• Title/Summary/Keyword: strong ideal

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Gas Separation Properties of Poly(ethylene oxide) and Poly(ethylene-co-vinyl acetate) Blended Membranes (Poly(ethylene oxide)와 Poly(ethylene-co-vinyl acetate)의 혼합막에 대한 기체분리 특성)

  • Lee, Hyun Kyung;Kang, Min Ji
    • Membrane Journal
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    • v.27 no.2
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    • pp.147-153
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    • 2017
  • In this study, we investigated permeation properties of single gas ($N_2$, $O_2$, $CO_2$) through membranes composed of poly(ethylene oxide) (PEO) and poly(ethylene-co-vinyl acetate) (EVA) blend. The prepared membranes showed no new absorbance peaks, which indicate the physical blending of PEO and EVA by FT-IR analysis. SEM observation showed that the crystalline phase of PEO decreased with increasing EVA content in the PEO/EVA mixed matrix. DSC analysis showed that the crystallinity of the PEO/EVA blend membrane decreased with increasing EVA content. Gas permeation experiment was performed with various feed pressure (4~8 bar). The permeability increased in the following order: $N_2$ < $O_2$ < $CO_2$. The permeability of $CO_2$ in PEO/EVA blend membranes were increased with increasing feed pressure, However, the permeability of $N_2$ and $O_2$ were independent of feed pressure. On the other hand, the permeability of all the gases in PEO/EVA blend membranes increased with increasing amorphous EVA content in semi-crystalline PEO. In particular, the blend membrane with 40 wt% EVA showed $CO_2$ permeability of 64 Barrer and $CO_2/N_2$ ideal selectivity of 61.5. The high $CO_2$ permeability and $CO_2/N_2$ ideal selectivity are attributed to strong affinity between the polar ether groups of PEO or the polar ester groups of EVA and polar $CO_2$.

Compensation of Radiation Pattern Distortion by Mutual Coupling in the Array Antenna Using the Particle Swarm Optimization Algorithm (입자군집 최적화 알고리즘을 이용한 배열안테나의 상호결합에 의한 방사패턴 왜곡보상)

  • Kim, Jae Hee;Ahn, Chi-Hyung;Chun, Joong-Chang
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.9 no.5
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    • pp.458-464
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    • 2016
  • This paper proposes the compensation method which decreases the radiation pattern distortion caused by the mutual coupling in an array antenna. If the element distance of an array antenna decreases, the radiation pattern could be distorted by the strong mutual coupling, which changes the magnitude and phase of input signals and causes an unwanted radiation pattern. To remove the pattern distortion, compensated input signals are inserted in an array antenna. The magnitude and phase of input signals are determined by Particle Swarm Optimization (PSO) algorithm. A $4{\times}1$ dipole array antenna with omnidirectional elements is used to confirm the validity of the algorithm, where each element is placed in 0.2 wavelength to evoke the strong coupling. After input signals are optimized by PSO, it is found that the compensated radiation results in the same as the ideal case.

Angle-Resolved Photoemission Spectroscopy and Raman Spectroscopy Study on the Quasi-free Standing Epitaxial Graphene on the 4H SiC(0001) surface

