• Proceedings of the KIEE Conference
• /
• 2004.07d
• /
• pp.2338-2340
• /
• 2004

탐지레이다 또는 TWS 레이다의 측정 정밀도는 추적 필터 설계에서 quantization 문제로써 고려해야 한다. 본 논문에서는 측정 정밀도가 추적필터에서 quantization 문제로 변환됨을 보이고 오차면적과 추정성능을 비교한다. 또한 오차면적을 줄이는 방안과 quantization이 존재하면 측정잡음과 관계한 공정잡음의 power spectral density를 선정함을 보인다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.17 no.12 s.115
• /
• pp.1189-1198
• /
• 2006

We analyze the radiated emission and mutual coupling problem from a single microstrip transmission line and double signal traces with various ground patterns. In this paper, it is shown that the reduction of the radiated emission from the signal traces can be accomplished by using the novel and compact patterns on the ground planes in a specific frequency band. The accuracy and validation of radiation mechanism from the transmission line on a novel ground plane are evaluated and explained by using a commercially available software and experiment, respectively.

• Korean Journal of Materials Research
• /
• v.15 no.8
• /
• pp.528-535
• /
• 2005

It is inclined to increase that use of hazardous substances such as lead(Pb), mercury (Hg), cadmium(Cd) etc. are prohibited in the electronics according to environmental friendly policies of an advanced nation for protecting environment of earth. As this reasons, many researches for ensuring the reliability were proceeding in Pb free soldering process. n the flux remains on the PCB(printed circuit board) in the soldering process or the electronics exposed to corrosive environment, it becomes the reasons of breakdown or malfunction of the electronics caused by corrosion. Therefore in this studies we researched the polarization and Tafel properties of Sn40Pb and SnCu system solders based on the electrochemical theory. The experimental polarization curves were measured in distilled ionized water and 1 mole $3.5 wt\%$ NaCl electrolyte of $40^{\circ}C$, pH 7.5. Ag/AgCl and graphite were utilized by reference and counter electrodes, respectively. To observe the electrochemical reaction, polarization test was conducted from -250mV to +250mV. From the polarization curves composed of anodic and cathodic curves, we obtained Tafel slop, reversible electrode potential(Ecorr) and exchange current density((cow). In these results, we compared the corrosion rate of SnPb and SnCu solders.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.14 no.4
• /
• pp.1773-1795
• /
• 2020

Unmanned aerial vehicles (UAVs) network are a very vibrant research area nowadays. They have many military and civil applications. Limited bandwidth, the high mobility and secure communication of micro UAVs represent their three main problems. In this paper, we try to address these problems by means of secure clustering, and a security clustering algorithm based on integrated trust value for UAVs network is proposed. First, an improved the k-means++ algorithm is presented to determine the optimal number of clusters by the network bandwidth parameter, which ensures the optimal use of network bandwidth. Second, we considered variables representing the link expiration time to improve node clustering, and used the integrated trust value to rapidly detect malicious nodes and establish a head list. Node clustering reduce impact of high mobility and head list enhance the security of clustering algorithm. Finally, combined the remaining energy ratio, relative mobility, and the relative degrees of the nodes to select the best cluster head. The results of a simulation showed that the proposed clustering algorithm incurred a smaller computational load and higher network security.

• Journal of the Korean Society for Aviation and Aeronautics
• /
• v.26 no.3
• /
• pp.87-92
• /
• 2018

This thesis is to provide procedures for documenting implementation performance and methodology of practical SMS enactment for Approved Training Organization(ATO). As an example, C flight training center, according MOLIT "Guidance on SMS Implementation", derived 32 implementation documents after writing the SMS manual to implement it. The 32 implementation documents are divided into 5 fields. In detail, they are (1) 2 documents on SMS Manual, (2) 7 documents on Safety policy and objectives (3) 3 documents on Safety risk management (4) 15 documents on Safety assurance (5) 5 documents on Safety promotion. By describing the documented performances according to these 32 implementation documents that was in use for 1 year in 2017, it is suggested that this procedure can be a methodology for practically enactment and implementing the SMS manual.

