A mobile communication system includes a plurality of radio base stations forming respective radio zones and a mobile station selecting a wait zone and a base station to which a request for a message channel is to be issued. Each of the plurality of radio base stations is assigned an order of priority. Information relating to the order of priority is used by the mobile station to select a wait zone and a base station to which a request for a message channel is to be issued.

1. Field of the Invention
The present invention generally relates to mobile communication systems and mobile station apparatuses, and, more particularly, to a mobile communication system in which a radio zone where a mobile station is to enter a wait state is determined by the electric field intensity of a received radio wave that arrives from a radio base station, and to a mobile station apparatus that receives communication service by accessing such a mobile communication system.
The present invention also relates to a mobile communication system wherein a mobile station selects a base station to which a request for a message channel is to be issued, based on announcement information from the base station.
2. Description of the Related Art
Recently, a variety of mobile stations including an automobile mobile station and a portable mobile station access a mobile communication system. With a competition between a plurality of carriers as a background, the number of mobile stations is increasing.
A mobile communication system may have a large-zone construction in which a base station covers a relatively wide service area or a small-zone construction in which a plurality of base stations cover a service area.
In a mobile communication system, radio base stations operated on a small transmission power and forming microcells or picocells are provided at the center of a big city characterized by a particularly large volume of traffic so that a multilayer cell is formed.
Radio base stations operated on a small transmission power are also provided in an underground passage and a tunnel in order to enlarge a radio zone sufficiently to eliminate a dead zone.
FIG. 1 shows a construction of a conventional mobile communication system.
Referring to FIG. 1, radio base stations 611 and 612 form adjacent radio zones 621 and 622, respectively. In the radio zone 621, a radio base station 613 forming a microcell 63 and a radio base station 614 forming a picocell 64 are provided so as to form a multilayer. Mobile stations 651-65N are located movable in the radio zones 621 and 622, the microcell 63 and the picocell 64.
In the radio base station 611, an antenna 661 is connected to an antenna terminal of a transmission and reception unit 681 via a common antenna equipment unit 671. A control terminal of the transmission and reception unit 681 is connected to an input and output terminal of a base station control device 691. A line terminal provided in the transmission and reception unit 681 and a communication port of the base station control device 691 are connected to a control station (not shown) via a transmission device 701 and a communication link 711.
Since the radio base stations 612-614 have the same construction as the radio base station 611, the corresponding elements are designated by using suffixes 2-4 in the description below, and the illustration and description thereof are omitted.
An antenna 721 of the mobile station 651, is connected to an antenna terminal of a transmission and reception unit 741 via a common antenna equipment unit 731. A modulated input and a demodulated output of the transmission and reception unit 741 are connected to a microphone 751 and a speaker 761, respectively. A control terminal of the transmission and reception unit 741 is connected to a control terminal of a control unit 771. An input and output terminal of the control unit 771 is connected to a display and operation unit 781.
Since the construction of the mobile stations 652-651 is the same as the mobile station 651, the corresponding elements are designated by using suffixes 2xe2x88x92N in the description below, and the illustration and description thereof are omitted.
The base station control device 691 of the radio base station 611 in the above-described mobile communication system is directed by a center (not shown) via the communication link 711 and the transmission device 701 to generate announcement information including a wait enabled level and a wait disabled level as shown in FIG. 2 and transmits the announcement information to a predetermined control radio channel (hereinafter, simply referred to as a control channel) via the transmission and reception unit 681, the antenna common equipment unit 671 and the antenna 661.
In addition to the wait enabled level and the wait disabled level, the announcement information also includes a message type identifying transmitted information as the announcement information, a mobile station transmission power specification specifying a transmission power of the mobile station, a location code indicating a location of the radio zone (service area), and the like. However, the information items other than the wait enabled level and the wait disabled level does not have to do with the present invention, and the description thereof is omitted.
The control unit 771 of the mobile station 651 maintains a control channel table listing all the radio channels over which the announcement information described above is transmitted from the radio base stations forming the respective radio zones to which the mobile station 651 may be located. Further, upon power-on, the control unit 771 measures sequentially the electric field intensity L1 of the control channel registered in the control table channel by controlling the transmission and reception unit 741 ((1) of FIG. 3). A determination is then made as to whether or not the measured electric field intensity is greater than a predetermined threshold level Lth ((2) of FIG. 3).
The control unit 771 registers the control channels for which a determination that the measured electric field intensity is greater than the threshold level Lth is obtained, in a prescribed area (hereinafter, referred to as a candidate zone register) in a main memory. The electric field intensity of the registered control channel is also registered in the candidate zone register so that the correspondence between the control channel and the associated electric field intensity is specified ((3) of FIG. 3).
When the control unit 771 has completed a series of the above-described processes (hereinafter, referred to as a measurement process) for all the control channels registered in the control channel table, the control unit 771 determines whether or not the candidate zone register stores any control channel ((4) of FIG. 3). If an affirmative answer is given, the control unit 771 sorts the entries in the candidate zone register according to the ascending order of the electric field intensity ((5) of FIG. 3).
The control unit 771 refers to the candidate zone register when the sorting process has been completed and receives the announcement information via the individual control channels registered in the candidate zone register ((6) of FIG. 3). The control unit 771 measures the electric field intensity again ((7) of FIG. 3). Further, the control unit 771 compares the electric field intensity L2 and the wait enabled level Lth included in the announcement information ((8) of FIG. 3). When the former is lower in level than the latter, a similar comparison is conducted for the other control channels registered in the candidate zone register ((9) of FIG. 3). Hereinafter, a series of processes performed subsequent to the measurement process is referred to as a zone determination process. The control unit 771 restarts the measurement process when the electric field intensity is found to be below the wait enabled level Lth for all the control channels subjected to the comparison ((10) of FIG. 3).
If the electric intensity field of any of the control channels is found to be equal to or exceeds the wait enabled level, the control unit 771 establishes that control channel as a control channel for the radio zone in which the mobile station is to register its location, issues a call and receives an incoming call ((11) of FIG. 3). Thereafter, the control unit 771 enter a wait state ((12) of FIG. 3).
The operations relating to registering of a location, issuing of a call or receiving of an incoming call performed by the mobile station 651 and the radio base station 611 are not directly related to the present invention, and the description thereof will be omitted below.
The operation performed by the radio base stations 612-614 is the same as the above-described operation of the radio base station 611, and the description thereof is omitted. Also, the operation performed by the mobile stations 652-65N is the same as the above-described operation of the mobile station 651, and the description thereof is omitted.
In the conventional system described above, if the mobile station 651 is located inside the microcell 63 and near the border with respect to the radio zone 621, as indicated by the broken line in FIG. 4, and if the electric field intensity of the radio wave arriving from the radio base station 611 is higher than that of the radio wave received from the radio base station 613, the mobile station 651 is set up for a wait in the radio zone 621. As illustrated, the radio zone 621 is formed outside the microcell 63 in which the mobile station 651 is actually located.
In such a case, the microcell 63 and the picocell 64 provided with the aim of handling a large volume of traffic are not accessed by the mobile station 651. The traffic otherwise handled by the microcell 63 is imposed as a load on the radio base station 611, thus causing the operating efficiency and the service quality to be dropped.
When the propagation loss of the radio wave that arrives at the mobile station 651 from the radio base station 611 increases due to the propagation characteristic of the radio transmission channel varying depending on the speed of the mobile station mobile station 651 and the path of the movement, the mobile station 651 may leave a zone when it is not necessary and performs the measurement process. Even when a call originated in the mobile station 651 becomes a successful call so that a conversation is established without the mobile station 651 leaving the zone, the speech quality may be dropped if there is a large propagation loss, with the result that switching of message channels occur too frequently during the conversation.
Given that the microcell 63 or the picocell 64 is provided in order to serve the dead area located inside the radio zone 621, the mobile station 651 may be set up for a wait in a radio zone located outside the cell (the microcell 63 or the picocell 64) in which the mobile station 651 is actually located. In this case, the microcell 63 or the picocell 64 remain unused so that the dead area is not efficiently served, a first aspect of the problem with the conventional mobile communication system.
A description will now be given, with reference to FIG. 5, of the flow of call origination operation in the conventional mobile communication system, in order to explain a second aspect of the problem with the conventional mobile communication system. In the following explanation of the second aspect, the PDC mobile communication system employed primarily in Japan is assumed.
In the conventional mobile communication system, when the user of a mobile station turns the power on (ST701), the mobile station measures a reception level of a perch channel provided for a base station (ST702). A perch channel is a term used in the PDC mobile communication system to refer to a channel provided for each of the base stations to allow a mobile station to determine a reception level with respect to the base station. In the PDC system, a perch channel is mainly used to transmit announcement information from the base station to the mobile station. The claims refer to a perch channel as a reception-level determining channel. If it is determined that the reception level exceeds a predetermined level (YES in ST703), the mobile station sorts the perch channels according to the ascending order of reception levels and stores the perch channels and the associated reception levels in a memory provided in the mobile station (ST704). A determination is then made as to whether the reception levels in all the perch channels have been measured (ST705).
If no perch channels and associated reception levels are stored in the memory (NO in S706), the mobile station displays an out-of-the-zone message in a display device (S707). When perch channels and associated reception levels are stored in the memory (YES in S706), the mobile station measures the reception level in the perch channel having the highest reception level according to the memory. If it is determined that the measured reception level exceeds a wait enabled level contained in the announcement information from the base station, the mobile stations is set up for a wait in the base station providing the highest reception level (S708).
The mobile station in a wait state sends a call request to the base station in which it is set up for a wait (S709). The mobile station notifies the base station of the perch channel codes and the reception levels provided by the base stations other than the notified base station.
