• 한국멀티미디어학회논문지
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• 제19권1호
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• pp.22-29
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• 2016

Hidden Markov Model is one of the most successful and popular tools for modeling real world sequential data. Real world signals come in a variety of shapes and variabilities, among which temporal and spectral ones are the prime targets that the HMM aims at. A new problem that is gaining increasing attention is characterizing missing observations in incomplete data sequences. They are incomplete in that there are holes or omitted measurements. The standard HMM algorithms have been developed for complete data with a measurements at each regular point in time. This paper presents a modified algorithm for a discrete HMM that allows substantial amount of omissions in the input sequence. Basically it is a variant of Baum-Welch which explicitly considers the case of isolated or a number of omissions in succession. The algorithm has been tested on online handwriting samples expressed in direction codes. An extensive set of experiments show that the HMM so modeled are highly flexible showing a consistent and robust performance regardless of the amount of omissions.

• Journal of the Korean Data and Information Science Society
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• 제17권1호
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• pp.245-257
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• 2006

A modified Anderson and Hauck(1983) test for analyzing a two-sequence two-period crossover design in bioequivalence trials is proposed when some observations at the second period are missing. It is based on the maximum likelihood estimators of average bioequivalence model and designed for handling missing at random(MAR) situation. The performance of the proposed test is compared to other tests using Monte Carlo simulations.

• 대한치과교정학회지
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• 제51권5호
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• pp.337-345
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• 2021

Objective: To investigate the phenotypes and predominant skeletodental pattern in pre-adolescent patients with Pierre-Robin sequence (PRS). Methods: The samples consisted of 26 Korean pre-adolescent PRS patients (11 boys and 15 girls; mean age at the investigation, 9.20 years) treated at the Department of Orthodontics, Seoul National University Dental Hospital between 1998 and 2019. Dental phenotypes, oral manifestation, cephalometric variables, and associated anomalies were investigated and statistically analyzed. Results: Congenitally missing teeth (CMT) were found in 34.6% of the patients (n = 9/26, 20 teeth, 2.22 teeth per patient) with 55.5% (n = 5/9) exhibiting bilaterally symmetric missing pattern. The mandibular incisors were the most common CMT (n = 11/20). Predominant skeletodental patterns included Class II relationship (57.7%), posteriorly positioned maxilla (76.9%) and mandible (92.3%), hyper-divergent pattern (92.3%), high gonial angle (65.4%), small mandibular body length to anterior cranial base ratio (65.4%), linguoversion of the maxillary incisors (76.9%), and linguoversion of the mandibular incisors (80.8%). Incomplete cleft palate (CP) of hard palate with complete CP of soft palate (61.5%) was the most frequently observed, followed by complete CP of hard and soft palate (19.2%) and CP of soft palate (19.2%) (p < 0.05). However, CP severity did not show a significant correlation with any cephalometric variables except incisor mandibular plane angle (p < 0.05). Five craniofacial and 15 extra-craniofacial anomalies were observed (53.8% patients); this implicated the need of routine screening. Conclusions: The results might provide primary data for individualized diagnosis and treatment planning for pre-adolescent PRS patients despite a single institution-based data.

• Journal of Ginseng Research
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• 제40권2호
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• pp.176-184
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• 2016

Background: Wild ginseng, Panax ginseng Meyer, is an endangered species of medicinal plants. In the present study, we analyzed variations within the ribosomal DNA (rDNA) cluster to gain insight into the genetic diversity of the Oriental ginseng, P. ginseng, at artificial plant cultivation. Methods: The roots of wild P. ginseng plants were sampled from a nonprotected natural population of the Russian Far East. The slides were prepared from leaf tissues using the squash technique for cytogenetic analysis. The 18S rDNA sequences were cloned and sequenced. The distribution of nucleotide diversity, recombination events, and interspecific phylogenies for the total 18S rDNA sequence data set was also examined. Results: In mesophyll cells, mononucleolar nuclei were estimated to be dominant (75.7%), while the remaining nuclei contained two to four nucleoli. Among the analyzed 18S rDNA clones, 20% were identical to the 18S rDNA sequence of P. ginseng from Japan, and other clones differed in one to six substitutions. The nucleotide polymorphism was more expressed at the positions 440-640 bp, and distributed in variable regions, expansion segments, and conservative elements of core structure. The phylogenetic analysis confirmed conspecificity of ginseng plants cultivated in different regions, with two fixed mutations between P. ginseng and other species. Conclusion: This study identified the evidences of the intragenomic nucleotide polymorphism in the 18S rDNA sequences of P. ginseng. These data suggest that, in cultivated plants, the observed genome instability may influence the synthesis of biologically active compounds, which are widely used in traditional medicine.

• 한국통신학회논문지
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• 제41권5호
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• pp.592-601
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• 2016

순환신경망은 순차적이거나 길이가 가변적인 데이터에 적합한 딥러닝 모델이다. LSTM은 순환신경망에서 나타나는 기울기 소멸문제를 해결함으로써 시퀀스 구성 요소간의 장기의존성을 유지 할 수 있다. 본 논문에서는 LSTM에 기반한 언어모델을 구성하여, 불완전한 한국어 문장이 입력으로 주어졌을 때 뒤 이어 나올 단어들을 예측하여 완전한 문장을 생성할 수 있는 방법을 제안한다. 제안된 방법을 평가하기 위해 여러 한국어 말뭉치를 이용하여 모델을 학습한 다음, 한국어 문장의 불완전한 부분을 생성하는 실험을 진행하였다. 실험 결과, 제시된 언어모델이 자연스러운 한국어 문장을 생성해 낼 수 있음을 확인하였다. 또한 문장 최소 단위를 어절로 설정한 모델이 다른 모델보다 문장 생성에서 더 우수한 결과를 보임을 밝혔다.

