Abstract: A device for mixing and discharging plural materials has a body, a housing and a sealing plug. The body has multiple barrels and multiple tubes communicating with the barrels. The housing is rotatably attached to the body in a thread manner and has a mixing chamber and a discharging segment. The sealing plug is mounted in the mixing chamber to seal the tubes and has a sealing disk and multiple sealing sleeves. The sealing disk has multiple holes and multiple sealing lids mounted respectively in the holes, and each sealing lid has an outer edge connected detachably to the inner surface of a corresponding hole and having a thickness smaller than that of the sealing lid. The sealing sleeves are formed on the sealing disk, align respectively with the holes in the sealing disk and are mounted respectively around the tubes.

Abstract: A dental agent applicator has a barrel, a sealing plug, a delivery head and a plunger. The barrel has a proximal end, a distal end and a chamber defined through the barrel. The sealing plug is mounted in the chamber and hermetically obstructs the chamber. The delivery head is movably mounted on the distal end of the barrel and has a hub and a nozzle tip. The hub is mounted movably in the distal end and selectively moves the sealing plug to make the chamber communicate with the delivery head. The nozzle tip is mounted on the hub. The plunger is mounted slidably in the proximal end of the barrel. The delivery head is mounted permanently on the barrel. Using the dental agent applicator without having to replace any sealing cap with the delivery head is simple and convenient.

Abstract: A user proceeds from one location to another location inside of a building by traveling in a sequence of several hops in response to different visual cues. A portable handheld device may provide the visual cues to the user. The user reaches the destination through the sequence of hops using the portable handheld device.

Abstract: A device for mixing and discharging plural materials has a body, a housing and a sealing plug. The body has multiple barrels and multiple tubes communicating with the barrels. The housing is rotatably attached to the body in a thread manner and has a mixing chamber and a discharging segment. The sealing plug is mounted in the mixing chamber to seal the tubes and has a sealing disk and multiple sealing sleeves. The sealing disk has multiple holes and multiple sealing lids mounted respectively in the holes, and each sealing lid has an outer edge connected detachably to the inner surface of a corresponding hole and having a thickness smaller than that of the sealing lid. The sealing sleeves are formed on the sealing disk, align respectively with the holes in the sealing disk and are mounted respectively around the tubes.

Abstract: A dental impression tray has a base and a relator. The base has a biting portion and a handle. The biting portion is curved. The handle is formed on the biting portion and has an arc hole that is defined through the handle to receive impression material. The relator has a vertical bar and a horizontal bar. The relator is mounted in the arc hole and is fastened in the arc hole by impression material. The horizontal bar connects perpendicularly to the vertical bar. Therefore, the impression of the teeth to be crowned or veneered as well as the relation between the impression and the patient's face are obtained simultaneously.

Abstract: A dental agent applicator has a barrel, a sealing plug, a delivery head and a plunger. The barrel has a proximal end, a distal end and a chamber defined through the barrel. The sealing plug is mounted in the chamber and hermetically obstructs the chamber. The delivery head is movably mounted on the distal end of the barrel and has a hub and a nozzle tip. The hub is mounted movably in the distal end and selectively moves the sealing plug to make the chamber communicate with the delivery head. The nozzle tip is mounted on the hub. The plunger is mounted slidably in the proximal end of the barrel. The delivery head is mounted permanently on the barrel. Using the dental agent applicator without having to replace any sealing cap with the delivery head is simple and convenient.

Abstract: A mixing device having a body, a pusher, an abutter and a mixer is provided. The body is tubular and has a fore end, a rear end and multiple chambers. Each chamber has a fore opening, a rear opening and a cap sealing the fore opening. The cap protrudes forwardly and has an outer surface and a top. The pusher has multiple rods respectively inserted in the chambers from the rear openings. The abutter has multiple tubes for respectively breaking the caps through to communicate with the chambers and each having a blunt end. The mixer is tubular and has an outlet, a connector and a mixing shaft mounted therein. The connector is connected to the fore end of the body and communicates with the tubes of the abutter. The cap may be easily injection-molded and agents may be filled directly into the chambers to ensure reliable operation.

