Die im Rahmen von Forschungsprojekten gewonnenen Forschungsdaten sind eine wesentliche Grundlage der wissenschaftlichen Arbeit. In nahezu allen Fachdisziplinen gewinnen sie immer mehr an Bedeutung. Die Nachvollziehbarkeit und die Qualität wissenschaftlicher Forschung wird durch die Dokumentation, die langfristige Sicherung und Bereitstellung der Forschungsdaten gefördert. Außerdem stellt die Publikation und die langfristige Sicherung von Forschungsdaten bei der DFG, EU und beim BMBF in vielen Fällen eine Voraussetzung für die Förderung von Forschungsvorhaben dar. Was genau sind Forschungsdaten? Was versteht man unter dem FAIR-Prinzip? Offene Forschungsdaten: Welche Vorteile bringen sie für die Forschenden? Wo kann man Forschungsdaten archivieren und veröffentlichen? Welche Services für Forschende der TU Bergakademie Freiberg zum Thema Forschungsdaten bieten die UB Freiberg und die Kontaktstelle Forschungsdaten der SLUB/ZiH Dresden? Diese und weitere Fragen beantworten Manuela Queitsch, Koordinatorin für Forschungsdaten an der SLUB Dresden und Teammitglied an der Kontaktstelle Forschungsdaten in Dresden und Dr. Dana Kuhnert, Fachreferentin für Wirtschafts- und Rechtswissenschaften der UB Bergakademie Freiberg.

In many ways the current publishing system in rhetoric and composition, which centers on the peer-reviewed journal, undermines core values we hold for ideal scholarly communication. These values include collaboration, dialogue, participation, and public engagement. Though the current system's methods of preserving, distributing, and maintaining quality control of scholarly work contradict our values, technological developments have made possible alternative publishing models that could better uphold our values. Developing a preprint archive where scholars develop and share ideas before submitting them for publication in traditional peer-reviewed journals would bring our publishing process closer to our ideals.

Artifact-based research provides a mechanism whereby researchers may study the creation of software yet avoid many of the difficulties of direct observation and experimentation. Open source software forges are of great value to the software researcher, because they expose many of the artifacts of software development. However, many challenges affect the quality of artifact-based studies, especially those studies examining software evolution. This thesis addresses one of these threats: the presence of very large commits, which we refer to as "Cliff Walls." Cliff walls are a threat to studies of software evolution because they do not appear to represent incremental development. In this thesis we demonstrate the existence of cliff walls in open source software projects and discuss the threats they present. We also seek to identify key causes of these monolithic commits, and begin to explore ways that researchers can mitigate the threats of cliff walls.

