• 한국세라믹학회지
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• 제45권4호
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• pp.238-244
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• 2008

Modeling and FEM analysis on Boron Nitride and/or Pyrolytic Carbon coating layers on SiC fibers under indentation contact loadings are investigated. Especially this study attempts to model the mechanical behavior of the SiC fibers with and without coatings. Tyranno S grade and Tyranno LoxM grade of SiC are selected for fiber and Boron Nitride and/or Pyrolytic Carbon as coating material. The modeling is performed by SiC fiber without coating layer, which includs single(BN or PyC) and double(BN-PyC or PyC-BN) coating layer. And then the analysis is performed by changing a type of coating layer, a type of fiber and coating sequence. In this study, the concepts of modeling and analysis techniques for optimum design of BN and PyC coating process on SiC fiber are shown. Results show that stresses are reduced when indentation contact loading applies on the material having lower elastic modulus.

• Molecules and Cells
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• 제37권1호
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• pp.36-42
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• 2014

The tomato (Solanum lycopersicum L.) is a model plant for genome research in Solanaceae, as well as for studying crop breeding. Genome-wide single nucleotide polymorphisms (SNPs) are a valuable resource in genetic research and breeding. However, to do discovery of genome-wide SNPs, most methods require expensive high-depth sequencing. Here, we describe a method for SNP calling using a modified version of SAMtools that improved its sensitivity. We analyzed 90 Gb of raw sequence data from next-generation sequencing of two resequencing and seven transcriptome data sets from several tomato accessions. Our study identified 4,812,432 non-redundant SNPs. Moreover, the workflow of SNP calling was improved by aligning the reference genome with its own raw data. Using this approach, 131,785 SNPs were discovered from transcriptome data of seven accessions. In addition, 4,680,647 SNPs were identified from the genome of S. pimpinellifolium, which are 60 times more than 71,637 of the PI212816 transcriptome. SNP distribution was compared between the whole genome and transcriptome of S. pimpinellifolium. Moreover, we surveyed the location of SNPs within genic and intergenic regions. Our results indicated that the sufficient genome-wide SNP markers and very sensitive SNP calling method allow for application of marker assisted breeding and genome-wide association studies.

• International Journal of Computer Science & Network Security
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• 제23권11호
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• pp.77-82
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• 2023

The article considers online discussion as an interactive learning method in the conditions of distance learning. The essence of discussion and the stages of its organization are described. The main objective of discussion in distance learning is defined as the stimulation of interest in learning and the involvement of various viewpoints in an active discussion of the stated problems. The key role in ensuring the efficiency of a discussion is identified. The article develops a model for organizing asynchronous online discussions on the Moodle platform, highlighting the sequence of stages and their content. An experimental study of the use of the discussion method in the training of students in distance learning conditions is carried out. Based on the results of the methodological experiment, conclusions are drawn about student interest in online discussions. The authors conclude that the interest of students of different specialties in asynchronous online discussions varies, and the greatest interest is demonstrated by linguistics students. Nevertheless, the differences in student interest in online discussions by groups (specialties) are more likely attributable to subjective factors, which do not affect the overall picture in a major way.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 2006년도 학술대회
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• pp.283-288
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• 2006

In the future television broadcasting a flood of information from various sources will not always be welcomed by everyone. The need of accessing specific information as required is becoming a necessity. We are interested to make the life of television consumer easier by providing an intelligent television set which can adaptively proposed certain shows to the viewer based on the user historical consumed shows. The TV watching history data consists of TV program titles with their respective genres, channels, watched times and durations, etc. The method proposed is by utilizing Hidden Markov Model (HMM) to model the user preference of kind of genres the viewer will watch based on recorded genres of several weeks time. We take watching schedule from 6 PM to midnight as boundary. The range thus divided into 3 independent time band of 2 hours each resulting in 3 time bands from 6 PM to 8 PM, 8 PM to 10 PM, and lastly 10 PM to midnight. Each time band will be represented by an HMM. From each HMM we can generate a sequence of predicted genre that the user will probably watch during corresponding time-band. Our approach assumes that the user shows a consistent behavior of watching pattern in week to week basis and during the moment of watching TV. To asses the method performance experiment is conducted using real data collected from December 2002 to May 2003. Some user's data are selected and based on that predictions are made. The resulting predictions are then compared with the actual user's history. The experiment shows satisfactory result for user with middle to high consistent behavior level.

