• Title/Summary/Keyword: Mirror Stage

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Decomposition of Surface Pressure Fluctuations on Vehicle Side Window into Incompressible/compressible Ones Using Wavenumber-frequency Analysis (파수-주파수 분석을 이용한 자동차 옆 창문 표면 압력 섭동의 비압축성/압축성 성분 분해)

  • Lee, Songjune;Cheong, Cheolung
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.26 no.7
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    • pp.765-773
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    • 2016
  • The vehicle interior noise caused by exterior fluid flow field is one of critical issues for product developers in a design stage. Especially, turbulence and vortex flow around A-pillar and side mirror affect vehicle interior noise through a side window. The reliable numerical prediction of the noise in a vehicle cabin due to exterior flow requires distinguishing between the aerodynamic (incompressible) and the acoustic (compressible) surface pressures as well as accurate computation of surface pressure due to this flow, since the transmission characteristics of incompressible and compressible pressure waves are quite different from each other. In this paper, effective signal processing technique is proposed to separate them. First, the exterior flow field is computed by applying computational aeroacoustics techniques based on the Lattice Boltzmann method. Then, the wavenumber-frequency analysis is performed for the time-space pressure signals in order to characterize pressure fluctuations on the surface of a vehicle side window. The wavenumber-frequency diagrams of the power spectral density shows clearly two distinct regions corresponding to the hydrodynamic and the acoustic components of the surface pressure fluctuations. Lastly, decomposition of surface pressure fluctuation into incompressible and compressible ones is successfully accomplished by taking the inverse Fourier transform on the wavenumber-frequency diagrams.

Growth of Nanocrystalline Diamond Films on Poly Silicon (폴리 실리콘 위에서 나노결정질 다이아몬드 박막 성장)

  • Kim, Sun Tae;Kang, Chan Hyoung
    • Journal of the Korean institute of surface engineering
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    • v.50 no.5
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    • pp.352-359
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    • 2017
  • The growth of nanocrystalline diamond films on a p-type poly silicon substrate was studied using microwave plasma chemical vapor deposition method. A 6 mm thick poly silicon plate was mirror polished and scratched in an ultrasonic bath containing slurries made of 30 cc ethanol and 1 gram of diamond powders having different sizes between 5 and 200 nm. Upon diamond deposition, the specimen scratched in a slurry with the smallest size of diamond powder exhibited the highest diamond particle density and, in turn, fastest diamond film growth rate. Diamond deposition was carried out applying different DC bias voltages (0, -50, -100, -150, -200 V) to the substrate. In the early stage of diamond deposition up to 2 h, the effect of voltage bias was not prominent probably because the diamond nucleation was retarded by ion bombardment onto the substrate. After 4 h of deposition, the film growth rate increased with the modest bias of -100 V and -150 V. With a bigger bias condition(-200 V), the growth rate decreased possibly due to the excessive ion bombardment on the substrate. The film grown under -150V bias exhibited the lowest contact angle and the highest surface roughness, which implied the most hydrophilic surface among the prepared samples. The film growth rate increased with the apparent activation energy of 21.04 kJ/mol as the deposition temperature increased in the range of $300{\sim}600^{\circ}C$.

The Ethics of the Othering in the Era of Transnationalism

  • Kim, Youngmin
    • Journal of English Language & Literature
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    • v.55 no.6
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    • pp.1013-1034
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    • 2009
  • The space of the Other assumes the space of Barthes's multiplicity and Foucault's transdiscursive position, and, therefore, aims at becoming the locus in which the speaking subject and the hearing subjects are supposed to communicate and constitute as if they were situated in the pscychoanalytic session. However, the wall of untranslatibility across language and cultures still exist there in the space of the Other in the form of trauma and aggressivity, as Lacan demonstrate perceptively through the reading of Kant avec Sade. In short, Lacan regards the moral commandment (to love one's neighbor as oneself) as the obstacle in the Freud's myth of transgression, and interprets this in terms of the emergence of the Other. Freud understands that the aggressivity in the subject's own heart was inherent in all humans, and that one's neighbor would be evil. Lacan goes beyond Freud and articulates that the aggressivity in the imaginary relation with the Other in the mirror stage insures that an evil inheres in the very being of humanity. A global phenomenon of the diasporic identities and hybridity, the phenomenon which has been represented by the complicated intermixture of terms which span from diaspora, postcolonialism, postnationalism. and transnationalism can be clarified, if they are put in the context of the ethics of Othering or becoming the Other. The ethics of Othering presupposes the situation in which the diasporic subjects encounter the lack of the cross-cultural negotiation and communication. The purpose of this paper is to demonstrate how the poetics of Other and the logic of the ethics of Othering can explain the postmodern or transmodern world which has become deterritorialized, diasporic, and transnational as well as how one can encounter the results of diasporic and postcolonial double consciousness, a consciousness which is a discursive category for multicultural or cross-cultural, focusing on the concept of liminality/interstitiality

