PREDICTION DEVICE, PREDICTION METHOD, AND PREDICTION PROGRAM

Abstract

An estimation device (10) includes an input unit (30) and an estimation unit (32). A first observation value (40) for each of a plurality of observation areas (50), the first observation value being the number of presences (S) of persons who are observation targets at each of a plurality of observation times, and a second observation value (42) for each of a plurality of observation points (52) included in any one of the plurality of observation areas (50), the second observation value being the number of passages (C) of the persons at each of the plurality of observation times, are input to the input unit (30). The estimation unit (32) estimate at least one of the number of passages (C) of the person at an arbitrary estimation time (48) at any one of the plurality of observation points (52) and the number of presences (S) of the person at the arbitrary estimation time (48) in any one of the plurality of observation areas (50) based on a constraint condition (G) satisfied between the first observation value (40) and the second observation value (42), the first observation value (40), and the second observation value (42).

Description

TECHNICAL FIELD

The present disclosure relates to an estimation device, an estimation method, and an estimation program.

BACKGROUND ART

A technology for analyzing a time series of a movement of an observation target includes a technology using a Markov chain that is a stochastic process in which a future state can be estimated from a present state regardless of a past state (for example, Non Patent Literature 1). Further, a scheme for searching for a parameter indicating the time series of the movement of the observation target includes a technology using Bayesian optimization known as an efficient parameter search scheme (for example, Non Patent Literature 2).

CITATION LIST

Non Patent Literature

• Non Patent Literature 1: Charles J. Geyer, “Practical markov chain monte carlo,” Statistical science vol. 7 No. 4, (1992), p. 473-483, Internet search <URL: https://projecteuclid. org/download/pdf 1/euclid.ss/1177011137> Non Patent Literature 2: J. Snoek, H. Larochelle, R. P. Adams, “Practical Bayesian Optimization of Machine Learning Algorithms”, In Advances In Neural Information Processing Systems (NIPS), 2012, Internet Search <URL: https://papers.nips.cc/paper/4522-practical-bayesian-optimization-of-machine-learning-algorithms.pdf>

SUMMARY OF THE INVENTION

Technical Problem

In the related art represented by Non Patent Literature 1 and Non Patent Literature 2, when measurement data is missing, accuracy of estimation regarding a movement of an observation target may be degraded.

An object of the present disclosure is to provide an estimation device, an estimation method, and an estimation program capable of improving accuracy of estimation for a movement of an observation target.

Means for Solving the Problem

An estimation device of the present disclosure includes an input unit to which a first observation value for each of a plurality of observation areas, the first observation value being the number of presences of observation targets at each of a plurality of observation times, and a second observation value for each of a plurality of observation points included in any one of the plurality of observation areas, the second observation value being the number of passages of the observation target at each of the plurality of observation times, are input; and an estimation unit configured to estimate at least one of the number of passages of the observation target at an arbitrary estimation time at any one of the plurality of observation points and the number of presences of the observation targets at the arbitrary estimation time in any one of the plurality of observation areas based on a constraint condition satisfied between the first observation value and the second observation value, the first observation value, and the second observation value.

Further, an estimation method of the present disclosure includes inputting, to an input unit, a first observation value for each of a plurality of observation areas, the first observation value being the number of presences of observation targets at each of a plurality of observation times, and a second observation value for each of a plurality of observation points included in any one of the plurality of observation areas, the second observation value being the number of passages of the observation target at each of the plurality of observation times; and estimating, at an estimation unit, at least one of the number of passages of the observation target at an arbitrary estimation time at any one of the plurality of observation points and the number of presences of the observation targets at the arbitrary estimation time in any one of the plurality of observation areas based on a constraint condition satisfied between the first observation value and the second observation value, the first observation value, and the second observation value.

An estimation program of the present disclosure is a program for causing a computer to execute: receiving a first observation value for each of a plurality of observation areas, the first observation value being the number of presences of observation targets at each of a plurality of observation times, and a second observation value for each of a plurality of observation points included in any one of the plurality of observation areas, the second observation value being the number of passages of the observation target at each of the plurality of observation times; and estimating at least one of the number of passages of the observation target at an arbitrary estimation time at any one of the plurality of observation points and the number of presences of the observation targets at the arbitrary estimation time in any one of the plurality of observation areas based on a constraint condition satisfied between the first observation value and the second observation value, the first observation value, and the second observation value.

