Impact on the Airport Performance by Diversity of Airport Operation
이영길 Yung-kil Lee , 박성식 Sung-sik Park
22(4) 247-263, 2018
이영길 Yung-kil Lee , 박성식 Sung-sik Park
DOI: JANT Vol.22(No.4) 247-263, 2018
In this article, it is that have highlighted the importance of the creative communication, convergence and identity of airport operations. This research verifies to influence in the airport performance by the diversity, mediator effect of creativity, and moderator effect of the public enterprise management evaluation performed degree in the operation of the airport. This study design how participants were selected as study the employees from two airports on the enterprise of the Incheon International Airport, Gimpo International Airport in Korea using the simple random sampling method. The findings indicate that the positively internal diversity, mediated creativity, and moderated public enterprise management evaluation performed degree affects performance of airports. This research provides a few implications and insights in the operation of airport.
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Research on Application of Requirements-based Software Reliability Verification to Domestic Military Aircraft
정상규 Sang-gyu Jeong , 서영진 Young-jin Seo , 장민욱 Min-uk Jang , 이윤우 Yoon-woo Lee
22(4) 264-270, 2018
정상규 Sang-gyu Jeong , 서영진 Young-jin Seo , 장민욱 Min-uk Jang , 이윤우 Yoon-woo Lee
DOI: JANT Vol.22(No.4) 264-270, 2018
In recent years, It is required to verify software reliability according to DO-178, which announced by radio technical commission for aeronautics (RTCA) and recognized by the Federal Aviation Administration (FAA), for civil aircraft developed or intended to fly in the United States or Europe. This is because the reliance on software in each field is deepening, and the efforts for improvement of software reliability have been made first in civil aviation field where economic and social impacts are catastrophic in the event of an accident. In this paper, we have identified some issues to be considered for requirements-based reliability verification required by DO-178 to improve software reliability and present the major elements of the present weapon system acquisition procedure of DAPA for each stage. In addition, we analyzed the results of applying the identified main check factors to a domestic aircraft development project based on the information accumulated in overseas aircraft development projects. As a result, we have shown that it is possible to verify requirements-based software reliability according to DO-178 by adding key checkpoints to the current weapon system acquisition procedure and providing objective inspection criteria.
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The Real-Time Determination of Ionospheric Delay Scale Factor for Low Earth Orbiting Satellites by using NeQuick G Model
김민규 Mingyu Kim , 명재욱 Jaewook Myung , 김정래 Jeongrae Kim
22(4) 271-278, 2018
김민규 Mingyu Kim , 명재욱 Jaewook Myung , 김정래 Jeongrae Kim
DOI: JANT Vol.22(No.4) 271-278, 2018
For ionospheric correction of low earth orbiter (LEO) satellites using single frequency global navigation satellite system (GNSS) receiver, ionospheric scale factor should be applied to the ground-based ionosphere model. The ionospheric scale factor can be calculated by using a NeQuick model, which provides a three-dimensional ionospheric distribution. In this study, the ionospheric scale factor is calculated by using NeQuick G model during 2015, and it is compared with the scale factor computed from the combination of LEO satellite measurements and international GNSS service (IGS) global ionosphere map (GIM). The accuracy of the ionospheric delay calculated by the NeQuick G model and IGS GIM with NeQuick G scale factor is analyzed. In addition, ionospheric delay errors calculated by the NeQuick G model and IGS GIM with the NeQuick G scale factor are compared. The ionospheric delay error variations along to latitude and solar activity are also analyzed. The mean ionospheric scale factor from the NeQuick G model is 0.269 in 2015. The ionospheric delay error of IGS GIM with NeQuick G scale factor is 23.7% less than that of NeQuick G model.
