• Composites Research
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• v.30 no.4
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• pp.241-246
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• 2017

The brittle nature in most FRP composites is accompanying other forms of energy absorption mechanisms such as fibre-matrix interface debonding and ply delamination. It could play an important role on the energy absorption capability of composite structures. To solve the brittle nature, the adhesion between pines and composites was studied. Thermal treated pines were attached on carbon fiber reinforced polymer (CFRP) by epoxy adhesives. To find the optimum condition of thermal treatment for pine, two different thermal treatments at 160 and $200^{\circ}C$ were compared to the neat case. To evaluate mechanical and interfacial properties of pines and pine/CFRP composites, tensile, lap shear and Izod test were carried out. The bonding force of pine grains was measured by tensile test at transverse direction and the elastic wave from fracture of pines was analyzed. The mechanical, interfacial properties and bonding force at $160^{\circ}C$ treated pine were highest due to the reinforced effect of pine. However, excessive thermal treatment resulted in the degradation of hemicellulose and leads to the deterioration in mechanical and interfacial properties.

• Journal of Korean Ophthalmic Optics Society
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• v.17 no.3
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• pp.279-284
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• 2012

Purpose: We measured the amplitude of accommodation using the push-up and push-away tests and near point of convergence (NPC) and investigated the accommodative insufficiency (AI) and convergence insufficiency (CI) in elementary school children of 12~13 years old. Methods: 88 students who aged 12~13 $12.63{\pm}0.51$ years old with more than 1.0 spectacle best corrected visual acuity were examined using push-up and push-away tests. The break and recovery points of NPC also were measured. Results: Mean amplitudes of accommodations using push-up and push-away tests were $11.52{\pm}2.50D$ and $10.06{\pm}1.97D$, respectively in right eye (P<0.001). Mean break and recovery points in NPC were $8.66{\pm}1.99cm$ and $10.98{\pm}2.06cm$. AI and CI showed 28.75% and 30.00% each. 48.75% was within normal range in both amplitudes of accommodations according to their age expected and convergence. Students having both AI and CI were 7.50%. Conclusions: A high correlation between the push-up test and push-away test was found in elementary school children (r=0.6025; P<0.05). Students having normal amplitude of accommodation by their age expected and normal convergence were 71.25% and 70.00%, respectively.

• Journal of Digital Convergence
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• v.13 no.4
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• pp.295-302
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• 2015

The purpose of this study was to evaluate the effects of convergence-based reeducation of core basic nursing skills (subcutaneous injection, indwelling catheterization) on competence, knowledge, attitude and confidence for nursing students. Subjects were 34 nursing students and 3rd grade. Experimental treatment and data collection was conducted from December 14 to 29, 2013. Skills for subcutaneous injection including simple blood glucose test and indwelling catheterization were evaluated before and after intervention. Knowledge, attitude and confidence were measured using structured questionnaires. Data were analyzed by the frequency, descriptive statistics and paired t-test using SPSS version 21. As a result, after reeducation, significant improvement was found in competence (p<.001), knowledge (p<.001) and confidence (p<.001) in subcutaneous injection and indwelling catheterization. Convergence-Based reeducation program was found effective to enhance the competence of core basic nursing skills before graduating nursing students. Therefore, it is necessary to continue to develop program and to evaluate the effects with further research.

• Journal of the Korea Convergence Society
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• v.8 no.7
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• pp.231-236
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• 2017

In this study, the inhomogeneous material composed of CFRP(carbon fiber reinforced plastic) and structural metal of SM45C is used for the light material. The finite element analysis on the basis of compact tension test was carried out by using the composite material for sandwich type bonded with the unidirectional CFRP that differs in fiber stacking angle at both sides with the core of SM 45C. CT test is the representative method to confirm the fracture behaviour due to crack in material under the load. The effect on crack and hole must be investigated in order to apply inhomogeneous material to mechanical structure. As the result of this study, the fracture behaviour by CT test of the composite material for sandwich was studied by simulation analysis. The sandwich composite of unidirectional CFRP with the stacking angle of [0/60/-60/0] has the superior strength and the maximum equivalent stress of about 182GPa.Also, the esthetic sense can be shown as the designed factor of shape with composite material is grafted onto the convergence technique.

• Journal of the Korea Convergence Society
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• v.11 no.3
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• pp.301-310
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• 2020

A Convergence study was attempted to identify the effects of stress on Suicidal ideation and mediating effects of depression in the relationship. The study were 166 elderly's over 65 years at G city and period was from August 29 to September 9, 2018. Data were analyzed PASW 18.0 program. As a result, stress had a significant effect on depression in stage 1, stress had a significant effect on suicide ideation in stage 2, stress and depression of parameter were significant predictors in stage 3. The explanatory power of the two variables was 24.3% in stress, 26.8% for stress accompanied with depression, and the partial mediating effect of depression on the effect of stress on suicide ideation. Based on this study, it can be used as a basic data for reducing suicide ideation of the elderly and study is needed to develop suicide prevention programs.

