A method is described for mapping dense sensory data to a Sensory Ego Sphere (SES). Methods are also described for finding and ranking areas of interest in the images that form a complete visual scene on an SES. Further, attentional processing of image data is best done by performing attentional processing on individual full-size images from the image sequence, mapping each attentional location to the nearest node, and then summing all attentional locations at each node.

An autonomous robot is a robot that is capable of operating completely on its own by considering its situation in its environment and deciding what actions to take in order to achieve its goals without human intervention. A robot is adaptive if it is capable of improving its ability to achieve its goals.
An adaptive autonomous robot must be capable of sensing and interacting with its environment. Therefore, a robot must include sensors and actuators. A sensor is any device capable of generating a signal that can be mapped to a characteristic of the environment. A sensor may be a proprioceptive sensor that measures an internal aspect of the robot such as, for example, the angle formed by two members at a joint or the angular speed of a motor shaft. A sensor may be an exteroceptive sensor that measures an aspect external to the robot such as, for example, the intensity of light from a direction or the presence of a force applied to the robot. An actuator is any device enabling the robot, in whole or in part, to perform an action. The physical state of the robot may be described by an (S+A)-dimensional state vector, R(t), where S is the dimensionality of the robot's sensor data and A is the dimensionality of the robot's actuator controllers. The state vector, R(t), is the only information accessible to the robot. In addition to sensors, actuators, and mechanical support structures, a robot must have one or more computers capable of receiving signals from the sensors, transmitting commands to the actuators, and executing one or more programs.
The task of building an adaptive autonomous robot is sufficiently complex that research groups have partitioned the problem into several more manageable tasks and have concentrated on solving each task independently of the others. Three tasks or behaviors are considered to be the most difficult in robotics; learning, planning, and world representation.
Initial efforts to implement these behaviors in robots were concentrated on building a complex program that processed environmental information from sensors and generated commands to actuators resulting in behaviors that resembled learning, planning, and abstraction (in order to represent the robot's world, or surroundings) in humans.
Although efforts to build a single, complex control program continue, many of the new and exciting advancements in robotics are based upon the rejection of the notion that complex behavior requires a complex control program. Instead, control is distributed to many interacting autonomous agents. Agents are small programs that act independently of other agents while interacting with the other agents. Complex behavior, such as learning or abstraction, emerge from the interaction of many independent agents rather than being controlled by any one agent.
Mataric and Brooks, "Learning a Distributed Map Representation Based on Navigation Behaviors," in "Cambrian Intelligence: the early history of the new AI," The MIT Press, 1999, demonstrated that complex behaviors, such as goal-directed navigation, could emerge from the interaction of simpler behaviors termed "reflexes." A reflex is an agent that couples an actuator signal to a sensor signal. For example, an avoid reflex may generate a signal to a wheel motor based on a signal from a proximity sensor. If the proximity sensor senses an object within a danger zone of the robot, the reflex generates a signal to stop the wheel motor. Mataric and Brooks showed that starting with only four reflexes, goal-directed navigation could emerge from their interaction. The reflexes, however, were not generated by the robot but required hand-coding by a programmer.
Pfeifer, R. and C. Scheier, "Sensory-motor coordination: the metaphor and beyond," Robotics and Autonomous Systems, Special Issue on "Practice and Future of Autonomous Agents," vol. 20, No. 2-4, pp. 157-178, 1997 showed that signals from the sensors and actuators tended to cluster for repeated tasks and termed such clustering category formation via Sensory Motor Coordination ("SMC"). Cohen has shown that robots can partition the continuous data stream received from sensors into episodes that can be compared to other episodes and clustered to form an exemplar episode. An exemplar episode is representative of the cluster of several episodes and may be determined by averaging over the episodes comprising each cluster. The exemplar episode is self-generated (by the robot) and replaces the external programmer. As the robot is trained, the robot will identify a set of exemplar episodes that may be used to complete an assigned task. The ability of the robot to identify episodes from a continuous sensor data stream and to create "categories" (exemplar episodes) from the clustered episodes may be considered to be a rudimentary form of robotic learning.
In order to gather a sufficient number of episodes for the identification of categories, the robot must be trained. Training is normally accomplished by a reinforcement learning ("RL") technique as will be known to those skilled in the art. In one example of RL, the robot is allowed to randomly generate actions while a trainer rewards actions that move the robot toward a desired goal. The rewards reinforce the most recent actions of the robot and over time, episodes corresponding to the rewarded actions will begin to cluster as similar actions are rewarded similarly. The training, however, requires many repetitions for each action comprising the desired task.
An autonomous robot must be able to select an action that will lead to or accomplish its desired goal. One known method for robot planning involves a spreading activation network ("SAN"), a set of competency modules ("CM") that, when linked together, initiate a sequence of commands that the robot may perform to accomplish the desired goal. A competency module includes information characterizing the state of the robot both before (state pre-conditions) and after (state post-conditions) a command to an actuator. Competency modules are linked by matching the state pre-conditions of one CM to the state post-conditions of another CM.
Planning begins by first identifying all terminal CMs, defined as CMs having state post-conditions corresponding to the state of the robot after accomplishment of the assigned goal. The state pre-conditions of each of the terminal CMs are then used to find other CMs having state post-conditions matching the state pre-conditions of the terminal CMs. The process is repeated until the state pre-conditions of a CM correspond to the present state conditions of the robot.
In one method of searching for the shortest path to a goal, each CM is assigned an activation value determined by CMs in contact (matching endpoints) with the CM. The order of execution is determined by the activation value of each CM where the CM with the largest activation value is executed next.
As the number of CMs increases, the time required to complete the search increases very rapidly and the reaction time of the robot increases until the robot is unable to respond to the dynamic changes in its environment. While such a search may be acceptable for planning before beginning a task, the exponential increase of the search time as more CMs are added (i.e. as the robot learns) renders such a search unsuitable for real-time response to the robot's changing environment.
The back-propagation of CM linking creates an unavoidable delay in the robot's responsiveness because the robot cannot begin to execute the linked CMs until the complete chain of CMs taking the robot from its present state to the goal state are found. This unavoidable delay limits the operating environments of the robots to situations that are usually predictable.
Therefore there remains a need for an efficient method for robotic planning capable of reacting to sudden or dynamic situations in the robot's environment while allowing for the addition of CMs as the robot learns.
In robots, as well as humans, the amount of sensory information received greatly exceeds the processing capability of the robot. In order to function in any environment, a robot must be able to condense the voluminous sensor data stream to a data rate that its processors can handle while retaining information critical to the robot's operation. In one method of condensing the sensor data stream, the robot builds a representation of the robot's environment (the world model) and compares the received sensory information to the representation stored by the robot. The world model allows the robot to orient itself in its environment and allows for rapid characterization of the sensory data to objects in the world model.
The world model may be allocentric or may be ego-centric. An allocentric world model places objects in a coordinate grid that does not change with the robot's position. An ego-centric model is always centered on the present position of the robot. One example of an ego-centric model is described in Albus, J. S., "Outline for a theory of intelligence", IEEE Trans. Syst. Man, and Cybern., vol. 21, no. 3, 1991. Albus describes an Ego-Sphere wherein the robot's environment is projected onto a spherical surface centered on the robot's current position. The Ego-Sphere is a dense representation of the world in the sense that all sensory information is projected onto the Ego-Sphere. Albus' Ego-Sphere is also continuous because the projection is affine. The advantage of the Ego-Sphere is its complete representation of the world and its ability to account for the direction of an object. The Ego-Sphere, however, still requires processing of the sensory data stream into objects and a filtering mechanism to distinguish important objects from unimportant objects. Furthermore, Albus does not disclose or suggest any method for using the Ego-Sphere to develop an action plan for the robot, nor is there a suggestion to link the Ego-Sphere to the learning mechanism of the robot.
Another example of an ego-centric model is the Sensory Ego Sphere (SES) described in U.S. Pat. No. 6,697,707 which is incorporated by reference herein. Again, the robot's environment is projected onto a spherical surface centered on the robot's current position. More particularly, in one embodiment, the SES is structured as a geodesic dome, which is a quasi-uniform triangular tessellation of a sphere into a polyhedron. A geodesic dome is composed of twelve pentagons and a variable number of hexagons that depend on the frequency (or tessellation) of the dome. The frequency is determined by the number of vertices that connect the center of one pentagon to the center of another pentagon, all pentagons being distributed on the dome evenly. Illustratively, the SES has a tessellation of 14 and, therefore, 1963 nodes.
The SES facilitates the detection of events in the environment that simultaneously stimulate multiple sensors. Each sensor on the robot sends information to one or more sensory processing modules (SPMs) designed to extract specific information from the data stream associated with that sensor. The SPMs are independent of each other and run continuously and concurrently on preferably different processors. Each SPM sends information messages to an SES manager agent which stores the data, including directional sensory information if available, in the SES. In particular, sensory data is stored on the sphere at the node closest to the origin of the data (in space). For example, an object that has been visually located in the environment is projected onto the sphere at azimuthal and elevation angles that correspond to the pan and tilt angles of the camera-head when the object was seen. A label that identifies the object and other relevant information is stored into a database. The vertex on the sphere closest to an object's projection becomes the registration node, or the location where the information is stored in the database. Each message received by the SES manager is also given a time stamp indicating the time at which the message was received.
The SES eliminates the necessity of processing the entire spherical projection field to find items of interest. Processing the entire projection field is very time consuming and decreases the robot's ability to respond quickly to dynamic changes in its environment. Significant events are quickly identified by the SES by identifying the most active areas of the SES. Processing resources are only used to identify objects at the most active areas and are not wasted on uninteresting or irrelevant areas of the projection field. Furthermore, the SES is able to fuse or associate independent sensor information written to the same vertex at little additional cost (in terms of computing resources) because each SPM writes to the SES independently of each other.
In one embodiment, the vertices of the SES are distributed uniformly over the spherical surface such that nearest-neighbor distances for each vertex are roughly the same. Discretization of the continuous spherical surface into a set of vertices enables the SES agents to quickly associate independent SPM information based on the direction of each sensor source. The selection of the size of the SES (the number of vertices) may be determined by one of skill in the art by balancing the increased time delay caused by the larger number of vertices against the highest angular resolution of the robot's sensors. In a preferred embodiment, the vertices are arranged to match the vertices in a geodesic dome structure.
FIG. 1 is an illustrative diagram of the SES reproduced from FIG. 3 of the '707 Patent. In FIG. 1, the SES is represented as a polyhedron 300. The polyhedron 300 comprises planar triangular faces 305 with a vertex 310 defining one corner of the face. In the polyhedron of FIG. 1, each vertex has either five or six nearest-neighbor vertices and nearest-neighbor distances are substantially the same although tessellations producing a range of nearest-neighbor distances are also within the scope of the present invention. The SES is centered on the current location of the robot, which is located at the center 301 of the polyhedron. Axis 302 defines the current heading of the robot, axis 304 defines the vertical direction with respect to the robot, and axis 303, along with axis 302 define the horizontal plane of the robot.
An object 350 is projected onto the SES by a ray 355 connecting the center 301 to the object 350. Ray 355 intersects a face 360 at a point 357 defined by azimuthal angle, φs, and elevation (or polar) angle, θs. Information about the object 350, such as φs and θs are stored at the vertex 370 that is closest to point 357.
In one embodiment, the SES is implemented as a multiply-linked list of pointers to data structures each representing a vertex on the tessellated sphere. Each vertex record contains pointers to the nearest-neighbor vertices and an additional pointer to a tagged-format data structure (TFDS). The TFDS is a terminated list of objects; each object consisting of an alphanumeric tag, a time stamp, and a pointer to a data object. The tag identifies the sensory data type and the time stamp indicates when the data was written to the SES. The data object contains the sensory data and any function specifications such as links to other agents associated with the data object. The type and number of tags that may be written to any vertex is unrestricted.