• 한국국방경영분석학회지
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• 제36권1호
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• pp.15-27
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• 2010

현대전에 있어서 대량의 화력, 신속한 기동력은 전승의 핵심요소이기 때문에 전쟁에서 승리하기 위해서는 이에 대한 과학적인 운용이 요구된다. 따라서 첨단기술을 이용한 치밀한 화력계획과 신속 정확한 타격으로 적에게 치명적인 피해를 줄 수 있어야 한다. 특히 사격이 작전개시 전에 미리 계획하여 수행하게 되는 경우는 표적별 사격 필요량에 의해 사격부대의 사격량을 할당함과 동시에 사격순서를 결정한 후 전체사격시간을 최소화함으로써 사격의 효과를 높일 수 있다. 따라서 본 연구에서는 이러한 사격완료시간을 최소화하기 위하여 동시에 표적을 타격하는 경우와 현재 야전부대에서 운용하고 있는 개별적으로 사격하는 문제 그리고 사격부대를 혼합하여 사격하는 경우의 최적의 사격완료시간을 비교하고, 사격시간 최소화를 위해 각 표적을 어떻게 할당할 것인지 수리모형을 이용하여 방안을 제시함으로써 작전계획에 맞는 사격계획표를 작성하는 것이다.

• 통상정보연구
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• 제9권2호
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• pp.19-40
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• 2007

In recent, T-commerce is widely dispersed as alternative type of commerce. It is forecasted that t-commerce system is used more than e-commerce system. Therefore more and more t-commerce-related industries are also recognizing that t-commerce is a critical business model. It is needed to understand the concept of t-commerce and develop the t-commerce marketing strategy. CEO analyses consumer's behaviors according to the data about buyers and applies the advantage of t-commerce to the communication with customers. This t-commerce system plays an important role in maximizing customer satisfaction and affecting their intention to reuse it. Therefore this paper attempts to identify T-commerce critical success factors and divide between use-intention group and unuse-intention group by taking out a discriminant function by the discriminant analysis. This lays a foundation in developing T-commerce strategy. According to the discriminant function extracted, convenience factor, amusement factor, system quality factor, product perception factor are significant in the sequence of influential degree. However, usefulness factor and speedy connection factor are not significant. In result, the target hitting rate is 77.9% in the first unuse-intention group and it is 95.2% in the second use-intention group. The total discriminant target hitting rate is computed to higher value, 86.55%. The statistic package, SPSS 12.0, is used to survey and analyse data and test the hypothesis. The validity and reliability of variables are verified by both reliability analysis and factor analysis. The discriminant analysis is used to tell the difference between use-intention group and unuse-intention group.

• 한국산학기술학회논문지
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• 제16권4호
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• pp.2757-2763
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• 2015

p-Snake는 기존의 동적윤곽모델(Active Contour Model)에 원형에너지를 추가로 적용한 에너지 최소화 알고리즘으로 에지 정보가 명확하지 않은 영역에서의 윤곽선 추출을 위해 사용된 방법이다. 본 논문에서는 원과 직선 프리미티브(primitive)의 조합으로 표현되는 가변 원형(prototype)과 퍼지 함수를 적용한 원형에너지장의 생성 기법을 제안하여 p-Snake의 윤곽선 추출 성능을 개선하였다. 제안 방법은 입력된 부품 코드를 기반으로 원형을 정의하고 전처리 과정을 통해 구해진 각 프리미티브 구간에서 대략적인 초기 윤곽을 검출한 후, 프리미티브들이 가변적으로 적응하여 원형을 생성하고 여기에 원형과의 거리에 따른 윤곽 확률을 퍼지 함수를 통해 계산하여 원형에너지 장을 생성하였다. 이를 p-Snake에 적용하여 다양한 소형부품들을 대상으로 준비한 200장의 영상에서 윤곽선을 검출하고, 원형과의 유사도를 비교한 결과 적응 원형을 사용한 p-Snake가 기존의 Snake에 비해 약 4.6% 가량 우수함을 보였다.

