• Title/Summary/Keyword: transition-edge

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Temperature Variation Corresponding to the Protection Method and Edge Distance in Near-Surface-Mounted FRP in Concrete with Fire Protection (콘크리트내 표면매립보강된 FRP의 내화단열방법과 연단거리에 따른 온도변화)

  • Lim, Jong-wook;Seo, Soo-yeon
    • Journal of the Architectural Institute of Korea Structure & Construction
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    • v.35 no.11
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    • pp.137-146
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    • 2019
  • Recently, the Near-Surface-Mounting method using Fiber reinforced polymer (FRP) has been developed and applied to the reinforcement of many concrete structural members. However, as a part of the fire resistance design, there is a lack of research related to fire insulation for the areas reinforced with FRP. In case of NSM reinforcement, there is a difference in the transferred temperature from the external surface to the groove corresponding to the location of the groove where the FRP is embedded, and the effect of this should be reflected in the fireproof insulation design. Therefore, in this study, after forming grooves for surface embedding in concrete blocks, fireproof insulation reinforcement was performed using Calcium Silicate (CS) fireproof board and an experiment to evaluate the temperature transfer was performed. By observing the temperature at these groove positions, the reduction of temperature transfer according to fireproof insulation detail was studied. As a result, when the NSM-FRP is properly fire-insulated using the CS-based fireproof board, the epoxy inside the groove does not reach its glass transition temperature until the external temperature reaches $800^{\circ}C$.

Synthesis and Characterization of the Layered Type $(C_nH_{2n+1}NH_3)_2PbCl_4$ System

  • Lee, Su Jong;Kim, Gye Ya;O, Eun Ju;Kim, Gyu Hong;Yeo, Cheol Hyeon
    • Bulletin of the Korean Chemical Society
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    • v.21 no.3
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    • pp.317-320
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    • 2000
  • Layered $K_2NiF_4$type ($C_nH_{2n+1}NH_3)_2PbCl_4$(n=6, 8 and 10) system, or alkylammonium tetrachloroplumbate compound, has been synthesized from $PbCl_2$ and $C_nH_{2n+1}NH_3Cl$ solutions under argon ambient pressure for 12hrs at $90^{\circ}C$. The crystal structure of the compound has been analyzed using X-ray powder diffaction in the range of $5^{\circ}{\leq}2{\theta}{\leq}55^{\circ}$, and all samples assigned to an orthorhombic system. Local distances of the Pb-Cl bond have been determined by Pb $L_{III}$-edge extended X-ray absorption fine structure (EXAFS) spectroscopy. The vibration modes of alkylammonium chains and the absorpton peaks of an excition have been examined by FT-IR and UV-Vis. reflectance spectra, respectively. The phase transition temperatures of the compounds have been studied by using DSC. According to the thermal analysis, two phase transition temperatures have been observed in the compositons of n=8 and 10.

A Study on ICD-11 through Mapping to KCD-8 - Focusing on the Circulatory and Respiratory System -

  • Hyun-Kyung LEE;Yoo-Kyung BOO
    • Journal of Wellbeing Management and Applied Psychology
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    • v.6 no.3
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    • pp.1-11
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    • 2023
  • Purpose: This research aims to facilitate a smooth transition from KCD-8 to ICD-11 through the study of ICD-11. Research design, data and methodology: Skilled Health Information Managers (HIMs) in Korea performed manual mapping and conducted a study of the code structure of ICD-11 chapters 11 and 12. Results: When comparing the granularity between ICD-11 and KCD-8, 58.1% of ICD-11 codes showed higher granularity, and 38.6% had similar granularity. The granularity of the circulatory system was higher than that of the respiratory system. When comparing the KCD-8 codes mapped by ICD-11 with the total 924 KCD-8 codes, it was found that about 50% of KCD-8 codes were not mapped to ICD-11. This means that 50% of diseases in the KCD-8 do not have individual codes as they did in ICD-11. Conclusions: ICD-11 demonstrated high granularity, indicating its effectiveness in describing cutting-edge medical technology in modern society. However, we also observed that some diseases were removed from KCD-8, while others were added to ICD-11. To ensure smooth statistics transition from KCD8 to ICD-11, especially for leading domestic diseases, integrated management, including the preparation of KCD-9 reflecting ICD-11 and ICD-11 training, will be necessary through the analysis of new codes and the removal of codes.

