Even light exercise can counter the damage of stroke in survivors, a new study suggests.

Next week I will be at WordCamp San Francisco and a week later at the WooConf! Maybe one or antoher […]

The accurate assembly of the system matrix is an important step in any code that solves partial differential equations on a mesh. We either explicitly set up a matrix, or we work in a matrix-free environment where we have to be able to quickly return matrix entries upon demand. Either way, the construction can become costly due to non-trivial material parameters entering the equations, multigrid codes requiring cascades of matrices that depend upon each other, or dynamic adaptive mesh refinement that necessitates the recomputation of matrix entries or the whole equation system throughout the solve. We propose that these constructions can be performed concurrently with the multigrid cycles. Initial geometric matrices and low accuracy integrations kickstart the multigrid, while improved assembly data is fed to the solver as and when it becomes available. The time to solution is improved as we eliminate an expensive preparation phase traditionally delaying the actual computation. We eliminate algorithmic latency. Furthermore, we desynchronise the assembly from the solution process. This anarchic increase of the concurrency level improves the scalability. Assembly routines are notoriously memory- and bandwidth-demanding. As we work with iteratively improving operator accuracies, we finally propose the use of a hierarchical, lossy compression scheme such that the memory footprint is brought down aggressively where the system matrix entries carry little information or are not yet available with high accuracy.

We study the specification and verification of hyperproperties for probabilistic systems represented as Markov decision processes (MDPs). Hyperproperties are system properties that describe the correctness of a system as a relation between multiple executions. Hyperproperties generalize trace properties and include information-flow security requirements, like noninterference, as well as requirements like symmetry, partial observation, robustness, and fault tolerance. We introduce the temporal logic PHL, which extends classic probabilistic logics with quantification over schedulers and traces. PHL can express a wide range of hyperproperties for probabilistic systems, including both classical applications, such as differential privacy, and novel applications in areas such as robotics and planning. While the model checking problem for PHL is in general undecidable, we provide methods both for proving and for refuting a class of probabilistic hyperproperties for MDPs.

Bitvector filtering is an important query processing technique that can significantly reduce the cost of execution, especially for complex decision support queries with multiple joins. Despite its wide application, however, its implication to query optimization is not well understood.

In this work, we study how bitvector filters impact query optimization. We show that incorporating bitvector filters into query optimization straightforwardly can increase the plan space complexity by an exponential factor in the number of relations in the query. We analyze the plans with bitvector filters for star and snowflake queries in the plan space of right deep trees without cross products. Surprisingly, with some simplifying assumptions, we prove that, the plan of the minimal cost with bitvector filters can be found from a linear number of plans in the number of relations in the query. This greatly reduces the plan space complexity for such queries from exponential to linear.

Motivated by our analysis, we propose an algorithm that accounts for the impact of bitvector filters in query optimization. Our algorithm optimizes the join order for an arbitrary decision support query by choosing from a linear number of candidate plans in the number of relations in the query. We implement our algorithm in Microsoft SQL Server as a transformation rule. Our evaluation on both industry standard benchmarks and customer workload shows that, compared with the original Microsoft SQL Server, our technique reduces the total CPU execution time by 22%-64% for the workloads, with up to two orders of magnitude reduction in CPU execution time for individual queries.

Artificial intelligence technology has made its way absolutely necessary in a variety of industries including the fitness industry. Human pose estimation is one of the important researches in the field of Computer Vision for the last few years. In this project, pose estimation and deep machine learning techniques are combined to analyze the performance and report feedback on the repetitions of performed exercises in real-time. Involving machine learning technology in the fitness industry could help the judges to count repetitions of any exercise during Weightlifting or CrossFit competitions.

This paper investigates a class of optimal control problems associated with Markov processes with local state information. The decision-maker has only local access to a subset of a state vector information as often encountered in decentralized control problems in multi-agent systems. Under this information structure, part of the state vector cannot be observed. We leverage ab initio principles and find a new form of Bellman equations to characterize the optimal policies of the control problem under local information structures. The dynamic programming solutions feature a mixture of dynamics associated unobservable state components and the local state-feedback policy based on the observable local information. We further characterize the optimal local-state feedback policy using linear programming methods. To reduce the computational complexity of the optimal policy, we propose an approximate algorithm based on virtual beliefs to find a sub-optimal policy. We show the performance bounds on the sub-optimal solution and corroborate the results with numerical case studies.

