Patent Publication Number: US-11023844-B2

Title: Flight attendant evaluation system and flight attendant evaluation method

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application is a continuation of U.S. application Ser. No. 15/800,077, filed Nov. 1, 2017, which claims the benefit of Japanese Application No. 2016-226694, filed Nov. 22, 2016. The contents of each of the above-mentioned documents are expressly incorporated herein by reference in their entireties. 
    
    
     BACKGROUND 
     1. Technical Field 
     The present disclosure relates to a technique for evaluating a flight attendant who provides service for a customer in transportation such as an airplane. 
     2. Description of the Related Art 
     In recent years, various techniques have been suggested which use vital data of a person to estimate stress to the person. Accordingly, studies of techniques for providing various services for users by using the technique have been progressing. Japanese Unexamined Patent Application Publication No. 2016-101307 discloses a technique for assessing stress to a target person from biological information of the target person who sits on a seat of an airplane. 
     SUMMARY 
     One non-limiting and exemplary embodiment provides a technique for evaluating a flight attendant by using biological data of a customer. 
     In one general aspect, the techniques disclosed here feature a flight attendant evaluation system including: a first biological sensor that measures first biological data of a customer on board transportation; a storage that stores attendant-associated data in which the first biological data, a seat identifier, and an attendant identifier are associated with each other, the seat identifier indicating a seat of the customer on board, the attendant identifier indicating a flight attendant in charge of the seat; an evaluation value calculator that classifies the attendant-associated data by the attendant identifier, calculates a stress indicator of the customer based on the first biological data associated with a first attendant identifier, and calculates an evaluation value of the flight attendant indicated by the first attendant identifier based on the stress indicator; and a display apparatus that presents the evaluation value. 
     It should be noted that general or specific embodiments may be implemented as an element, a device, an apparatus, a system, an integrated circuit, a method, or any selective combination thereof. 
     Additional benefits and advantages of the disclosed embodiments will become apparent from the specification and drawings. The benefits and/or advantages may be individually obtained by the various embodiments and features of the specification and drawings, which need not all be provided in order to obtain one or more of such benefits and/or advantages. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a diagram that illustrates one example of a general configuration of a flight attendant evaluation system according to a first embodiment of the present disclosure; 
         FIG. 2  is a block diagram that illustrates a configuration of the flight attendant evaluation system according to the first embodiment of the present disclosure; 
         FIG. 3  is a diagram that illustrates one example of a data configuration of a saved biological table that is stored in a biological data storage unit; 
         FIG. 4  is a diagram that illustrates one example of a data configuration of an assigned seat table; 
         FIG. 5  is a diagram that illustrates one example of a seat arrangement diagram which illustrates arrangement of seats in a cabin of an airplane; 
         FIG. 6  is a diagram that illustrates one example of a data configuration of an attendant-associated table; 
         FIG. 7  is a diagram that illustrates one example of a data configuration of an evaluation table; 
         FIG. 8  is a diagram that illustrates one example of a data configuration of an attendant table; 
         FIG. 9  is a diagram that illustrates one example of an evaluation image that is displayed by an evaluation display apparatus; 
         FIG. 10  is a flowchart that illustrates one example of a process from measurement of biological data to calculation of an evaluation value in the flight attendant evaluation system according to the first embodiment of the present disclosure; 
         FIG. 11  is a flowchart that illustrates one example of a process of presenting the evaluation value in the flight attendant evaluation system according to the first embodiment of the present disclosure; 
         FIG. 12  is a diagram that illustrates one example of a general configuration of a flight attendant evaluation system according to a second embodiment of the present disclosure; 
         FIG. 13  is a block diagram that illustrates a configuration of the flight attendant evaluation system according to the second embodiment of the present disclosure; 
         FIG. 14  is a diagram that illustrates one example of a data configuration of a first saved biological table in which first saved biological data are registered in the second embodiment of the present disclosure; 
         FIG. 15  is a diagram that illustrates one example of a data configuration of second saved biological data according to the second embodiment of the present disclosure; 
         FIG. 16  is a diagram that illustrates one example of a data configuration of an attendant-associated table in which attendant-associated data are registered according to the second embodiment of the present disclosure; 
         FIG. 17  is a flowchart that illustrates one example of a process from measurement of the first and second biological data to calculation of the evaluation value in the flight attendant evaluation system according to the second embodiment of the present disclosure; 
         FIG. 18  is a flowchart that illustrates one example of a process from measurement of the biological data to calculation of the evaluation value in a flight attendant evaluation system according to a third embodiment of the present disclosure; 
         FIG. 19  is a flowchart that illustrates one example of an evaluation value calculation process illustrated in  FIG. 18 ; 
         FIG. 20  is a diagram that illustrates one example of a data configuration of a reservation information table that is used in the flight attendant evaluation system according to the third embodiment of the present disclosure; and 
         FIG. 21  is a diagram that illustrates one example of a data configuration of a customer table that is used in the flight attendant evaluation system according to the third embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     (Underlying Knowledge Forming Basis of the Present Disclosure) 
     Above Japanese Unexamined Patent Application Publication No. 2016-101307 discloses a technique of detecting biological information of a target person who sits on a seat by a pressure sensing tube provided to the seat of an airplane, assessing stress of the target person from the detected biological information, and performing a notification to a flight attendant, a pilot, or the like in a case where the assessed stress is high. 
     However, a fundamental purpose of Japanese Unexamined Patent Application Publication No. 2016-101307 is to provide a biological information acquisition apparatus that may improve detection accuracy of the biological information of the target person (paragraph [0008]). Japanese Unexamined Patent Application Publication No. 2016-101307 only discloses a specific example in which the biological information acquisition apparatus is arranged in a seat portion of an airplane, as one aspect. Further, Japanese Unexamined Patent Application Publication No. 2016-101307 only discloses that a flight attendant or a pilot provides a service with full attention for a target person with high stress, as an effect of the specific example. 
     Accordingly, Japanese Unexamined Patent Application Publication No. 2016-101307 has a problem in that the flight attendant may not be evaluated based on the stress to the target person. 
     Incidentally, in a passenger plane, it is typical that an area which a flight attendant himself/herself is in charge of is in advance assigned to each of plural flight attendants and the flight attendant provides service for customers who sit on the seats in the area on board. 
     Accordingly, in a case where stress indicators of the customers are totaled in each of the areas which is assigned to each of the flight attendants, whether or not the service for the customers by each of the flight attendants is appropriate may be recognized, and as a result each of the flight attendants may be evaluated. 
     It is desirable to provide a technique for evaluating each of the flight attendants by using biological data of a customer. 
     A flight attendant evaluation system according to one aspect of the present disclosure includes: 
     a first biological sensor that measures first biological data of a customer on board transportation; 
     a storage that stores attendant-associated data in which the first biological data, a seat identifier, and an attendant identifier are associated with each other, the seat identifier indicating a seat of the customer on board, the attendant identifier indicating a flight attendant in charge of the seat; 
     an evaluation value calculator that classifies the attendant-associated data by the attendant identifier, calculates a stress indicator of the customer based on the first biological data associated with a first attendant identifier, and calculates an evaluation value of the flight attendant indicated by the first attendant identifier based on the stress indicator; and 
     a display apparatus that presents the evaluation value. 
     In this aspect, the attendant-associated data are stored in which the first biological data of the customer who is boarded on the airplane, the seat identifier which indicates the seat on which the customer sits on board, and the attendant identifier which indicates the flight attendant who is in charge of the seat are associated with each other. Then, the stored attendant-associated data are classified for each of the attendant identifiers, the stress indicators of the customers who on board sit on the seats which each of the flight attendants is in charge of are calculated from the classified attendant-associated data, and the evaluation value of each of the flight attendants is calculated from the calculated stress indicators. Thus, the stress indicators of the customers who each of the flight attendants is in charge of are totaled based on the first biological data, the evaluation value of each of the flight attendants may be calculated in such a manner that the service by the concerned flight attendant is inappropriate in a case where the totaled stress indicator is high and the service by the concerned flight attendant is appropriate in a case where the totaled stress indicator is low, and each of the flight attendants may thereby be evaluated. Then, an evaluation result is presented, customer satisfaction with the service by the flight attendant may thereby be fed back to the flight attendant, and an improvement in the service by the flight attendant may be intended. 