Effects of the Invention

According to the present disclosure, an effect that it is possible to improve the accuracy of estimation of the movement of the observation target can be obtained.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is an illustrative diagram illustrating estimation of the number of presences and the number of passages at an arbitrary estimation time by an estimation device of an embodiment.

FIG. 2 is a block diagram illustrating a hardware configuration of an example of the estimation device of the embodiment.

FIG. 3 is a block diagram illustrating a functional configuration of an example of the estimation device of the embodiment.

FIG. 4 is a diagram illustrating an example of a constraint condition.

FIG. 5 is a diagram illustrating another example of a constraint condition.

FIG. 6 is a diagram illustrating an example of geographic information that is an example of auxiliary information.

FIG. 7 is a diagram illustrating an example of event information that is an example of the auxiliary information.

FIG. 8 is a flowchart illustrating an example of a flow of a first estimation process in an estimation process of the estimation device of the embodiment.

FIG. 9 is a flowchart illustrating an example of a flow of a second estimation process of the estimation process of the estimation device of the embodiment.

DESCRIPTION OF EMBODIMENTS

Hereinafter, an example of an embodiment of the present disclosure will be described with reference to the drawings. The same or equivalent components and parts in the respective drawings are denoted by the same reference signs. Further, ratios of dimensions in the drawings are exaggerated for convenience of description and may differ from actual ratios.

As an example, in the estimation device of the present embodiment, the observation targets are persons, and estimation regarding a pedestrian flow due to movement of the persons is performed. The estimation device of the present embodiment estimates at least one of the so-called cross-sectional pedestrian flow, which is the number of passages of persons passing through the observation point at an arbitrary estimation time, and the so-called spatial pedestrian flow, which is the number of presences of persons present in the observation area at the arbitrary estimation time.

Further, with the estimation device of the present embodiment, it is possible to perform sufficient estimation even when an observation value of the number of persons present in the observation area at the observation time (hereinafter referred to as a “first observation value”) and an observation value of the number of persons passing through the observation point at the observation time (hereinafter referred to as a “second observation value”) are partially missing.

For example, the estimation device of the present embodiment can estimate at least one of the number of passages and the number of presences flow with respect to a pedestrian flow around a station 60 of a railway, as illustrated in FIG. 1. In the example illustrated in FIG. 1, the station 60 is present in an observation area 50₃, and railroad tracks are provided in observation areas 50₁ to 50₅. Further, in the example illustrated in FIG. 1, an event venue 64 is provided in an observation area 50₁₁. Hereinafter, when a plurality of observation areas 50 (15 areas: 50₁ to 50₁₅ in FIG. 1) are collectively referred to without distinguishment, reference signs for distinguishing the individual observation areas are omitted and the observation areas are referred to as an “observation area 50.” Similarly, when a plurality of observation points 52 (6 points: 52₁ to 52₁₀ in FIG. 1) to be described below are collectively referred to without distinguishment, reference signs for distinguishing the individual observation points are omitted and the observation points are referred to as an “observation point 52.”

The first observation value, which is an observation value of the number of presences, is obtained for each of the observation areas 50₆, 50₇, 50₉, and 50₁₃ among the observation areas 50₁ to 50₁₅. On the other hand, the first observation value is not obtained for the observation areas 50₁ to 50₅, 50₈, 50₁₀, 50₁₂, 50₁₄, and 50₁₅. Further, the second observation value, which is an observation value of the number of passages, is obtained for the observation points 52₁ and 52₆ in the observation area 50₁₁, the observation point 52₈ in the observation area 50₁₂, and the observation point 52₄ in the observation area 50₃. On the other hand, the second observation value is not obtained for the observation point 52₂ in the observation area 50₇ and the observation point 52₁₀ in the observation area 50₁₃.

With the estimation device of the present embodiment, even when both the observation area 50 in which the first observation value is obtained and the observation point 52 in which the second observation value is obtained are present as described above, it is possible to estimate at least one of the number of passages of persons passing through the desired observation point 52 at an arbitrary estimation time and the number of presences of persons present in the desired observation area 50 at the arbitrary estimation time. The arbitrary time includes a (future) time after a present point in time that is, for example, a point in time when the first observation value and the second observation value are obtained, and a (past) time before the present point in time.

