Patent Publication Number: US-11027814-B2

Title: Ship reverse-run detection system, ship reverse-run detection method, and recording medium storing ship reverse-run detection program

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a continuation application of International Application PCT/JP2016/054030 filed on Feb. 10, 2016 and designated the U.S., the entire contents of which are incorporated herein by reference. 
    
    
     FIELD 
     The embodiments discussed herein relate to a ship reverse-run detection system, a ship reverse-run detection method, and a ship reverse-run detection program. 
     BACKGROUND 
     Technologies of notifying the navigation state of a ship to another ship include a ship automatic identification device. 
     Related technologies are disclosed in Japanese Laid-open Patent Publication No. 2012-86670. 
     SUMMARY 
     According to an aspect of the embodiments, a ship reverse-run detection system includes a memory, and a processor coupled to the memory, wherein the processor is configured to: detect a direction of change in a position of a ship based on position information of the ship which is detected by a position detection device which is mounted on the ship, specify a traveling direction associated with a navigation region of the ship which is specified based on the position information, by referring to a storage which stores the navigation region and the traveling direction in association with each other, and detect reverse run of the ship in the navigation region based on the magnitude of an angle between the direction of the change and the traveling direction. 
     The object and advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the claims. 
     It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the invention, as claimed. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a diagram illustrating an exemplary configuration of a navigation management support system according to Embodiment 1; 
         FIG. 2  is a block diagram illustrating a functional configuration of a server device according to Embodiment 1; 
         FIG. 3  is a diagram illustrating exemplary navigation data; 
         FIG. 4  is a block diagram illustrating a functional configuration of a portable terminal device according to Embodiment 1; 
         FIG. 5  is a pattern diagram of a marine chart including a course; 
         FIG. 6  is a diagram for description of an exemplary reverse-run identification range; 
         FIG. 7  is a flowchart illustrating the procedure of course reverse-run detection processing according to Embodiment 1; and 
         FIG. 8  is a diagram illustrating an exemplary hardware configuration of a computer configured to execute a reverse-run detection program according to Embodiments 1 and 2. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     For example, in a ship automatic identification device using a universal shipborne automatic identification system (AIS), the AIS transmits ship information of the own ship to another ship, and upon reception of such ship information, the other ship displays information related to another ship on a display unit. The ship information includes the name and position information of a ship. It may be determined whether ship information has to be urgently received by referring to a sailing state such as a BLUE SIGN (binary data of information for notifying reverse run of a ship in a waterway to another ship). 
     However, this configuration only performs communication of ship information between ships. Thus, the configuration provides no method of detecting reverse run of a ship, and determination of reverse run is left to a crew member such as the operator of a ship. 
     For example, a ship reverse-run detection computer system capable of detecting reverse run of a ship may be provided. 
     The following describes embodiments of a ship reverse-run detection computer system, a ship reverse-run detection method, and a ship reverse-run detection program according to the embodiments with reference to the accompanying drawings. The embodiments do not limit the disclosed technology. The embodiments may be combined as appropriate while the contents of processing are maintained consistent. 
     Embodiment 1 
     [System Configuration] 
       FIG. 1  is a diagram illustrating an exemplary configuration of a navigation management support system according to Embodiment 1. In this navigation management support system  1  illustrated in  FIG. 1 , a user is a marina as a business operator who manages a port and provides navigation management service that manages operation of any ship belonging to the port. In the navigation management support system  1  illustrated in  FIG. 1 , an end user is a crew member of each ship belonging to the port, and the system provides the end user with navigation support service that supports safety navigation. 
     The navigation management service and the navigation support service are applicable to a ship of any classification, particularly to a small-sized ship, which makes the services further useful. Installation of a marine instrument such as an automatic identification system (AIS) is requested for large-sized ships, but not for small-sized ships. This situation makes it more difficult to provide navigation management and navigation support of small-sized ships, for example, ships used in marine leisure, which are called pleasure boats ( 5 A to  5 C) than those of large-sized ships. 
     Thus, the navigation management support system  1  utilizes, for the navigation management service and the navigation support service, functions of portable terminal devices  50 A to  50 C owned by crew members of the pleasure boats  5 A to  5 C, for example, ship operators thereof. Hereinafter, when collectively referred, the pleasure boats  5 A to  5 C are also referred to as a “pleasure boat  5 ”. 
     The following exemplarily describes a case in which the navigation management service and the navigation support service are provided to the pleasure boat  5 , but the navigation management service and the navigation support service may be provided to any other small-sized ship such as a fishing boat. In addition, the navigation management service and the navigation support service may be provided to any large-sized ship by exploiting the existing technology such as AIS. 
     As illustrated in  FIG. 1 , the navigation management support system  1  includes a server device  10 , client terminals  30 A to  30 C, and the portable terminal devices  50 A to  50 C. Hereinafter, when collectively referred, the client terminals  30 A to  30 C are also referred to as a “client terminal  30 ”. When collectively referred, the portable terminal devices  50 A to  50 C are also referred to as a “portable terminal device  50 ”. Although  FIG. 1  exemplarily illustrates a configuration in which the server device  10  houses the three client terminals  30  and the three portable terminal devices  50 , the present disclosure is not limited to the illustrated example. The server device  10  may house an optional number of client terminals  30  and an optional number of portable terminal devices  50 . 
     The server device  10  is a computer configured to provide the navigation management service to the client terminal  30 . 
     According to an embodiment, the server device  10  may be implemented by installing, to a desired computer, a navigation management program configured to achieve the navigation management service as package software or online software. For example, the server device  10  may be implemented as a Web server configured to provide the navigation management service or may be implemented as a cloud configured to provide the navigation management service by outsourcing. 
