• Title/Summary/Keyword: Time-delay system

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Vision-Based High Accuracy Vehicle Positioning Technology (비전 기반 고정밀 차량 측위 기술)

  • Jo, Sang-Il;Lee, Jaesung
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.41 no.12
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    • pp.1950-1958
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    • 2016
  • Today, technique for precisely positioning vehicles is very important in C-ITS(Cooperative Intelligent Transport System), Self-Driving Car and other information technology relating to transportation. Though the most popular technology for vehicle positioning is the GPS, its accuracy is not reliable because of large delay caused by multipath effect, which is very bad for realtime traffic application. Therefore, in this paper, we proposed the Vision-Based High Accuracy Vehicle Positioning Technology. At the first step of proposed algorithm, the ROI is set up for road area and the vehicles detection. Then, center and four corners points of found vehicles on the road are determined. Lastly, these points are converted into aerial view map using homography matrix. By analyzing performance of algorithm, we find out that this technique has high accuracy with average error of result is less than about 20cm and the maximum value is not exceed 44.72cm. In addition, it is confirmed that the process of this algorithm is fast enough for real-time positioning at the $22-25_{FPS}$.

An Adaptive Active Noise Cancelling Model Using Wavelet Transform and M-channel Subband QMF Filter Banks (웨이브릿 변환 및 M-채널 서브밴드 QMF 필터뱅크를 이용한 적응 능동잡음제거 모델)

  • 허영대;권기룡;문광석
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.25 no.1B
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    • pp.89-98
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    • 2000
  • This paper presents an active noise cancelling model using wavelet transform and subband filter banks based on adaptive filter. The analysis filter banks decompose input and error signals into QMF filter banks of lowpass and highpass bands. Each filter bank uses wavelet filter with dyadic tree structure. The decomposed input and error signals are iterated by adaptive filter coefficients of each subband using filtered-X LMS algorithm. The synthesis filter banks make output signal of wideband with perfect reconstruction to prepare adaptive filter output signals of each subband. The analysis and synthesis niter hants use conjugate quadrature filters for Pefect reconstruction. Also, The delayed LMS algorithm model for on-line identification of error path transfer characteristics is used gain and acoustic time delay factors. The proposed adaptive active noise cancelling modelis suggested by system retaining the computational and convergence speed advantage using wavelet subband filter banks.

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A Study on the Clustering Technique Associated with Statistical Term Relatedness in Information Retrieval (정보검색(情報檢索)에 있어서 용어(用語)의 통계적(統計的) 관련성(關聯性)을 응용(應用)한 클러스터링기법(技法))

  • Jeong, Jun-Min
    • Journal of Information Management
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    • v.18 no.4
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    • pp.98-117
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    • 1985
  • At the present time, the role and importance of information retrieval has greatly increased for two main reasons: the coverage of the searchable collections is now extensive and collection size may exceed several million documents; further more, the search results can now be obtained more or less instantaneously using online procedures and computer terminal devices that provide interaction and communication between system and users. The large collection size make it plausible to the users that relevant information will in fact be retrieved as a result of a search operation, and the probability of obtaining the search output without delay creates a substantial user demand for the retrieval services.

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Multipoint multimedia communcation service in broadband ISDN part I: a conversational communcation on DAVID STB environment (광대역ISDN상의 다지점 멀티미디어 통신서비스 I부:DAVIC 표준 STB에서의 대화형 멀티미디어통신)

  • 황대환;이종형;박영덕;조규섭
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.23 no.4
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    • pp.821-835
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    • 1998
  • The Digital Audio-Visual Council(DAVIC) that was established to develop useful multimedia communication services has completed the specifications for providing on-demand services such as Movie on Demand(MoD), Teleshopping and accepting Internet service. And then they are proceeding the works to suport converstional communcation services like Plain Old Telecphone Service(POTS), Video telephone, Video teleconferencing. In this paper, we prpose an efficient terminal architecture which can provide conversational multimedia communication services on DAVIC Set-Top Box (STB) environments. To apply the implemented conversational terminal to the multipoint communication environment, we considered the factors of Qurlity of Services(QoS) that determine grade of conversational communication service. We also present the inter-working scheme and that system structure to satisfy QoS by using new MPEG video bridge which gurantees end to end delay requirements as major element of QoS for achieving the real time communication and does not accompany visual quality degradation.

