• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.207-210
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• 2001

Recently, the study on the vibration analysis of machinery is greatly important and ESPI is widely used because of its many attractive features. Firstly, ESPI can be used to measure the vibration mode shape and the phase in real-time. Secondly, the conventional measuring methode, such as accelerometers, take much time to measure the whole field of object, but ESPI needs shorter time than other methods. Because ESPI is a field-inspection method. Thirdly, ESPI is a non-contact measuring system. ESPI does not have influence on the specimen. Beyond these features, there are several advantages in ESPI system. In this paper, the Stroboscopic ESPI system is described for measurement of a vibration mode shape. The Stroboscopic ESPI system had been used to visualize the vibration mode shape, in which EO(Electro-Optic)modulator was used to chop CW(Continuous Wavefront)laser. But it was not easy to control EO modulator and quantified the vibration amplitude and the phase of circular metal plate. At first, we found resonant frequency of the specimen by using time-averaged ESPI method. Nextly, the amplitudes of specimen were quantified by using Stroboscopic ESPI and we compare the results which were obtained in several chopping ratio.

• Journal of Korean Public Health Nursing
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• v.31 no.2
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• pp.311-326
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• 2017

Purpose: This study was conducted to explore women's experiences with domestic violence crises and needs of services. Methods: Data were collected using focus group interviews. Three focus group interviews were held with 16 victims of domestic violence in a shelter. All interviews were recorded and transcribed as they were spoken, and data were analyzed using Morgan & Krueger's four step analysis. Results: The results of this study were as follows: Four categories of crisis were perceived by victims of domestic violence, fear of death, possibility of suicide and murder, despair, facing forlorn positions when seeking help. Services that were needed for victims of domestic violence were classified into four categories: securing personal safety, providing active assistance to victims by first contact, providing information on helping facilities, continuous and preventive support. Conclusion: The results presented herein provide an opportunity to understand women who have experienced domestic violence, to recognize what type of crisis they are experiencing and to determine what help they need in a crisis situation.

• Journal of Korean Academy of Nursing
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• v.12 no.2
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• pp.31-44
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• 1982

The purpose of this study was to analyze the relationship between maternal attachment and discharge against advice in high risk infants and determine the factors which affect discharge against advice. Data of this study were collected by means of reviewing the medical records of 127 in-patients who were diagnosed as high risk infants in admission and interviewing of the mothers of these patients was done by telephone. The high risk categories were neonatal hyperbilirubinemia, congenital anomaly, congenital heart disease, blood disorder, neonatal infection and birth injury. Maternal attachment was measured by deviding the subjects into 2 groups, the one the continuing treatment group and the other the discharge against advice group. Maternal attachment is determined by an interplay of maternal attitude and specific infant behaviors. Maternal attachment developes through continuous physical and psychological contact between mother and infants. Later it developes into maternal love. The results were as follows: 1. There was a significant association between maternal attachment and discharge against advice, that is, the attachment score was higher in the continuing treatment group. 2. Inspite of controlling medical insurance, severity of disease and the length of stay, it was found that there continued to be either a partially significant or fully significant relationship between maternal attachment and discharge against advice. Stepwise multiple regression revealed that maternal attachment was second in importance as a predictor of discharge against advice, which indicates that maternal attachment was a significant predictor of discharge against advice. 3. Stepwise multiple regression revealed that in 32.3％ of these cases the significant predictors of discharge against advice were length of stay, maternal attachment, delivery type, feeding type and income.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.41 no.12
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• pp.1-6
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• 2004

In this study, heat and discharge treatments are arbitrary simulated for finding out the initiations and processes of surface degradation on the surface of polymer for using as a PCB substrate. Thermal-treatment changed the surface to the hydrophobic one with the increase of contact angle and surface potential decay, respectively. The XPS spectrum showed that the increased hydrophobicity in thermal treatment was originated from the continuous decrease of side-chains caused by secessions of oxygen groups and the increase of unsaturated double bond in carbon chains. Also, thermal-treatment caused the discoloration on the point of treated surface. These phenomena were attributed to the generation of ether group. In the chemical change by discharge treatment, a lot of side-chains occurred on the treated surface, and so the hydrophilicity increased as time elapsed.

• Journal of the Korean Society for Precision Engineering
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• v.13 no.2
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• pp.68-75
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• 1996

More accurate inspection method for facilities of nuclear power plants is required to guarantee the continuous and stable energy supply. The portion of inspection for pipes and pressure vessels is relatively big in the power plants. Conventional inspection methods using ultrasonic wave, x-ray and eddy current for nondestructive testing in nuclear power plants have been performed as the method of contact with objects to be inspected. With this reason these methods have been taken relatively much time, money and manpower. And the area to be inspected is limited by the location of probe or film. These difficulties make the inspection into a time-consuming work. We propose an optical defect detection method using phase shifting realtime holographic interferometry. This method has an advantage that the inspection can be performed at a time for relatively wide area illuminated by the laser beam, a coherent light source and can help an inspector recognize not only defects but also the high stressed areas. In this paper we show that the quantitative measurement using holographic interferometry and image processing for defect in pressure vessels is possible.

