• Title/Summary/Keyword: 유사성 탐색

Search Result 492, Processing Time 0.03 seconds

Hydrolytic and Metabolic Capacities of Thermophilic Geobacillus Isolated from Litter Deposit of a Lakeshore (수변 낙엽퇴적층에서 분리한 호열성 Geobacillus의 물질 분해 특성)

  • Baek, Hyun-Ju;Zo, Young-Gun;Ahn, Tae-Seok
    • Korean Journal of Microbiology
    • /
    • v.45 no.1
    • /
    • pp.32-40
    • /
    • 2009
  • To understand contribution of thermophilic microorganisms in decomposition of litter deposits on shore of lakes, we surveyed a lakeshore litter deposit for bacteria growing at $60^{\circ}C$. Ten thermophilic isolates were selected for in-depth characterization, based on their high capacity to degrade high molecular weight organic compounds. Based on phylogenetic analysis on their 16S rRNA gene sequences, all isolates were identified as Geobacillus. The optimal growth temperature and pH of the strains ranged $55{\sim}60^{\circ}C$ and 6.0${\sim}$8.0, respectively. Salinity was inhibitory to the growth of the isolates, showing marked decrease of growth rates at 3% salinity. Based on activities of hydrolytic enzymes and profiles of carbohydrate utilization (determined by API 50 CHB kit), three G. stearothermophilus strains showed patterns clearly distinctive from other isolates. Two G. kaustophilus strains also demonstrated distinctiveness in their metabolic pattern and ecological parameters. However, ecological and metabolic profiles of the other five isolates were more variable and showed some degree of digression from their phylogenetic classification. Therefore, it could be concluded that endospore-forming thermophilic bacteria in lakeshore litter deposits contribute to degradation of organic materials with diverse ecological niches while having successions similar to microbial flora in compost. We propose that the thermophilic isolates and/or their thermo-tolerant enzymes can be applied to industrial processes as appropriate mixtures.

Effect of Salt Fermentation on the Physicochemical Properties and Antioxidant Activities of Sea Urchin Roe from Anthocidaris crassispina and Pseudocentrotus depressus (염장처리가 성게 알의 이화학 품질 특성과 산화방지 활성에 미치는 영향)

  • Choi, Bogyoung;Surh, Jeonghee
    • Korean Journal of Food Science and Technology
    • /
    • v.47 no.4
    • /
    • pp.460-467
    • /
    • 2015
  • Sea urchin roe obtained from Anthocidaris crassispina and Pseudocentrotus depressus was briefly salt-fermented (5%), followed by ethanol treatment (1%) and the physicochemical properties as well as antioxidant activity were investigated. Compared to raw sea urchin roes, the salted one showed a significantly low amount of water (p<0.001) high salinity (p<0.05), ash content (p<0.001) and Na content (p<0.001). With salt-fermentation, the redness (p<0.05) and yellowness (p<0.001) of roe decreased noticeably, indicating the decomposition of endogenous carotenoids. Accordingly, the salted roe showed a lower DPPH radical scavenging activity than its unsalted counterpart. Additionally, it showed a significantly lower metal-chelating activity (p<0.05) and metal chelator content (e.g. ortho-phenolics) displayed by a negligible difference in titratable acidity. The salted roe showed significantly increased hardness (p<0.05) and total reducing capacity (p<0.001), which were attributed to the protein coagulation and the release of antioxidants bound to macromolecules after the ethanol treatment, respectively.

A Study on the International Research Trend in Education Development focused on Text Network Analysis(2002~2017) (교육개발협력에 관한 국제 학술지 연구 동향 고찰 : 텍스트 네트워크 분석을 중심으로(2002~2017))

  • Kim, Sang-Mi;Kim, Young-Hwan;Cho, Won-Gyeum
    • Korean Journal of Comparative Education
    • /
    • v.28 no.1
    • /
    • pp.1-24
    • /
    • 2018
  • The objective of the article is to find the research trends and the main traits presented in the keywords on abstracts of research articles of "International Journal of Education Development" from 2002 to 2017. To do this, Text Network Analysis(TNA) was applied targeting 966 papers on the journal and the major research outcomes are as follows. First, the frequency analysis on the keywords showed that the keywords like Administration of education program, Schools and instruction, Regional public administration, Educational support service, Elementary education, and Elementary and secondary school were analyzed more than 100 times and also high in centrality degree. Second, the analysis results of the keywords presented in those research articles by development goal periods showed that several new keywords like Elementary education, Elementary and secondary school, Education quality, Secondary education, Educational planning have emerged frequently after SDGs and these keywords showed high in their centrality analysis. Third, the analysis on education level showed that the keywords like Elementary education, Administration of education program, School children were high in frequency and centrality degree in Elementary level. In secondary level, Schools and instruction, Administration of education program, Academic achievement were high, and in high level, college and university was high, respectively.

