• Title/Summary/Keyword: 시간지연함수

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Design of an Integrated Interface Circuit and Device Driver Generation System (인터페이스 회로와 디바이스 드라이버 통합 자동생성 시스템 설계)

  • Hwang, Sun-Young;Kim, Hyoun-Chul;Lee, Ser-Hoon
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.32 no.6B
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    • pp.325-333
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    • 2007
  • An OS requires the device driver to control hardware IPs at application level. Development of a device driver requires specific acknowledge for target hardware and OS. In this paper, we present a system which generates a device driver together with an interface circuit. In the proposed system, an efficient device driver is generated by selecting a basic device driver skeleton, a function module code, and a header file table from the pre-constructed library and an interface circuit is constructed such that the generated device driver operates correctly. The proposed system is evaluated by generating a TFT-LCD device driver on the ARM922T core with 3.5 inch Samsung TFT-LCD in ARM-Linux environment. Experiment result shows that the writing time on the LCD is decreased by 1.12% and the compiled code size is increased by 0.17% compared to the manually generated one. The automatically generated device driver has no performance degradation in the latency of hardware control at the application program level. The system development time can be reduced using the proposed device driver generation system.

An Analysis on the Number of Advertisements for Device Discovery in the Bluetooth Low Energy Network (저전력 블루투스 네트워크에서 장치 탐색을 위한 Advertising 횟수에 관한 분석)

  • Kim, Myoung Jin
    • Journal of the Institute of Electronics and Information Engineers
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    • v.53 no.8
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    • pp.3-12
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    • 2016
  • Bluetooth Low Energy (BLE) protocol has attracted attention as a promising technology for low data throughput and low energy wireless sensor networks. Fast device discovery is very important in a BLE based wireless network. It is necessary to configure the network to work with minimized energy consumption because the BLE network nodes are expected to operate a long time typically on a coin cell battery. However, since it is difficult to obtain low energy and low latency at the same time, the BLE standard introduces wide range setting of parameters related to device discovery process and let the network operators to set up parameter values for the application. Therefore, it is necessary to analyze the performance of device discovery according to the related parameter values prior to BLE network operation. In this paper we analyze the expected value and the cumulative distribution function of the number of advertisements for device discovery in the BLE network. In addition, we propose a scheme for controlling the interval between advertising events that can improve the performance of device discovery without increasing energy consumption.

Modeling and Simulation of the Efficient Certificate Status Validation System on Public Key Infrastructure (공개키 기반 구조에서의 효율적인 인증서 상태 검증 방법의 모델링 및 시뮬레이션)

  • Seo, Hee-Suk;Kim, Tae-Kyoung;Kim, Hee-Wan
    • Journal of the Korea Computer Industry Society
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    • v.5 no.5
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    • pp.721-728
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    • 2004
  • OCSP (Online Certificate Status Protocol) server which checks the certificate status provides the real time status verification in the PKI (Public Key Infrastructure) system which is the essential system of certificate. However, OCSP server need the message authentication with the server and client, so it has some shortcomings that has slow response time for the demands of many clients concurrently and has complexity of the mathematical process in the public encryption system. In this research, simulation model of the certificate status vertification server is constructed of the DEVS (Discrete EVent system Specification) formalism. This sever model is constructed to practice the authentication with hash function when certificate is checked. Simulation results shows the results of increase of the certificate status verification speed and decrease of the response time to the client.

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The Effect of Temperature and Day-Length Conditions on the Growth and Fecundity of Green Rice Leafhopper, Nephotettix cincticeps Uhler (사육온도 및 광조시간이 끝동매미충의 발육과 산란에 미치는 영향)

  • Song Yoo-Han
    • Korean journal of applied entomology
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    • v.17 no.4 s.37
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    • pp.187-191
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    • 1978
  • This experiment was conducted to determine the optimum temperature and day-length condition for laboratory multiplication of Green Rice Leafhopper, Nephotettix cincticeps Uhler, and to obtain basic information for deriving temperature dependent growth rate function. The insects which were reared in $33-35^{\circ}C$ have relatively short nymphal periods and high adult emergence rate compared with the insects which were reared in $27-29^{\circ}C$ The adults which emerged in $35^{\circ}C$ laid significantly smaller number of eggs than the adult reared in $27-29^{\circ}C$ during their nymphal stage. Day length in $29^{\circ}C$ did not have any influence to the nymphal growth, adult emergence rate and egg laying of the insect. The growth rate of the insect did not have linear relation with rearing temperature.

