• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.606-608
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• 2017

The computational fluid analysis was carried out to investigate structural stability of exhaust duct for turboprop engine. In order to calculate the thrust and shear force acting on the flight condition of the aircraft, the flow in the exhaust duct and the flow in the direction of the exhaust duct flange were analyzed by Fluent software to obtain thrust, shear force and bending moment. As a result of the analysis, it was confirmed that the allowable loads set idle engine manual were not exceeded.

• Journal of the Korea Institute of Military Science and Technology
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• v.6 no.1
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• pp.49-58
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• 2003

Compared with generic GPS receiver, post-processing software GPS receiver has many advantages for high dynamic vehicle tracking. It has the advantage of the application of various tracking algorithms and aiding schemes. The post-processing system observes the carrier phase measurement data from the recorded GPS signals, detects and isolates the cycle slip. The observed carrier phase data and the raw data of the reference station are processed by carrier phase DGPS scheme. And the integer ambiguity resolution algorithm is used for resolving single frequency carrier phase ambiguity. The results of static and real flight test are presented and show that the proposed GPS translator processing system satisfies submeter accuracy.

• Proceedings of the Korea Information Processing Society Conference
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• 2015.10a
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• pp.290-292
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• 2015

인공위성을 제어하기 위한 원격명령에는 실시간 명령과 저장명령으로 구분할 수 있다. 실시간 명령은 위성에서 명령을 수신하고 바로 수행하는 명령을 말하고, 저장명령은 특정한 시간에 수행하는 절대시간 명령과 정해진 시간간격에 따라 일련의 명령들을 수행하는 상대시간 명령으로 구분할 수 있다. 상대시간 명령은 위성 운영 시 필요한 명령들을 위성에 업로드 하여 사용할 수도 있지만, 위성 발사 전에 정해진 명령 시퀀스는 위성 비행소프트웨어에 포함하여 비휘발성 메모리에 저장하여 사용한다. 명령시퀀스는 정해진 포맷에 따라 DB 파일로 정리되는데, 위성 비행소프트웨어에 포함하기 위한 헤더 생성프로그램이 필요하다. 본 논문은 위성 원격명령 처리방식에 대해서 소개하고, 저장명령 데이터 파일을 이용하여 위성에 저장하기 위한 헤더파일을 자동 생성하는 프로그램에 대해서 기술한 것이다.

• Proceedings of the Korea Information Processing Society Conference
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• 2013.11a
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• pp.1070-1073
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• 2013

위성 비행 소프트웨어의 개발 과정에는 소프트웨어의 신뢰성을 향상하기 위한 다양한 검증 활동이 이루어진다. 이러한 검증 활동에는 효율적으로 설계된 검증 환경이 필수적이다. 위성 비행 소프트웨어 개발 전반에 검증 환경을 효과적으로 적용하기 위해서는 사용 가능한 검증 환경이 보다 빠르게 구현되어야 한다. 검증 환경은 개념적으로 궤도 상의 위성과 통신하는 지상 시스템의 역할을 기본으로 하고 있으므로 Command 송신과 Telemetry 수신을 위성 비행소프트웨어와의 상호 작용으로 정의할 수 있다. 따라서 위성 비행소프트웨어의 동작을 Command와 Telemetry 관점에서 모델링하고 이를 모사하는 시스템을 이용함으로써 위성 개발 초기부터 위성 비행 소프트웨어 검증 환경 구현에 사용할 수 있고, 또한 위성 개발 과정에서 발생하는 다양한 변경 사항을 보다 효과적으로 반영할 수 있다. 본 논문에서는 위성 비행 소프트웨어의 검증 환경 구현을 위한 Command Telemetry Simulator의 설계 및 그 구현에 대하여 소개한다.

• Proceedings of the Korean Society of Computer Information Conference
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• 2021.07a
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• pp.271-272
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• 2021

본 논문에서는 Gazebo 시뮬레이터 기반 UAV 군집 시뮬레이션 구현 및 비행 고도 계층화를 구현한 결과를 보인다. Gazebo 시뮬레이션과 Autopilot Program인 Pixhawk4 SITL(Software In The Loop)을 이용하여 UAV를 시뮬레이터에 생성한 뒤 사전에 정의된 Mission에 대한 정보에 따라 비행이 되도록 구현하였다. 또한, Gazebo 시뮬레이터의 Box Object를 이용하여 UAV의 비행 고도를 시각적으로 계층화하여 표현하였다.

