• Journal of IKEEE
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• v.22 no.4
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• pp.1188-1194
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• 2018

This paper proposes an image enhancement-based license plate detection algorithm to improve the overall performance of system. Non-uniform illumination conditions have huge impact on overall plate detection system accuracy. In this paper, we propose an algorithm for color image enhancement-based license plate detection for improving accuracy of images degraded by excessively strong and low sunlight. Firstly, the image is enhanced by Multi-Scale Retinex algorithm. Secondly, a plate detection method is employed to take advantage of geometric properties of connected components, which can significantly reduce the undesired plate regions. Finally, intersection over union method is applied for detecting the accurate location of number plate. Experimental results show that the proposed method significantly improves the accuracy of plate detection system.

• Progress in Medical Physics
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• v.33 no.2
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• pp.11-24
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• 2022

X-ray detection has widely been applied in medical diagnostics, security screening, nondestructive testing in the industry, etc. Medical X-ray imaging procedures require digital flat detectors operating with low doses to reduce radiation health risks. Recently, metal halide perovskites (MHPs) have shown great potential in high-performance X-ray detection because of their attractive properties, such as strong X-ray absorption, high mobility-lifetime product, tunable bandgap, low-temperature fabrication, near-unity photoluminescence quantum yields, and fast photoresponse. In this paper, we review and introduce the development status of new perovskite X-ray detectors and imaging, which have emerged as a new promising high-sensitivity X-ray detection technology. We discuss the latest progress and future perspective of MHP-based X-ray detection in medical imaging. Finally, we compare the conventional detection methods with quantum-enhanced detection, pointing out the challenges and perspectives for future research directions toward perovskite-based X-ray applications.

• ETRI Journal
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• v.32 no.6
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• pp.881-890
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• 2010

Conventional fire detection systems use physical sensors to detect fire. Chemical properties of particles in the air are acquired by sensors and are used by conventional fire detection systems to raise an alarm. However, this can also cause false alarms; for example, a person smoking in a room may trigger a typical fire alarm system. In order to manage false alarms of conventional fire detection systems, a computer vision-based fire detection algorithm is proposed in this paper. The proposed fire detection algorithm consists of two main parts: fire color modeling and motion detection. The algorithm can be used in parallel with conventional fire detection systems to reduce false alarms. It can also be deployed as a stand-alone system to detect fire by using video frames acquired through a video acquisition device. A novel fire color model is developed in CIE $L^*a^*b^*$ color space to identify fire pixels. The proposed fire color model is tested with ten diverse video sequences including different types of fire. The experimental results are quite encouraging in terms of correctly classifying fire pixels according to color information only. The overall fire detection system's performance is tested over a benchmark fire video database, and its performance is compared with the state-of-the-art fire detection method.

• The KIPS Transactions:PartC
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• v.16C no.5
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• pp.555-562
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• 2009

In malware accident investigation, the most important thing is detection of malicious code. Signature based anti-virus softwares have been used in most of the accident. Malware can easily avoid signature based detection by using packing or encryption method. Because of this, packed file detection is also important. Detection methods can be divided into signature based detection and entropy based detection. Signature based detection can not detect new packing. And entropy based detection has a problem with false positive. We provides detection method using entropy statistics of entry point section and 'write' properties of essential characteristic of packed file. And then, we show packing detection tool and evaluate its performance.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.334.2-334.2
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• 2016

Silicon nitride (SiNx:H) films are generally used as passivation layer on solar cell and they are usually made by plasma enhanced chemical vapor deposition (PECVD). In this study, we investigated the properties of silicon nitride (SiNx:H) films made by PECVD. Effects of mixture ratio of process gases with silane (SiH4) and ammonia (NH3) on the passivation qualities of silicon nitride film are evaluated. Passivation properties of SiNx:H are focused by making antireflection properties identical with thickness and refractive index controlled. The absorption coefficient of each film was evaluated by spectrometric ellipsometery and the minority carrier lifetimes were evaluated by quasi-steady-state photo-conductance (QSSPC) measurement. The optical properties were obtained by UV-visible spectrophotometer. The interface properties were measured by capacitance-voltage (C-V) measurement and the film components were identified by Fourier transform infrared spectroscopy (FT-IR) and Rutherford backscattering spectroscopy detection (RBS) - elastic recoil detection (ERD).

• The Bulletin of The Korean Astronomical Society
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• v.35 no.2
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• pp.33.2-33.2
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• 2010

Galaxy clusters are known to be very bright in X-ray and contain a large number of X-ray point sources within the X-ray emission. However, due to the fluctuations of the X-ray emission, it is very difficult to detect faint X-ray sources and to extract accurately the photometric properties of the X-ray point sources in galaxy clusters. In addition, the most X-ray telescopes show spatially varying point spread function (PSF) and suffer from severe vignetting. The Chandra Archival Survey of Galaxy Clusters project is a wide-area ($\sim40deg^2$) survey of serendipitous Chandra X-ray sources in galaxy cluster fields, containing ~58,000 X-ray point sources in ~800 Chandra ACIS observations of ~600 galaxy clusters. This project aim to investigate the density environmental effects on the physical properties of the X-ray point sources, comparing physical properties of the X-ray point sources in galaxy clusters to those in typical fields. To utilize the sensitivity and detection probability of the X-ray point sources in galaxy clusters, we perform extensive Monte-Carlo simulations. In this poster, we compare the detection probability of the X-ray point sources in galaxy clusters to that of typical fields, and discuss quantitatively the difference between them.

• Nuclear Engineering and Technology
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• v.51 no.6
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• pp.1616-1625
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• 2019

Measuring occurrence times of random events, aimed to determine the statistical properties of the governing stochastic process, is a basic topic in science and engineering, and has been the subject of numerous mathematical modeling approaches. Often, true statistical properties deviate from measured properties due to the so called dead time phenomenon, where for a certain time period following detection, the detection system is not operational. Understanding the dead time effect is especially important in radiation measurements, often characterized by high count rates and a non-reducible detector dead time (originating in the physics of particle detection). The effect of dead time can be interpreted as a suitable rarefied sequence of the original time sequence. This paper provides a limit theorem for a high rate (diffusion-scale) counter with extendable (Type II) dead time, where the underlying counting process is a renewal process with finite second moment for the inter-event distribution. The results are very general, in the sense that they refer to a general inter arrival time and a random dead time with general distribution. Following the theoretical results, we will demonstrate the applicability of the results in three applications: serially connected components, multiplicity counting and measurements of aerosol spatial distribution.

• Proceedings of the Acoustical Society of Korea Conference
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• 1998.06c
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• pp.213-216
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• 1998

This paper proposes improved algorithm for multi-user detection in DS-CDMA. Each of algorithm is based on CMA algorithm. Improved LMS-CMS and LMAD-CMA are combined to macthed filter. Simulations results shown that Improved LMAD-CMA algorithm has a higher capacity than MOE in steady-state convergence properties.

• Proceedings of the Korean Society of Food Hygiene and Safety Conference
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• 2001.10a
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• pp.131-134
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• 2001

• 제어로봇시스템학회:학술대회논문집
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• 1994.10a
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• pp.7-12
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• 1994

This paper describes an outline of pseudorandom M-sequence and its applications to measurement and control engineering. At first, generation and properties of M-sequence is briefly described and then its applications to delay time measurement, information transmission by use of M-array, two dimensional positioning, fault detection of logical circuit, fault detection of RAM, linear and nonlinear system identification.