The SES may be implemented as a database using standard database products such as Microsoft Access® or MySQL®. An agent to manage communications between the database and other system components may be written in any of the programming languages, such as Basic or C++, known to one of skill in the art.
In one embodiment, the database is a single table that holds all registered information. The manager communicates with other agents in the control system and relays the requests generated to the database. The manager can receive one of four types of requests from any agent: post data, retrieve data using data name, retrieve data using data type and retrieve data using location. The post function takes all relevant data from the requesting agent and registers these data in the database at the correct vertex location. Relevant data includes data name, data type and the tessellation frequency at which the data should be registered. The vertex angles are determined by the SES according to the pan (or azimuthal) and tilt (or elevation) angles at which the data was found. Also, a time stamp is registered with the relevant data. The retrieve data using data name function queries the database using the specified name. This query returns all records in the database that contain the given name. All data is returned to the requesting agent. The retrieve data using data type function is like the previous function, but the query uses the data type instead of name. The retrieve data using location function determines the vertices to query from using the specified location and the neighborhood depth in which to search. When all vertices are determined, the query is placed and all records at the specified vertices are returned.
In another embodiment, the database consists of two tables wherein a vertex table holds the vertex angles and their indices and a data table holds all registered data. When the SES is created, the manager creates the vertices for the projection interface. Each vertex in the vertex table holds an azimuthal angle, an elevation angle, and indices uniquely identifying each vertex. The manager communicates with outside agents of the control system and relays the requests generated to the database. The manager can receive one of four requests from any agent: post data, retrieve data using data name, retrieve data using data type and retrieve data using location. The post function takes all relevant data from the requesting agent and registers this data in the database at the correct vertex location. The retrieve data using data name function queries the database using the specified name. This query returns all records in the database that contain the given name. All data is returned to the requesting agent. The retrieve data using data type function is similar to the retrieve data using data name function but the query uses the data type instead of name. The retrieve data using location function uses the indices and angles stored in the vertex table. The desired location specified in the request is converted into a vertex on the SES. The indices for this vertex are located, and all indices falling within the desired neighborhood of the initial location are collected. The angles matching these indices are then used in a query to the main database holding registered data. All information at these locations is returned to the requesting component.
In addition to post and retrieve agents, other agents may perform functions such as data analysis or data display on the information stored in the SES through the use of the post and retrieve agents.
As each SPM agent writes to a vertex on the SES, an attention agent searches through the vertex list to find the most active vertex, referred to as the focus vertex. High activity at a vertex, or a group of vertices, is a very rapid method of focusing the robot to an event in the environment that may be relevant to the robot without processing the information in all the vertices of the SES first. In one embodiment of the present invention, the attention agent identifies the focus vertex by finding the vertex with the highest number of SPM messages.
In a preferred embodiment, the attention agent weights the information written to the SES, determines an activation value of each message based, in part, on the currently executing behavior, and identifies the focus vertex as the vertex with the highest activation value. If the currently executing behavior terminates normally (the post-condition state is satisfied), the attention agent should expect to see the post-condition state and can sensitize portions of the SES to the occurrence of the post-condition state such that SPM data written to the sensitized portion of the SES are given a greater weight or activity. Each SPM may also be biased, based on the currently executing behavior from a database associative memory (DBAM), to give more weight to expected SPM signals.
For example, a currently executing behavior may have a post-condition state that expects to see a red object 45° to the left of the current heading. The attention agent would sensitize the vertices in the region surrounding the 45° left of current heading such that any SPM data written to those vertices are assigned an activity that is, for example, 50% higher than activities at the other vertices. Similarly, the SPM that detects red objects in the environment would write messages having an activity level that is, for example, 50% greater than the activity levels of other SPMs.
An event in the environment might stimulate several sensors simultaneously, but the messages from the various SPMs will be written to the SES at different times because of the varying delays (latencies) associated with each particular sensor. For example, finding a moving edge in an image sequence will take longer than detecting motion with an IR sensor array. A coincidence detection agent may be trained to account for the varying sensor delays using training techniques known to one of skill in the art such that messages received by the SES within an interval of time are identified as responses to a single event.
In addition to the SPM data written to a vertex, a vertex may also contain links to behaviors stored in the DBAM. Landmark mapping agents may also write to the SES, storing a pointer to an object descriptor at the vertex where the object is expected. Objects may be tracked during robot movement on the SES using transformations such as those described in Peters, R. A. II, K. E. Hambuchen, K. Kawamura, and D. M. Wilkes, "The Sensory Ego-Sphere as a Short-Term Memory for Humanoids", Proc. IEEE-RAS Int'l. Conf. on Humanoid Robots, pp. 451-459, Waseda University, Tokyo, Japan, Nov. 22-24, 2001 herein incorporated by reference in its entirety.
The ability to place an expected object onto the SES and to track objects enables the robot to know what to expect and to remember and recall where objects it has passed should be. The ability to recall passed objects also enables the robot to backtrack to a previous state if a sudden event causes the robot to "get lost" in the sense that a sudden event may displace the state of the robot to a point far from the robot's active map prior to the event.
The ability to place an object onto the SES provides the robot the capability for ego-centric navigation. The placement of three objects on the SES allows the robot to triangulate its current position and the capability of placing the goal state on the SES allows the robot to calculate the goal with respect to its current position.
The objects placed in the SES may also originate from sources external to the robot such as, for example, from another robot. This allows the robot to "know" the location of objects it cannot directly view.
The information written to the focus vertex is vector encoded to a current state vector and passed to the DBAM. The current state vector is used in the DBAM to terminate or continue the currently executing behavior and to activate the succeeding behavior.
Actuator controls are activated by executing behavior agents retrieved from the DBAM. Each behavior is stored as a record in the DBAM and is executed by an independent behavior agent. When the robot is operating in an autonomous mode and performing a task, the currently executing behavior agent receives information from the SES. The currently executing behavior agent either continues executing the current behavior if the SES information corresponds to the state expected by the current behavior or terminates the current behavior if the SES information corresponds to the post-condition state of the current behavior. The currently executing behavior may also be terminated by a simple time-out criteria.
Upon identifying a termination condition, the succeeding behavior is selected by propagation of activation signals between the behaviors linked to the currently executing behavior. Restricting the search space to only the behaviors that are linked to the currently executing behavior, instead of all of the behaviors in the DBAM, significantly reduces the search time for the succeeding behavior such that real-time responsiveness is exhibited by the robot.
Each of the behaviors linked to the current behavior computes the vector-space distance between the current state and its own pre-condition state. Each behavior propagates an inhibitory signal (by adding a negative number to the activation term) that is inversely proportional to the computed distance to the other linked behaviors. The propagation of the inhibitory signal between the linked behaviors has the effect that, in most instances, the behavior with the highest activation term is also the behavior whose pre-condition state most closely matches the current state of the robot.
The links between behaviors are created by the SAN agent during task planning but may also be created by a dream agent during the dream state. The links are task dependent and different behaviors may be linked together depending on the assigned goal.
When the robot is tasked to achieve a goal, the spreading activation network (SAN) agent constructs a sequence of behaviors that will take the robot from its current state to the goal state (active map) in the DBAM by back-propagating from the goal state to the current state. For each behavior added to the active map, the SAN agent performs a search for behaviors that have a pre-condition state close to the post-condition state of the added behavior and adds a link connecting the close behavior to the added behavior. An activation term characterizing the link and based on the inverse vector space distance between the linked behaviors is also added to the added behavior. The SAN agent may create several paths connecting the current state to the goal state.
A command context agent enables the robot to receive a goal defined task and to transition the robot between active mode, dream mode, and training mode.
During periods of mechanical inactivity when not performing or learning a task or when the current task does not use the full processing capabilities of the robot, the robot may transition to a dream state. While in the dream state, the robot modifies or creates new behaviors based on its most recent activities and creates new scenarios (behavior sequences never before executed by the robot) for possible execution during future activity.
Each time the robot dreams, the dream agent analyzes R(t) for the recent active period since the last dream state by identifying episode boundaries and episodes. Each recent episode is first compared to existing behaviors in the DBAM to confirm if the recent episode is another instance of the existing behavior. The comparison may be based on the average distance or end-point distances between the recent episode and the existing behavior or any other like criteria. If the episode is close to the behavior, the behavior may be modified to account for the new episode.
If the episode is distinct from the existing behaviors, the dream agent creates a new behavior based on the episode and finds and creates links to the nearest behaviors. The default activation link to the nearest existing behaviors may be based, in part, on the number of episodes represented in the exemplar behavior such that a new behavior generated from a single episode may be assigned a smaller activation value than behaviors generated from many episodes. The new behavior is added to the DBAM for possible future execution.
If a robot is limited to behavior sequences learned only through teleoperation or other known training techniques, the robot may not be able to respond to a new situation. In a preferred embodiment, a dream agent is activated during periods of mechanical inactivity and creates new plausible behavior sequences that may allow the robot, during its active state, to react purposefully and positively to contingencies never before experienced. The dream agent randomly selects a pairs of behaviors from the DBAM and computes the endpoint distances between the selected behaviors. The endpoint distances are the distances between the pre-condition state of one behavior and the post-condition state of the other behavior. The distance may be a vector distance or any appropriate measure known to one of skill in the art. If the computed distance is less than a cut-off distance, the preceding behavior (the behavior with the post-condition state close to the succeeding behavior's pre-condition state) is modified to include a link to the succeeding behavior.
The robots of Pfeifer and Cohen must be trained to identify episodes that lead to the accomplishment of a task. The training usually involves an external handler that observes and rewards robot behaviors that advance the robot through the completion of the task. The robot either makes a random move or a best estimate move and receives positive or negative feedback from the handler depending on whether the move advances the robot toward the goal. This move-feedback cycle must be repeated for each step toward the goal. The advantage of such a training program is that robot learns both actions that lead toward a goal and actions that do not accomplish a goal. The disadvantage of such a system is that the training time is very long because in addition to learning how to accomplish a task, the robot learns many more methods of not accomplishing a task.
A more efficient method of learning a task is to teach the robot only the tasks required to accomplish a goal. Instead of allowing the robot to make random moves, the robot is guided through the completion of the task by an external handler via teleoperation. During teleoperation, the handler controls all actions of the robot while the robot records the state (sensor and actuator information) of the robot during the teleoperation. The task is repeated several times under slightly different conditions to allow the formation of episode clusters for later analysis. After one or more training trials, the robot is placed in the dream state where the recorded state information is analyzed by the robot to identify episodes, episode boundaries, and to create exemplar episodes for each episode cluster.

