This thesis consists of three main parts, starting with the use of improved nitridation processes to grow acceptable quality gate oxides on silicon carbide (SiC)[1]–[7], to the comprehensive investigation of basic electron-hole generation process in 4H SiC-based metal–oxide–semiconductor (MOS) capacitors [8], [9], and concluding with the experimental demonstration and analysis of nonvolatile characteristics of 4H SiC-based memory devices [10]–[15]. In the first part of the thesis, two improved versions of nitridation techniques have been introduced to alleviate oxide-growth rate and toxicity problems. Using a combination of nitridation and oxidation processes, a sandwich technique (nitridation–oxidation–nitridation) has been proposed and verified to solve the lengthy and expensive oxide-growing process in direct nitric oxide (NO) gas [1]. The nitrogen source from the toxic-NO gas has been replaced by using a nontoxic nitrous oxide (N2O) gas. The best combination of process parameters in this gas is oxide-growing temperature at 1300oC with 10% N2O [2], [3]. The quality of nitrided gate oxides obtained by this technique is lower than the sandwich technique [6], [13]. Using 4H SiC-based MOS with nitrided gate oxides grown by either of the abovementioned nitridation techniques, the fundamentals of electron-hole generation have been investigated using high-temperature capacitance–transient measurements. The contributions of carrier generation, occurring at room temperature, in the bulk and at the SiC–SiO2 interface are evaluated and compared using a newly developed method [8], [9]. The effective bulk-generation rates are approximately equal for both types of nitrided oxides, whereas the effective surface-generation rates have been shown to exhibit very strong dependencies on the methods of producing the nitrided gate oxide. Based on analysis, the prevailing generation component in a SiC-based MOS capacitor with nitrided gate oxide is at SiC–SiO2 interface located below the gate. Utilizing the understanding of electron-hole generation in SiC, the nonvolatile characteristics of memory device fabricated on SiC have been explored. The potential of developing a SiC-based one-transistor one-capacitor (1T/1C) nonvolatile-dynamic memory (NDM) has been analyzed using SiC-based MOS capacitors as storage elements or test structures. Three possible leakage mechanisms have been evaluated [10]–[16]: (1) leakage via MOS capacitor dielectric, (2) leakage due to electron-hole generation in a depleted MOS capacitor, and (3) junction leakage due to generation current occurred at a reverse-biased pn junction surrounding the drain region of a select metal–oxide– semiconductor field–effect–transistor (MOSFET). Among them, leakage through capacitor oxide remains an important factor that could affect the nonvolatile property in the proposed device, whereas others leakage mechanisms are insignificant. Based on the overall results, the potential of developing a SiC-based 1T/1C NDM is encouraging.

This thesis aims to expand our knowledge about Naturalistic Decision Making (NDM) in strategic decision-making. A case study of the Cuban missile crisis has been conducted. The purpose of the case study is to enhance knowledge about how NDM can be performed on a strategic level. The thesis aims to answer the questions how the crisis can be explained from a NDM-perspective, which decisions is likely to be made in a NDM-manner. In what way decision-makers can be said to be experts or experienced decision-makers and what we can learn from the Cuban missile crisis in respect to NDM. No earlier research has been identified that has performed this kind of case study. The main theory in this thesis is NDM and mainly the part of NDM that is called Recognition Primed Decision (RPD) by Klein. As a complement the so called STEP-procedure (Story, Test, Evaluate, Plan) by Cohen is used as an indicator alongside RPD. The result of the case study shows that many decisions during the Cuban missile crisis may have been performed in a naturalistic manner. This shows that decisions on the strategic level may be performed in a naturalistic manner with good results and indicates the importance of utilizing more than rational decision making in order to achieve fast and satisfying results. It is the author beliefs that decision making will be much improved by applying more NDM.