     In the above aspect, the evaluation value calculator may calculate an average value of stress indicators of customers calculated based on the first biological data associated with the first attendant identifier as the evaluation value of the flight attendant. 
     In this aspect, because the average value of the stress indicators of the customers is calculated as the evaluation value of each of the flight attendants, the evaluation value of each of the flight attendants may accurately be calculated. 
     In the above aspect, the display apparatus may present the evaluation value of the flight attendant in a case where an output instruction for evaluation of the flight attendant is detected. 
     In this aspect, for example, the evaluation value of the desired flight attendant may easily be perceived. 
     In the above aspect, the evaluation value calculator may perform correction that adds a greater offset value to the stress indicator as the stress indicator is greater in a case where the stress indicator of the customer satisfying a predetermined condition is greater than a first threshold value, and may calculate the evaluation value of the flight attendant based on the corrected stress indicator. 
     This aspect may lower the evaluation of the flight attendant who performs the service which raises the stress of a highly important second customer such as the customer who uses a special seat (for example, first class or business class) or the customer whose frequent flyer points are high. 
     In the above aspect, the evaluation value calculator may perform correction that subtracts a greater offset value from the stress indicator as the stress indicator is smaller in a case where the stress indicator of the customer satisfying a predetermined condition is smaller than a second threshold value, and may calculate the evaluation value of the flight attendant based on the corrected stress indicator. 
     This aspect may raise the evaluation of the flight attendant who performs the service which lowers the stress of the highly important second customer such as the customer who uses the special seat (for example, first class or business class) or the customer whose frequent flyer points are high. 
     In the above aspect, the flight attendant evaluation system may further include a second biological sensor that measures second biological data of the customer at a time before boarding on the transportation, 
     the storage may store the second biological data associated with the first biological data as the attendant-associated data, and 
     the evaluation value calculator may calculate the stress indicator based on a difference between a first stress indicator and a second stress indicator, the first stress indicator being calculated based on the first biological data, the second stress indicator being calculated based on the second biological data. 
     In this aspect, the stress indicator is calculated based on the difference between the second stress indicator calculated from the second biological data at a time before the customer boards the airplane, for example, at a time when the customer passes through a boarding gate and the first stress indicator calculated from the first biological data of the customer who has boarded the airplane. Thus, the stress indicator of each of the customers may accurately be calculated. 
     First Embodiment 
       FIG. 1  is a diagram that illustrates one example of a general configuration of a flight attendant evaluation system  1  according to a first embodiment of the present disclosure. The flight attendant evaluation system  1  includes plural biological sensors  110  that are mounted on plural seats  101  of an airplane X, a recording apparatus  20  that records the biological data which are measured by the biological sensor  110 , a statistical processing apparatus  30  that performs a statistical process of the biological data which are recorded in the recording apparatus  20 , and an evaluation display apparatus  40  that displays an evaluation value which is calculated by the statistical processing apparatus  30 . 
     The airplane X is a passenger plane that is owned by an airline company, for example. The airplane X includes the plural seats  101  on which plural customers  102  sit. The biological sensors  110  are respectively provided to the plural seats  101 . However, this is one example, and in a case where the biological sensor  110  is configured with a biological sensor that is capable of simultaneously measuring biological data of plural persons, one biological sensor  110  may be provided for plural seats that correspond to plural persons whose biological data are measurable. 
     The seat  101  includes a seat portion  101   a  that supports a lumbus of the customer  102  and a back portion  101   b  that supports a back of the customer  102 . The biological sensor  110  is configured with a millimeter-wave radar, for example, and is arranged to be opposed to the customer  102  who sits on the rear seat  101  in the back portion  101   b . In the example of  FIG. 1 , the biological sensor  110  is arranged at an upper end of the back portion  101   b . However, this is one example, and the biological sensor  110  may be arranged at the back portion  101   b  to be positioned in front of a face of the customer  102 . The directivity of the biological sensor  110  is set such that a millimeter wave (measurement wave) radiated to the customer is radiated to the vicinity of the face of the sitting customer  102 . 
     Further, in the example of  FIG. 1 , the biological sensor  110  is provided to the back portion  101   b . However, this is one example, and the biological sensor  110  may be provided to a ceiling in a cabin of the airplane X. In this case, the biological sensor  110  may be provided to a ceiling to be positioned directly above each of the seats  101 . 
     The recording apparatus  20  is configured with a computer that includes a CPU, a ROM, a RAM, a communication apparatus, and so forth, for example, and is connected with the airplane X via a predetermined network so as to be capable of communication. The statistical processing apparatus  30  is configured with a computer that includes a CPU, a ROM, a RAM, a communication apparatus, and so forth, for example, and is connected with the recording apparatus  20  via a predetermined network so as to be capable of communication. The evaluation display apparatus  40  is configured with a computer that includes a CPU, a ROM, a RAM, a communication apparatus, and so forth and is connected with the statistical processing apparatus  30  via a predetermined network so as to be capable of communication. The evaluation display apparatus  40  is configured with a stationary computer, for example. However, this is one example, and the evaluation display apparatus  40  may be configured with a portable computer such as a smartphone, a tablet terminal, or a feature phone with buttons. 
     The evaluation display apparatus  40  may be configured with a computer that is installed in a management department that manages the flight attendants in an airline company or may be configured with a portable computer that is possessed by each of the flight attendants or a manager who manages each of the flight attendants, for example. 
       FIG. 2  is a block diagram that illustrates a configuration of the flight attendant evaluation system  1  according to the first embodiment of the present disclosure. The flight attendant evaluation system  1  includes a biological information acquisition apparatus  10  that is provided to the airplane X, the recording apparatus  20 , the statistical processing apparatus  30 , and the evaluation display apparatus  40  which are illustrated in  FIG. 1 . The biological information acquisition apparatus  10  and the recording apparatus  20  are connected via a network NT 1  so as to be capable of mutual communication. As the network NT 1 , a public telecommunication network, which includes a radio communication network such as Wi-Fi® which is capable of communication between an airplane and a base station on the ground, may be employed. 
     The recording apparatus  20 , the statistical processing apparatus  30 , and the evaluation display apparatus  40  are connected via a network NT 2  so as to be capable of mutual communication. As the network NT 2 , a public telecommunication network, which includes a cellular phone communication network, a Wi-Fi® communication network, an Internet communication network, and so forth, may be employed. Note that for convenience of description,  FIG. 2  separately illustrates the network NT 1  and the network NT 2 . However, this is one example, and both of the networks may be the same. 
     The biological information acquisition apparatus  10  is configured with a computer that is provided in the airplane X, for example, and includes the biological sensor  110  (one example of a first biological sensor), a processing unit  120 , a biological data storage unit  130 , and a communication unit  140 . 
     The biological sensor  110  is connected with the communication unit  140  so as to be capable of communication by a wireless LAN or a wired LAN, measures biological data of the customer  102  who sits on the seat  101 , and transmits the biological data to the communication unit  140 . In recent years, a measurement technique has been known which simultaneously and contactlessly measures the biological data of plural persons by using a millimeter-wave radar. Specifically, this measurement technique radiates a millimeter wave of 60 GHz band to a person, for example, extracts a heartbeat signal from a measured radar signal, extracts phase characteristic points from the extracted heartbeat signal, and estimates heartbeat intervals from a time-series pattern of the extracted phase characteristic points. 
     Then, in a case where the heartbeat intervals may be estimated, a frequency analysis of the fluctuation of the heartbeat intervals is performed as disclosed in Japanese Patent No. 5257525, for example, and the stress to a person may thereby be detected. 
