• Wind and Structures
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• v.15 no.5
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• pp.409-421
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• 2012

In this paper, the method of introducing additional source/sink terms in the turbulence and momentum transport equations was applied to appropriately model the effect of the tree canopy. At first, the new additional source term for the turbulence frequency ${\omega}$ equation in the SST k-${\omega}$ model was proposed through theoretical analogy. Then the new source/sink term model for the SST k-${\omega}$ model was numerically verified. At last, the proposed source term model was adopted in the wind environment optimal design of the twin high-rise buildings of CABR (China Academy of Building Research). Based on the numerical simulations, the technical measure to ameliorate the wind environment was proposed. Using the new inflow boundary conditions developed in the previous studies, it was concluded that the theoretically reasonable source term model of the SST k-${\omega}$ model was applicable for modeling the tree canopy flow and accurate numerical results are obtained.

• Nuclear Engineering and Technology
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• v.56 no.4
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• pp.1145-1152
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• 2024

To realize an initial objective of the negative ion-based neutral beam injection (N-NBI) at the Comprehensive Research Facility for Fusion Technology (CRAFT) test facility, which targets an H⁰ beam power of 2 MW at an energy of 200-400 keV and a pulse duration of 100 s, it is crucial to study the cesium dynamics of the negative ion source. Here a numerical simulation program CSFC3D is developed and applied to simulate the distribution and time dynamics of cesium during short pulses. The calculations show that most of the cesium on the plasma grid (PG) area originates from the release of cesium that is accumulated within the ion source in the plasma phase. Increasing the wall temperature reduces the loss of cesium on the wall of the ion source. Furthermore, the thickness of the cesium monolayer is directly influenced by the PG temperature. Both simulated and experimental results demonstrate that maintaining the PG temperature between 180 ℃ and 200 ℃ is essential for enhancing the performance of the ion source and optimizing the cesium behavior.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.1
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• pp.102-110
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• 2015

The purpose of this experiment was to determine and compare the digestibility of crude protein (CP) and amino acids (AA) in full-oil (no oil extracted) and de-oiled (oil extracted) corn distillers dried grains with solubles (DDGS) with different condensed distillers solubles (CDS) ratios. Six barrows ($29.6{\pm}2.3kg$) fitted with ileal T-cannula were allotted into a $6{\times}6$ Latin square design. Each period was comprised of a 5-d adaption period followed by a 2-d collection of ileal digesta. The five test diets contained 62% DDGS as the sole source of AA. A nitrogen-free diet was used to measure the basal endogenous losses of CP and AA. Chromic oxide (0.3%) was used as an index in each diet. The results showed that CP and AA were very similar in 5 DDGS, but the standardized ileal digestibility (SID) of lysine (from 56.16% to 71.15%) and tryptophan (from 54.90% to 68.38%) had the lowest values and largest variation within the essential AA, which suggests reduced availability of AA and different levels of Maillard reactions in the five DDGS. The apparent ileal digestibility and SID of CP and most of AA in full-oil DDGS (sources 1 and 2) were greater (p<0.05) than de-oiled DDGS (sources 3, 4, and 5). Comparing the AA SID in the 5 DDGS, full-oil with low CDS ratio DDGS (source 1) had non-significantly higher values (p>0.05) than full-oil with high CDS ratio DDGS (source 2); however, the SID of most AA of de-oiled with low CDS ratios DDGS (source 3) were non-significantly lower (p>0.05) than de-oiled with high CDS ratio DDGS (source 4); and the de-oiled DDGS with middle CDS ratio (source 5) but with different drying processing had the lowest SID AA values. In conclusion, de-oiled DDGS had lower SID of CP and AA than full-oil DDGS; a higher CDS ratio tended to decrease the SID of AA in full-oil DDGS but not in de-oiled DDGS; and compared with CDS ratio, processing, especially drying, may have more of an effect on AA digestibility of DDGS.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.5
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• pp.2778-2791
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• 2017

In the age of big data, distributed data providers need to ensure the privacy, while data analysts need to mine the value of data. Therefore, how to find the privacy-utility tradeoff has become a research hotspot. Besides, the adversary may have the background knowledge of the data source. Therefore, it is significant to solve the privacy-utility tradeoff problem in the distributed environment with side information. This paper proposes a distributed privacy-utility tradeoff method using distributed lossy source coding with side information, and quantitatively gives the privacy-utility tradeoff region and Rate-Distortion-Leakage region. Four results are shown in the simulation analysis. The first result is that both the source rate and the privacy leakage decrease with the increase of source distortion. The second result is that the finer relevance between the public data and private data of source, the finer perturbation of source needed to get the same privacy protection. The third result is that the greater the variance of the data source, the slighter distortion is chosen to ensure more data utility. The fourth result is that under the same privacy restriction, the slighter the variance of the side information, the less distortion of data source is chosen to ensure more data utility. Finally, the provided method is compared with current ones from five aspects to show the advantage of our method.

