• Title/Summary/Keyword: (D/C) ratio

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Fuzzy modelling approach for shear strength prediction of RC deep beams

  • Mohammadhassani, Mohammad;Saleh, Aidi MD.;Suhatril, M;Safa, M.
    • Smart Structures and Systems
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    • v.16 no.3
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    • pp.497-519
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    • 2015
  • This study discusses the use of Adaptive-Network-Based-Fuzzy-Inference-System (ANFIS) in predicting the shear strength of reinforced-concrete deep beams. 139 experimental data have been collected from renowned publications on simply supported high strength concrete deep beams. The results show that the ANFIS has strong potential as a feasible tool for predicting the shear strength of deep beams within the range of the considered input parameters. ANFIS's results are highly accurate, precise and therefore, more satisfactory. Based on the Sensitivity analysis, the shear span to depth ratio (a/d) and concrete cylinder strength ($f_c^{\prime}$) have major influence on the shear strength prediction of deep beams. The parametric study confirms the increase in shear strength of deep beams with an equal increase in the concrete strength and decrease in the shear span to-depth-ratio.

Fabrication of High Aspect Ratio Micro Structure for fine pitch probe production (Fine pitch probe 제작을 위한 고세장비 마이크로 구조물 제작)

  • Lee, S.I.;Kim, W.K.;Pyo, C.R.;Kim, D.Y.;Yang, S.J.;Ko, K.H.;Kim, H.J.;Jeon, B.H.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2007.10a
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    • pp.356-359
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    • 2007
  • Continuing improvements in integrated circuit chip density and functionality have mostly contributed toward a very large-scale integrated circuit(VLSI) and display device. In order to test (pass or fail) all of the high integrated semiconductor chip and display device, fine pitch probes are used. Fine pitch probes are manufactured by electroforming process of a Ni alloy in an electrolytic bath. In this paper, we expect that the electric field in bath with the Finite Element Method and applying the FEM result. So, we can obtained the probes that have high aspect ratio of 10 : 1

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Effect of rolling parameters on the evolution of texture during asymmetrical cold rolling of aluminum sheets (알루미늄 판재의 비대칭 냉간압연 시 집합조직 발달에 미치는 압연변수의 영향)

  • Kang, H.G.;Han, Y.H.;Huh, M.Y.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2007.10a
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    • pp.84-86
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    • 2007
  • Aluminum sheets were asymmetrically cold rolled without lubrication by using different roll velocities of upper and lower rolls in order to intensify the shear deformation. During asymmetrical cold rolling of aluminum sheets, a reduction per a rolling pass, initial sheet thickness, roll diameter, roll velocity ratio were varied to investigate the effect of rolling parameters. The formation of through thickness shear texture was related to the ratio of the contact length between the roll and sample($l_c$) to the sheet thickness(d). The strain states associated with asymmetrical rolling were investigated by the finite element method (FEM) simulation. FEM results indicated that the evolution of deformation texture in a thickness layer is strongly governed by integrated values of strain rates $\dot{\varepsilon}_{13}$ and $\dot{\varepsilon}_{11}$ along the streamline in the roll gap.

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A Comparison of the ASHRAE Simplified Energy Analysis Procedure with the HASP/ACLD Results (간이 에너지 계산법과 동적 열부하 계산법의 비교 연구)

  • Kim, D.C.;Choi, J.H.;Won, Y.S.
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.1 no.3
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    • pp.210-218
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    • 1989
  • The ASHRAE Simplified Energy Analysis Procedure using the Modified Bin Method(SEAP) is compared with the hourly calculation program, HASP/ACLD. The HASP/ACLD model office building with VAV system in Seoul is used as the basis for comparison. And the parameters considered are glass to wall area ratio and internal heat gains. The results show that SEAP predictions of annual energy use agree with HASP/ACLD predictions within 5% deviation. But there is a large difference in cooling and heating energy as glass to wall area ratio is varied. The SEAP cooling energy is 65-85% and the heating energy is 104-160% of the HASP/ACLD results. This is probably due to the solar heat gain data. the data related to the SEAP must be developed prior to use it.

