An apparatus for producing a low-PMD optical fiber having a furnace for melting a lower portion of an optical preform; a traction device for pulling an optical fiber from the lower portion of an optical preform; a spinning device for imparting a substantially constant and unidirectional spin to the optical fiber as it is pulled, which causes the fiber to undergo an elastic torsion; a winding device for winding the optical fiber onto a reel; and a twisting device for imparting to the spun optical fiber a unidirectional twist in a direction opposite the elastic torsion, so as to control the residual twist in the optical fiber. A process for producing the fiber, an optical fiber and a cable are also provided.

1. Field of the Invention
The present invention relates to a process for producing a low-polarization mode dispersion optical fiber.
2. Description of the Related Art
Optical signals transmitted through single-mode optical fibers comprise two orthogonal polarization modes (typically denoted TE and TM) that, in case of a fiber with a perfectly cylindrical core of uniform diameter, propagate at a common velocity. However, in real optical fibers the core cylindrical symmetry may be disrupted due to shape defects or non-uniform stresses. As a result, a phase difference can accumulate between the two modes, and the fiber is said to show "birefringence". In particular, the birefringence introduced by shape and stress asymmetry is known as "intrinsic linear birefringence".
The structural and geometrical irregularities of the optical fiber that give rise to birefringence typically originate from the preform itself and are modified during the process of drawing the fiber. This process is usually carried out by means of an apparatus known as a "drawing tower", starting from a glass preform. In practice, after the preform has been placed in a vertical position and heated to a temperature above the softening point within a suitable furnace, the molten material is drawn downwards at a controlled velocity in such a way as to produce a threadlike element that forms the optical fiber itself. In this process, asymmetrical stresses are typically applied to the fiber.
In a birefringent fiber, the two components of the fundamental mode, initially in phase with each other, come to be in phase again only after a certain length, commonly known as the "beat length". In other words, the beat length is the period of repetition of a certain state of polarization (on the assumption that the fiber maintains a constant birefringence over this length).
In the so-called "polarization-preserving fibers", asymmetry is deliberately introduced into the fiber to generate birefringence. However, in ordinary (i.e. non-polarization-preserving) fibers, birefringence is detrimental. In fact, when pulsed signals are transmitted into an optical fiber, the birefringence is a potential cause of pulse spreading, since the two polarization components excited by the pulses travel at different group velocities (i.e. become dispersed). This phenomenon, known as polarization mode dispersion (PMD), has been widely studied in recent years because of its importance in periodically amplified light guide systems.
Typically, the phenomenon of PMD leads to a limitation of the width of the signal transmission band and, consequently, a degradation of the performance of the optical fibers along which the aforesaid signals are transmitted. This phenomenon is therefore undesirable in systems of signal transmission along optical fibers, especially in those operating over long distances, in which it is necessary to minimize any form of attenuation or dispersion of the signals to guarantee high performances in transmission and reception.
U.K. patent application GB2101762A considers the effects on PMD of post-draw fiber twisting and observes that, although this twisting reduces the PMD resulting from intrinsic linear birefringence, it introduces torsional stresses that generate a substantial circular birefringence due to the photo-elastic effect. Twisting a drawn fiber thus reduces the bandwidth limitation due to one effect whilst replacing it with another. The same patent application thus propose to spin the preform during drawing, so that twisting can be effected whilst keeping the fiber material substantially unstressed. Spinning is performed at a relatively high rate, so that its spatial repetition frequency, or spin pitch, is small compared to the beat length due to intrinsic birefringence; as a result, an optical fiber is formed wherein the contribution of birefringence due to form and stress asymmetry is greatly reduced. Such a fiber is termed "spun" fiber to distinguish it from a twisted fiber. Conveniently the preform is spun at a substantially constant rate, but it could even reverse in direction, oscillating from a right-handed to a left-handed twist.
Due to spinning, the fiber undergoes a rotation of its polarisation axes. As a result, when the optical pulses are transmitted into the optical fiber, they propagate alternately on the slow and fast birefringence axes, thus compensating the relative delay and reducing the pulse spreading. This is equivalent to have a local effective refractive index for the pulses equal to the mean refractive index on the two axes, the average being taken over the pulse length along the fiber.
Theoretical studies have been carried out to analyse the effects of spinning on birefringence. For example, the article of A. J. Barlow et al., "Anisotropy in spun single-mode fibers", Electronics Letters, 4 Mar. 1982, Vol. 18, No. 5, shows that the dominant process for the reduction of PMD in a spun fiber is the averaging of the local fiber anisotropy by the rapid procession of the axes of asymmetry along the fiber. A further theoretical contribution is provided by the article of M. J. Li, "Effects of lateral load and external twist on PMD of spun and unspun fibers", ECOC '99, 26-30 Sep. 1999, Nice, France, which proposes a novel model (based on the coupled mode theory) to analyse the effects of lateral loads and external twist on PMD of spun and unspun fibers.
Apart from theoretical considerations, several techniques have been developed to reduce the PMD of an optical fiber, which take advantage of the effects of spinning during drawing.
Similarly to U.K. patent application GB2101762A, U.S. Pat. No. 5,581,647 describes a method of fabricating a dispersion compensation optical fiber, wherein the fiber is drawn while the preform is rotated about its axis. Particular process conditions are herein described: the fiber shall be drawn at a speed between 50 and 1,000 m/min and at a tension between 2.4 and 13 kg/mm2, and the preform rotated at a speed between 10 and 1.000 rpm.
International patent application WO 97/26221 observes that the reduction in PMD produced by spinning is proportional to the spin rate, that very high spin rates are generally required to deal with the asymmetries of typical fibers, e.g., spin rates greater than 5,000 rpm, and that spinning a preform at such rates is not a practical solution for commercial fiber production.
U.S. Pat. No. 4,504,300, relating to a technique for making an optical fiber having chiralic structure, addresses drawbacks related to preform rotation and proposes a new spinning technique, consisting in rotating the fiber instead of the preform. In particular, a device is disclosed comprising means disposed just below the preform for twisting the fiber during fiber drawing. The twisting means comprise a rotating hoop supporting three pulleys. The twisted fiber is coated by coating means, followed by cooling by fast-cooling means that facilitate freezing-in of the twist.
As observed in WO 97/26221, a drawback associated to this technique is connected to the high risk of damaging the fiber surface due to the fact that the latter gets in touch with the above-mentioned pulleys before being properly protected by a suitable coating film.
In order to overcome this drawback, U.S. Pat. No. 5,298,047 and U.S. Pat. No. 5,418,881 propose to arrange the device adapted to apply the torque to the fiber downstream of the coating station. In particular, in the techniques herein described, the torque is applied by alternately canting in clockwise and counterclockwise direction a fiber guiding roll having a rotation axis which extends perpendicularly to the drawing axis of the fiber.
US patent application N. 2001/0020374 observes that, although substantially achieving the object of reducing the PMD of the fiber, the use of a canting roll shows a series of problems (for example the need of limiting the canting frequency to avoid a relative sliding between fiber and roll) and is only suitable for the application of an alternate (i.e. bidirectional) spinning to the fiber. However, although a new device is proposed that overcomes the drawbacks of the canting-roll technique and allows both unidirectional and alternate spinning, alternate spinning is still considered as preferable since it prevents the presence of residual torsions on the fibers wound onto the collecting spool, thus making easier both the unwinding and wiring operations of the same.
The possible presence of unwanted elastic twist is also noticed in U.S. Pat. No. 5,298,047, in relation to the application of an intermittent torque to the fiber. Apart from stating that it is generally desirable to remove the elastic twist, for instance by appropriate respooling, the Authors of that patent consider as preferable to alternately impose a clockwise and a counteclockwise torque to the fiber to substantially prevent introduction of the elastic twist.
The Applicant observes that alternate spinning has several drawbacks not previously highlighted. Alternate spinning may for example cause a relatively low mechanical efficiency of the spinning device, due to the continuous accelerations and decelerations. Moreover, with respect to a unidirectional spin, an alternate spin requires a relatively high peak profile amplitude to compensate those positions of the profile where the rotation slows down to change direction and, therefore, to guarantee a sufficient average spin rate. Besides, the sites where the spin rate is zero are detrimental for the PMD because there is an increase of the effective birefringence seen by the pulse, and so a higher contribution for PMD.
The Applicant has therefore considered again the use of unidirectional spin, and tried to solve the problems associated thereto. The Applicant has verified that, to achieve an efficient PMD reduction, a technique making use of unidirectional spin must take into account the effects of spin and of the circular birefringence induced by elastic twist as well.

