the researcher identified common themes and aligned them with the two study constructs: cross-cultural interpersonal conflict resolution and multicultural skills. The findings of the research revealed that the project managers perceived challenges including language barriers, cycles of mistrust, and competitive attitudes when managing multicultural teams. In order to mitigate these difficulties, the participants reported that project managers require excellent communication, negotiation, and emotional intelligence skills. The contributions of this study to the field of conflict analysis and resolution include highlighting common cross-cultural complexities encountered in multicultural teams, as well as effective methods of minimizing, eliminating, or mitigating these issues and the resulting interpersonal conflict

Case-based argumentation infrastructure for agent societies

In this work, we propose an infrastructure to develop and execute argumentative agents in an open multi-agent system. This infrastructure offers the necessary components to develop agents with argumentation capabilities, including the communication skills and the argumentation protocol, and it offers support for agent societies and their agents' social context. The main advantage of having this infrastructure is that it is possible to create agents with argumentation capabilities to resolve a specified problem. In the argumentation dialogue the agents try to reach an agreement about the best solution to apply for each proposed problem. The proposed infrastructure has been validated with a real example and it has been evaluated obtaining, with argumentation strategies, better performance than other reasoning approaches that do not include argumentation.Jordán Prunera, JM. (2011). Case-based argumentation infrastructure for agent societies. http://hdl.handle.net/10251/15362Archivo delegad

A multi-agent crop production decision support system for technology transfer

The purpose of this research was to study agricultural crop production 'decision support systems' as a means of transferring agricultural technology from research labs and plots to producers, extension specialists, agriculture service agencies, and scientists, on the Western Canadian Prairies. A 'decision support system' is a computer program that analyses problems spanning several knowledge or problem areas producing results that aid the management decision-making process. The primary objective was to develop a computer application program that would fulfill the farm manager's decision support needs and be "open" to future enhancements. This interdisciplinary study has a strong agricultural presence in the application context of the resultant computerized agricultural decision support system, with agronomics being the foundation on which the system was built, and computer science being the toolbox used to build it. Farm Smart 2000 is the resultant decision support system, providing "single-window" access to three different tiers of decision support utilizing the Internet, ' expert systems' and integrated multiple heterogeneous 'reusable agents' in a cooperative problem-solving environment. An ' expert system' is a computer program that solves complicated problems, within a specific knowledge or problem area, that would otherwise require human expertise. Expert systems integrated with each other within a decision support system are called 'agents. Reusable agents' are modular computer programs (e.g. expert systems) which can be used in more than one computer application with little or no modification. Farm Smart 2000 provides support for most management aspects of crop production including variety selection, crop rotations, weed management, disease management, residue management, harvesting, soil conservation, and economics, for the crops of wheat, canola, barley, peas, and flax. Tier-3, the most sophisticated level of Farm Smart 2000, is the focus of this dissertation and utilizes multiple reusable agents, integrating them such that they cooperate together to solve complex interrelated crop production problems. A Global Control Expert achieves the required communication and coordination among the agents resulting in an "open system", enabling Farm Smart 2000 to extend its problem-solving capabilities by integrating additional agents and knowledge, without system re-engineering, thereby remaining an ongoing technology transfer vehicle

Impact of an Urban High School Conflict Resolution Program on Peer Mediators:

Urban high school students in the United States are often involved in conflicts related to bullying, physical fighting, and drug abuse. These conflicts create a hostile learning environment; interventions such as conflict resolution programs are implemented to reduce these disruptions to learning. The purpose of this qualitative case study was to explore how an urban high school conflict resolution program impacts trained peer mediators. The conceptual framework was based on Erikson\u27s psychosocial theory of human development and Freire\u27s critical theory about pedagogy of the oppressed. Participants included 4 high school students who participated as trained peer mediators in an urban high school conflict resolution program in a southern state. Data were collected from multiple sources, including individual interviews with students, reflective journals maintained by these students, and archival records and documents related to this program. At the first level of data analysis, line-by-line initial coding and categorization was used to analyze each data source. A content analysis was used for archival records and documents. At the second level, categorized data across all sources of data was examined to determine themes and discrepant data. The key finding was that this conflict resolution program positively impacted peer mediators because they learned cultural competency skills such as active listening and maintaining neutrality; these skills helped participants fulfill their desire to help peers resolve conflicts and to resolve personal altercations with friends and family. This study will help educators and policymakers develop a deeper understanding about how conflict resolution programs and peer mediators improve the learning environment in urban high schools

Proceedings ICPW'07: 2nd International Conference on the Pragmatic Web, 22-23 Oct. 2007, Tilburg: NL

Proceedings ICPW'07: 2nd International Conference on the Pragmatic Web, 22-23 Oct. 2007, Tilburg: N

Building Scalable and Consistent Distributed Databases Under Conflicts

Distributed databases, which rely on redundant and distributed storage across multiple servers, are able to provide mission-critical data management services at large scale. Parallelism is the key to the scalability of distributed databases, but concurrent queries having conflicts may block or abort each other when strong consistency is enforced using rigorous concurrency control protocols. This thesis studies the techniques of building scalable distributed databases under strong consistency guarantees even in the face of high contention workloads. The techniques proposed in this thesis share a common idea, conflict mitigation, meaning mitigating conflicts by rescheduling operations in the concurrency control in the first place instead of resolving contending conflicts. Using this idea, concurrent queries under conflicts can be executed with high parallelism. This thesis explores this idea on both databases that support serializable ACID (atomic, consistency, isolation, durability) transactions, and eventually consistent NoSQL systems. First, the epoch-based concurrency control (ECC) technique is proposed in ALOHA-KV, a new distributed key-value store that supports high performance read-only and write-only distributed transactions. ECC demonstrates that concurrent serializable distributed transactions can be processed in parallel with low overhead even under high contention. With ECC, a new atomic commitment protocol is developed that only requires amortized one round trip for a distributed write-only transaction to commit in the absence of failures. Second, a novel paradigm of serializable distributed transaction processing is developed to extend ECC with read-write transaction processing support. This paradigm uses a newly proposed database operator, functors, which is a placeholder for the value of a key, which can be computed asynchronously in parallel with other functor computations of the same or other transactions. Functor-enabled ECC achieves more fine-grained concurrency control than transaction level concurrency control, and it never aborts transactions due to read-write or write-write conflicts but allows transactions to fail due to logic errors or constraint violations while guaranteeing serializability. Lastly, this thesis explores consistency in the eventually consistent system, Apache Cassandra, for an investigation of the consistency violation, referred to as "consistency spikes". This investigation shows that the consistency spikes exhibited by Cassandra are strongly correlated with garbage collection, particularly the "stop-the-world" phase in the Java virtual machine. Thus, delaying read operations arti cially at servers immediately after a garbage collection pause can virtually eliminate these spikes. All together, these techniques allow distributed databases to provide scalable and consistent storage service