Study on stress transition mechanism by tensile and fracture characteristics of membrane material at bolting part in clamping part of membrane Structures (막구조 정착부의 볼트접합부 막재료의 신장 및 파단상태를 통한 응력전달체계에 관한 연구)

  • Kim, Hee-Kyun;Shim, Chun-Bo;Kim, Jae-Yeol
    • Journal of Korean Association for Spatial Structures
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    • v.23 no.4
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    • pp.97-105
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    • 2023
  • The membrane structure should maintain the membrane materials in tension for structural stability guaranty. The anchoring part in the membrane structure is an important part. It has the function to introduce tension into membrane materials and function to transmit stress which membrane materials receives to boundary structure such as steel frames. In this paper, it grasps anchoring system of the anchoring part in the membrane structure concerning the fracturing characteristic condition of membrane structure, and the influence which is caused to yield it designates the stress state when breaking the membrane structure which includes the anchoring part and that stress transition mechanism is elucidated as purpose. This paper follows to previous paper, does 1 axial tensile test concerning the bolting part specimen, grasp of fracturing progress of the bolting part and the edge rope and hardness of the rubber, does the appraisal in addition with the difference of bolt tightening torque. As a result, the influence which the bolt anchoring exerts on the fracturing characteristics of the membrane material in the membrane structure anchoring part is examined.

A new approach for overlay text detection from complex video scene (새로운 비디오 자막 영역 검출 기법)

  • Kim, Won-Jun;Kim, Chang-Ick
    • Journal of Broadcast Engineering
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    • v.13 no.4
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    • pp.544-553
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    • 2008
  • With the development of video editing technology, there are growing uses of overlay text inserted into video contents to provide viewers with better visual understanding. Since the content of the scene or the editor's intention can be well represented by using inserted text, it is useful for video information retrieval and indexing. Most of the previous approaches are based on low-level features, such as edge, color, and texture information. However, existing methods experience difficulties in handling texts with various contrasts or inserted in a complex background. In this paper, we propose a novel framework to localize the overlay text in a video scene. Based on our observation that there exist transient colors between inserted text and its adjacent background a transition map is generated. Then candidate regions are extracted by using the transition map and overlay text is finally determined based on the density of state in each candidate. The proposed method is robust to color, size, position, style, and contrast of overlay text. It is also language free. Text region update between frames is also exploited to reduce the processing time. Experiments are performed on diverse videos to confirm the efficiency of the proposed method.

Growth and defect structures of undoped and heavily MgO-doped LiNbO3 single crystals (Undoped and heavily MgO-doped $LiNbO_3$ 결정의 성장 및 결함구조)

  • 김상수
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.9 no.5
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    • pp.447-453
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    • 1999
  • Congruent $LiNbO_3$ crystals with doped Mg and codoped with Mn or Fe were grown by the Czochralski method. It is known that the physical properties of $LiNbO_3$ depend strongly on the addition of Mg and transition metals. This is established by studying the following properties; XRD patterns, the phase transition temperature, energy of the fundamental absorption edge, the shape of the absorption band of the $OH^-$ vibration and lines of the ESR of $Fe^{3+},\; Mn^{2+}$. The position of the UV absorption edge and the shape and peak point of the absorption band of the $OH^-$ vibrational band changed monotonously up to a critical concentration of $Mg^{2+}$ ions. The mechanism of the incorporation of Mg ions changes at this concentration. The transition temperature was estimated by measuring the dielectric temperature behavior up to $1230^{\circ}C$ in a frequency range of 100Hz to 10MHz. EPR of $Mn^{2+}\;and\; Fe^{3+}$ ions were employed to investigated the Mg doping effects in the $LiNbO_3$ crystal. The increase of linewidths and the asymmetry of signals were observed in all crystals. New signals of $Fe^{3+}$ arising from the new centers were observed I the heavily Mg-doped crystals.

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Depth-map Preprocessing Algorithm Using Two Step Boundary Detection for Boundary Noise Removal (경계 잡음 제거를 위한 2단계 경계 탐색 기반의 깊이지도 전처리 알고리즘)

  • Pak, Young-Gil;Kim, Jun-Ho;Lee, Si-Woong
    • The Journal of the Korea Contents Association
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    • v.14 no.12
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    • pp.555-564
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    • 2014
  • The boundary noise in image syntheses using DIBR consists of noisy pixels that are separated from foreground objects into background region. It is generated mainly by edge misalignment between the reference image and depth map or blurred edge in the reference image. Since hole areas are generally filled with neighboring pixels, boundary noise adjacent to the hole is the main cause of quality degradation in synthesized images. To solve this problem, a new boundary noise removal algorithm using a preprocessing of the depth map is proposed in this paper. The most common way to eliminate boundary noise caused by boundary misalignment is to modify depth map so that the boundary of the depth map can be matched to that of the reference image. Most conventional methods, however, show poor performances of boundary detection especially in blurred edge, because they are based on a simple boundary search algorithm which exploits signal gradient. In the proposed method, a two-step hierarchical approach for boundary detection is adopted which enables effective boundary detection between the transition and background regions. Experimental results show that the proposed method outperforms conventional ones subjectively and objectively.

