• The Bulletin of The Korean Astronomical Society
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• v.35 no.2
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• pp.35.2-35.2
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• 2010

It is crucial to understand the dust properties in the early universe since they provide important clues about how the early cosmic star formation should be interpreted in the presence of dust extinction. GRB 071025 is an unusually red GRB that occured at high redshift, offering an unique opportunity to study the dust properties in the early universe. We investigate the extinction properties of GRB 071025 through the analysis of RIJHK data obtained with the 1-m telescope at Mt. Lemmon Optical Astronomy Observatory (LOAO) and Simultaneous Quad Infrared Imaging Device (SQIID) on the Kitt-Peak Mayall 4-m telescope. Our dataset is independent from that in a previous work (Perley et al. 2010) where a small systematic photometric errors could complicate the interpretation. After determining the temporal power law exponent with five I-band frames from LOAO, we construct a multi-band monochromatic SED of the GRB afterglow. By using various extinction laws, we find that the SED is best fitted with models that incorporate SNe II dust and derive a photometric redshift of 4.99(+0.12/-0.03). Our results strongly support the prior claim that dusts in GRB 071025 originate mainly from supernovae, implying SNe II predominantly contributed to the dust enrichment in the early universe (z ~ 5).

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.2
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• pp.691-694
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• 2013

Purpose: By carrying out a meta-analysis of randomized controlled trials that compared sorafenib or combined chemotherapy with placebo or combined chemotherapy, the effectiveness of sorafenib in hepatocellular carcinoma was evaluated in the present study, which also provided clinical practice guidelines of evidence-based-medicine. Methods: We reviewed PubMed citations concerning sorafenib treating hepatocellular carcinoma in randomized controlled trials from Jan 2000 to July 2012. All the literature was extracted by Cochrane systematic reviews and underwent meta-analysis with RewMan 5.0 software. Results: Finally, four papers documenting randomized controlled studies were included. Compared with controls, sorafenib was shown to significantly increase overall survival (OS), time to progression (TTP), and disease control rates (DCR), but not the time to symptom progression (TTSP) in hepatocellular carcinoma patients. The incidence of grade-III/IV adverse reactions, including hand-foot-skin reactions, diarrhea, hypertension and skin rash or desquamation, in sorafenib treatment group was higher than that in controls. However, there was no significant difference in the incidence of hypodynamia between the two groups. Conclusions: Sorafenib exerts significant curative effects in hepatocellular carcinoma.

• Phonetics and Speech Sciences
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• v.2 no.1
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• pp.113-120
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• 2010

In this paper, we investigate the acoustic characteristics of sustained voices from normal subjects and patients with laryngeal pathologies. Perturbation methods (including jitter and shimmer), signal-to-noise ratio (SNR), and nonlinear dynamic methods (such as correlation dimension) are used to analyze normal and pathological voices. We find that jitter does not statistically discriminate between normal and pathological voices, but a significant difference is found for shimmer, SNR, and correlation dimension. The results suggest that nonlinear dynamic analysis may be valuable for the analysis of normal and pathological voices but perturbation analysis should be applied with caution for pathological voice analysis.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.1
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• pp.171-192
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• 2017

The change of any element in the network is possible to cause performance degradation of the multicast network. So it is necessary to optimize the topology path through the multicast update strategy, which directly affects the performance and user experience of the overlay multicast. In view of the above, a new multicast tree update strategy based on perturbation theory Musp (Multicast Update Strategy based on Perturbation theory) is proposed, which reduces the data transmission interruption caused by the multicast tree update and improves user experiences. According to the multicast tree's elements performance and the topology structure, the Musp strategy defines the multicast metric matrix and based on the matrix perturbation theory it also defines the multicast fluctuation factor. Besides it also demonstrates the calculability of the multicast fluctuation factor presents the steps of the Musp algorithm and calculates the complexity. The experimental results show that compared with other update strategies, as for the sensitivity of the multicast fluctuation factor's energized multicast tree to the network disturbance, the maximum delay of the Musp update strategy is minimal in the case of the local degradation of network performance.

• Journal of the Korean Wood Science and Technology
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• v.36 no.5
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• pp.49-55
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• 2008

This study was carried to investigate the effects of steaming and four different drying methods on the longitudinal liquid permeability of Korean pine (Pinus koraiensis Sieb.et Zucc.) board. Four drying methods were air drying, conventional kiln drying, microwave-vacuum drying and high temperature drying. Darcy equation was used for calculating the specific permeability of the small sapwood specimens taken from the treated boards while capillary rising method was used for the heartwood specimens. The sapwood specimens were extracted with water and benzene-alcohol solution to examine the mechanism of liquid flow in treated wood. No significant correlation was found between specific permeability and the number of resin canals of the sapwood specimens. Extraction decreased the differences of specific permeabilities of the sapwood specimens between the five treatment methods. The effects of extraction on the longitudinal permeability are different between five treatments. The fluid path in heartwood was observed by dynamic observation method.

