• Journal of Intelligence and Information Systems
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• v.14 no.1
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• pp.101-115
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• 2008

Combining collaborative filtering with some other technique is most common in hybrid recommender systems. As many recommended items from collaborative filtering seem to be similar with respect to content, the collaborative-content hybrid system suffers in terms of quality recommendation and recommending new items as well. To alleviate such problem, we have developed a novel method that uses a diversity metric to select the dissimilar items among the recommended items from collaborative filtering, which together with the input when fed into content space let us improve and include new items in the recommendation. We present experimental results on movielens dataset that shows how our approach performs better than simple content-based system and naive hybrid system.

• Journal of the Korea Society of Computer and Information
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• v.27 no.10
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• pp.19-28
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• 2022

In this paper, we propose the Detector Scheduler which determines the best tracking-by-detection (TBD) mechanism to perform real-time high-accurate multi-object tracking (MOT). The Detector Scheduler determines whether to run a detector by measuring the dissimilarity of features between different frames. Furthermore, we propose a self-supervision method to learn the Detector Scheduler with tracking results since it is difficult to generate ground truth (GT) for learning the Detector Scheduler. Our proposed self-supervision method generates pseudo labels on whether to run a detector when the dissimilarity of the object cardinality or appearance between frames increases. To this end, we propose the Detector Scheduling Loss to learn the Detector Scheduler. As a result, our proposed method achieves real-time high-accurate multi-object tracking by boosting the overall tracking speed while keeping the tracking accuracy at most.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1995.04a
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• pp.496-500
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• 1995

전문가 내지 구성원의 주관적인 의견에 의존하는 방법의 하나인 델파이법(Delphi Method)은 관련자료가 불충분한 중.장기 예측, 전략결정 등에 이용되고 있다. 이 방법을 더욱 발전시킨 퍼지 델파이법(Fuzzy Delphi Method)은 델파이법에 퍼지숫자(fuzzy number)의 개념을 도입하여 정확한 예측을 하고자 하는 것이다. 또한 이러한 예측치가 삼각 퍼지 숫자(Triangular Fuzzy Number)로 주어져 불확실성에 대한 예측과 의견종합을 쉽게 하며, 전문가에 의해 추정된 삼각 퍼지 숫자의 입력을 토애 그 추정치들의 비유사도(Dissemblance Index)와 퍼지거리(fuzzy distance)를 계산하고 간단한 그래프를 다시 전문가에게 피드백(feedback)할 수 있도록 나타내어지는 과정을 code화하여 전문가들로 하여금 다양한 정보를 통하여 좀 더 정확한 추정치를 예측하고자 한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2023.05a
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• pp.459-460
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• 2023

기존의 추천시스템은 상품간 혹은 사용자 간의 유사도를 기반으로 작동한다. 하지만 이는 사용자가 유사한 상품 추천 속에 갇히게 되는 필터 버블의 문제와 추천시스템의 고질적인 문제인 데이터 희소성 문제를 피할 수 없게 된다. 따라서 본 연구에서는 사용자의 취향과 체형 정보를 반영하여 사용자의 평점을 예측하는 협업 필터링 기반 딥러닝 추천과 상품간 비유사성을 고려하여 사용자의 평점을 예측하는 내용 기반 추천을 혼합한 하이브리드 추천 모델을 구축하여 기존 추천시스템의 문제점을 해결하였다. 모델의 성능평가를 위해 인터넷 의류 쇼핑몰을 대상으로 유사한 이미지를 활용한 하이브리드 추천 모델과 NDCG 값을 비교하였고 유사도가 낮은 이미지를 활용한 모델이 더 우수한 성능을 보였다. 이는 다른 제품과는 달리 소비자가 의류를 구매할 경우 이미 구매한 상품과 유사한 상품보다는 유사하지 않은 상품을 구매할 가능성이 크다는 것을 보여준다.

• Korean Journal of Plant Taxonomy
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• v.40 no.2
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• pp.118-129
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• 2010

A taxonomic study of Viola albida complex, containing the representative individuals of three taxa, V. albida var. albida, V. albida var. chaerophylloides, and V. albida var. takahashii, was done based on RAPD data. The amplified loci were 476 in total; obtained with 68 universal primers on seven OTUs. Nei's genetic dissimilarity appeared relatively low within individuals of V. albida var. albida and V. albida var. chaerophylloides (0.118-0.171 and 0.051 respectively), however, it was higher in individuals of V. albida var. takahashii (0.348). On the other hand, there is no specific trend in terms of genetic dissimilartiy among taxa, such as between individuals of V. albida var. albida and V. albida var. takahashii, between those of V. albida var. albida and V. albida var. chaerophylloides, and between those of V. albida var. albida and V. albida var. takahashii. The similarity of OTUs studied is high in clustering analysis, so that this result is compatible with the establishment of this complex. All OTUs are clustered within two groups. The individuals of V. albida var. takahashii, however, are clustered both to the group of V. albida var. albida and to the group of V. albida var. chaerophylloides, meaning that the genetic difference is high which would be commensurate with their morphological variations.

