• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.12
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• pp.4725-4747
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• 2020

Software defined networking (SDN) is considered to be one of the most promising paradigms in the future. To solve the scalability and performance problem that a single and centralized controller suffers from, the distributed multi-controller architecture is adopted, thus forms multi-domain SDN. In a multi-domain SDN network, it is of great importance to ensure a reliable control plane. In this paper, we focus on the reliability problem of multi-domain SDN against controller failure from perspectives of backup controller deployment and controller replication. We firstly propose a placement algorithm for backup controllers, which considers both the reliability and the cost factors. Then a controller replication mechanism based on shared data storage is proposed to solve the inconsistency between the active and standby controllers. We also propose a shared data storage layout method that considers both reliability and performance. Besides, a fault recovery and repair process is designed based on the controller backup and shared data storage mechanism. Simulations show that our approach can recover and repair controller failure. Evaluation results also show that the proposed backup controller placement approach is more effective than other methods.

• Journal of Korean Medical classics
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• v.36 no.3
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• pp.15-25
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• 2023

Objectives : This study aims to investigate a wide range of symptoms related to anger and their corresponding treatments as described in Traditional Korean Medical literature. Additionally, the study aims to propose key prescriptions for Intermittent Explosive Disorder(IED), thereby striving to explore potential therapeutic strategies. Methods : This comprehensive study examines the correlations between the pathologies, symptoms, and treatments related to anger, as described in the Yixuerumen (醫學入門), the Donguibogam (東醫寶鑑), and the Xiezhenglun (血證論), and their relevance to IED. Results : Anger impairs the liver, giving rise to a spectrum of symptoms including dry hair, headaches, dizziness, a bitter taste in the mouth, tinnitus, vomiting of blood, sharp chest and flank pains, abdominal discomfort, tremors, diarrhea, and hyperventilation. Furthermore, this heightened anger can serve as a potential trigger for strokes and, considering its potential to hinder recovery from various other conditions, calls for proactive therapeutic intervention. Conclusions : Severe anger has the potential to trigger strokes and hinder recovery from a range of illnesses, underscoring the necessity for tailored and proactive treatment based on the severity of symptoms. In the instance of IED, clinical application of the Danggui Luihuiwan (當歸蘆薈丸) is warranted.

• Journal of the Korean Society of Systems Engineering
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• v.20 no.1
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• pp.34-49
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• 2024

Since the outbreak of COVID-19, 'overcoming infectious disease' has emerged as a priority task for most policies. Each country has implemented policy programs to significantly shorten the vaccine development period with the goal of rapid vaccine development. This study judged this process to be a shock to the existing social and technological system and its recovery. Accordingly, the United States' Operation Warp Speed, CEPI's 100 days mission, and Japan's SCARDA were selected as examples of policy programs with 'rapid vaccine development' as their mission and analyzed difference from traditional vaccine development system in terms of rapid development. As a result, it was confirmed that the accumulation of innovative resources was shared as the key to achieving the mission in the preparation stage before the outbreak of an infectious disease. However, it was also possible to discover an approach to shortening the period of each stage without fundamentally changing the vaccine development structure itself.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.9
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• pp.4023-4043
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• 2016

Network virtualization has been regarded as a core attribute of the Future Internet. In a network virtualization environment (NVE), multiple heterogeneous virtual networks can coexist on a shared substrate network. Thus, a substrate network failure may affect multiple virtual networks. In this case, it is increasingly critical to provide survivability for the virtual networks against the substrate network failures. Previous research focused on mechanisms that ensure the resilience of the virtual network. However, the resource efficiency is still important to make the mapping scheme practical. In this paper, we study the survivable virtual network embedding mechanisms against substrate link and node failure from the perspective of improving the resource efficiency. For substrate link survivability, we propose a load-balancing and re-configuration strategy to improve the acceptance ratio and bandwidth utilization ratio. For substrate node survivability, we develop a minimum cost heuristic based on a divided network model and a backup resource cost model, which can both satisfy the location constraints of virtual node and increase the sharing degree of the backup resources. Simulations are conducted to evaluate the performance of the solutions. The proposed load balancing and re-configuration strategy for substrate link survivability outperforms other approaches in terms of acceptance ratio and bandwidth utilization ratio. And the proposed minimum cost heuristic for substrate node survivability gets a good performance in term of acceptance ratio.

