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Due to increased emissions of palladium nanoparticles in recent years, it is important to develop analytical techniques to characterize these particles. The synthesis of defined and stable particles plays a key role in this process, as there are not many materials commercially available yet which could act as reference materials. Polyvinylpyrrolidone- (PVP-) stabilized palladium nanoparticles were synthesized through the reduction of palladium chloride by tetraethylene glycol (TEG) in the presence of KOH. Four different methods were used for particle size analysis of the palladium nanoparticles. Palladium suspensions were analyzed by scanning electron microscopy (SEM), small angle X-ray scattering (SAXS), single-particle ICP-MS (SP-ICP-MS), and X-ray diffraction (XRD). Secondary particles between 30 nm and 130 nm were detected in great compliance with SAXS and SP-ICP-MS. SEM analysis showed that the small particulates tend to form agglomerates.
The antiradical and antimicrobial activity of lignin and lignin-based films are both of great interest for applications such as food packaging additives. The polyphenolic structure of lignin in addition to the presence of O-containing functional groups is potentially responsible for these activities. This study used DPPH assays to discuss the antiradical activity of HPMC/lignin and HPMC/lignin/chitosan films. The scavenging activity (SA) of both binary (HPMC/lignin) and ternary (HPMC/lignin/chitosan) systems was affected by the percentage of the added lignin: the 5% addition showed the highest activity and the 30% addition had the lowest. Both scavenging activity and antimicrobial activity are dependent on the biomass source showing the following trend: organosolv of softwood > kraft of softwood > organosolv of grass. Testing the antimicrobial activities of lignins and lignin-containing films showed high antimicrobial activities against Gram-positive and Gram-negative bacteria at 35 °C and at low temperatures (0-7 °C). Purification of kraft lignin has a negative effect on the antimicrobial activity while storage has positive effect. The lignin release in the produced films affected the activity positively and the chitosan addition enhances the activity even more for both Gram-positive and Gram-negative bacteria. Testing the films against spoilage bacteria that grow at low temperatures revealed the activity of the 30% addition on HPMC/L1 film against both B. thermosphacta and P. fluorescens while L5 was active only against B. thermosphacta. In HPMC/lignin/chitosan films, the 5% addition exhibited activity against both B. thermosphacta and P. fluorescens.
In the field of domestic service robots, recovery from faults is crucial to promote user acceptance. In this context, this work focuses on some specific faults which arise from the interaction of a robot with its real world environment. Even a well-modelled robot may fail to perform its tasks successfully due to external faults which occur because of an infinite number of unforeseeable and unmodelled situations. Through investigating the most frequent failures in typical scenarios which have been observed in real-world demonstrations and competitions using the autonomous service robots Care-O-Bot III and youBot, we identified four different fault classes caused by disturbances, imperfect perception, inadequate planning operator or chaining of action sequences. This thesis then presents two approaches to handle external faults caused by insufficient knowledge about the preconditions of the planning operator. The first approach presents reasoning on detected external faults using knowledge about naive physics. The naive physics knowledge is represented by the physical properties of objects which are formalized in a logical framework. The proposed approach applies a qualitative version of physical laws to these properties in order to reason. By interpreting the reasoning results the robot identifies the information about the situations which can cause the fault. Applying this approach to simple manipulation tasks like picking and placing objects show that naive physics holds great possibilities for reasoning on unknown external faults in robotics. The second approach includes missing knowledge about the execution of an action through learning by experimentation. Firstly, it investigates such representation of execution specific knowledge that can be learned for one particular situation and reused for situations which deviate from the original. The combination of symbolic and geometric models allows us to represent action execution knowledge effectively. This representation is called action execution model (AEM) here. The approach provides a learning strategy which uses a physical simulation for generating the training data to learn both symbolic and geometric aspects of the model. The experimental analysis, performed on two physical robots, shows that AEM can reliably describe execution specific knowledge and thereby serving as a potential model for avoiding the occurrence of external faults.
Interactive Object Detection
(2019)
The success of state-of-the-art object detection methods depend heavily on the availability of a large amount of annotated image data. The raw image data available from various sources are abundant but non-annotated. Annotating image data is often costly, time-consuming or needs expert help. In this work, a new paradigm of learning called Active Learning is explored which uses user interaction to obtain annotations for a subset of the dataset. The goal of active learning is to achieve superior object detection performance with images that are annotated on demand. To realize active learning method, the trade-off between the effort to annotate (annotation cost) unlabeled data and the performance of object detection model is minimised.