System and method for image mapping and visual attention


A low-pressure mercury vapour discharge lamp according to the invention is provided with a radiation-transmitting discharge vessel (10) which encloses a discharge space (11) in a gastight manner and comprises mercury as well as a rare gas. Mercury is also present in a vapour pressure control member (21) which is in communication with the discharge space (11) during nominal operation. The discharge lamp has means (40) for maintaining a discharge in the discharge space (11). The vapour pressure control member (21) forms part of a mercury control member (20) which also comprises mercury transport control means (22) which limit the mercury transport from the discharge space (11) to the vapour pressure control member (21), at least while the lamp is out of operation, to such an extent that this transport is at most 5 ng/h.cm.sup.3, measured at room temperature and in the presence of a saturated mercury vapour in the discharge vessel, per unit volume of the discharge space. The lamp according to the invention has a comparatively high initial radiation output and a comparatively high radiation output at comparatively high lamp temperatures.

The invention relates to a low-pressure mercury vapour discharge lamp provided with a radiation-transmitting discharge vessel which encloses a discharge space containing mercury and rare gas in a gastight manner, while also mercury is present in a vapour pressure control member which is in communication with the discharge space during nominal operation, the discharge lamp comprising means for maintaining a discharge in the discharge space.
Such a lamp, referred to as vapour pressure controlled Lamp hereinafter, is known from DE-PS 10 86 804 (1960). The term "nominal operation" in the present description and claims is used for indicating operating conditions under which the mercury vapour pressure is such that the radiation output of the lamp is at least 80% of the output during optimum operation, i.e. under operating conditions where the mercury vapour pressure is ideal. The vapour pressure control member, an amalgam in the known lamp, limits the mercury vapour pressure in the discharge vessel. This renders nominal operation of the lamp possible at comparatively high lamp temperatures such as may occur in the case of a high lamp load, or when the lamp is used in a closed or badly ventilated luminaire.
The mercury vapour pressure at room temperature is comparatively low in the known lamp. The known lamp as a result has the drawback that, when it is operated on a conventional lamp supply, the initial radiation output is also comparatively low, which output is defined here as the radiation output one second after switching-on of the lamp. The run-up period, i.e. the time which the lamp requires for achieving a radiation output of 80% compared with optimum operation, is comparatively long in addition because the vapour pressure rises only slowly after switching-on of the lamp.
A vapour pressure controlled lamp is disclosed in the U.S. Pat. No. 3,227,907 (1966), NL 151 212 (1967), and DE-AS 12 74 228 (1968) in which an electrode ring around an electrode is provided with an auxiliary amalgam in addition to a main amalgam which acts as a vapour pressure control member. Provided the auxiliary amalgam contains sufficient mercury, the lamp will have a comparatively short run-up period. Upon switching-on of the lamp, in fact, the auxiliary amalgam is heated by the electrode, so that it evolves a substantial portion of the mercury present therein comparatively quickly. A condition is that the lamp must have been out of operation sufficiently long before switching-on, so that the auxiliary amalgam has been able to take up sufficient mercury. If the lamp has been out of operation for a comparatively short period, the shortening effect on the run-up period is only weak. In addition, the initial radiation output is even lower then compared with that of a lamp with a main amalgam only because the auxiliary amalgam continues drawing mercury vapour from the discharge space up to the moment of switching-on of the lamp, thus keeping the vapour pressure low. Furthermore, the drawback arises in comparatively long lamps that comparatively much time is required before the mercury evolved by the auxiliary amalgam has spread over the entire discharge vessel, so that such lamps show a comparatively bright zone near the auxiliary amalgam and a comparatively dark zone remote from the auxiliary amalgam for a few minutes after switching-on.
In vapour pressure controlled lamps with an auxiliary amalgam, the quantity of mercury contained in the auxiliary amalgam depends on the quantity of auxiliary amalgam and the time the lamp has been out of operation, called off-time hereinafter. When the auxiliary amalgam in a lamp has a comparatively great mass, the auxiliary amalgam contains so much mercury after a long off-time that a renewed switching-on of the lamp evolves an excess quantity of mercury in the discharge space. It takes a few tens of minutes then before the main amalgam has absorbed this excess quantity. During this time, the mercury vapour pressure is too high and the lamp accordingly has a comparatively low radiation output. When the auxiliary amalgam in a lamp has a comparatively small mass, the auxiliary amalgam on the contrary contains too little mercury after a short off-time for compensating the absorption by the main amalgam during the first tens of minutes after switching-on. This leads to the effect that the mercury vapour pressure rises initially, then falls, and does not rise again until the main amalgam has also assumed its operational temperature. To counteract this effect, U.S. Pat. No. 3,629,641 (1971) proposes the use of a second auxiliary amalgam which is further removed from the electrode and which takes over the role of the first auxiliary amalgam when the latter is incapable of supplying any more mercury.
After switching-off of the lamp, however, it takes a long time before the auxiliary amalgam(s) has (have) absorbed the necessary quantity of mercury again. When this lamp is switched on before that time, the lamp has a long run-up period in spite of the presence of the auxiliary amalgam.

Low-pressure mercury vapour discharge lamp


A dead pixel correction apparatus includes a storage unit suitable for storing position information of dead pixels obtained from pixel data, a data scanning section suitable for scanning the position information stored in the storage unit, a valid data determination section suitable for determining valid data with respect to the scanned position information, a valid data pre-processing section suitable for pre-processing the determined valid data, and a dead pixel correction section suitable for correcting pixel values corresponding to the dead pixels in current pixel data based on the pre-processed valid data, and outputting the corrected pixel data.