Electricity generation at nuclear power plants produces a large amount of high-level radioactive waste (HLW) every year, which has long-term detrimental effects on humans and the environment. Other applications of nuclear technology (e.g., medicine, research, nuclear weapons, industry) also produce radioactive waste (e.g., low-level radioactive waste, LLW, Intermediate-level waste, ILW). The potential of deep geological repositories (DGRs) as an option for disposal of radioactive waste (HLW, ILW, LLW) has been examined in several countries, including Bulgaria, Canada, China, Finland, France, Germany, India, Japan, Russia, Spain, Sweden, Switzerland, Ukraine and the United Kingdom and are still under discussion. In Ontario, Canada, DGRs with a multi-barrier system comprised of a sedimentary rock formation (i.e., a natural barrier) and an engineered barrier system (EBS) are currently under consideration. An EBS consists of various components, such as waste containers, buffer, backfill, and tunnel sealing materials, intended to prevent the release of radionuclides. Several engineered barrier materials, including a mixture of bentonite and sand, are currently being considered for use in DGRs for nuclear waste in Ontario. Bentonite has some advantageous physical and chemical properties, such as low permeability, high plasticity, and high swelling potential, which provide it with a good sealing ability and thus make it an effective barrier. However, interaction between the compacted bentonite–sand mixture and underground water chemistry fluids (chemical factor) in the DGR could significantly alter the favourable properties of bentonite (e.g., swelling potential), thus influencing its performance when used in an EBS and eventually jeopardizing the overall safety of DGRs. In addition, other parameters, such as the clay content, initial dry density and moisture content of the compacted barrier (physical factors), as well as the presence of salts in groundwater may affect the physical and physiochemical properties of barrier materials. Moreover, during the lifetime of a DGR for used spent fuel, the bentonite–based barrier material will not only be exposed to a broad range of groundwaters with different chemical compositions, but also to high temperatures (heat generated by the nuclear wastes) (thermal factor). Thus, the interaction between the compacted bentonite–sand mixture, the surrounding groundwater and the heat from the nuclear waste material could jeopardize the favourable properties of the bentonite-based (bentonite-sand) barrier material. Properties of a bentonite-sand barrier is an important characteristic to study while designing and constructing an EBS for a DGR. Thus, to understand and assess the operations of DGRs in Ontario, comprehensive studies must be performed on engineering properties like swelling behaviour, permeability, and thermal conductivity. The goal of this research study is to experimentally investigate the physical, chemical and thermal factors that influencing the engineering properties of a barrier material made up of bentonite-sand composite used in DGRs for nuclear waste in Ontario. Compacted samples are subjected to one-dimensional free swell test to understand the swelling behaviour of the material. Hydraulic conductivity was investigated using a flexible wall permeability test. Thermal conductivity and diffusivity were tested using Decangon KD2 Pro with TR-1 and and KS-1 sensors. The specimens contain different bentonite–sand mixture ratios (20:80, 30:70, 50:50, and 70:30 dry mass), and they are tested under conditions with differing bentonite content, dry density, groundwater chemistry, and temperature. Additional tests were conducted to investigate the microstructure of the specimens. These tests include X-ray diffraction (XRD) analysis, mercury intrusion porosimetry (MIP), and thermogravimetric analyses (TG/DTG). The results reveal that the time and strain required to achieve maximum swelling of compacted bentonite–sand specimens increase with the increase of initial dry density. The simulated saline solutions of Guelph and Trenton groundwater are found to suppress the swelling of the bentonite–sand specimens. This in turn leads to the increase of hydraulic conductivity and decrease of thermal properties of the barrier material. However, the impact of the salinity is significantly reduced by increasing the dry densities and sand content of the compacted material. Moreover, the coupled effect of salinity and temperature decreases the swelling potential of the bentonite-sand mixture. Also, some transformation of Na-montmorillonite into Ca-Montmorillonite was observed. The results also indicate that some montmorillonites might have been transformed into illites, thereby further decreasing the swelling potential of the bentonite-based barrier.