     The client terminal  30  is a computer configured to receive provision of the navigation management service from the server device  10 . The client terminal  30  may be used by, for example, any person concerned with the marina such as a staff or manager of the marina. 
     According to the embodiment, the client terminal  30  may be achieved by a personal computer. The client terminal  30  is not limited to a stationary information processing device such as a personal computer as described above, but may be various portable terminal devices that the marina lends to a person concerned therewith. Examples of the “portable terminal devices” include mobile communication terminals such as a smartphone, a cellular phone, and a personal handyphone system (PHS) phone, a slate terminal, and a tablet terminal. 
     For example, the client terminal  30  receives request for login to the server device  10  by receiving inputting of account information allocated to the marina, for example, an identification (ID) and a password. When this login request is transmitted from the client terminal  30  to the server device  10 , the server device  10  executes login authentication. When the login authentication is successful, the navigation management service related to the marina is released to the client terminal  30  having succeeded the login authentication. 
     The server device  10  and the client terminal  30  are connected with each other through a predetermined network. Examples of such a network include optional kinds of wired and wireless communication networks such as the Internet, a local area network (LAN), and a virtual private network (VPN). 
     The portable terminal device  50  is used as a computer configured to provide the navigation support service. The “portable terminal device  50 ” is, for example, that used by a crew member such as the ship operator of the pleasure boat  5 . 
     According to the embodiment, an application program configured to achieve the navigation support service is installed on the portable terminal device  50 . Hereinafter, such an application program configured to achieve the navigation support service is also referred to as a “navigation support App”. The portable terminal device  50  performs, by executing the navigation support App through a processor thereof, various warnings that contribute to safety navigation as exemplary navigation support service. 
     As an aspect of the navigation support service, for example, the portable terminal device  50  automatically or manually notifies the server device  10  of departure and arrival of the pleasure boat  5  that the ship operator holding the portable terminal device  50  is on board from and at a ship port. This provides such port departure and arrival determination service that the notification of port departure and arrival of the pleasure boat  5  is output through a predetermined display device or a voice output device or the port departure and arrival notification of the pleasure boat  5  is uploaded to the server device  10  to record port departure and arrival in the server device  10 . In addition, the portable terminal device  50  performs, over a sailing duration between port departure and arrival of the pleasure boat  5 , various kinds of warnings such as a warning related to dangerous objects such as a shoal, a reef, and a fishing net, a warning related to ship operation exceeding a navigation range of the pleasure boat  5  determined based on skills and a license of the ship operator of the pleasure boat  5 , the size of the boat, and the like, a warning related to entry to a restricted region such as a port or a river, a warning related to anchor dragging to the pleasure boat  5  performing anchoring, a warning related to reverse-run of a course, and a warning related to approach of all kinds of other ships including small-sized and large-sized ships. 
     As another aspect, the portable terminal device  50  uploads, only during the above-described sailing duration, position information measured by a position detection unit, such as a global positioning system (GPS) receiver, included in the portable terminal device  50  to the server device  10 . Accordingly, the portable terminal device  50  establishes a foundation that allows the server device  10  to provide the navigation management service to the client terminal  30 . The server device  10  is capable of managing, based on the foundation, for example, port departure and arrival of the pleasure boat  5  and the current position after port departure of the pleasure boat  5 . In addition, the server device  10  is capable of receiving an emergency request for rescue of the pleasure boat  5  from the portable terminal device  50 , setting, on a map including a port under jurisdiction of the marina and a marine area around the port, a symbol of a dangerous object for which the portable terminal device  50  sets off a warning, and displaying, in a display manner different from those of other symbols, a symbol of the pleasure boat  5  for which the portable terminal device  50  is executing the above-described various warnings among symbols of ships indicated on the map. Hereinafter, a port under jurisdiction of the marina and a marine area around the port are also referred to as a “jurisdiction zone”. 
     Communication is performed between the server device  10  and the portable terminal device  50  through an optional network connected through a base station in which the portable terminal device  50  is housed. Although not illustrated, communication is performed between the client terminal  30  and the portable terminal device  50  in a similar manner. 
     [Configuration of Server Device  10 ] 
       FIG. 2  is a block diagram illustrating a functional configuration of the server device  10  according to Embodiment 1. As illustrated in  FIG. 2 , the server device  10  includes a communication I/F unit  11 , a storage unit  13 , and a control unit  15 .  FIG. 2  illustrates a solid line indicating a data inputting and outputting relation only in a minimum part for the purpose of illustration. In other words, data inputting and outputting related to each processing unit is not limited the illustrated example, but any other data inputting and outputting such as data inputting and outputting between processing units, between a processing unit and data, and between a processing unit and an external device may be performed. 
     The communication I/F unit  11  is an interface configured to control communication with another device such as the client terminal  30  or the portable terminal device  50 . 
     According to the embodiment, as an aspect, the communication I/F unit  11  may be achieved by a network interface card such as a LAN card. For example, the communication I/F unit  11  receives a request to browse a monitoring screen from the client terminal  30 , and transmits, to the client terminal  30 , display data of a monitoring screen including a map related to the jurisdiction zone of the marina. In addition, the communication I/F unit  11  receives a request to download the navigation support APP from the portable terminal device  50 , position information of the pleasure boat  5 , and an alert output status at the portable terminal device  50 , and transmits, for example, data of the navigation support APP and navigation support data including course data to the portable terminal device  50 . 
     The storage unit  13  is a storage device configured to store data used by various computer programs such as an operating system (OS) executed at the control unit  15  and an application program that achieves the navigation management service. 
