• Title/Summary/Keyword: 전파예측모델

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Breakage and Liberation Characteristics of Iron Ore from Shinyemi Mine by Ball Mill (신예미 광산 철광석의 볼밀 분쇄 및 단체분리 특성 연구)

  • Lee, Donwoo;Kwon, Jihoe;Kim, Kwanho;Cho, Heechan
    • Resources Recycling
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    • v.29 no.3
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    • pp.11-23
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    • 2020
  • This study aims to investigate breakage and liberation characteristics of iron ore from Shinyemi mine, Jeongseon by ball mill. Parameters of breakage functions for three grade samples of iron ore were obtained using single-sized-feed breakage test and back-calculation based on nonlinear programming. The results showed that with the increase in the grade of iron ore, the breakage rate factor decrease whereas the particle size sensitivity decreases. This results from retardation of microcrack-propagation by magnetite grain in the ore. Breakage distribution analysis showed that the breakage mechanism appear to be impact fracture dominant with the increase of grade owing to the stress distribution effect by magnetite grain. Degree of liberation (DOL) increased with the increase in grade and decrease in particle size, respectively. Using the breakage function and size-DOL relationship, a model that can predict time-dependent-DOL is established. When scale-up factors from operating condition are available, the model is expected to be capable of predicting size and DOL with time in actual mining process.

Railway Track Extraction from Mobile Laser Scanning Data (모바일 레이저 스캐닝 데이터로부터 철도 선로 추출에 관한 연구)

  • Yoonseok, Jwa;Gunho, Sohn;Jong Un, Won;Wonchoon, Lee;Nakhyeon, Song
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.33 no.2
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    • pp.111-122
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    • 2015
  • This study purposed on introducing a new automated solution for detecting railway tracks and reconstructing track models from the mobile laser scanning data. The proposed solution completes following procedures; the study initiated with detecting a potential railway region, called Region Of Interest (ROI), and approximating the orientation of railway track trajectory with the raw data. At next, the knowledge-based detection of railway tracks was performed for localizing track candidates in the first strip. In here, a strip -referring the local track search region- is generated in the orthogonal direction to the orientation of track trajectory. Lastly, an initial track model generated over the candidate points, which were detected by GMM-EM (Gaussian Mixture Model-Expectation & Maximization) -based clustering strip- wisely grows to capture all track points of interest and thus converted into geometric track model in the tracking by detection framework. Therefore, the proposed railway track tracking process includes following key features; it is able to reduce the complexity in detecting track points by using a hypothetical track model. Also, it enhances the efficiency of track modeling process by simultaneously capturing track points and modeling tracks that resulted in the minimization of data processing time and cost. The proposed method was developed using the C++ program language and was evaluated by the LiDAR data, which was acquired from MMS over an urban railway track area with a complex railway scene as well.

Human Sense-Based Simulation-Experience Model for Interactive Art Production (인터랙티브 아트 제작을 위한 인간의 감각 기반 시뮬레이션-체험 결합 모델)

  • Liu, Ting-Ting;Lim, Young-Hoon;Paik, Joon-Ki
    • Journal of the Korea Convergence Society
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    • v.12 no.11
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    • pp.169-184
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    • 2021
  • Recent advances in science and technology leveraged various artistic tools. Interactive art based on various media technologies became popular in a short period, and is widely appreciated as a new form of art. This new form of art has a different method of expression from traditional art such as painting or sculpture. It aims to strike a balance among the artist, audience, and piece of art through interaction between the work and viewers. Viewers can take part in the creation process, going beyond the conventional way of art appreciation. This paper analyzes interactive art production techniques based on human senses from the artist's perspective. "Simulation-experience model" will be suggested after looking at several example artworks. Charming, which was produced based on this model, will be introduced and its meaning will be analyzed. The objective of this paper is to predict the future of interactive art and changes in the art form by studying interactive art production techniques based on human senses. We believe that the prediction is helpful in understanding the artistic and technological value and the social influence of interactive art in the future.

