KR101756858B1

KR101756858B1 - Secure Trajectory Query Processing with Surrogate Vector Model

Info

Publication number: KR101756858B1
Application number: KR1020150188763A
Authority: KR
Inventors: 엄수현; 이우기; 박순형
Original assignee: 인하대학교 산학협력단
Priority date: 2015-12-29
Filing date: 2015-12-29
Publication date: 2017-07-26
Also published as: KR20170078343A

Abstract

The present invention provides a method for transforming directional vector of moving path data, which includes mapping GPS data representing a moving path of an object to grid-based cell data, and converting the cell data to direction vector data.

Description

Secure Trajectory Query Processing with Surrogate Vector Model.

According to the present invention, a movement path of an object is converted into a direction vector by using position information obtained from a position information collecting device, motion patterns of various objects are obtained through the converted direction vector data, And more particularly, to a system and method for reliably and accurately resolving problems with privacy exposures.

Generally, location information is collected through a number of devices including a GPS device, i.e., a mobile terminal or a navigator, and the movement path of the object through the collected location information includes original data, a grid, data transformed into a region such as a cell, and data converted into a road network through map matching.

There have been many researches on the system for solving the problem of privacy exposure according to the location information of the path.

In general, the degree of privacy exposures according to the location information of data based on k-anonymity, l-diversity, etc. have been studied in the methods for anonymity of individuals.

Conventional techniques have been mainly directed toward the protection of individual location information such as point data. Therefore, although the path data should be applied in a different way from the point data, it is not applied correctly or the research is insufficient. In addition, even in the case of advanced research, there has been a problem of ignoring the usefulness of data due to deletion or concealment of data in order to protect personal information.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made to solve the above problems.

According to an aspect of the present invention, there is provided a method for generating a motion vector, the method comprising: generating direction vector-based data representing a movement path of an object; And a method for securely performing path query processing using the direction vector-based data.

The generating of the direction vector-based data may include: generating cell data by mapping original data representing a movement path of the object to a grid; And converting the cell data into the direction vector-based data.

The direction vector-based data may be in two-dimensional or three-dimensional form.

In another aspect, the present invention provides a secure path query processing system through a data processing block that generates direction vector-based data representing an object's movement path.

Here, the data processing block may be configured to generate cell data by mapping original data representing a movement path of the object to a grid, and to convert the cell data into the direction vector-based data.

According to the present invention, by converting the position information data of the movement route into the grid-based direction vector data, it is possible to further improve the usability of the data and to protect the personal information more efficiently than the existing technology.

In addition, by converting the position information data into grid-based direction vector data, it is possible to reduce a huge amount of data size that has been processed by the existing technique.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram illustrating a method of representing a directional vector on which an object moving path matching method according to an embodiment of the present invention is based; FIG.
BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an apparatus and method for converting a direction vector of moving path data.
Figure 3 illustrates a method of mapping a vertex to a grid representing a location according to an embodiment of the present invention.
4 is a diagram illustrating a data processing method of a direction vector conversion system for moving path data according to an embodiment of the present invention;
5 is a configuration diagram showing a configuration of a direction vector conversion system for moving path data according to an embodiment of the present invention;

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

The following examples are intended to illustrate the present invention in detail and do not limit or limit the scope of the present invention. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein.

Although the accompanying drawings are shown in two dimensions for convenience of explanation of the embodiments of the present invention, it is obvious that the present invention also applies to three-dimensional spatial information.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram illustrating a method of representing a direction vector as a basis for explaining a direction vector conversion method of movement path data according to an embodiment of the present invention; FIG.

Referring to FIG. 1, when a region in which an object moves is represented by a grid, eight directions in which the object can move based on the current position are known. That is, if eight directions are expressed as vectors, [0,1], [1,1], [1,0], [1, -1]. [0, -1] -1,0], [- 1,1].

By using such a direction vector, it is possible to perform path query of an object while safeguarding privacy, which will be described in more detail below.

2 is a diagram illustrating an example of a movement path of two objects in processing an object movement path query according to an embodiment of the present invention.

Referring to FIG. 2, when two objects u and v are compared with a moving sequence of two objects u and v according to the conventional method, since there is no matching position data, The path similarity between the objects u and v is calculated to be very low.

That is, with respect to the movement paths of the two objects u and v, according to the conventional movement path expression method,

u: [A1024, B7386], [A1025, B7386], [A1025, B7387], [A1024, B7388], [A1025, B7389], [A1026, B7389];

v: [A1025, B7386], [A1026, B7386], [A1026, B7387], [A1026, B7388], [A1026, B7389]

And is represented by a cell sequence including position coordinates as shown in FIG.

In the conventional technology, u and v can be easily distinguished even if the cell data of two objects u and v are different from each other and only a small number of background knowledge is required.

In other words, it is very likely that personal information can be violated because an individual can be easily distinguished.

For example, a person who knows that v has visited an area of [A1026, B7387] can easily identify v among the two pieces of data, and can also identify the remaining places visited by v, so that v's personal information is easily infringed do.

In this regard, the movement paths of the two objects u and v are expressed using direction vectors according to an embodiment of the present invention as follows.

u: [A1024, B7386], [0, -1]. [1,0], [1,0], [1,0], [0,1];

v: [A1025, B7386], [0, -1]. [1,0], [1,0], [1,0].

As described above, when the movement path of the object is compared using the direction vector-based position data as in the embodiment of the present invention, not only the movement path can be reflected in detail but also the personal information can be protected.

In other words, except for the position of the first data, the position of the cell is represented by the same data as the direction vector data, so it is difficult to distinguish the possibility of protecting personal information.

Also, the direction vector-based position data has an advantage that the amount of data can be greatly reduced compared with the conventional coordinate-based position data.