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Flight Test Hazard Identification
김무근 Mu-geun Kim , 임인규 In-kyu Lim , 유병선 Beong-seon Yoo , 강자영 Ja-young Kang
22(4) 279-287, 2018
김무근 Mu-geun Kim , 임인규 In-kyu Lim , 유병선 Beong-seon Yoo , 강자영 Ja-young Kang
DOI: JANT Vol.22(No.4) 279-287, 2018
Flight tests for aircraft development and certification have higher air accidents risk than other aerospace industries. Accordingly risk identification necessary for risk management in the safety management system is a very important factor in preventing similar air accidents during flight tests. But internationally issued accident statistics are usually confined to commercial transport aircraft and they do not reflect characteristics of flight tests, also databases to hazards identification during flight tests are not established or available in Republic of Korea. Therefore, we identified flight test procedures and traced the major causes of aviation accidents based on the statistics and preventive materials for risk management which were issued by international organizations and advanced countries of aviation. A total of 312 final reports classified as flight test among air accident/incident database held by U.S. NTSB were researched and about 200 flight test hazard were identified. The results of this study will be used as basic data for establishing the safety management system of the national comprehensive flight performance test site.
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Hazard Identification and Risk Assessment for the Use of Passenger Portable Electronic Devices
임인규 In-kyu Lim , 김무근 Mu-geun Kim , 강자영 Ja-young Kang
22(4) 288-294, 2018
임인규 In-kyu Lim , 김무근 Mu-geun Kim , 강자영 Ja-young Kang
DOI: JANT Vol.22(No.4) 288-294, 2018
The entertainment system of the aircraft has changed its paradigm in the form of using passenger electronic devices instead of using a fixed monitor. This has simplified the on-board equipment while the risk of safety has increased with the electric charging of portable electronic devices. Unlike personal portable electronic devices that do not have a transmission function, the use of Wi-Fi enabled electronic devices(T-PED) is allowed and the battery is required to be charged in the cabin. In this study, we used the NASA Aviation Safety Reporting System to investigate the effects of changes in wireless environment and entertainment service. Based on this, we analyzed the risks of personal electronic devices by sharing event occurrence cases caused by in-flight electronic equipment or passenger portable electronic devices (especially smart phones) from the viewpoint of aircraft safety management. This analysis includes identification of potential hazards and risk assessment, and finally the strategies for risk mitigation for safe use of portable electronic devices are suggested.
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The Rejection of the GPS Interference Mirror Image by using the Three-dimensional Array Antenna
김준오 Jun O Kim , 이상정 Sang Jeong Lee
22(4) 295-301, 2018
김준오 Jun O Kim , 이상정 Sang Jeong Lee
DOI: JANT Vol.22(No.4) 295-301, 2018
Recently, GPS(Global Positioning System) array antenna technology is generally used and widely adopted as a national infrastructure structure and aero-vehicles for protection the GPS signal reception. Until now, the 2-dimensional planar array is universally used for its applications in the array antenna signal processing, however relatively higher altitude air vehicles such as UAV experiences additional null zones induced by low altitude GPS interferences which is located in a symmetry zone of antenna horizontal plane and this could make the receiving antenna pattern coverage reduction. In this paper, we improved 20% of the beam pattern receiving performance and 13 dB correlation value improvement by eliminating the interference mirror images.
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The effects of Wake-up Radio in WLAN V2P Communication
홍한슬 Hanseul Hong , 김용호 Ronny Yongho Kim
22(4) 302-310, 2018
홍한슬 Hanseul Hong , 김용호 Ronny Yongho Kim
DOI: JANT Vol.22(No.4) 302-310, 2018
To realize the self-driving technology, there have been various system designs based on the related V2X standards, especially the IEEE 802.11p and WAVE standard supporting the WLAN V2X communication. On the other hand, the new standard IEEE 802.11ba defining supplementary wake-up radio operation is now under standardization targeting the low power operation, and it includes the V2P operation in use cases. However, if IEEE 802.11ba is used with the IEEE 802.11ba for V2X operation, the additional transmission procedure of wake-up frame in IEEE 802.11ba may cause the congestion problem and fails to meet the delay requirement. In this paper, the system structure of the combination of IEEE 802.11ba with the 802.11p is studied. In addition, based on the analysis and simulation, the considerations and improvements for effective low-power V2P communication in future self-driving technology using IEEE 802.11ba are proposed.
