No description available.

No description available.

The thesis project described in this report was conducted at Scania CV (Scania), which is a global company that delivers transport solutions to customers all around the globe. The project was conducted as a simulation study of the production flow of the output shaft manufacturing line UGA (Utgående Axel), located at the transmission department (DX) in Södertälje. The main objectives for the simulation study was to identify possible enhancements to increase the line-capacity and -OPE, and based on the findings provide a set of recommended actions Scania can take to increase the performance of the production line. To conduct the project was a simulation model developed in another master’s thesis back in 2019 provided to the authors. But since both the production line and the products manufactured at UGA line have been subjected to changes since 2019 was this model outdated and the validity of the model had to be confirmed. Therefore was a thorough current state description developed that was utilized to identify the gap between the simulation model from 2019 and the current state at the productionline. Based on the gap-analysis was it decided that the model from 2019 did not reflect UGA line in its current state to a satisfying degree. Therefore was a new simulation model developed, which then was updated with new input data. During the development of the new simulation model was the old model used as a template where the features that still accurately described UGA line was retained. The new simulation model was validated by a comparison between simulated throughput from the simulation model and historical throughput from UGA line. The validation showed a difference in mean weekly throughput of 0,3 %. It was therefore concluded that the simulation model accurately describe UGA line in its current state. The validated model was then used to simulate a number of different scenarios, and the result was analysed to find different areas for improvements. Finally was the result from the analysis compiled as recommended actions, that in turn was divided into short- and long-term actions. Where the actions categorised as short term concerns actions that could bring improvements to the existing production line, while the long-term actions require reconfigurations of the layout to be realized. The result showed that continue working on decreasing cycle times to achieve the defined goal cycletimes will have a positive effect on the lines capacity, but not on the overall line OPE. The reason for this is that the effect from other losses in the production line will increase when the cycle times become more uniform. But since the capacity will be significantly improved as the goal cycle time is reached, is Scania still recommended to continue their work with cycle time reduction, and if possible reduce the cycle times in some specific machines below the current goal. In addition is Scania in short-term recommended to identify and reduce the undefined stop time that frequently occur, reduce quality losses and improve machine availability. Regarding the long-term actions is Scania recommended to investigate the possibility to reconfigure UGA line. The simulations showed that both increasing buffer sizes at strategic positions to improve bottleneck utilization, or decouple the line to make it less sensitive will positively affect the capacity and OPE. In addition did the simulations of the combination of these two configurations show the greatest improvement among all simulations. Scania is therefore recommended to investigate the business case around either of these configurations or a combination of both. / Examensarbetet som beskrivs i denna rapport genomfördes hos Scania CV (Scania), vilket är ett globalt företag som levererar transportlösningar till kunder över hela världen. Projektet genomfördes som en simuleringsstudie av produktionsflödet hos produktionslinjen för utgående axlar, UGA-linjen (Utgående Axel), som är belägen på transmissionsavdelningen (DX) i Södertälje. De huvudsakliga målen för simuleringsstudien var att identifiera möjliga förbättringar för att öka linjekapaciteten och -OPE, och baserat på resultaten tillhandahålla en uppsättning rekommenderade åtgärder Scania kan vidta för att öka produktionslinjens prestanda. För att genomföra projektet tilldelades författarna en simuleringsmodell som utvecklats i ett tidigare examensarbete under 2019. Eftersom både produktionslinjen och produkterna som tillverkats på UGA-linjen har genomgått förändringar sedan 2019 ansågs modell vara föråldrad och modellens validitet behövde bekräftas. Därför arbetades en grundlig nulägesbeskrivning fram som sedan användes för att identifiera gapet mellan simuleringsmodellen från 2019 och nuläget vid produktionslinjen. Baserat på gap-analysen konstaterades det att modellen från 2019 inte återspeglade UGA-linjen till en tillfredsställande grad. Därför utvecklades en ny simulerings modell som sedan uppdaterades med ny indata. Under utvecklingen av den nya simuleringsmodellen användes den gamla modellen som en mall där de funktioner som fortfarande beskrev UGA-linjen på ett bra sätt bibehölls. Den nya simuleringsmodellen validerades genom en jämförelse mellan simulerad produktion och historiskt rapporterad produktion från UGA-linjen. Valideringen visade en skillnad i genomsnittligt antal producerade produkter per vecka på 0,3%. De konstaterades därför att simuleringsmodellen på ett tillförlitligt sätt beskriver UGA-linjen i sitt nuvarande tillstånd. Den validerade modellen användes sedan för att simulera ett antal olika scenarier vars resultat analyserades för att hitta olika förbättringsområden. Slutligen sammanställd resultaten från analysen som rekommenderade åtgärder, som i sin tur delades in i åtgärder på kort- och lång-sikt. De åtgärder som kategoriserats som kortsiktiga är åtgärder som kan medföra förbättringar av den befintliga produktionslinjen, medan de långsiktiga åtgärderna kräver förändring av layouten för att genomföras. Resultatet visade att fortsatta arbetet med att minska cykeltider för att uppnå de uppsatta målcykeltiderna kommer att ha en positiv effekt på linjekapaciteten, men inte på total OPE för linjen. Anledningen till detta är att effekten av andra förluster i produktionslinjen ökar när variationen i cykeltid mellan maskinerna minskar. Men eftersom kapaciteten kommer att öka markant om målcykeltiderna uppnås rekommenderas Scania att fortsätta arbeta med cykeltidsreducering och om möjligt minska cykeltiderna under det nuvarande målet för vissa maskiner. Dessutom rekommenderas Scania på kort sikt att; identifiera och minska den odefinierade stopptid som ofta förekommer, minska kvalitetsförluster och förbättra maskintillgängligheten. När det gäller de långsiktiga åtgärderna rekommenderas Scania att undersöka möjligheten att bygga om UGA-linjen. Detta eftersom simuleringarna visade att både ökade buffertstorlekar vid strategiska positioner för att förbättra utnyttjandegraden hos flaskhalsmaskinerna, och att koppla isär linjen för att göra den mindre känslig kommer att påverka både kapacitet och OPE positivt. Dessutom visade simuleringarna av kombinationen av dessa två konfigurationer den största förbättringen bland alla simuleringar. Scania rekommenderas därför att undersöka möjligheten kring någon av dessa konfigurationer eller en kombination av båda.