A Study on the Tourism Resources of Baekje Restoration War : Focus on Yesan Imjon Fortress & Hongju Juryu Fortress (백제부흥전쟁의 관광자원화에 관한 연구: 예산임존성과 홍주주류성을 중심으로)

  • Choi, Inho
    • 지역과문화
    • /
    • v.7 no.2
    • /
    • pp.113-132
    • /
    • 2020
  • This study explored ways to make tourism resources based on the historical significance and major legacies of Yesan Imjon Fortress and Hongju Juryu Fortress, the center of the war where the core leadership of Baekje Restoration War was located. After the collapse of Baekje, it looked at the process of the restoration war centered on Imjon Fortress, the main characters, Imjon Fortress and Juryu Fortress, and the legends related to the restoration war. The tourism value of Baekje Restoration War is highlighted in terms of location identity and dark tourism. After reviewing cases of similar characteristics to the Baekje Restoration War, the method of tourism resourceization was presented. The elements of resourceization include characters, battles, relics, places, and name legends. Reproduction strategy, experience strategy, hard branding strategy and soft branding strategy were presented. As an example of the reenactment strategy, the Baekgang Battle reenactment event was presented. Experience strategies include walking and Baekje pottery. As for the hard-branding strategy, installation of sculptures of major characters and upgrading of tourist information signs were suggested. Soft branding strategies raised the need for logo marks, catch phrases, character products, video contents, and story maps through the branding of fortresses related to the Baekje Restoration War.

Analyzing the Co-occurrence of Endangered Brackish-Water Snails with Other Species in Ecosystems Using Association Rule Learning and Clustering Analysis (연관 규칙 학습과 군집분석을 활용한 멸종위기 기수갈고둥과 생태계 내 종 간 연관성 분석)

  • Sung-Ho Lim;Yuno Do
    • Korean Journal of Ecology and Environment
    • /
    • v.57 no.2
    • /
    • pp.83-91
    • /
    • 2024
  • This study utilizes association rule learning and clustering analysis to explore the co-occurrence and relationships within ecosystems, focusing on the endangered brackish-water snail Clithon retropictum, classified as Class II endangered wildlife in Korea. The goal is to analyze co-occurrence patterns between brackish-water snails and other species to better understand their roles within the ecosystem. By examining co-occurrence patterns and relationships among species in large datasets, association rule learning aids in identifying significant relationships. Meanwhile, K-means and hierarchical clustering analyses are employed to assess ecological similarities and differences among species, facilitating their classification based on ecological characteristics. The findings reveal a significant level of relationship and co-occurrence between brackish-water snails and other species. This research underscores the importance of understanding these relationships for the conservation of endangered species like C. retropictum and for developing effective ecosystem management strategies. By emphasizing the role of a data-driven approach, this study contributes to advancing our knowledge on biodiversity conservation and ecosystem health, proposing new directions for future research in ecosystem management and conservation strategies.

A Feature Re-weighting Approach for the Non-Metric Feature Space (가변적인 길이의 특성 정보를 지원하는 특성 가중치 조정 기법)

  • Lee Robert-Samuel;Kim Sang-Hee;Park Ho-Hyun;Lee Seok-Lyong;Chung Chin-Wan
    • Journal of KIISE:Databases
    • /
    • v.33 no.4
    • /
    • pp.372-383
    • /
    • 2006
  • Among the approaches to image database management, content-based image retrieval (CBIR) is viewed as having the best support for effective searching and browsing of large digital image libraries. Typical CBIR systems allow a user to provide a query image, from which low-level features are extracted and used to find 'similar' images in a database. However, there exists the semantic gap between human visual perception and low-level representations. An effective methodology for overcoming this semantic gap involves relevance feedback to perform feature re-weighting. Current approaches to feature re-weighting require the number of components for a feature representation to be the same for every image in consideration. Following this assumption, they map each component to an axis in the n-dimensional space, which we call the metric space; likewise the feature representation is stored in a fixed-length vector. However, with the emergence of features that do not have a fixed number of components in their representation, existing feature re-weighting approaches are invalidated. In this paper we propose a feature re-weighting technique that supports features regardless of whether or not they can be mapped into a metric space. Our approach analyses the feature distances calculated between the query image and the images in the database. Two-sided confidence intervals are used with the distances to obtain the information for feature re-weighting. There is no restriction on how the distances are calculated for each feature. This provides freedom for how feature representations are structured, i.e. there is no requirement for features to be represented in fixed-length vectors or metric space. Our experimental results show the effectiveness of our approach and in a comparison with other work, we can see how it outperforms previous work.

