Showing papers by "Saab AB published in 2003"

Work attendance despite headache and its economic impact: a comparison between two workplaces.

Abstract: Objective.—To study work attendance despite headache in 2 different workplaces and its economic impact. Background.—Literature on the economic impact of headache traditionally has focused on direct costs. Little is known concerning headache experienced at work and its costs due to loss of effectiveness and productivity. Method.—We sent a questionnaire to 800 employees in Sweden—400 at a technology company (private employee population) and 400 at a university hospital (public employee population). We attempted to assess the prevalence of headache, work attendance despite the presence of acute headache, and the impact of acute headache upon work effectiveness. Subjects self-scored decreased work effectiveness resulting from headache during the previous 3 months and recorded the number of days at work despite headache. From these data, we estimated the economic loss resulting from headache. Results.—The survey response rate was 71.5%. The prevalence of headache was 64% in the private employee population and 78% in the public employee population. Thirty-nine percent of the private employees and 57% of the public employees reported experiencing headache as a result of stress. Fifty percent reported that they went to work despite headache, and the mean number of days at work despite headache, during the previous 3 months, was 6.6 days in the private employee group and 6.1 days in the public employee group. A 25% decrease in work effectiveness was estimated, and, extrapolating from our data, we calculated the cost of lost effectiveness due to headache among employers in Sweden to be approximately 1.4 billion euros a year. Conclusion.—The economic burden of headache experienced at work is substantial, suggesting that workplace-based treatment and prevention programs emphasizing stress management may be financially, as well as clinically, advantageous.

An acoustic liner, use of such a liner and method for manufacturing an acoustic liner

Abstract: The present invention relates to an acoustic liner (1) arranged to attenuate sound. The acoustic liner (1) comprises a top sheet (5) having substantially linear characteristics and a liner core (2) or cavity. The top sheet (5) comprises a layer (3) of a metallic foam. The invention also relates to the use of said acoustic liner in a hot stream environment such as the outlet of an aircraft engine, and to the manufacture of an acoustic liner.

Method of forming a composite structure

Abstract: The present invention relates to methods for forming composite structures and composite structures formed by these methods. The methods include arranging a stack of prepreg sheets on a mold. The composite material is substantially sealed within a vacuum bag. One or more vacuum ports extend through the vacuum bag. Vacuum is applied through the vacuum ports for drawing air from the stack of prepreg sheets. Air in the space between adjacent prepreg sheets in the stack is evacuated through at least one less-impregnated layer within a least one of the two adjacent prepreg sheets. The less impregnated layer communicates with the vaccum port. The process may be repeated until the stack comprises a predetermined number of prepreg sheets. The composite material is cured and the structure is released from the mold and the vacuum bag, thus providing a composite structure formed from evacuated, cured stack of prepreg sheets.

Method and system for calculating a flight route

Abstract: The invention concerns a method and a system for calculating a flight route between a first position and a second position. According to the method, the first position is chosen as the current position, and the following steps are then repeated until the second position is reached: a loss function is determined corresponding to each flight path in a set of flight paths that are predefined in relation to the current direction of flight; a flight path that yields the most advantageous value for the loss function is selected; a subsection from the current position and a predetermined number of positions forward are registered for the selected flight path, and the position at the end of the subsection is chosen as the new current position.

A method for correlating and numbering target tracks from multiple sources

Abstract: The invention relates to a method for correlating target tracks (14) from multiple track sources into a single situation picture (15). Here the track sources are comprised of various sensors (11) and target tracking systems (12). The track correlator (13) embodies the new correlation method, which, unlike previous art, is based on correlating the tracks (14) to target numbers. A large number of correlation hypotheses are evaluated along with the probability for each hypothesis. The method runs recursively: existing probabilities are propagated until the current point of time, and then new probabilities are computed, e.g. using Bayes' rule, according to how well each hypothesis fits with the observed track data. To reduce the number of hypotheses that have to be handled individually, a simplified scheme is introduced where each track (14) is characterized by one (or more) target number and the corresponding probability, and where each target number is characterized by the probability that it represents a real and trackable target. The simplified representation is particularly useful for distributed correlation, where a number of correlators run at different sites, to form a common situation picture with common track numbers. Further, as the number of hypotheses can be very large, methods for just evaluating the most plausible hypotheses have been suggested.

