• Journal of Sensor Science and Technology
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• v.14 no.3
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• pp.137-143
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• 2005

Research in the field of biosensor has enormously increased over the recent years. The metal-oxide semiconductor field effect transistor (MOSFET) type protein sensor offers a lot of potential advantages such as small size and weight, the possibility of automatic packaging at wafer level, on-chip integration of biosensor arrays, and the label-free molecular detection. We fabricated MOSFET protein sensor and proposed the gold-black electrode as the gate metal to improve the response. The experimental results showed that the output voltage of MOSFET protein sensor was varied by concentration of albumin proteins and the gold-black gate increased the response up to maximum 13 % because it has the larger surface area than that of planar-gold gate. It means that the expanded gate allows a larger number of ligands on same area, and makes the more albumin proteins adsorbed on gate receptor.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.1
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• pp.90-96
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• 2014

IEEE802.15.4 that is a standard for sensor networks is mainly used the wireless personal area networks such as ZigBee networks and it features low-power, low-speed data communication. However, recently research for interworking sensor network based voice communication and Session Initiation Protocol (SIP) for long-range, multi-user support has been actively conducted. In this paper, we designed a integrated base station based existing systems for interworking sensor networks based voice communication and SIP. We measured number of packet and delay according to increase the number of users to evaluate the performance of designed Base Station.

• Journal of Sensor Science and Technology
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• v.15 no.4
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• pp.231-236
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• 2006

Single-mode planar waveguide type UV sensor was fabricated using SU-8 and photochromic dye. Polymer waveguide was fabricated $10{\mu}m$ width and $2{\mu}m$ thickness for single-mode operation. The UV sensor had an absorbance with $0.0396{\sim}0.114$ absorbance/mW respectively when the 5 mm sensing area was irradiated with UV for 3 sec. And sensor had a linear properties by sensing area variation. Proposed single-mode sensor had more excellent properties of UV sensitivity than other UV sensors.

• Journal of Korea Multimedia Society
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• v.22 no.6
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• pp.676-683
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• 2019

Wireless Sensor Networks (WSNs) consist of multiple tiny and power constrained sensors which use radio frequencies to carry out sensing in a designated sensor area. To effectively design and implement reliable WSN, it is critical to consider models, protocols, and algorithms that can optimize energy consumption of all the sensor nodes with optimal amount of packet delivery. It has been observed that deploying a single sink node comes with numerous challenges especially in a situation with high node density and congestion. Sensor nodes close to a single sink node receive more transmission traffic load compared to other sensors, thus causing quick depletion of energy which finally leads to an energy hole and sink hole problems. In this paper, we proposed the use of multiple energy efficient sink nodes with brute force technique under optimized parameters to improve on the number of packets delivered within a given time. Simulation results not only depict that, deploying N sink nodes in a sensor area has a maximum limit to offer a justifiable improvement in terms of packet delivery ratio but also offers a reduction in End to End delay and reliability in case of failure of a single sink node, and an improvement in the network lifetime rather than deploying a single static sink node.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.37 no.10
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• pp.33-41
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• 2000

Pyroelectric characteristics such as voltage responsivity, noise equivalent power and detectivity are modeled 3-dimensionaly considering th interaction of each parameters. Also, the circuit is designed to set up the frequency band width and the signal amplification of the pyroelectric IR sensor. The case of low frequency region shows that the voltage response increases with the independence of the sensor area as the thickness decreases. In the high frequency region, it is found that the voltage response with the load resistor of 20$G{\Omega}$ increases with the independence of the sensor thickness as the sensor area decreases. In the low frequency region, the detectivity becomes excellent at th load resistor of 20$G{\Omega}$, the sensor area larger than $4{\times}10^{-10}m^2$ and the sensor thickness thinner than $1{\times}10^{-5}m$, while, in the high frequency region, it shows high value at the sensor thickness thinner than $1{\times}10^{-5}m$ and the sensor area smaller than $2{\times}10^{-10}m^2$ with the independence of the load resistor. In the circuit design, quasi-boot-strap circuit is employed, in which a single op-amp is connected to the drain of JFFT. Desirable frequency band width, amplification rate and the remarkable drop of noise of about 56% from that of conventional circuits with double op-amps are obtained.