DNA Watermarking Method based on Random Codon Circular Code (랜덤 코돈 원형 부호 기반의 DNA 워터마킹)

  • Lee, Suk-Hwan;Kwon, Seong-Geun;Kwon, Ki-Ryong
    • Journal of Korea Multimedia Society
    • /
    • v.16 no.3
    • /
    • pp.318-329
    • /
    • 2013
  • This paper proposes a DNA watermarking method for the privacy protection and the prevention of illegal copy. The proposed method allocates codons to random circular angles by using random mapping table and selects triplet codons for embedding target with the help of the Lipschitz regularity value of local modulus maxima of codon circular angles. Then the watermark is embedded into circular angles of triplet codons without changing the codes of amino acids in a DNA. The length and location of target triplet codons depend on the random mapping table for 64 codons that includes start and stop codons. This table is used as the watermark key and can be applied on any codon sequence regardless of the length of sequence. If this table is unknown, it is very difficult to detect the length and location of them for extracting the watermark. We evaluated our method and DNA-crypt watermarking of Heider method on the condition of similar capacity. From evaluation results, we verified that our method has lower base changing rate than DNA-crypt and has lower bit error rate on point mutation and insertions/deletions than DNA-crypt. Furthermore, we verified that the entropy of random mapping table and the locaton of triplet codons is high, meaning that the watermark security has high level.

Enzymatic preparation and antioxidant activities of protein hydrolysates from defatted egg yolk (탈지난황을 이용한 단백가수분해물 제조 및 항산화 활성 평가)

  • Go-Eun Ko;Na-Yeong Kwak;Ha-Eun Nam;Su-Jin Seo;Syng-Ook Lee
    • Food Science and Preservation
    • /
    • v.31 no.3
    • /
    • pp.444-451
    • /
    • 2024
  • This study aimed to investigate the characteristics of protein hydrolysates derived from defatted egg yolk using various proteolytic enzymes and compare the antioxidant activity of the resulting hydrolysates. The defatted egg yolk powder was subjected to enzymatic hydrolysis using four different proteases (alcalase, bromelain, flavourzyme and neutrase), and the resulting hydrolysates were evaluated for their antioxidant properties. Through analysis of available amino group contents and sodium dodecyl sulfate-polyacrylamide gel electrophoresis, it was observed that the defatted egg yolk powder treated with alcalase, flavourzyme, and neutrase for 12 h exhibited a high degree of hydrolysis value. Based on the RC50 values obtained from two different antioxidant analyses, all hydrolysates showed comparable antioxidant activity, except for the alcalase hydrolysate, which demonstrated notably higher scavenging activity against hydrogen peroxide than the other hydrolysates. These findings suggest the potential of protein hydrolysates from defatted egg yolk, a by-product of lecithin extraction, as natural antioxidants.

Enhancing Predictive Accuracy of Collaborative Filtering Algorithms using the Network Analysis of Trust Relationship among Users (사용자 간 신뢰관계 네트워크 분석을 활용한 협업 필터링 알고리즘의 예측 정확도 개선)

  • Choi, Seulbi;Kwahk, Kee-Young;Ahn, Hyunchul
    • Journal of Intelligence and Information Systems
    • /
    • v.22 no.3
    • /
    • pp.113-127
    • /
    • 2016
  • Among the techniques for recommendation, collaborative filtering (CF) is commonly recognized to be the most effective for implementing recommender systems. Until now, CF has been popularly studied and adopted in both academic and real-world applications. The basic idea of CF is to create recommendation results by finding correlations between users of a recommendation system. CF system compares users based on how similar they are, and recommend products to users by using other like-minded people's results of evaluation for each product. Thus, it is very important to compute evaluation similarities among users in CF because the recommendation quality depends on it. Typical CF uses user's explicit numeric ratings of items (i.e. quantitative information) when computing the similarities among users in CF. In other words, user's numeric ratings have been a sole source of user preference information in traditional CF. However, user ratings are unable to fully reflect user's actual preferences from time to time. According to several studies, users may more actively accommodate recommendation of reliable others when purchasing goods. Thus, trust relationship can be regarded as the informative source for identifying user's preference with accuracy. Under this background, we propose a new hybrid recommender system that fuses CF and social network analysis (SNA). The proposed system adopts the recommendation algorithm that additionally reflect the result analyzed by SNA. In detail, our proposed system is based on conventional memory-based CF, but it is designed to use both user's numeric ratings and trust relationship information between users when calculating user similarities. For this, our system creates and uses not only user-item rating matrix, but also user-to-user trust network. As the methods for calculating user similarity between users, we proposed two alternatives - one is algorithm calculating the degree of similarity between users by utilizing in-degree and out-degree centrality, which are the indices representing the central location in the social network. We named these approaches as 'Trust CF - All' and 'Trust CF - Conditional'. The other alternative is the algorithm reflecting a neighbor's score higher when a target user trusts the neighbor directly or indirectly. The direct or indirect trust relationship can be identified by searching trust network of users. In this study, we call this approach 'Trust CF - Search'. To validate the applicability of the proposed system, we used experimental data provided by LibRec that crawled from the entire FilmTrust website. It consists of ratings of movies and trust relationship network indicating who to trust between users. The experimental system was implemented using Microsoft Visual Basic for Applications (VBA) and UCINET 6. To examine the effectiveness of the proposed system, we compared the performance of our proposed method with one of conventional CF system. The performances of recommender system were evaluated by using average MAE (mean absolute error). The analysis results confirmed that in case of applying without conditions the in-degree centrality index of trusted network of users(i.e. Trust CF - All), the accuracy (MAE = 0.565134) was lower than conventional CF (MAE = 0.564966). And, in case of applying the in-degree centrality index only to the users with the out-degree centrality above a certain threshold value(i.e. Trust CF - Conditional), the proposed system improved the accuracy a little (MAE = 0.564909) compared to traditional CF. However, the algorithm searching based on the trusted network of users (i.e. Trust CF - Search) was found to show the best performance (MAE = 0.564846). And the result from paired samples t-test presented that Trust CF - Search outperformed conventional CF with 10% statistical significance level. Our study sheds a light on the application of user's trust relationship network information for facilitating electronic commerce by recommending proper items to users.

