• Title/Summary/Keyword: Spin Test

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The study on the impacts of the foundation and management of the Innopolis start-ups focusing on the entrepreneurial intention of researchers (연구자의 창업의지를 중심으로 살펴본 연구소기업 설립.운영의 효과)

  • Lee, Seong-Sang
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.9 no.1
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    • pp.69-77
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    • 2014
  • Innopolis start-ups belong to the category of the research-based spin-offs, but in the meantime, has characteristics that separate them from the research-based spin-offs in terms of the process of technology commercialization. This study aims to assess the impacts of the foundation and management of the Innopolis start-ups in terms of expansion of entrepreneurship through entrepreneurial intention of researchers and economic achievements. A data set from 22 Innopolis start-ups and 200 researchers in 14 PRIs through door-to-door interviews and surveys is studied. Main findings are as follows: First, the foundation of the Innopolis start-up has a positive and strong impact on expansion of entrepreneurship through entrepreneurial intention of researchers. Second, technology transfer performance of researchers turns out to be major factor that affects entrepreneurial intention. Third, expansion of entrepreneurship, along with economic achievements characterized by sales, job creation and R&D investment, is a positive effect of the foundation and management of the Innopolis start-ups. The results of this paper provide an opportunity to test whether Innopolis start-up's strength in technology commercialization can be applied to actual management of the Innopolis startup and to examine the general direction in which the foundation and management of the Innopolis start-ups is heading.

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Study on the Spin Valve Giant Magnetoresistance With a New Mn-Ir-Pt Antife rromagnetic Material (Mn-Ir-Pt 새로운 반강자성체를 사용한 스핀밸브 거대자기저항에 관한 연구)

  • 서수정;윤성용;김장현;전동민;김윤식;이두현
    • Journal of the Korean Magnetics Society
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    • v.11 no.4
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    • pp.141-145
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    • 2001
  • The Mn$\_$80/Ir$\_$18.1/Pt$\_$1.9/ exchange bias layers (EBLs), which have a small amounts of Pt, exhibit a high value of H$\_$ex/. The Si/Ni-Fe/Mn$\_$80/Ir$\_$18.1/Pt$\_$1.9/ EBL shows the largest H$\_$ex/ of 187 Oe, which is equivalent to a exchange energy (J$\_$ex/) of 0.146 erg/cm$^2$. Mn$\_$80/Ir$\_$18.1/Pt$\_$1.9/ EBLS are estimated to have blocking temperature of about 250 $\^{C}$, which is higher than those of Mn-Ir EBLs and Mn-Ir-Pt EBLs with higher Pt contents. This result implies that a little addition of Pt element promotes thermal stability in the Mn-Ir-Pt EBLs. The chemical stability of Mn-Ir-Pt EBLs was characterized by potentiodynamic test, which was performed in 0.001 M NaCl solution. The current density of Mn-Ir-Pt films was gradually reduced with increasing Pt content. The present results indicate that the Mn-Ir-Pt with a small amount of Pt is suitable for an antiferromagnetic material for a reliable spin valve giant magnetoresistance device.

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Clinical Usefulness of Arterial Spin Labeling Perfusion MR Imaging in Acute Ischemic Stroke (급성 허혈성 뇌경색 환자에서 동맥스핀표지 관류자기공명영상의 유용성)