Method of extending countermass weaponry usability and of countermass weaponry produced in accordance therewith

Abstract: The subject invention concerns a method and a device enabling said packed countermass material (11) to open up said countermass packagings (10) in relation to the firing of countermass weaponry. The basic concept for the subject invention is, thus, that one near the rear outlet end (12) of a countermass weapon (1) barrel fashion a number of blades (15) to the interior of the outlet that protrude inwardly into the barrel sufficiently so as to cut into said countermass container (10), which is pressed past said blades (15) upon firing said weapon (1).

Radio signal positioning

Abstract: Positioning of a mobile signal transmitter. A respective distance between the transmitter and each of a plurality of sensors is determined based on a direct sequence spread spectrum signal. A transmission delay of the signal is estimated with high accuracy by, in each sensor, cross-correlating an over-sampled representation of the signal with an appropriate local spreading sequence, which contains poly-phased symbol values being different from a set of symbols in the direct sequence used to spread the transmitted signal. The local spreading sequence has a nominal chip period, which is equivalent to the chip period of the over-sampled representation of the signal.

Electrically controlled broadband group antenna, antenna element suitable for incorporation in such a group antenna, and antenna module comprising several antenna elements

Abstract: An electrically controlled group antenna including an antenna element suitable for incorporation in such a group antenna and an antenna module including several such antenna elements. The antenna elements include a rotationally-symmetrical body tapering towards one end of the body. The rotationally-symmetrical body is provided with a metallic casing surface. Several antenna elements are arranged separately on a common earth plane. A broadband group antenna is achieved that, among other things, is simple in design and is easy to manufacture and repair.

Event driven digital signal processor with time constraints

Abstract: The present invention relates to an event driven digital signal processor 1 comprising: a central arithmetical unit 5 , a register 4 , a controller 3 , an instruction memory 2 , and input/output devices. The instruction memory 2 is arranged to include time performance constraints and events. An event control unit 6 is arranged to recognize an event and to control processing to be carried out as a consequence of the event while fulfilling the time performance constraints. The controller 3 is arranged to suspend processing of the time performance constraints after initiating operations in the event control unit 6 . The controller 3 resumes processing when advised by the event control unit 6.

Method for conversion of waveguide modes, mode-converting arrangement and antenna arrangement.

Abstract: The invention relates to a method for conversion of waveguide modes from a mode of type TM01 to mode of type TE11 for transmission of power within the microwave range. The invention also relates to a mode-converting arrangement and an antenna arrangement with such a mode-converting arrangement. The mode-converting arrangement comprises an incoming waveguide (1) for reception of power of the type TM01, an outgoing waveguide (6) for outputting power of mode type TE11 and a waveguide-mode-converting section (2-5) arranged between the incoming and outgoing waveguides. According to the invention, incoming power of mode type TM01 is divided in an input section (2) between two or more waveguides with cross-sections in the shape of circle sectors. Thereafter, the divided power is phase-shifted by the waveguides in a subsequent phase-shift section (4) being designed with cross-sections that are essentially in the shape of circle sectors with different radii, after which the waveguides are changed into a common essentially circular waveguide (6) that emits an otugoing power of mode type TE11. By means of the invention, a relatively simple solution is produced, that can cope with high powers.

Passive terrain navigation

Abstract: The present invention relates to terrain navigation wherein an earth-reflected satellite signal is received from at least one reference signal source whose position is known ( 120 ), for example a navigation satellite. Based on information contained in the received signal a measured estimate of a shortest reflection distance (d 1 (t b )) to the satellite ( 120 ) is derived. A relative spatial movement (Δx, Δy, Δh) of a relevant craft ( 110 ) since a previous positioning instance (t a ) is registered onboard the craft ( 110 ). Moreover, stored surface information is retrieved pertaining to an elevation (h 1b ) of the earth surface (130) in relation to the mean sea level (z 0 ) at at least one geographical position (x 1b , y 1b ). Based on the relative spatial movement (Δx, Δy, Δh) and the retrieved surface information at least one calculated estimate of the shortest reflection distance (d 1 (t b )) to the satellite ( 120 ) is derived. Finally, a geographical position (x 1a , y 1a , h 1a ) is determined on basis of the measured and calculated estimates of the shortest reflection distance (d 1 (t b )). Thus, a highly reliable and entirely passive positioning may be accomplished on basis of external signals from as few satellites ( 120 ) as one.

