• Title/Summary/Keyword: key feature

Search Result 815, Processing Time 0.025 seconds

Concise Synthesis of Flurbiprofen via Palladium-Catalyzed Cross-Coupling Reactions (팔라듐 촉매하 결합반응을 이용한 플루비프로펜의 간결한 합성)

  • Han, Young Taek
    • YAKHAK HOEJI
    • /
    • v.59 no.2
    • /
    • pp.66-69
    • /
    • 2015
  • A concise synthesis of flurbiprofen, a member of the non-steroidal anti-inflammatory 2-arylpropionic acids, has been accomplished. The key feature of this synthesis involves successive palladium-catalyzed cross coupling reactions. In particular, a 2-arylacylate intermediate, which easily converted to the key 2-arylpropionic acid scaffold, was afforded by a versatile palladium-catalyzed cross coupling reaction between diazopropanate and bisphenylboronic acid. This synthetic procedure would facilitate synthesis of the flurbiprofen and anti-inflammatory 2-arylpropionic acid derivatives.

Automatic Fortified Password Generator System Using Special Characters

  • Jeong, Junho;Kim, Jung-Sook
    • International Journal of Fuzzy Logic and Intelligent Systems
    • /
    • v.15 no.4
    • /
    • pp.295-299
    • /
    • 2015
  • The developed security scheme for user authentication, which uses both a password and the various devices, is always open by malicious user. In order to solve that problem, a keystroke dynamics is introduced. A person's keystroke has a unique pattern. That allows the use of keystroke dynamics to authenticate users. However, it has a problem to authenticate users because it has an accuracy problem. And many people use passwords, for which most of them use a simple word such as "password" or numbers such as "1234." Despite people already perceive that a simple password is not secure enough, they still use simple password because it is easy to use and to remember. And they have to use a secure password that includes special characters such as "#!($^*$)^". In this paper, we propose the automatic fortified password generator system which uses special characters and keystroke feature. At first, the keystroke feature is measured while user key in the password. After that, the feature of user's keystroke is classified. We measure the longest or the shortest interval time as user's keystroke feature. As that result, it is possible to change a simple password to a secure one simply by adding a special character to it according to the classified feature. This system is effective even when the cyber attacker knows the password.

Efficient Image Search using Advanced SURF and DCD on Mobile Platform (모바일 플랫폼에서 개선된 SURF와 DCD를 이용한 효율적인 영상 검색)

  • Lee, Yong-Hwan
    • Journal of the Semiconductor & Display Technology
    • /
    • v.14 no.2
    • /
    • pp.53-59
    • /
    • 2015
  • Since the amount of digital image continues to grow in usage, users feel increased difficulty in finding specific images from the image collection. This paper proposes a novel image searching scheme that extracts the image feature using combination of Advanced SURF (Speed-Up Robust Feature) and DCD (Dominant Color Descriptor). The key point of this research is to provide a new feature extraction algorithm to improve the existing SURF method with removal of unnecessary feature in image retrieval, which can be adaptable to mobile system and efficiently run on the mobile environments. To evaluate the proposed scheme, we assessed the performance of simulation in term of average precision and F-score on two databases, commonly used in the field of image retrieval. The experimental results revealed that the proposed algorithm exhibited a significant improvement of over 14.4% in retrieval effectiveness, compared to OpenSURF. The main contribution of this paper is that the proposed approach achieves high accuracy and stability by using ASURF and DCD in searching for natural image on mobile platform.

Detection of Mammographic Microcalcifications by Statistical Pattern Classification 81 Pattern Matching (통계적 패턴 분류법과 패턴 매칭을 이용한 유방영상의 미세석회화 검출)

  • 양윤석;김덕원;김은경
    • Journal of Biomedical Engineering Research
    • /
    • v.18 no.4
    • /
    • pp.357-364
    • /
    • 1997
  • The early detection of breast cancer is clearly a key ingredient for reducing breast cancer mortality. Microcalcification is the only visible feature of the DCIS's(ductal carcinoma in situ) which consist 15 ~ 20% of screening-detected breast cancer. Therefore, the analysis of the shapes and distributions of microcalcifications is very significant for the early detection. The automatic detection procedures have b(:on the concern of digital image processing for many years. We proposed here one efficient method which is essentially statistical pattern classification accelerated by one representative feature, correlation coefficient. We compared the results by this additional feature with results by a simple gray level thresholding. The average detection rate was increased from 48% by gray level feature only to 83% by the proposed method The performances were evaluated with TP rates and FP counts, and also with Bayes errors.

  • PDF

Development of Emotional Feature Extraction Method based on Advanced AAM (Advanced AAM 기반 정서특징 검출 기법 개발)

  • Ko, Kwang-Eun;Sim, Kwee-Bo
    • Journal of the Korean Institute of Intelligent Systems
    • /
    • v.19 no.6
    • /
    • pp.834-839
    • /
    • 2009
  • It is a key element that the problem of emotional feature extraction based on facial image to recognize a human emotion status. In this paper, we propose an Advanced AAM that is improved version of proposed Facial Expression Recognition Systems based on Bayesian Network by using FACS and AAM. This is a study about the most efficient method of optimal facial feature area for human emotion recognition about random user based on generalized HCI system environments. In order to perform such processes, we use a Statistical Shape Analysis at the normalized input image by using Advanced AAM and FACS as a facial expression and emotion status analysis program. And we study about the automatical emotional feature extraction about random user.

