• Journal of the Korean Institute of Telematics and Electronics D
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• v.36D no.2
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• pp.31-40
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• 1999

Characteristics of monopole antenna and planar conductor structure mounted on handheld telephone are anlayzed by using FDTD method. Feeding of monopole antenna is implemented with lumped elements and plastic case is coated on the surface of conductor box. Otherwise, resonant frequency of handheld telephone mounting monopole antenna with no plastic case is 877MHz, when plastic case (${\varepsilon}_r=2$) is coated, the resonant frequency is down to 82MHz and the bandwidth is broadened about 1.5 times. Planar structure of handheld telephone mounted on the body makes to change far-field gain radiation patterns. In this case, radiation patterns are somewhat asymmetrical. Handheld telephone using PIFA(Planar Inverted F Antenna), instead of monopole antenna, is resonated at frequency 1.52GHz that is available onPCS. In the radiation pattern of this structure, azimuth that electric field intensity is presented below 20dB is 14$^{\circ}$.

• Journal of the Korea Convergence Society
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• v.6 no.1
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• pp.109-114
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• 2015

A circularly polarized small UHF RFID reader antenna is presented. The antenna is composed of four elements and printed on the plastic substrate(${\varepsilon}_r=2.2$, t=5mm). Each element is fed by a probe which is sequentially connected to the feed line. The feed line is manufactured on the FR-4 substrate(t=1.0mm, ${\varepsilon}_r=4.7$). The simulation results shows that the antenna can be achieved a return loss of 12dB, gain of 3.46dBic over the UHF band of 902-928MHz. According to our simulation results, two prototype antennas are manufactured and measured. The obtained antennas operate in UHF RFID bands and can be adapted for various portable applications. In addition, a parametric study is conducted to facilitate the design and optimization processes.

• JSTS:Journal of Semiconductor Technology and Science
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• v.3 no.1
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• pp.13-20
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• 2003

Both MgO and $Sc_2O_3$ are shown to provide low interface state densities (in the $10^{11}{\;}eV^{-1}{\;}cm{\;}^{-2}$ range)on n-and p-GaN, making them useful for gate dielectrics for metal-oxide semiconductor(MOS) devices and also as surface passivation layers to mitigate current collapse in GaN/AlGaN high electron mobility transistors(HEMTs).Clear evidence of inversion has been demonstrated in gate-controlled MOS p-GaN diodes using both types of oxide. Charge pumping measurements on diodes undergoing a high temperature implant activation anneal show a total surface state density of $~3{\;}{\times}{\;}10^{12}{\;}cm^{-2}$. On HEMT structures, both oxides provide effective passivation of surface states and these devices show improved output power. The MgO/GaN structures are also found to be quite radiation-resistant, making them attractive for satellite and terrestrial communication systems requiring a high tolerance to high energy(40MeV) protons.

• Korea Journal of Hospital Management
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• v.22 no.2
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• pp.28-43
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• 2017

The purpose of this study was to investigate the influence of professional self-concept and interpersonal relations on nursing competence of clinical nurses. This study was conducted as a descriptive cross sectional survey with 182 nurses who work at a tertiary hospital which has over 1,000 beds, located in Gyeounggi - do. The data was collected from October 11th, 2016 to October 28th, 2016. The main findings of this study were as follows. The mean score for professional self-concept was $2.65{\pm}0.29$ points in the range of 1 point to 4 points. And interpersonal relations was an average of $3.55{\pm}0.35$ points in the range of 1 point to 5 points. Nursing competence was an average of $2.65{\pm}0.39$ points in the range of 1 point to 4 points. Professional self-concept and interpersonal relations were positively correlated with nursing competence. Nursing competence was differed from clinical career(F=10.518, p<.001), working unit(F=4.139, p=.018), educational background(F=6.542, p=.002), and satisfaction on nursing(F=6.326, p<.001). The regression model with clinical career, working unit, educational background, satisfaction on nursing, 3 sub domain of professional self-concept(professional practice, satisfaction, communication), and interpersonal relation was statistically significant (F=31.94, p<.001). And this model could explain 51.5% of nursing competency(Adj R2=.515). Especially, professional practice(${\beta}=.532$, p<.001) of professional self-concept, interpersonal relations(${\beta}=.223$, p<.001), clinical career(${\beta}=.169$, p<.001), working unit: ICU (${\beta}=.169$, p<.05) were identified the factors influencing on nursing competence. Therefore, improving clinical nurses' nursing competence can be achieved with broad approach that includes improvements in professional self-concept and interpersonal relations. And also, working unit, and clinical career should be considered to develop the actual program for nursing competence, too.

