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A Comparative Study on the Subject of Exhibition Spaces Designed by F.L. Wright, Le Corbusier, & Mies van der Rohe (라이트(wright), 꼬르뷔제(Corbusier), 미스(Mies)의 전시공간구성 특성 비교연구)

  • 서수경
    • Korean Institute of Interior Design Journal
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    • no.21
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    • pp.89-93
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    • 1999
  • A museum architecture has been developed as important representation of a specific period in architectural history. Modern concept of museum architecture has started by Karl Fredrich van Schinkel(1781-1841) through das Altes Museum(1823-1830) back in early 20th century and it continues to be the model for museum architecture for over 30 years. By middle of the 20th century, the movement of redefining new model for the new era on the subject of museum architecture was developed. This development was lead by the three masters of the modern architecture at the time. F.L. Wright, Corbusier, Mies and they were responsible and very active in creating new concepts. Their works in museum design became the prototype and they tried hard to make sure their new concepts to be the stepping stone for further development. This study is to compare the three different museums designed by those masters of the modern architecture, particularly on the issue of the exhibition spaces. The purpose of the study will be focused on the point of interior architecture such as the matters of layout and design characteristics of the exhibition spaces. And it will reveal the impact made by those masters on the advanced development of the current generations of museum designers as well as to describe the prototype of exhibition space. The analyzation was done on FLW's Guggenheim Museum in New York, Corbusier's the National Museum of Western Art in Tokyo, and Mies' Die Neue National Galerie in Berliv. Comparable materials were collected through site visits and reference documents from various publications. It will be ideal if this study can be used for further development in new museum design in this country.

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Water vapor in high-mass star-forming regions and PDRs: the Herschel/HIFI view

  • Choi, Yunhee;van der Tak, Floris F.S.;van Dishoeck, Ewine F.;Bergin, Edwin A.
    • The Bulletin of The Korean Astronomical Society
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    • v.40 no.2
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    • pp.42.2-43
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    • 2015
  • Massive stars play a major role in the interstellar energy budget and the shaping of the galactic environment. The water molecule is thought to be a sensitive tracer of physical conditions and dynamics in star-forming regions because of its large abundance variations between hot and cold regions. Herschel/HIFI allows us to observe the multiple rotational transitions of H2O including the ground-state levels, and its isotopologues toward high-mass star-forming regions in different evolutionary stages. Photodissociation regions (PDRs) are also targeted to investigate the distribution of water and its chemistry. We present line profiles and maps of H2O using data from two guaranteed-time key programs "Water In Star-forming regions with Herschel" and "Herschel observations of EXtra-Ordinary Sources". We analyze the temperature and density structures using LTE and non-LTE methods. We also estimate turbulent and expansion velocities, and abundance of water in the inner and outer envelopes using the 1D radiative transfer code. Around high-mass protostars we find H2O abundances of ~10-8-10-9 for the outer envelope and ~10-4-10-5 for the inner envelope, and expansion and turbulent velocities range from 1.0 km s-1 to 2.0 km s-1. The abundances and kinematic parameters of the sources do not show clear trends with evolutionary indicators. The Herschel/HIFI mapping observations of H2O toward the Orion Bar PDR show that H2O emission peaks between the shielded dense gas and the radicals position, in agreement with the theoretical and the observational PDR structure. The derived H2O abundance is ~10-7 and peaks at the depth of AV ~8 mag from the ionization front. Together with the low ortho-to-para ratio of H2O (~1) presented by Choi et al. (2014), our results show that the chemistry of water in the Orion Bar is dominated by photodesorption and photodissociation.

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Optical Probing of Electronic Interaction between Graphene and Hexagonal Boron Nitride (hBN)

  • Ahn, Gwanghyun;Kim, Hye Ri;Ko, Taeg Yeoung;Choi, Kyoungjun;Watanabe, Kenji;Taniguchi, Takashi;Hong, Byung Hee;Ryu, Sunmin
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.02a
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    • pp.213-213
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    • 2013
  • Even weak van der Waals (vdW) adhesion between two-dimensional solids may perturbtheir various materials properties owing to their low dimensionality. Although the electronic structure of graphene has been predicted to be modified by the vdW interaction with other materials, its optical characterization has not been successful. In this report, we demonstrate that Raman spectroscopy can be utilized to detect a few % decrease in the Fermi velocity ($v_F$) of graphene caused by the vdW interaction with underlying hexagonal boron nitride (hBN). Our study also establishes Raman spectroscopic analysis which enables separation of the effects by the vdW interaction from those by mechanical strain or extra charge carriers. The analysis reveals that spectral features of graphene on hBN are mainly affected by change in vF and mechanical strain, but not by charge doping unlike graphene supported on $SiO_2$ substrates. Graphene on hBN was also found to be less susceptible to thermally induced hole doping.