• BMB Reports
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• v.41 no.5
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• pp.388-393
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• 2008

The Pphsc70 (heat shock cognate 70) gene was isolated from the endoparasitoid Pteromalus puparum and then characterized. The full-length cDNA was 2204 base pair (bp) and contained a single 1968 bp ORF that encoded a polypeptide of 656 amino acids with a predicted molecular mass of 71.28 kDa. Phylogenetic analysis based on Hsc70 amino acid sequences from fifteen insect species agreed with the present phylogeny. In addition, genomic DNA confirmed the presence of three introns located at the coding region as well as the 5'UTR. A significant elevation of Pphsc70 expression was observed following heat treatment, however, continued exposure to heat shock or recovery caused the expression of induced mRNA to gradually decline to levels that were significantly lower than those of control pupae (P < 0.05). In addition, a significant increase was observed in the emergence rate of pupae that were preheated at $40^{\circ}C$ and then exposed to $50^{\circ}C$ for 1 h when compared with the pupae that were not preheated, but instead directly exposed to $50^{\circ}C$. Taken together, these results revealed that exposure to gradually increasing temperatures can enhance an insects thermo-tolerance.

• Journal of Microbiology and Biotechnology
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• v.19 no.1
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• pp.65-71
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• 2009

Microbial oxidoreductive systems have been widely used in asymmetric syntheses of optically active alcohols. However, when reused in multi-batch reaction, the catalytic efficiency and sustainability of non-growing cells usually decreased because of continuous consumption of required cofactors during the reaction process. A novel method for NADPH regeneration in cells was proposed by using pentose metabolism in microorganisms. Addition of D-xylose, L-arabinose, or D-ribose to the reaction significantly improved the conversion efficiency of deracemization of racemic 1-phenyl-1,2-ethanediol to (S)-isomer by Candida parapsilosis cells already used once, which afforded the product with high optical purity over 97%e.e. in high yield over 85% under an increased substrate concentration of 15 g/l. Compared with reactions without xylose, xylose added to multi-batch reactions had no influence on the activity of the enzyme catalyzing the key step in deracemization, but performed a promoting effect on the recovery of the metabolic activity of the non-growing cells with its consumption in each batch. The detection of activities of xylose reductase and xylitol dehydrogenase from cell-free extract of C. parapsilosis made xylose metabolism feasible in cells, and the depression of the pentose phosphate pathway inhibitor to this reaction further indicated that xylose facilitated the NADPH-required deracemization through the pentose phosphate pathway in C. parapsilosis. moreover, by investigating the cofactor pool, the xylose addition in reaction batches giving more NADPH, compared with those without xylose, suggested that the higher catalytic efficiency and sustainability of C. parapsilosis non-growing cells had resulted from xylose metabolism recycling NADPH for the deracemization.

• Current Optics and Photonics
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• v.4 no.4
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• pp.286-292
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• 2020

Imaging through multicore fiber (MCF) is of great significance in the biomedical domain. Although several techniques have been developed to image an object from a signal passing through MCF, these methods are strongly dependent on the surroundings, such as vibration and the temperature fluctuation of the fiber's environment. In this paper, we apply a new, strong technique called deep learning to reconstruct the phase image through a MCF in which each core is multimode. To evaluate the network, we employ the binary cross-entropy as the loss function of a convolutional neural network (CNN) with improved U-net structure. The high-quality reconstruction of input objects upon spatial light modulation (SLM) can be realized from the speckle patterns of intensity that contain the information about the objects. Moreover, we study the effect of MCF length on image recovery. It is shown that the shorter the fiber, the better the imaging quality. Based on our findings, MCF may have applications in fields such as endoscopic imaging and optical communication.

