• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.4
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• pp.17-22
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• 2020

Behavior-based authentication technology, which is currently being researched a lot, requires a long extraction of a lot of data to increase the recognition rate of authentication compared to other authentication technologies. This paper uses the touch sensor and the gyroscope embedded in the smartphone in the Android environment to measure five times to the user to use only the minimum data that is essential among the behavior feature data used in the behavior-based authentication study. By requesting, a total of six behavior feature data were collected by touching the five touch screen, and the mean value was calculated from the changes in data during the next touch measurement to measure the cosine similarity between the value and the measured value. After generating the allowable range of cosine similarity by performing, we propose a user behavior based authentication method that compares the cosine similarity value of the authentication attempt data. Through this paper, we succeeded in demonstrating high performance from the first EER of 37.6% to the final EER of 1.9% by adjusting the threshold applied to the cosine similarity authentication range even in a small number of feature data and experimenter environments.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.42 no.6
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• pp.63-74
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• 2005

In Electronic Commerce, the latest most of the personalized recommender systems have applied to the collaborative filtering technique. This method calculates the weight of similarity among users who have a similar preference degree in order to predict and recommend the item which hits to propensity of users. In this case, we commonly use Pearson Correlation Coefficient. However, this method is feasible to calculate a correlation if only there are the items that two users evaluated a preference degree in common. Accordingly, the accuracy of prediction falls. The weight of similarity can affect not only the case which predicts the item which hits to propensity of users, but also the performance of the personalized recommender system. In this study, we verify the improvement of the prediction accuracy through an experiment after observing the rule of the weight of similarity applying Vector similarity, Entropy, Inverse user frequency, and Default voting of Information Retrieval field. The result shows that the method combining the weight of similarity using the Entropy with Default voting got the most efficient performance.

• Journal of Information Technology Applications and Management
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• v.21 no.3
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• pp.35-52
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• 2014

This study aims to examine how the relationship with an information source affects people to perceive credibility of online information. We developed a conceptual framework that explained how people perceived information credibility when they were familiar with the information source and/or when the information source seemed credible. We then compared the models in two different contexts, namely, online review and social media sites, to examine differences. We surveyed 136 online social media users with their online shopping experiences. Among our eight hypotheses, three (H6: the personality similarity between an information provider and an information seeker enhances the perceived credibility of the former; H7: the credibility of an information provider produces a much stronger mediating effect in review sites than in social media sites; H8: the familiarity of an information seeker with an information provider produces a stronger mediating effect in social media sites than in review sites) are fully supported and four (H1: the credibility of an information provider has a positive influence on the perceived credibility of the online information; H2: the familiarity of an information seeker with an information provider has a positive influence on the perceived credibility of the online information; H3: the goal similarity between an information provider and an information seeker enhances the perceived familiarity of the latter with the former; H5: the personality similarity between an information provider and an information seeker enhances the perceived familiarity of the latter with the former) are partially supported. The hypothesis of H4: the goal similarity between an information provider and an information seeker enhances the perceived credibility of the former is rejected. The result confirms that credibility of information is strongly mediated by credibility of information source than familiarity with information source in online review sites and vice versa in social media sites.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2003.11a
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• pp.259-262
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• 2003

Group technology(GT) is a manufacturing philosophy which identifies and exploits the similarity of parts and processes in design and manufacturing. A specific application of GT is cellular manufacturing. the first step in the preliminary stage of cellular manufacturing system design is cell formation, generally known as a machine-part cell formation(MPCF). This paper presents and tests a grouping gentic algorithm(GGA) for solving the MPCF problem and uses the measurements of e(ficacy. GGA's replacement heuristic used similarity coefficients is presented.

• Journal of Mechanical Science and Technology
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• v.17 no.2
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• pp.288-295
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• 2003

A preliminary series design of compressors for a two-stage centrifugal chiller is suggested. Six groups of hydrodynamically similar compressors, ranging from 233RT to 1,200RT, are introduced. Flow rates, impeller diameters, and wheel speeds for each group are determined from hydrodynamic similarity to share impellers of adjacent groups. It is expected that these compressors can have the same performance and efficiency from the smallest model to the largest one.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.12 no.4
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• pp.324-328
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• 2012

With the recent advances in information retrieval, cross-media retrieval has been attracting lot of attention, but several issues remain problems such as constructing effective correlations, calculating similarity between different kinds of media objects. To gain better cross-media retrieval performance, it is crucial to mine the semantic correlations among the heterogeneous multimedia data. This paper introduces a new method for cross-media retrieval which uses ontology to organize different media objects. The experiment results show that the proposed method is effective in cross-media retrieval.