If the level of reception from the mobile station issuing the request exceeds a predetermined level that enables assigning of a message channel (YES in S710), and if there is an unused message channel (YES in S711), the base station receiving the request from the mobile station assigns a message channel to the requesting mobile station (S712). If the level of reception from the mobile station is below the predetermined level (NO in S710), or if there is no unused message channel (NO in S711), the base station receiving the request refers to the reception levels of the adjacent base stations reported by the mobile station and designates one of the adjacent base stations as a base station for the requesting mobile station (S713).
The mobile station that receives, from the base station, a signal for assigning a message channel can use the assigned message channel to establish a call connection with the corresponding base station (S714).
Thus, the mobile station located at a point where there is an overlap of a plurality of zones formed by respective base stations is set up for a wait in the base station whose perch channel provides the highest reception level. When originating or receiving a call, the mobile station issues a request for a message channel to the base station in which the mobile station is set up for a wait.
However, it is not always best for the mobile station in the mobile communication system to issue a request for a message channel to the base station providing the highest reception level in the perch channel.
A relatively large service area formed, for example, by the base station A as shown in FIG. 31 is assumed. This large-zone construction formed by the base station A may include an area characterized by a concentrated traffic, resulting in a shortage of message channels in that area. In order to remedy this shortage, the base station B having a smaller transmission power and capable of forming a smaller-zone construction than the base station A is provided within the service area formed by the base station A. Provision of the base station B would serve the intended purpose if a mobile station within the zone formed by the base station B requests a message channel from the base station B.
However, a problem with the conventional mobile communication system is that the mobile station requests a message channel from the base station A providing a higher reception level than the base station B instead of requesting it from the base station B provided to handle an increased local traffic, with the result that the base station B remains unused to handle call originating or call incoming in the mobile station.
Accordingly, a general object of the present invention is to provide a mobile communication system and a mobile station apparatus in which the aforementioned problems of the conventional system are eliminated.
Another and more specific object of the present invention is to provide a mobile communication system and a mobile station apparatus in which a radio base station adapts itself to a dynamically established traffic distribution, or in which a mobile station can most successfully enter a radio zone in which it is actually located so as to be set up for a wait therein.
Still another object of the present invention is to assign order of priority to a plurality of base stations constituting a mobile communication system so that a mobile station requests a message channel from a base station having a higher priority than others in order to start communicating via that base station.
FIG. 6 is a block diagram of a mobile communication system according to claim 1 of the present invention. The mobile communication system according to claim 1 comprises a plurality of radio base stations 11-1N forming respective radio zones and effecting a radio channel setting control in accordance with a predetermined procedure, and a mobile station 2 selecting, as a wait zone, one of the radio zones that satisfies a criteria demanded by the predetermined procedure, and receiving communication service via the selected wait zone. Each of the radio base stations 11-1N comprises a traffic control unit 3 for setting a traffic distribution for the plurality of radio zones, and an announcing unit 4 for generating announcement information including the order of priority assigned to the plurality of radio zones, the order of priority being assigned in accordance with a probability density given to each of the plurality of radio zones under the distribution set by the traffic control unit 3, and for transmitting the announcement information to the radio zone formed by the radio station to which the announcing unit 4 belongs. The mobile station 2 comprises an announcement information receiving unit 5 for receiving the announcement information transmitted by the announcing unit 4 in accordance with the predetermined procedure, and a wait control unit 6 for selecting one of the radio zones as a wait zone, the radio zone to which a highest priority is assigned being a first candidate for selection by the wait control unit 6.
FIG. 7 shows a mobile communication system according to claim 2 of the present invention. The mobile communication system according to claim 2 comprises: a plurality of radio base stations 111-11N forming one or a plurality of radio zones and one or a plurality of small-scale radio zones, resulting in a hierarchy of overlapping radio zones, and effecting a radio channel setting control in accordance with a predetermined procedure; and a mobile station 12 accessing one of the radio zones formed by the respective one of the plurality of radio base stations 111-11N, in accordance with a predetermined procedure, and receiving communication service via the accessed radio zone. Each of the plurality of radio base stations 111-11N comprises an announcing unit 13 for transmitting announcement information which includes identification information for identifying radio channels assigned to respective radio zones and small-scale radio zones, via the radio channel assigned to the radio zone formed by the radio base station to which the announcing unit 13 belongs, the identification information being arranged in the announcement information so as to correspond to the hierarchy of overlapping radio zones. The mobile station 12 comprises: an announcement information receiving unit 14a for receiving the announcement information transmitted by the announcing unit 13a, in accordance with the procedure for radio channel setting control; a measuring unit 15a for measuring an electric field intensity for the radio channel corresponding to the identification information included in the announcement information received by the announcement information receiving unit 14a; and a wait control unit 16a for comparing an electric field intensity measured by the measuring unit 15a with a preset threshold level, and designating a radio zone to which the radio channel lowest in the hierarchy is assigned as a wait zone in which to receive the communication service, on the condition that the electric field intensity measured by the measuring unit 15a exceeds the preset threshold level.
The mobile communication system according to claim 3 comprises: a plurality of radio base stations 111-11N forming one or a plurality of radio zones and one or a plurality of small-scale radio zones, resulting in a hierarchy of overlapping zones, and effecting a radio channel setting control in accordance with a predetermined procedure; and a mobile station 12 accessing one of the radio zones formed by the respective one of the plurality of radio base stations 111-11N in accordance with a predetermined procedure, and receiving communication service via the accessed radio zone. Each of the plurality of radio base stations 111-11N comprises an announcing unit 13a for transmitting announcement information which includes identification information for identifying the one or the plurality of radio zones and the one or the plurality of small-scale radio zones, via the radio channel assigned to the radio zone formed by the radio base station to which the announcing unit 13a belongs, the identification information being arranged in the announcement information according to respective positions in the hierarchy of overlapping zones. The mobile station 12 comprises: an announcement information receiving unit 14a for receiving the announcement information transmitted by the announcing unit 13a, in accordance with the procedure for radio channel setting control; a measuring unit 15a for measuring an electric field intensity for the radio zone corresponding to the identification information included in the announcement information received by the announcement information receiving unit 14a; and a wait control unit 16a for comparing an electric field intensity measured by the measuring unit 15a with a preset threshold level, and designating, as a wait zone in which to receive the communication service, a radio zone lowest in the hierarchy of overlapping zones on the condition that the electric field intensity measured by the measuring unit 15a exceeds the threshold level.
The mobile communication system according to claim 4 comprises: a plurality of radio base stations 111-11N forming one or a plurality of radio zones and one or a plurality of small-scale radio zones, resulting in a hierarchy of overlapping zones, and effecting a radio channel setting control in accordance with a predetermined procedure; and a mobile station 12 accessing one of the radio zones formed by the respective one of the plurality of radio base stations 111-11N in accordance with a predetermined procedure, and receiving communication service via the accessed radio zone. Each of the plurality of radio base stations 111-11N comprises an announcing unit 13b for transmitting announcement information which includes identification information for identifying radio channels for the one or the plurality of radio zones and the one or the plurality of small-scale radio zones, via the radio channel assigned to the radio zone formed by the radio base station to which the announcing unit 13b belongs, the identification information being arranged in the announcement information according to respective positions in the hierarchy of overlapping zones. The mobile station 12 comprises: an announcement information receiving unit 14b for receiving the announcement information transmitted by the announcing unit 13b, in accordance with the procedure for radio channel setting control; a measuring unit 15b for measuring an electric field intensity for the radio channel corresponding to the identification information included in the announcement information received by the announcement information receiving unit 14b; and a wait control unit 16b for comparing an electric field intensity measured by the measuring unit 15b with a preset threshold level, and designating one of the radio channels, which is assigned to the radio zone lowest in the hierarchy and for which the control unit 16b has determined that the electric field intensity measured by the measuring unit 15b exceeds the preset threshold level, as a radio channel via which to receive the communication service.
The mobile communication system according to claim 5 comprises: a plurality of radio base stations 111-11N forming one or a plurality of radio zones and one or a plurality of small-scale radio zones, resulting in a hierarchy of overlapping zones, and effecting a radio channel setting control in accordance with a predetermined procedure; and a mobile station 12 accessing one of the radio zones formed by the respective one of the plurality of radio base stations 111-11N, in accordance with a predetermined procedure, and receiving communication service via the accessed radio zone. Each of the plurality of radio base stations 111-11N comprises an announcing unit 13c for transmitting announcement information which includes identification information for identifying the one or the plurality of radio zones and the one or the plurality of small-scale radio zones, via the radio channel assigned to the radio zone formed by the radio base station to which the announcing unit 13c belongs, the identification information being arranged in the announcement information according to respective positions in the hierarchy of overlapping zones. The mobile station 12 comprises: an announcement information receiving unit 14c for receiving the announcement information transmitted by the announcing unit 13c, in accordance with the procedure for radio channel setting control; a measuring unit 15c for measuring an electric field intensity for the radio zone corresponding to the identification information included in the announcement information received by the announcement information receiving unit 14c; and a wait control unit 16c for comparing an electric field intensity measured by the measuring unit 15c with a preset threshold level, and designating, as a wait zone in which to receive the communication service, a radio zone identified by the identification information to be lowest in the hierarchy of overlapping zones, on the condition that the electric field intensity measured by the measuring unit 15a exceeds the threshold level.
