• Proceedings of the Korea Information Processing Society Conference
• /
• 2009.04a
• /
• pp.762-765
• /
• 2009

무선 센서 네트워크상에서 센서노드의 소프트웨어 변경, 패치 등의 작업을 위해서 센서노드별로 ISP와 같은 케이블을 이용하여 프로그램 해야 한다. 이는 네트워크 내에 존재하는 노드의 수가 소량인 경우 크게 문제되지 않지만 대량의 노드로 구성된 경우 프로그래밍을 위한 시간적인 측면과 투여되는 인력적인 측면에서 매우 높은 비용이 소요된다. 본 논문에서는 현재 많이 사용하고 있는 IEEE 802.15.4기반의 단일-홉 무선 센서 네트워크 환경에서 노드의 수와 무관하게 고속 병렬로 센서노드 내부의 프로그램을 무선으로 업데이트 할 수 있는 기법을 제시하고 실험을 통하여 그 성능을 검증한다.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2008.05a
• /
• pp.975-978
• /
• 2008

무선 센서 네트워크에서 한번 배치된 노드들은 회수가 불가능하기 때문에 버그 수정이나 새로운 기능 추가 등을 위해 OTA 프로그래밍이 개발되었다. OTA 프로그래밍 기법들은 업데이트 이미지 데이터를 네트워크 내 모든 노드에게 전달하는 데이터 전달 프로토콜을 사용하는데, 이러한 프로토콜들은 다수의 수신노드들에게 여러 전송 노드가 동시에 데이터를 전송하고 중첩 영역이 발생함으로써 데이터 충돌 및 전송량이 늘어나 에너지 소모가 증가하게 된다. 이를 해결하기 위해 본 논문에서는 전송노드 선정 알고리즘을 이용한 BNRP 프로토콜을 제안한다. 시뮬레이션 결과 BNRP는 기존 수신 노드 요구 메시지에 의해서 전송 노드가 선정되는 방식보다 평균 11%이상 데이터 전송량이 감소하였고, 노드의 분포 밀집도가 10%인 영역에서는 16%이상 데이터 전송량 감소 결과를 보였다.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.25 no.3
• /
• pp.396-402
• /
• 2021

As the world is trying to establish smart city, unmanned vehicle control systems are being widely used. This paper writes about an unmanned parking control system that uses an adaptive background image modeling method, suggesting the method of updating the background image, modeled with an adaptive Gaussian mixture model, in both global and local way according to the moving object. Specifically, this paper focuses on suggesting two methods; a method of minimizing the influence of a moving object on a background image and a method of accurately updating the background image by quickly removing afterimages of moving objects within the area of interest to be monitored. In this paper, through the implementation of the unmanned vehicle control system, we proved that the proposed system can quickly and accurately distinguish both moving and static objects such as vehicles from the background image.

• Digital Contents
• /
• no.3 s.82
• /
• pp.36-37
• /
• 2000

인터넷 이용자가 급증하면서 물품구매를 비롯한 각종 비즈니스가 인터넷을 통해 급격히 증가하고 있다. 이에 따라 인터넷 검색엔진들도 과거와 다른 모습으로 많은 이용자를 확보하려는 노력을 거듭하고 있다. 지난해와 달리 각 검색엔진들이 어떤 모습으로 변모했는지 살펴봤다.

• Computational Structural Engineering
• /
• v.29 no.1
• /
• pp.11-15
• /
• 2016

• Journal of the Institute of Electronics Engineers of Korea CI
• /
• v.46 no.3
• /
• pp.116-122
• /
• 2009

