• Journal of the Institute of Electronics Engineers of Korea TC
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• v.47 no.2
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• pp.34-39
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• 2010

This paper proposes S/W Watch-Dog method between Dual CPU using the different OS. The proposed watch-dog method performs that it distinguishes the status of channel between dual CPU and status of processor itself. We find out the ideal value of threshold and priority for load test task. and we evaluate the accuracy of the proposed S/W Watch-Dog Method at the result of evaluation. We figure out that the accuracy of proposed method is higher than the accuracy of general S/W Watch-Dog Method in case of variable data rate. Therefore we confirm that the proposed Method has high accuracy of watch-dog function with the ideal value of threshold and priority for load test task through the performance evaluation.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.39 no.6
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• pp.259-267
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• 2002

In this paper, we focus on comparison and analysis of performance for existing Topology Aggregation algorithm. For these, we designed and implemented PNNI routing simulator which contain various TA schemes, and evaluate performance of TA schemes by this simulator. The PNNI 1.0 specification of the ATM Forum is recommended that hierarchical routing protocol and topology information is aggregated in the network constructed hierarchically Aggregating topology information is known as TA(Topology Aggregation) and TA is very important for scalability and security in network. Therefore, the performance of PNNI network would vary with TA schemes and routing algorithm. PNNI routing simulator can be applied to develope Routing algorithm and TA algorithm and can be develope these algorithms in short period.

• Journal of the Korean Society of Propulsion Engineers
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• v.6 no.1
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• pp.21-29
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• 2002

Hybrid propulsion systems provide many advantages in terms of stable operation and safety. However, classical hybrid rocket motors have lower fuel regression rate and combustion efficiency compared to solid propellant rocket motor. The recent research efforts are focused on the improvement of volume limitation and regression rate in the hybrid rocket engine. The present study has numerically investigated the combustion processes in the hybrid rocket engine. The turbulent combustion is represented by the eddy breakup model and Hiroyasu and Nagle and Strickland-Constable model are used for soot formation and soot oxidation. Radiative heat transfer is modeled by finite volume method. To reduce the uncertainties for convective heat transfer near solid fuel surface having strong blowing effect, the Low Reynolds number $\kappa-\varepsilon$ turbulent model is employed. Based on numerical results, the detailed discussion has been made for the turbulent combustion processes in the vortex hybrid rocket engine.

• Convergence Security Journal
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• v.21 no.2
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• pp.67-79
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• 2021

Lessons Learned(LL) is a military term defined as all activities that promote future development by finding problems and need improvement in education and reality in the field of warfare development. In this paper, we focus on presenting actual examples and applying AI analysis inference techniques to solve revealed problems in promoting LL activities, such as long-term analysis, budget problems, and necessary expertise. AI legal advice services using cognitive computing-related technologies that have already been practical and in use, were judged to be the best examples to solve the problems of LL. This paper presents intelligent LL inference techniques, which utilize AI. To this end, we want to explore theoretical backgrounds such as LL analysis definitions and examples, evolution of AI into Machine Learning, cognitive computing, and apply it to new technologies in the defense sector using the newly proposed L²-OODA ensemble algorithm to contribute to implementing existing power improvement and optimization.

• Knowledge Management Research
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• v.22 no.1
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• pp.269-286
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• 2021

As the un-tact and on-tact consumption culture has proliferated due to the impact of COVID-19, 'live commerce', a form of shopping while communicating with customers through real-time streaming broadcasting, is emerging in the commerce and distribution industry. Live commerce provides an environment where customers can get the convenience of online shopping and enjoy un-tact shopping more realistically while communicating with the broadcaster in real time, as if purchasing directly from an offline store. Therefore, purchases using live commerce are expected to increase further. In this study, based on the characteristics of live commerce, the main factors influencing the increase in purchase intention through live commerce were derived and their influences were verified. In particular, this study examined these factors in multiple dimensions with focusing on strong interactivity, realistic presence, and providing detailed reviews with high credibility for products as the features of live commerce. This research collected sample data from actual users of live commerce and empirically analyzed the significance of the factors influencing the purchase increase of live commerce, thereby providing implications for knowledge management in a newly changed commerce environment in the un-tact era.

• Journal of The Korean Association of Information Education
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• v.25 no.6
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• pp.987-994
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• 2021

Computational Thinking is an analytical thinking ability that is necessary for everyone and everywhere. The existing Computational Thinking development education provided in Practical textbooks leads to block-based programming languages from unplugged activities. Many unplugged activities focus on practicing sequential order, which may lack the learning of abstractions or automation concepts. In block-based programming languages, concepts such as coordinate planes, which are not introduced in elementary school curriculum, appear, making students feel burdened by the block-based programming language itself. In this study, a curriculum was designed for elementary student's computational thinking through game-based programming language education. The results and their effectiveness were analyzed through the beaver challenge. As a result of analyzing the pre-test and post-test scores, it was confirmed that students' computational thinking skills improved.

