Automatic logo transition detection in digital video contents

The amount of user created contents has been increasing rapidly and is associated with a serious copyright problem. Automatic logo detection and recognition in videos is a natural and efficient way of overcoming the copyright problem. However, logos have varying characteristics, which make logo detection and recognition very difficult. Moreover, logo transitions between two different logos exist in one video comprising several video contents. This disrupts the automatic logo detection and recognition. Therefore, in order to improve logo detection, it is necessary to take into account the logo transitions explicitly. This paper proposes an accurate logo transition detection method for recognizing logos in digital video contents. The proposed method accurately segments a video according to logo and efficiently recognizes various types of logos. The experimental results demonstrate the effectiveness of the proposed method for logo detection and video segmentation according to logo.     

A numerical study on the performance evaluation of ventilation systems for indoor radon reduction

Numerical simulations were conducted using computational fluid dynamics to evaluate the effect of ventilation conditions on radon (²²²Rn) reduction performance in a residential building. The results indicate that at the same ventilation rate, a mechanical ventilation system is more effective in reducing indoor radon than a natural ventilation system. For the same ventilation type, the indoor radon concentration decreases as the ventilation rate increases. When the air change per hour (ACH) was 1, the indoor radon concentration was maintained at less than 100 Bq/m³. However, when the ACH was lowered to 0.01, the average indoor radon concentration in several rooms exceeded 148 Bq/m³. The angle of the inflow air was found to affect the indoor air stream and consequently the distribution of the radon concentration. Even when the ACH was 1, the radon concentrations of some areas were higher than 100 Bq/m³ for inflow air angles of 5° and 175°.     

Characterization of the surface energies of functionalized multi-walled carbon nanotubes and their interfacial adhesion energies with various polymers

The surface energies of pristine multi-walled carbon nanotubes (MWCNTs) and MWCNTs functionalized with carboxylic acid (MWCNT-COOH), acyl chloride and ethyl amine were characterized, and the effects of the changes in MWCNT surface energies on the interfacial adhesion and reinforcement of the composites were explored. When the surface energy of pristine MWCNTs was compared to that of functionalized MWCNTs, a decrease in the dispersive surface energy and an increase in the polar surface energy were observed. Interfacial adhesion energies between MWCNTs and various polymers were estimated from surface energy values of MWCNTs and various polymers. Among the MWCNTs, polyethylene, polystyrene and bisphenol-A polycarbonate (PC) had the highest interfacial energy with pristine MWCNTs, while nylon 6,6 and polyacrylamine exhibited the highest interfacial energy with MWCNT-COOH. When tensile properties and adhesion at the interface of PC and nylon 6,6 composites containing MWCNTs were examined, composites having high interfacial adhesion energy exhibited greater adhesion at the interface and reinforcement.     

Quantum‐dots‐based detection of hepatitis C virus (HCV) NS3 using RNA aptamer on chip

BACKGROUND: Over 170 million people, more than 3% of the world's population, suffer from the hepatitis C virus (HCV) infection and the rate of death from liver‐related mortality to HCV has increased. In respect of this, the development of assays for biological imaging should be urgently considered as an essential factor in diagnosis. RESULTS: A novel HCV‐detecting technique using a nanoparticle‐supported aptamer probe was demonstrated. With the aid of nanoparticle quantum dots (QDs) with carboxyl group as an imaging probe, and 5′‐end‐amine‐modified RNA oligonucleotide as a capturing probe, target HCV NS3 was visually detected on chip. The QDs‐based RNA aptamer for HCV NS3 showed high selectivity and specificity against other protein such as BSA. The detection limit of HCV NS3 protein was 5 ng mL^?1 level. CONCLUSION: With a novel strategy for protein–aptamer interaction, the feasibility of applying QDs‐based fluorescent detection technique to HCV viral protein assay for the development of a protein biochip was demonstrated. This scheme of QDs‐mediated imaging with a target‐oriented specific RNA aptamer for the detection of infectious HCV diseases provides an efficient strategy and a promising new platform for monitoring applications. Copyright © 2010 Society of Chemical Industry     

Defect diagnostics of gas turbine engine using hybrid SVM-ANN with module system in off-design condition