Blood is a common type of medium with which patent fingerprints are deposited at crime scenes. Chemical enhancements are generally used on bloody fingerprints when some type of pattern is visible but ridge characteristics are not sufficiently defined to make the print suitable for comparison. Motor vehicles, which may be associated with crimes scenes or forensic investigations, can be exposed to a variety of contaminants from the environment, including mud, salt, pollen, dust and motor oil, as well as from the application of chemicals to protect the paint such as car wax and car polish. It is unknown if these contaminants in combination with the chemicals used to enhance bloody impressions or in combination with the blood itself, could impact the enhancement of bloody impressions found on vehicles. This study seeks to assess the effectiveness of a selection of blood enhancement methods in the presence of such contaminants. Three of the four enhancement chemicals that were tested, Amido Black, Hungarian Red, and Leucocrystal Violet, were determined to be similarly effective for the enhancement of bloody friction ridge patterns applied to the surfaces of contaminated glass and metal substrates.

Detailed heat transfer coefficient distributions have been obtained for narrow converging and diverging channels with and without enhancement features. The enhancement feature considered for this study is dimples (inline and staggered) on the main heat transfer surfaces. All the measurements are presented at Reynolds numbers of 3500, 8900, 18000, and 7000, 14000, 28000 for converging and diverging channels respectively. Pressure drop measurements for the overall channel are also presented to evaluate the heat transfer enhancement geometry with respect to pumping power requirements. The test models were studied for wall heat transfer coefficient measurements using the transient liquid crystal technique. The modeled wall inner surfaces were sprayed with thermochromic liquid crystals, and a transient test was used to obtain the local heat transfer coefficients from the measured color change. Analysis of results shows that dimples, in general, have very good enhancement capabilities and staggered dimpled surfaces provide considerably higher heat transfer coefficients and a reasonable pressure drop compared to inline dimpled configuration. Additionally, this study was extended to understand the effect of strategic placement of dimples (staggered) at various locations along the channel to understand regions that contribute significantly to the overall enhancement. / Master of Science

International Telemetering Conference Proceedings / October 27-30, 1997 / Riviera Hotel and Convention Center, Las Vegas, Nevada / This paper describes the status of the Edwards Digital Switch (EDS) [1] and the success of the Digital Switch Sustainment Program (DSSP); a multi-service program aimed at cost-effective means for providing maintenance and development of an advanced digital switching system. This digital communications switching system is deployed at the mission control centers of Edwards AFB, Eglin AFB, and China Lake Naval Air Warfare Center (NAWC). Each system provides the test ranges with mission-critical voice communications and Time Space Position Information (TSPI) switching. Through user-friendly Graphical User Interfaces (GUIs), the switch provides exceptional resource management of radios, telephones, user positions, secure communications, radars, trackers, 4-wire Ear & Mouth (E&M) devices, subscriber services, and other equipment. Developed using commercial equipment, such as the Lucent Technologies Digital Access and Cross-Connect System (DACS) II, the digital switch can integrate and interface with the technologies of other test ranges and customers. The DSSP sustaining engineering contract, a $10M contract awarded in 1997, is a multi-service effort in supporting cost effective maintenance and enhancement for the systems’ software and hardware. Eglin and China Lake have agreed to participate in a Digital Switch Working Group (DSWG) to ensure that this configuration management is in place and that all players follow the same system migration path. These ranges and other interested ranges that agree to purchase systems off the contract and participate in the working group will continue to derive benefits by reducing overhead and eliminating the duplication of effort involved in separate endeavors.

