• Journal of the Korean Chemical Society
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• v.30 no.3
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• pp.273-281
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• 1986

This study is focused on the correct measurement of the equations for the determination of the impedance parameters-the differential capacity of the double layer $C_d$, solution resistance $R_Q$, transfer resitance $R_i$, and adsorption pseudcapacity $C_{\phi}$/ The application of only an imaginary part of complex function of ${\omega}$ at the sinusoidal steady state indicates the following equations of total impedance: at low frequency $|Z_{LF}|=1/{\omega}_1\;C_{\phi}\;{\sqrt{1+{{\omega}_1}^2/{\omega}^2}$, at high frequency $|Z_{HF}|={\omega}_2/({\omega}_1{\omega}_3C{\phi})({\omega}^2+{{\omega}_2}^2)\;{\sqrt{{({\omega}^2+{\omega}_2{\omega}_3)}^2+{({\omega}_2{\omega}-{\omega_3{\omega})^2}}$. The values of the total impedance of cell, phase angle, and cell current that are necessary for the calculations of impedance parameters were experimentally measured from 200 to 6000Hz for the following supporting electrolytes, 0.5M $Na_2SO_4$, 1M NaCl, 19.373% sea water, 1M HCl, 1M $KNO_3$ and for $10^{-2}M$ KI and 60mM DBNA (Di-iso-Butylnitrosoamine) in these supporting electrolytes. The derived equations in this study shows that the values of impedance parameters of $C_d,\;C_{\phi},\;R_i\;and\;R_Q\;are\;15{\sim}40\;{\mu}F/cm^2,\;162{\sim}758\;{\mu}F/cm^2\;11.5{\sim}57.6\;ohm{\cdot}cm^2\;and\;0.5{\times}10^{-2}{\sim}4.1{\times}10^{-2}\;ohm{\cdot}cm^2$ respectively.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.12 no.3
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• pp.103-113
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• 2013

Shock wave model describes the propagation speed of kinematic waves in traffic flow. It was first presented by Lighthill and Whitham and has been deployed to solve many traffic problems. A recent paper pointed out that there are some traffic situations in which shock waves are not observable in the field, whereas the model predicts the existence of waves. The paper attempted to identify how such a counterintuitive conclusion results from the L-W model, and resolved the problem by deriving a new asymptotical shock wave model. Although the asymptotical model successfully eliminated the paradox of the L-W model, the validation of the new model is confined within the realm of the deceleration flow situation since the model was derived under such constraint. The purpose of this paper is to derive the remaining counter asymptotical shock wave model for acceleration traffic flow. For this, the vehicle trajectories in a time-space diagram modified to accommodate the continuously increased speed at every instant in such a way that the relationship between the spacing from the preceding vehicle and the speed of the following vehicle strictly follows Greenshield's model. To verify the validity of the suggested model, it was initially implemented to a constant flow where no shock wave exists, and the results showed that there exists no imaginary shock wave in a homogeneous flow. Numerical applications of the new model showed that the shock wave speeds of the asymptotical model for the acceleration flow tend to lean far toward the forward direction consistently. This means that the asymptotical models performs in a systematically different way for acceleration and for declaration flows. Since the output difference among the models is so distinct and systematic, further study on identifying which model is more applicable to an empirical site is recommended.

• The Journal of Korean Academic Society of Nursing Education
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• v.5 no.1
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• pp.58-71
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• 1999

Nursing process is an essential part for nursing practice. Nursing faculty members must focus on the clinical application for students and try to identify the possible problems that students might face in the fields. The purpose of this study is to examine the actual condition of nursing process education in curricula and to investigate the response of students in clinical experience of nursing process. From 462 students in the 6 associate programs(ADN) and the 6 baccalaureate programs (BSN) data was collected by questionnaire. The results were as followed. 1. Seven programs (58.3%) opened the nursing process in mainly sophomore (BSN) or freshman(ADN). If not opened, the nursing process was taught at the major subjects(espcially fundamental nursing or adult nursing). 2. All Students responded they we supposed to use nursing process in preparing the case report. The majority(94.6%) used NANDA lists for nursing diagnosis and 55.7% of subjects consulted the Korean terms by KNA when translating. The tutors for nursing process in clinical settings were the professor in charge of the subject (68.6) or clinical instructors (48.1%) , assistants(34%). 3. The problems in clinical application that students experienced consisted of 17 items and the mean was 2.27. The biggest problem was 'the lack of the model for RN of applying the nursing process in clinical settings'(2.97). Next the big problem was 'the lack of the competency for implementing the established nursing plans'(2.69). All items were significantly different according to the level of educational programs(ADN or BSN). ADN students had more problems in applying the each step of nursing process and BSN students perceived the NANDA as a guidance of nursing diagnosis and the inconsistency of advices from several instructors or practicum to be mere problematic. 4. The mean of merits after application of nursing process was relatively fair (2.82). The best merit was 'they can identify nursing problems more exactly'(3.07). The second high merit was 'they can study the rational of nursing action' (3.03). BSN than ADN and the subjects of second year than of one year in clinical experience perceived the use of nursing process to be better. Based on this results we need to enforce the application of nursing diagnosis in the class. The use of sample cases can be the efficient method. Students can identify the possible health problems for patient from the cases in imaginary world and discuss them each other. Also we can use the discussion session after practice every other day or as needed. All this is on the good interaction between tutor and student. We must consider to have enough time for student to seize the essence of the nursing process.

