• Transactions of the Korean hydrogen and new energy society
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• v.20 no.2
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• pp.125-132
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• 2009

Cylinder shaped air-breathing PEMFC has been developed to have small volume, low contact resistance and better air accessibility to the open cathode. This cylinder shaped design consists of an anode cylinder with helical flow channel and a cathode current collector with slits. The pressure distribution measurement according to the shapes was performed. The test result indicated that cylinder shaped fuel cell has better pressure distribution compared with the planar shaped fuel cell. The better pressure distribution was connected to the higher performance. The maximum power density of cylinder shaped fuel cell was about 20% higher than the planar shaped fuel cell. The maximum power density of the developed cylinder shaped air-breathing PEMFC with dry hydrogen was $220\;mW/cm^2$ and with humidified hydrogen was $293\;mW/cm^2$.

• Phonetics and Speech Sciences
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• v.9 no.1
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• pp.49-53
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• 2017

Formant frequencies depend on the position of tongue, the shape of lips, and larynx. In the auditory system, the external ear canal is an open-end resonator, which can modify the voice characteristics. This study investigates the effect of the real ear on formant frequencies. Fifteen subjects ranging from 22 to 30 years of age participated in the study. This study employed three corner vowels: the low central vowel /a/, the high front vowel /i/, and the high back vowel /u/. For this study, the voice of a well-educated undergraduate who majored in speech-language pathology, was recorded with a high performance condenser microphone placed in the upper pinna and in the ear canal. Paired t-test showed that there were significant difference in the formant frequencies of F1, F2, F3, and F4 between the free field and the real ear. For /a/, all formant frequencies decreased significantly in the real ear. For /i/, F2 increased and F3 and F4 decreased. For /u/, F1 and F2 increased, but F3 and F4 decreased. It seems that these voice modifications in the real ear contribute to interpreting voice quality and understanding speech, timbre, and individual characteristics, which are influenced by the shape of the outer ear and external ear canal in such a way that formant frequencies become centralized in the vowel space.

• Ocean and Polar Research
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• v.25 no.spc3
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• pp.373-384
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• 2003

When pile foundation is constructed by dynamic method, it is desirable to perform monitoring of drivability with pile penetration. Dynamic pile monitoring yields information regarding driving hammer, cushion, pile and soil behaviour that can be used to confirm the assumptions of wave equation analysis. In this study, dynamic monitoring of the steel pipe pile was performed with Pile Driving Analyser (PDA). The PDA utilizes the wave propagation theory to compute numerous variables which describe the conditions of the hammer-pile-soil system in real-time and following each hammer impact. This approach allows immediate field verification of hammer performance, driving efficiency, and estimation of pile bearing capacity. A series of PDA test were performed at the Ieodo Ocean Research Station (IORS) located in southeast of Marado, a southernmost small island south of Jeju Island. The drilling core sediments of Ieodo subsoil are composed of mud and sand, showing lamination and wavy or lenticular bedding, which were often bioturbated. This paper summarizes the results of PDA tests which were applied in measurement and estimation of large diameter open ended steel pipe pile driven by steam hammer, Vulcan-560 and MRBS-4600, at the marine sediments.

• Advances in Traditional Medicine
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• v.6 no.1
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• pp.34-38
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• 2006

The hot water extract of the seeds of Vernonia anthelmintica Kuntze (Compositae) in a dose of 10 ml/kg body weight of mice, showed significant analgesic activity on the hot plate analgesic method throughout the 4 h experimental period. The hole cross scores and the climbing out scores are of lower than the control animals. The hot water extract reduced the defecation in hole board study and significantly reduces the exploratory ambulation and head dipping behaviour. The seed also showed significant depressant activity on the exploratory ambulation of the open field scores. The drug decreased the spontaneous locomotion activity on brick-chip displacement method up to 45 min and also showed the ability to lessen the amphetamine induced hyperactivity up to 20 min. But it didn't show any effect on pentobarbital induced sleeping time test. The extract reduced gastrointestinal motility.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.6
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• pp.533-541
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• 2017

Recently, with the adoption of modern computing and communication technologies, manufacturing systems have become more autonomous and intelligent. Thus, as the number of field devices with smart sensors also increase, the need for an integrated management of such devices becomes essential. This paper proposes a smart encoder architecture that integrates the position sensing function with CANopen connectivity. In addition, an integrated system is proposed to simultaneously control and monitor multiple encoders over the Controller Area Network (CAN) fieldbus network. We evaluated the performance and functionalities of the proposed system by comparative experiments with commercial CANopen smart encoders using a CANopen conformance test.

