• The Journal of Korean Institute of Communications and Information Sciences
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• v.38C no.6
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• pp.503-511
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• 2013

This paper presents a speech enhancement method using non-negative matrix factorization. In training phase, we can obtain each basis matrix from speech and specific noise database. After training phase, the noisy signal is separated from the speech and noise estimate using basis matrix in enhancement phase. In order to improve the performance, we model the change of encoding matrix from training phase to enhancement phase using independent Gaussian distribution models, and then use the constraint of the objective function almost same as that of the above Gaussian models. Also, we perform a smoothing operation to the encoding matrix by taking into account previous value. Last, we apply the Log-Spectral Amplitude type algorithm as gain function.

• Journal of the Institute of Electronics and Information Engineers
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• v.54 no.2
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• pp.99-105
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• 2017

Generally, stereo matching methods are used to estimate depth information based on color and spatial similarity. However, most depth estimation methods suffer from the occlusion region because occlusion regions cause inaccurate depth information. Moreover, they do not consider the temporal dimension when estimating the disparity. In this paper, we propose a temporal stereo matching method, considering occlusion and disregarding inaccurate temporal depth information. First, we apply a global stereo matching algorithm to estimate the depth information, we segment the image to occlusion and non-occlusion regions. After occlusion detection, we fill the occluded region with a reasonable disparity value that are obtained from neighboring pixels of the current pixel. Then, we apply a temporal disparity estimation method using the reliable information. Experimental results show that our method detects more accurate occlusion regions, compared to a conventional method. The proposed method increases the temporal consistency of estimated disparity maps and outperforms per-frame methods in noisy images.

• The Korean Journal of Applied Statistics
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• v.28 no.2
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• pp.137-149
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• 2015

Flood planning needs to recognize trends for extreme precipitation events. Especially, the r-year return level is a common measure for extreme events. In this paper, we present a nonstationary temporal model for precipitation return levels using a hierarchical Bayesian modeling. For intensity, we model annual maximum daily precipitation measured in Korea with a generalized extreme value (GEV). The temporal dependence among the return levels is incorporated to the model for GEV model parameters and a linear model with autoregressive error terms. We apply the proposed model to precipitation data collected from various stations in Korea from 1973 to 2011.

• Journal of Oral Medicine and Pain
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• v.25 no.3
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• pp.265-276
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• 2000

스트레스가 타액선 조직을 변형시키고 파괴시킬 수 있다는 것은 이미 보고된 바 있다. 이는 구속스트레스 시에 관찰되는 apoptosis에 의한 것인데, 이 과정에 관여하는 caspase-3는 세포의 DNA를 분절시킴으로서 apoptosis를 일으킨다고 알려진 세포내 단백효소이다. 이에 기존에 관찰되었던 구속 스트레스에 의한 apoptosis의 형태적 변화가 apoptosis를 유도하는 caspase-3와 어떠한 시기적 상관관계를 가지고 있는지를 구명하기 위하여 본 실험을 시행하였다. 웅성 백서 (Sprague-Dawley, 8주) 를 사용하여 실험 전 기간에 걸쳐 구속스트레스를 가한 후 30분, 1시간, 3시간, 6시간, 24시간, 3일, 5일, 7일에 희생시켰다. 그 후 실험동물의 악하선을 절취하여 동결절편을 제작한 후, caspase-3에 대한 형광항체로 면역형광법을 시행하여 관찰하였다. 1. 정상대조군에서는 caspase-3가 타액선 조직 전반에서 미약하게 관찰되었다. 2. 구속스트레스 부여 30분에서 caspase-3는 강반응을 보였고, 실험기간이 경과됨에따라 점차 6시간군에서 부터는 현저히 감소하였다. 3. Caspase-3는 구속 스트레스 30분에 도관과 선포세포 모두에서 발현되었으나, 선포세포에서는 조기에 급격히 소실되었고 도관세포에서는 전 실험 기간에 걸쳐 서서히 소실되었다. 이와 같은 연구 결과에서, 세포내 caspase-3는 조직의 형태적 변화가 나타나기 이전에 발현하는 것으로 보아 caspase-3는 형태적 변화를 예견할 수 있는 진단 지표로 사용될 수 있을 것으로 사료되며 이후 임상적으로 적용하기 위한 지속적인 연구가 필요할 것으로 생각된다.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.29 no.1
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• pp.225-234
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• 2019

Bitcoin is a cryptocurrency with characteristics such as de-centralization and distributed ledger, and these features are maintained through a mining system called "proof of work". In the mining system, mining difficulty is adjusted to keep the block generation time constant. However, Bitcoin's current method to update mining difficulty does not reflect the future hash power, so the block generation time can not be kept constant and the error occurs between designed time and real time. This increases the inconsistency between block generation and real world and causes problems such as not meeting deadlines of transaction and exposing the vulnerability to coin-hopping attack. Previous studies to keep the block generation time constant still have the error. In this paper, we propose a machine-learning based method to reduce the error. By training with the previous hash power, we predict the future hash power and adjust the mining difficulty. Our experimental result shows that the error rate can be reduced by about 36% compared with the current method.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.514-514
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• 2022

