• Fire Science and Engineering
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• v.30 no.5
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• pp.36-45
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• 2016

Integral fire shutters are installed indiscriminately, regardless of evacuation. There is always the risk of an accident because integral shutters are applied mainly to corridors, passages, and stairs of schools This study evaluated the problem of integral shutter's entrance, evacuation, construction management, and maintenance control through a fire shutter accident case, including present condition of fire shutter installed at school of Okgil, Bucheon and Dongtan, Hwaseong. The results suggest that emergency lighting or signs for passage be set up to check location of entrance easily and install obstruction sensors at fire shutter to reduce life damage. In addition, the number of efficiency tests of fire shutters should be increased by running a trial test monthly or weekly to maintain the performance of fire shutter. Schools need to install a fire shutter- applied sprinkler at the entire floor.

• Journal of Korea Multimedia Society
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• v.14 no.4
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• pp.517-528
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• 2011

In this paper, we propose an indoor navigation system that can do walk safely to the destination for visually impaired persons. The proposed system analyzes images taken with the camera finds the ID of the marker to identify the absolute position of the pedestrian. Using the distance and angle obtained from IMU(Inertial Measurement Unit) accelerometer sensor and a gyro sensor, the system decides the relative position of a pedestrian for the previous position to determine the next direction. At the same time, we simplify a complex spatial structure in front of user by means of ultrasonic sensors and determine an avoidance direction by estimating the patterns. Then, it uses a few IR(Infrared Rays) sensors to detect stair. Our system offers position of visually impaired persons incorporating multiple sensors and helps users to arrive to destination safely.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.6
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• pp.1195-1200
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• 2007

This paper describes indoor location estimation intelligent robot. Indoor location estimation function using RSSI based indoor location estimation system and wireless sensor networks were implemented in the robot. Spartan III(Xilinx, U.S.A.) was used as a main control device in the mobile robot and the current direction data was collected in the indoor location estimation system. The data was transferred to the wireless sensor network node attached to the mobile robot through Zigbee/IEEE 802.15.4, a wireless communication. After receiving it, with the data of magnetic compass the node is aware of and senses the direction the robot head for and the robot moves to its destination. Indoor location estimation intelligent robot is can be moved efficiently and actively without obstacle on flat ground to the appointment position by user.

• Journal of Digital Convergence
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• v.19 no.12
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• pp.145-150
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• 2021

In order to continuously perform quarantine in public places, it is not easy to secure manpower, but using self-driving-based robots can solve problems caused by manpower. Self-driving-based quarantine robots can continuously prevent the spread of harmful viruses and diseases in public institutions and hospitals without additional manpower. The location of the autonomous driving function was estimated by applying the Pinnacle filter algorithm, and the UV sterilization system and chlorine dioxide injection system were applied for quarantine. The driving time is more than 3 hours and the position error is 0.5m.Soon, the stop-avoidance function was operated at 95% and the obstacle detection distance was 1.5 m, and the automatic charge recovery was charged by moving to the charging cradle at the remaining 10% of the battery capacity. As a result of quarantine with an unmanned quarantine system, UV sterilization is 99% and chlorine dioxide is sterilized more than 95%, which can contribute to reducing enormous social costs.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.23 no.1
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• pp.123-133
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• 2024

Existing autonomous driving technology has been developed based on sensors attached to the vehicles to detect the environment and formulate driving plans. On the other hand, it has limitations, such as performance degradation in specific situations like adverse weather conditions, backlighting, and obstruction-induced occlusion. To address these issues, cooperative autonomous driving technology, which extends the perception range of autonomous vehicles through the support of road infrastructure, has attracted attention. Nevertheless, the real-time analysis of the 3D centroids of objects, as required by international standards, is challenging using single-lens cameras. This paper proposes an approach to detect objects and estimate the centroid of vehicles using the fixed field of view of road infrastructure and pre-measured geometric information in real-time. The proposed method has been confirmed to effectively estimate the center point of objects using GPS positioning equipment, and it is expected to contribute to the proliferation and adoption of cooperative autonomous driving infrastructure technology, applicable to both vehicles and road infrastructure.

• Journal of Advanced Navigation Technology
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• v.28 no.3
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• pp.300-308
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• 2024

Urban air mobility (UAM) is emerging as a revolutionary transportation solution to urban congestion and environmental issues. Especially, electric vertical take-off and landing (eVTOL) aircraft are expected to enhance urban mobility, reduce traffic congestion, and decrease environmental pollution. However, the successful implementation and operation of UAM systems heavily rely on advanced technological infrastructure, particularly in sensor technology. Among these, 3D light detection and ranging (LiDAR) systems are essential for detecting obstacles and generating pathways in complex urban environments. This paper focuses on the challenges of developing LiDAR-based perception solutions, emphasizing the importance and performance of object detection capabilities using 3D LiDAR. It integrates LiDAR data processing algorithms and object detection methodologies to experimentally validate the effectiveness of perception solutions that contribute to the safe navigation of aircraft. This research significantly enhances the ability of aircraft to recognize and avoid obstacles effectively within urban settings.