There's one thing the Innovia Foundation can never say: That it hadn't been told.…

Uncut Gems is one of those "his own worst enemy" capers. You know, the kind of movie where you sit there for two hours watching some doofus constantly trip over his own laces — usually figuratively, sometimes literally — on the way to a personal epiphany about how all his bad choices and lack of useful self-awareness have led him to whatever unpleasant place they lead him to.…

An input combination of at least one condition value to be evaluated against at least one rule of a decision table is received. The at least one rule includes at least one condition and the rule is associated with a result. The at least one rule is evaluated against the input combination to determine conditions fulfilled for the at least one condition value. In one aspect, a rule from the at least one rule that best matches the input combination is determined and a result associated with the rule that best matches the input combination is outputted.

A speech recognition method including the steps of receiving a speech input from a known speaker of a sequence of observations and determining the likelihood of a sequence of words arising from the sequence of observations using an acoustic model. The acoustic model has a plurality of model parameters describing probability distributions which relate a word or part thereof to an observation and has been trained using first training data and adapted using second training data to said speaker. The speech recognition method also determines the likelihood of a sequence of observations occurring in a given language using a language model and combines the likelihoods determined by the acoustic model and the language model and outputs a sequence of words identified from said speech input signal. The acoustic model is context based for the speaker, the context based information being contained in the model using a plurality of decision trees and the structure of the decision trees is based on second training data.

When a user enters text into an application, the application can utilize an auto-complete feature to provide the user with estimations as to a complete term a user is attempting to enter into the application. Visualization can be provided along with an estimation to disclose the likelihood the estimation is what the user intends to enter. Furthermore, a rationale can be provided to the user for the reason an estimation was provided to the user.

An apparatus of muscle and/or joint exercise adapted to reeducation and/or physical conditioning of a body part of a user, including a hollow body; a mobile member translatable inside the body; a motor-driven means arranged on the bottom of the body and adapted for driving and decelerating in displacement the mobile member in both translatory directions; a cooperating means between the body and a frame, this cooperating means being arranged on the bottom of the body and including: at least one hinge of the body on the frame, the hinge providing at least at least one degree of rotational freedom for the body around an axis of rotation; and a removable means for installing and removing the body, the removable means being designed for removably installing the body on a base slidingly mounted in the frame.

A stretching and exercise device has a first strap member having a pair of end portions, a second strap member having a pair of end portions, and a pair of resistance members connected between respective end portions of the first and second strap members. A third strap member has a pair of end portions attached to respective first and second surface portions of the second strap member. A fourth strap member is attached to a third surface portion of the second strap member different from the first and second surface portions thereof.

There is provided an automatic tool changer which, in a precision roll turning lathe which feeds a tool post at a high speed, can automatically change a tool, such as a cutting tool, without stopping the machine, thereby enabling highly efficient ultra-Precision machining of a roll mold for molding of a large-sized plastic sheet. The automatic tool changer includes: a change device including a vertically movable pivot arm having a pivot axis and which pivots in a horizontal plane, a hand portion, mounted at the front end of the arm, for detachably gripping a tool holder, a pivot drive section for pivoting the pivot arm, and a lifting drive section for vertically moving the pivot arm; a tool holder stocker, having a plurality of circumferentially-arranged stages disposed at a predetermined distance from the pivot axis, each stage detachably holding a tool holder; a holder base, mounted to the tool post, for fixing and unfixing a tool holder through the rotation of a clamp shaft; and a clamp shaft operating device including an operating portion for clamping/unclamping the tool holder by rotating the clamp shaft.

A method in a portable data carrier for executing a cryptographic operation on security-relevant data comprises a step of determining a remainder (r) of a dividend (a) modulo a divisor (b). In so doing, the remainder (r) is determined iteratively by means of a division device of the data carrier. In each iteration there is carried out a Montgomery multiplication with the divisor (b) as the modulus and an additive linkage of an output value of the Montgomery multiplication with a coefficient (ai) derived from the dividend (a) and associated with the respective iteration. The Montgomery multiplication is carried out here by means of a multiplication device of the data carrier, preferably a corresponding coprocessor. The Montgomery multiplication of a subsequent iteration receives a result of a preceding iteration as an input value.

