• Journal of Advanced Marine Engineering and Technology
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• v.40 no.3
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• pp.223-227
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• 2016

Power supplies make the load compatible with its power source. DC power supplies are extensively used with most electrical and electronic appliances such as computers, television, and audio sets. The presence of non-linear loads results in a low power factor and higher harmonics in the power system. Several techniques for power-factor correction and harmonic reduction have been reported in the literature. This paper proposes a bridgeless boost converter that improves the power factor and reduces the harmonic content in input line currents as compared to full-bridge rectifiers. This bridgeless boost converter eliminates the need of a line-voltage bridge rectifier in conventional boost converter and thereby reduces conduction losses. The effectiveness of the proposed scheme is verified by computer simulations by using the PSIM software.

• Journal of Korean Academy of Nursing
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• v.28 no.2
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• pp.244-255
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• 1998

The purpose of this study was to verify the reliability and validity of the Rosenbaum self-control schedule (SCS) for assessing resourcefulness in Korea and to explore the simplified scale. The study subjects consisted of 787 adults in a community. The data was collected during the period from Oct. to Dec., 1995 and analyzed as Cronbach α, item correlation with total, Pearson correlation and factor analysis with varimax rotation using SAS. Results were as follows : The mean SCS score for this sample was 17.2 and there were statistical differences for gender(men, 13.1 ; women, 20.0) on the SCS scores. The cronbachα of SCS with 36 items was .74 and when simplified with 30 items, it's coefficient alpha was .78. The translated content of the SCS was validated by two nursing faculty members and one professor of psychology. Factor analysis revealed the most parsimonious structure was obtained when six factors were extracted and subsequently rotated via the varimax criterion. There was 40.2% of total communality variance in the SCS with 36 items. The total communality variance was slightly increased to 43.4% with 30 items of the SCS. In order to reduce from 36 items to 30 items, the process excepted 6 items having low item correlation with total and low MSA(means of sampling adequacy) of factor analysis. According to factor analysis, there are six factors such as emotion control, impulse control, self-efficacy, coping with problems, pain control and satisfaction control, The SCS was found to have low, but statistically significant, correlations with social desirability and helplessness. From the above results, it can be concluded that the reliability of the SCS(inherent and simplified) was a acceptable level and its validity was reasonable when comparing it with other validity studies. To determine the usefulness the simplified scale, further study is necessary to simultaneously compare and analyze both scales for stability.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.11
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• pp.4595-4599
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• 2014

Background: Colorectal cancer is a serious health problem. Early detection of colorectal cancer is crucial for treatment and reducing mortality. Beliefs related to colorectal cancer have been found to be a factor in a person's decision about colorectal cancer screening programs. To determine such beliefs, a valid and reliable instrument is necessary. Objective:The aim of this study was to adapt and determine the psychometric properties of the Persian version of Champion's Health Belief Model Scale of breast cancer screening in the measurement of beliefs toward colorectal cancer (CRC) screening. Materials and Methods: The 'forward-backward' procedure was applied to translate the instrument from English into Persian. This study was conducted in Iran from June 2012 to May 2013. A convenience sample of 200 individuals aged 50 years and older was recruited from the population at the outpatient clinics in the three teaching hospitals. Validity was assessed using content, face and construct validity. To test reliability, the internal consistency was assessed by using Cronbach's alpha coefficient and test-retest (intraclass correlation coefficient) analyses. Exploratory factor analysis was used to assess the construct validity and determine the factors of adapted Champion's Health Belief Model Scale. Results: The mean age of the participants were 62.5 years (SD=10.8 years) and the majority of them (75.5 percent) were female. The results of exploratory factor analysis indicated a six-factor solution for the questionnaire (benefits, motivation and confidence, seriousness, susceptibility, emotional barriers and background barriers) that jointly accounted for 55.52% of variance observed. Cronbach's alpha of the subscales ranged from 0.57 to 0.89 and test-retest reliability ranged from 0.81 to 0.93 indicating a good range of reliability. Conclusions: The findings of this study suggest that the Persian version of Champion's Health Belief Model Scale of CRC screening has good psychometric properties and could be an appropriate measure for health beliefs related to CRC screening in national and international studies.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.6
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• pp.3909-3919
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• 2013

