• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.18 no.7
• /
• pp.600-604
• /
• 2005

We studied that structural and optical properties of ZnO films depend on oxygen contents. ZnO films were deposited on Si (111) substrates at room temperature by rf sputtering system and the thickness of films was 100 nm. The ZnO films were annealed in thermal furnace for 2 h at 800 and $900^{\circ}C$ in $H_2O,\;N_2$, and air ambient gases to control oxygen contents. We used AES, PL, XRD, AFM. As our result, crystal quality and luminescence improved until O/Zn is 1. However, when O/Zn ratio Is larger than 1, the structural and optical properties were getting worse.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2004.11a
• /
• pp.89-92
• /
• 2004

Nowadays, the study on the ceramic components and modules that used in telecommunication system is being performed. The technology that co-fired both a ceramic material and a silver conductor is usually used to develop small telecommunication components and modules. In the study, It is that the lumped elements equivalent circuit with easy tuning control can be matched more accurate at the 50ohm than the transmission line.

• 제어로봇시스템학회:학술대회논문집
• /
• 2001.10a
• /
• pp.114.2-114
• /
• 2001

In steel works, Locomotives and torpedo ladle cars are used to convey the smelted iron that comes out Blast Furnace to the steel-making mill. Above conveying vehicles are operated in all steel works area. And to trace their positions, after partitioned their areas, Automatic Vehicle Identification(RF-ID method) is installed on the railroad and identifies vehicle numbers. But AVI facilities have many problem that means that are too expensive, cost too much maintenance fee and inefficient management. This paper is to revamp those inefficient operations and state the status of operations of train positioning system, get to know what the problem is. And also when we use GPS to monitor and trace the vehicle position ...

• 제어로봇시스템학회:학술대회논문집
• /
• 2001.10a
• /
• pp.114.6-114
• /
• 2001

According to expansion of wireless communication system and mobile device, interest has been growing in personal navigation system integrated with wireless system. In portable consumer electronics, such as cellular phones, GPS and PDA, one of major design factors is the power consumption. Solutions of reducing the power dissipation are low voltage, low system clock power management and so on. This paper develops a GPS receiver based on the advanced power management algorithm that achieves very low average power consumption. Both RF and DSP chips are powered down and reactivated only when the position fixing is required. In order to run, the developed includes the RTC calibration function and the fast reacquisition function using XMC (eXtended Multiple Correlator) ...

• 제어로봇시스템학회:학술대회논문집
• /
• 2002.10a
• /
• pp.33.6-33
• /
• 2002

For RF sensitivity enhancement, the previous assisted GPS acquisition architecture adopts not only the coherent integration technique but also the non-coherent integration technique since the long coherent integration time increases the number of the frequency search cells. But the non-coherent integration technique induces the squaring loss, which is the dominant factor among the acquisition losses of assisted GPS dealing with weak GPS signals. This paper proposes an efficient architecture for weak signal acquisition in assisted GPS. In this paper, it is explained that the proposed architecture reduces the squaring loss using a modified non-coherent integration technique. Furthermore, it is..

• Proceedings of the IEEK Conference
• /
• 2003.07a
• /
• pp.557-560
• /
• 2003

The increase of vehicles stagnations leads to the increasing attention to the way customers pay and a large number of projects on electronic cash system. Tranport system is comprised of a number of advanced technologies, including information processing, communications, control, and electronics. Recently many research on a system which provides contact in order to protect driver's vehicle passage have been carried out. And some potential problems from that system are being reviewed by electronic cash system. In this papers, we suggest RF protocol developing technology using the concept of electronic cash. ATM electronic cash developing is consist of component of pre-developed coin throw, integration of component using its, and production of more requirement-satisfactory ITS solution. Result increase 15~40% pre-type vehicles stagnations. Especially, we expect this proposed concept would be well adapted to our national environments.

• Proceedings of the KSR Conference
• /
• 2007.05a
• /
• pp.1908-1912
• /
• 2007

The metropolitan area needs to control the Automatic Fare Collection (AFC) and transportation card system in order to implement an efficient railway and subway. This paper introduces a suitable analysis to take advantage of the systematic method of the AFC and transportation card. These systems should consider the fare system, transportation pass and AFC equipment, which are organized with the Automatic Ticket Vending Machine, the Ticket Office Machine and the Card System of Radio Frequency (RF). However, the organization includes the fact the Automatic Ticket Vending Machine has a problem with the proceeding speed of passengers and inconvenience. Second, the majority of passengers have not utilized the Ticket Office Machine. Also, it should consider whether the transportation card is the proper system in the metropolitan area. Based on the analysis of national and international cases, it suggests that the AFC should make more improvements in the metropolitan area railway and subway.

• Proceedings of the IEEK Conference
• /
• 2001.06a
• /
• pp.21-24
• /
• 2001

Bluetooth wireless technology is a publicly available specification proposed for Radio Frequency (RF) communication for short-range and point-to-multipoint voice and data transfer. It operates in the 2.4GHz ISM(Industrial, Scientific and Medical) band and offers the potential for low-cost, broadband wireless access for various mobile and portable devices at range of about 10 meters. In this paper, we describe the structure and the test results of the bluetooth baseband module we have developed. This module has a UART interface for HCI and a audio codec for voice. The interface between controller and this module supports common control interface. An FPGA implementation of this module is tested for file and bit-stream transfers between PCs.

• Proceedings of the IEEK Conference
• /
• 2002.06e
• /
• pp.161-164
• /
• 2002

The increase of vehicles stagnations leads to the increasing attention to the way customers pay and a large number of projects on electronic cash system. Transport system is comprised of a number of advanced technologies, including information processing, communications, control, and electronics. Recently many research on a system which provides contact in order to protect driver's vehicle passage have been carried out. And some potential problems from that system are being reviewed by electronic cash system. In this papers, we suggest RF protocol developing technology using the concept of electronic cash. ATM electronic cash developing is consist of component of pre-developed coin throw, integration of component using its, and production of more requirement-satisfactory ITS solution. Result increase 15∼40% pre-type vehicles stagnations. Especially, we expect this proposed concept would be well adapted to our national environments.

• Journal of Yeungnam Medical Science
• /
• v.24 no.2
• /
• pp.97-106
• /
• 2007

Functional electrical stimulation (FES) has developed over the last 35 years to become a scientifically, technologically and clinically recognized field of interest in clinical medicine. FES has been applied to locomotion, grasping, ventilation, incontinence, and decubitus healing. However, all of these achievements illustrate the initial applications of FES; its true potential has not yet been realized. Recently, FES systems, which are miniaturized stimulation devices, have been utilized in the clinical setting. However, because the stimulating electrodes of the current FES devices are percutaneous electrodes, which are susceptible to wire breakage, and skin infection an implantable FES stimulating electrode has been introduced in the U.S. and Japan. In the present study, an external power supply method using radio frequency (RF) coupling and data transmission was developed for the control of the implantable FES device. In addition, we review the current understanding of FES devices and their application in clinical medicine.