• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.16 no.6
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• pp.448-453
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• 2023

As the production of small quadcopter drones has diversified and multi-sensors have been installed in FC due to the spread of MCU capable of high-speed processing, small drones that can perform special-purpose operations rather than simple operations have been realized. Hovering, attitude control, and position movement control were possible through the IMU in the FC mounted on the drone, but control is not easy when GPS connection and video communication are not possible in a closed building with a complex structure. In this study, when encountering an obstacle with a change in altitude in such a space, we proposed a method to overcome the obstacle and perform autonomous flight using optical flow and IR sensors using the Lucas-Kanade method. Through experiments, the drone's altitude flight on stairs that replace the complex structure of a closed space with stable hovering motion has a success rate of 98% within the tolerance of 10 [cm] due to external influences, and reliable autonomous flight up and down is achieved.

• Journal of the Korean Society of Industry Convergence
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• v.14 no.4
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• pp.157-165
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• 2011

The study figures out the alternatives of training BIM design experts which is the biggest obstacle in training manpower of professional BIM designer, the largest problem when the plant introduce BIM design about the change in Construction Environment by Equipment Based BIM Design in reality of design followed by equipment based BIM design, education institution plan. BIM is the system which is built to make these information be used easier and technique which enables design construction and maintenance in 3-dimensional virtual space by designing buildings in 3-dimensional space, and by data-basing the generated information of every life-cycle information. As the essential contents of the study, educational institutions with the public authority should invest the opening of educational programs, recruit of experts and development of textbooks from a long-term perspective. And also, the role of public institution is important above all for the development of construction industry.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1416-1418
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• 2004

This paper proposes an image processing algorithm for detecting obstacles on road-lane using DLI(disparity of lane-related information) that is generated by stereo images acquired from dual cameras mounted on a moving vehicle. The DLI is a disparity that is acquired using single lane information from road lane detection. For the purpose to reduce processing time, we use small blocks obtained by edge-histogram based blocking logic. This algorithm detects moving objects such as preceding vehicles and obstacles. The proposed algorithm has been implemented in a personal computer with the road image data of a typical highway. We successfully performed experiments under a wide variety of road conditions without changing parameter values or adding human intervention. Experimental results also showed that the proposed DLI is quite successful.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.758-761
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• 2003

This paper introduces a method that can detect obstacles and corridor environments from the images captured by a CCD camera in an automobile or mobile robot is proposed. Processing the input dynamic images in real time requires high performance hardware as well as efficient software. In order to relieve these requirements for detecting the useful information from the images in real time, a "Moving Window" scheme is proposed. Therefore, detecting the useful information, it becomes possible to search the obstacles within the driving corridor of an automobile or mobile robot. The feasibility of the proposed algorithm is demonstrated through the simulated experiments of the corridor driving.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.3
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• pp.1210-1230
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• 2015

Android is the world's most utilized smartphone OS which consequently, also makes it an attractive target for attackers. The most representative method of hacking used against Android apps is known as repackaging. This attack method requires extensive knowledge about reverse engineering in order to modify and insert malicious codes into the original app. However, there exists an easier way which circumvents the limiting obstacle of the reverse engineering. We have discovered a method of exploiting the Android code-signing process in order to mount a malware as an example. We also propose a countermeasure to prevent this attack. In addition, as a proof-of-concept, we tested a malicious code based on our attack technique on a sample app and improved the java libraries related to code-signing/verification reflecting our countermeasure.

• Proceedings of the KIEE Conference
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• 2008.10b
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• pp.433-434
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• 2008