• Journal of Advanced Navigation Technology
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• v.27 no.4
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• pp.351-355
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• 2023

The need for Advanced LOSA arises from the limitations and drawbacks of traditional LOSA. Amended LOSA aims to address some of the shortcomings of the original methodology and make it more effective and relevant to current aviation safety needs. Some of the key reasons for developing Advanced LOSA include Enhancing the scope, Improving data collection and analysis, Providing more targeted safety recommendations. First, Traditional LOSA mainly focuses on flight deck operations, but Advanced LOSA expands the scope to include other operational areas such as cabin operations, ground handling, and maintenance. Second, Advanced LOSA can build a Forecasting System that can predict the future through data collection and data analysis. Third, Advanced LOSA aims to provide more specific and targeted safety recommendations based on the Aviation data collection and Aviation data analysis. Overall, Advanced LOSA seeks to improve aviation safety by addressing the limitations of traditional LOSA and providing a more comprehensive and effective methodology for identifying and mitigating safety risks in aviation operations.

• Journal of the Korean Geotechnical Society
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• v.22 no.5
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• pp.69-81
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• 2006

The micropile, which is a kind of the in-situ manufactured pile with small diameter of $150\sim300mm$, is constructed by installing a steel bar or pipe and injecting grout into a borehole. The application fields of micropile are being gradually expanded in a limited space of down-town area, because the micropile has various advantages with low vibration and noise in method and compact size in machine, etc. Mostly, the micropile has been applied to secure the safety of structures, depending on the increment of bearing capacity and the restraint of displacement. The micropile is expected to be used in various fields due to its effectiveness and potentiality in the future. The model test, focused on the interaction between micropile and soil in this study, was carried out. The micropile is installed in a soil adjacent to footing (concept of 'soil reinforcement'). With the test results and soil deformation analysis, the reinforcement effect (relating to bearing capacity and settlement) was analysed in a qualitative and quantitative manner, respectively. Consequently, it is expected that we nay demonstrate the improvement of an efficiency and application in the design and construction of micropile.

• Journal of the Korean Geotechnical Society
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• v.23 no.12
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• pp.109-116
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• 2007

This study has reviewed the applicability of displacement measurement by using a digital vision technique based on typical photogrammetric methods. In this study, a series of experimental measurements have been performed in order to improve the accuracy of digital vision measurement by establishing criteria of factors of various vision measurements. It is found that the digital vision measurement tends to show higher accuracy as the image size(resolution) and the focal length become larger and the distance to an object becomes closer. It is also observed that measurement error decreases with processing as many images as possible in various angles. Applicability on high-resolution displacement measurement is proved by applying the digital vision measurement developed in this study to a large scale loading test of concrete lining.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.293-293
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• 2021

자연유량이란 인위적 행위에 의한 하천의 유량 변화가 없는 개발되지 않은 상태의 하천유량을 말하며, 실제 유량을 측정하거나 관측자료를 활용한 장기유출모형을 통해 산정할 수 있다. 미계측 유역에 대한 강우-유출 모형 구축시, 무엇보다 실제 미계측유역에 적용시 나타날 수 있는 문제점을 최소화할 수 있는 방향으로 모형 개발이 이루어지는 것이 필요하다. 강우-유출 모형 매개변수의 수가 많아질수록 과적합(over-fitting)의 발생 소지가 증가하게 되며, 지역화 모형 구축시 불확실성을 더욱 가중시키게 된다. 이러한 이유로, 모형의 검정보다는 검증에 초점이 맞춰져 있어야 하며, 더불어 사용되는 강우-유출 모형의 매개변수가 적어야 한다. 본 연구에서는 대표 강우-유출모형의 선정시 여러 평가 기준 중 예측의 정확성 측면에서 통계적 지표를 통해 모형의 수행능력에 중점을 두었으며, 적은 개수의 매개변수를 갖음에도 불구하고 상대적 우수한 모의결과를 제공하는 GR4J(Ge'nie Rural a 4 parame tres Journalier)모형을 최적 유출모형으로 선정하여 댐 상류유역에 대한 자연유량 재현성능을 평가하였다. 최종적으로 강우-유출모형의 최적매개변수와 유역특성인자 사이의 상호연관성을 고려해 매개변수를 지역화하기 위하여, 본 연구에서는 두 가지 이상의 변량에 대한 상관성을 효과적으로 재현하는데 효과적이며, 자유로운 주변확률분포 선택과 결합확률분포의 추정이 용이한 장점이 있는 Copula 함수를 활용하였다. 제시된 방법론에 대한 적합성을 평가하기 위해 교차검증 관점에서 지역화된 매개변수의 적합성을 검토하였으며, 본 연구에서 도출된 결과는 유역특성에 따른 미계측유역의 자연유량 산정시 지역 매개변수를 강우-유출모형에 활용함으로써 신뢰성 있는 자연유량 산정 결과를 제공할 수 있을 것으로 판단된다.