• Composites Research
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• v.34 no.5
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• pp.305-310
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• 2021

Mechanical properties of fiber reinforced composites were affected to fiber volume fractions (FVF) and interfacial property by sizing agent conditions. An optimum interface can relieve stress concentration by transferring the mechanical stress from the matrix resin to the reinforcements effectively, and thus can result in the performance of the composites. The interfacial properties and wettability between the epoxy resin and glass fiber (GF) were evaluated for different sizing agent conditions and FVFs. The surface energies of epoxy resin and different sizing agent treated GFs were calculated using dynamic and static contact angle measurements. The work of adhesion, W_a was calculated by using surface energies of epoxy matrix and GFs. The wettability was evaluated via the GF tow capillary test. The interfacial shear strength (IFSS) was evaluated by microdroplet pull-out test. Finally, the optimized GFRP manufacturing conditions could be obtained by using wettability and interfacial property.

• Journal of the Korea Convergence Society
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• v.10 no.2
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• pp.113-124
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• 2019

This is a convergence study to investigate the relationship between cereal intake level and food and nutrient intake in 218 Chinese middle aged women aged 40 to 65 years. Data were analyzed by ${\chi}^2$ test, ANOVA, correlation analysis and Jonckheere-Terpstra trend test using SPSS 22.0 program. The results of the study were as follows. The higher the level of cereal intake in the subjects, the lower were the rate of breakfast fasting (p for trend=0.000), overeating (p for trend=0.019), and eating out (p for trend=0.003). The intake of root and tuber crops(p for trend=0.008), meat(p for trend=0.043), pulses(p for trend=0.020), and light colored vegetables(p for trend=0.015) per 1,000 kcal of energy increased when the level of cereal intake was 6 to 9 units. Therefore, it is necessary to discuss and study for continuous education and improvement through the feedback so that the middle-aged women can take the cereal appropriately.

• Journal of Institute of Control, Robotics and Systems
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• v.21 no.12
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• pp.1130-1135
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• 2015

The bond pull test is the most widely used technique for the evaluation and control of wire bond quality. The wire being tested is pulled upward until the wire or bond to the die or substrate breaks. The inspector test strength of wire by manually and it takes around 3 minutes to perform the test. In this paper, we develop a 3D vision system to measure 3D position of wire. It gives 3D position data of wire to move a hook into wires. The 3D measurement method to use here is a confocal imaging system. The conventional confocal imaging system is a spot scanning method which has a high resolution and good illumination efficiency. However, a conventional confocal systems has a disadvantage to perform XY axis scanning in order to achieve 3D data in given FOV (Field of View) through spot scanning. We propose a method to improve a parallel mode confocal system using a micro-lens and pin-hole array to remove XY scan. 2D imaging system can detect 2D location of wire and it can reduce time to measure 3D position of wire. In the experimental results, the proposed system can measure 3D position of wire with reasonable accuracy.

• Journal of Digital Convergence
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• v.14 no.10
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• pp.375-380
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• 2016

This study aimed to evaluate the possibility for assessment of binocular visual function about alteration for near point of convergence (NPC). Study subjects were total 30 (emmetropia 16, myopia 14), who had no eye disease except for the phoria and monocular corrected vision 1.0 and over. Near point of accommodation (NPA), NPC and phoria test were measured both at ordinary and stimulation of +1D. Ordinary NPC was 1.77cm shorter than NPC stimulated +1D and the NPC of emmetropia was shorter than that of myopia. The difference between NPC stimulated +1D and ordinary were increased in the emmetropia. As the NPC increased, the AC/A ratio was elevated and the feature of near exophoria appeared. The results suggested that the alteration of NPC might substitute AC/A ratio for reference variable of binocular vision. If converged and analyzed comparatively with another binocular visual evaluation test, the alteration of NPC could be developed for substitution of evaluation test.

• Journal of the Korea Convergence Society
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• v.7 no.6
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• pp.275-285
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• 2016

The purpose of this study is to identify the factors influencing on the burden on the family caregivers of patient with more than second degree burn. The participants of this study were 120 family caregivers sampled for convenience from 4 Burn hospitals in D, S, B, P cities in South Korea. Data analysis was performed by t-test, ANOVA, Scheffe' test, Multiple linear regression. According to the result, the burden of assess & mean of care and the future of the patient was the highest score for family caregivers. Factors that affect the burden of family caregiver with burn patients were marital status, time, care, skin transplants, body surface area (%) and these factors explained 25.9%. This study concludes that intervention program is developed to reduce physical and emotional burden and nursing care services is required to adjust the amount time to care for the family caregivers with burn patients for a long time.