• Journal of Institute of Control, Robotics and Systems
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• v.11 no.7
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• pp.633-643
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• 2005

An unmanned aerial vehicle (UAV) is an aircraft controlled by .emote commands from ground station and/o. pre-programmed onboard autopilot system. A navigation system in the UAV provides a navigation data for a flight control computer(FCC). The FCC requires accurate and reliable position, velocity and attitude information for guidance and control. This paper proposes an ADGPS/INS integrated navigation system for a UAV. The proposed navigation system comprises an attitude determination GPS (ADGPS) receive., a navigation computer unit, and a low-cost commercial MEMS inertial measurement unit(IMU). The navigation algorithm contains a fault detection and isolation (FDI) function fur integrity. In order to evaluate the performance of the proposed navigation system, two flight tests were preformed using a small aircraft. The first flight test was carried out to confirm fundamental operation of the proposed navigation system and to check the effectiveness of the FDI algorithm. In the second flight test, the navigation performance and the benefit of the GPS attitude information were checked in a high dynamic environment. The flight test results show that the proposed ADGPS/INS integrated navigation system gives a reliable performance even when anomalous GPS data is provided and better navigation performance than a conventional GPS/INS integration unit.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.06a
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• pp.1234-1239
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• 2000

KOMPSAT-1(Korea Multi-Purpose Satellite), which opened the space era in Korean peninsula, was developed from 1994 and launched successfully in December of 1999 at VAFB, USA. This paper presents a launch environment test of KOMPSAT and a short description of environment test facilities at Korea Aerospace Research Institute as well. The launch environment tests of KOMPSAT-1 satellite, such as vibration, acoustic, pyro-shock and mass properties measurement test, were performed during its system integration and test period. The participating engineers concluded that KOMPSAT-1 satellite would withstand environment during its launch period.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.1821-1828
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• 2010

In this study we suggest a method of optimization of verification hierarchy structure and system requirements management by using a verification matrix with traceability consideration. Verification items were gathered in the process of CDR(Critical Design Review), and analyzed with respect to requirements traceability structure. Missed or overlapped items were adjusted, and cross-correlated items between sub-systems were clustered and rearranged in order to structurize verification requrements (VRs). Those VRs are to be used as a guideline for the test and evaluation planning, development of test items and procedure, and system requirements management throughout the system integration stages.

• Journal of the Korea Institute of Military Science and Technology
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• v.17 no.1
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• pp.135-141
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• 2014

In order to guide a flying object which uses a seeker(SKR) and an inertial navigation system(INS) properly, we should confirm that axes of both equipments are aligned in the scope expected. In this paper we have proposed a method to measure the misaligned angle between a SKR and an INS during the system integration procedure. And we expanded this method to measure misalignments between several SKRs and an INS in case of captive flight test.

• Journal of Korean Academy of Nursing
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• v.51 no.3
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• pp.294-304
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• 2021

Purpose: This study aimed to investigate objectively measured physical activity (PA) in institutionalized older adults with mild cognitive impairment (MCI) and to elucidate the influence of autonomic nervous function, salivary cortisol, and PA on cognitive functions based on neurovisceral integration model. Methods: Overall cognitive function was evaluated using the mini-mental state examination (MMSE) and executive function was evaluated using semantic verbal fluency test and clock drawing test. Actigraph for PA, HRV and sAA for autonomous function, and the geriatric depression scale for depression were used. Saliva specimens were collected in the morning for sAA and cortisol. Results: Ninety-eight older adults from four regional geriatric hospitals participated in the study. They took 4,499 steps per day on average. They spent 753.93 minutes and 23.12 minutes on average in sedentary and moderate-to-vigorous activity, respectively. In the multiple regression analysis, lower salivary cortisol level (β = - .33, p = .041) and greater step counts (β = .37, p = .029) significantly improved MMSE score. Greater step count (β = .27, p = .016) also exerted a significant influence on verbal fluency, and greater sAA (β= .35, p = .026) was significantly associated with a better clock drawing test result. Conclusion: Salivary cortisol, sAA and physical activity were significantly associated with cognitive functions. To prevent older adults from developing dementia, strategies are needed to increase their overall PA amount by decreasing sedentary time and to decrease salivary cortisol for cognitive function, and to maintain their sympathetic nervous activity for executive function.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.35 no.3
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• pp.260-267
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• 2007

