• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.955-958
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• 2003

Strip top mark is one of the major problem areas in hot strip coiling operation. The key for good coiling is having a precise detection instrument of strip head end and an understanding of QOC(quick open control) control algorithm and mechanism. Therefore, this study aims at developing QOC monitoring system that is useful for avoiding strip top mark at coiling process. In this study, strip movement between mandrel and unit roll(wrapper roll) was thoroughly studied using high speed camera. The monitoring system was developed to calculate QOC open time and to estimate optimal open time values for good coiling operation. Its performance has been proven by extensive field tests on downcoiler of #2 Hot Strip Mill Line in Pohang Works.

• Proceedings of the KSPS conference
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• 2003.10a
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• pp.37-40
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• 2003

This paper presents the preliminary result of the automatic pronunciation scoring for non-native English speakers, and shows the developmental process for an English speech recognizer for the educational and evaluational purposes. The proposed speech recognizer, featuring two refined acoustic model sets, implements the noise-robust data compensation, phonetic alignment, highly reliable rejection, key-word and phrase detection, easy-to-use language modeling toolkit, etc., The developed speech recognizer achieves 0.725 as the average correlation between the human raters and the machine scores, based on the speech database YOUTH for training and K-SEC for test.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.566-568
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• 2008

An E-OPMT(Electronically-controllable OPMT) was developed as an alternative of OPMT which could adjust the direction of the generated guided waves in a plate manually. The key idea of controlling the wave direction electronically is based on a few sets of axisymmetric figure-of-eight coils and the magnet which is located for making static omni-directionally biasing magnetic field over the patch. However, in order to explain wave phenomenon generated by this transducer, a new approach is required because there are various combinations between static biasing magnetic field and dynamic actuating magnetic field on the patch, not similar to OPMT. In this paper, the experiments were performed to understand characteristics of E-OPMT and the new theoretical analysis was set up for explaining the result.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.3
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• pp.1135-1139
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• 2016

Background: Head and neck cancer (HNC) is one of the deadliest cancers worldwide. Early detection is a key determinant of HNC prognosis. Hence, raising awareness of this disease may improve survival rates. The present study evaluated the level of awareness and screening status for HNC in the general population of Jeddah, Saudi Arabia. Materials and Methods: An e-questionnaire was distributed during our HNC awareness campaign at the Red Sea Mall in Jeddah. The questions assessed HNC knowledge and screening status among participants. Results: Of the 112 respondents, 68% indicated that they had no knowledge of HNC. Social media was the major source of information (39%) for respondents. The majority (40%) believed that it was the joint responsibility of dentists, dental hygienists, and general physicians to screen for HNC; 82% had never been screened. Conclusions: Knowledge and awareness of HNC must be increased in the general population and among dental health professionals.

• Asia-Pacific Journal of Business
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• v.9 no.2
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• pp.1-13
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• 2018

Physics simulation is an important part of many interactive 2D applications and collision detection and response is key component of this simulation. While methods for reducing the number of collision tests that need to be performed has been well researched, methods for performing the final checks with collision primitives have seen little recent development. This paper presents a new collision primitive, the n-arc, constructed from piecewise circular curves or biarcs. An algorithm for performing a collision check between these primitives is presented and compared to a convex polygon primitive. The n-arc is shown to exhibit similar, though slightly slower, performance to a polygon when no collision occurs, but is considerably faster when a collision does occur. The goodness of fit of the new primitive is also compared to a polygon. While the n-arc often gives a looser fit in terms of area, the continuous tangents of the n-arcs makes them a good choice for organic, soft or curved surfaces.

• Proceedings of the IEEK Conference
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• 2000.11c
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• pp.69-72
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• 2000

In this paper, a novel algorithm for digital watermarking is proposed. We use two pattern keys from BCH (15, 7) code and one randomizing key. In the embedding process, optimal watermark coefficients are determined by statistical analysis of the DCT coefficients from the standpoint of HVS. In the detection, watermark coefficients are restored by correlation matching of the possible pattern keys and minimizing the estimation errors. Attacks tested in the experiments ate image enhancement and image compression (JPEG). Performance is evaluated by BER of the logo images and SNR/PSNR of the restored images. Our method has higher performance against JPEG attacks. Analysis for the performance is included.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.953-958
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• 2007

Passenger safety is a primary concern of railway system but, it has been urgent issue that dozens of people are killed every year when they are fallen from train platforms. In this paper, we propose a vision based monitoring system for railway station platform. The system immediately perceives dangerous factors of passengers on the platform by using image processing technology. To monitor almost entire length of the track line in the platform, we use several video cameras. Each camera conducts surveillance its own preset monitoring area whether human or dangerous object was fallen in the area. Moreover, to deal with the accident immediately, the system provides local station, central control room employees and train driver with the video information about the accident situation including alarm message. This paper introduces the system overview and detection process with experimental results. According to the results, we expect the proposed system will play a key role for establishing highly intelligent monitoring system in railway.

• Nuclear Engineering and Technology
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• v.44 no.8
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• pp.961-970
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• 2012

Often, probabilistic fracture mechanics (PFM) approaches have been adopted to quantify the failure probabilities of Ni-base alloy components, especially due to primary water stress corrosion cracking (PWSCC), in a primary piping system of pressurized water reactors. In this paper, the key features of an advanced PFM code, PINEP-PWSCC (Probabilistic INtegrity Evaluation for nuclear Piping-PWSCC) for such purpose, are described. In developing the code, we adopted most recent research results and advanced models in calculation modules such as PWSCC crack initiation and growth models, a performance-based probability of detection (POD) model for Ni-base alloy welds, and so on. To verify the code, the failure probabilities for various Alloy 182 welds locations were evaluated and compared with field experience and other PFM codes. Finally, the effects of pre-existing crack, weld repair, and POD models on failure probability were evaluated to demonstrate the applicability of PINEP-PWSCC.

• Economic and Environmental Geology
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• v.29 no.5
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• pp.623-627
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• 1996

Combined SP/VLF surveys were carried out at tide embankment, Changgi-ri, Anmyeon-up, Chungcheongnamdo in order to confirm the seawater seepage zone of the embankment using the 128 Channels SP monitor system and VLF/Magnetometer system. These methods were successful in the detection of the seawater seepage zone. The self-potential method can give better resolution of the seepage zone than do VLF method.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.1
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• pp.20-33
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• 2015

Spectrum sensing is a key component of cognitive radio. The prediction of the primary user status in a low signal-to-noise ratio is an important factor in spectrum sensing. However, because of noise uncertainty, secondary users have difficulty distinguishing between the primary signal and an unauthorized signal when an unauthorized user exists in a cognitive radio network. To resolve the sensitivity to the noise uncertainty problem, we propose an entropy-based spectrum sensing scheme to detect the primary signal accurately in the presence of an unauthorized signal. The proposed spectrum sensing uses the conditional entropy between the primary signal and the unauthorized signal. The ability to detect the primary signal is thus robust against noise uncertainty, which leads to superior sensing performance in a low signal-to-noise ratio. Simulation results show that the proposed spectrum sensing scheme outperforms the conventional entropy-based spectrum sensing schemes in terms of the primary user detection probability.