The electronic structure of the ion-beam-mixed Pt-Cu alloys by XPS and XANES

  • Lim, K.Y.;Lee, Y.S.;Chung, Y.D.;Lee, K.M.;Jeon, Y.;Whang, C.N.
    • Proceedings of the Korean Vacuum Society Conference
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    • 1998.02a
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    • pp.133-133
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    • 1998
  • In the thin film alloy formation of the transition metals ion-beam-mixing technique forms a metastable structure which cannot be found in the arc-melted metal alloys. Sppecifically it is well known that the studies about the electronic structure of ion-beam-mixed alloys pprovide the useful information in understanding the metastable structures in the metal alloy. We studied the electronic change in the ion-beam-mixed ppt-Ct alloys by XppS and XANES. These analysis tools pprovide us information about the charge transfer in the valence band of intermetallic bonding. The multi-layered films were depposited on the SiO2 substrate by the sequential electron beam evapporation at a ppressure of less than 5$\times$10-7 Torr. These compprise of 4 ppairs of ppt and Cu layers where thicknesses of each layer were varied in order to change the alloy compposition. Ion-beam-mixing pprocess was carried out with 80 keV Ae+ ions with a dose of $1.5\times$ 1016 Ar+/cm2 at room tempperature. The core and valence level energy shift in these system were investigated by x-ray pphotoelectron sppectroscoppy(XppS) pphotoelectrons were excited by monochromatized Al K a(1486.6 eV) The ppass energy of the hemisppherical analyzer was 23.5 eV. Core-level binding energies were calibrated with the Fermi level edge. ppt L3-edge and Cu K-edge XANES sppectra were measured with the flourescence mode detector at the 3C1 beam line of the ppLS (ppohang light source). By using the change of White line(WL) area of the each metal sites and the core level shift we can obtain the information about the electrons pparticippating in the intermetallic bonding of the ion-beam-mixed alloys.

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Effect of Relative Position of Vane and Blade on Heat/Mass Transfer Characteristics on Stationary Turbine Blade Surface (베인과 블레이드 사이의 상대위치 변화에 따른 터빈 블레이드 표면에서의 열/물질전달 특성)

  • Rhee, Dong-Ho;Cho, Hyung Hee
    • 유체기계공업학회:학술대회논문집
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    • 2004.12a
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    • pp.140-150
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    • 2004
  • In this study, the effect of relative position of the blade for the fixed vane has been investigated on blade surface heat transfer. The experiments were conducted in a low speed stationary annular cascade, and heat transfer of blade was examined for six positions within a pitch. Turbine test section has one stage composed of sixteen guide vanes and blades. The chord length of the tested blade is 150 mm and the mean tip clearance of the blade having flat tip is about $2.5\%$ of the blade chord. For the detailed mass transfer measurements on the blade surfaces, a naphthalene sublimation technique was used. The inlet flow Reynolds number is fixed to $1.5{\times}10^5$. Complex heat transfer characteristics are observed on the blade surface due to various flow characteristics, such as separation bubble, relaminarization, transition to turbulence and leakage vortices. The distributions of velocity and turbulence intensity change significantly with the relative position due to the blockage effect of the blade. This causes the variation of heat transfer patterns on the blade surface. The results show that the flow near the leading edge get highly disturbed and deflected toward the either side of the blade when the blade leading edge is positioned close to the trailing edge of the vane. Therefore, separation bubble disappears on the pressure side and overall heat transfer on the relaminarization region is increased. But, due to reduced tip gap flow at the upstream region, the effect of leakage flow on the upstream region of the blade surface is weakened. Thus, the heat transfer characteristics significantly change with the blade positions.

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Comparative Study of Tetrahydrothiophene and Thiophene Self Assembled Monolayers on Au(111): Structure and Molecular Orientation

  • Ito, Eisuke;Hara, Masahiko;Kanai, Kaname;Ouchi, Yukio;Seki, Kazuhiko;Noh, Jaegeun
    • Bulletin of the Korean Chemical Society
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    • v.30 no.8
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    • pp.1755-1759
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    • 2009
  • Surface structure and molecular orientation of self-assembled monolayers (SAMs) formed by the spontaneous adsorption of tetrahydrothiophene (THT) and thiophene (TP) on Au(111) were investigated by means of scanning tunneling microscopy (STM) and carbon K-edge near edge X-ray absorption fine structure (NEXAFS) spectroscopy. STM imaging revealed that THT SAMs have a commensurate (3 ${\times}\;2\sqrt[]{3}$) structure containing structural defects in ordered domains, whereas TP SAMs are composed of randomly adsorbed domains and paired molecular row domains that can be described as an incommensurate packing structure. The NEXAFS spectroscopy study showed that the average tilt angle of the aliphatic THT ring and $\pi$-conjugated TP ring in the SAMs were calculated to be about $30^o\;and\;40^o$, respectively, from the surface normal. It was also observed that the $\pi$* transition peak in the NEXAFS spectrum of the TP SAMs is very weak, suggesting that a strong interaction between $\pi$-electrons and the Au surface arises during the self-assembly of TP molecules. In this study, we have clearly demonstrated that the surface structure and adsorption orientation of organic SAMs on Au(111) are strongly influenced by whether the cyclic ring is saturated or unsaturated.