• Journal of the Institute of Electronics Engineers of Korea CI
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• v.46 no.4
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• pp.42-50
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• 2009

Ubiquitous computing technology is widely used in not only our everyday lives but also in education, medical care, military, environment and administration. RFID system, the basis of ubiquitous, is in the spotlight which can be an alternative solution of a bar code recognition system and magnetic system as they basically have practicality and security issues. An electronic authentication named smart-key system is recently concerned by an alternative solution of the security unit for an automobile. RFID system which has a general purpose is also in the limelight by an application technology. In this paper we designed vehicle smart key system with general-propose RFID system that is already in use. First, we designed control unit and RFID card reader for vehicle smart key system. Then we propose an algorithm and prove that the vehicle key system is controllable by showing the result of implementing and testing, after installing. Also security level is enlarged by proposing a authentication protocol between RFID reader and control unit.

• Journal of IKEEE
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• v.24 no.2
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• pp.638-648
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• 2020

Currently, the method of user-follwoing in intelligent cooperative robots usually based in vision system and using Lidar is common and have excellent performance. But in the closed space of Corona 19, which spread worldwide in 2020, robots for cooperation with medical staff were insignificant. This is because Medical staff are all wearing protective clothing to prevent virus infection, which is not easy to apply with existing research techniques. Therefore, in order to solve these problems in this paper, the ultrasonic sensor is separated from the transmitting and receiving parts, and based on this, this paper propose that estimating the user's position and can actively follow and cooperate with people. However, the ultrasonic sensors were partially applied by improving the Median filter in order to reduce the error caused by the short circuit in communication between hard reflection and the number of light reflections, and the operation technology was improved by applying the curvature trajectory for smooth operation in a small area. Median filter reduced the error of degree and distance by 70%, vehicle running stability was verified through the training course such as 'S' and '8' in the result.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.11 no.2
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• pp.21-28
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• 2012

The continuous deployment of Urban Traffic Information System (UTIS) in Korea has increased the need for developing more practical applications utilizing the standard functions of UTIS facilities installed on urban arterials beyond its basic applications like gathering traffic data and providing traffic information. The UTIS-based bus signal priority may be one of UTIS-based applications meeting such demands. However, the studies on BSP have not been sufficient for actual field deployment in terms of theories and algorithms so that there have been few actual installations on real urban arterials. Thus, this study was aimed at developing a UTIS-based bus priority signal system and evaluating its effectiveness through a field study. To this end, this study presents the system development processes by dividing the UTIS-based bus priority signal system into hardware and software. In addition, the positive effectiveness of the UTIS-based bus priority signal system was verified through a field application test which was conducted at Gyeonggi Global Trade High School intersection.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.44 no.5
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• pp.38-48
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• 2007

In ubiquitous environment, sensor networks that sense and transmit surrounding data without human intervention will become more important. If sensors are installed for detecting vehicles and measuring their speed in the road and that real-time information is given to drivers, it will be very effective for enhancing safety and controlling traffic in the road. In this paper, we proposed a new reliable and real-time sensor MAC protocol between AP and sensor nodes in order to provide real-time traffic flow information based on ubiquitous sensor networks. The proposed MAC allocates one TDMA slot for each sensor node on the IEEE 802.15.4 based channel structure, introduces relayed communication for distant sensors, and adopts a frame structure that supports retransmission for the case of errors. In addition, the proposed MAC synchronizes with AP by using beacon and adopts a hybrid tracking mode that supports economic power consumption according to various traffic situations, We implemented a simulator for the proposed MAC by using sim++ and evaluated various performances. The simulation results show that the proposed MAC reduces the power consumption and reveals excellent performance in real-time application systems.

• Journal of Broadcast Engineering
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• v.25 no.4
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• pp.497-506
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• 2020

A chameleonic surface proposed in this study was a pin-art and 3D display device for generating arbitrary shapes. A smooth and continuous surface was formed using slim telescopic actuators and high-elasticity composite material. Realistic 3D shapes were continuously generated by projecting dynamic mapping images on the surface. A slim telescopic actuator was designed to show long strokes and minimize area for staking. A 3D shape was formed by thrusting and extruding the high-elasticity material using multiple telescopic actuators. This structure was advantageous for generating arbitrary continuous surface, projecting dynamic images and lightening weight. Because of real-time synchronization, a distributed controller based on EtherCAT was applied to operate hundreds of telescopic actuators smoothly. Integrated operating software consecutively generated realistic scenes by coordinating extruded shapes and projecting 3D image from multiple projectors. An opera content was optimized for the chameleon surface and showed to an audience in an actual concert.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.3
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• pp.573-586
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• 2016