Optical fiber having a low polarization mode dispersion and process and apparatus for producing it


A sound absorbing mechanism using a porous material has a sound absorbing plate of a thin plate porous material made by partially heating for welding plastic particles and a supporting member for supporting the sound absorbing plate and forming a back air space. More than one pair of resonators having a separated back air space in the aforementioned back air space are fixed to the sound absorbing plate, and the resonators are disposed to be opposed to a sound insulator with the supporting member between. Plural reflecting members or increased sound absorbers may be disposed to be opposed to the surface of the sound absorbing plate opposite to the surface equipped with the resonators, or a perforated protecting plate fixing the plural reflecting members or the increased sound absorbers thereon are may be equipped. The sound absorbing mechanism has a superior sound absorption characteristic from lower frequencies to higher frequencies.

1. Field of the Invention
This invention relates to an improvement of a sound absorbing mechanism to be placed around a noise generating source or in a propagation path of a noise, and more particularly relates to a sound absorbing mechanism using a porous material.
2. Description of the Prior Art
Prior Art 1
FIG. 44 is a sectional view showing the construction of a conventional sound absorbing mechanism using a hard porous material as a first prior art (prior art 1), and the figure also has an explanatory diagram for showing a sound pressure distribution of a sound wave to be input into the sound absorbing plate thereof. In FIG. 44, reference numeral 1 designates a sound insulator such as a wall: and numeral 2 designates a sound absorbing plate of a hard porous material made of plastic particles, a ceramic, foam metal or the like, for example. Reference numeral 11 designates a back air space of the sound absorbing plate 2; numeral 11a designates the thickness of the back air space 11; numeral 81 designates an input sound; reference character .beta. designates an average input angle of the input sound 81; and character .lambda. designates a wavelength of a sound wave having the highest sound pressure level among the input sounds 81. In the explanatory diagram showing a sound pressure distribution, mark + designates the operation of positive pressure on the sound absorbing plate 2; and mark - designates the operation of negative pressure on the sound absorbing plate 2. Arrows 85 and 86 designate directions of an input sound wave operating on the back air space 11 through the sound absorbing plate 2.
Next, the operation thereof will be described. The input sound 81 passes through the sound absorbing plate 2 to be input into the back air space 11. The sound absorbing plate 2 has acoustic mass m and acoustic resistance r as the acoustic characteristics thereof, and the back air space 11 has acoustic capacity c as the acoustic characteristic thereof. The acoustic equivalent circuit according to the acoustic characteristics of the sound absorbing plate 2 and the back air space 11 can be expressed as a series resonance circuit of r-m-c. According to this series resonance circuit, the resonance frequency thereof f.sub.0 is expressed as the following formula. EQU f.sub.0 =(1/2 .pi.).times..sqroot.(1/mc) (1)
When a sound wave having a frequency close to this resonance frequency f.sub.0 is input into the sound absorbing plate 2, the input impedance observed from the sound source side becomes minimum. Accordingly, only the acoustic resistance r of the sound absorbing plate 2 should be considered. If the acoustic resistance r of the sound absorbing plate 2 is tuned to be a value close to the characteristic impedance .rho..times.a (.rho.: density of air; a: sound velocity) of air, the sound absorption coefficient becomes 1.0 at the resonance frequency f.sub.0. Consequently, the sound wave having the frequency close to the resonance frequency f.sub.0 penetrates into the sound absorbing mechanism most efficiently. The penetrated sound wave forces the air existing in the back air space 11 and having an acoustic characteristic of acoustic capacity c to vibrate. The vibrated air goes in and out through gaps in the sound absorbing plate 2, and the sound wave is transformed into thermal energy by the acoustic resistance r of the gaps. That makes it possible to radiate energy. This means that the energy of the input sound wave was absorbed in the sound absorbing mechanism, namely sound absorption has been performed.
In the aforementioned sound absorption mechanism, it is known that the efficiency of sound absorption is highest in the case where the input sound 81 is input into the sound absorption plate 2 perpendicularly. That is to say, in the case where a sound wave is input perpendicularly, the phase relation of the sound wave on the top surface of the sound absorbing plate 2 is equal at any place on the top surface, and the whole of the sound absorbing plate 2 and the whole of the back air space 11 are unified consequently, so that the effective operation of resonance and sound absorption is performed. On the other hand, the case where the input sound 81 is input into the sound absorbing plate 2 not perpendicularly but at a certain input angle .beta. ill be considered as an ordinary case. As shown in FIG. 44, when a sound wave having a wavelength .lambda. is input into the sound absorbing plate 2 at an input angle B, a phase difference having a period of .lambda./cos (.beta.) of sound pressure distribution is generated on the sound absorbing plate 2. A sound wave is basically absorbed by utilizing a resonance phenomenon. But, if a distribution of the strength of sound pressure is generated along a direction on a surface of the sound absorbing plate 2, pressures 85 and 86 having reverse directions to each other operate on the back air space 11, so that adjoining parts of the back air space 11 is acoustically oscillated reversely. Then, pressures are balanced in the back air space 11, and consequently it becomes difficult that air vibrations synchronized with input sound waves are generated. That is to say, it becomes difficult that resonance phenomena are generated between the sound absorbing plate 2 and the back air space 11, so that sound absorption effect is extremely checked.
Prior Art 2
FIG. 45 is a longitudinal sectional view showing a sound absorbing mechanism utilizing a sound absorbing material and a resonance phenomenon by combining them as a second prior art (prior art 2), which is shown, for example, in Japanese Patent Gazette No. 76116/1992 (Tokko-Hei 4-76117). FIG. 46 is a sound absorption characteristic diagram of the sound absorbing mechanism shown in FIG. 45. In FIG. 45, reference numeral 91 designates a wall; numerals 92 and 93 designate air spaces; numeral 94 designates a small opening or a slit; numeral 95 designates a nozzle; numeral 96 designates a porous plate; and numeral 97 designates a sound absorbing material.
Next, the operation thereof will be described. The aforementioned sound absorbing mechanism of the prior art 2 is provided with a porous plate 96 apart from the wall 91 with the air space 92 between. The porous plate 96 has a large number of small openings or slits 94, which are provided with nozzles 95 connected to them. Across the porous plate 96, the sound absorbing material 97 which is made of a fibrous material or a material made of a large number of particles is set over the whole plane at the tips of the nozzles 95 with the air space 93 between. In this connection, the air space 92, the small openings or slits 94 and the nozzles 95 comprise sound absorbing mechanisms utilizing a resonance phenomenon, and the sound absorbing material 97 and the air spaces 93 comprise sound absorbing mechanisms utilizing sound absorbing materials. The aforementioned elements of the sound absorbing mechanisms utilizing a resonance phenomenon are connected to each other through the air space 92, and the elements of the sound absorbing mechanisms utilizing sound absorbing materials are connected to each other through the air space 93.
The sound absorbing mechanism of the prior art 2 has a sound absorption characteristic of the curved line 3 shown with a solid line in FIG. 46. A sound absorption characteristic of a sound absorbing mechanism utilizing only a resonance phenomenon is shown with a dotted line (curved line 2) in FIG. 46, which sound absorbing mechanism has large sound reduction effects at lower frequencies. A sound absorption characteristic of a sound absorbing mechanism utilizing only sound absorbing materials is shown with a dashed line (curved line 1) in FIG. 46, which sound absorbing mechanism has large sound reduction effects at higher frequencies.
Prior Art 3
FIG. 47 is a partially cutaway perspective view showing the construction of a conventional sound absorbing mechanism as a third prior art (prior art 3), which utilizes both the slits and a porous material and is shown, for example, at pp. 245-250 and pp. 351-356 of Kenchiku Onkyo Kogaku Hando Bukku (Architectural Acoustics Handbook) ed. by Nippon Onkyo Zairyo Kyokai (Japan Acoustical Materials Association) (Gihodo, Tokyo, 1963). FIG. 48 is a sound absorption characteristic diagram of the sound absorbing mechanism shown in FIG. 47. In FIG. 47, reference numeral 91 designates a wall; numerals 92 and 93 designate air spaces; numeral 98 designates a porous material; and numeral 99 designates a slit plate.
Next, the operation thereof will be described. The aforementioned sound absorbing mechanism of the prior art 3, which uses a structure utilizing slits and a porous material, raises the sound absorption characteristics of the porous material 98 and the air space 92 by means of the resonance phenomena of the slit plates 99 and the air spaces 93. As shown in FIG. 48, the raised sound absorption characteristics are particularly effective at lower frequencies around 200 to 500 Hz due to the resonance phenomena at the slit parts.
Since the sound absorbing mechanism of the prior art 1 is constructed as mentioned above, the resonance frequency f.sub.0 is determined in accordance with the thickness 11a of the back air space 11 if the sound absorbing plate 2 is specified. The sound absorption coefficient becomes maximum at the resonance frequency f.sub.0, and the sound absorption characteristic has large values in a narrow frequency band with the resonance frequency f.sub.0 as a 1/3 octave band center frequency. Since some sound pressure distributions are generated in some directions on the sound absorbing plate 2 when sound waves are input into the sound absorbing plate 2 at angles other than a right angle, the prior art 2 has a problem that the interference of input sound waves is generated at some frequencies according to phase differences to bring about the reduction of the sound absorption coefficient.
Since the sound absorbing mechanism of the prior art 2 is constructed as mentioned above so that a sound absorbing mechanism utilizing a resonance phenomenon to be generated by elements connected to each other and a sound absorbing mechanism utilizing sound absorbing materials connected to each other are combined to absorb sound waves, the prior art 2 has problems that some sound pressure distributions are generated in some directions on the sound absorbing material 97 when sound waves are input into the sound absorbing material 97 at angles other than a right angle similarly in the prior art 1, so that the interference of input sound waves is generated at some frequencies according to phase differences to bring about the reduction of the sound absorption coefficients at lower frequencies as shown in, for example, FIG. 46.
The sound absorbing mechanism of the prior art 3, which utilizes slits and a porous material, has a problem that the sound absorption coefficients at lower frequencies around 200 Hz to 500 Hz are large due to sound resonance phenomena at the slits but the sound absorption coefficients at higher frequencies more than 500 Hz are small.

