• Korean Chemical Engineering Research
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• v.53 no.6
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• pp.723-729
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• 2015

The moment analysis of cyclic adenosine monophosphate (cAMP) was performed using chromatograms that were obtained with the pulse input method from an octadecyl silica (ODS) high-performance liquid chromatography (HPLC) column. The general rate (GR) model was employed to calculate the first absolute moment and the second central moment. Three important coefficients for moment analysis, which are molecular diffusivity ($D_m$), external mass transfer coefficient ($k_f$), and intra-particle diffusivity ($D_e$), were estimated by the Wilke-Chang equation, Wilson-Geankoplis equation, and comparing van Deemter equation to theoretical plate number equation, respectively. Experiments were conducted by various conditions of flow rates, methanol volume ratio of the mobile phase, and solute concentration. After the moment analysis, results were organized by van Deemter plots. Also van Deemter coefficients were compared each other to effect $H_{ax}$, $H_f$, and $H_d$ on height equivalent to a theoretical plate (HETP, $H_{total}$). The value of intraparticle diffusion ($H_d$) was the primary factor which makes for HETP whereas external mass transfer ($H_f$) was disregardable factor.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.10C
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• pp.967-983
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• 2003

In wireless spread-spectrum communication systems utilizing PN (pseudo noise) sequences, a variety of noise sources from the channel affect the data reception performance. Among them, in this paper we are concerned with the narrowband interference that may arise from the use of the spectral bands overlapped by the existing narrowband users or the intentional jammers as in military communication. The effect of this interference can be reduced to some extent at the receiver with the PN demodulation by processing gain. It is known, however, that when the interferers are strong, the reduction cannot be sufficient and thereby requiring the extra use of narrowband interference cancellers (NIC's) at the receivers. A class of adaptive NIC's are studied here based on different two cost functions. One is the chip mean-squared error (MSE) computed prior to the PN demodulation and used in the conventional cancellers. Since thses conventional cancellers should be operated at the chip rate, the computational requirements are enormous. The other is the symbol MSE computed after the PN demodulation in which case the weights of the NIC's can be updated at a lot lower symbol rate. To compare the performance of these NIC's, we derive a common measure of performance, i.e., the symbol MSE after the PN demodulation. The analytical results are verified by computer simulation. As a result, it is shown that the cancellation capability of the symbol-rate NIC's are similar or better than the conventional one while the computational complexity can be reduced a lot.

• Journal of the Korean Applied Science and Technology
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• v.37 no.6
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• pp.1659-1668
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• 2020

The purpose of this study is to analyze the effect of the application of hand washing education program for the children with intellectual disability on hand washing frequency and methods during COVID-19 Pandemic. Subjects were 14 children with intellectual disability and they participated in the program using visual video materials. Hand washing education program was consisted of introduction, theory education, and practice and it performed 2 times a week, total 16 sessions during 8 weeks. Hand washing theory education was consisted about the importance and application of hand washing, proper hand washing steps and methods, use of hand washing tools, use of hand sanitizers including characteristics, and prevention of skin damage from hand washing. Hand washing assessment was used by hand washing frequence and methods observation report. Hand washing frequency was measured by the hand washing frequency during the daily routine and it was analyzed by the items divided into day and month units. Hand washing methods was measured by the items divided into use of hand washing tools, time, areas, drying methods after hand washing. As the results, after hand washing education program, the hand washing frequence was increased and hand washing methods were improved. Hand washing is much important as a active method to prevent the infection during the COVID-19 Pandemic. Thus, based on this findings, the application of hand washing education program should be considered to increase the hand washing frequency and improve the hand washing methods of the children with intellectual disability.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.4B
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• pp.335-344
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• 2006

In this study, sequential mixing model (SMM) was proposed based on the Taylor's theory which can be summarized as the fact that longitudinal advection and transverse diffusion occur independently and then the balance between the longitudinal shear and transverse mixing maintains. The numerical simulation of the model were performed for cases of different mixing time and transverse velocity distribution, and the results were compared with the solutions of 1-D longitudinal dispersion model (1-D LDM) and 2-D advection-dispersion model (2-D ADM). As a result it was confirmed that SMM embodies the Taylor's theory well. By the comparison between SMM and 2-D ADM, the relationship between the mixing time and the transverse diffusion coefficient was evaluated, and thus SMM can integrate 2-D ADM model as well as 1-D LDM model and be an explanatory model which can represents the shear flow dispersion in a visible way. In this study, the predicting equation of the longitudinal dispersion coefficient was developed by fitting the simulation results of SMM to the solution of 1-D LDM. The verification of the proposed equation was performed by the application to the 38 sets of field data. The proposed equation can predict the longitudinal dispersion coefficient within reliable accuracy, especially for the river with small width-to-depth ratio.

