• Title/Summary/Keyword: distributed algorithm

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Case Study: Cost-effective Weed Patch Detection by Multi-Spectral Camera Mounted on Unmanned Aerial Vehicle in the Buckwheat Field

  • Kim, Dong-Wook;Kim, Yoonha;Kim, Kyung-Hwan;Kim, Hak-Jin;Chung, Yong Suk
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.64 no.2
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    • pp.159-164
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    • 2019
  • Weed control is a crucial practice not only in organic farming, but also in modern agriculture because it can lead to loss in crop yield. In general, weed is distributed in patches heterogeneously in the field. These patches vary in size, shape, and density. Thus, it would be efficient if chemicals are sprayed on these patches rather than spraying uniformly in the field, which can pollute the environment and be cost prohibitive. In this sense, weed detection could be beneficial for sustainable agriculture. Studies have been conducted to detect weed patches in the field using remote sensing technologies, which can be classified into a method using image segmentation based on morphology and a method with vegetative indices based on the wavelength of light. In this study, the latter methodology has been used to detect the weed patches. As a result, it was found that the vegetative indices were easier to operate as it did not need any sophisticated algorithm for differentiating weeds from crop and soil as compared to the former method. Consequently, we demonstrated that the current method of using vegetative index is accurate enough to detect weed patches, and will be useful for farmers to control weeds with minimal use of chemicals and in a more precise manner.

Channel Sorting Based Transmission Scheme For D2D Caching Networks (채널 정렬을 활용한 D2D 캐싱 네트워크용 전송 기법)

  • Jeong, Moo-Woong;Ryu, Jong Yeol;Kim, Seong Hwan;Lee, Woongsup;Ban, Tae-Won
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.22 no.11
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    • pp.1511-1517
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    • 2018
  • Mobile Device-to-Device (D2D) caching networks can transmit multimedia data to users directly without passing through any network infrastructure by storing popular multimedia contents in advance that are popular among many mobile users at caching server devices (CSDs) in distributed manners. Thus, mobile D2D caching networks can significantly reduce backhaul traffic in wired networks and service latency time of mobile users. In this paper, we propose an efficient transmission scheme that can enhance the transmission efficiency of mobile D2D caching networks by using multiple CSDs that are caching the contents that are popular among mobile users. By sorting the multiple CSDs that are caching a content that mobile users want to receive according to their channel gains, the proposed scheme can reduce the complexity of algorithm significantly, compared to an optimal scheme based on Brute-force searching, and can also obtain much higher network transmission efficiency than the existing Blanket and Opportunistic transmission schemes.

Deep Learning Based Short-Term Electric Load Forecasting Models using One-Hot Encoding (원-핫 인코딩을 이용한 딥러닝 단기 전력수요 예측모델)

  • Kim, Kwang Ho;Chang, Byunghoon;Choi, Hwang Kyu
    • Journal of IKEEE
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    • v.23 no.3
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    • pp.852-857
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    • 2019
  • In order to manage the demand resources of project participants and to provide appropriate strategies in the virtual power plant's power trading platform for consumers or operators who want to participate in the distributed resource collective trading market, it is very important to forecast the next day's demand of individual participants and the overall system's electricity demand. This paper developed a power demand forecasting model for the next day. For the model, we used LSTM algorithm of deep learning technique in consideration of time series characteristics of power demand forecasting data, and new scheme is applied by applying one-hot encoding method to input/output values such as power demand. In the performance evaluation for comparing the general DNN with our LSTM forecasting model, both model showed 4.50 and 1.89 of root mean square error, respectively, and our LSTM model showed high prediction accuracy.