Sound absorbing mechanism using a porous material

Mitsubishi Electric Home Appliance Co., Ltd.


A method of determining a directional change of a vehicle carries out dead-reckoning for which it utilizes sensors provided on two wheels. In order to compensate for differences between the wheels, the method utilizes given parameters in processing the data from the wheel sensors. The invention provides an extension of the method by estimating the parameters during normal operation of the vehicle, so that they are adapted to changing circumstances encountered by the vehicle. Estimation is performed by comparing data from the wheel sensors with independently determined directional data for a given period of time.

The invention relates to a method of determining a directional change during navigation, comprising a left wheel sensor and a right wheel sensor, each of which is operative to supply pulses which are a measure of excursion of an associated wheel, which method comprises the following steps for a sampling interval:
recording a number of pulses pL from the left wheel sensor and a number of pulses pR from the right wheel sensor, PA1 supplying a left correction factor ratioL and a right correction factor ratioR, PA1 determining the directional change from (ratioL.times.pL-ratioR.times.pR). PA1 a left input for receiving a signal pL which is representative of the number of left pulses, PA1 a right input for receiving a signal pR which is representative of the number of right pulses, PA1 storage means for storing a left correction factor ratioL and a right correction factor ratioR, PA1 arithmetic means which are coupled to the left input, the right input and the storage means in order to calculate (ratioL.times.pL-ratioR.times.pR). PA1 the above steps are executed, during operation of the vehicle and during a number of sampling intervals, for each sampling interval there being collected values for pL and pR and a directional change being independently determined, and PA1 by comparison of the values collected for pL and pR and the independently determined directional changes, for further use a first estimate is made for the left correction factor and a second estimate is made for the right correction factor. PA1 a further input for receiving information relating to a series of directional changes, PA1 further arithmetic means for associating the series of directional changes with series of left pulses and right pulses in order to make a first estimate of the left correction factor and a second estimate of the right correction factor.
The invention also relates to an apparatus for determining directional changes, comprising
The invention also relates to a vehicle provided with such an apparatus.
A method of this kind forms a part of the determination of the position of a vehicle on a dead-reckoning basis. During the determination of the position of a vehicle on the basis of dead-reckoning, a next position is determined on the basis of the position of a vehicle at a given instant and the data acquired from vehicle sensors. Such a method of determining directional changes of a vehicle is known from U.S. Pat. No. 4,791,574 (PHN 11.122). The cited Patent relates to the determination of a directional change on the basis of data from two independent sources, i.e. from wheel sensors and from a compass sensor. The combination of data from the two sources results in improved determination of the directional change.
Such a method is also known from U.S. Pat. No. 5,307,278 (PHN 13.395) in which a calculated position, determined on the basis of a directional change obtained from the wheel sensors, is compared with feasible positions determined on the basis of data from a cartographic data base. If the calculated position deviates from a position determined from the route followed and by means of the cartographic data, the calculated position is corrected and the corrected position is subsequently used for a next position calculation.
The cited Patent Specifications utilize a directional change calculated from the wheel sensor data so as to determine a next position of the vehicle. This is done by determining the path travelled by each of the wheels, followed by calculation of the directional change from the difference. It has been found in practice that this method of determining a directional change is insufficiently accurate. Because the inaccuracies accumulate, in the course of time an unacceptable error occurs in the direction thus determined, even when the deviations per individual step are small. Inaccuracies may be due to, for example wear of the tyres, loading of the vehicle and other changing circumstances. In systems which combine a directional change calculated from the wheel sensor data with data acquired in another manner, as in the cited Patent Specifications, there is also a need to enhance the accuracy.

Method of determining a directional change during vehicle navigation, apparatus for carrying out such a method, and vehicle comprising such an apparatus


A communication apparatus is provided. The communication apparatus includes a radio transceiver module and a processor. The processor receives a neighbor cell advertisement message from a serving base station via the radio transceiver module and scans neighbor base stations according to information carried in the neighbor cell advertisement message to obtain a measurement result. The neighbor base stations are scanned in a prioritized order.

1. Field of the Invention
The invention relates to a method for scanning neighbor base stations of a communication apparatus, and more particularly to a method for scanning of neighbor base stations of a communication apparatus according to a prioritized order.
2. Description of the Related Art
Orthogonal frequency division multiplexing (OFDM) is an efficient modulation scheme for signal transmission over frequency-selective channels. In OFDM, a wide bandwidth is divided into multiple narrow-band sub-carriers, which are arranged to be orthogonal with each other. The signals modulated on the sub-carriers are transmitted in parallel. Orthogonal frequency division multiple access (OFDMA) is one way of using the basic format of OFDM to support multiple access for multiple subscribers. In OFDMA, multiple subscribers simultaneously use different sub-carriers, in a fashion similar to frequency division multiple access (FDMA).
A heterogeneous network, including at least two different cells from macro, micro, pico, and femto cells, is designed to fulfill the requirement of future communication (i.e. 4G) system. In IEEE 802.16-like system, Hierarchical Cell Structure (HCS) has been proposed, and HCS is one of the promising techniques for heterogeneous network deployment. FIG. 1 shows an exemplary communication network, constructed by cells in the hierarchical cell structure. As shown in FIG. 1, hierarchical cell structure is a multi-layered network structure with cells and base stations of overlapped geographic coverage, in which base stations within a same layer have common associations and services, and may be configured independently from the base stations in other layers. Such kind of network deployment is called a heterogeneous network deployment.
However, the heterogeneous network deployment, to a certain extent, increases difficulties when exchanging neighbor cell information between the base stations and the mobile stations due to the configuration differences between the base stations. Thus, a novel scheme for managing the neighbor cell information to further improve system performance is highly required.

Methods for scanning neighbor base stations and communication apparatuses utilizing the same


A flow control device for a fluid dispenser provides independent adjustment and control of both stroke length and spring load of a needle valve which ultimately controls outward flow from a nozzle. Independent adjustment and control of stroke length and spring load enable an operator to independently set the dispensing gap which is directly proportional to dispensing rate, and the closing force of the needle valve so that a single dispenser may be used for dispensing materials of different viscosity. An axially movable stop member is aligned with a piston carried by the needle valve. A compression spring circumscribes the stop member, and a cylindrical retainer surrounds the compression spring. An axially adjustable screw holds the retainer in place, thereby holding the spring in compression between the retainer and the piston. The axial positions of the stop member and the retainer may be adjusted independently to independently set stroke length and closing force.