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A Feedback-Form of Terminal-Phase Optimal Guidance Law for BTT Missiles Considering Autopilot Dynamics (자동조종장치 동역학을 고려한 궤환 형태의 BTT 미사일용 최적 종말 유도 법칙)

  • Yoo, Seong-Jae;Hong, Jin-Woo;Ha, In-Joong
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.44 no.3
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    • pp.203-211
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    • 2016
  • In contrast with STT missiles, the guidance law design for BTT missiles should be based on 3-dimensional pursuit kinematics, since the pitch and roll channels of BTT missiles are coupled dynamically. More generally than the prior works, the dynamics of pitch and roll channels, as well as 3-dimensional pursuit kinematics are considered in the design of our terminal-phase optimal guidance law for BTT missiles proposed in this paper. Thereby, the proposed optimal guidance law guarantees high capturability with small miss distance without significant performance degradation due to time-lag effect even in case of relatively slow autopilot dynamics. Moreover, the resulting optimal guidance law is expressed explicitly in feedback-form with the coefficients given as the functions of time-to-go. The effectiveness and practicality of our work is demonstrated through various simulation results.

Inhibitory Effect of adding Phase Change Material (PCM) to Fire Fighter Protective Clothing on Burn Injuries (Phase Change Material (PCM) 소재 적용 소방보호복의 화상발생 억제효과에 관한 연구)

  • Lee, Jun Kyoung
    • Fire Science and Engineering
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    • v.30 no.3
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    • pp.16-22
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    • 2016
  • Fire fighters rely on fire fighter protective clothing (FFPC) to provide adequate protection in the various hazardous environments. To enhance its protection performance, the FFPC material must be thick and thus it is difficult to achieve weight reduction. One of the methods of overcoming this problem, the addition of phase change material (PCM) to FFPC, is a new technology. In previous studies, the researches was mostly related to the temperature characteristics of the fibers incorporating PCM, but little information is available about its effect on burn injuries. Thus, in this study, the inhibitory effects of adding PCM to FFPC on second degree burns were investigated through numerical calculations. Thermal analyses of biological tissues and FFPC with embedded PCM exposed to several fire conditions causing severe tissue damage were studied by using a finite difference method based on the Pennes bio-heat equation. FFPC with embedded PCM was found to provide significantly greater protection than conventional fire fighting clothing, because the heat of absorption due to the phase change within the material is used to limit the heat conduction of the material.

Design and VLSI Implementation of Reassembly Controller for ATM/AAL Layer (ATM/AAL 처리를 위한 재조립 처리기의 설계 및 VLSI 구현)

  • 박경철;심영석
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.40 no.5
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    • pp.369-378
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    • 2003
  • This paper presents design and VLSI implementations of a reassembly processor for ATM/AAL. The assembly processor is responsible for processing ATM cells from the receive physical interface. It controls the transfer of the AAL payload to host memory and performs all necessary SAR and CPCS checks. We propose the improved structure of cell identification algorithm and smart scatter method for host memory management. The proposed cell identification algorithm quickly locates the appropriate reassembly VC table based on the received VPI./VCI channel value in the ATM header. The cell identification algorithm also allow complete freedom in assignment of VCI/VPI values. The reassembly processor uses a smart scatter method to write cell payload data to host memory. It maintains the scatter operation and controls the incoming DMA block during scatter DMA to host memory. The proposed reassembly processor can perform reassembly checks on AAL. OAM cell. For an AAL5 connection, only CPCS checks, including the CRC32, are performed. In this paper, we proposed a practical reassembly architecture. The design of reassembly processor has become feasible using 0.6${\mu}{\textrm}{m}$ CMOS gate array technology.