The aim of the present investigation was to evaluate the effect of A ferruginea extract on Dalton's lymphoma ascites (DLA) induced tumours in BALB/c mice. Experimental animals received A ferruginea extract (10 mg/kg.b.wt) intraperitoneally for 14 consecutive days after DLA tumor challenge. Treatment with extract significantly increased the life span, total white blood cell (WBC) count and haemoglobin (Hb) content and decreased the level of serum aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), gamma glutamyl transferase (${\gamma}$-GT) and nitric oxide (NO) in DLA bearing ascites tumor models. In addition, administration of extract significantly decreased the tumour volume and body weight in a DLA bearing solid tumor model. The levels of pro-inflammatory cytokines such as tumor necrosis factor-alpha (TNF-${\alpha}$), interleukin-1 beta (IL-$1{\beta}$), interleukin-6 (IL-6) and granulocyte monocyte-colony stimulating factor (GM-CSF), as well as pro-angiogenic growth factors such as vascular endothelial growth factor (VEGF) and inducible nitric oxide synthase (iNOS) were elevated in solid tumour controls, but significantly reduced by A ferruginea administration. On the other hand, the extract stimulated the production of interleukin-2 (IL-2) and interferon-gamma (IFN-${\gamma}$) in animals with DLA induced solid tumours. Increase in $CD4^+$ T-cell population suggested strong immunostimulant activity for this extract. GC/MS and LC/MS analysis showed quinone, quinoline, imidazolidine, pyrrolidine, cyclopentenone, thiazole, pyrazole, catechin and coumarin derivatives as major compounds present in the A ferruginea methanolic extract. Thus, the outcome of the present study suggests that A ferruginea extract has immunomodulatory and tumor inhibitory activities and has the potential to be developed as a natural anticancer agent.

• Physical Therapy Korea
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• v.23 no.1
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• pp.31-37
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• 2016

Background: The assessment tool developed in other countries should be translated into Korean language using rigorous methodological approaches in order to be used in Korea. Because these procedures are insufficient for establishing the cross-cultural and linguistic equivalence, the need for statistical methods is raised. The Fullerton Advanced Balance Scale was translated into Korean and the content validity was verified through the back translation method, but the reliability and validity have not yet been proven by statistical methods. Objects: The purpose of this study was to investigate the reliability and validity of the Korean version of the Fullerton Advanced Balance Scale (KFAB) by statistical methods in elderly people. Methods: A total of 97 elderly adults (39 males and 58 females) participated in this study. Internal consistency of the KFAB was measured using Cronbach's alpha and an intraclass correlation coefficient (ICC) was used to assess test-retest reliability between the two measurement sessions. Concurrent validity was measured by comparing the KFAB responses with the Korean version of the Berg Balance Scale (KBBS) using the Spearman correlation coefficient. Construct validity of the KFAB was measured using the exploratory factor analysis to evaluate the unidimensionality of the questionnaire. The significance level was set at ${\alpha}=.05$. Results: The internal consistency of the KFAB was found be adequate with Cronbach's alpha (.96), and test-retest reliability was excellent as evidenced by the high ICC (r=.996). Concurrent validity showed high correlation between the KFAB and KBBS (r=.89, p<.001). Construct validity was evaluated using exploratory factor analysis. The result from Bartlett test of sphericity was statistically significant (p<.001), and the value of Kaiser-Meyer-Olkin measure of sampling adequacy was .93. Exploratory factor analysis revealed the existence of only one dominant factor that explained 76.43% of the variance. Conclusion: The KFAB is a reliable, valid and appropriate tool for measuring the balance functions in elderly people.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.30 no.2
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• pp.124-127
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• 2019

Vocal fold scarring is an intractable phonosurgical condition. The number of patients with vocal fold scars is increasing with the aging of society and with the increasing application of laryngeal microsurgery. Many methods are available to treat these, including voice therapy, stem cells, regenerative scaffolds, and growth factors. However, no standard treatment strategy has yet been established, and novel techniques are required. Basic fibroblast growth factor has been shown to be effective for the treatment of mild chronic vocal fold scarring. The combined use of basic fibroblast growth factor and regenerative scaffolds is currently under investigation. Here, we report a female patient in whom vocal fold scarring developed after two laryngeal microsurgeries. We performed laryngeal microsurgery to remove the scar tissue and used basic fibroblast growth factor and a collagen scaffold to promote healing. The patient's voice quality was greatly increased, and she was content with her voice after 2 years of follow-up. This is the first report of this methodology in Korea and is presented along with a review of the literature.

