• Title/Summary/Keyword: Transmission matrix

Search Result 601, Processing Time 0.025 seconds

Fault Line Detection Methodology for Four Parallel Lines on the Same Tower

  • Li, Botong;Li, Yongli;Yao, Chuang
    • Journal of Electrical Engineering and Technology
    • /
    • v.9 no.4
    • /
    • pp.1217-1228
    • /
    • 2014
  • A method for faulted line detection of four parallel lines on the same tower is presented, based on four-summing and double-differential sequences of one terminal current. Four-summing and double-differential sequences of fault current can be calculated using a certain transformation matrix for parameter decoupling of four parallel transmission lines. According to fault boundary conditions, the amplitude and phase characteristics of four-summing and double-differential sequences of fault current is studied under conditions of different types of fault. Through the analysis of the relationship of terminal current and fault current, a novel methodology for fault line detection of four parallel transmission line on the same tower is put forward, which can pick out the fault lines no matter the fault occurs in single line or cross double lines. Simulation results validate that the methodology is correct and reliable under conditions of different load currents, transient resistances and fault locations.

Mechanical Property and Corrosion Resistance of Mg-Zn-Y Alloys Containing Icosahedral Phase (준결정상을 포함한 Mg-Zn-Y 합금의 기계적 특성 및 부식 저항성)

  • Kim, Do Hyung;Kim, Young Kyun;Kim, Won Tae;Kim, Do Hyang
    • Korean Journal of Metals and Materials
    • /
    • v.49 no.2
    • /
    • pp.145-152
    • /
    • 2011
  • Mechanical and property corrosion resistance of Mg-Zn-Y alloys with an atomic ratio of Zn/Y of 6.8 are investigated using optical microscopy, scanning electron microscopy, transmission electron microscopy, uniaxial tensile test and corrosion test with immersion and dynamic potentiometric tests. The alloys showed an in-situ composite microstructure consisting of α-Mg and icosahedral phase (I-phase) as a strengthening phase. As the volume fraction of the I-phase increases, the yield and tensile strengths of the alloys increase while maintaining large elongation (26~30%), indicating that I-phase is effective for strengthening and forms a stable interface with surrounding α-Mg matrix. The presence of I-phase having higher corrosion potential than α-Mg, decreased the corrosion rate of the cast alloy up to I-phase volume fraction of 3.7%. However further increase in the volume fraction of the I-phase deteriorates the corrosion resistance due to enhanced internal galvanic corrosion cell between α-Mg and I-phase.

A State Feedback Controller Design for a Networked Control System with a Markov Delay (마코프 지연을 갖는 네트워크 제어 시스템을 위한 상태 궤환 제어기 설계)

  • Yang, Janghoon
    • Journal of Advanced Navigation Technology
    • /
    • v.24 no.6
    • /
    • pp.549-556
    • /
    • 2020
  • This paper proposes several suboptimal methods of designing a controller for a networked control system with state feedback where delay due to transmission error and transmission delay is modeled as a Markov process. A stability condition for a control system with Markov delay is found through an equivalent relationship that corresponding delay-dependent Lyapunov-Krasovskii functional has the same form of the Lyapunov function of an augmented control system. Several suboptimal methods of designing a controller from the stability condition are proposed to reduce complexity. A simple numerical experiment shows that a restricted subspace method which limits the search space of a matrix variable to a block diagonal form provides the best tradeoff between the complexity and performance.

A Hierarchical Bilateral-Diffusion Architecture for Color Image Encryption

  • Wu, Menglong;Li, Yan;Liu, Wenkai
    • Journal of Information Processing Systems
    • /
    • v.18 no.1
    • /
    • pp.59-74
    • /
    • 2022
  • During the last decade, the security of digital images has received considerable attention in various multimedia transmission schemes. However, many current cryptosystems tend to adopt a single-layer permutation or diffusion algorithm, resulting in inadequate security. A hierarchical bilateral diffusion architecture for color image encryption is proposed in response to this issue, based on a hyperchaotic system and DNA sequence operation. Primarily, two hyperchaotic systems are adopted and combined with cipher matrixes generation algorithm to overcome exhaustive attacks. Further, the proposed architecture involves designing pixelpermutation, pixel-diffusion, and DNA (deoxyribonucleic acid) based block-diffusion algorithm, considering system security and transmission efficiency. The pixel-permutation aims to reduce the correlation of adjacent pixels and provide excellent initial conditions for subsequent diffusion procedures, while the diffusion architecture confuses the image matrix in a bilateral direction with ultra-low power consumption. The proposed system achieves preferable number of pixel change rate (NPCR) and unified average changing intensity (UACI) of 99.61% and 33.46%, and a lower encryption time of 3.30 seconds, which performs better than some current image encryption algorithms. The simulated results and security analysis demonstrate that the proposed mechanism can resist various potential attacks with comparatively low computational time consumption.

