• Korea-Australia Rheology Journal
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• v.15 no.2
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• pp.91-96
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• 2003

The sensitivity of the product to the ongoing sinusoidal disturbances of the process has been investigated in the film casting of viscoelastic polymer fluids using frequency response analysis. As demonstrated for fiber spinning process (Jung et al., 2002; Devereux and Denn, 1994), this frequency response analysis is useful for examining the process sensitivity and the stability of extensional deformation processes including film casting. The results of the present study reveal that the amplification ratios or gains of the process/product variables such as the cross-sectional area at the take-up to disturbances exhibit resonant peaks along the frequency regime as expected for the systems having hyperbolic characteristics with spilt boundary conditions (Friedly, 1972). The effects on the sensitivity results of two important parameters of film casting, i.e., the fluid viscoelasticity and the aspect ratio of the casting equipment have been scrutinized. It turns out that depending on the extension thinning or thickening nature of the fluid, increasing viscoelasticity results in enlargement or reduction of the sensitivity, respectively. As regards the aspect ratio, it has been found that an optimum value exists making the system least sensitive. The present study also confirms that the frequency response method produces results that corroborate well those by other methods like linear stability Analysis and transient solutions response. (Iyengar and Co, 1996; Silagy et al., 1996; Lee and Hyun, 2001).

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.274.2-274.2
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• 2013

We described a simple and efficient fabrication method for generating microfluidic channels with a circular-cross sectional geometry by exploiting the reflow phenomenon of a thick positive photoresist. Initial rectangular shaped positive photoresist micropatterns on a silicon wafer, which were fabricated by a conventional photolithography process, were converted into a half-circular shape by tuning the temperature to around $105^{\circ}C$. Through optimization of the reflow conditions, we could obtain a perfect circular micropattern of the positive photoresist, and control the diameter in a range from 100 to 400 ${\mu}m$. The resultant convex half-circular photoresist was used as a template for fabricating a concave polydimethylsiloxane (PDMS) through a replica molding process, and a circular PDMS microchannel was produced by bonding two half-circular PDMS layers. A variety of channel dimensions and patterns can be easily prepared, including straight, S-curve, X-, Y-, and T-shapes to mimic an in vivo vascular network. To inform an endothelial cell layer, we cultured primary human umbilical vein endothelial cells (HUVECs) inside circular PDMS microchannels, and demonstrated successful cell adhesion, proliferation, and alignment along the channel.

• Journal of Community Nutrition
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• v.3 no.1
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• pp.8-13
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• 2001

The purpose of study was to test the hypothesis that three are differences in body size dietary behavior and nutrient intakes of adolescent girls with weight control experience. Cross-sectional survey was carried out with a questionnaire and anthropometric measurements . Subjects were 724 healthy adolescent girls from middle and high schools of urban and rural areas in Inchon and divided into two subgroups with weight control experience. Subjects trying to lose weigh were 25.1% in middle school girls and 47.1% in high school girls. There were significant differences in weight and BMI between weight control experience and non- experienced groups in middle school students. There were significant differences in skipping meals and reason of skipping meals between weigh control experience and non-experience groups which might show that skipping meal was used as a weight loss method among female school students. There was no significant difference in nutrient intakes between weight control experienced and non-experienced groups in middle and high school subjects. these results suggest that nutrition education is necessary for adolescent girls to practice appropriate weigh control strategies including desirable eating habits and adequate intake of nutrients such as energy vitamin A vitamin B$_2$calcium and iron.

• Journal of Surface Science and Engineering
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• v.32 no.3
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• pp.467-471
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• 1999

BN films were grown on silicon (l00) substrate by magnetically enhanced activated reactive evaporation (ME-ARE) with pulsed DC power instead of r.f. for substrate biasing. The deposited films were analyzed using Fourier transform infrared spectroscopy (FTIR) and transmission electron microscopy (TEM). FTIR results show that the intensity of absorption band of $sp^2$ bond of BN decreased and that of $sp^3$ bond of c-BN increased with increasing pulsed DC bias voltage applied to substrate. The initially grown layer at the interface was observed by TEM and considered to be of$ sp^2$-bonded BN. The cross-sectional and planar TEM micrographs show that the upper layer on the initial layer was the single phase c-BN. It is concluded that cubic boron nitride films could be synthesized by ME-ARE process with pulsed DC biasing.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.18 no.3
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• pp.373-382
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• 2011

Purpose: The purpose of this study was to assess the educational needs of ICU nurses based on an analysis of importance, frequency, and difficulty for ICU nursing practice. Method: A cross-sectional survey was conducted using a questionnaire with 80 questions in 14 ICU nursing categories. Data were collected from August to October 2009. A total of 295 ICU nurses from five hospitals who had minimum of one year clinical experience participated. Data were analyzed with using descriptive statistics. Results: For importance, emergency care had the highest score, followed by physical assessment, communication, cardiovascular care, and ICU basic nursing. Regarding the frequency, physical assessment had the highest score, followed by communication, medication, ICU basic nursing, and respiratory care. Cardiovascular care was the most difficult task, followed by neurological care, emergency care, other ICU related nursing care, diagnostic test, and communication. Conclusion: The findings indicate a high educational need in the areas of communication, medication, physical assessment, diagnostic test, emergency care, and cardiovascular care. Thus the development of educational programs on communication, medication, physical assessment, diagnostic test, emergency care, and cardiovascular care are needed for ICU nurses.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.20 no.1
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• pp.46-55
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• 2013

