• Title/Summary/Keyword: robustness

Search Result 4,447, Processing Time 0.035 seconds

A-team Based Approach for Reactive Power/Voltage Control Considering Steady State Security Assessment (정태 안전성 평가를 고려한 무효전력 전압제어를 위한 A-team기반 접근법)

  • Kim, Doo-Hyun
    • Journal of the Korean Society of Safety
    • /
    • v.11 no.2
    • /
    • pp.150-159
    • /
    • 1996
  • In this paper, an A-team(Asynchronous Team ) based approach for Reactive power and volage control considering static security assessment in a power system with infrastructural deficiencies is proposed. Reactive power and voltage control problem is the one of optimally establishing voltage level given several constraints such as reactive generation, voltage magnitude, line flow, and other switchable reactive power sources. It can be formulated as a mixed-integer linear programming(MILP) problem without deteriorating of solution accuracy to a certain extent. The security assessment is to estimate the relative robustness of the system in Its present state through the evaluation of data provided by security monitoring. Deterministic approach based on AC load flow calculations is adopted to assess the system security, especially voltage security. A security metric, as a standard of measurement for power system security, producting a set of discrete values rather than binary values, is employed. In order to analyze the above two problems, reactive power/voltage control problem and static security assessment problem, in an integrated fashion for real-time operations, a new organizational structure, called an A-team, is adopted. An A-team is an organization for agents which ale all autonomeus, work in parallel and communicate asynchronously, which is well-suited to the development of computer-based, multi-agent systems for operations. This A-team based approach, although it is still in the beginning stage, also has potential for handling other difficult power system problems.

  • PDF

A GPS Initial Synchronization Method for Robust DGPS Reference Stations in Noisy Environment (잡음환경에 강인한 DGPS 기준국을 위한 GPS 초기동기 방법)

  • Park Jeong-Yeol;Park Sang-Hyun;Sin Jae-Ho
    • Journal of Navigation and Port Research
    • /
    • v.30 no.5 s.111
    • /
    • pp.343-349
    • /
    • 2006
  • In order to enhance the robustness against noisy environment, the previous GPS initial synchronization method of DGPS reference stations adopts not only the coherent integration method but also the non-coherent integration method. However the previous GPS initial synchronization method muses the non-coherent integration loss, which is a dominant factor among the signal acquisition losses in noisy environment. And the non-coherent integration loss increases with the strength of noise signal. In this paper, a novel GPS initial synchronization method is proposed for robust DGPS reference stations in noisy environment. This paper presents that the proposed GPS initial synchronization method suppresses the non-coherent acquisition loss. Furthermore, with regard to the mean acquisition time, it is shown that the number of the search cells of the proposed GPS initial synchronization method is much smaller than that of the previous GPS initial synchronization method Finally, through the simulation by the GPS simulator, it is seen that the GPS signal of nigh signal-to-noise ratio can be acquired under increased noise floor using the proposed GPS initial synchronization method.

Watermarking Using Multiresolution Wavelet Transform and Image Fusion (다중 해상도 웨이블릿 변환과 영상 융합을 이용한 워터마킹)

  • Kim Dong-Hyun;Jun Kye-Suk;Lee Dae-Young
    • The KIPS Transactions:PartB
    • /
    • v.12B no.7 s.103
    • /
    • pp.729-736
    • /
    • 2005
  • In this paper. the proposed method for the digital watermarking is based on the multiresolution wavelet transform. The 1-level Discrete Wavelet Transform(DWT) coefficients of a $2N_{wx}{\times}2N_{wy}$ binary logo image used as a watermarks. The LL band and middle frequency band of the host image that the 3-level DWT has been performed are divided into $N_{wx}{\times}N_{wy}$ size and we use large coefficients at the divided blocks to make threshold. we set the thresholds that completely insert the watermark in each frequency of the host image. The thresholds in each frequency of the host image differ each other. The watermarks where is the same positions are added to the larger coefficients than threshold in the blocks at LL band and middle frequency band in order to prevent the quality deterioration of the host image. The watermarks are inserted in LL band and middle frequency band of the host image. In order to be invisibility of the watermark, the Human Visual System(HVS) is applied to the watermark. We prove the proper embedding method by experiment. We rapidly detect the watermark using this watermarking method. And because the small size watermarks are inserted by HVS, the results confirm the superiority of the proposed method on invisibility and robustness.