• 한국균학회지
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• 제41권4호
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• pp.205-211
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• 2013

한국산 흑주름버섯속(Melanophyllum)의 종 다양성과 분포상을 조사하는 과정에서 2종이 확인되었고, M. eyrei는 국내 미기록종과 M. haematospermum은 기존 보고된 종이었다. 종 동정은 형태학적 현미경적 특징을 기초로 이루어졌고, 또한 ITS 염기서열 분석을 통해 이루어졌다. 미기록종은 '청흑주름버섯'으로 신칭하고, 기록종인 잔피막흑주름버섯은 종의 특징을 보완하였다.

• 식물병연구
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• 제17권3호
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• pp.391-395
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• 2011

지금까지 우리나라에서 팽나무 뒷면흰가루병 및 병원균 Pleochaeta shiraiana의 존재에 대하여 확실하게 알려지지 않았으므로 이를 확인하기 위하여 고려대학교 표본실에 보존된 9개 시료를 대상으로 병원균의 무성세대와 유성세대의 형태적 특징을 현미경으로 관찰하고 기록하였다. 또한 4개 시료에서 획득한 ITS 염기서열을 일본의 2개 시료에서 알려진 자료와 비교하여 99% 이상의 상동성을 확인하였다. 이로써 P. shiraiana에 의한 뒷면흰가루병이 우리나라에서 발생함을 확인할 수 있었다.

• 혜화의학회지
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• 제24권1호
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• pp.15-24
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• 2015

Objectives : This study was carried out to assess the risk of bias of clinical trials on acne treatment with herbal medicine that have been published in Korea. Methods : 7 electronic databases in Korea were searched for clinical trials on acne treatment. Two independent reviewers selected clinical trials on herbal medicine treatment for acne. Selected studies are categorized according to DAMI(Study Design Algorithm for Medical literature of Intervention). RCTs are assessed according to Cochrane RoB(Risk of Bias), non-randomized studies(Before-after studies) are assessed according to RoBANS(Risk of Bias Assessment tool for Non-randomized Study). Results : After selection process, 25 articles are left. Among 25 articles, 3 RCTs and 4 before-after studies are finally included. In RCTs, the proportion of 'unclear' is high in criteria of 'random sequence generation', 'allocation concealment', and 'blinding'. In before-after studies, 'high' is high in criteria of 'blinding for outcome assessment' and 'incomplete outcome data'. Conclusions : Considering the above results of the assessment, it is necessary to conduct more well designed clinical trials on acne treatment with herbal medicine.

• ALGAE
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• 제26권4호
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• pp.289-297
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• 2011

Ceramium riosmenae sp. nov. is described from Baja California Sur, Mexico based on morphological and molecular data. The new species is characterized by erect thalli only, penetrating rhizoids on Gracilaria, 7-8 periaxial cells, five cortical initials per periaxial cell, complete cortication throughout, an average of 11-12 segments between branching points, rare adventitious branchlets, and cruciate tetrasporangia. Although C. riosmenae sp. nov. is similar to C. interruptum, C. sinicola, and C. codicola reported from Baja California Sur, Mexico in size and habit, it differs from these species in the number of cortical initials, habit, degree of cortication, host, and the shape of rhizoidal tips. C. riosmenae is separated from C. interruptum with interrupted cortication and four cortical initials from C. sinicola with spins near the apex and incomplete cortication near the base and from C. codicola with bulbous rhizoids on Codium. Our rbcL sequences reveal sufficient sequence divergence (2.4-3.9%) between C. riosmenae and C. interruptum, C. sinicola, and C. codicola to warrant species recognition and to separate C. riosmenae from these species on a phylogenetic tree.

• Journal of Animal Science and Technology
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• 제46권6호
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• pp.937-946
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• 2004

Duroc 품종은 돼지 사육에 있어 산육성과 육질 향상을 위해 이용되고 있다. 본 연구는 육종에 많이 이용되는 Duroc 품종의 모계 특이적인 서열의 검색과 계통유전학적 유연관계의 정립을 위하여 미토콘드리아 유전체의 전체 염기서열을 결정하고 집단 내 다형성을 조사하였다. mtDNA 전체 서열의 길이는 16,584-bp 이고, D-loop과 tRNA, rRNA 유전자 영역에서는 삽입/결실이 확인되었다. 4개의 coding gene (COⅡ, COⅢ, ND3, ND4)에서 불완전한 종결코돈을, ND4L과 ND2 유전자는 선택적 개시코돈 양상을 보였다. Duroc 집단에 대한 분석 결과 조절영역에서의 특이적인 11-bp 중복 단위가 일부 개체(15.2%)에서 발견되었고, ND2의 개시코돈과 CYTB 유전자에서도 다형현상을 보였다. 각각의 유전자 영역에서의 다형성은 서로 연관되어 있었고, 그 결과 Duroc 집단은 크게 두 가지 haplotype으로 구분되었다. 계통수에서 Duroc mtDNA 서열은 유럽계열 cluster에 위치하였으나, haplotype 분석과 기존에 연구결과들을 종합해 보면 Duroc 품종은 여러 모계선조 집단에서 기원한 것으로 보이며, 유럽과 아시아 계열 모두가 품종 형성에 이용된 것으로 사료된다된 것으로 사료된다.