Abstract: A dental impression tray has a base and a relator. The base has a biting portion and a handle. The biting portion is curved. The handle is formed on the biting portion and has an arc hole that is defined through the handle to receive impression material. The relator has a vertical bar and a horizontal bar. The relator is mounted in the arc hole and is fastened in the arc hole by impression material. The horizontal bar connects perpendicularly to the vertical bar. Therefore, the impression of the teeth to be crowned or veneered as well as the relation between the impression and the patient's face are obtained simultaneously.

Abstract: A network device utilizes fair bandwidth allocation techniques based on configurable service classes. The network device comprises a scheduler that receives a packet associated with a service flow for delivery to a destination. The scheduler identifies a service credit associated with the service flow that represents a bandwidth allocation available for consumption by an associated service flow. Based on the identified service credit, the downstream scheduler assigns the packet to one of a plurality of hold queues. The number of hold queues may remain static during the allocation of bandwidth, which reduces the complexity of the scheduler and permits fair bandwidth allocation to occur. Such a queuing architecture also allows the downstream scheduler to achieve rate limiting and minimum bandwidth guarantee without using separate algorithms and/or architectures.

Abstract: A wireless network (100) and method (200) for assigning a set of channels to a set of wireless devices (102-126) in the network where there are less channels than devices such that wireless devices are grouped in channel groups such that the wireless devices assigned to each channel group are positioned so as not to interfere with each other. In assigning an nth wireless device to a kth channel group, the nth and preferably one member of the kth channel group at a time are instructed to transmit simultaneously in order to ascertain if the nth wireless device interferes with or is interfered with by any member of the kth channel group.

Abstract: The invention is directed to techniques for improving upstream communication in a DOCSIS-based cable network or other reservation-based TDMA system. In one example, the techniques may involve dynamically adjusting the size of a contention region in a MAP interval in which upstream time slot allocation is conveyed by a MAP message broadcasted by a cable modem transmission system (CMTS) to cable modems (CMs) sharing a common upstream DOCSIS channel. By adjusting the size of the contention region in the MAP intervals based on measured traffic parameters, the system can be dynamically responsive to different upstream traffic scenarios and thereby exploit maximal upstream data throughput continually.

Abstract: A network protocol for low-cost, low-power devices coupled to a self-organizing wireless network using a spanning tree backbone architecture is described. In this protocol, physical and logical network construction and maintenance operations, which supports efficient data routing in the network, are performed. The construction phase in conjunction with the maintenance phase insures the self-organizing capability of the network. At the same time, the maintenance operations provide a self-healing mechanism so that the network can recover from node failures and a self-updating mechanism so that the network can expand as more nodes enter the system. Also, the logical backbone hierarchy will facilitate multi-hop communication. The construction of a logical layered spanning tree backbone architecture from an underlying physical topology allows seamless data communication routing between all nodes in the network.

Abstract: A wireless network (100) and method (200) for assigning a set of channels to a set of wireless devices (102-126) in the network where there are less channels than devices such that wireless devices are grouped in channel groups such that the wireless devices assigned to each channel group are positioned so as not to interfere with each other. In assigning an nth wireless device to a kth channel group, the nth and preferably one member of the kth channel group at a time are instructed to transmit simultaneously in order to ascertain if the nth wireless device interferes with or is interfered with by any member of the kth channel group.

Abstract: A network protocol for low-cost, low-power devices coupled to a self-organizing wireless network using a spanning tree backbone architecture is described. In this protocol, physical and logical network construction and maintenance operations, which supports efficient data routing in the network, are performed. The construction phase in conjunction with the maintenance phase insures the self-organizing capability of the network. At the same time, the maintenance operations provide a self-healing mechanism so that the network can recover from node failures and a self-updating mechanism so that the network can expand as more nodes enter the system. Also, the logical backbone hierarchy will facilitate multi-hop communication. The construction of a logical layered spanning tree backbone architecture from an underlying physical topology allows seamless data communication routing between all nodes in the network.