This report frames the debate over studded tires in terms of economic principles of marginal cost pricing and efficient resource allocation. In the absence of a user tax, the pavement damage caused by studded tires results in inefficient pricing because social costs associated with the damage are excluded from the price paid by consumers. This leads to over use of studded tires. No attempt was made to quantify the safety effects of studded tire use. A review of research literature was provided to qualitatively support the premise that there is no social benefit from studded tires in Oregon. Quantitative cost analysis was limited to pavement rutting on the state highway system that is sufficient to reduce the useful life of the pavement. The cost estimation was conducted in two stages: first, the wear rates for asphalt and Portland cement concrete (PCC) pavement surfaces were estimated, expressed as inches of rut depth per 100,000 studded tire passes. Linear regression analysis was conducted using rut depth, traffic, and studded tire data from a sample of Oregon highways. A range of wear rates was estimated, reflecting the numerous factors that influence rutting susceptibility of pavements. The mid-points of wear rates for asphalt and PCC were 0.0386" and 0.0093", respectively. Second, the wear rate estimates were used to approximate rutting for the state highway system and to predict resurfacing expenses attributable to studded tire traffic. The results indicate that the cost of studded tire damage on Oregon state highways in 1995 was approximately $10 million. This averages to $8 per tire per year. The implications of the cost are then discussed in terms of the allocation effects of underpricing due to an untaxed externality. The external costs pavement damage caused by studded tires result in inefficient pricing because external costs associated with the damage are excluded from the price paid by consumers. This leads to excess use of studded tires. A studded tires tax sufficient to cover attributable maintenance costs would be in the neighborhood of 30% of the purchase price and would result in a sharp decline in the quantity of studded tires in use. / Graduation date: 1998

In the semiconductor industry, numerous potential occupational exposures exist as a result of the diversity of chemical and physical hazards unique to integrated circuit manufacturing. The hazards associated with maintenance tasks are challenging because the sporadic nature of the tasks make exposure monitoring difficult. In particular, vacuum pump maintenance is hazardous due to the close contact with chemical waste by-products. The purpose of this study was to characterize the chemical and physical occupational exposures associated with vacuum pump maintenance (VPM) in a semiconductor manufacturing environment. The study population consisted of 9 VPM technicians at a semiconductor manufacturing plant in Oregon. VPM tasks were observed and prioritized according to potential risk of exposure. For each task studied, an exposure monitoring strategy was developed to quantify both chemical and noise exposures. Personal and area air samples of potential waste gases were conducted during maintenance tasks. All air samples were below established governmental standards. Detectable levels were found for three tasks: 0.040 milligrams per cubic meter (mg/m��) of hydrochloric acid, 0.014 mg/m�� of chlorine, and 0.08 mg/m�� of fluoride containing gases during tasks associated with the metal etch tool, polynitride etch tool, and tungsten deposition tool, respectively. Several bulk samples of waste residues collected during the tasks where corrosive having low pH levels. Representative noise sampling was conducted during a 12 hour shift to characterize noise exposures. Noise samples revealed that 43% of the samples were above the 80 dBA action limit thus requiring the VPM technicians to be involved in a hearing conservation program. Field observations revealed that there were many chemical hazards associated with waste gases and residues, therefore it is likely that occupational exposures occur even though they were not detected at significant levels in this study. In addition, there were several ergonomic risk factors associated with dismantling the pump during the maintenance activities. Specific improvements in personal protective equipment, general work practices, ergonomics, and engineering controls will help to reduce the potential for occupational exposures unique to VPM. Results from this study indicate the need to conduct in depth hazard evaluations of high risk populations such as the VPM technicians. / Graduation date: 1997