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Die Problematik auf gesetzliche Terminologie und gewerbliche Nutzung von Drohne (드론의 현행 법적 정의와 상업적 운용에 따른 문제점)

  • Kim, Sung-Mi
    • The Korean Journal of Air & Space Law and Policy
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    • v.33 no.1
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    • pp.3-43
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    • 2018
  • Auf die ganze Welt macht unbemannte $Flugger{\ddot{a}}te$(sog.Drohnen) in vielen Bereichen rasch Fortschritte und Anwendungen gezeigt. Nachdem ferngesteuerte Drohnen $urspr{\ddot{u}}nglich$ $prim{\ddot{a}}r$ $f{\ddot{u}}r$ $milit{\ddot{a}}rische$ Zwecke entwickelt wurden, $erh{\ddot{o}}cht$ sich derzeit ihre zivile Nutzung sowohl im Freizeit- als auch im Dienstleistungsbereich(Paketdrohnen, Drohnen-taxi) stetig. Mit der vermehrten Drohnennutzung steigen allerdings auch die damit verbundenen Risiken und Herausforderungen. In Zusammenhang damit stellt sich dann die Frage, ob $gegenw{\ddot{a}}rtige$ Vorschriften im Bereich von Luftrecht zurecht gekommen sind. Es sieht sich gerade der zwei Schwerpunkt $gegen{\ddot{u}}ber$. Erstens kann $Passagierebef{\ddot{o}}rderung$ mit unbemanntem Luftfahrzeug(mehr als 150kg) im $gegenw{\ddot{a}}ritigen$ Luftrecht keine Anwendung finden. Denn das kor. Luftsicherheitsgesetz und sein Durchsetzungsverordnung definieren die Terminologie von unbemannten Luftfahrzeugen und unbemannten $Flugger{\ddot{a}}te$ als "wenn eine Person nicht an Bord geht und ferngesteuert wird". Also soll Drohne nach dieser gesetzlichen Definition nur "ohne Person" geflogen werden. Das besagt ohne Piloten und ohne Passagiere. Zweitens ist unbemannte $Flugger{\ddot{a}}te$(weniger als 150kg) nicht auf Handelsgesetz anzuwenden, auf das ${\ddot{u}}ber$ Anspruchsgrundlage und Zurechnungsnorm des gewerblichen Luftverkehr geregelt ist. Der unbemannte Luftfahrzeuglieferdienst bringt nicht nur die Gefahr einer $Besch{\ddot{a}}digung$ des Frachtguts mit sich, sondern auch die Gefahr von $Bodensch{\ddot{a}}den$ durch Dritte. Gemäß ${\S}$ 896 des Handelsgesetzes ist aber die Anwendung von unbemannte $Flugger{\ddot{a}}te$(weniger als 150kg) $hierf{\ddot{u}}r$ begrenzt, weil unbemannt $Flugger{\ddot{a}}te$ $einschl{\ddot{a}}gig$ in Ultralight $Flugger{\ddot{a}}t$ ist, die im Handelsgesetz ausschließlich besteht. Technische Fortschritt und die dadurch $erm{\ddot{o}}glichten$ kommerziellen Anwendungen werden die Nachfrage nach unbemannter $Flugger{\ddot{a}}te$ wecken. Die Umsetzung der $bez{\ddot{u}}glichen$ Vorschriften sollte auch diese Entwicklung aktiv begleitet und $fr{\ddot{u}}hzeitig$ kommuniziert und erarbeitet werden, damit Hersteller und Nutzer $fr{\ddot{u}}hzeitig$ Planungssicherheit haben.