Study on the Implementation of Primitive Visual Cortex Model in Retina Using Gabor Wavelet (가버 웨이블릿을 이용한 원시 시각 피질 모델 구현에 관한 연구)

  • Lee, Youngseok
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.13 no.6
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    • pp.477-482
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    • 2020
  • The human visual cortex has the characteristic that reacts sensitively to stimuli with special directional or temporal frequency changes while it is insensitive to selective stimuli of spatial phases. In this paper we implemented the model of complex cell using an image estimation iterative algorithm by Gabor wavelet transform. The performance of implemented model evaluated the consistency between the physiological experimental results in related papers. The implemented model is limited in the complete model of the receptive field in the retina where simple cells and complex cells are distributed together. But the implemented model express the reaction of the complex cells from the point of view of the detection of corners and edges.

Development of Caravan Sway Reduction System using the Hitch Angle Control Algorithm (히치 각도 제어 알고리즘을 통한 카라반 스웨이 저감 장치 개발)

  • Kim, Chang-Young;Yoo, Jung-Joo;Byun, Kyung-Seok
    • Journal of the Institute of Convergence Signal Processing
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    • v.22 no.4
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    • pp.171-178
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    • 2021
  • Caravans are easily affected by external physical factors and often cause dangerous situations for passengers. Therefore, in order to secure the stability of the passenger, there is a need to develop a sway reduction device capable of preventing the sway phenomenon in advance. This paper aims to minimize the hitch angle between the tow vehicle and the caravan. Specifically, the initial instability of the caravan is detected through an IMU sensor mounted on each of the tow vehicle and the caravan, and a control value is calculated to reduce errors from the Hitch angle and Hitch yaw rate using a PID controller. Different braking torques are generated, distributed, and controlled on the left and right brakes of the caravan according to the calculated control value. It could be verified through the driving experiment that the hitch angle was decreased compared to the case where the performance of the sway reduction device was not controlled, and the transverse stability improvement rate was improved by 94.49% compared to before control.

Semantic Object Detection based on LiDAR Distance-based Clustering Techniques for Lightweight Embedded Processors (경량형 임베디드 프로세서를 위한 라이다 거리 기반 클러스터링 기법을 활용한 의미론적 물체 인식)

  • Jung, Dongkyu;Park, Daejin
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.26 no.10
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    • pp.1453-1461
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    • 2022
  • The accuracy of peripheral object recognition algorithms using 3D data sensors such as LiDAR in autonomous vehicles has been increasing through many studies, but this requires high performance hardware and complex structures. This object recognition algorithm acts as a large load on the main processor of an autonomous vehicle that requires performing and managing many processors while driving. To reduce this load and simultaneously exploit the advantages of 3D sensor data, we propose 2D data-based recognition using the ROI generated by extracting physical properties from 3D sensor data. In the environment where the brightness value was reduced by 50% in the basic image, it showed 5.3% higher accuracy and 28.57% lower performance time than the existing 2D-based model. Instead of having a 2.46 percent lower accuracy than the 3D-based model in the base image, it has a 6.25 percent reduction in performance time.

Containment Control for Second-order Multi-agent Systems with Input Saturations (입력 포화를 고려한 2차 다중 에이전트 시스템을 위한 봉쇄제어)

  • Young-Hun, Lim
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.27 no.1
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    • pp.109-116
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    • 2023
  • In this paper, we study the containment control problem for second-order multi-agent systems, which consists of multiple leaders and followers. The goal is to drive the followers toward the convex hull spanned by the leaders. Thus, the swarm behavior can be obtained by controlling the entire group by the leaders. This paper considers the leaders move at a constant speed and the followers have input saturations. Moreover, we assume that the followers can exchange information with neighbors, and only relative state information is available. Under these assumptions, we propose the Proportional-Integral based distributed control algorithm to solve the containment control problem with moving leaders. Moreover, based on Lasalle's invariance principle, the conditions for the control gains that guarantee the convergence of the followers to the convex hull spanned by the leaders are investigated, and it was shown that it can be designed only using the system parameter. Finally, the simulations are conducted to validate the theoretical result.