A Numerical Study on the Fracture Evolution and Damage at Rock Pillar Near Deposition Holes for Radioactive Waste (방사성폐기물 처분공 주변 암주에서의 균열 진전 및 손상에 대한 수치해석적 연구)

  • 이희석
    • Journal of the Korean Geotechnical Society
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    • v.19 no.5
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    • pp.211-221
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    • 2003
  • At Aspo hard rock laboratory in Sweden, an in-situ heater experiment called "$\"{A}"{s}"{p}"{o}$ Pillar Stability Experiment (APSE)" is prepared to assess capability to predict spatting and stability in a rock mass between deposition holes for radioactive waste. To Predict reasonably fracturing process at rock pillar under a planned configuration before testing, a boundary element code FRACOD has been applied for modelling. The code has been improved to simulate explicitly fracture evolution both at rock boundaries and in intact rocks. A new inverse stress reconstruction technique using boundary element has been also developed to transfer stress field by excavation and thermal loading into the FRACOD model. This article presents the results from predictive modelling far the planned in-situ test condition. Excavation induced stresses might cause slight fracturing in the pillar walls. Typical shear fractures have been initiated and propagated near central pillar walls during 120 days of heating, but overall rock mass remained stable under the considered configuration. The effects of pre-existing joints and properties of fractures are also discussed. It is found from the results that FRACOD can properly model essential rock spatting and propagation at deep tunnels and boreholes.at deep tunnels and boreholes.

One-health Approach in the Post-COVID-19 Era: Focusing on Animal Infection (One-health 관점에서 본 Post-COVID-19 시대의 동물 감염)

  • Hye-Jeong Jang;Sun-Nyoung Yu;O-Yu Kwon;Soon-Cheol Ahn
    • Journal of Life Science
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    • v.33 no.2
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    • pp.199-207
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    • 2023
  • To prepare for the threat of a future epidemic in the post-COVID-19 era, research based on the one-health concept (i.e., the health of humans, animals, and the environment as "one") is essential. Cross-species infections are being identified as a result of the high infection rate and viral load of SARS-CoV-2 in humans. The possibility of transmission of SARS-CoV-2 from humans to mink has been determined. In addition, the transmission of SARS-CoV-2 from humans to cats through contact has been considered possible. The data so far show that livestock and poultry are less likely to be infected with SARS-CoV-2. However, if infections are established through a new mutation, the resulting diseases are expected to have enormous ripple effects on various fields, such as human food security, the economy, and trade. In addition, there are concerns about the endemic prospect of SARS-CoV-2 and the high accessibility of companion animals. This is because the evolution of the virus likely occurs in animal hosts. Once SARS-CoV-2 is established in other species, they might serve as intermediate hosts for the re-emergence of the virus in the human population. Thus, it is necessary to ensure a rapid response to future outbreaks by accumulating research data on the animal infection of SARS-CoV-2. These data can have implications for the development of animal models for vaccines and therapeutics against SARS-CoV-2. Therefore, in this study, epidemiological reviews were analyzed, and response strategies against SARS-CoV-2 infection in animals were presented using the One-health approach.

Methodology of Interference Analysis Between TACAN/DME Beacons and Ground-based Link-16 Terminals (TACAN/DME 비콘과 Link-16 지상국 간의 간섭분석 방법)

  • Suh, Kyoung-Whoan
    • Journal of Advanced Navigation Technology
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    • v.20 no.1
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    • pp.45-52
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    • 2016
  • In this paper, the method of interference analysis and its simulation have been suggested for the frequency sharing between aeronautical radio navigation systems and Link-16 platforms. In order to get the criteria for interoperability, the algorithm of interference analysis and protection ratio are derived to assure frequency sharing. Also the receiving power of wireless system has been illustrated with the help of radio propagation model of ITU-R Rec. P.1546 in VHF-UHF band. Finally the required receiving power or separation distance between DME/TACAN beacons and Link-16 ground station terminals has been considered based on system link budget in terms of evaluating interoperability as well as actual applications. As a result, if the suggested interference analysis and test set-up are applied to the field trial, it will lead to easy means to make a decision on interoperability over the existing incumbent systems.