1. Field
Exemplary embodiments of the present invention relate to an image signal processing technology, and more particularly, to a dead pixel correction apparatus and an image sensor having the same.
2. Description of the Related Art
In a conventional dead pixel correction method, since a dead pixel correction algorithm operates based on inputted image pixel values, dead pixel detection and correction may not be accurately performed, so that uncorrected dead pixel data may exist due to the usage of a probabilistic compensation method.
That is, an image signal processing unit in an image sensor recognizes and processes the dead pixel using a kernel having a limited size only within an inputted kernel due to the limitation in a hardware resource. Accordingly, when an obtained pixel information pattern is similar to the pattern of a dead pixel, the dead pixel may not be normally corrected. Furthermore, when two or more dead pixels exist, a compensation ratio may be reduced. Particularly, when the dead pixels are adjacent to each other, the compensation ratio may be significantly reduced.

Dead pixel correction apparatus, image sensor having the same, and operation method of image sensor


A method of manufacturing no-stick multi-color incense is to mix wood powder and an adhesive in powder form evenly and then the mixture is added into a liquid containing pigment and fragrance, stirred into a one-color glutinous paste and compressed into a single-color chunk by machines. The same procedures above-mentioned are repeated several times to obtain chunks with different colors. These mono-color chunks are cut into small cubes. The cubes are mixed together, piled on top of each other with different colors and then extruded by extruding machine to form incense with multiple colors. After drying, no-stick multi-color incense is obtained.

I. Field of the Invention
This invention relates generally to a method of manufacturing no-stick multi-color incense and, more specifically, to a method of manufacturing incense having two or more than two colors and a variety of shapes, which usually used in festivities, religious services or for other special purposes so that novelty and amusement are added to incense products and their market value can be enhanced.
II. Description of the Prior Art
Incense products are widely used in modern time. Especially for people from oriental culture, incense is adopted on various occasions, such as in memorial ceremonies, during meditation, or as insecticide. Incense products come with a stick or without a stick. No-stick incense has a variety of forms, such as incense coil, pastille, incense loop, and mini incense coil. Heretofore, almost all kind of incense has only one color. Incense with mono-color is lack of variety. It does not look appealing to consumers and thus restricts its value on the consumer market.
The present invention is directed to solving above-mentioned problems, and it is a primary object of the invention to provide an improved method of manufacturing no-stick multi-color incense which brings variety and novelty to incense products and is expected to boost the market value of incense.
In a method of manufacturing no-stick multi-color incense according to the present invention, no-stick incense with various colors is prepared. Wood powder and an adhesive in powder form are mixed evenly and then the mixture is added into a liquid containing pigment and fragrance. The solution is stirred into a one-color glutinous paste and is compressed into a chunk by machines. The same procedures above-mentioned are repeated several times to obtain chunks with different colors. These mono-color chunks are cut into small cubes. These cubes are mixed together, piled on top of each other with different colors and then extruded by extruding machine to form incense with multiple colors. After drying, no-stick multi-color incense is obtained.
With the method described above, each no-stick incense would be decorated with at least two colors. Whether the incense is in form of coil, pillar, or mini coil, the distinctive feature of colorfulness adds novelty and attractiveness that enhances product value and competitiveness on the consumer market.

Method of manufacturing no-stick multi-color incense


Apparatus and methods are provided for generating an output signal representing a selectively reduced coding rate for use in compressing a digital signal. The digital signal includes a plurality of digital sets wherein at least one of the digital sets are non-unique. A current coding rate and a threshold coding rate compared to determine whether the current coding rate satisfies a predetermined criteria. In response to the determination, at least one of the digital sets are selectively discarded, a rate difference resulting from selectively discarding at least one of the plurality of digital sets is determined, and the current coding rate is recalculated using the determined rate difference.

Conventional communication systems, including networks, include two or more interconnected nodes wherein each node functions as a junction point within the system. Information is transferred between nodes using electric, light, and/or radio waves, and typically involves transferring one or more codewords. Each codeword represents a symbol in a symbol set, such as an alphabet, and includes data for use by, and/or instructions for, a receiving node. Each codeword is defined by one or more binary digits, or bits.
Communication systems have limited bandwidth. In other words, there exists an upper limit, or maximum number, of bits which may be transferred per unit time. Contrary to this limitation is the need of many communication systems to transfer large quantities of symbols. This is particularly true in video applications, such as videophone and direct television, where video symbols typically represent chrominance and/or luminance values for picture elements ("pixels"), motion information, instructions indicating the content of the chrominance, and luminance values or marker codes. Marker codes are sync codes.
Data compression techniques have been incorporated into many communication systems to increase the number of codewords transferred given the available bandwidth. These techniques eliminate unnecessary data, redundancies, and the like from transmissions. Huffman Coding is one popular approach which is commonly used for video, audio/speech and high-speed data compression. Huffman Codes use variable length symbols wherein each symbol's length depends upon the probability of occurrence of the one or more codewords defining it.
Assume for example a symbol set of {bear, dart, wear, beet}. Each of the codewords used to represent the symbol set has a length inversely proportional to its symbol's usage. Assuming this symbol set is used in the English language, "wear" is likely to be said more often than "bear", more often than "dart", and more often than "beet". The coding may accordingly be {be, dar, w, beet}, where codeword length is equivalent to the number of letters. In point of fact, the English language presents another good example of variable length codewords wherein common words such as {it, in, a, car, the, if, I, a, an} are shorter than words used less frequently, such as {approximately, university, automobile, individually, myself, particularly}.
Source entropy is an optimal "loss-less" coding rate, in other words, the smallest average number of bits per symbol required to represent a particular symbol set or alphabet. Huffman Coding techniques have been found to reduce coding rates to nearly source entropy. In many conventional applications, such as video processing, however, the probability of all occurrences of the various symbols tends to change as the video image changes. This causes the current Huffman Codes to be an inefficient representation of the symbols. Worse, these changes typically occur at random.
The Huffman Codes accordingly cease to reduce coding rates to source entropy and require recalculation. This is often computationally difficult as the codeword for any one symbol depends on the probability of occurrence of the symbols in the alphabet. For large alphabets therefore each codeword, of which there are typically many, requires substantial computation.
One conventional solution periodically recalculates the Huffman Codes. Another solution determines the source entropy, and then estimates from that determination the coding rate for recalculating the Huffman Codes. Each approach is typically inaccurate, and in many situations demands substantially the same processing resource requirements needed to recalculate the Huffman Codes as when originally defined. The inability of conventional communication systems to generate, and regenerate, Huffman Codes to maintain substantially source entropy remains a dominant obstacle to producing high quality video, audio/speech and high-speed communication.

Method and apparatus for selectively discarding data when required in order to achieve a desired Huffman coding rate


A collapsible forklift vehicle has three frame sets, namely a main frame, a pair of front wheel frames which can be retracted into the main frame, and a mast frame which runs partly on the main frame and partly on the front wheel frames. The main frame defines a rear space for the rear wheels, and motor and operator platforms, all of which can be retracted into the rear space to shorten the vehicle for transport. The mast, carried by the mast frame, includes intermediate channels running in outer channels using top and bottom rollers, enabling the use of lighter gauge steel for the mast.

Vehicles such as forklift vehicles must often be carried from one location to another. It is common to do so by carrying the forklift vehicle on the rear end of another vehicle, such as a tractor trailer. However since the forklift vehicle then projects rearwardly from the tractor trailer, the combined length of the two vehicles can be unduly long. In addition the leverage on the rear axle of the tractor trailer, created by the overhanging forklift vehicle, can be unacceptably high. For this reason it is known to have portions of a forklift vehicle which are retractable, so that the vehicle will occupy less length or otherwise will occupy a smaller space.
For example, U.S. Pat. No. 4,061,237 issued Dec. 6, 1977 shows a forklift vehicle in which the front wheel portion of the vehicle can be retracted to a position such that the front to rear dimension of the vehicle is shortened.
U.S. Pat. No. 5,174,415 issued Dec. 29, 1992 shows another forklift vehicle in which the front wheels and their support arms can be swung upwardly, again to reduce the front to rear length of the vehicle.
U.S. Pat. No. 3,799,379 issued Mar. 26, 1974 shows yet another forklift vehicle in which the front wheels and their support arms are retractable to reduce the overall length of the vehicle.
U.S. Pat. No. 3,908,849 issued Sep. 30, 1975 shows a form of forklift vehicle which is collapsible to a tripod arrangement, again to reduce the overall length of the vehicle.
The forklift vehicles shown in the above mentioned patents suffer from various difficulties. One of these difficulties is that since the rear wheels in the vehicles shown are not retractable, the over all length of the vehicles remains relatively substantial.

Vehicle with retractible rear wheel assembly


A circuit and method for controlling the color balance of a flat panel display without losing gray scale resolution of the display screen. Within a FED screen, a matrix of rows and columns is provided and emitters are situated within each row-column intersection. Rows are activated sequentially by row drivers and corresponding individual gray scale information (voltages) is driven over the columns by column drivers. When the proper voltage is applied across the cathode and anode of the emitters, they release electrons toward a phosphor spot, e.g., red, green, blue, causing an illumination point. Within each column driver, a digital to analog converter that contains two data-in voltage-out transformation functions, a first function corresponding to a first voltage intensity and a second function corresponding to a lesser voltage intensity for a same digital color value. During the row on-time window, the present invention time multiplexes application of the voltages for the first and second functions when driving color information (e.g., voltages) over the column lines. There is a separate timing signal for each color that controls the multiplexing intervals. By adjusting the timing signal for a particular color, the intensities for all pixels of that color are adjusted up or down relative to the other colors. This provides an effective color balancing technique that does not require expansion of the color driver substrate area nor does it degrade the gray scale capability of the FED screen. Adjustment of color balancing can be done in response to tube aging and/or manufacturing variations in the phosphor.

