• 한국컴퓨터정보학회논문지
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• 제20권2호
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• pp.47-54
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• 2015

관객의 감정 반응은 개별 관객들의 반응을 관측하여 판단할 수 있다. 영상 카메라를 이용한 시각적 데이터를 분석하여 활용하는 방법을 이용할 경우, 관객의 반응을 적은 비용으로 데이터를 추출하여 판단할 수 있는 것이 가능하다. 하지만, 영상 카메라를 이용할 경우 다수의 관객으로부터 발생하는 대규모의 영상 신호로부터 관객의 특징값들을 분석하여 반응을 판단하기 위한 방법과 시스템이 필요하다. 이를 위해 본 논문에서는 관객의 영상 데이터를 신경회로망 기법을 이용하여 관객의 반응을 관측하여 판단하는 방법과 시스템을 제안하고, 기존의 관객석을 고정적인 영역으로 분할하여 데이터를 취합하여 분석하기 때문에 발생하는 문제를 개선하기 위해 얼굴 검출을 통해 자동적으로 관객 영역을 분할하는 방법을 제안한다. 또한 실험을 통해 기존의 고정적으로 관객 영역을 지정하는 방법에 비해 10.5 %(7.75의 Hit Ratio)의 성능향상이 있음을 확인하였다. 이를 통해 제안하는 방법이 실제 관객 반응을 판단하는데 더 적합하다는 것을 알 수 있다.

• Clinical and Experimental Pediatrics
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• 제55권11호
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• pp.420-423
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• 2012

Purpose: We phylogenetically analyzed the Escherichia coli strains isolated from children with urinary tract infection (UTI) in 2 regions of Korea. Virulence factors (VFs) and antibiotic resistance of the strains were also determined to compare the possible differences. Methods: A total of 138 E. coli strains were collected from the 2 regions; Gyeongin (78 strains) and Gyeongnam (60 strains). The phylogenetic groups were determined using the triplex polymerase chain reaction (PCR) method and multiplex PCRs were used to detect 7 VFs genes (fimH, papC, iutA, hlyA, sfa/focDE, afa/draBC, and kpsMT II). We also tested for antibiotic resistance. Results: Phylogenetic groups, B2 (61.6%) and D (26.8%), comprised the majority of all isolated strains. Regional comparisons revealed that more B2 strains and fewer non-B2 (A+B1+D) strains were found in Gyeongnam, than in the Gyeongin region (P=0.033), and certain VFs were predominantly detected in Gyeongnam (P<0.05). Neither regional nor phylogenetic differences, in antibiotic resistance of the strains, were significant. Conclusion: We were able to confirm that the geographic location is an important determinant of the distribution of the phylogenetic groups and VFs among the E. coli strains that cause UTI in children.

• Journal of Electrical Engineering and Technology
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• 제2권4호
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• pp.468-477
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• 2007

The DTC of voltage source inverter-fed PMSMs is based on hysteresis controllers of torque and flux. It has several advantages, namely, elimination of the mandatory rotor position sensor, less computation time, and rapid torque response. In addition, the stator resistance is the only parameter, which should be known, and no reference frame transformation is required. The DTC theory has achieved great success in the control of induction motors. However, for the control of PMSM drives proposed a few years ago, there are many basic theoretical problems that must be clarified. This paper describes an investigation into the effect of the zero voltage space vectors in the DTC system and points out that if using it rationally, not only can the DTC of the PMSM drive be driven successfully, but torque and flux ripples are reduced and overall performance of the system is improved. The implementation of DTC in PMSM drives is described and the switching tables specific for an interior PMSM are derived. The conventional eight voltage-vector switching table, which is namely used in the DTC of induction motors does not seem to regulate the torque and stator flux in a PMSM well when the motor operates at low speed. Modelling and simulation studies have both revealed that a six voltage-vector switching table is more appropriate for PMSM drives at low speed. In addition, the sources of difficulties, namely, the error in the detection of the initial rotor position, the variation of stator resistance, and the offsets in measurements are analysed and discussed.

• Computers and Concrete
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• 제25권2호
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• pp.119-132
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• 2020

There is a growing interest in the use of by-product materials such as ceramics as alternative materials in construction. The aim of this study is to investigate the mechanical properties and durability of sustainable concrete containing waste ceramic powder (WCP), and to predict the results using artificial neural network (ANN). In this order, different water to binder (W/B) ratios of 0.3, 0.4, and 0.5 were considered, and in each W/B ratio, a percentage of cement (between 5-50%) was replaced with WCP. Compressive and tensile strengths, water absorption, electrical resistivity and rapid chloride permeability (RCP) of the concrete specimens having WCP were evaluated by related experimental tests. The results showed that by replacing 20% of the cement by WCP, the concrete achieves compressive and tensile strengths, more than 95% of those of the control concrete, in the long term. This percentage increases with decreasing W/B ratio. In general, by increasing the percentage of WCP replacement, all durability parameters are significantly improved. In order to validate and suggest a suitable tool for predicting the characteristics of the concrete, ANN model along with various multivariate regression methods were applied. The comparison of the proposed ANN with the regression methods indicates good accuracy of the developed ANN in predicting the mechanical properties and durability of this type of concrete. According to the results, the accuracy of ANN model for estimating the durability parameters did not significantly follow the number of hidden nodes.

• Journal of Advanced Marine Engineering and Technology
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• 제38권10호
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• pp.1217-1224
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• 2014

This paper provides a practical scaling method to solve an old problem for scaling and developing the speed and resistance of a model to full-scale submarine in fully submerged underwater test. In every experimental test in towing tank, water tunnel and wind tunnel, in the first step, the speed of a model should be scaled to the full-scale vessel (ship or submarine). In the second step, the obtained resistance of the model should be developed. For submarine, there are two modes of movement: surface and submerged mode. There is no matter in surface mode because, according to Froude's law, the ratio of speed of the model to the full-scale vessel is proportional to the square root of lengths (length of the model on the length of the vessel). This leads to a reasonable speed and is not so much for the model that is applicable in the laboratory. The main problem is in submerged mode (fully submerged) that there isn't surface wave effect and therefore, Froude's law couldn't be used. Reynold's similarity is actually impossible to implement because it leads to very high speeds of the model that is impossible in a laboratory and inside the water. According to Reynold's similarity, the ratio of speed of the model to the full-scale vessel is proportional to the ratio of the full-scale length to the model length that leads to a too high speed. This paper proves that there is no need for exact Reynold's similarity because after a special Reynolds, resistance coefficient remains constant. Therefore, there is not compulsion for high speeds of the model. For proving this finding, three groups of results are presented: two cases are based on CFD method, and one case is based on the model test in towing tank. All these three results are presented for three different shapes that can show; this finding is independent of the shapes and geometries. For CFD method, Flow Vision software has been used.