A tool cartridge for a material removal tool has a cartridge body with, among other things, a recess extending through at least a portion of the cartridge body from a first side toward a second side, a long axis of the recess non-parallel to a long axis of the cartridge body and at least a portion of the recess open to a bottom side of the cartridge body, and a threaded opening for a differential screw proximate a second end of the tool body and positioned longitudinally between an opening for a clamping screw and at least a portion of a seat for a cutting tool insert. A thread axis of the threaded opening is at an angle G relative to a long axis of the tool cartridge. A material removal tool, a tool, and a method of adjusting a cutting tool insert are also disclosed.

Methods and systems for a go/no-go Landing Decision Point (LDP) are disclosed. The methods and systems provide a graphical LDP on a cockpit display that pilots can use to determine whether to continue the landing or execute a go-around. The methods and systems may be implemented in embodiments having an onboard portion, an off-board portion, or both operatively coupled to provide an LDP in a preview/planning mode and real time mode.

An RFID event tracking and management system provides a standardized approach that can be utilized by various industry verticals. Loss of captured event data, such as RFID generated through an RFID event, can be prevented through a series of guarantee semantics. Approaches also provide for role-based data visibility. Queries received from a user or entity can be dynamically modified based on the role of the user/entity using a virtual private database (VPD). The modified query can result in a virtual private database automatically hiding or restricting access to event data at row, column, and/or cell levels, so that an authorized user/entity is only able to access data to which that user/entity should have access.

A method for selectively applying a reflectance modifying agent (RMA) to an area of skin, the method comprising receiving an image of the area of skin, identifying, using the image, a nominated point within the area of skin, determining an actual reflectance of the nominated point, applying an edge protection technique based on the image to generate one or more outputs, determining a desired reflectance of the nominated point based on the one or more outputs, calculating an amount of RMA to be applied based on the output, and determining whether to apply the RMA to the area of skin based on the amount of RMA.

An animal defensive barrier device comprising a hand-grip portion having end caps; a strap connected to the hand-grip through one of the end caps; a loop portion distal at one end of the hand-grip and a loop portion distal from the first loop end; a plurality of knots between the hand-grip and the distal loop portion; and a plurality of sleeves on the strap between the hand-grip portion and the distal loop portion.

Wood particles having fibers aligned in a grain, wherein: the wood particles are characterized by a length dimension (L) aligned substantially parallel to the grain, a width dimension (W) normal to L and aligned cross grain, and a height dimension (H) normal to W and L; the L×H dimensions define two side surfaces characterized by substantially intact longitudinally arrayed fibers; the W×H dimensions define two cross-grain end surfaces characterized individually as aligned either normal to the grain or oblique to the grain; the L×W dimensions define two substantially parallel top and bottom surfaces; and, a majority of the W×H surfaces in the mixture of wood particles have end checking.

Embodiments of digital high-speed bi-phase modulator and method for bi-phase modulation are generally described herein. In some embodiments, the digital high-speed bi-phase modulator comprises a high-speed digital divider, a high-speed digital multiplexer, and matched signal paths provided between the divider and the multiplexer. The high-speed digital divider is configured to receive a carrier signal and generate complementary output signals. The high-speed digital multiplexer is configured to switch between the complementary output signals and generate a bi-phase modulated output at a carrier frequency (fc) modulated with a bi-phase code. The bi-phase code may be provided to control inputs of the multiplexer.

In various embodiments, systems and methods for generating high-precision pulse-width modulation include a delay-locked loop comprising multiple delay units having time-variable delays, control logic for selecting a subset S of the multiple delay units to thereby generate a time-invariant shift amount having a precision finer than that of a system clock and circuitry for applying the shift amount to rising and falling edges of a pulse-width modulation waveform to thereby generate a high-precision pulse-width modulation waveform.

There is disclosed an apparatus for forming a surgical incision member comprising which includes a first die associated with a base and having a first groove therein for receipt of at least a portion of a needle blank. A second die is mounted for movement on the base between a position remote from the first die and a position adjacent the first die. The second die includes a second groove alignable with the first groove to hold a needle blank therebetween, the first and second dies each having spaced apart channels intersecting the first and second grooves. A notching die is provided and is mounted for movement within at the channels so as to engage and notch an edge of the needle blank contained within the first and second grooves. The apparatus also includes structure for curving a needle blank contained within the first and second grooves. A method of forming a surgical incision member is also disclosed, and a surgical incision member blank.