1. Field of the Invention
The present invention relates to the field of flat panel display screens. More specifically, the present invention relates to the field of flat panel field emission display (FED) screens.
2. Related Art
In the field of flat panel display devices, much like conventional cathode ray tube (CRT) displays, a white pixel is composed of a red, a green and a blue color point or "spot." When each color point of the pixel is excited simultaneously, white can be perceived by the viewer at the pixel screen position. To produce different colors at the pixel, the intensity to which the red, green and blue points are driven is altered in well known fashions. The separate red, green and blue data that corresponds to the color intensities of a particular pixel is called the pixel's color data. Color data is often called gray scale data. The degree to which different colors can be achieved within a pixel is referred to as gray scale resolution. Gray scale resolution is directly related to the amount of different intensities to which each red, green and blue point can be driven.
Field emission display (FED) screens, like CRT displays, utilize phosphor spots to generate the red, green and blue points of a pixel. Often, during the manufacturing process, the characteristics of the phosphor of the display screen for a particular color can vary from screen to screen. If the phosphor has different characteristics, then its color intensity will vary from screen to screen thereby producing screens with different color balance. Therefore, it is important that a display screen have a mechanism for altering the relative color intensities of the color points so that manufacturing variations in the phosphor can be compensated for in the display screen. The method of altering the relative color intensities of the color points across a display screen is called white balance adjustment (also referred to as color balance adjustment or color temperature adjustment).
Another reason for providing color balance adjustment, in addition to correcting for manufacturing variations in the phosphor, is to correct for phosphor aging through prolonged display use. It is typical for the light emitting characteristics of the phosphor of a FED screen to change over time as it is used. Therefore, it is important that a display screen have a mechanism for altering its color balance to correct for phosphor aging to maintain image quality throughout the life of the FED screen. A further reason for providing color balance adjustment within a display screen is to allow the viewer to manually adjust the color balance. Using a manual adjustment, users can adjust the white balance of the display screen to their particular viewing taste.
One method for correcting or altering the color balance within a display screen is to alter, on the fly, the color data used to render a screen. Instead of sending a particular color point a color value of X, the color value of X is first passed through a function that has a gain and an offset. The output of the function, Y, is then sent to the color point. The function compensates for any variations in the color temperature caused by phosphor variations. The values of the above function can be altered as the color temperature needs to be increased or decreased. Although offering dynamic color balance adjustment, this prior art mechanism for altering the color balance is disadvantageous because it requires relatively complex circuitry for altering the large volume of color data. The additional circuitry this prior art mechanism requires may also add to the overall size of the driver circuits. Assuming a horizontal screen resolution of 1024 white pixels, there can be as many as 3072 column drivers per FED screen. Any increase in column driver size is therefore duplicated several thousand times. Secondly, this prior art mechanism may degrade the quality of the image by reducing the gray-scale resolution of the flat panel display. It is desirable to provide a color balance adjustment mechanism for a flat panel display screen that does not alter the image data nor compromise the gray-scale resolution of the image.
Another method of correcting for color balance within a flat panel display screen is used in active matrix flat panel display screens (AMLCD). This method pertains to altering the physical color filters used to generate the red, green and blue color points. By altering the color the filters, the color temperature of the AMLCD screen can be adjusted. However, this adjustment is not dynamic because the color filters need to be physically (e.g., manually) replaced each time adjustment is required. It would be advantageous to provide a color balancing mechanism for a flat panel display screen that can respond, dynamically, to required changes in the color temperature of the display.
FIG. 1 is a graph 6 of a typical data-in voltage-out curve that is embedded within a digital to analog converter circuit of an AMLCD flat panel display. The digital to analog converter is responsible for transforming the digital color data to voltages that are used to generate the actual color intensity. When presented with color data from 0 to 63, the voltages corresponding to curve portion 2 are supplied as output to drive the color points. When presented with color data from 64 to 127, the voltages corresponding to curve portion 4 are supplied as output to drive the color points. Curve portion 4 may be the same as curve portion 2 except with a DC voltage offset. Curve portion 4 and curve portion 2 are used in alternating refresh cycles so that no net DC voltage is applied to the cells of the AMLCD display. Prolonged exposure to DC voltage can destroy the AMLCD display. Therefore, the gray scale resolution of the AMLCD device using curves 2 and 4 is only from 0 to 63, although 127 data positions exist. This is the case because positions 64 to 127 are only duplicates, respectively, of positions 0 to 63. Although used in the manner described above, the data-in voltage-out function of FIG. 1 has never been applied to perform any type of color balancing operations.
Accordingly, the present invention provides a mechanism and method for dynamically adjusting the color balance of a flat panel display. The present invention provides a mechanism and method for adjusting the color balance of a flat panel display screen that does not compromise the gray-scale resolution of the pixels of the display screen. Further, the present invention provides a mechanism and method for adjusting the color balance of a flat panel display screen without increasing the size of the column driver circuits. The present invention also provides a mechanism for altering the color balance of a flat panel display screen that does not alter the image data supplied to the column driver circuits. Further, the present invention provides a mechanism and method for controlling the color balance of a flat panel FED screen. These and other advantages of the present invention not specifically mentioned above will become clear within discussions of the present invention presented herein.

Circuit and method for controlling the color balance of a flat panel display without reducing gray scale resolution


Disclosed is a system for providing multiple window environments in a mobile computing system and a method thereof, which enables a user to conveniently and selectively use a window system suitable for the use environment. A plurality of sub-window systems having different user interfaces and application programs are installed in separate user partitions provided in a non-volatile memory. If a predetermined event occurs, a currently executing sub-window system, from among the plurality of sub-window systems, is terminated, and a user partition corresponding to the terminated sub-window system is dismounted. Then, a user partition from among the separate user partitions, designated corresponding to the predetermined event is mounted so that the sub-window system of the mounted user partition is executed.

1. Field of the Invention
The present invention relates generally to a portable terminal, and more particularly to a system for providing multiple window environments in a portable terminal adopting a mobile computing system having a non-volatile memory and a method thereof.
2. Description of the Related Art
Typically, a mobile computing system, which is adopted in various kinds of portable terminals such as PDAs (Personal Digital Assistants), smart phones, etc., has one OS (Operating System) image installed in a programmable non-volatile memory. A flash memory is typically used as the programmable non-volatile memory.
FIG. 1 illustrates a memory map of a programmable non-volatile memory provided in a typical mobile computing system. The programmable non-volatile memory 100 has an area in which a boot loader 102, a kernel 104, a root file system 106, and a window system 108 are stored, and a storage area 110, used to store data required for the execution of the window system 108.
The boot loader 102 is a boot code having a size of about 100 Kbytes, which starts when a CPU (Central Processing Unit) is reset. The kernel 104 and the root file system 106 are the minimum OS codes required for the operation of the window system 108, and commonly have a size of about 3 Mbytes. The window system 108 is composed of a user interface, an application program, and commonly has a size of about 20 Mbytes to 30 Mbytes.
In the mobile computing system having a non-volatile memory 100 as described above, during a booting operation of the system, the boot loader 102 initializes the CPU, memory and peripheral devices (not illustrated), copies itself, the kernel 104 and the root file system 106 into a memory, i.e., RAM (Random Access Memory), and then assigns a control authority to the kernel 104.
Then, the kernel 104 activates a system service related to the OS, mounts the root file system 106, and then assigns the control authority to the root file system 106. The root file system 106 executes the window system 108 through its initialization routine. If the window system 108 is executed, all the system booting processes are terminated.
Since the mobile computing system is not adopted in devices such as a PC (Personal Computer) used in a fixed place or for a fixed purpose, but is adopted in a portable terminal that is carried by a user, its purpose may be repeatedly changed even during a day. By contrast, a typical mobile computing system has only one OS image as described above, and thus if the user intends to use an OS image having a new function according to the use environment, he/she must remove the existing OS image installed in the non-volatile memory, and install a different OS image instead.
The programmable non-volatile memory used in the mobile computing system has a memory capacity of more than 1 Gbytes, and this memory capacity is constantly increasing. However, since only about 40 Mbytes of memory are actually used, even if all the code areas and data storage area are put together as described above, the most of the available storage area may not be used unless a great amount of data such as a GPS (Global Positioning System) map is used in the mobile computing systems.

System for providing multiple window environments in a mobile computing system and method thereof


A nonvolatile semiconductor memory device includes a semiconductor substrate, a select gate formed above the semiconductor substrate, a floating gate formed above the semiconductor substrate and an erase gate positioned lower than an upper surface of the floating gate, and opposite an edge of a lower surface of the floating gate.

