• Proceedings of the Korean Information Science Society Conference
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• 2006.10d
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• pp.421-425
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• 2006

본 논문에서는 TinyOS 기반의 센서 네트워크에 대한 리프로그래밍을 에너지 효율적으로 수행하기 위한 매커니즘을 제안한다. 베이스 스테이션에서 센서노드에게 프로그램 전체를 보내는 대신 이전 버전과의 차이인 델타를 생성해서 전송할 때 Multi-round Rsync 알고리즘을 적용해 델타 파일의 크기를 최대한 줄이는 기법과 업데이트가 불필요한 플래시메모리 페이지에 대한 업데이트를 방지하기 위한 페이지 맵 기법을 통해 Rsync만을 사용하는 기존 방식보다 최대 30% 이상 에너지를 절감할 수 있음을 확인하였다.

• Journal of Information Processing Systems
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• v.5 no.3
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• pp.135-144
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• 2009

Most of the tasks in wireless sensor networks (WSN) are requested to run in a real-time way. Neither EDF nor FIFO can ensure real-time scheduling in WSN. A real-time scheduling strategy (RTS) is proposed in this paper. All tasks are divided into two layers and endued diverse priorities. RTS utilizes a preemptive way to ensure hard real-time scheduling. The experimental results indicate that RTS has a good performance both in communication throughput and over-load.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.05a
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• pp.616-619
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• 2008

In this paper, we design and implement the authentication system for home network service and applied it to actual sensor nodes. We achieved authentication key, encryption and decryption applied RC5 encryption algorithm of SNEP. In addition, we used pair-wise key pre-distribution for prevention of authentication sniffing in wireless sensor network. The experiment environment consists of a base station receiving data and sensor nodes sending data. Each sensor nodes sends both the data and encrypted authentication key to the base station. As a simulation environment, we assumed some what-if scenarios of security menaces in home network service. And we slightly altered the TOS_Msg construction of TinyOS. The experiences had shown that the malfunction doesn't happen in communication among other groups. And we confirmed in tests that the system is secure when a sensor having malicious propose is added.

• Journal of the Korean Association of Geographic Information Studies
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• v.17 no.1
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• pp.119-128
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• 2014

The environmental survey in advance in the construction works is very important for planning and designing as well as the service of field survey before carrying out construction. The topographical application of spatial information coupled with USN is the very economical method for the survey and research every processing stage of construction field in advance. Therefore the execution of very important role for environmental planning and fundamental designing of construction reduces the unnecessary trial and error through the environmental survey in advance. In this research the environment of existent construction field is transformed to that of digital spatial information by fusing the sensor network with wireless technique on the base of spatial position. In addition, the sink sensor cumulates the environmental data measured from each USN sensor using small wireless environmental sensors installed at the construction site and changes of various environmental data at the present constructing site are able to be monitored at 3-D topographical space in real time by using the method for transmitting the image of PC output based on TinyOS.

• Journal of Advanced Marine Engineering and Technology
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• v.40 no.1
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• pp.50-54
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• 2016

A Wireless Sensor Network (WSN) is better than a conventional network for use in construction and Operations and Maintenance (O&M) because of its lower surveillance system cost. However, effective operation of a WSN is often difficult to obtain because the surveillance targets are usually fixed inside the building or underground. Therefore, this environmental constraint should be considered in the design of the WSN plant equipment surveillance system prior to installation. This study employs simulations of WSN-based fixed facility surveillance using the TinyOS TOSSIM simulator to investigate ideal types and setups of the WSN. Simulation target protocols included LEACH and flooding and gossiping protocols. The results show that the hierarchically-structured LEACH protocol demonstrated better load-balancing and efficiency than the flatly-structured flooding and gossiping protocol.

• Journal of Internet Computing and Services
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• v.10 no.3
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• pp.27-33
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• 2009

With the upcoming u-healthcare era, a way of measurement for vital sign monitoring of cardiac patients is changing as well. In existing measurement of cardiac patients, various wire in ECG measuring equipment has caused much discomfort and inconvenience. In order to decrease the problem, we are developing an efficient measurement of ECG signal using Wireless sensor network. In this paper, we present a way to reduce amount of data by transmitting ECG data collected from radio electrocardiogram sensor based on Zigbee after calculating cardiac rate. And in order to control the error which can be caused by the different ECG signal intensity each individual can has, we also suggest an adaptive pulse measurement model which can measure heart rate with correcting according to different ECG intensity. To verify the suggested model, sensor application was developed and the data was acquired in TinyOS 2.0 environment and the adaptive pulse measurement model was evaluated through the data from the experiments.

