• Title/Summary/Keyword: KT model

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Novel Maritime Wireless Communication based on Mobile Technology for the Safety of Navigation: LTE-Maritime focusing on the Cell Planning and its Verification

  • Shim, Woo-Seong;Kim, Bu-Young;Park, Chan-Yong;Lee, Byeong-Hyeok
    • Journal of Navigation and Port Research
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    • v.45 no.5
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    • pp.231-237
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    • 2021
  • Enhancing the performance of maritime wireless communication has been highlighted by the issue of cell planning in the sea area because of lack of an appropriate Propagation Loss Model (PLM). To resolve the cell planning issue in vast sea areas, it was essential to develop the (PLM) matching the intended sea area. However, there were considerable gaps between the prediction of legacy PLMs and field measurement in propagation loss and there was a need to develop the adjusted PLM (A-PLM). Therefore, cell planning was performed on this adjusted model, including modification of the base station's location, altitude, and antenna azimuth to meet the quality objectives. Furthermore, in order to verify the availability of the cell planning, Communication Service Quality Monitoring System (CS-QMS) was developed in the LTE-Maritime project to collect LTE signal quality information from the onboard equipment at regular intervals and to ensure that the service quality was high enough to satisfy the goals in each designated grid. As a result of verification, the success rate of RSRP was 95.7% for the intensive management zone (IMZ) and 96.4% for the interested zone (IZ), respectively.

Comparison of Greenhouse Gas Emissions from Road Transportation in Local Cities/Counties of Gyeonggi Province by Calculation Methodologies (도로수송부문의 온실가스 배출량 산정방법에 따른 경기도 시·군별 배출량 비교)

  • Lee, Tae-Jung;Kim, Ki-Dong;Jung, Won-Seok;Kim, Dong-Sool
    • Journal of Korean Society for Atmospheric Environment
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    • v.28 no.4
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    • pp.454-465
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    • 2012
  • The Korean government decided to reduce 30% of GHG (greenhouse gas) emissions BAU in 2020. Since many efforts to reduce emissions are urgently needed in Korea, the central administrative organization urges local governments to establish their own reduction schemes. Among many GHG emission categories, the emission from mobile source in Gyeonggi Province accounted for 25.3% of total emissions in 2007 and further the emission from road transport sector occupied the most dominant portion in this transportation category. The objective of this study was to compare 3 types of GHG emissions from road transport sector in 31 local cities/counties of Gyeonggi Province, which have been estimated by Tier 1, Tier 2, and Tier 3 methodologies. As results, the GHG emission rates by the Tier 1 and Tier 2 were $19,991kt-CO_2\;Eq/yr$ and $18,511kt-CO_2\;Eq/yr$, respectively. On the other hand, the emission rate by Tier 3 excluding a branch road emission portion was $18,051kt-CO_2\;Eq/yr$. In addition, the total emission rate including all the main and branch road portions in Gyeonggi Province was $24,152kt-CO_2\;Eq/yr$, which was estimated by a new Tier 3 methodology. Based on this study, we could conclude that Tier 3 is a reasonable methodology than Tier 1 or Tier 2. However, more accurate and less uncertain methodology must be developed by expanding traffic survey areas and adopting a suitable model for traffic volumes.

Rapid Quantification of Chloride in Tobacco Leaves by a Chloride Meter (Model: CL-2Z) (Chloride Meter(CL-2Z형)를 이용한 담배잎 중 chloride의 신속한 검정방법)