A typical hot melt dispenser provides for fluid flow through a body cavity and then out a nozzle orifice toward a substrate or work-piece. A needle valve located inside the dispenser body seats within a valve seat formed by the nozzle orifice, thereby preventing flow of the dispensing fluid out of the nozzle orifice. Movement of the needle valve away from the valve seat permits fluid flow out of the nozzle orifice at a rate commensurate with the dimensions of the gap between the needle valve and the valve seat.
It is desirable to accurately and adjustably control the flow of dispensing fluid through the nozzle orifice. For a given gap size between the needle valve and the valve seat, the dispensing rate will vary with the viscosity of the material being dispensed. To accurately control dispensing rate for materials having a wide range of viscosities without requiring time consuming nozzle changes, it is desirable for a fluid dispenser to provide reliable and repeatable control and adjustment of the gap between the needle valve and the valve seat.
Typically, the needle valve for dispensers of this type carries a piston at an end opposite the valve seat. The piston is centered within the body, and the application of pressurized air on one face of the piston causes the needle valve to move away from the valve seat.
To set a maximum gap between the needle valve and the valve seat, i.e., a maximum stroke distance, a stop member is housed within the body, in alignment with the piston. The stop member limits the travel distance of the piston, and hence the gap between the needle valve and the valve seat during dispensing. By providing for adjustment of the position of the stop member with respect to the piston, the maximum gap between the needle valve and the valve seat may be varied. Thus, adjustment of the position of the stop member enables a single dispenser to be used with materials which vary in viscosity.
To prevent undesired dispensing of fluid and to maintain maximum control of fluid dispensing, the needle valve is biased to a closed position. This biasing force is usually supplied by a compression spring which acts upon a face of the piston opposite the face acted upon by the pressurized air. The biasing force applied to the piston determines the closing force of the needle valve when dispensing ceases. It is necessary for the spring to maintain a sufficiently high closing force on the piston to effectively terminate dispensing with little or no dripping. Because the closing force will vary with the viscosity of the material being dispensed, it is also desirable to provide for adjustment of this applied biasing force, i.e. the spring load.
Thus, it is desirable to provide adjustability for the stop member of a fluid dispenser to control the stroke distance of the needle valve, thereby to achieve a desired flow rate for materials of varying viscosity. At the same time, it is also desirable to provide adjustability for the spring load used to bias the needle valve to a closed position.
Applicant's U.S. Pat. No. 4,801,051, entitled "Flow Control Devise for Fluid Dispensing Apparatus", and which is expressly incorporated by reference herein in its entirety, discloses a device which provides for microadjustment of the stroke length of a hot melt dispensing module. This device provides for adjustment of both stroke length an closing force to enable a single dispensing gun to be used with materials of different viscosities.
However, because of the structural arrangement of the stop member and the compression spring of this dispenser, adjustment of the position of the stop member also affects the spring load, while adjustment of the spring load affects the stroke length. As a result, it is difficult to simultaneously quantify both of these parameters, i.e., closing force and gap size, to achieve predetermined and predictable results in dispensing fluids of varying viscosity from a single dispensing gun. Typically, after changing over to a different dispensing fluid, an operator must run several tests to verify that the adjustable settings of stroke length and spring load produce the desired result.
It is an object of this invention to eliminate guesswork commonly associated with setting and controlling the gap size and the closing force of a needle valve of a fluid dispenser.
It is another object of this invention to enhance accuracy and predictability in dispensing fluids of varying viscosity from a single liquid dispenser.
This invention meets the above-stated objectives by structurally isolating compression spring adjustment components from stop member adjustment components within the body of a fluid dispenser so that the closing force and the gap size of the needle valve can be independently controlled.
Because this invention provides for independent control of the closing force and the gap size of a fluid dispenser, these two parameters may be accurately quantified and repeated so that optimum dispensing is achieved with a single dispenser, regardless of variation in the viscosities of the materials dispensed.
This invention eliminates the guesswork formerly associated with simultaneous control of both closing force and gap size. The fluid dispenser of this invention enables an operator to select, for a material of known viscosity, both a desired gap size, i.e. determined by stroke length of the needle valve, and a desired closing force, i.e., determined by the biasing force applied to the needle valve by the compression spring.
To achieve independent control of both closing force and gap size, this invention contemplates an adjustable stop member aligned axially with the needle valve. Adjustment of the axial position of the stop member with respect to the radial center of a piston carried by the needle valve adjusts the maximum stroke distance of the needle valve, thereby setting the gap between the nozzle orifice and the needle valve.
A compression spring and the components which control the compression applied by the spring are located radially outside of the stop member, so that the spring acts upon the piston radially outside of, and independently of the stop member. The stop member extends axially through the compression spring and a cylindrical retainer which holds the compression spring in place.
According to a preferred embodiment of the invention, a fluid dispenser includes a body with an axial bore therethrough which terminates in a nozzle orifice. A needle valve located within the dispenser is aligned along the axis of the bore, and the needle valve carries a piston which is acted upon by pressurized air to move the needle valve away from the nozzle orifice to dispense fluid therethrough. A stop member is axially aligned with the center of the piston to limit travel of the needle valve away from the nozzle orifice. An upper end of the stop member threadably connects to an upper section of the body, which is bolted to a lower section of the body. Threadable adjustment of the stop member with respect to the piston varies the maximum stroke length of the needle valve.
A compression spring has one end which bears directly against the piston, outside of the stop member, and a cylindrical retainer located within the bore has a lip which bears against the opposite end of the spring. The retainer lip defines a circular passage through which the stop member extends. An adjustment screw spaced away from and parallel with the bore threadably connects to the body. The adjustment screw carries a washer which contacts the retainer to hold it in place. The axial position of the washer determines the axial position of the retainer with respect to the body, and the distance between the retainer lip and the piston determines the axial compression of the spring, and hence the compressive force applied to the piston by the spring. Adjustment of this screw adjusts the spring bias on the piston, thereby setting the closing force for the needle valve.
Because the stop member extends through the compression spring and the cylindrical retainer, adjustment of the axial position of the stop member, and thus the stroke length, does not affect the spring load applied to the piston. Moreover, because the spring and the retainer circumscribe the stop member, adjustment of the axial position of the retainer varies the spring load but does not affect the stroke distance of the needle valve.
Thus, this invention provides independent adjustment of the applied spring load and the stroke length of a needle valve of a liquid dispenser, thereby to improve accuracy in setting a desired closing force and a desired gap size for the needle valve during fluid dispensing. As a result of the independent adjustment capability for both stroke length and spring bias, a single dispenser may be used to accurately and repeatably dispense materials of varying viscosity.
These and other features of the invention will be more readily understood in view of the following detailed description and the drawings.


A semiconductor device includes a fuse element that can be cut and removed by laser irradiation. The fuse element has a large width portion having a large sectional area to be irradiated with a laser spot, and two small width portions having a small sectional area connected to opposite sides of the large width portion. Penetration of moisture is suppressed even after cutting of the fuse element since the large width portion is removed by the laser irradiation and only the small width portions having the small sectional area remain as exposed cut surfaces.

1. Field of the Invention
The present invention relates to a semiconductor device, in particular, a semiconductor device including a fuse element that can be cut for changing a circuit configuration of the semiconductor device.
2. Description of the Related Art
There is a method of changing a circuit configuration of a semiconductor device by cutting, in a semiconductor device manufacturing process, a fuse element formed of polysilicon, metal, and the like by using, for example, a laser after a wafer manufacturing process is finished. By using this method, a resistance value can be corrected to obtain desired characteristics after electrical characteristics of the semiconductor device are measured. This method is thus effective particularly for a semiconductor device that places emphasis on its analog characteristics.
In this method, it is required for the fuse element to be stably cut by the laser and have a high corrosion resistance. Hitherto, an insulating protective film is formed on an upper portion of a semiconductor device, and, for example, a silicon nitride film is used for the purpose of preventing the penetration of moisture from the outside and other purposes. However, because a fuse element is supposed to be cut by laser irradiation later, the silicon nitride film that absorbs the laser cannot be arranged on the fuse element, and hence the protective film formed above the fuse element is removed so as to open the protective film. Therefore, the fuse element is easily affected by the penetration of moisture and needs to have an improved corrosion resistance.
In Japanese Patent Application Laid-open No. 2011-49252, there is proposed a method of improving a corrosion resistance by forming a moisture resistance insulating film such as a silicon nitride film or a silicon oxynitride film on at least a side surface of a fuse element, or on the side surface and an upper portion of the fuse element in such a manner that the moisture resistance insulating film is thinner on the upper portion than on the side surface.
However, the above-mentioned related art has the following problems. Although moisture basically penetrates from a portion above the fuse element from which the protective film is removed, in the method, no moisture resistance insulating film is arranged or the thin moisture resistance insulating film is formed on the upper portion of the fuse element. Therefore, the protection of the upper portion is insufficient. Further, because the silicon nitride film or the silicon oxynitride film is used as the moisture resistance insulating film, the radiated laser beam is absorbed, which makes it difficult to cut the fuse. In this method, the moisture resistance improvement and the stability of cutting the fuse element by the laser have a trade-off relationship. It is considered that obtaining a condition that satisfies both requirements is difficult to achieve. In particular, the related-art configuration focuses only on an uncut fuse element and has no effect on a fuse element cut by the laser. This is because, when the fuse element is cut, the fuse element is exposed from the cut surface to cause corrosion. The fuse element is corroded from the cut surface and the fuse element thus expands, resulting in cracking of the insulating film formed on the fuse element. Further, a problem arises in that the crack becomes a penetration route of the moisture, and hence the corrosion progresses inside the semiconductor device.


