• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.3
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• pp.667-673
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• 2015

A laser diode(LD) has been studied in many fields what medical, industrial processing, sensor, advertising equipment, printing equipment. And the LD is being used in industry. However, LD will require precision handling. Therefore, the actual use of LD is limited to areas of specialization. In this study, attend to the characteristics of the LD what weak to electrostatic and physical impact, current and heat. And will make a sample module that use comfortably a various wavelength LD. Furthermore, Furthermore, through the printing CTP(Computer to Plate) equipment used the 128-channel LD-Driver, compares it with a 64-channel CTP device about the print speed and resolution. And will solved the problem of delay between the dot and the dot. Finally, consider the potential of the 256-channel LD-Driver.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.6
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• pp.1130-1137
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• 2003

This performance is motivated to develop a tracking antenna system for receive the satellite broadcasting signal in the coast sailing ship. Therefore, this system is made to small size, light weight and simple operation which is must to low cost system for popularization of small size ship and adaptive possibilities with useful on a ship in the coast using 1 axis Az-mount. The antenna mount structure is a compact size and easy operation to the Az-axis type which is operated by step motor. The antenna unit is a domestic made plate type of patch array and ship's moving detection is using the gyro sensor for ship's moving control. We are designed to algorithm, which walking is abreast for step track and ship's moving compensation. Ship's moving compensation is adapted to the closed loop control method by detection from gyro sensor. This system is consisted of micro processor, ADC, comparative amplifier, step motor driver, mount mechanism and algorithm. We have analysised the tracking performance of prototype on sailing ship board.

• The Journal of the Acoustical Society of Korea
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• v.16 no.6
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• pp.76-84
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• 1997

Loose parts monitoring system(LPMS), which is used to detect metallic loose parts in the nuclear power plant, plays an important role in safe and reliable operation of the plant. To prevent from the damage due to the loose parts, most domestic nuclear power plants are using, or planning to use LPMS. However, these LPMS's, which are all invented from overseas and thereby depend on the oversea technologies, are very expensive, and are known to be inefficient to diagnose loose parts due to the lack of fundamental know-how of LPMS. Therefore, the main purpose of this paper is to propose and to realize a new loose parts localization algorithm which is simple and efficient enough even for the inexperienced operators to diagnose loose parts accurately and promptly. Considering practical nuclear power plant circumstances, some simulations for estimating the loose parts location have been done. The results show that the proposed method, called a modified circle intersection method, performs high resolved loose parts localization with 3.4% of error.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.48 no.4
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• pp.153-159
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• 2011

The MUSIC (MUltiple SIgnal Classification) method estimates the directions of arrival (DOAs) of the signals impinging on a sensor array based on the fact that the noise subspace is orthogonal to the signal subspace. In the conventional MUSIC, an estimate of the basis for the noise subspace is obtained by eigendecomposing the sample matrix, which is computationally expensive. In this paper, we present a simple DOA estimation method which finds an estimate of the signal subspace basis directly from the columns of the sample matrix from which the noise power components are removed. DOA estimates are obtained by searching for minimum points of a cost function which is defined using the estimated signal subspace basis. The minimum points are efficiently found through the Brent method which employs parabolic interpolation. Simulation shows that the simple estimation method virtually has the same performance as the complex conventional method based on the eigendecomposition.

• Journal of the Korea Society for Simulation
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• v.23 no.4
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• pp.41-49
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• 2014

Detection and processing techniques for small objects on seabed by the active synthetic aperture sonar can be increased the detection performance because it can be used by short sensor array in small unmanned underwater systems that are spatially constrained. But the limited conditions on constant speed and straight movement of the platform cause a large error in the number of external environmental factors and exact phase synthesis process. In this study, analyzed the applicability of active synthetic aperture processing that is mounted on such a system, and compared detection resolution change in accordance with the phase difference mismatch caused by the along track disturbance. Various simulations were performed as a coherently focus processing model by adding along track disturbance mismatched parameter on the configuring simulator. As the result, detection performance of active synthetic processing for small objects on seabed was found a number of changes by the phase difference mismatch errors according to track disturbances and S/N ratio variations.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.40 no.1
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• pp.15-23
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• 2003

