KR100918704B1 - Apparatus and Method for generating a virtual tuple - Google Patents

Abstract

The present invention relates to an apparatus and method for generating a virtual tuple, wherein the apparatus and method for generating a virtual tuple according to the present invention comprise generating a combination attribute value in which a first attribute value and a second attribute value satisfy a predetermined requirement; Combining the first corresponding attribute value corresponding to the first attribute value and the second corresponding attribute value corresponding to the second attribute value.

Sensor networks, tuples, relations, views

Description

Apparatus and Method for generating a virtual tuple}

The present invention relates to an apparatus and method for generating a virtual tuple, and more particularly, to generate a virtual tuple by performing a range join operation based on existing information to provide information about a place where a sensor does not exist in a sensor network. The present invention relates to an apparatus and method for generating a virtual tuple.

As the application range of sensor networks becomes wider, there are attempts to use database concepts in sensor networks to efficiently process and manage the vast amounts of data collected. However, in the sensor network, the data for each point where the sensor is important is important, but the data for the entire area where the sensor is scattered is also important, so there is a problem in that information about the place where the sensor does not actually exist is unknown.

Therefore, there is a need for a method of creating a virtual tuple of a place where a sensor does not actually exist by using an added operation such as range join operation to an existing relational database.

There is also a need for a method of sharing a virtual tuple generated between a base station and a sensor node in a sensor network.

The present invention has been made to solve the above problems, the technical problem to be achieved by the present invention, the first attribute value and the second attribute value by performing a range join operation to generate a combination attribute value, An apparatus and method are provided for generating a virtual tuple having a combination attribute value, a first corresponding attribute value, and a second corresponding attribute value as an attribute value.

Another object of the present invention is to provide a method for sharing a virtual tuple between a base station and a sensor node in a sensor network.

The objects of the present invention are not limited to the above-mentioned objects, and other objects that are not mentioned will be clearly understood by those skilled in the art from the following description.

In order to achieve the above object, an operation module for generating a combination attribute value in which the first attribute value and the second attribute value satisfy a predetermined requirement and a first corresponding to the first attribute value according to an embodiment of the present invention. And a combining module for combining the corresponding attribute value and the second corresponding attribute value corresponding to the second attribute value.

The method may further include generating a combination attribute value in which the first attribute value and the second attribute value satisfy a predetermined requirement, and a first corresponding attribute value corresponding to the first attribute value and the first attribute value according to an embodiment of the present invention. Combining the second corresponding attribute values corresponding to the second attribute values.

Specific details of other embodiments are included in the detailed description and the drawings.

According to the apparatus and method for generating a virtual tuple of the present invention as described above, there is an advantage in that information about a place or a predetermined section in which a sensor node does not actually exist can be obtained.

Advantages and features of the present invention and methods for achieving them will be apparent with reference to the embodiments described below in detail with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but can be implemented in various different forms, and only the embodiments make the disclosure of the present invention complete, and the general knowledge in the art to which the present invention belongs. It is provided to fully inform the person having the scope of the invention, which is defined only by the scope of the claims. Like reference numerals refer to like elements throughout.

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

를 충족하는 속성집합,

,

를 구성하는 모든 속성의 도메인을 실수의 부분집합이라고 하면, 가능한 모든 속성값의 조합

은

의 부분집합이 된다. 이때 릴레이션 R의 임의의 튜플 t에 대하여

을

에 대한 튜플 t의 튜플 벡터로 정의한다.Terms used in the present invention will be defined. However, the interpretation of the terms defined in the present invention is not limited thereto, and may be extended to those skilled in the art to which the present invention pertains. The relation R's schema is A,

Set of attributes that satisfy

,

If the domain of all the attributes that make up a is a subset of real numbers, then the combination of all possible attribute values

silver

Is a subset of. For any tuple t of relation R

of

Defined as a tuple vector of tuples t for.

1 is a conceptual diagram of a sensor network according to an embodiment of the present invention.

Referring to FIG. 1, the sensor network includes a base station 110 and a sensor node 120. When the base station 110 requests the neighboring sensor node 120 for a virtual tuple not stored in the base station 110, the sensor node 1 130, which is one of the neighboring sensor nodes 120, is the neighboring sensor node 2 140. Requests attribute values from. The sensor node 1 130 receiving the attribute values checks whether the first attribute value, which is its attribute value, and the second attribute value, which is the attribute value received from the sensor node 2 140, satisfy the predetermined requirements. When a predetermined requirement is satisfied, a virtual tuple is generated by combining a combination attribute value, a first corresponding attribute value corresponding to the first attribute value, and a second corresponding attribute value corresponding to the second attribute value. To the base station 110. In this case, the virtual tuple may be transmitted to the sensor node 120, and thus, the virtual tuple may be shared between the base station 110 and the sensor node 120. In addition, the sensor node 130 may request attribute values from other sensor nodes. A method for generating a predetermined requirement and a combination attribute value will be described later with reference to FIGS. 2 and 3.