TEM investigation of helium bubble evolution in tungsten and ZrC-strengthened tungsten at 800 and 1000℃ under 40keV He+ irradiation

  • I. Ipatova;G. Greaves;D. Terentyev;M.R. Gilbert;Y.-L. Chiu
    • Nuclear Engineering and Technology
    • /
    • v.56 no.4
    • /
    • pp.1490-1500
    • /
    • 2024
  • Helium-induced defect nucleation and accumulation in polycrystalline W and W0.5 wt%ZrC (W0.5ZrC) were studied in-situ using the transmission electron microscopy (TEM) combined with 40 keV He+ irradiation at 800 and 1000℃ at the maximum damage level of 1 dpa. Radiation-induced dislocation loops were not observed in the current study. W0.5ZrC was found to be less susceptible to irradiation damage in terms of helium bubble formation and growth, especially at lower temperature (800 ℃) when vacancies were less mobile. The ZrC particles present in the W matrix pin the forming helium bubbles via interaction between C atom and neighbouring W atom at vacancies. This reduces the capability of helium to trap a vacancy which is required to form the bubble core and, as a consequence, delays, the bubble nucleation. At 1000 ℃, significant bubble growth occurred in both materials and all the present bubbles transitioned from spherical to faceted shape, whereas at 800 ℃, the faceted helium bubble population was dominated in W.

The Structure of Korean Consonants as Perceived by the Japanese (일본인이 지각하는 한국어 자음의 구조)

  • Bae, Moon-Jung;Kim, Jung-Oh
    • Korean Journal of Cognitive Science
    • /
    • v.19 no.2
    • /
    • pp.163-175
    • /
    • 2008
  • Twelve Japanese students living in South Korea have been examined for their perceptual identification of an initial consonant in Korean syllables with or without a white noise. A confusion matrix was then subject to analyses of additive clustering, individual difference scaling, and probability of information transmission, the results of which were also compared to those of South Koreans. The Japanese in the present experiment confused /다/and/타/ most frequently, followed by /가/ and /카/, /자, 차, 짜/, /타/ and /따/, and so on. The results of additive clustering analysis of the Japanese significantly differed from those of the South Koreans. Individual difference scaling revealed dimensions of sonorant, aspiration and coronal. While South Koreans showed binary values on aspiration and tenseness dimensions, the Japanese did continuous values on such dimensions. An information transmission probability analysis revealed that the Japanese participants could not perceive very well such larynx features as tenseness and aspiration compared to the South Korean participants. The former group, however, perceived very well place of articulation features such as labial and coronal. The present results suggest that an approach dealing with structures of base representations is important in understanding the phonological categories of languages.

  • PDF

Study on the Physicochemical Change of Human Hair Shaft Following Radiation with Ultraviolet (자외선 조사에 따른 모발의 물리화학적 변화에 관한 연구)

  • Chang, Byung-Soo;Na, Su-Kyong;Lee, Gui-Yeong
    • Applied Microscopy
    • /
    • v.36 no.2
    • /
    • pp.109-118
    • /
    • 2006
  • The physicochemical properties of damaged hair by irradiation of ultraviolet-B (UV-B) have been investigated by using transmission electron microscope and scanning electron microscope. The range of irradiation of hair irradiated for expectative 6 hours, 12 hours, 24 hours and 48 hours with stimulated ultraviolet ray. The treated hairs showed characteristic morphological damage pattern in the cornified cell of matrix and the cuticle following time past. The various sized vacuoles in the endocuticle of the cuticular cells was formed. The statistically significant differences in diameter of cuticular cell were observed in terms of tranverse swelling by formation of vacuoles. The hair cortex and matrix undergo long term exposure to UV-B radiation. The macrofibrils of cortex appeared to be affected most by UV-B, although the morphology and volume of melanin granule was not changed. The physicochemical destruction of hair matrix and cuticular cells is largely accelerated by long term irradiation of UV-B.

