• Genomics & Informatics
• /
• v.5 no.4
• /
• pp.174-178
• /
• 2007

The earliest stages of mammalian embryogenesis are governed by the activity of maternally inherited transcripts and proteins. Cytoplasmic polyadenylation of selected maternal mRNA has been reported to be a major control mechanism of delayed translation during preimplantation embryogenesis in mice. The presence of cis-elements required for cytoplasmic polyadenylation (e.g., CPE) can serve as a useful tag in the screening of maternal genes partaking in key functions in the transcriptionally dormant egg and early embryo. However, due to its relative simplicity, UA-rich sequences satisfying the canonical rule of known CPE consensus sequences are often found in the 3'-UTR of maternal transcripts that do not actually undergo cytoplasmic polyadenylation. In this study, we developed a method to confirm the validity of candidate CPE sequences in a given gene by a multiplex comparison of 3'-UTR sequences between mammalian homologs. We found that genes undergoing cytoplasmic polyadenylation tend to create a conserved block around the CPE, while CPE-like sequences in the 3'-UTR of genes lacking cytoplasmic polyadenylation do not exhibit such conservation between species. Through this cross-species comparison, we also identified an alternative CPE in the 3'-UTR of tissue-type plasminogen activator (tPA), which is more likely to serve as a functional element. We suggest that verification of CPEs based on sequence conservation can provide a convenient tool for mass screening of factors governing the earliest processes of mammalian embryogenesis.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.16 no.4
• /
• pp.812-820
• /
• 2012

In this paper, multiple pedestrians tracking system using Histogram of Oriented Gradient and occlusion detection is proposed. The proposed system is applicable to Intelligent Surveillance System. First, we detect pedestrian in a image sequence using pedestrian's feature. To get pedestrian's feature, we make block-histogram using gradient's direction histogram based on HOG(Histogram of Oriented Gradient), after that a pedestrian region is classified by using Linear-SVM(Support Vector Machine) training. Next, moving objects are tracked by using position information of the classified pedestrians. And we create motion trajectory descriptor which is used for content based event retrieval. The experimental results show that the proposed method is more fast, accurate and effective than conventional methods.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.33 no.10C
• /
• pp.787-797
• /
• 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.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.8 no.10
• /
• pp.3475-3489
• /
• 2014

Here we present a simple flame detection method for an infrared (IR) thermal camera based real-time fire surveillance digital signal processor (DSP) system. Infrared thermal cameras are especially advantageous for unattended fire surveillance. All-weather monitoring is possible, regardless of illumination and climate conditions, and the data quantity to be processed is one-third that of color videos. Conventional IR camera-based fire detection methods used mainly pixel-based temporal correlation functions. In the temporal correlation function-based methods, temporal changes in pixel intensity generated by the irregular motion and spreading of the flame pixels are measured using correlation functions. The correlation values of non-flame regions are uniform, but the flame regions have irregular temporal correlation values. To satisfy the requirement of early detection, all fire detection techniques should be practically applied within a very short period of time. The conventional pixel-based correlation function is computationally intensive. In this paper, we propose an IR camera-based simple flame detection algorithm optimized with a compact embedded DSP system to achieve early detection. To reduce the computational load, block-based calculations are used to select the candidate flame region and measure the temporal motion of flames. These functions are used together to obtain the early flame detection algorithm. The proposed simple algorithm was tested to verify the required function and performance in real-time using IR test videos and a real-time DSP system. The findings indicated that the system detected the flames within 5 to 20 seconds, and had a correct flame detection ratio of 100% with an acceptable false detection ratio in video sequence level.

• Journal of Broadcast Engineering
• /
• v.3 no.1
• /
• pp.85-92
• /
• 1998

The block matching algorithm is the most popular motion estimation method in image sequence coding. In this paper, we propose a VLSI architecture. for implementing a recently proposed fast bolck matching algorith, which uses spatial correlation of motion vectors and hierarchical searching scheme. The proposed architecture consists of a basic searching unit based on a systolic array and two shift register arrays. And it covers a search range of -32~ +31. By using the basic searching unit repeatedly, it reduces the number of gatyes for implementation. For basic searching unit implementation, a proper systolic array can be selected among various conventional ones by trading-off between speed and hardware cost. In this paper, a structure is selected as the basic searching unit so that the hardware cost can be minimized. The proposed overall architecture is fast enough for low bit-rate applications (frame size of $352{\times}288$, 3Oframes/sec) and can be implemented by less than 20,000 gates. Moreover, by simply modifying the basic searching unit, the architecture can be used for the higher bit-rate application of the frame size of $720{\times}480$ and 30 frames/sec.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.39A no.3
• /
• pp.149-154
• /
• 2014

The cross-correntropy concept can be expressed with inner products of two different probability density functions constructed by Gaussian-kernel density estimation methods. Blind algorithms based on the maximization of the cross-correntropy (MCC) and a symbol set of randomly generated N samples yield superior learning performance, but have a huge computational complexity in the update process at the aim of weight adjustment based on the MCC. In this paper, a method of reducing the computational complexity of the MCC algorithm that calculates recursively the gradient of the cross-correntropy is proposed. The proposed method has only O(N) operations per iteration while the conventional MCC algorithms that calculate its gradients by a block processing method has $O(N^2)$. In the simulation results, the proposed method shows the same learning performance while reducing its heavy calculation burden significantly.