2 is a diagram illustrating a configuration of an apparatus for generating a virtual tuple according to an embodiment of the present invention.

Referring to FIG. 2, the apparatus for generating a virtual tuple includes a combination module 210, a calculation module 220, a control module 230, a storage module 240, and a transmission / reception module 250.

The combining module 210 removes the first attribute value and the second attribute value and combines the corresponding attribute value, the first corresponding attribute value corresponding to the first attribute value, and the second corresponding attribute value corresponding to the second attribute value. Combine to create a virtual tuple. Here, the first attribute value and the second attribute value include at least one attribute value. In addition, the first attribute value and the second attribute value may include one or more data strings. For example, the first attribute value may be represented by (X, Y) and the second attribute value may be represented by (Z, W).

The calculation module 220 plays the following role.

을 생성하는 역할을 한다. 여기서, 소정의 요건은 다음과 같다. First, a valid tuple in which the first and second attribute values meet certain requirements,

Serves to create Here, the predetermined requirements are as follows.

는 속성집합 C에 대한 튜플벡터의 거리가 ρ이하인 조합된 두 개의 튜플을 의미한다. 두 개의 튜플은 r에서 임의의 튜플

과 s에서 임의의 튜플

를 의미한다. 구체적인 내용은 후술하여 설명하기로 한다.Here, p denotes a threshold value, and the threshold value may be a constant value set by a user. Also,

Denotes two combined tuples whose distance to the attribute set C is less than or equal to ρ. Two tuples are random tuples in r

And random tuples in s

Means. Details will be described later.

Secondly, it creates a combination attribute value. As described above, the combination attribute value may be generated only for the first attribute value and the second attribute value satisfying a predetermined requirement. Here, the combination attribute value is calculated as follows.

는 제 1 속성 값,

는 제 2 속성 값을 의미한다. 구체적인 내용은 후술하여 설명하기로 한다.here,

Is the first attribute value,

Means a second attribute value. Details will be described later.

The control module 230 manages and controls the combination module 210, the calculation module 220, the storage module 240, and the transmission / reception module 250.

The storage module 240 may store the first attribute value, the first corresponding attribute value corresponding to the first attribute value, the second attribute value, the second corresponding attribute value corresponding to the second attribute value, and the combination attribute value. In addition, as described above, the first attribute value and the second attribute value include at least one attribute value. Here, the first attribute value and the second attribute value may include one or more data strings.

The transmission / reception module 250 serves to receive a request for a virtual tuple from the base station 110 or the sensor node 120 or to transmit a virtual tuple generated from the virtual tuple generating device to the base station 110 or the sensor node 120. do.

3 is a diagram illustrating a virtual tuple generation method according to an embodiment of the present invention.

Referring to FIG. 3, attribute values and corresponding attribute values are collected (S310). The base station 110 requests the sensor node 120 to generate a virtual tuple, and the received sensor node 1 130 requests the sensor node 2 140 for attribute values and corresponding attribute values. . Upon receiving the request, the sensor node 2 140 transmits its own property values and corresponding property values to the sensor node 1 130. Here, the sensor node 130 collecting attribute values and corresponding attribute values is called a master sensor node. In addition, the base station 110 and the sensor node 120 may include a virtual tuple generation device.

The sensor node 1 130, which has collected the attribute values and the corresponding attribute values, compares the first attribute value with its second attribute value received from the sensor node 2 140, and compares the first attribute value with the second attribute value. It is checked whether the value meets a predetermined requirement (S320). Here, the predetermined requirement must satisfy that an absolute value of the first attribute value and the second attribute value is less than the threshold value, which will be described later.

When the predetermined requirement is met, a combination attribute value corresponding to the first attribute value and the second attribute value is generated (S330). Here, the combined attribute value means an average value of the first attribute value and the second attribute value, which will be described later.

A virtual tuple corresponding to the combined attribute value is generated (S340). Here, the virtual tuple generates a new virtual tuple having the combination attribute value, the first corresponding attribute value corresponding to the first attribute value, and the second corresponding attribute value corresponding to the second attribute value as attributes. Here, the generated virtual tuple may be transmitted to the base station 110 or the sensor node 120.

