JP5873236B2 - Attendance management method and system - Google Patents

Description

  The present invention relates to an attendance management method and system, and more particularly to an attendance management method and system suitable for managing whether or not a student is attending a class.

  In lectures held at universities, student attendance is managed as part of grade evaluation. Traditional attendance management methods include call-back by teachers, distribution of paper-based attendance cards and collection of attendees' names and student ID numbers. Time and labor are a heavy burden on teachers, and especially in lectures with many attendees, an increase in work volume and work time becomes a problem. In addition, in the above attendance management, fraud such as a fake attendance where one attendee pretends to be a plurality of attendees and a surrogate attendance where another attends on behalf of the original attendee cannot be checked.

  In response to such a technical problem, Patent Document 1 discloses a method in which an attendee confirms attendance by connecting to a web server from a confident cellular phone. In this system, a central device as a web server computer and a terminal device such as a mobile phone connected to and communicate with the central device are used, and the central device is connected from a terminal device operated by a student who should attend a lecture. If the connection is established in response to the request and the presence information is received multiple times from the terminal device, if the received presence information is valid and the established connection is not disconnected, the terminal device It is determined that the student to be operated is present.

  Patent Document 2 discloses an attendance confirmation method in which attendees send e-mails that answer questions using their mobile phones. In this method, attendees who attend a specific lecture input attendance information for the lecture together with their own identification information and transmit the information to indicate that they have attended. Before and after this, the question information related to the information transmitted in the lecture is transmitted / displayed on the attendee's mobile terminal, and the attendee sends the answer to the question based on the information transmitted in the lecture to the mobile terminal. The response information is stored in association with the attendee identification information. An administrator such as a teacher can confirm whether the sender of the email was actually present by checking the attendance information and the answer information.

  Patent Document 3 discloses an attendance confirmation method that performs code authentication by mail. In this method, a student database with an attendance table for each student's course, using an email address as a key, an authentication code database with an authentication code for each course and the validity period of that code, and a mail server are provided. When the authentication code is notified in the classroom, the authentication code is written in the subject of the mobile mail and sent to the mail server. The mail server collates the authentication code of the received mail, the validity period of the code, and the mail address with the database, and if it can be collated, registers attendance and returns the mail. As a result, the burden on the student can be reduced because the student can simply enter the authentication code in the email and send it.

  Patent Document 4 discloses an attendance confirmation method that performs two-step determination of voice recognition and image recognition. In this method, in order to reduce the work burden at the time of attendance confirmation, the attendance confirmer terminal transmits the voice information of the attendance confirmer and the captured image with the attendance confirmed person as the subject to the server device, and the server device It is determined whether or not the information is the same as the information registered therein.

  Patent Document 5 discloses a method for confirming attendance using RFID. In this system, a terminal unit with a built-in RFID reader / writer that reads an IC card that stores the attendee ID information that identifies the attendee is installed at the seating location, and the attendee places the IC card close to the terminal unit to obtain the ID information. At the receiving end, the PC screen has the function of displaying the seating chart, and the attendance is determined by displaying the color of the screen display of the seat on which the IC card is placed on the terminal unit.

JP 2005-128885 JP 2007-334652 JP 2009-290525 A JP 2008-262271 A JP 2008-009558 A

  In Patent Document 1, since the mobile phone can communicate with the web server computer that manages the attendance status via the Internet, by transmitting data indicating that the absent person who has not attended the lecture is attending from outside the classroom Unauthorized attendance can be done easily.

  According to Patent Document 2, the attendees enter the answers to the questions several times during the class based on the identification information transmitted in the lecture and send them to the mobile terminal, including late arrivals and leaving the class. It is possible to confirm attendance with higher accuracy. However, since identification information is easily leaked by means of communication such as e-mail or SMS, absentees at remote locations can obtain the identification information in a short time, or two mobile phone terminals together with their own It is not possible to deal with camouflaged attendance, such as simultaneously operating in the classroom to send confirmations. In addition, attending on behalf of the person himself / herself and filling out the questions is not possible. In addition, identification information (answers to questions) must be entered one by one during the course of the lecture, so there is a problem that the operation is complicated and erroneous input is likely to occur.

