A court for accommodating players in play of a game that employs a ball comprising a floor including a playing surface having ends, goals each supported proximate one of the ends, markings on the playing surface that define fields that govern the play of the game, a spring-loaded bias provided by the floor at each of the fields and padded fields proximate the goals for absorbing player falls.

This invention relates to floor structures for accommodating players in play of a game.
Main stream sports like basketball, football, hockey and baseball enjoy large consumer markets. Throughout the last decade, however, the entirety of sports has suffered from fans""s shortened attention spans and busy schedules. This is especially true given that the typical sports enthusiast of the day enjoys and follows such a wide range of different sports. Because most fans do not have the time to attend or watch a wide spectrum of sports and sporting events, most sports enthusiasts greatly depend on sports news and highlight shows to keep them aware of what is happening in the world of sports.
Sports news and highlight shows, by their very nature, feature mainly the exciting sports highlights as a means not so much of communicating scores and other sport-related information but of entertainment value. The entertainment value of these shows is obviously important for achieving a high level of viewership, which is the case for most of the high quality programming. Given this, it is apparent that fans crave highlights because they are often exciting, or at least of great interest as they distill down a large number of sporting events into just a short news show.
To satiate sports enthusiasts"" increasing desire for sports entertainment, and to bring sports back from a mere collection of short highlight shows, there is a need for a new and improved sport which utilizes a novel court or flooring structure for facilitating the objects and advantages of the sport.
The above problems and others are at least partially solved and the above purposes and others realized in a new and improved court for accommodating players in play of a game that employs a ball of a type substantially like that of a conventional basketball. The court is comprised of a spring-loaded floor that includes a playing surface. The playing surface is substantially rectangular and includes ends and goals that are each supported proximate one of the ends. The goals are preferably baskets that are each supported by one of a plurality of padded support
The playing surface is provided with markings that define fields, which govern the play of the game. A first springiness or spring bias is provided by the floor at selected ones of the fields, and a second springiness or spring bias is provided by the floor at other selected ones of the fields. The first bias is different from the second bias, and the first and second biases provide players with the ability to jump high into the air during play of a game, and especially around the goals. The floor includes padded fields each positioned near one of the goals for providing soft landing areas for cushioning player falls. In terms of structure, the floor is comprised generally of a spring layer supported by a rigid foundation, and a rugged and deformable resilient layer supported by the spring layer in opposition to the foundation. The resilient layer carries the markings.


An inkjet head including a flow path unit and a plurality of actuator units, each of the plurality of actuator units has a parallelogram shape defined by two sets of opposing sides, which is substantially parallel to a first direction and a second direction intersecting with each other along a plane, the side of the actuator unit parallel to the second direction is substantially parallel to that of an adjacent actuator unit and is shifted from that of the adjacent actuator unit in the second direction, the plurality of actuator units are inclined with respect to two contour lines of a flow path unit, the two contour lines being parallel with each other and extending in a longitudinal direction of the flow path unit, and centers of gravity of contours of the plurality of actuator units are arranged on substantially one straight line which is parallel to the contour lines.

Some inkjet heads having a relatively long shape and ejecting an ink from nozzles to perform printing have a plurality of actuator units, each actuator units being placed on a surface of a flow path unit. JP-A-10-217452 (FIG. 1) discloses an inkjet head having four actuator units which have a parallelogram-like contour in a plan view. Each actuator units has a same structure and is placed on the surface of a flow path unit such that one set of opposing sides of a parallelogram is substantially parallel to a contour line of the flow path unit. Adjacent actuator units are shifted from each other by a predetermined distance in one direction. According to such configuration, even when the inkjet head is prolonged, it is not necessary to make the actuator units themselves long. Therefore, fabrication yield of the actuator units may be prevented from lowering.

Inkjet head, inkjet head subassembly, inkjet head assembly and inkjet printer


A photographing apparatus and method employ an imaging device arranged including a matrix of pixels each which accumulates accumulation charges according to an amount of light incident thereon, an accumulation charge read device for reading the accumulation charges at a time difference based on the position of each row or column of the pixels, and a reset device resetting an entirety of the accumulation charges of the imaging device before a main exposure. The photographing apparatus and method each further employ a reset timing change device capable of changing a reset timing for resetting the accumulation charges with respect to a synchronization pulse corresponding to a time for reading the accumulation charges.

1. Field of the Invention
The present invention relates to a photographing apparatus and method, and more particularly, to a photographing apparatus and method in which a time difference between a preliminary flashing and a main flashing can be variably set.
2. Description of the Related Art
A photographing apparatus, such as a camera or a camcorder, typically includes image sensors such as an imaging device, a lens assembly, a diaphragm, a shutter, and the like, so that electric charges generated in response to light arriving in a photographic plane of the imaging device can be read as electric signals in order to record an image. When an amount of light is not sufficient to obtain an appropriate image using a photographing apparatus in a dark environment such as at night or indoors, photographing is performed by increasing the amount of light using a flash unit.
However, when a photo-sensor is not provided in the photographing apparatus in order to reduce the size of the photographing apparatus or a manufacturing cost, it is generally difficult to simultaneously adjust focus or exposure while the amount of flashing light is measured during a main shot in which an image of an object is actually recorded on a recording medium if flashing is only performed once.
Accordingly, preliminary flashing can be performed before main flashing in a main shot in order to measure the required amount of light. Subsequently, focusing or exposure can be adjusted, and then the main shot is performed. In association with this technique, Japanese Patent Application Publication No. 2000-196951 discloses a method of detecting the amount of exposure light during the preliminary flashing, and then optimally adjusting a lens focusing position, white balance, or exposure on the basis of the detection result during the main flashing when the main shot is taken.
Meanwhile, if a time difference between the preliminary flashing and the main flashing is too long when the preliminary flashing is performed before the main flashing, the subject of the main shot may misunderstand the preliminary flashing as the main flashing, and he or she may erroneously move or close his or her eyes during the main shot. Therefore, it may not be possible to obtain an appropriate image.
In addition, in order to accurately detect the amount of exposure light during the preliminary flashing before a main shot, a measurement value of the amount of exposure light should not be saturated, and a flashing period or an exposure period should be appropriately controlled during the preliminary flashing measurement. However, the measurement value of the amount of exposure light is often saturated during the preliminary flashing, and thus, in that case, it can be difficult to detect an appropriate amount of exposure light even while the exposure period in the preliminary flashing was being controlled (for example, when the flash unit is used in a bright indoor environment). In this case, it may be impossible to obtain the appropriate amount of light required for main flashing.


A fiber laser system with a fiber laser device including a fiber laser; a laser output end part; and a delivery fiber. The delivery fiber is constituted by a double cladding fiber. An SFBG is provided on the output end side of the delivery fiber, which reflects part of laser light propagating in the core of the delivery fiber to thereby couple the part of the laser light with a backward-propagating cladding mode propagating in a first cladding in a backward direction. A backward-propagating cladding mode detecting section is provided on the input end side of the delivery fiber, which detects the intensity of backward-propagating light in a cladding mode, which light is the part of the laser light coupled by the SFBG with the backward-propagating cladding mode.

When material processing is carried out with laser light, a laser power of only about several watts may be sufficient depending on the material to be processed. However, in a case where for example thick metal is to be processed, a laser power on the order of kilowatts is necessary. Examples of a laser source for metal processing include a YAG laser, a CO2 laser, an excimer laser and a fiber laser. Out of these, a fiber laser is a high-efficient, high-gain laser that produces good-quality laser light. Since the fiber laser is mainly constituted by optical fibers, the fiber laser is attracting attention as a laser source that is easy to maintain.
A fiber laser also has the following advantage. A path through which laser light propagates is also made of optical fibers, and for example the length of a delivery fiber that connects an output end part through which the laser light is outputted and a main body of the fiber laser is freely changeable. Therefore, it is possible to carry out material processing by moving only the output end part without moving the main body.
As is clear from above, a delivery fiber needs to be movable freely to some extent. Therefore, the delivery fiber may be more prone to breaks than the main body. If a break occurs in the delivery fiber, high-power light may be emitted from a site of the break and pass through a hose etc. that protects the delivery fiber. If this is the case, the light may escape into a surrounding area.
In view of this, for safety reasons, it is necessary to detect a break in the delivery fiber. Further, the stability of the power of laser light to be emitted is important for the purpose of achieving stable processing. Therefore, it is necessary to stabilize, by use of a light intensity monitoring circuit, the intensity of laser light to be outputted.
Conventionally, there has been a light monitoring device as shown in Patent Literature 1. The light monitoring device is a device in which (i) a slanted Bragg grating is provided in a core of an optical fiber so that light guided through the core is partly emitted to the outside of the optical fiber and (ii) a photoreceptor detects the light thus emitted. Further, Patent Literature 2 discloses a method of detecting scattered light leaking from a fused part of a fiber by another fiber near the fused part.