• Bulletin of the Korean Chemical Society
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• v.32 no.1
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• pp.127-130
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• 2011

One new tirucallane-type triterpenoid, alianthusaltinin A (1), one new $C_{29}$ sterone, alianthaltone A (2), and 12 known compounds have been isolated from the stem bark of Ailanthus altissima. The structures of new compounds were identified by means of spectroscopic methods. Compound 3 was isolated from natural sources for the first time, and compounds 4, 5, and 9 were isolated from this plant for the first time.

• Phonetics and Speech Sciences
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• v.2 no.2
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• pp.109-115
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• 2010

In this paper, we investigate a signal typing on the basis of visual impression of distinctive spectrogram. Pathological voices are classified into signal type 1, 2, 3, or 4 to estimate perturbation parameters and to mark perceptual rating based on Consensus Auditory-Perceptual Evaluation of Voice (CAPE-V). The results suggest that perturbation analysis can be applied to only type 1 and 2 signals and the perceptual ratings of overall grade increase with each signal type, overall. A good inter-rater reliability is showed among three raters. We recommend that pathological voices should be marked the signal typing and CAPE-V, together, to definitely describe the characteristics of pathological voices.

• Korean Journal of Pharmacognosy
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• v.43 no.1
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• pp.6-9
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• 2012

The $CH_2Cl_2$ soluble part of the leaves of Helianthus tuberosus L. (Compositae) exhibited a potent cytotoxic activity against the cultured human tumor cell lines including A-549, SK-OV-3, SK-MEL-2, XF498 and HCT-15 in vitro. Bioassaydirected fractionation of the $CH_2Cl_2$ soluble part of this plant led to the isolation of four cytotoxic sesquiterpene lactones having ${\alpha}$-methylene-${\gamma}$-lactone ring in the molecule. On the basis of physical and spectral evidences, their structures were characterized as ${\Delta}^{4,15}$-isoatripliciolide tiglate (1), ${\Delta}^{4,15}$-isoatripliciolide methacrylate (2), budlein A isobutylate (3) and budlein A tiglate (4). The ${\Delta}^{4,15}$-isoatripliciolide tiglate (1) showed the most potent cytotoxic activity ($0.26{\mu}M<ED_{50}<2.16{\mu}M$) against all of the cell lines tested.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.6
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• pp.3121-3143
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• 2019

Segmentation plays an important role in the field of image processing and computer vision. Intuitionistic fuzzy C-means (IFCM) clustering algorithm emerged as an effective technique for image segmentation in recent years. However, standard fuzzy C-means (FCM) and IFCM algorithms are sensitive to noise and initial cluster centers, and they ignore the spatial relationship of pixels. In view of these shortcomings, an improved algorithm based on IFCM is proposed in this paper. Firstly, we propose a modified non-membership function to generate intuitionistic fuzzy set and a method of determining initial clustering centers based on grayscale features, they highlight the effect of uncertainty in intuitionistic fuzzy set and improve the robustness to noise. Secondly, an improved nonlinear kernel function is proposed to map data into kernel space to measure the distance between data and the cluster centers more accurately. Thirdly, the local spatial-gray information measure is introduced, which considers membership degree, gray features and spatial position information at the same time. Finally, we propose a new measure of intuitionistic fuzzy entropy, it takes into account fuzziness and intuition of intuitionistic fuzzy set. The experimental results show that compared with other IFCM based algorithms, the proposed algorithm has better segmentation and clustering performance.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.1
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• pp.305-326
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• 2019

Discriminative correlation filter (DCF) based tracking algorithms have recently shown impressive performance on benchmark datasets. However, amount of recent researches are vulnerable to heavy occlusions, irregular deformations and so on. In this paper, we intend to solve these problems and handle the contradiction between accuracy and real-time in the framework of tracking-by-detection. Firstly, we propose an innovative strategy to combine the template and color-based models instead of a simple linear superposition and rely on the strengths of both to promote the accuracy. Secondly, to enhance the discriminative power of the learned template model, the spatial regularization is introduced in the learning stage to penalize the objective boundary information corresponding to features in the background. Thirdly, we utilize a discriminative multi-scale estimate method to solve the problem of scale variations. Finally, we research strategies to limit the computational complexity of our tracker. Abundant experiments demonstrate that our tracker performs superiorly against several advanced algorithms on both the OTB2013 and OTB2015 datasets while maintaining the high frame rates.