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An Improved Genetic Algorithm for Integrated Planning and Scheduling Algorithm Considering Tool Flexibility and Tool Constraints (공구유연성과 공구관련제약을 고려한 통합공정일정계획을 위한 유전알고리즘)

  • Kim, Young-Nam;Ha, Chunghun
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.40 no.2
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    • pp.111-120
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    • 2017
  • This paper proposes an improved standard genetic algorithm (GA) of making a near optimal schedule for integrated process planning and scheduling problem (IPPS) considering tool flexibility and tool related constraints. Process planning involves the selection of operations and the allocation of resources. Scheduling, meanwhile, determines the sequence order in which operations are executed on each machine. Due to the high degree of complexity, traditionally, a sequential approach has been preferred, which determines process planning firstly and then performs scheduling independently based on the results. The two sub-problems, however, are complicatedly interrelated to each other, so the IPPS tend to solve the two problems simultaneously. Although many studies for IPPS have been conducted in the past, tool flexibility and capacity constraints are rarely considered. Various meta-heuristics, especially GA, have been applied for IPPS, but the performance is yet satisfactory. To improve solution quality against computation time in GA, we adopted three methods. First, we used a random circular queue during generation of an initial population. It can provide sufficient diversity of individuals at the beginning of GA. Second, we adopted an inferior selection to choose the parents for the crossover and mutation operations. It helps to maintain exploitation capability throughout the evolution process. Third, we employed a modification of the hybrid scheduling algorithm to decode the chromosome of the individual into a schedule, which can generate an active and non-delay schedule. The experimental results show that our proposed algorithm is superior to the current best evolutionary algorithms at most benchmark problems.

A Study on the Equivalence Requirement of WTO Retaliation (WTO 보복조치의 동등요건에 관한 연구)

  • Kang, Soo-Mi
    • Journal of Arbitration Studies
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    • v.23 no.2
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    • pp.81-113
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    • 2013
  • The World Trade Organization (WTO) offers remedies for non-compliance by the introduction of compensation or retaliation in the Dispute Settlement Understanding (DSU). There are no the provisions under the WTO DSU and it seems unclear what retaliation is attempting to achieve. Therefore, it is unclear whether the goal of WTO retaliation is to induce compliance or to restore the balance between the rights and the obligations of WTO members. It has been claimed the WTO has a strong dispute settlement system by providing retaliation when the recommendations and rulings of Dispute Settlement Body (DSB) are not complied with. But this seems to be inadequate to bring about effective and timely compliance. Especially there is a problem with free riding by a violating member because the level of retaliation is determined from the expiration of a reasonable period of time, providing an incentive to delay compliance. Also the level of the suspension of concessions or other obligations authorized by the DSB is equivalent to the level of nullification or impairment, according to DSU Article 22.4. However, if the member concerned objections to the level of the suspension proposed, the matter shall be referred to arbitration. The arbitrator shall not examine the nature of the suspension of concessions or other obligations to be suspended but shall determine whether the level of such suspension is equivalent to the nullification or impairment. The arbitrator makes an assessment standard of equivalence by comparing the suspension of concessions or other obligations and the nullification or impairment calculated in terms of the amount of trade. But it is necessary that other standards replace the quantitative standards when the level of the nullification or impairment cannot be quantified by concrete damages.

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Design of a high-performance floating-point unit adopting a new divide/square root implementation (새로운 제산/제곱근기를 내장한 고성능 부동 소수점 유닛의 설계)

  • Lee, Tae-Young;Lee, Sung-Youn;Hong, In-Pyo;Lee, Yong-Surk
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.37 no.12
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    • pp.79-90
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    • 2000
  • In this paper, a high-performance floating point unit, which is suitable for high-performance superscalar microprocessors and supports IEEE 754 standard, is designed. Floating-point arithmetic unit (AU) supports all denormalized number processing through hardware, while eliminating the additional delay time due to the denormalized number processing by proposing the proposed gradual underflow prediction (GUP) scheme. Contrary to the existing fixed-radix implementations, floating-point divide/square root unit adopts a new architecture which determines variable length quotient bits per cycle. The new architecture is superior to the SRT implementations in terms of performance and design complexity. Moreover, sophisticated exception prediction scheme enables precise exception to be implemented with ease on various superscalar microprocessors, and removes the stall cycles in division. Designed floating-point AU and divide/square root unit are integrated with and instruction decoder, register file, memory model and multiplier to form a floating-point unit, and its function and performance is verified.