Synthesis and Structural Characterization of Benzene-sorbed Cd2+-Y(FAU) Zeolite (벤젠이 흡착된 Cd2+-Y(FAU) 제올라이트의 합성 및 구조연구)

  • Moon, Dae Jun;Suh, Jeong-Min;Park, Jong Sam;Choi, Sik Young;Lim, Woo Taik
    • Journal of the Mineralogical Society of Korea
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    • v.30 no.2
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    • pp.45-57
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    • 2017
  • Two single crystals of fully dehydrated $Cd^{2+}$-exchanged zeolites Y were prepared by the exchange of ${\mid}Na_{75}{\mid}[Si_{117}Al_{75}O_{384}]-FAU$ ($Na_{75}-Y$, Si/Al = 1.56) with aqueous $0.05M\;Cd(NO_3)_2$ (pH = 3.65) at 294 K, followed by vacuum dehydration at 723 K (crystal 1) and a second crystal, similarly prepared, was exposed to zeolitically dried benzene for 72 hours at 294 K and evacuated (crystal 2). Their structures were determined crystallographically using synchrotron X-rays and were refined to the final error indices using $F_o$>$4{\sigma}(F_o)$ of $R_1/wR_2=0.040/0.121$ and 0.052/0.168, respectively. In crystal $1({\mid}Cd_{36}H_3{\mid}[Si_{117}Al_{75}O_{384}]-FAU)$, $Cd^{2+}$ ions primarily occupy sites I and II, with additional $Cd^{2+}$ ions at sites I', II', and a second site II. In crystal $2({\mid}Cd_{35}(C_6H_6)_{24}H_5{\mid}[Si_{117}Al_{75}O_{384}]-FAU)$, $Cd^{2+}$ ions occupy five crystallographic sites. The 24 benzene molecules are found at two distinct positions within the supercages. The 17 benzene molecules are found on the 3-fold axes in the supercages where each interacts facially with one of site IIa $Cd^{2+}$ ions. The remaining 7 benzene molecules lie on the planes of the 12-rings where each is stabilized by multiple weak electrostatic and van der Waals interactions with framework oxygens.

A Study on Stress and Coping Methods of Mothers of Children with Brain Disease (뇌질환아 어머니의 스트레스와 대처방법)

  • 윤정희;조결자
    • Journal of Korean Academy of Nursing
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    • v.24 no.3
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    • pp.389-412
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    • 1994
  • This study was done to investigate stress and coping methods of mothers with brain disease children. The subjects for this study were obtained by taking a sample of mothers with brain disease children hospitalized in neurosurgery ward of K medical center in Seoul from Nov. 20, 1992 to Mar. 10, 1993. The collected date were analized by S.P.S.S. program(frequency, percentage, mean, t-test, ANOVA, Pearson Correlation). The results of the study were as follow. 1. The mean of the degree of mothers' stress was 3.681. Of the stress categories, illness treatment (4.216) was highest, and the next were in order of ill-ness status and prognosis(4.154) , family relation-ships and personal roles(3.202), interpersonal relationships(2.916). 2. The mean of the degree of mothers' coping method was 2.930. Of the coping method categories, communication with medical team or parents in similar situations(3.332) was highest, and the next were in or-der of family cooperation and optimistic thought about the situation(3.241), reforcement of self esteem and maintenance of psychological stability(2.538). 3. There was not seen a stastically significant correlation between stress factors and coping methods of mothers. But with categories, the higher the stress to illness status and prognosis was, the hight coping methods' degree of communication with medical team or parents in similar situations was shown a positive correlation, if not high (r=.2776, P=.046) . And the higher the stress to illness treatment was, the higher coping methods' degree of communication with medical team or parents in simial situations was shown a positive correlation, if not high (r=.2727, P=.049). 4. With the difference of stress according to mothers' general characteristics, religion and monthly income shew a statically significant difference. The mothers' group who have a religion shew the higher degree of stress(t=-3.17, P=.003), The group who get the most income shew highest degree of stress (F=.4693, P=.0156). With the difference of coping according to mothers' general characteristics, the most support-ing person, satisfaction with husbands and mothers' own health status shew a statistically significant difference. The group who get the most support from parents-in-law(F=3.7508, P=.013), the group who are much satisfied with husband(F=3.589, P=.016), and the group whose health status are good(F=3.3675, P=.046), shew the highest coping degree. 5. There were no significant difference in degree of stress and coping by children's characteristics The significance of the study will be concluded as follows. 1. Investigating the stress factors, which mothers are perceiving, it will be utilized as the basic materials of nursing plan so as to reduce the stress of mothers. 2. In searching for the ways of mothers' more helpful coping methods, it shows the necessity of the active nursing intervention for the mothers in the process of coping with their stress. That is, the nurse should serve the earnest nursing as counselor, supporter, educator, and information - provider. 3. Recogning mothers as well as children with brain disease as a client, the nurse will be able to help the mother, who is taking care of the children, cope with the stress situation well, and to make a contribution to the recovery, rehabilitation, and health of the children and to the enhancement of the family' health.

