• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.9
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• pp.1220-1227
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• 2018

Avionics electronic equipment refers to the electronic equipment installed on an aircraft. Failure of avionics equipment can have a significant impact on aircraft operations as well as threaten the safety of pilots and passengers. Therefore, avionics electronic equipment is required to have higher reliability and safety than electronic equipment used for other purposes. Avionics equipment must consider various component selection and system design to meet reliability and safety-related requirements from the initial design stage. In this paper, we describe safety, reliability performance analysis method of avionics equipment, and introduce various design improvement methods that can be performed to meet safety requirement performance. Finally, the safety performance of the improved avionics equipment was reanalyzed and compared with the value before the improvement, the validity of the proposed design change was verified.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.3
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• pp.425-433
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• 2018

In this paper, we propose a super-resolution reconstruction algorithm for plenoptic images based on the reliability of disparity. The subperture image generated by the Flanoptic camera image is used for disparity estimation and reconstruction of super-resolution image based on TV_L1 algorithm. In particular, the proposed image reconstruction method is effective in the boundary region where disparity may be relatively inaccurate. The determination of reliability of disparity vector is based on the upper, lower, left and right positional relationship of the sub-aperture image. In our method, the unreliable vectors are excluded in reconstruction. The performance of the proposed method was evaluated by comparing to a bicubic interpolation method, a conventional disparity based method and dictionary based method. The experimental results show that the proposed method provides the best performance in terms of PSNR(Peak Signal to noise ratio), SSIM(Structural Similarity).

• Journal of KIISE:Computing Practices and Letters
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• v.16 no.9
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• pp.898-903
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• 2010

Popularity of smartphones such as Google Android phones and Apple iphones, is increasing the demand on more reliable high performance file system for flash memory. In this paper, we propose two techniques to improve the performance of YAFFS (Yet Another Flash File System), while enhancing the reliability of the system. Specifically, we first propose to manage metadata and user data separately on segregated blocks and indexing information piggy-back technique for reducing mount time and also enhancing performance. Second, we tailor the wear-leveling to the segregated metadata and user data blocks. Performance evaluation results based on real hardware system with 1GB NAND flash memory show that the YAFFS with our proposed techniques realized outperforms the original YAFFS by six times in terms of mount speed and five times in terms of benchmark performance, while reducing the average erase count of blocks by 14%.

• Journal of Advanced Navigation Technology
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• v.27 no.1
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• pp.126-132
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• 2023

Object recognition is a technology that detects and identifies various objects in images and videos. LBP is a descriptor that operates robustly to illumination variations and is actively used in object recognition. LBP considers the range of neighboring pixels, the order of combining the neighbors after the comparison operation, and the starting position of combining. In particular, the starting position of the LBP becomes the "most significant bit"; it dramatically affects the performance of object recognition. In this paper, based on the N starting positions, the data most similar to the input data are searched in each of the N feature spaces. Object recognition is performed by the confidence measure that can compare different results of each feature space under the same criterion and select the most reliable result. In the experimental results, it was confirmed that there is a difference in performance depending on the starting position of LBP. The proposed method showed a high performance of up to 12.66% compared to the recognition performance of the existing LBP.

• Journal of the Korean Institute of Gas
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• v.27 no.4
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• pp.27-33
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• 2023

In a petrochemical plant, various mechanical equipments and structures are interconnected to ensure operability. Since the production activities of petrochemical plants have a great impact on the national economy, it is very important to maintain not only structural safety but also the operability of the facilities. However, the current seismic design standards present the design requirements of facilities mainly aimed at preventing collapse, and do not provide the requirements for securing operability of facilities. Depending on the behavioral characteristics of the facility, operability of the facility can be secured by seismic performance levels other than the collapse prevention level, so it is necessary to present seismic design methods that can apply various seismic performance levels. Spherical (ball) storage tanks are supported by columns and braces and exhibit complex nonlinear behavior because of buckling and yielding of support members. In this study, nonlinear seismic behavior characteristics were statistically analyzed and a new performance-based seismic design method was proposed based on them.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.5
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• pp.475-482
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• 2014