The purpose of this study was to evaluate what forms of maintenance programs for the home are currently available on the market, and to develop a structured, organized framework for an easy-to-use system. From an inventory of what was available at national bookstore chains and from public libraries, it was evident that there was a void in information about scheduled maintenance accessible to the public. Therefore this paper addressed this issue. This thesis first investigated the history of upkeep and maintenance and its published materials and then assessed how best to fill the void in the area of continuous home care.This area was of interest because haphazard and random describe an owner's usual approach to maintenance around the home. Quality maintenance should not be hasty nor superficial. Rather, it should be an in-depth, consciously organized effort of preserving the building fabric. Treating a repair as a quick fix-it job is comparative to applying a band-aid to a cut which requires further medical treatment. This type of care is inadequate because it has not solved the problem which still exists. Therefore, maintenance should have the characteristic of being a conscious, in-depth effort. Quality maintenance should also be an organized effort, thereby avoiding the possibility of being hit-or-miss or lackadaisical.Simply, maintenance is the process of upkeep, of cleaning and monitoring the interior and exterior of a structure. Detecting an arising problem within the fabric, swiftly dealing with it, solving the situation and avoiding further deterioration is preventive maintenance. In other words upkeep is two-fold: 1) inspecting and repairing damage from general wear and tear (maintenance) and 2) preparing the house and its support systems for future use (preventive measures). Whether new construction or an older home, any aged structure can benefit from simple scheduled maintenance.In terms of conservation technology, a preventive maintenance program can significantly contribute to the preservation of historic and nonhistoric structures. Maintenance is a direct intervention process; it involves a one-on-one relationship and an ongoing interaction between owner and building. The goal in implementing a maintenance program is preservation: the sustaining and prolonging of the life and integrety of a special building--the home.Ball State UniversityMuncie, IN 47306

The creative project is an educational film that will be used in vocational auto mechanics classes as an aid to the lecture and demonstration of brake repair.Eight millimeter Kodak color film was used and is supplemented with magnetic taped sound.The film deals with the steps and procedures that are necessary to complete a brake repair job. Each step explains the procedures and outlines the technical knowledge needed to complete the brake repair job.

