A Case Study on Safety Analysis Procedure of Aircraft System using the Relex
이동우 Dong-woo Lee , 김입수 Ip-su Kim , 나종화 Jong-whoa Na
22(3) 179-188, 2018
이동우 Dong-woo Lee , 김입수 Ip-su Kim , 나종화 Jong-whoa Na
DOI: JANT Vol.22(No.3) 179-188, 2018
In developing avionics systems, safety analysis and evaluation specified in SAE ARP4761 (Methods and Guidelines for Civil Aviation System and Equipment Safety Assessment Process) are carried out to prevent air accidents. Safety analysis requires knowledge of the abnormal state of the system, not its normal state, and its interrelationships with other standards. Therefore, a tool that automatically outputs data which proves compliance with safety certification standards is required. In this study,In this study, Schematized the safety analysis procedure of the specification and studied the method of applying the safety analysis CAD tools to individual procedure. As an example study, ARP4761 analysis was performed on the wheel brake system (WBS) of the ARP4761 appendix.
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Establishment of Standard Model for Training Flight Infrastructure
임재환 Jae-hwan Lim , 김영록 Young-rok Kim , 최연철 Yun-chul Choi
22(3) 189-197, 2018
임재환 Jae-hwan Lim , 김영록 Young-rok Kim , 최연철 Yun-chul Choi
DOI: JANT Vol.22(No.3) 189-197, 2018
In Korea, most of the land area is composed of mountainous areas, making it difficult to develop airports because there is not enough open space to operate airports or airfields. However, the current development of the air transportation industry and the rapid increase of aviation demand, the construction of the training airfield infrastructure should be more actively reviewed for safe and smooth flight training. In this study, we analyze the actual condition of operation of domestic training airfield and the case study of overseas training site in order to establish appropriate level standard model of training infrastructures. In addition, this study suggests implications for the appropriate scale and operational efficiency of the training flight infrastructure.
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Development of Integrated Data Management Prototype System for Aviation Accident and Incident Investigation
김도현 Do-hyun Kim , 홍승범 Seung-beom Hong
22(3) 198-204, 2018
김도현 Do-hyun Kim , 홍승범 Seung-beom Hong
DOI: JANT Vol.22(No.3) 198-204, 2018
In this paper, It proposed the development of integrated data management's prototype system for aviation accident and incident system. With the recent development of the aviation accident investigation equipment, accident investigation system should collect and manage the various types of jpg, avi, and wav data files. However, the ECCAIRS system does not have a separate database for managing the various generated data during the accident investigation. And the Korea aviation accident management system also has the same problem. Therefore, in this paper, we analyze the aviation accident report system of major foreign countries and prepare a method to apply it to the domestic environment. Through the prototype of the integrated data management system, we confirmed the performance through inputting the existing data and the recently investigated data. We will use this result as basic data for completion of final integrated data management system.
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A Stress Analysis for Pressure Vessel to Prevent Spontaneous Ignition of Coal Stockpile
김영인 Young In Kim , 김승훈 Seung Hun Kim , 지민석 Min-seok Jie , 염찬섭 Chan Sub Yeum , 최원혁 Won Hyuck Choi
22(3) 205-212, 2018
김영인 Young In Kim , 김승훈 Seung Hun Kim , 지민석 Min-seok Jie , 염찬섭 Chan Sub Yeum , 최원혁 Won Hyuck Choi
DOI: JANT Vol.22(No.3) 205-212, 2018
Spontaneous ignition is not only severe economic damage but also a typical plant damage caused by harmful gases generated during the fire. Because coal is porous, it causes oxygen to be absorbed in the amount of oxygen per unit weight of oxygen, resulting in low humidity and low thermal conductivity. The cause and effect of spontaneous ignition are very complex, so it is difficult to prevent it beforehand and once it is difficult to digest it, it is difficult to digest it. This study examines structural safety by conducting a structural analysis of the cooling ball system to prevent spontaneous combustion of coal stockpile plants and external pressures.
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Design of Hybrid V2X Communication Module for Cooperative Automated Driving
임기택 Ki-taeg Lim , 진성근 Seong-keun Jin , 곽재민 Jae-min Kwak
22(3) 213-219, 2018
임기택 Ki-taeg Lim , 진성근 Seong-keun Jin , 곽재민 Jae-min Kwak
DOI: JANT Vol.22(No.3) 213-219, 2018
In this paper, we propose a design method and process for hardware and software of hybrid V2X communication module that supports both C-ITS communication protocol designed for vehicle environment and Legacy LTE communication technology. C-ITS is suitable for safety service applications due to its low latency characteristics, and Legacy LTE is a technology suitable for non-safety applications such as traffic information and infotainment due to high latency and high capacity. The hybrid V2X communication module supports multiple communication technologies of WAVE and LTE, in which WAVE supports multiple channels, so that it is designed to transmit road information such as LDM and positioning correction information to an autonomous vehicle in real time. The main design results presented in this paper will be applied to the implementation of future hybrid V2X communication terminals for vehicles.
