• Journal of KIISE:Computing Practices and Letters
• /
• v.16 no.1
• /
• pp.75-79
• /
• 2010

Wireless sensor networks (WSN) are widely used in many applications. WSN acquires the data of surrounding environments with sensors attached to each node. It is important to design sensor networks that can communicate energy-efficiently as well as to get sensor readings with high accuracy. In this paper, we propose a novel routing scheme that assures high accuracy and significantly reduces data transmission costs in WSN with faults. First, we organize a number of network topologies randomly for routing sensor readings to the base station. Because every sensor node is connected each other with a single path, redundant transmissions are not incurred. It can reduce unnecessary transmissions and guarantee final sensor readings with high accuracy. To show the superiority of our scheme, we compare it with an existing multi-path routing scheme. In the result, our scheme has similar accuracy as the existing scheme and reduces unnecessary data transmissions by about 70% over the existing technique.

• Journal of the Korea Society of Computer and Information
• /
• v.25 no.4
• /
• pp.97-103
• /
• 2020

Wireless sensor networks collect and analyze sensing data in a variety of environments without human intervention. The sensor network changes its lifetime depending on routing protocols initially installed. In addition, it is difficult to modify the routing path during operating the network because sensors must consume a lot of energy resource. It is important to measure the network performance through simulation before building the sensor network into the real field. This paper proposes a WSN model for a low-energy adaptive clustering hierarchy protocol using DEVS kernel models. The proposed model is implemented with the sub models (i.e. broadcast model and controlled model) of the kernel model. Experimental results indicate that the broadcast model based WSN model showed lower CPU resource usage and higher message delivery than the broadcast model.

• Journal of the Korea Society of Computer and Information
• /
• v.16 no.2
• /
• pp.113-120
• /
• 2011

The information of the IT convergence has extended through the whole business ares with supplying intelligence terminal such as smart phone and the technology of sensors and wireless networks. And also, the existed industry became to high technology and extended various parts. The industry of the elevator became the center of the life offering the diversification of the user environment access and high building control. In this paper, we suggest the elevator control system integrated wire and wireless based on Information technology. We suggest the service model of user friendly connected by internet. For this, we make the relation model of the elevator system and IT environments and then design the service model for wire service and wireless service using smart phone. It can make to supply efficient information with wire and wireless environments and also make improvement in accessability for the disabled peoples.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.32 no.11B
• /
• pp.685-692
• /
• 2007

Recent advances in wireless communications and electronics have enabled the development of low-cost, low-power, multi-functional sensors. A typical wireless sensor network (WSN) consists of a large number of sensor nodes that can measure and process data while communicating through wireless channels. In this paper, we propose a hybrid query processing (HQP) algorithm for user queries submitted to the WSN. Unlike previous algorithms that consider continuous queries only, HQP supports both continuous queries and ad-hoc queries. Specially. HQP tries to reduce energy consumption of ad-hoc queries by using query results cached at each sensor node which are created during the execution of the previous continuous query. HQP can also exploit a trade-off between energy consumption and data accuracy. We evaluate the performance of HQP under a variety of WSN configurations.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.19 no.5
• /
• pp.809-816
• /
• 2024

In a Wireless Sensor Network (WSN) environment, where numerous small sensors are arranged in a certain space to form a wireless network, each sensor has limited battery power. Therefore, the lifetime of each sensor node is directly related to the network's lifetime, necessitating efficient routing to maximize the network's lifespan. This study proposes a routing protocol based on PEGASIS, a representative energy-efficient routing protocol in WSN environments. The proposed protocol categorizes nodes into groups based on their distance from the sink node, forms multiple chains within each group, and selects the leader node for each group by comparing the remaining energy levels. The proposed method ensures that each group's leader node is the one with the highest energy within that group, which has been shown to increase the network's lifespan compared to the traditional PEGASIS method.

• Proceedings of the Korea Contents Association Conference
• /
• 2006.11a
• /
• pp.604-608
• /
• 2006

In ubiquitous home where a variety of home devices and sensors are inter-connected, various services can be provided through wired and wireless networks invisibly. The convenience of users can be maximized by using intelligent and adaptive interoperability technologies in the home. In this paper, we present the core techniques including context-awareness, management of context information from various sensors, an inference module using JESS and so on. Also we design the ubiquitous home service systems based on context-awareness.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.27 no.4
• /
• pp.477-484
• /
• 2009

An Integrated Management Platform, which plays a core role in managing u-City, intelligently control various infra-structure components by accommodating a large number of sensors and devices; and analyzing data received from these sensors and devices through wired/wireless sensor networks. In this paper, the services provided by the integrated management platform for u-City are classified into common application service, operational management service, and platform gateway service, and furthermore detailed functions for each service are defined. These functions, through their roles and information flows, will clarify the requirements of the integrated management platform, and through their addition and modification will be utilized as a reference model for the functional organization of the integrated management platform.

• Journal of KIISE:Computing Practices and Letters
• /
• v.15 no.12
• /
• pp.938-942
• /
• 2009

In this paper, we propose a novel filtering method for processing continuous skyline queries on wireless sensor network environments. The existing filtering methods use the filter based on router paths. However, because these filters are applied not to a whole area but to a partial area, these methods send almost data of sensor nodes to transmit to the base station and have no sufficient effect in terms of energy efficiency. Therefore, we propose an efficient method to dramatically reduce the transmission data of sensors through applying a low-cost and effective filter to all sensor nodes. The proposed effective filter is generated by using characteristics such as the data locality and the clustering of sensors. An extensive performance study verifies the merits of our new method.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2018.05a
• /
• pp.65-67
• /
• 2018

We introduce a system that detects smoking in a specific area. The proposed system is implemented on a wireless ad hoc network consisting of Raspberry Pi boards. It is more economical owing to low-cost device than commercial smoking monitoring system and is scalable than the existing system with single Raspberry Pi. In this paper, the probability density function of carbon monoxide concentration during smoking and non-smoking is approximated as Gauusian distribution, respectively, using data measured from sensors for a long time. Based on this, a maximum likelihood detection technique is adopted to estimate the smoking status by observing the concentration of carbon monoxide. We aim at improving the reliability by estimating the smoking status using the collected values from multiple sensors connected to the ad hoc network.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.10 no.12
• /
• pp.1329-1336
• /
• 2015

Due to the advances in hardware technologies for low-power CMOS cameras, there have been various researches on wireless video sensor network(WVSN) applications including agricultural monitoring and environmental tracking. In such a system, its core technologies include video compression and wireless transmission. Since data of video sensors are bigger than those of other sensors, it is particularly necessary to estimate precisely the traffic after video encoding. In this paper, we present an estimation method for the encoded video traffic in WVSN networks. To estimate traffic characteristics accurately, the proposed method first measures complexities of frames and then applies them to the bit rate estimation adaptively. It is shown by experimental results that the proposed method improves the estimation of bit rate characteristics by more than 12% as compared to the existing method.