  • Oh, Keun-Taek;Jung, Hong-Ryang;Lim, Cheong-Hwan;Cho, Young-Ki;Ha, Bon-Chul;Hong, Doung-Hee
    • Journal of radiological science and technology
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    • v.34 no.4
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    • pp.323-331
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    • 2011
  • We evaluated clinical usefulness of Arterial spin labeling perfusion MR imaging on the acute ischemic cerebral infarction patients through this study. We compared 22 patients who were done with DSC imaging and ASL imaging in admitted emergency room with acute ischemic cerebral infarction, with 36 normal comparison persons (DSC image on 21persons, ASL images on 15persons). Siemens Magnetom Verio 3.0T with 12 channel head coil was used for this study. DSC image obtained 4 maps(rCBV, rCBF, rMTT, TTP) through post-processing. For qualitative analysis we compared the area of lesion macro-diagonal with the size of diffusion weighted MR image for rMTT, TTP, rCBF, rCBV, ASL maps. For Quantitative analysis we analyzed significant correlations between less than 3 cm infarction group and normal comparison group using mean relative value of flowing image with Mann-Whitney U test. TTP(95.5%) and rCBF(95.5%) maps showed high recognition rate in qualitative analysis for >3cm infarction group. The rCBF and rCBV map tests were highly related with final stage stroke areas. Mean relative value of infarction group showed a significant correlations in quantitative analysis(p<0.05). As a conclusion, arterial spin labeling image showed high lesion recognition rate in the >3cm infarction group. Mean relative values in quantitative evaluation were used for reference data. If we do more sustainable researches, ASL image will be useful for an early diagnosis of cerebral infarction, determination of the range of ischemic pneumbra and effective treatments.

인공위성 반작용휠의 미소진동 측정 및 분석

  • Oh, Shi-Hwan;Rhee, Seung-Wu
    • Aerospace Engineering and Technology
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    • v.3 no.2
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    • pp.25-33
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    • 2004
  • In this paper, we briefly introduce the micro-vibration test bench of KARI and the test and analysis method of RWA(Reaction Wheel Assembly) micro-vibration. The micro-vibration of RWA is measured on a KISTLER dynamic plate which can measure the time signal of 6 DOF simultaneously up to 400Hz. Measured data are extensively evaluated with respect to the wheel spin rate to identify the complicate wheel dynamic characteristics, and the static/dynamic unbalances are estimated from the extracted first harmonic component as a part of evaluation process. The estimated static and dynamic unbalances. 0.79gcm and 17.4gcm² respectively. The structural resonance mode and two rocking modes observed as a results of its frequency analysis. Several higher order harmonic components observed, which come from its rotor shape as well as the wheel bearing characteristics.

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Golf Club Fitting Using Robot Machine Data (로봇머신 데이터를 이용한 골프 클럽 피팅)

  • Park, Sung-Jin;Jun, Jai-Hong;Park, Young-Jin
    • Korean Journal of Applied Biomechanics
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    • v.22 no.1
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    • pp.75-82
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    • 2012
  • The purpose of this study was to suggest the proper shaft and head fitting methods of the golf club to increase the flight distance of the golf ball. Rotations per minute of the golf ball(RPM), ratio of Ball speed to club head speed(T-Ratio) and launch angle right after impact(LA), which are directly related to ball flight distance, were measured using Spectra with shutter speed of 1/1000sec at the constant head speed of 95mph which was controlled by robot golf swing machine. In order to investigate the effect of club shaft to the 3 selected variables, 10 shafts were used to make ten test clubs with one controlled club head which is the most commonly used by golf players. To measure the effect of the club head to the 3 selected variables, 6 golf club heads which are most commonly used by golfers were selected to make 6 test clubs with a controlled shaft which is one of the best known by players. The shafts and the heads were identified by statistical analysis to increase or decrease the RPM, T-ratio and LA. A proper fitting method of the selected shafts and the club head was suggested to increase the ball flight distance in golf.

Experimental Evaluation on Power Loss of Coreless Double-side Permanent Magnet Synchronous Motor/Generator Applied to Flywheel Energy Storage System

  • Kim, Jeong-Man;Choi, Jang-Young;Lee, Sung-Ho
    • Journal of Electrical Engineering and Technology
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    • v.12 no.1
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    • pp.256-261
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    • 2017
  • This paper deals with the experimental evaluation on power loss of a double-side permanent magnet synchronous motor/generator (DPMSM/G) applied to a flywheel energy storage system (FESS). Power loss is one of the most important problems in the FESS, which supplies the electrical energy from the mechanical rotation energy, because the power loss decreases the efficiency of energy storage and conversion of capability FESS. In this paper, the power losses of coreless DPMSM/G are separated by the mechanical and rotor eddy current losses in each operating mode. Moreover, the rotor eddy current loss is calculated by the 3-D finite element analysis (FEA) method. The analysis result is validated by separating the power loss as electromagnetic loss and mechanical loss by a spin up/down test.