Purpose: The purpose of this study was to identify university students' willingness to write advance directives and factors related to this willingness. Method: A cross-sectional survey design was used and 400 nursing students and 287 non-nursing students participated in the study. Data were collected by convenience sampling using self-report questionnaires. Data were analyzed with descriptive statistics, t-test, ANOVA, correlation, and multiple regression. Results: The mean score for willingness to write advance directives was 4.09. From the multiple regression analysis, predictors of willingness to write advance directives were found to be majoring in nursing, awareness of advance directives, preference for autonomous decision making related to the end of life care, family preference related to the end of life care, and self esteem. Conclusion: The study results indicate that various factors are related to willingness to write advance directives and nurses need to consider client characteristics, knowledge, and own values when taking care of issues on advance directives.

• Women's Health Nursing
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• v.17 no.5
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• pp.491-498
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• 2011

Purpose: Recently as couples have only one or two children, they concern about their children's optimal health. Furthermore, as the basic principles of Korean traditional prenatal education (Taegyo) are supported by scientific evidence, and as increasing numbers of pregnant women are recognizing Taegyo refresh, the practice of Taegyo is growing. The purpose of this study was to identify the factors associated with the practice of Taegyo among pregnant Korean women. Methods: This was a cross-sectional, survey study of 228 pregnant women recruited at a health center in South Korea using a convenience sampling method. The instruments included the perception of Taegyo scale, the spouse's support scale, the self-confidence for infant care scale, and the practice of Taegyo scale. The data were analyzed using descriptive statistics and multiple regression analyses. Results: The results of the stepwise multiple regression analysis indicated that the following factors accounted for 26.5% of the variance in the practice of Taegyo: the perception of Taegyo, family income. Conclusion: Consequently, this result showed that the pregnant women were influenced by family income, spouses' support as requisite factors, and also they developed the level of self-confidence for infant care and the perception of Taegyo as self-care agency for the practice of Taegyo. The present study findings will add to the accumulated knowledge of health care professionals about the cultural factors involved in the practice of Taegyo and the traditional cultural beliefs and culture-specific health promoting behaviors of ethnic minority pregnant women to provide culturally competent care for them.

• Journal of Menopausal Medicine
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• v.24 no.3
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• pp.210-216
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• 2018

Objectives: The present study aimed to determine the barriers influencing the sexual conversation. Methods: In this descriptive cross-sectional study, 200 midwives were selected through convenience sampling method from private and public clinics in Mashhad, North East of Iran. A self-structured questionnaire was used to collect the study data. Results: The mean age of subjects was $39.58{\pm}8.12years$ with $13.49{\pm}7.59years$ of work experience. A number of cultural conditions act as an inhibitory force for the midwives to address sexual issues with menopausal women. Menopausal women visit a doctor at the acute stage when emotional and physical problems make sexual discussion difficult for the midwives (86.5%). Other related causes for not having proper sexual conversation were insufficient knowledge (51.4%), inadequate education provided via public media through health providers (83.5%), midwives or their patient's shame (51.5%), and attempt to get help from traditional healers, friends, relatives and supplicants instead of midwifery staff (78.5%). Also, we found that sexual workshops, communication workshops, and work experiences had a significant influence in changing the views of midwives. Conclusions: Cultural barriers prevent the patients and providers from communicating effectively with each other, thus highlighting the need for sexual and communication workshops for the health care providers.

• Korean Journal of Metals and Materials
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• v.48 no.1
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• pp.90-100
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• 2010

Micro-conductive patterns were microfabricated on an insulating substrate ($SiO_2$) surface by a selective electroless nickel plating process in order to investigate the formation of seed layers. To fabricate micro-conductive patterns, a thin layer of metal (Cu.Cr) was deposited in the desired micropattern using laser-induced forward transfer (LIFT). and above this layer, a second layer was plated by selective electroless plating. The LIFT process. which was carried out in multi-scan mode, was used to fabricate micro-conductive patterns via electroless nickel plating. This method helps to improve the deposition process for forming seed patterns on the insulating substrate surface and the electrical conductivity of the resulting patterns. This study analyzes the effect of seed pattern formation by LIFT and key parameters in electroless nickel plating during micro-conductive pattern fabrication. The effects of the process variables on the cross-sectional shape and surface quality of the deposited patterns are examined using field emission scanning electron microscopy (FE-SEM) and an optical microscope.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.19 no.5
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• pp.386-393
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• 2007

This paper studies the ventilation characteristics according to the jet fan location at the long road tunnel using the CFD software 'FLUENT' which is based on the finite volume method. The tunnel model used in the analysis has a length of 1600m, a cross sectional area of $120m^3$, and is composed of 3 lanes and one way. The velocity profile, the distribution of CO concentration and the ventilation flow rate within the tunnel are analyzed, respectively. In the analysis, it is found that the dependence of the ventilation flow rate upon the jet fan location is small, but the CO concentration in the tunnel is at the lowest when the jet fans are installed near the tunnel outlet. An air stream right below the jet fan is almost inactive due to the strong stream injection near the jet fan. Thus, the pollution level below the jet fan must be higher than the other area.