Light intensity monitor capable of detecting light intensity and fiber breaking


The present invention relates to a dehydrogenation catalyst in which a platinum-group metal, an assistant metal, and an alkali metal or alkaline earth metal component are supported on a carrier, wherein the molar ratio of platinum to the assistant metal is 0.5 to 1.49, and the catalyst has an acidity amount of 20 to 150 μmol KOH/g catalyst when it is titrated with KOH. The dehydrogenation catalyst according to the present invention may prevent coke formation from increasing rapidly when the hydrogen/hydrocarbon ratio in a dehydrogenation reaction is reduced, thereby increasing the productivity of the process. Accordingly, it makes it possible to operate the process under a condition in which the hydrogen/hydrocarbon ratio in a dehydrogenation reaction is reduced, thereby improving the economy of the process.

The catalytic dehydrogenation of alkanes used to produce alkenes (olefin hydrocarbons) is an important and well-known hydrocarbon conversion process in the petroleum refining industry. The reason for this is that alkenes are generally useful as intermediates in the production of other more valuable hydrocarbon conversion products. For example, propylene can be used in the production of polymers and propylene glycol, butylene can be used in the production of high-octane motor fuel, and isobutylene can be used to produce methyl-t-butyl ether, a gasoline additive.
Dehydrogenation of hydrocarbon gases, such as the catalytic dehydrogenation of alkanes, is carried out at a high temperature of 550° C. or above. Since the catalytic reaction is carried out at high temperatures, it is accompanied by side reactions, such as thermal decomposition and coke formation. The extent of such side reactions becomes an important factor that determines catalytic selectivity and activity. Coke formation which is a side reaction causes an active catalytic material to be covered with coke, which blocks its contact with a reactant, thereby decreasing the total conversion of the reactant. Furthermore, as coke formation occurs, it blocks the entrance of pores in the catalyst, thereby accelerating the deactivation of the active material in the pores.
U.S. Patent Application Publication No. 2015/0202601 A1 discloses an alkane dehydrogenation catalyst composition including: a Group IIIA metal selected from gallium, indium, thallium, and combinations thereof; a Group VIII noble metal selected from platinum, palladium, rhodium, iridium, ruthenium, osmium, and combinations thereof; at least one dopant selected from iron, chromium, vanadium, and combinations thereof; an optional promoter metal selected from sodium, potassium, rubidium, cesium, magnesium, calcium, strontium, barium, and combinations thereof; and a catalyst support selected from silica, alumina, silica-alumina composites, rare earth modified alumina, and combinations thereof.
Korean Patent Application Publication No. 2014-0123929 discloses a dehydrogenation catalyst composition for hydrocarbons, including: a nano-sized complex containing a Group VIII component; a group IVA component and a sulfur-containing capping agent; an alkali component; a halogen component; and a support having an inner core of alpha alumina and an outer layer including a mixture of gamma alumina and delta alumina.
Conventionally known patents related to dehydrogenation catalysts are directed mainly to the types of active catalytic components and supports, and there is still no content related to acidity amount which is one of the physical properties of catalysts. Therefore, there is an urgent need to develop a dehydrogenation catalyst which has an acidity amount within an appropriate range and which is excellent in terms of catalytic activity, selectivity, and stability against coke formation.


A wireless network has nodes, which can be accessed by wireless terminals via wireless access links, coupled via wireless transit links using multiple directional antenna beams. The nodes are self-organizing and self-adapting as nodes are added and as other changes occur. A new node uses beam scanning to listen for signals from any existing nodes and responds accordingly to join a network. Established nodes each recurrently transmit a welcome message on unused beams, to be received by a new node. Failure of transit links, e.g. due to interference on a channel frequency, is detected with automatic restoration using another frequency. Beam scanning can be enhanced using alternate overlapping beams and diversity techniques.

To facilitate communications in a wireless system or communications network, it is desirable to provide a plurality of wireless access and routing points (WARPs) or nodes among which communications can take place via wireless links, the nodes optionally communicating via one or more wired connection paths with a communications network, with wireless terminals communicating with the nodes also via wireless links. For clarity herein, the wireless links via which the wireless terminals communicate with the nodes are referred to as access links, and the wireless links for communications among the nodes are referred to as transit links.
In such a wireless system, for example, the nodes can be distributed within a geographical region or area within which wireless access services are to be provided, and the wireless terminals can communicate among themselves and/or with the network via the various nodes. The wireless terminals can have any of various forms, and the communicated signals can comprise any desired form of information. Such a wireless system conveniently operates in a packet communications mode, in which for example a node is only active (transmitting or receiving radio signals) when it is sending or receiving data packets, and is otherwise in a quiescent or quiet state in which it only listens for traffic and occasionally exchanges signalling messages for administration of the wireless system.
By way of example, the wireless communications via the access and transit links can be in accordance with known standards, such as the IEEE 802.11 standard for wireless LAN (local area network) communications. Conveniently channels in different frequency bands are used for the access and transit links; for example channels in the 2.4 GHz band (IEEE 802.11b) for the access links and channels in the 5.2 and 5.7 GHz bands (IEEE 802.11a) for the transit links. However, this need not be the case and the access and transit links can use other frequency bands and/or can both use the same frequency band.
Such a system desirably provides multiple beams using directional antennas, i.e. directive wireless communication paths, for at least some of the transit links between pairs of nodes, thereby facilitating re-use of channel frequencies on the transit links. In particular, directional antenna beams can provide increased gain, and hence greater range, and directional azimuth beam patterning, which attenuates unwanted co-channel and adjacent channel interference, for example arising from simultaneous transmissions over a plurality of transit links. Each node can provide any desired number and configuration of directional antenna beams and the individual beams of each node can be similar to or different from one another. Conveniently, all of the nodes are similar to one another and all of the beams of each node are similar to one another; for example each node may provide 3, 6, 8, or more similar beams, but any other (smaller or larger) number of beams may be provided.
A known way of designing such a wireless system uses laborious centralized planning to address issues such as frequency re-use, scalability (expansion or contraction) of the system over time, and adaptability to changes. With a rigid frequency re-use plan, the system must be redesigned when the interference environment changes; this is a particular problem for a system operating in an unlicensed frequency band, and is costly in terms of both labour and system capacity. If the system needs to be expanded or modified, for example to provide additional nodes, a system with centralized planning again requires massive redesign.
It would be desirable to provide an improved wireless system which is self-organizing or self-adapting as nodes are added and/or removed and/or in dependence upon changes in the environment of the system.

This patent is subject to a terminal disclaimer.


In a constant voltage circuit including: an error amplifier circuit amplifying a difference voltage between an output voltage and a reference voltage; and an output transistor controlling the output voltage based on an output of the error amplifier circuit, a voltage proportional to a leakage current detected by a monitoring transistor is generated by an oscillation circuit and a charge pump circuit and is supplied to a back gate of the output transistor.

As a constant voltage circuit that steps down a power supply voltage (an input voltage) to be supplied and generates a constant voltage to output it to a load coupled to its output terminal, a linear regulator circuit such as an LDO (Low Drop Out) circuit exists. FIG. 12 is a circuit diagram depicting a configuration example of a conventional linear regulator circuit. In FIG. 12, 101 denotes an error amplifier circuit, 102 denotes an output transistor using a P-channel transistor, and 103 denotes a load coupled to an output terminal of the linear regulator circuit. Further, Vref denotes a constant reference voltage supplied from a not-illustrated reference voltage circuit and Vout denotes an output voltage output from the output terminal of the linear regulator circuit.
In the linear regulator circuit depicted in FIG. 12, when the output voltage Vout becomes lower than the reference voltage Vref, an output voltage of the error amplifier circuit 101, namely a voltage to be supplied to a gate of the output transistor 102 drops. As a result, an on resistance of the output transistor 102 reduces and the output voltage Vout rises. Conversely, when the output voltage Vout becomes higher than the reference voltage Vref, the output voltage of the error amplifier circuit 101 rises. As a result, the on resistance of the output transistor 102 increases and the output voltage Vout drops. In this manner, the output voltage Vout output from the output terminal of the linear regulator circuit is maintained to the reference voltage Vref being a constant voltage.
Here, in the linear regulator circuit depicted in FIG. 12, when in the case of a current flowing through the load being quite small, a leakage current flowing between a drain and a source of the output transistor 102 increases such as at the time of high temperature, the output voltage Vout becomes uncontrollable to rise up to a power supply voltage level. This is because even though the output transistor 102 operates in an off direction according to the output of the error amplifier circuit 101, the output voltage Vout continues to rise due to the leakage current generated in the output transistor 102.
In order to avoid the above problem, there has been proposed a method in which a high voltage is supplied to a back gate (that is also referred to as a substrate gate) of an output transistor to thereby increase a threshold voltage of the output transistor and reduce a leakage current of the output transistor (see, for example, Patent Documents 1 and 3). In the Patent Document 1, in order to suppress the leakage current of the output transistor, there has been disclosed a configuration in which according to an operation mode, a voltage to be supplied to a back gate of an output transistor is switched by a switch. In the Patent Document 1, at the time of a standby mode when a load is brought into a low current consumption state rather than a normal operation, for suppressing the leakage current, it is controlled that a voltage HVcc higher than a voltage LVcc at the time of the normal operation is input to the back gate of the output transistor. Further, in the Patent Document 3, there has been disclosed a configuration in which a voltage to be supplied to a back gate of an output transistor is switched from VDD1 to VDD2 (>VDD1) when it becomes a certain temperature or higher, and thereby a leakage current of the output transistor under a high temperature condition is suppressed. Further, there has been proposed a technique in which according to a drive current value of an output transistor, a voltage to be supplied to a back gate of the output transistor is switched by a switch (see, for example, Patent Document 2).
[Patent Document 1] Japanese Laid-open Patent Publication No. 2007-206948
[Patent Document 2] Japanese Laid-open Patent Publication No. 2002-116829
[Patent Document 3] Japanese Laid-open Patent Publication No. 2004-94788
In the above-described conventional constant voltage circuit, the voltage to be supplied to the back gate of the output transistor is switched by a switch, but there is a problem that in the switching operation, a rapid fluctuation in the output voltage due to switching noise is caused. The above fluctuation in the output voltage causes malfunctions of a logic circuit and an analog circuit caused by power noise, element breakdown by occurrence of a pulse voltage equal to or higher than a withstand voltage, and the like.