  • Yang, Gwang-Eun;Park, Jun;Park, Byeong-Gyu;Kim, Hyeong-Do;Jo, Eun-Jin;Hwang, Chan-Yong;Kim, Won-Dong
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.02a
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    • pp.277-277
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    • 2013
  • The epitaxial graphene on the 4H- or 6H-SiC(0001) surface has been intensively studied due to the possibility of wafer-scale growt. However the existence of interface layer (zero layer graphene) and its influence on the upper graphene layer have been considered as one of the main obstarcles for the industrial application. Among various methods tried to overcome the strong interaction with the substrate through the interface layer, it has been proved that the hydrogen intercalation successfully passivate the Si dangling bond of the substrate and can produce the quasi-free standing epitaxial graphene (QFEG) layers on the siC(0001) surface. In this study, we report the results of the angle-resolved photoemission spectroscopy (ARPES) and Raman spectroscopy for the QFEG layers produced by ex-situ and in-situ hydrogen intercalation.From the ARPES measurement, we confirmed that the Dirac points of QFEG layers exactly coincide with the Fermi level. The band structure of QFEG layer are sustainable upon thermal heating up to 1100 K and robust against the deposition of several metals andmolecular deposition. We also investigated the strain of the QFEG layers by using Raman spectroscopy measurement. From the change of the 2D peak position of graphene Raman spectrum, we found out that unlike the strong compressive strain in the normal epitaxial graphene on the SiC(0001) surface, the strain of the QFEG layer are significantly released and almost similar to that of the mechanically exfoliated graphene on the silicon oxide substrate. These results indicated that various ideas proposed for the ideal free-standing graphene can be tested based on the QFEG graphene layers grown on the SiC(0001) surface.

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A Study on Comicality of Animation (애니메이션의 희극성(喜劇性) 연구)

  • Cho, Mil-Ra
    • Cartoon and Animation Studies
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    • s.12
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    • pp.103-119
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    • 2007
  • This study investigated the comical essence of animations and the comicality found in Korean animations focusing on the comical elements signifying the promotion of laughing and its meaning. In addition, it has been found from this study that the comical essence of animations was the laughing that expanded the recognition and awareness for the entity to be revived, by suggesting the following: 1) the fact that the laughing would be unexpected and it would stimulate the imagination of audience in unprecedented situations in which the method of creation would be unthinkable and thereby the laughing occurred would endow audience with thought, feeling and sense etc. that would not have been perceived so far; and 2) furthermore, the ideal world through grotesque expressions. Meanwhile, unlike the general preconception that animations would be considered one of the popular art forms with strong comical elements, it has been noted that there have been a very few Korean animations with strong comical elements. Besides, it has been confirmed that they have focused not on created and grotesque comicality, but on linguistic comicality based on the forms of characters or their movement itself, or humor and witty remarks.

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An Inquiry into Causal Perceptions of Cancer (암의 원인지각에 관한 탐색적 연구 -Q 방법론 적용-)

  • 김분한
    • Journal of Korean Academy of Nursing
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    • v.24 no.3
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    • pp.364-376
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    • 1994
  • This study was initiated to find the characteristic awareness of disease in Korean culture and then, with its applying to psychological nursing, to help cancer victims cope with their disease. Research period was from Dec. 1, 1989 to Aug.3, 1992. The research method, while the method of face-to-face interview with 33 cancer victims were mainly adopted, was to identify the causal perception through analyses of literature and traditional sayings deeply rooted in Korean culture. The causal perceptions were differentiated into 4 sections, which apply to 32 cancer victims with Q-sorting. Be-ing coded into grades from 1 to 9, the data were analyzed with the aid of Quanal program on PC ; in analyzing Q-factor principal component analysis method was used. The results were revealed as follows : 1. Subject victims owe their disease to 1) the omnipotent and animating powers in Shamanism rooted in Korean culture, 2) their intimate persons, i.e. their husband, wife, children, or other fellows ameng their groups. 3) victims themselves, and 4) nowhere, for they thought the disease is the struggle with their own self. 2. In Q-methodology analysis, cancer victims are categorized into 5 types. The first type, self-mastery type, consisting of 11 subjects, has the characteristic of overcoming their disease with their own strong will or by the help of the Omnipotent God, which is estimated to be the ideal type to cope with the disease. The second type, omnipotent & animating powers-dependent type, consisted of 7 subjects, who have the causal perception of traditional shamanism. The third type, intimate person-dependent type, consisted of 4, all of whom are women and whose causal perception has the characteristic of the their complains about each member of their family, espectially about their husband. The fourth type, fate-recipient type, was the com-plex form of the first and the second types. It consisted of 6 subjects, to whom cancer had meant bad fate coming on them but had to be overcome by their strong will. The fifth type, personal type, consisted of 4, whose causal perception is toward themselves personality It is hoped that the study provide the chance of developing nursing intervention to help cancer victims accept and overcome their disease as their own reality instead of attributing to anyone or any-thing else.