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Use of Ergonomic Measures Related to Musculoskeletal Complaints among Construction Workers: A 2-year Follow-up Study

  • Boschman, Julitta S.;Frings-Dresen, Monique H.W.;van der Molen, Henk F.
    • Safety and Health at Work
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    • v.6 no.2
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    • pp.90-96
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    • 2015
  • Background: The physical work demands of construction work can be reduced using ergonomic measures. The aim of this study was to evaluate the use of ergonomic measures related to musculoskeletal disorders (MSDs) among construction workers. Methods: A questionnaire was sent at baseline and 2 years later to 1,130 construction workers. We established (1) the proportion of workers reporting an increase in their use of ergonomic measures, (2) the proportion of workers reporting a decrease in MSDs, (3) the relative risk for an increase in the use of ergonomic measures and a decrease in MSDs, and (4) workers' knowledge and opinions about the use of ergonomic measures. Results: At follow-up, response rate was 63% (713/1,130). The proportion of workers using ergonomic measures for vertical transport increased (34%, 144/419, p < 0.01); for measures regarding horizontal transport and the positioning of materials, no change was reported. The proportion of workers reporting shoulder complaints decreased (28%, 176/638, p = 0.02). A relationship between the use of ergonomic measures and MSDs was not found; 83% (581/704) of the workers indicated having sufficient knowledge about ergonomic measures. Lightening the physical load was reported to be the main reason for using them. Conclusion: Only the use of ergonomic measures for vertical transport increased over a 2-year period. No relationship between the use of ergonomic measures and MSDs was found. Strategies aimed at improving the availability of ergonomic equipment complemented with individualized advice and training in using them might be the required next steps to increase the use of ergonomic measures.

Diffusion Length Measurement of the Triplet Exciton in PHOLEDs by using Double Quantum Well Structure

  • Park, Won-Hyeok
    • Proceedings of the Korean Vacuum Society Conference
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    • 2016.02a
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    • pp.225-225
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    • 2016
  • PHOLED devices which have the structure of ITO/HAT-CN(5nm)/NPB(50nm)/EML(47nm)/TPBi(10nm)/Alq3(20nm)/LiF(0.8nm)/Al(100nm) are fabricated to investigate the diffusion length of the triplet exciton by using double-quantum-well(DQE) EML structure. To fabricate DQW structures, Ir(ppy)3(2% wt) and Ir(btp)2(8% wt) are used as green and red emission zones, respectively. In DQW structured EML, as shown in Fig. 1, 1nm thick layers of green and red emission zones are located middle of the EML, and the distance between these wells(x) is changed from 0nm to 10nm. As shown in Fig. 2, the emission spectra from DQW PHOLED devices are changed with different x. The intensity of the green emission(520nm) is decreased when x is decreased, and it goes to near zero when x=0nm. This behavior can be identified as the diffusion of the triplet excitons from Ir(ppy)3 to Ir(btp)2 by the Dexter energy transfer(DET). From the external quantum efficiency(EQE) of the red emission, as shown in Fig. 3, the diffusion length of the triplet excitons can be determined by the equation of DET rate, R=A Exp(-2RDA/L), where RDA is donor-acceptor distance and L is the sum of the van der Wals radii. As a result, the measured data of the red EQEs with different x are identified to theoretical result from the equation of DET rate(Fig. 4). From this results, we could confirm that the diffusion length of the triplet excitons can be determined by using DQW structure and this method is very useful to investigate the behavior of the excitons in PHOLEDs.