Numerical Simulation for Behavior of Tidal Elevation and Tidal Currents in the South Sea (남해안의 조위 및 조류거동 수치모의)

  • Kwon, Seok-Jae;Kang, Tae-Soon
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.19 no.3
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    • pp.253-265
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    • 2007
  • This study applied the previous results of the NAO model, a tidal correction model, to the open boundary condition for the behavior of tidal elevation and tidal currents in the South Sea. This study used the EFDC model considering the wetting and drying problem and using the $\sigma-coordinate$ as a vertical coordinate and generated two mesh cases of the constant grid size of 2.0 km and the variable grid size of $0.5\sim2.0km$. The numerical results for the tides showed that the predicted results were in quite good agreements with the observational data acquired from the tidal stations of the NORI. The predicted tides were observed to propagate from the east area to the west area in the South Sea. The verification results reveal that the numerical results are more correlated with the measured tidal data as the grid size decreases. The grid size of 2 km results in proper simulation of tidal currents in wide waterway and offshore area whereas the numerical results from the grid size of 0.5 km tend to somewhat underestimate the tidal currents affected by narrow waterway and topography in inner-bay.

A Numerical Study on the Fire Behavior Phenomena in a Special Fire Protection Compartment (특수 방호공간에서 가상화재의 발생으로 인한 화재거동에 관한 수치적 연구)

  • Kim, Tae-Kuk;Son, Bong-Sei
    • Journal of the Korean Society of Hazard Mitigation
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    • v.1 no.1 s.1
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    • pp.157-163
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    • 2001
  • The objective of the present study is to predict the characteristics of the fire and smoke propagations in a clean room. Numerical calculations have been performed by using the finite volume method to obtain temperature and velocity distributions in the clean room. In odor to account for the turbulent flow characteristics, the standard $k-{\varepsilon}$ model is used. From this study, it was found that the fire propagation could be fully developed only after 150 seconds when the ventilation system in the clean room was off. And the smoke mass fraction showed a similar distribution as the gas temperature. Since the simulated fire was proceeded up to $20{\sim}30%$ of the room within 60 seconds. it could be recommended that the occupants should be evacuated from the room within 30 seconds.

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Analysis and Detection Method for Line-shaped Echoes using Support Vector Machine (Support Vector Machine을 이용한 선에코 특성 분석 및 탐지 방법)

  • Lee, Hansoo;Kim, Eun Kyeong;Kim, Sungshin
    • Journal of the Korean Institute of Intelligent Systems
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    • v.24 no.6
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    • pp.665-670
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    • 2014
  • A SVM is a kind of binary classifier in order to find optimal hyperplane which separates training data into two groups. Due to its remarkable performance, the SVM is applied in various fields such as inductive inference, binary classification or making predictions. Also it is a representative black box model; there are plenty of actively discussed researches about analyzing trained SVM classifier. This paper conducts a study on a method that is automatically detecting the line-shaped echoes, sun strobe echo and radial interference echo, using the SVM algorithm because the line-shaped echoes appear relatively often and disturb weather forecasting process. Using a spatial clustering method and corrected reflectivity data in the weather radar, the training data is made up with mean reflectivity, size, appearance, centroid altitude and so forth. With actual occurrence cases of the line-shaped echoes, the trained SVM classifier is verified, and analyzed its characteristics using the decision tree method.

Packetizing Scheme for Reliable Transmission of Wavelet Video Stream (신뢰성있는 웨이블릿 비디오 전송을 위한 패킷화 기법)

  • Lee, Joo-Kyong;Kang, Jin-Mi;Kim, Chung-Kil;Chung, Ki-Dong
    • The KIPS Transactions:PartB
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    • v.10B no.5
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    • pp.553-560
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    • 2003
  • Since Wavelet Transform decomposes a video frame into subbands with various frequencies and resolutions, the reconstructed video qualify at a receiver fluctuates according to the location of transmission errors within frames. This deteriorates the whole visual duality of the video. Specifically, for a wavelet based video which exploits the motion estimation prediction scheme, the transmission errors of a subband not only have a bad effect on other subbands within a same frame but also propagates to the subsequent frames. In this paper, we propose BDP(Block Based Dispersive Packetization) scheme, for a wavelet based video stream, which maintains constant video quality despite packet location that a transmission error occurs. To evaluate the performance of the proposed scheme, we use MRME(Multi-Resolution Motion Estimation) scheme to compress a video in Inter coding mode and Gilbert´s error model to generate the error patterns in wireless network environment. The simulation results show that BDP is more efficient than BP (Block based Packetization) or DP (Dispersive Packetization) in both PSNR and visual quality.