• Title/Summary/Keyword: Digital HF

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A Study on Policy Making for e-Navigation from the Viewpoint of a Maritime Digital Communication Network (e-Navigation을 위한 해상디지털통신 구축에 관한 정책 연구)

  • Lim, Hyuntaek;Cho, Yong-Gab
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.24 no.6
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    • pp.679-685
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    • 2018
  • In order to reduce marine accidents using advanced information and communication technology, various research and development projects are conducted globally on e-Navigation related technologies and services. Existing studies do not provide policy measures for LTE-M. In order for these technologies and services to be installed on vessels and to contribute to the prevention of accidents at sea, the law should be expand operational organizations and systems. In particular, communication equipment and related technical standards should be prepared, and its digital communication technology (LTE-M, VDES, Digital-MF / HF, etc.) In this study, we conducted short, medium, and long term performance assessment of the identification system and the policy for effective implementation of Korean e-Navigation. We presented a visible plan of the relevant policy. For example, e-Navigation core services, e-Navigation communication networks and operating systems, e-Navigation international standard leading technologies and e-navigation services activated in the field. To do this, we conducted research based on the progress data of the Korean e-Navigation project, which was led by the Ministry of Maritime Affairs and Fisheries, and conducted research discussions with practitioners and experts in related fields. As a result of this study, it is expected that the proposed policies will contribute to the reduction of marine accidents, the promotion of the maritime industry and the development of additional government policies for national security.

A Study on the Implementation of Digital Fishing Network Using Data Communication (데이터 통신을 이용한 디지털 어업통신망 구현에 관한 연구)

  • Seo, Gon;Kim, Jeong-Nyun;Choi, Jo-Chen;Jo, Hag-Hyun;Choi, Byung-Ha
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.7 no.1
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    • pp.59-68
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    • 2003
  • It's about time we had to think an alternative to recover our insufficient fishery market caused by IMF locally as well as the fishery agreement on Japan and China. It's essencial that we have to build up the foundation of information-oriented fishery market In order to improve the infrastructure of the market like developed countries. In this paper We present digital data communication network to exchange information for fishery and safety between fishing ship and coast station in cheeper communication fee using SSB(Sing Side Band) in HF(High Frequency) band.

A Study on the Implementation of Digital Fishing Network Using Data Communication (데이터 통신을 이용한 디지털 어업통신망 구현에 관한 연구)

  • Seo, Gon;Kim, Jeong-Nyun;Choi, Jo-Chen;Jo, Hag-Hyun;Choi, Byung-Ha
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2002.11a
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    • pp.288-295
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    • 2002
  • It's about time we had to think an alternative to recover our insufficient fishery market caused by IMF locally as well as the fishery agreement on Japan and China. It's essential that we have to build up the foundation of information-oriented fishery market In order to improve the infrustructure of the market like developed countries. In this paper We present digital data communication network to exchange information for fishery and safety between fishing ship and coast station in cheeper communication fee using SSB(Sing Side Band) in HF(High Frequency) band.

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Study on OCR Enhancement of Homomorphic Filtering with Adaptive Gamma Value

  • Heeyeon Jo;Jeongwoo Lee;Hongrae Lee
    • Journal of the Korea Society of Computer and Information
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    • v.29 no.2
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    • pp.101-108
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    • 2024
  • AI-OCR (Artificial Intelligence Optical Character Recognition) combines OCR technology with Artificial Intelligence to overcome limitations that required human intervention. To enhance the performance of AI-OCR, training on diverse data sets is essential. However, the recognition rate declines when image colors have similar brightness levels. To solve this issue, this study employs Homomorphic filtering as a preprocessing step to clearly differentiate color levels, thereby increasing text recognition rates. While Homomorphic filtering is ideal for text extraction because of its ability to adjust the high and low frequency components of an image separately using a gamma value, it has the downside of requiring manual adjustments to the gamma value. This research proposes a range for gamma threshold values based on tests involving image contrast, brightness, and entropy. Experimental results using the proposed range of gamma values in Homomorphic filtering suggest a high likelihood for effective AI-OCR performance.

A Study on the Protocol of SSB Wireless Data for Advancing of Fishery Communication (어업통신의 선진화를 위한 SSB 무선데이타 프로토콜에 대한 연구)

  • Kim, Jeong-Nyun;Jo, Hag-Hyun
    • Journal of Navigation and Port Research
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    • v.28 no.5
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    • pp.443-448
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    • 2004
  • The Ministry of Maritime Affairs & Fisheries have plaining the advancing fishery information integrated system for the fishing present condition, marine resource administration and applicability considering. The fishery info17nation communication system is build up to the raw data & process-network-content. The communication system must be small size, low cost and adapted SSB transceiver, that is using fishery shipping. In this paper We present digital data communication network to exchange information for fishery and safety between fishing ship and coast station in cheeper communication fee using SSB in HF band.