FIG. 2 is a block diagram illustrating a hardware configuration of an example of the estimation device 10 of the present embodiment.

As illustrated in FIG. 2, the estimation device 10 includes a central processing unit (CPU) 12, a read only memory (ROM) 14, a random access memory (RAM) 16, a storage 18, an input interface (I/F) 20, a display unit 22, and a communication interface (I/F) 24. The respective components are communicably connected to each other via a bus 29.

The CPU 12 is a central processing unit that executes various programs or controls each unit. That is, the CPU 12 reads various programs such as the estimation program 15 from the ROM 14, and executes the programs using the RAM 16 as a work area. The CPU 12 performs control of each of the components and various operations according to the programs stored in the ROM 14. In the present embodiment, as illustrated in FIG. 2, the estimation program 15 is stored in the RAM 16, but the present embodiment is not limited thereto and, for example, the estimation program 15 may be stored in the storage 18.

The ROM 14 stores various programs including the estimation program 15 and various pieces of data. The RAM 16 is a work area that temporarily stores a program or data. The storage 18 is configured of a hard disk drive (HDD) or a solid state drive (SSD), and stores various programs including an operating system and various pieces of data.

The input I/F 20 includes a pointing device such as a mouse, and a keyboard, and is used to perform various inputs. The input I/F 20 is not limited to the present embodiment, and may have a form that can be used to perform various inputs by voice.

The display unit 22 is, for example, a liquid crystal display and displays various types of information. The display unit 22 may adopt a touch panel scheme to function as the input I/F 20. Further, the display unit 22 is not limited to a visible display, and may have a function of performing an audible display such as a speaker.

The communication I/F 24 is an interface for communicating with, for example, a device external to the estimation device 10, and standards such as Ethernet (registered trademark), FDDI, and Wi-Fi (registered trademark) are used.

Next, a functional configuration of the estimation device 10 will be described. FIG. 3 is a block diagram illustrating the functional configuration of an example of the estimation device 10.

As illustrated in FIG. 3, the estimation device 10 of the present embodiment includes an input unit 30 and an estimation unit 32 as functional components. Further, as an example, the estimation device 10 of the present embodiment further includes an output unit 34 and a parameter storage unit 35. Each function component is realized by the CPU 12 reading the estimation program 15 stored in the ROM 14, loading the estimation program 15 into the RAM 16, and executing the estimation program 15.

A first observation value 40 and a second observation value 42 are input to the input unit 30, which outputs the first observation value 40 and the second observation value 42, which have been input, to the estimation unit 32. The first observation value 40 is an observation value of the number of persons that are present in the observation area 50 at an arbitrary observation time, as described above. Further, the second observation value 42 is an observation value of the number of passages of persons passing through the observation point at an arbitrary observation time, as described above. A plurality of first observation values 40 and second observation values 42 are input to the input unit 30. The respective numbers of first observation values 40 and second observation values 42 input to the input unit 30 are not limited and may be, for example, numbers depending on estimation accuracy of the estimation device 10 and a size of an area that is an estimation target. Further, the numbers of first observation values 40 and second observation values 42 to be input may be the same or different.

Further, a constraint condition 44 and auxiliary information 46, which will be described in detail below, are input to the input unit 30, and the constraint condition 44 and the auxiliary information 46, which have been input, are output to the estimation unit 32. Further, an estimation time 48, which is a time that is an estimation target, is input to the input unit 30, and the input auxiliary information 46 is output to the estimation unit 32. In the estimation device 10 of the present embodiment, the auxiliary information 46 is not always input, and may not be input.

The first observation value 40, the second observation value 42, the constraint condition 44, the auxiliary information 46, and the estimation time 48 are input from the input unit 30 to the estimation unit 32. The estimation unit 32 of the present embodiment estimates at least one of the number of passages and the number of existences based on a prediction function F satisfying a constraint condition G shown in Equation (1) or (2) below to obtain an estimation result Y. Equation (1) below represents a calculation equation of the estimation result Y that is used when the auxiliary information 46 is not input to the input unit 30, and Equation (2) below represents a calculation equation of the estimation result Y that is used when the auxiliary information 46 is input to the input unit 30.