Past and Present Viable Pavilions Remain in Architecture: Envisioning New Directions for a Better Future Research on pavilions within the history of world fairs, from the mid-19th to the 21st Century

  • Shim, Sodahm Suzanne;Lee, Yoonhie;Yoon, Chaeshin
    • Architectural research
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    • v.21 no.3
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    • pp.79-90
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    • 2019
  • The ephemeral and temporal nature of pavilions is the underlying motivation that led to the development of this paper. From the beginning of the industrial era through contemporary history, there have been many instances of architects attempting to rethink architectural design in the context of modern social, cultural, and technical imperatives. Today, the leading changes in humanity are accompanied by a revolutionary electronic digital medium. The pavilion has been in an amalgamation of architectural integration since the beginning of human history. World's Fairs/Expos have, since their establishment, served as international presentations of goods and achievements of particular nations. They became a popular stage wherein potential architectural achievements were showcased through the evocative architecture of pavilions. Due to the pavilion's "temporary nature," its coverage includes various perspectives: social, historical, geographical, post-colonial, iconographical, temporal, and ephemeral. It has also served as a receptacle due to its representational value at a given time. The pavilion has offered architectural designers, clients, and visitors a place to use their imaginations. Moreover, the architect's role in creating pavilions cannot be overestimated. Due to fact that they abound in symbolism, contemporary designs, and innovative solutions, pavilions often mirror modern mankind and plan for the next aesthetic revolutions and ideological architectural theories. To understand and appreciate architects' original intentions with their pavilions, this paper focuses on noteworthy pavilions that were created from the beginning of industrialization through the present. It explores and discusses the pavilion's characteristics, highlights the significance of its physical form as generated by a specific theme.

Investment Process of Start-up: A Case Study of LetinAR (스타트업의 초기 투자유치 프로세스: (주)레티널 사례를 바탕으로)

  • KIM, HA YOUNG;BAE, TAE JUN;WON, CHI WOON
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.14 no.6
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    • pp.119-130
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    • 2019
  • Although a well-established line of research has addressed the funding decision, the activities of investee startups to receive funding have been overlooked because prior research has been conduced from investor's point of view. In addition, funding does not result from one off decisions but from decision process with many stages. Moreover, the emphasis placed on specific investment criteria varies by different stages during the process. Therefore, understanding the initial funding of startups requires to analyze the strategic behaviors of startups throughout the entire funding decision process from first meeting with investors to funding success. This study investigates the initial funding process of startups, and the analysis is based on a case study of LetinAR one of the successful startups founded by students in South Korea. This study investigates how early start-ups were able to receive funding from startup's point of view, and the analysis is based on a case study of LetinAR, an augmented reality(AR) startup using Pin mirror technology. By adding "legitimacy building" stage that had not been addressed previously, we divided funding process into four stages: 1) legitimacy building, 2) familiarization, 3) screening, and 4) bargaining phase. We did not only analyze major criteria, but also strategic activities of startup at each stage. This study makes a contribution by helping us understand complicated process of funding and the successful strategic behavior of investor backed startups.