The present invention relates to novel intermediates of Eribulin and process for the preparation of the same. The process of the present invention is commercially viable and can be easily adopted for plant scale operations. The present invention relates to tetrahydrofuran compounds of formula I, X, XI, D and B.

Eribulin, is a synthetic macrocyclic analogs of halichondrin B, and is represented by structural formula as shown in below.

Eribulin is marketed as Eribulin Mesylate under the brand name HALAVEN® and it is indicated for the treatment of patients with metastatic breast cancer. U.S. Pat. No. 6,214,865 discloses Eribulin.
PCT application WO 2005/118565 discloses process for the synthesis of Eribulin. Tetrahydrofuran compound of formula IA is used as one of the intermediate.

During development of the process, we observed some disadvantageous with the above compound of formula-IA. The final step of the process involves ozonolysis which is not commercially viable, and also observed that degradation of the compound of formula-IA during purification by column chromatography. Accordingly, there is a need for the invention of stable and novel intermediates of Eribulin.

Intermediates for the preparation of eribulin thereof


A display apparatus includes a substrate, a display unit on the substrate and including an emission area and a non-emission area, a first blocking layer at the non-emission area on the display unit, the first blocking layer having a thickness that tapers toward an edge of the first blocking layer, and a second blocking layer on the first blocking layer and configured to block external light reflection.

1. Field
Aspects of one or more embodiments of the present invention are directed toward display apparatuses and methods of manufacturing the same.
2. Description of the Related Art
An organic light-emitting display apparatus is a self-luminous display apparatus that displays an image by using (utilizing) organic light-emitting devices (OLEDs) that emit light. The organic light-emitting display apparatus displays an image by using light generated by energy generated when excitons, which are generated by the combination of electrons and holes in an intermediate layer, drop from an excited state to a ground state.
However, when the organic light-emitting display apparatus is used (utilized) in a bright place or location, the black color representation and the contrast thereof become poor due to the reflection of external light.

Display apparatus and method of manufacturing the same


A device for the graphic representation on a display surface of an object defined by a plurality of triangles which are respectively specified by three points in homogeneous object coordinates comprises a device for transforming the homogeneous object coordinates of the plurality of triangles into homogeneous clip coordinates of a clip coordinate system with an observer standpoint located on an observation axis which is perpendicular to the display surface, a device for determining the position of the observer standpoint in relation to each of the plurality of triangles by determining the orientation of each triangle of the plurality of triangles in the clip coordinate system with repect to the observer standpoint using the homogeneous clip coordinates of the plurality of triangles, a device for marking the position of the observer standpoint in relation to each triangle of the plurality of triangles in association with the homogeneous object coordinates of the plurality of triangles, and a device for processing the triangles specified in the object coordinates using the marked position of the observer standpoint in relation to each triangle so as to graphically represent the object on the display surface.

