• Journal of Advanced Navigation Technology
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• v.7 no.2
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• pp.135-141
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• 2003

During flight the analysis of aircraft data recorded has played an important role in determining the causes of accidents. However, using the QAR, recently some airlines have begun to analyze flight data from uneventful airline flights to identify potential problems and correct them before they lead to accident. This paper, after the flight using the recorded data in QAR, proposes an estimated method which determines CL/CD values. The generalized aircraft dynamic equations were expressed as an estimated equation, which verified the effectiveness with simulation. The results of the present method showed that the understand of variation values of CL/CD is of great use for performance enhancement.

• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.2
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• pp.335-342
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• 2020

ESS(Environmental Stress Screening) is an important production process to remove 'latent defects' introduced in the production of products. Recently, ESS is included in QAR(Quality Assurance Report) as an essential quality assurance requirement for products in the defense business. However, depending on the author of the QAR or the classification of the weapon system, it is often identified that the content and form are different or important elements are omitted. Therefore, this paper proposes a MIL-HDBK-344A based quantitative ESS requirement standard to secure the consistency and completeness of QAR. and to make easier to calculate PE(Precipitation Efficiency), which is an indicator for identifying the latent defects elimination effect.

• Journal of the Korean Society of Earth Science Education
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• v.9 no.2
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• pp.123-138
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• 2016

The purpose of this study is to examine the effects of applying the Question-Answer Relationship (QAR)strategy on the attitude toward science of the elementary fifth grade students whose learning styles have beenidentified. The population of the study constitutes the total of 97 elementary fifth grade students who wereassigned into a comparison (n=48) or experimental group (n=49). To understandhow the QAR strategy potentially influencedscientific attitude, both groups were surveyedin the areas of scientific attitude before and after the experiment. TheKolb's Test was used to identifythe students' learning stylein the experimental group. According tothe learners' learning style, the results have been compared and analyzed. The results of this study are as follows:First, the findings revealed a significant difference in the experimental group students' attitude toward sciencecompared to the comparison group. Second, four learning styles were identified among the studentsin theexperimental group: a) Accommodators (46.9%), b) Convergers (24.5%), c) Divergers (20.4%), and d) Assimilator (8.2%). Following the data analysis, there was no meaningful statistical difference between four groups oflearning styles with respect to their scientific attitude.Applyingthe QAR strategy in a science class seemed toimprove the accommodators, convergers, and divergers' scientific attitude positively.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.26 no.4
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• pp.36-42
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• 2018

Although continuous passenger injuries and physical damages are repeated due to the unexpected aviation turbulence encountered during operations, there is still exist the limitation for preventing recurrence of similar events because the lack of real-time information and delay in technological developments regarding various operating conditions and variable weather phenomena. The purpose of this study is to compare and analyze the meteorological data of the aviation turbulence occurred and actual flight data extracted from the Quick Access Recorder(QAR) to provide some precursors that the pilot can identify aviation turbulence early by referring thru the flight instrumentation indications. The case applied for this study was recent event, a scheduled flight from Incheon Airport, Korea to Narita Airport, Japan that suddenly encountered turbulence at an altitude of approximately 14,000 feet during approach. According to the Korea Meteorological Administration(KMA)'s Regional Data Assessment and Prediction System(RDAPS) data, it was observed that the strong amount of vorticity in the rear area of jet stream, which existed near Mount Fuji at that time. The QAR data analysis shows significant changes in the aircraft's parameters such as Pitch and Roll angle, Static Air Temperature(SAT), and wind speed and direction in tens of seconds to minutes before encounter the turbulence. If the accumulate reliability of the data in addition and verification of various parameters with continuous analysis of additional cases, it can be the precursors for the pilot's effective and pre-emptive action and conservative prevention measures against aviation turbulence to reduce subsequent passenger injuries in the aviation operations.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.11 no.1
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• pp.17-25
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• 2003