1. Field of the Invention
The present invention relates to a nonvolatile semiconductor memory containing an erase gate, and to a manufacturing method for the nonvolatile semiconductor memory containing the erase gate.
2. Description of Related Art
A memory device such as a flash memory and an electrically erasable programmable read-only memory (EEPROM) is a nonvolatile semiconductor device capable of being electrically erased and programmed. A memory cell in this type of nonvolatile semiconductor device is usually a transistor containing a floating gate and a control gate. The control gate is in some cases stacked on the floating gate, and in some cases formed at least on a channel region to a side of the floating gate. A type of the latter memory cell is called a "split-gate" and type memory cell, and is superior in terms of higher read speed and in controlling over-erasure.
A typical data programming/erasing method for the memory cell is as follows. Data programming is implemented by the Channel Hot Electron (CHE) method. More specifically, a specified program voltage potential is applied to the respective control gate and drain, and hot electrons emitted in the vicinity of the drain are injected into the floating gate. Data erasure however is implemented by the Fowler-Nordheim (FN) tunneling method. More specifically, a high voltage potential is applied to the control gate, and electrons within the floating gate are extracted via the tunnel insulation film to the control gate by FN tunneling.
Here, the following problem is encountered. The control gate in the above-described split-gate type memory cell is formed on the channel region via a gate insulation film. Moreover, to achieve FN tunneling during data erasure, a high voltage potential must be applied to the control gate as described above. The gate insulation film directly below the control gate where the high-voltage potential is applied, cannot be thinned (i.e., reduced in thickness) due to the need for reliability. Failing to thin the gate insulation film between the channel region and the control gate causes problems of a reduced read current during data read, and a drop in the read speed.
To resolve the aforementioned problems, a technology was disclosed (See JP-A No. 2001-230330, JP-A No. 2000-286348) for forming an "erase gate" for data erasure that is separate from the control gate. During data erasure, a high voltage potential is applied to this erase gate rather than the control gate. Consequently, FN tunneling then extracts electrons within the floating gate to the erase gate. The gate insulation film directly below the control gate can therefore be made thin because a high voltage potential no longer has to be applied to the control gate during data erasure. A drop in the read speed is therefore also prevented.
In the technology disclosed in JP-A No. 2001-230330, the erase gate is stacked via an insulation film on the floating gate, and the control gate is formed to a side of a laminated structure made up of the floating gate and the erase gate. In the technology disclosed in JP-A No. 2000-286348, the erase gate is formed on a source region of a semiconductor substrate surface, and formed so as to adjoin an entire side of the floating gate and a portion of an upper surface of the floating gate via a tunnel oxide film.

Nonvolatile semiconductor memory with erase gate and its manufacturing method


This invention provides methods of using phagocytic cells alone or in combination with non-phagocytic cells in the diagnosis, prognosis, or monitoring of prenatal or pregnancy-related diseases or conditions. The invention also provides methods of using phagocytic cells alone or in combination with non-phagocytic cells to identify markers of prenatal or pregnancy-related diseases or conditions.

Early diagnosis of a disease often increases the likelihood of successful treatment or cure of such disease. Current diagnostic methods, however, depend largely on population-derived average values obtained from healthy individuals. Personalized diagnostic methods are needed that enable the diagnosis, especially the early diagnosis, of the presence of a disease or a condition in individuals who are not known to have the disease or who have recurrent disease. This is of particular importance in prenatal and pregnancy-related diseases or conditions, wherein early diagnosis is especially difficult, and which can affect a pregnant woman as well as the unborn fetus.
Leukocytes begin as pluripotent hematopoietic stem cells in the bone marrow and develop along either the myeloid lineage (monocytes, macrophages, neutrophils, eosinophils, and basophils) or the lymphoid lineage (T and B lymphocytes and natural killer cells). The major function of the myeloid lineage cells (e.g., neutrophils and macrophages) is the phagocytosis of infectious organisms, live unwanted damaged cells, senescent and dead cells (apoptotic and necrotic), as well as the clearing of cellular debris. Phagocytes from healthy animals do not replicate and are diploid, i.e., have a DNA content of 2n. On average, each cell contains <10 ng DNA, <20 ng RNA, and <300 ng of protein.
The lifetime of various white blood cell subpopulations varies from a few days (e.g., neutrophils) to several months (e.g., macrophages). Like other cell types, leukocytes age and eventually die. During their aging process, human blood- and tissue-derived phagocytes (e.g., neutrophils) exhibit all the classic markers of programmed cell death (i.e., apoptosis), including caspase activation, pyknotic nuclei, and chromatin fragmentation. These cells also display a number of "eat-me" flags (e.g., phosphatidylserine, sugars) on the extracellular surfaces of their plasma membranes. Consequently, dying and dead cells and subcellular fragments thereof are cleared from tissues and blood by other phagocytic cells.

This patent is subject to a terminal disclaimer.

Methods of detecting prenatal or pregnancy-related diseases or conditions

PRESIDENT AND FELLOWS OF HARVARD COLLEGE


A method is provided for determining a category of a location. The method comprises determining, at a first time, information identifying a first device location of a first device associated with a user; and storing the first device location information and information identifying the first time in a location history. The method further comprises determining, at a second time, information identifying a second device location of the first device; and storing, in the location history, the second device location information and information identifying the second time. The method still further comprises determining, based on the location history, a category of a location.

The present disclosure relates to an electronic apparatus, an information determining server, an information determining method, a program, and an information determining system.
A device measuring a current position using a satellite positioning system such as GPS (Global Positioning System) and displaying the measured current position on a map is proposed along with the development of information processing technology (for example, see Japanese Unexamined Patent Application Publication No. 11-51663).

Electronic apparatus, information determining server, information determining method, program, and information determining system


A directional valve (170) includes an actuator (92, 144) responsive to feedback pressure from a closed volume load (182) for regulating fluid pressure of the load proportional to an electric signal (172). A double-acting cylinder (64, 148) has a plunger (58, 150) operatively associated with the actuator (92, 144) for opposing movement of the actuator proportional to the feedback pressure of the closed volume load. Opposite faces (66, 68 and 156, 158) of the plunger (58, 150) are arranged to balance the directional valve (170) against working pressure within the valve and to control the magnitude of the feedback force opposing movement of the actuator (92, 144).

Proportional control valves can be actuated by proportional solenoids to regulate back pressure from remote devices. For example, my copending U.S. patent application Ser. No. 505,889, filed Apr. 6, 1990, now U.S. Pat. No. 5,123,718, discloses a solenoid actuated valve for controlling a flow of fluid under pressure to a brake cylinder. The flow of fluid is maintained until back pressure from the brake cylinder reaches a desired proportional relationship with an increased force exerted by the solenoid. Back pressure is reduced by exhausting fluid flowing from the brake cylinder until the back pressure returns to the desired proportional relationship with a decreased solenoid force.
However, fluid flows between the proportional valves and remote devices are accompanied by friction, which causes a pressure drop between the source and the destination of the fluid flow. Accordingly, pressure changes in remote devices such as brake cylinders or other closed volume loads tend to lag behind the changes in back pressure regulated by proportional control valves. This can cause instability in the operation of the valves.
While charging, for example, proportional control valves can momentarily close off the supply of pressurized fluid to the remote devices before the remote devices have reached the desired pressure level. Upon closing the supply, static pressure within the valves approaches the prior average dynamic pressure of the valves and remote devices, which is below the desired pressure level and can cause the valves to momentarily reopen. This sequence can be repeated many times until the desired pressure increase in the remote devices is reached.
Similar instability problems can be caused by a pressure difference between the proportional control valves and the remote devices while discharging. The valves can momentarily close off the exhaust of pressurized fluid from the remote devices before the pressure in the remote devices has reduced to a desired level. A static pressure increase in the valves up to the prior average dynamic pressure of the valves and the remote devices can cause the valves to momentarily reopen to continue to exhaust more of the pressurized fluid from the remote devices. Although the desired pressure level is eventually reached while either charging or discharging, the additional openings and closings of the valves, which are required to reach the desired pressure level, can cause accelerated wear, noise, pressure fluctuations, and a decreased response time.
In addition to instability problems caused by restrictions to fluid flow between proportional control valves and remote devices, these valves can also have design problems relating to limiting proportional solenoids to a reasonable size and power rating while sizing the valves to accommodate high rates of fluid flow that are required to achieve fast response times. For example, exhaust passages accommodating high rates of fluid flow are associated with large valve seats over which the back pressure from remote devices is applied. The solenoids are sized to overcome the forces generated by the back pressure applied over the area of the seats to regulate the back pressure proportional to a control force.
My copending application Ser. No. 505,889 reduces solenoid size requirements by providing two separate exhaust passages. One of the passages is sized to accommodate low rates of fluid flow, and the other passage is sized to accommodate high rates of fluid flow. The low-flow passage conveys back pressure to the solenoid, whereas the high-flow passage is opened in response to a pressure increase in the low-flow exhaust. This reduces the size and power requirements of the solenoid but makes the valve more complicated.

Proportional control valve with pressure compensation


Systems for assembling and supporting roofing members on a roof structure are described. An exemplary system includes at least one batten extending along a portion of the roof structure. The batten includes receiving portions for removably securing hanger devices along the batten. Related methods for support and assembly are also described.

