• 제목/요약/키워드: Descriptors

검색결과 506건 처리시간 0.025초

3D-QSAR of Angiotensin-Converting Enzyme Inhibitors: Functional Group Interaction Energy Descriptors for Quantitative Structure-Activity Relationships Study of ACE Inhibitors

  • Kim, Sang-Uk;Chi, Myung-Whan;Yoon, Chang-No;Sung, Ha-Chin
    • BMB Reports
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    • 제31권5호
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    • pp.459-467
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    • 1998
  • A new set of functional group interaction energy descriptors relevant to the ACE (Angiotensin-Converting Enzyme) inhibitory peptide, QSAR (Quantitative Structure Activity Relationships), is presented. The functional group interaction energies approximate the charged interactions and distances between functional groups in molecules. The effective energies of the computationally derived geometries are useful parameters for deriving 3D-QSAR models, especially in the absence of experimentally known active site conformation. ACE is a regulatory zinc protease in the renin-angiotensin system. Therapeutic inhibition of this enzyme has proven to be a very effective treatment for the management of hypertension. The non bond interaction energy values among functional groups of six-feature of ACE inhibitory peptides were used as descriptor terms and analyzed for multivariate correlation with ACE inhibition activity. The functional group interaction energy descriptors used in the regression analysis were obtained by a series of inhibitor structures derived from molecular mechanics and semi-empirical calculations. The descriptors calculated using electrostatic and steric fields from the precisely defined functional group were sufficient to explain the biological activity of inhibitor. Application of the descriptors to the inhibition of ACE indicates that the derived QSAR has good predicting ability and provides insight into the mechanism of enzyme inhibition. The method, functional group interaction energy analysis, is expected to be applicable to predict enzyme inhibitory activity of the rationally designed inhibitors.

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Human Action Recognition Via Multi-modality Information

  • Gao, Zan;Song, Jian-Ming;Zhang, Hua;Liu, An-An;Xue, Yan-Bing;Xu, Guang-Ping
    • Journal of Electrical Engineering and Technology
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    • 제9권2호
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    • pp.739-748
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    • 2014
  • In this paper, we propose pyramid appearance and global structure action descriptors on both RGB and depth motion history images and a model-free method for human action recognition. In proposed algorithm, we firstly construct motion history image for both RGB and depth channels, at the same time, depth information is employed to filter RGB information, after that, different action descriptors are extracted from depth and RGB MHIs to represent these actions, and then multimodality information collaborative representation and recognition model, in which multi-modality information are put into object function naturally, and information fusion and action recognition also be done together, is proposed to classify human actions. To demonstrate the superiority of the proposed method, we evaluate it on MSR Action3D and DHA datasets, the well-known dataset for human action recognition. Large scale experiment shows our descriptors are robust, stable and efficient, when comparing with the-state-of-the-art algorithms, the performances of our descriptors are better than that of them, further, the performance of combined descriptors is much better than just using sole descriptor. What is more, our proposed model outperforms the state-of-the-art methods on both MSR Action3D and DHA datasets.

색상과 움직임 정보를 이용한 내용기반 동영상 검색 시스템 (Content-Based Video Retrieval System Using Color and Motion Features)

  • 김소희;김형준;정연구;김회율
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2001년도 하계종합학술대회 논문집(3)
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    • pp.133-136
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    • 2001
  • Numerous challenges have been made to retrieve video using the contents. Recently MPEG-7 had set up a set of visual descriptors for such purpose of searching and retrieving multimedia data. Among them, color and motion descriptors are employed to develop a content-based video retrieval system to search for videos that have similar characteristics in terms of color and motion features of the video sequence. In this paper, the performance of the proposed system is analyzed and evaluated. Experimental results indicate that the processing time required for a retrieval using MPEG-7 descriptors is relatively short at the expense of the retrieval accuracy.

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Dorsal Hand Vein Identification Based on Binary Particle Swarm Optimization

  • Benziane, Sarah Hachemi;Benyettou, Abdelkader
    • Journal of Information Processing Systems
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    • 제13권2호
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    • pp.268-284
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    • 2017
  • The dorsal hand vein biometric system developed has a main objective and specific targets; to get an electronic signature using a secure signature device. In this paper, we present our signature device with its different aims; respectively: The extraction of the dorsal veins from the images that were acquired through an infrared device. For each identification, we need the representation of the veins in the form of shape descriptors, which are invariant to translation, rotation and scaling; this extracted descriptor vector is the input of the matching step. The optimization decision system settings match the choice of threshold that allows accepting/rejecting a person, and selection of the most relevant descriptors, to minimize both FAR and FRR errors. The final decision for identification based descriptors selected by the PSO hybrid binary give a FAR =0% and FRR=0% as results.

Utility of Structural Information to Predict Drug Clearance from in Vitro Data

  • Lee, So-Young;Kim, Dong-Sup
    • Interdisciplinary Bio Central
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    • 제2권2호
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    • pp.3.1-3.4
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    • 2010
  • In the present research, we assessed the utility of the structural information of drugs for predicting human in vivo intrinsic clearance from in vitro intrinsic clearance data obtained by human hepatic microsome experiment. To compare with the observed intrinsic clearance, human intrinsic clearance values for 51 drugs were estimated by the classical methods using in vivo-in vitro scale-up and by the new methods using the in vitro experimental data and selected molecular descriptors of drugs by the forward selection technique together. The results showed that taking consideration of molecular descriptors into prediction from in vitro experimental data could improve the prediction accuracy. The in vitro experiment is very useful when the data can estimate in vivo data accurately since it can reduce the cost of drug development. Improvement of prediction accuracy in the present approach can enhance the utility of in vitro data.