The present invention relates to computer systems and in particular to graphic processing systems which graphically represent or render on a display surface objects defined in an object coordinate system.
Methods for rendering object coordinate system data into screen coordinate system data (screen space data) have been known for some time. A comprehensive description of a known method can be found in the book entitled xe2x80x9cComputer Graphics, (Pinciples and Practicexe2x80x9d, by Foley, van Dam, Feiner, Hughes, published by Addison-Wesley Publishing Company, ISBN 0-201-84840-6. Normally objects are defined by triangles in an object coordinate system or object space. A triangle is defined by its three vertices P1, P2, P3. In the case of a three-dimensional graphic application, each point in the three-dimensional coordinate system requires three coordinate values. The origin of the three-dimensional rectangular coordinate system in the object space or object coordinate system can be chosen at random. If the object to be represented is a sphere, for example, the origin of the object coordinate system is normally located at the centre of the sphere. The representation in the object coordinate system is thus defined from the outset and is independent of an observer standpoint.
An observer should now be able to move through space so as to be able to observe the surfaces defined in the object coordinate system, and thus objects, from his particular standpoint. A simple example should make this clear. Consider a house which has been specified in object coordinates. An observer should now be able to approach this house from e.g. the garden gate, in which case it is clear that he can then only see the facade but not any objects inside the house. Furthermore the observer can only see one side of the house wall, the visible side of the house call being of course the outer side if he is outside the house and the inner wall of a room if he is inside the house. The object coordinate system origin could e.g. be located on the ground floor, so that the cellar of the house will have negative y-coordinates in the object coordinate system while the first floor will have positive y-coordinates. It is therefore necessary to process the polygons, and thus triangles, specified xe2x80x9cabsolutelyxe2x80x9d in the object coordinate system in order to represent only what the observer sees on a screen. In addition it is necessary to light or shade the objects in the house in three dimensions. While the light source, e.g. the sun or a lamp in a room, may here be fixed absolutely in object coordinates, the observer will see different lit objects depending on his standpoint.
FIG. 4 shows a flowchart of a known method for rendering object coordinate system data so as to be able to display them on a monitor. Such a method is shown in J. D. Foley, A. Van Dam et al., xe2x80x9cComputer Graphicsxe2x80x9d, Addison-Wesley, 1996, FIG. 18.3.3.
In a first step 100 the object coordinate system data are transformed into an eye coordinate system or eye space, in which necessary lighting calculations 200 are performed. After the lighting 200 in the eye coordinate system a perspective projection is preferably performed so as to obtain clip coordinates or clip-space coordinates from the original object coordinates. After clipping 300 in the clip coordinate system, the homogeneous clip coordinates are dehomogenized.
In a first step 100 the object coordinate system data are transformed into an eye coordinate system or eye space, in which necessary lighting calculations 200 are performed. After the lighting 200 in the eye coordinate system a perspective projection is preferably performed so as to obtain clip coordinates or clip-space coordinates from the original object coordinates. After clipping 300 in the clip coordinate system, the homogeneous clip coordinates are dehomogenized.
The position of a triangle in the object coordinate system is normally represented redundantly in that the three coordinates of each vertex of the triangle in the coordinate system each has a respective scaling factor assigned to it. In accordance with the technical terminology, an unambiguous representation of points is termed an inhomogeneous representation, whereas an overdetermined or redundant representation of points is termed a homogeneous representation of these points. If a point on a two-dimensional surface is represented by means of two coordinates, this constitutes an inhomogeneous representation of the point. If a point on a two-dimensional surface is represented by means of three coordinates, this representation is overdetermined and is termed a homogeneous representation. By analogy thereto, a point in the three-dimensional coordinate system can be represented in an inhomogeneous way by its x-, y- and z-coordinates if the three-dimensional space is defined by a Cartesian coordinate system. A homogeneous representation of the point in the three-dimensional space is achieved by specifying 4 xe2x80x9ccoordinatesxe2x80x9d for the point in the three-dimensional space. The fourth coordinate w is by definition a scaling factor. A homogeneous x-, y-, z-coordinate is converted into an inhomogeneous x-, y- or z-coordinate by dividing by the scaling factor w. If a point in the space has inhomogeneous coordinates (1, 2, 3), its homogeneous representation could be (1, 2, 3, 1) or (2, 4, 6, 2), etc.
The advantage of the homogeneous representation of a point in the space is that all transformations which normally occur in a three-dimensional graphic processing or graphic pipeline (e.g. a translation, a rotation, a scaling and in particular a perspective projection) can be represented as a multiplication of the position of the point with a 4xc3x974 transformation matrix. The coordinates used in the steps 100, 200 and 300 are homogeneous coordinates, which are converted into inhomogeneous coordinates in the dehomogenization step 400. This dehomogenization is effected in a simple way by dividing the homogeneous x-, y-, z-values by the corresponding scaling factor w of this point. After dehomogenization, the talk is of coordinates in the screen coordinate system or screen space. The step 500 is then performed in the screen coordinate system. In this step triangles which do not have the desired orientation are culled. If two-sided lighting is employed, triangles with undesired orientation are not culled but are simply lit differently. The step 500 thus determines the type of lighting to be used for a triangle. In the case of a house where the outer wall is also the inner wall of a room, the outer wall is lit e.g. in yellow, if the house is painted yellow, while the inner wall of the room is lit up in white. Thus if an observer is outside the house, the graphic rendering method determines that only triangular surfaces which represent outer walls, i.e. which have a particular orientation, are to be displayed, while inner walls, i.e. triangular surfaces with opposite orientation, can be ignored. If there is only one type of lighting, the triangular surfaces whose orientation corresponds by definition to an interior orientation, are culled or, in the case of two-sided lighting, are provided with a type of lighting which discloses that what is involved here is a triangular surface which should describe the outer wall of a house.
It should be pointed out here that in the step 200 in the known method all the triangles are lit or both types of lighting are calculated for all triangles in the case of two-sided lighting, although half the triangles are culled again in the step 500 or one of the two types of lighting of a triangle is ignored when the triangles are subsequently displayed on a screen in a step 600.
As an alternative to the prior art described in FIG. 4, triangles can also be lit directly in the object coordinate system, whereupon the lit object coordinate surfaces are transformed directly into the clip coordinate system (clip space) without involving the eye coordinate system. This approach is favourable from the point of view of numerical considerations, since the lit object coordinates can be transformed into the clip coordinate system using a single matrix, this combined transformation matrix resulting from a matrix multiplication of the individual transformation matrices.
In the following the step 500 of culling triangles with undesired orientation is considered. First of all the orientation of a triangle is determined. FIG. 3 shows two triangles with different orientations. The orientation is determined by the sense of rotation, which results when the first vertex P1 is connected to the second vertex P2 and the second vertex P2 is then connected to the third vertex P3 and the third vertex P3 is then connected to the first vertex P1, as is represented by the arrows in FIG. 3. The left-hand triangle in FIG. 3 then exhibits an orientation out of the plane of the drawing, while the right-hand triangle has an orientation into the plane of the drawing.
It should be noted that this orientation is determined solely by the sequence of the vertices, i.e. can be chosen at will, since a triangle displayed on a screen and having a clockwise orientation cannot be distinguished from a corresponding triangle with a counterclockwise orientation if the triangles have been lit in the same manner. It is therefore e.g. possible, in the example of the house which has been presented, to provide all the outer surfaces of the house with an orientation according to the left-hand triangle of FIG. 3, while all the inner surfaces of the house have an orientation according to the right-hand triangle of FIG. 3. When a graphic rendering method has recognized that an observer is outside the house, it can immediately cull all the triangles with the other orientation since they are, on the basis of their definition, interior triangles.
The determination of the orientation of the surface of a triangle on a display surface thus plays an important role. It is this that determines whether the observer is looking at the front or the back of the triangle. From geometry it is known how to calculate the orientation of a triangle which is spanned by three points in space. This orientation is determined by the sign of the z-coordinate of the normal vector to the surface of the triangle. If the triangle is skewed in space, the normal vector will have a component in the x-direction, a component in the y-direction and a component in the z-direction. If the orientation of a triangle relative to an axis on which the observer finds himself is required, only the component of the normal vector parallel to this axis is needed. In graphic rendering systems the horizontal extension of the screen will normally be parallel to the x-axis and the vertical extension of the screen will normally be parallel to the y-axis. The z-axis, which is perpendicular to the screen or display surface, is then the observation axis. Thus what is needed is the orientation of a triangle relative to this observation axis.
This is given by the z-component of the vector product of the 2 directional vectors which result when the position of one vertex of a triangle is subtracted from the other two vertices. This relationship can be expressed in equational form as follows:                     a        =                              [                                          (                                                      v                    2                                    -                                      v                    1                                                  )                            xc3x97                              (                                                      v                    3                                    -                                      v                    1                                                  )                                      ]                    z                                    (        1        )                                          xe2x80x83                                  =                                                    (                                                      x                    2                                    -                                      x                    1                                                  )                                                          (                                                      y                    3                                    -                                      y                    1                                                  )                                      -                                          (                                                      y                    2                                    -                                      y                    1                                                  )                                                          (                                                      x                    3                                    -                                      x                    1                                                  )                                                                        (        2        )
In this equation v1, v2 and v3 represent the vectors from the origin of the coordinate system to the three vertices of the triangle, i.e. to P1, P2 and P3. P1 is given by (x1, y1), P2 is given by (x2, y2) and P3 is given by (x3, y3). The point coordinates used in the equations (1) and (2) are inhomogeneous coordinates. Unfortunately, however, inhomogeneous coordinates are obtained only after the dehomogenization 400, since the operations performed previously must be performed in homogeneous coordinates, mainly for numerical reasons. This is also the reason why all the existing triangles are lit in step 200, after which each second triangle is culled in step 500, as a result of which a known graphic pipeline expends a great deal of unnecessary processor effort, since in general 50% of the computational effort for calculating the lighting is discarded again further on in the graphic pipeline.
It should be noted that a dehomogenization of the homogeneous coordinates cannot be executed prior to the lighting step since clipping must be performed in homogeneous coordinates. A prerequisite for correct clipping is, however, that the lighting operations are performed previously so as to make colour interpolation possible. These constraints are known to experts in the field and are thus not pursued further here.
To summarize, it can be stated that in a known graphic pipeline, regardless of whether the lighting is performed in the object coordinate system or in the eye coordinate system, there is a considerable unnecessary extra outlay since triangles which are later culled are first lit or because both types of lighting are calculated for each triangle whereas only one type of lighting is later displayed.
EP 0 740 272 A2 discloses a method and a device for the fast rendering of three-dimensional objects. Triangles are originally specified in a model space, which is the reference coordinate system for the graphic data which are finally to be displayed on a screen, which is described by a device space, i.e. by a screen coordinate system. Before transforming the triangles from the model space into the screen space, in which the lighting and clipping take place, the orientation of the triangles with respect to an observation standpoint is determined. To this end a vector, termed the eye vector, is formed by joining a point of the triangle in the model space to the observation point. The normal vector for the triangle is then either read or calculated and the scalar product of the eye vector and the normal vector for the triangle is calculated. This scalar product is calculated in the model coordinate system. Its sign indicates whether a triangle is directed away from the observer or towards the observer. This property of the triangle is stored in a list, which is accessed when the triangles are subsequently rendered so that if triangles which are directed away from the observer standpoint are culled, only those triangles which are directed towards the observer have to be transformed. In other words, only those triangles whose list entry indicates an orientation towards the observation standpoint are transformed from the model coordinate system into the device coordinate system and are there lit and clipped before being displayed on a screen after some further steps.
It is the object of the present invention to provide a more efficient concept for the graphic representation of a triangle.
In accordance with a first aspect of the present invention, this object is achieved by a device for the graphic representation on a display surface of an object defined by a plurality of triangles which are respectively specified by three points in homogeneous object coordinates, comprising: a device for transforming the homogeneous object coordinates of the plurality of triangles into homogeneous clip coordinates of a clip coordinate system with an observer standpoint located on an observation axis which is perpendicular to the display surface; a device for determining the position of the observer standpoint in relation to each of the plurality of triangles by determining the orientation of each triangle of the plurality of triangles in the clip coordinate system with respect to the observer standpoint using the homogeneous clip coordinates of the plurality of triangles, where the device for determining the position of the observer standpoint in relation to each of the plurality of triangles is designed to execute the following equation to determine the orientations of the triangles:
axe2x80x2=w1(I2y3xe2x88x92I3y2)+w2(I3y1xe2x88x92I1y3)+w3(I1y2xe2x88x92I2y1)
where (x1, y1, w1), (x2, y2, w2) and (x3, y3, w3) are homogeneous clip coordinates of the three vertices of the triangle and where the sign of axe2x80x2 indicates which of two orientations with respect to the observer standpoint each triangle has; a device for marking the position of the observer standpoint in relation to each triangle of the plurality of triangles in association with the homogeneous object coordinates of the plurality of triangles; and a device for processing the triangles specified in the object coordinates using the marked position of the observer standpoint in relation to each triangle so as to graphically represent the object on the display surface, where the device for processing is designed to cull the triangles specified in the object coordinate system which are directed away from the observer standpoint.
In accordance with a second aspect of the present invention, this object is achieved by a method for the graphic representation on a display surface of an object defined by a plurality of triangles which are respectively specified by three points in homogeneous object coordinates, comprising the following steps: transforming the homogeneous object coordinates of the plurality of triangles into homogeneous clip coordinates of a clip coordinate system with an observer standpoint located on an observation axis which is perpendicular to the display surface; determining the position of the observer standpoint in relation to each of the plurality of triangles by determining the orientation of each triangle of the plurality of triangles in the clip coordinate system with repect to the observer standpoint using the homogeneous clip coordinates of the plurality of triangles, where the device for determining the position of the observer standpoint in relation to each of the plurality of triangles is designed to execute the following equation to determine the orientations of the triangles:
axe2x80x2=w1(I2y3xe2x88x92I3y2)+w2(I3y1xe2x88x92I1y3)+w3(I1y2xe2x88x92I2y1)
where (x1, y1, w1), (x2, y2, w2) and (x3, y3, w3) are homogeneous clip coordinates of the three vertices of the triangle and where the sign of axe2x80x2 indicates which of two orientations with respect to the observer standpoint each triangle has; marking the position of the observer standpoint in relation to each triangle of the plurality of triangles in association with the homogeneous object coordinates of the plurality of triangles; and processing the triangles specified in the object coordinates using the marked position of the observer standpoint in relation to each triangle so as to graphically represent the object on the display surface, where the step of processing comprises the culling of the triangles specified in the object coordinate system which are directed away from the observer standpoint.
The present invention is based on the finding that the culling of triangles or the definitive establishment of the type of lighting for two-sided lighting must be performed before lighting in order to avoid unnecessary lighting calculations. If the culling of triangles is already performed in clip coordinates prior to clipping, then it is also possible when clipping to economize on clipping operations, which in the prior art are also performed on triangles which are subsequently culled and are not displayed on a screen. As can be seen from FIG. 4, culling a triangle prior to lighting or determining the type of lighting for two-sided lighting requires that the determination of the orientation of a triangle be performed using homogeneous coordinates. Until now, however, there has only been an equation for inhomogeneous coordinates.
To enable the determination of the orientation of a triangle to be performed in homogeneous coordinates, the following equation is proposed:
axe2x80x2=w1(I2y3xe2x88x92I3y2)+w2(I3y1xe2x88x92I1y3)+w3(I1y2xe2x88x92I2y1)
As can be seen from this equation, homogeneous coordinates (x, y, w) are employed, which are coordinates in the clip coordinate system, where the sign of axe2x80x2 indicates the orientation of the surface of a triangle defined by a point P1, a point P2 and a point P3. In the equation it is assumed that in the clip coordinate system the xy-plane of the clip coordinates is parallel to the display surface while an observer axis, relative to which the orientation of the surface of the triangle is determined, is perpendicular to the display surface, i.e. perpendicular to the xy-plane of the clip coordinate system.
The previous equation thus enables the orientation of a triangle to be determined before it is clipped. Consequently, according to the present invention, triangles with a particular orientation are culled before they have to be lit and clipped. In the case of two-sided lighting the triangles are, according to the present invention, now lit only on the side which is directed towards the observer. This provides the possibility of a more efficient graphic pipeline, wherein culling of triangles with a particular orientation or the side determination for two-sided lighting is carried out before lighting and clipping are necessary.
According to the present invention, therefore, the position of the observer standpoint in relation to each of the plurality of triangles is established at the start of a graphic pipeline by determining the orientation of each triangle in clip-space coordinates. The position of the observer standpoint is then marked in relation to each triangle in association with the homogeneous object coordinates of the plurality of triangles in such a way that the triangles defined in object coordinates can, after marking, be processed in the known manner but with the profound difference from the prior art that only those triangles whose orientation is such that they are to be displayed have to pass through the complete graphic pipeline.
In the case of one-sided lighting, marking ensures that only those triangles which are directed towards the observer standpoint are selected from all the triangles in the object space and these are then lit, transformed into the clip space and clipped.
In the case of two-sided lighting, the type of lighting is, according to the present invention, determined before lighting and possibly before the transformation into the eye coordinate system, in such a way that only one lighting operation has to be performed for each triangle, namely for that side of the triangle which has to be used for the display, i.e. that side of the triangle which is directed towards the observer.
Concerning the culling of triangles of a particular orientation, the method and devices of the present invention provide the possibility that, seen statistically, only half of all triangles have to be lit and clipped, which results in an increase in efficiency of 50% as regards lighting and clipping. In the case of two-sided lighting, only one lighting calculation has to be performed for each triangle instead of two lighting calculations for each triangle as On the prior art, which also, seen statistically, brings with it an increase in performance of 50% for the lighting processor.
From the short description of the present invention given above it is clear that the further steps for representing a triangle after orientation determination and culling or single-sided lighting are not essential to the present invention and can be carried out in any known way. Thus lighting can take place optionally in the object coordinate system or, after a transformation into the eye coordinate system, in this coordinate system.