In construction jobs, a combination of various kinds of machinery is used to perform earthworks at a large-scale site. Individual equipments essentially cooperate with each other on task such as excavation, load, transfer and compaction. While other area have studied cooperation system, related study in domestic construction is in poor condition. In this study, construction equipment fleet management system is developed for solving this problem and find way to improving efficiency in earthworks site. The entire concept of the fleet management system, including its components and process, has been systematically outlined in this paper. An operational methodology has also been suggested, where a number of machines, such as the excavators, trucks and compactors, are chosen and further grouped into a cluster. A case study verify fleet management system's effectiveness on performing task package by comparing existing work method with methodology in this study. Fleet management system in this study is expected to curtail fuel consumption by the reduction of working time and moving distance. Furthermore, it can be anticipated to declining carbon emission effect.

• Journal of Korean Society for Geospatial Information Science
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• v.23 no.4
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• pp.43-48
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• 2015

We studied on pseudo-range correction(PRC) modeling in order to improve differential GNSS(DGNSS) accuracy. The PRC is the range correction information that provides improved location accuracy using DGNSS technique. The digital correction signal is typically broadcast over ground-based transmitters. Sometimes the degradation of the positioning accuracy caused by the loss of PRC signals, radio interference, etc. To prevent the degradation, in this paper, we have designed a PRC model through polynomial curve fitting and evaluated this model. We compared two quantities, estimations of PRC using model parameters and observations from the reference station. In the case of GPS, the average is 0.1m and RMSE is 1.3m. Most of GPS satellites have a bias error of less than ${\pm}1.0m$ and a RMSE within 3.0m. In the case of GLONASS, the average and the RMSE are 0.2m and 2.6m, respectively. Most of satellites have less than ${\pm}2.0m$ for a bias error and less than 3.0m for RMSE. These results show that the estimated value calculated by the model can be used effectively to maintain the accuracy of the user's location. However;it is needed for further work relating to the big difference between the two values at low elevation.

• Journal of Korean Society of Transportation
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• v.36 no.2
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• pp.98-111
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• 2018

Truck platooning, which is a cluster of trucks in support of vehicle-to-vehicle communication and automated longitudinal vehicle control, is a promising method to both operational efficiency and prevent traffic crashes. Although a variety of studies have been conducted to identify the effects of vehicle platooning on traffic stream, we are not aware of any study attempting to identify promising road segments for vehicle platooning. This study aims to develop a methodology for determining the priority of freeway segments that would potentially lead to maximize the effectiveness of truck platooning. Evaluation measures derived in this study includes truck crash rates, the percentage of truck traffic, segment length, and the number of entry and exit points. Weighting values obtained from an analytical hierarchical process (AHP) method were applied to compute the proposed priority score to determine better freeway segment for truck platooning. Results suggested that a 46.9km freeway segment, from Sacheon IC to Sanin JC, was the most promising segment for maximizing the effectiveness of truck platooning. It is expected that the outcome of this study would be effectively used as a fundamental to establish operational strategies for truck platooning.

• Journal of Korean Society of Transportation
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• v.36 no.2
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• pp.67-85
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• 2018

Vehicle platooning through wireless communication and automated driving technology has become realized. Platooning is a technique in which several vehicles travel at regular intervals while maintaining a minimum safety distance. Truck platooning is of keen interest because it contributes to preventing truck crashes and reducing vehicle emissions, in addition to the increase in truck flow capacity. However, it should be noted that interactions between vehicle platoons and adjacent manually-driven vehicles (MV) significantly give an impact on the performance of traffic flow. In particular, when vehicles entering from on-ramp attempt to merge into the mainstream of freeway, proper interactions by adjusting platoon size and inter-platoon spacing are required to maximize traffic performance. This study developed a methodology for establishing operational strategies for truck platoonings on freeway on-ramp areas. Average speed and conflict rate were used as measure of effectiveness (MOE) to evaluate operational efficiency and safety. Microscopic traffic simulation experiments using VISSIM were conducted to evaluate the effectiveness of various platooning scenarios. A decision making process for selecting better platoon operations to satisfy operations and safety requirements was proposed. It was revealed that a platoon operating scenario with 50m inter-platoon spacing and the platoon consisting of 6 vehicles outperformed other scenarios. The proposed methodology would effectively support the realization of novel traffic management concepts in the era of automated driving environments.