멀티미디어 서비스에서 연관 QoS 지원을 위한 트래픽 기술자 (Additional Traffic Descriptors for Associatiove QoS Parameters in a Multimedia Service)

  • 김지영;이상목최봉근이상홍
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 1998년도 하계종합학술대회논문집
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    • pp.86-89
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    • 1998
  • Multiple types of information in a multimedia service are delivered though multiple virtual connections on ATM network, while each virtual connection may be controlled independently. A multimedia service requires an associative relationship among multiple information streams to provide required harmonization. There may be required additional traffic descriptors to guarantee the required harmonization among multiple information streams in a multimedia service. For buffering of large bandwidth information stream(e.g., video), extremely large buffer size is necessary, but this approach should not be efficient way to compensate a severely delayed cells/blocks experienced at network. The best way to solve this problem will be minimization of relative-delayed-transfer of cells/blocks to application processes through ATM network control. To minimize a delayed transfer the mapping between relative delay parameter(i.e., associative Group QoS parameters) and per-VC traffic descriptor will be necessary. This paper is present additional functions and parameters to interpret the mapping between relative delay parameters(i.e., associative Group QoS parameters) and per-VC traffic descriptors in ATM API for multimedia application services.

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A Comparative Study of Local Features in Face-based Video Retrieval

  • Zhou, Juan;Huang, Lan
    • Journal of Computing Science and Engineering
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    • 제11권1호
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    • pp.24-31
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    • 2017
  • Face-based video retrieval has become an active and important branch of intelligent video analysis. Face profiling and matching is a fundamental step and is crucial to the effectiveness of video retrieval. Although many algorithms have been developed for processing static face images, their effectiveness in face-based video retrieval is still unknown, simply because videos have different resolutions, faces vary in scale, and different lighting conditions and angles are used. In this paper, we combined content-based and semantic-based image analysis techniques, and systematically evaluated four mainstream local features to represent face images in the video retrieval task: Harris operators, SIFT and SURF descriptors, and eigenfaces. Results of ten independent runs of 10-fold cross-validation on datasets consisting of TED (Technology Entertainment Design) talk videos showed the effectiveness of our approach, where the SIFT descriptors achieved an average F-score of 0.725 in video retrieval and thus were the most effective, while the SURF descriptors were computed in 0.3 seconds per image on average and were the most efficient in most cases.

Prediction Partial Molar Heat Capacity at Infinite Dilution for Aqueous Solutions of Various Polar Aromatic Compounds over a Wide Range of Conditions Using Artificial Neural Networks

  • Habibi-Yangjeh, Aziz;Esmailian, Mahdi
    • Bulletin of the Korean Chemical Society
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    • 제28권9호
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    • pp.1477-1484
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    • 2007
  • Artificial neural networks (ANNs), for a first time, were successfully developed for the prediction partial molar heat capacity of aqueous solutions at infinite dilution for various polar aromatic compounds over wide range of temperatures (303.55-623.20 K) and pressures (0.1-30.2 MPa). Two three-layered feed forward ANNs with back-propagation of error were generated using three (the heat capacity in T = 303.55 K and P = 0.1 MPa, temperature and pressure) and six parameters (four theoretical descriptors, temperature and pressure) as inputs and its output is partial molar heat capacity at infinite dilution. It was found that properly selected and trained neural networks could fairly represent dependence of the heat capacity on the molecular descriptors, temperature and pressure. Mean percentage deviations (MPD) for prediction set by the models are 4.755 and 4.642, respectively.

이조시대 사랑방 가구에 대한 현대인의 미의식 (Aesthetic Characteristic of‘Sarangbang’Furniture of The Yi-dynasty Period)

  • 유영희
    • 대한가정학회지
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    • 제24권4호
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    • pp.139-146
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    • 1986
  • The purpose of this study was to identify aesthetic concepts of‘Sarangbang’furniture during the Yi-dynasty period and aesthetic descriptions indicating each concept expressed by experts in traditional furniture. The furniture selected for the study includes desks, table bookcases, document and stationary boxes (mungab), letter holders (Kobi) and inkstone boxes (younsang) with lacquer and oil finish on. The respondents were 72 traditional furniture experts; researchers collectors, sellers and artists related to period furniture. The important points of aesthetic descriptors were collected 123 from related literature. From experts' answers, 47 representative descriptors were selected. Data were analyzed with the SPSS using frequency, Percentage mean, factor analysis, t-test and C2. The results were as follows; 1. The aesthetic concept of sarangbang furniture during the Yi-dynasty can be categorized into 9 aspects; appearance of beauty, stability the interior space, naturalness, nobleness/harmony of lines, detail/refinement, simplicity, diversity solidity and surface division. 2. The characteristics of the Korean traditional furniture can be described using 47 descriptors explaining 9 concepts mentioned above.

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Racemic Descriptors for Quantitative Structure Activity Relationship of Spirosuccinimide Type Aldose Reductase Inhibitors

  • Kim, Jeong-Rim;Won, Young-Do
    • Bulletin of the Korean Chemical Society
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    • 제25권12호
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    • pp.1874-1876
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    • 2004
  • Quantitative structure activity relationship has been probed for spirosuccinimide-fused tetrahydropyrrolo[1,2-a]pyrazine-1,3-dione derivatives acting as aldose reductase inhibitors. While the spirosuccinimide compounds contain a chiral center, the aldose reductase inhibition assay was performed with racemic mixtures in the published work. As the physicochemical descriptors of the QSAR analysis must be evaluated for a definite molecular structure, we devise a new 'racemic' descriptor as the arithmetic mean of the (R)-enantiomer descriptor and the (S)-enantiomer descriptor. The resultant QSAR model derived from the racemic descriptors outperforms the original QSAR models, closely reproducing the observed activity of optically pure enantiomers as well as racemic mixtures.