• Title/Summary/Keyword: MaaS

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Photocurrent of CdSe nanocrystals on singlewalled carbon nanotube-field effect transistor

  • Jeong, Seung-Yol;Lim, Seung-Chu;Lee, Young-Hee
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2010.03b
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    • pp.40-40
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    • 2010
  • CdSe nanocrystals (NCs) have been decorated on singlewalled carbon nanotubes (SWCNTs) by combining a method of chemically modified substrate along with gate-bias control. CdSe/ZnS core/shell quantum dots were negatively charged by adding mercaptoacetic acid (MAA). The silicon oxide substrate was decorated by octadecyltrichlorosilane (OTS) and converted to hydrophobic surface. The negatively charged CdSe NCs were adsorbed on the SWCNT surface by applying the negative gate bias. The selective adsorption of CdSe quantum dots on SWCNTs was confirmed by confocal laser scanning microscope. The measured photocurrent clearly demonstrates that CdSe NCs decorated SWCNT can be used for photodetector and solar cell that are operable over a wide range of wavelengths.

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A Study on the Acquisition Policy of Military Affairs Administration Manuscripts (병무행정 매뉴스크립트 수집정책 연구)

  • Lee, Jung-Hee
    • Journal of Korean Society of Archives and Records Management
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    • v.9 no.1
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    • pp.5-32
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    • 2009
  • The purpose of this paper is to establish the manuscripts acquisition policy on the Military Affairs Administration focused on historical, cultural, and informational value. The collection of manuscripts is part of 40 anniversary of MMA to build the MMA archives and to establish acquisition policy. To achieve this objective, we proposed the MAA's archival mission statement, collection coverage, collection methods and procedures.

Attack Trends by Malware Type (악성코드 유형별 공격동향)

  • JongDo-Kim;Hoon-Jae Lee;Young-Sil Lee
    • Proceedings of the Korean Society of Computer Information Conference
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    • 2023.07a
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    • pp.195-196
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    • 2023
  • 코로나19로 인한 비대면 사회의 발전으로 일반인들의 IT이용이 증가하였고, 우크라이나 전쟁이 장기화됨에 따라 주요 기반시설 및 글로벌 기업을 대상으로 대규모 사이버 공격 시도가 증가할 것으로 전망된다. 사이버 공격에는 대부분 악성코드가 활용이 된다. 본 논문에서는 2022년 및 2023년 1분기 중 사이버공격에 많이 활용된 악성코드들의 특징과 동향을 파악한다.

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Analysis of domestic and foreign future automobile research trends based on topic modeling (토픽모델링 기반의 국내외 미래 자동차 연구동향 비교 분석: CASE 키워드 중심으로)

  • Jeong, Ho Jeong;Kim, Keun-Wook;Kim, Na-Gyeong;Chang, Won-Jun;Jeong, Won-Oong;Park, Dae-Yeong
    • Journal of Digital Convergence
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    • v.20 no.5
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    • pp.463-476
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    • 2022
  • After industrialization in the past, the automobile industry has continued to grow centered on internal combustion engines, but is facing a major change with the recent 4th industrial revolution. Most companies are preparing for the transition to electric vehicles and autonomous driving. Therefore, in this study, topic modeling was performed based on LDA algorithm by collecting 4,002 domestic papers and 68,372 overseas papers that contain keywords related to CASE (Connectivity, Autonomous, Sharing, Electrification), which represent future automobile trends. As a result of the analysis, it was found that domestic research mainly focuses on macroscopic aspects such as traffic infrastructure, urban traffic efficiency, and traffic policy. Through this, the government's technical support for MaaS (Mobility-as-a-Service) is required in the domestic shared car sector, and the need for data opening by means of transportation was presented. It is judged that these analysis results can be used as basic data for the future automobile industry.