Current Status of the Synchrotron Small-Angle X-ray Scattering Station BL4C1 at the Pohang Accelerator Laboratory

  • Jorg Bolze;Kim, Jehan;Huang, Jung-Yun;Seungyu Rah;Youn, Hwa-Shik;Lee, Byeongdu;Shin, Tae-Joo;Moonhor Ree
    • Macromolecular Research
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    • v.10 no.1
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    • pp.2-12
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    • 2002
  • The small-angle X-ray scattering (SAXS) beamline BL4C1 at the 2.5 GeV storage ring of the Pohang Accelerator Laboratory (PAL) has been in its first you of operation since August 2000. During this first stage it could meet the basic requirements of the rapidly growing domestic SAXS user community, which has been carrying out measurements mainly on various polymer systems. The X-ray source is a bending magnet which produces white radiation with a critical energy of 5.5 keV. A synthetic double multilayer monochromator selects quasi-monochromatic radiation with a bandwidth of ca. 1.5%. This relatively low degree of monochromatization is sufficient for most SAXS measurements and allows a considerably higher flux at the sample as compared to monochromators using single crystals. Higher harmonics from the monochromator are rejected by reflection from a flat mirror, and a slit system is installed for collimation. A charge-coupled device (CCD) system, two one-dimensional photodiode arrays (PDA) and imaging plates (IP) are available its detectors. The overall performance of the beamline optics and of the detector systems has been checked using various standard samples. While the CCD and PDA detectors are well-suited for diffraction measurements, they give unsatisfactory data from weakly scattering samples, due to their high intrinsic noise. By using the IP system smooth scattering curves could be obtained in a wide dynamic range. In the second stage, stating from August 2001, the beamline will be upgraded with additional slits, focusing optics and gas-filled proportional detectors.

Theatricality of Absence: Male Identity and O'Neill's Self-reflection in Before Breakfast (부재의 연극성-『조식 전』에서 남성 정체성과 오닐의 자기반영)

  • Park, Jungman
    • Journal of English Language & Literature
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    • v.58 no.2
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    • pp.249-277
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    • 2012
  • Eugene O'Neill's one-act play Before Breakfast (1916) depicts a morning scene of a married couple who live in a slovenly flat at Greenwich Village. There is no apparent dramatic action occurring in the play. Instead, the play is full of Mrs. Rowland's incessant complaints about her husband Alfred's loafing around bars with artists friends, neglecting his role as breadwinner. An irony is that every morning she prepares breakfast for the good-for-nothing husband even in the moment of complaining. It is worth noting that Alfred is an 'unseen character' who is never directly observed by the audience but is only described by her wife. Deprived of all chances to speak and present himself on stage, he is kept in the room throughout the play. In contrast, Mrs. Rowland dominates the stage, monopolizing language and action. The audience has to listen to her, judge from her statements, and take her one-sided complaints. The accused husband, with zero chance of showing up and defending himself, has no choice but to be the sinner as the wife intends. Another irony is that the audience's feeling about the situation is quite different from what is expected. The wife's complaints are regarded to be unfair and groundless in the reason that the situation is monopolized by her. In case of the husband, in contrast, the loss of voice and presence stresses the injustice of his dead-lock situation. In other words, the 'absent' quality of Alfred works to evoke the audience's sympathy for himself and subsequently makes his presence recognized, not visually but emotionally, by the audience throughout the play. Discovered in this paradoxical moment where the spectators understand or 'see' the status of the unseen and the devoiced message is successfully conveyed to the listeners, is the theatricality of absence. Adding to the function as theatrical device, the 'unseen character' Alfred works as a device of self-reflection to mirror the author's own life. Alfred, the alter-ego of O'Neill, effectively exorcises the author's life-long feeling of guilty as the unfaithful husband and father in the unhappy first marriage, successfully evoking the audience's sympathy for himself.

The 4bit Cell Array Structure of PoRAM and A Sensing Method for Drive this Structure (PoRAM의 4bit 셀 어레이 구조와 이를 동작시키기 위한 센싱 기법)

  • Kim, Jung-Ha;Lee, Sang-Sun
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.44 no.6 s.360
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    • pp.8-18
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    • 2007
  • In this paper, a 4bit cell way structure of PoRAM and the sensing method to drive this structure are researched. PoRAM has a different operation from existing SRAM and DRAM. The operation is that when certain voltage is applied between top electrode and bottom electrode of PoRAM device we can classify the cell state by measuring cell current which is made by changing resistance of the cell. In the decoder selected by new-addressing method in the cell array, the row decoder is selected "High" and the column decoder is selected "Low" then certain current will flow to the bit-line. Because this current is detect, in order to make large enough current, the voltage sense amplifier is used. In this case, usually, 1-stage differential amplifier using current mirror is used. Furthermore, the detected value at the cell is current, so a diode connected NMOSFET, that is, a device resistor is used at the input port of the differential amplifier to converter current into voltage. Using this differential amplifier, we can classify the cell states, erase mode is "Low" and write mode is "High", by comparing the input value, Vin, that is a product of current value multiplied by resistor value with a reference voltage, Vref.