Decision making study has been the multi-disciplinary research involving operations researchers, management scientists, statisticians, mathematical psychologists and economists as well as others. This study aims to investigate the theory and methodology of decision making research and apply them to different contexts in real cases. The study has reviewed the literature of Multiple Criteria Decision Making (MCDM), Evidential Reasoning (ER) approach, Naturalistic Decision Making (NDM) movement, Social Judgment Theory (SJT), and Adaptive Toolbox (AT) program. On the basis of these literatures, two methods, Evidence-based Trade-Off (EBTO) and Judgment Analysis with Heuristic Modelling (JA-HM), have been proposed and developed to accomplish decision making problems under different conditions. In the EBTO method, we propose a novel framework to aid people s decision making under uncertainty and imprecise goal. Under the framework, the imprecise goal is objectively modelled through an analytical structure, and is independent of the task requirement; the task requirement is specified by the trade-off strategy among criteria of the analytical structure through an importance weighting process, and is subject to the requirement change of a particular decision making task; the evidence available, that could contribute to the evaluation of general performance of the decision alternatives, are formulated with belief structures which are capable of capturing various format of uncertainties that arise from the absence of data, incomplete information and subjective judgments. The EBTO method was further applied in a case study of Soldier system decision making. The application has demonstrated that EBTO, as a tool, is able to provide a holistic analysis regarding the requirements of Soldier missions, the physical conditions of Soldiers, and the capability of their equipment and weapon systems, which is critical in domain. By drawing the cross-disciplinary literature from NDM and AT, the JA-HM extended the traditional Judgment Analysis (JA) method, through a number of novel methodological procedures, to account for the unique features of decision making tasks under extreme time pressure and dynamic shifting situations. These novel methodological procedures include, the notion of decision point to deconstruct the dynamic shifting situations in a way that decision problem could be identified and formulated; the classification of routine and non-routine problems, and associated data alignment process to enable meaningful decision data analysis across different decision makers (DMs); the notion of composite cue to account for the DMs iterative process of information perception and comprehension in dynamic task environment; the application of computational models of heuristics to account for the time constraints and process dynamics of DMs decision making process; and the application of cross-validation process to enable the methodological principle of competitive testing of decision models. The JA-HM was further applied in a case study of fire emergency decision making. The application has been the first behavioural test of the validity of the computational models of heuristics, in predicting the DMs decision making during fire emergency response. It has also been the first behavioural test of the validity of the non-compensatory heuristics in predicting the DMs decisions on ranking task. The findings identified extend the literature of AT and NDM, and have implications for the fire emergency decision making.

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Att det idag finns flera metoder och modeller för att fatta beslut är inte konstigt då beslutsfattande sker varje dag och i vissa sammanhang kan ge ödesdigra konsekvenser om det blir fel. Denna kandidatuppsats kan ses som en förstudie för hur naturligt beslutsfattande skulle kunna stödjas genom en förbättrad utbildning till beslutsfattare. Uppsatsen ämnar behandla naturligt beslutsfattande och intuition hos experter inom räddningstjänsten, närmare bestämt om de använder intuition och i så fall vad som ligger till grund för denna intuition. Intervjuer utfördes på räddningstjänsten i Motala efter critical decision method som är framtagen för cognitive task analysis. Inom räddningstjänsten använder sig befälen av intuition när de tar det flesta av sina beslut i fält. Resultaten av intervjuerna pekar på att intuition verkar ske undermedvetet vilket ger stöd för recognition primed decision model, i kombination med negativa ledtrådar och hävstångspunkter.

This thesis presents a study in which an attempt to verify a new protocol for evaluating team performance in terms of control was made, and this on teams performing navigation in high speed in real life, natural contexts. A second objective was to identify key factors for achieving control during high-speed navigation. The study was built upon the theories of Cognitive Systems Engineering and Naturalistic Decision Making (NDM). The study also made a first attempt to expand the protocol with the theories of NDM. A pilot test in the form of a field study was conducted upon military crews driving and navigating the Combat Boat 90H off the coast of Gothenburg, Sweden. The results of the study indicated both teams being in, at lowest, the tactical control mode, and one team occasionally making the transition to the strategic control mode. There were some methodological issues with using the protocol in real life, natural contexts and these were examined. In general, the protocol was found to be applicable in this field. Key factors for achieving control during high-speed navigation could not be properly identified because of contextual problems, but one possible factor was that the use of Hollnagel’s TETO principle appeared to increase control. / I denna rapport presenteras en studie vari ett försök har gjorts att verifiera ett nytt protokoll som utvärderar gruppers prestationsförmåga i termer av kontroll. Protokollet testades på grupper som utförde navigation i hög fart under verkliga och naturliga kontexter med ett andra syfte att identifiera nyckelfaktorer för att uppnå kontroll under navigering i hög fart. Studien byggde på teorier om Cognitive Systems Engineering och Naturalistic Decision Making (NDM). Denna studie var också ett första försök i att expandera protokollet med teorier om NDM. En pilotstudie med protokollet i formen av en fältstudie utfördes på militärbesättningar som körde och navigerade Stridsbåt 90H utanför Göteborgs kust. Studiens resultat indikerade att båda grupperna befann sig som lägst i den taktiska kontrollnivån varav en grupp vid enstaka några tillfällen uppnådde den strategiska kontrollnivån. Det uppstod en del metodologiska problem med att använda protokollet i en verklig och naturlig miljö vilket utvärderades i rapporten. Generellt så gick protokollet att använda på grupper som utförde navigering i hög fart. Nyckelfaktorer för att uppnå kontroll i under navigering i hög fart kunde inte väl identifieras på grund av kontextuella problem, men en möjlig nyckelfaktor ar användandet av Hollnagels TETO-princip, vilket verkade leda till en ökad kontrollnivå.

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