<p>A helicopter based system equipped with a millimetre-wave fire control radar is studied for improvement of the detection probability for moving ground targets. The system is a pulse doppler radar that sends out the electromagnetic wave in repetitive pulses. The frequency in which radar sends this pulse is called Pulse Repetition Frequency (PRF). </p><p>The velocity of the moving targets is measured by spectral analysis of the pulses received. With this sort of system some targets will not be possible to detect. These targets are said to be blind for the radar. Also the measured targets can be ambiguous. A solution to this is to shift PRF during the time the radar emits itspulses on the target. This method is called PRF block staggering. The antenna is mounted on a mechanical sweep on top of the rotor of the helicopter. Because of this the time on target is limited. This means that the measured velocity resolution of the radar is also limited. </p><p>With the studied method it is possible to resolve range and velocity ambiguities. This is under the condition that it is acceptable with a reduction in the velocity resolution by a factor equal to the number of PRF blocks used. </p><p>The work leading to this thesis included developing a program in Mathworks Matlab for studying different configurations of PRFs and the effect on the detection probability.</p>

<p>The waveform of a radar signal affects the resolution in velocity and distance. The ambiguity function is used as an aid for analysing narrow band radar signals simultaneously in time and frequency. An analysing tool for wide band radar signals is missing.</p><p>This thesis describes a generalised ambiguity function to be utilised for study of wide band signals. Waveforms are further synthesised with help of the developed analysing tool. The aim is to start with a certain ambiguity function and find a waveform that reproduces the same ambiguity function.</p><p>Mathematical formulas are presented and implemented in Matlab to produce the wide band ambiguity function. Functions for developing waveforms by synthesis is also implemented.</p><p>It turns out that the Hermitian functions used as base functions do not preserve the orthogonality when implemented as wide band signals. The synthesis is not fully successful. Therefore an alternative method with numerical optimisation is used in an attempt to find an optimal waveform.</p>

Three dimensions can be distinguished in a cross-linguistic account of information structure. First, there is the definition of the focus constituent, the part of the linguistic expression which is subject to some focus meaning. Second and third, there are the focus meanings and the array of structural devices that encode them. In a given language, the expression of focus is facilitated as well as constrained by the grammar within which the focus devices operate. The prevalence of focus ambiguity, the structural inability to make focus distinctions, will thus vary across languages, and within a language, across focus meanings.

The study takes its point of departure in a widespread notion that decisions should be based on the ‘facts of the matter’. Normative theories of organizational choice, in particular, encourage organizations to base decisions on facts. Many organizations also face explicit requirements to justify their decision-making with factual knowledge. But what if ‘the facts’ are ambiguous? How do organizations make justifiable decisions with ambiguous knowledge? A study of efforts on the part of the Swedish Pharmaceutical Benefits Board to decide whether prescription drugs are ‘reasonable’ to subsidize, suggests that organizations can employ various methods to remove ambiguity of knowledge. However, such attempts at achieving coherent knowledge on which to base decisions often fail. In these cases, though a decision can be made, the choice of one future action to the exclusion of others is delegated – along with the unresolved ambiguity of knowledge. Thus, the study argues that rationalistic demands for ‘knowledgeable’ and ‘justifiable’ decision outcomes, when taken seriously, make it difficult to make choices. Such demands lead to more decisions and fewer choices, since the difficulty in achieving coherence between multiple knowledge claims will delegate the actual choices to practice. Knowledge-based decision-making could therefore tend to be conservative vis-à-vis the practices that it seeks to control. This has, for instance, implications for the possibility of using ‘evidence-based policy-making’ as a means of setting priorities in healthcare. / Diss. Stockholm : Handelshögskolan i Stockholm, 2006

This thesis aims to explore the area of communication and its links to anxiety. The methods used are interviews in conjunction with a grounded theory approach. We found that there are several different types of misunderstandings that can occur between management and employees, which also cause the level of anxiety felt among the employees to rise. Important aspects to consider for management seem to be to use several communication channels and choose the appropriate channel depending on the content of the message. It is also necessary for management to convey information on the same knowledge level as the employees and to take the interests of the employees into account when deciding what information to give them. To create a positive attitude and to avoid ambiguous messages will also improve communication and lessen the anxiety felt. / Denna uppsats avser att undersöka ämnet kommunikation och dess länkar till oro. Den använda metoden är intervjuer i samband med en grounded theory ansats. Vi fann att det är en antal olika typer av missförstånd som kan uppkomma mellan ledningen och de anställda, vilka även leder till att den upplevda oron hos de anställda stiger. Viktiga aspekter för ledningen att tänka på är att använda flera kommunikations kanaler och att välja kanal beroende av meddelandets innehåll. Det är också nödvändigt för ledningen att förmedla information på de anställdas kunskapsnivå och att tänka på vad de anställda kan förväntas vara intresserade av. Att skapa en positiv attityd och att undvika tvetydiga meddelanden kan också förbättra kommunikationen och minska den upplevda oron.