• Proceedings of the Korea Society of Information Technology Applications Conference
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• 2005.11a
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• pp.207-210
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• 2005

Ubiquitous computing is one of the key technology areas in the "Project on Development of Ubiquitous computing and network technology" promoted by the Ministry of Science and Technology as a frontier business of the $21^{st}$ century in Korea, which is based on the new concept merging physical space and computer-based cyber space. With recent advances in Micro Electro Mechanical System (MEMS) technology, low cost and low-power consumption wireless micro sensor nodes have been available. Using these smart sensor nodes, there are many activities to monitor real world, for example, habitat monitoring, earthquake monitoring and so on. In this paper, we introduce web-based real environment monitoring system incorporating wireless sensor nodes. It collects sensing data produced by some wireless sensor nodes and stores them into a database system to analyze. Our environment monitoring system is composed of a networked camera and environmental sensor nodes, which are called Mica2 and developed by University of California at Berkeley. We have modified and ported network protocols over TinyOS and developed a monitoring application program using the MTS310 and MTS420 sensors that are able to observe temperature, relative humidity, light and accelerator. The sensed data can be accessed user-friendly because our environment monitoring system supports web-based user interface. Moreover, in this system, we can setup threshold values so the system supports a function to inform some anomalous events to administrators. Especially, the system shows two useful pre-processed data as a kind of practical uses: a discomfort index and a septicity index. To make both index values, the system restores related data from the database system and calculates them according to each equation relatively. We can do enormous works using wireless sensor technologies, but just environment monitoring. In this paper, we show just one of the plentiful applications using sensor technologies.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.8
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• pp.1510-1518
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• 2006

As a promising technology that enables ubiquitous computing and leads IT(information Technology) industries of next generation, the exciting new field of sensor networks is attracting so much attention and considered to be the one of the hottest research topics these days. From now on, all the each node, forming a network, and even the sensor network itself will interact with the generic network and evolve dynamically according to the change of environment with the perpetual creation and extinction. In this paper, we purpose the dynamic address interworking scheme for interactive networking between sensor network and Internet(IPv6). Proposed scheme is enable to interworking dynamically between sensor network address scheme based on Zigbee and Internet address scheme based on IP. Additionally, we implement the proposed address interworking scheme using Berkeley TinyOS, mica motes, and IP protocol. And, we verify the proposed scheme by the interconnection experimental between wireless sensor networks and Internet based on IPv4/IPv6.

• The Journal of the Korea Contents Association
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• v.13 no.5
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• pp.19-27
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• 2013

This paper implements the standby power control system composed of a master device and slave devices. The standby power is managed by cutting power supply after controlling the relay of a slave device based on the authentication of master device's RFID card. RFID interface and wireless communication module are embedded in a master device, and one master device is linked with many slave devices in wireless. Each slave device executes the operation needed in power control independently. We implements the function of manual power on/off system in a slave device, and the function of user ID enrollment by switch manipulation in a master device. Also this system can communicate bidirectionally in wireless and runs on TinyOS. The result of experiment shows that the user authentication is executed in a master device and this authenticated information is transmitted to a slave device in wireless, and standby power is cutted by controlling the relay of a slave device. Installing this system in a building or an office, we can expect energy saving.

• The Journal of the Korea Contents Association
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• v.8 no.1
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• pp.143-151
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• 2008

In this paper, we have implemented a ubiquitous healthcare system that can measure and check human's health in anytime and anywhere. The implemented prototype are composed of both front-end and back-end. The front-end have several groups: environment sensor group such as temperature, humidity, photo, voice sensor, health sensor group such as blood pressure, heart beat, electrocardiogram, spo2 sensor, gateway for wired/wireless communication, and RFID reader to identify personal. The back-end has a serial forwarder to propagate measurment results, monitor program, and medical information server The implemented sensor node constructs a sensor network using the Zigbee protocol and is ported the tinyOS. The data gathering base node is linux-based terminal that can transfer a sensed medial data through wireless LAN. And, the medical information server stores the processed medical data and can promptly notify the urgent status to the connected medical team. Through our experiments, we've confirmed the possibility of ubiquitous healthcare system based on sensor network using the Zigbee.