If the first attribute value and the second attribute value do not satisfy the predetermined requirement, request the attribute values and the corresponding attribute values from another sensor node, and collect the attribute values and the corresponding attribute values (S310). Thereafter, steps S320 to S340 are repeated.

As described above, a range join operation method for generating predetermined requirements and combination attribute values using defined terms will be described in detail.

First, we define range join operation for two relations.

를 사용하며 두 릴레이션에 대한 범위조인연산은 다음과 같다. Range join operation

The range join operation for the two relations is as follows.

와

를 만족하는 두 릴레이션의 범위조인속성집합

가 있을 때, r과 s의 범위조인연산 식은 식(1)과 같다. There are two relations r and s with schemas R and S respectively.

Wow

Set of range join attributes of two relations that satisfy

When is, the range join operation of r and s is the same as Equation (1).

식 (1)

Formula (1)

에서 선택될 튜플의 조인속성값의 최대 거리를 나타낸다. Where every element in C is a subset of domain real and ρ is a range constant

The maximum distance of join attribute values of the tuple to be selected from.

에서 소정의 요건을 충족하는 유효한 튜플을 선택한다. r에서 임의의 튜플

과 s에서 임의의 튜플

에 의하여 조합된 튜플

가 식(2)를 만족할 때 해당 튜플

를 유효한 튜플이라고 한다. 즉 유효한 튜플

는 속성집합 C에 대한 튜플벡터의 거리가 ρ이하인 두 튜플로 조합된 튜플을 의미한다. first,

Selects a valid tuple that meets a given requirement. random tuple in r

And random tuples in s

Combined Tuples

The tuple when Eq. (2) is satisfied

Is called a valid tuple. Valid tuple

Denotes a tuple combined with two tuples whose distance of the tuple vector to the property set C is ρ or less.

식 (2)

Formula (2)

와

의 평균값을 할당한다. Second, add the attribute set C to the resulting relation and add each attribute value as shown in equation (3).

Wow

Assign the average value of.

식 (3)

Formula (3)

Third, remove the attribute set C of r and s from the resulting relation and complete the range join operation.

Next, we define a range join operation that targets three or more relations.

,

,

,

에 대한 범위조인연산은 식(4)와 같이 표기하며 ρ는 첫 번째 조인연산자와 함께 표기한다. Multiple range join operations are treated as one join operation. n relations

,

,

,

The range join operation for is written in equation (4), and ρ is written with the first join operator.

식(4)

Formula (4)

으로부터 추출한다. 이때 소정의 요건을 충족하는 유효한 튜플은 다음과 같다. Equation (4) is a range join operation rather than a plurality of join operations, so a valid tuple

Extract from. At this time, valid tuples satisfying the predetermined requirements are as follows.

가 각각

에 포함된 튜플이고

는 이 튜플로 조합된 튜플이라고 하자. 이때

를 조합하는 모든 튜플이 식(5)를 만족하면

는 유효한 튜플이다. 이는 유효한 튜플을 구성하는 모든 튜플의 조인속성 C에 대한 튜플 벡터들의 거리가 ρ이하임을 의미한다. Tuple

Each

Is a tuple contained in

Let 's be a tuple combined with this tuple. At this time

If all tuples combining

Is a valid tuple. This means that the distance of tuple vectors to join attribute C of all tuples constituting a valid tuple is less than or equal to ρ.

식 (5)

Equation (5)

의 속성값은

를 구성하는 모든 튜플들의 속성값에 대한 평균으로 식(6)과 같이 정의할 수 있다. After selecting a valid tuple, add C and assign an attribute value as described above. Valid tuples, like range joins for two relations

The attribute value of

The average of the attribute values of all the tuples constituting can be defined as in Equation (6).

식(6)

Formula (6)

의 C를 삭제하고 범위조인연산을 마친다. After assigning property values,

Delete C and complete the range join operation.

4 is a diagram showing the relationship between position and temperature in accordance with one embodiment of the present invention. 5 is a diagram illustrating a relationship between position and humidity in accordance with an embodiment of the present invention. 6 is a diagram illustrating a virtual tuple generated by performing a range join operation according to an embodiment of the present invention.

