• Journal of Advanced Navigation Technology
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• v.25 no.1
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• pp.52-59
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• 2021

According to the International Air Transport Association (IATA), 61% of the accidents occurred during the approach and landing phase of the flight, with 16% of the accidents caused by unstable access of the commercial aircraft. It was identified that the pilot's unstable approach and poor manipulation of correction led to accidents by continuing the excessive approach without go-around manuever. The causes of unstable access may vary, including airport approach procedures, pilot error, misplanning, workload, ATC (Air Traffic Contol) congestion, etc. In this study, we use the flight data analysis system to select domestic case airports and aircraft type where unstable approach events occur repeatedly. Through flight data analysis, including main events, airport approach procedures, pilot operations, as well as various environmental factors such as weather and geographical conditions at the airport. It aims to identify and eliminate the tendency of unstable approach events and the causes and risks of them to derive implications for mitigating unstable approach events and for developing navigation safety measures.

• Journal of Advanced Navigation Technology
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• v.26 no.5
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• pp.338-343
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• 2022

The Air Radio Station plays a role in creating skyways for aircraft and helping them fly safely through aviation mobile communication facilities (U/VHF transceivers) and various navigation safety facilities. It is necessary to remove large trees and weeds around the aircraft because accurate and safe signals must be provided without interruption. During the mowing work for the efficient management of landscaping facilities, there have been cases in which noise is introduced by Lawn Mower, which hinders control work. Accordingly, in order to analyze how mower affects air mobile communication facilities, the interference effect on air mobile communication facilities was analyzed for four types of mower, two-stroke, and battery type. As a result of the analysis, it was found that the two-stroke mower greatly affects air mobile communication facilities.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.1669-1679
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• 2010

Related to the on-going "Train Control System Project of Pilot Line Construction for Urban MAGLEV Train", activities by each phase shall be conducted to achieve SIL4 level and obtain safety certification from the Independent Safety Assessment(ISA), based on the IEC standards((IEC 62278/62279 and IEC 62425) for the first time in Korea. This thesis describes the introduction of IEC standards, system assurance activities (such as plan, analysis, test, verification and validation) in compliance with requirements management and project life-cycle and relations with the safety assessment activities; and certification activities (such as document reviews and audits) through system RAMS activities, software quality assurance activities and safety assessment, for the purpose of achieving a successful safety certification at the time of completing the project as system assurance activities including software and safety certification activities in order to acquire the safety certification for train control system which does not exist at all in domestic cases. It is believed that overall system safety assurance activities in this project will contribute to develop more upgraded products of the domestic train control system on the quality and safety point of view, find overseas markets and establish a bridgehead in the future.

• Journal of information and communication convergence engineering
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• v.7 no.3
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• pp.404-411
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• 2009

In this paper, in order to increase system capacity and reduce the transmitting power of the user's equipment, we propose an efficient power estimation consisting of a modified open-loop power control (OLPC) and closed-loop power control (CLPC) schemes for mobile/satellite communications systems. The OLPC works well if the forward and reverse links are perfectly correlated and the CLPC is sensitive to round-trip delay (RTD). Therefore, it is not effective in mobile/satellite system. In order to solve the above problem, we added monitoring equipment to both the OLPC and CLPC to use information about transmitting power that has not yet been received by the receiver over the satellite/ATC channel. Moreover, we adapted an efficient pilot diversity of both OLPC and CLPC in order to get a better signal to interference plus noise ratio (SIR) estimation of the received signal.