• Journal of the Korea Society of Computer and Information
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• v.18 no.10
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• pp.109-119
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• 2013

An unmanned ground vehicle(UGV) today plays a significant role in both civilian and military areas. Predominantly these systems are used to replace humans in hazardous situations. To take unmanned ground vehicles systems to the next level and increase their capabilities and the range of missions they are able to perform in the combat field, new technologies are needed in the area of command and control. For this reason, we present war field simulator based on information fusion technology to efficiently control UGV. In this paper, we present the war field simulator which is made of critical components, that is, simulation controller, virtual image viewer, and remote control device to efficiently control UGV in the future combat fields. In our information fusion technology, improved methods of target detection, recognition, and location are proposed. In addition, time reduction method of target detection is also proposed. In the consequence of the operation test, we expect that our war field simulator based on information fusion technology plays an important role in the future military operation significantly.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.128-128
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• 2010

중적외선 영역은 장애물에 의해서 파장의 흡수가 거의 일어나지 않기 때문에 적외선 소자에서 널리 이용되고 있다. 현재 대부분의 중적외선 소자에는 HgCdTe (MCT)가 사용되고 있지만, 3성분계 화합물이 가지는 여러 문제를 가지고 있다. 반면에, 2성분계 화합물인 인듐안티모나이드 (InSb)는 중적외선 영역 ($3-5\;{\mu}m$) 파장 대에서 HgCdTe와 대등한 소자 특성을 나타냄과 동시에 낮은 기판 가격, 소자 제작의 용이성, 그리고 야전과 우주 공간에서 소자 동작의 안정성 때문에 HgCdTe를 대체할 물질로 주목을 받고 있다. InSb는 미국과 이스라엘과 같은 일부 선진국을 중심으로 연구가 되었지만, 국방 분야의 중요한 소자로 인식되었기 때문에 소자 제작에 관한 기술적인 내용은 국내에 많이 알려지지 않은 상태이다. 따라서 본 연구에서는 InSb 소자 제작의 기초연구로 절연막과 pn 접합 형성에 대한 연구를 수행하였다. 절연막의 특성을 알아보기 위해, InSb 기판위에 $SiO_2$와 $Si_3N_4$를 PECVD (Plasma Enhanced Chemical Vapor Deposition)로 증착을 하였다. 절연막의 계면 트랩 밀도는 77K에서 C-V (Capacitance-Voltage) 분석을 통하여 계산하였으며, Terman method 방법을 이용하였다.[1] $SiO_2$는 $120-200^{\circ}C$의 온도 영역에서 계면 트랩 밀도가 $4-5\;{\times}\;10^{11}cm^{-2}$범위를 가진 반면, $240^{\circ}C$의 경우 계면 트랩 밀도가 $21\;{\times}\;10^{11}cm^{-2}$로 크게 증가하였다. $Si_3N_4$는 $SiO_2$ 절연막에 비해서 3배 정도의 높은 계면 트랩 밀도 값을 나타내었으며. Remote PECVD 장비를 이용하여 $Si_3N_4$ 절연막에 관한 연구를 추가적으로 진행하여 $7-9\;{\times}\;10^{11}cm^{-2}$ 정도의 계면 트랩 밀도 값을 구할 수가 있었다. 따라서 InSb에 대한 절연막은 $200^{\circ}C$ 이하에서 증착된 $SiO_2$와 Remote PECVD로 증착 된 $Si_3N_4$가 적합하다고 할 수 있다. 절연막 연구와 더불어 InSb 소자의 pn 접합 연구를 진행하였다. n-InSb (100) 기판 ($n\;=\;0.2-0.85\;{\times}\;10^{15}cm^{-3}$ @77K)에 $Be^+$이온 주입하여 p층을 형성하여 제작 되었으며, 열처리 조건에 따른 소자의 특성을 관찰 하였다. $450^{\circ}C$에서 30초 동안 RTA (Rapid Thermal Annealing)공정을 진행한 샘플은 -0.1 V에서 $50\;{\mu}A$의 높은 암전류가 관찰되었으며, 열처리 조건을 60, 120, 180초로 변화하면서 소자의 특성 변화를 관찰하였다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.5
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• pp.538-549
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• 2019

This study suggests a new platform in which VI can communicate with their guardians who serve as a system administrator optimizing personal characteristics. In terms of interaction between platform components, this study can contribute to enhancing stability of walking by giving substantial information to VI through server processing and setups of guardians with real-time interaction to VI through server processing and setups of guardians with real-time interaction. Therefore, developing smart phone applications can facilitate both portability and cost effectiveness, by the users' downloading the application and registration. In terms of guardians' cost, this system is cost-effective because they can access to the administration system through personal computers or smart phones, not through specialized system devices. This system is web-based, which automatically communicates with the surroundings of, such as provides the guardians with the necessary information or approaches to the danger through IoT devices, which results in enhancing safety. Moreover, it is possible for guardians to utilize the personalized platform since the system not only senses personal characteristics but also sends a number of information to VI. a new platform makes it possible for guardians to provide electronic support and interaction with the application with the application users, which contributes to systematic and safe walk for VI.

• Journal of Platform Technology
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• v.11 no.2
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• pp.26-38
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• 2023

This paper is a study on a transport robot capable of autonomously driving to a destination using a QR code in an indoor environment. The transport robot was designed and manufactured by attaching a lidar sensor so that the robot can maintain a certain distance during movement by detecting the distance between the camera for recognizing the QR code and the left and right walls. For the location information of the delivery robot, the QR code image was enlarged with Lanczos resampling interpolation, then binarized with Otsu Algorithm, and detection and analysis were performed using the Zbar library. The QR code recognition experiment was performed while changing the size of the QR code and the traveling speed of the transport robot while the camera position of the transport robot and the height of the QR code were fixed at 192cm. When the QR code size was 9cm × 9cm The recognition rate was 99.7% and almost 100% when the traveling speed of the transport robot was less than about 0.5m/s. Based on the QR code recognition rate, an experiment was conducted on the case where the destination is only going straight and the destination is going straight and turning in the absence of obstacles for autonomous driving to the destination. When the destination was only going straight, it was possible to reach the destination quickly because there was little need for position correction. However, when the destination included a turn, the time to arrive at the destination was relatively delayed due to the need for position correction. As a result of the experiment, it was found that the delivery robot arrived at the destination relatively accurately, although a slight positional error occurred while driving, and the applicability of the QR code-based destination self-driving delivery robot was confirmed.