We consider the problem of optimal evasion when the pursuer is known to employ fixed gain proportional navigation. The performance index is a measure of closest approach. The analysis is done for planar motions at constant speed. The kinematics are first linearized around a nominal collision course. The dynamics of the opponents are modeled by first order systems and their accelerations may be bounded. Three cases are studied: unconstrained optimal evasion (where the evader is not subjected to any path constraint) against a single pursuer, optimal evasion with a terminal path angle constraint for the evader and optimal evasion against more than one pursuer. The optimal controls are shown to be 'bang - bang' with the number of switches depending on the pursuer’s navigation gain and on the particular constraints of each case. / Master of Science

<p>A study of communication content, frequency and problems was performed at the Swedish Air Force Air Combat Simulation Centre, FLSC. The purpose was to investigate the connection between team communication and performance variables, to study communication problems during air combat and to employ and develop the PILOT method of communication problem analysis. Ten fighter pilots and four fighter controllers engaged in simulated air combat beyond visual range in teams on two sides, Blue and Red, with four pilots and one fighter controller each. Eight such training runs lasting 15 to 25 minutes were analyzed with regard to the Blue team’s communication during launch situations, i.e. one minute before launching a missile to either missile impact of failure, and problems during whole runs. The performance of the Blue team was rated by an experienced training instructor in six of the runs. It was hypothesized that positive outcomes would be associated with high communication frequencies but low communication problem rates. Results showed that high utterance frequencies were positively associated with positive global outcomes, i.e. wins, but not associated with high instructor ratings or launching hitting missiles. Incoherent results were found for communication problems. The results were discussed and further research suggested.</p>

Doctor of Philosophy / Department of History / Donald J. Mrozek / In the late 20th and early 21st centuries, military aviation technology grew expensive and politically divisive, and this is not without precedent. In the 1960s and 1970s, the F-15 Eagle and F-16 Falcon represented a controversial shift both in the cost of development and in tactical doctrine for the United States Air Force (USAF), yet the motivating factors that influenced their design are not fully understood. Most of the literature either has focused on a teleological exploration of technical evolution or has held to a “genius inventor” paradigm, lionizing individual engineers and planners. Other works have focused on these aircraft as factors that changed the Air Force's tactical approach to warfighting or have simply evaluated their combat performance. Although these approaches are valuable, they do not account for the effect that institutional culture and historical memory had on the F-15 and F-16 programs. This dissertation argues that the culture of the fighter pilot community was based on a constructed memory of World War I fighter combat, idealizing a heroic, romanticized image of “Knights of the Air.” This fighter pilot community attempted to influence the F-15 and F-16 programs to conform to their vision of an idealized past. Furthermore, a smaller group of these pilots, calling themselves the “Fighter Mafia” (and later the “Reformers”) radicalized these ideas, rejecting the Eagle and Falcon as not representative of their ideal vision. Through public and political activism, this group affected the discourse of military technology from the mid-1970s to the present. Drawing on David Nye’s work on the connections between technology and cultural historical narratives and identity, this work will demonstrate that culture and institutional historical memory can be important factors in driving the development of military technology.

A study of communication content, frequency and problems was performed at the Swedish Air Force Air Combat Simulation Centre, FLSC. The purpose was to investigate the connection between team communication and performance variables, to study communication problems during air combat and to employ and develop the PILOT method of communication problem analysis. Ten fighter pilots and four fighter controllers engaged in simulated air combat beyond visual range in teams on two sides, Blue and Red, with four pilots and one fighter controller each. Eight such training runs lasting 15 to 25 minutes were analyzed with regard to the Blue team’s communication during launch situations, i.e. one minute before launching a missile to either missile impact of failure, and problems during whole runs. The performance of the Blue team was rated by an experienced training instructor in six of the runs. It was hypothesized that positive outcomes would be associated with high communication frequencies but low communication problem rates. Results showed that high utterance frequencies were positively associated with positive global outcomes, i.e. wins, but not associated with high instructor ratings or launching hitting missiles. Incoherent results were found for communication problems. The results were discussed and further research suggested.