A Study on Optical Coherence Tomography System by Using the Optical Fiber (광섬유를 이용한 광영상단층촬영기 제작에 관한 연구)

  • 양승국;박양하;장원석;오상기;이석정;김기문
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.18 no.4
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    • pp.34-40
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    • 2004
  • In this paper, we have studied the OCT(Optical Coherence Tomography) system which has been advantages of high resolution, 2-D cross-sectional images, low cost and small size configuration. The characteristics of light source determine the resolution and coherence length. The light source has a commercial SLD with a central wavelength of 1,285 ill11, 35.3 nm(FWHM). The optical delay line is necessary to make equal with the optical path length to scattered light or reflected light from a sample. In order to make equal the optical path length, the stage that is attached to a reference mirror is controled by a step motor. And the interferometer is configured with the Michelson interferometer by using a single mode fiber, and the scanner can be focused on the sample by using a reference ann Also, the 2-dimension cross-sectional images were measured with scanning the transverse direction of the sample by using a step motor. After detecting the internal signal of lateral direction, a scanner is moved to obtain the cross-sectional image of 2-dimension by using step motor. A photodiode, which has high detection sensitivity and excellent noise characteristics has been used. The detected small signal has a noise and interference. After filtering and amplifying the signal, the output signal is demodulated the waveform And then, a cross-sectional image is seen through converting this signal into a digitalized signal by using an AID converter. The resolution of the sample is about 30${\mu}{\textrm}{m}$, which corresponds to the theoretical resolution. Also, the cross-sectional images of onion cells were measured in real time scheme.

PRELIMINARY FEASIBILITY STUDY OF THE SOLAR OBSERVATION PAYLOADS FOR STSAT-CLASS SATELLITES

  • Moon, Yong-Jae;Cho, Kyung-Seok;Jin, Ho;Chae, Jong-Chul;Lee, Sung-Ho;Seon, Kwang-Il;Kim, Yeon-Han;Park, Young-Deuk
    • Journal of Astronomy and Space Sciences
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    • v.21 no.4
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    • pp.329-342
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    • 2004
  • In this paper, we present preliminary feasibility studies on three types of solar observation payloads for future Korean Science and Technology Satellite (STSAT) programs. The three candidates are (1) an UV imaging telescope, (2) an UV spectrograph, and (3) an X-ray spectrometer. In the case of UV imaging telescope, the most important constraint seems to be the control stability of a satellite in order to obtain a reasonably good spatial resolution. Considering that the current pointing stability estimated from the data of the Far ultraviolet Imaging Spectrograph (FIMS) onboard the Korean STSAT-1, is around 1 arc minutes/sec, we think that it is hard to obtain a spatial resolution sufficient for scientific research by such an UV Imaging Telescope. For solar imaging missions, we realize that an image stabilization system, which is composed of a small guide telescope with limb sensor and a servo controller of secondary mirror, is quite essential for a very good pointing stability of about 0.1 arcsec. An UV spectrograph covering the solar full disk seems to be a good choice in that there is no risk due to poor pointing stability as well as that it can provide us with valuable UV spectral irradiance data valuable for studying their effects on the Earth's atmosphere and satellites. The heritage of the FIMS can be a great advantage of developing the UV spectrograph. Its main disadvantage is that two major missions are in operation or scheduled. Our preliminary investigations show that an X-ray spectrometer for the full disk Sun seems to be the best choice among the three candidates. The reasons are : (1) high temporal and spectral X-ray data are very essential for studying the acceleration process of energetic particles associated with solar flares, (2) we have a good heritage of X-ray detectors including a rocket-borne X-ray detector, (3) in the case of developing countries such as India and Czech, solar X-ray spectrometers were selected as their early stage satellite missions due to their poor pointing stabilities, and (4) there is no planned major mission after currently operating Reuven Ramaty High-Energy Solar Spectroscopic Imager (RHESSI) mission. Finally, we present a preliminary design of a solar X-ray spectrometer covering soft X-ray (2 keV) to gamma ray (10 MeV).