Slate roofs are appreciated for their aesthetic and durable qualities. Slate is one of the finest roofing materials available and has several advantages over asphalt shingle roofs. For example, state roofing is fireproof, resists hail damage, and often has a service life of 100 years or more. However, slate is a rigid natural stone product which unfortunately can be damaged by stress. Stress can be introduced into slate in several ways, but the most common cause of stress to slate is nails used to attach the slate to the roof deck. With nail installation, the nails need to be fastened so the slate hangs on the nail. If the nail is inserted too tightly, the nail will pinch the slate. On the other hand if the nail is not inserted deep enough, the overlapping piece of slate may crack from the hidden pressure point. Environmental effects on the wood decking and nails may also contribute to the stress. Environmental changes such as swings in temperature and humidity can cause the decking to expand and contract. If the nails are in a bind in this situation, the slate can crack or fall.
Furthermore, slate roofs are quite expensive (typically two to three times more expensive than composition asphalt roofing), and the weight of the slate is quite high compared to composition shingles (which may require additional support for the roof, further adding cost). Slate materials are expensive themselves, so any reduction in the amount of slate necessary for effective roofing would lead to both a decrease in cost and weight of a roof.
A good background for slate roofing and the method for installing the same may be found in the NRCA Roofing and Waterproofing Manual—4th Edition, pp. 1179-1227, that document being incorporated herein by reference. Typical slate roofs are constructed such that a wood roof is first covered with an underlayment layer, typically asphalt felt paper. Overlapping slate courses are then applied with slate covering the roof in two plies except where there is overlap, in which case there are three plies of slate. Through joints should not occur from the slate roof surface to the felt. So using the conventional slate roofing technique, slate tiles must be elongated sufficiently to allow for three-ply overlap (and two plies of slate on the exposed portions of the roof) in order to ensure that water cannot penetrate the roof between the seams between slate tiles. Accordingly, the conventional slate roofing technique requires the use of a great deal of slate material, due to the need for double ply coverage and three-ply overlap for water resistance, greatly increasing the cost and weight of a slate roof.
Slate roofs may be improved by reducing the amount of slate used to create a waterproof roofing surface, and by eliminating the use of nails (or any other penetration or system requiring a hole in the slate) to secure the slate tiles in place on the roof. This may allow for a more durable, but less expensive and heavy, slate roof. Furthermore, the slate roof would be more durable if there was some means of resisting uplift forces generated by winds on the slate tiles. High winds may catch under the leading edge of the slate tiles, applying a lifting force to the slate. In this manner, wind may increase stresses on the slate tiles. In addition, the wind may actually lift the slate tiles, exposing the underlying roof to the elements. Thus, an improved slate roofing system would attach the slate tiles to the rook deck using some means that would resist wind uplift forces, providing a more durable and weather resistant roof.

Building Materials Investment Corporation


A plurality of different pilot signal components are selectively superposed on an information signal, and mark signals which can indicate the types of pilot signals to be superposed are recorded, together with the information signal, on tracks on a recording medium, on which the pilot signals associated with the mark signals are recorded. The types of pilot signals can be quickly detected in a reproduction mode, and a satisfactory tracking control state is quickly achieved by modifying the tracking control signal.

1. Field of the Invention
The present invention relates to an information signal recording apparatus and information signal reproduction apparatus, which record or reproduce information on or from a large number of parallel tracks on a recording medium and, more particularly, to tracking control thereof. For example, the present invention relates to tracking control used in an apparatus such as a VTR for reproducing a video signal from oblique tracks recorded and formed on a magnetic tape by a rotary head.
2. Related Background Art
As conventional reproduction tracking methods for home VTRs, the following two methods have been proposed and put into practical applications. That is, one method is a method (CTL method) of recording a vertical sync signal separated from a recording signal upon recording on a special-purpose control track formed along the longitudinal direction of a tape using a stationary magnetic head provided adjacent a portion of a tape path. The other method is a method (4fATF method) of obtaining a tracking error signal by comparing crosstalk components reproduced from two neighboring tracks of a reproduction track upon reproduction by cyclically recording pilot signals having four different relatively low frequencies to be superposed on main signals such as a video signal, an audio signal, and the like on a track for recording the main signals using a rotary head for recording/reproducing the main signals.
However, the CTL method requires a space for the stationary head, and is disadvantageous in consideration of downsizing of a set. On the other hand, the 4fATF method is advantageous for downsizing, but requires a relatively complex circuit arrangement since a large number of analog circuits are required for four different pilot signals. In addition, in the 4fATF method, when the pilot signals are superposed on a digital signal, since these signals occupy a relatively broad frequency band, reliability of the digital signal is undesirably impaired.
On the other hand, in order to record/reproduce a relatively large information amount to meet requirements for high-image quality VTRs and digital VTRs in recent home VTRs, a VTR which divisionally records an image signal for one field on a plurality of tracks has been developed, and a new tracking method used in these VTRs has been examined. More specifically, upon modulation of a digital signal to be recorded, a recording signal is recorded, so that a modulated signal includes a frequency component corresponding to a specific pilot signal, and with this modulation, the pilot signal for tracking control is multiplexed on a digital information signal.
FIG. 1A is a schematic plan view of a drum for a VTR. A rotary drum 40 contacts a tape 41, and has a ch1 head 42 of a (+) azimuth, a ch2 head 43 of a (-) azimuth, a ch3 head 44 of a (+) azimuth, and a ch4 head 45 of a (-) azimuth.
FIG. 1B is a front view of the heads which can be observed upon rotation of the drum for explaining the mounting heights of the heads 42 to 45. The ch1 and ch2 heads and the ch3 and ch4 heads are respectively paired, and are arranged adjacent to each other. These pairs of heads are arranged on the drum 40 to have a 180.degree. angular interval therebetween. As can be seen from FIG. 1B, the ch2 and ch4 heads are respectively offset from the ch1 and ch3 heads by a distance h, and the distance h corresponds to one track pitch on the tape. With this arrangement, two tracks can be simultaneously subjected to recording or reproduction for every half revolution of the drum, thus allowing recording/reproduction of a large amount of information.
A new tracking method will be described below. FIG. 2 is a view showing a recording pattern on the tape 41. Two different pilot signals having frequencies f1 and f2 are used for obtaining a tracking error signal, and are recorded on every other tracks to be superposed on main signals. The generation rotation of the pilot signals requires four tracks to complete one cycle. On a track corresponding to a (+) azimuth of the head, no pilot signal is superposed; on a track corresponding to a (-) azimuth of the head, the pilot signals of the frequencies f1 and f2 are alternately recorded. (1) to (10) in FIG. 2 represent intra-frame numbers of tracks since a signal for one frame is divisionally recorded on 10 tracks.
As described above, in this method, since four tracks are subjected to recording or reproduction during one revolution of the drum, scanning of tracks for one frame requires 2.5 revolutions, and the pilot rotation and frames are synchronized with each other in units of two frames (20 tracks).
FIG. 3 is timing charts showing pilot signals recorded by the heads (ch1 to ch4) to be superposed on main signals, and pilot signals reproduced by the heads upon reproduction. The following explanation will be given with reference to FIG. 3.
FIG. 3, (a) shows a frame signal upon recording or reproduction, FIG. 3, (b) shows a head SW (switch) signal for switching the heads, and FIG. 3, (c) shows the pilot timings of the ch1 and ch3 heads upon recording, at which no pilot signals are superposed. FIG. 3, (d) shows the pilot timings to be recorded by the ch2 and ch4 heads, at which the pilot signals of the frequencies f1 and f2 are alternately recorded. FIG. 3, (e) shows the pilot signals reproduced by the ch1 and ch3 heads in a good reproduction tracking state, and FIG. 3, (f) similarly shows the reproduction timings of pilot components reproduced by the ch2 and ch4 heads.
As can be seen from FIG. 2, in this method, when a head width w of each head is set to be wider than the track pitch, the pilot signals recorded on two neighboring tracks can be reproduced as crosstalk components at the reproduction timings of the ch1 and ch3 heads, and by utilizing the fact that the two crosstalk component amounts become equal to each other in a good tracking state, a tracking error signal (ATF error signal) is obtained.
FIG. 4 is a block diagram showing the circuit arrangement for detecting the ATF error signal upon reproduction.
Referring to FIG. 4, a head SW signal (HSW) 70 is used for switching reproduction signals from the ch1 and ch3 heads in synchronism with the rotation of the drum. An SW circuit 79 switches reproduction signals from the ch1 and ch3 heads in response to the HSW 70. A band-pass filter (BPF) 71 extracts only the frequencies f1 and f2 as those of reproduction pilot signals from a reproduction RF signal, and an amplifier 72 amplifies reproduction pilot signals as the outputs from the BPF 71. A band-pass filter 73 (BPF) extracts only the frequency component f2 from the output from the amplifier 72, and a band-pass filter (BPF) 74 extracts only the frequency component f1 from the output from the amplifier 72. A detecting circuit 75 converts the frequency component f2 as the output from the BPF 73 into a DC level, and a detecting circuit 76 similarly converts the frequency component f1 into a DC level. A differential amplifier 77 receives the outputs from the two detecting circuits. The output from the differential amplifier 77 is supplied to an inverting circuit (amplifier)78. An SW circuit 80 selects one of the output from the differential amplifier 77 and the output from the inverting circuit 78 in response to the HSW 70. A video & audio system reproduced signal processing circuit 81 obtains a reproduction video signal and a reproduction audio signal by processing a reproduction RF signal.
The operation will be described below. As described above, in this system, reproduction pilot signals are included as crosstalk components from two neighboring tracks ((-) azimuth tracks) in reproduction signals from the (+) azimuth ch1 and ch3 heads. Therefore, reproduction signals from only the ch1 and ch3 heads of the four heads are necessary, and the reproduction pilot signals are converted into one system of reproduction signal by an SW circuit 79. Since this reproduction signal is also included in main signals, it is supplied to the video & audio system reproduced signal processing circuit 81, and is also supplied to the BPF 71 for extracting reproduction pilot signals as an ATF circuit. Thereafter, the crosstalk pilot components f1 and f2 are separated and detected, and are compared by the differential amplifier 77, thus obtaining one system of ATF error signal.
In order to cope with the positional switch of tracks corresponding to the frequencies f1 and f2 between the ch1 and ch3 heads, an ATF error signal is obtained by selecting the output from the inverting amplifier 78 by the SW circuit 80 in synchronism with the HSW 70 upon selection of the ch3 head.
The new tracking method has been described. The new tracking method will be referred to as a 2fATF method hereinafter, as needed.
However, the above-mentioned new tracking method poses the following problems. That is, as a first problem, since a tracking error signal is obtained based on only pilot signals reproduced by heads which trace every other tracks (the ch1 and ch3 heads in the above-mentioned method), the ch1 and ch3 heads can be set in a good tracking state. However, other heads (the ch2 and ch4 heads offset by one track pitch from the ch1 and ch3 heads) may often cause an off-track state in accordance with their mounting precision.
As a second problem, the servo characteristics of a tracking control loop change due to a variation in reproduction output level caused by a reproduction level difference between the two pilot signals (frequencies f1 and f2), the performance of a tape to be used, and a difference in characteristic of the heads. In addition, the flutter characteristics in every four-track section of a capstan are impaired. In the conventional 4fATF method, as a countermeasure against these problems, a circuit for performing auto-gain control (AGC) of reproduction pilot signals by detecting pilot levels reproduced from main reproduction tracks has been put into practical application. However, in the new tracking method, since no pilot signals are recorded on tracks mainly traced by the ch1 and ch3 heads for obtaining reproduction pilot signals, the same arrangement as in the 4fATF method cannot be realized.
As a third problem, when information recorded by one head is reproduced by another head which has the same azimuth as that of the former head but is mounted at a different position like in a case wherein information recorded on a track using the ch1 head is reproduced by the ch3 head and vice versa, i.e., when a two-track offset occurs in tracking control, a position where the state of the ATF error signal becomes the same as an on-tracking state (back lock position) is present, and the presence of the back lock position disturbs satisfactory tracking control. In other words, a long period of time is required until the back lock position returns to a normal lock position, and an image is disturbed during this interval.
Furthermore, as a fourth problem, in the new tracking method, the pilot section requires four tracks to complete one cycle. For example, when a signal for one frame is divisionally recorded on 10 tracks, the pilot section and the frame section coincide with each other in units of two frames (20 tracks). In addition, when pilot signals are discontinuous in a joint recording portion, tracking control and an image are disturbed. As described above, in order to smoothly perform joint recording operations, a long preparation time is required.