     Accordingly, in this embodiment, the millimeter-wave radar is employed as the biological sensor  110 . 
     Further, Japanese Unexamined Patent Application Publication No. 2016-101307, which is described in description of the related art, discloses a technique for measuring the biological data of a target person based on a pressure sensing tube attached to the seat portion  101   a  and the signal that corresponds to an internal pressure which occurs in the pressure sensing tube. Accordingly, in the present disclosure, the biological information of the customer  102  may be measured by using the technique disclosed in Japanese Unexamined Patent Application Publication No. 2016-101307. 
     The processing unit  120  is configured with a CPU, for example, and conducts general control of the biological information acquisition apparatus  10 . The processing unit  120  generates saved biological data by associating the biological data measured by the biological sensor  110  with a seat identifier and with a flight number identifier of the airplane X and stores the saved biological data in the biological data storage unit  130 . The biological data storage unit  130  is configured with a non-volatile storage apparatus, for example, and stores a saved biological table T 1  in which the saved biological data are registered. 
       FIG. 3  is a diagram that illustrates one example of a data configuration of the saved biological table T 1  that is stored in the biological data storage unit  130 . The saved biological table T 1  is a table in which one piece of saved biological data is registered in one record and includes fields of “flight number identifier”, “seat identifier”, and “biological data”. 
     “Flight number identifier” is an identifier of the airplane X and includes a flight number, a flight date, and a flight route. In the example of  FIG. 3 , the flight number identifier that is configured with the flight number of “PAL485”, the flight date of “Oct. 1, 2016”, and the flight route of “Airport A to Airport B” is registered. 
     “Seat identifier” is information that identifies each of plural seats in the cabin of the airplane X and employs a symbol string that is uniquely allocated to each of the seats. In the field of “biological data”, the biological data measured by the biological sensor  110  are registered. 
     Here, because the biological sensor  110  measures the biological data at regular sampling intervals while the airplane X is flying, the biological data become time-series data of measurement values of the biological data by the biological sensor  110 . The biological sensor  110  transmits the biological data that are associated with the seat identifier which is in advance allocated to the biological sensor  110 . Thus, the processing unit  120  may generate the saved biological data while associating the seat identifier with the biological data. Note that as the seat identifier allocated to the biological sensor  110 , as illustrated in  FIG. 1 , the seat identifier of the seat  101  on which the customer  102  to be a measurement target sits is employed. Note that the processing unit  120  in advance stores the flight number identifier. 
       FIG. 2  will be referred to. The communication unit  140  is configured with a communication apparatus that connects the biological information acquisition apparatus  10  with the network NT 1  by using radio communication such as Wi-Fi®, for example. The communication unit  140  transmits the saved biological data stored in the biological data storage unit  130  to the recording apparatus  20  via the network NT 1  under control of the processing unit  120 . Here, the communication unit  140  may transmit the saved biological data to the recording apparatus  20  under control of the processing unit  120  when the airplane X arrives at a destination. However, this is one example, and the communication unit  140  may transmit the saved biological data to the recording apparatus  20  at each time when the saved biological data are generated, that is, each time when the biological sensor  110  measures the biological data. 
     Further, the communication unit  140  acquires the biological data measured by the biological sensor  110  via a wireless LAN or a wired LAN, which is provided in the airplane X. 
     The recording apparatus  20  includes a biological data management unit  210 , an attendant-associated data storage unit  220  (one example of a storage), and a communication unit  230 . In  FIG. 2 , the biological data management unit  210  is configured with a CPU, for example. Further, the attendant-associated data storage unit  220  is configured with a non-volatile storage apparatus, for example. The communication unit  230  is configured with a communication apparatus that connects the recording apparatus  20  with the networks NT 1  and NT 2 , for example. 
     The biological data management unit  210  generates the attendant-associated data by associating the saved biological data transmitted from the biological information acquisition apparatus  10  with an attendant identifier and stores the attendant-associated data in the attendant-associated data storage unit  220 . Here, in a case where the saved biological data are transmitted from the biological information acquisition apparatus  10 , the biological data management unit  210  may acquire the attendant identifier that corresponds to the seat identifier and the flight number identifier, which are included in the transmitted saved biological data, by referring to an assigned seat table T 2  ( FIG. 4 ). 
       FIG. 4  is a diagram that illustrates one example of a data configuration of the assigned seat table T 2 . The assigned seat table T 2  is configured with a database in which one piece of assigned seat data is registered in one record and includes fields of “flight number identifier”, “attendant identifier”, and “seat identifier”. The assigned seat data are data that indicate which seats of which airplane flights each of the flight attendants is in charge of. 
     “Flight number identifier” and “seat identifier” are the same as  FIG. 3 . “Attendant identifier” is configured with a symbol string that is uniquely allocated in order to distinguish each of the flight attendants. In the example of the assigned seat data in the first row in  FIG. 4 , for the flight number identifier “PAL485, Oct. 1, 2016, Airport A→Airport B”, the flight attendant of the attendant identifier “J 01 ” is in charge of the area that is configured with the seats indicated by the seat identifiers “line  3  A, line  3  B, . . . ”. 
     In such a manner, “flight number identifier”, “attendant identifier”, and “seat identifier”, which are associated with each other, are registered in the assigned seat table T 2 . Thus, the biological data management unit  210  may specify the associated “attendant identifier” from “flight number identifier” and “seat identifier” included in the saved biological data and may generate the attendant-associated data. 
       FIG. 5  is a diagram that illustrates one example of a seat arrangement diagram which illustrates arrangement of the seats  101  in the cabin of the airplane X. The arrow in this seat arrangement diagram points towards the front of the cabin. Further, in this seat arrangement diagram, the seat identifier is given to each of the seats  101  by a pair of a value that indicates the order in a line in a transverse direction and a symbol that indicates the order in a line in a longitudinal direction. Values such as “1”, “2”, and “3” are assigned to the lines in the transverse direction in the order from the front, and symbols such as “A”, “B”, and “C” are assigned to the lines in the longitudinal direction from the left to the right. In this example, because the nine lines of seats  101  in the longitudinal direction are provided, nine symbols of “A” to “I” are assigned to the lines in the longitudinal direction. Accordingly, the seat  101  that is positioned in the upper left apex has the seat identifier “ 1 A”, and the seat  101  that is in the next position on the right has the seat identifier “ 1 B”. Note that in  FIG. 5 , the nine lines of seats  101  in the longitudinal direction are provided. However, this is one example, and 10 or more or 8 or less lines of seats  101  may be provided. A boarding door  601  that communicates with the outside of the airplane X is provided in front of the seat of the seat identifier “ 1 A”. 
     An area of the seats  101  which the flight attendant himself/herself is in charge of is in advance defined for each of the flight attendants, and the flight attendant basically performs service for the customers  102  who sit on the seats  101  in the area. In the example of  FIG. 5 , such as the area formed with the lines “ 1 ” to “ 4 ” in the transverse direction and the lines “A” to “C” in the longitudinal direction for the flight attendant of “J 01 ”, the area formed with the lines “ 1 ” to “ 4 ” in the transverse direction and the lines “D” to “F” in the longitudinal direction for the flight attendant of “J 02 ”, and the area formed with the lines “ 1 ” to “ 4 ” in the transverse direction and the lines “G” to “H” in the longitudinal direction for the flight attendant of “J 03 ”, the area which the flight attendant himself/herself is in charge of is in advance defined for each of the flight attendants. Accordingly, in a case where the stress indicator of the customer  102  who sits on the seat  101  in a certain area is high, it may be considered that the service by the flight attendant who is in charge of the area is inappropriate. On the other hand, in a case where the stress indicator of the customer  102  who sits on the seat  101  in the area which the flight attendant is in charge of is low, it may be considered that the service by the flight attendant who is in charge of that area is appropriate. This embodiment focuses on this point and evaluates the service for the customers  102  by each of the flight attendants. 