Natural Frequency of 2-Dimensional Heaving Circular Cylinder: Time-Domain Analysis (상하동요하는 2차원 원주의 고유진동수: 시간 영역 해석)

  • Kim, Ki-Bum;Lee, Seung-Joon
    • Journal of the Society of Naval Architects of Korea
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    • v.50 no.4
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    • pp.224-231
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    • 2013
  • The concept of the natural frequency is useful for understanding the characters of oscillating systems. However, when a circular cylinder floating horizontally on the water surface is heaving, due to the hydrodynamic forces, the system is not governed by the equation like that of the harmonic one. In this paper, in order to shed some lights on the more correct use of the concept of the natural frequency, a problem of the heaving circular cylinder is analyzed in the time domain. The equation of motion, an integro-differential equation, was derived following the fashion of Cummins (1962), and its coefficients including the retardation function were obtained using the numerical solution of Lee (2012). The equation was solved numerically, and the experiment was also carried out in the CNU flume. Using our numerical and experimental results, the natural frequency was defined as its average value given by the motion data excluding those of the initial stage. Our results were then compared with those of the existing investigations such as Maskell and Ursell (1970), Ito (1977) and Yeung (1982) as well as the newly obtained results of Lee (2012). Comparison showed that the natural frequency obtained here agrees well with that of Lee (2012), which was found through the frequency domain analysis. It was also shown that the approximation of heaving motion by a damped harmonic oscillation, which was regarded as suitable by most previous investigators, is not physically suitable for the reason that can be clearly shown through comparing the shape of MCFRs(Modulus of Complex Frequency Response). Furthermore, we found that although the previous approximations yield the damping ratio significantly different from our result the magnitude of natural frequency is not much different from our result.

An Indoor Positioning Algorithm Based on 3 Points Near Field Angle-of-Arrival Estimation without Side Information (청취자 거리정보가 필요 없는 도달각 기반 실내 위치 추정기법)

  • Kim, Yeong-Moon;Yoo, Seung-Soo;Kim, Sun-Yong
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.35 no.11C
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    • pp.957-964
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    • 2010
  • In this paper, we propose an indoor positioning algorithm based on 3 points near field angle-of-arrival estimation without side information. The conventional angle-of-arrival based positioning scheme requires the distance between the listener and the center of two points which is obtained by a received signal strength based range estimation. However, a received signal strength is affected by structure of room, placement of furniture, and characteristic of signal, these effects cause a large error to estimation of angle. In this paper, the proposed positioning scheme based on near field angle-of-arrival estimation can be used to estimate the position of listener without a prior distance information, just using time-difference-of-arrival information given from 3 points microphones. The performance of the proposed scheme is shown by cumulative distribution function of root mean squared error.

Optimal LAN Design Using a Pareto Stratum-Niche Cubicle Genetic Algorithm (PS-NC GA를 이용한 최적 LAN 설계)

  • Choi, Kang-Hee;Jung, Kyoung-Hee
    • Journal of the Korea Computer Industry Society
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    • v.6 no.3
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    • pp.539-550
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    • 2005
  • The spanning tree, which is being used the most widely in indoor wiring network, is chosen for the network topology of the optimal LAN design. To apply a spanning tree to GA, the concept of $Pr\ddot{u}fer$ numbers is used. $Pr\ddot{u}fer$ numbers can express he spanning tree in an efficient and brief way, and also can properly represent the characteristics of spanning trees. This paper uses Pareto Stratum-Niche Cubicle(PS-NC) GA by complementing the defect of the same priority allowance in non-dominated solutions of pareto genetic algorithm(PGA). By applying the PS-NC GA to the LAN design areas, the optimal LAN topology design in terms of minimizing both message delay time and connection-cost could be accomplished in a relatively short time. Numerical analysis has been done for a hypothetical data set. The results show that the proposed algorithm could provide better or good solutions for the multi-objective LAN design problem in a fairly short time.

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