  • Lee, Mee-Kyoung;Jeong, Hun-Chae;Kim, Yong-Yeon;Yu, Yun-Hyun
    • Journal of the Korean Society of Tobacco Science
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    • v.28 no.2
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    • pp.83-93
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    • 2006
  • The aim of this study is to develop a simple and rapid field method for the determination of chloride content in tobacco green or cured leaves. To set up a practical process, several factors such as the proper sampling position of each leaf, the size of leaf lamina pieces for blending, the substitution of deionized water fur the extracting solution, 0.1N $HNO_3$, the submerging durations before blending, and the standing times before measuring were studied using flue-cured and burley tobacco with a stable and reproducible Chloride Meter, KRK CL-2Z. From the results, chloride contents of tobacco leaves could be analyzed with the Chloride Meter(CL-2Z) using the suspension of 14 mm diameter leaf disks after soaking in distilled water for 30 min., blending with a mini-blender for 30 seconds. The chloride contents measured in this way showed highly significant correlations with ones by the conventional potentiometric method using an ion meter-chloride electrode and $AgNO_3$ titration. In our method, the procedures such as drying, powdering and weighing samples, and using chemical reagents for extraction (0.1N $HNO_3$) and titration(0.028N $AgNO_3$) could be eliminated. These results suggest that the newly constructed method using the Chloride Meter is more efficient to determine the chloride content of tobacco leave in comparison with the one by the Ion $Meter:AgNO_3$ titration.

A Study on the MMPP Model Verification for the Real-time VBR Traffic of ATM Network (ATM망의 실시간 VBR 트래픽에 대한 MMPP 모델 적합성 검증 연구)

  • 정승국;이영훈
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.28 no.8B
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    • pp.699-706
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    • 2003
  • This paper is to verify that 2-state MMPP Model conform to ATM VBR traffic characteristics by measuring and analyzing real-time VBR traffic in KT's ATM network. As a result, we validated the fact that real-time VBR traffic of ATM network cannot be apply to MMPP model and must be represented by previously general On-Off Model with characteristics as follows: arrival rate of On state (λ$_1$) is deterministic, arrival rate of Off state (λ$_2$) is zero, and two transition rate (T$_1$,T$_2$) is only random variable. As research results are to handle real traffic, these results can be used to all ATM network traffic model with traffic management function such as KT's ATM network.

Kinetics of Thermal Dehydration of Ha-dong Kaolin (하동카오린의 열분해속도에 관한 연구)

  • 박희찬;손명모
    • Journal of the Korean Ceramic Society
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    • v.18 no.1
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    • pp.35-40
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    • 1981
  • The kinetics of the dehydration of Ha-dong kaolin was studied isothermally at various temperatures. Dehydration rate was measured by thermogravimetry method in the temperature range of 440~50$0^{\circ}C$ and the particle size range of 170~325mesh. The general equation f($\alpha$)=kt, where $\alpha$ is the fraction reacted in the time and the function f($\alpha$) depends on the reaction mechanism, was applied to this reaction. The function, f($\alpha$) was obtained by application of reduced-time plot and plot of lnln (1-$\alpha$) vs. ln (time), and expressed as (1-$\alpha$) ln (1-$\alpha$)+$\alpha$=kt. The dehydration followed the diffusion-controlled reaction model and gave activation energy of 30Kcal/mole.

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SER/BER Analysis for 2-by-N MIMO-STBC Systems in Rayleigh Fading Channels (레일레이 페이딩 채널에서 2-by-N MIMO-STBC 시스템의 SER/BER 성능 해석)

  • Gil, Gye-Tae;Lee, Seong-Choon;Hyun, Kwang-Min
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.35 no.6C
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    • pp.547-553
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    • 2010
  • In this paper, novel approximated closed-form expressions of the SER(Symbol Error Rate) and BER(Bit Error Rate) are presented for the multi-input multi-output space-time block coding(MIMO-STBC) system employing two transmit and N receive antenna(s) in Rayleigh fading channels. Assuming a zero-forcing equalizer and a single-symbol maximum-likelihood (ML) decoder, the formulas are derived for the SER and BER, and then their approximated counterparts are also derived. In the derivation of the approximated expressions, acurve-fitting model is adopted that can eliminate the integral operators in the exact expressions.