An edge flap arrangement for an aircraft wing includes a main flap element and an actuator. A linkage arrangement supports the main flap. The linkage arrangement includes a drop hinge link arrangement. The drop hinge link arrangement includes a fixed strut and a drop link. The fixed strut and the drop link are pivotally connected by a hinge point. The hinge point includes an hourglass bearing. The hourglass bearing includes an inner member, an outer member, and a plurality of hourglass rollers. Any combination of the inner member, the outer member, and the hourglass rollers are fabricated from CREN, Cronidur 30, XD15NW, 422 Stainless Steel, CRES, and/or 440C Stainless Steel. A cage is disposed between the inner member and the outer member. The cage includes a plurality of first rails and a plurality of second rails. Opposing pairs of first rails and second rails define a plurality of pockets.

There are many types of bearings that are used in various applications. Such bearings include journal bearings, roller bearings, spherical bearings and hourglass type bearings. In general, these bearings have an inner race that is disposed at least partially in an outer race. The inner race and outer race are movable relative to one another. There is an annular cavity between the inner race and the outer race that typically contains a lubricant. One well known problem with bearings is the ingress of debris and contaminants into the annular cavity which can cause premature failure of the bearings due to degradation of the lubrication. Moreover, operation of the bearing can cause the lubricant to inadvertently escape from the annular cavity.
In an effort to mitigate the aforementioned problems, seals have been positioned across the annular cavity to maintain the lubricant in the cavity and to prevent the ingress of debris into the annular cavity. However, during operation, such seals become dislodged from the bearing and fail to function. In addition, such seals have often been too flexible, thereby allowing the seal to glide over debris and sweep the debris into the annular cavity.
Referring to FIG. 8, typical hourglass roller bearings 500, include an inner member 510, for example a ball, surrounded by an outer member 512. A plurality of hourglass shaped rollers 515 are disposed between the inner member 510 and the outer member 512. The inner member 510 defines a radially outwardly facing convex bearing surface 520. The outer member 512 defines a first radially inwardly facing convex bearing surface 522A and a second radially inwardly facing convex bearing surface 522B. Each of the rollers 515 has a concave exterior surface 525 extending between axial end faces 525A and 525B of the roller 515.
When bearings are operated at high loads, the typical rollers 515 can experience a detrimental effect referred to as "end-stress." As shown in FIG. 9, each of the rollers 515 has an effective length LE that extends between axially outermost portions of two high stress zones 535A and 535B. The concave exterior surface 525 of the typical hourglass roller 515 has a constant radius of curvature RC over the entire effective length LE. As shown in FIG. 10, typically the peak surface stress 550P occurs in the high stress zones 535A and 535B. The peak surface stress 550P causes accelerated wear of: 1) the radially outwardly facing convex bearing surface 520; 2) the first radially inwardly facing convex bearing surface 522A; 3) the second radially inwardly facing convex bearing surface 522B; and 4) the concave exterior surface 525 of the roller 515.
For example, FIG. 11 illustrates the outer member 512 having a line of surface distress 555 extending circumferential around a portion of the first radially inwardly facing convex bearing surface 522A, shown after testing (but before spalling) with a prior art hourglass shaped roller 515. FIGS. 12 and 13 illustrate the inner member 510 having lines of surface distress 555A, 555B, 555C and 555D at four locations where the high stress zones 535A and 535B of the prior art roller 515 contact the inner member 510, shown after testing (but before spalling). FIG. 14 illustrates additional wear in the form of spalling 566 on the radially outwardly facing convex bearing surface 520 of the inner member 510. FIG. 15 illustrates the prior art roller 515 having lines of burnished material 577 at an edge of the effective length LE that extends between the axially outermost portions of two high stress zones 535A and 535B.
Typical bearings include an inner member, for example a ball, surrounded by an outer member. A typical roller bearing includes a plurality of rollers disposed between the inner member and the outer member. A typical hourglass bearing includes a plurality of hourglass shaped rollers disposed between the inner member and the outer member. The inner member defines a radially outwardly facing convex bearing surface. The outer member defines a first radially inwardly facing convex bearing surface and a second radially inwardly facing convex bearing surface. Each of the rollers has a concave exterior surface extending between axial end faces and of the roller.
Corrosion is a major cause of bearing failure on aerospace structures. Corrosion can be due to moisture, salt spray, cleaning fluids, etc. There are several ways to prevent corrosion which include plating, such as Cadmium, on standard steel product, and the use of stainless steels. Stainless steels have differing corrosion resistance. CREN steels have much more corrosion protection than typical stainless steels used in bearings such as 440C (AMS 5630) Corrosion of the inner member, of the rollers and of the outer member impedes the ability of the bearing to function as intended. For example, a corroded bearing is less efficient than a bearing that has not undergone corrosion due to increased friction between contact surfaces as a result of said corrosion.
Bearings are typically used in aircraft wing flap arrangements. For example, U.S. Pat. No. 8,714,493 describes a trailing edge flap arrangement for an aircraft wing that includes a drop linkage arrangement that includes one or more bearings. The subject matter of U.S. Pat. No. 8,714,493 is incorporated by reference herein, in its entirety.

Bearing installed on an aircraft structure


A coil support with a coil of a trimmer line has a coil core with an outer wall surface and first and second axial ends. At the axial ends securing elements that project past the wall surface of the coil core are provided for positional fixation of the coil wound onto the coil core. A securing element provided at the first axial end is a support plate with a longitudinal center axis. The size of the support plate is provided in the direction of the longitudinal center axis with a greater extension than transverse to the longitudinal center axis such that the support plate in a first radial direction of the coil core is greater than in a second radial direction. The coil core is fixedly connected with the support plate and with the further securing elements that are provided on the second axial end.

The invention concerns a coil support with a coil of a trimmer line for a trimmer.
EP 1 446 002 B1 discloses a trimmer line mowing head which operates with a trimmer line that is secured by clamping in the cutter head. When a trimmer line is worn, it is exchanged for a new trimmer line section. For this purpose, the user must carry with him a supply coil of trimmer line from which, as needed, he cuts the required length of the trimmer line and inserts it into the cutter head. The supply coil of a trimmer line is carried on a coil support.
U.S. No. D524,643 S discloses a packaging for a coil of a trimmer line that is embodied as a blister pack. The coil of the trimmer line is wound separate from the packaging and is then inserted into the blister pack. This is manually complicated and time-consuming. When a section of the trimmer line is to be removed, the packaging must be opened, the desired length of trimmer line unwound and cut to length, and the packaging must be closed again. In this context, it may happen that the coil will unwind accidentally so that the line becomes entangled and the packaging can no longer be closed.
The object of the invention is to configure a coil support with a coil of a trimmer line for a trimmer in such a way that, on the one hand, the labor expenditure for winding the coil onto the coil support is minimal and, on the other hand, a simple removal of trimmer line sections from the coil support should be possible without the coil automatically unwinding or the trimmer line becoming entangled.


A method and apparatus for estimating a carrier frequency of an incoming signal. The carrier frequency estimator determines the phase difference between the phases for two successive modulation symbols when the two successive modulation symbols are within a particular magnitude range having at least two evenly spaced modulation phase states. The carrier frequency estimator includes a magnitude selector for selecting modulation symbols within the particular magnitude range and a phase subtractor coupled to the magnitude selector for determining phase differences between the successive modulation symbol phases. A signal receiver of the present invention uses the phase differences for tuning a locally generated frequency for tracking a carrier frequency of an incoming radio frequency (RF) signal.

