• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.5
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• pp.17-24
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• 2006

Anti-lock brake system(ABS) are designed to prevent wheel lock on all wheels of the vehicle by sensing wheel angular speed, processing the speed sensor signals in suitable digital electronic control circuits and comanding electrohydraulic actuators to control brake pressure. This study considers a control of ABS using wheel circumferential acceleration thresholds which avoids dangerous wheel locking due to excessive brake pressure during the vehicle braking and discusses the 3-channels, 3-sensors ABS system that employs "independent control" technique for the front wheels and "select low" technique for the rear wheels. The validities of the ABS such as vehicle stability, steerability and stopping distance during braking are assured through the vehicle tests on uniform asphalt straight roads.

• Journal of the Korean Society for Precision Engineering
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• v.13 no.8
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• pp.120-127
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• 1996

Anti-lock Brake System has been developed to reduce tendency for wheel lock and improve vehicle control during sudden braking on slippery road surfaces. This is achieved by controlling the braking pressure, avoiding wheel lock, while retaining handling and brake performance. This paper is concerned about pressurecharacteristics of hydraulic modulator. Experimental sets which is consists of hydraulic modulator, duty controller, pressure regulator, pressure senset is consuructed. System modelling and computer simulation are performed for comparison with experimental results. Brake wheel pressure are measured under various driving pulse. The result of experiment show fairly agreement with the simulation. As a result, it is known that wheel pressure is affected by duty ratio, orifice diameter through computer simulation.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.6 no.1
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• pp.47-80
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• 1984

The aim of this paper is to study the classification and arrangement system, the original texts, and the bibliographic deseription of Dae-Jang-Mock-Lock. The results of this study can be summarized as followings; 1. The first carving of Dae-Jang-Mock-Lock was assumed to be completed at latest by 1087 (King Sun-Jong 4, Koryo) when the first carving of Dae-Jang-Kyong, the complete collection of Buddhist Sutra, mas finished. Henee, Dae-Jang-Mock-Lack is safely said to be the oldest catalog in Korea. 2. The major function of Dae-Jang-Mock-Lock mas to facilitate the job of printing, managing, or arranging the Sutra tablets, rather than to serve as its references. 3. Dae-Jang-Mock-Lock mas classified in accordance with the classification sys tern of Gae-Woon-Suck-Kyo-Lock, a chinese Buddhist catalog. This system classified the complete collection of Buddhist Sutra into the three categories of "Mah$\={a}$y$\={a}$na Tripitaka", "Hinayan$\={a}$ Tripitaha", and "collected Biographies of Samgha", at the first gradation. And then the Mah$\={a}$yan$\={a}$ Tripitaka mas divided into the three categories of "Mah$\={a}$y$\={a}$na Sutra", "Mah$\={a}$y$\={a}$na Uparaksa", and "Mah$\={a}$y$\={a}$na Upadesa", at the second gradation. In the same manner the "Hinayan$\={a}$ Tripitaka was divided into "Hinayan$\={a}$ Sutra", "Hinayan$\={a}$ Uparaksa", and "Hinayan$\={a}$ Upadesa". The "Collected Biographies of Samgha" was divided into Brahman Samgha and Chinese Samgha. For this reason we Can name this main classification system as a Tripitaka Classification. 4. The first carving tablets of the Buddhist Sutra from Choen Shelf (天函) to Young Shelf (英函) were the same Sutra that were included in Gae-Woen-Suck-Kyo-Lock (開元釋敎錄), except those 4 omitted sutras of 22 volumes. But the other 7 sutras of 24 volumes were included as an extra addition in "Dae-Jang-Mock-Lock." 5. The 40 shelves and 376 volumes of Buddhist Sutra from the Doo Shelf (杜函) to the Kyong Shelf (輕函) in Dae-Jang-Mock-Lock were copied from the texts of Guran Edition (契丹本) 6. The 36 shelves of Buddhist Sutras from the Bun shelf (磻函) to the Mil shelf (密函) in Dae-Jang-Mock-Lock were the same as those included in Sock-Jung-Woen-Suck-Kyo-Lock (續貞元釋敎錄), except the 3 omitted sutras.

