• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.7
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• pp.2938-2956
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• 2020

Objective image quality assessment (IQA) models have been developed by effective features to imitate the characteristics of human visual system (HVS). Actually, HVS is extremely sensitive to color degradation and complex texture changes. In this paper, we firstly reveal that many existing full reference image quality assessment (FR-IQA) methods can hardly measure the image quality with contrast and masking texture changes. To solve this problem, considering texture masking effect, we proposed a novel FR-IQA method, called Texture and Color Quality Index (TCQI). The proposed method considers both in the masking effect texture and color visual perceptual threshold, which adopts three kinds of features to reflect masking texture, color difference and structural information. Furthermore, random forest (RF) is used to address the drawbacks of existing pooling technologies. Compared with other traditional learning-based tools (support vector regression and neural network), RF can achieve the better prediction performance. Experiments conducted on five large-scale databases demonstrate that our approach is highly consistent with subjective perception, outperforms twelve the state-of-the-art IQA models in terms of prediction accuracy and keeps a moderate computational complexity. The cross database validation also validates our approach achieves the ability to maintain high robustness.

• Journal of KIISE:Databases
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• v.31 no.2
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• pp.122-131
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• 2004

Traditional works on indexing have been suggested for low dimensional data under dynamic environments. But recent database applications require efficient processing of huge sire of high dimensional data under static environments. Thus many indexing strategies suggested especially in partitioning ones do not adapt to these new environments. In our study, we point out these facts and propose a new partitioning strategy, which complies with new applications' requirements and is derived from analysis. As a preliminary step to propose our method, we apply a packing technique on the one hand and exploit observations on the Minkowski-sum cost model on the other, under uniform data distribution. Observations predict that unbalanced partitioning strategy may be more query-efficient than balanced partitioning strategy for high dimensional data. Thus we propose our method, called CSP (Cyclic Spliced Partitioning method). Analysis on this method explicitly suggests metrics on how to partition high dimensional data. By the cost model, simulations, and experiments, we show excellent performance of our method over balanced strategy. By experimental studies on other indices and packing methods, we also show the superiority of our method.

• Proceedings of the Korean Information Science Society Conference
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• 2011.06c
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• pp.112-114
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• 2011

On multimedia databases, in order to realize the fast access method, indexing methods for the multidimension data space are used. However, since it is a premise to use the Euclid distance as the distance measure, this method lacks in flexibility. On the other hand, there are metric indexing methods which require only to satisfy distance axiom. Since metric indexing methods can also apply for distance measures other than the Euclid distance, these methods have high flexibility. This paper proposes an improved method of VP-tree which is one of the metric indexing methods. VP-tree follows the node which suits the search range from a route node at searching. And distances between a query and all objects linked from the leaf node which finally arrived are computed, and it investigates whether each object is contained in the search range. However, search speed will become slow if the number of distance calculations in a leaf node increases. Therefore, we paid attention to the candidates selection method using the triangular inequality in a leaf node. As the improved methods, we propose a method to use the nearest neighbor object point for the query as the datum point of the triangular inequality. It becomes possible to make the search range smaller and to cut down the number of times of distance calculation by these improved methods. From evaluation experiments using 10,000 image data, it was found that our proposed method could cut 5%~12% of search time of the traditional method.

• Journal of the Korea institute for structural maintenance and inspection
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• v.12 no.5
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• pp.109-115
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• 2008

As structures are getting super-rise and large-sized, introducing the construction methods such as prefabrication of bar-meshes and complex method are being actively discussed to pursue the high quality of reinforced concrete, the simplification of field works, and the reduction of duration, as well as the study on how to connect reinforcing rods, which occurs while applying the same methods, is in progress Also, the pressure welded joint is a kind of method that heats the ends of reinforced bars locally and joint them, and after the pressure welding, the vulnerable part in the reinforced bar occur. Thus, in the construction field, the throughout quality control is necessary because of the delayed duration and the lowered construct ability. In this study, of the traditional lap splice method and the mechanical splice one, the screw coupler, we tried to look into through experiments the prefabrication method of bar-meshes, a typical joint method usually used for the joint parts for PSC structures applying the reinforced bar with its big diameter, and a newly-developed up-set coupler method. And we also examined the characteristic of tensile.

• Journal of Pharmacopuncture
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• v.20 no.3
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• pp.213-219
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• 2017

Objectives: Based on data from Chinese and Indian traditional herbal medicines, gum resin of Ferula assa-foetida (sometimes referred to asafetida or asafoetida) has several therapeutic applications. The authors of various studies have claimed that asafetida has cytotoxic, antiulcer, anti-neoplasm, anti-cancer, and anti-oxidative effects. In present study, the anti-aging effect of asafetida on senescent human dermal fibroblasts was evaluated. Methods: Senescence was induced in in vitro cultured human dermal fibroblasts (HDFs) through exposure to $H_2O_2$, and the incidence of senescence was recognized by using cytochemical staining for the activity of ${\beta}$-galactosidase. Then, treatment with oleo gum resin of asafetida was started to evaluate its rejuvenating effect. The survival rate of fibroblasts was evaluated by using methyl tetrazolium bromide (MTT) assays. Real-time quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and western blot assays were performed to evaluate the expressions of apoptotic and anti-apoptotic markers. Results: Our experiments show that asafetida in concentrations ranging from $5{\times}10^{-8}$ to $10^{-7}g/mL$ has revitalizing effects on senescent fibroblasts and significantly reduces the ${\beta}$-galactosidase activity in these cells (P < 0.05). Likewise, treatment at these concentrations increases the proliferation rate of normal fibroblasts (P < 0.05). However, at concentrations higher than $5{\times}10^{-7}g/mL$, asafetida is toxic for cells and induces cell death. Conclusion: The results of this study indicate that asafetida at low concentrations has a rejuvenating effect on senescent fibroblasts whereas at higher concentrations, it has the opposite effect of facilitating cellular apoptosis and death.