A Study on Signal Estimation of Modified Beamformer Method using Perturbation Covariance Matrix (섭동공분산행렬을 이용한 수정 빔형성기 방법의 신호 추정에 대한 연구)

  • Lee, Kwan-Hyeong;Cho, Tae-Jun
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
    • /
    • v.10 no.4
    • /
    • pp.333-339
    • /
    • 2017
  • Transmission signal in wireless environment receives a signal in which a source signal, interference, and noise are mixed. The goal of this study is to estimate the desired signal from the received signal. In this paper, we have studied a method correctly estimating a target in spatial by modified beamformer method. The modified bemaformer uses an adaptive array antenna and perturbation matrix to obtain the optimal weight, and estimate the desired signal by radiating the beam in spatial. We estimate a desired signal of the target by improving resolution with the modified beamformer method which does not have complicated calculation amount. Through simulation, we compare and analyze the modified beamformer method and the MUSIC method with good resolution. In result of simulation, we showed that modified beamformer method has better resolution of 10degree than classical beamformer method and showed similar performance as the MUSIC method. The resolution of this paper was estimated to be about 5 degrees.

Matrix-based Filtering and Load-balancing Algorithm for Efficient Similarity Join Query Processing in Distributed Computing Environment (분산 컴퓨팅 환경에서 효율적인 유사 조인 질의 처리를 위한 행렬 기반 필터링 및 부하 분산 알고리즘)

  • Yang, Hyeon-Sik;Jang, Miyoung;Chang, Jae-Woo
    • The Journal of the Korea Contents Association
    • /
    • v.16 no.7
    • /
    • pp.667-680
    • /
    • 2016
  • As distributed computing platforms like Hadoop MapReduce have been developed, it is necessary to perform the conventional query processing techniques, which have been executed in a single computing machine, in distributed computing environments efficiently. Especially, studies on similarity join query processing in distributed computing environments have been done where similarity join means retrieving all data pairs with high similarity between given two data sets. But the existing similarity join query processing schemes for distributed computing environments have a problem of skewed computing load balance between clusters because they consider only the data transmission cost. In this paper, we propose Matrix-based Load-balancing Algorithm for efficient similarity join query processing in distributed computing environment. In order to uniform load balancing of clusters, the proposed algorithm estimates expected computing cost by using matrix and generates partitions based on the estimated cost. In addition, it can reduce computing loads by filtering out data which are not used in query processing in clusters. Finally, it is shown from our performance evaluation that the proposed algorithm is better on query processing performance than the existing one.

Fatigue Crack Growth Behavior of a Magnesium-Based Composite (마그네슘 금속복합재의 피로균열거동해석)

  • Kim, Doo Hwan;Park, Yong Gul;Kim, Sung Hoon;Han, Suk Kyu
    • Journal of Korean Society of Steel Construction
    • /
    • v.9 no.4 s.33
    • /
    • pp.515-521
    • /
    • 1997
  • The effects of heat treatment and fiber orientation on tensile strength and fatigue behavior were studied in a continuously reinforced. magnesium-based composite Following an earlier TEM investigation, specimens were thermally aged to modified the interfacial zone between the alumina fibers and the magnesium alloy matrix. From the tensile experimental results, the ultimate tensile strength of the aged specimens were lower than that of the as-fabricated due to weak fiber-matrix interfacial strength with chemical reaction during the thermal processing. The fatigue crack growth experiments were conducted with specimens having the fiber orientation normal to the crack growth direction (longitudinal) and also specimens with the fibers oriented parallel to the crack growth direction(transverse). A comparison of the fatigue crack growth behavior indicates that aged longitudinal specimens are more resistant to fatigue crack growth the as-fabricated longitudinal specimens. Conversely, as-fabricated transverse specimens are more resistant to fatigue crack growth than aged transverse specimens.

  • PDF