[pt] Contexto: Várias mudanças de código aplicadas ao evoluir funcionalidades visam melhorar atributos internos de qualidade como coesão. Tais mudanças são as refatorações. Refatorações não dirigidas podem piorar, e não melhorar, atributos internos. Porém, o saber atual é insuficiente para gerir atributos internos durante a evolução do sistema. Objetivo: Nosso primeiro objetivo é entender como refatorações afetam atributos internos ao evoluir sistemas, mitigando limitações de escopo de estudos anteriores. Nosso segundo objetivo é atender uma carência por evidência quantitativa sobre como gerir atributos internos críticos via refatorações ao evoluir sistemas. Um atributo interno é crítico se sua medição assume valores anômalos. Baixa coesão é um exemplo de atributo crítico. Método: O primeiro estudo estende uma avaliação quantitativa da relação entre refatorações e cinco atributos internos: acoplamento, coesão, complexidade, herança e tamanho. Incluímos novas análises e resolvemos ameaças à validade da literatura. O segundo estudo contém estudos de caso qualitativos baseados em grupo focal. Em dois casos industriais, promovemos discussões sobre o quanto (e por que) atributos críticos são relevante ao evoluir funcionalidades. Por fim, cruzamos os achados dos dois estudos para discutir como gerir atributos críticos via refatoração ao evoluir funcionalidades. Resultados: Aproximadamente 64 por cento das refatorações melhoram ou não afetam os atributos internos. Desenvolvedores parecem refatorar até melhorar os atributos mais relevantes, ignorando outros atributos internos possivelmente críticos. Baixa coesão e alta complexidade são percebidos como relevantes e tornam mais difícil evoluir funcionalidades. Alto acoplamento, herança larga e tamanho largo são percebidos como irrelevantes ao implementar funcionalidades especialmente complexas, por exemplo. Ao cruzar dados entre estudos, discutimos como refatorações podem melhorar atributos internos, inclusive atributos críticos. Conclusões: Os achados dos nossos estudos podem apoiar a gestão de atributos críticos relevantes aos desenvolvedores, mas também preservar outros atributos que podem se tornar críticos. / [en] Context: Several software changes applied while evolving software features aim at improving internal quality attributes, e.g. cohesion. These changes are the refactorings. Non-assisted refactorings might worsen, rather than improve, internal attributes. However, current knowledge is insufficient for managing internal attributes during software evolution. Objective: Our first objective is assessing how refactorings affect internal attributes during software evolution by filling gaps of past work on study scope. Our second objective is filling gaps of qualitative evidence on how to manage critical internal attributes via refactorings while evolving features. An internal attribute is critical when its measurement has anomalous values. Low cohesion is an example of critical attribute. Method: Our first study extends a large quantitative assessment of the relationship between refactorings and five internal attributes: cohesion, complexity, coupling, inheritance, and size. We include a more detailed statistical analysis and address major threats to validity of past work. Our second study is a qualitative case study based on focus group. We selected two industry cases to promote discussions on how much (and why) critical attributes are relevant while evolving features. Finally, we crossed the findings from both conducted studies aimed at discussing how critical attributes can be addressed via refactoring when evolving features. Results: About 64 per cent of refactorings either improve or keep the internal attributes unaffected. Developers seem to perform refactorings until the most relevant internal attributes are improved, thereby neglecting other internal attributes that may be critical. Low cohesion and high complexity are perceived as relevant because they often make evolving features harder than usual. High coupling, large inheritance, and large size are perceived as irrelevant when developers implement especially complex features. By crossing the findings from both studies, we discuss how refactorings can improve internal attributes, especially the critical ones. Conclusions: The findings of our studies can support managing critical attributes that developers typically find relevant, while preserving other attributes that may become critical.

Yes / Passwords are the most popular and constitute the first line of defence in computer-based security systems; despite the existence of more attack-resistant authentication schemes. In order to enhance password security, it is imperative to strike a balance between having enough rules to maintain good security and not having too many rules that would compel users to take evasive actions which would, in turn, compromise security. It is noted that the human factor is the most critical element in the security system for at least three possible reasons; it is the weakest link, the only factor that exercises initiatives, as well as the factor that transcends all the other elements of the entire system. This illustrates the significance of social engineering in security designs, and the fact that security is indeed a function of both technology and human factors; bearing in mind the fact that there can be no technical hacking in vacuum. This paper examines the current divergence among security engineers as regards the rules governing best practices in the use of passwords: should they be written down or memorized; changed frequently or remain permanent? It also attempts to elucidate the facts surrounding some of the myths associated with computer security. This paper posits that destitution of requisite balance between the factors of technology and factors of humanity is responsible for the purgatory posture of password security related problems. It is thus recommended that, in the handling of password security issues, human factors should be given priority over technological factors. The paper proposes the use of the (k, n)-Threshold Scheme, such as the Shamir’s secret-sharing scheme, to enhance the security of the password repository. This presupposes an inclination towards writing down the password: after all, Diamond, Platinum, Gold and Silver are not memorised; they are stored. / Petroleum Technology Development Fund

No description available.