를 수행한다. 여기서, 전술한 바와 같이, 두 좌표간의 거리를 임계 값으로 설정하며, 임계 값을 10으로 설정한다. temp의 위치좌표를 제 1 속성 값, temp의 온도를 제 1 대응 속성 값, hum의 위치 좌표를 제 2 속성 값 및 hum의 습도를 제 2 대응 속성 값으로 한다. 따라서, 제 1 속성 값 및 제 2 속성 값 간의 거리, 즉 임계 값이 10 이하인 경우에만, 유효한 속성 값으로 하고 이를 이용하여 가상 튜플을 생성한다. 유효한 속성 값에 한해, 제 1 속성 값과 제 2 속성 값의 평균 값으로 하는 조합 속성 값을 계산한다. 조합 속성 값, 제 1 대응 속성 값 및 제 2 대응 속성 값을 속성으로 하는 가상 튜플을 생성한다. 전술한 과정을 통해 생성된 가상 튜플은 도 6과 같다.4 to 6, an embodiment of the present invention will be described. 4 is a relation 1 representing the relation between position and temperature, that is, a relation between temp and position and humidity, and a relation 2 is called hum. Attributes X and Y represent the coordinates of the sensor and T and H represent the temperature and humidity, respectively. In this case, the range join operation using coordinates X and Y as property values,

Perform Here, as described above, the distance between the two coordinates is set to a threshold value, and the threshold value is set to 10. The position coordinate of temp is the first attribute value, the temperature of temp is the first corresponding attribute value, the position coordinate of hum is the second attribute value, and the humidity of hum is the second corresponding attribute value. Therefore, only when the distance between the first attribute value and the second attribute value, that is, the threshold value is 10 or less, is set as a valid attribute value and a virtual tuple is generated using the attribute value. Only the valid attribute values are calculated as the combined attribute value which is the average value of the first and second attribute values. A virtual tuple having the combined attribute value, the first corresponding attribute value, and the second corresponding attribute value as an attribute is generated. The virtual tuple generated through the above process is shown in FIG. 6.

Those skilled in the art will appreciate that the present invention can be embodied in other specific forms without changing the technical spirit or essential features of the present invention. Therefore, it should be understood that the embodiments described above are exemplary in all respects and not restrictive. The scope of the present invention is indicated by the scope of the following claims rather than the detailed description, and all changes or modifications derived from the meaning and scope of the claims and the equivalent concept are included in the scope of the present invention. Should be interpreted.

1 is a conceptual diagram of a sensor network according to an embodiment of the present invention.

2 is a block diagram of a virtual tuple generation device according to an embodiment of the present invention.

3 is a flowchart illustrating a virtual tuple generation method according to an embodiment of the present invention.

4 is a diagram showing the relationship between position and temperature in accordance with one embodiment of the present invention.

5 is a diagram illustrating a relationship between position and humidity in accordance with an embodiment of the present invention.

6 is a diagram illustrating a virtual tuple generated by performing a range join operation according to an embodiment of the present invention.

Description of the main parts of the drawing

110: base station

120: sensor node

130: sensor node 1

140: sensor node 2

210: combination module

220: arithmetic module

230: control module

240: storage module

250: transmit / receive module

Claims (14)

In the method for generating a virtual tuple in a sensor network comprising a base station and a sensor node, Determining whether the first attribute value and the second attribute value meet a predetermined requirement; Generating a combination attribute value using the first attribute value and the second attribute value when the requirement is satisfied; Generating a virtual tuple using a first corresponding attribute value corresponding to the first attribute value, a second corresponding attribute value corresponding to the second attribute value, and the generated combined attribute value; And Receiving a request for providing a virtual tuple, and transmitting the generated virtual tuple to the base station and the sensor node so that the generated virtual tuple is shared between the base station and the sensor node. delete The method of claim 1, And the first attribute value and the second attribute value comprise at least one or more attribute values. delete The method of claim 1, The predetermined requirement is And generating an absolute value of a difference between the first attribute value and the second attribute value less than a predetermined threshold. The method of claim 1, And the combination attribute value comprises an average value of the first attribute value and the second attribute value. The method of claim 5, And the threshold value is defined by a user's setting. An apparatus for generating a virtual tuple in a sensor network comprising a base station and a sensor node, A control module for determining whether the first attribute value and the second attribute value satisfy a predetermined requirement; A calculation module for generating a combined attribute value using the first attribute value and the second attribute value when the requirement is satisfied as a result of the determination; A combining module for generating a virtual tuple using a first corresponding attribute value corresponding to the first attribute value, a second corresponding attribute value corresponding to the second attribute value, and the generated combination attribute value; And A transmission / reception module configured to receive a request for providing a virtual tuple and to transmit the generated virtual tuple to the base station and the sensor node, The generated virtual tuple is shared between the base station and the sensor node. delete delete The method of claim 8, The predetermined requirement is And an absolute value of a difference between the first attribute value and the second attribute value is less than a predetermined threshold value. The method of claim 8, And the combination attribute value comprises an average value of the first attribute value and the second attribute value. The method of claim 11, And the threshold value is defined by a user's setting. The method of claim 8, And the first attribute value and the second attribute value comprise at least one or more attribute values.

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