• Journal of Korea Society of Digital Industry and Information Management
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• v.10 no.2
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• pp.13-20
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• 2014

In this paper, we implemented the object scanning with nxtOSEK which is an open source platform. nxtOSEK consists of device driver of leJOS NXJ C/Assembly source code, TOPPERS/ATK(Automotive real time Kernel) and TOPPERS/JSP Real-Time Operating System source code that includes ARM7 specific porting part, and glue code make them work together. nxtOSEK can provide ANSI C by using GCC tool chain and C API and apply for real-time multi tasking features. We experimented the 3D scanning with ultra sonic and laser sensor which are made directly by laser module diode and experimented the measurement of scanning the object by knowing x, y, and z coordinates for every points that it scans. In this paper, the laser module is the dimension of $6{\times}10[mm]$ requiring 5volts/5[mW], and used the laser light of wavelength in the 650[nm] range. For detecting the object, we used the beacon detection algorithm and as the laser light swept the objects, the photodiode monitored the ambient light at interval of 10[ms] which is called a real time. We communicated the 3D scanning platform via bluetooth protocol with host platform and the results are displayed via DPlot graphic tool. And therefore we enhanced the functionality of the 3D scanner for identifying the image scanning with laser sensor modules compared to ultra sonic sensor.

• Journal of Korea Multimedia Society
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• v.15 no.7
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• pp.885-890
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• 2012

In this Paper, we propose a Real-Time Localization Platform Built on WUSB (Wireless USB) over WBAN (Wireless Body Area Networks) protocol required for Wearable Computer systems. Proposed Real-Time Localization Platform Technique is executed on the basis of WUSB over WBAN protocol at each sensor node comprising peripherals of a wearable computer system. In the Platform, a WUSB host calculates the location of a receiving sensor node by using the difference between the times at which the sensor node received different WBAN beacon frames sent from the WUSB host. And the WUSB host interprets motion of the virtual object.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.11
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• pp.2185-2191
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• 2007

The traditional sensor network is composed of the cable and the sensor of high price, when collecting a sensing data, there is a weak point which is not pliability. WSN uses the equipment of low price, it will be able to collect the data which is diverse from various node. In this paper we composed coal mining topology which used IEEE802.15.4 MAC in Korea Coal Corporation site. We proposed models for the mobility support of the work manager from the coal mining, we selected the optimum model through simulation experiments. When applying the WSN in the Korea Coal Corporation and other mines, this result can be used as a basis.

• Smart Media Journal
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• v.9 no.4
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• pp.170-175
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• 2020

It is important to select the most appropriate channel for efficient transmission of massive multimedia data between smart devices in wireless sensor network. In the fixed channel method, sensor nodes can restrict usefulness of frequency and may be a major constraint to support frequency at various environments. In this paper, we propose a modified efficient channel search algorithm that determines available channel and tolerance of interference of links between two nodes. From the results of computer simulation, the proposed method shows that the link of channel can be set efficiently than the other methods even if the number of interference links increases and the beacon packet waiting time caused by interference is reduced remarkably.

• Journal of Digital Convergence
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• v.14 no.11
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• pp.241-247
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• 2016

As a domestic traffic control signal system, either the system with which a traffic signal turns into green at regular intervals or the system with which an amber or a red signal flickers on local roads without heavy traffic at midnight has been utilized. However, when the former system is used for roads with light traffic at midnight, delays and congestion can be incurred. Besides, in case of the latter signal system, the risk of vehicle crash is high. This study proposes a response type of flickering green signal system that rearranges signal system after analyzing beacon messages including sensor data. The proposed system, on a trunk road or a branch road at midnight, makes the signal keep flickering in green; When a vehicle enters the range of RSE, the transfer coverage, it transmits beacon messages regularly and Agent System analyzes the messages and alters the signal. It is a system by which vehicles move following the altered signal system, which will not only ensure smooth flow but also prevent vehicles from crashing on a road with light traffic. As a result of a simulation, traffic throughput and the average waiting time displayed 10 to 30 percent better improvement than existing signal systems, in terms of performance.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.1
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• pp.187-192
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• 2017