No / The Versatile and Ubiquitous Secret Sharing System, a cloud data repository secure access and a web based authentication scheme. It is designed to implement the sharing, distribution and reconstruction of sensitive secret data that could compromise the functioning of an organisation, if leaked to unauthorised persons. This is carried out in a secure web environment, globally. It is a threshold secret sharing scheme, designed to extend the human trust security perimeter. The system could be adapted to serve as a cloud data repository and secure data communication scheme. A secret sharing scheme is a method by which a dealer distributes shares of a secret data to trustees, such that only authorised subsets of the trustees can reconstruct the secret. This paper gives a brief summary of the layout and functions of a 15-page secure server-based website prototype; the main focus of a PhD research effort titled ‘Cryptography and Computer Communications Security: Extending the Human Security Perimeter through a Web of Trust’. The prototype, which has been successfully tested, has globalised the distribution and reconstruction processes. / Petroleum Technology Development Fund

The objective of this project was to study the influence of increased salinities on interaction processes in the system radionuclide – organics – clay – aquifer. For this purpose, complexation, redox, sorption, and diffusion studies were performed under variation of the ionic strength (up to 4 mol/kg) and the background electrolyte. The U(VI) complexation by propionate was studied in dependence on ionic strength (up to 4 mol/kg NaClO4) by TRLFS, ATR FT-IR spectroscopy, and DFT calculations. An influence of ionic strength on stability constants was detected, depending on the charge of the respective complexes. The conditional stability constants, determined for 1:1, 1:2, and 1:3 complexes at specific ionic strengths, were extrapolated to zero ionic strength. The interaction of the bacteria Sporomusa sp. MT-2.99 and Paenibacillus sp. MT-2.2 cells, isolated from Opalinus Clay, with Pu was studied. The experiments can be divided into such without an electron donor where biosorption is favored and such with addition of Na-pyruvate as an electron donor stimulating also bioreduction processes. Moreover, experiments were performed to study the interactions of the halophilic archaeon Halobacterium noricense DSM-15987 with U(VI), Eu(III), and Cm(III) in 3 M NaCl solutions. Research for improving process understanding with respect to the mobility of multivalent metals in systems containing humic matter was focused on the reversibility of elementary processes and on their interaction. Kinetic stabilization processes in the dynamics of humate complexation equilibria were quantified in isotope exchange studies. The influence of high salinity on the mobilizing potential of humic-like clay organics was systematically investigated and was described by modeling. The sorption of Tc(VII)/Tc(IV) onto the iron(II)-containing minerals magnetite and siderite was studied by means of batch sorption experiments, ATR FT-IR and X-ray absorption spectroscopy. The strong Tc retention at these minerals could be attributed to surface-mediated reduction of Tc(VII) to Tc(IV). An influence of ionic strength was not observed. The influence of ionic strength (up to 3 mol/kg) and background electrolyte (NaCl, CaCl2, MgCl2) on U(VI) sorption onto montmorillonite was studied. The U(VI) sorption is influenced by the background electrolyte, the influence of ionic strength is small. Surface complexation modeling was performed applying the 2SPNE SC/CE model. Surface complexation constants were determined for the NaCl and CaCl2 system and were extrapolated to zero ionic strength. Surface complexation in mixed electrolytes can be modeled applying surface complexation constants derived for pure electrolytes. The influence of citrate on U(VI) diffusion in Opalinus Clay was studied using Opalinus Clay pore water as background electrolyte. The diffusion parameter values obtained for the HTO through-diffusion and the U(VI) in-diffusion in the absence of citric acid were in agreement with literature data. In the presence of citric acid, U(VI) diffusion was significantly retarded, which was attributed to a change in speciation, probably U(VI) was reduced to U(IV). Larger-scale heterogeneous material effects on diffusive transport were investigated with PET. Diffusion parameters were derived by optimum fit of a FEM-model to the measurement. These parameters are in accordance with the results from 1D-through-diffusion experiments. Deviations from the simple transversal-isotropic behavior, which are identified as residuals from the model, are indications for heterogeneous transport on the mm-scale. PET measurements were also conducted in order to display the improvement of the EDZ with waterglass injections. These experiments enable to draw conclusions on the complex reactive transport process and thus an estimation of the achieved improvement of the barrier function. The image reconstruction procedure was largely improved, mainly with the aid of Monte-Carlo simulations, and now allows quantitative analysis and error estimation.