     According to the embodiment, the storage unit  13  may be provided as an auxiliary storage device of the server device  10 . For example, the storage unit  13  may be achieved by a hard disk drive (HDD), an optical disk, or a solid state drive (SSD). The storage unit  13  does not necessarily have to be provided as an auxiliary storage device, but may be provided as a main storage device of the server device  10 . In this case, the storage unit  13  may be achieved by various semiconductor memory elements such as a random access memory (RAM) and a flash memory. 
     The storage unit  13  stores, as exemplary data used by a computer program executed at the control unit  15 , map data  13   a , navigation support data  13   b , and navigation data  13   c . In addition to the map data  13   a , the navigation support data  13   b , and the navigation data  13   c , the storage unit  13  may store property information related to a ship, such as information in which a ship name, a captain name, the number of crew members are associated with each other for each ship number. Among the map data  13   a , the navigation support data  13   b , and the navigation data  13   c , the navigation support data  13   b  will be described at a situation in which the navigation support data  13   b  is referred to. 
     The map data  13   a  is electronic data of a marine chart. The marine chart is, for example, a general chart, sailing chart, a nautical chart, a coast chart, or a harbor chart. All or some of these charts are stored in the storage unit  13  as the map data  13   a . The map data  13   a  includes pieces obtained by dividing, in mesh, the entire map included in the map data  13   a . Thus, when the server device  10  transmits the map data  13   a  to the client terminal  30  or the portable terminal device  50 , not the entire map included in the map data  13   a  has to be transmitted, but only part of the map data  13   a  may be transmitted. For example, when the map data  13   a  is transmitted from the server device  10  to the client terminal  30 , map data of the jurisdiction zone corresponding to the client terminal  30  or an element corresponding to part of the jurisdiction zone is extracted from the map data  13   a  and then transmitted. When the map data  13   a  is transmitted from the server device  10  to the portable terminal device  50 , map data of an element corresponding to a predetermined range with respect to position information specified by the portable terminal device  50 , in other words, a current position is extracted from the map data  13   a  and then transmitted. 
     The navigation data  13   c  is data related to navigation. 
     According to the embodiment, the navigation data  13   c  may be data including items such as a marina ID, a port departure ID, a ship ID, a port departure scheduled date and time, a port arrival scheduled date and time, a port departure date and time, a port arrival date and time, and a current position. The “marina ID” is identification information of the marina, and may be, for example, any optional system identifier as information that allows the server device  10  to identify the marina. The “port departure ID” is information for identifying a ship departing from the port managed by the marina, and is allocated with a number in the order of port departure notice submission among port departure notices having the same date of the port departure scheduled date and time. The “ship ID” is information for identifying a ship, and may be, for example, a ship number provided to the ship. The ship number is also called a “ship identification number”. 
     Values may be registered to the items of the “port departure ID”, the “ship ID”, the “port departure scheduled date and time”, and the “port arrival scheduled date and time”, for example, when a port departure notice is submitted to the marina. For example, when a port departure notice is received online by the marina, or when a port departure notice is received online by, on behalf of the marina, a business operator that provides the navigation management service and the navigation support service, the port departure ID, the ship ID, the port departure scheduled date and time, and the port arrival scheduled date and time that are included in electronic data of the port departure notice in association with the marina ID of the marina to which the port departure notice is submitted may be registered to the storage unit  13 . 
     Only when a port departure notification is received from the portable terminal device  50 , the date and time of the reception of the port departure notification is registered to the “port departure date and time”. Only when a port arrival notification is received from the portable terminal device  50 , the date and time of the reception of the port arrival notification is registered to the “port arrival date and time”. The “current position” is overwritten with position information uploaded from the portable terminal device  50 , a status related to port departure and arrival of which is set to “departed”, at each uploading in a predetermined duration, for example, one minute. 
       FIG. 3  is a diagram illustrating exemplary navigation data  13   c .  FIG. 3  only illustrates, as an example, records related to a marina identified by the marina ID of “M001”. The exemplary navigation data  13   c  illustrated in  FIG. 3  indicates that a ship identified by the ship ID of “JP-ABC12345D404” departed from the marina identified by the marina ID of “M001” and has already arrived at the marina. The exemplary navigation data  13   c  illustrated in  FIG. 3  also indicates that a ship identified by the ship ID of “JP-DEF54321N505”, a ship identified by the ship ID of “JP-HIJ56789J123”, and a ship identified by the ship ID of “JP-HIJ98765J200” have departed from the marina identified by the marina ID of “M001”. An alert of “anchor dragging” is output to the ship identified by the ship ID of “JP-DEF54321N505”, and an alert of “shoal warning” is output to the ship identified by the ship ID of “JP-HIJ98765J200”. No alert is output to the ship identified by the ship ID of “JP-HIJ56789J123”, but a notification that the ship has been anchored, in other words, moored has been uploaded. 
     The above-described table is exemplary, and may have, for example, no status column or may store an additional item other than the status column. When the kind of alert is received from a data communication unit  58   e  to be described later, the kind of alert may be stored as an alert state in association with a ship ID. As long as the above-described data items are allowed to be stored in association with each other and referred to, data does not have to be collectively stored in a single table but may be managed in a divided manner in a plurality of tables. 
     The control unit  15  includes an internal memory configured to store various computer programs and various kinds of control data, and executes various kinds of processing based on these computer programs and control data. 
     According to the embodiment, the control unit  15  is achieved as a central processing unit (CPU). the control unit  15  does not necessarily have to be achieved as a central processing unit, but may be achieved as a micro processing unit (MPU). Alternatively, the control unit  15  may be achieved by a hard-wired logic such as an application specific integrated circuit (ASIC) or a field programmable gate array (FPGA). 