1. Field of the Invention
The invention relates generally to carrier frequency recovery systems and more particularly to a carrier frequency estimator for estimating the carrier frequency of a QAM signal.
2. Description of the Prior Art
Modern communication signals carry information in the form of modulation symbols, where each of the modulation symbols represents a state for one or more bits of data. Each modulation symbol state has a particular in-phase (I) amplitude and a particular quadrature phase (Q) amplitude. When observed in a quadrature IQ plane, the I amplitudes and the Q amplitudes of the modulation symbols form a pattern or format. Many IQ formats have been used and proposed including formats termed 16 quadrature amplitude modulation (QAM), 64 QAM, 256 QAM, 1024 QAM, and the like.
FIG. 1 is an IQ diagram of the modulation symbol states for the 16 QAM format. The IQ diagram has an I axis and a Q axis. The 16 QAM format has sixteen modulation symbol states having relative I component amplitudes of -3, -1, 1, and 3 and relative Q component amplitudes of 3, 1, -1, and -3. Each modulation symbol state has a total amplitude or magnitude that is a square root of the sum of the squares of its I component amplitude and its Q component amplitude; and a phase that is an arc tangent of its I component amplitude divided by its Q component amplitude. A signal receiver uses locally generated signals for tracking (recovering) the carrier frequency and phase of an incoming communication signal in order to demodulate and decode the modulation symbols into data bits. When the locally generated frequencies do not match or have a frequency offset from the incoming frequency, the IQ diagram of FIG. 1 rotates at the rate of the frequency offset. This rotation causes the modulation symbols to change phase but not magnitude. A similar IQ diagram may be drawn for any format using modulation symbol states that can be described in terms of an I amplitude level and a Q amplitude level.
Quadrature amplitude modulation formats such as 16 QAM and the like have the benefits of being relatively easy to generate at the transmitting end of a communication signal link and relatively easy to decode into data bits at the receiving end. However, the circuitry for recovering the carrier frequency and phase is relatively complex and expensive because the communications signals for such formats do not have significant energy at the carrier frequency and therefore traditional simple phase lock loops are of no use. Typically, the complexity and expense increase where there is a relatively large frequency ambiguity over which a carrier recovery phase lock loop system is required to operate. Many specialized carrier recovery systems have been developed or proposed. However, all such systems have limitations and so there continues to be a need for improvement.

Carrier frequency estimator for a signal receiver


Systems and methods for analyzing the jitter content of an oversampled digital communication signal are disclosed. Advantageously, the communication signal can correspond to an arbitrary data sequence, rather than only to a repeating test sequence. For example, the systems and methods can be embodied in test equipment and in simulation equipment as design tools and/or validation tools. The systems and methods disclosed advantageously facilitate the decomposition and quantification of the main jitter components (random and deterministic), as well as its various subcomponents (periodic jitter, data-dependent jitter, inter-symbol interference, device-state-dependent jitter, other bounded uncorrelated jitter, and data-dependent-random jitter).

