• Title/Summary/Keyword: autonomous system

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Elimination of the State-of-Charge Errors for Distributed Battery Energy Storage Devices in Islanded Droop-controlled Microgrids

  • Wang, Weixin;Wu, Fengjiang;Zhao, Ke;Sun, Li;Duan, Jiandong;Sun, Dongyang
    • Journal of Power Electronics
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    • v.15 no.4
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    • pp.1105-1118
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    • 2015
  • Battery energy storage devices (ESDs) have become more and more commonplace to maintain the stability of islanded power systems. Considering the limitation in inverter capacity and the requirement of flexibility in the ESD, the droop control was implemented in paralleled ESDs for higher capacity and autonomous operation. Under the conventional droop control, state-of-charge (SoC) errors between paralleled ESDs is inevitable in the discharging operation. Thus, some ESDs cease operation earlier than expected. This paper proposes an adaptive accelerating parameter to improve the performance of the SoC error eliminating droop controller under the constraints of a microgrid. The SoC of a battery ESD is employed in the active power droop coefficient, which could eliminate the SoC error during the discharging process. In addition, to expedite the process of SoC error elimination, an adaptive accelerating parameter is dedicated to weaken the adverse effect of the constraints due to the requirement of the system running. Moreover, the stability and feasibility of the proposed control strategy are confirmed by small-signal analysis. The effectiveness of the control scheme is validated by simulation and experiment results.

Reinforcement Learning Based Evolution and Learning Algorithm for Cooperative Behavior of Swarm Robot System (군집 로봇의 협조 행동을 위한 강화 학습 기반의 진화 및 학습 알고리즘)

  • Seo, Sang-Wook;Kim, Ho-Duck;Sim, Kwee-Bo
    • Journal of the Korean Institute of Intelligent Systems
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    • v.17 no.5
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    • pp.591-597
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    • 2007
  • In swarm robot systems, each robot must behaves by itself according to the its states and environments, and if necessary, must cooperates with other robots in order to carry out a given task. Therefore it is essential that each robot has both learning and evolution ability to adapt the dynamic environments. In this paper, the new polygon based Q-learning algorithm and distributed genetic algorithms are proposed for behavior learning and evolution of collective autonomous mobile robots. And by distributed genetic algorithm exchanging the chromosome acquired under different environments by communication each robot can improve its behavior ability Specially, in order to improve the performance of evolution, selective crossover using the characteristic of reinforcement learning is adopted in this paper. we verify the effectiveness of the proposed method by applying it to cooperative search problem.

DCGAN-based Compensation for Soft Errors in Face Recognition systems based on a Cross-layer Approach (얼굴인식 시스템의 소프트에러에 대한 DCGSN 기반의 크로스 레이어 보상 방법)

  • Cho, Young-Hwan;Kim, Do-Yun;Lee, Seung-Hyeon;Jeong, Gu-Min
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.14 no.5
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    • pp.430-437
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    • 2021
  • In this paper, we propose a robust face recognition method against soft errors with a deep convolutional generative adversarial network(DCGAN) based compensation method by a cross-layer approach. When soft-errors occur in block data of JPEG files, these blocks can be decoded inappropriately. In previous results, these blocks have been replaced using a mean face, thereby improving recognition ratio to a certain degree. This paper uses a DCGAN-based compensation approach to extend the previous results. When soft errors are detected in an embedded system layer using parity bit checkers, they are compensated in the application layer using compensated block data by a DCGAN-based compensation method. Regarding soft errors and block data loss in facial images, a DCGAN architecture is redesigned to compensate for the block data loss. Simulation results show that the proposed method effectively compensates for performance degradation due to soft errors.

Design of Educational Model for Convergence Minor in Culinary Art·Robot Technology Fields

  • Kim, Won
    • Journal of the Korea Society of Computer and Information
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    • v.26 no.10
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    • pp.109-116
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    • 2021
  • In this paper, we propose the educational model for a convergence minor by fusing culinary arts with robot technology to develop coding ability for the students in the culinary arts major which is not originally related to software field. It is meaningful that the educational model follows the trend along the development of the fourth industrial revolution technology and has the function to make the students who are not in software major grow as software experts. However there are difficulties in designing the convergence minor because the culinary arts major is distant to the robot technology in the view of technology. To overcome this difficulty the convergence minor is designed to attract the interest for the students in culinary arts major by construct educational subjects systematically such as cooking, dessert making, barista working, autonomous serving and so on based on robots. Also the practices in which various robots are utilized are included in the convergence minor to develop actual coding ability. By comparison to the other models of convergence minors, the proposed model shows enhanced educational effects in 20% than the others.