     The control unit  15  virtually achieves processing units described below by loading, as a process onto a work area of a RAM, such as a dynamic random access memory (DRAM) or a static random access memory (SRAM), mounted as a main storage device (not illustrated), the navigation management program stored in the storage unit  13  as an application program that achieves the above-described the navigation management service. 
     For example, as illustrated in  FIG. 2 , the control unit  15  includes a distribution unit  15   a , a navigation recording unit  15   b , an alert reception unit  15   c , and a map display unit  15   d.    
     The distribution unit  15   a  is a processing unit configured to perform distribution to the portable terminal device  50 . 
     According to the embodiment, when having received, from the portable terminal device  50 , a request to download the navigation support App, the distribution unit  15   a  distributes the navigation support data  13   b  stored in the storage unit  13  to the portable terminal device  50 . The navigation support data  13   b  includes the data of the navigation support App and various kinds of data to be used by the navigation support App. Examples of the data to be used by the navigation support APP include navigation data in which a navigation region on a course is associated with a traveling direction. The navigation region may be defined by position information of a buoy disposed on a course in accordance with navigation rules. 
       FIG. 5  is a pattern diagram of a marine chart including a course.  FIG. 5  only includes a buoy used to define a navigation region among buoys disposed on the course. For example, a navigation region is defined by a polygon by using position information of a plurality of buoys. In the example illustrated in  FIG. 5 , a navigation region E 1  is defined by the position information of a buoy  41   a , a buoy  41   b , a buoy  41   e , and a buoy  41   d , and a navigation region E 2  is defined by the position information of the buoy  41   b , a buoy  41   c , a buoy  41   f , and the buoy  41   e . The navigation regions E 1  and E 2  are included in a south sailing route according to the navigation rules. For example, when an azimuth is defined in the clockwise direction with 0° at the up direction, which is North, in the marine chart, the navigation region E 1  is associated with a traveling direction of 160° and the navigation region E 2  is associated with a traveling direction of 180° according to the above-described navigation rules. In addition, a navigation region E 3  is defined by the position information of the buoy  41   d , the buoy  41   e , a buoy  41   h , and a buoy  41   g , and a navigation region E 4  is defined by position information of the buoy  41   e , the buoy  41   f , a buoy  41   j , and the buoy  41   h . The navigation regions E 3  and E 4  are included in a north sailing route according to the navigation rules. Accordingly, the navigation region E 3  is associated with a traveling direction of 340°, and the navigation region E 4  is associated with a traveling direction of 0°. Thus, the course illustrated in  FIG. 5  is defined by a record associating the navigation region E 1  with the traveling direction of “160°”, a record associating the navigation region E 2  with the traveling direction of “180°”, a record associating the navigation region E 3  with the traveling direction of “340°”, and a record associating the navigation region E 4  with the traveling direction of “0°”.  FIG. 5  illustrates the example in which each navigation region is defined by a rectangle, but any polygon may be defined. 
     The navigation recording unit  15   b  is a processing unit configured to perform recording related to navigation. 
     According to the embodiment, when having received a port departure notification from the portable terminal device  50 , the navigation recording unit  15   b  executes processing as follows. Specifically, the navigation recording unit  15   b  records the date and time of reception of the port departure notification to the port departure date and time of a record having a marina ID and a port departure ID identical to those included in the port departure notification among records stored as the navigation data  13   c  in the storage unit  13 . In this example, it is assumed that duplicate port departure IDs are allocated to marinas, and both of a marina ID and a port departure ID are used to search records. However, the record search may be performed by only using the port departure ID when different port departure IDs are allocated to marinas. When having received a port arrival notification from the portable terminal device  50 , the navigation recording unit  15   b  executes processing as follows. Specifically, the navigation recording unit  15   b  records the date and time of reception of the port arrival notification to the port arrival date and time of a record having a marina ID and a port departure ID identical to those included in the port arrival notification among records stored as the navigation data  13   c  in the storage unit  13 . The navigation recording unit  15   b  also executes processing as follows each time position information is notified from the portable terminal device  50 . Specifically, the navigation recording unit  15   b  overwrites and updates the position information with the current position of a record having a marina ID and a port departure ID identical to those notified together with the position information among records stored as the navigation data  13   c  in the storage unit  13 . 
     The alert reception unit  15   c  is a processing unit configured to receive an alert execution notification from the portable terminal device  50 . 
     According to the embodiment, when an alert is output at the portable terminal device  50 , the alert reception unit  15   c  receives, from the portable terminal device  50 , an alert execution notification including the kind of the alert output at the portable terminal device  50 . 
     The map display unit  15   d  is a processing unit configured to cause the client terminal  30  display a map. 
     According to the embodiment, when a request to browse a monitoring screen is received on a menu screen (not illustrated) displayed on the client terminal  30 , the map display unit  15   d  executes processing as follows. For example, the map display unit  15   d  specifies a marina ID from an account used, at login authentication, by the client terminal  30  having issued a request to browse the monitoring screen. Subsequently, the map display unit  15   d  further specifies a jurisdiction zone corresponding to the specified marina ID by referring to jurisdiction data (not illustrated) in which the marina ID of each marina is associated with the jurisdiction zone of the marina. Then, the map display unit  15   d  extracts, from the map data  13   a  stored in the storage unit  13 , map data including the jurisdiction zone corresponding to the specified marina ID. Thereafter, the map display unit  15   d  causes the client terminal  30  to display a monitoring screen including the extracted map of the jurisdiction zone of the marina. 