$\left[\mathrm{Math}.1\right]$ $\begin{array}{cc}Y=F\left(S,C\right)s.t.G\left(S,C\right)& \left(1\right)\end{array}$ $\begin{array}{cc}\begin{array}{c}Y=F\left(S,C,A\right)s.t.G\left(S,C,A\right)\\ A=\left(M,E,\mathrm{Tr}\right)\end{array}\}& \left(2\right)\end{array}$

In Equations (1) and (2) above, S is the first observation value 40 and includes a missing value. Further, C is the second observation value 42 and includes a missing value. Further, s. t represents subject to. Further, G represents the constraint condition 44. The constraint condition G (the constraint condition 44) is a constraint condition that is satisfied between the first observation value 40 and the second observation value 42.

Examples of the constraint condition G may include a constraint condition for sizes of the number of presences S in the observation area 50 and the number of passages C forming a part of the number of presences S.

For example, as illustrated in FIG. 4, it is assumed that the first observation value 40 of a number of presences S_i,t in the observation area 50₁₈ is obtained. It is also assumed that the number of passages C_{i, 1, t} at the observation point 52₁₄ in the observation area 50₁₈ is not obtained, and the number of passages C_{i, 2, t} at the observation point 52₁₆ in the observation area 50₁₈ is obtained. i in the number of presences S_{t, t} and the number of passages C_{i, t} is a sign representing the observation area 50, and t is a sign representing the observation time. In this case, for example, Equation (3) below is satisfied as the constraint condition G. Equation (3) below represents the constraint condition G in which the number of presences S_{i, t} is equal to or greater than a value obtained by adding the number of passages C_{i, 1, t} to the number of passages C_{i, 2, t}.

S _i,t ≥C _i,1,t +C _i,2,t . . .  [Math. 2](3)

Further, an example of the constraint condition G may include a constraint condition for a range of the observation area 50, which has an influence on the number of presences S in a certain observation area 50.

For example, in an example illustrated in FIG. 5, when a moving speed of a person is taken into consideration, a number of presences S_j,t in each of the observation areas 50₂₀ to 50₂₃ and 50₂₅ to 50₂₈ at time t can have an influence on the number of presences S_{i, t+1} of the observation area 50₂₄ at time t+1. Thus, the constraint condition G using the observation areas 50₂₀ to 50₂₃ and 50₂₅ to 50₂₈ is satisfied for the estimation of the number of presences S in the observation area 50₂₄.

Needless to say, the constraint condition G is not limited to each of the examples.

Further, in Equation (2) above, A represents the auxiliary information 46. Auxiliary information A (the auxiliary information 46) is auxiliary information that has an influence on a movement of a person who is an observation target. Using the auxiliary information A, it is possible to improve accuracy of derivation of a parameter regarding a correlation between the number of presences S and the number of passages C. In the present embodiment, geographic information M, event information E, and transportation volume information Tr of a transportation facility are used as an example of the auxiliary information A.

The geographic information M is information indicating whether or not an area is an area in which persons can walk. For example, according to the geographic information M, it is possible to consider a degree of pedestrian flow that the observation point 52 can cover in the entire observation area 50 when there is one observation point 52 in the observation area 50. A specific example of the geographic information M will be described with reference to FIG. 6. In an observation area 50₃₀ illustrated in FIG. 6, the area in which persons can walk is limited. In the example illustrated in FIG. 6, an area 51₁ is an area such as a forest that persons do not pass through, an area 51₂ is an area such as a pedestrian path that is used for persons to pass through, and an observation point 52₂₀ is a point on the area 51₂. In this case, only a portion of the area 51₂ may be considered for the number of presences S_{i, t} of the observation area 50₃₀. In the example illustrated in FIG. 6, a ratio of the number of passages C_{i,1, t} of the observation point 52₂₀ to the number of presences S_{i, t} of the observation area 50₃₀ becomes high.

Further, the event information E is information indicating a position of the observation area 50 in which the event venue 64 in which various events are performed is provided, a start time of the events, an end time of the events, and the like. For example, a pedestrian flow moving toward the event venue 64 increases before and after the start time of the event. On the other hand, a pedestrian flow moving from the event venue 64 to other places increases before and after the end time of the event. Thus, it is preferable to perform the estimation separately from other time periods before and after the start time and the end time of the event. A specific example of the event information E will be described with reference to FIG. 7. In the example illustrated in FIG. 7, the event venue 64 is present in an observation area 50₃₄. Thus, before and after a start time of an event, a pedestrian flow from observation areas 50₃₀ to 50₃₃ and 50₃₅ to 50₃₈ around the observation area 50₃₄ to the observation area 50₃₄ increases, and the number of presences S_i of the observation area 50₃₃ increases. On the other hand, before and after an end time of the event, a pedestrian flow from the observation area 50₃₄ to the observation areas 50₃₀ to 50₃₃ and 50₃₅ to 50₃₈ around the observation area 50₃₄ increases, and the number of presences S_i of the observation area 50₃₃ decreases.