Analysis of Festival Ordinances of Gyeonggi Province: Focusing on Developing A Representative Festival of Seongnam City

  • PARK, Hyun Jung;HAN, Seon Mi;KWON, Ki Hyun;SEO, Won Jae
    • Journal of Sport and Applied Science
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    • v.5 no.1
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    • pp.1-9
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    • 2021
  • Purpose: In Seongnam City, a number of festivals are held in various areas, led by the city and private organizations. The necessity of developing a representative festival of Seongnam City, which can enhance the brand value of Seongnam, a cultural city, and promote a sense of local community and economic effects, is emerging. The purpose of this study is to analyze festival-related ordinances of Gyeonggi-do local governments, and to derive implications necessary for the development of festival support ordinances representing Seongnam City. Research design, data, and methodology: This study used the database of National Legal Information Center of the Ministry of Legislation and the autonomous legal information system to thoroughly investigate the ordinances related to festival support of basic local governments in Gyeonggi-do and the whole country. To do this, descriptive statistics analysis was conducted. Results: As a result of the study, it was found that 168 organizations (68.6%) of 245 local governments nationwide have adopted the festival support ordinance, and there are a total of 231 ordinances. In the case of basic organizations, out of 228 basic organizations, 151 organizations, including Seongnam City, adopted the ordinance on festival support, showing an adoption rate of about 66%. As a result of analyzing the basic organizations that enacted representative festival related ordinances among Gyeonggi-do basic organizations, 9 out of 28 cities adopted 16 representative festival ordinances, based on the legal and institutional basis for supporting representative festivals. Conclusions: In the case of Seongnam City, it is believed that in order to develop a representative festival, an ordinance to support the representative festival must be established. Considerations regarding the composition of the ordinance for the representative festival were discussed.

Normative Issues of Maritime Autonomous Surface Ships(MASS) Pursuant to the State Jurisdictions under UNCLOS (유엔해양법협약상 국가관할권에 따른 자율운항선박의 규범적 쟁점사항)

  • 한국해양수산개발원
    • Ocean policy research
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    • v.33 no.2
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    • pp.147-181
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    • 2018
  • Currently, we are living in the era of the 4th industrial revolution. In the field of shipping industry, the MASS is a revolutionary game changer in the making arising out of such an industrial and technical innovation in the pursuit of radically challenging the pre-existing system of a human-operated vessel. Given this trend, the entire maritime regulatory regime, which has been designed by, and intertwined with, human seaworthiness, abruptly faces the most unprecedented normative confrontations now and increasingly in the coming days. As the constitution of ocean, UNCLOS, provides, every flag state is obliged to effectively exercise its jurisdiction to secure technical and human seaworthiness. Moreover, the coastal state may institute protective proceedings against vessels in respect of any violations of its laws to protect its marine environment in maritime zones of the coastal state. Further, UNCLOS acknowledges that the port state's authority extends to take administrative measures to prevent sub-standard ships from sailing within the ports or offshore-terminals of the state. These three jurisdictional functions will be required to more closely interface with each other than ever over the legal and political implications created by MASS. Although states' jurisdictional nuances are significant in this present world tilting back to protectionism, there are few articles to present jurisdictional issues of states and conceivable normative discourse with regard to MASS. This articles visits potential jurisdictional conflicts underlying MASS and tries to strike balance between contradictory interpretive approaches under UNCLOS while it is undeniable that this doctrinal research tends to strive to find justifications within the current framework of international law.

Regional Variations and Related Factors of Mastication Difficulty Rate among the Korean Elderly (우리나라 노인의 저작불편 호소율의 지역 간 변이와 관련 특성)

  • Kim, Ranhee;Kim, Ji Man;Park, Chong Yon;Park, Keun-Young;Lee, Changwoo;Shin, Euichul
    • The Journal of Health Technology Assessment
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    • v.6 no.2
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    • pp.100-105
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    • 2018
  • Objectives: The purpose of this research is to investigate regional variations of mastication difficulty rates in the elderly over 65 in 229 primary autonomous districts in Korea and explore relevant characteristics. For the research data, local community health survey conducted in 2015 and data from Ministry of the Interior and Safety, Ministry of Health & Welfare, National Health Insurance Service and Statistics Korea were used. Methods: Frequency analysis was conducted for general characteristics and mastication difficulty rates of each region, and distribution of mastication difficulty rates was displayed for each town, city and province by mapping them. Extremal quotient (EQ), coefficient of variation (CV) values were calculated for regional variations, and logistic regression analysis was performed to reveal the relationship between each independent variable and mastication difficulty rates. Results: The average of standardized mastication difficulty rate was 46.78%, and regional variations were significant with EQ 3.46, CV 0.18. Characteristic factors that have significant effects on mastication difficulty rate included sex ratio, elderly population and the number of dentists per 10000 people. Conclusion: As a result, there were variations among mastication difficulty rates in 229 primary local governments across the country, and the distribution of health care resources by the characteristics of the local environment by region affected mastication difficulty rates. Accordingly, it is required to provide political supports to overcome regional inequality of oral health levels and develop cooperative system between local governments and local dentists.