• Journal of the Korea Safety Management & Science
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• v.16 no.3
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• pp.101-110
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• 2014

This study tried to identify the effects of ergonomic risk factors for absence from work of fire fighters in Korea. A self-administered questionnaire was prepared for this study. The questionnaire consisted of several parts such as 'general information', 'work-related factors', 'physical & chemical risk factors', 'ergonomic risk factors', and 'absence information'. A total of 7,098 fire fighters participated in this study. The data obtained from the survey was mainly analyzed by logistic regression. A total of 856 out of 7,098 fire fighters experienced absence from work. The risk factors such as gender, age, marital status, education level, total work year, work area. position, job rotation, noise, dust, organic solvent, skin contact with chemical substance, toxic waste, regional vibration, manual material handling, continuous standing posture, awkward working posture were associated with absence from work. Specifically, awkward working posture and manual material handling from ergonomic risk factors were major risk factors for absence from work.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.183-188
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• 2009

RFID method is a non-contact automatic identification technology, which attaches microchips and antennas to an object in a tag form, to send and process information sent to the network using wireless frequency. Drying and curing process is extremely important which minimizes the resistivity of RFID antennas. This research is about the drying characteristic of conductivity ink, and analyzes and compares the hot-air drying process and infrared drying process. Also, the research was done for the improvement in drying performance by using combined process of hot-air and infrared mechanism. The experiment result shows that the hot-air or infrared drying system used alone cannot meet the required performance in drying printing method using conductivity ink. The combined drying system of hot-air and infrared ray showed resistance low enough in short drying and curing time, and this mechanism makes drying and curing process for mass and continuous production possible on-line.

• Journal of the Korean Society of Visualization
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• v.6 no.2
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• pp.39-44
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• 2008

The Roll-to-Roll system including continuous flexible thin materials and roller has its wide range of applications especially in the electronic printing industry. The industry is growing rapidly and the printing speed is also improving. However, the printing machine based on web and roller system has it own problem. As the web speed increases, the failure to maintain the contact may occur and the air entrain between the roller and the paper web may exist. Air bubbles may remain attached to electronic ink on the web causing defects on product surface. With the development of image processing technique, the airflow around the web and rolls can be visualized and calculated by PIV method. In our experiment, the simple web and rolls system is used to R2R simulator. The flow field is studied at various web speeds and positions. The result shows that the flow field has complicated structure with turbulent characteristic and the main trend of flow is obtained by taking time average of flow field.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.9 s.186
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• pp.61-67
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• 2006

Sandwich structures, which are composed of a thick core between two faces, are commonly used in many engineering applications because they combine high stiffness and strength with low weight. Accordingly, the usage of sandwich structure is very widely applied to the aircraft, the automobile and marine industry, etc., because of these advantages. In this paper, we have investigated the buckling protection of an inner structure plate and the useful corrugated configuration for contact, and the fabrication method of the inner structure plate for large area using the continuous molding process. Also, we have guaranteed the accuracy of the molding process through the micro corrugated mold fabrication and secured the accuracy and analyzed aspect properties of the inner structure plate fabricated for a large area using the partial mold process. We have compared molding simulation according to the aspect thickness of the corrugated configuration with the molding experiment results.

• Journal of Electrical Engineering and Technology
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• v.8 no.3
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• pp.603-609
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• 2013

In this paper, we describe the analysis of inkjet-printed silver (Ag) patterns on epoxy-coated substrates according to several reliability evaluation test method guidelines for conventional printed circuit boards (PCB). To prepare patterns for the reliability analysis, various regular test patterns were created by Ag inkjet printing on flame retardant 4 (FR4) and polyimide (PI) substrates coated with epoxy for each test method. We coated the substrates with an epoxy primer layer to control the surface energy during printing of the patterns. The contact angle of the ink to the coated epoxy primer was $69^{\circ}$, and its surface energy was 18.6 $mJ/m^2$. Also, the substrate temperature was set at $70^{\circ}C$. We were able to obtain continuous line patterns by inkjet printing with a droplet spacing of $60{\mu}m$. The reliability evaluation tests included the dielectric withstanding voltage, adhesive strength, thermal shock, pressure cooker, bending, uniformity of line-width and spacing, and high-frequency transmission loss tests.