• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.10
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• pp.941-948
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• 2016

In this paper, we efficiently simulated for collecting the data from the fixed sensor and mobile sensor of patients using the LEACH-Mobile method. The LEACH-Mobile method is the protocol to increase the mobility by adding the mobile node to the existed LEACH(:Low Energy Adaptive Clustering Hierarchy) protocol. It improves the mobility of The LEACH-Mobile in the LEACH, however it consumes more energy than the existed LEACH. There is reason why we use the LEACH-Mobile that the monitoring system is generally done by the CCTV and an periodic checkup by nurses. However the number of nurse is a few in the most of hospital. It can happen the accidents of the patients in out of the CCTV when the nurse can not see the monitoring system in the hospital. Therefore it is simulated to continuously gather the data of the position and sensors in the five situation of moving the patients in the hospital, it gets the result that the management of the mobile patients is more efficient.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.41 no.6 s.324
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• pp.69-78
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• 2004

This paper proposes architecture and characteristics of a multi-ring based optical network with single-hop between edge nodes using the concept of circuit switching and multi-wavelength label switching to solve delay problem caused by applying crossconnectors as transit nodes in the wavelength division multiplexing(WDM) network. We suggest multi-ring based architecture composed single and multiple wavelength-bands with multi-wavelength labels, and analyze characteristics of two models. To avoid the packet collision in output ports of edge nodes due to output contention, the static and dynamic allocation scheme, which packets are allocated in time slots, is provided. Based on our analysis, it shows that delay only occur in not core nodes but edge nodes in the proposed architecture. In addition, we evaluate the probabilities of delay, packet loss, and call blocking in the proposed optical packet network.

• The Journal of the Korea Contents Association
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• v.7 no.6
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• pp.44-51
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• 2007

For real-time recognizing of model objects in remote position a new Neural Networks algorithm is proposed. The proposed neural networks technique is the real time computation methods through the inter-node diffusion. In the networks, a node corresponds to a state in the quantized input space. Each node is composed of a processing unit and fixed weights from its neighbor nodes as well as its input terminal. The most reliable algorithm derived for real time recognition of objects, is a dynamic programming based algorithm based on sequence matching techniques that would process the data as it arrives and could therefore provide continuously updated neighbor information estimates. Through several simulation experiments, real time reconstruction of the nonlinear image information is processed. 1-D LIPN hardware has been composed and various experiments with static and dynamic signals have been implemented.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.7B
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• pp.557-566
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• 2008

Some types of network nodes such as mobile network node, mobile access point, and ad-hoc network node can be relocated frequently and, by the nature of its usage, are deployed over broad area. In this environment, the network topology is changed constantly since even the manager node as well as the managed nodes can leave or join the management network frequently. The many of existing network management technologies are mostly for small sized and homogeneous networks with static topologies and not proper for the mobile network devices. In this paper, employing peer-to-peer (P2P), the secure group communication techniques, and simple network management protocol (SNMP), we propose a highly secure and available management technique that can be used to manage the mobile network nodes through insecure management network such as the Internet. The proposed technique is implemented to show that it is practically usable.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.11
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• pp.1068-1077
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• 2014

In this paper, we propose a novel method for path setup that optimizes energy consumptions for wireless sensor network. Existing studies usually generate paths according to Random way point approach so that it requires unnecessary energy consumptions for estimating location of the mobile sink node and transmission paths of packets. To address this problem, we propose a method that creates paths for mobile sink node using the Hilbert curve. Moreover, our method adjusts the path of the mobile sink node according to the density of sensor nodes to minimize data transmission delay. In our experiments, the proposed method outperforms existing work such as TTDD and CBPER by up to 50 times in terms of energy efficiency.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.2
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• pp.217-222
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• 2006

To find a location, GPS has been wildly used. But, it is hard to use in indoor because of very weak signal level. To meet indoor requirements, there have been many studies applying wireless communication networks such as WLAN, UWB and ZigBee. Among these, ZigBee is widely adopted in many WSN applications because it has an advantage of low-power and low-cost. In ZigBee, the RSSI is used as range measurement for ad-hoc network. The RSSI are converted to ranges using the signal attenuation model and these ranges become inputs of positioning methods. The obtained position with RSSI has large error because of its poor accuracy. To overcome this problem, ultrasonic sensors are added in many researches. By measuring the arrival time difference of ZigBee and ultrasound as a range measurement, the precise position can be found. However, there are still many problems: scheduling of beacons to transmit signals in a correct order, addition and synchronization of beacons and low-rate positioning rate. At this paper, an efficient method to solve these problems is proposed. In the proposed method, a node transmits ZigBee and ultrasound signal simultaneously. And beacons find the range with the received signals and send it back to a node with ZigBee. The position is computed in a node with the received ranges. In addition, a new positioning algorithm to solve the risk of the divergence in the linearization method and the singularity problem in the Savarese method is presented. Both static and dynamic experimental results show 0.02m RMS errors with high output rate.