A hybrid method of an artificial neural network (ANN) and a support vector machine (SVM) has been used for a health monitoring algorithm of a gas turbine engine. The method has the advantage of reducing learning data and converging time without any loss of estimation accuracy, because the SVM classifies the defect location and reduces the learning data range. In off-design condition, however, the operation region of the engine becomes wide and the nonlinearity of learning data increases considerably. Therefore, an improved hybrid method with the module system and the advanced SVM has been suggested to solve the problems. The module system divides the whole operating region into reasonably small-sized sections, and the advanced SVM has two steps of the classification. The proposed algorithm has been proven to reliably and effectively diagnose the simultaneous defects of the triple components as well as the defects of the single and dual components of the gas turbine engine in off-design condition. This paper was recommended for publication in revised form by Associate Editor Tong Seop Kim Tae-Seong Roh received his B.S. and M.S. degrees in Aeronautical Engineering from Seoul National University in 1984 and 1986. He then went on to receive his Ph.D. degree from Pennsylvania State University in 1995. Dr. Roh is currently a Professor at the department of Aerospace Engi-neering at Inha University in Incheon, Korea. His research interests are in the area of combustion instabilities, rocket and jet propulsions, interior ballistics, and gas turbine engine defect diagnostics. Dong-Whan Choi received his B.S. degree in Aeronautical Engineering from Seoul National University in 1974. He then went on to receive his M.S. and Ph.D. degrees from University of Washington in 1978 and 1983. Dr. Choi served three years as a President of Korea Aerospace Research Institute from 1999. He is currently a professor at the department of Aerospace Engineering at Inha University in Incheon, Korea. His research interests are in the area of turbulence, jet propulsions, and gas turbine defect diagnostics.     

Exposure assessment of caffeine in children’s snacks in Korea

This study was conducted to develop an appropriate management strategy for the safe consumption of children’s snacks. In this study, a caffeine content analysis was performed on children’s snacks which were distributed at stores located near to schools. A total of 213 samples (63 chocolates, 40 ice cakes, 19 canned instant coffees, and 91 beverages) were analyzed for caffeine content. The caffeine content of chocolates, ice cakes, canned instant coffees, and beverages was 94.30, 35.03, 391.78, and 68.32 mg/kg, respectively. The results of the exposure assessment for caffeine were expressed as estimated daily intake (EDI) compared to the acceptable daily intake (ADI). The EDI/ADI ratio of the high risk group (95^th percentile) for caffeine intake was 7.63–27.13 %. The results of this study indicate that the EDI of caffeine from snacks sold at stores located near to schools is much lower than the ADI in general. Consequently, children’s snacks are thought to be safe for consumption.     

Backward-motion control of a mobile robot with n passive off-hooked trailers

A passive multiple-trailer system provides various practical advantages for multi-functional service robots. However, motion control is difficult because the kinematic model is highly nonlinear. The kinematic design of a trailer system was proposed in prior research of ours. In this paper, it is shown how the backward motion of a robot with n passive trailers can be controlled. Once the desired trajectory of the last trailer is computed, the control input of the pushing robot is obtained through the proposed control scheme. Some experimental issues on reversing the trailer system are addressed. This paper provides an answer to the following question: “Does the system work well even if there are sensing or modeling errors?” Although it is difficult to obtain general analytic solutions for the above research question, a practical answer will be explored though simplified analysis and experiments. Experimental verifications are carried out using a mobile robot with three passive trailers. The experimental results show that backward-motion control can be successfully carried out by applying the proposed control scheme.     

Mechanism of droplet generation in silver thin films for organic light-emitting diode displays

Thin silver film is widely used as the cathode in organic light-emitting diode displays and it is generally fabricated using the thermal evaporation method. But during the evaporation process, there is an inevitable outgassing problem and this creates high viscosity bubbles in melted silver. When the bubbles break, the high energy released scatters silver droplets which damage the silver surface. In this study, we were able to decrease the number of droplets from 6,171 to 278 with a degassing process of 400 °C for 6 h before proceeding with a thermal evaporation process.     

Advancement of MIMO technology in WiMAX: from IEEE 802.16d/e/j to 802.16m

WiMAX is the first cellular standard that employs OFDMA technology and provides true integrated services for both fixed and mobile broadband access. Among the many new technologies adopted in WiMAX, MIMO antenna technology plays an essential role in delivering fast, rich-content, mobile broadband service reliably over extended coverage areas. In this article we provide a survey on the state of art of MIMO technologies in current WiMAX standards with an emphasis on practical engineering considerations. Moreover, we also briefly discuss the ongoing MIMO technologies in the evolution toward the next-generation WiMAX network.     

Finite element analysis of underwater capacitor micromachined ultrasonic transducers

A simple electromechanical equivalent circuit model is used to predict the behavior of capacitive micromachined ultrasonic transducers (cMUT). The equivalent circuit model of the cMUT lacks important features such as coupling to the substrate and the ability to predict crosstalk between elements of an array of transducers. To overcome these deficiencies, a finite element model of the cMUT is constructed using the commercial code ANSYS(R). Calculation results of the complex load impedance seen by single capacitor cells are presented, then followed by a calculation of the plane wave real load impedance seen by a parallel combination of many cells that are used to make a transducer. Crosstalk between 1-D array elements is found to be due to two main sources: coupling through a Stoneley wave propagating at the transducer-water interface and coupling through Lamb waves propagating in the substrate. To reduce the crosstalk level, the effect of structural variations of the substrate are investigated, which includes a change of its thickness and etched trenches or polymer walls between array elements