• The KIPS Transactions:PartC
• /
• v.12C no.7 s.103
• /
• pp.1039-1046
• /
• 2005

TCP SACK is the unique mechanism to reflect the situation of sink's sequence space, some TCP variants and proposals can perform in conjunction with SACK mechanism for achieving optimal performance. By definition of RFC 2018, however, each contiguous block of data queued at the data receiver is defined in the SACK option by two 32-bit unsigned integers in network byte order. Since TCP Options field has a 40-byte maximum length, when error bursts now, we note that the available option space may not be sufficient to report all blocks present in the receiver's queue and lead to unnecessarily force the TCP sender to retransmit Packets that have actually been received by TCP sink. For overcoming this restriction, in this thesis, a new solution named 'one-byte offset based SACK mechanism' is designed to further improve the performance or TCP SACK and prevent those unwanted retransmissions. The results or both theory analysis and simulation also show that his proposed scheme operates simply and more effectively than the other existing schemes by means of the least bytes and most robust mechanism to the high packet error rates often seen in networks environment.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.40 no.9
• /
• pp.702-713
• /
• 2003

The importance of protection for data and information is increasing by the rapid development of information communication and network. And the concern for protecting private information is also growing due to the increasing demand for lots of services by users. Asymmetric cryptosystem is the mainstream in encryption system rather than symmetric cryptosystem by above reasons. But asymmetric cryptosystem is restricted in applying fields by the reason it takes more times to process than symmetric cryptosystem. In this paper, encryption system which executes authentication works of asymmetric cryptosystem by means of symmetric cryptosystem. The proposed cryptosystem uses an algorithms combines that combines block cipherment with stream cipherment and has a high stability in aspect of secret rate by means of transition of key sequence according to the information of plaintext while symmetric/asymmetric cryptosystem conducts encipherment/deciphermeent using a fixed key. Consequently, it is very difficult to crack although unauthenticator acquires the key information. So, the proposed encryption system which has a certification function of asymmetric cryptosystem and a processing time equivalent to symmetric cryptosystems will be highly useful to authorize data or exchange important information.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.14 no.7
• /
• pp.677-684
• /
• 2003

This paper addresses the subblock phase weighting(SPW) method to reduce the PAPR in OFDM system. This method divides the input block of OFDM signal into many subblocks and lower the peak power by weighting the phase of each subblocks properly. SPW method can be realized by only one IFFT. PAPR reduction performance is novelly examined when the adjacent, interleaved and random subblock partitioning schemes are used in the SPW system. The random subblock partition scheme has the most effective. More subblocks can effectively reduce the PAPR, but there is a problem that the processing time of iteration is increased. We propose a new weighting factor combination of the complementary sequence characteristic with threshold technique. OFDM data can be recovered by the inserted side information of weighting factor in the feed forward type. Also, BER performance of this SPW system is analyzed when error happens in the side information.

• Journal of The Korean Astronomical Society
• /
• v.40 no.3
• /
• pp.67-82
• /
• 2007

The basic building block of solar filaments/prominences is thin threads of cool plasma. We have studied the spectral properties of velocity threads, clusters of thinner density threads moving together, by analyzing a sequence of $H{\alpha}$ images of a quiescent filament. The images were taken at Big Bear Solar Observatory with the Lyot filter being successively tuned to wavelengths of -0.6, -0.3, 0.0, +0.3, and +0.6 ${\AA}$ from the centerline. The spectra of contrast constructed from the image data at each spatial point were analyzed using cloud models with a single velocity component, or three velocity components. As a result, we have identified a couple of velocity threads that are characterized by a narrow Doppler width($\Delta\lambda_D=0.27{\AA}$), a moderate value of optical thickness at the $H{\alpha}$ absorption peak($\tau_0=0.3$), and a spatial width(FWHM) of about 1". It has also been inferred that there exist 4-6 velocity threads along the line of sight at each spatial resolution element inside the filament. In about half of the threads, matter moves fast with a line-of-sight speed of $15{\pm}3km\;s^{-1}$, but in the other half it is either at rest or slowly moving with a line-of-sight velocity of $0{\pm}3km\;s^{-1}$. It is found that a statistical balance approximately holds between the numbers of blue-shifted threads and red-shifted threads, and any imbalance between the two numbers is responsible for the non-zero line-of-sight velocity determined using a single-component model fit. Our results support the existence not only of high speed counter-streaming flows, but also of a significant amount of cool matter either being at rest or moving slowly inside the filament.