• Journal of the Korean Society for Precision Engineering
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• v.12 no.7
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• pp.92-98
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• 1995

In the cluster tool, it is necessary to precisely control the vacuum pressure for the wafer transportation between transport module and cassette or process modules with the range of 1*10$^{-4}$ to 5*10$^{-5}$ torr. So we have designed the pressure control system for the transport module of the cluster tool and have evaluated its performance. Digital PID is utilized with the weighted sum of both three previous errors and one current error. The feedback signal is put into the nitrogen mass flow controller using the transport module controller. This pressure control system can prevent the transport module from the particle generation and backstreaming of hazardous process gases of the process chamber.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.1
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• pp.109-114
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• 2017

In this study, we have developed the active leakage current detection module based on a MSP430 processor, 16bit signal processor. This module can be operated in a desired trip threshold within 0.03 seconds as specified in KS C 4613. This developed module is expected to be applicable as a module for prevention of electric shock in smart distribution panel of smart grid.

• ETRI Journal
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• v.35 no.4
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• pp.617-624
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• 2013

Low power consuming and highly responsive semiconductor-type microelectromechanical systems (MEMS) gas sensors are fabricated for real-time environmental monitoring applications. This subsystem is developed using a gas sensor module, a Bluetooth module, and a personal digital assistant (PDA) phone. The gas sensor module consists of a $NO_2$ or CO gas sensor and signal processing chips. The MEMS gas sensor is composed of a microheater, a sensing electrode, and sensing material. Metal oxide nanopowder is drop-coated onto a substrate using a microheater and integrated into the gas sensor module. The change in resistance of the metal oxide nanopowder from exposure to oxidizing or deoxidizing gases is utilized as the principle mechanism of this gas sensor operation. The variation detected in the gas sensor module is transferred to the PDA phone by way of the Bluetooth module.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.42 no.3 s.333
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• pp.25-34
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• 2005

In this paper, we analyzed and measured the electrical crosstalk characteristics of a triplex transceiver module for ethernet Passive optical networks(EPONS). And we improved the electrical crosstalk levels using Dummy ground lines with signal lines. The triplex transceiver module consists of a laser diode as a transmitter, a digital photodetector as a digital data receiver, and a analog photodetector as a community antenna television signal receiver. And there are integrated on silicon substrate. The digital receiver and analog receiver sensitivity have to meet -24 dBm at $BER=10^{-l2}$ and -7.7 dBm at 44 dB SNR. And the electrical crosstalk levels have to maintain less than -86 dB from DC to 3 GHz. From analysis and measurement results, the proposed silicon substrate structure that contains the Dummy ground line with $100\;{\mu}m$ space from signal lines and separates 4 mm among devices respectively, is satisfied the electrical crosstalk level compared to simple structure. This proposed structure can be easily implemented with design convenience and greatly reduced the silicon substrate size about $50\%$.

• Proceedings of the KSRS Conference
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• 2008.10a
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• pp.220-223
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• 2008

A camera system for the satellite application performs the mission of observation by measuring radiated light energy from the target on the earth. As a development stage of the system, the signal level analysis by estimating the number of electron collected in a pixel of an applied CCD is a basic tool for the performance analysis like SNR as well as the data path design of focal plane electronic. In this paper, two methods are presented for the calculation of the number of electrons for signal level analysis. One method is a quantitative assessment based on the CCD characteristics and design parameters of optical module of the system itself in which optical module works for concentrating the light energy onto the focal plane where CCD is located to convert light energy into electrical signal. The other method compares the design\ parameters of the system such as quantum efficiency, focal length and the aperture size of the optics in comparison with existing camera system in orbit. By this way, relative count of electrons to the existing camera system is estimated. The number of electrons, as signal level of the camera system, calculated by described methods is used to design input circuits of AD converter for interfacing the image signal coming from the CCD module in the focal plane electronics. This number is also used for the analysis of the signal level of the CCD output which is critical parameter to design data path between CCD and A/D converter. The FPE(Focal Plane Electronics) designer should decide whether the dividing-circuit is necessary or not between them from the analysis. If it is necessary, the optimized dividing factor of the level should be implemented. This paper describes the analysis of the electron count of a camera system for a satellite application and then of the signal level for the interface design between CCD and A/D converter using two methods. One is a quantitative assessment based on the design parameters of the camera system, the other method compares the design parameters in comparison with those of the existing camera system in orbit for relative counting of the electrons and the signal level estimation. Chapter 2 describes the radiometry of the camera system of a satellite application to show equations for electron counting, Chapter 3 describes a camera system briefly to explain the data flow of imagery information from CCD and Chapter 4 explains the two methods for the analysis of the number of electrons and the signal level. Then conclusion is made in chapter 5.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.6
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• pp.1405-1410
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• 2015

In this study we designed the radiation-hardened sensor signal processing modules that can be commonly used for a variety of sensors during normal operation and even in high-radiation environments caused by an accident. First development module was designed to receive the change of the R and C value from the sensors and to process the signal as a PWM modulation scheme. This module was assessed to have ± 10% error to the Full-Scale in the radiation test in the range of 12 kGy TID. The main cause of the error was analyzed as the annealing of the common circuit in the switching element and the consequent increase in the duty ratio of the pulse width modulation circuit according to the radiation dose increasement. The redesigned module for higher radiation resistivity with Stub transistor circuit was found to have less than 5% error to the Full-scale from the radiation test results for 20.7 kGy TID range.