Replacement of the in vivo Bioassay for Erythropoietin with the in vitro Bioassay (Erythropoietin in vivo 시험법의 in vitro 대체 시험법 확립)

  • 백상훈;김진만;권기성;박송용;허재욱
    • KSBB Journal
    • /
    • v.18 no.4
    • /
    • pp.255-260
    • /
    • 2003
  • In vivo bioassays for biological medicines have been considered final resort to unequivocally assess the biological activities for them because there are some cases in which the biological activities obtained from in vivo bioassay and in vitro bioassay quite differ each other. The in vivo biological activity of EPO depends on its sialic acid contents which confer microheterogeneity-isoforms to this protein. We have devise a method which consists of a in vitro bioassay using BaF3 cell line and a capillary zone electrophoresis (CZE) for the measurement of the EPO isoform distribution. The biological activity of EPO obtained using in vitro bioassay with BaF3 cell line showed good correlation (C.V.(%) 7.34, 5.85, 8,16, 8.08, 8.8) to EPO content measured either spectrophotometric assay (A280 0.1 % =0.743) or radio immunoassay. The assay validation results of in vitro bioassay with 3 lot of in house EPO showed good results to EPO content measured either in vivo assay or radio immunoassay. and also showed good results the robustness of our method in terms of precision, accuracy, repeatability. The isoform distribution for EPO-BRP (1 : 1 mixture of epoetin-${\alpha}$ and epoetin-${\beta}$, European Pharmacopoeia) by CZE method resulted in isoform 2 through isoform 8. The major peaks in electrophoregram were composed of isoform 3 through 7. Our recombinant EPO (epoetin-${\alpha}$) having equivalent in vivo biological activity showed the isoform distribution of isoform 3 through 9. The major peaks consisted of isoform 4 through 8. The peak area of isoform 4 was always smaller than that of isoform 5. The preparations of recombinant epoetin-${\alpha}$ with lower in vivo biological activity than EPO-BRP showed the isoform 2 through 8 in their electrophoregrams whose major peaks consisted of the isoform 3 through 7. The peak area of isoform 4 was larger than that of isoform 5.

Development and validation of a HPLC method for the simultaneous determination of chlorquinaldol and promestriene in complex prescription (복방제제 내 클로르퀴날돌과 프로메스트리엔에 대한 HPLC 기반 동시분석법의 개발 및 밸리데이션)

  • Lee, Seul-Ji;Shin, Sang-Yeon;Shin, Hae-Jin;Lee, Jin-Gyun;Kim, Dong-Hwan;Lee, Su-Jung;Han, Sang-Beom;Park, Jeong-Hill;Lee, Jeong-Mi;Kwon, Sung-Won
    • Analytical Science and Technology
    • /
    • v.25 no.2
    • /
    • pp.152-157
    • /
    • 2012
  • Currently, many types of compound preparations are being used but the quality control guidelines for their use are lacking. In case of single compound drug, the quality control methods are specified in the pharmacopeia. However, there is no method to simultaneously analyze compound preparations. In this study, a simple validated analytical method for HPLC separation of chlorquinaldol and promestriene is introduced. Validation was divided into categories including linearity, precision, accuracy (recovery) and system suitability. The contents of the products which are on the market were monitored using the validated analytical method and the robustness of the analytical method was tested by conducting an inter-laboratory validation.

A Robust Hand Recognition Method to Variations in Lighting (조명 변화에 안정적인 손 형태 인지 기술)

  • Choi, Yoo-Joo;Lee, Je-Sung;You, Hyo-Sun;Lee, Jung-Won;Cho, We-Duke
    • The KIPS Transactions:PartB
    • /
    • v.15B no.1
    • /
    • pp.25-36
    • /
    • 2008
  • In this paper, we present a robust hand recognition approach to sudden illumination changes. The proposed approach constructs a background model with respect to hue and hue gradient in HSI color space and extracts a foreground hand region from an input image using the background subtraction method. Eighteen features are defined for a hand pose and multi-class SVM(Support Vector Machine) approach is applied to learn and classify hand poses based on eighteen features. The proposed approach robustly extracts the contour of a hand with variations in illumination by applying the hue gradient into the background subtraction. A hand pose is defined by two Eigen values which are normalized by the size of OBB(Object-Oriented Bounding Box), and sixteen feature values which represent the number of hand contour points included in each subrange of OBB. We compared the RGB-based background subtraction, hue-based background subtraction and the proposed approach with sudden illumination changes and proved the robustness of the proposed approach. In the experiment, we built a hand pose training model from 2,700 sample hand images of six subjects which represent nine numerical numbers from one to nine. Our implementation result shows 92.6% of successful recognition rate for 1,620 hand images with various lighting condition using the training model.