Nutzungsdaten von elektronischen wissenschaftlichen Publikationen und insbesondere die Anzahl ihrer Downloads rücken mit der Verbreitung des Internets zunehmend in den Blickpunkt des Interesses der Autoren, der Herausgeber, der technischen Anbieter und der Nutzer solcher Publikationen. Downloadzahlen von Publikationen, welche durch Auswertung der Protokolle der IT-Systeme der Anbieter ermittelt werden, sind solche Nutzungsdaten. Die Erhebung erfolgt durch Filterung aller stattgefundenen Zugriffe und Summierung über eine definierte Zeiteinheit. Downloadzahlen sind Gegenstand wissenschaftlicher Untersuchungen, in welchen das Konzept des Citation Impact auf die Nutzungshäufigkeit einer Publikation übertragen und der sogenannte Download Impact gebil-det wird. Besonderes Augenmerk wird dem Zusammenhang von Citation Impact und Download Impact gewidmet. Handelt es sich um Open-Access-Publikationen, muss davon ausgegangen werden, dass in den Downloadzahlen nicht nur menschliche, sondern auch maschinelle Zugriffe erfasst wurden, da eine sichere Unterscheidung unmöglich ist. Das hat zur Folge, dass die gewonnenen Daten für die einzelnen Publikationen unzuverlässig sind und starken Schwankungen unterliegen. Trotzdem enthalten sie wertvolle Informationen, welche mit Hilfe der Mathematischen Statistik nutzbar gemacht werden können. Mit nichtparametrischen Methoden ausgewertet, geben Downloadzahlen Auskunft über die Sichtbarkeit von elektronischen Publikationen im Internet. Diese Methoden bilden den Kern von NoRA (Non-parametric Repository Analysis), mit deren Hilfe die Betreiber von Open Access Repositories die Downloadzahlen ihrer elektronischen Publikationen auswerten können, um Sichtbarkeitsdefizite zu ermitteln und zu beheben und so die Qualität ihres Online-Angebotes zu erhöhen. Die Analysemethode NoRA wurde auf die Daten von vier universitären Institutional Repositories erfolgreich angewendet. Es konnten jeweils Gruppen von Publikationen identifiziert werden, die sich hinsichtlich ihrer Nutzung signifikant unterscheiden. Die Parallelen in den Ergebnissen weisen auf Einflussfaktoren für die Nutzungsdaten hin, welche in der gegenwärtigen Diskussion bisher keine Berücksichtigung finden. Hier erschließen sich weitere Anwendungsfelder für NoRA. Gleichzeitig geben die Ergebnisse Anlass, den Informationsgehalt von Downloadzahlen für die einzelne Publikation kritisch zu hinterfragen. / With the spread of internet usage over the past decades, access characteristics of electronic scientific publica-tions, especially the number of document downloads, are of increasing interest to the authors, publishers, technical providers and users of such publications. These download data of publications are usually obtained from the protocols of the IT systems of the provider. A data set is then created by filtering all accesses and subsequent summarizing over a certain time unit. Download data are the subject of scientific investigations, in which the concept of the Citation Impact is applied to the rate of use of a publication and the so-called Download Impact is formed. Special attention is paid to the relation between Citation Impact and Download Impact. In the case of Open Access publications, two types of access need to be distinguished. Human access and machine access are both captured and a reliable distinction is not possible yet. As a result, the data obtained for single publications are unreliable and subject to strong fluctuations. Nevertheless, they contain valuable information that can be made useful with the help of mathematical statistics. Analyzed with nonparametric methods, download data give information about the visibility of electronic publications on the Internet. These methods form the core of NoRA (Non-parametric Repository Analysis). With the help of NoRA, the operators of Open Access Repositories are able to analyze the download data of their electronic publications, to identify and correct deficiencies of visibility and to increase the quality of their online platform. The analytical method NoRA was successfully applied to data from Institutional Repositories of four universities. In each case, groups of publications were identified that differed significantly in their usage. Similarities in the results reveal factors that influence the usage data, which have not been taken into account previously. The presented results imply further applications of NoRA but also raise doubts about the value of download data of single publications.