Method and device for aligning sight and barrel

Abstract: The present invention relates to a method and an arrangement for use with a barrelled weapon for aligning the centre line of the barrel (2) with the weapon’s sight (3). The invention is primarily intended to be used with such barrelled weapons (2) as are mounted on a gun carrier 81), such as a tank or the like, and which have a sight (3) that is mounted separately on the gun carrier (1). The invention is characterized in that, during aligning, an image-generating sensor (9) is used as reference for the centre line of the barrel, which image-generating sensor is moved forward through the barrel from its breech to a position immediately inside its muzzle, and which image-generating sensor has its line of vision along the direction of fire of the barrel.

Method for planning a trajectory

Abstract: The present invention relates to planning of a trajectory for minimum threat exposure in a given geographical region. A trajectory is planned from a start node to a final node in a digital representation of the geographical region. The threat exposure for a vehicle moving along the trajectory is determined. Navigation performance of the vehicle along the trajectory is evaluated. A rate of survival based on threat exposure and navigation performance along the trajectory is estimated. A new trajectory is planned from the start node to the final node until a best rate of survival is established for the planned trajectory.

Nuclear, biological or chemical warfare simulator

Abstract: The present invention relates to a method for training behavior during a nuclear, biological or chemical warfare attack, including a number of players. The method is characterized in determining exposure to a simulated nuclear, biological or chemical attack for each player; providing a signal indicating said exposure in at least one alarm simulator unit, said alarm simulating unit generating an audio/visible alarm signal; and establishing the effect of said exposure for each player.

A Modeling Approach of a Magnetic Amplifier

Abstract: New soft magnetic materials made possible the use of the magnetic amplifier technology in designing competitive electric power supplies. This technology is used in the Swedish. fighter aircraft Gri ...

Holding device for an item and a method for hardening together said item

Abstract: The invention concerns a holding device for holding an item ( 3 ) in connection with hardening of the item under elevated pressure in a pressure tank. The holding device includes one or more support elements that entirely or partly surround the lateral surfaces of the item and are arranged to support the item ( 3 ) during hardening. The holding device is characterized in that at least one of the support elements ( 4 a ) is arranged in relation to the item in such a way that the support element ( 4 a ) presses, in a first region along its length, against the item with a pressure that is elevated relative to the pressure-tank pressure and, in a second region along its length, presses against the item with a pressure that is lower relative to the pressure-tank pressure.

Application-oriented synthesis of work

Abstract: The current main chapter contains 14 contributions which cover all applications treated within the context of UNSI. Emphasis was placed on cross comparison of data in order to support potential scientists in their own work on validation/verification of all these test cases.

Recoilless weapon system and method for use of such a system

Abstract: The subject invention concerns a method and a device enabling said packed countermass material (11) to open up said countermass packagings (10) in relation to the firing of countermass weaponry. The basic concept for the subject invention is, thus, that one near the rear outlet end (12) of a countermass weapon (1) barrel fashion a number of blades (15) to the interior of the outlet that protrude inwardly into the barrel sufficiently so as to cut into said countermass container (10), which is pressed past said blades (15) upon firing said weapon (1).

Electrically controlled broadband group antenna

Abstract: A broadband group antenna, comprising a plurality of antenna elements (3) and an earth plane element (2), wherein the antenna elements (3) are arranged in a common plane on top of the earth plane element (2) and connected to a microwave transceiver unit (11) via conductors provided in channels that extend through the earth plane element (2) in a direction perpendicular to a main extension plane of the earth plane element (2), the antenna elements(3) are arranged in a matrix pattern comprising first rows (14) extending in a first direction (y) and second rows (15) extending in a second direction (x) perpendicular to said first direction (y), wherein the antenna elements (3) are in alignment with each other in said first rows (14) and in said second rows (15).First and second channels (13) via which the first and second conductors (10', 10'') of each of said plurality of antenna elements (3)of said one first row (14) are configured to be connected to a microwave transceiver unit (11)are in alignment along a line parallel with said first direction (y).

Method for reinforcing a core and article containing said core

Abstract: This invention concerns a method for reinforcing a core ( 2 ) constructed of at least two core parts ( 2 a, 2 b, 2 c, 2 d ), each of which exhibits a top side, a bottom side and walls joining the top side and bottom side. The core parts ( 2 a, 2 b, 2 c, 2 d ) are arranged joined wall-to-wall with one another along a joint seam ( 4 a, 4 b, 4 c ) filled with glue, preferably in the form of a glue film. The method is characterized in that notches ( 5 a, 5 b, 5 c ) are realized in a number of places in the glue joint, which notches extent between the walls from the top side to the bottom side of the core parts so that the glue joint can be divided into pieces. The invention also encompasses an article fabricated in accordance with the aforementioned method.