Abstract:
네트워크를 확장하는 방법 및 게이트웨이가 제공된다. 본 발명의 게이트웨이가 이더캣(EtherCAT) 네트워크를 무선 네트워크로 확장하는 방법은 (a) 이더캣 네트워크로부터 제 1 데이터를 수신하고, 상기 수신된 제 1 데이터를 프로토콜 변환을 통해 무선 네트워크에 적합한 제 2 데이터로 변환하는 단계 및 (b) 상기 변환된 제 2 데이터를 상기 무선 네트워크로 전송하는 단계를 포함하되, 상기 (b) 단계는 내부 버퍼(internal buffer)를 이용하여 상기 이더캣 네트워크 및 무선 네트워크간 통신 속도 차이를 감소시킨다.
Abstract:
The present invention discloses a method and an apparatus for controlling access based on a key in a social network service. The present invention relates to the method for controlling access based on the key in the social network service by the access control apparatus comprising the steps of: (a) separating a unique master key of a file owner and generating one core key and a plurality of sub-keys wherein each of the sub-keys is differently allocated for each of plural groups classified according to a reliability level and a relation; (b) when key distribution is requested by a file requester, determining a group to which the file requester is affiliated by using at least one among a friend list of the file requester, a reliability level between the file requester and the file owner, and a friend list of the file owner and distributing a sub-key corresponding to the determined group to the file requester; and (c) when a file is requested by the file requester, determining whether access to the file of the file owner is allowed by using the sub-key distributed to the file requester and the core key.
Abstract:
광 송신기의 발광 각도 변화 장치 및 방법이 개시된다. 개시된 광 송신기의 발광 각도 변화 장치는 복수의 광 송신기에서 각각 측정되는 광 수신기로부터 전송된 신호대 간섭비(Signal to Noise Ratio, 이하 SNR) 정보의 수신세기 및 상기 SNR 정보를 상기 복수의 광 송신기로부터 수신하는 수신부; 상기 SNR 정보가 미리 설정된 임계치 값 이상인지 판단하는 판단부; 및 상기 SNR 정보가 상기 임계치 값 미만인 경우 상기 수신세기를 이용하여 상기 복수의 광 송신기 중 적어도 하나의 광 송신기의 발광 각도를 변화시키는 제어부를 포함할 수 있다. 본 발명에 따르면, 광 송신기의 발광 각도를 변화시킬 수 있으며 광 송신기의 발광 각도의 변화를 통해 가시광 무선 통신 시스템의 성능을 향상시킬 수 있다.
Abstract:
PURPOSE: A server device and a data communication method of a wireless field bus system using the same are provided to adaptively set the number of data time slots. CONSTITUTION: A searching unit(121) searches for a plurality of nodes executing data communication with a server device. A setting unit(122) sets the number of data time slots for transmitting data within a communication frame used in data communication of the nodes based on the number of the searched nodes. The searching unit searches for the nodes according to the set period. The setting unit repetitively sets the number of the data time slots according to the set period. [Reference numerals] (120) Server device; (121) Searching unit; (122) Setting unit; (123) Communication unit
Abstract:
PURPOSE: A portable terminal, a positioning server, and a positioning method of a portable terminal using the same are provided to accurately measure the location of the portable terminal according to a TDoA(Time Difference of Arrival) method using a visible ray signal. CONSTITUTION: A control unit(221) controls the transmission of visible signals in a plurality of transmission devices. A location calculation unit(222) calculates the location of the portable terminal based on the time information of which a portable terminal receives a visible ray signal from each of the transmission devices. The control unit controls a plurality of transmission devices in order not to overlap the transmission time of the transmission devices. [Reference numerals] (210) Visible ray transceiving device; (211) Visible ray transmission unit; (212) Visible ray reception unit; (220) Positioning server; (221) Control unit; (222) Location calculation unit; (223) Communication unit; (224) Control message generation unit; (230) Mobile terminal; (231) Reception unit; (232) Time measurement unit; (233) Transceiving unit
Abstract:
