• Journal of Advanced Navigation Technology
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• v.27 no.6
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• pp.861-864
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• 2023

Recently, V2X (vehicle-to-everyting) communication has established itself as an essential technology for cooperative autonomous driving. V2X communication currently includes DSRC (dedicated short range communication) communication technology, which is a WLAN (wireless local area network) based communication technology, and C-V2X (cellular-V2X) communication technology, which is a Cellular-based communication technology. Since these two communication methods are not compatible with each other, various studies and experiments are being conducted to select one of the two communication methods. In the case of C-V2X communication, there are LTE-V2X (long term evolutionV2X) communication technology, which is an initial version, and 5G-V2X communication technology, which is a next-generation version. 5G-V2X communication technology has been completed only until standardization, so LTE-V2X communication technology is mainly used. In this paper, we introduce trends related to various issues in V2X communication, including communication method decisions.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.8C
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• pp.489-496
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• 2011

Energy efficiency in wireless sensor networks is a principal issue to prolong applications to track the movement of the large-scale phenomena. It is a selective wakeup approach that is an effective way to save energy in the networks. However, most previous studies with the selective wakeup scheme are concentrated on individual objects such as intruders and tanks, and thus cannot be applied for tracking continuous objects such as wild fire and poison gas. This is because the continuous object is pretty flexible and volatile due to its sensitiveness to surrounding circumferences so that movable area cannot be estimated by the just spatiotemporal mechanism. Therefore, we propose a cluster-based algorithm for applying the efficient and more accurate technique to the continuous object tracking in enough dense sensor networks. Proposed algorithm wakes up the sensors in unit cluster where target objects may be diffused or shrunken. Moreover, our scheme is asynchronous because it does not need to calculate the next area at the same time.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.1C
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• pp.28-36
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• 2011

As Power Line has been already installed over 60% of a residential area all over the world, Broadband Service has been possible using high-speed PLC(Power Line Communication) without new access line installed for Internet access. Because of such reason, PLC is researched as the most suitable service for Last Mile Solution. But, Power Line is designed for transmitting electric power, so peripheral Wireless Communication System is affected by a leak of electric wave. In this paper, we propose a High Performance Notch Filter algorithm in comparison with a existing notch filter for reduction of interference between existing Wireless Communication Service and Power Line Service. In addition, we implement the Notch Filter emulator appling a High Performance Notch Filter and using a embedded board.

• The KIPS Transactions:PartD
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• v.13D no.5 s.108
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• pp.731-740
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• 2006

WIPI is developed by KWISF(Korea Wireless Internet Standardization Forum) and a wireless internet standard platform adopted by TTA. It needs the certification Process for standard specification in order to confirm interoperability. The WIPI is composed of the HAL, the Runtime Engine, and APIs(WIPI-C, WIPI-Java). nl applications are implemented through WIPI APIs that can be finished by themselves or provided essential functions from runtime engine or HAL. Therefore it needs to certify where the problems occur when errors occurred in a application. In this paper we propose the PCT that certifies a WIPI platform's functionality and APIs and the HCT that certifies HAL APIs. Because the PCT reports the final certification results for the platform it is impossible to know where the problems occur when it fails to certify platform. So, it needs to certify the HAL regardless of platform certification.

• The KIPS Transactions:PartC
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• v.16C no.6
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• pp.737-746
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• 2009

Given the increased interest in ubiquitous computing, wireless sensor network has been researched widely. The localization service which provides the location information of mobile user, is one of important service provided by sensor network. Many methods to obtain the location information of mobile user have been proposed. However, these methods were developed for only one mobile user so that it is hard to extend for multiple mobile users. If multiple mobile users start the localization process concurrently, there could be interference of beacon or ultrasound that each mobile user transmits. In the paper, we propose APL(Adaptive Power Control based Resource Allocation Technique for Efficient Localization Technique), the localization technique for multiple mobile nodes based on adaptive power control in mobile wireless sensor networks. In APL, collision of localization between sensor nodes is prevented by forcing the mobile node to get the permission of localization from anchor nodes. For this, we use RTS(Ready To Send) packet type for localization initiation by mobile node and CTS(Clear To Send) packet type for localization grant by anchor node. NTS(Not To Send) packet type is used to reject localization by anchor node for interference avoidance and STS(Start To Send) for synchronization between 모anchor nodes. At last, the power level of sensor node is controled adaptively to minimize the affected area. The experimental result shows that the number of interference between nodes are increased in proportion to the number of mobile nodes and APL provides efficient localization.