• Journal of Korean Academy of Nursing
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• v.37 no.3
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• pp.305-312
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• 2007

Purpose: This study was to examine effects of muscle electric stimulation on chronic knee pain, activities of daily living, and living satisfaction for Korean elderly women. Methods: The design was a nonequivalent control group pretest-posttest study. Subjects were 60 (experimental: 30, control: 30) elderly women 65 years old or above with good orientation and communication. The experimental treatment was electric stimulation on both thigh quadriceps muscles for 15 minutes per time, 3 times per week, for a total of 12 weeks. Measures were the S-F McGill Pain Questionnaire and Arthritis Impact Measurement Scale for chronic knee pain, activities measurement of daily living for activities of daily living, and living satisfaction measurement for living satisfaction. Data was analyzed through the SPSS Win 12.0. Results: Chronic knee pain by S-F MPQ (t=43.563, p=.000) and chronic knee pain by AIMS (t=31.364, p=.000) were significantly decreased in the experimental group, and the activities of daily living (t=124.353, p=.000) and living satisfaction (t=71.268, p=.000) were significantly increased in the experimental group for Korean elderly women. Conclusion: Muscle electrical stimulation decreased chronic knee pain, and increased the activities of daily living and living satisfaction for Korean elderly women. Further studies for muscle electric stimulation need to be done.

• Journal of Korean Public Health Nursing
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• v.16 no.1
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• pp.64-76
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• 2002

This study was performed to identify the level of stress of clinical practice and clinical competency and the relationships between stress of clinical practice and clinical competency in nursing students. The subjects of this study were 379 senior nursing students in 2 nursing colleges in M city. The data were collected from November 5th to 24th, 2000, using questionnaire. The instruments used were the Stress of Clinical Practice Scale and the Clinical Competency Measurement Tool. The data were analyzed using frequency, percentage, t-test, ANOVA, and Pearson's Correlation Coefficient, using the SPSS program. The results of the study were as follows : 1. The mean score for the level of stress of clinical practice was 3.83 points. The stress of clinical practice were classified into six dimensions and their order of getting score was nurse(3.99), relationship between nursing theory and practice(3.94), human relationship (3.92), clinical education and evaluation by professors(3.87), environment(3.70), and patient(3.59). 2. The mean score for the level of clinical competency was 3.91 points. The clinical competency were classified into five dimensions and their order of getting score was professional development (4.08), skills (4.06) , interpersonal relationship/communication(3.95), teaching/coordinating(3.81), and nursing process(3.70), 3. The stress of clinical practice showed significant difference in the score of grade(t=-2.82, p=.005), interpersonal relationship(t=1.97, p=.049) and satisfaction of major(F=3.38, p=.035) of nursing students. 4. The clinical competency showed significant difference in the score of grade(t=-5.97, p=.000). interpersonal relationship(t=3.64, p=.000) and satisfaction of major(F=8.73, p=.000) of nursing students. 5. The data showed the positive correlations between stress of clinical practice and clinical competency(r=.209, p=.000). In conclusion. this study found that the stress of clinical practice was significantly related to clinical competency in nursing students. Therefore further study is needed to examine the efficient coping strategies about stress of clinical practice in nursing students.