• Structural Engineering and Mechanics
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• v.74 no.3
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• pp.395-406
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• 2020

Many prefabricated concrete frame joints have been proposed, and most of them showed good seismic performance. However, there are still some limitations in the proposed fabricated joints. For example, for prefabricated prestressed concrete joints, prefabricated beams and prefabricated columns are assembled as a whole by the pre-stressed steel bar and steel strand in the beams, which brings some troubles to the construction, and the reinforcement in the core area of the joints is complex, and the mechanical mechanism is not clear. Based on the current research results, a new type of fabricated joint of prestressed concrete beams and confined concrete columns is proposed. To study the seismic performance of the joint, the quasi-static test is carried out. The test results show that the nodes exhibit good ductility and energy dissipation. According to the experimental fitting method and the "fixed point pointing" law, the resilience model of this kind of nodes is established, and compared with the experimental results, the two agree well, which can provides a certain reference for elasto-plastic seismic response analysis of this type of structure. Besides, based on the analysis of the factors affecting the shear capacity of the node core area, the formula of shear capacity of the core area of the node is proposed, and the theoretical values of the formula are consistent with the experimental value.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.48 no.4
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• pp.68-76
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• 2011

In this paper, we propose a method for joining mobile nodes in wireless sensor networks using hysteresis features. It is possible to use static hysteresis, whereby joining and withdrawal are carried out repeatedly when a mobile node is located at boundary points. The energy consumption of the nodes can be effectively managed by a decrease in the response packets of the neighbors under the joining requests of the mobile nodes. However, static hysteresis causes a decrease in the joining rate. In order to increase the joining rate, dynamic hysteresis is used. To evaluate the performance of the proposed technique, the joining rate is investigated and analyzed. Simulation results show that the proposed method enables efficient joining according to the mobility of nodes in wireless sensor networks.

• Journal of KIISE:Computing Practices and Letters
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• v.14 no.3
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• pp.321-325
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• 2008

Void areas(holes) as an inevitable phenomenon exist in geographic routing of wireless sensor networks, because the unpredictable and harsh nature application environment or uneven energy consumption. Most of the existing schemes for the issue tend to construct a static detour path to bypass a hole. The static detour path may lead to uneven energy consumption of the nodes on the perimeter of the hole; thus it may enlarge the hole. At the same time, traffic would concentrate on the peripheral node of the hole; thus the nodes on the perimeter of the hole tend to be depleted quietly. In previous work, we have proposed a hole geometric model to reduce the energy consumption and packet collisions of the nodes on the hole boundary. This scheme, however, still has the static detour path problem. Therefore, we extend the previous work by constructing a dynamic detour path hole geometric model for wireless sensor networks in this paper. The location of hole detour anchors is dynamically shifted according to Gaussian function, just generating dynamic hole detour paths.

• The Journal of the Korea Contents Association
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• v.6 no.12
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• pp.40-49
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• 2006

As a promising integrated circuit, wireless communication and micro-computing technology, the technology of sensor network that will lead the information technology industries of the next generation and realize the ubiquitous computing is one of the most active research topics and its research activities are also making today. From now on, each node, the network formation, and even the sensor network itself will interact with the generic network and evolve dynamically according to environmental changes in a process of continual creation and extinction. Therefore, address-internetworking between sensor network and generic network which are used different address mechanism is required. In this paper, we propose a static address-internetworking scheme for interactive networking between a sensor network and the Internet. The proposed scheme that possess a gateway approach to perform the protocol translation from one protocol to another, an overlay approach to constructs an overlay network on the WSNs and enables static internetworking between a sensor network address scheme based on Zigbee and the Internet address scheme based on the Internet Protocol. In addition, we verify the proposed scheme by an interconnection experiment.