• Annals of Clinical Neurophysiology
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• 제2권2호
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• pp.119-124
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• 2000

Background : We studied EEG changes during pilocarpine-induced status epilepticus(SE), a widely used model whose EEG characteristics have not been fully described previously. Methods : Male Sprague-Dawley rats weighing 250-350 grams were used as subjects. SE was induced 5-7 days after placement of chronic epidural electrodes, using 360-380 mg/Kg pilocarpine IP. Rats were observed with continuous EEG recording following pilocarpine injection until end of the SE episode. Results : SE occurred in 10/12 rats studied. SE began with a series of discrete seizures $11.1{\pm}3.93$ minutes after pilocarpine injection. $5.2{\pm}2.71$ seizures occurred over $10.9{\pm}4.62$ minutes, until the EEG converted to a waxing and waning pattern, during which the amplitude and frequency of epileptiform activity increased. After $1.4{\pm}1.82$ minutes, a pattern of continuous high amplitude rapid spiking was established. Continuous spiking continued for $3.4{\pm}0.48$ hours with a very gradual decline in amplitude and frequency, until periodic epileptiform discharges(PEDs) began to occur. The EEG consisted primarily of PEDs for another $7.4{\pm}3.09$ hours, until electrographic generalized seizures began to occur. These continued for $5.8{\pm}4.82$ hours until death. Duration of SE was $17.0{\pm}5.88$ hours. Flat periods were a prominent feature during all EEG patterns in this model. Conclusion : EEG features distinctive in pilocarpine SE(but not unique to it) include flat periods during all patterns and resumption of continuous spiking episodes after the onset of PEDs. The sequence of discrete seizures to waxing and waning to continuous spiking to PEDs was identical to that which has been described in humans and other animal models.

• 천문학논총
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• 제30권2호
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• pp.201-204
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• 2015

The common-envelope process is a complicated phase in binary evolution. A lot of effort has been dedicated to study the common-envelope stage, but many questions related to this process are yet to be answered. If one member of the binary survives the common-envelope phase, the binary will emerge as a white dwarf accompanied by a low-mass main sequence star in close orbit, often referred as a post common-envelope binary (PCEB). SDSS J0745+2631 is among the list of newly found PCEBs from the Sloan Digital Sky Survey (SDSS). This star is proposed to be a strong eclipsing system candidate due to the ellipsoidal modulation in its light curve. In this work, we aim to confirm the eclipsing nature of SDSS J0745+2631 and to determine the stellar and orbital parameters using the software Binary Maker 3.0 (BM3.0). We detected the primary eclipse in the light curve of SDSS J0745+2631 in our follow-up observation from January 2014 using the ULTRASPEC instrument at the Thai National Observatory. The data obtained on 7th and 8th January 2014 in g filter show an evident drop in brightness during the eclipse of the white dwarf, but this eclipse is less prominent in the data taken on the next night using a clear filter. According to our preliminary model, we find that SDSS J0745+2631 hosts a rather hot white dwarf with an effective temperature of 11500K. The companion star is a red dwarf star with a temperature of 3800K and radius of 0.3100 $R_{\odot}$. The red dwarf star almost fills its Roche lobe, causing a large ellipsoidal modulation. The mass ratio of the binary given by the Binary Maker 3.0 (BM3.0) model is M2/M1 = 0.33.

• Journal of Biosystems Engineering
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• 제38권1호
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• pp.1-8
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• 2013

Purpose: Path planning and tracking algorithms applicable to various agricultural operations, such as tillage, planting, and spraying, are needed to generate steering angles for auto-guidance tractors to track a point ahead on the path. An optimal coverage path algorithm can enable a vehicle to effectively travel across a field by following a sequence of parallel paths with fixed spacing. This study proposes a path generation and tracking algorithm for an auto-guided Korean tractor with a tillage implement that generates a path with C-type turns and follows the generated path in a paddy field. A mathematical model was developed to generate a waypoint path for a tractor in a field. This waypoint path generation model was based on minimum tractor turning radius, waypoint intervals and LBOs (Limit of Boundary Offsets). At each location, the steering angle was calculated by comparing the waypoint angle and heading angle of the tractor. A path following program was developed with Labview-CVI to automatically read the waypoints and generate steering angles for the tractor to proceed to the next waypoint. A feasibility test of the developed program for real-time path tracking was performed with a mobile platform traveling on flat ground. The test results showed that the developed algorithm generated the desired path and steering angles with acceptable accuracy.