• Journal of KIISE:Software and Applications
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• v.32 no.8
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• pp.704-716
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• 2005

Assembling new software systems from Prepared components is an attractive alternative to traditional software development method to reduce development cost and schedule dramatically. However, if separately developed components are tested, integrated and verified with unreasonable effort and high cost, it would not be an effective way to software development. Components are not distributed in the shape of white-box source code so that should be hard to validate and test in new application environment. For solving this problem, built-in tester components are suggested to check the contract-compliance of their server components. If components have various and complex function, built-in tester should be heavy and unflexible to test in composition of components. This paper suggests enhancing automated wrapper technique which substitutes with built-in tester components and shows the usability of the wrapper by design and implementation. Component testing in this way reduces the cost and effort associated with preparation of component testing and makes the various test experiments in components assembly.

• Steel and Composite Structures
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• v.19 no.3
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• pp.569-583
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• 2015

Recent years, explosive welding structures have been widely used in many engineering fields. The bonding state detection of explosive welding structures is significant to prevent unscheduled failures and even catastrophic accidents. However, this task still faces challenges due to the complexity of the bonding interface. In this paper, a new method called dual-tree complex wavelet transform based permutation entropy (DTCWT-PE) is proposed to detect bonding state of such structures. Benefiting from the complex analytical wavelet function, the dual-tree complex wavelet transform (DTCWT) has better shift invariance and reduced spectral aliasing compared with the traditional wavelet transform. All those characters are good for characterizing the vibration response signals. Furthermore, as a statistical measure, permutation entropy (PE) quantifies the complexity of non-stationary signals through phase space reconstruction, and thus it can be used as a viable tool to detect the change of bonding state. In order to more accurate identification and detection of bonding state, PE values derived from DTCWT coefficients are proposed to extract the state information from the vibration response signal of explosive welding structure, and then the extracted PE values serve as input vectors of support vector machine (SVM) to identify the bonding state of the structure. The experiments on bonding state detection of explosive welding pipes are presented to illustrate the feasibility and effectiveness of the proposed method.

• Journal of the Korean Society for Railway
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• v.19 no.1
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• pp.46-53
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• 2016

LED light sources have been known to have a long life and good energy efficiency compared to traditional light sources. Recently, headlamps using LED light sources have ensured the forward visibility and safe operation of high-speed rolling stock. However, assessing the lifespan of LED headlamps based on real test data is not easy because it depends on the multiple stress factors such as a fixed driving current, junction temperature, vibration and so on. Generally, LED headlamps have failed before their advertised life span mainly due to temperature. Thus, the performance assessment of a temperature control unit should be done before a life cycle test of LED headlamps. This study attempted to develop a prototype temperature control module for a lifecycle test system using a commercial LED headlight and verified the system through experiments.

• Geophysics and Geophysical Exploration
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• v.12 no.1
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• pp.114-120
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• 2009

Rupture directivity is the important parameter in estimating damage due to earthquakes. However, the traditional moment tensor inversion technique cannot resolve the real fault plane or the rupture directivity. To overcome these limitations, we have developed a new inversion algorithm to determine the moment tensor solution and the rupture directivity for moderate earthquakes, using the waveform inversion technique in the frequency domain. Numerical experiments for unilateral and bilateral rupture models with various rupture velocities confirm that the method can resolve the ambiguity of the fault planes and the rupture directivity successfully. To verify the feasibility of the technique, we tested the sensitivity to velocity models, which must be the most critical factor in practice. The results of the sensitivity tests show that the method can be applied even though the velocity model is not perfect. If this method is applied in regions where the velocity model is well verified, we can estimate the rupture directivity of a moderate earthquake. This method makes a significant contribution to understanding the characteristics of earthquakes in those regions.

• Archives of Pharmacal Research
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• v.27 no.5
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• pp.547-553
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• 2004

The pyrrolizidine alkaloids (PAs), contained in a number of traditional remedies in Africa and Asia, show wide variations in metabolism between animal species but little work has been done to investigate differences between animal strains. The metabolism of the PA senecionine (SN) in Fischer 344 (F344) rats has been studied in order to compare to that found in the previously investigated Sprague-Dawley (SO) rats (Drug Metab. Dispos. 17: 387, 1989). There was no difference in the formation of ($\pm$) 6,7-dihydro-7-hydroxy-1-hydroxymethyl-5H-pyrrolizine (DHP, bioactivation) by hepatic microsomes from either sex of SO and F344 rats. However, hepatic microsomes from male and female F344 rats had greater activity in the Noxidation (detoxication) of SN by 88% and 180%, respectively, when compared to that of male and female SD rats. Experiments conducted at various pH showed an optimum pH of 8.5, the optimal pH for flavin-containing monooxygenase (FMO), for SN N-oxidation by hepatic microsomes from F344 females. In F344 males, however, a bimodal pattern was obtained with activity peaks at pH 7.6 and 8.5 reflecting the possible involvement of both cytochrome P450 (CYP) and FMO. Use of specific inhibitors (SKF525A, 1-benzylimidazole and methimazole) showed that the N-oxide of SN was primarily produced by FMO in both sexes of F344 rats. In contrast, SN N-oxide formation is known to be catalyzed mainly by CYP2C11 rather than FMO in SD rats. This study, therefore, demonstrated that there were substantial differences in the formation of SN N-oxide by hepatic microsomes from F344 and SD rats and that this detoxification is catalyzed primarily by two different enzymes in the two rat strains. These findings suggest that significant variations in PA biotransformation can exist between different animal strains.