• Journal of the Korea Institute of Military Science and Technology
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• v.23 no.6
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• pp.639-649
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• 2020

Air data systems measure airspeed, pressure altitude, angle of attack and angle of sideslip. These measurements are essential for operating flight control laws to ensure safe flights. Since the loss or corruption of air data measurements is considered as catastrophic, a high level of operational reliability needs to be achieved for air data systems. In the case of unmanned air vehicles, failure of any of air data sensors is more critical due to the absence of onboard pilot decision aid. This paper presents design of a dual redundancy air data system and the integration process for an unmanned air vehicle. The proposed dual-redundant architecture is based on two independent air data probes and redundancy management by central processing in two independent flight control computers. Starting from unit testing of single air data sensor, details are provided of system level tests used to meet overall requirements. Test results from system integration demonstrate the efficiency of the proposed process.

• 전자공학회논문지 IE
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• v.46 no.4
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• pp.25-30
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• 2009

The cooling water circulation pipes had been used to drop the temperature of refractory outside shell of blast furnace by cooling plate or stave type. They were attacked by surrounding CO gas and it was the cause that they were corroded and the water inflow in the refractory due to leakage of water. So, the life of refractory material was shorten and changed for the worse the conditions of blast furnace. The automatic sensing device for water leakage of cooling pipe was developed to check the position of trouble by use the micro-process system when cooling water leak and then CO gas will be inflowed into the cooling pipe at the leakage position. The inflowed CO gas will be detected in the micro-process system and delivered the detected position of cooling plate or stave to main control room through the wireless-radio relay station. This system can be possible to detect the position of cooling plate or stave the water leakage part immediately and then deliver the signal to main control room by use the micro-process system and wireless-radio relay station. This system will develop the working condition from manual system to unmanned auto alarm system.

• Journal of Advanced Navigation Technology
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• v.21 no.5
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• pp.466-471
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• 2017

SOTM is a device for the satellite communication on the move. Many studies are conducted on microstrip, waveguide and array antenna for the low profile of the SOTM's antenna. But those antennas have a problem that is difficult to adjust the polarization, and for that reason we have studied the parabolic antenna structure. The general form of parabolic reflector structure is circular, but we used cut-off shape reflector by cutting the upper and lower reflector for low profile antenna. Accordingly, this results in the decrease of reflector area which causes reduced gain and G/T ratio. In order to solve this problem, we have transformed and designed the sub reflector for improving the efficiency and gain of the cut- off shape parabolic antenna.

• Journal of Advanced Navigation Technology
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• v.23 no.6
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• pp.487-494
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• 2019

Recently, interest in and use of drones is increasing. In this study, to provide accurate wind prediction at ultra low altitudes of 150 meters or below, the sensitivity of the physical process parameterization and initial conditions was assessed to select the optimal physical process and initial conditions. For this purpose, GFS and LDAPS data were used as initial and boundary conditions, and 7 experiments were constructed using a combination of PBL schemes such as YSU, RUC, ACM2, and LSM such as Noah, RUC, and Pleim. The experiment conducted for 1 month in April 2018. As a result, the RUC-YSU physical process combination using the GFS initial data showed the best performance. This study is meaningful in establishing an optimal modeling method for ultra low altitude wind prediction through experiments using different initial conditions and combination of physical processes.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.06a
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• pp.213-216
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• 2007

The paper deals with a approach to underwater acoustic based Ad-hoc communication, which allows major design strategies for Media Access Control (MAC) within a group of the autonomous underwater vehicles(AUV). The proposed MAC aims at deploying AUV-centric star topology, which minimizes overhead of sensor nodes and improves energy-efficiency. Furthermore, that is also well under long and unknown propagation delays of the underwater acoustic medium. The implemented MAC protocol makes it easier to achieve frame synchronization than TDMA due to deploying localized schedule time, in addition to saving energy consumption by letting nodes sleep. It is also superior to MACA and MACAW in terms of propagation delay. This scalable centralized protocol has the potential to serve as a primer for development of MAC protocol for future underwater acoustic based ad-hoc networks.