  In Patent Document 3, since the authentication code is only transmitted by e-mail instead of the answer to the question, the input burden is reduced compared to Patent Document 2. However, this system cannot prevent proxy attendance as in Patent Document 2. In addition, the authentication code must be input several times, and there is still a problem that the work load during the course cannot be ignored.

  In Patent Document 4, by introducing biometric authentication by voice recognition and face recognition, fraudulent attendance and proxy attendance fraud can be prevented. Since operations for photographing and transmission are required, there is a problem that an input burden is extremely large.

  In Patent Document 5, attendance information can be easily obtained by associating an IC card with an individual. However, this method makes it easy to attend by proxy because the IC card owner cannot be associated with the actual attendee. In addition, since a dedicated card reader must be provided for each seat, the system configuration becomes complicated.

  An object of the present invention is to provide an attendance management method and system capable of solving the above-described problems of the prior art and preventing impersonation attendance and proxy attendance with a simple system configuration while minimizing the burden on attendance managers. It is in.

  In order to achieve the above object, the present invention provides an attendance in which a plurality of wireless access points are distributed in a space where attendees gather, and attendance is managed based on communication between each wireless access point and the attendee's wireless terminal. The management system is characterized by the following measures.

  (1) A management table for storing attribute information of candidate attendees in association with identification information of wireless terminals, means for storing location information of each wireless access point, and a search request message from each wireless access point to each wireless terminal. Means for transmitting, means for measuring the received radio wave intensity of the search response message returned from each wireless terminal and received by each wireless access point, means for identifying the wireless terminal that has returned the search response message, and the same radio Means for estimating the current position of each wireless terminal based on the received radio wave intensity of the search response message returned from each terminal and received by each wireless access point and the position information of each wireless access point; Thus, attribute information of candidate attendees who own the respective wireless terminals is arranged at positions corresponding to the estimated positions of the respective wireless terminals. And means for creating a situation map, equipped with a means for displaying the attendance map.

  (2) The attribute information includes face images of candidate attendees, means for photographing the space, and extracts the face images of the attendee from the photographed video, and stores them in association with the position information in the space Means for creating an attendance situation map is arranged in the attendance situation map together with face images of candidate attendees who own the wireless terminal, extracted from the estimated position of the wireless terminal To do.

  (3) The attendance face map extracted at the estimated position of the wireless terminal is further compared with the face image of the candidate attendee who owns the wireless terminal to determine the identity, and an attendance situation map is created. The means for placing the determination result in the attendance situation map.

  According to the present invention, the following effects are achieved.

  (1) Since the attribute information of candidate attendees who own each wireless terminal is displayed at a position corresponding to the estimated position of the wireless terminal on the map simulating the classroom, instructors who manage attendance in the classroom By comparing the position of each attendee and the attribute information displayed at the estimated position of each wireless terminal on the map, it is possible to detect fraudulent acts such as fake attendance and proxy attendance.

  (2) Extract the attendee's face image from the video taken in the classroom, and the face image of the attendee candidate who owns the wireless terminal at the estimated position of each wireless terminal on the map simulating the classroom, and the estimated The attendee's face image extracted from the video at the position is displayed together, so it is possible to detect the proxy attendance simply by comparing the two.

  (3) Extract the attendee's face image from the video taken in the classroom, and the face image of the candidate attendee who owns the wireless terminal at the estimated position of each wireless terminal on the map simulating the classroom, and the estimated Since the matching result with the face image of the attendee extracted from the video at the position is displayed, it is possible to easily detect the attendance of the substitute.

It is the figure which showed the structure of 1st Embodiment of the attendance management system which concerns on this invention. It is the functional block diagram which showed the structure of 1st Embodiment of an attendance management apparatus. It is a sequence flow of a 1st embodiment. It is the figure which showed the position estimation method of the radio | wireless terminal based on the distance of a radio | wireless terminal and radio | wireless AP. It is the figure which showed the position estimation method of the radio | wireless terminal in this invention. It is the figure which showed an example of the attendance status map. It is the figure which showed the other example of a display of the attendee's symbol mark. It is the figure which showed the structure of 2nd Embodiment of the attendance management system which concerns on this invention. It is the functional block diagram which showed the structure of 2nd Embodiment of an attendance management apparatus. It is the figure which showed an example of the attendance status map in 2nd Embodiment. It is the functional block diagram which showed the structure of 3rd Embodiment of an attendance management apparatus. It is the figure which showed an example of the attendance status map in 3rd Embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a diagram showing a configuration of a first embodiment of an attendance management system according to the present invention, an attendance management apparatus 1 managed by a lecturer or attendance manager (hereinafter, represented by a lecturer 4), and this A plurality (three in this embodiment) of wireless access points (AP) 2a, 2b, 2c connected to the attendance management apparatus 1 via a home LAN, and mobile phones owned by the attendees Ua, Ub, Uc. , PDA, PC, smart phone and other portable wireless terminals 3a, 3b, 3c (hereinafter, represented by wireless terminal 3).

