• 대한기계학회논문집A
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• 제21권10호
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• pp.1636-1647
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• 1997

As most of today's automatic transmissions in passenger car adopt a electro-hydraulic control system, the role of electronically controlled solenoid valves occupies an important position and it is essential to predict solenoid transient characteristics in order to design and evaluate the performance of the hydraulic control system. However, in general, both the magnetic and electrical parameters f the solenoid system are hardly known and it is not easy to model this section with moderate complexity although mechanical system could be developed using the classical second order system. This paper presents a dynamic modelling technique of a solenoid valve, that is controlled by pulse width modulation for an automatic transmission, in terms of system identification theory. In nonlinear computer simulation, it is shown that the identified systems which produce magnetic force to input duty cycle for various excitation signals predict the static and dynamic performance very well near the operating point and in experiment conducted to confirm the validity of identification theory for PWM solenoid valve, we find that there is a good agreement between the experimental data and simulation result. Hence, this model can be utilized in the development of pressure control system with PWM solenoid valve.

• 우주기술과 응용
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• 제2권2호
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• pp.121-136
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• 2022

선박 통신에 있어서 선박자동식별시스템(automatic identification system)은 연안 해역의 선박 운항 모니터링, 선박 간의 항해 안전을 위한 정보 교환뿐만 아니라 해상관제 수단에도 필요하다. 그러나 이는 대략 160 MHz의 very high frequency (VHF) 대역을 사용함과 동시에 지구의 곡률로 인해 통신 거리의 한계가 존재한다. 이를 인공위성을 통해 해결하고 있지만, 저궤도의 초소형 위성에 대해서는 아직 많은 작업이 이루어지지 않았다. 본 논문에서는 소프트웨어 정의 라디오(SDR)를 활용하여 초소형위성용 선박정보수집장치의 수신시험을 증명하였다. R820T2 SDR을 활용하여 부산항에 정박해 있는 선박으로부터 AIS(automatic identification system) 데이터를 수집하였고, Adalm-Pluto와 매트랩 시뮬링크를 활용하여 이를 송신할 수 있는 환경을 구축하였다. 또한 감쇠기를 활용하여 위성까지 신호세기가 약해지는 과정을 모사하였다. 일련의 과정을 통해 AIS 탑재체에서 AIS 데이터의 수신 성공 여부를 시연하였다.

• 대한의용생체공학회:의공학회지
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• 제28권3호
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• pp.325-331
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• 2007

Personal identification is essential for the automatic measurement of biosignal information in home healthcare systems. Personal identification is usually achieved with passive radio frequency identification (RFID), which does little more than store a unique identification number. However, passive RFID is not ideal for automatic identification. We present a user identification system based on radio signal strength indication (RSSI) using ZigBee for active RFID tags. Personal identification is achieved by finding the largest RSSI value from aggregated beacon messages that are periodically transmitted by active RFID tags carried by users. Obtaining reliable person!'.! identification without restricting the orientation requires a certain distance between the closest active RFID tag from the ZED and the second closest tag. The results show that the closest active RFID tag from the ZED and the second closest tag must be at least 70 cm apart to achieve reliable personal identification.

• Journal of Power Electronics
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• 제5권3호
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• pp.198-205
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• 2005

The mechanical system of a drive can often be modeled as a two- or three-mass-system. The load is coupled to the driving motor by a shaft able to perform torsion oscillations. For the automatic tuning of the control, it is necessary to know the mathematical description of the system and the corresponding parameters. As the manpower and setup-time necessary during the commissioning of electrical drives are major cost factors, the development of self-operating identification strategies is a task worth pursuing. This paper presents an identification method which can be utilized for the assisted commissioning of electrical drives. The shaft assembly can be approximated as a two-mass non-rigid mechanical system with four parameters that have to be identified. The mathematical background for an identification procedure is developed and some important implementation issues are addressed. In order to avoid the excitation of the system with its natural resonance frequency, the frequency response can be obtained by exciting the system with a Pseudo Random Binary Signal (PRBS) and using the cross correlation function (CCF) and the auto correlation function (ACF). The reference torque is used as stimulation and the response is the mechanical speed. To determine the parameters, especially in advanced control schemes, a numerical algorithm with excellent convergence characteristics has also been used that can be implemented together with the proposed measurement procedure in order to assist the drive commissioning or to achieve an automatic setting of the control parameters. Simulations and experiments validate the efficiency and reliability of the identification procedure.

