• 한국항공운항학회지
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• 제17권3호
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• pp.32-39
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• 2009

Due to the lack of navigable airspace caused by worldwide air traffic increases, air traffic control(ATC) services are becoming more complex, which results in the increase of aircraft accidents. To cope with these challenges, major aviation institutes abroad are actively conducting research regarding the human factors affecting controllers but as of late, no such specialized activities have been found in Korea. Due to the dynamic attributes of ATC operations, management of controller's situation awareness(SA) and workload, and knowledge on the impact of abnormal aircraft to controllers are very important. Furthermore, using actual flight data of each country will lead to valuable results, because individually, it has different airspace characteristics and air traffic volumes. This study assumed that air traffic difficulties would affect the controller's SA and workload. To testify the above hypothesis, the abnormal air traffic situations are simulated by using ATC simulator. The findings indicated that the effect of traffic situations containing abnormal aircraft on the controller's SA and workload, it led to demand increase and supply decrease in SA, and increased mental demand, temporal demand, effort and mean workload score in the workload.

• 한국정밀공학회지
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• 제22권1호
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• pp.61-72
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• 2005

In this paper, we develop anti-sway control in proposed techniques for an ATC system. The developed algorithm is to build the optimal path of container motion and to calculate an anti-collision path for collision avoidance in its movement to the finial coordinate. Moreover, in order to show the effectiveness in this research, we compared NNP PID controller to be tuning parameters of controller using NN with 2 DOF PID controller. The experimental results for an ATC simulator show that the proposed control scheme guarantees performances, trolley position, sway angle, and settling time in NNP PID controller than other controller. As a result, the application of NNP PID controller is analyzed to have robustness about disturbance which is wind of fixed pattern in the yard. Accordingly, the proposed algorithm in this study can be readily used for industrial applications

• 한국철도학회:학술대회논문집
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• 한국철도학회 2010년도 춘계학술대회 논문집
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• pp.1118-1125
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• 2010

This paper presents the methods to acquire the Safety Certificate from Independent Safety Assessment based on the IEC standard62279 which is commonly applied to railway system for Automatic Train Control(ATC) system in accordance with Urban Maglev project. This also shows approach methods and relative activities for project life-cycle to accomplish and ensure the system requirements of ATC system, RAMS and S/W quality activities. Furthermore, the key tasks conducted with ISA are noted in detail. These kind of activities for software quality of ATC system to obtain Safety Certificate could be a CASE model to improve the quality of domestic railway system and products, and also contribute to the growth of railway business and toward the achievement of overseas' railway signaling markets.

• 전기학회논문지
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• 제57권5호
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• pp.797-802
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• 2008

High Speed Rail Train Control System consists of CTC, IXL and ATC. IXL and ATC perform train control and command via interchanging relevant information between a signal room and CTC. However, it is proved that IXL and ATC are attributed to train delay error since those systems are highly sensitive to trackside conditions. Especially, network error on IXL blocks transmitting signal information to adjacent signal room so that its effects give rise to system overall problems. In order to figure out the measures for which minimizing the occurrence rate of train delay error due to HSR TCS, This paper is performed analysis on communication network structure, the length of SSI network roof and SSI-TFM distance by examining and analyzing the error cases related to IXL in a network aspect.

• 약학회지
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• 제56권3호
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• pp.164-172
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• 2012

This study was aimed to increase the solubility, dissolution and permeation rates of atorvastatin calcium (ATC) using bile salt and/or 2-hydroxypropyl-${\beta}$-cyclodextrin ($HP{\beta}CD$). From solubility studies, sodium deoxycholate (SDC) among bile salts studied was found to have the highest solubilizing effect on ATC ($4.4{\pm}0.4$ mg/ml), and the order of increasing solubility was SDC>sod. cholate>sod. glycocholate>sod. taurodeoxycholate>sod. taurocholate>conjugated bile acid. ATC solid dispersions were prepared at various ratios of drug to SDC and/or $HP{\beta}CD$, and evaluated by differential scanning calorimetry (DSC), dissolution studies and dissolution-permeation studies. DSC curves showed amorphous state of ATC in the physical mixture and solid dispersion. Dissolution rates of ATC-SDC solid dispersions and physical mixture were markedly increased at pH 6.8, but decreased at pH 1.2 with greater proportions of SDC due to the precipitation of SDC, compared with that of drug alone. On the other hand, dissolution rates of ATC-$HP{\beta}CD$ solid dispersion and physical mixture at pH 1.2 were varied with the ratio of drug to carriers. From duodenal permeation studies, it was found that fluxes of ATC (donor dose: 0.5 mg/3.5 ml) in the presence of 25 mM sodium glycocholate, SDC, sod. cholate and sod. taurocholate $(5.7{\pm}0.9$, $5.6{\pm}0.9$, $4.8{\pm}0.7$ and $4.6{\pm}0.9\;{\mu}g/cm^2/hr$, respectively) were enhanced, compared with drug alone ($3.4{\pm}0.9\;{\mu}g/cm^2/hr$). In the dissolution-permeation studies, 1 : 9 : 10 (w/w) ATC-SDC-$HP{\beta}CD$ solid dispersion increased the flux 2.2 times, compared with 1 : 5 : 4 (w/w) ATC-lactose-corn starch mixture as control. In conclusion, solid dispersions with bile salt and $HP{\beta}CD$ were found to be an effective means for increasing the dissolution and permeation rates of ATC.