FIG. 3 is a diagram illustrating a method of mapping a vertex representing a position to a grid according to an embodiment of the present invention.

Referring to FIG. 3, the vertex p can be expressed by latitude (lat), longitude (lngt), and time (t) of the corresponding vertices as follows.

p = (lat, lngt, t).

Here, for a grid set G corresponding to a two-dimensional (i.e., 2D) space made up of the coordinates (lat, lngt) of the vertices p, a grid g as an element of the grid set G is divided into a latitude lat0 to lat1 range and a longitude lngt0 If we assume that the range of ~ lngt1 is dominant, g can be expressed as:

lngt? g, lat? g where lat0? x? latt1, lngt0? y? lngt1.

In this situation, the position of the corresponding vertex can be mapped to the grid using the grid mapping function.

On the other hand, by adding the altitude information to the position data, it becomes possible to use the three-dimensional (i.e., 3D) position data, and in such a case, the path data query in the 3D space can be performed.

FIG. 5 is a block diagram showing a configuration of a direction vector conversion system for moving path data according to an embodiment of the present invention, and FIG. 4 is a diagram illustrating a data processing method of the direction vector conversion system of FIG.

4 and 5, the direction vector conversion system 10 for moving path data according to an embodiment of the present invention includes a GPS data input processing block 20, a cell data output processing block 30, (40), a direction vector data sequence output processing block (50), and a direction vector de-mapping processing block (60). These blocks may be configured in a physical form or a logical form.

Hereinafter, the data processing blocks 20 to 50 process and process the position data.

In this regard, the data processing blocks 20 to 50 map the received original data (for example, GPS data) to a grid. Thereafter, the mapped set of cell data sequences is transformed into a direction vector. That is, a vector data sequence set is generated by grid vectorizing the mapped cell data sequence. Thus, a vector-based movement path for each object is created.

The direction vector de-mapping processing block 60 converts the direction vector data sequence generated through the data processing blocks 20 to 50 into an existing cell data sequence and efficiently re-applies the same to a system using existing cell data And it is also possible to recreate accurate unique position information data.

The embodiment of the present invention described above is an example of the present invention, and variations are possible within the spirit of the present invention. Accordingly, the invention includes modifications of the invention within the scope of the appended claims and equivalents thereof.

10: Direction vector conversion system of moving path data
20: GPS data input processing block
30: Cell data output processing block
40: cell data input processing block
50: direction vector data sequence output processing block
60: direction vector dequantization processing block

Claims

Inputting GPS data into a grid mapping function to obtain cell data;
Obtaining a cell data sequence as an output through the grid mapping function;
Inputting a cell data sequence into a direction vector mapping function to vectorize the cell data sequence;
Outputting from the direction vector mapping function a direction vector data sequence indicating a movement path using cell data;
Mapping the direction vector data sequence back through a direction vector inverse mapping function to obtain existing cell data
And converting the moving path data into a direction vector.

The method according to claim 1,
A method for converting the movement path data into a direction vector,
GPS data including one of coordinate data, road data, and location data for an identifiable place is used,
The grid mapping function maps GPS data to each region range, and if the continuous data belongs to one cell, the corresponding continuous data is converted into one cell data,
The direction vector mapping function transforms the direction vector into a direction vector through operation of successive cell data,
Wherein the direction vector de-mapping function is reversed to a previous cell data sequence.

3. The method of claim 2,
The movement path data includes spatial information including one of two-dimensional and three-dimensional information, and data including time information of day, hour, and minute
A method for converting movement path data to a direction vector.

3. The method of claim 2,
The road data means road name data having unique information meaning each road,
The position data of the identifiable place is data representing the unique position of the building or mountain
A method for converting movement path data to a direction vector.

The method according to claim 1,
Wherein the grid is a set comprising cells representing all regions on the earth,
The cell is a range that represents each region represented by one of two-dimensional data or three-dimensional data
A method for converting movement path data to a direction vector.

6. The method of claim 5,
Wherein the two-dimensional data includes latitude and longitude,
The three-dimensional data is data including latitude, longitude and altitude
A method for converting movement path data to a direction vector.

A GPS data input processing block for inputting GPS data to a grid mapping function to obtain cell data;
A cell data output processing block for obtaining a cell data sequence as an output from the grid mapping function;
A cell data input processing block for inputting a cell data sequence to a direction vector mapping function to vectorize the cell data sequence;
A direction vector data sequence output processing block for indicating a movement path using the cell data;
A direction vector de-mapping process block for mapping the direction vector data sequence back to obtain the existing cell data,
And a direction vector conversion unit for converting the direction vector of the moving path data.

8. The method of claim 7,
In the direction vector conversion system of the moving path data,
GPS data including one of coordinate data, road data, and location data for an identifiable place is used,
The grid mapping function maps GPS data to each region range, and if the continuous data belongs to one cell, the corresponding continuous data is converted into one cell data,
The direction vector mapping function transforms the direction vector into a direction vector through operation of successive cell data,
Wherein the direction vector inverse mapping function is obtained inversely as a previous cell data sequence.

9. The method of claim 8,
The movement path data includes spatial information including one of two-dimensional and three-dimensional information, and data including time information of day, hour, and minute
Direction vector conversion system of moving path data.

9. The method of claim 8,
The road data means road name data having unique information meaning each road,
The position data of the identifiable place is data representing the unique position of the building or mountain
Direction vector conversion system of moving path data.

8. The method of claim 7,
Wherein the grid is a set comprising cells representing all regions on the earth,
The cell is a range that represents each region represented by one of two-dimensional data or three-dimensional data
Direction vector conversion system of moving path data.

12. The method of claim 11,
Wherein the two-dimensional data includes latitude and longitude,
The three-dimensional data is data including latitude, longitude and altitude
Direction vector conversion system of moving path data.