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Characteristics of ZnO:Al thin films deposited with differentworking pressures (증착 압력에 따른 ZnO:Al 박막의 특성)

  • Kim, Seong-Yeon;Sin, Beom-Gi;Kim, Du-Su;Choe, Yun-Seong;Park, Gang-Il;An, Gyeong-Jun;Myeong, Jae-Min
    • Proceedings of the Materials Research Society of Korea Conference
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    • 2009.11a
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    • pp.49.2-49.2
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    • 2009
  • 투명전극은 디스플레이, 태양전지와 같은 광전자 소자에 필수적이며, 지금까지 개발된 재료 중에는 ITO가 가장 투명하면서 전기전도도가 높고 생산성도 좋기 때문에 투명전극의 재료로 사용하고 있다. ITO는 낮은 비저항(${\sim}10^{-4}{\Omega}cm$) 과 높은 투과율 (~85 %), 상대적으로 넓은 밴드갭 에너지 (3.5 eV) 의특성과 같이 뛰어난 전기적 광학적 특성에 반해서 높은 원자재 가격, 불안정한 공급량 등으로 인한 문제점이꾸준히 제기되고 있다. 따라서 $In_2O_3$:Sn, ZnO:Al, ZnO:Ga, ZnO:F, ZnO:B, TiN 등과 같은 물질들로대체하려는 연구가 활발하게 진행되고 있다. ZnO는 ITO보다원자재의 수급이 원활하기 때문에 원가가 낮으며, 상대적으로 낮은 온도에서도 제작이 가능하다. 또한 화학적으로 안정적이므로 ZnO에 Al, Ga 등의 3족 원소를 도핑함으로써 낮은 비저항의 박막 제작이 가능하고, ITO 박막과 비교하여 etching이 쉬우며 기판과의 접착성이 좋으며, sputtering 공정시 plasma 분위기에서의 안정성이 뛰어나고 박막증착율이 높기 때문에 투명전극으로 적합한 재료이다. 본 연구에서는 cylindrical type의 Aldoping된 ZnO single target을 사용하여 박막 증착 압력의 변화를 주어 유리기판 위에 DC sputtering을 하였다. Fieldemission scanning electron microscope (FESEM)을 통해 ZnO:Al 박막의 표면의 형상과 두께를 확인하였으며, X-ray diffraction (XRD) 분석을 통해 박막의 결정학적 특성을 관찰하였다. 투명전극용 물질로서 ZnO:Al 박막의 적합성 여부를 확인하기 위하여 Van der Pauw 방법을 이용하여 박막의 비저항, 전자 이동도, 캐리어 농도를 측정하였으며, 박막의 기계적 성질 및 표면 접착성을 확인하기 위하여 nano-indentaion 분석을 하였다. 또한 UV-vis spectrophotometer를 이용하여 ZnO:Al 박막의 투과율을 분석하여 투명전극으로의 응용 가능성을 확인하였다.

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Application of Pulsed Laser Deposition Method for ZnO Thin Film Growth and Optical Properties (ZnO 박막 성장과 광학적 특성 분석을 위한 펄스 레이저증착(PLD)방법 적용)

  • Hong Kwang Joon;Kim Jae Youl
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.14 no.2
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    • pp.33-41
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    • 2005
  • ZnO epilayer was synthesized by the pulsed laser deposition(PLD) process on Al$_2$O$_3$ subsorte after irradiating the surface of ZnO sintered pellet by ArF(193nm) excimer laser. The epilayers of ZnO were achieved on sapphire(A1203) substrate at the 境mperature of 400$^{circ}$C. The crystalline structure of epilayer was investigated by the Photoluminescence and double crystal X-ray diffraction(DCXD). The carrier density and mobility of ZnO epilayer measure with Hall effect by van der Pauw mothod are $8.27\times$1016cm$^{-3}$ and 299 cm$^{2}$/V$\cdot$s at 293 K respectively, The temperature dependence of the energy band gap of the ZnO obtained from the absorption spectra was well described by the Varshni's relation, E$_g$(T)= 3.3973 eV - ($2.69\times$ 10$^{-4}$ eV/K)T$^{2}$/(T + 463K). After the as-grown ZnO epilayer was annealed in Zn atmospheres, oxygen and vaccum the origin of point defects of ZnO atmospheres has been investigated by the photoluminescence(PL) at 10K. The native defects of V$_{Zn}$, V$_{O}$, Zn$_{int}$, and O$_{int}$ obtained by PL measurements were classified as a donor or acceptor type. In addition we concluded that the heat-treatment in the oxygen atmosphere converted ZnO thin films to an optical p-type. Also, we confirmed that vacuum in ZnO/Al$_2$O$_3$ did not firm the native defects because vacuum in ZnO thin films existed in the form of stable bonds.