• International Journal of Internet, Broadcasting and Communication
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• v.16 no.2
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• pp.10-21
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• 2024

Recently, audio systems are changing the configuration of conventional sound reinforcement (SR) systems and public address (PA) systems by using audio over IP (AoIP), a technology that can transmit and receive audio signals based on internet protocol (IP). With the advancement of IP technology, AoIP technologies are leading the audio market and various technologies are being released. In particular, audio networks and control hierarchy over peer-to-peer (Anchor) technology based on AoIP is a system that transmits and receives audio signals over a wide bandwidth without an audio mixer, creating a novel paradigm for existing audio system configurations. Anchor technology forms an audio system by connecting audio sources and output equipment with On-site audio center (OAC), a device that can transmit and receive IP. Anchor's receiving OAC is capable of receiving and mixing audio signals transmitted from different IPs, making it possible to configure a novel audio system by replacing the conventional audio mixer. However, Anchor technology does not have the ability to provide audio effects to input devices such as microphones and instruments in the audio system configuration. Due to this, when individual control of each audio source is required, there is a problem of not being able to control the input signal, and it is impossible to individually affect a specific input signal. In this paper, we implemented a tone control module that can individually control the tone of the audio source of the input device using the audio processor core in the audio system based on Anchor technology, tone control for audio sources is possible through a tone control module connected to the transmitting OAC. As a result of the study, we confirmed that OAC receives the signal from the audio source, adjusts the tone and outputs it on the tone control module. Based on this, it was possible to solve problems that occurred in Anchor technology through transmitting OAC and tone control modules. In the future, we hope that the audio system configuration using Anchor technology will become established as the standard for audio equipment.

• Progress in Superconductivity
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• v.9 no.1
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• pp.23-28
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• 2007

In order to have a superconductive connection between the wire-wound pickup coil and input coil, typically Nb terminal blocks with screw holes are used. Since this connection structure occupies large volume, large stray pickup area can be generated which can pickup external noise fields. Thus, SQUID and connection block are shielded inside a superconducting tube, and this SQUID module is located at some distance from the distal coil of the gradiometer to minimize the distortion or imbalance of uniform background field due to the superconducting module. To operate this conventional SQUID module, we need a higher liquid He level, resulting in shorter refill interval. To make the fabrication of gradiometers simpler and refill interval longer, we developed a novel method of connecting the pickup coil into the input coil. Gradiometer coil wound of 0.125-mm diameter NbTi wires were glued close to the input coil pads of SQUID. The superconductive connection was made using an ultrasonic bonding of annealed 0.025-mm diameter Nb wires, bonded directly on the surface of NbTi wires where insulation layer was stripped out. The reliability of the superconductive bonding was good enough to sustain several thermal cycling. The stray pickup area due to this connection structure is about $0.1\;mm^2$, much smaller than the typical stray pickup area using the conventional screw block method. By using this compact connection structure, the position of the SQUID sensor is only about 20-30 mm from the distal coil of the gradiometer. Based on this compact module, we fabricated a magnetocardiography system having 61 first-order axial gradiometers, and measured MCG signals. The gradiometers have a coil diameter of 20 mm, and the baseline is 70 mm. The 61 axial gradiometer bobbins were distributed in a hexagonal lattice structure with a sensor interval of 26 mm, measuring $dB_z/dz$ component of magnetocardiography signals.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.1
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• pp.140-146
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• 2018

Recently, VLC(Visible Light Communication) fusing with LED(Light Emitting Diode) used in indoor lighting and wireless communication technology has attracted attention. However, the VLC can communicate only within the coverage to measure the optical signal and the communication disconnection phenomenon is occur in the NLoS(Non-Line-of-Sight) area. In this paper, we propose VLC relay module to extend the coverage of VLC and improve the communication disconnection phenomenon in NLoS area. The proposed VLC relay module transmits the packet received from the transmitter to the VLC relay module and receiver. The experiment was carried out by installing one VLC transmitter and three VLC relay modules, communication coverage expansion and the improvement of communication disconnection phenomenon in the NLoS were confirmed by the increase of the VLC relay module. Also, we confirmed that the optical signal measurement performance is improved 2.4 times by using the dual sampling method.

• Journal of the Institute of Convergence Signal Processing
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• v.2 no.1
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• pp.1-11
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• 2001

This paper presents a learning-based approach for the construction of license Plate recognition system. The system consist of three modules. They are respectively, car detection module, license plate recognition module and recognition module. Car detection module detects a car in the given image sequence obtained from the camera with simple color-based approach. Segmentation module extracts the license plate in detect car image using neural network as filters for analyzing the color and texture properties of license plate. Recognition module then reads characters in detected license plate with support vector machine (SVM)-based characters recognizer. The system has been tested from parking lot and tollgate, etc. and have show the following performances on average: Car detect rate 100%, segmentation rate 97.5%, and character recognition rate about 97.2%. Overall system performances is 94.7% and processing time is one sec. Then our propose system does well using real world.