There is disclosed an apparatus and a method for progressively forming high strength surgical needles from bulk needle stock material. The apparatus generally includes a series of progressive needle processing stations. A first series of needle processing stations removes material from needle stock material to rough form needle blanks attached to a carrier strip while a second series of processing stations refine the rough formed needle blanks attached to the strip into the desired surgical needles. The disclosed method generally includes the steps of gutting needle stock material to rough form needle blanks attached to a carrier strip and progressively coining the rough formed blanks into surgical needles. Finally, there is disclosed a high bend strength surgical needle formed on the disclosed apparatus or by the disclosed method. Preferably, the surgical needle is a surgical incision member having a predetermined radius of curvature and an optimized conical radius at the tips.

The invention relates to a high-precision revolving center (10) for machine tools. Prestressed bearings 40 and 45 are brought into abutment on the one hand against internal 33 and external 25 cylindrical surfaces whose deviation, at any point on the surface, with respect to the theoretical surfaces centered on the axis, is less than 1 μm, and on the other hand against reference surfaces 26 and 34 perpendicular to the axis. Threaded elements 50, 55 enable the bearings 40, 45 to be stressed. Once the center 10 has been assembled and the bearings stressed, the revolving center is mounted on a grinder in order to give a precision finish to the tip 90, the concentricity reference surface 91 and the perpendicularity reference surface 92.

A pair of garden scissors with an adjustable cutting angle is provided with first and second scissor members. A positioning protrusion of the first scissor member cooperates with a positioning end of the angle-restricting member of the second scissor member to restrict the maximum cutting angle of the first scissor member, and an adjust member is able to adjust the cutting angle by adjusting the position of the angle-restricting member, so that the cutting angle can be freely adjusted within the movement range of the angle-restricting member.

A protective riser guide for scissors is provided in the present disclosure. In certain embodiments, the protective riser guide is integrally formed with an arm of a pair of scissors. In other embodiments, the protective riser guide is removably attached to the exterior surface of a scissor arm. Preferably, the protective riser guide is in the shape of an arc extending away from the interior surface of the arm if the guide is integrally formed with the arm, or from the exterior surface if the guide is removably attached to the exterior surface. Due to the shape and position of the protective riser guide on the arm of a pair of scissors in certain embodiments, the protective riser guide is ergonomic and increases the safety of the operator of the scissors without interfering with the operator's cutting techniques.

A precision coaxial water jet disruption explosive device system that holds a blasting cap precisely to the surface of a cylindrically cut positioned plastic explosive that couples a detonation shock wave into water surrounding a hollow forming cavity. A pressure relief vent enables the water filled system to be assembled without deforming the thin walled hollow jet forming cavity, enabling forming repeatable supersonic jets on centerline axis. This system is positioned with two triangular pivot legs and aligned with two fan light beams or a line sight to define a projected jet route to deliver a water jet that can cut through over 1 inch of steel and disrupt target objects more than 9 feet away. This system is used to disable improvised explosive devices, and other dangerous objects, without detonating the targeted explosives and electronic devices such that the contents are destroyed without explosion sequences occurring.

An improved cartridge case completely produced net shape on a progressive cold former that includes a trim to lengthy station with an internal shearing tool.

An exercise mat can include a knit spacer fabric having a first ground fabric spaced apart from a second ground fabric in an uncompressed state. The exercise mat can be configured to be rolled up and compressed for storage and to expand into a planar spaced apart arrangement between the first and second ground fabrics for use. The knit spacer fabric can be formed from a plurality of knit polymeric threads and can include a first wall fabric extending between the first ground fabric and the second ground fabric. The first wall fabric can support the first ground fabric and the second ground fabric in a compressible spaced-apart configuration. The spacer fabric can include a traction-enhancing coating at an outer surface.

A method of health management of a monitored system includes collecting component condition indicator data used to calculate a plurality of component health indicators. Component fault severity and potential failure modes are determined utilizing the component condition indicator data. The potential failure modes are ranked in order of likelihood to isolate the failure mode. A system of health management for monitored apparatus includes a fault severity module to derive a plurality of component health indicators from collected component condition indicator data, the plurality of component health indicators indicative of fault severity of a plurality of components. A fault isolation module separately derives a ranked listing of potential fault/failure modes utilizing the component condition indicator data. The system further includes a communication portion to which the plurality of component health indicators and the ranked listing of fault/failure modes are transmitted for review and/or action by cognizant personnel.