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Experimental Study on the Cooling seasonal Performance Factor of Room Air-conditioner (에어컨의 냉방기간 에너지 효율 산출을 위한 실험적 연구)

  • Lee, H.W.;Moon, J.H.;Bae, Y.D.;Park, J.C.
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.4 no.3
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    • pp.204-216
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    • 1992
  • In most cases, EER(Energy Efficiency Ratio) is available to present energy efficiency of air-conditioners. But, EER is not adapt to measure energy efficiency at actual life environment because it is based on fixed temperature and humidity contditions. To overcome this disadvantage, there is need to introduce SEER(Seasonal Energy Efficiency Ratio) established at time varient temperature and humidity conditions. In this paper, SEER measurement method and conditions based on actual life environment of the country is introduced, and discussed SEER value about two air-conditioner type, that is, non inverter air-conditioner and inverter air-conditioner. As a result of, inverter air-conditioner was superior to non inverter air-conditioner at cooling seasonal energy efficiency.

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A study on the combustion instability in a bluffbody dump combustor (가스터빈 연소기의 화염 불안정성에 관한 연구)

  • Lee, Byeong-Jun;Preston, L.H.;Santavicca, D.A.
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.22 no.7
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    • pp.1022-1029
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    • 1998
  • The relation of the inlet fuel distribution, velocity, and overall equivalence ratio to the stability of a lean burning no-swirl dump combustor was examined. Premixed or partially premixed natural gas was introduced into the air stream, which flowed to the dump region through an annular inlet pipe. Inlet air was preheated upto 400 deg.C. Combustion instability was observed to occur at higher value of equivalence ratio (> 0.6) as the degree of unpremixedness was increased. Instabilities exhibited a dominant frequency of ~ 500 Hz, which corresponded to a half wave mode of combustor. CH chemiluminescence and pressure fluctuations were in-phase when combustion instabilities occurred. Acetone LIF images revealed that there was a strong fuel concentration gradient across the inlet annulus. Phase resolved OH LIF images showed that inlet fuel distribution was affected by the combustion instabilities.

Bioavailability of Aspartic Acid Chelated Iron on Iron-deficient Rats (아스파르트산 킬레이트 철분의 철분 결핍쥐에서의 생물학적 유용성)

  • Park, Myoung-Gyu;Ha, Tae-Yul;Shin, Kwang-Soon
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.40 no.12
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    • pp.1720-1725
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    • 2011
  • Aspartic acid chelated iron (Asp-Fe) was synthesized by a new method using calcium carbonate, aspartic acid, and ferrous sulfate. This study was carried out to investigate the bioavailability of Asp-Fe in iron-deficient rats. We divided the rats into four experimental groups. The first was the normal diet control group, or NC. The second was the no treated control group of iron-deficient (ID) rats, or ID+C. The third was the heme-iron (heme-Fe) treated group of ID rats, ID+heme-Fe. And the fourth was the Asp-Fe treated group of ID rats, or ID+Asp-Fe. There were no differences among any of the experimental groups in diet consumption, change of body weight, or the weight of the livers, kidneys, or spleens. After 7 days of feeding, the iron content in the sera of the ID+Asp-Fe group (175.2 ${\mu}g$/dL) and the ID+heme-Fe group (140.8 ${\mu}g$/dL) were significantly higher than that of the ID-C group (96.1 ${\mu}g$/dL). The total iron binding capacity (TIBC) of the ID+Asp-Fe group (735.4 ${\mu}g$/dL) was significantly normalized compared to the ID+C group (841.9 ${\mu}g$/dL) or ID+heme-Fe group (824.6 ${\mu}g$/dL). The hematocrit level of the ID+Asp-Fe group was increased to normal levels, but there was no statistical difference among ID groups. The absorption ratio of heme-Fe was 21.3% and that of Asp-Fe was 50.2%, which indicates a 2.3 times higher ratio in comparison with heme iron. With the above results we found that Asp-Fe seems to be an efficient form of iron to supply iron deficient rats in order to cure them of anemia. Thus, these findings suggest that aspartic acid chelated iron has the potential to serve as a functional food related to iron metabolism.