• Journal of Life Science
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• v.24 no.11
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• pp.1174-1179
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• 2014

This research was carried out to evaluate whether gamma ray is a useful tool for breeding new strains of mushrooms. For this research, 5 mutant groups, 20 strains of Hypsizigus marmoreus, 2 strains of Lyophyllum decastes, and 1 strain of Lyophyllum shimeji were used. Monokaryon spores from one variety of H. marmoreus were irradiated with 50~2,000 Gy of gamma ray. The propriety dose was 50~200 Gy for mutagenesis. Mutant monokaryon mycelia crossed each order to become dikaryon mycelia. The internal transcribed spacer (ITS) regions of rDNA were amplified using PCR, and the products were sequenced. The sequences of the ITS regions (16 partial rDNA, complete ITS1, 5.8 rDNA and partial rDNA) were analyzed by PCR, and strains of H. marmoreus, L. decastes, and L. shimeji were auto-sequenced. The lengths of the sequenced ITSs were 1,052~1,143 nucleotides. Genetic matrices were calculated using Nei-Li's genetic distance coefficient based on ITS sequence. The dissimilarities were 0~3.35% in strains of H. Hypsizigus. In addition, a phylogenetic tree was constructed based on ITS sequences using the neighbor-joining (NJ) method. The phylogenetic tree revealed that 23 strains and 5 mutant groups were divided into 12 clusters; the mutant groups fell into different clusters. These results show that mushroom spores were mutated effectively by gamma ray; therefore, gamma ray could be a useful tool for breeding new strains of mushrooms.

• Journal of Life Science
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• v.22 no.11
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• pp.1470-1476
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• 2012

A genetic variation of Lepista nuda and two genus Lepista species (L. irina and L. sordida) were analyzed by random amplified polymorphic DNA (RAPD) and internal transcribed spacer (ITS) sequence analysis. In the resulting RAPD analysis, 22 out of 40 random primers amplified polymorphic RAPD fragment patterns, the amplified bands were 355, and DNA fragment sizes were 200-400bp. Intraspecific genetic dissimilarity of the 10 L. nuda strains were calculated to range from 0% to 21.60%, L. sordida from 16.93% to 24.82%, L. irina were 20.62% to 25.54%, and intraspecific genetic dissimilarity of L. sordida and L. irina was 23.49%. The 673 base pairs were sequenced during the analysis of the ITS I and II region; six L. nuda strains intraspecific genetic dissimilarities ranged from 1.58% to 11.47%, L. nuda and L. sordida from 3.83% to 12.88%, L. nuda and L. irina from 7.11% to 15.61%, and intra-specific genetic variation between L. sordida and L. irina was 4.79%. The findings showed that RAPD and ITS sequencing could be used for developing molecular genetic markers and screening of unidentified genus Lepista species.

• Korean Journal of Plant Resources
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• v.22 no.2
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• pp.152-158
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• 2009

We performed RAPD analysis to investigate the inter-/intraspecific relationships and regional variations of Phragmites japonica and P. communis according to the environmental change. One hundred and fourty nine genetic effective polymorphic bands between 300 bp and 1,900 bp were marked from RAPD PCR with nine oligoprimers. From the RAPD analysis by Nei-Li's genetic distance, the dissimilarity indices among the populations of Phragmites japonica were relatively low from 0.012 to 0.061, and Phragmites communis were also low from 0.033 to 0.095. It showed the close genetic relationships among the same species populations, and both species were distinctly independent with relatively high level of dissimilarity indices (0.043 - 0.132). The obvious genetic markers to distinguish two species were confirmed and those profiles were suggested. From the UPGMA phenogram by RAPD analysis, both species showed the water environment related cluster patterns by distributional regions. RAPD analysis was useful to delimit two species taxonomically and to investigate the genetic relationships among inter-/intraspecific populations.

• Journal of Plant Biotechnology
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• v.31 no.1
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• pp.19-23
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• 2004

This study was conducted to observe the morphological characteristics and to analyse genetic relationship using RAPD markers in 9 species of Iris. The period of flowering was shown very broad among 9 species of Iris, from April 22 to June 9. The flower stalk was fluctuated from 9.0cm (I. rossii) to 104.0cm (I. ensata). I. ensata has the largest flower size and followed by I. laevigata, I. tectorum, I. sanguinea, I. pseudacorus, I. lactea, I. rossii, I. minutoaurea, I. odaesanensis. Among the 108 amplified bands by PCR with 8 random primers, 107 showed polymorphism and only one showed monomorphism among 9 species of Iris. The average dissimilarity coefficient among 9 species of Iris was 0.252. The range of dissimilarity coefficient was shown as from 0.095 to 0.609. Nine species were divided into three groups. The first group was I. tectorum, and the second group was I. lactea, I. laevigata, I. pseudacorus, I. odaesanensis. I. minutoaurea, I. rossii, I. sanguinea, I. ensata were belong to group three.

• Korean Journal of Plant Taxonomy
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• v.38 no.1
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• pp.17-29
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• 2008

Phylogenetic relationships were examined for 17 taxa of Lycoris by RAPD analysis. The length of the amplified DNA fragments ranged from 300 bp to 1,700 bp. 57 scorable RAPD markers were observed from PCR reactions with five random oligoprimers. The analysis by UPGMA sepatated the examined taxa of Lycoris into were clusters. First group was comprised of ten taxa of L. chinensis var. sinuolata, L. sanguinea var. koreana, L. uydoensis, L. flavescens, L. radiata var. pumila, L. radiata, L. squamigera, L. chejuensis, L. aurea and L. guangxiensis, second group of L. haywardii, L. sprengeri, L. rosea, L. straminea and L. houdyshii, third group of outgroup of Narcissus tazetta var. chinensis and Crinum asiaticum var. japonicum. From the viewpoint of cytological characters such as polyploidy and karyotype, the RAPD analysis was very useful to show the relationship among the intraspecific taxa of Lycoris.