GPS adapter kit (GAK) is a GPS/INS guided range extension system to improve the accuracy and availability of existing dumb bombs. In this paper, a van test result of GPS/INS navigation module (NM) for guided bomb with GAK has been presented. The NM consists of a commercial MEMS IMU, embedded GPS receiver and navigation computer unit (NCU). The GPS receiver of NM was designed to use multiple antennas for satellite visibility and GPS attitude determination. The real-time navigation software was designed by modularized structure to guarantee the maintainability and extensibility. In order to evaluate the performance of the NM, a van test was preformed by using a high performance INS - Honeywell H-726 MAPS(Modular Azimuth Position System).The van test results show that the GAK NM with GPS attitude measurement gives better navigation performance than a conventional GPS/INS integration and good coasting capabilities under jamming environment.

• Aerospace Engineering and Technology
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• v.2 no.2
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• pp.76-82
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• 2003

To guarantee the proper functions of a satellite in the extreme space environment, the several test models are developed generally. There are advantages that the design and the analysis of Flight Model(FM) can be validated through these test models, and the functional reliabilities can be increased by reflecting the modifications on the final design of FM. The integration and test of Structure & Thermal Model(STM) of KOMPSAT, being currently developed, have been completed. In this paper, the processes of design and analysis of the STM propulsion system, one of the KOMPSAT modules, are described.

• ETRI Journal
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• v.36 no.2
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• pp.301-308
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• 2014

Three-dimensional integration technology results in area savings, platform power savings, and an increase in performance. Through-silicon via (TSV) assembly and manufacturing processes can potentially introduce defects. This may result in increases in manufacturing and test costs and will cause a yield problem. To improve the yield, spare TSVs can be included to repair defective TSVs. This paper proposes a new built-in self-test feature to identify defective TSV channels. For defective TSVs, this paper also introduces dynamic self-repair architectures using code-based and hardware-mapping based repair.

• Korean Journal of Computational Design and Engineering
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• v.20 no.2
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• pp.145-158
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• 2015

ISO 15926 is an international standard for the sharing and integration of plant lifecycle information. Plant design data consist of logical configuration, equipment specifications, 2D piping and instrument diagrams (P&IDs), and 3D plant models (shape data). Although 3D computer-aided design (CAD) data is very important data across the plant lifecycle, few studies on the exchange of 3D CAD data using ISO 15926 have been conducted so far. For this, we analyze information requirements regarding plant 3D design in the process industry. Based on the analysis, ISO 15926 templates are defined for the representation of constructive solid geometry (CSG) - based 3D design data. Since system environments for 3D CAD modeling and Semantic Web technologies are different from each other, we present system architecture for processing and visualizing plant 3D design data in the Web Ontology Language (OWL) format. Through the visualization test of ISO 15926-based 3D design data for equipment with a prototype system, feasibility of the proposed method is verified.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2004.02a
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• pp.82-94
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• 2004

This paper addresses solutions to the challenges of carrier phase integer ambiguity resolution and cycle slip detection/identification, for maintaining high accuracy of an integrated GPS/Pseudolite/INS system. Such a hybrid positioning and navigation system is an augmentation of standard GPS/INS systems in localized areas. To achieve the goal of high accuracy, the carrier phase measurements with correctly estimated integer ambiguities must be utilized to update the system integration filter's states. The occurrence of a cycle slip that is undetected is, however, can significantly degrade the filter's performance. This contribution presents an effective approach to increase the reliability and speed of integer ambiguity resolution through using pseudolite and INS measurements, with special emphasis on reducing the ambiguity search space. In addition, an algorithm which can effectively detect and correct the cycle slips is described as well. The algorithm utilizes additional position information provided by the INS, and applies a statistical technique known as the cumulative-sum (CUSUM) test that is very sensitive to abrupt changes of mean values. Results of simulation studies and field tests indicate that the algorithms are performed pretty well, so that the accuracy and performance of the integrated system can be maintained, even if cycle slips exist in the raw GPS measurements.