• Journal of the Korean Society for Railway
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• v.15 no.1
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• pp.37-41
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• 2012

Kyung-Bu High Speed Railway is operated in train control system(tcs) of fixed block operated in a way of dividing track circuits into several blocks in accordance with operation circumstances such as rolling stocks, grade, curves and facilities. The TCS of fixed block system refers to a continuous train control system, which transfers operational information such as entry and exit speed, distance-to-go, and deceleration etc. into on-board train control equipment on the basis of block occupancy of a preceding train. It guarantees a safe operation of trains by giving an emergency braking order, in case that a train exceeds an entry and exit speed of a corresponding block. In this paper, we analyze the speed control code deducing in accordance with maximum operation speed and characteristics of rolling stocks by analyzing principles of generation of speed control code allocated in blocks for safe operation, then train operational efficiency was analyzed by means of analysis of operation headway in accordance with the deduced speed control code. This study will be used to design in case of getting an increase in speed for existing high speed line or new high speed line TCS.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.11a
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• pp.596-602
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• 2002

An easy elevator for learning originated is opened to compare the existed learning equipment, and it had a high studying efficient that the sequence control circuit can opens and closes with the wire. The structure of equipment to be controlled from the first floor to the fifth floors is demonstrated a constructive apparatus by a lamp atc to express the function of the open-close of the door according to the cage moving with a mechanical actuation of the forward-reverse breaker and the motor of load and a mechanical actuation of hand-operation control components of push-button S/W and L/S and relay etc. These components let connects each other in order to control of the elevator function with the auto program and the designed sequence control circuit. Consequent1y the process of these functions of 1~5steps could operates the cage with an auto program of the elevator and the sequence control circuit. The sequence control circuit is controlled by the step of forward and reverse to follow as that the sensor function of the L/S1~L/S5 let posit with the control switchs of S/W1~S/W5 of PLC testing panel and switchs of S/W1~S/W5 installed on the transparent acryl plate of the frame. In here, improved apparatus is a hand-auto operation combined learning equipment to study the principle and a technique of the originated sequence control circuit and the auto program of PLC.

• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.1220-1222
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• 2002

The railway signaling system consists of several vital computerized equipments. Now the project for development of signaling system for the next-generation high-speed train is progressed according to the consortium. The developing signaling system by this project, kTCS(Korean Train Control System), is composed of kTCS-CTC, kTCS-IXL, kTCS-ATC and etc. The KTCS signaling has to be operated as a integrated system by interface between each signaling. To achieve these, communication protocols between each signaling have to be designed and message codes are defined. In this paper the configuration of integrated kTCS system and designed communication protocol is presented.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.363-367
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• 2011

In this paper a simulator for Integrated Onboard Signalling System(IOSS) will be presented and illustrated. IOSS which is integrated with there signalling systems such as ERTMS/ETCS Level 1 ATP(Automatic Train Protection), ATC(Automatic Train Control) and ATS(Automatic Train Stop) is a signalling system for HEMU-400X(Highspeed Electric Multiple Unit - 400km/h eXperiment). HEMU-400X is under development as the next generation high-speed train in Korea. Before conducting a trial run of HEMU-400X with IOSS, we must carry out functional test of IOSS. The simulator is suggested in this paper for testing and verification of IOSS. The simulator can help to test all function of IOSS although a real train and trackside equipments are not existed. Also the simulator can make a fault in trackside equipment intentionally. In that scenario, we can figure out how IOSS handle emergency situations.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.100-103
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• 2002

The recent machine tools are requested so high-quality processing and productivity increasing. Therefore it is so necessary to develop technology far high-speed and high-precision. This thesis touches on the development of high speed and intellectual line center. At first, the line center is necessary that strong structure, compact structure and light weight design far high-speed processing and transfer. So. It is necessary that examination of new materials and structures for light-weight and control devices for precision processing. So. It is going to make mention of the process of 1st model production for the above-mentioned base on test model production and evaluation.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.18 no.2
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• pp.60-66
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• 2010

Normal Operations Safety Survey (NOSS), a methodology for capturing safety data during normal Air Traffic Control (ATC) operations. The NOSS methodology is based on the Threat and Error Management (TEM) framework, and is a safety management tool to monitor safety during normal aviation operations. Monitoring safety in normal operations is an essential activity within the safety management systems of Air Traffic Services (ATS) providing organizations, and NOSS is proposed as a suitable way to do this. This study, operating in the latter half of the year of 2010 in South Korea on NOSS was the understanding and to apply.