Method and device for graphic representation of an object defined by a plurality of triangles on a display surface


Notes and other input may be entered directly onto computer based content. The notes may be taken on a portable computing device that contains metadata from the computer based content. The metadata and input are stored and once the portable computing device is in communication with the second computing device displaying the computer based content, the input is displayed near the computer based content that was displayed at the time the input was created.

This Background is intended to provide the basic context of this patent application and it is not intended to describe a specific problem to be solved.
Communication through electronic means is becoming more common. Individuals, companies, and institutions often use electronic authoring tools in their communications, and are broadcasting these across the Internet. At the same time, users make notes on paper, and often on small, portable computing devices. The notes are usually related to the content being viewed. However, for a variety of reasons, the comments are separate from the original content and the application displaying the original content.

Associating input with computer based content


The invention relates to a transmission module, especially a transmission module in countershaft design, having at least one input and one output which are connected with each other by way of at least one speed-torque converter device, with a reverse gear which is arranged between a countershaft and the transmission output, with a hydrodynamic retarder. The hydrodynamic retarder having at least one rotor blade wheel and a stator. The rotor blade wheel is connected via a high gear with the transmission output. The high gear is a component of the reverse gear.

1. Field of the Invention
The invention relates to a transmission module, especially a transmission module in countershaft design.
2. Description of Related Art
Transmission modules in countershaft design are known from a large number of configurations from the state of the art. They comprise at least one input and one output, between which are arranged speed-torque converter devices which are driven via a countershaft transmission which is torsionally rigidly connected at least indirectly with the transmission input. Reference is hereby made in lieu of the above to the following specifications:    FR 2 719 355 A1    DE 949 990 C
For changing the direction of travel, a reverse gear is usually provided which is also arranged in countershaft configuration and is situated as, seen in the axial direction, downstream of the individual speed-torque converter devices between transmission input and output. The reverse gear is arranged in the simplest of cases by providing an additional intermediate gear in analogy to the individual speed-torque converter devices. A reversal of the direction of rotation is enabled via the intermediate gear.
Such transmissions are usually of a relatively large size, especially with respect to their axial overall length. In addition, they usually also comprise a hydrodynamic retarder arranged on the transmission output or in the transmission for producing a braking torque. It is preferably arranged as a secondary retarder. The rotor blade wheel of the hydrodynamic retarder is preferably coupled with the output of the transmission module and flanged on the housing or integrated in the housing of the transmission module. The rotor blade wheel is directly connected with the output shaft in a torsionally rigid manner or in a high gear. This leads to the consequence however that when discharging the retarder in non-braking operation, the ventilation losses are very high as a result of the continual rotation of the rotor blade wheel and the revolving of the air masses present in the retarder, i.e. there are loss moments which are not available for drive in the drive train. In order to reduce ventilation losses in non-braking operation, the retarder is arranged in the high gear, i.e. in a side branch of the main drive branch. Reference in this respect is hereby made to DE 44 45 024 A1 which discloses a drive unit with an engine and a transmission and a hydrodynamic retarder. In order to avoid ventilation losses in non-braking operation, the hydrodynamic retarder is provided with a configuration so as to be activated in braking operation and is uncoupled from the same when necessary without any influence on the power flow in the main drive branch, with the speed of the rotor blade wheel being reduced to zero in non-braking operation. The arrangement in high gear is used in order to produce only low ventilation losses by the transmission into fast in non-braking operation in the case of uncoupling of the rotor blade wheel that has not occurred or was not intended. The high gear is integrated as a separate spur wheel set on the transmission and thus leads to an increase in the required number of components and the overall space because the same needs to be provided separately.
Reference is hereby made to the following specifications concerning the further state of the art:    DE 197 51 776 A1    WO 86/02608 A1    DE 103 34 731 A1    DE 198 37 776 A1    DE 198 40 288 A2    DE 34 15 909 C2


A method and communication system (e.g., a time-division duplex (TDD) system) that uses adaptive antennas at the base stations to monitor metrics associated with the quality of one or more common physical channel (CPCH) timeslots, so as to determine whether to reuse some or all of the CPCH timeslots to transmit a dedicated physical channel (DPCH). If it is determined to reuse some or all of the CPCH timeslots, an additional determination is made as to what limit to apply on the DPCH transmission powers. Adaptive antennas may be used at the base stations to allow the system to reuse some or all of the CPCH timeslots to transmit DPCH, thus improving the overall capacity of the system while maintaining the CPCH coverage and quality at a desired level throughout the system.