• 정보보호학회논문지
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• 제10권4호
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• pp.47-57
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• 2000

본 논문에서는 디지털 컨텐츠의 전자상거래에서 사용될 수 있는 재분배자의 개선된 자동 식별기능을 갖는 효율적 인 익명성을 제공하는 핑거프린팅 방식을 제안한다. Domingo가 Electronic Letters에서 제안한 방식은 등록 프로토콜의 통신 회수와 식별프로토콜에서 지수 연산 회수가 너무 많아 전자상거래에서 비효율적이다. 제안하는 방식은 등록 프로토콜에서 통신 회수를 2-pass로 줄였고, 식별 프로토콜에서는 평균적으로 공개키 디렉토리 상에 있는 공개키 수에 반정도의 지수 연산의 회수가 필요했던 것을 단지 1번의 지수 연산으로 줄였다. 따라서, 디지털 컨텐츠의 전자상거래 가 일상 생활에서 쓰이게 됨에 따라 제안하는 방식의 이용 가치는 증대될 것이다.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2000년도 International Workshop for AIS / ECDIS / VTS Interface
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• pp.137-153
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• 2000

• IEIE Transactions on Smart Processing and Computing
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• 제3권2호
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• pp.74-82
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• 2014

Automatic identification is pervasive in many areas and its applicable areas are increasing gradually. 2D bar-code, NFC, and RFID technologies are representative examples of the automatic identification. This paper explains the implementation of mobile tourism application software on RFID technology. The mobile application provides the location and navigation information by combining the tag inventory and web database. The interactions among the user, application and database server are described in detail. This paper proposes a simple way of minimizing the efforts to build the entire system by storing the URLs for the tag and accessing existing tourism information services through the URLs.

• 한국언어정보학회:학술대회논문집
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• 한국언어정보학회 2007년도 정기학술대회
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• pp.375-384
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• 2007

This paper describes a method for automatic acquisition of wide-coverage treebank-based deep linguistic resources for Japanese, as part of a project on treebank-based induction of multilingual resources in the framework of Lexical-Functional Grammar (LFG). We automatically annotate LFG f-structure functional equations (i.e. labelled dependencies) to the Kyoto Text Corpus version 4.0 (KTC4) (Kurohashi and Nagao 1997) and the output of of Kurohashi-Nagao Parser (KNP) (Kurohashi and Nagao 1998), a dependency parser for Japanese. The original KTC4 and KNP provide unlabelled dependencies. Our method also includes zero pronoun identification. The performance of the f-structure annotation algorithm with zero-pronoun identification for KTC4 is evaluated against a manually-corrected Gold Standard of 500 sentences randomly chosen from KTC4 and results in a pred-only dependency f-score of 94.72%. The parsing experiments on KNP output yield a pred-only dependency f-score of 82.08%.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2001년도 추계종합학술대회
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• pp.753-756
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• 2001

선박의 자동식별 시스템(Automatic Identification System(AIS))은 다중접속 방법으로서 SOTDMA를 채택하고 있다. SOTDMA 시스템은 Aloha 영역에서 슬롯 재사용으로부터 기인하는 Gaussian Minimum Shift Keying(GMSK) Co-Channel Interference(CCI)에 의해서 시스템 성능이 저하된다 이 논문에서는 CCI를 제거할 수 있는 여러 가지 방법을 소개하고 비교 분석하여 향후 선박의 자동식별 시스템에 적용 가능한 CCI 제거기법 개발 방안에 대해서 논하도록 하겠다.

• Structural Engineering and Mechanics
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• 제19권2호
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• pp.123-139
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• 2005

An automatic modal identification program is developed for continuous extraction of modal parameters of three cable-supported bridges in Hong Kong which are instrumented with a long-term monitoring system. The program employs the Complex Modal Indication Function (CMIF) algorithm for identifying modal properties from continuous ambient vibration measurements in an on-line manner. By using the LabVIEW graphical programming language, the software realizes the algorithm in Virtual Instrument (VI) style. The applicability and implementation issues of the developed software are demonstrated by using one-year measurement data acquired from 67 channels of accelerometers permanently installed on the cable-stayed Ting Kau Bridge. With the continuously identified results, variability in modal vectors due to varying environmental conditions and measurement errors is observed. Such an observation is very helpful for selection of appropriate measured modal vectors for structural health monitoring use.