     For example, any record having a registered current position is extracted from among records included in the navigation data  13   c , and then the current position of any ship included in the record may be mapped on the map of the jurisdiction zone of the marina included in the above-described monitoring screen. When the current position of a ship is mapped in this manner, the client terminal  30  may display, for example, property information related to the ship in association with a symbol indicating the ship. The property information of a ship may be displayed on a window different from the monitoring screen. Moreover, among symbols of ships mapped on the map of the jurisdiction zone of the marina, the symbol of a ship from which an alert execution notification is received by the alert reception unit  15   c  may be displayed on the monitoring screen in a display manner different from that for the symbol of any other ship. In this case, the symbol of this ship may be displayed in a display manner that further differs between the kinds of outputting on the portable terminal device  50 . 
     [Configuration of Portable Terminal Device  50 ] 
       FIG. 4  is a block diagram illustrating a functional configuration of the portable terminal device  50  according to Embodiment 1. As illustrated in  FIG. 4 , the portable terminal device  50  includes a touch panel  51 , a wireless communication unit  52 , a camera  53 , a position detection unit  54 , a storage unit  55 , and a control unit  57 . The portable terminal device  50  may include various functional components, such as a voice output unit, included in a known portable terminal device in addition to functional components illustrated in  FIG. 4 . 
     The touch panel  51  is a device capable of performing display and receiving inputting. 
     As an aspect related to display, the touch panel  51  displays images output from an OS executed on the portable terminal device  50  and an application program such as the navigation support App. As an aspect related to input, the touch panel  51  receives touch operations such as tap, flick, swipe, pinch-in, and pinch-out performed on a screen of the touch panel  51 . In this example, the touch panel  51  is described as an exemplary display unit, but does not necessarily have to provide both displaying and inputting functions. The touch panel  51  may be achieved individually by a display device and an input device. 
     The wireless communication unit  52  is a processing unit configured to connect with the base station through an antenna (not illustrated) to perform data transmission and reception to and from any other device such as the server device  10  through, for example, a mobile communication network connected with the base station. 
     The camera  53  is an image capturing apparatus configured to capture images. 
     According to the embodiment, the camera  53  includes an image sensor such as a charge coupled device (CCD) or a complementary metal oxide semiconductor (CMOS). For example, the camera  53  may include light receiving elements of three kinds such as R (red), G (green), and B (blue). 
     The position detection unit  54  is a kind of hardware configured to detect the position of the portable terminal device  50 . 
     According to the embodiment, the position detection unit  54  may be a GPS receiver configured to detect a position based on time information transmitted from a plurality of GPS satellites. The position detected by the GPS receiver in this manner does not necessarily have to be directly used, but may be subjected to various kinds of correction by using, for example, position information transmitted from the base station connected with the portable terminal device  50 . 
     The storage unit  55  is a storage device configured to store the OS executed by the control unit  57  and data used by various computer programs such as application programs. 
     According to the embodiment, the storage unit  55  may be provided as a main storage device of the server device  10 . For example, the storage unit  55  may be achieved by various semiconductor memory elements such as a RAM such as a DRAM or a SRAM and a flash memory. The storage unit  55  does not necessarily have to be provided as a main storage device, but may be provided as an auxiliary storage device of the portable terminal device  50 . In this case, the storage unit  55  may be achieved by a HDD, an optical disk, or a SSD. 
     The storage unit  55  stores, as exemplary data used by a computer program executed by the control unit  57 , navigation support data  56 . In addition to the navigation support data  56 , the storage unit  55  may store user data of the portable terminal device  50 . 
     The control unit  57  is a processing unit configured to govern entire control of the portable terminal device  50 . 
     According to the embodiment, the control unit  57  is provided as a central processing unit (CPU). The control unit  57  does not necessarily have to be provided as a central processing unit, but may be provided as an MPU. The control unit  57  may be achieved by a hard-wired logic such as an ASIC or an FPGA. 
     As illustrated in  FIG. 4 , the control unit  57  includes a download unit  57   a  and a navigation support App execution unit  58 . 
     The download unit  57   a  is a processing unit configured to execute various kinds of downloading. 
     The following describes an exemplary method of downloading the navigation support App installed on the portable terminal device  50 . For example, downloading of the above-described navigation support App starts when a two-dimensional bar code issued by the marina is read through the camera  53  of the portable terminal device  50 . Such a two-dimensional bar code is read, for example, when a port departure notice is submitted to the marina. Once the port departure notice is submitted to the marina in this manner, a port departure ID is allocated by the server device  10 , and then a new record in which, for example, the port departure ID, the marina ID of the marina having received the port departure notice, a ship ID, a port departure scheduled date and time, and a port arrival scheduled date and time received through the port departure notice are associated with each other is generated in the navigation data  13   c . Thereafter, address information such as a uniform resource locator (URL) through which the server device  10  is accessed, the marina ID, and the port departure ID are coded. In this manner, a two-dimensional bar code including the marina ID and the port departure ID is generated. Thereafter, the two-dimensional bar code including the URL, the marina ID, and the port departure ID is read by capturing, through the camera  53 , a sheet on the two-dimensional bar code is output by printing or a screen of a display device on which the two-dimensional bar code is displayed. 
     When the two-dimensional bar code including the URL, the marina ID, and the port departure ID is read in this manner, the download unit  57   a  transmits, by referring to the address of the URL, a request to download the navigation support App including the marina ID and the port departure ID to the server device  10 . As a result, the navigation support App data  56   a  included in the navigation support data  13   b , and navigation support data including various kinds of data (for example, the course data  56   b ) used by the navigation support App are downloaded as the navigation support data  56  from the server device  10 . In addition, for example, the marina ID and the port departure ID are registered to the storage unit  55  for identification of a marina to which the pleasure boat  5  belongs and the pleasure boat  5  itself by the server device  10 . Thereafter, the download unit  57   a  activates the navigation support App data  56   a  downloaded from the server device  10  by loading the navigation support App execution unit  58  onto a work area of a RAM such as the storage unit  55 . 