1. Field of the Invention
The invention generally relates to measurement systems. In particular, the invention relates to measurement systems for analyzing jitter.
2. Description of the Related Art
Jitter in a digital communication signal is the variation in time of data (or clock) edges from integer multiples of the bit period unit interval (UI) time. In an ideal signal, the edges would occur at exact interval times. In a real signal there is variation in the edge locations due to various phenomena in the signal generation and transmission system. FIG. 1 shows a representation of a digital data signal labeled jittered data 102 relative to a reference clock 104. In the illustrated example, the jittered data 102 is capable of changing states approximately at times corresponding to the rising edges of the reference clock 104. This data signal has variation in the edge locations. The variation is plotted relative to the ideal location, at the bottom of FIG. 1. This variation is known as the jitter 106, or time interval error (TIE), of the signal. It will be understood that whether there is an actual transition in the jittered data 102 corresponding to an edge of the reference clock 104 will depend on the data itself. For example, the data can remain at a "one" or a "zero" state for multiple clock periods.
Many current industry specifications divide jitter into two main categories: unbounded random jitter (RJ), and bounded deterministic jitter (DJ). Random jitter (RJ) is modeled as having a zero-mean Gaussian distribution and is quantified by the standard deviation. Deterministic jitter (DJ) is parameterized as a peak-to-peak value. The total jitter (TJ) is also parameterized as a peak-to-peak value, which is a combination of deterministic jitter (DJ) and random jitter (RJ). Given that the total jitter (TJ) is unbounded on account of the random jitter (RJ) contribution, it is specified as the peak-to-peak time interval between which all but a fraction of the jitter population falls. A fraction commonly specified is 10−12, but it will be understood by one of ordinary skill in the art that the specified fraction can vary in a very broad range and can include larger fractions and smaller fractions. For example, some emerging applications specify fractions that are orders of magnitude smaller than 10−12. A relatively direct method of measuring the total jitter (TJ) under this stipulation is to measure the jitter for 1014 bits in order to obtain reliable statistical information on the total jitter (TJ) range that occurs with a 1-10−12 probability. However, this would be relatively time consuming, taking over 27 hours if 1014 consecutive bits at 1 Gbit/s were to be observed. A more feasible method is to observe the jitter for a shorter period, and estimate the 10−12 peak-to-peak jitter by fitting its distribution to a statistical model.
A simplified jitter model is illustrated in FIG. 2 with periodic jitter (PJ) represented by a dual-Dirac, random jitter (RJ) represented by a Gaussian in an upper trace 202. The resulting convolution of both is shown in a lower trace 204. It should be noted that the dual-Dirac has been scaled for visibility in the plot of FIG. 2. The model typically used to represent the distribution of the jitter components is a zero mean Gaussian for random jitter (RJ), and a dual-Dirac function for deterministic jitter (DJ) (the dual-Dirac function being an approximation to the distribution of a sinusoid). In this case, the total jitter is simply two Gaussian distributions with means offset equal to the offsets in the Dirac functions (see FIG. 2). For this distribution, the approximate calculation of all but 10−12 of the population is given as the sum of the peak-to-peak of the deterministic jitter and 14 times the standard deviation, or RMS value, of the random jitter (see Equation 1 below).TJpp(10−12)=RJpp(10−12)+DJpp≈14RJrms+DJpp  Equation 1
Some instruments and specifications define TJpp explicitly according to Equation 1. Others generate a histogram distribution for total jitter (TJ) based on the convolution of the calculated random jitter (RJ) and deterministic jitter (DJ) distributions. The TJpp is then extrapolated for the specified population by fitting the total jitter (TJ) distribution to a bathtub curve model. In each case however, there is a common underlying problem:                1. The jitter content of a signal will typically be demodulated from the signal itself.        2. The random jitter (RJ) and deterministic jitter (DJ) components will typically be decomposed from the measured jitter and quantified.        3. The TJpp will typically then be calculated based on the combination of random jitter (RJ) and deterministic jitter (DJ) for the specified population.
FIG. 3 is a tree diagram that illustrates selected components of jitter. Jitter at each level of the hierarchy in the tree diagram is not necessarily independent, for example, duty cycle distortion (DCD) jitter 316 may be due to inter-symbol interference (ISI) jitter 314. Deterministic jitter (DJ) 306 is commonly subdivided further into the following components: periodic jitter (PJ) 308, data-dependent jitter (DDJ) 310, and bounded uncorrelated jitter (BUJ) 312, with data-dependent jitter (DDJ) 310 further subclassified as linear inter-symbol interference (ISI) jitter 314 and duty cycle distortion (DCD) jitter 316.
Periodic jitter (PJ) 308 includes tones that are uncorrelated with the data. Data-dependent jitter (DDJ) 310 is correlated to the data pattern where: inter-symbol interference (ISI) jitter 314 is due to band-limiting in the system, and duty cycle distortion (DCD) jitter 316 is related to a mismatch between the falling and rising edges of the signal due to the signal transmitter. Bounded uncorrelated jitter (BUJ) 312 is the grouping of other effects that are bounded but are not correlated to the data pattern, and do not exhibit a periodic behavior. One possible source of bounded uncorrelated jitter (BUJ) 312 is cross-talk from asynchronous aggressors. Although most current specifications only state limitations on random jitter (RJ) 304, deterministic jitter (DJ) 306, and total jitter (TJ) 302, the subcomponents of deterministic jitter (DJ) 306 are often of interest for device analysis.
Conventional Jitter Analysis
There are several standard methods in the industry to deal with the problem of jitter decomposition. They are based on either a method of undersampling the data, typically with the use of a time interval analyzer, or oversampling the data with a single-shot sampling oscilloscope. After the jitter data has been recovered from the captured data, it is typically separated using one of two methods. The first method involves the construction of a histogram of the jitter in the time domain. This histogram is divided into its random and deterministic parts through an analysis of its shape. The second method involves the transformation of the jitter into the frequency domain using a Fourier Transform (FT), such as a Fast Fourier Transform (FFT). Once in the frequency domain, it is stated that the deterministic components may be identified as tones in jitter spectrum, while the random components make up the noise floor of the spectrum. The spectrum is then separated into two parts and the random jitter (RJ) 304 is calculated from the noise floor, and the deterministic jitter (DJ) 306 is calculated from the tones.
While these existing methods may be applied successfully to make jitter approximations in specific cases, there are many situations in which these methods fail.
General Undersampling Methods
FIG. 4 illustrates a sampled waveform and its corresponding time interval error (TIE). Some industry standard methods are based on the use of undersampled data. See, for example: U.S. Pat. Nos. 6,185,509; 6,356,850; and 6,449,570. These methods can use either an undersampling time interval analyzer or an undersampling oscilloscope. The methods were typically developed in this way due to hardware limitations that would not allow for every contiguous edge to be measured. One problem with such methods is that sporadic events that are not correlated with the data and do not occur regularly can be completely overlooked. FIG. 4 shows the jitter data for a signal where this is the case. When measured using an undersampling time interval analysis method, this signal yields a total jitter value of less than 0.25 UI (well within specifications), even though this signal causes a failure in the receiver. Using an oversampling method reveals that the total jitter is actually greater than 0.5 UI.
Time Interval Analyzer Span Measurements to Acquire Jitter Data and to Determine Data Dependent Jitter Component
The method of time interval analyzer span measurements is implemented to calculate the data-dependent jitter (DDJ) component of jitter in a signal. See for example: U.S. Pat. Nos. 6,185,509; 6,356,850; and 6,449,570. Collections of time interval measurements are gathered for every edge in a repeating data sequence. These collections are processed to generate a histogram distribution of jitter for each edge independently. The mean offset of each histogram represents the data-dependent jitter (DDJ) associated with the edge in question. The difference between the maximum and minimum mean offsets is the peak-to-peak data-dependent jitter (DDJ). This method is dependent on a priori knowledge of the repeating data pattern and will fail if the pattern is not repeating or if the pattern is unknown.
Time-Domain Histogram Tail-Fitting Method
The tail-fitting method is based on the generation of a histogram of the jitter data. See, for example, U.S. Pat. No. 6,298,315. It has been suggested by conventional techniques that fitting Gaussian curves to the tail portions of the distribution can identify the random jitter (RJ) content. The RMS value of the random jitter (RJ) is then calculated as average value of the standard deviation of the two Gaussian curves, and the peak-to-peak deterministic jitter (DJ) is calculated as the separation between the means of the two Gaussian curves.
In reference to the dual-Dirac and Gaussian model described earlier in connection with FIG. 2, this suggested solution is a relatively accurate approximation. The convolution of the dual-Dirac with the Gaussian has a negligible effect on the shape of the tails. It should be noted that the shape of the tail corresponds to the sum of the Gaussian with its shifted duplicate. Due to the rapidly decaying nature of the Gaussian curve, if there is significant separation between the two Gaussian distributions, then the value of the tail portion of one will be insignificant at the tail location of the other as illustrated in FIG. 2. However, if the dual-Dirac distribution model is replaced with one representing an actual tone, or multiple tones for deterministic jitter (DJ), the suggested solution is relatively inaccurate. In generating the total jitter (TJ) distribution, by convolving the Gaussian and the new deterministic jitter (DJ) distribution, the shape of the resulting tail region will be significantly altered from the original Gaussian. The parameters estimated from this data set will be biased due to model mismatch.
Frequency-Domain Spectral Separation Method
The spectral separation method is based on oversampled data acquired using a single-shot sampling oscilloscope. See, for example, U.S. Patent Application Publication US2003/0004664. The threshold crossings for each consecutive edge are interpolated between the sample points, and the jitter data is derived. The jitter data is transformed into the frequency domain using a Fourier Transform (FT). It is claimed that the deterministic jitter (DJ) components can be distinguished from the random jitter (RJ) as peaks in the spectrum. Although this may be accurate for a simple case where the deterministic jitter (DJ) is composed of a single periodic jitter (PJ) tone, or a very small amount of data-dependent jitter (DDJ), this method will fail in the presence of multiple periodic jitter (PJ) tones, periodic jitter (PJ) tones of relatively large amplitudes, or a significant amount of data-dependent jitter (DDJ). Due to the windowing effects of the Fourier Transform (FT), a certain amount of power from any tones in the spectrum will be distributed into side lobes of the tone. When the major lobe, or peak, of the tone is removed from the spectrum, the side lobes will remain and inappropriately contribute to the random component of the jitter. In cases where the side lobes are relatively few and relatively small, then this will not matter. However, in cases where there are relatively many sidelobes, or they are relatively large, then the random component can be dramatically inflated. Examples of this are described.
In a first example, in cases where there is a relatively large tone in the spectrum whose frequency does not fall precisely on a bin center, the side lobes may become significant. This occurs in jitter tolerance testing when signals with relatively large amounts of periodic jitter (PJ) are artificially created to stress device receivers.
In a second example, in cases where there are relatively many tones in the spectrum, the sum of all the resultant side lobes becomes significant. This occurs commonly with data-dependent jitter (DDJ), when the high frequency content of the signal is approaching the bandwidth of the transmission channel. Jitter tones due to data-dependent jitter (DDJ) occur throughout the spectrum at multiples related to the bit pattern length. A relatively large amount of data-dependent jitter (DDJ) can be intentionally introduced in jitter tolerance measurements to stress device receivers. Relatively large amounts of data-dependent jitter (DDJ) are also common in system intrinsic jitter measurements where signals are measured after long transmission channels such as back-planes and multiple connectors.
FIG. 5 illustrates an example of time interval error (TIE) associated with data-dependent jitter (DDJ). The frequency domain spectral separation method is dependent on a repeating data pattern so that data-dependent jitter (DDJ) shows up as tones in the jitter spectrum. In the case of random data, data-dependent jitter (DDJ) does not show as tones in the spectrum. Rather, it is broadband and cannot be distinguished from the noise floor. Therefore, this method fails in the presence of random data. FIG. 5 depicts a simulated random data signal containing only data-dependent jitter (DDJ) (no random jitter (RJ) or periodic jitter (PJ)), the TIE signal, and the power spectrum of the TIE signal.
Further Jitter Component Analysis
FIG. 6 illustrates an example of further components of jitter that can advantageously be distinguished using the techniques disclosed herein. It will be shown that by doing this a more accurate calculation of the total jitter (TJ) 302 can be performed, and a better analysis can advantageously be performed on the jitter content to aid in the identification of sources of jitter in the signal. FIG. 6 illustrates selected additional jitter categories that can be recognized using the techniques disclosed herein versus the limited categories previously described in connection with FIG. 3.
Data-Dependent Random Jitter (DDRJ) 602
Random jitter (RJ) 304 may be further categorized as data-dependent random jitter (DDRJ) 602. In certain cases, the random jitter (RJ) 304 standard deviation is dependent on the data surrounding any given transition. This phenomenon has been observed in data where the slew rate of each edge is also data dependent. It is most evident in situations where signals are intentionally degraded for jitter tolerance testing, and random jitter (RJ) 304 is imposed on the signal through the addition of amplitude noise. The transformation of amplitude noise into random jitter (RJ) 304 is a linear function of the slew rate.
Conventional jitter decomposition methods disadvantageously assume an equal distribution for random jitter (RJ) 304 across all edges in the signal, and calculate random jitter (RJ) 304, and subsequently total jitter (TJ) 302, based on this assumption. This can result in an underestimation of the critical peak-to-peak random jitter (RJ) contribution. Advantageously, disclosed techniques include a method to account for these effects in the RJpp and TJpp computations.
Device State Dependent Jitter (DSDJ) 604
Data generation and transmission systems are subject to performance variations depending on the pattern content of the data, and other factors within the system that relate to the data. For example, the transmission of data with a high transition density, e.g., 01010101, can consume relatively more power than data with a low transition density, e.g., 00001111. Power fluctuations and other phenomena can dramatically affect the jitter content of the signal, contributing to device state dependent jitter (DSDJ) 604. Analyzing device state dependent jitter (DSDJ) 604 can be useful in identifying problems in a system. Existing jitter decomposition methods lump device state dependent jitter (DSDJ) 604 and inter-symbol interference (ISI) jitter 314 together, whereas disclosed techniques advantageously permit them to be distinguished from one another.
Current state of the art jitter analysis and decomposition is represented by the following public domain publications, the disclosures of which are incorporated herein by reference in their entirety:
U.S. Pat. No. 6,298,315: Method and Apparatus for Analyzing Measurements
U.S. Pat. No. 6,298,315 to Li, et al describes a method of analyzing data to separate it into random and deterministic components. The method generates a time-domain histogram of the data and identifies the tail segments of that histogram. A Gaussian curve is fitted to each of the tails. The Gaussian curves are associated with the random component and the remainder of the distribution is associated with deterministic component.
U.S. Pat. No. 6,356,850: Method and Apparatus for Jitter Analysis
U.S. Pat. No. 6,356,850 to Wilstrup, et al., describes a method and apparatus for separating the components of a jitter signal. It identifies a reference edge in a repeating data signal and makes multiple time span measurements between that reference edge and the other edges in the data signal. The variation in these time span measurements is a representation of the jitter in the signal. It generates variation estimates of the time spans, calculates the autocorrelation function of the jitter signal, and transforms the autocorrelation function into the frequency domain using a Fourier Transform (FT). The random and deterministic components are separated in the frequency domain using a Constant False Alarm Rate (CFAR) filter, where the peaks of the frequency spectrum are associated with the deterministic components. This technique is limited to the analysis of periodic waveforms, such as repetitive digital bit sequences.
U.S. Pat. No. 6,185,509 and U.S. Pat. No. 6,449,570: Analysis of Noise in Repetitive Waveforms
U.S. Pat. No. 6,185,509 to Wilstrup, et al., and U.S. Pat. No. 6,449,570 also to Wilstrup, et al., describe a method for measuring time intervals in a repeating pattern, and characterizing the variation in those time intervals. It is directly applied to measuring the jitter in a repeating pattern.
US2003/0004664: Apparatus and Method for Spectrum Analysis-Based Serial Data Jitter Measurement
U.S. Patent Application Publication No. US2003/0004664 by Ward, et al., describes an apparatus and method of jitter separation for repeating patterns. It is based on spectral analysis of the jitter signal to separate deterministic jitter and random jitter. The jitter signal is transformed into the frequency domain using a Fourier Transform (FT). The CFAR filter using a single sliding window is employed to separate the deterministic jitter (DJ) components from the random jitter (RJ) component. The data-dependent components (DDJ), periodic jitter components (PJ), and duty cycle distortion (DCD) components are separated by analyzing the spectrum of the components identified as deterministic jitter (DJ).

