• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2009.10a
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• pp.153-157
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• 2009

A Highly efficient Mercury-free Flat Fluorescent Lamp (MFFL) with dielectric barrier Xe gas discharge was developed for an alternative of conventional line-type Cold Cathode Fluorescent Lamps (CCFLs) which shows a wide voltage margin and a stable discharge operation for diffuse glow discharge with an application of a auxiliary electrode. Electro-optic characteristics of the MFFL were examined through the changes in ambient temperature, total pressure and Xe partial pressure. the single cell is expanded into a multi-structured configuration to realize a large sized lamp by a simple repetition of the single cells, and a new driving scheme is proposed for an adaptive brightness control using dual auxiliary electrodes and bi-polar drive scheme. In addition, interesting application of this ultra high luminance flat lamp by the optimization of the gas condition and the pattern of the rear phosphor layer is suggested as a good alternative of daylight lamp source

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.6
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• pp.1285-1290
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• 2012

People have been interested in the next generation media and service over 3D by development of 3D industry and generalization of 3D-related content and equipment in recent year. Many researchers predict that a strong candidate is digital hologram. Holographic technology is classified to capture(or generation), processing, and display(or reconstruction). This paper discusses the digital holographic display system using hybrid image pickup system and proposes a new structure of digital holographic display system. Through the proposed method a digital hologram can be scalably serviced according to display equipments with various resolutions, computing power of decoding part, and network bandwidth.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.4
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• pp.57-63
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• 2004

This paper describes a method for digitizing the compound surfaces which are comprised of several unknown feature shapes such as base surface, and draft wall. From the reverse engineering's point of view, the main step is to digitize or gather three-dimensional points on an object rapidly and precisely. As well known, the non-contact digitizing apparatus using a laser or structured light can rapidly obtain a great bulk of digitized points, while the touch or scanning probe gives higher accuracy by directly contacting its stylus onto the part surface. By combining those two methods, unknown features can be digitized efficiently. The paper proposes a digitizing methodology using the approximated surface model obtained from laser-scanned data, followed by the use of a scanning probe. Each surface boundary curve and the confining area is investigated to select the most suitable digitizing path topology, which is similar to generating NC tool-paths. The methodology was tested with a simple physical model whose shape is comprised of a base surface, draft walls and cavity volumes.

• Journal of Powder Materials
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• v.24 no.3
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• pp.216-222
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• 2017

Synthesized monocrystalline nanodiamond (nD) particles are heat-treated at various temperatures to produce highly structured diamond crystals. The heat-treated nDs show different weight loss ratios during thermogravimetric analysis. The crystallinities of the heat-treated nDs are analyzed using Raman spectroscopy. The average particle sizes of the heat-treated nDs are measured by a dynamic light scattering (DLS) system and direct imaging observation methods. Moreover, individual dispersion behaviors of the heat-treated nD particles are investigated based on ultrasonic dispersion methods. The average particle sizes of the dispersed nDs according to the two different measurement methods show very similar size distributions. Thus, it is possible to produce highly crystallized nD powder particles by a heat-treatment process, and the nD particles are relatively easy to disperse individually without any dispersant. The heat-treated nDs can lead to potential applications such as in nanocomposites, quantum dots, and biomedical materials.

• Journal of Nutrition and Health
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• v.34 no.8
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• pp.929-935
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• 2001

The purpose of this study was to investigate the effects of regular maternal exercise on maternal nutrients intake and pregnancy outcome. The number of subjects were 567 pregnant women at local general hospital in Daegu. General characteristics data and 24- hour food recalls were collected by trained interviewer. Structured interview and medical record review were carried out at first prenatal and delivery visit(included age, delivery history, height, pre-pregnancy weight, and pregnancy outcome etc). Regular exercise performance was surveyed at third trimester and 31.4% of subjects exercised regularly Overall weight gains during pregnancy were 13.9 $\pm$ 3.8kg and 14.7 $\pm$ 4.7kg in the exercise and sedentary group, respectively. The type of exercise was mainly strolling and light aerobic exercise. Usually firstpara subjects exercised more regularly than multipara subjects. There is no significant difference between regular exercise and severity of morning sickness. Weight gain during pregnancy was not relate to regular exercise. Though there is not statistically significant, the nutrients intakes were higher in regular exercise group than in sedentary group. We concluded regular exercise during pregnancy neither influenced pregnancy weight gain, severity of morning sickness nor baby birth weight but it could affect the nutritional and health statues of mother.

• Journal of Korean Academy of Nursing
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• v.47 no.4
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• pp.562-574
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• 2017

Purpose: This study attempts to explore the subjective experience of frailty among elderly individuals in Korea. Methods: From June to August in 2014, 11 elderly persons who had experienced frailty in a community were interviewed. For data analysis, the method suggested by Colaizzi was applied as a phenomenological method. Results: According to the analysis, the study participants' frailty process was structured in seven categories: (a) 'natural phenomenon with ageing,' (b) 'life force comes to an end,' (c) 'the light in my heart turns off,' (d) 'unavoidable situation,' (e) 'continuous and connected vicious cycle,' (f) 'the limit of recovery energy already passes,' and (g) 'life is supported by someone's help.' Conclusion: The frailty experience in the participants is a natural process of aging, which cause vicious cycle acting with each other among physical, psychological, and social health. It is said that the cycle of frailty was started from weight loss and insufficient sleep, and boostered by pain. The participants from repetition of the vicious cycle become exhausted and pass the threshold of their recovery energy at some points. If they meet with sudden accidents such as falling, traffic accident and so on, they become to live a dependent life supported by someone's help in a moment. To prevent frailty and worsening conditions in Korean elderly individuals, it is recommended to provide a interventional programs using this study's results.