     The activation of the navigation support App allows the portable terminal device  50  to start providing the navigation support service. After the activation at the portable terminal device  50 , the navigation support App continues operating on background until completion of port departure and port arrival submitted through the port departure notice, irrespective of any operation to end the navigation support App by a user. 
     As illustrated in  FIG. 4 , the navigation support App execution unit  58  includes an acquisition unit  58   a , a first detection unit  58   b , a specification unit  58   c , a second detection unit  58   d , and the data communication unit  58   e.    
     The acquisition unit  58   a  is a processing unit configured to acquire position information. 
     According to the embodiment, the acquisition unit  58   a  acquires position information from the position detection unit  54  at each position detection by the position detection unit  54 . The acquired position information is, for example, latitude and longitude coordinates. The following description assumes an example in which position information sampled in predetermined period, for example, five seconds by the position detection unit  54  is acquired. 
     The first detection unit  58   b  is a processing unit configured to detect a direction in which the position of the pleasure boat  5  changes. 
     According to the embodiment, at each acquisition of position information by the acquisition unit  58   a , the first detection unit  58   b  executes processing as follows. Specifically, the first detection unit  58   b  refers to the course data  56   b  stored as the navigation support data  56  in the storage unit  55 . Then, the first detection unit  58   b  determines whether the position information acquired by the acquisition unit  58   a  is included in a navigation region included in the course data  56   b . When the position information is included in a navigation region included in the course data  56   b , it is identified that the current position of the pleasure boat  5  is in a course. In this case, the first detection unit  58   b  detects the direction of change in the position of the pleasure boat  5  based on the position information acquired by the acquisition unit  58   a  and position information acquired by the acquisition unit  58   a , for example, 30 seconds before the position information. In this exemplary description, the position information acquired 30 seconds before, in other words, six frames before is used to detect the direction of change in the position of the pleasure boat  5 , but any position information acquired in the past, namely, position information acquired N frames (N is a natural number) before may be used. 
     The specification unit  58   c  is a processing unit configured to specify the traveling direction of the pleasure boat  5 . 
     According to the embodiment, when the position information acquired by the acquisition unit  58   a  is included in a navigation region included in the course data  56   b , the specification unit  58   c  specifies, by referring to the course data  56   b , the traveling direction of a course associated with the navigation region in which the position information is included. 
     The second detection unit  58   d  is a processing unit configured to detect reverse run of the pleasure boat  5  in a navigation region. 
     According to the embodiment, the second detection unit  58   d  calculates an angle between the traveling direction of the course specified by the specification unit  58   c  and the direction of change in the position of the pleasure boat  5  detected by the first detection unit  58   b . The angle indicates an angle at which the moving direction of the pleasure boat  5  deviates from the traveling direction of the course, and thus is also referred to as a “course deviation angle”. Then, the second detection unit  58   d  determines whether the course deviation angle is equal to or larger than a predetermined threshold, for example, 90°. When the course deviation angle is equal to or larger than the threshold, it is estimated that the pleasure boat  5  is likely to be reversely running the course. In this case, the second detection unit  58   d  outputs a message telling reverse run in the course as an alert through display on the touch panel  51 , or outputs a sound effect telling reverse run in the course or the above-described message as an alert by voice through a speaker (not illustrated) or the like. The threshold is 90° in this example, but may be 160° or 165° to reduce the occurrence of false reverse-run detection due to error in positioning by the GPS receiver. 
     In addition, the second detection unit  58   d  may set a course reverse-run distance to be the distance between the position information acquired by the acquisition unit  58   a  and position information acquired by the acquisition unit  58   a , for example, 30 seconds before the position information, and may further determine whether the course reverse-run distance is equal to or larger than a predetermined threshold, for example, 30 m. Then, an alert related to course reverse run may be output only when the course reverse-run distance is equal to or larger than the threshold. 
     According to another embodiment, the second detection unit  58   d  calculates an angle identified as a direction opposite to the traveling direction of the course in accordance with the traveling direction of the course specified by the specification unit  58   c . Hereinafter, the angle identified as a direction opposite to the traveling direction of the course is also referred to as a “reverse-run identification angle”. In accordance with the reverse-run identification angle, the second detection unit  58   d  sets a range in which the moving direction of the pleasure boat  5  is identified to be opposite to the traveling direction of the course with respect to position information acquired by the acquisition unit  58   a , for example, 30 seconds before the position information acquisition by the acquisition unit  58   a . Hereinafter, the range in which the pleasure boat  5  is identified to be moving in the direction opposite to the traveling direction of the course is also referred to as a “reverse-run identification range”. 
       FIG. 6  is a diagram for description of an exemplary reverse-run identification range.  FIG. 6  illustrates a case in which the traveling direction of the course is 90° when an azimuth is defined in the clockwise direction with 0° at the up direction, which is North, in  FIG. 6 . In  FIG. 6 , reference sign “P” denotes a position acquired as position information 30 seconds before. In addition, in  FIG. 6 , the reverse-run identification angle is illustrated with a densely dotted part, a non-reverse-run identification angle is illustrated with a sparsely dotted part, and the reverse-run identification range is illustrated with a hatched part. 
     As illustrated in  FIG. 6 , the course has a traveling direction D at the azimuth of 90°, and thus a direction D′ opposite to the traveling direction D of the course is at the azimuth of 270°. Accordingly, the second detection unit  58   d  calculates the reverse-run identification angle to be an angle sandwiched between the azimuth of 255° and the azimuth of 285°, which are obtained by adding a predetermined allowable range±α, for example, ±15° to the opposite direction D′ of the course. Then, the second detection unit  58   d  sets two border lines L 1  and L 2  that define the reverse-run identification range in accordance with the reverse-run identification angle with respect to the position P acquired as position information 30 seconds before. In the example illustrated in  FIG. 6 , the border line L 1  defined by the azimuth of 255° with respect to the position P, and the border line L 2  defined by the azimuth of 285° with respect to the position P are set. Then, the second detection unit  58   d  sets the reverse-run identification range to be the range sandwiched between the two border lines L 1  and L 2 , in other words, the hatched part in  FIG. 6 . 