The mobile communication system according to claim 6 comprises: a plurality of radio base stations 111-11N forming one or a plurality of radio zones and one or a plurality of small-scale radio zones, resulting in a hierarchy of overlapping zones, and effecting a radio channel setting control in accordance with a predetermined procedure; and a mobile station 12 accessing one of the radio zones formed by the respective one of the plurality of radio base stations 111-11N, in accordance with a predetermined procedure, and receiving communication service via the accessed radio zone. Each of the plurality of radio base stations 111-11N comprises an announcing unit 13d for transmitting announcement information which includes first identification information for identifying a radio channel assigned to the radio zone formed by the radio base station to which the announcing unit 13d belongs, as well as including second identification information identifying the radio zones and the small-scale radio zones which overlap the radio zone formed by the radio base station to which the announcing unit 13d belongs, via the radio channel assigned to the radio zone formed by the radio base station to which the announcing unit 13d belongs, the second identification information being arranged in the announcement information according to respective positions in the hierarchy of overlapping zones. The mobile station 12 comprises: an announcement information receiving unit 14d for receiving the announcement information transmitted by the announcing unit 13d, in accordance with the procedure for radio channel setting control; a measuring unit 15d for measuring an electric field intensity for the radio channel corresponding to the identification information included in the announcement information received by the announcement information receiving unit 14d; and a wait control unit 16d for comparing an electric field intensity measured by the measuring unit 15d with a preset threshold level, determining the radio channel which is identified by the associated second identification information, if available, to have a lowest hierarchical order, and designating, as a wait zone in which to receive the communication service, the radio zone to which the determined radio channel is assigned, on the condition that the electric field intensity measured by the measuring unit 15d exceeds the threshold level.
The mobile communication system according to claim 7 comprises: a plurality of radio base stations 111-11N forming one or a plurality of radio zones and one or a plurality of small-scale radio zones, resulting in a hierarchy of overlapping zones, and effecting a radio channel setting control in accordance with a predetermined procedure; and a mobile station 12 accessing one of the radio zones formed by the respective one of the plurality of radio base stations 111-11N in accordance with a predetermined procedure, and receiving communication service via the accessed radio zone. Each of the plurality of radio base stations 111-11N comprises an announcing unit 13e for transmitting announcement information which includes first identification information for identifying a radio channel assigned to a radio zone formed by the radio base station to which the announcing unit 13e belongs, as well as including second identification information identifying the radio zones and the small-scale radio zones which overlap the radio zone formed by the radio base station to which the announcing unit 13e belongs, over the radio zone formed by the radio base station to which the announcing unit 13e belongs, the second identification information being arranged in the announcement information according to respective positions in the hierarchy of overlapping zones. The mobile station 12 comprises: an announcement information receiving unit 14e for receiving the announcement information transmitted by the announcing nit 13e, in accordance with the procedure for radio channel setting control; a measuring unit 15e for measuring an electric field intensity for the radio zone corresponding to the identification information included in the announcement information received by the announcement information receiving unit 14e; and a wait control unit 16e for comparing an electric field intensity measured by the measuring unit 15e with a preset threshold level, determining the radio zone corresponding to the radio channel which is identified by the associated second identification information, if available, to have a lowest hierarchical order, and designating the determined radio zone as a wait zone in which to receive the communication service on the condition that the electric field intensity measured by the measuring unit 15e exceeds the threshold level.
The mobile communication system according to claim 8 comprises: a plurality of radio base stations 111-11N forming one or a plurality of radio zones and one or a plurality of small-scale radio zones, resulting in a hierarchy of overlapping zones, and effecting a radio channel setting control in accordance with a predetermined procedure; and a mobile station 12 accessing one of the radio zones formed by the respective one of the plurality of radio base stations 111-11N, in accordance with a predetermined procedure, and receiving communication service via the accessed radio zone. Each of the plurality of radio base stations 111-11N comprises an announcing unit 13f for transmitting announcement information which includes a hierarchical (equal or subordinate) order of the radio zone formed by the radio base station to which the announcing unit 13f belongs with respect to the overlapping radio zones and small-scale radio zones, and which also includes identification information for identifying radio channels assigned to the radio zone formed by the radio base station to which the announcing unit 13f belongs and the overlapping radio zones and small-scale radio zones, via the radio channel assigned to the radio zone formed by the radio base station to which the announcing unit 13f belongs. The mobile station 12 comprises: an announcement information receiving unit 14f for receiving the announcement information transmitted by the announcing unit 13f, in accordance with the procedure for radio channel setting control, for extracting the identification information from the announcement information, and for determining the hierarchy of the radio zones to which the radio channels identified by the identification information are assigned; a measuring unit 15f for measuring an electric field intensity for the radio channel corresponding to the identification information obtained by the announcement information receiving unit 14f; and a wait control unit 16f for comparing an electric field intensity measured by the measuring unit 15f with a preset threshold level, and designating a radio zone to which the radio channel lowest in the hierarchy is assigned as a wait zone in which to receive the communication service, on the condition that the electric field intensity measured by the measuring unit 15f for the radio channel lowest in the hierarchy exceeds the preset threshold level.
The mobile communication system according to claim 9 comprises: a plurality of radio base stations 111-11N forming one or a plurality of radio zones and one or a plurality of small-scale radio zones, resulting in a hierarchy of overlapping zones, and effecting a radio channel setting control in accordance with a predetermined procedure; and a mobile station 12 accessing one of the radio zones formed by the respective one of the plurality of radio base stations 111-11N, in accordance with a predetermined procedure, and receiving communication service via the accessed radio zone. Each of the plurality of radio base stations 111-11N comprises an announcing unit 13g for transmitting announcement information which includes a hierarchical (equal or subordinate) order of the radio zone formed by the radio base station to which the announcing unit 13g belongs with respect to the overlapping radio zones and small-scale radio zones, and which also includes identification information for identifying the radio zone formed by the radio base station to which the announcing unit 13g belongs and the overlapping radio zones and small-scale radio zones, over the radio zone formed by the radio base station to which the announcing unit 13g belongs. The mobile station 12 comprises: an announcement information receiving unit 14g for receiving the announcement information transmitted by the announcing unit 13g, in accordance with the procedure for radio channel setting control, for extracting the identification information from the announcement information, and for determining the hierarchy of the radio zones corresponding to the identification information; a measuring unit 15g for measuring an electric field intensity for the radio zone corresponding to the identification information extracted by the announcement information receiving unit 14g; and a wait control unit 16g for comparing an electric field intensity measured by the measuring unit 15g with a preset threshold level, and designating a radio zone lowest in the hierarchy determined by the announcement information receiving unit 14g as a wait zone in which to receive the communication service, on the condition that the electric field intensity measured by the measuring unit 15g for the radio zone lowest in the hierarchy exceeds the preset threshold level.
The announcing unit of the mobile communication system according to claim 10 comprises a unit for adding, in the announcement information, preset threshold values individually provided for the radio zone formed by the radio base station to which the announcing unit belongs and the overlapping radio zones and small-scale radio zones, resulting in a hierarchy that corresponds to the hierarchy of overlapping zones. The wait control unit 16 employs the threshold values added to the announcement information by the announcing unit in making comparisons with the electric field intensity.
The announcing unit of the mobile communication system according to claim 11 comprises a unit for adding a relative value indicating the preset threshold value for the zone formed by the radio base station to which the announcing unit belongs, in the form of a difference with respect to a reference value for the threshold value. The announcement information receiving unit includes a unit for determining the relative value added to the announcement information, in relation to the radio zone in which the announcement information is received. The wait control unit compares the electric field intensity measured by the measuring unit with a sum of the reference value and the relative value determined by the announcement information receiving unit in relation to the radio zone in which the electric field intensity is measured.
The announcing unit of the mobile communication system according to claim 12 comprises a unit for adding relative values indicating the preset threshold values for the radio zone formed by the radio base station to which the announcing unit belongs and the overlapping radio zones and small-scale radio zones, in the form of differences with respect to a reference value common to the threshold values, resulting in a hierarchy that corresponds to the hierarchy of overlapping zones. The wait control unit compares the electric field intensity with a sum of the relative value and the reference value.
The mobile station 12 of the mobile communication system according to claim 13 comprises a zone determination unit 17 for performing a cyclic measurement of the electric field intensity of the radio zones in which the mobile station 12 can be located, comparing a measured electric field intensity with a lower acceptance value by which an entry into the radio zone is enabled, stopping processes of measurement and comparison when it is found that the former exceeds the latter, and selecting the associated radio zone as a candidate in which the announcement information receiving unit 14 is to receive the announcement information.
The wait control unit of the mobile communication system according to claim 14 compares the electric field intensity measured by the measuring unit with the threshold value in the descending order of the hierarchy in the radio zones subject to the measurement, and designates the radio zone for which it is found that the former exceeds the latter as a wait zone.
The measuring unit of the mobile communication system according to claim 15 comprises a unit which omits a measurement of the radio zone selected by the zone determination unit 17 and substitutes therefor the electric field intensity measured by the zone determination unit.
FIG. 8 is a block diagram showing the invention described in claim 16.
The mobile station according to claim 16 comprises an announcement information receiving unit 21 for receiving announcement information including orders of priority assigned to radio zones formed by a plurality of radio base stations, the reception by the announcement information receiving unit 21 being conducted according to a descending order of preset traffic distribution and in accordance with a radio channel setting control procedure; a wait unit 23 for determining whether the radio zone associated with the order of priority included in the announcement information received by the announcement information receiving unit 21 satisfies a criteria adapted for the radio channel setting control procedure, and for designating the radio zone for which an affirmative answer is given as a wait zone; and a communication control unit 25 which receives communication service from the radio base station forming the radio zone designated by the wait unit 23.
The mobile communication system according to claim 17 comprises: a plurality of base stations forming respective radio zones that overlap each other; a mobile station transportable between said radio zones; wherein each of said plurality of base stations comprises: announcing means for sending announcement information including an order of priority of said plurality of base stations to the mobile station located in one of said radio zones, and said mobile station comprises: control means for selecting the base station to which a request for a message channel is to be issued, based on the order of priority of the base stations included in the announcement information transmitted from said plurality of base stations.