• The Journal of Korean Academic Society of Nursing Education
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• v.14 no.1
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• pp.5-11
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• 2008

Purpose: The purpose of this study was to identify the effects of interpersonal relationships and communication curriculum on interpersonal relations and self-esteem. Method: This study employed a two-group pre-post test study design. Data was collected from 70 subjects from April to June, 2006 at C university in Jeju, Korea. Forty subjects were in the control group and 30 subjects were in the experimental group. A structured curriculum was conducted for the experimental group once a week for 12 weeks, but not for the control group. For both groups the scores of interpersonal relations and self-esteem were measured before and after the curriculum. Data was analysed by $X^2$-test, t-test, paired t-test and Pearson correlation with SPSS. Results: The scores of interpersonal relations and self-esteem significantly increased in the experimental group. There were significant positive correlations between interpersonal relationships and self-esteem. Conclusion: In light of these results, interpersonal relationships and communication curriculum have a positive effect on interpersonal relations and self-esteem. Therefore, this study can provide basic data and direction in developing and applying a curriculum in education.

• Korean Journal of Adult Nursing
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• v.21 no.2
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• pp.257-267
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• 2009

Purpose: The purpose of this study was to identify risk factors of fall and to examine its results among patients aged 60 and over diagnosed with osteoporosis. Methods: A retrospective descriptive survey was conducted with 91 patients admitted in a university hospital in a city. Data were collected using an interview method with a structured questionnaire, and were analyzed using descriptive statistics and multiple logistic regression. Results: In patients with osteoporosis, the intrinsic risk factors of falls were aging (OR = 3.742), gait disturbance (OR = 12.565), taking one or fewer medicine (OR = 7.873), and having two or more diseases (OR = 5.173). The extrinsic risk factors included the use of a bed (OR = 3.093), slippery floors (OR = 12.130), bathroom mat without anti-slip rubber backing (OR = 3.564), and presence of a night light on the passage from the bedroom to the bathroom (OR = 2.980). Conclusion: For the elderly aged over 70 who are most vulnerable to falls, screening tests such as bone mineral density (BMD) should be conducted in health examinations and the risk of fracture caused by osteoporosis should be communicated to the vulnerable elderly. Besides, development of new exercise programs combining weightbearing exercise is needed to prevent bone loss and increase functional activities.

• Bulletin of the Korean Chemical Society
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• v.25 no.5
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• pp.652-656
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• 2004

A new luminescent polymer, poly{1,4-phenylene-1,2-ethenediyl-2'-[2"-(4'"-octyloxyphenyl)-(5"-yl)-1",3",4"-oxadiazole]-1,4-phenylene-1,2-ethenediyl-2,5-bis-dodecyloxy-1,4-phenylene-1,2-ethenediyl} (Oxd-PPV), was synthesized by the Heck coupling reaction. Electron withdrawing pendant, conjugated 1,3,4-oxadiazole (Oxd), is on the vinylene unit. The band gap of the polymer figured out from the UV-visible spectrum was 2.23 eV and the polymer film shows bright yellow emission maximum at 552 nm. The electroluminescence (EL) maximum of double layer structured device (ITO/PEDOT:PSS/Oxd-PPV/Al) appeared at 553 nm. Relative PL quantum yield of Oxd-PPV film is 3.6 times higher than that of MEH-PPV film. The HOMO and LUMO energy levels of Oxd-PPV figured out from the cyclic voltammogram and the UV-visible spectrum are -5.32 and -3.09 eV, respectively, so that more balanced hole and electron injection efficiency can be expected compared to MEH-PPV. A double layer EL of Oxd-PPV has an maximum efficiency of 0.15 cd/A and maximum brightness of 464 cd/$m^2$.

• Journal of Power System Engineering
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• v.19 no.3
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• pp.11-15
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• 2015

In this paper, the multi-point hydrogen detection system based on the combination of the hetero-core optical fiber SPR hydrogen tip sensor and interrogator by pseudorandom noise (PN) code correlation reflectometry has been developed. In a light intensity-based experiment with an LED operating at 850 nm, it has been presented that a transmitted loss change of 0.32dB was induced with a response time of 25 s for 4% $H_2$ in $N_2$ in the case of the 25-nm Au, 60-nm $Ta_2O_5$, and 5-nm Pd multi-layers film. The proposed sensor characteristic shows excellent reproducibility in terms of loss level and time response for the in- and out- $H_2$ action. In addition, in the experiment for multi-point hydrogen detection, all sensors show the real-time response for 4% hydrogen adding with reproducible working. As a result, the real-time multi-point hydrogen detection could be realized by means of the combination of interrogating system and hetero-core optical fiber SPR hydrogen tip sensors.