     After having set the reverse-run identification range, the second detection unit  58   d  determines whether the position information acquired by the acquisition unit  58   a , in other words, the current position of the pleasure boat  5  is included in the reverse-run identification range. When the current position of the pleasure boat  5  is included in the reverse-run identification range, it is determined that the moving direction of the pleasure boat  5  is opposite to the traveling direction of the course. 
     In this case, the second detection unit  58   d  extracts a movement component in the direction opposite to the course from displacement between each pair of temporally sequential pieces of position information among a plurality of pieces of position information acquired over a predetermined past duration, for example, 30 seconds, including the position information acquisition by the acquisition unit  58   a . Subsequently, the second detection unit  58   d  tallies the movement component in the opposite direction, which is extracted for each pair of pieces of position information. Then, the second detection unit  58   d  further determines whether the tallied value of the movement component in the opposite direction is equal to or larger than a predetermined threshold, for example, 30 m. 
     When the tallied value of the movement component in the opposite direction is equal to or larger than the threshold, it is determined that the moving direction of the pleasure boat  5  is opposite to the traveling direction of the course and the amount of movement in the opposite direction is large. In this case, the second detection unit  58   d  outputs a message telling reverse run in the course as an alert through display on the touch panel  51 , or outputs a sound effect telling reverse run in the course or the above-described message as an alert by voice through a speaker (not illustrated) or the like. A diagram such as that illustrated in  FIG. 6  does not necessarily have to be explicitly displayed on a screen, but the reverse-run identification range may be set through calculation by the second detection unit  58   d.    
     The data communication unit  58   e  is a processing unit configured to perform communication such as data uploading and downloading with the server device  10 . 
     According to the embodiment, when a port arrival operation or a port departure operation is received through the touch panel  51 , the data communication unit  58   e  uploads a port departure notification or a port arrival notification to the server device  10 . The data communication unit  58   e  also uploads, only during a sailing duration from reception of a port departure operation to reception of a port arrival operation through the touch panel  51 , position information measured by the position detection unit  54  to the server device  10 . The position information may be uploaded at each measurement of position information by the position detection unit  54 , but may be uploaded in a period longer than a period in which the position detection unit  54  samples the position information. In addition, at each detection of reverse run by the second detection unit  58   d , the data communication unit  58   e  uploads an alert execution notification including the kind of this alert, a marina ID, and a port departure ID to the server device  10 . The data communication unit is an exemplary transmission unit. 
     [Processing Flow] 
       FIG. 7  is a flowchart illustrating the procedure of the alert control processing according to Embodiment 1. For example, the processing is repeatedly executed during a sailing duration from reception of a port departure operation to reception of a port arrival operation through the touch panel  51 . The following description will be made with an example in which port departure and port arrival events are received through the touch panel  51 , but a sailing duration may be specified by automatically determining departure and arrival of the pleasure boat  5  from and at a port by using an existing technology. 
     As illustrated in  FIG. 7 , the specification unit  58   c  acquires the course data  56   b  stored in the storage unit  55  (step S 101 ). Thereafter, the acquisition unit  58   a  acquires position information through the position detection unit  54  (step S 102 ). 
     Subsequently, the specification unit  58   c  determines whether the position information acquired at step S 102  is included in a navigation region included in the course data  56   b  acquired at step S 101  (step S 103 ). When the position information is included in the navigation region (Yes at step S 103 ), it is identified that the current position of the pleasure boat  5  is in the course. In this case, the specification unit  58   c  specifies the traveling direction of the course associated with the navigation region in which the position information acquired at step S 102  is included among traveling directions included in the course data  56   b  acquired at step S 101  (step S 104 ). 
     Then, the second detection unit  58   d  sets the reverse-run identification range based on the traveling direction of the course specified at step S 104  and position information acquired by the acquisition unit  58   a , for example, 30 seconds before the position information acquisition at step S 102  (step S 105 ). 
     Subsequently, the second detection unit  58   d  determines whether the position information acquired at step S 102 , in other words, the current position of the pleasure boat  5  is included in the reverse-run identification range set at step S 105  (step S 106 ). When the current position of the pleasure boat  5  is included in the reverse-run identification range (Yes at step S 106 ), it is determined that the moving direction of the pleasure boat  5  is opposite to the traveling direction of the course. 
     In this case, the second detection unit  58   d  tallies a movement component in the opposite direction of the course, which is extracted for each pair of temporally sequential pieces of position information among a plurality of pieces of position information acquired over predetermined past duration, for example, 30 seconds including the position information acquisition at step S 102  (step S 107 ). Then, the second detection unit  58   d  further determines whether the tallied value of the movement component in the opposite direction, which is obtained at step S 107  is equal to or larger than a predetermined threshold, for example, 30 m (step S 108 ). 
     When the tallied value of the movement component in the opposite direction is equal to or larger than the threshold (Yes at step S 108 ), it is determined that the moving direction of the pleasure boat  5  is opposite to the traveling direction of the course and the amount of movement in the opposite direction is large. In this case, the second detection unit  58   d  outputs a message telling reverse run in the course as an alert through display on the touch panel  51 , or outputs a sound effect telling reverse run in the course or the above-described message as an alert by voice through a speaker (not illustrated) or the like (step S 109 ), and the process transitions to step S 102 . 
