• Journal of the Institute of Electronics Engineers of Korea SD
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• v.41 no.12
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• pp.35-42
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• 2004

In this paper, we report Mach Zehnder Interleaver of optical fiber type is fabricated by the fabrication system only for interfermeter design, and it is used $CO_2$ laser to adjust precisely the wavelength. The optical fiber is very sensitive in the thermal variation around. Thus, When fabrication the prototype, it is applied a technique to compensate the optical thermal effect because the center wavelength at the output is shifted according to the thermal variation around. it can he done by applying a substrate with high thermal expansion coefficient as well as an adjusting the position between two optical fiber couplers. Consequently, the output wavelength is shifted within 0.05 nm when the surrounding temperature varies until $60^{\circ}C$.

• International Journal of Highway Engineering
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• v.16 no.6
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• pp.95-104
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• 2014

PURPOSES : The purpose of this study is to evaluate the degree of restraint (DOR) of longitudinal steel at continuously reinforced concrete pavement (CRCP) against environmental loadings. METHODS : To measure the longitudinal steel strain, 3-electrical resistance and self-temperature compensation gauges were installed to CRCP test section (thickness = 250mm, steel ratio = 0.7%) and continuously measured 10 min. intervals during 259 days. In order to properly analyze the steel strains first, temperature compensation process has been conducted. Secondly, measured steel strains were divided into 12 phases with different events such as before paving, during concrete hardening, and after first cracking, etc. RESULTS : Thermal strain rate (TSR) concept is defined as the linear strain variations with temperature changes and restraints rate of longitudinal steel against environmental loadings (especially thermal loading) with different cases is defined as degree of restraint(DOR). New concept of DOR could be indirect indicator of crack width behaviors of CRCP. CONCLUSIONS : Before paving, DOR of longitudinal steel is almost same at the coefficient of thermal expansion of steel ($12.44m/m/^{\circ}C$) because of no restraint boundary condition. After concrete pouring, DOR is gradually changed into -1 due to concrete stiffness developing with hydration. After first cracking at crack induced area, values of DOR are around -3~-5. The negative DOR stands for the crack width behavior instead of steel strain behavior. During winter season, DOR reached to -5.77 as the highest, but spring this values gradually reduced as -1.7 as the lowest. Based on this observation, we can presume crack width decreased over time within the time frame of this study. This finding is not consistent with the current theory on crack width variations over time, so further study is necessary to identify the causes of crack width reducing. One of the reasons could be related to concrete stress re-distribution and stress relaxation.

• Korean Journal of Adult Nursing
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• v.26 no.2
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• pp.149-158
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• 2014

Purpose: The purpose of this study was to determine whether Selection, Optimization and Compensation (SOC) Strategy mediated the relationship between job stress and health promoting behaviors among nurses. Methods: A descriptive causal relationship research design was used. 245 subjects recruited from the five general hospitals, which have over 500 beds in Seoul and Kyunggi-do, participated in the study by completing a survey which included questions about SOC strategy, job stress and health promoting behaviors. t-test, ANOVA, Pearson's correlation coefficient and multiple regression were used to analyze the data. SPSS/WIN 20.0 was used for all analysis. Results: The mean job stress score was 47.89; mean SOC strategy score was .71. 'Spiritual development' was the highest reported health promoting behavior with a mean of 3.57. Job stress was significantly and negatively related to health promoting behaviors. The result showed that all the mediating paths of SOC strategy were significant. The partial mediating model showed high goodness of fit demonstrating that the model was outstanding. Conclusion: SOC strategy mediated the relationship between job stress and health promoting behaviors. Applying better SOC strategies among nurses will increase flexibility in responding to job stress and will also better perform health promoting behaviors.

• Journal of Korean society of Dental Hygiene
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• v.9 no.3
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• pp.329-343
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• 2009

Purpose : This study was to figure out the factors affecting the job satisfaction of dental hygienists working in dental clinics. To gain the data to establish the systems for enhancing the job satisfaction of the dental hygienists. This research has been conducted dental hygienists working in dental clinics institutes located in Jeonju and Iksan city, Jeollabuk-do, korea. Methods : The collected data were analyzed by using an SPSS statistical program, obtaining the following results. Result : The average satisfactory level of the dental hygienists was 3.45 out of 5 points. The most important factor affecting of the job satisfaction was the relationship with patients as 3.83 points and the least influencing factor was the compensation as 3.09 points. The management system and the satisfactory level were also correlated. For each of details, communication structure and working environment showed the highest correlation with Pearson's correlation coefficient of 0.610. Among the management system the general job satisfaction according to the communicational structure was higher when they had better communication with dentists. Among the management system, the job satisfaction according to structural factors was higher when they have manuals for the job, when their job is taken partial charge of the responsibility As for job satisfaction by the welfare support factor in the clinic management system, the better an informal social gathering, the higher general job satisfaction. As for job satisfaction by the job autonomy factor in the clinic management system, the more evenly distributed job opportunities and chances of reeducation for professional development led to higher general job satisfaction. Conclusion : The compensation-related grade was the lowest among the 6 constituent factors of the job satisfaction, it seems that improvement of wages and incentives is required to enhance the satisfaction of the dental hygienists. Also, improving factors affecting the management system of the dental service institute can increase the job satisfaction since the job satisfaction was higher when the institutes have the better management system.