In dense deployments of sensor nodes in Wireless Sensor Networks, the MAC protocol has challenges to solve problems such as reducing delivery delay and reducing energy consumption. To solve these problems lots of protocols are suggested. This paper proposed a sensor nodes' residual energy based wake-up control mechanism, in which each node decides whether it wakes up or stays in sleep mode to save energy consumption by reducing unnecessary idle listening. The main idea of the wake-up control mechanism is to save node's energy consumption. The proposed wake-up control mechanism is based on the RI-MAC protocol, which is one of the receiver-initiated MAC protocols. A receiver node in the proposed mechanism periodically wakes up and broadcasts a beacon signal based on the energy status of the node. A receiver node also adjusts wake-up period based on the traffics. Results have shown that the proposed MAC protocol outperformed RI-MAC protocol in the terms of energy consumption.

• Journal of Internet of Things and Convergence
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• v.8 no.2
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• pp.1-6
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• 2022

This paper presents a regionalized time slotted channel hopping (TSCH) slotframe-based aerial data collection using wake-up radio. The proposed scheme aims to minimize the delay and energy consumption when an unmanned aerial vehicle (UAV) collects data from sensor devices in the large-scale service area. To this end, the proposed scheme divides the service area into multiple regions, and determines the TSCH slotframe length for each region according to the number of cells required by sensor devices in each region. Then, it allocates the cells dedicated for data transmission to the TSCH slotframe using the ID of each sensor device. For energy-efficient data collection, the sensor devices use a wake-up radio. Specifically, the sensor devices use a wake-up radio to activate a network interface only in the cells allocated for beacon reception and data transmission. The simulation results showed that the proposed scheme exhibited better performance in terms of delay and energy consumption compared to the existing scheme.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.1
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• pp.351-356
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• 2011

In this paper, we design a pet location tracking and remote monitoring system that uses ultrasonic, temperature, humidity and illumination sensors to study behavioral patterns and habits. Using ultrasonic waves to calculate distances, a WSN(Wireless Sensor Network) was constructed to transmit data at pet's location, such as temperature, humidity and illumination, to a sink mote. Data received by the system are stored in the database in real time to trace pet's location. Interference among transmitting motes was eliminated by sequentially transmitting RF beacons using sink mote's beacon as the reference signal. Experiments were performed with the laboratory prototype of a pet animal monitoring system implemented for this study. The system analyzes locations of a pet and displays movement patterns, areas of movement, temperature, humidity and illumination using a GUI (graphical user interface).

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.12
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• pp.2387-2394
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• 2016

It is important to select the most appropriate channel for efficient transmission of massive data in wireless sensor network. In the fixed channel method for wireless sensor node, shortage of frequency may be a major constraint to support a variety of environments. In this paper, the method that seeks common channels between two nodes without common control channels in the existing wireless cognitive radio network is introduced in order to use efficiently the channel of wireless sensor network. The problem of existing method shows the severe degradation of performance that is caused by interference of linkage between selected channels, so that the sequential algorithm is suggested to improve the performance. From the results of computer simulation, the suggested method shows that the link can be set 50% faster than the other methods as the number of links increases because the beacon packet waiting time caused by the interference decreases remarkably.

• Journal of the Korea Society of Computer and Information
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• v.16 no.2
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• pp.101-111
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• 2011

A new MAC protocol, MT-MAC(Multi-Tier Medium Access Control) by name, is proposed for dense sensor networks. Depending on the density of nodes in a virtual cluster, the cluster header performs the splitting to several tiers in nodes of virtual cluster. MT-MAC split the tiers to use modfied-SYNC message after receiving the beacon message from the cluster header. Because only the sensor nodes in the same tier communicate each other, less power is consumed and longer network life time is guaranteed. By a simulation method with NS-2, we evaluated our protocol. In dense nodes environments, MT-MAC protocol shows better results than S-MAC in terms of packet delivery rates throughput and energy consumption.