According to this aspect of the present invention, the base station as shown in FIG. 31 in which the mobile station is set up for a wait transmits the announcement information that includes the order of priority specifying, for example, that the base station B be given the priority over the base station A in selecting a base station from which to request a message channel. Therefore, the mobile station requests a message channel from the base station B in accordance with the order of priority included in the announcement information from the base station A.
Since the mobile station requests a message channel from the base station B instead of the base station A providing a higher reception level, the base station B can be used efficiently to handle call originating and call incoming in the mobile station.
The mobile station according to claim 18 further comprises: announcement information receiving means for receiving the announcement information including the order of priority of said plurality of base stations and transmitted from said plurality of base stations; and transmission means for issuing a request for a message channel to the base station selected by said control means.
According to this aspect of the present invention, the announcement information receiving means of the mobile station receives the announcement information including the order of priority of the base stations from, for example, the base station A and the base station B as shown in FIG. 31. The transmission means of the mobile station transmits a request for a message channel from a base station selected by the control means. For example, the mobile station may send the request to the base station B having the highest priority.
The mobile station according to claim 19 further comprises: storage means for storing the announcement information; measuring means for measuring a reception level in reception-level determining channels in a descending order of priority of said plurality of base stations, based on the announcement information stored in said storage means and including the order of priority and based on information relating to the reception-level determining channels.
According to this aspect of the present invention, the memory means of the mobile station stores the announcement information received by the announcement information receiving means from, for example, the base station A and the base station B as shown in FIG. 31 and including the order of priority of the base stations. Measurement of the reception level by the measuring means starts with the base station B having the highest priority, based on the order of priority of the base stations A and B stored in the storing means and the information relating to the perch channel corresponding to the respective base stations. The measuring means notifies the control means of the reception level.
Therefore, the mobile station stores the order of priority of the base stations included in the announcement information received by the announcement information receiving means and notifies the control means of the reception level so that selection can be made on the base station to which a request for a message channel is to be issued. In this way, the control means is able to select the base station B to which the request should be sent.
The control means according to claim 20 includes determining means for determining whether the reception level in a reception-level determining channel is equal to or exceeds a predetermined level that enables a request for a message channel.
According to this aspect of the present invention, the control means of the mobile station can determine whether the reception level of the perch channel of, for example, the base station A or the base station B as shown in FIG. 31 is equal to or exceeds a predetermined level.
The announcing means according to claim 21 includes first arranging means for ordering the announcement information so as to arrange information relating to reception-level determining channels in a descending order of priority.
According to this aspect of the present invention, the announcing means of, for example, the base station A as shown FIG. 31 can order the announcement information such that information relating to the perch channel of the base station A and that of the base station B are arranged in the order of priority.
The announcing means according to claim 22 includes second arranging means for ordering the announcement information so as to couple information relating to each reception-level determining channel to an order of priority associated therewith.
According to this aspect of the present invention, the announcing means of, for example, the base station A as shown in FIG. 31 can order the announcement information such that information relating to the perch channel of the base station A is coupled to the priority assigned thereto and information relating to the perch channel of the base station B is coupled to the priority assigned thereto.
The transmission means according to claim 23 includes first transmission means for issuing a request for a message channel to the base station selected by the control means when a call is originated.
According to this aspect of the present invention, the control means of the mobile station as shown in FIG. 31 can select the base station B assigned the highest priority when the mobile station originates a call, so that the transmission means can request a message channel from the base station B.
The transmission means according to claim 24 includes second transmission means for issuing a request for a message channel to the base station selected by the control means when a call is incoming.
According to this aspect of the present invention, the control means of the mobile station as shown in FIG. 31 can select the base station B assigned the highest priority when the mobile station receives an incoming call, so that the transmission means can request a message channel from the base station B.
The transmission means according to claim 25 includes third transmission means for transmitting a request for a communication to the base station selected by the control means when a message channel is switched from one to another in the event of a handover of a call.
According to this aspect of the present invention, the control means of the mobile station as shown in FIG. 31 can select the base station B assigned the highest priority when a switching of channels occurs in the event of a handover, so that the transmission means can request a message channel from the base station B.
The mobile station according to claim 26 comprises control means for selecting a base station to which a request for a message channel is to be issued, based on an order of priority of a plurality of base stations included in announcement information from said plurality of base stations.
Referring to 31, based on the announcement information from the base station A including the order of priority of the base stations A and B, the mobile station can request a message channel from the base station B instead of the base station A providing a higher reception level. Thus, the base station B, provided to handle an increased local traffic, can be efficiently used to handle call originating and call incoming in the mobile station.
The mobile station according to claim 27 comprises: announcement information receiving means for receiving, from said plurality of base stations, the announcement information including the order of priority of said plurality of base stations; and transmission means for transmitting a request for a message channel to the base station selected by said control means.
According to this aspect of the present invention, the announcement information receiving means of the mobile station receives the announcement information including the order of priority of the base stations from, for example, the base station A and the base station B as shown in FIG. 31. The transmission means of the mobile station transmits a request for a message channel from a base station selected by the control means. For example, the mobile station may send the request to the base station B having the highest priority.
The mobile station according to claim 28 comprises: storage means for storing the announcement information; measuring means for measuring a reception level in reception-level determining channels in a descending order of priority of said plurality of base stations, based on the announcement information stored in said storage means and including the order of priority and based on information relating to the reception-level determining channels.
According to this aspect of the present invention, the memory means of the mobile station stores the announcement information received by the announcement information receiving means from, for example, the base station A and the base station B as shown in FIG. 31 and including the order of priority of the base stations. Measurement of the reception level by the measuring means starts with the base station B having the highest priority, based on the order of priority of the base stations A and B stored in the storing means and the information relating to the perch channel corresponding to the respective base stations. The measuring means notifies the control means of the reception level.
Therefore, the mobile station stores the order of priority of the base stations included in the announcement information received by the announcement information receiving means and notifies the control means of the reception level so that selection can be made on the base station to which a request for a message channel is to be issued. In this way, the control means is able to select the base station B to which the request should be sent.
The control means according to claim 29 includes determining means for determining whether the reception level in a reception-level determining channel is equal to or exceeds a predetermined level that enables a request for a message channel.
According to this aspect of the present invention, the control means of the mobile station can determine whether the reception level of the perch channel of, for example, the base station A or the base station B as shown in FIG. 31 is equal to or exceeds a predetermined level.
The transmission means according to claim 30 includes first transmission means for issuing a request for a message channel to the base station selected by the control means when a call is originated.
According to this aspect of the present invention, the control means of the mobile station as shown in FIG. 31 can select the base station B assigned the highest priority when the mobile station originates a call, so that the transmission means can request a message channel from the base station B.
The transmission means according to claim 31 includes second transmission means for issuing a request for a message channel to the base station selected by the control means when a call is incoming.
According to this aspect of the present invention, the control means of the mobile station as shown in FIG. 31 can select the base station B assigned the highest priority when the mobile station receives an incoming call, so that the transmission means can request a message channel from the base station B.
The transmission means according to claim 32 includes third transmission means for transmitting a request for a communication to the base station selected by the control means when a message channel is switched from one to another in the event of a handover of a call.
According to this aspect of the present invention, the control means of the mobile station as shown in FIG. 31 can select the base station B assigned the highest priority when a switching of channels occurs in the event of a handover, so that the transmission means can request a message channel from the base station B.
The base station according to claim 33 comprises: announcing means for sending announcement information including an order of priority of a plurality of base stations constituting the mobile communication system to a mobile station located in one of the radio zones.
A mobile communication system as shown in FIG. 31 is assumed. The base station A forms a relatively large service area (zone) and a base station B having a smaller transmission power than the base station A forms a relatively small service area (zone) inside the service area formed by the base station A. The mobile station is set up for a wait in the base station A. According to the invention of claim 33, the base station A can transmit the announcement information including the order of priority of the base stations. For example, the base station B could be given a higher priority over the base station A according to the announcement information.
The announcing means according to claim 34 includes first arranging means for ordering the announcement information so as to arrange information relating to reception-level determining channels in a descending order of priority.
According to this aspect of the present invention, the announcing means of, for example, the base station A as shown FIG. 31 can order the announcement information such that information relating to the perch channel of the base station A and that of the base station B are arranged in the order of priority.
The announcing means according to claim 35 includes second arranging means for ordering the announcement information so as to couple information relating to each reception-level determining channel to an order of priority associated therewith.
According to this aspect of the present invention, the announcing means of, for example, the base station A as shown in FIG. 31 can order the announcement information such that information relating to the perch channel of the base station A is coupled to the priority assigned thereto and information relating to the perch channel of the base station B is coupled to the priority assigned thereto.