Random Forests based method called Hough Forest is chosen as the object detection model and the annotation cost is calculated as the predicted false positive and false negative rate. The framework is successfully evaluated on two Computer Vision benchmark and two Carl Zeiss custom datasets. Also, an evaluation of RGB, HoG and Deep features for the task is presented.
Experimental results show that using Deep features with Hough Forest achieves the maximum performance. By employing Active Learning, it is demonstrated that performance comparable to the fully supervised setting can be achieved by annotating just 2.5% of the images. To this end, an annotation tool is developed for user interaction during Active Learning.
Destination Development for Entrepreneurial Tourism in Lake Bosomtwe and Kintampo falls (Ghana)
(2019)
The tourism industry is one of the world’s largest industries (direct, indirect and induced Africa has the potential with its cultural and natural resources to outpace other regions in attracting valuable tourism dollars. The main aim of the study is to improve visitor experience on the two tourist sites. To do this it is necessary to explore the elements and success factors of Tourism Destination Development and using these as a checklist to identify the strength and weaknesses of the selected Tourist Destinations in Ghana West Africa. The rationale behind the study is to outline the crucial Destination Management (DM) criteria of all aspect that contribute to boost ultimate visitor experience, articulating the roles of the different stakeholders and identifying clear actions for effective Tourism Development in Ghana. The interview technique was employed to collect data from staff and management of the selected destinations. Data was analyzed for themes related to elements, success factors and challenges of destination development and new ideas for development was also solicited. It was revealed that some of the elements that feature for tourists’ attraction are good hotels, high hygiene and sanitation standards, good food and activities of amusements. Competency gaps identified suggest collaboration with academia to secure a high level of knowledge through research in this present world of dynamism. Some of the critical success factors found are: systematic provision of cultural events, advance knowledge of agents and tour operators and quality leisure and recreation. It is recommended that product and service development should be a joint idea of all stakeholders. The research team therefore, have plans underway to proceed on the second phase of the project: that is to gather resources together to make lake Bosomtwe and Kintampo falls sites attractive to tourists.
Dieses Buch enthält die wichtigsten statistischen Instrumente und Formeln, die Sie in den Wirtschafts- und Sozialwissenschaften benötigen. Besonderer Wert wird darauf gelegt, dass Sie jede einzelne Formel verstehen und anwenden können. Zu jeder Formel finden Sie deshalb eine Erläuterung der Anwendungsfälle, eine detaillierte Beschreibung der einzelnen Symbole in der Formel und der notwendigen Rechenschritte, ein Anwendungsbeispiel mit vollständigem und erläutertem Rechenweg sowie eine Interpretation des jeweiligen Ergebnisses.
Datenmodellierung
(2019)
Andreas Gadatsch schließt mit dem vorliegenden essential eine Lücke in einführenden Werken zur Datenmodellierung. Diese Modelle gehören zum Basiswissen in Einführungsveranstaltungen zur Wirtschaftsinformatik für Betriebswirte. Die Literatur dazu ist für diese Zielgruppe häufig zu speziell, da sie sich eher an Informatiker richtet. Der Autor bietet hier nun einen kompakten Einstieg in die klassische CHEN-Notation anhand eines durchgängigen Fallbeispiels, auf der viele neue Modellierungsansätze aufbauen. Die zweite Auflage enthält einige formale Korrekturen und Ergänzungen (z. B. Rekursive Relationen).
Bioinspired stem cell-based hard tissue engineering includes numerous aspects: The synthesis and fabrication of appropriate scaffold materials, their analytical characterization, and guided osteogenesis using the sustained release of osteoinducing and/or osteoconducting drugs for mesenchymal stem cell differentiation, growth, and proliferation. Here, the effect of silicon- and silicate-containing materials on osteogenesis at the molecular level has been a particular focus within the last decade. This review summarizes recently published scientific results, including material developments and analysis, with a special focus on silicon hybrid bone composites. First, the sources, bioavailability, and functions of silicon on various tissues are discussed. The second focus is on the effects of calcium-silicate biomineralization and corresponding analytical methods in investigating osteogenesis and bone formation. Finally, recent developments in the manufacturing of Si-containing scaffolds are discussed, including in vitro and in vivo studies, as well as recently filed patents that focus on the influence of silicon on hard tissue formation.