A Multimodal Profile Ensemble Approach to Development of Recommender Systems Using Big Data (빅데이터 기반 추천시스템 구현을 위한 다중 프로파일 앙상블 기법)

  • Kim, Minjeong;Cho, Yoonho
    • Journal of Intelligence and Information Systems
    • /
    • v.21 no.4
    • /
    • pp.93-110
    • /
    • 2015
  • The recommender system is a system which recommends products to the customers who are likely to be interested in. Based on automated information filtering technology, various recommender systems have been developed. Collaborative filtering (CF), one of the most successful recommendation algorithms, has been applied in a number of different domains such as recommending Web pages, books, movies, music and products. But, it has been known that CF has a critical shortcoming. CF finds neighbors whose preferences are like those of the target customer and recommends products those customers have most liked. Thus, CF works properly only when there's a sufficient number of ratings on common product from customers. When there's a shortage of customer ratings, CF makes the formation of a neighborhood inaccurate, thereby resulting in poor recommendations. To improve the performance of CF based recommender systems, most of the related studies have been focused on the development of novel algorithms under the assumption of using a single profile, which is created from user's rating information for items, purchase transactions, or Web access logs. With the advent of big data, companies got to collect more data and to use a variety of information with big size. So, many companies recognize it very importantly to utilize big data because it makes companies to improve their competitiveness and to create new value. In particular, on the rise is the issue of utilizing personal big data in the recommender system. It is why personal big data facilitate more accurate identification of the preferences or behaviors of users. The proposed recommendation methodology is as follows: First, multimodal user profiles are created from personal big data in order to grasp the preferences and behavior of users from various viewpoints. We derive five user profiles based on the personal information such as rating, site preference, demographic, Internet usage, and topic in text. Next, the similarity between users is calculated based on the profiles and then neighbors of users are found from the results. One of three ensemble approaches is applied to calculate the similarity. Each ensemble approach uses the similarity of combined profile, the average similarity of each profile, and the weighted average similarity of each profile, respectively. Finally, the products that people among the neighborhood prefer most to are recommended to the target users. For the experiments, we used the demographic data and a very large volume of Web log transaction for 5,000 panel users of a company that is specialized to analyzing ranks of Web sites. R and SAS E-miner was used to implement the proposed recommender system and to conduct the topic analysis using the keyword search, respectively. To evaluate the recommendation performance, we used 60% of data for training and 40% of data for test. The 5-fold cross validation was also conducted to enhance the reliability of our experiments. A widely used combination metric called F1 metric that gives equal weight to both recall and precision was employed for our evaluation. As the results of evaluation, the proposed methodology achieved the significant improvement over the single profile based CF algorithm. In particular, the ensemble approach using weighted average similarity shows the highest performance. That is, the rate of improvement in F1 is 16.9 percent for the ensemble approach using weighted average similarity and 8.1 percent for the ensemble approach using average similarity of each profile. From these results, we conclude that the multimodal profile ensemble approach is a viable solution to the problems encountered when there's a shortage of customer ratings. This study has significance in suggesting what kind of information could we use to create profile in the environment of big data and how could we combine and utilize them effectively. However, our methodology should be further studied to consider for its real-world application. We need to compare the differences in recommendation accuracy by applying the proposed method to different recommendation algorithms and then to identify which combination of them would show the best performance.