• Journal of Advanced Navigation Technology
• /
• v.12 no.6
• /
• pp.539-547
• /
• 2008

In this paper, preliminary results for design of prototype ADS-ADS-B/TIS-B Validation Testbed (AVT) are described. Automatic Dependent Surveillance (ADS-B) is a novel surveillance concept using the Global Navigation Satellite System (GNSS) and a digital datalink. Air traffic information from ADS-B non-equipped aircraft is not acquired since ADS-B is a dependent surveillance. Traffic Information Service-Broadcast (TIS-B) provides surveillance data from Secondary surveillance Radar (SSR) for ADS-B non-equipped aircraft. AVT is based on ADS-B and TIS-B as an integrated platform for air traffic surveillance system for CNS/ATM.

• Journal of the Korean Society for Aviation and Aeronautics
• /
• v.19 no.3
• /
• pp.43-53
• /
• 2011

It is well known some Foreign aircraft used to fly INCHEON FIR(Flight Information Region), especially the island of IEODO without a flight plan, even though foreign aircraft is subject to submitting a flight plan to Flight Information Center(FIC) before its flight. IEODO is a sunken rock 4.6m beneath the sea level, 149km away from Marado. Facing the Yangtze river's sea entrance horizontally and military zones of Korea and China vertically, IEODO is a very important place for national security of North East Asia because it is located at the boundary between China East Sea and Yellow Sea of South Korea. Moreover, JDZ(the 7th mine lot) is just 77NM from IEODO, which possesses natural gas eight times bigger than the gulf region and oil 4.5 times bigger than that of the U.S. In addition, INCHEON FIR, managed by MLTM(Air Traffic Control Center) and Japanese Self-Defense Force's JADIZ(Japanese Air Defense Identification Zone) are overlapping on IEODO whose air space is very complex. This paper focuses on air space, FIR, ADIZ(Air Defense Identification Zone) and related airspace system and suggests strategic implications of how to prevent foreign aircraft from invading INCHEON FIR without permission and of how to utilize the airspace efficiently.

• Journal of the Korean Society for Aviation and Aeronautics
• /
• v.32 no.2
• /
• pp.112-123
• /
• 2024

Responding to rapid changes of global supply chain and fast increasing air cargo volume and demand for e-commerce market, this paper researched the development plans for regional airport specially focused on air cargo logostics through policy research. According to this research, political implications and development plans for Cheong Ju airport (CJJ) to become a part of global supply chain, a regional air cargo hub. Firstly, it is necessary to increase the length of the existing runway from 2,744m to 3,200m or to develop 3^rd runway only for a civil aircraft use. Secondly, it is inevitable to develop new air cargo terminal to handle and export such high value-added products as semi-conductor or rechargeable battery through airport. In addition, facing re-shoring trends among global supply chain, CJJ can increase its air cargo volume and also provide feeder service to Incheon airport, inducing global distribution center near airport site.

• Journal of the Korean Society for Aviation and Aeronautics
• /
• v.5 no.1
• /
• pp.31-50
• /
• 1997

A new variable wing that can be swept back and forward synchronously were developed to enhance the aerodynamic and stability characteristics of a high speed airplane. The configuration of the new variable wing changes in such a way that inner part of the wing sweeps forward and outer part of the wing sweeps backward, the shift of aerodynamic center of the wing is small, therfore the static margin that is required for the stability of a airplane is not affected. In this study, various configurations of wing models by combined swept back and forward were designed and a wind tunnel tests were conducted to investigate the aerodynamic characteristics of these variable wings. The experimental results showed that the variable wing by combined swept back and forward has no effect on the pitching moment coefficient affecting on an aircraft stability margin and enhance the aerodynamic characteristics for a given approach angle of attack.

• Journal of the Korean Society for Aviation and Aeronautics
• /
• v.16 no.3
• /
• pp.1-6
• /
• 2008

The stalling speed flight test of light airplane, ChangGong-91, was performed to acquire the certification. With power-off engine condition, the wings level stall flight tests were conducted at the aircraft configuration of various flap angle - clean, 20degree, and full flap, respectively. They were performed considering with the combination of the maximum and minimum test weight, and forward and afterward center of gravity. The stalling speeds and the minimum speeds of light airplane were determined from the results of flight test. Also, the appropriateness of stall warning speeds are evaluated through the flight test measures. The airplane is recoverable only with pitch control and engine throttle from stall state without exceptional operation.