  The three wireless access points 2a, 2b, and 2c are distributed in a space such as a classroom or a venue where attendees gather, and all the wireless access points 2 have a communication range within the space. Each wireless access point 2 and wireless terminal 3 are mounted with a Bluetooth (registered trademark) module and perform short-range wireless communication with each other using a communication protocol compliant with Bluetooth.

  FIG. 2 is a functional block diagram showing the configuration of the main part of the attendance management apparatus 1. Here, the configuration unnecessary for the description of the present invention is omitted.

  The database (DB) 101 includes a management table 101a that stores attribute information of all attendee candidates and identification information (MAC addresses in the present embodiment) unique to the attendee candidate wireless terminals 3 in association with each other. AP location information 101b for managing the installation location of each wireless access point 2 is stored. In this embodiment, face image, gender, mobile phone number, student ID number, name, courses taken, number of classes, room information, attendance status, etc. are stored as attribute information of each attendee candidate. In this embodiment, a candidate for attendance is a student who has registered for a lecture if the subject of attendance management is a university lecture.

  The search request unit 102 transmits a search request message from each wireless access point 2 to all wireless terminals 3. The reception strength acquisition unit 103 returns the received radio wave strength of the search response message returned from each wireless terminal 3 and received by each wireless access point 2, the identification information IDap of the wireless access point 2 that received the message, and the message. Acquired together with the MAC address of the wireless terminal 3 that has returned.

  Based on the received radio wave intensity measured for each wireless access point 2 with respect to the same search response message and the installation position of each wireless access point 2, the terminal position estimation unit 104, for example, the current position of the wireless terminal 3 based on the principle of triangulation Estimate the position. The attendance situation map creation unit 105 includes an attribute information extraction unit 105a, creates an attendance situation map that associates the estimated position of each wireless terminal 3 with the attribute information of the candidate attendees who own the wireless terminal 3, and displays the attendance situation map on the display 106. .

  Next, the operation of the first embodiment of the present invention will be described in detail with reference to the sequence flow of FIG. When a search request is instructed from the search request unit 102 of the attendance management device 1 to each wireless access point 2a, 2b, 2c at times t1, t2, t3, at each time t4, t5, t6, each wireless access point 2a, A search request message is transmitted from 2b and 2c into the classroom. At times t7, t8, and t9, a search response message is returned from the wireless terminal 3 in response to each search request message. At time t10, each wireless access point 2a, 2b, 2c measures the received radio wave intensity of each search response message and extracts the MAC address of the wireless terminal described as the transmission source ID in the message.

  In Bluetooth, in order to search for the presence / absence of a terminal having a Bluetooth communication function and the received radio wave intensity, an “Inquiry With RSSI” command having high-speed response by asynchronous communication is prepared. "Inquiry With RSSI" communicates while periodically switching the use frequency by frequency hopping, sends a search request to all Bluetooth frequency bands, and finds the MAC address and received radio wave intensity of the discovered wireless terminal You can get it. The RSSI (Received Signal Strength Indicator) expresses the strength of the received radio wave signal at the wireless access point 2, and if this value increases, the communication distance is near and a strong signal is received. Conversely, the communication distance increases as the value decreases. There is evidence that the signal is far away. The Class 1 standard RSSI range is -127 dBm to 20 dBm, and stable response information can be obtained up to a radius of several tens of meters.

  At times 11, t12, and t13, the extracted MAC address and received radio wave strength pair is notified to the received strength acquisition unit 103 of the attendance management device 1 together with the identification information IDap of the wireless access point 2 that has received the search response message. Is done. At time t14, the received radio wave intensity and the identification information IDap of the wireless access point are totaled for each MAC address of each wireless terminal 3 and notified to the terminal position estimating unit 104.