The precision hydraulic valve is widely used in various industrial field like aircraft, automobile, and general machinery. Servo actuator is the most important device for driving the precise hydraulic valve. The reliable operation of servo actuator effects on the overall hydraulic system. The performance of servo actuator relies on frequency response and step response according to arbitrary input signal. In this paper, we performed the analysis for the components of servo actuator to satisfy the reliable operation and response characteristics through the reliability analysis, and also induced the design parameters to realize the reliable operation and fast response characteristics of servo actuator for hydraulic valve operation through the empirical knowledge of experts and electromagnetic theories. We suggested the design equations to determine the values of design parameters of servo actuator as like bobbin size, length of yoke and plunger and turn number of coil, and verified the achieved design values through FEM analysis and performance tests using some prototypes of servo actuators adapted in hydraulic valve.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.11B
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• pp.1685-1695
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• 2010

In this paper, we propose a new reliable multicast MAC protocol over the IEEE 802.11-based tactical ad hoc networks. The major contribution compared to the previous reliable multicast schemes using consecutive CTSs/ACKs is that the proposed scheme can send multiple CTS/ACK messages concurrently assisted by MC-DS/CDMA mechanisms. When multiple receivers receive the RTS/DATA message from a sender, they respond with the CTS/ACK message spread with pre-assigned code in the same time interval. The proposed scheme can reduce the overhead of multiple CTSs/ACKs. It is also possible to alleviate the received signal strength at the enemy detector and thus it improves low probability of detection performance. Through simulations and analysis, the proposed scheme outperforms that of the multiple CTSs/ACks in terms of the throughput, transmission delay and low probability of detection.

• Journal of Convergence for Information Technology
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• v.8 no.6
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• pp.173-186
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• 2018

While cloud services are expanding, many users are having difficulty in adopting cloud services. This is because there is no information as to which cloud services can be trusted by users. loud service level agreement (Cloud SLA) is an agreement between cloud service providers and cloud service consumers using qualitative and quantitative indicators including quality and performance, etc. of cloud services. In this study, we propose a framework for cloud SLA that can be applied to the domestic cloud industry to improve service levels for cloud service providers and to protect users and also derive the detailed components of cloud SLA applicable to the domestic cloud industry using the proposed framework. Through this result, it is expected that the government will utilize the policy to enhance the reliability between cloud service providers and users under "the Act on the Development of Cloud Computing and Protection of Users", and eventually to activate cloud services by improving the quality and performance level of domestic cloud services and building a user trust.

• Proceedings of the Korean Information Science Society Conference
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• 2003.04d
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• pp.10-12
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• 2003

GridFTP는 광대역의 WAN 상에 최적화된 고성능의 안전하고 신뢰할 수 있는 데이터 전송 프로토콜이다. 본 논문에서는 다음과 같은 세가지 측면에서 GridFTP의 성능 향상을 도모하였다. 1) GridFTP 서버 측에서는 성능 향상을 위해 커먼드 파이프라이닝 기법을 제시하고, 2) GridFTP 클라이언트 측에서는 데이터 채널 재사용 기법을 제안하며. 3) GridFTP 프로토콜은 third-party maltitransfer 메커니즘을 지원하기 위하여 수정이 이루어겼다. 이러한 성능 향상 기법을 통하여 그리드 상에서 대규모 데이터의 효율적인 전송이 가능할 것으로 판단된다.

• Annual Conference on Human and Language Technology
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• 2015.10a
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• pp.23-28
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• 2015

본 논문에서는 한국어 트리플 생성 시스템의 정확도를 향상시키기 위한 distant supervision 기반의 신뢰도 측정 방법을 제안한다. 기존의 많은 패턴 기반의 트리플 생성 시스템에는 distant supervision의 기본 가정으로 인해 다수의 오류 패턴이 발생할 여지가 크다. 기존의 연구에서는 오류 패턴을 제거하기 위하여 발생 빈도, 공기 횟수 등의 통계에 기반하여 간접적으로 신뢰도를 측정하였다. 본 논문에서는 한국어 패턴과 영어 프로퍼티 사이의 의미 유사도를 측정함으로써 통계에 기반한 방법보다 더 정확한 신뢰도 측정 방법을 제안한다. 비지도 학습 방법인 워드임베딩을 활용하여 어휘의 의미를 학습하고, 이들 사이의 유사도를 측정한다. 한국어 패턴과 영어 프로퍼티의 어휘 불일치 문제를 해결하기 위하여 정준상관분석을 활용하였다. 실험 결과에 따르면 본 논문에서 제안한 패턴 신뢰도 측정 방법은 통계 기반의 방법에 비해 정확률이 9%나 더 높은 트리플 집합을 생성함을 보여주어, 의미 유사도를 반영한 신뢰도 측정이 기존의 통계 기반 신뢰도 측정보다 고품질 트리플 생성에 더 적합함을 확인하였다.