Aus der Einleitung: "Dem steigenden globalen Wettbewerb begegnen produzierende Unternehmen durch schnellere Innovationsfolgen (und damit kürzeren Produktlebenszyklen), durch Funktionserweiterungen (und damit komplexeren Produkte), durch variantenreichere Angebote sowie durch höhere Produktzuverlässigkeit und Robustheit. Um den daraus resultierenden Herausforderungen an die Produktentwicklung zu begegnen, werden in immer größerem Umfang digitale Modelle und Methoden eingesetzt (Virtuelle Produktentwicklung) (Weber and Husung, 2011). Diese dienen dazu, das Produktverhalten möglichst frühzeitig auf Basis virtueller Prototypen ermitteln und absichern zu können. Eine Anforderung, die in den letzten Jahren verstärkt dazugekommen ist, ist den Produktentwicklern frühzeitig detaillierte Informationen über das Produkt, sein Verhalten und seine Wechselwirkungen in möglichst allen Produktlebensphasen zur Verfügung zu stellen. Um diese Informationen in heterogenen Entwicklerteams anschaulich und schnell zugänglich zu machen, werden zunehmend Technologien wie die Virtual Reality (VR) eingesetzt. ..."

The project aims to detect rear approaching vehicles for cycslist with a low power consumption. Study focuses on acoustic features of the sound of rear approaching vehicles and examines the useful indicators to detect the vehicles. The project includes more then one correlation and reveals their success rates for as many as samples possible.

Technology may play a critical role in impacting student engagement, specifically within an assessment context. Using a mixed methods approach, I examined the relationship between varying degrees of technology-enhancements applied in a mathematics performance task on the outcome of student cognitive engagement. Using a counterbalanced quasi-experimental design, I evaluated the impact of three performance task platforms on student self-reported cognitive engagement in from a sample of students in grades 6-8 in Oregon, Washington, and North Carolina (N = 450). The three performance task platforms (a) included technology-enhanced (technology-based including animation and interactivity), (b) technology-enabled (computer-based without including animation and interactivity), (c) and paper-and-pencil. The measure used for cognitive engagement (CE-S-DSP & SOS) was a hybrid of previously used self-reporting tools and showed preferable reliability for the overall score of cognitive engagement. The data were not able to be explored using a 5-factor confirmatory factory analysis, due to model fit limitations. Results from the between subjects analysis of variance and did not suggest a relationship between performance task platform (modality type) and student cognitive engagement. Qualitative interview data indicated that students preferred using technology to take tests and overall showed favorability for the technology-enhanced performance task, specifically the interactivity and animations to help visualize and work through the problem. Yet, despite the positive links to technology-enhancements, there were features of paper-and-pencil tasks that students appreciated such as the ability to navigate between the items and the ability to take notes. Results indicated that just putting tests on computers may not be enough and technological affordance should be purposefully implemented. Findings from this study can help inform future use of platform type, technological enhancements employed, and strategies for technology use within an assessment context.

Aus der Einleitung: "Dem steigenden globalen Wettbewerb begegnen produzierende Unternehmen durch schnellere Innovationsfolgen (und damit kürzeren Produktlebenszyklen), durch Funktionserweiterungen (und damit komplexeren Produkte), durch variantenreichere Angebote sowie durch höhere Produktzuverlässigkeit und Robustheit. Um den daraus resultierenden Herausforderungen an die Produktentwicklung zu begegnen, werden in immer größerem Umfang digitale Modelle und Methoden eingesetzt (Virtuelle Produktentwicklung) (Weber and Husung, 2011). Diese dienen dazu, das Produktverhalten möglichst frühzeitig auf Basis virtueller Prototypen ermitteln und absichern zu können. Eine Anforderung, die in den letzten Jahren verstärkt dazugekommen ist, ist den Produktentwicklern frühzeitig detaillierte Informationen über das Produkt, sein Verhalten und seine Wechselwirkungen in möglichst allen Produktlebensphasen zur Verfügung zu stellen. Um diese Informationen in heterogenen Entwicklerteams anschaulich und schnell zugänglich zu machen, werden zunehmend Technologien wie die Virtual Reality (VR) eingesetzt. ..."