  At time t15, the terminal position estimation unit 104 acquires the position information of the installation position from the DB 101 based on the identification information IDap of each wireless access point 2a, 2b, 2c. At time t16, the terminal location estimation unit 104 receives the location information of each wireless access point 2a, 2b, 2c and three search response messages received from the same wireless terminal 3 by each wireless access point 2a, 2b, 2c. Based on the received radio wave intensity, the current position is estimated for each wireless terminal 3 as follows.

  That is, the property (distance attenuation) that the received radio wave intensity attenuates in inverse proportion to the distance in Bluetooth communication can be modeled by an exponential distribution. The distance r from the wireless terminal 3 to the wireless access point 2 and the received radio wave intensity σ ( The relationship with r) is given by the following equation (1). Here, the constant C and the attenuation coefficient α are determined when modeling the propagation environment by measuring the radio wave intensity while changing the distance r in the actual environment. The following equation (1) indicates that the received radio wave intensity at each wireless access point 2 of the search response message returned from the wireless terminal 3 at each sample position for each sample position in the space such as a classroom or a venue is the wireless access point. Is stored as an exponential distribution model that decays in inverse proportion to the distance r.

  Therefore, as shown in FIG. 4, if the distances r1, r2, r3 from the three wireless access points 2a, 2b, 2c to the wireless terminal 3 are obtained, the position of the wireless terminal 3 is determined from each wireless access point 2. It is obtained as a point where three circles with radii r1, r2, and r3 intersect. However, the distance r obtained from the radio wave reception intensity is theoretical, and it is rare that three circles intersect at one point. This is because a radio wave transmitted from a transmitter via Bluetooth communication passes through various paths depending on the direction and arrives at a receiver (multipath fading characteristics). Therefore, a direct wave, a reflected wave, or a transmitted wave is used as a received wave. It is because it is included.

  In general, it is known that the influence of multipath fading characteristics on received radio wave intensity can be modeled using a probability distribution. The following equation (2) shows a conditional probability density function p (P | r) of the received radio wave intensity P in consideration of multipath fading characteristics.

  Here, the position of the wireless terminal 3 is assumed to be a distance θ = (r1, r2, r3) from each wireless access point, and the search response message transmitted from this wireless terminal is transmitted at each wireless access point 2a, 2b, 2c. If the received signal strength is P = (P1, P2, P3), the probability that the received signal strength measured at each wireless access point is p can be expressed as a conditional probability density function p (P | θ). it can. Here, when the propagation path between the wireless terminal and each wireless access point is considered to be independent, the conditional probability density function p (P | θ) is expressed by the following equation (3). It can be expressed as a product of conditional probability density functions at each position.

  In this embodiment, the conditional probability density function p (P1 |) of the received radio field strength P is applied by applying the received radio field strengths P1, P2, and P3 measured at the wireless access points 2a, 2b, and 2c to the above equation (2). r1), p (P2 | r2), p (P2 | r2) are obtained, and the product p (P | θ) is used as a likelihood function, and the likelihood function among n sample positions θ1, θ2,. θ that maximizes p (P | θ) is estimated as the position of the wireless terminal 3.

  In the embodiment, by applying the radio wave reception intensity measured at the wireless access points 2a, 2b, and 2c to the above equation (1), the existence range Q of the wireless terminal 3 is narrowed down in advance as shown in FIG. Next, a sample position θmax that maximizes the above equation (3) is obtained from the n sample positions θ1 to θn distributed within the existence range Q, and this is estimated as the position of the wireless terminal 3. Therefore, if the number of wireless access points is increased, the position of the wireless terminal 3 can be estimated more accurately.

  Returning to FIG. 3, at time t <b> 17, the estimated position of each wireless terminal 3 is notified to the attendance situation map creation unit 105. At time t18, the attribute information of each attendee associated with the MAC address of each wireless terminal 3 is taken from the management table 101a of the DB 101 by the attribute information extraction unit 105a. At time t19, an attendance situation map is created that visually indicates the estimated position of each wireless terminal 3 together with the attribute information of the owner. At time t20, the attendance status map is displayed on the display 106. In the present embodiment, each process from time t1 to time t20 is repeated at a predetermined cycle.