Mobile communication system enabling efficient use of small-zone base stations


A method of upgrading a 1,500 rpm reactor coolant pump motor having a vertically oriented rotor shaft supported by a lower guide bearing disposed in an oil reservoir. The method includes removing a lower guide bearing support to enhance circulation of the oil to facilitate cooling of the oil and operating the reactor coolant pump motor at 1,500 rpm without the lower guide bearing support or the oil baffle or flinger ring attached to the lower guide bearing support. The method further includes thickening a keeper to support the guide bearing.

1. Field of the Invention
This present invention relates in general to nuclear reactor main coolant pumps and in particular to such coolant pumps that have vertically oriented shafts with lower guide bearings. More particularly, the invention relates to such main reactor coolant pumps that operate at 1,500 rpm.
2. Description of Related Art
The reactor main coolant pump motors drive the reactor main coolant pumps which are part of the primary reactor coolant system in a pressurized water reactor nuclear power plant. The motors are typically arranged with vertical shafts. The bearing and lubrication system of a vertical motor is usually contained in two separate oil pots (also referred to as oil reservoirs). An upper oil pot contains the upper guide or radial bearings and the total thrust bearing system. The lower oil pot contains the lower guide or radial bearings. Each of these oil pots is typically provided with cooling coils for carrying cooling water to dissipate the heat which is generated by the bearing systems.
The design of the oil pots is such that the oil level within the pot should be monitored during operation to ensure that the oil level is not rising above or falling below the expected levels. A rising level might indicate, for example, a water leak within the cooling coils which results in water entering the pot and mixing with the oil. If such a situation were to persist, the lubricating ability of the oil would be sharply diminished and, more importantly, the oil/water mixture would overflow the pot and migrate toward the hot reactor coolant pump, where a fire could result.
Reactor coolant pump motors that normally operate at 1,500 rpm, are installed at many facilities outside the United States wherever grid electrical power is supplied at 50 Hz. In comparison, the corresponding reactor main coolant pumps installed in the United States where the grid electrical power is supplied at 60 Hz, operate at 1,200 rpm. One type of 1,500 rpm vertically oriented reactor coolant pump motor has a baffle and support arrangement between the lower guide bearings and the lower portion of the oil pot that contains the cooling coils, to reduce turbulence of the oil that was an anticipated result from the increased speed of the coolant pumps and to avoid oil splashing over the edges of the pot and possibly migrate toward the hot reactor coolant pump where a fire could result. The lower guide bearings in these 1,500 rpm motors historically have exhibited higher than expected operating temperatures at the bearing pads. The overheating cannot be explained by the difference in speed alone. While these higher temperatures have not been known to affect operability, they typically are greater than the specified normal operating temperature of 160° F. (71.21° C.) and may run close to the normal alarm point of 190° F. (87.8° C.) when their oil cooler component cooling water approaches the maximum normal operating temperature of 105° F. (40.6° C.). These temperatures are typically achieved with component cooling water flow rates of 6 GPM nominal. The high operating temperatures may have adverse consequences for long-term bearing, shaft and oil performance, particularly with sustained component cooling water temperatures at or near maximum. Based on the principles of fluid mechanics and heat transfer and experience with over 150 60Hz reactor coolant pump motors, the inventors have concluded that these high lower guide bearing temperatures are due to the lack of oil flow within the reservoir caused by three components that do not exist in the 1,200 rpm motors. These three components isolate the portion of the oil reservoir that contains the bearings from the portion that contains the oil cooler, except for some relatively small passages in and between these components and the remaining parts of the lower guide bearing assembly.
Accordingly, it is an object of this invention to improve the oil circulation within the lower guide bearing oil pots to reduce the operating temperatures of the lower guide bearings.
It is a further object of this invention to improve the circulation of the oil within the lower guide bearing oil pot without increasing the turbulence of the oil to the point where the oil splashes over the edges of the pot.
It is an additional object of this invention to achieve the foregoing objectives without reducing the support for the bearing.

Reactor coolant pump motor load-bearing assembly configuration


Disclosed is a disc brake including a carrier on which a pair of pad plates are movably installed and a caliper housing, which is slidably installed on the carrier and is provided with a cylinder having a piston mounted so as to move forward and backward by a hydraulic braking pressure, the disc brake including: an adjuster installed in the piston to prevent the pad plates from moving away from a disc and to maintain the pad plates at a constant distance from the disc; a push rod installed in the cylinder, a front portion thereof being screw-coupled to the adjuster and a rear portion thereof being provided with a flange extending toward an inner circumferential surface of the cylinder; a ramp unit into which the rear portion of the push rod is inserted and which is installed in the cylinder and compresses the push rod toward the piston in cooperation with a parking cable to prevent rotation of the push rod; a spring case having an end portion of one side thereof fixed to the cylinder and forming a predetermined accommodation space between the inner circumferential surface of the cylinder and the push rod; a first elastic member and a second elastic member arranged in series with each other in the accommodation space of the spring case to provide elastic force to the push rod; and a support plate supported by an end portion of the ramp unit and interposed between the first elastic member and the second elastic member.