Improvement of Classification Accuracy on Success and Failure Factors in Software Reuse using Feature Selection (특징 선택을 이용한 소프트웨어 재사용의 성공 및 실패 요인 분류 정확도 향상)

  • Kim, Young-Ok;Kwon, Ki-Tae
    • KIPS Transactions on Software and Data Engineering
    • /
    • v.2 no.4
    • /
    • pp.219-226
    • /
    • 2013
  • Feature selection is the one of important issues in the field of machine learning and pattern recognition. It is the technique to find a subset from the source data and can give the best classification performance. Ie, it is the technique to extract the subset closely related to the purpose of the classification. In this paper, we experimented to select the best feature subset for improving classification accuracy when classify success and failure factors in software reuse. And we compared with existing studies. As a result, we found that a feature subset was selected in this study showed the better classification accuracy.

Vehicle Face Re-identification Based on Nonnegative Matrix Factorization with Time Difference Constraint

  • Ma, Na;Wen, Tingxin
    • KSII Transactions on Internet and Information Systems (TIIS)
    • /
    • v.15 no.6
    • /
    • pp.2098-2114
    • /
    • 2021
  • Light intensity variation is one of the key factors which affect the accuracy of vehicle face re-identification, so in order to improve the robustness of vehicle face features to light intensity variation, a Nonnegative Matrix Factorization model with the constraint of image acquisition time difference is proposed. First, the original features vectors of all pairs of positive samples which are used for training are placed in two original feature matrices respectively, where the same columns of the two matrices represent the same vehicle; Then, the new features obtained after decomposition are divided into stable and variable features proportionally, where the constraints of intra-class similarity and inter-class difference are imposed on the stable feature, and the constraint of image acquisition time difference is imposed on the variable feature; At last, vehicle face matching is achieved through calculating the cosine distance of stable features. Experimental results show that the average False Reject Rate and the average False Accept Rate of the proposed algorithm can be reduced to 0.14 and 0.11 respectively on five different datasets, and even sometimes under the large difference of light intensities, the vehicle face image can be still recognized accurately, which verifies that the extracted features have good robustness to light variation.

Harmonic Structure Features for Robust Speaker Diarization

  • Zhou, Yu;Suo, Hongbin;Li, Junfeng;Yan, Yonghong
    • ETRI Journal
    • /
    • v.34 no.4
    • /
    • pp.583-590
    • /
    • 2012
  • In this paper, we present a new approach for speaker diarization. First, we use the prosodic information calculated on the original speech to resynthesize the new speech data utilizing the spectrum modeling technique. The resynthesized data is modeled with sinusoids based on pitch, vibration amplitude, and phase bias. Then, we use the resynthesized speech data to extract cepstral features and integrate them with the cepstral features from original speech for speaker diarization. At last, we show how the two streams of cepstral features can be combined to improve the robustness of speaker diarization. Experiments carried out on the standardized datasets (the US National Institute of Standards and Technology Rich Transcription 04-S multiple distant microphone conditions) show a significant improvement in diarization error rate compared to the system based on only the feature stream from original speech.

Presentation-Oriented Key-Frames Coding Based on Fractals

  • Atzori, Luigi;Giusto, Daniele D.;Murroni, Maurizio
    • ETRI Journal
    • /
    • v.27 no.6
    • /
    • pp.713-724
    • /
    • 2005
  • This paper focuses on the problem of key-frames coding and proposes a new promising approach based on the use of fractals. The summary, made of a set of key-frames selected from a full-length video sequence, is coded by using a 3D fractal scheme. This allows the video presentation tool to expand the video sequence in a "natural" way by using the property of the fractals to reproduce the signal at several resolutions. This feature represents an important novelty of this work with respect to the alternative approaches, which mainly focus on the compression ratio without taking into account the presentation aspect of the video summary. In devising the coding scheme, we have taken care of the computational complexity inherent in fractal coding. Accordingly, the key-frames are first wavelet transformed, and the fractal coding is then applied to each subband to reduce the search range. Experimental results show the effectiveness of the proposed approach.

  • PDF

Implementation of an RFID Key Management System for DASH7

  • Vegendla, Aparna;Seo, Hwajeong;Lee, Donggeon;Kim, Howon
    • Journal of information and communication convergence engineering
    • /
    • v.12 no.1
    • /
    • pp.19-25
    • /
    • 2014
  • The wireless sensor networking standard DASH7 operates in low-power communication with a better transmission quality in active RFID networks. The DASH7 security standard supports public key cryptography. At present, the DASH7 standard uses the message authentication code in the network layer for authentication and integrity. However, its security standard is still in an incubation stage with respect to the implementation of a crypto exchange over a DASH7 network. Effective key management is an important factor for privacy and security. If organizations are not careful about where and how keys are stored, they leave the encrypted data vulnerable to theft. In this regard, we present a key management system designed for efficient key management through public key infrastructure authentication as well as a non-repudiation feature for the DASH7 standard. We analyze the performance of the proposed system on a basis of various performance criteria such as latency and throughput.