PURPOSE: A location and reception angle estimation apparatus of a light receiver and method thereof are provided to estimate the location and reception angle of a light receiver by measuring light emitted from a visible light emission apparatus. CONSTITUTION: A candidate position computation unit(505) computes candidate locations of a light receiver using one of the measured reception strengths. An analysis unit(507) predicts the reception strengths of visible light according to the first reception angle variation of the light receiver in the candidate locations. The analysis unit analyzes the first variation estimation of the predicted reception strengths. An estimation unit(509) measures a second reception angle and the location of the light receiver using the second variation estimation of the measured reception strengths and the first variation estimation of the candidate locations. [Reference numerals] (102) Light receiver; (501) Estimated information request unit; (503) Reception strength reception unit; (505) Candidate location calculation unit; (507) Analysis unit; (509) Estimation unit; (510) Estimation reception angle transmission unit; (511) Linear distance calculation unit; (513) Candidate location coordinate calculation unit; (515) Direction recognition unit; (521) Reception strength prediction unit; (523) Trend curve creation unit; (531) Trend curve selection unit; (533) Light receiver location estimation unit; (535) Light receiver reception angle estimation unit; (AA) Light receiver location/ reception angle estimation apparatus
Abstract:
PURPOSE: An automatic manufacturing system error detection and automatic report system is provided to secure safety of a product through an automatic manufacturing system through an error sensing system construction. CONSTITUTION: A VLC(Visible Light Communications) transceiving modem transceives data through VLC wireless communication. A server collects data which is transmitted from a machine control unit. The server supplies the collected data to a central management and monitoring system. A lighting control sensor is attached inside an indoor lighting device. The lighting control sensor changes the color of the light.
Abstract:
PURPOSE: A multi-hop collection based routing method in order to supply stable routing in the ad-hoc wireless network without increasing network overhead is provided to collect resource information in a multi-hop relay method by including resource information within a hello message field. CONSTITUTION: Each node collects multi hop resources while broadcasting a hello message to a neighbor node(S10). Each node calculates quantified path stability value through a signal strength arithmetic mean value and a signal strength variation based on the signal strength of a collected Hello message(S20). Each node searches for the most stabilized routing path to a reception node through internal and external path search processes of an area(S30).
Abstract:
본 발명은 멀티 채널 멀티 라디오 기반 무선 메쉬 네트워크 설계에 관한 것으로, 이를 위하여 본 발명은, 규칙적인 육각형 형태의 메쉬 클러스터를 사용하여 다양한 무선 경로의 제공 및 부하분산을 용이하게 하며, 메쉬 클러스터에서 발생하는 트래픽을 계산하여 메쉬 네트워크의 규모를 설정한다. 또한, 메쉬 클러스터의 게이트웨이와 무선 메쉬 라우터 간 연결 홉 수와 이에 따른 무선 채널 사용량에 따라 안테나를 차등적으로 배치하여 병목현상을 제거하는 동시에 구축 비용을 최소화한다. 이렇게 비용 최적화된 메쉬 클러스터를 기존의 셀룰러 네트워크와 유사하게 짜임새있게 배치함으로써 전체 무선 메쉬 네트워크를 구성하여 전파 난청지역이 없이 구축 비용이 최소화된 무선 메쉬 네트워크의 구축이 가능하다. 무선 메쉬 네트워크, 클러스터, 안테나 배치, 구축 비용, 최적화
Abstract:
A method for solving hidden preferred-user problems in a communication system using the cognitive radio technique is provided to prevent the signal interference by establishing a safety area in which a hidden preferred-user is not generated, and then guiding the transmission radius of a CR node inside the safety area. A transmission CR node searches a neighbor node in a safety area(401) and then grasps whether the neighbor node exists in a safety area(402). If the neighbor node does not exist, the transmission CR node connects to a preset common control channel(404) and then establishes a connection with the neighbor node after controlling the transmission radius(405).