Identifying damage of a bridge from a vehicle moving over it is an attractive idea especially for those bridges without structural health monitoring systems as it is faster than putting sensors on the bridges. Many parts of highways and railways have been constructed on bridges and it is important to ensure that they are in good conditions. Therefore a large amount of bridges need to be monitored and for the sake of economy the monitoring should be efficient. If an instrumented vehicle can identify the occurrence and locations of damage by running over the bridges, it would save a lot of labor and time. As acceleration is easier to acquire, it is used as the main signal for damage detection. Research in this area is relatively little, not to mention the need to take into account road surface roughness and experimental verification. Frequencies can be conveniently extracted from the vehicle response. The damage can hence be identified based on the relationship between the change of frequencies and the fractional change of strain energy. A vehicle-bridge interaction system is used to simulate the process of a vehicle running over a bridge and obtain the vehicle response for investigation. The proposed method can identify damage of simply supported and multi-span continuous bridges taking into account road surface roughness and measurement noise. They are also validated in the laboratory where a simply supported bridge is modeled using an aluminum beam and the vehicle is modeled with aluminum vehicles. This method can limit the damage location to two potential locations. The multi-level multi-pass strategy makes use of the identification from the above method, applies genetic algorithm and lets the vehicle run over the bridge at various speeds. The unique damage location can then be identified. A numerical study for simply supported bridges and multi-span continuous bridges has verified its effectiveness. Continuous wavelet transform (CWT) can identify local changes in a signal as damage is assumed to cause local change to the vehicle response, which makes it suitable for damage detection from vehicle response. However, the road surface roughness and measurement noise often mask the information about damage. Smoothing technique and damage indicators are proposed to help with the identification. By validating the method with a numerical vehicle-bridge interaction system and model tests in the laboratory, the damage can be correctly identified. Additional masses and sinusoidal excitation force can help with the identification too. Repeated application of CWT involves applying the CWT to the coefficients of continuous wavelet again and again, which can also improve the results. If CWT is treated as a mathematical microscope, repeated application of CWT is like amplifying the signal several times. The effectiveness of the method has been verified numerically and experimentally. In summary, a convenient and efficient technique to test the conditions of bridges by putting sensors on a moving vehicle is proposed and the method is verified by numerical and experimental studies. It can provide an alternative or a useful complement to conventional structural health monitoring systems. / published_or_final_version / Civil Engineering / Doctoral / Doctor of Philosophy

The data of the research shows that the idea of continual and uninterrupted education has not been put into practice yet due to a great number of truants, the students remaining for the second year in the same class and those who have experienced learning failures. Because of these reasons, the necessity arises to turn help conveyed by teachers to students into more effective one. The aim of the work is to reveal specific features of pedagogic activity related to work with students who experienced learning failures. It was tried to investigate the point of view of students, who experienced learning failures, towards teachers’ help. The analysis of the research data showed, that truants usually complain of a big homework load, the students facing learning failures speak about difficulties to understand and memorize teachers’ explanations; the truants mention problems connected with reading and writing. The students who unwillingly attend school in comparison with other students, who were investigated, stress the importance of communication for a successful learning process. The data research proved that most often class and subject teachers help to overcome learning failures. Social pedagogues, psychologists, speech therapists not so often render their assistance to students with learning problems. The research states that students playing truants get all necessary help from teachers more often that other participants of the research.

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This thesis was conducted to assess how the privatization of Iran Air process managed in last efforts and how should it be in right way. It increases the knowledge about privatization in Iran and the need for it. Iran air as our case study is a flag-carrier airline company that is protected by government regulations and subsidies. We try to find the reasons for failure of privatization in Iran Air and their attempt on privatization. The method used to collect data was a qualitative methodology, consisting of semi-structured interviews with relevant managers, and knowledgeable professors and the official sites and press. In conclusion, we find that privatization is an important need for Iran Air Company and the main problems that are against Iran Air can be categorized to political, financial, and social. The effects of political connections are most pronounced in countries with high levels of corruption. Iran’s level of corruption and law enforcement environment are lower than those are in developed countries. The root of financial problems of government and the company is the deficiency of liquidity to compensate the debts, but the share did not sell. The social problem arises from the uncertainty of the future of employees of going private company. Decreasing the level of corruption and increasing law enforcement in country are general solution for political problem. Preparing transparent financial statements and fair evaluation of share base price are our suggestion to Iran Air. The staff must be sure of their future. Social Security Organization and employment laws of country or any other response organization must protect them

Until recently, research has been scarce in the field of physical modelling of dam breaching. Over the past few years, teams from the University of Ottawa, Canada, Delft University of Technology, Netherlands, and HR Wallingford, United Kingdom have worked on several physical models to help determine how various dam breaching characteristics vary due to changes in dam geometry and geotechnical properties. The purpose of this project is to use these new experimental data sets to compare and validate the applicability range of two existing pieces of software, MIKE11-DB and BREACH developed by the Danish Hydraulic Institute and National Weather Service, respectively. Several breaching characteristics such as the outflow hydrograph, peak flow, lag time, breaching time, breach width, and water level are considered in the present study. A sensitivity analysis is also performed on the model’s main input parameters and their sensitivity and performance is ranked accordingly.

Information Systems (IS) are being developed and used in organizations to achieve their business goals and to enhance organizational effectiveness. The rate of systems success is questionable. One of the causes of IS failures might be user dissatisfaction with the systems. The success of an Information System is difficult to measure directly, so user satisfaction and system usage are frequently used as surrogate measures of system success. User participation in IS development has been advocated to achieve user satisfaction with the system and consequently system success. Past research findings about the effect of user participation on user satisfaction leading to system success are mixed and inconclusive. Past research has not been successful in showing whether user participation in IS development is necessary or not. So further research in this respect is justifiable. This thesis investigated the effect of user participation/involvement on user satisfaction. The effect of user expectations, and user-developer effective communications on user satisfaction has also been explored. A research model was proposed to proceed with this research. Meta-Analysis was carried out to investigate the relationship between user participation, user expectations and user-developer effective communication each with user satisfaction respectively. This thesis found some relationship of these factors with user satisfaction. The strength of the relationship (i. e. correlation 'r') was found to be 'medium' but not large'. The results also show that user involvement has a larger correlation with user satisfaction as opposed to user participation. The findings not only lead to the conclusions that user participation/involvement, user expectations, and user-developer effective communication have positive relationship with user satisfaction, but also contribute to the existing alternative views among IS researchers. The relationship between system usage and user satisfaction was found to be positive and of 'medium' strength and contrasts with the prevailing view that no correlation exists between them. So research findings are not only useful to resolve controversies that exists in past research but also lead to conclusions that user participation may contribute towards successful IS development and consequently user satisfaction with IS. Further, the causes of the emergence of unrealistic user expectations are explored and suggestions for future research are made.

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