Scalable Fingerprinting Scheme based on Angular Decoding for LCCA Resilience (선형결합 공모공격에 강인한 각도해석 기반의 대용량 핑거프린팅)

  • Seol, Jae-Min;Kim, Seong-Whan
    • The KIPS Transactions:PartD
    • /
    • v.15D no.5
    • /
    • pp.713-720
    • /
    • 2008
  • Fingerprinting scheme uses digital watermarks to trace originator of unauthorized or pirated copies, however, multiple users may collude and escape identification by creating an average or median of their individually watermarked copies. Previous research works are based on ACC (anti-collusion code) for identifying each user, however, ACC are shown to be resilient to average and median attacks, but not to LCCA and cannot support large number of users. In this paper, we propose a practical SACC (scalable anti-collusion code) scheme and its angular decoding strategy to support a large number of users from basic ACC (anti-collusion code) with LCCA (linear combination collusion attack) robustness. To make a scalable ACC, we designed a scalable extension of ACC codebook using a Gaussian distributed random variable, and embedded the resulting fingerprint using human visual system based watermarking scheme. We experimented with standard test images for colluder identification performance, and our scheme shows good performance over average and median attacks. Our angular decoding strategy shows performance gain over previous decoding scheme on LCCA colluder set identification among large population.

Recent Strategy for Superior Horses (우수 마 선택을 위한 최신 전략)

  • Gim, Jeong-An;Kim, Heui-Soo
    • Journal of Life Science
    • /
    • v.26 no.7
    • /
    • pp.855-867
    • /
    • 2016
  • The horse is relatively earlier domesticated animal species. Domesticated horses have been selected for their ability of racing, robustness, and disease-resistance. As a result, the thoroughbred horse genome has been condensed many genotypes related to exercise ability. In recent years, with the advent of NGS technologies, many studies were concentrated on finding superior genetic species in the horse genome in terms of genomics. Consequently, GWAS (Genome-wide Association study) is applied to horse genome, then genetic marker is revealed for superior racing ability. In addition, RNA-Seq is utilized as a method for analyze of whole transcript profiling in specific samples. By using this approach, specific gene expression patterns and transcript sequences can be revealed in various samples such as each individual, before and after exercise state, and each tissue. DNA methylation, a strong factor that regulate gene expression without the change of DNA sequence, have got a lot of attention. In horse genome, exercise- or individual-specific DNA methylation patterns were detected, and could be useful to develop selective marker of superior horses. MicroRNAs inhibit gene expression, and transposable elements accounted for half of the mammalian genome. These two elements are the crucial factors in functional genomics, and could be applied to the selection of superior horses. As the functional genomics and epigenomics advance, then these technologies introduced in this paper were applied to select superior horses. In this paper, the studies for selection of superior horses through genetic technologies, and development possibilities of these studies were discussed.

A Realtime Expression Control for Realistic 3D Facial Animation (현실감 있는 3차원 얼굴 애니메이션을 위한 실시간 표정 제어)

  • Kim Jung-Gi;Min Kyong-Pil;Chun Jun-Chul;Choi Yong-Gil
    • Journal of Internet Computing and Services
    • /
    • v.7 no.2
    • /
    • pp.23-35
    • /
    • 2006
  • This work presents o novel method which extract facial region und features from motion picture automatically and controls the 3D facial expression in real time. To txtract facial region and facial feature points from each color frame of motion pictures a new nonparametric skin color model is proposed rather than using parametric skin color model. Conventionally used parametric skin color models, which presents facial distribution as gaussian-type, have lack of robustness for varying lighting conditions. Thus it needs additional work to extract exact facial region from face images. To resolve the limitation of current skin color model, we exploit the Hue-Tint chrominance components and represent the skin chrominance distribution as a linear function, which can reduce error for detecting facial region. Moreover, the minimal facial feature positions detected by the proposed skin model are adjusted by using edge information of the detected facial region along with the proportions of the face. To produce the realistic facial expression, we adopt Water's linear muscle model and apply the extended version of Water's muscles to variation of the facial features of the 3D face. The experiments show that the proposed approach efficiently detects facial feature points and naturally controls the facial expression of the 3D face model.

  • PDF

eRPL : An Enhanced RPL Based Light-Weight Routing Protocol in a IoT Capable Infra-Less Wireless Networks (사물 인터넷 기반 기기 간 통신 무선 환경에서 향상된 RPL 기반 경량화 라우팅 프로토콜)

  • Oh, Hayoung
    • KIPS Transactions on Computer and Communication Systems
    • /
    • v.3 no.10
    • /
    • pp.357-364
    • /
    • 2014
  • The first mission for the IoT based hyper-connectivity communication is developing a device-to-device communication technique in infra-less low-power and lossy networks. In a low-power and lossy wireless network, IoT devices and routers cannot keep the original path toward the destination since they have the limited memory. Different from the previous light-weight routing protocols focusing on the reduction of the control messages, the proposed scheme provides the light-weight IPv6 address auto-configuration, IPv6 neighbor discovery and routing protocol in a IoT capable infra-less wireless networks with the bloom filer and enhanced rank concepts. And for the first time we evaluate our proposed scheme based on the modeling of various probability distributions in the IoT environments with the lossy wireless link. Specifically, the proposed enhanced RPL based light-weight routing protocol improves the robustness with the multi-paths locally established based on the enhanced rank concepts even though lossy wireless links are existed. We showed the improvements of the proposed scheme up to 40% than the RPL based protocol.