• Title/Summary/Keyword: Center Loss

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Mandibular full-arch rehabilitation with increased vertical dimension of a patient with severe tooth wear (심한 치아 마모 환자의 수직 교합고경 증가를 동반한 하악 편악 수복 증례)

  • Kim, Hyun-Jin;Kim, Jong-Jin;Baik, Jin;Cha, Hyun-Suk;Lee, Joo-Hee
    • Journal of Dental Rehabilitation and Applied Science
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    • v.38 no.3
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    • pp.162-170
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    • 2022
  • In the case of patients with pathological tooth wear, it is necessary to evaluate the loss of the vertical dimension. Setting the appropriate vertical dimension is important to rehabilitate the patient's stable intermaxillary relationship. A 77-year-old female patient's chief complaint was the pain of the mandibular incisors and the lack of molars. At the first visit, pathologic tooth wear of the mandibular incisors were observed. After diagnosis and evaluation, loss of vertical dimension was not observed, but insufficient intermaxillary space for prosthetic restoration was confirmed. Mandibular rehabilitation was performed with vertical dimension increase and this showed satisfactory results both functionally and aesthetically.

Micromachined Millimeter-Wave Cavity Resonators

  • Song, K.J.;Yoon, B.S.;Lee, J.C.;Lee, B.;Kim, J.H.;Kim, N.Y.;Park, J.Y.;Kim, G.H.;Bu, J.U.;Chung, K.W.
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.12 no.1
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    • pp.27-36
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    • 2001
  • In this paper, micromachined millimeter-wave cavity resonators ar presented. One-port and two-port cavity resonators at Ka-band are designed using 3D design software, HP $HFSS^{TM}$ ver. 5.5 Cavity resonators are fabricated on Si substrate, which is etched down for the cavity, bonded with a Quartz wafer in which metal patterns for the feeding line coupling slot are formed. One-port resonator shows the resonant frequency of 39.34 GHz, the return loss of 14.5 dB, and the loaded $Q(Q_{L})$ of 150. Two-port cavity resonator shows the resonant frequency of 39 GHz, the insertion and return losses of 4.6dB and 19,9dB, the loaded($Q_{L}$) and unloaded $Q(Q_{U})$) of 44.3 and 107, respectively.

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Losses and Flow Structure for the Movement of Turbine Blade Row (터빈익렬의 이동에 따른 손실 및 유동장에 관한 실험적 연구)

  • Cho, Soo-Yong;Jung, Yang-Beom
    • Journal of Power System Engineering
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    • v.21 no.1
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    • pp.70-79
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    • 2017
  • The output power of turbine is greatly affected by the losses generated within the passage. In order to develop a better turbine or loss models, an experimental study was conducted using a linear cascade experimental apparatus. The total pressure loss and flow structures were measured at two cross-sectional planes located downstream of blade row. Measurement was conducted in a steady state for the several different locations of the blade row along the rotational direction. The blade row moved by 20 % of the pitch, and tip clearance was varied from 2% to 8%. Axial-type blades were used and its blade chord was 200mm. A square nozzle was applied and its size was $200mm{\times}200mm$. The experiment was conducted at a Reynolds number of $3{\times}10^5$ based on the chord. Nozzle flow angle sets to $65^{\circ}$ based on the axial direction and the solidity of blade row was 1.38. From the experimental results, the total pressure loss was greatly varied in the receding region than in the entering region. The flow properties within the blade passage were strongly changed according to the location of blade row.

Design of a Interdigital Microstrip Bandpass Filter (깍지낀 마이크로스트립 대역통과 여파기 설계)

  • 신진옥;전성근;이문수
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.4 no.3
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    • pp.565-573
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    • 2000
  • In this paper, a interdigital microstrip bandpass filter is designed. A interdigital microstrip bandpass filter has many advantages such as insertion return loss, lower return loss, higher frequency selectivity and smaller in size in comparison with the conventional coupled line filter. A interdigital microstrip bandpass filter consists of quasi TEM-mode strip line resonators between parallel ground plant. Each resonator element is a quarter wavelength long of the center frequency and is short circuited at one end and open circuited at the other end. In the filter design, Ensemble software is used. Experimental results show that the bandwidth of interdigital microstrip bandpass filter is 2.52GHz, insertion loss is -1.8dB and return loss is -17.0dB at 11.20Hz.