• Journal of Communications and Networks
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• v.12 no.4
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• pp.289-307
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• 2010

The problem of model selection arises in a number of contexts, such as subset selection in linear regression, estimation of structures in graphical models, and signal denoising. This paper studies non-asymptotic model selection for the general case of arbitrary (random or deterministic) design matrices and arbitrary nonzero entries of the signal. In this regard, it generalizes the notion of incoherence in the existing literature on model selection and introduces two fundamental measures of coherence-termed as the worst-case coherence and the average coherence-among the columns of a design matrix. It utilizes these two measures of coherence to provide an in-depth analysis of a simple, model-order agnostic one-step thresholding (OST) algorithm for model selection and proves that OST is feasible for exact as well as partial model selection as long as the design matrix obeys an easily verifiable property, which is termed as the coherence property. One of the key insights offered by the ensuing analysis in this regard is that OST can successfully carry out model selection even when methods based on convex optimization such as the lasso fail due to the rank deficiency of the submatrices of the design matrix. In addition, the paper establishes that if the design matrix has reasonably small worst-case and average coherence then OST performs near-optimally when either (i) the energy of any nonzero entry of the signal is close to the average signal energy per nonzero entry or (ii) the signal-to-noise ratio in the measurement system is not too high. Finally, two other key contributions of the paper are that (i) it provides bounds on the average coherence of Gaussian matrices and Gabor frames, and (ii) it extends the results on model selection using OST to low-complexity, model-order agnostic recovery of sparse signals with arbitrary nonzero entries. In particular, this part of the analysis in the paper implies that an Alltop Gabor frame together with OST can successfully carry out model selection and recovery of sparse signals irrespective of the phases of the nonzero entries even if the number of nonzero entries scales almost linearly with the number of rows of the Alltop Gabor frame.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.30 no.1
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• pp.101-119
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• 2019

This study reviewed important elements that should be considered in developing natural disaster plan in libraries and archives. In Korea, research on natural disaster planning in libraries and archives was rarely conducted. Therefore, it was necessary to study and analyse overseas literature for natural disaster preparedness planning. The key elements for establishing a natural disaster preparedness plan commonly identified in overseas research can be divided into six factors. 'The disaster preparedness committee and roles of staff' should be designated for starting disaster preparedness, and 'Risks' vulnerable to disaster should be assessed and managed in advance. A 'Handbook for immediate response' should be produced for all employees to respond promptly in the event of disaster, and 'Recovery and business continuity plan' should be reviewed for strategic recovery based on disaster scale and return to work after disaster. Also, in order to strengthen the capacity of all staff related to disaster preparedness and to improve plan for disaster, 'Training' is needed, and 'Cooperation activities' between related organisations should be taken into consideration in order to obtain various perspectives for disaster preparedness and to cope with and recover from large-scale disasters. This study can help Korean libraries and archives to establish natural disaster preparedness plan for serious natural disaster that can likely occur in the future.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.31 no.5
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• pp.345-350
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• 2018

Nanomaterials have considerable potential to solve several key challenges in various electrochemical devices, such as fuel cells. However, the use of nanoparticles in high-temperature devices like solid-oxide fuel cells (SOFCs) is considered problematic because the nanostructured surface typically prepared by deposition techniques may easily coarsen and thus deactivate, especially when used in high-temperature redox conditions. Herein we report the synthesis of a self-regenerated Pd metal nanoparticle on the perovskite oxide anode surface for SOFCs that exhibit self-recovery from their degradation in redox cycle and $CH_4$ fuel running. Using Pd-doped perovskite, $La(Sr)Fe(Mn,Pd)O_3$, as an anode, fairly high maximum power densities of 0.5 and $0.2cm^{-2}$ were achieved at 1,073 K in $H_2$ and $CH_4$ respectively, despite using thick electrolyte support-type cell. Long-term stability was also examined in $CH_4$ and the redox cycle, when the anode is exposed to air. The cell with Pd-doped perovskite anode had high tolerance against re-oxidation and recovered the behavior of anodic performance from catalytic degradation. This recovery of power density can be explained by the surface segregation of Pd nanoparticles, which are self-recovered via re-oxidation and reduction. In addition, self-recovery of the anode by oxidation treatment was confirmed by X-ray diffraction (XRD) and scanning electron microscopy (SEM).