• The Journal of the Korea Contents Association
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• v.9 no.10
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• pp.59-66
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• 2009

A strong designated verifier signature scheme is a special type of signature scheme which provides signer anonymity by enabling the specified recipient, called a designated verifier, to simulate a signature which is indistinguishable from the signer's signature. It has many applications such as software distribution or electronic voting. In this paper, we consider two important security properties of strong designated verifier signature scheme - source hiding and security against key-compromise attack. We show that the two properties cannot be achieved at the same time. Finally, we present a new ID-based strong designated verifier signature scheme which is secure against key-compromise attack.

• Journal of Power Electronics
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• v.18 no.5
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• pp.1545-1554
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• 2018

This paper proposes a modified control strategy to improve the performance of three-phase four-leg shunt active power filters (APFs) for the compensation of three phase unbalanced loads. Unbalanced current cannot be obtained accurately by a harmonic detector due to the lower frequency. The proposed control strategy eliminates conventional harmonic detectors by directly regulating the source current. Therefore, the computational complexity is greatly reduced and the performance of the APF is improved. A mathematic model has been developed based on the source currents. The corresponding controllers have been designed based on the sinusoidal internal model principle. The proposed control strategy can guarantee excellent compensation performance and stable operation after an extreme disturbance such as a short circuit fault. In addition, the proposed technique can selectively compensate specific harmonics. A 50kVA prototype APF is implemented in the laboratory to validate the feasibility and performance of the proposed control strategy.

• Journal of Electrical Engineering and Technology
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• v.10 no.5
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• pp.2179-2188
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• 2015

Recently, many researches have been done to solve the challenging problem of Blind Source Separation (BSS) problems in the underdetermined cases, and the “Two-step” method is widely used, which estimates the mixing matrix first and then extracts the sources. To estimate the mixing matrix, conventional algorithms such as Single-Source-Points (SSPs) detection only exploits the sparsity of original signals. This paper proposes a new underdetermined mixing matrix estimation method for time-delayed mixtures based on the receiver prior exploitation. The prior information is extracted from the specific structure of the complex-valued mixing matrix, which is used to derive a special criterion to determine the SSPs. Moreover, after selecting the SSPs, Agglomerative Hierarchical Clustering (AHC) is used to automaticly cluster, suppress, and estimate all the elements of mixing matrix. Finally, a convex-model based subspace method is applied for signal separation. Simulation results show that the proposed algorithm can estimate the mixing matrix and extract the original source signals with higher accuracy especially in low SNR environments, and does not need the number of sources before hand, which is more reliable in the real non-cooperative environment.

• Journal of Microbiology
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• v.45 no.3
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• pp.205-212
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• 2007

Anoxygenic photosynthesis, performed primarily by anoxygenic photosynthetic bacteria (APB), has been supposed to arise on Earth more than 3 billion years ago. The long established APB are distributed in almost every corner where light can reach. However, the relationship between APB phylogeny and source environments has been largely unexplored. Here we retrieved the pufM sequences and related source information of 89 pufM containing species from the public database. Phylogenetic analysis revealed that horizontal gene transfer (HGT) most likely occurred within 11 out of a total 21 pufM subgroups, not only among species within the same class but also among species of different phyla or subphyla. A clear source environment feature related phylogenetic distribution pattern was observed, with all species from oxic habitats and those from anoxic habitats clustering into independent subgroups, respectively. HGT among ancient APB and subsequent long term evolution and adaptation to separated niches may have contributed to the coupling of environment and pufM phylogeny.

• Journal of Electrical Engineering and Technology
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• v.11 no.5
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• pp.1116-1127
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• 2016

• Journal of Power Electronics
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• v.17 no.3
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• pp.725-732
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• 2017

This paper proposed a real-time, low-cost, fast transistor open-circuit fault diagnosis method for voltage-source inverter fed induction motors. A transistor open-circuit changes the symmetry of the inverter topology, leading to different similarities among three phase load currents. In this paper, dynamic time warping is proposed to describe the similarities among load currents. The proposed diagnosis is independent of the system model and needs no extra sensors or electrical circuits. Both simulation and experimental results show the high efficiency of the proposed fault diagnosis method.