• The Journal of the Korea Contents Association
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• v.13 no.12
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• pp.9-18
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• 2013

In recent years, the demands of multimedia data in wireless sensor networks have been significantly increased for the high-quality environment monitoring applications that utilize sensor nodes to collect multimedia data. However, since the amount of multimedia data is very large, the network lifetime and network performance are significantly reduced due to excessive energy consumption on particular nodes. In this paper, we propose an energy-efficient dynamic area compression scheme in wireless multimedia sensor networks. The proposed scheme minimizes the energy consumption in the huge multimedia data transmission process by compression using the Chinese Remainder Theorem(CRT) and dynamic area detection and division algorithm. Our experimental results show that our proposed scheme improves the data compression ratio by about 37% and reduces the amount of transmitted data by about 56% over the existing scheme on average. In addition, the proposed scheme increases network lifetime by about 14% over the existing scheme on average.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.12
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• pp.4492-4507
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• 2021

In camera sensor networks (CSNs), in order to better identify the point, full-view problem requires capture any facing direction of target (point or intruder), and its coverage prediction and sensor density issues are more complicated. At present, a lot of research supposes that a large number of homogeneous camera sensors are randomly distributed in a bounded square monitoring region to obtain full-view rate which is close to 1. In this paper, we deduce the sensor density prediction model in heterogeneous deployed CSNs with arbitrary full-view rate. Aiming to reduce the influence of boundary effect, we introduce the concepts of expanded monitoring region and maximum detection area. Besides, in order to verify the performance of the proposed sensor density model, we carried out different scenarios in simulation experiments to verify the theoretical results. The simulation results indicate that the proposed model can effectively predict the sensor density with arbitrary full-view rate.

• Journal of Multimedia Information System
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• v.4 no.1
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• pp.9-18
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• 2017

Ubiquitous computing is a novel paradigm that is rapidly gaining in the scenario of wireless communications and telecommunications for realizing smart world. As rapid development of sensor technology, smart sensor system becomes more popular in automobile or vehicle. In this study, a new vehicle detection mechanism in real-time for blind spot area is proposed based on imaging sensors. To determine the position of other vehicles on the road is important for operation of driver assistance systems (DASs) to increase driving safety. As the result, blind spot detection of vehicles is addressed using an automobile detection algorithm for blind spots. The proposed vehicle verification utilizes the height and angle of a rear-looking vehicle mounted camera. Candidate vehicle information is extracted using adaptive shadow detection based on brightness values of an image of a vehicle area. The vehicle is verified using a training set with Haar-like features of candidate vehicles. Using these processes, moving vehicles can be detected in blind spots. The detection ratio of true vehicles was 91.1% in blind spots based on various experimental results.

• Proceedings of the IEEK Conference
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• summer
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• pp.330-333
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• 2004

Microsensor nodes is energy limited in sensor networks. If nodes had been stop in working, sensor network can't acquire sensing data in that area as well as routing path though the sensor can't be available. So, it's important to maximize the life of network in sensor network. In this paper, we look at communication protocol, which is modified by LEACH(Low-Energy Adaptive Clustering Hierarchy). We extend LEACH's stochastic cluster-head selection algorithm by a Position-based Selection (PB-Leach). This method is that the sink divides the topology into several areas and cluster head is only one in an area. PB-Leach can prevent that the variance of the number of Cluster-Head is large and Cluster-Heads are concentrated in specific area. Simulation results show that PB-Leach performs better than leach by about 100 to $250\%.$

• Journal of Information Processing Systems
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• v.11 no.4
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• pp.509-527
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• 2015

Wireless Video Sensor Networks (WVSNs) have become a leading solution in many important applications, such as disaster recovery. By using WVSNs in disaster scenarios, the main goal is achieving a successful immediate response including search, location, and rescue operations. The achievement of such an objective in the presence of obstacles and the risk of sensor damage being caused by disasters is a challenging task. In this paper, we propose a fault tolerance model of WVSN for efficient post-disaster management in order to assist rescue and preparedness operations. To get an overview of the monitored area, we used video sensors with a rotation capability that enables them to switch to the best direction for getting better multimedia coverage of the disaster area, while minimizing the effect of occlusions. By constructing different cover sets based on the field of view redundancy, we can provide a robust fault tolerance to the network. We demonstrate by simulating the benefits of our proposal in terms of reliability and high coverage.