This paper proposes a fast direction of arrival (DOA) estimation algorithm that can rapidly estimate incidence angles of incoming signals using a pseudo covariance matrix. The conventional subspace DOA estimation methods such as MUSIC (multiple signal classification) algorithms need many sample signals to acquire covariance matrix of input signals. Thus, it is difficult to estimate the DOAs of signals because they cannot perform DOA estimation during receiving sample signals. Also if the D0As of signals are changing rapidly, conventional algorithms cannot estimate incidence angles of signals exactly. The proposed algorithm obtains bearing response and directional spectrum after acquiring pseudo covariance matrix of each snapshot. The incidence angles can be exactly estimated by using the bearing response and directional spectrum. The proposed DOA estimation algorithm uses only concurrent snapshot so as to obtain covariance matrix. Compared to conventional DOA estimation methods. The proposed algorithm has an advantage that can estimate DOA of signal rapidly.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.2
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• pp.451-456
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• 2016

Because GPS signals are weak, system jamming is a real and present danger. This can happen when the receiver is subjected to intentional or unintentional interference by a transmitter. If the jamming signal is strong enough, the receiver can be operated to take corrective action automatically. Current methods to protect GPS receiver from jamming condition are based on spatial filtering. In this paper, the beamforming as referred to in signal processing technique used in arrays for directional signal reception was suggested and analyzed for anti-jamming. In order to change the directionality of the array when receiving a jamming signal, a beamformer can control the signal at each sensor. Therefore, cutoff angle ${\theta}$ was measured in the opposite direction of the jammer. GPS signals are only processed when the antenna element is within inside the cutoff angle. As a result, GPS positioning can be used in condition under cutoff angle $30^{\circ}$.

• Korean Journal of Acupuncture
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• v.24 no.3
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• pp.105-116
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• 2007

Objectives : This study was performed to determine whether a pulse analyzer using array piezoresistive sensor was useful to characterize the variables of pulse wave of hypertentive patients (HT) , compared with those of healthy subjects. Methods : One hundred twenty two subjects participated in this study. Sixty nine subjects had hypertension and fifty three subjects had no specific history or disease associated with hypertension. We used automatic pulse analyzer with array piezoreslstive sensor. Results : Calibrated in Chon, no specific differences was between HT group and the healthy group. Calibrated in Gwan. sum of pulse pressure (SPP) of HT group was higher than that of the healthy group. Calibrated in Cheek, mean of height of main peak (Mm) and height of main peak (h1) of HT group were higher than those of the healthy group. Conclusions : Pulse analyzer was useful to determine the risk degree or development possibility of hypertension.

• Journal of the Microelectronics and Packaging Society
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• v.30 no.4
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• pp.1-7
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• 2023

The ability of 3D/4D printing technology to create arbitrary 3D structures provides a greater degree of freedom in the design of printed structures. This capability has influenced the field of electronics and biomedical applications by enabling the trends of device miniaturization, customization, and personalization. Here, the current state-of-the-art knowledge of 3D printed electronics and biomedical applications with the unique and unusual properties enabled by 3D/4D printing is reviewed. Specifically, the review encompasses emerging areas involving recyclable and degradable electronics, metamaterial-based pressure sensor, fully printed portable photodetector, biocompatible and high-strength teeth, bioinspired microneedle, and transformable tube array for 3D cell culture and histology.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.48 no.2
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• pp.28-34
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• 2011

In previous reports, we investigated a selective assembly method of fabricating single-walled carbon nanotubes (SWCNTs) on a silicon-dioxide ($SiO_2$) surface by using only a photolithographic process. In this paper, we have fabricated field effect transistors (FETs) with SWCNT channels by using the technique mentioned above. Also, we have electrically measured gating effects of these FETs under different source-drain voltages ($V_{SD}$). These FETs have been fabricated for sensor applications. Photoresist (PR) patterns have been made on a $SiO_2$-grown silicon (Si) substrate by using a photolithographic process. This PR-patterned substrate have been dipped into a SWCNT solution dispersed in dichlorobenzene (DCB). These PR patterns have been removed by using aceton. As a result, a selectively-assembled SWCNT channels in FET arrays have been obtained between source and drain electrodes. Finally, we have successfully fabricated 4 FET arrays based on SWCNT-channels by using our simple self-assembly technique.