Enzyme-Conjugated CdSe/ZnS Quantum Dot Biosensors for Glucose Detection

  • Kim, Gang-Il;Sung, Yun-Mo
    • Korean Journal of Materials Research
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    • v.19 no.1
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    • pp.44-49
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    • 2009
  • Conjugated nanocrystals using CdSe/ZnS core/shell nanocrystal quantum dots modified by organic linkers and glucose oxidase (GOx) were prepared for use as biosensors. The trioctylphophine oxide (TOPO)-capped QDs were first modified to give them water-solubility by terminal carboxyl groups that were bonded to the amino groups of GOx through an EDC/NHS coupling reaction. As the glucose concentration increased, the photoluminescence intensity was enhanced linearly due to the electron transfer during the enzymatic reaction. The UV-visible spectra of the as-prepared QDs are identical to that of QDs-MAA. This shows that these QDs do not become agglomerated during ligand exchanges. A photoluminescence (PL) spectroscopic study showed that the PL intensity of the QDs-GOx bioconjugates was increased in the presence of glucose. These glucose sensors showed linearity up to approximately 15 mM and became gradually saturated above 15 mM because the excess glucose did not affect the enzymatic oxidation reaction past that amount. These biosensors show highly sensitive variation in terms of their photoluminescence depending on the glucose concentration.

Fabrication and Characterization of 70 nm T-gate AlGaAs/InGaAs/GaAs metamorphic HEMT Device (70 nm T-게이트를 갖는 InGaAs/InAlAs/GaAs metamorphic HEMT 소자의 제작 및 특성)

  • 김성찬;임병옥;백태종;고백석;신동훈;이진구
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.41 no.9
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    • pp.19-24
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    • 2004
  • In this paper, we have demonstrated the fabrication of a 70 nm foot print of the T-gate by using a positive resist ZEP520/P(MMA-MAA)/PMMA trilayer by double exposure method without a thin dielectric supporting layer on the substrate. The device performance was characterized by DC and RF measurement. The fabricated 70 nm InGaAs/InAlAs MHEMTS with 70 ${\mu}{\textrm}{m}$ unit gate width and 2 fingers showed good DC and RF characteristics of Idss, max =228.6 mA/mm, gm =645 mS/mm, and fT =255 GHz, respectively.

The Effects of Functional Monomers on the Synthesis andPhysical Properties of Solution Type Quaternary Polymer Acrylic Pressure-Sensitive Adhesives (관능성 단량체 종류에 따른 4원 용액형 아크릴계 점착제의 합성과 물성에 관한 연구)

  • Kim, Nam-Seok;Kim, Sung-Hoon
    • Journal of the Korean Applied Science and Technology
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    • v.25 no.4
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    • pp.525-532
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    • 2008
  • To prepare a solution type acrylic pressure-sensitive adhesive, quarter polymers were synthesized from butyl acrylate(BA), 2-ethylhexylacrylate(2-EHA) as a base monomer, methyl methacrylate(MMA) as a comonomer, each of methacrylic acid(MAA), acrylic acid(AA) as a functional monomer. Acrylic solution type pressure-sensitive adhesives(PSA's) of isocyanate derivative crosslinking PSA's were prepared by crosslinking of BEMM, BEMA with toluene-2,4-diisocyanate. The structure of adhesive was identified by FT-IR. The viscosity was measured by using Brookfield DV-III and molecular weight was measured by using gel permeation chromatography. The physical properties of polyethylene film coated with BEMMT, BEMAT were measured as a function of the concentration. As the result, BEMMT(0.6, 0.8), BEMAT(0.6) showed peel adhesion of $160{\sim}180\;g_f$/25 mm width and shear adhesion of more than 24 hours, and tackiness of $4/32{\sim}6/32$ which was relevant to commercial usage.