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Test-bed Design for the Evaluation of Wireless Communication System on Small Launch Vehicle
이대현 Dae-hyun Lee , 오택근 Taeckkeun Oh , 박동화 Dong-hwa Park , 이홍기 Hong-ki Lee , 박동현 Dong-hyun Park , 송호진 Ho-jin Song
22(4) 311-318, 2018
이대현 Dae-hyun Lee , 오택근 Taeckkeun Oh , 박동화 Dong-hwa Park , 이홍기 Hong-ki Lee , 박동현 Dong-hyun Park , 송호진 Ho-jin Song
DOI: JANT Vol.22(No.4) 311-318, 2018
In this paper, test-bed for the evaluation of wireless communication system on a small launch vehicle is proposed. The proposed test-bed consists of antenna test-coupler, RF attenuators, and RF switch modules. The antenna test-coupler isolates antennas for each band and transmits / receives wireless signals. The RF attenuator and switch are used for path selection of testing signal path. In design and measurement result of the antenna test-coupler, the antenna test-coupler has shielding effect higher than 39.3, 47.1, 56.1 dB at UHF-, S-, X-band. Through testing on small launch vehicle wireless communication system, we were able to successfully transmit and receive data between each test system and launch vehicle with antenna path switching.
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Implementation of a High Power Amplifier using Low Loss Radial Power Combiner and Water Cooling System
최성욱 Sung-wook Choi , 김영 Young Kim
22(4) 319-324, 2018
최성욱 Sung-wook Choi , 김영 Young Kim
DOI: JANT Vol.22(No.4) 319-324, 2018
In this paper, a high power amplifier using RF power solid-state semiconductor is implemented to overcome a problem of plasma generator which has the low efficiency, short life span, the difficult maintenance and the high-operation cost. This power amplifier consists of a radial combiner of low-loss and high power operation and the sixteen 300 W power amplifiers to obtain 3 kW output power for high power operation implemented in semiconductors at industrial scientific medical (ISM) band of 2.45 GHz. In addition, this amplifier overcomes the problem of heat generation due to high power by applying a water-cooled structure to the individual amplifiers. This power amplifier, which is made up of a small system, achieves 50% efficiency at the desired output.
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Stability and Complexity of Static Output Feedback Controllers
양장훈 Janghoon Yang
22(4) 325-335, 2018
양장훈 Janghoon Yang
DOI: JANT Vol.22(No.4) 325-335, 2018
Limited access to state information in the design of a feedback controller has brought out a significant amount of research on the design of an output feedback controller. Despite its long endeavor to find an optimal one, it is still an open problem. Thus, we focus on the comparison of existing states of arts in the design of a static output feedback controller in terms of stability and complexity so as to find further research direction in this field. To this end, we present eight design methods in a unified presentation. We also provide the complete description of algorithms which can be applicable to any system configuration. Stability performance and complexity in terms of processing time are evaluated through numerical simulations. Simulation results show that the algebraic controller (AC) algorithm [20] has the smallest complexity while the scaling linear matrix inequality (SLMI) algorithm [18] seems to achieve the best stability in most cases with much higher complexity.
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Design and Implementation of UWB Antenna with 5G Mobile Communication and WLAN Bands Rejection Characteristics
양운근 Woon Geun Yang , 남태현 Tae Hyeon Nam
22(4) 336-341, 2018
양운근 Woon Geun Yang , 남태현 Tae Hyeon Nam
DOI: JANT Vol.22(No.4) 336-341, 2018
In this paper, we designed and implemented an ultra wideband (UWB) antenna with 5G mobile communication and WLAN bands rejection characteristics. The proposed antenna consists of a planar radiation patch with two slots, parasitic elements on both sides of the strip line and ground plane on back side. The upper n-type slot contributes for 5G mobile communication band (3.42~3.70 GHz) rejection and the lower n-type slot contributes for wireless local area network (WLAN) band (5.15~5.825 GHz) rejection. Parasitic elements were used in order to satisfy the voltage standing wave ratio (VSWR) less than or equal to 2.0 for UWB band (3.10~10.60 GHz) except two rejection bands. The Ansoft's high frequency structure simulator (HFSS) was used for antenna design and simulations. The simulated antenna showed dual rejection bands of 3.36 ~3.71 GHz and 5.13 ~ 5.92 GHz in UWB band, and measured result for the implemented antenna showed dual rejection bands of 3.40~3.72 GHz and 5.08~5.858 GHz. Simulated and measured VSWRs are less than or equal to 2.0 for all UWB band except dual rejection bands.
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