  FIG. 6 is a diagram showing an example of the attendance status map. At the position on the display 106 corresponding to the estimated position of the wireless terminal 3, along with the attendance symbol mark 51, the attendee candidates who own the wireless terminal Are displayed in a list. Therefore, instructors who manage attendance compare this attendance situation map with the actual seating position of each attendee, for example, if there are fewer actual attendees than the number of attendance symbol marks, Even if the gender in the attribute information attached to the attendance symbol is “male”, if the actual attendee seated at that position is a female, the surrogate attendance is missed be able to.

  FIG. 7 is a view showing another display example of the attendance symbol mark 51. In the example of FIG. 6, a common symbol mark is used for all attendances. In this example, the face images of each attendee candidate managed as one of the attribute information are used as the attendance symbol marks. Yes. In this way, if the face information of each attendee candidate is used as the attendance symbol mark 51, the representative attendance can be almost surely made by comparing each face image on the attendance situation map with the actual face of each attendee. You can see through.

  Next, a second embodiment of the present invention will be described. FIG. 8 is a diagram showing the configuration of the attendance management system according to the second embodiment of the present invention. Since the same reference numerals as those described above represent the same or equivalent parts, description thereof will be omitted. The present embodiment is different from the first embodiment in that it includes a camera 5 that captures the faces of attendees in the classroom.

  FIG. 9 is a functional block diagram showing the configuration of the main part of the attendance management apparatus 1 in the present embodiment, and here again, the same reference numerals represent the same or equivalent parts, and the description thereof will be omitted. .

  The face recognition unit 107 identifies each attendee's face area from the video in the classroom photographed by the camera 5, extracts the face image, and temporarily stores it along with the position in the classroom. In the attendance status map creation unit 105, the attribute information extraction unit 105a extracts a face image as one piece of attribute information of the owner (participant candidate) of each wireless terminal 3 whose position is estimated, and the face recognition unit 107 Thus, an attendance situation map in which the face image of the attendee extracted at the estimated position of each wireless terminal 3 and the face image as the attribute information are written together is created and output to the display 106.

  FIG. 10 is a diagram illustrating a display example of the attendance situation map in the present embodiment, and attendances that own the wireless terminal 3 are located at positions on the screen corresponding to positions where the wireless terminal 3 is estimated to exist. Along with the face image (attribute information) of the candidate, the face image of the attendee photographed by the camera 5 at the estimated position is displayed side by side.

  According to this embodiment, the face image of the attribute information previously associated with the attendee's wireless terminal 3 and the face image recognized at the estimated position of the wireless terminal 3 are written together at the corresponding position on the display 106. Will be able to see the proxy attendance.

  Next, a third embodiment of the present invention will be described. Unlike the first embodiment, this embodiment differs from the first embodiment in that the camera 5 for photographing the attendee's face is provided in the classroom, as in the second embodiment, and the attendance situation map creation unit 105 includes a face matching unit 105b. This is different from the second embodiment.

  The face collating unit 105b is a face image extracted by the attribute information extracting unit 105a as one of the attribute information of the owner (participant candidate) of each wireless terminal 3 estimated by the terminal position estimating unit 104; The face recognition unit 107 compares the face images of the attendees extracted at the estimated position of each wireless terminal 3 to determine whether or not they match, and creates and displays an attendance situation map including the determination result. The data is output to 106.

  FIG. 12 is a diagram illustrating a display example of an attendance situation map in the present embodiment, and attendances that own the wireless terminal 3 are located at positions on the screen corresponding to positions where the wireless terminal 3 is estimated to exist. The face image of the candidate and the face image of the attendee photographed by the camera 5 at the position are displayed side by side, and the match / mismatch determination result by the face matching unit 105b is also displayed.

  In this embodiment, fraud such as proxy attendance and camouflage attendance can be automatically detected, so the above attendance confirmation was conducted at least twice, including the first and second half of the class, and regular attendance was confirmed in the first half. In the latter half of the thing, if the absence or fraud is confirmed, it may be treated as early departure, and conversely, in the first half, if the absence or fraud is confirmed, the latter part may be treated as late if the regular attendance is confirmed.

  According to the present embodiment, a teacher or the like who manages attendance uses the face matching unit 105b without comparing himself / herself with a face image of an attendee candidate selected from the identification information of the wireless terminal 3 by himself / herself. Based on the judgment result, it will be possible to see the attendance of the substitute or the camouflage.

