• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.3
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• pp.707-714
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• 2010

Since an LFSR(linear feedback shift register) as a pattern generator has solely linear dependency in itself, it generates sequences by moving the bit positions for pattern generation. So the correlation between the generated patterns is high and thus reduces the possibility of fault detection. To overcome these problems many researchers studied to have goodness of randomness between the output test patterns. In this paper, we propose the new and effective method to construct phase shifter as PRPG(pseudo random pattern generator).

• Transactions of the Korean hydrogen and new energy society
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• v.31 no.1
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• pp.151-159
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• 2020

This study aimed to investigate the performance characteristics of vertical axis turbine of tidal energy convertor. Three-dimensional Reynolds-averaged Navier-Stokes equation with shear stress transport turbulence model has been solved to analyze the fluid flow of the vertical axis turbine. The hexahedral grids have been used to construct the computational domain and the grid dependency test has been performed to find the optimum grid system. Four steps have been carried out to design the vertical axis turbine of the 100 kW class tidal energy convertor.

• IE interfaces
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• v.21 no.4
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• pp.394-402
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• 2008

The objective of this paper is to design segmentation algorithm for applying the breast ultrasound image to CAD(Computer Aided Diagnosis). This study is conducted after understanding limits, used algorithm and demands of CAD system by interviewing with a medical doctor and analyzing related works based on a general CAD framework that is consisted of five step-establishment of plan, analysis of needs, design, implementation and test & maintenance. Detection function of CAD is accomplished by Canny algorithm and arithmetic operations for segmentation. In addition to, long computing time is solved by extracting ROI (Region Of Interests) and applying segmentation technical methods based morphology algorithm. Overall course of study is conducted by verification of medical doctor. And validity and verification are satisfied by medical doctor's confirmation. Moreover, manual segmentation of related works, restrictions on the number of tumor and dependency of image resolution etc. was solved. This study is utilized as a support system aided doctors' subjective diagnosis even though a lot of future studies is needed for entire application of CAD system.

• Journal of the Korean Home Economics Association
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• v.33 no.5
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• pp.177-186
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• 1995

The purpose of this study was to investigate the differences in the maternal behavior between mothers of tic-disordered children and mothers of normal. The subjects of this study were 30 mothers of tic-disordered children from Seoul National University Hospital, Seoul National Mental Hospital and two personal mental practice offices, also, there were another 30 mothers of normal. Statistical methods selected for data analyses were freqences, t-test. The main results of this study were summerized as follows; 1. The maternal behavior of normal children was warmer than that of tic-disordered at the level of p<.001. 2. The maternal behavior of normal children was more acceptable than that of tic-disordered. But, no statistical significance. 3. Mothers of normal children were more extrovert than mothers of tic-disordered at the level of p<.01. 4. The maternal behavior of tic-disordered provoked more dependency than that of normal at the level of p<.001. 5. Mothers of tic-disordered controlled children more than those of normal. But, no statistical significance. 6. Mothers of tic-disordered evaluated children and themselves more negative than those of normal at the level of p<.001. 7. Mothers of tic-disordered have more dependent tendencies than those of normal. But, no statistical significant.

• Journal of Korean Academy of Nursing
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• v.46 no.5
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• pp.663-674
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• 2016

Purpose: The purposes of this study were to develop and test a prediction model for caregiving experiences including caregiving satisfaction and burden in dementia family caregivers. Methods: The stress process model and a two factor model were used as the conceptual frameworks. Secondary data analysis was done with 320 family caregivers who were selected from the Seoul Dementia Management Survey (2014) data set. In the hypothesis model, the exogenous variable was patient symptomatology which included cognitive impairment, behavioral problems, dependency in activity of daily living and in instrumental activity of daily living. Endogenous variables were caregiver's perception of dementia patient's unmet needs, caregiving satisfaction and caregiving burden. Data were analysed using SPSS/WINdows and AMOS program. Results: Caregiving burden was explained by patient symptomatology and caregiving satisfaction indicating significant direct effects and significant indirect effect from unmet needs. The proposed model explained 37.8% of the variance. Caregiving satisfaction was explained by patient symptomatology and unmet needs. Mediating effect of unmet needs was significant in the relationship between patient symptomatology and caregiving satisfaction. Conclusion: Results indicate that interventions focusing on relieving caregiving burden and enhancing caregiver satisfaction should be provided to caregivers with high levels of dementia patients' unmet needs and low level of caregiving satisfaction.

