• Title/Summary/Keyword: Training conditions

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Application of Artificial Neural Network to Predict Aerodynamic Coefficients of the Nose Section of the Missiles (인공신경망 기반의 유도탄 노즈 공력계수 예측 연구)

  • Lee, Jeongyong;Lee, Bok Jik
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.49 no.11
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    • pp.901-907
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    • 2021
  • The present study introduces an artificial neural network (ANN) that can predict the missile aerodynamic coefficients for various missile nose shapes and flow conditions such as Mach number and angle of attack. A semi-empirical missile aerodynamics code is utilized to generate a dataset comprised of the geometric description of the nose section of the missiles, flow conditions, and aerodynamic coefficients. Data normalization is performed during the data preprocessing step to improve the performance of the ANN. Dropout is used during the training phase to prevent overfitting. For the missile nose shape and flow conditions not included in the training dataset, the aerodynamic coefficients are predicted through ANN to verify the performance of the ANN. The result shows that not only the ANN predictions are very similar to the aerodynamic coefficients produced by the semi-empirical missile aerodynamics code, but also ANN can predict missile aerodynamic coefficients for the untrained nose section of the missile and flow conditions.

Estimating the workability of self-compacting concrete in different mixing conditions based on deep learning

  • Yang, Liu;An, Xuehui
    • Computers and Concrete
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    • v.25 no.5
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    • pp.433-445
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    • 2020
  • A method is proposed in this paper to estimate the workability of self-compacting concrete (SCC) in different mixing conditions with different mixers and mixing volumes by recording the mixing process based on deep learning (DL). The SCC mixing videos were transformed into a series of image sequences to fit the DL model to predict the SF and VF values of SCC, with four groups in total and approximately thirty thousand image sequence samples. The workability of three groups SCC whose mixing conditions were learned by the DL model, was estimated. One additionally collected group of the SCC whose mixing condition was not learned, was also predicted. The results indicate that whether the SCC mixing condition is included in the training set and learned by the model, the trained model can estimate SCC with different workability effectively at the same time. Our goal to estimate SCC workability in different mixing conditions is achieved.

Two-Step Neural Network Approach for Determining EDM(Electrical Discharge Machining) Parameters in Low Tool Erosion (전극 저소모 방전조건 결정을 위한 2단계 신경망 접근)

  • 이건범;주상윤;왕지남
    • Journal of the Korean Society for Precision Engineering
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    • v.15 no.7
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    • pp.44-51
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    • 1998
  • Two-step neural network is designed for determining electrical discharge machining parameters in low erosion. The first neural network, which is used as a classification network, checks whether the current conditions are appropriate to electrical discharge machining in low tool erosion. If the conditions are appropriate to EDM in low erosion, suitable EDM parameters are generated by the second neural network. Theoretically known EDM conditions are produced and also utilized for training the second neural network. The trained neural network is tested how well suitable EDM machining conditions are generated under unknown machining situations Experimental result shows that the proposed two-step neural network approach could be effectively used for determining EDM parameters in low tool erosion. The results also have a practical contribution to EDM area in that it could be applied for maintaining low tool wear as well as obtaining maximum machining rates simultaneously.

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Performance Analysis of Machine Learning Based Spatial Disorientation Detection Algorithm Using Flight Data (비행데이터를 활용한 머신러닝 기반 비행착각 탐지 알고리즘 성능 분석)

  • Yim Se-Hoon;Park Chul;Cho Young jin
    • Journal of Advanced Navigation Technology
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    • v.27 no.4
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    • pp.391-395
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    • 2023
  • Helicopter accidents due to spatial disorientation in low visibility conditions continue to persist as a major issue. These incidents often stem from human error, typically induced by stress, and frequently result in fatal outcomes. This study employs machine learning to analyze flight data and evaluate the efficacy of a flight illusion detection algorithm, laying groundwork for further research. This study collected flight data from approximately 20 pilots using a simulated flight training device to construct a range of flight scenarios. These scenarios included three stages of flight: ascending, level, and descent, and were further categorized into good visibility conditions and 0-mile visibility conditions. The aim was to investigate the occurrence of flight illusions under these conditions. From the extracted data, we obtained a total of 54,000 time-series data points, sampled five times per second. These were then analyzed using a machine learning approach.