Uppsatsens syfte har varit att, ur ett systemperspektiv, kartlägga dels vilka problem som funnits inomavhjälpande underhåll för amfibiebåtsystemet fram till idag, dels att kartlägga vilka framtida möjligheter som finnsför att förbättra detsamma. Två frågor har besvarats i uppsatsen: Vilka problem finns inom avhjälpande underhållför amfibiebåtsystemet fram till idag? Vilka framtida möjligheter finns för att förbättra det avhjälpande underhålletför amfibiebåtsystemet?Frågeställningarna har besvarats med hjälp av systemteori och metoden kvalitativ fallstudie. Tekniken somanvänds för att samla in det empiriska materialet har varit intervjuer i form av frågeundersökning.Uppsatsens svar på den första frågan kan sammanfattas till:Det har varit problem i och med att det inte genomförts någon underhållsberedning. Detta har fått till följd att detär brister i uppläggningen av verktyg och reservmateriel på olika resursnivåer samt brister i utbildning av tekniker.Vidare är det brister i samband och informationsflöde. Dessa begränsar möjligheterna att snabbt få beslutsstödoch tekniskt systemstöd. Dokumentation och s.k. expertstöd uppvisar också brister. Dessa innebär problem vidutbildning och vid genomförande av åtgärder. Slutligen upplevs också brister i rutiner och avseende hjälpmedelför sökning, inventering och återfyllnad av reservmateriel. Följden blir att det uppstår tidsfördröjningar och att detsker återfyllnad med fel reservmateriel.Uppsatsens svar på den andra frågan kan sammanfattas till:Det framtida försvaret tros ge möjlighet till förbättrat informationsflöde. Följden blir att tekniker får en bättretillgång till beslutsstöd och tekniskt systemstöd. Detta reducerar bl.a. de begränsningar som upplevts vid val avreparationsmetoder och beställning av resurser. I framtiden ses en möjlighet till att nyttja centrala databaser vilketfår till följd att det blir bättre tillgång till, och utnyttjande av, uppdaterad dokumentation samt en överblick och ettbättre utnyttjande av verktyg och reservmateriel. Det kommer att finnas en bättre möjlighet att nyttjakombinationen av databaser och nätverk. Detta kan leda till en bättre drifts- och statusuppföljning. Slutligen trosdet finnas en möjlighet till inbyggda test-, referens- och kontrollsystem i båtarna. Denna möjlighet kan då geförbättrade fellarmsfunktioner, möjlighet till fjärrdiagnostik samt möjlighet till självreparationer. / The purpose of this essay has been on the one hand, to identify what problemsthere have been within corrective maintenance for amphibious vessel systemsup till now. The second purpose has been to identify the possibilities availablefor improving the corrective maintenance. The essay has answered thefollowing two questions at issue:1. What problems have there been within corrective maintenance foramphibious vessel systems up till now?2. What future possibilities are available for improving the correctivemaintenance?The questions at issue in this essay have been answered by using a systemstheoreticaland qualitative case study as a method. The technique of gatheringempirical material has been in the way of survey interviews.The first question at issue in the essay can be summarised as follows:There have been problems, in as much as; there has never been a study into therequirements of maintenance. Consequently, this has resulted in scarcity oftools and spare parts at various resource levels and also insufficient training fortechnicians. Furthermore, there is a deficiency within the flow ofcommunication and information. These constrain the possibility of quicklyobtaining decision support and technical systems support. Documentation andso called expert support systems also show deficiencies. Subsequently, theseimply difficulties when training and when implementing repair measures.Finally, deficiencies are apparent in routines, searching, inventory andreplenishment of spare parts. The consequences are time-delays and that thewrong types of spare parts are replaced.The second question at issue in the essay can be summarised as follows:The defence of the future will provide opportunities for an improved flow ofinformation. This will result in technicians receiving decision support andtechnical support systems easier. This will reduce the constraints, among otherthings, which were experienced when choosing methods of repair and orderingof resources. In the future, there will be an opportunity to utilise centraldatabases, which will result in an improved accessibility and use of updateddocumentation. Moreover, an overview and more efficient use of tools andspare parts will be possible. Combining databases and networks will also beenhanced in the future. This can then lead to better surveillance of the runningof the vessel and its state of condition.FÖRSVARSHÖGSKOLAN C-UPPSATS Beteckning 19100:2007Mj Peter Fagrell, ChP 01- 03 2003-07-21 sida 2(50)Finally, there is believed to be the possibility of built- in tests, reference andcontrol systems in the vessels. This possibility can in turn provide improvedfaulty alarm functions, opportunities for remote diagnostics and self-reparation. / Avdelning: ALB - Slutet Mag 3 C-upps.Hylla: Upps. ChP 01-03

A Damage Assessment Model, Construction Process Model and Parametric Quantity Model were developed with the purpose of capturing the engineering knowledge involved in the estimating process of bridge repair construction projects. The Damage Assessment Model was used to create a sample database in which detailed inspection data was stored in a format compatible with the existing Pontis?tabase. Detailed inspection data, which provided quantitative values for the different damage types observed in bridges, could be retrieved from the sample database so that data could be used as either input parameters in the knowledge rules that triggered the selection of construction tasks in the Construction Process Model, or data could be used as variables in the equations used to estimate quantities in the Parametric Quantity Model. The Construction Process Model was used to incorporate the logic behind the construction process for different repair methods. The Construction Process Model was composed of seven repair matrices that defined specific repair methods for each Pontis?idge element. Construction tasks were grouped in construction modules that were modeled as flowcharts. Each construction module flowchart was composed of construction tasks arranged in sequential order and decision points that triggered the selection of construction tasks based on input parameters and knowledge rules. Input parameters were provided by the user, retrieved from the model or pre-defined in the model by expert knowledge. The construction modules developed involved construction tasks related to the repair of concrete bridge piles that were damaged due to reinforcement corrosion and related concrete deterioration. Data describing the construction tasks that were considered in the construction module flowcharts were modeled using the entity-relationship model and were stored in the sample database described previously. The Parametric Quantity Model combined data generated by the Damage Assessment Model and the Construction Process Model with additional expert knowledge and parameters into equations that were used to estimate quantities. The author investigated the use of neural networks as a tool to predict actual damage in bridge piles, conducted a preliminary survey to define labor productivity factors and collected data to define the duration of construction activities related to bridge repair.