• Journal of Environmental Health Sciences
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• v.40 no.1
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• pp.55-62
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• 2014

Objectives: $^{32}P$-postlabeling assay is the most sensitive method of detecting DNA adduct formation. However, it is limited by a low sample throughput and use of radioisotopes (RI). In this study, we modified it to minimize these limitations and applied it to Z. platypus exposed to Benzo(a)pyrene (BaP) in order to investigate DNA adduct formation (effect biomarker for pollutants) in Z. platypus for assessing risk of waterborne BaP exposure. Methods: DNA hydrolysis was performed only with Micrococcal nuclease (MNase), RI reduction test was performed and the overlapping steps between thin layer chromatography (TLC) and radioisotope high-performance liquid chromatography (RI-HPLC) were omitted. The application of a modified method to Z. platypus exposed to BaP was performed. Results: The results revealed that the amount of RIs used can be reduced roughly 10-fold. Because the analysis time was shortened by 8.5 hours, the sample throughput per hour was increased compared with the previous method. The results of applying modified $^{32}P$-postlabeling assay to Z. platypus, DNA adduct formation in Z. platypus showed dose-dependency with the BaP concentration. Only BPDE-dGMP was detected as a DNA adduct. Conclusion: These results demonstrate that the modified $^{32}P$-postlabeling assay is a suitable method for detecting DNA adduct formation in Z. platypus exposed to waterborne BaP and will be useful in risk assessment of carcinogenic effect in aquatic environment due to BaP.

• Transactions of the Korean hydrogen and new energy society
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• v.28 no.1
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• pp.113-119
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• 2017

An investigation on aerodynamic performance of a highly-loaded axial fan has been conducted to find the effects of tip injection and casing groove on aerodynamic performance in this study. Three-dimensional Reynolds-averaged Navier-Stokes equations with $k-{\varepsilon}$ turbulence model were used to analyze the fluid flow in the fan with Fluid-Structure Interaction (FSI) analysis. The hexahedral grid was used to construct computational domain, and the grid dependency test drew the optimal grid system. FSI analysis was also carried out to predict the deformation of rotor and stator blades, and the effect of deformation on the aerodynamic performance of axial fan was analyzed compared to the performance predicted without FSI analysis.

• Transactions of the Korean hydrogen and new energy society
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• v.31 no.3
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• pp.314-321
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• 2020

In this work, a preliminary design of an inlet guide vane and runner for developing a 2.5 kW hydraulic turbine was conducted by using computational fluid dynamic analysis. Three-dimensional Reynolds-averaged Navier-Stokes equations with shear stress transport turbulence model were used to analyze the fluid flow in the hydraulic turbine. The hexahedral grid system was used to construct computational domain, and the grid dependency test was performed to obtain the optimal grid system. Velocity triangle diagram considering the flow angles of the inlet guide vane and runner was analyzed to obtain a basic geometry of the inlet guide vane and runner. Through modification of the preliminary design, the hydraulic performances of the turbine have improved under overall drop conditions. Especially, the efficiency and power of the turbine increased by 0.95% and 1.45%, respectively, compared to those of the reference model.

• Journal of The Korean Society of Integrative Medicine
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• v.5 no.1
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• pp.19-24
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• 2017

Purpose : The purpose of this study was to find out the difference motion of hip, knee and ankle joint during walking according to using walker on older people. Method : Korean older people of 34 subjects was participated in this study. Participants was measured joint motion on hip, knee and ankle joint during both conditions (walking with walker and without walker). The measured data were analyzed using independent t-test to investigate the difference of joint motion on the both condition. The statistical analyses were performed using Predictive Analytics Soft Ware (PASW) for windows(Ver. 19) and p-value less than .05 were considered significant for all cases. Result : The study showed that more joint motion on hip flexion and ankle pronation is increased by using walker. And hip extension, knee external rotation and ankle plantar flexion is decreased by using walker. Conclusion : This study suggest that using walker on older people was change the motion of the lower limb joint during walking. Therefore, It is necessary to develop a new walker that can reduce dependency and ensure stability on older people during walking.

• International Journal of Aeronautical and Space Sciences
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• v.14 no.2
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• pp.193-199
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• 2013

This work investigates the orbital perturbations of the cubesats that lie on LEO due to Earth albedo. The motivation for this paper originated in the investigation of the orbital perturbations for closed- Earth pico-satellites due to the sunlight reflected by the Earth (the albedo). Having assumed that the Sun lies on the equator, the albedo irradiance is calculated using a numerical model in which irradiance depends on the geographical latitude, longitude and altitude of the satellite. However, in the present work the longitude dependency is disregarded. Albedo force and acceleration components are formulated using a detailed model in a geocentric equatorial system in which the Earth is an oblate spheroid. Lagrange planetary equations in its Gaussian form are used to analyze the orbital changes when $e{\neq}0$ and $i{\neq}0$. Based on the Earth's reflectivity data measured by NASA Total Ozone Mapping Spectrometer (TOMS project), the orbital perturbations are calculated for some cubesats. The outcome of the numerical test shows that the albedo force has a significant contribution on the orbital perturbations of the pico-satellite which can affect the satellite life time.