Further, the transportation volume information Tr of the transportation facility is information representing a transportation volume by public transportation facilities such as railroads and buses and transportation facilities such as vehicles, which can have an influence on the number of presences S and the number of passages C. A specific example of the transportation volume information Tr of the transportation facility will be described with reference to FIG. 1. In the example illustrated in FIG. 1, when the number of passengers who use the station 60 of the railway is relatively large, the number of passengers, an arrival time of the railway, and the like have a great influence on the number of presences S_{i, t} in the observation area 50₃ and the number of passages C_{i, i, t} of the observation point 52₄ around a ticket gate.

Needless to say, the auxiliary information A is not limited to each of the examples and may be, for example, any one of the geographic information M, the event information E, and the transportation volume information Tr of the transportation facility. Further, for example, the auxiliary information A may be weather information of the observation area 50 and the observation point 52.

In the estimation unit 32, calculation of Equation (1) or (2) is performed by optimizing an objective function represented by an absolute value of a difference between the first observation value 40 and the estimation result Y corresponding to the first observation value 40 and an absolute value of a difference between the second observation value 42 and the estimation result Y corresponding to the second observation value 42, under a condition that the estimation result Y satisfies the constraint condition. For example, when the number of presences S at an arbitrary estimation time 48 is estimated, an absolute value |S′-Y| of a difference between the estimation result Y that is the number of presences S at the arbitrary estimation time 48 and an observation value S′ of the number of presences becomes an objective function. For example, when the number of passages C at the arbitrary estimation time 48 is estimated, an absolute value |C′-Y| of a difference between the estimation result Y that is the number of passages C at the arbitrary estimation time 48 and the observation value C′ of the number of presences becomes the objective function.

Further, the estimation unit 32 of the present embodiment considers F(S, C) as a regression equation and optimizes the regression parameter β of the regression equation to obtain a parameter regarding a correlation between the first observation value 40 and the second observation value 42 satisfying the constraint condition G.

As an example, in the present embodiment, the parameter β optimized by the estimation unit 32 is stored in a parameter storage unit 35. The parameter storage unit 35 is, for example, the storage 18 or the like.

Further, the estimation unit 32 of the present embodiment uses the parameter β stored in the parameter storage unit 35 to derive the estimation result Y according to an arbitrary estimation time 48 based on Equation (1) or (2) above, and outputs the estimation result Y to the output unit 34. The output unit 34 uses the estimation result Y input from the estimation unit 32 as an estimation result 36, and outputs the estimation result 36 to the outside of the estimation device 10 via the communication IN 24 or the like. The present disclosure is not limited to the present embodiment, and the output unit 34 may output the estimation result 36 to the display unit 22 of the own device so that the estimation result 36 is displayed on the display.

Next, an operation of the estimation device 10 of the present embodiment will be described.

The estimation process in the estimation device 10 of the present embodiment includes a first estimation process for optimizing the parameter β and a second estimation process for estimating at least one of the number of presences S and the number of passages C at the arbitrary estimation time using Equation (1) or (2) in which the optimized parameter β is used.

First, the first estimation process will be described. FIG. 8 is a flowchart illustrating an example of a flow of the first estimation process in the estimation process of the estimation device 10 of the present embodiment. The first estimation process is performed by the CPU 12 reading the estimation program 15 from the ROM 14, loading the estimation program 15 into the RAM 16, and executing the estimation program 15. In the first estimation process illustrated in FIG. 8, it is assumed that the constraint condition G is obtained within the estimation device 10 in advance.

In step S100, the number of presences S, which is the first observation value 40, and the number of passages C, which is the second observation value 42, are input to the CPU 12 as the input unit 30. Further, the geographic information M, the event information E, and the transportation volume information Tr of the transportation facility, which are auxiliary information A, are input to the CPU 12 as the input unit 30. In FIG. 8, a form in which the auxiliary information A, which is the auxiliary information 46, is input to the input unit 30 is illustrated, but the input of the auxiliary information A is not essential as described above.