1. Field
Embodiments of the present invention relate to a disc brake, and more particularly, to a disc brake capable of stably returning a piston after a braking operation is terminated while improving the effect of return of a piston.
2. Description of the Related Art
A disc brake is an apparatus for braking a vehicle by forcedly causing friction pads to be pressed against both sides of a disc that rotates together with a wheel of the vehicle to stop the disc rotating. In the disc brake, a parking brake configured to keep a vehicle stationary is used at the time of parking.
In general, a disc brake includes one pair of pad plates disposed at both sides of a disc that rotates with a wheel of a vehicle and compress the disc to generate a braking force, a carrier supporting the pad plates, a caliper housing slidably installed on the carrier to compress the pad plates and equipped with a piston moved by hydraulic braking pressure, and an actuator configured to operate the piston in a mechanical manner.
The actuator is connected to a parking cable for operating the actuator, and the parking cable is manually or automatically operated by being connected to a parking cable manipulating apparatus that is operated by a parking lever directly manipulated by a driveror an electro motive apparatus.
There are two types of actuating. One is a cam-strut actuating that uses a cam rotated by operation of a parking cable and a strut installed between the cam and a piston. The other is a ball-in-ramp actuating that includes a fixed ramp plate fixedly installed in a caliber housing, a rotating ramp plate rotated by operation of a parking cable, a ball installed between the fixed ramp plate and the rotating ramp plate to advance the rotating ramp plate at the time of rotation of the rotating ramp plate, a push rod provided adjacent to the rotating ramp plate to push a piston, and a spring returning the push rod to the original position thereof.
In general, the ball-in-ramp scheme is referred to as a BIR (ball-in-ram) caliper type, and BIR caliper type disc brake is disclosed in Korean Patent Publication No. 10-2011-0029267. According to the disclosure, a rotating ramp plate pushes a push rod by rotating and advancing, and the push rod pushes a piston such that disc pads come into close contact with a disc.
The BIR caliper type disc brake does not have a subsidiary member securing a predetermined running clearance between a disc and pad plates in the initial braking, which causes friction pads installed on the pad plate to unnecessarily make friction with the disc, leading to abrasion of the friction pads and noise resulting therefrom. In addition, a short restoring distance at the time of releasing the brake leads to a drag in which the friction pads are not sufficiently separated from the disc and thus the friction pads are worn out.


A microchip to be used for measuring a plurality of types of objects to be measured. The microchip includes at least a reagent retaining portion and a detecting portion. The test reagent retaining portion includes a plurality of types of test reagents corresponding respectively to the plurality of types of objects to be measured. A plurality of time courses for a change in detected value at the detecting portion caused by a reaction between the test reagents and the objects to be measured corresponding respectively thereto are all different from each other.

1. Field of the Invention
The present invention relates to a microchip, measurement system and method using the same, and a test reagent that is used for a microchip. A microchip is used for biochemical tests of DNA, protein, cell, immunity, blood, and the like as well as environmental analysis and chemical synthesis, for example.
2. Description of the Background Art
In recent years, in the fields of medical care, health, food, drug discovery, and the like, detection or quantitation of biological substances such as DNA (Deoxyribo Nucleic Acid), enzyme, antigen, antibody, protein, virus, and cell as well as chemical substances has become increasingly important, and various biochips and micro chemical chips (such chips will hereinafter be collectively referred to as microchip) with which the above-described substances can be easily and conveniently measured have been proposed.
The microchip can be used to allow a series of experimental and analytical operations usually performed in a laboratory to be conducted within the chip of several centimeters to 10 centimeters per side and approximately several millimeters to several centimeters in thickness. The microchip accordingly provides many advantages that the amounts of samples and reagents to be used are very small, the cost is low, the reaction rate is high, high throughput test or analysis can be conducted, and the test results can be immediately obtained at the site where the sample was taken, for example.
The microchip has a fluid circuit therein. The fluid circuit is mainly constituted of: portions including, for example, a reagent retaining portion for retaining a test reagent to be mixed or reacted with a sample (such as blood) to be tested or analyzed or to treat the sample, a measuring portion for measuring the sample and/or test reagent, a mixing portion for mixing the sample and the test reagent together, and a detecting portion for testing or analyzing the liquid mixture; and a fine fluid channel appropriately connecting these portions. For use, the microchip is mounted typically in a device that can apply a centrifugal force thereto. By applying a centrifugal force in an appropriate direction to the microchip, treatments such as measurement of a sample (or a specific component in the sample) and/or a test reagent, mixing of the sample (or a specific component in the sample) and the test reagent together, and introduction of the obtained liquid mixture into the detecting portion can be performed. It is noted that treatments of various fluids (such as a sample, a specific component in the sample, a test reagent, or a mixture or a reactant of two or more types thereof) performed in the microchip, such as transfer from a portion to any other portion, measurement, and mixing of the fluids will hereinafter sometimes be referred to as "fluid treatment".
Various microchips including such a fluid circuit have been disclosed (see for example Japanese Patent Laying-Open No. 2006-239538). However, in a measurement method using such a conventional microchip, one detecting portion (optical cell) has been able to perform measurement on only one test item. Thus, in order to perform measurement on a plurality of test items, a plurality of optical cells (cuvettes), optical systems, and the likes have been required.
In addition, in such a case where a fluid treatment is performed by application of a centrifugal force, when a metal colloid reagent is used as a test reagent, since metal has a specific gravity (e.g., Au: 19.3, Pt: 21.45, Ag: 10.49) that is greater than the water's specific gravity of 1, application of a centrifugal force in the fluid treatment may cause metal 5 to separate in a liquid mixture 31 containing a gold colloid reagent, as shown in FIG. 14.

Microchip, measurement system and method using the same, and test reagent to be used for microchip


The applicator system is designed to distribute agriculturally beneficial matter across a field. The system includes a supply reservoir and an agitator assembly that grates and abrades matter in the supply reservoir until the abraded matter precipitates out of the supply reservoir and onto a supply conveyor. The supply conveyor conveys the matter to a distribution device. The distribution device meters the matter onto at least two lateral distribution conveyors. At the end of each of the distribution conveyors the matter is funneled downwardly into an open trench created by a trenching device associated with each distribution conveyor. After the matter is deposited into the trench, a trench closing assembly directs soil back into the trench and compresses the soil surface.

Approximately 8.5 billion broilers are raised and harvested by the domestic poultry industry every year. The manure by-product of the industry is mixed with absorbent materials such as pine shavings, rice hulls, or peanut hulls to create a biodegradable product commonly known as "poultry litter". The industry generates approximately 17 million tons of poultry litter per year. The litter is high in nitrogen and phosphorous and consequently makes an excellent fertilizer, however there are problems and issues associated with the agricultural application of the litter.
The most common method of applying the litter to farmland is to simply broadcast the litter across the surface of the soil. Although this method is relatively quick and inexpensive, it is inefficient and may damage the environment. To be beneficial, the nutrients within the litter must vertically penetrate the soil to reach the root systems of the associated crops. However, heavy rains may dissolve the soluble materials within the litter and carry the nutrients away from the crops and into the area watershed, thereby contaminating local lakes and streams. Further, in areas where litter is applied repeatedly to the soil surface, the chemical nutrients within the litter may become concentrated on the soil's surface so that associated crops are damaged or otherwise adversely affected. Consequently state and federal guidelines may prohibit further surface application of litter until levels of some of the potentially damaging chemicals have decreased and normalized.
An alternative approach is to trench a field and simultaneously place the litter (or other materials) into a relatively deep trench so that a greater amount of material can be deposited without the environmental problems associated with surface applications. This approach is described and exemplified by U.S. Pat. No. 5,401,119 to Washington et al (hereinafter "Washington"). However, the dimensions of the trench described in Washington preclude this method from being employed in close proximity to the root systems of crops, which could be damaged by the deep trenching process. Further, the deep trenching process is relatively slow and a significant amount of power is required to tow the Washington placement device, particularly in applications in which multiple trenching devices are employed simultaneously.
The need exists for an apparatus capable of placing poultry litter (or any other matter) at a sufficient depth so that the nutrients associated with the matter are not easily lost to runoff. The biodegradable matter should be placed at a sufficient depth to facilitate the penetration of the soil by the fertilizing elements of the matter, but shallow enough not to disturb row crops. The current invention allows the placement of biodegradable matter in multiple trenches that are two to three inches in depth and allows a side-dress application that is compatible with row crops.

Applicator system and method for the agricultural distribution of biodegradable and non-biodegradable materials

The United States of America as represented by the Secretary of Agriculture


An apparatus for cooling a live well includes a cooling chamber, and a pump connected in fluid communication between the cooling chamber and the live well for circulating water between the live well and the cooling chamber. At least one thermoelectric cooler is positioned in a heat exchange relationship with the cooling chamber for removing heat from the cooling chamber and from water circulating in the cooling chamber.

Fishing is a popular sport for many people. Frequently, people who catch fish (also known as "fishermen," used herein to refer collectively to women who fish as well) desire to preserve fish alive and healthy until they have finished fishing, for example, upon completion of a fishing expedition or competition. Conventionally, once fish are caught, they are preserved for a period of time in a "live well," which is similar to an aquarium, but is filled with water drawn from the area, such as a lake or river, from which such fish was caught.
A live well is effective for keeping fish alive and healthy for a period of time longer than would be possible if a fish were, for example, laid out on the deck of a boat without water. However, the period of time that a fish may remain alive in a live well is limited, and often results in such fish not surviving until the end of a fishing expedition. The reason fish do not fare well in a live well is two-fold. First, the temperature of water in a live well is often warmer than the temperature of water from which fish are caught, potentially creating thermal shock to a fish. Since fish are cold-blooded, they cannot long withstand such thermal shock or survive in such elevated temperatures. A second reason that fish often do not survive in live wells is that the water in the live well is not adequately aerated. Thus, fish cannot obtain sufficient oxygen needed to sustain life. Thus, the combination of sudden and sustained heat together with a lack of oxygen substantially shorten the life and diminish the health of a fish in a live well.
Thus, there is a need for an apparatus and associated method for preserving fish alive and healthy for a longer period of time after they are caught than what is currently possible using conventional technology.

