• International Journal of Advanced Culture Technology
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• 제11권2호
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• pp.315-322
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• 2023

Intelligent IoT environments that accommodate a very large number of clients require technologies that provide secure information service regardless of the number of clients. Wireless data broadcast is an information service technique that ensures scalability to deliver data to all clients simultaneously regardless of the number of clients. In wireless data broadcasting, clients access the wireless channel linearly to explore the data, so the access time of clients is greatly affected by the broadcast cycle. Data compression-based data broadcasting can reduce the broadcast cycle and thus reduce client access time. Therefore, a simulation framework that can evaluate the performance of data broadcasting by applying different data compression algorithms is essential and important. In this paper, we propose a simulation framework to evaluate the performance of data broadcasting that can adopt data compression. We design the framework that enables to apply different data compression algorithms according to the data characteristics. In addition to evaluating the performance according to the data, the proposed framework can also evaluate the performance according to the data scheduling technique and the kind of queries the client wants to process. We implement the proposed framework and evaluate the performance of data broadcasting using the framework applying data compression algorithms to demonstrate the performances of data compression broadcasting.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제8권1호
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• pp.11-17
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• 2008

Typical wireless sensor networks used in structural monitoring are continuous types wherein data transmission is progressive at all time that may include irrelevant and insignificant data and information. Continuous types of wireless monitoring systems often pose problems of handling large-sized data that may deteriorate the performance of the system. The proposed method is to suggest an event-triggered monitoring system that captures and transmits relevant data only. An error signal generated by the Principal Components Analysis (PCA) is utilized as an index for event detection and selective data transmission. With this new monitoring scheme, the remote server is relieved of unwanted data by receiving only relevant information from the wireless sensor networks. The performance of the proposed scheme was verified with simulation studies.

• 한국멀티미디어학회논문지
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• 제8권6호
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• pp.827-835
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• 2005

In this paper, self-networking and replaceable structure in vector graphics contents are presented for wireless internet service. The wireless networks over 2G or 3G are limited in the sense of the speed and the cost. Considering these characteristics of wireless network, self-networking method and replaceable structure in downloaded contents are introduced in order to save the amount of data and provide variations for contents. During the display of contents, a certain data for the contents is downloaded from the server and it is managed appropriately for the operation of the contents. The downloaded materials are reflected to the original contents using replaceable structure. Also, the downloading and modification are independent of the play. In this implementation, the data consists of control data for control and resource data for image, sound or text. Comparing to the conventional methods which download the whole data, the amount of the transmitted data is very small since only the difference is downloaded. Also, during the play of the contents, the changes are adopted immediately. The whole functions are implemented in wireless handset and the various applications are discussed.

• 대한산업공학회지
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• 제35권1호
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• pp.119-128
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• 2009

In this paper, we analyze the effect of the data aggregation level on the MAC performance when RFID (Radio Frequency Identification) logistics data, which can be aggregated at RFID readers to reduce the transmission overhead, are transmitted in IEEE 802.11 wireless LANs. For various data aggregation levels, the throughputs and latencies of the DCF (Distributed Coordination Function) and PCF (Point Coordination Function) MAC protocols are analyzed by computer simulation. From the simulation analysis, we propose the appropriate input traffic load for real-time RFID logistics data transmitted in IEEE 802.11 wireless LANs.

• Journal of information and communication convergence engineering
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• 제10권3호
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• pp.237-241
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• 2012

In wireless sensor networks, the importance of transporting data correctly with reliability is increasing gradually along with the need to support communications between the nodes and sink. Data flow from the sink to the nodes requires reliability for control or management that is very sensitive and intolerant of error; however, data flow from the nodes to the sink is relatively tolerant. In this paper, with emphasis on the data flow from the sink to the nodes, we propose a mechanism that considers accurate transport with reliability hop-by-hop. During the process of sending the data, if errors occur or data is missing, the proposed mechanism supports error recovery using a fixed window with selective acknowledgment. In addition, this mechanism supports congestion control depending on the buffer condition. Through the simulation, we show that this mechanism is accurate, reliable, and proper for transport in wireless sensor networks.