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DIAGNOSIS OF MESIODENS BY $SCANORA^{(R)}$ ($SCANORA^{(R)}$를 이용한 Mesiodens의 진단)

  • Jeon, Hyung-Joon;Kim, Jong-Soo;Kwon, Soon-Won
    • Journal of the korean academy of Pediatric Dentistry
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    • v.27 no.4
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    • pp.490-493
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    • 2000
  • Mesiodens are supernumerary teeth in the region of the maxillary central incisors, a condition which can lead to disorders of the dentition. Their presence may lead to disorders, such as delay in eruption of permanent teeth, development of dentigerous cysts, resorption of adjacent roots and eruption of a supernumerary tooth into nasal cavity. The optimal time for surgical intervention is controversial. Early diagnosis is important so as to enable good prognosis. Diagnosis primarily depends on x-ray films. Panorama film, occlusal film, periapical film have been used for detection of mesiodens. But, all of them have disadvantages. $SCANORA^{(R)}$ is a multimodal radiology system which utilizes the principles of narrow beam radiology and spiral tomography. Pre-programmed imaging procedure are provided for many dental situations An optional personal computer can be connected into the unit to help design the examination. We report two cases diagnosed by $SCANORA^{(R)}$. When compared with tube shift technique, it is simple and exact method of detecting mesiodens.

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Deciding Priority of Safety Messages using Decision Tree in IEEE 802.11p/1609.4 Vehicular Network (802.11p/1609 차량네트워크에서 Decision Tree를 이용한 안전메세지 우선순위 결정 기법)

  • Baik, Hyein;Kwon, YongHo;Rhee, Byung Ho
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2015.10a
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    • pp.794-797
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    • 2015
  • As the interest in VANET is increased, a study on the beacon message transmission between vehicles is actively being made. IEEE 802.11p/1609.4 standard is based on a multichannel system consisting of multiple service channels (SCH) and a control channel (CCH). Multiple SCHs are defined for nonsafety data transfer, while the CCH is used to broadcast safety messages called beacons and control messages (i.e., service advertisement messages). However, most messages broadcast in the only one CCH belong to safety application that must be contested in dense vehicular network. This paper suggests safety message transfer algorithm in dense vehicular congestion. The proposed algorithm is that the priority of safety messages is decided by decision tree and messages are stored in proper queues according to their priorities. Then, safety messages with higher priorities are sent in turn by CCH in the assigned time. The proposed algorithm decreases the beacon transmission delay and increase on the probability of a successful beacon reception in an IEEE 802.11p/1609.4-based network.

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A study of the development of a simple driver for the Pockels cell Q-switch and Its characteristics (단순화된 Pockels cell Q-switch용 구동기 개발 및 특성에 관한 연구)

  • Park, K.R.;Joung, J.H.;Hong, J.H.;Kim, B.G.;Moon, D.S.;Kim, W.Y.;Kim, H.J.;Cho, J.S.
    • Proceedings of the KIEE Conference
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    • 2000.07c
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    • pp.2116-2118
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    • 2000
  • In the technique of Q-switching, very fast electronically controlled optical shutters can be made by using the electro-optic effect in crystals or liquids. The driver for the Pockels cell must be a high-speed, high-voltage switch which also must deliver a sizeable current. Common switching techniques include the use of vacuum tubes, cold cathode tubes, thyratrons, SCRs, and avalanche transistors. Semiconductor devices such as SCRs, avalanche transistors, and MOSFETs have been successfully employed to drive Pockels cell Q-switch. In this study, a simple driver for the Pockels cell Q-switch was developed by using SCRs, pulse transformer and TTL ICs. The Pockels cell Q-switch which was operated by this driver was employed in pulsed Nd:YAG laser system to investigate the operating characteristics of this Q-switch. And we have investigated the output characteristics of this Q-switch as a function of the Q-switch delay time to Xe flashlamp current on.

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