Systems and methods for jitter analysis of digital signals


A multiple gear transmission with magnetic control for vehicles or for use in drive technology includes an input shaft supported on a frame and an output shaft. The input shaft protrudes from the frame at least one end and the output shaft protrudes from the frame at one end. Transmission gear ratios with transmission wheels are embodied as gear trains or belt and chain drives and are located between the input shaft and the output shaft. Transmission wheels are supported in a rotatable manner on the input shaft or on the output shaft. The transmission wheels are connected to the input shaft or the output shaft in a torsionally fixed manner by a clutch mechanism. The transmission wheels are constantly in rotation during operation. A state of the clutch mechanism changes through the change of an additional magnetic field inside or in a direct vicinity of the clutch mechanism.

1. Field of the Invention
The invention relates to a multiple gear transmission with magnetic control for vehicles or for use in drive technology with an input shaft supported on a frame and an output shaft, the input shaft and the output shaft protruding from the frame.
2. Discussion of Background Information
For the past 100 years it has been impossible to imagine the field of motorized vehicles without manual transmissions. They are also used in numerous machines in drive technology. These are very often transmission constructions that operate with the aid of gear wheels as a spur gear transmission or planetary gear train. However, the production engineering of these transmissions is generally very complex and expensive.
Since these power transmitting transmission components are generally made of steel, the weight is currently increasingly the focus of criticism and should be seen as a disadvantage. Lighter transmissions would reduce energy consumption, for example.
Ground vehicles, aircraft and watercraft should be seen by way of example here which may be equipped with internal combustion engines, electric motors or other units. Likewise a use in vehicles that are driven by muscular energy is conceivable. In order to guarantee easy propulsion, the vehicles must be extraordinarily light. The functional description of the transmission for this reason will provided using a bicycle by way of an illustrative example.
In the past forty years the chain drive with a shifting capability at the rear axle has become widely used with bicycles. To this end, a rotatable bottom bracket with one or more chain rings is mounted onto the frame which forms the load-bearing component of the bicycle with all its receiving points for the front wheel fork, the seat post and the rear wheel. A cassette comprising up to ten sprockets of different sizes is located on the hub of the rear wheel. At one dropout located directly at the rear axle a rear derailleur is installed, which has the task of guiding the chain in the sprockets of the cassette and to render possible shifting processes. Through a front derailleur that is usually installed at the seat tube it is possible to switch between the various chain rings at the bottom bracket. The capability of shifting allows the rider to adapt the gear ratio of his/her drive to the respective riding situation. Bicycles with a shifting system as described above are generally referred to as bicycles with derailleur gears.
As the components are mounted outside on the frame for constructional reasons with a bicycle with derailleur gears, the components are particularly exposed to environmental influences. Dirt and water thus come into contact with the rear derailleur, chain, cassette and other components in an unobstructed manner. This drastically reduces the efficiency of the derailleur gears, which is initially very good. For this reason, a considerable part of the force must be used to overcome the resistance within the shifting system.
In order to ensure functionality it is necessary to regularly service the components of the derailleur gears, which includes cleaning and greasing the components and adjusting them precisely. This adjustment can easily change, e.g., with falls or contact with objects (stones, branches, etc.). As tiny dirt particles always remain in the shifting system and in particular in the bearings even with the most intensive servicing, some parts need to be replaced regularly. In particular the parts susceptible to wear, such as chain rings and chain require an annual replacement, which in turn incurs additional expenses.
Shifting with derailleur gears is possible only with rotating sprockets, since otherwise the chain cannot be changed. It is therefore to be seen as a disadvantage that switching at stop is impossible due to the structural design. Furthermore, components can be damaged or torn off the frame with a fall or contact with stones or branches or other objects. The listed circumstances are to be seen as a disadvantage of derailleur gears.
Alternatively to the derailleur gears, the so-called "integral rear hub" was developed in which the shifting processes take place in a transmission in the rear wheel hub. The parts required with the derailleur gears, i.e., rear derailleur, front derailleur and cassette are thus omitted. Bicycles of this type are generally called bicycles with integral rear hub. An integral rear hub thus avoids the disadvantages of derailleur gears.
Because of the transmission integrated into the rear wheel hub, however, the weight of the rear wheel increases. In particular with so-called mountain bikes, which are moved off-road, an increase in mass at the rear wheel becomes highly noticeable. This applies in particular to bicycles with rear wheel suspension. The ratio of sprung to unsprung mass is of decisive importance for the riding behavior of a sprung wheel. The larger the unsprung mass is in relation to the sprung mass, the more critical is the riding behavior of the wheel. With high unsprung mass (heavy rear wheel) thrusts caused by road bumps cannot be compensated for in an optimum manner by the chassis.
With a known bicycle (cf. DE 103 39 207) the transmission is located within the bicycle frame. The bottom bracket shell of the classic bicycle frame is omitted and replaced by the transmission housing. This is a joint housing for the transmission and bottom bracket. Similar to the bicycles with the transmission hub, the power is transmitted to the rear wheel via a chain or a toothed belt, where the chain and the rear wheel hub do not have a shifting function with this system. The rear wheel hub can thus be built in a very light manner, which results in a more efficient rear wheel suspension. Furthermore, the center of gravity shifts to the center of the bicycle, directly below the rider, which results in a more agile and controlled riding behavior. In addition, the so-called "platform strategy" can be used with the aid of the transmission integrated into the frame.
It has been customary in bicycle construction to first build a frame and then to equip it with its components; however, the concept of the transmission integrated into the frame renders it possible for the first time to use the platform strategy known from automobile construction in bicycle production. For example components, such as the shifting system, suspension, the complete power transmission, brakes, generator and lighting are firmly installed in the transmission housing as a platform. The customer-specific parts, which complete the bicycle according to customer or manufacturer specification, are then mounted to the transmission thus equipped.
The transmission according to DE 103 39 207 comprises a planetary transmission and a primary drive. The primary drive is necessary because the planetary transmission developed for use in a transmission hub does not withstand the high torque acting in the bottom bracket. The primary drive brings the planetary transmission to a higher rotational speed, so that it can withstand the acting forces. This construction, however, lowers the efficiency of the drive. This is to be seen as a disadvantage.
Likewise similar transmissions are known, e.g., from U.S. Pat. No. 5,553,510, U.S. Pat. No. 4,955,247, U.S. Pat. No. 5,924,950, DE 2020178U1, WO 2006/039880 A1, US 2004/0067804 A1 and US 2004/0066017 A1. These designs are generally very heavy and complex. One of the shafts is generally the drive shaft and another shaft is the driven shaft. The drive shaft is also referred to below as the input shaft. The driven shaft is also referred to below as the output shaft. If only the term shaft is used below, either the input or the output shaft is meant.
A chain-drive transmission is known, e.g., from U.S. Pat. No. 4,158,316. In this transmission several sprockets with different diameters are rotatably mounted on the axle. The sprockets can be locked in a rotationally fixed manner to the shaft by a coupling and thus transmit a torque. The disadvantage of this lies in the high weight, in particular through the use of a steel chain, and through the large space required, the complexity of the couplings and the coupling control.
A similar chain-drive transmission is known, e.g., from US 2004/0067804 A1 and US 2004/0066017 A1. In these bicycle transmissions various drive wheels are mounted on the input shaft and output shaft, which wheels are connected in pairs to drive mechanisms. Different gear ratios are achieved in that a shifting component inside the drive shaft is axially displaced with the aid of a cable. A connection element on the shifting component engages in the desired drive wheel and generates a rotationally fixed connection between the driven shaft and the drive wheel. However, the described structure has disadvantages, which will be described in more detail below.
Both U.S. Publications, e.g., US 2004/0067804 A1 and US 2004/0066017 A1, disclose that the drive wheels are arranged next to one another such that they form the shape of a conical envelope. The shape of a conical envelope is formed when the diameter of the drive wheels increases from small to large on the shaft. This special feature of US 2004/0067804 A1 and US 2004/0066017 A1 is in fact to be regarded as a disadvantage:
Gear ratios on bicycles should increase speed in the range of 0.7-4.0. Considering the size of the sprocket wheels and their number of teeth in US2004/0067804 A1 and US2004/0066017 A1, this range of gear ratios will be difficult to achieve. Furthermore, considered in terms of sports biology, only gear steps of less than 15% can be handled well by a person.
The so-called secondary transmission is formed by two further belt wheels, which transfer the torque from the transmission to the rear wheel. It is advantageous if these belt wheels do not impair the function of the pedal bearings and the rear wheel hub by their proportions. The design according to US 2004/0067804 A1 and US 2004/0066017 A1 would make a very large and voluminous structure, if the framework conditions with respect to secondary transmission, overall transmission and gear transition were to be achieved.
Belt and chain drives in general have a discrete axial distance, which depends exclusively on the pitch and the length of the belt, and the diameter or the number of teeth of the belt wheels used. This axial distance can be described by the following formula:
  a  =            p      /      4                  ⌊              X        -                              (                                          z                1                            +                              z                2                                      )                    /          2                +                                                            [                                  X                  -                                                            (                                                                        z                          1                                                +                                                  z                          2                                                                    )                                        /                    2                                                  ]                            2                        -                                          8                                                  [                                                            (                                                                        z                          2                                                -                                                  z                          1                                                                    )                                        /                                          (                                              2                                                π                                            )                                                        ]                                            2                                          ⌋      a=axial distancep=chain pitch of the chainX=number of links of the chainz1=number of teeth of the small sprocket wheelz2=Number of teeth of the large sprocket wheel
If this formula is applied to US 2004/0067804 A1 and US 2004/0066017 A1, it is found that not every individual belt wheel has the correct axial distance. A structure according to US 2004/0067804 A1 and US 2004/0066017 A1 is thus disadvantageous, since some chains are taut and others are loose. This must be considered a major disadvantage, since incorrectly tightened chains have excessive wear. This disadvantage is referred to below as "only discrete axial distances possible." Only discrete axial distances are possible with U.S. Pat. No. 4,158,316 due to the belt used. This must also be seen as a disadvantage. At the same time, it should be noted that this disadvantage of the discrete axial distances also occurs with gear trains.
Another major disadvantage is to be found inside the shifting control with U.S. Pat. No. 4,158,316, US 2004/0067804 A1 and US 2004/0066017 A1. If a gear change is to be performed, first a belt wheel is disengaged from the driven shaft and only thereafter is another belt wheel engaged to the shaft. As a result, with these drives a permanent rotationally fixed connection between the shaft and a gear wheel is not guaranteed. During a change of gear, a neutral position can occur. To the cyclist this means suddenly pedaling "into a void." This can cause injuries, particularly in the knee area.
In the past, belt and chain drives were often found with belts running parallel, in which the belt wheels are engaged to one axle (see also CH 167867, U.S. Pat. No. 6,146,296 and U.S. Pat. No. 5,871,412). However, all of these constructions exhibit the disadvantage that a small time window with a neutral position could always develop between two engaged gear ratios. In particular under load it cannot be ensured that a brief clutch slip cannot occur during this time window. Likewise a clutch slip of this type leads to enormous wear on the clutches. Over the long term damage cannot be excluded under certain circumstances.
To sum up, many transmissions according to the above systems have problems with respect to weight, production costs, ability to shift under load, neutral position and ability to switch at stop.