• Journal of the Institute of Convergence Signal Processing
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• v.9 no.3
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• pp.195-200
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• 2008

To compress the moving picture data effectively, it is needed to reduce spatial and temporal redundancy of input image data. While motion estimation! compensation methods is effectively able to reduce temporal redundancy but it is increased computation complexity because of the prediction between frames. So, the study of algorithm for computation reduction and real time processing is needed. This paper is presenting quantizer effectively able to quantize DCT coefficient considering the human visual sensitivity. As quantizer that proposed DCT-based H.263 could make transmit more frame than TMN5 at a same transfer speed, and it could decrease the frame drop effect. And the luminance signal appeared the difference of $-0.3{\sim}+0.65dB$ in the average PSNR for the estimation of objective image quality and the chrominance signal appeared the improvement in about 1.73dB in comparision with TMN5. The proposed method reduces $30{\sim}31%$ compared with NTSS and $20{\sim}21%$ compared to 4SS in comparition of calculation quantity.

• Journal of Broadcast Engineering
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• v.14 no.6
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• pp.749-768
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• 2009

In this paper, an intra prediction offset compensation method is proposed to improve intra prediction in H.264/AVC. In H.264/AVC, intra prediction based on various directions improves the coding efficiency by removing spatial correlation between neighboring blocks. In details, neighboring pixels in reconstructed block can be used as intra reference block for the current block to be coded when intra prediction method is used. In order to reduce further the prediction error of the intra reference block, the proposed method introduces an intra prediction offset which is determined in the sense of the rate-distortion optimization and is added to the conventional intra prediction block. Besides the intra prediction offset compensation, the coefficient thresholding method which is used for inter coding in JM 11.0, is used for chroma component in intra block, which leads the improvement of the luma coding efficiency of the proposed method. In experiments, we show that the proposed method achieves average 2.45% in High Profile condition and maximum 4.41% of bitrate reduction relative to JM 11.0.

• The KIPS Transactions:PartB
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• v.18B no.5
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• pp.265-270
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• 2011

In this paper, we propose a method for intensity correction using binarization-based region segmentation in 3D stereoscopic images. In the proposed method, 3D stereoscopic right image is segmented using binarizarion. Small regions in the segmented image are eliminated. For each region in right image, a corresponding region in left image is decided through region matching using correlation coefficient. When region-based matching, in order to prevent overlap between regions, we remove a portion of the area closed to the region boundary using morphological filter. The intensity correction in left and right image can be performed through histogram specification between the corresponding regions. Simulation results show the proposed method has the smallest matching error than the conventional method when we generate the right image from the left image using block based motion compensation.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.26 no.8
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• pp.740-747
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• 2015

Recently, mobile communication systems using the millimeter-wave frequency band have been proposed, and the importance of efficient compensation of the nonlinearity caused by 60 GHz high-power amplifiers(HPAs) is increasing. In this paper, we propose a predistorter structure based on multiple coefficient sets which are separately used to different ranges of input power values. These ranges correspond to varying levels of nonlinearity characteristics. The structure is applied to the 60 GHz HPA FMM5715X and the performance of correcting the nonlinearity of LTE signals is evaluated. Evaluation results using a hardware testbed demonstrate that the proposed predistorter structure achieves the maximum of 6 dB gain over the conventional method in terms of the adjacent channel leakage ratio(ACLR).

• The Journal of the Acoustical Society of Korea
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• v.18 no.6
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• pp.77-83
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• 1999

H.263 is an international standard of ITU-T that can makes the service such as video phone, video conference in the transmission line less than 64Kbps. This recommendation draft has used motion estimation/compensation, transform coding and quantizing methods. TMN5 used for the performance estimation of H.263 has fundamentally used DCT in transform coding method and presented quantizer for quantizing the DCT transform coefficient. This paper is presenting adaptive quantizer effectively able to quantize DCT coefficient considering the human visual sensitivity while the structure of TMN5 is maintaining. As quantizer that proposed DCT-based H.263 could make transmit more frame than TMN5 in a same transfer speed, it could lower the frame drop effect. And the luminance signal appeared the difference of -0.3 ～ +0.7dB in the average PSNR for the estimation of objective image quality and the chrominance signal appeared the improvement in about 1.5dB in comparision with TMN5. As a result it can attain the better image quality compared to TMN5 in the estimation of subjective image quality.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.11 no.10
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• pp.826-832
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• 1998

In this study the thin films with the structure of Si+SiO$_2$+TiN are made by RF supttering method. TiN, which has small diffusion coefficient and low resistivity, is evaporated between SiO$_2$ and Al layers. It investigates the V-R characteristics depending on the thickness of SiO$_2$ which is used as insulation layer and researches its effects on voltage stability of thin film and varistor. These films show very small resistance valus in negative(-) voltage and large and large value in positive voltage band, and with the increase of voltage, resistance value is rapidly reduced and the satisfactory characteristic of varistor is shown at +1[V]. It is found that resistance value of TiN thin film is small and also TiN thin film has more current than the thin film which is not evaporated by TiN thin film. When Al electrode is evaporated of SiO$_2$ thin film, spiking occurs, but the spiking can be prevented with evaporation of TiN between SiO$_2$ and Al layers and this thin films in made easily because of its good attachment. With the increase of voltage, the resistance is changed into non-linear pattern and the bidirectional varistor characteristic is shown and then its theory can be verified by this experiment. Accordingly, when TiN is evaporated of Si Wafer(n-100), it obtains better voltage-resistance than thin film which is not evaporated and also when varistor character is used electrically to automatic control element such as elimination of flame, power distribution arrestor and constant voltage compensation, satisfactory reproducibilities are expected.