This thesis provides an experimental approach to abstract anaphora resolution in Turkish written discourse. The core of this work consists of identifying various manifestations of abstract anaphoric expressions &ndash / bu vs. bu durum, bu olay, bu is, bu ger&ccedil / ek (bu as the bare abstract object anaphor vs. bu+label abstract anaphors)- in Turkish discourse, and investigating whether any difference is observed in their processing. To this end, two offline experiments are conducted with human subjects, and the results indicate that label anaphors, compared to the bare anaphor bu, have a tendency to disambiguate the antecendent in some cases.

This thesis provides an experimental approach to abstract anaphora resolution in Turkish written discourse. The core of this work consists of identifying various manifestations of abstract anaphoric expressions &ndash / bu vs. bu durum, bu olay, bu is, bu ger&ccedil / ek (bu as the bare abstract object anaphor vs. bu+label abstract anaphors) - in Turkish discourse, and investigating whether any difference is observed in their processing. To this end, two offline experiments are conducted with human subjects, and the results indicate that label anaphors, compared to the bare anaphor bu, have a tendency to disambiguate the antecendent in some cases.

In any organization, formal and informal face-to-face meetings make up a profound part in the daily life of its members. Meetings are played out continuously, some formal, such as a management board meeting, an information meeting, or a project meeting. The formal meetings people “attend to”, “participate in”, or “are in charge of” depending on a person’s position within them. Other meetings are less formal, such as a desk-side discussion, a chat in the hallway, or a private conversation between two colleagues. The latter often just appear, seemingly by chance. This dissertation examines meetings, as a way of observing the organizing process of complex product development projects. More specifically, organizations engaging in complex product development can be viewed as tension systems, where the dominant tension is between innovation and control. From this perspective, a critical challenge for a product development project becomes one of managing a balancing act between individual action and creativity, on one hand, and collaboration and control, on the other, ensuring that ideas and knowledge retrieved by their parts can be pooled into an integrated whole. By studying the interplay between different types of face-to-face meetings that took place in two projects developing telecommunication systems, this thesis engages in an inquiry of how this balancing act was played out in practice. The findings of the study suggest that the informal meetings comprised occasions that facilitated the perception of complex and ambiguous issues and gave rise to innovative interpretations of how to deal with them. When issues have been defined and interpreted, formal meetings were used to “elevate” and “enter” them into a formal existence. Then, formal claims for action could be established in which people in the projects were organized around the task of solving a specific and recognized problem.  Thus, formal meetings served as a controlling and structuring function. / <p>Diss. Stockholm : Handelshögskolan, 2002</p>

The objective of the proposed research is to develop a new algorithm for range and Doppler ambiguity resolution in radar detection data using L1 minimization methods for sparse signals and to investigate the properties of such techniques. This novel approach to ambiguity resolution makes use of the sparse measurement structure of the post-detection data in multiple pulse repetition frequency radars and the resulting equivalence of the computationally intractable L0 minimization and the surrogate L1 minimization methods. The ambiguity resolution problem is cast as a linear system of equations which is then solved for the unique sparse solution in the absence of errors. It is shown that the new technique successfully resolves range and Doppler ambiguities and the recovery is exact in the ideal case of no errors in the system. The behavior of the technique is then investigated in the presence of real world data errors encountered in radar measurement and detection process. Examples of such errors include blind zone effects, collisions, false alarms and missed detections. It is shown that the mathematical model consisting of a linear system of equations developed for the ideal case can be adjusted to account for data errors. Empirical results show that the L1 minimization approach also works well in the presence of errors with minor extensions to the algorithm. Several examples are presented to demonstrate the successful implementation of the new technique for range and Doppler ambiguity resolution in pulse Doppler radars.

A helicopter based system equipped with a millimetre-wave fire control radar is studied for improvement of the detection probability for moving ground targets. The system is a pulse doppler radar that sends out the electromagnetic wave in repetitive pulses. The frequency in which radar sends this pulse is called Pulse Repetition Frequency (PRF). The velocity of the moving targets is measured by spectral analysis of the pulses received. With this sort of system some targets will not be possible to detect. These targets are said to be blind for the radar. Also the measured targets can be ambiguous. A solution to this is to shift PRF during the time the radar emits itspulses on the target. This method is called PRF block staggering. The antenna is mounted on a mechanical sweep on top of the rotor of the helicopter. Because of this the time on target is limited. This means that the measured velocity resolution of the radar is also limited. With the studied method it is possible to resolve range and velocity ambiguities. This is under the condition that it is acceptable with a reduction in the velocity resolution by a factor equal to the number of PRF blocks used. The work leading to this thesis included developing a program in Mathworks Matlab for studying different configurations of PRFs and the effect on the detection probability.