Multiple gear transmission with magnetic control


A system for repairing polymer structures, for example, polypropylene storage tanks for liquid, includes the application of a unique primer in connection with a plurality of layers of other adhesives to attach a liquid-impermeable elastomeric liner. The system permits the liquid-impermeable elastomeric liner to expand and contract along with the polymer tank, thus resisting separation of the liner from the polymer.

Polymer, for example, polypropylene, is used for a variety of structures, for example, storage tanks for liquids. Some of these liquids may be acids, bases, or otherwise corrosive. The tank must be able to withstand not only the weight and pressure of the liquid, but also any degradation that the liquid would tend to cause to the tank.
When a polymer tank degrades, develops cracks, etc., previous attempts to repair that tank have proven to be problematic or unsuccessful. For example, if a liner is added to the tank, and if the liner has a different rate of thermal expansion than the tank, the differences in thermal expansion rates tends to cause prior repair efforts to fail. In particular, polypropylene can expand and contract about 1 inch for every 10 feet of material when heated to a temperature of about 180° F., and any repair must take this expansion and contraction into account.
Accordingly, there is a need for a system for repairing polymer tanks. There is a need for this system to accommodate any differences in the rate of thermal expansion between the polymer tank and any liner added to repair the tank.


A methodology for retrieving textual data objects in a multiplicity of languages is disclosed. The data objects are treated in the statistical domain by presuming that there is an underlying, latent semantic structure in the usage of words in each language under consideration. Estimates to this latent structure are utilized to represent and retrieve objects. A user query is recouched in the new statistical domain and then processed in the computer system to extract the underlying meaning to respond to the query.

In the field of information retrieval, a long-standing objective has been the development of an automated procedure by which documents in one language could be effectively accessed by requests in another language without needing to translate either the documents or the requests. Among other things, such a capability would allow users to determine what documents were available in languages that the users could not read before incurring the expense and delay of translation.
One technique representative of some previously proposed procedures, disclosed in an article entitled "Automatic Processing of Foreign Language Documents," was published by G. Salton in 1970 in the Journal of American Society for Information Sciences. Salton reported experimenting with a method for automatic retrieval of documents in one language in response to queries in another using a vector representation and search technique in conjunction with a manually created dual-language thesaurus. The results for test samples of abstracts and queries were promising. However, creating an adequate multi-language thesaurus is difficult and requires considerable intellectual labor. Moreover, a traditional thesaurus necessarily imposes a discrete and rather restricted model of the languages in question and of their relation to one another.
U.S. Pat. No. 4,839,853, issued to one of the present co-inventors and assigned to the same assignee as is the present invention, utilizes the Latent Semantic Indexing (LSI) approach to model the underlying correlational structure of the distribution of terms in documents. Instead of representing documents and queries directly as sets of words, the LSI technique represents them as parameters in such a way that dependencies between words and between documents are taken into account. For example, if two terms are used in exactly the same contexts, that is, have identical distribution across a target collection of documents, LSI is designed to treat them not as two independent indexing entries but as two instances of an abstract indexing variable with the same vector value. Lesser and more indirect relations between terms and between documents are represented in an appropriate analogous fashion.
In the implementation of LSI as set forth in the above-identified patent, the modeling is accomplished by approximating the original term-by-document matrix by the product of three lower rank matrices of orthogonal derived indexing variables. The first matrix represents terms as values on a smaller set of independent "basis" vectors; the second matrix contains scaling coefficients; and the third matrix represents documents as values on the smaller set of basis vectors. The method can be interpreted geometrically as a means by which each document and each term is assigned to a point in a hyperspace. The mathematics and implementation of the method construct a derived space in which terms, documents, and queries can all be represented in the hyperspace. The mathematical procedure employed is singular value decomposition (SVD), which is closely related to factor analysis and eigenvalue decomposition.
The retrieval process is the same as in standard vector methods, e.g. using document-query cosines as the similarity measure. Various preprocessing steps, such as term weighting, may also be done in standard ways. The principal difference between LSI and previous vector models as represented by the work of Salton is that the vectors are constructed in a space with many fewer dimensions than the number of original terms, and that these dimensions are the subset of linearly independent basis vectors by which the original term-by-document matrix can be best approximated in a least squares sense. The number of dimensions retained has been determined empirically; optimal retrieval performance has usually been obtained with about 100 dimensions for collections of many hundreds to several thousands of documents.
The dimension reduction step of LSI has the advantageous property that small sources of variability in term usage are dropped and only the most important sources kept. Among other things, this can cause synonyms or near synonyms to be collapsed into similar vector representations, with the result that queries can retrieve similar documents even though they share no terms. This cannot happen in the usual raw term vector representation, necessitating manually constructed thesauri with their attendant problems.
The LSI method has previously been applied only within a single language, and there has been no teaching or suggestion in the art regarding the application of LSI to multi-language information retrieval.