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Observability Analysis of INS/GNSS System for Vehicles Moving with a Large Pitch Angle Change
김현석 Hyun-seok Kim , 백승준 Seung-jun Baek , 김형수 Hyung-soo Kim , 조민수 Min-su Jo
22(3) 220-227, 2018
김현석 Hyun-seok Kim , 백승준 Seung-jun Baek , 김형수 Hyung-soo Kim , 조민수 Min-su Jo
DOI: JANT Vol.22(No.3) 220-227, 2018
The most widely used method for constructing an inertial navigation system (INS)/global navigation satellite system (GNSS) coupling system is to construct an integrated navigation system using a Kalman filter. However, depending on the trajectory, non-observable state variables may be generated. In this case, the state variables are not estimated. To solve this problem, a integrated navigation system is constructed and then an observability analysis is performed. In this paper, a 24th order position-matched Kalman filter is defined to design an INS/GNSS integrated navigation system for vehicles moving with a large pitch angle change. To verify the appropriateness of the error state variables applied to the Kalman filter, an observability analysis was performed. The trajectory was divided into five segments, and the piece-wise constant system (PWCS) was assumed for each segment, and the results were analytically analyzed. The analytical results and the simulation results confirm that the error state parameters of the Kalman filter are well-designed to the estimation side.
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Data Rate Condition for Quantizer Achieving Practical Stability
양장훈 Janghoon Yang
22(3) 228-232, 2018
양장훈 Janghoon Yang
DOI: JANT Vol.22(No.3) 228-232, 2018
Dealing with quntization error in a control system properly becomes much more important as many devices are connected through network and controlled. Thus, in this paper, we study a data rate condition on quantizer to achieve practical stability in a discrete time linear time invariant system with state feedback control. First, required data rate is shown to depend on eigenvalue of the closed loop system, the size of the initial state vector, the magnitude of initial quantization error, and control gain in the absence of process noise. It additionally depends on the maximum magnitude of process noise when noise is not zero. Asymptotic analysis shows that a new design method may be needed to reduce the date rate for a networked control in the presence of quantization error and noise.. We provide a simple numerical evaluation of uniform quantizer and logarithmic qunatizer to assess their characteristics of practical stability depending on data rate in the presence of noise.
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Short Term Forecast Model for Solar Power Generation using RNN-LSTM
신동하 Dong-ha Shin , 김창복 Chang-bok Kim
22(3) 233-239, 2018
신동하 Dong-ha Shin , 김창복 Chang-bok Kim
DOI: JANT Vol.22(No.3) 233-239, 2018
Since solar power generation is intermittent depending on weather conditions, it is necessary to predict the accurate generation amount of solar power to improve the efficiency and economical efficiency of solar power generation. This study proposes a short - term deep learning prediction model of solar power generation using meteorological data from Mokpo meteorological agency and generation data of Yeongam solar power plant. The meteorological agency forecasts weather factors such as temperature, precipitation, wind direction, wind speed, humidity, and cloudiness for three days. However, sunshine and solar radiation, the most important meteorological factors for forecasting solar power generation, are not predicted. The proposed model predicts solar radiation and solar radiation using forecast meteorological factors. The power generation was also forecasted by adding the forecasted solar and solar factors to the meteorological factors. The forecasted power generation of the proposed model is that the average RMSE and MAE of DNN are 0.177 and 0.095, and RNN is 0.116 and 0.067. Also, LSTM is the best result of 0.100 and 0.054. It is expected that this study will lead to better prediction results by combining various input.
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Dispersion-managed Links with the Irregular Distribution of the Lengths and Dispersion Coefficients of the SMFs and the DCFs
이성렬 Seong-real Lee
22(3) 240-245, 2018
이성렬 Seong-real Lee
DOI: JANT Vol.22(No.3) 240-245, 2018
A flexible dispersion-managed link configuration is proposed by using single-mode fibers (SMFs) and dispersion-compensating fibers (DCFs) with irregular dispersion coefficients and lengths over all fiber spans for compensating of WDM channels distortion due to the group velocity dispersion and nonlinear effects of optical fibers. The flexibility of link is enabled by artificially distributing of these fibers based on the dispersion coefficients of DCFs in each half transmission section. The simultaneous ascending and descending (AD) distribution of the DCF’s coefficients before and after the optical phase conjugator, respectively, best compensates the distorted wavelength division multiplexed signals in the optical link. Therefore, to improve the compensation effect of the distorted WDM channels, AD distribution is needed to choice regardless of fiber lengths and the residual dispersion per span and fiber’s dispersion coefficients.
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