     When the position information is not included in the navigation region (No at step S 103 ), when the current position of the pleasure boat  5  is not included in the reverse-run identification range (No at step S 106 ), or when the tallied value of the movement component in the opposite direction is smaller than the threshold (No at step S 108 ), outputting of an alert related to course reverse run is canceled (step S 110 ), and the process transitions to step S 102 . Specifically, when an alert related to course reverse run has been output based on position information sampled before position information sampling at step S 102 , the alert outputting is canceled. When no alert related to course reverse run has been output, the processing at step S 110  is skipped. 
     [Aspects of Effects] 
     As described above, the navigation management support system  1  according to the present embodiment detects reverse run of a ship in a navigation region in which position information of the ship is included based on an angle between the direction of change in the position of the ship, which is determined from the locus of the position information and the traveling direction of the course, which is stored in association with the navigation region. Accordingly, the navigation management support system  1  according to the present embodiment is capable of detecting reverse run of a ship. 
     Embodiment 2 
     Although the embodiment related to devices according to the disclosure is described above, the present disclosure may be achieved in various kinds of different configurations other than the above-described embodiment. The following describes any other embodiment included in the disclosure. 
     [Processing Executor] 
     In Embodiment 1 described above, the processing illustrated in  FIG. 7  is executed by the portable terminal device  50 , but the executor of the processing is not limited to the portable terminal device  50 . Specifically, the processing illustrated in  FIG. 7  may be executed by the server device  10 . In this case, the server device  10  may execute the navigation support App on a processor. Specifically, the server device  10  stores, in the storage unit  13 , the navigation data  13   c  as distribution original data of the navigation support data  56 . Accordingly, the server device  10  is capable of executing the processing illustrated in  FIG. 7  through by periodically transmitting position information from the portable terminal device  50  to the server device  10  to prepare all data to be used in the processing illustrated in  FIG. 7 . 
     [Separation and Integration] 
     The components of each device illustrated in the drawings do not necessarily have to be physically configured as illustrated. Specifically, a specific configuration of separation and integration of the devices is not limited to that illustrated in the drawings, but all or part of the configuration may be functionally or physically separated or integrated in arbitrary units in accordance with, for example, various loads and use statuses. For example, the distribution unit  15   a , the navigation recording unit  15   b , the alert reception unit  15   c  or the map display unit  15   d  may be provided as an external device of the server device  10  and connected with the server device  10  through a network. In addition, part or all of the processing units included in the navigation support App execution unit  58  may be provided as external devices of the portable terminal device  50  and connected with the portable terminal device  50  through a network. For example, the server device  10  may include part of the processing units included in the navigation support APP execution unit  58 . 
     [Reverse-Run Detection Program] 
     The various kinds of processing described in the above-described embodiments may be achieved by a computer, such as a personal computer or a work station, executing a computer program prepared in advance. The following describes, with reference to  FIG. 8 , an exemplary computer configured to execute a reverse-run detection program having functions same as those in the above-described embodiments. 
       FIG. 8  is a diagram illustrating an exemplary hardware configuration of the computer configured to execute the reverse-run detection program according to Embodiments 1 and 2. As illustrated in  FIG. 8 , a computer  100  includes an operation unit  110   a , a speaker  110   b , a camera  110   c , a display  120 , and a communication unit  130 . The computer  100  also includes a CPU  150 , a ROM  160 , a HDD  170 , and a RAM  180 . These components  110  to  180  are connected with each other through a bus  140 . 
     As illustrated in  FIG. 8 , the HDD  170  stores a reverse-run detection program  170   a  configured to achieve a function same as that of the navigation support App execution unit  58  described above in Embodiment 1. Similarly to the components of the navigation support App execution unit  58  illustrated in  FIG. 4 , the reverse-run detection program  170   a  may be integrated or separated. Specifically, the HDD  170  does not necessarily have to store all data described above in Embodiment 1, but may only store data used in processing. 
     Under such an environment, the CPU  150  reads the reverse-run detection program  170   a  from the HDD  170  and then loads the reverse-run detection program  170   a  onto the RAM  180 . As a result, as illustrated in  FIG. 8 , the reverse-run detection program  170   a  functions as a reverse-run detection process  180   a . The reverse-run detection process  180   a  loads various kinds of data read from the HDD  170  onto a region allocated to the reverse-run detection process  180   a  among storage regions included in the RAM  180 , and executes various kinds of processing by using the loaded various kinds of data. Examples of processing executed by the reverse-run detection process  180   a  include the processing illustrated in  FIGS. 7 to 9 . Not all processing units described above in Embodiment 1 necessarily have to operate on the CPU  150 , but only a processing unit corresponding to processing to be executed may be virtually achieved. 
     The reverse-run detection program  170   a  does not necessarily have to be initially stored in the HDD  170  or the ROM  160 . For example, each computer program may be stored in a “portable physical medium” such as a flexible disk (FD), a CD-ROM, a DVD disk, a magneto-optical disc, or an IC card to be inserted into the computer  100 . Then, the computer  100  may acquire the computer program from the portable physical medium and execute the computer program. Alternatively, each computer program may be stored in another computer or a server device connected with the computer  100  through a public line, the Internet, a LAN, or a WAN, and the computer  100  may acquire the computer program from the other computer or the server device and execute the computer program. 
     All examples and conditional language recited herein are intended for pedagogical purposes to aid the reader in understanding the invention and the concepts contributed by the inventor to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions, nor does the organization of such examples in the specification relate to a showing of the superiority and inferiority of the invention. Although the embodiments of the present invention have been described in detail, it should be understood that the various changes, substitutions, and alterations could be made hereto without departing from the spirit and scope of the invention.