Development of a Deep-Learning Model with Maritime Environment Simulation for Detection of Distress Ships from Drone Images (드론 영상 기반 조난 선박 탐지를 위한 해양 환경 시뮬레이션을 활용한 딥러닝 모델 개발)

  • Jeonghyo Oh;Juhee Lee;Euiik Jeon;Impyeong Lee
    • Korean Journal of Remote Sensing
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    • v.39 no.6_1
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    • pp.1451-1466
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    • 2023
  • In the context of maritime emergencies, the utilization of drones has rapidly increased, with a particular focus on their application in search and rescue operations. Deep learning models utilizing drone images for the rapid detection of distressed vessels and other maritime drift objects are gaining attention. However, effective training of such models necessitates a substantial amount of diverse training data that considers various weather conditions and vessel states. The lack of such data can lead to a degradation in the performance of trained models. This study aims to enhance the performance of deep learning models for distress ship detection by developing a maritime environment simulator to augment the dataset. The simulator allows for the configuration of various weather conditions, vessel states such as sinking or capsizing, and specifications and characteristics of drones and sensors. Training the deep learning model with the dataset generated through simulation resulted in improved detection performance, including accuracy and recall, when compared to models trained solely on actual drone image datasets. In particular, the accuracy of distress ship detection in adverse weather conditions, such as rain or fog, increased by approximately 2-5%, with a significant reduction in the rate of undetected instances. These results demonstrate the practical and effective contribution of the developed simulator in simulating diverse scenarios for model training. Furthermore, the distress ship detection deep learning model based on this approach is expected to be efficiently applied in maritime search and rescue operations.

A scheme on strengthening of R.O.K reserved force (예비전력 정예화 방안)

  • Kim, Jae-Sam
    • Journal of National Security and Military Science
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    • s.5
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    • pp.1-45
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    • 2007
  • Reserved forces of ROKA are in charge of replacement of TOE in the wartime and mission of rear area operation. But there is institutional inertia in the law and organization oriented to fill human resources rather than take mission. We need to prepare for the investment and arrangement of reserved forces as military power that would be replaced standing forces. In this portion, to reinforce reserve forces elite, First, efficient mobilization regulations and systems are suggested. I covered a maintenance of relevant mobilization ordinances which need to legislated and approved by national assembly for wartime and development of mobilization system which might lose the appropriate time for mobilization due to complicated declaration procedures and measures to overcome the panic at the initial stage of the war and organization and employment of nationwide transportation system and mobilization center. To ensure efficient resource management and mobilization of reserve forces with a number of approximately 3 million, there's a necessity of organization for integration and conciliation. To make it real, I suggested establishing and employing the mobilization center, on first phase, employ the mobilization center focusing on homeland divisions, on second phase, it is advisable to convert to national level mobilization system and develop to central mobilization center focusing on national emergency planning committee. During peacetime, in conjunction with Mobilization Cell, mobilization center can conduct resource survey and integrate and manage mobilization resources and take charge of mobilization training of subordinate units, and during wartime, in conjunction with mobilization coordination team and Cell, can ensure the execution of mobilization. Second, Future oriented reserve forces management system such as service system of reserve forces and support system of homeland defense operations. Current service and trainings of reserve forces by the year have very low connection, as it is very complex to manage the resources and trainings, and service and training lack the equity, re-establishment of service system is required. Also in an aspect of CSS and cultivation support for reserve forces, as the scope and limitation of responsibility between the armed forces and autonomous organization is obscure, conditions to conduct actual-fighting exercises are limited. Concentrated budgetting is extremely difficult because reserve forces training fields are scattered nationwide, and facilities and equipments are rapidly getting older. To improve all these, I suggest the organization of homeland defense battalion with a unit of "City-Gun-District" and supporting the local reserve forces. Conduct unit replacement or personal replacement for those who have finished their 1 or 2 years and homeland defense operation duty for those with 3-5 years for consistency and simplification. Third, I suggest Future oriented Reserved Training(FRT) and Training Center oriented training management to establish a reliable reserve training. Reserves carry out expansion of unit, conventional combat mission, homeland defense and logistics support during wartime, and actual-fighting exercise, and disaster relief, peace keeping activities. Despite diverse activities and roles, their training condition still stays definitely poor. For these reasons, Modernization of weapons and facilities through gradual replacement and procurement is essential to enhance mobilization support system.

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A Study on Teachers' Understanding of the Training of Invention·Patent Personnel in Specialized High Schools (발명·특허 분야 인력 양성에 대한 교사 인식 - 발명·특허 특성화고등학교 교사를 대상으로 -)

  • Lee, Byung-Wook;Lee, Chang-Hoon
    • 대한공업교육학회지
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    • v.33 no.1
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    • pp.134-148
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    • 2008
  • In this study, a survey was conducted to determine the understanding by teachers at KIPO-funded high schools of the specialized training of invention patent personnel. The subjects were 4 high schools and 126 copies of questionnaires were collected for analysis. The results of this study are as follows. First, teachers understand that it is particularly important to provide a specialized training for students so that they can more effectively adapt to the changes in their lives. They also consider basic job skills training, moral education and job readiness training as equally important. Second, they recognize the necessity for a specialized training of invention patent personnel. Third, they think that redundant teachers arising from the reform of the curriculum for specialized training should be provided with minor training. Fourth, they think that the reform of the curriculum for specialized training should consider the following aspects: the development of a curriculum for invention patent-specialized high schools, the strengthening of administrative financial supports, the creation of a consensus among those involved for the success of the specialized training, the development of textbooks and materials, and the consideration of the future prospects and current conditions of the invention patent industry. Fifth, they think that the successful operation of specialized high schools requires the consideration of the following factors: users' understanding, conformance, selection & concentration and uniqueness.