Study on the Adhesive Properties of Polyesters Reinforcing Materials

  • Krump, H.;Hudec, I.;Cernak, M.;Janypka, P.
    • Elastomers and Composites
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    • v.37 no.3
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    • pp.192-194
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    • 2002
  • Polyester cord yarns have been treated in an atmospheric-pressure nitrogen plasma reactor in order to enhance their adhesion to rubber. A thin layer or the plasma was generated in the close vicinity of the yam surface using various types or surface discharge. To assess the effect of the plasma treatment on fiber surface properties, the cord thread/rubber matrix adhesion values measured using the untreated and threads cord threads were compared. The static and dynamic adhesion of the cord thread to rubber was characterized by using the standard Henley test. The dynamic adhesion values for the reference and plasma treated fiber were $7,3{\pm}1,2\;N$ and $83,5{\pm}3,5\;N$. The surface properties were investigated by scanning electron microscopy, infrared spectroscopy and electron spin resonance spectroscopy. It is concluded that both polar group interactions and increased surface area of the fibers are responsible for the improved adhesive strength.

Nanotribology of PMMA Thin Films Using an AFM (AFM을 이용한 PMMA (Poly Methyl Methacrylate) 박막의 나노트라이볼로지 연구)

  • 김승현;김용석
    • Transactions of Materials Processing
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    • v.13 no.1
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    • pp.59-64
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    • 2004
  • Nano-scratch tests were performed on PMMA thin films spin-coated on a Si substrate using an atomic force microscopy (AFM) with loads ranging form 10nN to 100nN. At low loads, a ridge pattern was formed on the PMMA thin film surface. No wear particles were observed during the pattern-forming mild wear. At high loads, severe wear by plowing occurred, accompanied by wear particles. The film with the highest hardness showed the highest wear resistance. Friction force generated during the scratching was measured, which was closely related with surface deformation of the film. A simple empirical equation to deduce scratch hardness of the film from a linear fixed-distance scratch test was proposed, and scratching-speed dependency of the scratch hardness was displayed.

An Estimation on Characteristics of SOG Film for MEMS Application (MEMS 응용을 위한 SOG 막의 특성 평가)

  • Kim, Hyoung-Dong;Lee, Seong-Jun;Pack, Seung-Ho;Kim, Chul-Ju
    • Proceedings of the KIEE Conference
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    • 1995.11a
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    • pp.609-611
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    • 1995
  • In this study, we experimented the properties of SOG film as sacrificials layers in surface micromachining and made $SiO_2$ films through spin, bake, cure process. When we culled SOG films once, SOG film thickness is 1000 $\sim$ 3000 ${\AA}$. Then we coaled 200-${\AA}$ SOG film on 9000 ${\AA}$-CVD oxide and then we fabricated test structure, cantilever and ring/beam structure. We estimated deformed structure by SEM. As the results, The deformation of the structure layer in the SOG-coated sacrificial layers is small compared with that or the structure layer on CVD oxide or PSG. In the future, we use multi coated SOG films, SOG film become adequate material as sacrificial layer.

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Experimental Investigation Into the Dynamic Characteristics of Flexible Matrix Composite Driveshafts (유연복합재 구동축의 동특성에 관한 실험 분석)

  • Shin Eung-Soo
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.15 no.2
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    • pp.93-98
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    • 2006
  • This study provides a comprehensive experimental study on the dynamic characteristics of a flexible matrix composite(FMC) driveshaft. A primary objective is to verify the analytic results of the FMC drivetrain based on the equivalent complex modulus approach and the classical lamination theory. A test rig has been constructed, which consists of a FMC shaft, a foundation beam, bearings, external dampers and a driving motor. The frequency response functions and transient responses are obtained from the external excitation and the spin-up testings. It turns out that the analytic results are in good agreement with the experimental ones.