An elliptical climbing exercise apparatus includes a base frame, a swing unit including a pair of swing arms, a pedal unit including a pair of pedal shafts respectively pivotally connected to the swing arms, a damping unit including a rotating wheel with a spindle, a guiding unit including a pair of cranks respectively affixed to the two opposite ends of the spindle, a pair of rockers respectively pivotally connected to the cranks and a pair of links respectively pivotally connected to the rocker. Cooperation between the base frame, the swing unit, the pedal unit, the resistance unit and the guiding unit is used to achieve a training of the leg muscles.

In one example, a muscle exercise device includes a first arm, and a second arm rotatably connected to the first arm, and the second arm and first arm are movable to cooperatively define a recess. The muscle exercise device also includes a resistance element configured to reside in the recess and be compressed between the arms.

A multi-purpose balance exercise device designed to be used in multiple positions and for diverse exercises. For example, various embodiments allow for the multipurpose device to be use as an aerobic step device as well as the ability to easily adjust the device to various heights to easily decrease the level of difficulty of the device for use during various exercises. The balance exercise device can provide a polarity of handles and grab points both horizontally and vertically, which allow for an enhanced number of exercises or movements using either the top and/or bottom of the device. The balance exercise device includes a flexible bladder filled with air, other gases, or gels attached to a substantially rigid base. The base can include an interior within which features such as handles are disposed to provide a gripping or lifting exercise to which the balance exercise device can be used.

Apparatus (2) for exercising a person's calves (4) in two different ways, which apparatus (2) comprises a footrest (8), a kneerest (10), and a length of stretchable material (12) for extending between the footrest (8) and the kneerest (10), and the apparatus (2) being such that: (i) the length of stretchable material (12) is flat sided;(ii) the footrest (8) has roller means (14);(iii) the roller means (14) allows the length of stretchable material (12) to connect to the footrest (8) such that the flat sides of the length of stretchable material (12) slide over the roller means (16);(iv) the kneerest (10) has anchor means (16) for the length of stretchable material (12);(v) the anchor means (16) allows the length of stretchable material (12) to connect to the kneerest (10) such that the flat sides of the length of stretchable material (12) pass over the anchor means (16); and(vi) the footrest (8), the kneerest (10), and the length of flexible material (12) are separable from each other.

A multiple position locking handle for an exercise machine for that is movable into a plurality of different positions when unlocked and that is retained in a single secure position when locked. The multiple position locking handle for an exercise machine generally includes a tubular base having a lower end and an upper end, an elongated member extending through the opening of the upper end of the tubular base and extending downwardly through at least a portion of the tubular base, a handle extending outwardly from the elongated member at an angle, and a locking device. The elongated member is movable within the tubular base when the locking device is in the unlocked state and is substantially not movable within the tubular base when the locking device is in the locked state.

The invention provides an exercise device for a rotator cuff of a shoulder of a user comprising a container housing, wherein the container housing comprises a first container shell, wherein the first container shell comprises a first container shell exterior surface and a first container shell interior surface surrounding a first container shell void, wherein the first container shell interior surface forms a substantially spherical surface; a second container shell, wherein the second container shell comprises a second container shell exterior surface and a second container shell interior surface, wherein the second container shell interior surface surrounds the first container shell exterior surface whereby the first container shell is nested inside the second container shell; and a spherical ball positioned within the first container shell void; wherein when the exercise device is in use, movement and rotation of an arm of a user causes movement and rotation of the container housing and movement and rotation of the ball within the container housing in a direction that follows a circumference of the first container shell interior surface, thereby exercising the rotator cuff of the shoulder of the user.

A machine for exercising the rotator cuff muscles that is operable to individually and separately isolate and exercise each of the four rotator cuff muscles while the user is in a seated position. The exercise machine includes a plurality of structural elements including a main vertical beam and a base frame operable to be positioned on the ground, where the main beam extends vertically from the base frame. The machine includes a plurality of pulleys mounted to the structural elements and a plurality of exercise cables running through the pulleys, where handles are coupled to the exercise cables. A seat is mounted to the vertical beam and the handles are positioned relative thereto to allow the user to grasp the handles and perform the several exercises for each arm.