쌀 공급과잉이 사회적 문제가 되면서 논에 타작물 재배를 위한 논의 다각적 활용 시스템 구축이 매우 중요해지고 있다. 정부는 이러한 논의 다각적 활용을 위해 2020년에 우리나라 최초의 농지범용화 시범사업 지구를 선정하였다. 전북 김제시 옥성지구는 농지범용화 시범사업 지구로 선정되어 용·배수로 정비가 실시되었다. 따라서 본 연구에서는 전북 김제시 옥성지구 용배수로 정비의 효과를 살펴보기 위해 시범사업 전후의 주요 영농여건 변화 실태를 살펴보았다. 이를 위해 본 연구에서는 농업경영체 DB, 흙토람 등을 이용해 옥성지구 일대 수혜 필지와 비수혜 필지를 추출하고, 각 필지별 실제 경작자 명단을 작성 후 1:1 면담 조사를 실시하였다. 옥성지구 농지범용화 시범사업 면적은 총 50.4ha인데, 169개 필지로 구성되었다. 이 중에서 129개 필지의 총 69명의 경작자 명단이 작성되었다. 그리고 본 연구의 조사에 총 30명이 참여했고, 이 가운데 수혜구역과 비수혜구역의 논을 동시에 경작하고 있는 9농가를 대상으로 논의 다각적 활용을 위한 용·배수 정비 전후의 성과를 조사하여 분석하였다. 첫째, 9농가는 모두 논콩을 재배하고 있다. 이들의 평균 논콩 재배면적은 2020년 1.76ha에서 2021년에는 2.22ha로 증가했다. 그리고 논콩 10a 당 생산량을 살펴보면, 2020년 355.8kg/10a에서 2021년에는 567.2kg/10a로 사업 전후 논콩 단수가 211.4kg/10a 증가했다. 평균 우리나라 전국 콩의 생산량이 203kg/10a, 전북 248kg/10a(2021년 기준)인데 반해 농지범용화 시범사업 지구의 논콩 생산성은 전국 평균보다 높은 것을 알 수 있다. 따라서 논의 다각적 활용을 위한 용배수로 정비를 통해 평균 단수는 211.4kg/10a 증가하기 때문에, 용배수로 정비는 논타작물 생산성 향상에 기여하고 있는 것을 알 수 있다. 둘째, 논의 다각적 활용을 위한 용배수로 정비 이전에 평균 침수 시간은 24시간 이내였다. 이러한 침수로 인해 논콩 재배농가들은 대부분 논타작물 재배의 어려움을 겪었다. 하지만 용배수로 정비 후 평균 침수 시간은 3시간 이내로 단축되었다. 이러한 침수시간 단축은 논콩 생산비 절감으로 이어져 용배수로 정비 후 시범사업 수혜 농가들의 논콩 직접생산비는 10a당 210,200원으로 전년 대비 34,250원/10a 감소하였다.

• Korean Journal of Medicinal Crop Science
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• v.4 no.4
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• pp.308-313
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• 1996

The appropriate drying method in medicinal compounds and color of peony root was that predrying at briquet fire $(40{\sim}60^{\circ}C)$ for 6 hours or more, and then hot air drying at $40^{\circ}C$ during 60 hours. But this method needs too much time in drying. And the method that drying at $40^{\sim}C$ with hot air drying has bad result in color. In case Peony was seld by cutting product, before cutting, the Peony root was retted for 30 min. and sealed for 12 hrs. is good for drying time, Peoniflorin content and commodity.

• Journal of the Korea Institute of Building Construction
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• v.10 no.1
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• pp.163-173
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• 2010

A significant number of projects have been managed by US Army Corps of Engineers FED. Today, more information must be provided to the parties involved in the projects by phase than ever before. Specifically, USFK`s construction projects have been managed by FED(Far East District). Recently, however, large US private construction companies have been filling the role previously taken by FED. However, there is few construction managers to implement FED project in Korea. Accordingly, this study analyzes FED projects practices with focus on the construction management actors in order to suggest guideline. This study suggests a model FED construction process(Bid, Contract, Construction, As-Built Phase) by analyzing the existing FED project process using a IDEF0 methodology.

• Journal of the Korea Computer Graphics Society
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• v.9 no.3
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• pp.23-29
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• 2003

There is the temporal correlation of the video sequence between the motion vector of current block and the motion vector of the previous block. If we can obtain useful and enough information from the motion vector of the same coordinate block of the previous frame, the total number of search points used to find the motion vector of the current block may be reduced significantly. In this paper, we propose the block-matching motion estimation using an adaptive initial search point by the predicted motion information from the same block of the previous frame. And the first search point of the proposed algorithm is moved an initial point on the location of being possibility and the searching process after moving the first search point is processed according to the fast search pattern. Simulation results show that PSNR(Peak-to-Signal Noise Ratio) values are improved UP to the 1.05dB as depend on the image sequences and improved about 0.33~0.37dB on an average. Search times are reduced about 29~97% than the other fast search algorithms. Simulation results also show that the performance of the proposed scheme gives better subjective picture quality than the other fast search algorithms and is closer to that of the FS(Full Search) algorithm.

• Journal of Korea Entertainment Industry Association
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• v.15 no.4
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• pp.113-125
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• 2021

This research has the purpose to approach 'Audience participation theatre' through applying the concept of 'Hybrid' which newly come to the fore after 21st in a theatre space. In fact, 'Hybrid' has been suppling crucial power to create and pass a culture down for a long time, and it could not different to a theatre space. The hybridity in previous traditional theatre which is central 'text' and 'architectural theater' is limited movement only on the stage, such as 'an actor between presence and absence', 'a theatrical time between real and fiction' and 'an objet between An Sich(thing itself) and Fur Sich(thing with inner meaning). However after 20st's 'Avant-Garde' with 'decomposition sprit', the hybridity become broader from only on the stage to entire theatre space including auditorium caused by collapse the boundary between auditorium and stage. In other words, 'auditorium' and 'audience' are considered as 'a theatrical element' coequal with other elements, and it can create various special results through they are mixed equally. Therefore, 'Audience participation theatre' could regarded a kind of hybrid phenomenon between 'auditorium and audience' and 'actor and stage' which are most disparate relation, and it is also approached 'hybridized audience', 'hybridized space' and 'hybridized text' as a new identity.