Then, in step S102, the CPU 12 as the estimation unit 32 sets an initial value of the regression parameter β of the regression equation when F(S, C) is considered as the regression equation, as described above.

Then, in step S104, the CPU 12 as the estimation unit 32 optimizes the parameter β so that an absolute value of the difference from the observation value corresponding to the estimation result Y is minimized using the objective function as described above.

Then, in step S106, the CPU 12 as the estimation unit 32 determines whether or not a value of the parameter β has converged. As an example, in the present embodiment, when the absolute value of the difference from the observation value corresponding to the estimation result Y is in a predetermined range, the CPU 12 regards the value of the parameter β as having converged. When the value of the parameter β has not converged, in other words, when the absolute value of the difference from the observation value corresponding to the estimation result Y is out of the predetermined range, the determination in step S106 becomes a negative determination (NO), and the first estimation process returns to step S104. In this case, the parameter β is optimized again through the process of step S104. On the other hand, when the value of the parameter β has converged, in other words, when the absolute value of the difference from the observation value corresponding to the estimation result Y is in the predetermined range, the determination in step S106 becomes a positive determination (YES), and the first estimation process proceeds to step S108.

In step S108, the CPU 12 as the estimation unit 32 stores a convergent value of the parameter β in the parameter storage unit 35, and then ends the first estimation process.

Next, the second estimation process will be described. FIG. 9 is a flowchart illustrating an example of a flow of the second estimation process in the estimation process of the estimation device 10 of the present embodiment. The second estimation process is performed by the CPU 12 reading the estimation program 15 from the ROM 14, loading the estimation program 15 into the RAM 16, and executing the estimation program 15.

In step S200, the arbitrary estimation time 48 is input to the CPU 12 as the input unit 30.

Then, in step S202, the CPU 12 as the estimation unit 32 acquires the parameter β from the parameter storage unit 35.

Then, in step S204, the CPU 12 as the estimation unit 32 derives at least one of the number of presences S of the desired observation area 50 and the number of passages C of the desired observation point 52 in the auxiliary information 46, which are the estimation result Y according to the estimation time 48, based on Equation (1) or (2) above as described above, and outputs the number to the output unit 34.

Then, in step S206, the CPU 12 as the output unit 34 outputs the estimation result 36 as described above and, then ends the second estimation process.

In the present embodiment, a form in which the first estimation process and the second estimation process performed in the estimation device 10 are treated as separate processes has been described above by way of example, but the present disclosure is not limited to the embodiment, and the first estimation process and the second estimation process may be treated as a series of processes. When the first estimation process and the second estimation process are treated as separate processes as in the present embodiment, the estimation programs 15 may also be separate programs corresponding to the respective processes. Further, a function of the estimation unit 32 that performs the first estimation process and a function of the estimation unit 32 that performs the second estimation process may be included in the separate estimation devices 10.

As described above, the estimation device 10 of the present embodiment includes the input unit 30 and the estimation unit 32. The first observation value 40 for each of the plurality of observation areas 50, the first observation value being the number of presences S of persons that are observation targets at each of a plurality of observation times, and the second observation value 42 for each of the plurality of observation points 52 included in any one of the plurality of observation areas 50, the second observation value being the number of passages C of the persons at each of the plurality of observation times, are input to the input unit 30. The estimation unit 32 estimates at least one of the number of passages C of the person at the arbitrary estimation time 48 at any one of the plurality of observation points 52 and the number of presences S of persons at the arbitrary estimation time 48 in any one of the plurality of observation areas 50 based on the constraint condition G satisfied between the first observation value 40 and the second observation value 42, the first observation value 40, and the second observation value 42.

With the estimation device 10 having the above configuration according to the present embodiment, because the estimation of the movement of persons (pedestrian flow) is performed in consideration of a correlation between the number of presences S in the observation area 50 and the number of passages C of the observation point 52, it is possible to improve the accuracy of the estimation. With the estimation device 10 of the present embodiment, because the correlation between the number of presences S in the observation area 50 and the number of passages C of the observation point 52 is considered, it is possible to perform highly accurate estimation even when the observation values of the number of presences S and the number of passages C are missing.