• Journal of information and communication convergence engineering
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• 제7권1호
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• pp.78-85
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• 2009

In order to increase system capacity and reduce the transmitting power of the user's equipment, we propose an advanced power control scheme consisting of a modified open-loop power control (OLPC) and closed-loop power control (CLPC) for land mobile satellite communication systems. The improved CLPC scheme, combining delay compensation algorithms and pilot diversity, is mainly applied to the ancillary terrestrial component (ATC). ATC link in urban areas, because it is more suitable to the short round-trip delay (RTD).

• 한국철도학회논문집
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• 제3권3호
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• pp.154-160
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• 2000

The automatic/driverless operation which are great important techniques in metro railway are required to increase higher safety, greater reliability, and transport capacity. To satisfy such demands, we must have the system design and testing technique for the railway system operation. These techniques are related to the onboard train control and communication systems which include TCMS(Train Control and Monitoring System), ATO(Automatic Train Operation), ATC(Automatic Train Control), and TWC(Train to Wayside Communication). These sub-systems must be interfacing with not only each others but also the signal system on the ground. We tested the train control system on Test line that has been developed on the basis of the standardized type EMU for korea railway systems. This test line which is located in Sangju, have been constructed for testing 7 ＆ 8 line of Seoul Metro railway.

• 한국항공우주학회지
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• 제41권4호
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• pp.305-313
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• 2013

본 논문에서는 항공관제사의 훈련을 위한 시뮬레이터를 개발하였다. 이를 위해 항공관제 시스템의 구성을 분석하여 훈련용 시뮬레이터가 만족해야 할 요구조건을 도출하였으며, 그 결과는 시뮬레이터 설계에 반영되었다. 훈련용 시뮬레이터는 조종사 인터페이스, 항공기, 레이더의 세 가지 모듈로 구성되어 있으며, 각 모듈들은 요구사항에서 도출된 알고리듬의 확장성, 편의성, 실시간성, 운용범위 등을 기준으로 엄격한 단위시험과 통합시험을 수행하였다. 최종적으로 개발된 시뮬레이터는 관제사가 항공기 관제를 위해 운용하는 관제시스템과 연동이 가능하며, 관제사의 요구에 따라 항공기 500대와 레이더 30대를 운용할 수 있으며, 확장성을 위해 최대 1200대 항공기를 운용할 수 있도록 설계되었다.

• 한국산학기술학회논문지
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• 제10권12호
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• pp.3594-3599
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• 2009

경부고속선에서 사용하는 열차제어시스템은 ATC, IXL, CTC로 분류되며, 열차 속도 제어 및 간격 제어에 관련된 ATC 정보는 UM71 AF 궤도회로와 BSP Loop를 통해 지상에서 차상으로 전송된다. 궤도회로를 통해 전송되는 정보는 주로 열차 운행에 직접적인 영향을 주는 운영 정보로 구성된다. 특히 BSP Loop를 통해 전송되는 정보는 터널, 차축온도 검지장치, 또는 절연구간과 같이 특수한 선로변 환경에 대해 추가적인 정보 전송을 필요로 하는 구간에서 사용된다. 본 논문에서는 경부고속선 개통 이후부터 현재까지 기존선과 고속선 연결 구간에서 주로 사용되는 UM71 AF 궤도회로의 BA형 동조 유니트 특성을 기준값과 측정값을 비교하여 분석하였다. 이러한 분석을 통해 BA형 동조 유니트가 설치된 구간의 궤도회로 장애와 같은 문제 발생시 원인규명 및 유지보수를 보다 쉽게 이룰 수 있을 것이다.

• 한국철도학회논문집
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• 제13권4호
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• pp.412-418
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• 2010

본 논문에서는 최근 들어 철도신호시스템분야에서 중요한 이슈로 부각되고 있는 소프트웨어 측면에서의 신뢰성과 안전성 수준을 국제규격(IEC 62279)에 부합할 수 있도록 하기 위한 접근방법을 모색하며, 실제 적용사례(국토해양부 및 한국건설교통기술평가원이 주관하는 국가 대형연구개발 실용화 사업인 "도시형 자기부상열차 실용화사업 시범노선 건설 열차제어시스템 구매/설치")를 통하여 현실적이고 접근가능한 구체적인 활동 사항들을 프로젝트 수행과 연관하여 기술한다. 또한 열차제어시스템의 안전성 인증 획득을 위한 소프트웨어를 포함한 시스템 보증활동 및 시스템 보증을 위한 조직체계를 확립하고, 요구사항 관리 및 프로젝트 공정에 따른 절차적 시스템 보증 활동과 안전성평가 활동과의 연관관계, 시스템 전반에 걸친 RAMS 및 소프트웨어 품질보증 활동과 안전성 평가를 통한 인증활동에 대한 부분을 상세 제시하고자 한다. 본 활동을 통하여 지금까지 국제규격에 따른 활동기준에 대해서 모호하거나, 명확하게 정의되지 않은 사항들이 체계적으로 정리될 수 있을 것으로 사료되며, 타 사업 및 국내 철도신호시스템 적용을 위한 소프트웨어 품질 및 안전 무결성 수준 확보에 따른 안전성 확보방안의 구체적인 케이스 모델이 될 것으로 기대된다.