       FIG. 2  will be referred to again. The attendant-associated data storage unit  220  stores an attendant-associated table T 3  in which the attendant-associated data are registered.  FIG. 6  is a diagram that illustrates one example of a data configuration of the attendant-associated table T 3 . The attendant-associated table T 3  is a database in which one piece of attendant-associated data is registered in one record and includes fields of “flight number identifier”, “seat identifier”, “attendant identifier”, and “biological data”. The attendant-associated data are data in which “attendant identifier” is further associated with the saved biological data illustrated in  FIG. 3 . “Flight number identifier” and “seat identifier” are the same as  FIG. 3 . In the field of “biological data”, the biological data of each of the customers  102  are registered. “Attendant identifier” is the same as “attendant identifier” indicated in  FIG. 4 . 
     In  FIG. 6 , with respect to the attendant identifier “J 01 ”, biological data VT 11  are registered as “biological data” of the customer  102  of the seat identifier “line  3  A”, and biological data VT 13  are registered as “biological data” of the customer  102  of the seat identifier “line  3  B”. Further, with respect to the attendant identifier “J 02 ”, biological data VT 12  are registered as “biological data” of the customer  102  of the seat identifier “line  10  A”. However, this is one example. Actually, the attendant-associated data about all the seats, which all the flight attendants to be management targets are in charge of, are registered in the attendant-associated table T 3 . 
     In such a manner, because the biological data of the customers whom each of the flight attendants is in charge of are registered in the attendant-associated table T 3 , an evaluation value calculation unit  310  that will be described later may calculate the evaluation value of each of the flight attendants. 
       FIG. 2  will be referred to again. The communication unit  230  transmits the attendant-associated data registered in the attendant-associated table T 3  to the statistical processing apparatus  30  via the network NT 2  under control of the biological data management unit  210 . 
     Here, the communication unit  230  may transmit the attendant-associated data to the statistical processing apparatus  30  at each time when the number of pieces of attendant-associated data registered in the attendant-associated table T 3  increases by a certain number, or the communication unit  230  may transmit the attendant-associated data to the statistical processing apparatus  30  at each time when a certain time elapses (for example, by one day). In this case, the communication unit  230  may not transmit the attendant-associated data that are already transmitted. Further, the communication unit  230  may delete the attendant-associated data that are already transmitted from the attendant-associated table T 3 . Further, in a case where the saved biological data are transmitted from the biological information acquisition apparatus  10  to the recording apparatus  20  at each time when the biological data are measured, the communication unit  230  may transmit the attendant-associated data to the statistical processing apparatus  30  at each time when new attendant-associated data are registered in the attendant-associated table T 3 . 
     The statistical processing apparatus  30  includes the evaluation value calculation unit  310 , a processing unit  320 , a storage unit  330 , a presentation processing unit  340 , and a communication unit  350 . In  FIG. 2 , the evaluation value calculation unit  310 , the processing unit  320 , and the presentation processing unit  340  are configured with CPUs, for example, and the storage unit  330  is configured with a non-volatile storage apparatus, for example. The communication unit  350  is configured with a communication apparatus for connecting the statistical processing apparatus  30  with the network NT 2 . 
     In a case where the communication unit  350  receives the attendant-associated data transmitted from the recording apparatus  20 , the processing unit  320  causes the storage unit  330  to store the received attendant-associated data. Specifically, similarly to the attendant-associated data storage unit  220 , the storage unit  330  stores the attendant-associated table T 3  ( FIG. 6 ) in which the attendant-associated data which is transmitted from the recording apparatus  20  are registered. Accordingly, the processing unit  320  registers the attendant-associated data transmitted from the recording apparatus  20  in the attendant-associated table T 3 . 
     The evaluation value calculation unit  310  classifies the attendant-associated data that are registered in the attendant-associated table T 3  stored in the storage unit  330  for each of the attendant identifiers, calculates the stress indicators of the customers  102  who sit on the seats  101  which each of the flight attendants is in charge of from the biological data included in the classified attendant-associated data, and calculates the evaluation value of each of the flight attendants from the calculated stress indicators. 
     In this embodiment, the millimeter-wave radar is employed as the biological sensor  110 . Accordingly, the evaluation value calculation unit  310  estimates the heartbeat intervals from the biological data measured by the biological sensor  110 , performs the frequency analysis of the fluctuation of the heartbeat intervals, which is disclosed in above-described Japanese Patent No. 5257525, for the estimated heartbeat intervals, and may thereby calculate the stress indicator (the stress indicator for each piece of attendant-associated data) of the customer  102  who on board sits on the seat  101  which each of the flight attendants is in charge of. 
     Specifically, the evaluation value calculation unit  310  performs the frequency analysis of the estimated heartbeat intervals, thereby detects a level HF of a high-frequency peak that occurs around a frequency of 0.3 Hz and a level LF of a low-frequency peak that occurs around 0.1 Hz, and may thereby calculate LF/HF as the stress indicator. Note that the value of LF/HF increases as the stress becomes higher. Accordingly, the higher value of the stress indicator indicates the higher stress. 
     Then, the evaluation value calculation unit  310  classifies the stress indicators calculated for each piece of the attendant-associated data for each of the flight attendants and calculates the average value of the stress indicators for each of the flight attendants as the evaluation value of each of the flight attendants. In the example of  FIG. 6 , with respect to the flight attendant of the attendant identifier “J 01 ”, for example, the average value of the stress indicator that is obtained from the biological data VT 11  and the stress indicator that is obtained from the biological data VT 13  is calculated as the evaluation value. 
     The evaluation value calculation unit  310  registers the evaluation value that is calculated for each of the flight attendants in an evaluation table T 4  that is stored in the storage unit  330 .  FIG. 7  is a diagram that illustrates one example of a data configuration of the evaluation table T 4 . The evaluation table T 4  is configured with a database in which one flight attendant is assigned to one record and includes fields of “attendant identifier” and “evaluation value”. “Attendant identifier” is the same as  FIG. 4 . “Evaluation value” is a value for evaluating each of the flight attendants. In such a manner, because the evaluation value of each of the flight attendants is registered in the evaluation table T 4 , the evaluation display apparatus  40  that will be described later may display the evaluation value of each of the flight attendants. 
     Note that in the attendant-associated table T 3  stored in the storage unit  330 , the evaluation value calculation unit  310  may not calculate the stress indicators for the attendant-associated data for which the stress indicators are already calculated. In this case, the evaluation value calculation unit  310  may calculate the stress indicators only for the attendant-associated data that are newly added to the attendant-associated table T 3 . Then, the evaluation value calculation unit  310  classifies the calculated stress indicators for each of the flight attendants, calculates the evaluation value of each of the flight attendants from the classified stress indicators, calculates the average value of the calculated evaluation value and the evaluation value that is already registered in the evaluation table T 4 , and may thereby newly calculate the evaluation value for each of the flight attendants. Then, the evaluation value calculation unit  310  updates the evaluation table T 4  with the newly calculated evaluation value for each of the flight attendants. 
     The storage unit  330  stores the attendant-associated table T 3  ( FIG. 6 ), the evaluation table T 4  ( FIG. 7 ), and an attendant table T 5  ( FIG. 8 ).  FIG. 8  is a diagram that illustrates one example of a data configuration of the attendant table. The attendant table T 5  is a database in which personal data of one flight attendant is assigned to one record and includes fields of “attendant identifier”, “sex”, “name”, “age”, and “division”. 
     “Attendant identifier” is the same as  FIG. 4 . The sex, name, and age of the concerned flight attendant are respectively registered in the fields of “sex”, “name”, and “age”. The air route or department which the concerned flight attendant works for or belongs to in an airline company is registered in the field of “division”. Here, “domestic line” and “international line” are registered as “division”. However, this is one example. 