In the summer of 1940 around five thousand aircraft clashed during several months for control of the skies over Britain. The fighter aircraft used by the German Luftwaffe and British Royal Air Force were, for the most part, very similar. They were monoplane airframes made with a metal structure and covered with fabric or metal skin, their engines produced around 1,000 h.p., and the aircraft themselves achieved speeds of around 350 to 370 m.p.h. They had retractable undercarriages and were bristling with armaments. These aircraft stood in stark contrast to those used just over twenty years earlier in the First World War. Those machines were biplanes, almost exclusively made from wood, covered in a doped fabric, their engines produced around 400 h.p., with speeds at around 120 m.p.h., they had fixed undercarriages, one or two machine guns and were largely un-armoured. In a little over twenty years the basic form of fighter aircraft had changed, and the materials used in their construction had changed. The engines, guns, interior structure and even the operational roles to which they were assigned had been altered to greater or lesser extents. The period 1918-1939 was, therefore, very important in the development of British fighter aircraft, as it was in aviation technology more generally. The inter-war period suggested itself for several reasons. Firstly, the historiography upon which part of this thesis is hinged deals largely with its latter years and the years leading to World War Two. Due to this concentration on the mid-late 1930s, there is no real sense of what was going on in the 1920s, or attempts to understand the changes that the technology, and the institutions behind them, went through over the years. Secondly, following the First World War, the British aircraft industry was possessed of some considerable degree of competence and experience. To study the development of aviation technology before the war would be to catalogue the efforts of a number of pioneers each doing their own thing and following their own beliefs. To look at such development during the First World War would be to look at what happens when money is no serious object to research and development, production space, labour, management and so on. In looking at the inter-war years, we can examine a new industry that has just come out of a very considerable baptism of fire (in the case of Britain this baptism came just five years after her first successful flight was conducted). We can examine an industry that had to deal with enormous cutbacks, governmental micromanagement and lacking, for a long time, a fertile market in which to operate. Furthermore, the twenty years of the inter-war period allows us to look at a protracted period of technological change enabling us to account for the many varied and changing factors influencing the development of British fighter aircraft. Finally, the approach of the Second World War, the danger of Adolf Hitler and National Socialism and the proliferation of the Luftwaffe was not lost on policymakers and so this period also allows us to examine the effects of wider international events on technology. As it will be shown in the section dealing with historiography there has been plenty of work examining the British aircraft industry, individual aircraft and even the technologies which appeared over the twenty years that this thesis covers. However, there has been a great scarcity of work attempting to explain how such technologies appeared, how they linked together and how aircraft technology changed over the period. These are important questions, not only in terms of providing comprehensive explanations for their creation, development and existence but also in providing crucial context when attempting to pass judgement (as many historians have done) on the industry and the technology it created, and the politics and bureaucracy involved in shaping the technology. Using the example of British fighter aircraft during the 1920s and 1930s, this thesis will look at how the pace of technological change was set. How and why did British fighter aircraft develop the way they did and at the pace that they did? In particular, it will address the central issue of how the shift from the wooden biplanetype fighter of 1918 to the metal monoplane-type of 1939 came about. And can this change be conceptualised as a ‘paradigm shift’ from one ‘technological paradigm’ to another? This is particularly interesting because many consider that aviation now needs to carry out another paradigm shift, due to concerns about environmental impacts, especially as regards climate change.

No description available.