A layered exercise contact counter display tracking and showing repetitive contacts with the lens contact surface of a housing covering a sensor pad, which responds to contacts sending a signal to a powered circuit board and remote tracking devices to record and display the number of repetitive hits adapted for mounting on an exercise device or a support surface to encourage an exerciser to complete and exercise or contact event.

An exercise machine includes a motor that drives a belt to move, and an analysis system to collect a peak energy from the motor and to convert the peak energy into different user exercising data.

A portable paddleboard exercise apparatus having a balance platform, an elongated member, a paddle handle, and a number of resistance bands. The apparatus may further include a frame with one or more support members configured to support the balance platform. The balance platform includes an upper surface for a user to balance thereon. The elongated member extends from the balance platform. The resistance bands extend from a distal end of the elongated member to the paddle handle. A user may balance on the balance platform in one of a number of positions while pulling the paddle handle against a resistive force generated by the resistance bands.

Exercise equipment, particularly a linear movable structure and associated selectable elastic resistance bands with or without guide track members are designed to allow low-impact exercises for one or two persons at the same time while permitting either or both participants to remain stationary when utilizing the equipment.

An exercise machine rail system for improved exerciser mounting and dismounting, improved functional ergonomics, and reduced risk of exerciser injury when using an exercise machine. The exercise machine rail system generally includes either two rails in close relationship which are linked together via connectors or a singular rail. Bias members are disclosed as either extending along either outer side of the rails, internally to the rail, or underneath the rail. Due to the narrow nature of the rails used by the present invention, an exerciser is able to mount and dismount the exercise machine easily and efficiently.

An exercise device that includes a frame, a user interface; a connection cable and a plurality of components that provide resistance to the cable and user interface. These components include a programmable, driven carriage capable of vertical movement between first and second positions and including one or more pulleys mounted thereon, wherein the cable extending away from the first end and user interface passes around the one or more pulleys on the carriage, a slider mechanism moveable between first and second positions and including one or more pulleys mounted thereon, and a pneumatic resistance device that is secured to the frame and that is operatively associated with the slider mechanism to provide resistance to slider mechanism movement between the first and second positions.

An exercise device that includes a frame, a user interface; a connection cable and a plurality of components that provide resistance to the cable and user interface. These components include a programmable, driven carriage capable of vertical movement between first and second positions and including one or more pulleys mounted thereon, wherein the cable extending away from the first end and user interface passes around the one or more pulleys on the carriage, a slider mechanism moveable between first and second positions and including one or more pulleys mounted thereon, and a pneumatic resistance device that is secured to the frame and that is operatively associated with the slider mechanism to provide resistance to slider mechanism movement between the first and second positions.

An exercise apparatus comprising a foot support movable by the user on the frame back and forth through any one of a plurality of complete, reproducible and different arc segments of a master arcuate path, the foot support being interconnected to an arc segment selection device that is manually actuatable to enable the user to manually select any one of the plurality of different arc segments, the foot support being interconnected to an arm having a handle manually graspable by the user to reduce or increase power or energy required by the user to move the foot support.

An exercise device includes a base frame having a first baseboard member, a second baseboard member, and a base pad disposed in between. The first baseboard member includes a first locking member disposed on a first headend of the first baseboard member, and the second baseboard member includes a second locking member disposed on a second headend of the second baseboard member. The exercise device further includes a pole frame having a top crossbar, a bottom crossbar, a first side pole, and a second side pole. The first lock member of the first baseboard member is inserted into a cross section of the first side pole and the second lock member of the second baseboard member is inserted into a cross section of the second side pole, such that the pole frame is interlocked with the base frame substantially perpendicularly.

An abdominal twist exercise device includes a device frame, front and rear rotational axles, a main handle bar, a rotation converter, an adjustable gear, a disengaging lever, a weight, a weight bar, a support rail, a safety handle bar, rotation counters, and a user platform, such that when the main handle bar rotates to one side, the user platform rotates to an opposing side. A rotation converter can include a front chain sprocket, an intermediate rotational axle, an intermediate chain sprocket, a roller chain, an intermediate gear, a rear gear; or a front belt sprocket, a rear belt sprocket, and a twisted belt, connecting the sprockets. Optionally, the front and rear axles can be telescoping.