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Acoustic Characteristics of Underwater Noise from Uldolmok Tidal Current Pilot Power Plant (울돌목 시험조류발전소의 수중소음 특성 연구)

  • Ko, Myungkwon;Choi, Jee Woong;Yi, Jin-Hak;Jeong, Weonmu
    • The Journal of the Acoustical Society of Korea
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    • v.31 no.8
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    • pp.523-531
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    • 2012
  • Recently, as a result of increasing concern about eco-friendly power, the demand for the power stations using environmentally friendly powers such as photovoltaic energy, wind force, tidal power, and tidal current has been increasing worldwide. Among these power stations tidal current power plant requires strong current generated by the topographic characteristics of the ocean floor. Uldolmok waterway producing very strong current is an ideal location for a tidal current power generation. However the occurrence of anthropogenic underwater noise generated by the tidal current power station may affect the marine environment. Therefore, it is necessary to evaluate the noise radiated from the station and predict the range influenced by the radiated noise. In this paper, the measurements of radiated noise spectrum level by the tidal current power station are presented, and the source level per unit area is estimated. Finally, the propagation properties of the radiated noise in the Uldolmok waterway is evaluated from the model simulation using the parabolic equation method, RAM.

Parameters Affecting India Ink Artifacts on Opposed-Phase MR Images

  • Kim, Bo Ra;Ha, Dong-Ho
    • Investigative Magnetic Resonance Imaging
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    • v.23 no.4
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    • pp.341-350
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    • 2019
  • Purpose: To determine the MR parameters affecting India ink artifacts on opposed-phase chemical shift magnetic resonance (MR) imaging. Materials and Methods: The use of a female Sprague-Dawley rat was approved by our Institutional Animal Care and Use Committee. Using an iterative decomposition of water and fat with echo asymmetry and least-squares estimation (IDEAL) images, which is a modified Dixon method, axial opposed-phase images of the abdominal cavity were obtained with different MR parameters: series 1, different repetition times (TRs; 400, 2000, and 4000 ms); series 2, different echo times (TEs; 10, 50, and 100 ms); series 3, different field of views (FOVs; 6, 8, 16, and 24 cm); series 4, different echo train lengths (ETLs; 2, 4, and 8); series 5, different bandwidths (25, 50, and 85); and series 6, different slice thicknesses (1, 2, 4, 8, and 16 mm). Artifacts on opposed images obtained with different parameters were compared subjectively by two radiologists. For objective analysis, the thickness of the artifact was measured. Spearman's correlation between altered MR parameters and thicknesses of India ink artifact was obtained via objective analysis. Results: India ink artifact was increasingly apparent using shorter TE, larger FOV and ETL, and thicker slices upon subjective analysis. The objective analysis revealed a strong negative correlation between the thickness of the artifact and TE (r = -0.870, P < 0.01); however, strong positive correlations were found between FOV (r = 0.854, P < 0.01) and slice thickness (r = 0.971, P < 0.01). Conclusion: India ink artifact was thicker with shorter TE, larger FOV, and larger slice thickness.

Research on the relationship of store unit configuration and business activation of street mall - Based on case studies of street malls in Korea - (스트릿 몰(Street Mall)의 매장 배분계획과 영업활성화의 관계에 대한 연구 - 국내 스트릿 몰의 사례를 중심으로 -)