Roof venting is often utilised in large warehouses to remove smoke in order to reduce damage to a building and its contents, and to maintain access for fire-fighters. In New Zealand, the Compliance Document for the New Zealand Building Code C clauses recommends 15 % opening area for unsprinklered single floor buildings. This opening area is required to be designed for effective fire venting. There is no justification for why 15 % is required, and no definition of how fire venting qualifies as being effective. Fire Dynamics Simulator (FDS) was used to simulate the performance of various roof venting strategies in two different-sized industrial warehouses (both larger than 1,500 m²) with a 50 MW fire with both a rapid and an extreme t³ growth rate. In particular, roof venting areas of 15 %, 10 %, and 5 % of the floor area were tested with each of the following inlet areas for make-up air: 100 %, 50 %, and 0 % of roof venting area. In each of these cases, the vents were treated as permanently-open holes in the roof. It was shown that roof venting with 15 % geometric area is ample to provide and maintain tenability for fire-fighters. With sufficient inlet area for make-up air, smaller venting areas could also be employed. Further simulations were run to test the effect of square-shaped vents that opened simultaneously at 100°C compared with square-shaped vents that opened sequentially at 100°C, 200°C, and 300°C, and strip-shaped vents that opened progressively as each portion of a vent reached activation temperatures of 200°C and 300°C. Vents that opened at 100°C were intended to represent mechanical vents, while vents opening at higher temperatures were intended to represent plastic sky-light or drop-out type vents. The activation temperature proved to be more influential than the opening sequence or shape: there was a significant advantage to be gained by having vents that activated at 100°C as opposed to 200°C or 300°C. The role of downstands in aiding the effectiveness of roof venting was also investigated, with downstand depths of 10 %, 20 %, and 30 % of the ceiling height being simulated. Downstands were shown to be incredibly useful for exhausting smoke and hot gases, provided their installation was appropriately coordinated with placement of roof venting. It is concluded that a clear definition of effective fire venting must not only include the area of roof venting, but equally important is the definition of required inlet area for make-up air, as it plays a crucial role in the effectiveness of the specified roof venting area. In addition, the clear aerodynamic area should be specified. This could be achieved by use of a discharge coefficient that describes the proportion of the roof venting area that is clear aerodynamic area for a particular material, vent, and geometric area. Development of a clear definition of effective fire venting will help to determine how an economic fire protection system can be continued to be used, while going a long way to ensuring predictable and tenable conditions for fire-fighters in New Zealand.

This report comprises a product development of an ergonomically designed hose basket that can be used by the firefighters when storing or carrying a fire hose. A study on ergonomics in the profession as a firefighter conducted by the Research Institutes of Sweden (RISE) showed that fire hose deployment was very physically exhausting. This study also revealed that some load may become too heavy and difficult to carry due to the design of the equipment. Injury to the user during lifting is common within the profession. Therefore there is a need for equipment that is more ergonomically designed.  The project follows a product development phase that includes market research and feasibility study which was accomplished by a literature study and through study visits and interviews at fire stations.  A common type of hose basket was used as the starting point for the project. This hose basket is in this report referred as "Skövde basket" and was considered heavy and un-ergonomic to carry, especially for shorter people. From the gathered information a ‘house of quality’ and a two-step idea generation was created. Several concepts that were made opposed the Skövde basket in an evaluation matrix. A material selection using a program, CES Selector 3.2 was made on the winning concept that became a hose basket which is carried under the arm.   The hose basket was then constructed in the program Creo Parametric 4.0 and detail drawings were created. A prototype was then made and tested by firefighters of both sexes and of different heights. The results pointed out improvements and deteriorations from the Skövde basket. The deterioration was that the basket became more difficult to pack, which was due to the reduced number of bars. Improvements were noticed on lift height; significant increase on lift height facilitated easy carrying by shorter individuals. / Denna rapport omfattar en produktutveckling av en ergonomiskt utformad slangkorg som kan användas av räddningstjänsten då brandslang ska placeras ut. Enligt en studie kring ergonomi inom räddningstjänsten gjord av Research Institutes of Sweden, RISE, ansåg många brandmän att slangutläggning var mycket fysiskt ansträngande. Syftet är att främja ergonomi inom brandmannayrket. Trots de fysiska kraven hos brandmän, kan vissa laster bli för tunga och svåra att bära på grund av utrustningens utformning. Därför behövs utrustning som är mer ergonomiskt utformad.   Projektet följer övergripligt en produktutvecklingsfas där det ingår dels en marknadsundersökning och en förstudie vilket gjordes genom en litteraturstudie, intervjuer och studiebesök på brandstationer.   En vanlig variant av slangkorg användes som utgångspunkt för projektet, denna slangkorg kallas i rapporten för ”Skövdeväskan” och ansågs tung och oergonomisk att bära, framför allt för kortare personer. Utifrån den information som samlats in gjordes ett kvalitetshus och en tvåstegs idégenerering där koncept togs fram. Koncepten ställdes mot varandra och mot Skövdeväskan i en konceptvalsmatris. Materialval med programmet CES Selector 3.2 gjordes på det vinnande konceptet som blev en slangkorg som bärs under armen.  Slangkorgen modellerades sedan i programmet Creo Parametric 4.0 och detaljritningar skapades. En prototyp konstruerades och denna testades av brandmän av båda könen och av olika längd. Testpersonerna fick därefter göra en utvärdering som visade på både förbättringar och försämringar jämfört med Skövdeväskan. Försämringar som uppkom var att korgen blev mer svårpackad vilket berodde på det reducerade antalet stödstänger i ramen. Förbättringar gjordes på lyfthöjd vilket underlättade framför allt för de kortare personerna.