MPEG-DASH based 3D Point Cloud Content Configuration Method (MPEG-DASH 기반 3차원 포인트 클라우드 콘텐츠 구성 방안)

  • Kim, Doohwan;Im, Jiheon;Kim, Kyuheon
    • Journal of Broadcast Engineering
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    • v.24 no.4
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    • pp.660-669
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    • 2019
  • Recently, with the development of three-dimensional scanning devices and multi-dimensional array cameras, research is continuously conducted on techniques for handling three-dimensional data in application fields such as AR (Augmented Reality) / VR (Virtual Reality) and autonomous traveling. In particular, in the AR / VR field, content that expresses 3D video as point data has appeared, but this requires a larger amount of data than conventional 2D images. Therefore, in order to serve 3D point cloud content to users, various technological developments such as highly efficient encoding / decoding and storage, transfer, etc. are required. In this paper, V-PCC bit stream created using V-PCC encoder proposed in MPEG-I (MPEG-Immersive) V-PCC (Video based Point Cloud Compression) group, It is defined by the MPEG-DASH (Dynamic Adaptive Streaming over HTTP) standard, and provides to be composed of segments. Also, in order to provide the user with the information of the 3D coordinate system, the depth information parameter of the signaling message is additionally defined. Then, we design a verification platform to verify the technology proposed in this paper, and confirm it in terms of the algorithm of the proposed technology.

Exploring the Applicability of the Appropriate Technology as a Means Endogenous Development of Rural Areas - Focused on Yeonggwang-gun in Jeollanam-do - (내생적 농촌지역발전 수단으로서의 적정기술 적용 가능성 탐색 - 전남 영광군을 사례로 -)

  • Ko, Kyungho;Ann, Byeong-il
    • Journal of Korean Society of Rural Planning
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    • v.25 no.3
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    • pp.45-57
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    • 2019
  • This study aims to explore the policy directions to apply and activate the appropriate technology in rural areas from the perspective of the endogenous and sustainable regional development theories. To this end, according to the analysis framework based on ideas, values, and strategies that are common to both endogenous regional development strategic theories and sustainable regional development theories, in this paper, various surveys and reviews were conducted on the study areas to explore the possibility of localization of the appropriate technology. The policy implications derived from research results are as follows; first, rural areas have high potential and scalability to apply and activate the appropriate technology, particularly in the field of renewable energy, due to their nature based on local resources. Second, for the practical application of the appropriate technology, first of all, together with the establishment of the role of public sector, it is necessary to plan the projects based on the cooperation network of the relevant innovation entities within and outside the regions and to build the implementation systems. Third, the training system for high skilled manpower and indigenous entrepreneurs should be stably built in order to create independent conditions, which are key elements for growth of the appropriate technology. Fourth, there is a need to find the market and establish policies that can solve the typical economic problems of rural areas such as aging population, depopulation and decline in youth, economic unrest. Fifth, in order for the appropriate technology to contribute to socio-economic innovations and the revitalization of the virtuous circle economy in the region, technical items and various business items suitable for the industrial infrastructures and autonomous conditions of rural areas are essential.

The Preservation of maul-gut and meaning of the folklore-transmission (마을굿의 보전과 민속전승의 의미 - 서울지역의 부군당굿을 중심으로 -)

  • Yu, Seung-Hun
    • Korean Journal of Heritage: History & Science
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    • v.35
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    • pp.320-343
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    • 2002
  • In Seoul city, The maul-gut(마을굿) called bugundang-gut(부군당굿) have been transmitted by people lived on the banks of han-river. The purpose of this document is to make a study the present meaning of bugundang-gut that have been transmitted in metropolitan city. The bugundang-gut was the official ritual in a government office during the Chosun dynasty. However, the bugundang-gut had been spread along kyunggang(경강, Han-river in Seoul) in the late Chosun period. At that times, the population kyunggang area was increased with the inflow of outside population and the commercial destrict was extended to many district along kyunggang. The main points of this study are as follows. Firstly, I investigate that bugundang-gut have been transmitted by a Seoulite to the backbone. They are the main body of bugundang-gut transmitting from generation to generation. Secondly, I study about nami-janggun-sadangje(남이장군사당제) appointed to seoul city immaterial cutural properties. It is a kind of bugundang-gut. So namijanggun-sadangje was appointed to seoul city immaterial cutural properties, as it was supported by a local autonomous entity. Thirdly, I investigate a plan that can be handed down an offspring in seoul city. We must revise the cultural properties system like that of Japan. Even though many bugundang-gut isn't appointed to cutural propertie except nami-janggun-sadangje, we must recognize their importance and keep a record character of bugundang-gut by investigation in detail. Fourthly, I think that bugundang-gut must be developed a regional public holiday. If it is developed a regional public holiday, many young person can be take part in bugundang-gut.