  • Woo, Seung-Hyun;Yoon, Hea-Kyung
    • Korean Institute of Interior Design Journal
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    • v.18 no.6
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    • pp.202-210
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    • 2009
  • This research was undertaken to prove the relationship between street mall activation and architectural plan design. The research methodology was established based on the analysis of data of two existing street malls in Korea (Western Dome & LaFesta) and theoretical studies of outdoor space design. The findings from this study are the following: First, building blocks with segments in every 50m or so are ideal for detailed communication between visitors and building contents. Second, the ratio of width of main corridor and building height should be less than 1 to provide intimate feel and keep visitors' attention concentrated in the facility. Third, store unit should have more storefronts to be exposed more to passers-by and lead more pedestrian traffic. Fourth, shape of store unit would rather be wide and shallow, instead of narrow and deep, to have more exposure to the central corridor. Fifth, the building block of the busiest(most expensive) area that is usually at the main entrance area of street mall should be flexible to fit more smaller units to maximize the profitability. Sixth, the main entrance of store should face the main pedestrian corridor to induce the influx of visitors. Lastly seventh, anchor tenant that has strong name recognition is usually located on basement or higher level to induce pedestrian traffic into the mall, key tenants that are strong and familiar brand names should be located at the corner of building block with spacing to attract visitors, provide even distribution of traffic, and support wayfinding, and local tenant should be located at small units along the central corridor or remainder spaces occurred from building core layout.

A Study on the Clothing of Art Nouveau and Art Deco through Cinema Costume: Focusing on The Wings of the Dove and The Great Gatsby

  • Yun, Ji-Young
    • International Journal of Costume and Fashion
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    • v.6 no.1
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    • pp.71-83
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    • 2006
  • This study is about how Art Nouveau and Art Deco clothing are represented in the costume design of film created after those periods and examines the recreation process of visual media. The costume design of The Wings of the Dove tried to reflect the mixture of fashion trends that could be seen during the times. Milly???s clothes seem to focus on recreating the special features of the 1900???s fashion trends more visually while Kate???s clothes are represented in a strong and simple way to emphasize her personality. The costumes in The Great Gatsby, tried to reinvent the 1920???s clothes in a romantic way. Daisy???s and Gatsby???s costumes were based on the aesthetics of the 1920???s clothing. but emphasized the symbolic nature of the characters to give a greater dramatic effect. By analyzing and comparing, it can be seen that, while costume design usually begin with painstaking research into the historical period in which the film is set it is often altered to highlight aspects of the story. such as the theme and the characters, in an effort to create a stronger dramatic effect. Costume design remains one of the most effective means for a director to visually express the personality and desires of a film???s characters. The ideal aim of costume design is to create something new but at the same time, remain true to the period by being grounded in accurate research.

A General Method for Error Probability Computation of UWB Systems for Indoor Multiuser Communications

  • Durisi, Giuseppe;Tarable, Alberto;Romme, Jac;Benedetto, Sergio
    • Journal of Communications and Networks
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    • v.5 no.4
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    • pp.354-364
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    • 2003
  • A general method for the evaluation of the symbol error probability (SER) of ultra wideband (UWB) systems with various kind of modulation schemes (N-PAM, M-PPM, Bi-Orthogonal), in presence of multipath channel, multiuser and strong narrowband interference, is presented. This method is shown to be able to include all the principal multiaccess techniques proposed so far for UWB, time hopping (TH), direct sequence (DS) and optical orthogonal codes (OOC). A comparison between the performance of these multiple access and modulation techniques is given, for both ideal Rake receiver and minimum mean square error (MMSE) equalizer. It is shown that for all the analyzed multiple access schemes, a Rake receiver exhibits a high error floor in presence of narrowband interference (NBI) and that the value of the error floor is in-fluenced by the spectral characteristics of the spreading code. As expected, an MMSE receiver offers better performance, representing a promising candidate for UWB systems. When the multiuser interference is dominant, all multiple access techniques exhibit similar performance under high-load conditions. If the number of users is significantly lower than the spreading factor, then DS outperforms both TH and OOC. Finally 2PPM is shown to offer better performance than the other modulation schemes in presence of multiuser interference; increasing the spreading factor is proposed as a more effective strategy for SER reduction than the use of time diversity.