     In a case where the communication unit  350  receives an inquiry signal for inquiring the evaluation value of a certain flight attendant, the presentation processing unit  340  extracts the evaluation value of the flight attendant who is designated by the inquiry signal from the evaluation table T 4 . The presentation processing unit  340  transmits the extracted evaluation value to the evaluation display apparatus  40  by using the communication unit  350  and causes the evaluation display apparatus  40  to present the evaluation value. In this case, the presentation processing unit  340  may read out the personal data of the concerned flight attendant from the attendant table T 5 , combine the personal data that are read out with the evaluation value, transmit the personal data and the evaluation value to the evaluation display apparatus  40  by using the communication unit  350 , and thereby cause the evaluation display apparatus  40  to present the personal data. 
     The communication unit  350  receives the attendant-associated data transmitted from the recording apparatus  20  via the network NT 2  under control of the processing unit  320 . Further, the communication unit  350  receives the inquiry signal for the evaluation value from the evaluation display apparatus  40 . 
     The evaluation display apparatus  40  includes a processing unit  410 , a display unit  420 , an operation unit  430 , and a communication unit  440 . In  FIG. 2 , the processing unit  410  is configured with a CPU, for example. The display unit  420  is configured with a display apparatus such as a liquid crystal panel. The operation unit  430  is configured with input apparatuses such as a touch panel, a keyboard, and a mouse. The communication unit  440  is configured with a communication apparatus for connecting the evaluation display apparatus  40  with the network NT 2 . 
     In a case where the operation unit  430  receives an output instruction for the evaluation value of any flight attendant among the flight attendants, the processing unit  410  transmits the output instruction to the statistical processing apparatus  30  by using the communication unit  440 . Further, in a case where the evaluation value is transmitted from the recording apparatus  20 , the processing unit  410  causes the display unit  420  to display an evaluation image ( FIG. 9 ) that indicates the evaluation value. 
     The display unit  420  displays various kinds of images (such as the evaluation image) under control of the processing unit  410 . The operation unit  430  receives various kinds of operations (such as the output instruction for the evaluation value) from an operator. Here, the operation unit  430  causes the name or the attendant identifier of the flight attendant, evaluation value of which is desired to be output, to be input in a name input section and/or an identifier input section that are provided to an input image (not illustrated) displayed on the display unit  420  and thereby receives the output instruction. The processing unit  410  generates the inquiry signal for the evaluation value that includes the name and/or the attendant identifier of the flight attendant who is designated by the received output instruction and transmits the inquiry signal to the evaluation display apparatus  40  by using the communication unit  440 . 
     The communication unit  440  receives various kinds of information (such as the evaluation value) from the statistical processing apparatus  30  and transmits various kinds of information (such as the inquiry signal for the evaluation value) to the statistical processing apparatus  30 . 
       FIG. 9  is a diagram that illustrates one example of an evaluation image G 900  that is displayed by the evaluation display apparatus  40 . The evaluation image G 900  includes a face image display section R 901  that displays a face image of the concerned flight attendant and a personal data display section R 902  that displays the personal data of the concerned flight attendant. The personal data display section R 902  includes “name”, “age”, and “evaluation value” of the concerned flight attendant. Note that “name”, “age”, and the face image of the concerned flight attendant are transmitted together with the evaluation value of the concerned flight attendant from the statistical processing apparatus  30 . 
       FIG. 10  is a flowchart that illustrates one example of a process from measurement of the biological data to calculation of the evaluation value in the flight attendant evaluation system  1  according to the first embodiment of the present disclosure. 
     First, the biological sensor  110  of the biological information acquisition apparatus  10  measures the biological data (S 601 ). Here, the biological sensor  110  measures the biological data at predetermined sampling intervals. 
     Next, the processing unit  120  of the biological information acquisition apparatus  10  registers the measured biological data in the saved biological table T 1  (S 602 ). Specifically, the processing unit  120  generates the saved biological data by associating the measured biological data with the seat identifier and with the flight number identifier, and stores the saved biological data in the saved biological table T 1 . 
     Next, the communication unit  140  of the biological information acquisition apparatus  10  transmits all the saved biological data registered in the saved biological table T 1  to the recording apparatus  20  when the airplane X arrives at a destination (S 603 ). Note that in a case where the transmission of the saved biological data to the recording apparatus  20  finishes, the processing unit  120  may delete the saved biological data that are registered in the saved biological table T 1 . Further, in a case where the saved biological data are transmitted to the recording apparatus  20  at each time when the saved biological data are generated, the saved biological table T 1  is not requested. 
     Next, the communication unit  230  of the recording apparatus  20  receives the saved biological data from the biological information acquisition apparatus  10  (S 611 ). Next, the biological data management unit  210  of the recording apparatus  20  extracts the attendant identifier that corresponds to the flight number identifier and the seat identifier, which are included in the received saved biological data, by referring to the assigned seat table T 2 . The biological data management unit  210  associates the extracted attendant identifier with the saved biological data, generates the attendant-associated data, and registers the attendant-associated data in the attendant-associated table T 3  (S 612 ). 
     Next, the communication unit  230  of the recording apparatus  20  transmits the attendant-associated data registered in the attendant-associated table T 3  to the statistical processing apparatus  30  under control of the biological data management unit  210  (S 613 ). In this case, as described above, the communication unit  230  may transmit the attendant-associated data to the statistical processing apparatus  30  at each time when the number of pieces of attendant-associated data registered in the attendant-associated table T 3  increases by a certain number or at each time when a certain time elapses, for example. 
     Next, the communication unit  350  of the statistical processing apparatus  30  receives the attendant-associated data transmitted from the recording apparatus  20  (S 621 ). In this case, the processing unit  320  registers the received attendant-associated data in the attendant-associated table T 3  stored in the storage unit  330 . 
     Next, the evaluation value calculation unit  310  of the statistical processing apparatus  30  classifies the attendant-associated data registered in the attendant-associated table T 3  for each of the attendant identifiers (S 622 ). 
     In the example of  FIG. 6 , because the attendant-associated data of the flight attendants of the attendant identifier “J 01 ” and the attendant identifier “J 02 ” are registered, the attendant-associated data are classified for each of both flight attendants. 
     Next, the evaluation value calculation unit  310  calculates the stress indicators of the customers  102  who on board sit on the seats  101  which each of the flight attendants is in charge of from the biological data included in the classified attendant-associated data (S 623 ). In the example of  FIG. 6 , with respect to the flight attendant of the attendant identifier “J 01 ”, the stress indicator that corresponds to the biological data VT 11  is calculated, and the stress indicator that corresponds to the biological data VT 13  is calculated. Further, in the example of  FIG. 6 , with respect to the flight attendant of the attendant identifier “J 02 ”, the stress indicator that corresponds to the biological data VT 12  is calculated. 
     Next, the evaluation value calculation unit  310  calculates the average of the calculated stress indicators for each of the flight attendants as the evaluation value of each of the flight attendants (S 624 ) and registers the evaluation value in the evaluation table T 4 . 
     As a result, the stress indicators are calculated from the biological data of the customers  102  whom each of the flight attendants is in charge of, and the evaluation value of each of the flight attendants is calculated from the calculated stress indicators. 
       FIG. 11  is a flowchart that illustrates one example of a process of presenting the evaluation value in the flight attendant evaluation system  1  according to the first embodiment of the present disclosure. 
     First, the operation unit  430  of the evaluation display apparatus  40  receives an input of the output instruction of the evaluation value of any of the flight attendants (S 711 ). In a case where the input of the output instruction is received (YES in S 711 ), the communication unit  440  of the evaluation display apparatus  40  transmits the inquiry signal for the evaluation value that includes the name and/or the attendant identifier of the flight attendant who is designated by the output instruction to the statistical processing apparatus  30  (S 712 ). 
     On the other hand, in a case where the input of the output instruction is not received (NO in S 711 ), the process is returned to S 711 . 
