431 research outputs found
The design of a defence mechanism to mitigate the spectrum sensing data falsification attack in cognitive radio ad hoc networks
No full textThesis ( M.Sc. ( Computer Science)) -- University of Limpopo, 2018Dynamic spectrum access enabled by cognitive radio networks is envisioned to address the problems of the ever-increasing wireless technology. This innovative technology increases spectrum utility by allowing unlicensed devices to utilise the unused spectrum band of licenced devices opportunistically. The unlicensed devices referred to as secondary users (SUs) constantly sense the spectrum band to avoid interfering with the transmission of the licenced devices known as primary users (PUs).Due to some environmental challenges that can interfere with effective spectrum sensing, the SUs have to cooperate in sensing the spectrum band. However, cooperative spectrum sensing is susceptible to the spectrum sensing data falsification (SSDF) attack where selfish radios falsify the spectrum reports. Hence, there is a need to design a defence scheme that will defend the SSDF attack and guaranty correct final transmission decision.
In this study, we proposed the integration of the reputation based system and the qout-of-m rule scheme to defend against the SSDF attack. The reputation-based system was used to determine the trustworthiness of the SUs. The q-out-of-m rule scheme where m sensing reports were selected from the ones with good reputation and q was the final decision, which was used to isolate the entire malicious nodes and make the correct final transmission decision. The proposed scheme was implemented in a Cognitive Radio Ad Hoc Network (CRAHN) where the services of a data fusion centre (FC) were not required. The SUs conducted their own data fusion and made their own final transmission decision based on their sensing reports and the sensing reports of their neighbouring nodes. Matlab was used to implement and simulate the proposed scheme. We compared our proposed scheme with the multifusion based distributed spectrum sensing and density based system schemes. Metrics used were the success probability, missed detection probability and false alarm probability. The proposed scheme performed better compared to the other schemes in all the metrics.CSIR,
NRF and,
University of Limpopo research offic
THE INFLUENCE OF FAMILY OWNERSHIP ON M&AS AND INNOVATION
No full textI draw from the concept of mixed gambles to investigate the socioemotional wealth trade-offs associated with high risk strategic decisions such as firm acquisition decisions of family firms. We contrast the predictions from mixed gambles with those of the commonly used behavioural agency model (BAM). Our empirical results for a panel data set of large U.S. firms support the mixed gambles predictions and reject those derived from BAM. They reveal that family firms are more likely to engage in horizontal acquisitions than non-family firms and that the engagement of family firms in horizontal acquisitions is even higher when they are in a gain frame
Managing Corporate Social Responsibility with Management Control Systems
No full textPurpose- This study aims to explore how management control systems are used to manage their corporate social responsibility strategies in organizations. This paper dives into how sustainability managers use existing controls in planning, executing, measuring, and reporting on their CSR. The challenges they face in implementing their CSR strategies with these control systems are also covered. Methodology- The research was conducted using a qualitative research approach and a multiple case study strategy. The multiple case study involved three companies within a CSR network in Sweden. Secondary data from sustainability reports, internal financial control (IFC) reports were used together with seven semi-structured interviews. Findings- Control systems monitor influence and steer the employee's behavior and actions towards achieving organizational goals. The thesis provides practical insights into how sustainability managers from the studied companies use management control systems. The findings indicate that companies use similar clusters of management controls in planning, executing, measuring and reporting on their corporate social responsibility. However, there are differences in how the same management controls are used. The author identified a different type of control which is mostly not included in discussing when discussing MCS
Digital Elevation Model Data from: Measuring Erosional and Depositional Patterns Across Comet 67P's Imhotep Region
No full textRecommended citation for this dataset:
Abhinav Jindal, Samuel Birch, Alexander Hayes, Fiona P. Özyurt, Adam Issah, Megan Barrington, Jason Soderblom, Randolph Kirk, Raphael Marschall, Jean-Baptiste Vincent. (2023) Digital Elevation Model Data from: Measuring Erosional and Depositional Patterns Across Comet 67P's Imhotep Region. [dataset] Cornell University eCommons Repository. https://doi.org/10.7298/qgyq-ym43These files contain the Digital Elevation Model (DEM) data for the results reported in Jindal et al. Measuring Erosional and Depositional Patterns Across Comet 67P's Imhotep Region. In Jindal et al. we found: Comet 67P/Churyumov-Gerasimenko displays a pronounced hemispherical dichotomy in surface morphology where the southern hemisphere exhibits more erosional features than the northern hemisphere due to receiving much greater solar radiation. Consequently, it is generally assumed that particles are ejected from the southern hemisphere through sublimation and a significant fraction eventually descends as airfall, covering the northern terrains. To investigate this south-to-north material transfer during the comet's perihelion passage, we use photoclinometry to measure material redistribution within its most extensive smooth terrain deposit around the Imhotep region. However, our findings do not align with this expected trend. Instead, we show that local-scale processes substantially impact the erosion and accumulation of material, with one area experiencing net erosion while another nearby region, just a few dozen meters away, sees sediment buildup. Our analysis underscores the complex interplay of processes shaping Comet 67P's surface, and likely comets more generally.This research was supported by the Rosetta Data Analysis Program (80NSSC19K1307) and the Heising-Simons Foundation (51 Pegasi b Fellowship to S.P.D.B)
The Correlation between Aspect and Transitivity Alternation in Dagbani