• Journal of the Korean Geographical Society
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• v.42 no.5
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• pp.710-727
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• 2007

This paper suggests an inquiry into the characteristics and implications of urbanscapes produced by Internet cafes, widely called PC Bangs in Korea, and their effects on the motions and boundaries of human bodies as cyborgs which exist in between actual and virtual spaces or between human and machine spaces in PC Bangs. The paper, which is organised into two main sections, first investigates the streetscapes of PC Bangs as electronic architectural spaces and suggests the urban electronic space of PC Bangs in terms of hypertext space. Then, it looks at the effects of PC Bangs on human bodies which exist as human-machine hybrids or cyborgs in PC Bangs. The paradoxical socio-spatial characteristics of PC Bangs as third, liminal or hybrid spaces between actual and virtual spaces or between human and machine spaces can be explained as follows. Firstly, there appear both nomadic and sedentary landscapes in that people in PC Bangs move in virtual spaces on the one hand, and are static in actual spaces on the other hand. Secondly, both open and closed spaces are shaped in that although PC Bangs act as open or public electronic spaces, they involve invisible social boundaries, forming the gendered space of masculinism. Thirdly, the boundaries of the human body are extended and are shrunk at the same time in that while the sensory boundaries of the body in PC Bangs are extended through electronic networks, its social boundaries are shrunk through the imaginary space of solipsism. Thus and finally, PC Bangs can be characterised not only as social spaces entailing embodied and gendered landscapes, but also as non-places involving the cyborg landscapes of human-machine connections.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.10
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• pp.96-106
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• 2014

Previous academic research on FPGA tools has relied on simple imaginary models for the targeting architecture. As the first step to overcome such restriction, the issues on analytic placement and legalization which are applied to commercial FPGAs have been brought up, and several techniques to remedy them are presented, and evaluated. First of all, the center of gravity of the placed cells may be far displaced from the center of the chip during analytic placement. A function is proposed to be added to the objective function for minimizing this displacement. And then, the density map is expanded into multiple layers to accurately calculate the density distribution for each of the cell types. Early fixation is also proposed for the memory blocks which can be placed at limited sites in small numbers. Since two flip-flops share control pins in a slice, a compatibility constraint is introduced during legalization. Pre-packing compatible flip-flops is proposed as a proactive step. The proposed techniques are implemented on the K-FPGA fabric evaluation framework in which commercial architectures can be precisely modeled, and modified for enhancement, and validated on twelve industrial strength examples. The placement results show that the proposed techniques have reduced the wire length by 22%, and the slice usage by 5% on average. This research is expected to be a development basis of the optimization CAD tools for new as well as the state-of-the-art FPGA architectures.

• The Journal of the Korea Contents Association
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• v.15 no.1
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• pp.64-73
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• 2015

Describing the filmography of Yong-ho KIM simply in a few sentences is considered nearly impossible. For the last 20 years and longer, KIM has been building up his career energetically as he never lets himself obsessed with any particular boundaries or areas but work on everything from paper advertisements to art galleries, advertising photographs and pure photographs. The Photolanguage personally mentioned by Yong-ho KIM himself is to visualize this imaginary story in a form of photograph, which one would come up with before shooting. When it comes to the advertising photographs, since they are used basically to sell products, they are considered rather temporary, and in addition, they photograph the products mostly under these bright lights with colorful backgrounds behind. However, Yong-ho KIM was recognized for presenting very much different work as he went even beyond these old stereotypes of the advertising photographs. The advertising photographs processed by KIM do more than merely introducing details or functions of some products, but they deliver these values and cultures that consumers can enjoy and gain through these original stories about the products. Of several pieces of KIM's work, this advertisement on Hyundai Card named was invited to an exhibition by a private gallery after the work was exposed through various media. The work was even purchased, and that was something that had not happened before in the history of the relevant field. When a photograph is purchased, it makes the photograph recognized for its value to be possessed, and when a photograph is displayed, it, again, makes the photograph win recognition as an art work. This thesis discusses the Photolanguage found in the works of Yong-ho KIM, one of the most well-known advertising photographers in South Korea. The research inquiries that have been analyzed in the body of the thesis, therefore, are the photographs and language in the digital era, the story-telling advertisements and these works by Yong-ho KIM.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.7 no.3
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• pp.13-21
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• 1987