• International Journal of Concrete Structures and Materials
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• v.7 no.3
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• pp.239-249
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• 2013

In the present scenario to fulfill the demands of sustainable construction, concrete made with multi-blended cement system of OPC and different mineral admixtures, is the judicious choice for the construction industry. Silica fume (SF) and fly ash (FA) are the most commonly used mineral admixtures in ternary blend cement systems. Synergy between the contributions of both on the mechanical properties of the concrete is an important factor. This study reports the effect of replacement of OPC by fly ash (20, 30, 40 and 50 % replacement of OPC) and/or silica fume (7 and 10 %) on the mechanical properties of concrete like compressive strength and split tensile strength, with three different w/b ratio of 0.3, 0.4 and 0.45. The results indicate that, as the total replacement level of OPC in concrete using ternary blend of OPC + FA + SF increases, the strength with respect to control mix increases up to certain replacement level and thereafter decreases. If the cement content of control mixes at each w/b ratio is kept constant, then as w/b ratio decreases, higher percentage of OPC can be replaced with FA + SF to get 28 days strength comparable to the control mix. A new method was proposed to find the efficiency factor of SF and FA individually in ternary blend cement system, based on principle of modified Bolomey's equation for predicting compressive strength of concrete using binary blend cement system. Efficiency factor for SF and FA were always higher in ternary blend cement system than their respective binary blend cement system. Split tensile strength of concrete using binary and ternary cement system were higher than OPC for a given compressive strength level.

• The KIPS Transactions:PartC
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• v.13C no.6 s.109
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• pp.795-802
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• 2006

The Electronic Commerce with development was advanced information technique in transaction from at the election, and now it is sharply evolving into Mobile Commerce capable of Electronic commerce while the user moves. Mobile Commerce has some feature in Electronic Commerce, but has the different feature. analyzed the feature of Mobile Commerce were carried out, but those were processed according to its location and field only and special of view. This study sought the new characteristic which is different from the existing Electronic Commerce, and took account of the successful factor for Mobile Commerce which includes the position in a user, a developer and an operator. In addition, AHP (Analytic Hierarchy Process) was used in order to evaluate the extract factor applied to each related to through more objective methods. The analysis results identified in this study such as the quality trust and the accessibility to understanding for an content duality might be the one of the chief elements of success in Mobile Commerce which applies at the present.

• Transactions on Electrical and Electronic Materials
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• v.11 no.3
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• pp.126-129
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• 2010

(1-X) $(Na_{0.5}K_{0.5})NbO_3-X$ $K_4CuNb_8O_{23}$ (NKN-X KCN) ceramics were produced using the conventional solid state sintering method, and their sinterability and electric properties were investigated. The density, dielectric constant (${\varepsilon}_r$), piezoelectric constant $d_{33}$, electromechanical coupling factor $k_p$ and mechanical quality factor $Q_m$ value of the NKN ceramics depended upon the KCN content and the sintering temperature. In particular, the KCN addition to the NKN greatly improved the mechanical quality factor $Q_m$ value. The ceramic with X = 2.0 mol% sintered at $1,150^{\circ}C$ possesses the optimum properties (${\varepsilon}_r=241$, $d_{33}=78$, $k_p=0.34$ and $Q_m=1,121$). These results indicate that the ceramic is a promising candidate material for applications in lead free piezoelectric transformer and filter materials.

• Journal of Korean Elementary Science Education
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• v.39 no.2
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• pp.183-203
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• 2020

The purpose of this study is to investigate the factor for improving elementary and secondary students' positive experiences about science (PES). In-depth interviews with 32 students and 8 teachers from 8 elementary and secondary Science Core schools were conducted to explore the factors for improving the student's PES. The analysis of the results reveal that the eight key factors which had a decisive impact on a student's PES were 'practice-centered exploratory activities', 'student-led class', 'positive and professional feedback', 'construction of knowledge through exploration', 'class considering student's interest and aptitude', 'use of materials related to real life', 'smooth communication and collaboration in group activities', and 'appropriate difficulty in learning content'. There were also five environmental factors that affected these key factors: 'teacher's professionalism for science classes', 'science class environment', 'teacher community in unit schools', 'change in curriculum', and 'scientific activities other than regular classes'. Based on these results, the practical implications for improving the student's PES are suggested.