Mobile Wireless Sensor Network is an organized collection of sensor nodes and mobile sink nodes, in which the sensor node transmits the signal to the sink node. In real environment, there are many cases in which sinks have mobility caused by the people, the vehicle and etc. Since all nodes in the sensor networks have limited energy, many researches have been done in order to prolong the lifetime of the entire network. In this paper we propose Dynamic Local Update-based Routing Protocol(D-LURP) that prolong the lifetime of the entire network to efficiently maintain frequent location update of mobile sink static sensor nodes in Mobile WSNs. When the sink node moves out of the local broadcasting area the proposed D-LURP configures dynamically the local update area consisted of the new local broadcasting area and the previous dissemination node(DN) and find the path between the DN and the sink node, instead of processing a new discovering path like LURP. In this way the processing of broadcasting sink node's location information in the entire network will be omitted. and thus less energy will be consumpted. We compare the performances of the proposed scheme and existing Protocols.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.38 no.4
• /
• pp.505-516
• /
• 2018

In order to establish an efficient bridge maintenance strategy, the future performance of a bridge must be estimated by considering the current performance, which allows more rational way of decision-making in the prediction model with higher accuracy. However, personnel-based existing maintenance may result in enormous maintenance costs since it is difficult for a bridge administrator to estimate the bridge performance exactly at a targeting management level, thereby disrupting a rational decision making for bridge maintenance. Therefore, in this work, we developed a representative performance prediction model for each bridge element considering uncertainty using domestic bridge inspection data, and proposed a bayesian updating method that can apply the developed model to actual maintenance bridge with higher accuracy. Also, the feasibility analysis based on calculation of maintenance cost for monitoring maintenance scenario case is performed to propose advantages of the Bayesian-updating-driven preventive maintenance in terms of the cost efficiency in contrast to the conventional periodic maintenance.

• Journal of the Korea Society of Computer and Information
• /
• v.20 no.4
• /
• pp.1-10
• /
• 2015

NAND flash systems require deletion operation and do not support in-place update, so the storage systems should use Flash Translation Layer (FTL). However, there are a lot of memory consumptions using mapping table in the FTL, so recently, many studies have been proposed to resolve mapping table overhead. These studies try to solve update propagation problem in the nand flash system which does not use mapping table. In this paper, we present a novel index structure, called CL-Tree(Cache List Tree), to solve the update propagation problem. The proposed index structure reduces write operations which occur for an update propagation, and it has a good performance for search operation because it uses multi-list structure. In experimental evaluation, we show that our scheme yields about 173% and 179% improvement in insertion speed and search speed, respectively, compared to traditional B+tree and other works.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.25 no.4
• /
• pp.363-372
• /
• 2012

In this study, a new information-based hybrid modeling framework is proposed. In the hybrid framework, a conventional mathematical model is complemented by the informational methods. The basic premise of the proposed hybrid methodology is that not all features of system response are amenable to mathematical modeling, hence considering informational alternatives. This may be because (i) the underlying theory is not available or not sufficiently developed, or (ii) the existing theory is too complex and therefore not suitable for modeling within building frame analysis. The role of informational methods is to model aspects that the mathematical model leaves out. Autoprogressive algorithm and self-learning simulation extract the missing aspects from a system response. In a hybrid framework, experimental data is an integral part of modeling, rather than being used strictly for validation processes. The potential of the hybrid methodology is illustrated through modeling complex hysteretic behavior of beam-to-column connections.

• The Journal of the Korea Contents Association
• /
• v.21 no.5
• /
• pp.129-138
• /
• 2021

Today we are getting a lot of information and various activities on our website through the internet. These websites are maintained by individuals or by website specialists. The basic method is to change the files that make up the running website. Changing the entire file in this process takes a long time and changes the files that do not need to be changed, so the efficiency is greatly reduced. When only the files that need to be changed are changed, it takes a lot of effort as a person must manually search each path to check the files and change the files one by one. To solve this problem, automatic distribution systems were developed. Additional resources and learning are required, resulting in additional cost, time and labor. Therefore, in this paper, we propose an automatic update system to minimize resource consumption by using the resources and technologies of the existing website. The proposed system does not require learning new skills. This aims to improve reliability and reduce time compared to human work.