• Journal of Engineering Education Research
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• v.17 no.6
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• pp.53-61
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• 2014

This study aims to identify on the possibility of the convergence education in engineering. Delphi survey on a panel of experts was chosen to be the main methodology for this study, drawing the main factors of convergence education in engineering. From Oct. 10 to Nov. 25, 2013, a three-round Delphi survey was implemented to collect data. A panel of eighteen experts were involved in this survey. For statistical processing, descriptive statistics including frequency, percentage, mean and standard deviation were carried out along with internal reliability test on the survey instrument. First, the possible convergence of disciplines in engineering were found to Design, Industrial design, ICT, Health care services, Video media, Business and Administration, Organizational psychology, Sociology, Humanities and Aesthetics. Second, the convergence education factors to be most important demanded creativity, idea generation techniques such as the expression of thought communication skills, technical expertise in the field per line, understanding of basic knowledge, verification of common elements among different disciplines, understanding of other disciplines fusion in engineering, artistry and imagination, etc. Third, requirements for the talented person of convergence were the open mind and enthusiasm, creative imagination, accept the opinions of others, skills capacity as a creative expression, and challenges. Above-mentioned requirements are found to be the necessary elements for convergence education.

• Computers and Concrete
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• v.24 no.6
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• pp.561-570
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• 2019

Understanding the realistic behavior of concrete up to failure under different loading conditions within the framework of damage mechanics and plasticity would lead to an enhanced design of concrete structures. In the present investigation, QR (Quick Response) code based random speckle pattern is used as a non-contact sensor, which is an innovative approach in the field of digital image correlation (DIC). A four-point bending test was performed on RC beams of size 1800 mm × 150 mm × 200 mm. Image processing was done using an open source Ncorr algorithm for the results obtained using random speckle pattern and QR code based random speckle pattern. Load-deflection curves of RC beams were plotted for the results obtained using both contact and non-contact (DIC) sensors, and further, Moment (M)-Curvature (κ) relationship of RC beams was developed. The loading curves obtained were used as input data for material model parameters in finite element analysis. In finite element method (FEM) based software, concrete damage plasticity (CDP) constitutive model is used to predict the realistic nonlinear quasi-static flexural behavior of RC beams for monotonic loading condition. The results obtained using QR code based DIC are observed to be on par with conventional results and FEM results.

• YAKHAK HOEJI
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• v.40 no.5
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• pp.545-549
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• 1996

Male Sprague-Dawley rats were exposed to the toluene at 3,000${\pm}$200ppm via inhalation for two hours in the single inhalation group and three weeks by two hours per day, six da ys per week in the repeated inhalation group. The blood toluene concentration in the repeated inhalation group was significantly lower than that in the single inhalation group after 210 and 240 minutes of exposure. The peak concentration of blood toluene was 58.13${\pm}$4.63${\mu}$g/ml in the single inhalation group and 54.24${\pm}$6.87mcg/ml in the repeated at the end of 120 minutes of the exposure. The behavioral change of rats for the initial 30 minutes of the toluene inhalation showed mildly increased movement and excitement but remained calm and inhibitory behaviors after that period; more inhibitory behaviors in the single inhalation group compared with the repeated inhalation group. In open-field test, after the termination of the toluene inhalation, no difference had been statistically observed between the toluene inhalation group and the control group in ambulation, rearing, preening and grooming.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.7
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• pp.647-655
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• 2021

Job crafting refers to changes that individuals make in their work to achieve their preferences and needs. Contingent on the social exchange theory, the aim of this study is to explore the relationship between job crafting and job performance. In addition, the study examines the mediating effect of social capital in the relationship between job crafting and job performance. The data was collected from 387 employees in Vietnamese industrial enterprises through a questionnaire survey using both qualitative and quantitative methods. The information was then analyzed by explanatory factor analysis (EFA) confirmatory factor analysis (CFA) as well as structural equation modeling (SEM). The results show that all three dimensions of job crating positively affect job performance and that social capital plays a mediating role in that relationship. This study contributes to the field of human resources management, particularly job crafting, by examining different dimensions of job crafting that impacts job performance. Moreover, this is the first study to test the mediating role of social capital on the relationship between job crafting and job performance. These insights may help the organizational managers to encourage beneficial job crafting.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.8
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• pp.503-511
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• 2021

The emerging competitive environment in today's global marketplace is one where businesses no longer compete with each other as autonomous, individual firms. Global, economic, and technological development pressure forces organizations to continually enhance their performance through knowledge sharing and innovativeness. The purpose of this paper is to explore the moderating role of knowledge sharing and the mediating role of innovativeness in the relationship between transformational leadership and organizational performance. The data was collected from 389 employees in Vietnamese industrial enterprises through a questionnaire survey. The information was then analyzed by explanatory factor analysis (EFA) confirmatory factor analysis (CFA) as well as structural equation modeling (SEM). The results show that the mediating role of innovativeness and the moderating role of knowledge sharing in the relationship between transformational leadership and performance, are supported. Organizations may reap the benefits of an innovative workforce by selecting, nurturing transformational leaders. This study contributes to the field of human resources management, particularly leadership, by exploring the role of transformational leadership. Moreover, this is the first study to test the moderating role of knowledge sharing and the mediating role of innovativeness in the relationship between transformational leadership and the organizational performance.