     Next, the communication unit  350  of the statistical processing apparatus  30  receives the inquiry signal for the evaluation value (S 701 ). Next, the presentation processing unit  340  extracts the evaluation value of the concerned flight attendant from the evaluation table T 4  (S 702 ). Next, the communication unit  350  of the statistical processing apparatus  30  transmits the extracted evaluation value that is combined with the personal data of the concerned flight attendant to the evaluation display apparatus  40  (S 703 ). 
     Next, the communication unit  440  of the evaluation display apparatus  40  receives the evaluation value and the personal data (S 713 ). Next, the processing unit  410  of the evaluation display apparatus  40  generates the evaluation image G 900  from the received evaluation value and personal data and causes the display unit  420  to display the evaluation image G 900  (S 714 ). Accordingly, the evaluation image G 900  illustrated in  FIG. 9  is presented. 
     In such a manner, in the flight attendant evaluation system  1 , the attendant-associated data are stored in which the biological data of the customers  102  who are boarded on the airplane X, the seat identifiers which indicate the seats  101  on which the customers  102  sit, and the attendant identifier which indicates the flight attendant who is in charge of the seats  101  are associated with each other. Then, the stored attendant-associated data are classified for each of the attendant identifiers, and the stress indicators of the customers  102  who on board sit on the seats  101  which each of the flight attendants is in charge of are calculated from the classified attendant-associated data. Then, the evaluation value of each of the flight attendants is calculated from the calculated stress indicators. Thus, the stress indicators of the customers whom each of the flight attendants is in charge of are totaled based on the biological data, and the evaluation value of each of the flight attendants may be calculated in such a manner that the service by the concerned flight attendant is inappropriate in a case where the totaled stress indicator is high and the service by the concerned flight attendant is appropriate in a case where the totaled stress indicator is low. Then, an evaluation result is presented, customer satisfaction with the service by the flight attendant may thereby be fed back to the flight attendant, and an improvement in the service by the flight attendant may be intended. 
     Second Embodiment 
       FIG. 12  is a diagram that illustrates one example of a general configuration of a flight attendant evaluation system  1 A according to a second embodiment of the present disclosure. In addition to the measurement of the biological data in the airplane X, the flight attendant evaluation system  1 A has a characteristic that the biological data are measured by using a biological sensor  510  (one example of a second biological sensor) that is provided to a boarding gate  501  in an airport and the stress indicator is calculated by using both pieces of the biological data. Note that in the second embodiment, the same reference characters will be given to the same configuration elements as the first embodiment, and a description will not be made. 
     The boarding gate  501  is a gate through which the customer  102  passes immediately before boarding the airplane X. 
     The biological sensor  510  is used for measuring the stress of the customer  102  in a state where the customer  102  does not board the airplane X. In a case where the customer  102  boards the airplane X of a domestic line in the airport, for example, it is typical to follow the procedures in which the customer  102  first performs boarding procedures at a check-in counter, next leaves a large baggage at a baggage counter, next goes through a security check at an inspection area, and finally passes through the boarding gate. It is sufficient that the biological sensor  510  may measure the biological data of the customer  102  at a time before boarding the airplane X. Thus, the installation place of the biological sensor  510  is not limited to the boarding gate  501  but may be the check-in counter, the baggage counter, or the inspection area. 
       FIG. 13  is a block diagram that illustrates a configuration of the flight attendant evaluation system  1 A according to the second embodiment of the present disclosure. The flight attendant evaluation system  1 A is further provided with a second biological information acquisition apparatus  50  compared to the flight attendant evaluation system  1  illustrated in  FIG. 2 . Note that in the second embodiment, in order to distinguish the biological information acquisition apparatus  10  of the first embodiment from the second biological information acquisition apparatus  50 , the biological information acquisition apparatus  10  will be referred to as a first biological information acquisition apparatus  10 A. Further, in the second embodiment, in order to distinguish the biological data that are measured by the biological sensor  510  from the biological data that are measured by the biological sensor  110 , the biological data measured by the biological sensor  510  will be referred to as second biological data, and the biological data measured by the biological sensor  110  will be referred to as the first biological data. 
     The second biological information acquisition apparatus  50  includes the biological sensor  510 , a processing unit  520 , and a communication unit  530 . The biological sensor  510  employs the millimeter-wave radar, for example, similarly to the biological sensor  110 . 
     The processing unit  520  is configured with a CPU, for example, and conducts general control of the second biological information acquisition apparatus  50 . The processing unit  520  associates the second biological data measured by the biological sensor  510  with the seat identifier and with the flight number identifier, and transmits the second biological data to the recording apparatus  20  via the network NT 2 . Note that the processing unit  520  reads seat information and the flight number of the airplane X, which are described on a ticket for the airplane X which is owned by the customer  102 , by using a scanner (not illustrated), for example, and may thereby acquire the seat identifier and the flight number identifier. 
     The communication unit  530  is configured with a communication apparatus that connects the second biological information acquisition apparatus  50  with the network NT 2  by using wireless communication such as Wi-Fi® or wired communication, for example. The communication unit  530  transmits the second biological data (hereinafter referred to as “second saved biological data”) that are associated with the flight number identifier and the seat identifier to the recording apparatus  20  under control of the processing unit  520 . Note that in the second embodiment, the saved biological data that are generated by the first biological information acquisition apparatus  10 A will be referred to as first saved biological data. 
       FIG. 14  is a diagram that illustrates one example of a data configuration of a first saved biological table T 11  in which the first saved biological data are registered in the second embodiment of the present disclosure. In the first saved biological table T 11 , the difference from the saved biological table T 1  illustrated in  FIG. 3  is only a point that “biological data” becomes “first biological data”, and no fundamental difference is present. 
       FIG. 15  is a diagram that illustrates one example of a data configuration of the second saved biological data according to the second embodiment of the present disclosure. The second saved biological data include fields of “flight number identifier”, “seat identifier”, and “second biological data”. Note that in the second saved biological data, the difference from the first saved biological data illustrated in  FIG. 14  is only a point that “first biological data” becomes “second biological data”, and no fundamental difference is present. 
       FIG. 13  will be referred to again. In the second embodiment, the biological data management unit  210  generates the attendant-associated data by associating the second biological data included in the second saved biological data with the first saved biological data, and stores the attendant-associated data in the attendant-associated data storage unit  220 . 
       FIG. 16  is a diagram that illustrates one example of a data configuration of an attendant-associated table T 31  in which the attendant-associated data are registered according to the second embodiment of the present disclosure. In the attendant-associated table T 31 , the different point from the attendant-associated table T 3  illustrated in  FIG. 6  is a point that a field of “second biological data” is further added. 
     The biological data management unit  210  specifies the first saved biological data that have the same “flight number identifier” and “seat identifier” as “flight number identifier” and “seat identifier” in the second saved biological data, associates the second biological data included in the second saved biological data with the specified first saved biological data, and may thereby generate the attendant-associated data. 
       FIG. 17  is a flowchart that illustrates one example of a process from measurement of the first and second biological data to calculation of the evaluation value in the flight attendant evaluation system  1 A according to the second embodiment of the present disclosure. Note that in  FIG. 17 , the same reference characters are given to the same processes as  FIG. 10 , and a description will not be made. 
     First, the biological sensor  510  of the second biological information acquisition apparatus  50  measures the second biological data of the customer  102  who passes through the boarding gate  501  (S 1001 ). Next, the processing unit  520  of the second biological information acquisition apparatus  50  generates the second saved biological data by associating the second biological data measured in S 1001  with “flight number identifier” and “seat identifier”, and transmits the second saved biological data to the recording apparatus  20  by using the communication unit  530  (S 1002 ). 
     Next, the communication unit  230  of the recording apparatus  20  receives the second saved biological data (S 1011 ). Then, the process of S 611  is executed similarly to the first embodiment. Next, the biological data management unit  210  of the recording apparatus  20  generates the attendant-associated data by associating the second biological data included in the received second saved biological data with the corresponding first saved biological data, and registers the attendant-associated data in the attendant-associated table T 31  (S 1012 ). 