Kenya, like all other developing countries in the world, is faced with the task of working strategically towards the achievement of the Sustained Development Goals (SDGs) 2030. These goals whose due date of accomplishment coincides with those of the national development blueprint, namely, the Kenya Vision 2030, have become a major focus of attention in the country. Conferences, workshops, and seminars are organized throughout the country on regular bases by joint multiplicity of organizations to address modalities of ensuring a timely achievement of SDGs in the country. Universities either individually or jointly are working towards this same target. More specifically, there are great areas of concern or priority areas that the country is focusing on as a strategic focus towards the achievement of the Kenya Vision 2030 and SDGs 2030. These strategic areas of focus have been isolated and declared by the President of the Republic of Kenya, His Excellency Uhuru Kenyatta, as the country’s “big four priority areas”, namely, affordable housing, affordable health care, food security, and manufacturing as a grandiose effort towards achievement of the SDGs, Kenya Vision 2030 as well as job and wealth creation. Similarly, Mount Kenya University’s top management established the Graduate Enterprise Academy (GEA) in 2013 under the direct Patronage of the university’s Founder with the primary aim of assisting graduates to be job and wealth creators rather than being job seekers. So far, over twenty start-ups are running throughout the country under Graduate Enterprise Academy (GEA). Incidentally, although the Graduate Enterprise Academy’s diverse areas of focus extend beyond the President of Kenya’s “Big Four” to include ICT and creative arts, among others, there are justifiable cases to indicate that GEA’s activities are also in support of the national “Big Four” agenda. This paper gives an exposition of different start-ups under MKU’s Graduate Enterprise Academy and are show-cased as evidence of MKU’s support towards the achievement of the national “Big Four” agenda. The paper covers a part of an ongoing program through desk-top analyses of reports, with an objective of show-casing MKU’s contribution to the national agenda through the Graduate Enterprise Academy for possible scale - up.
This study sought to examine the relationship between the components of SMEs social capital and firm performance. Using the social capital theory and the resource-based view as the theoretical foundations and census, 1,532 SMEs were selected in the Accra Metropolis for the study. Empirical results from 717 SMEs, utilising the hierarchical linear regression model, revealed that owner/manger’s network relationships are beneficial to the firm depending on when the relationships are closed or opened. Moreover, the study found that social capital has a significant impact on the sales and market performance of small and medium-sized enterprises. The results also brought to the fore the fact that most social networks of SME entrepreneurs are family, friends and relatives, which most times can only be used for expressive purposes and not for instrumental gain. The practical implications of the results are also discussed.
The aim of the descriptive study is to gain an understanding of the perceived level of fairness in their experience of security screening relation to their satisfaction. The context of the study was a major aviation hub in East Africa. The target population was all departing international passengers. Primary data was collected using a self-administered questionnaire. The respondents were selected using convenience sampling of passengers who had just completed the final security check at the departure area of the airport. A total of 251 usable responses were collected from a target of 384 respondents giving a response rate of 65 percent.
The findings contribute to the existing body of knowledge on the relationship between the perceptions of fairness of security procedures and their influence on satisfaction. One way between groups analysis of variance (ANOVA) was conducted to test for statistical significance. A Cronbach’s alpha of 88.7 was computed demonstrating a high level of internal consistency of the survey instrument. The adequacy of security procedures, level of communication provided before and during the screening process, consistency and fairness were found to have a significant relationship to the level of satisfaction reported by passengers. The findings suggest that there are significant differences between groups’ perception of different elements security procedures.
The implications of the study are twofold. The study was cross sectional and indeed was impacted by significant changes in security procedures at the airport at the time of the study. A longitudinal survey may further mitigate the impact of the variances of responses and support a robust contribution to the development of a theoretical model of airport passenger satisfaction. Airport managers could use the results of this study as inputs to enhance the design of screening procedures in modern hubs to enhance the passenger experience to drive revenue growth.