• Membrane Journal
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• v.22 no.5
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• pp.326-331
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• 2012

In this study, rejection behavior of 2-MIB (methylisoborneal) and geosmin which are known as taste-and-odor (T & O) causing micropollutants in drinking water source was investigated using hydrophobic polyethersulfone (PES) nanofiltration "loose" membrane (MWCO : 400 Da). It was found that the rejection of the geosmin was higher than that of the 2-MIB in all experimental conditions tested. This study also showed that the rejections of 2-MIB and geosmin were increased by increasing solution pH due to enhancing electrostatic repulsions between micropollutants and membrane surface. The presence of natural organic matter led to increase the rejection of the hydrophobic 2-MIB and geosmin and the effectiveness was more pronounced at higher solution pH. Increasing hydrophilicity of the hydrophobic membrane surface by coating with $TiO_2$ particles resulted in the significant increase in the rejection of 2-MIB and geosmin. In addition to the charge repulsion, this result suggests that hydrophobic-hydrophobic interaction should be one of main rejection mechanisms of T & O compounds by NF membrane.

• Korean Journal of Construction Engineering and Management
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• v.14 no.5
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• pp.153-163
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• 2013

As recent buildings have been more higher and larger, construction vertical lifting planning and operation is a key factor for successful project in tall building. Although many studies have been trying to set up a construction lifting planning system at early stage, there's not existing a control real-time lift operation control system with respect to during construction stage. Therefore, In this study, we use the sensor device to collect the lift operating data for improvement of lift operation efficiency and develope optimum lift operating system which can perform real-time analysis. Finally, we verify the efficiency of proposed system through comparison between realtime operating data and simulated data using proposing system. In this paper, the proposed system show more efficient moving line compared with previous system. This can contribute to development of unmanned lift system.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.04a
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• pp.39-39
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• 2018

지금까지 통조화(Stachyurus praecox)는 일본특산식물로 알려져 있으며, 일부 수목원 식물원에서만 식재된 국내 미기록종이다. 본 조사에서는 전남 완도군 생일면 일대 무인섬에서 통조화 자생지를 최초 발견하였다. 이 일대 해발고 50m 이하의 지점에서 불규칙적으로 최대 H8.0m, R24cm 등 150여 개체 이상 분포하는 것으로 확인되었다. 조사지 식생의 교목층은 생달나무(Cinnamomum japonicum), 아교목층은 통조화(Stachyurus praecox), 관목층은 참식나무(Neolitsea sericea), 초본층은 두루미천남성(Arisaema heterophyllum)이 우점하고 있었다. 국내에서는 통조화(Stachyurus praecox)에 대한 기초자료가 부족하여 그간 암수딴그루, 낙엽활엽관목으로 여겨왔다. 그러나 이번 자생지 발견을 통해 암꽃만 있는 단성화 개체뿐만 아니라 암술과 수술이 함께 있는 양성화 개체가 더 많이 자생하고 있는 것으로 조사되었다. 또한, 단성화(암꽃)에서만 전년도에 결실한 종자가 달려있다는 점과, 양성화에서는 화기의 탈락이 빈번하고 수정된 개체를 발견할 수 없었던 점으로 보아 이 지역에서 자생하는 통조화는 암꽃양성화딴그루로 사료된다. 향후, 이 지역 통조화의 정확한 동정을 위해 동일한 속의 유사분류군과의 유연관계를 비교하고, 관찰 및 조사가 필요하다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.10
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• pp.1987-1996
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• 2009

Recently, the color of vehicle license plate has been changed from green to white. Thus the vehicle plate recognition system used for parking management systems, speed and signal violation detection systems should be robust to the both colors. This paper presents a vehicle license plate recognition system, which works on both of green and white plate at the same time. In the proposed system, the image of license plate is taken from a captured vehicle image by using morphological information. In the next, each character region in the license plate image is extracted based on the vertical and horizontal projection of plate image and the relative position of individual characters. Finally, for the recognition process of extracted characters, PCA(Principal Component Analysis) and LDA(Linear Discriminant Analysis) are sequentially utilized. In the experiment, vehicle license plates of both green background and white background captured under irregular illumination conditions have been tested, and the relatively high extraction and recognition rates are observed.

• The Transactions of the Korea Information Processing Society
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• v.6 no.12
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• pp.3710-3717
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• 1999

For the development of unmanned autonomous vehicle, it is essential to detect obstacles, especially vehicles, in the forward direction of navigation. In order to reliably exclude regions that do not contain obstacles and save a considerable amount of computational effort, it is often necessary to confine computation only to ROI(region of interest)s. A ROI is usually chosen as the interior region of the lane. We propose a computationally simple and efficient method for the detection of lanes based on Hough transform and quadratic curve fitting. The proposed method first employs Hough transform to get approximate locations of lanes, and then applies quadratic curve fitting to the locations computed by Hough transform. We have experimented the proposed method on real outdoor road scene. Experimental results show that our method gives accurate detection of straight and curve lanes, and is computationally very efficient.