이 논문은 실내에서 로봇의 주행 시 생기는 오차를 수정하는 것이다. 실내에 있는 장애물(문턱)을 넘을 경우 슬립에 의하여 주행거리와 실제거리의 오차가 생기고 또한 헤드 앵글 값이 변화함에 따라서 차후 엄청난 주행 오차를 발생시키게 된다. 그에 따라 PSD 센서를 이용하여 장애물을 감지하고 감지 후 장애물을 넘을 수 있도록 모터를 제어한다. 또한 PSD를 이용하여 장애물의 크기를 계산한 후 로봇이 장애물을 넘는 동안에 엔코더 값을 받아 들여서 장애물을 넘는 동안에 로봇이 실제 이동한 거리를 측정한다. 그리고 장애물을 넘은 후에 PSD로 계산한 장애물의 크기 값과 엔코더에서 받아들인 값을 비교하여 거리오차를 수정한다. 또한 전자컴퍼스를 이용하여 장애물을 넘기 전에 로봇의 헤드 앵글 값을 구하고, 장애물을 넘은 후에 로봇의 헤드 앵글 값을 구하여 두 개의 값을 비교한다. 두 개의 값의 차이를 측정하여 수정함으로써 헤드 앵글을 오차를 수정할 수 있다.

• Proceedings of the Korean Information Science Society Conference
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• 2007.10c
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• pp.398-403
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• 2007

본 논문에서는 스테레오 비전을 이용하여 지하철 선로에 존재하는 장애물을 검출하는 기법을 제안한다. 본 논문에서는 두 대의 아날로그 카메라를 이용하여 좌우 영상을 획득하며, 영역 기반 정합을 이용하여 영상의 불균형을 계산한다. 불균형 영상의 배경을 매 프레임에서 갱신하고 현재 프레임의 불균형과의 차이에 의해 선로상의 장애물을 검출한다. 실내 역사에서 임의로 투척한 신문지, 상자, 인형과 임의로 진압한 사람을 모두 검출하였으며, 한 대의 카메라를 이용하는 기법에서 해결하기 어려운 배경과 비슷한 색상을 가지는 물체도 모두 검출하였다. 따라서 제안하는 기법은 선로상의 위험물을 검출하는 핵심 기술로 이용될 수 있다.

• Journal of Electrical Engineering and Technology
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• v.10 no.3
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• pp.1284-1292
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• 2015

As visual surveillance systems become more and more common in human lives, approaches based on these systems to solve security problems in practice are boosted, especially in railway applications. In this paper, we first propose a robust snag detection algorithm and then present a railway security system by using a combination of multiple sensors and the vision based snag detection algorithm. The system aims safety at several repeatedly occurred situations including slope protection, inspection of the falling-object from bridges, and the detection of snags and foreign objects on the rail. Experiments demonstrate that the snag detection is relatively robust and the system could guarantee the security of the railway through these real-time protections and detections.

• Korean Parent-Child Health Journal
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• v.20 no.1
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• pp.39-47
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• 2017

Purpose: This study was conducted to investigate the factors predicting HPV (Human Papilloma Virus) vaccination practices among female college students. Methods: A convenience sample of 207 female students attending four universities in one metropolitan city participated. Self-report questionnaires consisted of general characteristics, characteristics related prevention of cervical cancer, knowledge of HPV, knowledge of cervical cancer vaccination, and health beliefs related to HPV vaccination. Data were analyzed by $x^2$ test, independent t-test, and bivariate logistic regression. Results: Factors predicting HPV vaccination practices were information about HPV (OR=3.37), experience of HPV test (OR=12.71), and health beliefs related to HPV vaccination (OR=1.13). Conclusion: In order to increase the practice rate of HPV vaccination, it is necessary to provide simple key information that is easy to understand, rather than expert knowledge about HPV. Therefore, it is necessary to provide a way for college students to get information about virus easily. It is necessary to intervene integrally with the facilitation factor and obstacle factor of vaccination practice.

• Journal of information and communication convergence engineering
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• v.7 no.3
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• pp.281-285
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• 2009

Mobile robot has various sensors for describing the external world. The ultrasonic sensor widely applied to the most mobile robot to detect the obstacle and environment owing to low cost, its easy to use. However, ultrasonic sensor has major problems: the uncertainty information of sensor, false readings caused by specular reflection, multi path effect, low angular resolution and sensitivity to changes in temperature and humidity. This paper describes a sensor system for map building of mobile robot. It was made of low cost PSD (Position Sensitive Detector) sensor array and high speed RISC MPU. PSD sensor is cost effective and light weighting but its output signal has many noises. We propose heuristic S/W filter to effectively remove these noises. The developed map building sensor system was equipped on a mobile robot and was compared with ultrasonic sensor through field test.