• East Asian mathematical journal
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• v.27 no.1
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• pp.35-49
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• 2011

In this paper, we study multi-step iterative algorithm with errors and give the necessary and sufficient condition to converge to com mon fixed points for a finite family of asymptotically quasi-nonexpansive type mappings in Banach spaces. Also we have proved a strong convergence theorem to converge to common fixed points for a finite family said mappings on a nonempty compact convex subset of a uniformly convex Banach spaces. Our results extend and improve the corresponding results of [2, 4, 7, 8, 9, 10, 12, 15, 20].

• Bulletin of the Korean Mathematical Society
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• v.47 no.4
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• pp.825-837
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• 2010

In this paper, we obtain a Korovkin type approximation theorem for double sequences of positive linear operators of two variables from $H_w$ (K) to C (K) via A-statistical convergence. Also, we construct an example such that our new approximation result works but its classical case does not work. Furthermore, we study the rates of A-statistical convergence by means of the modulus of continuity.

• Journal of the Korean Society of Industry Convergence
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• v.26 no.2_2
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• pp.255-263
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• 2023

The shell and tube-type heat exchangers have been frequently used in many industrial field because of its simple structure and wide operation conditions and so on. The purpose of this study is to investigate the flow characteristics in single shell of shell and tube-type heat exchanger according to velocity and temperature of hot air released from heat exchanger simulator through numerical analysis. As the results, the temperature was decreased in almost quadratic curve from top to bottom in single shell of the shell and tube-type heat exchanger. Further the changes of pressure and velocity in outlet according to change of inlet temperature were not observed. The cost for operating the shell and tube-type heat exchanger should be compared the supply cost of hot air with that of velocity in order to make a economic decision.

• Journal of applied mathematics & informatics
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• v.17 no.1_2_3
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• pp.559-565
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• 2005

In this paper, we establish the convergence of semigroups that are strongly continuous on (0, $\infty$). By using Laplace transform theory, we show some properties of semigroups and the convergence result.

• Journal of the Korea Convergence Society
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• v.6 no.3
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• pp.1-12
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• 2015

The purpose of this study is to examine the structure of subjective cognition for first aid in persons taking first aid eduction. The perception of first aid styles were classified by using the PC QUANL program. Data were collected from March to July, 2010. As a result of the study, the cognition for first aid in persons taking first aid eduction can be classified into these four types: 'Time-oriented type', 'First responder-oriented type', 'Convergence education-oriented type', 'Lay person using-oriented type'. Therefore, in the field of first aid practice and education this study has provided practical guidelines helpful to nursing intervention and family-centered nursing by considering each character of the types centering on the relationship of lay person, and will be useful as basic data for relevant disciplines in education.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.29 no.11
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• pp.696-701
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• 2016

In this study, to increase output of road piezoelectric energy harvester, it was made into rack type in which many piezoelectric materials can be installed and load transfer device of the leverage type to transfer vehicle load was made. By paving it in the road, the output characteristics depending on vehicle load and speed were evaluated. Changing vehicle load, harvester output characteristics depending on speed changes were evaluated at the interval of 10 km/h from 10 km/h to 100 km/h. Also, by making a wireless switch and sending wireless signal with output of rack type harvester, whether to receive it was evaluated by distance. It was checked that all switches work up to front-to-back 100 m from harvester.

• ETRI Journal
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• v.38 no.1
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• pp.195-205
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• 2016

This paper presents a novel follicular unit (FU) classification method based on an angle variation of a boundary vector according to the number of hairs in several FU images. The recently developed robotic FU harvest system, ARTAS, classifies through digital imaging the FU type based on the number of hairs with defects in the contour and outline profile of the FU of interest. However, this method has a drawback in that the FU classification is inaccurate because it causes unintended defects in the outline profile of the FU. To overcome this drawback, the proposed method classifies the FU's type by the number of variation points that are calculated using an angle variation a boundary vector. The experimental results show that the proposed method is robust and accurate for various FU shapes, compared to the contour-outline profile FU classification method of the ARTAS system.

• Journal of the Korea Convergence Society
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• v.10 no.8
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• pp.283-289
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• 2019

The purpose of this study was to classify the elementary school students to latent groups according to the type of mobile phone usage and to verify the relationship with mobile phone dependency. The latent profile analysis was conducted using the first grade panel data of the elementary school in the Korea Children 's Youth Panel in 2016. The results found 3 latent classes of mobile phone usage: family and friend concentration (Type1), family concentration low level (Type2) and essential (Type3). The results of multiple regression analysis for verifying the relationship between mobile phone use type and mobile phone dependency showed a significant effect. The Type 2 showed more dependency than the Type 1, and the Type 1 showed more dependency than the Type 3. These findings provided basis for the guideline of mobile phones use and for proper intervention to prevent mobile phone dependency for elementary school students.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.13 no.2
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• pp.191-197
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• 2013

In this paper, we present the college curriculum for the acoustics and audio engineering on digital convergence environment. For these purposes, we categorized the colleges which linked on the ASA and AES websites into three types according to their characteristics such as an acoustics-oriented type, an applied-acoustics type, and a convergence-oriented type. And a basic step-by-step curriculum model for the audio acoustics is suggested based on the characteristics of the category analysis. The proposed model can be effectively used to build an acoustics and audio technology course at the domestic colleges.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.22 no.9
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• pp.614-619
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• 2010

Recently, a problem related to the thermal management in portable electronic and telecommunication devices is becoming issued. That is due to the trend of a slimness of the devices, so it is not easy to find the optimal thermal management solution for the devices. From now on, a pressed circular type cooling device has been mainly used, however the cooling device with thin thickness is becoming needed by the inner space constraint of the applications. In the present study, the silicon flat plate type cooling device with the separated vapor and liquid flow path was designed and fabricated. The normal isothermal characteristics created by vapor-liquid phase change was confirmed through the experimental study. The cooling device with 70 mm of total length showed 6.8 W of the heat transfer rate within the range of $4{\sim}5^{\circ}C/W$ of thermal resistance. In the future, it will be possible to develop the commercialized cooling device by revising the fabrication process and enhancing the thermal performance of the silicon and glass cooling device.