In the present embodiment, a form in which the observation target is a person has been described, but the observation target is not limited to this form. For example, the observation target may be a vehicle. As described above, the estimation device of the present disclosure can be applied to data having a time series.

In each of the embodiments, various processors other than the CPU may execute the estimation process executed by the CPU reading software (program). In this case, examples of the processor may include a programmable logic device (PLC) of which a circuit configuration can be changed after manufacture of a field-programmable gate array (FPGA), and a dedicated electric circuit that is a processor having a circuit configuration specially designed so that a specific process is executed, such as an application specific integrated circuit (ASIC). Further, the estimation process may be executed by one of these various processors or may be executed by a combination of two or more processors of the same type or different types (for example, a combination of a plurality of FPGAs or a combination of a CPU and an FPGA). Further, a hardware structure of these various processors is, more specifically, an electric circuit in which circuit elements such as semiconductor elements are combined.

Further, an aspect in which the estimation program 15 is stored (installed) in the ROM 14 in advance has been described in each of the embodiments, but the present disclosure is not limited thereto. The program may be provided in a form of being in a non-transitory storage medium such as a compact disk read only memory (CD-ROM), a digital versatile disk only memory (DVD-ROM), or a universal serial bus (USB) memory. Further, the program may be downloaded from an external device via a network.

The following supplement will be further disclosed for the embodiments.

Supplementary Note 1

An Estimation Device Includes

a memory, anda processor connected to the memory,wherein the processor is configured toreceive a first observation value for each of a plurality of observation areas, the first observation value being the number of presences of observation targets at each of a plurality of observation times, and a second observation value for each of a plurality of observation points included in any one of the plurality of observation areas, the second observation value being the number of passages of the observation target at each of the plurality of observation times, and estimate at least one of the number of passages of the observation target at an arbitrary estimation time at any one of the plurality of observation points and the number of presences of the observation targets at the arbitrary estimation time in any one of the plurality of observation areas based on a constraint condition satisfied between the first observation value and the second observation value, the first observation value, and the second observation value.

Supplementary Note 2

A non-transitory storage medium storing a program that can be executed by a computer so that an estimation process is executed,wherein the estimation process includes, when a first observation value for each of a plurality of observation areas, the first observation value being the number of presences of observation targets at each of a plurality of observation times, and a second observation value for each of a plurality of observation points included in any one of the plurality of observation areas, the second observation value being the number of passages of the observation target at each of the plurality of observation times are input, estimating at least one of the number of passages of the observation target at an arbitrary estimation time at any one of the plurality of observation points and the number of presences of the observation targets at the arbitrary estimation time in any one of the plurality of observation areas based on a constraint condition satisfied between the first observation value and the second observation value, the first observation value, and the second observation value.

REFERENCE SIGNS LIST

• 10 Estimation device
• 12 CPU
• 14 ROM
• 15 Estimation program
• 18 Storage
• 30 Input unit
• 32 Estimation unit
• 40 First observation value
• 42 Second observation value
• 44 Constraint condition
• 46 Auxiliary information

Claims

1. An estimation device comprising circuitry configured to execute a method comprising: receiving input, the input including: a first observation value for each of a plurality of observation areas, the first observation value being a number of presences of observation targets at each of a plurality of observation times, anda second observation value for each of a plurality of observation points included in any one of the plurality of observation areas, the second observation value being a number of passages of the observation target at each of the plurality of observation times, are input; andestimating at least one of the number of passages of the observation target at an arbitrary estimation time at any one of the plurality of observation points and a number of presences of the observation targets at the arbitrary estimation time in any one of the plurality of observation areas based on a constraint condition satisfied between the first observation value and the second observation value, the first observation value, and the second observation value.

2. The estimation device according to claim 1, the circuitry further configured to execute a method comprising: estimating the at least one of the number of passages so that an objective function expressed using a difference between the first observation value and an estimation result corresponding to the first observation value and a difference between the second observation value and an estimation result corresponding to the second observation value is optimized under a condition that the estimation result satisfies the constraint condition.

3. The estimation device according to claim 1, wherein the constraint condition includes the first observation value at the observation time for the observation area being equal to or greater than a sum of the second observation values at the observation time for the plurality of observation points included in the observation area.