System, and associated method, for cooling and aerating a live well


A network evaluation apparatus that evaluates a design of an optical network, the network evaluation apparatus including: a processor that selects two nodes, between which a lightpath is to be set up, from a plurality of nodes based on a traffic volume demand values, calculates a decreased amount of cost based on numbers of the plurality of nodes and a plurality of routers for relaying a signal transmitted between the two nodes selected, calculates an increased amount of cost based on a transmission distance of the lightpath and a number of a plurality of repeaters to be inserted according to a segment distance, and determines a value of the optical network based on the decreased amount of cost and the increased amount of cost.

To accommodate traffic increase in networks, optical networks that use optical fibers are being used in core networks. The optical network allows for very high capacity communication by employing a wavelength division multiplexing (WDM) technology that multiplexes a plurality of different wavelengths in a single optical fiber.
A WDM network includes a plurality of nodes, which are referred to as optical cross connects (OXCs), and optical fibers that provide connections between the nodes. The OXC is capable of creating a logical communication path, which is referred to as a lightpath, as an optical layer in between arbitrary nodes. The lightpath is actualized by setting a wavelength that may be commonly shared between two nodes. Setting a single lightpath allows creation of a logical high capacity communication path that corresponds to a capacity of one wavelength between two nodes.
An upper layer of the WDM network includes an internet protocol (IP) layer. In the IP layer, information from a user is transmitted and received on a packet by packet basis. In the WDM network, a router is connected to each OXC. A packet signal arrived at each OXC is analyzed by the router and forwarded to a forwarding destination OXC.
A network including the optical layer and the IP layer is referred to as an IP/WDM network. In the IP/WDM network, packets transmitted from users are aggregated by the router. Aggregated packets are forwarded to other nodes using the optical layer, which is a lower layer when viewed from the IP layer, as a transmission path.
Even if one or other nodes exist physically in the transmission path between two nodes, it is recognized that the two nodes are adjacent to each other when they are viewed from the IP layer in a case where the lightpath is set up therebetween in the optical layer. Each of the other nodes existing between the two nodes, between which the lightpath is set up, performs a process for switching an optical signal path by the OXC. The optical signal processed by the OXC does not go through the router. Accordingly, optical signals in the optical layer are not processed on a packet by packet basis. Such a process of the optical signals, which does not involve the router, is referred to as a cut-through.
Compared to forwarding by the lightpath, a complicated process is typically performed in the IP layer. The process includes operations such as converting an optical signal received at the OXC to an electrical signal, identifying a forwarding destination for each packet at the router based on the electrical signal converted, and forwarding the packet to the forwarding destination identified. The more complicated the process becomes, the higher the router performance is desirable. Accordingly, a network cost rises as the volume of signal processing in the IP layer increases.
An IP/WDM network design is carried out by selecting one or more lightpaths in such a way that a cost of the whole network is reduced by using, as inputs, a set of start point nodes, end point nodes, and traffic volume information flowing between the respective pairs of nodes, and a physical topology of the optical layer. A topology that is logically constructed with one or more lightpaths is referred to as a logical topology. Mukherjee (B. Mukherjee, "Optical WDM Networks", Springer, 2006) teaches a maximizing multi-hop traffic (MMT) algorithm as an evaluation technology of the IP/WDM network design. In the MMT algorithm, the logical topology that reduces the cost of the whole network is obtained by setting the lightpath in between two nodes where the traffic volume is large as well as the number of relaying routers (hop count) is large.

Network evaluation apparatus and network evaluation method


The present invention relates to a meal service management system and an operating method therefor, the system being capable of providing information on food ingested by a user to whom a meal service is to be provided and customized information related thereto, and managing food leftover in a meal service. According to an embodiment of the present invention, a scanner device is used such that a user to whom a meal service is to be provided and a food tray before and after meals are identified, and thus a meal service amount and a leftovers food amount are acquired, and leftovers food information of each user and useful information associated therewith are provided on the basis of the same, and thus users can easily determine their eating habits, nutritional status and the like and the users can be induced to attempt reducing leftovers food by themselves.

Currently, students, office workers, or other meal service recipients who are served meals at school cafeterias, company cafeterias, and other cafeterias often have one or more meals a day at the same establishment. In particular, students eat lunch at school cafeterias during most of the week, excluding the weekend, and it is important to provide these growing students with an environment in which they can eat nutritious meals.
However, children in early elementary school are unfamiliar with eating a meal as much as they need and often tend to eat only what they like without eating a balanced diet, but there is no way to check whether the children are eating a balanced diet. This is the same for late elementary school students.
In particular, parents with elementary school children have a great desire to manage their children's diet, and are struggling with ways to improve their children's eating habits, such as the rate and amount of food intake and the habit of not leaving leftovers.
In addition, office workers who frequently use company cafeterias also desire to check and manage their eating habits, and it is necessary for nurses of hospitals providing a meal service system to accurately know the amount of food intake of patients. However, there is currently no service that is capable of providing eating habit information based on accurate data.

Meal service management system and operating method therefor


An intake device of a V-type engine provided with two cylinders inclining in a longitudinal direction of a motorcycle includes a center air cleaner arranged above a V-bank space formed between the two cylinders, a pair of right and left side air cleaners arranged on both sides of the V-bank space, and an air/fuel mixture supply device disposed between the center air cleaner and the V-bank space. An internal space of the center air cleaner is communicated with an intake port of each of the cylinders through the air/fuel mixture supply device. The internal space of the side air cleaner is divided into a dirty side and a clean side with an air filter being interposed therebetween, in which the clean side is connected to the center air cleaner and the dirty side is provided with an intake port communicating with an outside. The intake port is opened so as to face the V-bank space side.

1. Field of the Invention
The present invention relates to an intake device of a V-type engine of a motorcycle.
2. Related Art
A motorcycle is equipped with a V-type engine having two cylinders including one inclined to the front side and the other inclined to the rear side in the vehicle longitudinal direction.
There is known an arrangement of air/fuel mixture supply device such as a carburetor or a throttle body constituting an intake device and an air cleaner for purifying the intake air as disclosed in the Japanese Patent Laid-Open Publication No. HEI 8-108877. That is, a recess is formed on a lower surface of a fuel tank located above the engine with a center air cleaner being arranged therein, and side air cleaners are arranged on right and left side surfaces of the engine, respectively. Further, an internal space of these side air cleaners is divided into a dirty side and a clean side with an air filter being interposed therebetween. An intake pipe extending right and left from the center air cleaner is connected to the dirty side of the side air cleaner, while the clean side being connected to the mixture supply device.
An external air to be sucked into the engine first enters the center air cleaner and then, after being divided into right and left, it flows into the dirty side of the side air cleaner. After being purified by the air cleaner, the external air flows to the mixture supply device through the clean side and is taken into the engine.
In this way, if three air cleaners in total are provided at the center and side portions, and the air sucked from the center air cleaner is supplied to the mixture supply device after being divided into the right and left side air cleaners, intake passages of the front and rear cylinders can be made substantially independent so that intake interference is difficult to occur, and an intake efficiency can be improved to some extent. In addition, attaching/detaching working for washing or replacement of the air filter inside the side air cleaner is favorably done.
However, since the air filter is located immediately before the mixture supply device in the arrangement mentioned above, the capacity of the clean side cannot be increased and the intake efficiency cannot be largely improved by using an intake inertia effect, for example. If the capacity of the side air cleaner is increased, the intake efficiency can be improved more or less. However, this arrangement makes the side air cleaner extend outward in the vehicle-width direction, thereby degrading compactness. Moreover, the side air cleaners will interfere with the knees of a rider, impairing riding stability.

Intake device of V-type engine of motorcycle


The invention relates to a process for the production of higher dialkyl carbonates corresponding to formula (I): EQU (R.sup.1 O)(R.sup.2 O)CO (I). which R.sup.1 and R.sup.2 may be the same or different and represent a linear or branched, saturated or unsaturated and/or alkoxylated alkyl group, by transesterification of lower dialkyl carbonates with higher alcohols in the presence of a catalyst. The process is characterized in that the transesterification is carried out in a column equipped with packings or internals through which the reactants flow in countercurrent to one another. Predominantly symmetrical dialkyl carbonates are obtained.