• The Korean Journal of Mycology
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• v.24 no.3 s.78
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• pp.186-205
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• 1996

This study was carried out to obtain data concerning the genetic variability of Pleurotus ostreatus. Monospores of P. ostreatus were isolated and cultured to estimate differences in the rate of mycelial growth and genetic similarity among the isolates. Although the overall growth rates were slow compared to their parental dikaryon except 2-MI 4, significant differences in the rate of mycelial growth were observed among isolates. Random amplified polymorphic DNA (RAPD) analysis using twenty six random primers showed 345 polymorphic DNA bands from 35 monospore isolates and their parental dikaryon. DNA bands ranged from 0.1 to 4.0 Kb in size. Most various polymorphic DNA bands within monospore isolates were obtained when we used J (OPA-01) or W (OPB-04). The 36-MI 103 showed totally different band patterns from those of the others. RAPD analysis revealed that there is approximatly 75% genetic similarity between monospore isolates and their parental dikaryon except 36-MI 103, which showed only 49% genetic similarity. In addition, genetic similarity degrees were classified into four groups: I (parental dikaryon), II (fast growing type), III (moderate growing type), and IV (slow growing type). However, there is no correlation between mating type and mycelial growth rates.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2002.05a
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• pp.279-280
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• 2002

Genomic DNA from the muscle of marsh clam (Corbicula leana) from Gochang was extracted in order to identify genetic differences and similarity by randomly amplified polymorphic DNAs-polymerase chain reaction. 3.28 of the 23.0 polymorphic bands per lane were found to be polymorphic in marsh clam. Also, about 4.34% of total polymorphic bands were either specific to marsh clam. The major common bands of 0.28 kb generated by primer OPB-15 (GGAGGGTGTT) were present in every individuals, respectively, which were polymorphic. This common bands which present in every individuals should be diagnostic of specific strains, species and/or their relatedness. Primer OPB-19 (ACCCCCGAAG) produced the highest number of specific bands, which was 12. The specific minor band of 0.07 kb was present in lane 22, which were polymorphic. Especially, only a specific band (1.35 kb) identifying individuals was observed in lane 22.

• Journal of Computing Science and Engineering
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• v.9 no.2
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• pp.73-82
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• 2015

Understanding how the topic evolves is an important and challenging task. A topic usually consists of multiple related events, and the accurate identification of event evolution relationship plays an important role in topic evolution analysis. Existing research has used the traditional vector space model to represent the event, which cannot be used to accurately compute the semantic similarity between events. This has led to poor performance in identifying event evolution relationship. This paper suggests constructing a semantic aspect-based vector space model to represent the event: First, use hierarchical Dirichlet process to mine the semantic aspects. Then, construct a semantic aspect-based vector space model according to these aspects. Finally, represent each event as a point and measure the semantic relatedness between events in the space. According to our evaluation experiments, the performance of our proposed technique is promising and significantly outperforms the baseline methods.

• Journal of international Conference on Electrical Machines and Systems
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• v.2 no.1
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• pp.9-15
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• 2013

This paper presents a uniform analytical model by energy method and Fourier series expansion to analyze detent force in uneven magnetic field for permanent magnet linear synchronous motor (PMLSM). The model reveals that detent force in long-primary type is mainly influenced by non-ideal distribution of permanent magnet magnetic motive force, while nounified air-gap permeance makes a great impact on detent force of short-primary type. Hence, magnetic field similarity of motor design techniques referring rotary counterpart are adopted. For long-primary type novel method of splitting edge magnets is proposed to reduce end effects force, and optimal widths of edge tooth in short-primary type also verify the effectiveness of magnetic field similarity. The experimental results validate finite element analysis results.