Design, fabrication, and evaluation of RF module in compliance with the IEEE 802.11a standard for 5GHz-band Wireless-LAN applications (IEEE 802.11a 규격을 만족하는 5GHz 대역 무선 랜용 RF 모듈의 설계, 제작과 성능 평가)

  • 권도훈;김영일;이성수;박현철
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.27 no.3C
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    • pp.248-255
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    • 2002
  • An RF module in compliance with the IEEE 802.11a standard has been designed and its performance has been measured. Conventional heterodyne architecture with 580MHz intermediate frequency has been realized. Measurement results show that the receiver has a low Noise Figure of 5dB, the maximum gain of 70dB, and dynamic range as wide as 61dB. Also, the SAW filter used for channel selection in the IF section allowed minimum inter-channel interference. in addition to satisfying the RF output power requirement, the transmitter features its output P1dB as high as 34dBm so that the high peak-to-average ratio of the Orthogonal Frequency Division Multiplexing (OFDM) modulation scheme can be handled with minimum nonlinear distortion. The output P1dB of 34dBm of the transmitter corresponds to back-off powers of 18dB and 11dB with respect to the output power for the low and the middle frequency bands, respectively.

AICAR (5-aminoimidazole-4-carboxamide-1-β-D-ribonucleoside) Decreases Protein Synthesis in C2C12 Myotubes Cultured in High Glucose Media (근육세포 내 Glucose 농도와 AICAR에 의한 단백질 합성 저해)

  • Park, Chang-Seok;Kim, Jae-Hwan;Oh, Young-Kyoon;Kim, Kyoung-Hoon;Choi, Chang-Weon;Cho, Eun-Seok;Jeong, Yong-Dae;Park, Sung-Kwon
    • Journal of Animal Science and Technology
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    • v.54 no.5
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    • pp.369-373
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    • 2012
  • AMP-activated protein kinase (AMPK) maintains energy homeostasis in skeletal muscle. Nonetheless, its functional role on protein synthesis with different nutrient availability has not been elucidated. Therefore, the purpose of this study is to examine the effect of AMPK activity on protein content in C2C12 myotubes incubated with low (5 mM; LG) or high (25 mM; HG) glucose media. LG stimulated (p<0.05) AMPK and acetyl CoA carboxylase (ACC) activity compare to those in HG group. Total protein content was higher in myotubes cultured with HG than in those cultured with LG and further increased by AICAR (5-amino-1-${\beta}$-D-ribofuranosyl-imidazole-4-carboxamide). Myotubes cultured with HG showed 7.5% lower UbFL (Ubiquitin Firefly Luciferase)-to-SV40 (Simian virus40) ratio compared to those in LG. Glucose level did not change the phosphorylation level of mammalian target of rapamycin (mTOR). Interestingly, administration of AICAR significantly increased phosphorylation level of mTOR in myotubes cultured with LG but not in those with HG. Overall, this data indicate that AMPK activity and protein turnover are finely regulated in response to different glucose concentration.

Fast Disparity Estimation Method Considering Temporal and Spatial Redundancy Based on a Dynamic Programming (시.공간 중복성을 고려한 다이내믹 프로그래밍 기반의 고속 변이 추정 기법)

  • Yun, Jung-Hwan;Bae, Byung-Kyu;Park, Se-Hwan;Song, Hyok;Kim, Dong-Wook;Yoo, Ji-Sang
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.33 no.10C
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    • pp.787-797
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    • 2008
  • In this paper, we propose a fast disparity estimation method considering temporal and spatial redundancy based on a dynamic programming for stereo matching. For the first step, the dynamic programming is performed to estimate disparity vectors with correlation between neighboring pixels in an image. Next, we efficiently compensate regions, which disparity vectors are not allocated, with neighboring disparity vectors assuming that disparity vectors in same object are quite similar. Moreover, in case of video sequence, we can decrease a complexity with temporal redundancy between neighboring frames. For performance comparison, we generate an intermediate-view image using the estimated disparity vector. Test results show that the proposed algorithm gives $0.8{\sim}2.4dB$-increased PSNR(peak signal to noise ratio) compared to a conventional block matching algorithm, and the proposed algorithm also gives approximately 0.1dB-increased PSNR and $48{\sim}68%$-lower complexity compared to the disparity estimation method based on general dynamic programming.