• The KIPS Transactions:PartC
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• v.16C no.1
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• pp.91-100
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• 2009

Given the increased interest in ubiquitous computing, wireless sensor network has been researched widely. The localization service which provides the location information of mobile user, is one of important service provided by sensor network. Many methods to obtain the location information of mobile user have been proposed. However, these methods were developed for only one mobile user so that it is hard to extend for multiple mobile users. If multiple mobile users start the localization process concurrently, there could be interference of beacon or ultrasound that each mobile user transmits. In the paper, we propose IAL, the localization technique with interference avoidance for multiple mobile nodes in mobile wireless sensor networks. In IAL, interference is prevented by forcing the mobile node to get the permission of localization from anchor nodes. For this, we define LIP packet type for localization initiation by mobile node and LGP packet type for localization grant by anchor node. LRP packet type is used to reject localization by anchor node for interference avoidance. The experimental result shows that the number of interference between nodes are increased in proportion to the number of mobile nodes and IAL provides efficient localization.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.9
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• pp.1575-1583
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• 2008

Wireless sensor network has merit of low-power, low-cost and self-organization network, so there are many researches substituted for existing wire network. As structure reinforcement work need a high accuracy, many sensors are installed in structure and connected with data logger for monitoring. However this wire data logger method takes a long time to install wires and installed wires obstruct to work. Additionally, wire data logger method represent sensor data by only numeric and graph, it is not able to support a rapid decision-making for working. To resolve wiring problem and support decision-making, we designed and implemented the monitoring system based in wireless sensor network. For verifying performance, accuracy and availability, we simulated and tested our system in real field. Consequently, wireless sensor network method is easier to install and deploy than wire data logger method, user is able to monitor instinctively and overall by 3D representation of structure and sensors, and it show not only accuracy but also performance for many sensors.

• IEIE Transactions on Smart Processing and Computing
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• v.6 no.2
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• pp.129-132
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• 2017

A conventional pulse oximeter has high power consumption; thus, its mobility is severely limited. In this paper, we discuss the drawbacks of the existing pulse oximeters and propose a new ultra-low-power pulse oximeter that supports wireless data transmission for remotely monitoring vital signs, such as peripheral capillary oxygen saturation (SpO2) and beats per minute (BPM). We could notably reduce power consumption by using a low-frequency single clock in all well-customized modules. Also, our device is publicly certified, and thus, possibly engaged in clinical trials for commercial use.

• Proceedings of the KIEE Conference
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• 2006.10c
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• pp.570-572
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• 2006

This paper discusses the method of moving object detection for biped robot walking. Most researches on vision based object detection have mostly focused on fixed camera based algorithm itself. However, developing vision systems for biped walking robot is an important and urgent issue since hired walking robots are ultimately developed not only for researches but to be utilized in real life. In the research, method for moving object detection has been developed for task assignment and execution of biped robot as well as for human robot interaction (HRI) system. But these methods are not suitable to biped walking robot. So, we suggest the advanced method which is suitable to biped walking robot platform. For carrying out certain tasks, an object detecting system using modified optical flow algorithm by wireless vision camera is implemented in a biped walking robot.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.150.1-150
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• 2001

This paper introduces a real time inspecting and monitoring system by using wireless communication and image processing technique. The communication system is developed by using 80c196kc microprocessor and it has data acquisition function for several kinds of sensors such as pluviometer, temperature, tension meter, elinometer and so on. The image processing method adopts Lalacian of Gaussian operator and least square method to extract line features for the captured images and uses a relaxation matching algorithm based in global structure constraint satisfaction to distinguish the matching error for those features. When the algorithm is processed, motion parameters of displacement area and its direction are computed. Once movement is recognized ...