AWGN Removal using Laplace Distribution and Weighted Mask (라플라스 분포와 가중치 마스크를 이용한 AWGN 제거)

  • Park, Hwa-Jung;Kim, Nam-Ho
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.25 no.12
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    • pp.1846-1852
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    • 2021
  • In modern society, various digital devices are being distributed in a wide range of fields due to the fourth industrial revolution and the development of IoT technology. However, noise is generated in the process of acquiring or transmitting an image, and not only damages the information, but also affects the system, causing errors and incorrect operation. AWGN is a representative noise among image noise. As a method for removing noise, prior research has been conducted, and among them, AF, A-TMF, and MF are the representative methods. Existing filters have a disadvantage that smoothing occurs in areas with high frequency components because it is difficult to consider the characteristics of images. Therefore, the proposed algorithm calculates the standard deviation distribution to effectively eliminate noise even in the high frequency domain, and then calculates the final output by applying the probability density function weight of the Laplace distribution using the curve fitting method.

Matrix Character Relocation Technique for Improving Data Privacy in Shard-Based Private Blockchain Environments (샤드 기반 프라이빗 블록체인 환경에서 데이터 프라이버시 개선을 위한 매트릭스 문자 재배치 기법)

  • Lee, Yeol Kook;Seo, Jung Won;Park, Soo Young
    • KIPS Transactions on Computer and Communication Systems
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    • v.11 no.2
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    • pp.51-58
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    • 2022
  • Blockchain technology is a system in which data from users participating in blockchain networks is distributed and stored. Bitcoin and Ethereum are attracting global attention, and the utilization of blockchain is expected to be endless. However, the need for blockchain data privacy protection is emerging in various financial, medical, and real estate sectors that process personal information due to the transparency of disclosing all data in the blockchain to network participants. Although studies using smart contracts, homomorphic encryption, and cryptographic key methods have been mainly conducted to protect existing blockchain data privacy, this paper proposes data privacy using matrix character relocation techniques differentiated from existing papers. The approach proposed in this paper consists largely of two methods: how to relocate the original data to matrix characters, how to return the deployed data to the original. Through qualitative experiments, we evaluate the safety of the approach proposed in this paper, and demonstrate that matrix character relocation will be sufficiently applicable in private blockchain environments by measuring the time it takes to revert applied data to original data.

Intellectual structure and research trends of The Research Journal of the Costume Culture - Bibliometric quantitative and qualitative semantic network approaches - (<복식문화연구>의 지적구조와 연구동향 - 계량정보학적 양적 접근과 의미연결망의 질적 접근 -)

  • Choi, Yeong-Hyeon;Choi, Mi-Hwa
    • The Research Journal of the Costume Culture
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    • v.30 no.4
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    • pp.608-630
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    • 2022
  • The purpose of this study is to examine the relationships between citations and the research trends of The Research Journal of the Costume Culture (RJCC) using bibliometric and network analyses. The results are as follows. First, the RJCC has been cited by a greater number of journals and high-reputation journals today. The RJCC has been mentioned in global academic journals in various fields, and it has been noted the most in environmental science. Second, because of examining the articles published in the RJCC over the past three years (2019 - 2021), it was found that the number of topics was evenly distributed in various subfields of the clothing and textiles sector. The RJCC principally deals with traditional clothing, ethics and sustainability, and technology, which means that the RJCC reflects the past, present, and future. As a result of conducting a cluster analysis using the Wakita-Tsurumi algorithm, the subjects of ethical fashion and sustainability were derived from the subdivisions of the RJCC. This suggests that the RJCC is a journal specialized in ethical fashion and sustainability sectors such as environmental, animal, and labor ethics. This study outlined the current status and future direction of academic journals in the field of clothing through an analysis of the RJCC's influence change and the relationship between citations. In addition, it is academically significant because it identifies research trends and knowledge-structure changes in the apparel science field by identifying changes in research keywords and significant research topics by sector.