Computerized cross-language document retrieval using latent semantic indexing


A vehicular lamp has a light-emitting portion connected in series to an input terminal to which a power supply voltage based on an on-board battery is configured to be applied, and having a plurality of light-emitting elements connected in series, a series connection circuit having a first current limiting resistor and a second current limiting resistor, which is inserted in series between the input terminal and the light-emitting portion, a resistor switching switch connected in parallel to one of the first current limiting resistor and the second current limiting resistor, bypass switches, each of which is connected in parallel to a required one of the light-emitting elements in the light-emitting portion, and a control circuit that turns off the resistor switching switch when at least one of the bypass switches is turned on.

1. Technical Field
The present invention relates to a technical field of vehicular lamps capable of independently lighting/extinguishing a required one of a plurality of light-emitting elements by a bypass switch.
Patent Document 1
Japanese Patent Application Laid-Open (Kokai) No. 2009-35105
2. Related Art
For example, vehicular lamps are known which include a plurality of semiconductor light-emitting elements such as light-emitting diodes. Such vehicular lamps include a vehicular lamp capable of independently driving a required one of the plurality of semiconductor light-emitting elements to emit light. For example, FIG. 5 of Patent Document 1 discloses a configuration capable of independently lighting/extinguishing each light-emitting element by turning on/off bypass switches connected in parallel to the semiconductor light-emitting elements. Patent Document 1 discloses that only a required one of the plurality of bypass switches is driven by PWM to drive the light-emitting element having connected thereto the bypass switch that is driven by PWM and the other light-emitting elements with different driving current values (average current values).


An instant messaging or chat (IM/chat) communication method can include a series of steps. The steps can include inserting in an instant message (IM) a voice conference identifier comprising a voice conference call list identifying conference call nodes. The IM can be transmitted to a recipient at a recipient node. Responsive to the recipient selecting the voice conference identifier, a voice conference call between selected ones of the identified conference call nodes can be established.

1. Technical Field
This invention relates generally to Internet-based communication systems, and more particularly to text-based Internet communications system such as instant messaging and on-line chat.
2. Description of the Related Art
Text-based Internet communication systems such as instant messaging and chat over a data communications link have become increasingly popular due to the substantially real time nature of the communication, low cost, and simplicity of use. The instant messaging or chat (IM/chat) client typically has a message text window in which an incoming text-based instant message (IM) can be presented to an end user. IMs that are sent by the end user through the IM/chat client also can appear in the message text window.
IM/chat systems work well for many communications, but there are times when clients would prefer voice communications. For example, on occasion the contents or subject matter of an IM/chat session can give rise to a desire for voice communications. In such instances, it is usually necessary to terminate the IM/chat session, drop the data communications link, and establish a voice communications link through known methods such as conventional telephony over the publically switched telephone network (PSTN). In such instances, the spontaneity of the conversation is lost, and details of the conversation can be forgotten. The voice communications link sometimes cannot be established, in which case all communications, both data and voice, are terminated. In other instances, the extra steps necessary to establish a voice communications link impedes some from establishing such a link even when a voice link can be necessary or desirable.
Conventional IM/chat systems also can support the exchange of attachments. Attachments are electronic files such as images, documents, or binary objects which can be attached to an IM and transmitted therewith from a sender to a recipient. Attachments can be embedded in a labeled section of an IM such that an IM/chat client processing the IM can identify the presence of an attachment and can decode the contents of the attachment so that the attachment can be further processed by the recipient. Hence, attachments can enhance the utility of exchanging IMs and can provide a supplemental medium for communicating ideas between participants in an IM/chat session.
Still, IM and IM attachments are not always an adequate replacement for live voice conversations between IM/chat session participants, particularly where extensive interaction between the participants is necessary or desirable. In some instances, live voice conversations are necessary to explain or discuss the message text included in the IM, attached documents, or audio/visual files. Moreover, a telephone sometimes is not available to the participants, or the use of a telephone requires lengthy dialing procedures which interrupt the spontaneity of the communication. Sometimes telephone access by the participants requires that at least one of the participants terminate an on-line connection to the Internet, which further can disrupt the process of discussing the contents of an IM.
The aforementioned difficulties further can be exacerbated when more than two parties need to be involved within a given IM communication chain. Moreover, inclusion of more than two parties within an IM/chat session assumes that each party's IM/chat client has the capability of handling IM/chat sessions with more than two other IM/chat clients simultaneously and within a single text window. If so, though the sending party can be identified easily, it can be difficult to determine the party to which a particular IM is directed. If an IM client only supports two-way IM communications, the parties must initiate multiple two-way IM sessions. In that case, IMs can be sent in a serial fashion from one party to the next, resulting in duplicate information being transmitted to each party within the IM chain. This redundant transmission of data can result in unnecessary communication delays between the parties. For example, the content of an IM can be retyped and re-sent to several different parties before ultimately reaching the proper party.

Instant messaging with voice conference feature

International Business Machines Corporation


An optical transmission device includes: a switching configured to be capable of switching a transmission path to which light is input from a first transmission path to a second transmission path; a first calculation unit configured to calculate, based on a difference between a first light level of the first transmission path and a second light level of the second transmission path, a first control amount for the second light level; and a control unit configured to perform a first control in which the second light level is decreased or increased based on the first control amount upon switching of the transmission path.

In an optical transmission network, a double transmission path that couples optical transmission devices is provided. In an optical protection scheme, when a failure has occurred in one of transmissions path (work system), the transmission path is switched to the other transmission path (protection system), so that optical transmission continues. In an optical unidirectional path-switched ring (OUPSR) scheme that is an optical protection scheme, a transmission-side transponder device transmits the same optical signal to both of the work system and the protection system, and a reception-side transponder device switches between the work system and the protection system using an optical switch or the like. The reception-side transponder device transfers the optical signal to a subsequent client device. The light receiving properties of the transponder devices differ in accordance with the level of the optical signal received from the optical transmission network, for example, the light level. Variation in the level of input light markedly affects the receiving properties of the transponder devices at an optical transmission speed of about 10 Gbps.
Related art is disclosed in International Publication Pamphlet No. WO 2006/035481 and Japanese Laid-open Patent Publication No. 2005-12689.

Optical transmission device and optical transmission method


The invention relates to novel bis-benzimidazole compounds which have the ability to bind to the minor groove of DNA and to alkylate DNA, to methods of preparing the compounds, and the use of the compounds in the treatement of neoplastic disease.

Alkylating agents are an important class of anticancer drugs, which express their cytotoxic and antitumour effects by forming adducts with cellular DNA. The bisbenzimidazole moiety itself has been reported in the literature as an efficient DNA minor groove binding agent, and a number of compounds of this general structure have been reported to have DNA binding and cytotoxic properties. In particular, the compound pibenzimol (Hoechst 33258), which binds to regions of the minor groove rich in adenine and thymine bases, and its analogues, have been intensively investigated. See for example:
Loewe, V. H. and Urbanietz, I. "Basisch substituierte 2,6-Bis-benzimidazolederivate, eine neue chemotherapeutisch aktive Korperklass" Arz.-Forschung, 1974 24 1927-1933. PA0 Bathini, Y. and Lown, J. W. "Convenient routes to substituted benzimidazoles and imdazolo[4,5-b]pyridines using nitrobenzene as oxidant" Synth. Comm., 1990 20 955-963. PA0 Beerman, T. A., McHugh, M. M., Sigmund, R., Lown, J. W., Rao, K. E. and Bathini, Y. "Effects of analogs of the DNA minor groove binder Hoechst 33258 on topoisomerase II and I mediated activities" Biochim. Biophys. Acta., 1992 1131 53-61. PA0 Kelly, D. P., Bateman, S. A., Martin, R. F., Reum, M. E., Rose, M. and Whittaker, A. R. D. "DNA binding compounds. V. Synthesis and characterisation of boron-containing bisbenzimidazoles related to the DNA minor groove binder Hoechst 33258" Aus. J. Chem., 1994 47 247-262. PA0 Wang, H., Gupta, R. and Lown, J. W. "Synthesis, DNA binding, sequence preference and biological evaluation of minor groove selective N1-alkoxyalkyl bisbenzimidazoles" Anti-Cancer Drug Design, 1994 9 153-180.
A recent publication [Lee, M., Walker, C. D., Eckert, J. M., Bowers, S. K., Montague, D., McAdams, S. and Hartley, J. A., "DNA sequence selective alkylation and cytotoxicity of monoheterocyclic analogues of Hoechst 33258", Med. Chem. Res., 1993 3 79-86] describes three monobenzimidazole mustard compounds. Subsequent to the priority date of this application, a further publication [Gupta, R., Wang, H., Huang, L. And Lown, J. W. "Design, synthesis, DNA sequence preferential alkylation and biological evaluation of N-mustard derivatives of Hoechst 33258 analogues", Anti-Cancer Drug Design, 1995 10 25-41] has described four mixed benzimidazole/benzoxazole mustard analogues of Hoechst 33258.
We have now developed a novel class of bisbenzimidazole compounds which have not only the ability to bind to DNA in the minor groove, but also to alkylate DNA. These compounds show good anti-tumour activity both in vitro and in vivo.

Auckland Division Cancer Society of New Zealand Inc.

Circadian Pharmaceuticals (Australia) Pty. Ltd.