No full textThis paper attempts to describe and analyze the relation between aspect and transitivity in Dagbani, a Gur language spoken in the Northern Region of Ghana by the Dagbamba. The author does this by focusing on the fact that there are different (perfective and imperfective) aspectual markers that correlate with the presence or absence of NP objects or adjunct phrases, such as adverbs. I conclude that pronouncing any syntactic element after a Dagbani verbal phrase or otherwise is determined by the aspectual suffixes of that verbal phrase.In an attempt to find explanations to this transitivity alternations, I make two hypothesises; the incorporated pronouns hypothesis and the focus hypothesis. None of these however, seems to adequately address the problem and I leave the working out of this to future research. It is shown that the correlation between aspect and transitivity in Dagbani sounds (at least superficially), very similar to the so-called “conjoint/disjoint” or “short/long” verb phenomenon that is found in a number of Bantu languages
Improving employee performance through quality improvement initiatives:DMAIC analysis of Wartsila Zambia
No full textOrganizations in recent times have experienced a period of massive change in their ways of operation due to the trend of increasing competition both at the local and international level. To succeed in the competing markets of today means that an organization should have good quality performance and quality improvement systems in place. Companies are beginning to realize that employee involvement is critical to quality performance and quality improvement making them essential to the total quality management strategy. This research focuses on investigating the main causes of the employee performance problems at the operations department of Wartsila Zambia using DMAIC analysis for quality improvement.
The study involved the use of SIX SIGMA to conduct a quality and continuous improvement assessment by assessing people, process, equipment, environment and management processes that contribute to the causes of slow progress of employees’ performance. The key areas under investigation were categorized into five sections to identify which aspect needs to be improved in order to ensure an increase in employee and organizational performance.
Primary data for the study were collected through a survey by distributing questionnaires to the employees working at the operations department of Wartsila Zambia. Secondary data from the company’s internal documentation- performance charts and reports, meeting minutes and company profile document were utilized to describe the research environment, case company operations and other background data for the DMAIC analysis. Questionnaires were designed based on previous literature, problems identified in root cause analysis and brainstorming. Results from the questionnaire were analyzed, the implication of the responses from the study were explained and an overview of the areas which needs more attention were addressed based on the results from the study. The results were prioritized according to the mean score of responses and the most important findings were labelled high under each category.
The DMAIC analysis results indicate that there are several issues related to people, work process, machine and equipment, environment and managements at the target company. It also provided a platform for the improvement, monitoring and sustaining suggested improvements that leads to better performance. This study proposed that quality and performance improvement team needs to be put in place to monitor and sustain improvements. It also proposed that management should invest in the use of people and process-related dashboards to measure performance as an essential element in creating a SIX SIGMA culture of continuous improvement.
Further research should be carried to find out how successful this improvement project has been for the case company. Also, studies can be done to find the strength of relationships between continuous improvement initiatives like SIX SIGMA and employee performance as relationship with process optimization
HOW EFFECTIVE HAS THE GHANA NATIONAL HEALTH INSURANCE SCHEME (NHIS) BEEN IN IMPROVING HEALTHCARE ACCESS FOR THE ECONOMICALLY VULNERABLE?
No full textBackgroundGhana’s National Health Insurance Scheme (NHIS) was designed to provide universal health coverage (UHC), healthcare access, and financial risk protection against catastrophic episodes of illness and accident to all Ghanian citizens. It has yet to achieve UHC.SignificanceAlthough significant improvements have been made, the system is still challenged by poor enrollment, healthcare access, quality of care, and stakeholder involvement and lacks clear policies on how to improve the scheme. Average national enrollment is 54%. The economically vulnerable remain the least likely to be enrolled, which results in healthcare inequity. Developing effective strategies for improving the scheme is critical for addressing healthcare inequities and achieving UHC.Research QuestionThe primary research question asked how effectively the NHIS has improved healthcare access for the economically vulnerable (i.e., those living in poverty or employed in the informal sector). Effectiveness was defined as free access to prescriptions, clinic visits, and other healthcare needs.MethodsThe study used an explanatory mixed-method approach with quantitative data from the NHIS and qualitative data from interviews with NHIS officials, policymakers, and civil society representatives. These provided insights on the policies needed for improving healthcare access and the strategies that would help NHIS meet its goals.FindingsFrom 2018 to 2022, enrollment remained steady among workers in the informal sector (in the mid 30%), but the poor remained the least enrolled (generally 4%-9%). Income appears to affect who enrolls in the scheme, probably because of the cost of enrollment (i.e., processing fees and premiums). The qualitative analysis revealed the diverse challenges the scheme faced, including those in financial management, governance, leadership structure, and policy implementation.Plan for ChangeA proposed framework for a plan for change used the eight steps of the Kotter process for leading change. The NHIS will need a revised strategic vision that incorporates accountability as a transformational tool for long-term change and will need to leverage key stakeholders to develop partnerships that can remove barriers to the proper functioning of the NHIS and institute sustained change. Doctor of Public Healt
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