<p>Syftet med denna examensuppsats var att undersöka och beskriva svenska stridspiloters upplevda mentala hälsa. En enkät utformades bestående av ett skattningsbatteri med frågor om sömn och trötthet, OSLO-3, CAGE, HADS, frågor om fysiska symptom, GHQ-12 och SRE. Enkäten skickades ut till 129 JAS 39 piloter i ordinarie tjänst vid flygdivisioner i Försvarsmakten och Förvarets Materielverk (FMV). Resultatet visade att 77% av piloterna i studien bedömdes ha symptom på mild depression och 46% hade symptom på mild ångest. De flesta av de deltagande piloterna hade inte några alkoholrelaterade problem och 83% uppgav att de hade lätta fysiska besvär.</p><p>ANOVA-analysen visade att de deltagande piloterna på utbildningsförbandet i medeltal hade signifikant högre poäng på GHQ-12 än piloterna på insatsförbanden. ANOVA visade också att utbildningsförbandets piloter hade signifikant fler fysiska symptom än utvecklingsförbandens. Pearson-korrelationer mellan bakgrundsfaktorerna och de olika självskattningsdelarna i enkäten samt korrelationer mellan de olika delarna i skattningsformuläret uppvisade relativt svaga samband varav några var signifikanta. </p><p>Slutsatsen är att de svenska stridspiloterna i studien mådde sämre än vad man kunde förvänta sig med tanke på det gedigna uttagnings- och uppföljningsförfarandet. Det kan därför finnas anledning att se över den nu icke anonyma hälsouppföljningen av svenska stridspiloter eftersom den inte bedöms vara tillräcklig för att upptäcka personer med symptom på psykisk ohälsa. Detta är viktigt för att i ett tidigt skede minska och förebygga mental ohälsa inom denna yrkesgrupp, inte bara ur ett flygsäkerhetsperspektiv utan också på grund av att tidiga interventioner ger bättre resultat.</p> / <p>The purpose of this study was to investigate and describe the mental health among Swedish fighter pilots. A questionnaire comprising questions concerning sleep and fatigue, OSLO-3, CAGE, HADS, physical symptoms, GHQ-12 and SRE was presented. The questionnaire was distributed to 129 JAS 39 pilots on regular flying duty in the Swedish Air Force and the Swedish Defence Material Administration. The results indicated that 77% of the respondents were found to have mild depression and 46% had symptoms of mild anxiety.</p><p>ANOVA-analysis indicated that the pilots at the training unit on average scored significantly higher on GHQ-12 than the pilots at the fighter squadrons. ANOVA also indicated that the pilots at the training unit had significantly more physical symptoms than the pilots at the development units. Pearson correlations between background factors and the different self-evaluation parts of the questionnaire in addition to correlations between the different parts of the evaluation questionnaire were relatively weak although some of them were significant.</p><p>These findings imply that the Swedish fighter pilots, considering the rigorous selection and evaluation processes, were not as free from mental health problems as expected. Thus there is a reason to revise the follow-up study on the pilots’ mental health. It is important to detect any mental health vulnerability early, not only for maintaining high flight safety standards, but also because of the advantage of implementing early therapeutic intervention.</p>