Information recording reproducing apparatus using pilot signals to correct tracking error


A system, method and kit for managing RFID-tagged articles. The kit allows transforming a cabinet to an RFID-enabled cabinet. The transformation can be performed in the field. The RFID-enabled cabinet is fitted with a controller, communication means, one or more RFID readers, one or more antennae for reading RFID tags, and a multiplexer connecting the RFID reader and the antennae. Each antenna comprises a switch for activating and deactivating the antenna and a tuning board. No more than one antenna is activated at a given time thus avoiding interference between the different antennae. A central database can communicate with the RFID-enabled cabinets thus managing an inventory of RFID-enabled articles across multiple cabinets in multiple geographies.

Managing inventories of Radio Frequency Identification (RFID) tagged articles is a common practice in the industry. Numerous commercial applications exist for managing RFID-tagged inventories either in a warehouse type location or in a specific storage cabinet. Typically, the RFID tags are read by an RFID reader when articles enter or exit the warehouse or cabinet, or the warehouse or cabinet are sampled at certain time points in order to determine the inventory levels or specific conditions of the tagged-articles. For example, an RFID tag may contain information about the expiration date of the article, so it could be interesting to read all RFID tags in order to determine the expected shelf life of each article.
One of the main problems that companies marketing high-value items such as medical devices, pharmaceuticals and perfumes, need to overcome is the ability to control different pricing schemes in different geographical regions. Sometimes the difference in prices of the same item in different geographical locations can be very significant. Accordingly, one of the manufacturer's main concerns is to block the possibility of a product destined to be sold in a low price market finding its way to a high price market.
RFID-based inventory systems are common in the industry and a variety of implementations are known. Key-Trac's U.S. Pat. Nos. 6,707,381 and 6,407,665 disclose a container that registers access and exit of objects using a coupled computer outside or inside the container. Key-Trac's container does not include integrated processing capabilities.
American Greetings Corporation's U.S. Pat. No. 6,927,692 establishes a system for real-time management of an inventory with RFID tags using a computing component to manage inventory quantities. It does not provide time-based reports regarding the status of the inventory.
Safety Syringes' U.S. Pat. No. 6,935,560 establishes a medication dispensing unit coupled with a processor unit that registers entry and exit of medications, and issues alerts if inventory quantities fall below a certain threshold.
Techtalion Limited U.S. Pat. No. 6,650,240 discloses a briefcase with articles, wherein the presence of articles inside the briefcase is detected when desired. Alerts are issued if an article is missing. U.S. Pat. No. 6,650,240 only checks the presence or absence of objects when requested, and does not register events in real-time.
In situations where articles without RFID tags are stored in a non-RFID enabled cabinet, it may be easy to fit articles with RFID tags, but a regular cabinet cannot be fitted with efficient RFID reading means in the field. Rather, cabinets adapted to storing RFID-tagged articles are custom made and as such are priced accordingly.
Building a cabinet for storing RFID-tagged articles presents certain challenges to the manufacturer. Some of these challenges include: creating a full RF coverage of the storage areas of the cabinet; having the ability to locate inventory up to shelf level, even when the shelves are very closely located; overcome major RF issues mainly adapting RF antennas in an area where many antennas are on the same surface (fields of planar antennas on the same surface); overcome the influence of the physical location of the cabinet RFID performance; and having full flexibility on easily building any size of antenna needed at the cabinet.
As a result, the antenna or antennae in the cabinet need to be positioned in very specific places in the cabinet in order maximize the coverage of the storage area of the cabinet and minimize interference between the different antennae.
It would be desirable to be able to use existing cabinets and transform them in the field to RFID-enabled cabinets. It would also be desirable to enable the transformed cabinets to read RFID-tagged articles in multiple formats and protocols.
Organizations, such as hospitals, buying large quantities of disposable or renewable articles from different suppliers and manufacturers need to track diligently the inventory levels of these articles in order to replace on time articles that were either consumed or that their shelf life has ended.
On the other hand, suppliers of such disposable or renewable articles do not have a clear idea, and frequently have no idea, how their products are used within a customer organization. It would be highly valuable, for example, for a supplier to know that a given article is depleted or near depletion in one department since the supplier could ship necessary quantities of that article on time to that department.
Hospitals usually buy their medical devices from several suppliers or vendors and lately many hospitals are trying to move to a consignment procurement method. The new inventory methods oblige the hospital to provide suppliers and vendors with easy access to its current inventory level including inventory inside surgery rooms. This creates a great need of remote and seamlessly inventory control. This emerging need is greatly felt especially in the healthcare, telecommunications, and military industries.

System, method and kit for managing inventory


Method of making MMC components by an infiltration process, with a preform (3) which is disposed inside a crucible (6) and, optionally, held by a preform holder (2), being placed inside a pressure container (1), wherein the atmosphere inside the pressure container (1) is changeable during the production process, and after the infiltration metal (4) has melted on, the preform (3) is contained inside a sealed atmosphere in the presence of an oxygen-binding material.

The invention relates to a method of making MMC components by an infiltration process, with the preform which is disposed inside a crucible and, optionally, held by a preform holder, being placed inside a pressure container, wherein the atmosphere inside the pressure container is changeable during the manufacturing process.
Composite materials can be infiltrated with molten metal by applying gas under pressure to thereby produce so called metal matrix composites (MMC) are formed. Prior to such an infiltration process, the metal must be heated above its melting point so as to be able to permeate into the preform of the composite material. At the temperatures generated herein, the oxygen in the surrounding air, however, reacts with the metal surface, forming oxides which are detrimental to the properties of the formed component. In addition, the preforms themselves can react with the oxygen in the air. As a result, substances, like oxides, oxynitrides, oxycarbides, or the like are formed in dependence on the composition of the preform. These substances which are formed mainly on the surface of the preform, may adversely affect the open porosity which is required for the infiltration process to work. Consequently, as a result of the growth of these oxide compounds, the diameter of the pores may decrease to such extent that the pressure created by gas is no longer sufficient to overcome the capillary forces acting on the liquid infiltration metal, so that the infiltration metal can no longer migrate into the preform. In the worst case scenario, the aforedescribed oxidation processes may even completely seal the open pores.
The reaction between preform material and air alters thus in addition the material properties of the preform, thereby effecting an unintentional alteration of the physical and thermal properties, on the one hand, and complicating or eliminating the reproducibility of the desired material properties of the composite.
In order to eliminate this drawback, there is the possibility to evacuate the preform before the infiltration metal is melted on, to thereby expel the oxygen from the pores.
In another known process, the air (and thus the oxygen) is expelled from the preform by an inert gas purge. This process, however, is rather unreliable and time-consuming since it takes a long time until the oxygen molecules are adequately purged from the pores of the preform or of the preform holder.
In summary, both these processes are complex and time-consuming.

Electrovac, Fabrikation elektrotechnischer Spezialartikel Gesellschaft m.b.H.