Blood Pressure Simulation using an Arterial Pressure-volume Model

  • Yoon, Sang-Hwa;Kim, Jae-Hyung;Ye, Soo-Young;Kim, Cheol-Han;Jeon, Gye-Rok
    • Transactions on Electrical and Electronic Materials
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    • v.9 no.1
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    • pp.38-43
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    • 2008
  • Using an arterial pressure-volume (APV) model, we performed an analysis of the conventional blood pressure estimation method using an oscillometric sphygmomanometer with computer simulation. Traditionally, the maximum amplitude algorithm (MAA) has been applied to the oscillation waveforms of the APV model to obtain the mean arterial pressure and the characteristic ratio. The estimation of mean arterial pressure and characteristic ratio was significantly affected by the shape of the blood pressure waveforms and the cutoff frequency of high-pass filter (HPF) circuitry. Experimental errors result from these effects when estimating blood pressure. To determine an algorithm independent of the influence of waveform shapes and parameters of HPF, the volume oscillation of the APV model and the phase shift of the oscillation with fast Fourier transform (FFT) were tested while increasing the cuff pressure from 1 mmHg to 200 mmHg (1 mmHg/s). The phase shift between ranges of volume oscillation was then only observed between the systolic and the diastolic blood pressures. The same results were obtained from simulations performed on two different arterial blood pressure waveforms and one hyperthermia waveform.

Seismic performance of a building base-isolated by TFP susceptible to pound with a surrounding moat wall

  • Movahhed, Ataallah Sadeghi;Zardari, Saeid;Sadoglu, Erol
    • Earthquakes and Structures
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    • v.23 no.1
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    • pp.87-100
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    • 2022
  • Limiting the displacement of seismic isolators causes a pounding phenomenon under severe earthquakes. Therefore, the ASCE 7-16 has provided minimum criteria for the design of the isolated building. In this research the seismic response of isolated buildings by Triple Friction Pendulum Isolator (TFPI) under the impact, expected, and unexpected mass eccentricity was evaluated. Also, the effect of different design parameters on the seismic behavior of structural and nonstructural elements was found. For this, a special steel moment frame structure with a surrounding moat wall was designed according to the criteria, by considering different response modification coefficients (RI), and 20% mass eccentricity in one direction. Then, different values of these parameters and the damping of the base isolation were evaluated. The results show that the structural elements have acceptable behavior after impact, but the nonstructural components are placed in a moderate damage range after impact and the used improved methods could not ameliorate the level of damage. The reduction in the RI and the enhancement of the isolator's damping are beneficial up to a certain point for improving the seismic response after impact. The moat wall reduces torque and maximum absolute acceleration (MAA) due to unexpected enhancement of mass eccentricity. However, drifts of some stories increase. Also, the difference between the response of story drift by expected and unexpected mass eccentricity is less. This indicates that the minimum requirement displacement according to ASCE 7-16 criteria lead to acceptable results under the unexpected enhancement of mass eccentricity.

Radioisotope Perfusion Lung Scanning in Takayasu's Arteritis (Takayasu 동맥염에서 폐관류스캔에 관한 연구)

  • Park, Seok-Gun;Bom, Hee-Seung;Oh, Yeon-Sang;Han, Jin-Suk;Chung, June-Key;Choi, Sung-Jae;Kim, Byung-Kook;Lee, Jung-Sang;Lee, Young-Woo;Koh, Chang-Soon;Lee, Mun-Ho
    • The Korean Journal of Nuclear Medicine
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    • v.20 no.2
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    • pp.73-78
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    • 1986
  • Of 18 patients with Takayasu's arteritis who underwent $^{99m}Tc-MAA$ (macroaggregated albumin) perfusion luing scanning, 9 (50%) showed perfusion defects. Chest X-rays of them were nonspecific. One patient underwent $^{99m}Tc-DTPA$ radio aerosol inhalation lung scanning simultaneously, which revealed normal. So routine screening radioisotope perfusion lung scanning is helpful to evaluate pulmonary arterial involnmement in Takayasu's arteritis patients. And Takayasu's arteritis should be included in differential diagnosis of pulmonary embolism.

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