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An investigation on the mortars containing blended cement subjected to elevated temperatures using Artificial Neural Network (ANN) models

  • Ramezanianpour, A.A.;Kamel, M.E.;Kazemian, A.;Ghiasvand, E.;Shokrani, H.;Bakhshi, N.
    • Computers and Concrete
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    • v.10 no.6
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    • pp.649-662
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    • 2012
  • This paper presents the results of an investigation on the compressive strength and weight loss of mortars containing three types of fillers as cement replacements; Limestone Filler (LF), Silica Fume (SF) and Trass (TR), subjected to elevated temperatures including $400^{\circ}C$, $600^{\circ}C$, $800^{\circ}C$ and $1000^{\circ}C$. Results indicate that addition of TR to blended cements, compared to SF addition, leads to higher compressive strength and lower weight loss at elevated temperatures. In order to model the influence of the different parameters on the compressive strength and the weight loss of specimens, artificial neural networks (ANNs) were adopted. Different diagrams were plotted based on the predictions of the most accurate networks to study the effects of temperature, different fillers and cement content on the target properties. In addition to the impressive RMSE and $R^2$ values of the best networks, the data used as the input for the prediction plots were chosen within the range of the data introduced to the networks in the training phase. Therefore, the prediction plots could be considered reliable to perform the parametric study.

Analysis of Contact Loss Arc Spectrum between Contact Wire and Pantograph Material using a Spectrometer (광계측기를 이용한 전차선-팬터그래프 재질별 이선아크 스펙트럼 분석)

  • Chang, Chin-Young;Jung, No-Geon;Park, Jong-Gook;Koo, Kyung-Wan;Kim, Jae-Moon
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.62 no.12
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    • pp.1803-1808
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    • 2013
  • To maintain contact between catenary and pantograph copper is important in order to transmit power smoothly on Current collection system. But, Arc discharge with strong light is generated because of contact loss. Therefore, Arc discharge detection is important measurement factor judging performance of current collection system. In this paper, It is described to results of arc discharge applying UV detection technology using arc generator. And Arc discharge was detected using the most commonly used processing catenary and rigid catenary and pantograph copper of electric rolling stock for securing arc detection instrument reliability. Results of contact loss detection instrument in this paper will be used for maintenance of current collection quality and system.

Z-Source Inverter with SiC Power Semiconductor Devices for Fuel Cell Vehicle Applications

  • Aghdam, M. Ghasem Hosseini
    • Journal of Power Electronics
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    • v.11 no.4
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    • pp.606-611
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    • 2011
  • Power electronics is a key technology for electric, hybrid, plug-in hybrid, and fuel cell vehicles. Typical power electronics converters used in electric drive vehicles include dc/dc converters, inverters, and battery chargers. New semiconductor materials such as silicon carbide (SiC) and novel topologies such as the Z-source inverter (ZSI) have a great deal of potential to improve the overall performance of these vehicles. In this paper, a Z-source inverter for fuel cell vehicle application is examined under three different scenarios. 1. a ZSI with Si IGBT modules, 2. a ZSI with hybrid modules, Si IGBTs/SiC Schottky diodes, and 3. a ZSI with SiC MOSFETs/SiC Schottky diodes. Then, a comparison of the three scenarios is conducted. Conduction loss, switching loss, reverse recovery loss, and efficiency are considered for comparison. A conclusion is drawn that the SiC devices can improve the inverter and inverter-motor efficiency, and reduce the system size and cost due to the low loss properties of SiC devices. A comparison between a ZSI and traditional PWM inverters with SiC devices is also presented in this paper. Based on this comparison, the Z-source inverter produces the highest efficiency.