본 논문은 비행 정보 등 각종 운항 자료를 보다 다양하게 분석하고, 좀더 쉽게 이해하기 위하여 시각적으로 구현할 수 있는 비행정보 분석시스템 개발에 대한 개념 설계서이다. 비행이 완료된 후, 항공기에 탑재된 비행 데이터 저장 장치(QAR, Quick Access Recorder)로부터 비행 및 관련 시스템 데이터를 추출한 후, 이 데이터를 변환한다. 또한 변환된 데이터를 이용하여 각종 비행 및 시스템 정보 분석과 운항 궤적 및 ND, PFD 등 조종실 내 운항 시스템들의 상황을 운항 시와 동일하게 3차원 그래픽으로 재현하는 시스템을 구축하였다. 이는 시스템 분석 및 안전, 표준 운항 체계 구축에 도움을 줄 수 있으며 유사 관련 분야로의 확대도 가능하다.

• Nonlinear Functional Analysis and Applications
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• v.27 no.1
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• pp.189-201
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• 2022

The aim of the current work is to investigate the numerical study of a nonlinear Volterra-Fredholm integro-differential equation with initial conditions. Our approximation techniques modified adomian decomposition method (MADM) and variational iteration method (VIM) are based on the product integration methods in conjunction with iterative schemes. The convergence of the proposed methods have been proved. We conclude the paper with numerical examples to illustrate the effectiveness of our methods.

• International Journal of Computer Science & Network Security
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• v.23 no.6
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• pp.193-201
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• 2023

In this paper, we consider the maximum scatter traveling salesman problem (MSTSP), a travelling salesman problem (TSP) variant. The problem aims to maximize the minimum length edge in a salesman's tour that travels each city only once in a network. It is a very complicated NP-hard problem, and hence, exact solutions can be found for small sized problems only. For large-sized problems, heuristic algorithms must be applied, and genetic algorithms (GAs) are found to be very successfully to deal with such problems. So, this paper develops a hybrid GA (HGA) for solving the problem. Our proposed HGA uses sequential sampling algorithm along with 2-opt search for initial population generation, sequential constructive crossover, adaptive mutation, randomly selected one of three local search approaches, and the partially mapped crossover along with swap mutation for perturbation procedure to find better quality solution to the MSTSP. Finally, the suggested HGA is compared with a state-of-art algorithm by solving some TSPLIB symmetric instances of many sizes. Our computational experience reveals that the suggested HGA is better. Further, we provide solutions to some asymmetric TSPLIB instances of many sizes.

• Nonlinear Functional Analysis and Applications
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• v.29 no.1
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• pp.113-130
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• 2024

In this work, we explore the existence and uniqueness results for a class of boundary value issues for implicit Volterra-Fredholm nonlinear integro-differential equations (IDEs) with Atangana-Baleanu-Riemann fractional (ABR-fractional) that have non-instantaneous multi-point fractional boundary conditions. The findings are supported by Krasnoselskii's fixed point theorem, Gronwall-Bellman inequality, and the Banach contraction principle. Finally, a demonstrative example is provided to support our key findings.

• Journal of IKEEE
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• v.18 no.1
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• pp.165-171
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• 2014

This paper presents a low complexity QR decomposition (QRD) architecture for MIMO detector. In the proposed approach, various CORDIC-based QRD algorithms are efficiently combined together to reduce the computational complexity of the QRD hardware. Based on the computational complexity analysis on various QRD algorithms, a low complexity approach is selected at each stage of QRD process. The proposed QRD architecture can be applied to any arbitrary dimension of channel matrix, and the complexity reduction grows with the increasing matrix dimension. Our QR decomposition hardware was implemented using Samsung $0.13{\mu}m$ technology. The numerical results show that the proposed architecture achieves 47% increase in the QAR (QRD Rate/Gate count) with 28.1% power savings over the conventional Householder CORDIC-based architecture for the $4{\times}4$ matrix decomposition.

• Journal of the Korea Institute of Military Science and Technology
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• v.14 no.4
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• pp.607-614
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• 2011

This paper describes the development of pulse code modulation(PCM) data recorder with design, implementation and environmental test. PCM serial data that diverged from telemetry encoder output is used as the input and is reformed to parallel signal through FPGA processing. Controllers construct the packet by the sector and record it into non-volatile memory. Compact flash(CF) memory for data storage media, USB interface for data downloading, and a software for operating status diagnosis and file format conversion are used.