• Journal of Platform Technology
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• 제10권4호
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• pp.47-55
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• 2022

사물인터넷 환경에서는 다양한 무선 통신 기술을 사용하는 기기들이 점점 증가하고 있다. 특히, 다양한 무선 신호 변조 유형을 정확하게 식별하기 위해 효율적인 특성 추출 기법을 설계하고 무선 신호의 종류를 분류하는 것이 필수적이다. 하지만, 실제 환경에서 레이블이 지정된 무선 신호 데이터를 수집하는 것은 쉬운 문제가 아니다. 최근 무선 신호 분류를 위해 딥러닝 기반의 다양한 학습 기법들이 제안되어졌다. 딥러닝의 경우 훈련 데이터셋이 적을 경우 과대적합에 빠질 가능성이 높으며, 이는 딥러닝 모델을 활용한 무선 신호 분류 기법의 성능 저하를 유발한다. 본 연구에서는 다양한 무선 신호들이 존재할 때 분류 성능을 높이기 위해 생성적 적대 신경망 기반 데이터 증대 기법을 제안한다. 분류해야 하는 무선 신호의 종류가 다양할 때 특정 무선 신호를 나타내는 데이터의 양이 적거나 균형이 맞지 않는 경우 제안한 기법을 활용하여 필요한 무선 신호와 관련된 데이터의 양을 증가시킨다. 제안한 데이터 증강 알고리즘의 유효성을 검증하기 위해 무선 신호의 데이터양을 증가시키고 균형을 맞춘 결과를 바탕으로 CNN 및 LSTM 기반 무선 신호 분류기를 구현하여 실험해본 결과 데이터 균형을 맞추지 않았을 때보다 분류 정확도가 높아지는 것을 확인하였다.

• 한국통신학회논문지
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• 제38B권11호
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• pp.934-936
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• 2013

A routing scheme for a group of mobile users for wireless ad-hoc networks is presented. The proposed scheme mines social activity patterns from wireless traces, and exploits social user group for efficient data routing among users based on a data publish approach. Simulation results based on real-world wireless traces show that our routing scheme reduces routing cost for a large mobile user group with a factor of 1.8 compared to a baseline counterpart.

• 인터넷정보학회논문지
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• 제6권3호
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• pp.45-54
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• 2005

최근 무선 인터넷 서비스를 위한 다양한 기반기술이 연구되고 있으며, WAP(Wireless Application Protocol) 포럼에서는 기존의 유선인터넷 프로토콜과 무선 WAP 프로토콜간의 상호변환을 담당하는 WAP 게이트웨이를 제안하였다. 본 논문에서는 제한적인 환경을 가지는 이동무선통신망에서의 효율향상을 위한 방법의 일환으로써, WAP 게이트웨이를 위한 에이전트들을 설계하고 구현하였다. WAP 게이트웨이 에이전트들인 CSA(Client Side Agent)와 SSA(Sewer Side Agent)는 이동 WAP 단말기와 WAP 게이트웨이에 각각 위치하며, 패킷 헤더 데이터축소와 데이터 차이분석을 통한 데이터축소 방법들을 이용하여 이동무선통신 환경에서의 통신효율을 향상시킨다 구현된 에이전트들이 제대로 동작된다는 것을 입증하기 위하여 Phone.com의 인터넷폰 에뮬레이터를 사용하였다. 실험 결과, WAP 게이트웨이만을 이용한 데이터 전송량에 비하여, 본 논문에서 구현한 에이전트들을 이용하면 데이터 전송량을 $20\%$ 내지 $35\%$가량 줄일 수 있음을 알 수 있었다.

• 정보처리학회논문지D
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• 제11D권2호
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• pp.485-494
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• 2004

무선 인터넷 단말기 이용자들은 최근에 휴대폰이나 PDA와 같은 무선 인터넷 단말기를 이용한 고객 관계 관리로, 영업 사원들은 모바일 그룹웨어와 연동해 실시간으로 영업데이터와 고객정보를 알아내고 고객들은 무선으로 제품정보와 매입처 검색, 배송, 주문, 결제까지 편리하게 할 수 있다는 게 이점이다. 이에 본 논문에서는 사용자의 성향, 위치, 구매 정보를 이용해 실시간 맞춤 프로모션 정보를 모바일로 제공하는 서비스를 위해, 무선인터넷단말기의 안전한 데이터 전송을 위한 무선 인터넷 환경의 전환과 암호화 기술의 강조, 그리고 안전하고 신뢰할 수 있는 통신 환경 구축에 있어서 핵심적인 역할을 수행할 WTLS(Wireless Transport Layer Security) 기반의 무선인터넷단말기의 데이터 무결성 보장을 위한 보안 모듈 구현에 대한 방안을 제시한다.

• 정보통신설비학회논문지
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• 제5권1호
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• pp.13-24
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• 2006

This paper proposes a wireless management system for a pet dog using wireless sensor network. The developed intelligent wireless management system is compose of a central control system, auto-feeder, miniguidance robot, and wireless sensing devices. The developed system uses three types of sensed data such as light, temperature, md sounds from a pet dog and surrounded environment respectively. The presented design method using these data provides an efficient way to controlling and monitoring the pet dog. The implemented system can be used as a design framework of portable device for the pet management.