     In S 1021  that follows S 622 , the evaluation value calculation unit  310  of the statistical processing apparatus  30  calculates first and second stress indicators of the customers  102  who on board sit on the seats  101  which each of the flight attendants is in charge of from the first and second biological data included in the classified attendant-associated data. 
     In the example of  FIG. 16 , with respect to the flight attendant of the attendant identifier “J 01 ”, the first stress indicator that corresponds to first biological data VT 11  is calculated, and the first stress indicator that corresponds to the biological data VT 13  is calculated. Similarly, with respect to the flight attendant of the attendant identifier “J 01 ”, the second stress indicator that corresponds to second biological data VT 21  is calculated, and the second stress indicator that corresponds to biological data VT 23  is calculated. Note that the first and second stress indicators are calculated by using the same scheme as the stress indicator described in the first embodiment. 
     Next, the evaluation value calculation unit  310  calculates the stress indicator for each piece of the attendant-associated data by subtracting the second stress indicator from the first stress indicator for each piece of the attendant-associated data (S 1022 ). One example of a calculation process of the stress indicator will be described by using the attendant-associated table T 31  in the first row in  FIG. 16 . The evaluation value calculation unit  310  calculates the stress indicator with respect to the attendant-associated data in the first row by subtracting the second stress indicator calculated from the second biological data VT 21  from the first stress indicator calculated from the first biological data VT 11 . The evaluation value calculation unit  310  performs a similar process for the other pieces of attendant-associated data, and thereby calculates the stress indicators. 
     Next, the evaluation value calculation unit  310  calculates the average of the stress indicators calculated in S 1022  for each of the flight attendants as the evaluation value of each of the flight attendants (S 1023 ) , and registers the evaluation value in the evaluation table T 4 . 
     As the stress to the customer  102  who is boarded on the airplane X increases, the difference between the first stress indicator and the second stress indicator increases. Furthermore, because the stress indicator obtained from the difference is based on the stress indicator at a time before the customer  102  boards the airplane X as a reference, it may be considered that the stress indicator accurately reflects the influence of the stress that is given to the customer  102  by the airplane X. Accordingly, in this embodiment, the evaluation value is calculated by using the stress indicator that is obtained by subtracting the second stress indicator from the first stress indicator. 
     In such a manner, in the flight attendant evaluation system  1 A according to the second embodiment, the stress indicator is calculated based on the difference between the second stress indicator calculated from the second biological data at a time before the customer  102  boards the airplane X and the first stress indicator calculated from the first biological data of the customer  102  who has boarded the airplane X. Thus, the stress indicator may accurately be calculated. 
     Third Embodiment 
     A flight attendant evaluation system  1 B according to a third embodiment has characteristics that the evaluation of the flight attendant who performs service which raises the stress for a second customer who is more important than a first customer is lowered and the evaluation of the flight attendant who performs service which lowers the stress for the second customer is raised. The second customer is classified as a customer who sits on a special seat (for example, first class and business class) or a customer whose frequent flyer points are a certain value or more. The first customer is classified as the other customer than the second customer. 
     Note that in the third embodiment, the same reference characters will be given to the same configuration elements as the first embodiment, and a description will not be made. Further, the third embodiment is applicable to cases where the configurations of both of the first and second embodiments are employed. However, in the following description, a description will be made about an example where the configuration of the first embodiment is employed. Accordingly, in the flight attendant evaluation system  1 B according to the third embodiment, the general configuration is the same as  FIG. 1  and  FIG. 2 . 
       FIG. 2  will be referred to. In the third embodiment, with respect to the second customer, in a case where a stress indicator K 1  calculated from the biological data is higher than a first threshold value TH 1 , the evaluation value calculation unit  310  of the statistical processing apparatus  30  decides an offset value α for increasing the stress indicator K 1  as the difference between the stress indicator K 1  and the first threshold value TH 1  increases, and calculates a stress indicator K 2  by correcting the stress indicator K 1  by adding the offset value a to the stress indicator K 1 . Meanwhile, in a case where the stress indicator K 1  is lower than a second threshold value TH 2  (&lt;TH 1 ), the evaluation value calculation unit  310  decides an offset value β for decreasing the stress indicator K 1  as the difference between the stress indicator K 1  and the second threshold value TH 2  increases, and calculates the stress indicator K 2  by correcting the stress indicator K 1  by subtracting the offset value β form the stress indicator K 1 . 
     Here, as the first threshold value TH 1 , an empirically obtained value may be employed at which the stress to the second customer is assumed to excess the stress in a usual condition in a case where the stress indicator K 1  increases to the first threshold value TH 1  or more. Further, as the second threshold value TH 2 , an empirically obtained value may be employed at which the stress to the second customer is assumed to fall below the stress in the usual condition and the second customer is assumed to be comfortable in a case where the stress indicator K 1  decreases to the second threshold value TH 2  or less. 
     The offset value α is decided by a function in which the value monotonically increases as a difference (K 1 −TH 1 ), which results from the subtraction of the first threshold value TH 1  from the stress indicator K 1 , increases, for example. The offset value β is decided by a function in which the value monotonically increases as a difference (TH 2 −K 1 ), which results from the subtraction of the stress indicator K 1  from the second threshold value TH 2 , increases, for example. 
       FIG. 18  is a flowchart that illustrates one example of a process from measurement of the biological data to calculation of the evaluation value in the flight attendant evaluation system  1 B according to the third embodiment of the present disclosure. In  FIG. 18 , only the process of S 1101  is different from  FIG. 10 . In S 1101 , the evaluation value calculation unit  310  of the statistical processing apparatus  30  executes an evaluation value calculation process. 
       FIG. 19  is a flowchart that illustrates one example of the evaluation value calculation process indicated by S 1101  of  FIG. 18 . First, the evaluation value calculation unit  310  specifies one piece of attendant-associated data to be a process target from the attendant-associated data that are classified for each of the attendant identifiers (S 1201 ). Here, the evaluation value calculation unit  310  may specify one piece of attendant-associated data from the attendant-associated data that are classified for each of the attendant identifiers in a predetermined order (for example, a registration order). 
     Next, the evaluation value calculation unit  310  assesses whether a customer identifier included in the specified one piece of attendant-associated data is the customer identifier of the second customer. Here, the evaluation value calculation unit  310  refers to a reservation information table T 6  ( FIG. 20 ) that is in advance stored in the storage unit  330  and a customer table T 7  ( FIG. 21 ) that is in advance stored in the storage unit  330 , and may thereby assess whether or not the concerned customer identifier is the customer identifier of the second customer. 
       FIG. 20  is a diagram that illustrates one example of a data configuration of the reservation information table T 6  that is used in the flight attendant evaluation system  1 B according to the third embodiment of the present disclosure. The reservation information table T 6  is a database in which one piece of reservation information is registered in one record, and includes fields of “flight number identifier”, “seat identifier”, and “customer identifier”. The reservation information is information that indicates which seat of which airplane flight is reserved with respect to each of the customers  102 . 
     “Flight number identifier” and “seat identifier” are the same as  FIG. 3 . “Customer identifier” is data for uniquely identifying the customer to be a management target. In  FIG. 20 , the reservation information is registered which indicates that the customer  102  of the customer identifier “UO 3 ” has reserved the seat of the seat identifier “line  3  A” for the airplane X of the flight number identifier “PAL 485 , Oct. 1, 2016, Airport A to Airport B”. 
     Note that in the example of  FIG. 20 , only one piece of reservation information is illustrated. However, actually, pieces of reservation information for plural seats of plural airplanes X to be management targets are registered. Note that the reservation information table T 6  is in advance stored in the storage unit  330  of the statistical processing apparatus  30 . 