The object of this study was to evaluate the management alternatives with respect to the attainable water quality and total cost(construction+O & M cost) in order to devise a reasonable water quality management system. Joong Ryang-cheon stream located Seoul, Korea was taken as the study area, and dissolved oxygen concentration as the water quality index. Water quality simulation model QUAL2E and linear programming optimization technique were used for scientific and rational analyses. It was assumed that the improvement of water quality could be obtained by the treatment of major point sources where imaginary treatment plants were constructed. And by this, the relationship between total cost of the treatment plants and the stepwise improvement of water quality was studied. The result showed that 3.5mg/l of DO(=dissolved oxygen) level at best could be attained in Joong Ryang-cheon stream during summer. When the DO standard was set 3.0mg/l in the severely polluted regions, more than 5.0mg/l of DO level can be achieved by the construction of 4 treatment plants. Also, the cost comparisons showed that the uniform treatment method is economically inefficient(\$24.8{\times}10^8$) in comparison with the least cost method(\$22.9{\times}10^8$), and there is little difference between the least cost method and the the zoned treatment method(\$23.0{\times}10^8$) that is regarded as more equitable, which shows the characteristics of this basin.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.37 no.2
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• pp.197-204
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• 2013

A method was developed for analyzing the radiation heat transfer from the duct burner flame to the heat exchanger in a heat recovery steam generator (HRSG) in order to supplement the existing thermal design process. The burner flame and the heat exchanger were considered to be imaginary planes, and the flame temperature, surface, and emissivity were simplified using an engineering approach. Three analysis cases in which the duct burner position and fuel were changed were considered. The calculated flame radiative heat transfer and local flux on the heating surface were compared with those of 3-atomic gas radiation and convection. In all analysis cases, heat transfer by 3-atomic gas radiation was very small. The ratio of the flame radiative heat transfer to the convection heat transfer on the heating surface was estimated to be as high as 8-41%. Moreover, the local heat flux on the heating surface centerline was dominated by flame radiative heat flux.

• Journal of the Korean Magnetics Society
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• v.15 no.3
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• pp.202-206
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• 2005

The present investigation provides an electromagnetic radiation absorptive composition which comprises silver-coated ferrite microspheres dispersed in silicon rubber matrix for the aim of thin microwave absorber in GHz frequencies. Ni-Zn ferrite spheres with $50{\mu}m$ size in average were prepared by spray-drying and sintering at $1130^{\circ}C$. Conductive silver layer was plated on ferrite spheres by electroless plating. Conductive Ni-Zn ferrite sphere with uniform silver layer were obtained in the concentration of 10 g/L $AgNO_3$ per 20 g ferrite spheres. For this powder, electrical resistance is reduced as low as $10^{-2}\~10^{-3}\;\Omega$. The most sensitive material parameters with silver plating is real and imaginary parts of complex permittivity. The conductive Ni-Zn ferrite spheres have large values of dielectric constant. Due to this high dielectric constant of microspheres, matching thickness is reduced to as low as 2 mm at the frequency of 7 GHz, which is much thinner than conventional ferrite absorbers.

• Geophysics and Geophysical Exploration
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• v.7 no.2
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• pp.136-147
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• 2004

In this study, the characteristics of magnetotelluric (MT) responses due to a three-dimensional (3-D) body are analyzed with 3-D numerical modeling. The first model for the analysis consists of a single isolated conductive body embedded in a resistive homogeneous half-space. The second model has an additional conductive overburden while the other conditions remain the same as the first one. The analysis of apparent resistivities shows well that the 3-D effects are dominant over some frequency range for the first model. Two mechanisms, current channeling and induction, for secondary electric fields due to the conductive body are analyzed at various frequencies: at high frequencies induction is more dominant than channeling, while at low frequencies channeling is more dominant than induction. Tippers have a strong relation to the position of anomalous body and the real and imaginary parts of induction vector also indicate the position of anomalous body. off-line conductive anomaly sometimes causes severe problem in 2-D interpretation. In such case, induction vector analysis can give information on the existence and location of the anomalous body. Each parameter of the second model shows similar responses as those of the first model. The only difference is that the magnitude of all parameters is decreased and that the domain showing the 3-D effects becomes narrower. As shown in this study, the analysis of 3-D effects provides a useful and effective means to understand the 3-D subsurface structure and to interpret MT survey data.