• Journal of the Korean Vacuum Society
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• v.9 no.4
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• pp.328-334
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• 2000

DLC (Diamond-Like Carbon) films were deposited by ECR-PECVD (electron cyclotron resonance plasma-enhanced chemical vapor deposition) method with the variation of substrate bias voltage under the others are constant except it. We have investigated the ion bombardment effect induced by the substrate bias voltage on films during the deposition of film. The characteristics of the film were analyzed using the Dektak surface profiler, SEM, FTIR spectroscopy, Raman spectroscopy and Nano Indentation tester. FTIR spectroscopy analysis shows that the amount of dehydrogenation in films was increased with the increase of substrate bias voltage and films thickness was decreased. Raman scattering analysis shows that integrated intensity ratio $(I_D /I_G)$ of the D and G peak was increased as the substrate bias voltage increased, and films hardness was increased. From these results, it can be concluded that films deposited at this experimental have the enhanced characteristics of DLC because of the ion bombardment effect on films during the deposition of film.

• Journal of the Korean Society for Precision Engineering
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• v.18 no.2
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• pp.152-160
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• 2001

Six degrees of freedom measurement systems are required in many fields: Precision machine control. precision assembly, vibration analysis, and so on. This paper presents a new six degrees of freedom measurement system utilizing typical features of a diffraction grating. It is composed of a laser source, three position sensitive detectors, a diffraction grating target, and several optical components. Six degrees of freedom displacement is calculated kinematically from the coordinates of diffracted rays on the detectors. Optical measurement error was caused by the fact that a laser source had a Gaussian intensity distribution. This error was analyzed and compensated using simple equations. The performance of the compensation equation was verified in the experiment. The experimental results showed that the compensation equation could reduce the optical measurement error remarkably and the error in six degrees of freedom measurement less than $\pm$10$\mu$m for translation and $\pm$0.012$^{\circ}$for rotation.

• Journal of the Institute of Convergence Signal Processing
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• v.11 no.2
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• pp.97-103
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• 2010

In this paper, we propose a new digital watermarking technique. The main idea of the proposed algorithm relies on the assumption that any real number can be expressed as a summation of the exponential form with base of 2 and if only consider the first few summations some numbers can be expressed in the same form. Therefore, we can be sure that some amount of changes does not affect the first few summations. The algorithm decomposes a host image in wavelet domain and intensity of the significant wavelet coefficient is expressed in exponential form with base of 2. Multiple barcode watermarks are then embedded by modifying the parity of the exponent. The proposed scheme is semi-blind and also offers either objective or subjective deteew su as well. From extracted watermarks, more accurate watermark is obtained by merging technique as a final watermark. As a simulation result, the proposed algorithm could resist most cases of salt and pepper noise, Gaussian noise and JPEG compression.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 2001.05a
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• pp.224-231
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• 2001

Hydrogenated amorphous carbon films were deposited by ERC-PECVD with deposition conditions, such as ECR power, gas composition of methane and hydrogen, deposition time, and substrate bias voltage. The characteristics of the film were analyzed using the AES, ERDA, FTIR. Raman spectroscopy and micro hardness tester. From the results of AES and ERDA, the elements in the deposited film were confirmed as carbon and hydrogen atoms. FTIR spectroscopy analysis shows that the atomic bonding structure of a-C:H film consisted of sp³and sp²bonding, most of which is composed of sp³bonding. The structure of the a-C:H films changed from CH₃bonding to CH₂or CH bonding as deposition time increased. We also found that the amount of dehydrogenation in a-C:H films was increased as the bias voltage increased. Raman scattering analysis shows that integrated intensity ratio (I/sub D//I/sub G/) of the D and G peak was increased as the substrate bias voltage increased, and films hardness was increased.

• Journal of the Korean Institute of Intelligent Systems
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• v.24 no.1
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• pp.22-27
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• 2014

Blocking and ringing artifacts continue to be the most serious defects that occur in images and video streams compressed to low bit rates using block-based discrete cosine transform(DCT) compression standards. These artifacts contain the high frequency components near the block and the edge boundaries. Usually the lowpass filter can remove them. However, simple lowpass filter results into blur by removing important information such as edges at the same time. To overcome these problems, we propose a novel postfiltering algorithm that calculate the weight value based on the intensity similarity in the neighboring pixels and multiply this weight to the Gaussian lowpass filter coefficient. Experimental results show that the proposed technique provides satisfactory performance in both objective and subjective image quality.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.45 no.5
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• pp.95-102
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• 2008

This paper presents an appropriate approach for modeling noise in Computed Radiography(CR) images of high strength materials. The approach is specifically designed for types of noise with the statistical and nonlinear properties. CR images Ere degraded even before they are encoded by computer process. Various types of noise often contribute to contaminate radiography image, although they are detected on digitalization. Quantum noise, which is Poisson distributed, is a shot noise, but the photon distribution on Image Plate(IP) of CR system is not always Poisson process. The statistical properties are relative and case-dependant due to its material characteristics. The usual assumption of a distribution of Poisson, binomial and Gaussian statistics are considered. Nonlinear effect is also represented in the process of statistical noise model. It leads to estimate the noise variance in regions from high to low intensity, specifying analytical model. The analysis approach is tested on a database of steel tube step-wedge CR images. The results are available for the comparative parameter studies which measure noise coherence, distribution, signal/noise ratios(SNR) and nonlinear interpolation.

