• Journal of the Korean Society for Precision Engineering
• /
• v.24 no.6
• /
• pp.37-44
• /
• 2007

• Journal of the Korea Society of Computer and Information
• /
• v.22 no.9
• /
• pp.33-40
• /
• 2017

In this paper, we propose a sink-location management and data-routing scheme to effectively support the mobile sink in solar-powered WSN. Battery-based wireless sensor networks (WSNs) have a limited lifetime due to their limited energy, but solar energy-based WSNs can be supplied with energy periodically and can operate forever. On the other hand, introduction of mobile sink in WSNs can solve some energy unbalance problem between sink-neighboring nodes and outer nodes which is one of the major challenges in WSNs. However, there is a problem that additional energy should be consumed to notify each sensor node of the location of the randomly moving mobile sink. In the proposed scheme, one of the nodes that harvests enough energy in each cluster are selected as the cluster head, and the location information of the mobile sink is shared only among the cluster heads, thereby reducing the location management overhead. In addition, the overhead for setting the routing path can be removed by transferring data in the opposite direction to the path where the sink-position information is transferred among the heads. Lastly, the access node is introduced to transmit data to the sink more reliably when the sink moves frequently.

• Journal of the Korea Society of Computer and Information
• /
• v.13 no.7
• /
• pp.67-73
• /
• 2008

This paper describes a system for location tracking wireless sensor nodes in an indoor environment. The sensor reading used for the location estimation is the received signal strength indication (RSSI) as given by an RF interface. By tagging users with a mobile node and deploying a number of reference nodes at fixed position in the room, the received signal strength indicator can be used to determine the position of tagged users. The system combines Euclidean distance technique with signal strength obtained by measurement driven log-normal path loss model of 2.4 GHz wireless channel. The experimental results demonstrated the ability of this system to estimate the location with a error less than 1.3m.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.39C no.9
• /
• pp.820-827
• /
• 2014

One of the basic problems in Wireless Sensor Networks (WSNs) is the localization of the sensor nodes based on the known location of numerous anchor nodes. WSNs generally consist of a large number of sensor nodes and recording the location of each sensor nodes becomes a difficult task. On the other hand, based on the application environment, the nodes may be subject to mobility and their location changes with time. Therefore, a scheme that will autonomously estimate or calculate the position of the sensor nodes is desirable. This paper presents an intelligent localization scheme, which is an artificial neural network (ANN) based localization scheme used to estimate the position of the unknown nodes. In the proposed method, three anchors nodes are used. The mobile or deployed sensor nodes request a beacon from the anchor nodes and utilizes the received signal strength indicator (RSSI) of the beacons received. The RSSI values vary depending on the distance between the mobile and the anchor nodes. The three RSSI values are used as the input to the ANN in order to estimate the location of the sensor nodes. A feed-forward artificial neural network with back propagation method for training has been employed. An average Euclidian distance error of 0.70 m has been achieved using a ANN having 3 inputs, two hidden layers, and two outputs (x and y coordinates of the position).

• Journal of Digital Convergence
• /
• v.10 no.9
• /
• pp.289-295
• /
• 2012

Routing technique of wireless sensor network that is presented to improve effectiveness of consumption in energy at the previous study is existing in various ways, however for routing, its own location data and nodes' location data close to with 1-hop distance should be kept. And it uses multi-hop transmission method that transmits data to BS node via several nodes. This technique makes electronic consumption of sensor node and entire network's energy consumption so that it makes effective energy management problem. Therefore, this paper suggests location based 1-hop routing technique of BS node that satisfies distance $d{\pm}{\alpha}$ with source node using RSSI and radio wave range of sensor node.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.34 no.6
• /
• pp.547-557
• /
• 2016

Due to threats caused by social disasters, operating surveillance devices are essential for social safety. CCTV, infrared cameras and other surveillance equipment are used to observe threats. This research proposes a method for searching for the optimum location of surveillance sensors. A GA (Genetic Algorithm) was used, since this algorithm is one of the most reasonable and efficient methods for solving complex non-linear problems. The sensor specifications, a DEM (Digital Elevation Model) and VITD (Vector Product Interim Terrain Data) maps were used for input data. We designed a chromosome using the sensor pixel location, and used elitism selection and uniform crossover for searching final solution. A fitness function was derived by the number of detected pixels on the borderline and the sum of the detection probability in the surveillance zone. The results of a 5-sensor and a 10-sensor were compared and analyzed.

• KIPS Transactions on Software and Data Engineering
• /
• v.4 no.12
• /
• pp.585-588
• /
• 2015

The technical challenge of 3D image display using the wireless sensor were applied to variable areas and scopes. This techniques need to very accurate location and speed informations and recognitions to moving objects. The tracking challenges of the moving objects location that combined 3D location and speed sensor were applied to sports and healthcare areas. This areas seek to the accuracy and collections and tightly related to image display and analysis techniques. In this paper, We developed the 3D motion display that can be monitor moving objects on the 3D virtual space. For this works, we constructed the database that collected informations through 9-axis sensor and demonstrated the result of 3D motion display on the Window based environments.

• International Journal of Contents
• /
• v.4 no.2
• /
• pp.1-6
• /
• 2008

Pre schools with state of the art facilities that would provide not just academic excellence but also ensure the safety and provide efficient healthcare to their pupils relative to Atopic Dermatitis with Asthma is the main objective of this research One of the most promising applications of sensor networks is for human healthcare monitoring. Due to recent technological advances in sensor, low power microelectronics and miniaturization, and wireless networking enable the design and proliferation of this wireless sensor networks capable of autonomously monitoring and controlling environments. Thus, this research presents the utilization of such microelectronic sensor and plots the hardware and software architecture of a wireless sensor network system with real-time pupil monitoring that integrates vital sign sensors, location sensor and allergen sensor. This proposed architecture for wearable sensors can be used as active tags which can track pupil's location within the school's premises, identify possible atopic dermatitis with asthma allergens, it would monitor and generate a health status report of the pupil.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2008.04a
• /
• pp.747-752
• /
• 2008

Fiber-guided sensor system using a generator and a receiver can detect the amplitude of load or pressure. However, this type of sensor can show some difficulties in detecting the location of damages and pressure loadings. To overcome this weakness of this type, the ultrasonic active fiber sensor, which has an integrated ultrasonic generator and sensing part, was developed in this study. By using this sensor system, the location of mechanical loads can be exactly detected. Moreover, the ultrasonic active fiber sensor is more cost-effective than an ultrasonic fiber sensor using two piezoelectric transducers which are used as a generator and a receiver, respectively. Two applications of the ultrasonic active fiber sensor are demonstrated: cure monitoring of lead and measurement of liquid level. Present results showed that the active fiber sensor can be applied for various environmental sensing.

• Proceedings of the KIEE Conference
• /
• 2005.10b
• /
• pp.606-608
• /
• 2005

In this paper, we introduce localization server system calculated real location of objects using raw data of location-awareness from sensor node gateway. The software architecture of localization server system consists of location calculation and actuator control based on location. Also, this system supports for collecting raw data, calculating location of real objects using raw data, correcting error from outer environment, and server for applications based on location.