Lower alkyl carbonates may be obtained by the reaction of ethylene and propylene glycol carbonates (glycol carbonates) with alcohols in the presence of catalysts. Although this reaction can take place with high selectivity, the processes used to carry it out have a number of disadvantages. In general, the transesterification reaction is relatively slow under normal pressure, so that it is recommended to apply elevated temperatures, in many cases above the boiling point of the alcohol used, which means carrying out the reaction in pressure vessels (EP 1082, EP 1083). Normally, the reaction only proceeds as far as the equilibrium state of the transesterification reaction. After removal from the pressure vessel, the reaction mixture has to be separated very quickly from the catalyst, for example by flash distillation, to prevent the starting compounds from reforming in a reversal of the formation reaction, for example during removal of the lower boiling alcohol by distillation. During separation from the catalyst by distillation, the glycol carbonate still in equilibrium can decompose into carbon dioxide and polyglycols and is thus lost to the transesterification process with a consequent reduction in yield. All the secondary products mentioned interfere with working up. However, even if this removal of the catalyst is satisfactory, several distillations still have to be carried out. First, separation of high boilers from the low boilers is necessary. However, the purification of ethylene glycol by removal of incompletely reacted ethylene glycol carbonate, which is preferably used for the production of the dialkyl carbonates, is not unconditionally possible because both compounds form an azeotrope. A similar difficulty is encountered when methanol, which is the preferred alcoholic component, has to be separated from the dimethyl carbonate formed. These compounds also form an azeotrope which is difficult to separate by distillation (EP 894). In many cases, higher carbonates are also produced by discontinuous reaction of short-chain carbonates, such as diethyl carbonate, dimethyl carbonate, dibutyl carbonate and/or dipropyl carbonate, with alcohols in a stirred tank reactor. During the reaction, the alcohol formed (methanol, ethanol, propanol, butanol) is distilled off so that the equilibrium position is displaced towards the product side. The product alcohol cannot be distilled off in pure form; a mixture of alcohol and short-chain educt carbonate is always obtained. Where dimethyl carbonate is used, a mixture of azeotropic composition (ca. 30% by weight dimethyl carbonate and 70% by weight methanol) is obtained in the most favorable case. This mixture can only be separated by very elaborate processes, for example azeotropic rectification, or so-called hybrid processes (Chem. Ing. Techn. 68 (1996) No. 4, pages 441-444).
DE 41 29 316 describes a process for the transesterification of glycol carbonates with lower alcohols in which lower alkyl carbonates are obtained. In this process, the formation of an azeotrope is avoided and the reaction takes place under mild conditions.
The problem addressed by the present invention was to provide a simple process for the production of higher dialkyl carbonates. Another problem addressed by the invention was to enable higher dialkyl carbonates with a high percentage content of symmetrical dialkyl carbonates to be produced.

Process for the production of dialkyl carbonates


The invention relates to a test system for analyzing body fluids of the type comprising a test element tape carrying a plurality of test elements, a tape deflector for the test element tape for the selective application of body fluid, and a light source as well as a detector for optically analyzing test elements to which body fluid has been applied. The tape deflector has a rotatable optical element which acts as a deflection roller during transport of the test element tape. The optical element is positioned in the optical path between the light source and the detector.

The present invention relates to a test system for analyzing body fluids, in particular blood, of the type comprising a test element tape carrying a plurality of test elements that is preferably wound in a tape cassette, a tape deflector for the test element tape for the directed application of body fluid, and a light source as well as a detector to optically analyze test elements to which body fluid has been applied.
Portable devices operating as minilaboratories, which can also be used by laymen to carry out the required steps in a simple and rapid manner are known for self-monitoring blood glucose by diabetics. In order to replace conventional test strips, it is proposed in WO 2004/047642 that instead of individual test strips, a wound test tape should be used on which a plurality of test fields provided with a suitable test chemistry are arranged consecutively. The body fluid is applied to a test field that is moved into an active position by advancing the tape over a tip and analyzed. Details on blood collection as well as on the known test media and detection systems especially for blood glucose are disclosed in this document to which reference is herewith made and the contents of which are incorporated by reference into this application. This document also shows that a transparent tip can be used to directly couple the instrument optics. Constraints that have to be observed in this case are that the total height of the deflector tip and its opening angle should be as small as possible but it should still be possible to optically analyze the test field for example on the basis of a reflectance measurement or a fluorescence measurement.


The invention relates to a drive arrangement for the motor-operated adjustment of an adjusting element in a motor vehicle, wherein the drive arrangement comprises two electrical drives having in each case a drive motor and a control device, wherein in the assembled state the drives act in the same manner on the adjusting element and are embodied in an essentially identical manner apart from deviations that are a result of tolerances, wherein the control device influences the two drive motors by a pulse width modulation voltage (“PWM” voltage). It is proposed that the control device influences the two drive motors by PWM voltages having PWM switching frequencies that vary continuously during the adjustment process in such a manner that the PWM switching frequencies that are allocated to the two drive motors are different from each other at least for periods of time.

The known drive arrangement (DE 10 2008 057 014 A1) on which the invention is based is equipped with two electrical spindle drives which each have a drive motor. In order to counteract any uneven wear of the two drives that are embodied in an identical manner, a control device ensures that the two drive motors are supplied with an identical amount of drive power.
The control device acts upon the two drive motors with a pulse width modulation voltage ("PWM" voltage) in order to be able to ensure as low as possible a power loss when controlling the rotational speed or torque of the drive motors. In the case of the PWM power control of consumers, in this case drive motors, the problem quite generally arises that interfering harmonic waves are formed, the frequency of which regularly amounts to many times the switching frequency of the respective PWM voltage. This can be particularly problematic with respect to the electromagnetic compatibility (EMC).
U.S. Pat. No. 6,433,507 B1 discloses one approach for reducing EMC interference when controlling the PWM power. This document proposes to continuously vary the duty cycle, in other words the ratio of high duration time to low duration time of a PWM pulse, during the motor-operated adjustment. As a consequence, the above-mentioned interference is reduced in a simple manner.

Drive arrangement the motor-operated adjustment of an adjusting element in a motor vehicle

Brose Fahrzeugteile GmbH & Co. KG, Hallstadt


A system and method of determining a sampling rate for rendering a volumetric image, the method includes determining a regional variation value representing regional data, color, and/or alpha variation. An accumulated opacity value is determined that represents opacity accumulated over a ray in the image, and a regional opacity value is determined that represents regional opacity. A quality setting is accessed that represents a default image quality, and the sampling rate is adjusted as a function of the regional variation value, the accumulated opacity value, the regional opacity value, and the quality setting. The regional variation value may be determined by iteratively generating a maximum regional variation table during pre-processing, quantizing the maximum regional variation table where the transfer function is defined based on a histogram of the volumetric image, and computing the regional variation value using the maximum regional variation table. Also disclosed are methods to calculate the accumulated opacity value, and the regional opacity value, as well as systems and methods of rendering a volumetric image by using the sampling rate.

1. Field of the Invention
This invention relates generally to volume rendering for computer-aided diagnosis (CAD) in medical imaging. More specifically, the present invention is directed to systems and methods of determining sampling rates for volume rendering based on regional variations, regional and accumulated opacities, and quality settings.
2. Background Discussion
Direct volume rendering is an important technique to visualize three-dimensional (3-D) datasets from medical and other sources. With the advance of the computation power and medical devices, the sizes of the 3D volumetric datasets are expanding quickly. The Visible Human project from the National Library of Medicine produced massive datasets with the size of 512×512×1728 (864 MB). Typical Computed Tomography (CT) machines from Siemens® Medical Solutions can generate a pixel image dataset at a size of 512×512×6000 (3 GB). The capacity to visualize such datasets with high interactivity and high image quality is helpful to medical professionals in diagnosing disease.
Direct volume rendering is a well studied problem in the visualization community. Raycasting, splatting, shearwarp and 3D texture mapping are some of the most popular volume rendering techniques. Among these technologies, raycasting can generate the highest quality images and the algorithms scale well with the increase of the dataset size. Rendering quality can be improved in the ray-casting technique by increasing the sampling rate in 3 dimensions. However, interactivity is difficult to achieve using the brute-force approach due to the intensive memory access and computational nature of the algorithm.
In order to speed up ray-cast rendering, techniques like space leaping and early ray termination can be used. They are particularly effective if the transfer function used for rendering indicates a high degree, or a high proportion, of empty space (totally transparent) or occluded space by an opaque object (early ray termination). On the contrary, if the transfer function reveals a high degree, or high proportion, of partial translucency but no completely transparent regions, space leaping and early ray termination techniques are not very effective. Therefore, for translucent transfer functions, even with these optimization methods, ray-casting can be very slow. If super-sampling is used for higher resolution rendering, performance will be even slower and therefore, interactivity is no longer possible.
Therefore, it would be an advancement in the state of the art to provide a system and method of efficient interactive volume rendering of large datasets that does not sacrifice image quality.

Systems and methods of determining sampling rates for volume rendering