• Journal of Sensor Science and Technology
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• v.30 no.6
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• pp.436-440
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• 2021

The impact of the gate length (L_g) on the DC and high-frequency characteristics of indium-rich In_0.8Ga_0.2As channel high-electron mobility transistors (HEMTs) on a 3-inch InP substrate was inverstigated. HEMTs with a source-to-drain spacing (L_SD) of 0.8 ㎛ with different values of L_g ranging from 1 ㎛ to 19 nm were fabricated, and their DC and RF responses were measured and analyzed in detail. In addition, a T-shaped gate with a gate stem height as high as 200 nm was utilized to minimize the parasitic gate capacitance during device fabrication. The threshold voltage (V_T) roll-off behavior against L_g was observed clearly, and the maximum transconductance (g_{m_max}) improved as L_g scaled down to 19 nm. In particular, the device with an L_g of 19 nm with an L_SD of 0.8 mm exhibited an excellent combination of DC and RF characteristics, such as a g_{m_max} of 2.5 mS/㎛, On resistance (R_ON) of 261 Ω·㎛, current-gain cutoff frequency (f_T) of 738 GHz, and maximum oscillation frequency (f_max) of 492 GHz. The results indicate that the reduction of L_g to 19 nm improves the DC and RF characteristics of InGaAs HEMTs, and a possible increase in the parasitic capacitance component, associated with T-shap, remains negligible in the device architecture.

• Fashion & Textile Research Journal
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• v.17 no.4
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• pp.513-523
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• 2015

The purpose of this study is to develop house caddie uniforms design which reflects the CI and image of 'Golfzon County Sunwoon', a representative golf course in the Honam circle, to enhance a positive image of a golf course and improve house caddies' service quality and their working efficiency. Study methods were as follows. In literature review, the domestic golf industry, golf culture, and house caddie uniforms as one of golf course CI elements were investigated. In empirical study, the formativeness of domestic golf course CI and house caddie uniforms was analyzed. Then, house caddie uniforms were developed using CI which is the symbolic element of a golf course. A concept for uniforms design development was 'Golf & Culture Communication' to symbolically represent an image of IT-based total golf culture club. It was limited to female uniforms design for spring or autumn that is high in application. A symbol and a logo which are symbolic elements of a golf course were freely worn in the form of a brooch. Symbolism and practicality were reinforced using PB(v), R(v), YR(v), and Y(vp) colors only for a golf course. Functionality was improved by using UV protection materials and aesthetics was expressed by reflecting 2014-15 F/W trends.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.4
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• pp.692-710
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• 2013

Conventional interference alignment (IA) for a MIMO interference channel (IFC) requires global and perfect channel state information at transmitter (CSIT) to achieve the optimal degrees of freedom (DoF), which prohibits practical implementation. In order to alleviate the global CSIT requirement caused by the coupled relation among all of IA equations, we propose an IA scheme with a single feedback link of each receiver in a limited feedback environment for a three-user MIMO IFC. The main feature of the proposed scheme is that one of users takes out a fraction of its maximum number of data streams to decouple IA equations for three-user MIMO IFC, which results in a single link feedback structure at each receiver. While for the conventional IA each receiver has to feed back to all transmitters for transmitting the maximum number of data streams. With the assumption of a random codebook, we analyze the upper bound of the average throughput loss caused by quantized channel knowledge as a function of feedback bits. Analytic results show that the proposed scheme outperforms the conventional IA scheme in term of the feedback overhead and the sum rate as well.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.142-147
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• 2007

A series of styrene-butadiene-styrene/aluminium (SBR/Al) composites have been compounded with different weight ratios of Al. The prepared SBR-Al systems have been characterized for different mechanical properties such as tensile strength, tensile modulus and surface hardness have improved with the increase in content of Al in SBR matrix. This may is because of the increase in polymer-filler interaction. The electrical properties such as volume conductivity, surface resistivity, dielectric constant, dissipation factor (tan delta), and break down voltage of SBR/Al composites have been measured with reference to volume fraction $(V_{f}),$ frequency and temperature. The resistance of the SBR-Al composites is found to be ohmic. The voltage-current (V-I) characteristics for SBR-Al also exhibit a linear relationship indicating the ohmic behavior.