• Bulletin of the Korean Chemical Society
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• v.31 no.10
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• pp.2923-2928
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• 2010

This study examined the synthesis of the crystal structure of bis(2,2'-bipyridine)nitrato zinc (II) nitrate, $[Zn(bipy)_2(NO_3)]^+NO_3^-$ using a microwave treatment at 300 W and 60 Hz for the application to dye-sensitized solar cells. The simulated complex structure of the complex was optimized with the density functional theory calculations for the UV-vis spectrum of the ground state using Gaussian 03 at the B3LYP/LANL2DZ level. The structure of the acquired complex was expected a penta-coordination with four nitrogen atoms of bipyridine and the oxygen bond of the $NO_3^-$ ion. The reflectance UV-vis absorption spectra exhibited two absorptions (L-L transfers) that were assigned to the transfers from the ligand ($\sigma$, $\pi$) of $NO_3$ to the ligand ($\sigma^*$, $\pi^*$) of pyridine at around 200 - 350 nm, and from the non-bonding orbital (n) of O in $NO_3$ to the p-orbital of pyridine at around 450 - 550 nm, respectively. The photoelectric efficiency was approximately 0.397% in the dye-sensitized solar cells with the nanometer-sized $TiO_2$ at an open-circuit voltage (Voc) of 0.39 V, a short-circuit current density (Jsc) of $1.79\;mA/cm^2$, and an incident light intensity of $100\;mW/cm^2$.

• Korean Journal of Oriental Medicine
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• v.17 no.3
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• pp.97-104
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• 2011

Objectives : In this paper, we proposed a method for selecting reliable variables from various vocal features such as frequency derivative features, frequency band ratios, intensities of 5 vowels and an intensity of a sentence, since some features are sensitive to the variation of a subject's utterance. Methods : To obtain the reliable voice variables, the coefficient of variation (CV) was used as the index to evaluate the level of reliability. Since the distributions of a few features are not Gaussian, but are instead skewed to the right or left, we transformed the features by taking the log or square root. Moreover, the definition of the variables that are suitable to represent the vocal property was explained and analyzed. Results : At first, we recorded the vowels and the sentence five times both in the morning and afternoon of the same day, totally ten recordings from each of six subjects (three males and three females). We then analyzed the CVs of each subject's voice to obtain the stable features with a sufficient repeatability. The features having less than 20% CVs for all six subjects were selected. As a result, 92 stable variables from the 222 features were extracted, which included all the transformed variables. Conclusions : Voice can be widely used to classify the four constitution types and to recognize one's health condition from extracting meaningful features as physical quantity in traditional Korean medicine or Western medicine. Therefore, stable voice variables can be useful in the u-Healthcare system of personalized medicine and for improving diagnostic accuracy.

• Korean Journal of Optics and Photonics
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• v.14 no.3
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• pp.306-311
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• 2003

In this paper, we modeled the incident beam in order to analyze and evaluate the optical thin film device for wavelength division multiplexing in optical telecommunication network. As applied ray tracing method to the optical path, we were compared the accuracy of coupling efficiency simulated by two modeling methods. In the results of sinulation, ceil modeling method was preferred to annual modeling method in micro-optic device because of accuracy for coupling efficiency and Gaussian intensity distribution. In the results of optimal simulation for optical device using thin film filter, the distance (d1) between optical fiber and GRIN lens, the distance (d2) between GRIN lens and thin film filter and the coupling efficiency were 0.24 mm, 0.25 mm and -0.11 ㏈ respectively. As d2 was displaced at 0.25 mm and d1 was varied in order to evaluate the optimal value, d1 and maximum coupling efficiency were 0.24 mm and -0.35㏈, respectively. Then the results of experiment were corresponded to that of optimal simulation by cell modeling and it was possible to analyze the performance for optical device using thin film filter by the simulation.

• Journal of Animal Science and Technology
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• v.65 no.2
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• pp.365-376
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• 2023

Pig breeding management directly contributes to the profitability of pig farms, and pregnancy diagnosis is an important factor in breeding management. Therefore, the need to diagnose pregnancy in sows is emphasized, and various studies have been conducted in this area. We propose a computer-aided diagnosis system to assist livestock farmers to diagnose sow pregnancy through ultrasound. Methods for diagnosing pregnancy in sows through ultrasound include the Doppler method, which measures the heart rate and pulse status, and the echo method, which diagnoses by amplitude depth technique. We propose a method that uses deep learning algorithms on ultrasonography, which is part of the echo method. As deep learning-based classification algorithms, Inception-v4, Xception, and EfficientNetV2 were used and compared to find the optimal algorithm for pregnancy diagnosis in sows. Gaussian and speckle noises were added to the ultrasound images according to the characteristics of the ultrasonography, which is easily affected by noise from the surrounding environments. Both the original and noise added ultrasound images of sows were tested together to determine the suitability of the proposed method on farms. The pregnancy diagnosis performance on the original ultrasound images achieved 0.99 in accuracy in the highest case and on the ultrasound images with noises, the performance achieved 0.98 in accuracy. The diagnosis performance achieved 0.96 in accuracy even when the intensity of noise was strong, proving its robustness against noise.