• Advances in aircraft and spacecraft science
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• v.10 no.6
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• pp.545-554
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• 2023

The widespread introduction of unmanned aircrafts has led to the understanding of the need to organize a common information space for manned and unmanned aircrafts, which is reflected in the Russian Unmanned aircraft system Traffic Management (RUTM) project. The present article deals with the issues of spatial information database (DB) organization, which is the core of RUTM and provides storage of various data types (spatial, aeronautical, topographical, meteorological, vector, etc.) required for flight safety management. Based on the analysis of functional capabilities and types of work which it needs to ensure, the architecture of spatial information DB, including the base of source information, base of display settings, base of vector objects, base of tile packages and also a number of special software packages was proposed. The issues of organization of these DB, types and formats of data and ways of their display are considered in detail. Based on the analysis it was concluded that the optimal construction of the spatial DB for RUTM system requires a combination of different model variants and ways of organizing data structures.

• Proceedings of the Korea Information Processing Society Conference
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• 2007.11a
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• pp.1040-1041
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• 2007

본 논문은 차세대 위성 개발을 위한 선행 연구의 일환으로, 다양한 플랫폼에 적용할 수 있는 위성 전자 전산 시스템 개발 검증 장비의 구성 요소인 상/하향 명령 처리 장치를 PC 에서 구동할 수 있도록 개발한 것이다. 이 PC 기반의 상/하향명령처리 시험환경은 위성의 Flight Software 로직의 검증용으로도 활용될 수 있다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.42 no.5
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• pp.406-414
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• 2014

In this paper, it is introduced characteristics of FMCW-type Radar Altimeter for KUH, and its defects occurred during ground/flight test in initial product phase. In addition, it is also described 'data/control flow model' based fault analysis results of S/W and processes of verifying improvement design through flight test as well as aircraft system integration test called MEP SIL. As a result of design improvement and verification, it is validated that settling the defects and improving not only safety but also capability of the KUH.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2017.04a
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• pp.45-45
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• 2017

On-site monitoring of vegetable growth parameters, such as leaf length, leaf area, and fresh weight, in an agricultural field can provide useful information for farmers to establish farm management strategies suitable for optimum production of vegetables. Unmanned Aerial Vehicles (UAVs) are currently gaining a growing interest for agricultural applications. This study reports on validation testing of previously developed vegetable growth estimation models based on UAV-based RGB images for white radish and Chinese cabbage. Specific objective was to investigate the potential of the UAV-based RGB camera system for effectively quantifying temporal and spatial variability in the growth status of white radish and Chinese cabbage in a field. RGB images were acquired based on an automated flight mission with a multi-rotor UAV equipped with a low-cost RGB camera while automatically tracking on a predefined path. The acquired images were initially geo-located based on the log data of flight information saved into the UAV, and then mosaicked using a commerical image processing software. Otsu threshold-based crop coverage and DSM-based crop height were used as two predictor variables of the previously developed multiple linear regression models to estimate growth parameters of vegetables. The predictive capabilities of the UAV sensing system for estimating the growth parameters of the two vegetables were evaluated quantitatively by comparing to ground truth data. There were highly linear relationships between the actual and estimated leaf lengths, widths, and fresh weights, showing coefficients of determination up to 0.7. However, there were differences in slope between the ground truth and estimated values lower than 0.5, thereby requiring the use of a site-specific normalization method.

• KIPS Transactions on Software and Data Engineering
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• v.3 no.12
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• pp.523-530
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• 2014

Ontology alignment is the way to share and reuse of ontology knowledge. Because of the ambiguity of concept, most ontology alignment systems combine a set of various measures and complete enumeration to provide the satisfactory result. However, calculating process becomes more complex and required time increases exponentially since the number of concept increases, more errors can appear at the same time. Lately the focus is on meta-matching using the heuristic algorithm. Existing meta-matching system tune extra parameter and it causes complex calculating, as a consequence, the results in the various data of specific domain are not good performed. In this paper, we propose a high performance algorithm by using DCS that can solve ontology alignment through simple process. It provides an efficient search strategy according to distribution of Levy Flight. In order to evaluate the approach, benchmark data from the OAEI 2012 is employed. Through the comparison of the quality of the alignments which uses DCS with state of the art ontology matching systems.