• Journal of the Korea Society of Computer and Information
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• v.4 no.2
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• pp.105-112
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• 1999

Spread Spectrum Communication is a core technique in CDMA system, but the problem for SS Communication schemes is synchronous method. There are DLL(Delay Lock Loop), Tau-dither Loop, SO(Synchronous Osillator) etc., in the sychronous method. But since there are analog operations, the setting is difficult and circuit size is large. In this paper we proposed Digital Delay Lock Loop (DDLL) and estimated it's performance through the experiment.

• Journal of Industrial Technology
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• v.18
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• pp.355-362
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• 1998

The deadlock detector is a DBMS sub-component that examines periodically whether system is in a deadlock state based on lock waiting information of transactions. The deadlock detector and transactions execute concurrently in a DBMS and read and/or write the lock waiting information simultaneously. Since the lock waiting information is a shared one, we need an efficient method guaranteeing its physical consistency by using mutual exclusion. In this paper, we propose a new method that effectively guarantees physical consistency of lock waiting information. Two primary goals of our method is to minimize the processing overhead and to maximize system concurrency.

• Korean Journal of Optics and Photonics
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• v.30 no.1
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• pp.1-7
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• 2019

MANPADS (man-portable air defense system) is a counterweapon system against enemy aircraft, tracking the MWIR (mid-wavelength of infrared) signature of the plume. Under foggy conditions, however, multiple scattering phenomenon caused by the particles affects the MWIR transmittance, and the MANPADS detection performance. Therefore, in this study we analyzed the lock-on range of MANPADS with varying fog conditions and plume characteristics. To analyze the optical extinction properties and transmittance in fog, Mie scattering theory and analytic solution of the radiative-transfer equation are utilized. In addition, we used flare signature as an alternative MWIR light source. We confirmed that the lock-on range could be noticeably reduced under conditions of mist, and proportional to the flare temperature.

• Journal of the korean Society of Automotive Engineers
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• v.24 no.2
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• pp.108-113
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• 2002

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.560-563
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• 2015

Door lock system is used for the conventional method by using a key or a card, a pad Replication, loss, and the risk of damage, and has a problem that exposure to others. In this paper, Bluetooth communication and OTP built into smartphones in order to complement the existing door lock system problems OTP(One-Time-Password), Hide-Key utilizing the authentication method and the Arduino smartphone-based design of wireless OTP door lock system by enabling users it allows for more convenient and safe life free from the risk of theft and robbery.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1836-1840
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• 2003

This paper, we propose a new phase-locked loop (PLL) system with the controllable output phase, independent from the output frequency, and lock-up time. This PLL system has a dual control loop is described, the inner loop greatly improved VCO characteristic such as faster speed response as well as higher operation bandwidth, to minimize the effect of the VCO noise and the power supply variation and also get better linearity of VCO output. The main loop is the heart of this PLL which greatly improved the output frequency instability due to the external high frequency noise coupling to the input reference frequency also the main loop can control the output phase, independent from the output frequency, and reduce the lock-up time of the step frequency response. The experimental results confirm the validity of the proposed strategy.

• Journal of the Institute of Convergence Signal Processing
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• v.15 no.3
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• pp.97-103
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• 2014

Recently, digital door locks have been widely used as physical security devices for the door. Although they are convenient compared to the existing lock system, they have the problem of being opened by an electric shock. In this study, to improve safety, a method to hide the door-lock device inside and to display the door-lock on a user's smart-phone screen through the augmented reality is suggested. Furthermore, an additional function has been added which provides memo notes to facilitate communication among family members. The results of this study have been implemented by using motors to control locks, Wi-Fi shield, Arduino, and a virtually created door and showed desirable experimental results.