Syftet med denna examensuppsats var att undersöka och beskriva svenska stridspiloters upplevda mentala hälsa. En enkät utformades bestående av ett skattningsbatteri med frågor om sömn och trötthet, OSLO-3, CAGE, HADS, frågor om fysiska symptom, GHQ-12 och SRE. Enkäten skickades ut till 129 JAS 39 piloter i ordinarie tjänst vid flygdivisioner i Försvarsmakten och Förvarets Materielverk (FMV). Resultatet visade att 77% av piloterna i studien bedömdes ha symptom på mild depression och 46% hade symptom på mild ångest. De flesta av de deltagande piloterna hade inte några alkoholrelaterade problem och 83% uppgav att de hade lätta fysiska besvär. ANOVA-analysen visade att de deltagande piloterna på utbildningsförbandet i medeltal hade signifikant högre poäng på GHQ-12 än piloterna på insatsförbanden. ANOVA visade också att utbildningsförbandets piloter hade signifikant fler fysiska symptom än utvecklingsförbandens. Pearson-korrelationer mellan bakgrundsfaktorerna och de olika självskattningsdelarna i enkäten samt korrelationer mellan de olika delarna i skattningsformuläret uppvisade relativt svaga samband varav några var signifikanta. Slutsatsen är att de svenska stridspiloterna i studien mådde sämre än vad man kunde förvänta sig med tanke på det gedigna uttagnings- och uppföljningsförfarandet. Det kan därför finnas anledning att se över den nu icke anonyma hälsouppföljningen av svenska stridspiloter eftersom den inte bedöms vara tillräcklig för att upptäcka personer med symptom på psykisk ohälsa. Detta är viktigt för att i ett tidigt skede minska och förebygga mental ohälsa inom denna yrkesgrupp, inte bara ur ett flygsäkerhetsperspektiv utan också på grund av att tidiga interventioner ger bättre resultat. / The purpose of this study was to investigate and describe the mental health among Swedish fighter pilots. A questionnaire comprising questions concerning sleep and fatigue, OSLO-3, CAGE, HADS, physical symptoms, GHQ-12 and SRE was presented. The questionnaire was distributed to 129 JAS 39 pilots on regular flying duty in the Swedish Air Force and the Swedish Defence Material Administration. The results indicated that 77% of the respondents were found to have mild depression and 46% had symptoms of mild anxiety. ANOVA-analysis indicated that the pilots at the training unit on average scored significantly higher on GHQ-12 than the pilots at the fighter squadrons. ANOVA also indicated that the pilots at the training unit had significantly more physical symptoms than the pilots at the development units. Pearson correlations between background factors and the different self-evaluation parts of the questionnaire in addition to correlations between the different parts of the evaluation questionnaire were relatively weak although some of them were significant. These findings imply that the Swedish fighter pilots, considering the rigorous selection and evaluation processes, were not as free from mental health problems as expected. Thus there is a reason to revise the follow-up study on the pilots’ mental health. It is important to detect any mental health vulnerability early, not only for maintaining high flight safety standards, but also because of the advantage of implementing early therapeutic intervention.