  In each of the above embodiments, the present invention has been described as an example of applying the present invention to attendance confirmation for lectures and classes, but the present invention is not limited to this, and conferences, meetings, academic conferences, The same applies to checking the attendance status of individuals for work management or various events.

  In the above embodiment, the wireless terminal 3 and the wireless access point 2 have been described as performing Bluetooth communication. However, the present invention is not limited to this, and other wireless LAN, ZigBee, UWB, and the like can be used. The short-range wireless communication method may be used.

  DESCRIPTION OF SYMBOLS 1 ... Attendance management apparatus, 2 ... Wireless access point, 3 ... Wireless terminal, 5 ... Camera

Claims (8)

In an attendance management system in which a plurality of wireless access points are distributed in a space where attendees gather, and attendance is managed based on communication between each wireless access point and the attendee's wireless terminal.
A management table for storing attribute information of candidate attendees in association with identification information of the wireless terminal;
Means for storing location information of each wireless access point;
Means for transmitting a search request message from each wireless access point to each wireless terminal;
Means for measuring a received radio wave intensity of a search response message returned from each wireless terminal and received at each wireless access point;
Means for identifying the wireless terminal that has returned the search response message;
Means for estimating the current position of each wireless terminal based on the received radio wave intensity of the search response message received from each wireless access point and returned from the same wireless terminal, and the position information of each wireless access point;
Means for creating an attendance situation map in which attribute information of candidate attendees possessing each wireless terminal is arranged at a position corresponding to the estimated position of each wireless terminal on a map simulating the space;
An attendance management system comprising: means for displaying the attendance status map.   2. The attribute information includes attendee candidate face images, and the means for creating the attendance status map places the face images of each attendee candidate at an estimated position of each wireless terminal. Attendance management system. The attribute information includes attendee candidate face images,
Means for photographing the space;
Means for extracting an attendee's face image from the captured video and storing it in association with positional information in the space;
The means for creating the attendance situation map arranges the attendee's face image extracted at the estimated position of the wireless terminal together with the face images of candidate attendees possessing the wireless terminal in the attendance situation map, The attendance management system according to claim 1. Further comprising means for comparing the face image of the attendee extracted at the estimated position of the wireless terminal with the face image of the candidate attendee who owns the wireless terminal to determine identity;
4. The attendance management system according to claim 3, wherein the means for creating the attendance status map places the determination result in the attendance status map. The means for estimating the current position of the wireless terminal is:
Exponential distribution in which the received radio wave intensity at each radio access terminal of the search response message returned by the radio terminal at the sample position attenuates in inverse proportion to the distance to each radio access point for each of a plurality of sample positions in the predetermined space Means for storing the model;
Means for estimating the presence range of the wireless terminal based on the radio wave reception intensity at each wireless access point;
The maximum likelihood sample position is estimated from each sample position within the estimation range based on the exponential distribution model, and the sample position is set as an estimated position of a wireless terminal. Attendance management system described in.   The attendance management system according to claim 1, wherein the wireless terminal and the wireless access point communicate with each other by Bluetooth (registered trademark). The determination of the identity of the face image is performed in the first half and second half of a predetermined period of time, the determination result is set to leave early treatment if Re matching Der only in the first half, and late treatment if Re matching Der only in the second half The attendance management system according to claim 4. In an attendance management method that is connected to a plurality of wireless access points distributed in a predetermined space and manages attendance based on communication between each wireless access point and a wireless terminal owned by an attendee,
An attendance management system comprising a management table that stores attribute information of attendee candidates in association with identification information of a wireless terminal and means for storing location information of each wireless access point,
A search request message is transmitted from each wireless access point to each wireless terminal;
Measure the received radio wave intensity of the search response message that is returned from each wireless terminal and received at each wireless access point,
Identifying the wireless terminal that has returned the search response message;
Estimating the current position of each wireless terminal based on the received radio wave strength of the search response message received from each wireless access point that is returned from the same wireless terminal and the position information of each wireless access point,
Create an attendance situation map in which attribute information of candidate attendees who own each wireless terminal is arranged at a position corresponding to the estimated position of each wireless terminal on the map imitating the predetermined space,
An attendance management method comprising displaying the attendance status map.

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