Bayesian Model Uncertainty for Open-domain Question Answering (베이지안 모델 불확실성에 기반한 오픈도메인 질의응답)

  • Lee, Young-Hoon;Na, Seung-Hoon;Choi, Yun-Su;Chang, Du-Seong
    • Annual Conference on Human and Language Technology
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    • 2019.10a
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    • pp.93-96
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    • 2019
  • 최근 딥러닝 모델을 다양한 도메인에 적용하여 뛰어난 성능을 보여주고 있다. 하지만 딥러닝 모델은 정답으로 제시된 결과가 정상적으로 예측된 결과인지, 단순히 오버피팅에 의해 예측된 결과인지를 구분하기 어렵다. 이러한 불확실성(Uncertainty)을 측정 할 수 없다는 문제점을 해결하기 위해서 본 논문에서는 베이지안 딥러닝 방법 중 하나인 변분추론(Variational Inference)과 몬테카를로 Dropout을 오픈도메인(Open-Domain) 태스크에 적용하고, 예측 결과에 대한 불확실성을 측정하여 예측결과에 영향을 주는 모델의 성능을 측정해 효과성을 보인다.

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Language Model Evaluation Based on Korean-English Empathetic Dialogue Datasets and Personality (한국어-영어 공감대화 데이터셋과 성격을 기반으로 한 언어모델 평가)

  • Young-Jun Lee;JongHwan Hyeon;DoKyong Lee;Joo-Won Sung;Ho-Jin Choi
    • Annual Conference on Human and Language Technology
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    • 2023.10a
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    • pp.312-318
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    • 2023
  • 본 연구는 다양한 대규모 언어 모델들의 한국어/영어 공감 대화 생성에서 성능을 실험적으로 비교 분석하는 것과 개인의 성향과 공감 사이에서의 상관 관계를 실험적으로 분석하는 것을 목표로 한다. 이를 위해, 한국어 공감 대화 데이터셋인 KorEmpatheticDialogues 를 구축하였고, personality-aware prompting 방법을 제안한다. 실험을 통해, 총 18개의 언어 모델들 간의 공감 대화 생성 성능을 비교 분석하였고, 개인의 성향에 맞춤형 제공하는 공감이 더 상호작용을 이끌어낼 수 있다는 점을 보여준다. 코드와 데이터셋은 게재가 허용되면 공개할 예정이다.

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Prediction of Highy Pathogenic Avian Influenza(HPAI) Diffusion Path Using LSTM (LSTM을 활용한 고위험성 조류인플루엔자(HPAI) 확산 경로 예측)

  • Choi, Dae-Woo;Lee, Won-Been;Song, Yu-Han;Kang, Tae-Hun;Han, Ye-Ji
    • The Journal of Bigdata
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    • v.5 no.1
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    • pp.1-9
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    • 2020
  • The study was conducted with funding from the government (Ministry of Agriculture, Food and Rural Affairs) in 2018 with support from the Agricultural, Food, and Rural Affairs Agency, 318069-03-HD040, and in based on artificial intelligence-based HPAI spread analysis and patterning. The model that is actively used in time series and text mining recently is LSTM (Long Short-Term Memory Models) model utilizing deep learning model structure. The LSTM model is a model that emerged to resolve the Long-Term Dependency Problem that occurs during the Backpropagation Through Time (BPTT) process of RNN. LSTM models have resolved the problem of forecasting very well using variable sequence data, and are still widely used.In this paper study, we used the data of the Call Detailed Record (CDR) provided by KT to identify the migration path of people who are expected to be closely related to the virus. Introduce the results of predicting the path of movement by learning the LSTM model using the path of the person concerned. The results of this study could be used to predict the route of HPAI propagation and to select routes or areas to focus on quarantine and to reduce HPAI spread.

Performance Simulation of Turboprop Engine using SIMULINK$\circledR$ (SIMULINK$\circledR$를 이용한 터보프롭 엔진의 성능모사)

  • 공창덕;노흥석
    • Journal of the Korean Society of Propulsion Engineers
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    • v.5 no.2
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    • pp.44-50
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    • 2001
  • After modeling an aircraft turboprop engine using SIMULINK$\circledR$, performance simulation of PT6A-62 engine, which is main power plant of KT-1, was performed. For validation, performance parameters of the SIMULIINK model were compared with the simulated results by GASTURB program. It was confirm that the results by the SIMULINK model were well agreed with those by GASTURB within 1.07%, It was assumed that installation losses were bleed-air exteraction with a range from 0% to 5%, and power for accessories with a range from 0 to 20hp. In this investigation, it was found that the shafthorsepower was decreased by maxium 0.68%, but specific fuel consumption ratio was not effected nearly by these losses.

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