Formation of New Approaches to the Use of Information Technology and Search For Innovative Methods of Training Specialists within the Pan-European Educational Space

  • Stratan-Artyshkova, Tetiana;Kozak, Khrystyna;Syrotina, Olena;Lisnevska, Nataliya;Sichkar, Svitlana;Pertsov, Oleksandr;Kuchai, Oleksandr
    • International Journal of Computer Science & Network Security
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    • v.22 no.8
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    • pp.97-104
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    • 2022
  • European integration processes have acted as a catalyst for the emergence of a new type of educational environment, which is characterized by competent flexibility of specialists. Therefore, the article focuses on professional training of teachers in the context of European integration processes using information technology and the search for innovative methods of training specialists. One of the educational priorities in Europe is to create a new model of a teacher who has an academic education, knows innovative methods, is able to perform functions and tasks efficiently and professionally, adequately, quickly and correctly respond to changes and innovations. The tasks facing education in the European dimension are formulated. The main trends in the education of teachers in modern Europe are described: the need to deepen and expand subject training programs in pedagogical institutions of Higher Education, which will allow autonomy of activity, awareness of responsibility for independent creative decisions, create favorable conditions for the development of professionalism through the use of Information Technology and the search for innovative methods of training specialists. At the present stage, various models of teacher training are being developed based on the University and practical concept using information technology and searching for innovative methods of training specialists. On this basis, two different theories of perception of teacher education were formed: as preparation of teachers for work throughout their professional career; as preparation for the first years of professional work, which is periodically repeated in the process of continuous professional training and improvement. Among the advantages that the use of Information Technology and the search for innovative methods of training specialists to implement the learning process, it is worth mentioning the following: simultaneous use of several channels of perception of the student or student in the learning process, thanks to which the integration of information processed by different sensory organs is achieved; the ability to simulate complex real experiments; visualization of abstract information by dynamic representation of processes, etc.

Pre-Equalization Techniques for Mitigating Rain Attenuation Channels in a Broadband Fixed Wireless Uplink System

  • Lee, Yeon-Woo;Cho, Choon-Geun;Hur, Kyeong;Cho, Kwang-Moon;Alsusa, Emad
    • International Journal of Contents
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    • v.2 no.4
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    • pp.19-24
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    • 2006
  • In this paper, the performance of pre-equalization technique which can be applicable for the B-WLL uplink is evaluated and compared to post-equalization technique under three kinds of rain attenuation channels such as rain, intermittent light rain and thundershower. The BER performance comparisons of two algorithms (LMS and RLS) are investigated in the context of channel models and the length of training sequence. From the simulation results, it is shown that the post-equalization outperforms only at quite good channel conditions such as AWGN, while the pre-equalization can guarantee better BER performance at every channel conditions, especially performance gain increases as the severity of channel increases. It is concluded that the pre-equalizer using LMS algorithm is preferable at delay-tolerant situation where the complexity of algorithm is not a strict factor, while one using RLS is suitable for fast burst transmission with a relatively short training sequence.

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Oral history study on Japanese menswear custom-tailoring culture (일본의 남성 맞춤복 테일러링 문화에 관한 구술사 연구)

  • Lee, Yhe-Young;Yoo, Yung-Hyun
    • The Research Journal of the Costume Culture
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    • v.28 no.2
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    • pp.166-180
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    • 2020
  • This oral history study explores the past and present Japanese menswear custom-tailoring culture. Two master tailors with more than 50 years of experience and two young tailors with less than a year of experience were interviewed about the tailor training process and environment, working conditions, thinking and behavior, and societal and governmental efforts for vitalizing custom-tailoring. The results indicate, first, a 10-year apprenticeship was required in the past, whereas young tailors today must register for three-year professional tailoring classes. Tailors then and now have been trained in a similar sequence of pants, vests, and jackets. Second, regarding working conditions, tailors had to provide gratitude services to their masters for a few years, even after their training ended. In contrast, young tailors today must continue a probationary period after their three-year schooling; however, they experience difficulty with finding tailoring shops for their probation. Third, in terms of thinking and behavior, master tailors learned their trade to earn a living, whereas young tailors today entered the field due to their interests in it. In addition, young tailors want a systematic learning process, whereas master tailors learned their skills while on the job. Last, tailoring academies today are run by tailoring shops and societies. Career exploration programs are offered to elementary and middle school students by the Kobe government in association with the local tailoring society to provide tailoring experiences.