• Proceedings of the Korean Society of Applied Entomolohy Conference
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• 2006.09a
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• pp.45-60
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• 2006

최근 국제적으로 생물자원의 중요성이 재인식됨에 따라 이들에 대한 체계적이고 안정적인 정보의 구축 및 활용이 국가경쟁력의 척도로 간주할 정도로 중요성이 커지고 있는 실정이다. 또한, 우리나라는 국토의 64%가 산림으로 되어 있어서 다양한 생물종이 서식하는데 매우 적합한 조건을 갖추고 있다. 이에 따라 산림청과 국립수목원은 국가식물자원정보시스템에 이어 곤충정보에 대한 정보화 사업을 2001년부터 추진해오고 있으며 이 결과로 현재 33만여 점에 곤충표본정보가 구축되기에 이르렀다. 현재까지 국내 유수 곤충표본보유기관 22개 기관이 본 사업에 참여하여 다양하고 내실 있는 정보구축이 이루어져 왔으며 이를 통해 명실 공히 국가적인 곤충자원정보망을 갖추게 되었다. 곤충DB의 국가적인 사업이 추진된 지 6년차에 이르는 2006년도에는 정보통신부의 지원을 받아 14개 표본보유기관이 참여하여 곤충표본DB구축을 중점 추진할 계획이다. 2006년도의 목표량은 곤충표본정보 17,000점으로 기존구축자료 이외에 추가가 필요한 표본정보위주로 구축될 예정이다. 또한, 이미 구축된 곤충표본자원의 활용도와 가치를 높이기 위해서는 더욱 다양하고 많은 자료의 표본을 추가하여 DB화를 추진함은 물론 이들 각각의 정보들을 식물정보와 연계하여 분석 가능토록 하고 GIS시스템을 도입하여 명실공히 국가적인 곤충자원정보의 종합관리가 될 수 있도록 추진하고 있다. 본 사업이 충실히 수행될 경우 국가 주요 생물자원 중 하나인 곤충정보의 DB확대 구축을 통한 전체적인 현황파악 및 체계적인 관리가 가능해 질 것이며, 이와 관련하여 정보화적인 측면, 경제적 측면, 사화 문화적 측면에서 다양한 효과가 기대되며 앞으로도 이에 대한 내실 있는 운영을 위해서는 정부차원의 종합적인 지원 및 관리가 요구되는 시점으로 판단된다.pm3.42$, 저층수 $23.43\pm3.38$이었으며, 전반적으로 해역별 수질기준 I등급 내지는 II등급을 유지하고 있었고, 공간적으로는 외해측으로 갈수록 외해수와 혼합 확산되어 양호한 수질을 나타내었다. 장기적인 변동특성은 세그룹으로 구분되어진다.기 실험결과 용출용매로 증류수와 해수를 이용했을 때, 제강 슬래그에서 용출되는 납, 구리, 카드뮴, 수은의 용출 경향의 차이를 확인할 수 있었고 이에 따라서, 납, 구리, 카드뮴의 용출 유해성은 낮기 때문에 해양구조물로의 제강슬래그 유효이용은 적합할 것으로 판단되었다.im80%$로 계산되었다. 열형광선량계로 측정된 방사선량은 각각 1.8, 1.2, 0.8, 1.2, 0.8 (70 cm 거리) cGy로 측정되었으며, 환자의 복부 표면에서의 서베이메터를 이용한 측정량은 10.9 mR/h였다. 차폐구조물의 사용 시 전체 치료 동안에 태아선량은 약 1 cGy 정도로 평가되었다. 결론 : AAPM Report No.50의 자료에 따르면, 임산부의 방사선 치료 시 태아의 방사선 피폭선량은 5 cGy 이하일 경우에 방사선 피폭에 따른 태아의 위험이 거의 없는 것으로 제시되고 있다. 본원에서 차폐 구조물을 설치하였을 경우에 측정된 태아선량은 약 1 cGy로 측정되었고, 고안된 차폐구조물은 태아에 도달하는 방사선량을 감소시키기에 적합한 설계임이 입증되었다. 아니라 일반종합병원에서도 CTX-M형 ESBL 생성 E. coli와 K. pneumoniae가 존재하며 확산 중임을 시사한다. 앞으로 CTX-M형 ESBL의 만연과 변종 CTX-M형 ESBL의 출연을 감시하기 위한 정기적인 연구와 조사가 필요한 것으로 생각한다., A2-1, B1-1, B2-1의 경우, 강우 일수 감소 이전과 연 유출량 변화는 거의