Analysis of the Coordination Relationship and Muscle Fatigue of Agonist and Synergist During Dumbbell Side Lateral Raise Using Biosignals (생체신호를 이용한 덤벨 사이드 레터럴 레이즈 시 주동근과 협력근의 협응 관계 및 근피로 분석)

  • Jong min Kim;Chang hyun Song;Jun won Choi ;Han Sung Kim
    • Journal of Biomedical Engineering Research
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    • v.44 no.3
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    • pp.218-224
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    • 2023
  • This study aimed to analyze the coordination of muscle and muscle fatigue between biceps, lateral deltoid, and anterior deltoid during dumbbell side lateral raise using bio-signal. One male subject performed dumbbell side lateral raise with 3% of 1RM dumbbell at the rate of 30bpm until failure (8 minutes). While performing, ECG were recorded to observe the participant's performance. EMG were recorded from biceps, lateral deltoid, and anterior deltoid for observing coordination and fatigue. ECG were analyzed in time and frequency domain to observe Heart rate, normLF, normHF. Changes in heart rate, normLF, and normHF indicate that the sympathetic nervous system is activated, while changes in median frequency (MDF) indicate the occurrence of muscle fatigue. Moreover, the coordination relationship of muscle changed. The correlation of MDF between each muscles indicated that lateral deltoid is associated with biceps and anterior deltoid. These results showed that our study can contribute to improving understanding of muscle fatigue and muscle coordination relationships.

Reduction of Quantum Noise using Adaptive Weighted Median filter in Medical Radio-Fluoroscoy Image (적응성 가중 메디안 필터를 이용한 의료용 X선 투시 영상의 양자잡음 제거)

  • Lee, Hoo-Min;Nam, Moon-Hyon
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.51 no.10
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    • pp.468-476
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    • 2002
  • Digital images are easily corrupted by noise during the data transmission, data capture and data processing. A technical method of noise analyzing and adaptive filtering for reducing of quantum noise in medical radio-fluoroscopy images is presented. By adjusting the characteristics of the filter according to local statistics around each pixel of the image as moving windowing, it is possible to suppress noise sufficiently while preserve edge and other significant information required in diagnosis. We proposed adaptive weighed median(AWM) filters based on local statistics. We showed two ways of realizing the AWM filters. One is a simple type of AWM filter, which is constructed by Homogeneous factor(HF). Homogeneous factor(HF) from the noise models that enables the filter to recognize the local structures of the image is introduced, and an algorithm for determining the HF fitted to the diagnostic systems with various inner statistical properties is proposed. We show by the experimented that the performances of proposed method is superior to these of other filters and models in preserving small details and suppressing the noise at homogeneous region. The proposed algorithms were implemented by Visual C++ language on a IBM-PC Pentium 550 for testing purposes and the effects and results of the filter in the various levels of noise and images were proposed by comparing the values of NMSE(normalized mean square error) with the value of the other existing filtering methods.

Autonomic Nervous System response affected by 3D visual fatigue evoked during watching 3D TV (3D TV 시청으로 유발된 시각피로가 자율신경계 기능에 미치는 영향)

  • Park, Sang-In;Whang, Min-Cheol;Kim, Jong-Wha;Mun, Sung-Chul;Ahn, Sang-Min
    • Science of Emotion and Sensibility
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    • v.14 no.4
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    • pp.653-662
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    • 2011
  • As technology in 3D industry has rapidly advanced, a lot of studies primarily focusing on visual function and cognition have become vigorous. However, studies on effect of 3D visual fatigue on autonomic nervous system have not less been conducted. Thus, this study was to identify and determine the effect that might have a negative influence on sympathetic nervous system, parasympathetic nervous system, and cardiovascular system. Fifteen undergraduates (female: 9, mean age: $22.53{\pm}2.55$) participated and were sat on a comfortable chair, viewing a 3D content during about 1 hour. Cardiac responses like SDNN(standard deviation of RR intervals), RMS-SD(root mean squared successive difference), and HF/LF ratios extracted from the measured PPG(Photo-PlethysmoGram) before viewing 3D were compared to those after viewing 3D. The results showed that after subjects watched the 3D, responses in sympathetic nervous system and parasympathetic nervous system were activated and deactivated, respectively relative to those before watching the 3D. The results showed that HF/LF ratio, Ln(LF), and Ln(HF) after viewing 3D were significantly reduced relative to those before viewing 3D. No significant effects were observed in SDNN and RMS-SD. Results obtained in this study showed that visual fatigue induced by watching 3D adversely influenced autonomic nervous system, and thereby reduced heart rate variability causing sympathetic nervous acceleration.

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Electromagnetic Interference of GMDSS MF/HF Band by Offshore Wind Farm (해상풍력 발전단지에 의한 GMDSS MF/HF 대역 전자파 간섭 영향 연구)

  • Oh, Seongwon;Park, Tae-Yong
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.27 no.1
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    • pp.47-52
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    • 2021
  • Recently, the share of wind power in energy markets has sharply increased with the active development of renewable energy internationally. In particular, large-scale wind farms are being developed far from the coast to make use of abundant wind resources and to reduce noise pollution. In addition to the electromagnetic interference (EMI) caused by offshore wind farms to coastal or air surveillance radars, it is necessary to investigate the EMI on global maritime distress and safety system (GMDSS) communications between ship and coastal stations. For this purpose, this study investigates whether the transmitted field of MF/HF band from a ship would be subject to interference or attenuation below the threshold at a coastal receiver. First, using geographic information system digital maps and 3D CAD models of wind turbines, the area of interest is electromagnetically modeled with patch models. Although high frequency analysis methods like Physical Optics are appropriate to analyze wide areas compared to its wavelength, the high frequency analysis method is first verified with an accurate low frequency analysis method by simplifying the surrounding area and turbines. As a result, the received wave power is almost the same regardless of whether the wind farms are located between ships and coastal stations. From this result, although wind turbines are large structures, the size is only a few wavelengths, so it does not interfere with the electric field of MF/HF distress communications.