Optimum target values for manufacturing processes when drifting rate in the process mean is normally distributed (공정평균의 변화율이 정규분포인 제조공정의 최적 목표값)

  • Lee, Jae-Hoon;Park, Tae-Ho;Kwon, Hyuck-Moo;Hong, Sung-Hoon;Lee, Min-Koo
    • Journal of Korean Society for Quality Management
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    • v.38 no.4
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    • pp.540-548
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    • 2010
  • We consider the problem of selecting the most profitable initial process mean and length of production cycle for manufacturing processes subject to a constant linear trend during the same cycle that varies after resetting the processes. Assuming that the quality characteristic of interest is normally distributed, the optimum initial process mean and the length of production cycle are jointly obtained by minimizing the expected loss per unit time. We assume that the quality loss function due to the deviation from the target value is quadratic and resetting loss is constant. We consider both cases of symmetric and asymmetric quality loss function. An illustrative example is given and sensitivity analysis performed.

Effect of Edible Coatings Containing Soy Protein Isolate (SPI) on the Browning and Moisture Content of Cut Fruit and Vegetables

  • Shon, Jin-Han;Choi, Yong-Hwa
    • Journal of Applied Biological Chemistry
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    • v.54 no.3
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    • pp.190-196
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    • 2011
  • Effectiveness of edible coatings containing soy protein isolate (SPI), in reducing oxidative browning and moisture loss during storage ($4^{\circ}C$) of cut apples, potatoes, carrots, and onions was investigated. The SPI coatings were shown to have antioxidative activity. Furthermore, addition of carboxymethyl cellulose (CMC) to the formulations significantly improved its antioxidative activity. Oxidative discoloration, as determined by Commission Internationale De I'Eclairage (CIE) lightness ($L^*$), redness ($a^*$), and yellowness ($b^*$) color scale, was significantly reduced (p <0.05) by SPI coating treatments over a storage time of 120 min. Loss of lightness was reduced by SPI coatings with and without CMC. These respectively showed 4.03 and 3.71% change of $L^*$ value compared to 8.56% for control. Browning of the control in cut potatoes was significantly increased by 106.6% in contrast to 34.3 and 35.2% for SPI coatings with and without CMC, respectively. The $b^*$ values also reflected effectiveness of SPI. Moisture barrier effect was significantly better for the treatments, compared to the control. SPI coatings reduced moisture loss in apples and potatoes, respectively, by 21.3 and 29.6% over the control. Cut onions did not show any treatment effect both in terms of browning and moisture loss. SPI coatings prove to be good moisture barrier and antioxidative property.

Microstructure and Soft Magnetic Properties of Fe-6.5 wt.%Si Sheets Fabricated by Powder Hot Rolling

  • Kim, Myung Shin;Kwon, Do Hun;Hong, Won Sik;Kim, Hwi Jun
    • Journal of Powder Materials
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    • v.24 no.2
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    • pp.122-127
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    • 2017
  • Fe-6.5 wt.% Si alloys are widely known to have excellent soft magnetic properties such as high magnetic flux density, low coercivity, and low core loss at high frequency. In this work, disc-shaped preforms are prepared by spark plasma sintering at 1223 K after inert gas atomization of Fe-6.5 wt.% Si powders. Fe-6.5 wt.% Si sheets are rolled by a powder hot-rolling process without cracking, and their microstructure and soft magnetic properties are investigated. The microstructure and magnetic properties (saturation magnetization and core loss) of the hot-rolled Fe-6.5 wt.% Si sheets are examined by scanning electron microscopy, electron backscatter diffraction, vibration sample magnetometry, and AC B-H analysis. The Fe-6.5 wt.% Si sheet rolled at a total reduction ratio of 80% exhibits good soft magnetic properties such as a saturation magnetization of 1.74 T and core loss ($W_{5/1000}$) of 30.7 W/kg. This result is caused by an increase in the electrical resistivity resulting from an increased particle boundary density and the oxide layers between the primary particle boundaries.