Conventional cellular systems typically use a Broadcast Channel (BCH) to communicate information to a mobile user specific to the Radio Access Network (RAN) as well as to a given cell, even before a connection is established. In a TDD system, the BCH is transmitted on the Primary Common Control Physical Channel (PCCPCH). Another example of common channels transmitted on CPCH timeslots is the Forward Access Channel (FACH) which, in TDD, is transmitted on the Secondary Common Control Physical Channel (SCCPCH). As disclosed herein, the term "CPCH timeslot" refers to any timeslot that is used to transmit the CPCH.
Certain reserved timeslots are typically used throughout a subsystem of the TDD system to transmit the CPCH. The subsystem is an ensemble of TDD cells that can interfere with each other because of their relative close proximity, from a path loss point of view, to one another. For example, a subsystem could consist of one floor of a building deployed using multiple cells if the walls of the building would not provide sufficient isolation (from a path loss point of view) to prevent interference from one cell to another. Similarly, an entire building could be considered a subsystem if the floors and ceilings of the building would not provide sufficient isolation (from a path loss point of view) to prevent interference between floors. In an outdoor deployment, a subsystem can be anything from a small district consisting of a few cells to a large metropolitan area.
Depending on the performance of the receivers of the TDD system as well as the radio frequency (RF) isolation between cells, the TDD system may limit the number of timeslots required to transmit the CPCH to one CPCH timeslot. Alternatively, the TDD system may have to use more than one timeslot to ensure good quality on the CPCH (e.g., BCH reception if it is the PCCPCH, FACH block error rate (BLER) if it is the SCCPCH, etc.).
FIG. 1 illustrates the case when more than one timeslot is used in a conventional wireless communication system. Each base station (BS) A-F of the system would use only one of the timeslots 1, 2, 3 for its own CPCH transmission while refraining from transmitting anything on the other timeslots that the system uses for CPCH. Neighboring base stations would use the other timeslots for their CPCH transmissions. A given CPCH timeslot would be used only by base stations that are a certain distance apart from each other, thus enhancing the signal-to-interference ratio (SIR) of the CPCH for the mobile units served by these base stations and ensure contiguous coverage of CPCH. However, this diminishes the system capacity since less time timeslots are available for traffic in Dedicated Physical Channels (DPCHs).
There exists a need for a method and system which selectively reuses some of the CPCH timeslots in a TDD system for transmitting user data.

This patent is subject to a terminal disclaimer.

System and method using adaptive antennas to selectively reuse common physical channel timeslots for dedicated channels


Methods and systems for modeling user arrival and choice in the context of off-street parking solutions. A first component models the arrival and duration of stay of users as a function of time, taking into account different user profiles (or “clusters”), captured by a latent variable. A second component provides a ranking function (for each user cluster), wherein the input features describing the “choice” constitute status variables associated different car park(s), and the output constitutes a preferred car park and a pricing scheme. The system simulates different user behaviors by assuming some standard groups of users will behave similarly. Groups of users or user profiles are learned automatically. The profiles are then employed as a key element for automatically learning a decision function of parking users, and automatically learning one decision function per profile.

Parking areas such as parking garages and parking lots are used at various locations, ranging from shopping malls to airports. A particular aspect of parking areas involves off-street parking and the management of parking users, costs, and revenue. In a number of off-street parking situations, it is desirable to optimize a given characteristic of measure from an off-street parking area. Such a characteristic may be, for example, the overall revenue of the parking area or lot. Currently, all that is available is historical data from the parking lot or area itself, such as records of user arrival and leave times, in addition to some information about the parking lot infrastructure. It would be desirable to know in advance what would happen if a parking area (e.g., a parking zone, parking lot, etc.) is open, closed, or some of its characteristics (e.g., current price rates, average time distance from points of interest) have changed.
Several highly specialized approaches have been proposed to model parking user demand. One model, for example, is an agent-based system that can simulate parking and traffic situations under different parking management conditions in the context of an entire city. In this system, the number of agents operating inside the city was roughly estimated from a travel survey and was further tuned by running the model several times after gradually reducing the number of agents at each time. The parking demand was specified for different places by considering different attraction factors per trip motive (e.g., recreation, work, shopping) for each kind of budding (e.g., restaurant, residential or office). Afterwards, the calibration process was performed by asking field experts of the city administration to assess results based on their knowledge.
Simulation models for parking systems have also been proposed. However, when confronted with the specific problem of simulating duration time (e.g., the time a car stays parked in the parking lot), such models have adopted an average duration time for all vehicles within a certain period. Another approach that has been discussed involves designing a parking search model based on a utility maximization theory. This approach, however, is centered on on-street parking or parking lots spread throughout a city. It is not based on learning the user behavior nor on user profiles.
Another related work involves the use of MISIM (a microscopic traffic simulator developed at MIT) to simulate off-street parking and investigate how to create a user-choice model for this task. However, in this work, the author chose to define behavior groups a priori, dividing users into fixed, guided and un-guided. Moreover, a manually-crafted algorithm was used in this case to determine whether a user would chose to park or queue for a new option. In our system, the groups are determined automatically by an unsupervised algorithm. Furthermore, in our system the choice behaviors of each group are learned using a supervised algorithm from the historical data, instead of being manually and rigidly programmed into a computer. Other demand strategies include a regression model, which attempts to estimate parking demand as a parametric formula whose general form has to be specified manually or picked among candidates.

Method and system for simulating users in the context of a parking lot based on the automatic learning of a user choice decision function from historical data considering multiple user behavior profiles


This invention relates to a medical device and, in particular, to a prosthesis or stent graft assembly for use within the human or animal body and, more particularly, to the fastening of a stent to the graft material of the stent graft assembly or prosthesis.

Various implantable medical devices are advantageously inserted within various body vessels, for example to improve blood flow through a restricted or weakened vessel. Minimally invasive techniques and instruments for placement of intraluminal medical devices have been developed to treat and repair undesirable conditions within body vessels. Various percutaneous methods of implanting medical devices within the body using intraluminal transcatheter delivery systems can be used to treat a variety of conditions. One or more intraluminal medical devices can be introduced to a point of treatment within a body vessel using a delivery catheter device passed through the vasculature communicating between a remote introductory location and the implantation site, and released from the delivery catheter device at the point of treatment within the body vessel. Intraluminal medical devices can be deployed in a body vessel at a point of treatment and the delivery device subsequently withdrawn from the vessel, while the medical device retained within the vessel to provide sustained improvement in blood flow or to increase vessel patency.
Stent grafts have proven to be effective medical devices for minimally invasive treatment of vascular occlusions such as atherosclerosis and restenosis and treatment of weakened or diseased vessels. Stent grafts include a graft member inside or outside a stent structure. The graft member reestablishes a flow lumen, the stent structure supports the graft member, reinforces the weakened vessel, and prevents occlusion or stenosis.
It is desirable that there is some secure method for fastening of the stent to the graft member. Examples of fastening of a stent to a graft member are described in commonly owned U.S. Publication No. 2004/0225348, published Nov. 11, 2004 and U.S. Pat. No. 6,939,369 filed Sep. 6, 2005 which are both incorporated by reference. In particular, the method of fastening must be compatible with compressed and expanded states of the stent graft and must allow the graft member to remain fastened to the stent as the device is moved between the compressed and expanded states. For medical devices which move or slide circumferentially, there is a need for a fastening system which allows the support frame to move circumferentially with respect to the graft member such that the graft member and stent remained fastened in and during the transition between the expanded and compressed states and during.