Satellite constellations are an increasingly attractive option for many commercial and military applications. They provide a robust and distributed method of accomplishing the goals of expensive monolithic satellites. Among the many challenges that satellite constellations engender (challenges in control, coordination, disposal, and other areas), refueling is of particular interest because of the many methods one can use to refuel a constellation and the lifetime implications on the satellites. The present work presents a methodology for carrying out peer-to-peer refueling maneuvers within a constellation. Peer-to-peer (P2P) refueling can be of great value both in cases where a satellite unexpectedly consumes more fuel than it was alloted, and as part of a mixed refueling strategy that will include an outside tanker bringing fuel to the constellation. Without considering mixed-refueling, we formulate the peer-to-peer refueling problem as an assignment problem that seeks to guarantee that all satellites will have the fuel they need to be functional until the next refueling, while concurrently minimizing the cost in fuel that the refueling maneuvers entail. The assignment problem is then solved via auctions, which, by virtue of their distributed nature, can easily and effectively be implemented on a constellation without jeopardizing any robustness properties. Taking as a given that the P2P assignment problem has been solved, and that it has produced some matching among fuel deficient and fuel sufficient satellites, we then seek to sequence those prescribed maneuvers in the most effective manner. The idea is that while a constellation can be expected to have some redundancy, enough satellites leaving their assigned orbital slots will eventually make it impossible for the constellation to function. To tackle this problem, we define a wide class of operability conditions, and present three algorithms that intelligently schedule the maneuvers. We then briefly show how combining the matching and scheduling problems yields a complete methodology for organizing P2P satellite refueling operations.

Following results over recent years, this thesis enhances the problem of minimizing a cost functional defined on a state trajectory of an autonomous switched dynamical system. The cost functional traditionally used, is augmented with explicit costs on the switching times and the final time is set by a constraint as opposed to being given. An equation for the gradient of the cost functional is derived and an algorithm is proposed for computing local minima. The algorithm is based on existing steepest descent methods including the Armijo procedure and gradient projection. A matlab implementation of the algorithm is developed in order to solve optimal problems that can be modelled with costs on or between the switching times. An existing problem, the motivation for this research, where repairs on a bridge is to be optimized, is provided and solved.

published_or_final_version / Housing Management / Master / Master of Housing Management

Fair face lime-based brickwork is one of the most popular types of fa?ade in early colonial buildings in Hong Kong. A good proportion of such buildings are slowly but inexorably disappearing. Since the sixties, the awareness of the general public in heritage preservation of Hong Kong started in its embryonic form, gradually evolved through the seventies and eighties, gaining momentum to active involvement in the nineties, and finally to the organized and pragmatic approach of today. In 1976, the Hong Kong Government enacted the Antiquities and Monuments Ordinance to ensure that the best examples of Hong Kong’s heritage are protected. With the establishment of the Antiquities and Monuments Office in at the same year, a number of buildings with historical and architectural values have been declared as monument or included in the list of graded heritage buildings since then and their conditions are being concerned. However, conservation principles have not been highlighted in our local heritage building maintenance practices. Perhaps, due to client’s intention, funding constrains, and/or lacking of skillful craftsmen and expert supervision, incompatible building materials and inappropriate methods have been applied on those fair face brickwork fa?ade. More and more evidence shows that such maintenance practices worsen the condition of the historic fa?ade and causing damages to the heritage. No doubt, fa?ades of those deteriorating heritage buildings are deserved proper maintenance and repair under appropriate conservation approaches. The focus of this dissertation is upon the understanding the issue of brickwork failure particularly owning to the saturation of soluble salt in brickwork attributed to various inappropriate maintenance approaches. To establish a guideline for lime-based brickwork fa?ade maintenance to ensure longevity, reduce costs and improve value. / published_or_final_version / Conservation / Master / Master of Science in Conservation