• Journal of Digital Convergence
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• v.10 no.8
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• pp.21-28
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• 2012

The study aims to explore industrial and firms' strategic factors affecting diffusion of digital convergence by studying major global IPTV markets. Market and firm variables are selected using the Industrial Organization's SCP approach. Data for the variables are collected from global 31 IPTV operators representing 20 countries. The analysis indicates that the penetration of broadband Internet and the market share of a dominant player in the Pay TV positively affect the penetration of the IPTV service, whereas the penetration of Pay TV, ARPU, firms' strategy and resource do not have influence on its penetration. The study is the cross-country analysis and contributes to the media study by exploring the relationship between market variables and the development of convergent media. Consequently, the study is expected to help policy makers tailor their digital policy for local environment.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.13 no.1
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• pp.235-241
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• 2013

This article examines the Internet fandom culture of YouTube and Facebook and Twitter for Korea Wave Fandom. This article the principle of shared network connection and re-mediated and looked at in terms of the spread and the value passed. Useful field of view which korea wave look forward to continue to release and Challenges. At the same time, Korea wave fandom optimized to analyze and understand the fundamental principles of the SNS, the new media and the spread of the wave, the need arises. Korea Wave fandom connection value granted, through the process of tracking. Watch for them through the propagation and spread of Korean culture and virtuous principles. Korea Wave fandom research this article in the future for fandom korea wave and dig into the more fundamental principles of deductive help understand expected.

• The Journal of Small Business Innovation
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• v.19 no.2
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• pp.17-36
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• 2016

The current paper examines the role of the identity of entrepreneurs in the emergence and evolution of a new organizational form by empirically analyzing the evolution of eBook publishers in Korea from 1996 to 2011. Drawing on the recently developed identity-based theory of organizational form in the organizational ecology literature, we test hypotheses on the effects of focused and diffused organizational identities on organizational founding in an emergent organizational population. The results of our empirical analysis that tested three hypotheses about a positive relationship between focused identity and form emergenceand negative relationships between diffused (horizontal and vertical) identity and form emergence largely supported the argument of identity-based entrepreneurship. General implications are discussed.

• Transactions of the Korean hydrogen and new energy society
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• v.10 no.1
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• pp.9-17
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• 1999

The hydriding and dehydriding kinetics were studied for a Mg-25wt.%Ni mixture which has the most excellent hydrogen-storage characteristics among many mechanically-alloyed mixtures. The hydriding and dehydriding rates were measured and the rate-controlling steps were determined by comparing the hydriding and dehydriding rates with the theoretical rate equations. The rate-controlling step in the hydriding reaction is the Knudsen flow and the ordinary gaseous diffusion of hydrogen molecules through interparticle channels, cracks, etc. in the various ranges of weight percentage of absorbed hydrogen $H_a$ below $H_a$=4.0. In the $H_a$ range 4.0 < $H_a{\leq}4.25$, the diffusion of hydrogen atoms through the growing hydride layer is considered the rate-controlling step. The rate-controlling step in the dehydriding reaction is the Knudsen flow and the ordinary gaseous diffusion of hydrogen molecules for all the ranges of weight percentage of desorbed hydrogen $H_d$.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.1
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• pp.22-33
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• 2005

In this paper, an efficient signal interference control technique to improve the high convergence speed of LMS algorithms is introduced in the adaptive transversal filter of DS/SS. The convergence characteristics of the proposed algorithm, whose coefficients are multiply adapted in a symbol time period by recycling the received data, is analyzed to prove theoretically the improvement of high convergence speed. According as the step-size parameter ${\mu}$ is increased, the rate of convergence of the algorithm is controlled. Also, an increase in the stop-size parameter ${\mu}$ has the effect of reducing the variation in the experimentally computed learning curve. Increasing the eigenvalue spread has the effect of controlling which is downed the rate of convergence of the adaptive equalizer. Increasing the steady-state value of the average squared error, proposed algorithm also demonstrate the superiority of signal interference control to the filter algorithm increasing convergence speed by (B+1) times due to the data-recycling LMS technique.

• Archives of design research
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• v.16 no.2
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• pp.121-130
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• 2003

The diffusion expressive power means the flexibility of which creative power test spheres(fluency, originality) by Torrance is ability making the considerations, thoughts and concepts to the meaningful symbolic change. This study is willing to develop and improve program toward the diffusion expressive power and is to testify training effect of the students are majoring design with the object. The training programs composed of six levels which is based on the theory of Eskild Tjalve. And the parameters of each levels are element, function, number, arrangement, form geometric, size and have to practice 2 weeks at once by 12 weeks. For successful measuring the effective results of this study, 40 undergraduate junior students in the department of design are grouped to excercise with experimental pilot group and regulated group. The standard type of creative paper is used to evaluate the results of student's training. This study give proof that creative power of the experimental pilot and under training group is higher than the regulated and under comparison group at in the conclusion.