       FIG. 21  is a diagram that illustrates one example of a data configuration of the customer table T 7  that is used in the flight attendant evaluation system  1 B according to the third embodiment of the present disclosure. The customer table T 7  is a database in which one piece of customer data is assigned to one record, and includes fields of “customer identifier”, “name”, “frequent flyer points” and “attribute”. “Customer identifier” is the same as  FIG. 20 . In the field of “name”, the name of the customer is registered. In the field of “frequent flyer points”, the frequent flyer points possessed by the customer are registered. The frequent flyer points increases as the total distance in which the customer  102  boards airplanes of the concerned airline company increases, for example. In the field of “attribute”, the data that indicate whether or not the customer has the attribute of the second customer are registered. Here, in a case where “premium” is registered in the field of “attribute”, the customer is the second customer. Here, the attribute of “premium” is given to the customer whose frequent flyer points are a certain value or more or whose frequency of boarding with the special seats is a certain value or more. Note that the customer who sits on the special seat may be treated as the second customer. In this case, whether or not the customer sits on the special seat may be specified by the seat identifier. 
     The evaluation value calculation unit  310  extracts “customer identifier” that corresponds to “flight number identifier” and “seat identifier”, which are included in one piece of attendant-associated data, from the reservation information table T 6 . Then, the evaluation value calculation unit  310  refers to the customer table T 7  and may thereby assess the concerned customer as the second customer in a case where “premium” is registered in the field of “attribute” of the customer data that correspond to the extracted “customer identifier”. Alternatively, the evaluation value calculation unit  310  may assess the concerned customer as the second customer in a case where “seat identifier” included in one piece of attendant-associated data indicates the seat that matches the special seat which is in advance defined. 
       FIG. 19  will be referred to again. In a case where the customer identifier indicates the customer identifier of the second customer (YES in S 1202 ), the evaluation value calculation unit  310  calculates the stress indicator K 1  from the biological data included in one piece of attendant-associated data (S 1203 ). On the other hand, in a case where the customer identifier does not indicate the customer identifier of the second customer (NO in S 1202 ), the evaluation value calculation unit  310  assesses the concerned customer as the first customer and causes the process to progress to S 1211 . 
     In S 1204 , in a case where the stress indicator K 1  is higher than the first threshold value TH 1  (YES in S 1204 ), the evaluation value calculation unit  310  decides the offset value α from the difference (K 1 −TH 1 ) (S 1205 ). On the other hand, in a case where the stress indicator K 1  is the first threshold value TH 1  or lower (NO in S 1204 ), the process progresses to S 1208 . 
     In S 1206 , the evaluation value calculation unit  310  calculates the stress indicator K 2  by adding α to K 1 . Here, the offset value α increases as the difference (K 1 −TH 1 ) increases. Thus, the stress indicator K 2  increases as the amount by which the stress indicator K 1  exceeds the first threshold value TH 1  increases, that is, as the stress to the second customer increases. Thus, correction is made such that the stress indicator K 1  of the flight attendant who is in charge of this second customer increases, and the evaluation value of this flight attendant lowers. 
     In S 1208 , in a case where the stress indicator K 1  is lower than the second threshold value TH 2  (YES in S 1208 ), the evaluation value calculation unit  310  decides the offset value β from the difference (TH 2 −K 1 ) (S 1209 ). Next, the evaluation value calculation unit  310  calculates the stress indicator K 2  by subtracting β from K 1  (S 1210 ). Here, the offset value β increases as the difference (TH 2 −K 1 ) increases. Thus, the stress indicator K 2  lowers as the stress to the second customer lowers. Thus, correction is made such that the stress indicator K 1  of the flight attendant who is in charge of this second customer decreases, and the evaluation value of this flight attendant rises. 
     In S 1211 , the evaluation value calculation unit  310  calculates the stress indicator K 1  from the biological data included in one piece of attendant-associated data. Next, the evaluation value calculation unit  310  calculates the stress indicator K 1  that is calculated in S 1211  or S 1203  as the stress indicator K 2  (S 1212 ). 
     That is, with respect to the first customer, the stress indicator K 1  is not corrected but is calculated as the stress indicator K 2  with no change (NO in S 1202 , S 1211 , and S 1212 ). Further, even with respect to the second customer, in a case where the stress indicator K 1  is the first threshold value or lower and the second threshold value or higher (NO in S 1204  and NO in S 1208 ), the stress indicator K 1  is not corrected but is calculated as the stress indicator K 2  with no change. 
     In S 1207 , in a case where the attendant-associated data for which the stress indicator K 2  is not yet calculated are present, the evaluation value calculation unit  310  assesses that a finishing condition is not satisfied (NO in S 1207 ) and causes the process to return to S 1201 . On the other hand, in a case where the attendant-associated data for which the stress indicator K 2  is not yet calculated are not present, the evaluation value calculation unit  310  assesses that the finishing condition is satisfied (YES in S 1207 ) and finishes the process. 
     In such a manner, in the third embodiment, the evaluation of the flight attendant with respect to the second customer may be made more strict than the evaluation of the flight attendant with respect to the first customer. 
     The present disclosure may employ the following modifications. 
     (1) In the first to third embodiments, because the evaluation value is defined to increase as the stress indicator becomes higher, the evaluation value indicates that the evaluation becomes lower as the value increases. The present disclosure is not limited to this, but the evaluation value may be defined to increase as the stress indicator becomes lower. In this case, as the evaluation value, the average value of the reciprocals of the stress indicators for each of the flight attendants may be employed. 
     (2) In the first to third embodiments, the average value of the stress indicators is employed as the evaluation value. However, the present disclosure is not limited to this, but the deviation value of the average value of the stress indicators may be employed as the evaluation value. 
     (3) In the first to third embodiments, the recording apparatus  20 , the statistical processing apparatus  30 , and the evaluation display apparatus  40  are configured with different computers. However, the present disclosure is not limited to this, but the recording apparatus  20 , the statistical processing apparatus  30 , and the evaluation display apparatus  40  may be configured with one computer. 
     (4) In the above embodiments, a description is made that the sensor which uses the millimeter-wave radar or the pressure sensing tube may be employed as the biological sensor  110 . However, the present disclosure is not limited to this. 
     For example, Japanese Patent No. 5735592 discloses that the comfortableness of a user is evaluated by 10 levels of −5 to +5 from the biological data such as a heart rate, a pulse, and a body temperature. Accordingly, in the present disclosure, the comfortableness disclosed in Japanese Patent No. 5735592 may be employed as the stress indicator. In this case, the stress indicator may be calculated from a brain wave, a brain blood flow, a pulse wave, a blood pressure, a respiration rate, the body temperature, and a sweat rate. 
     Further, Japanese Unexamined Patent Application Publication No. 2012-249797 discloses that a value that results from a linear combination of the heart rate, the body temperature, the blood pressure, and the sweat rate is calculated as the stress value. Accordingly, in the present disclosure, the stress value disclosed in Japanese Unexamined Patent Application Publication No. 2012-249797 may be employed as the stress indicator. 
     Further, for example, Japanese Unexamined Patent Application Publication (Translation of PCT Application) No. 2003-534864 discloses a technique for assessing the stress to a person by using thermal image data of a face of the person. Accordingly, in the present disclosure, the stress indicator may be calculated by using the technique disclosed in Japanese Unexamined Patent Application Publication (Translation of PCT Application) No. 2003-534864. 
     (5) In the first to third embodiments, the evaluation display apparatus  40  is provided on the outside of the airplane X but may be provided on the inside of the airplane X. In this case, the flight attendant evaluation system may calculate the evaluation value of the flight attendant in real time and cause the evaluation display apparatus  40  to present the evaluation value. In addition, in this case, the statistical processing apparatus  30  may calculate the evaluation value of each of the flight attendants by using only the biological data of the customers  102  who are boarded in the present time. 
     The present disclosure enables a flight attendant to be evaluated by using biological data and is thus useful for an improvement in service by the flight attendant.