4. The estimation device according to claim 1, the circuitry further configured to execute a method comprising: estimating the at least one of the number of passages by further using auxiliary information having an influence on movement of the observation target.

5. An estimation method comprising: inputting a first observation value for each of a plurality of observation areas, the first observation value being a number of presences of observation targets at each of a plurality of observation times, and a second observation value for each of a plurality of observation points included in any one of the plurality of observation areas, the second observation value being a number of passages of the observation target at each of the plurality of observation times; andestimating at least one of the number of passages of the observation target at an arbitrary estimation time at any one of the plurality of observation points and a number of presences of the observation targets at the arbitrary estimation time in any one of the plurality of observation areas based on a constraint condition satisfied between the first observation value and the second observation value, the first observation value, and the second observation value.

6. A computer-readable non-transitory recording medium storing computer-executable program instructions that when executed by a processor cause a computer system to execute a method comprising: receiving a first observation value for each of a plurality of observation areas, the first observation value being a number of presences of observation targets at each of a plurality of observation times, and a second observation value for each of a plurality of observation points included in any one of the plurality of observation areas, the second observation value being a number of passages of the observation target at each of the plurality of observation times; andestimating at least one of the number of passages of the observation target at an arbitrary estimation time at any one of the plurality of observation points and a number of presences of the observation targets at the arbitrary estimation time in any one of the plurality of observation areas based on a constraint condition satisfied between the first observation value and the second observation value, the first observation value, and the second observation value.

7. The estimation device according to claim 2, wherein the constraint condition includes the first observation value at the observation time for the observation area being equal to or greater than a sum of the second observation values at the observation time for the plurality of observation points included in the observation area.

8. The estimation device according to claim 2, the circuitry further configured to execute a method comprising: estimating the at least one of the number of passages by further using auxiliary information having an influence on movement of the observation target.

9. The estimation device according to claim 3, the circuitry further configured to execute a method comprising: estimating the at least one of the number of passages by further using auxiliary information having an influence on movement of the observation target.

10. The estimation method according to claim 5, the method further comprising: estimating the at least one of the number of passages so that an objective function expressed using a difference between the first observation value and an estimation result corresponding to the first observation value and a difference between the second observation value and an estimation result corresponding to the second observation value is optimized under a condition that the estimation result satisfies the constraint condition.

11. The estimation method according to claim 5, wherein the constraint condition includes the first observation value at the observation time for the observation area being equal to or greater than a sum of the second observation values at the observation time for the plurality of observation points included in the observation area.

12. The estimation method according to claim 5, the method further comprising: estimating the at least one of the number of passages by further using auxiliary information having an influence on movement of the observation target.

13. The computer-readable non-transitory recording medium according to claim 6, the computer-executable program instructions when executed further causing the system to execute a method comprising: estimating the at least one of the number of passages so that an objective function expressed using a difference between the first observation value and an estimation result corresponding to the first observation value and a difference between the second observation value and an estimation result corresponding to the second observation value is optimized under a condition that the estimation result satisfies the constraint condition.

14. The computer-readable non-transitory recording medium according to claim 6, wherein the constraint condition includes the first observation value at the observation time for the observation area being equal to or greater than a sum of the second observation values at the observation time for the plurality of observation points included in the observation area.

15. The computer-readable non-transitory recording medium according to claim 6, the computer-executable program instructions when executed further causing the system to execute a method comprising: estimating, the at least one of the number of passages by further using auxiliary information having an influence on movement of the observation target.

16. The estimation method according to claim 10, wherein the constraint condition includes the first observation value at the observation time for the observation area being equal to or greater than a sum of the second observation values at the observation time for the plurality of observation points included in the observation area.

17. The estimation method according to claim 10, the method further comprising: estimating the at least one of the number of passages by further using auxiliary information having an influence on movement of the observation target.

18. The estimation method according to claim 10, the method further comprising: estimating the at least one of the number of passages by further using auxiliary information having an influence on movement of the observation target.

19. The computer-readable non-transitory recording medium according to claim 13, wherein the constraint condition includes the first observation value at the observation time for the observation area being equal to or greater than a sum of the second observation values at the observation time for the plurality of observation points included in the observation area.

20. The computer-readable non-transitory recording medium according to claim 13, the computer-executable program instructions when executed further causing the computer system to execute a method comprising: estimating the at least one of the number of passages by further using auxiliary information having an influence on movement of the observation target.