Calculating Wind Variability Costs with Considering Ramping Costs of Conventional Power Plants

Xuemei Dai,Kaifeng Zhang,Jian Geng,Ying Wang,Kun Yuan 대한전기학회 2019 Journal of Electrical Engineering & Technology Vol.14 No.3

Due to the variability of the wind power, conventional power plants are required to ramp more frequently to mitigate the imbalance of generation and supply, which increase the total cost of power systems. The increase of the cost is termed the “variability cost” of wind power. Generally, it includes the additional ramping cost, reserve cost and fuel cost of conventional plants. In this paper, we propose an alternative scenario construction method to calculate the “variability cost” of wind power from the viewpoint of the power system schedule. Firstly, in the alternative scenario, a new energy proxy with zero wind variability costs is constructed. Then, a unit commitment optimization model considering ramping costs is developed. The operation costs of power systems under two scenarios (alternative one and real one) are calculated and the diff erence between two costs is the variability cost. Furthermore, we apply the proposed method to calculate the variability costs of the wind farm cluster. The simulations show that the variability cost increases with higher penetration and higher variability of wind power. Meanwhile, it is found that the variability cost of the wind farm cluster as a whole is lower than the sum of variability costs of each wind farm.

Optical Encryption Scheme with Multiple Users Based on Computational Ghost Imaging and Orthogonal Modulation

Sheng Yuan,Xuemei Liu,Xin Zhou,Zhongyang Li 한국광학회 2016 Current Optics and Photonics Vol.20 No.4

For the application of multiusers, the arrangement and distribution of the keys is a much concerningproblem in a cryptosystem. In this paper, we propose an optical encryption scheme with multiple usersbased on computational ghost imaging (CGI) and orthogonal modulation. The CGI encrypts the secret imageinto an intensity vector rather than a complex-valued matrix. This will bring convenience for post-processingand transmission of the ciphertext. The orthogonal vectors are taken as the address codes to distinguishusers and avoid cross-talk. Only the decryption key and the address code owned by an authorized userare matched, the secret image belonging to him/her could be extracted from the ciphertext. Therefore, thereare two security levels in the encryption scheme. The feasibility and property are verified by numericalsimulations.

A Self-adaptive Spectral Clustering Based on Geodesic Distance and Shared Nearest Neighbors

Chunmiao Yuan,Kaixiang Fan,Xuemei Sun 보안공학연구지원센터 2016 International Journal of Hybrid Information Techno Vol.9 No.4

Spectral clustering is a method of subspace clustering which is suitable for the data of any shape and converges to global optimal solution. By combining concepts of shared nearest neighbors and geodesic distance with spectral clustering, a self-adaptive spectral clustering based on geodesic distance and shared nearest neighbors was proposed. Experiments show that the improved spectral clustering algorithm can fully take into account the information of neighbors, but also measure the exact distance and better process the geodetic data.

Simple denoising method for novel speckle-shifting ghost imaging with connected-region labeling

Sheng Yuan,Xuemei Liu,Pibin Bing 한국광학회 2019 Current Optics and Photonics Vol.3 No.3

A novel speckle-shifting ghost imaging (SSGI) technique is proposed in this paper. This method can effectively extract the edge of an unknown object without achieving its clear ghost image beforehand. However, owing to the imaging mechanism of SSGI, the imaging result generally contains serious noise. To solve the problem, we further propose a simple and effective method to remove noise from the speckle-shifting ghost image with a connected-region labeling (CRL) algorithm. In this method, two ghost images of an object are first generated according to SSGI. A threshold and the CRL are then used to remove noise from the imaging results in turn. This method can retrieve a high-quality image of an object with fewer measurements. Numerical simulations are carried out to verify the feasibility and effectiveness.

Angle-stable top-emitting white organic light-emitting devices employing a down-conversion layer

Shihao Liu,Xuemei Wen,Wenbo Liu,Wei Zhang,Jing-Yuan Wang,Wenfa Xie,Letian Zhang 한국물리학회 2014 Current Applied Physics Vol.14 No.11

Angle-stable white top-emitting organic light-emitting devices (WTEOLEDs) by the combination of a blue TEOLED with a down-conversion (DC) layer are demonstrated. The DC layer is composed of red fluorescent dye doped in a host of tris (8-hydroxy-quinolinato) aluminum. The TEWOLED shows a CIE coordinates of (0.240, 0.332) and a maximum current efficiency of 3.95 cd/A. Furthermore, theWTEOLED shows excellently angle-stable characteristic, the CIE coordinates at 20 mA/cm2 only shift by (0.023, 0.007) from 0 to 60. It can be attributed to the angle-stable blue TEOLED based on the Ag/Ge/Ag transparent cathode.

Abnormal Brain Activity Changes in Patients with Migraine: A Short-Term Longitudinal Study

Ling Zha,Jixin Liu,Xuemei Yan,Wanghuan Dun,Jing Yang,Liyu Huang,Yuan Kai,Dahua Yu,Wei Qin,Tian Jie,Fanrong Liang 대한신경과학회 2014 Journal of Clinical Neurology Vol.10 No.3

Background and Purpose Whether or not migraine can cause cumulative brain alterationsdue to frequent migraine-related nociceptive input in patients is largely unclear. The aim of thisstudy was to characterize longitudinal changes in brain activity between repeated observationswithin a short time interval in a group of female migraine patients, using resting-state functional magnetic resonance imaging. Methods Nineteen patients and 20 healthy controls (HC) participated in the study. Regionalhomogeneity (ReHo) and functional interregional connectivity were assessed to determine thefocal and global features of brain dysfunction in migraine. The relationship between changes inheadache parameters and longitudinal brain alterations were also investigated. Results All patients reported that their headache activity increased over time. AbnormalReHo changes in the patient group relative to the HC were found in the putamen, orbitofrontalcortex, secondary somatosensory cortex, brainstem, and thalamus. Moreover, these brain regions exhibited longitudinal ReHo changes at the 6-week follow-up examination. These headache activity changes were accompanied by disproportionately dysfunctional connectivity inthe putamen in the migraine patients, as revealed by functional connectivity analysis, suggesting that the putamen plays an important role in integrating diverse information among othermigraine-related brain regions. Conclusions The results obtained in this study suggest that progressive brain aberrations in migraine progress as a result of increased headache attacks.

Impact of a Dust Storm on Characteristics of Particle Matter (PM) in Guangzhou, China

Qi Fan,Chong Shen,Xuemei Wang,Yuan Li,Wei Huang,Guixiong Liang,Shaoyi Wang,Zhuoer Huang 한국기상학회 2013 Asia-Pacific Journal of Atmospheric Sciences Vol.49 No.1

A strong dust-storm (23-25 April, 2009) occurred in the provinces of Inner Mongolia, Gansu, and Shanxi, North China. Cities along the storm path (from north to south: Xi’ning, Lanzhou,Chengdu, Changsha, and Guangzhou) all experienced a sharp increase in particle matter (PM10) concentration. This is the first case that an Asian dust storm hit Guangzhou in Southern China. The impacts of dust storm on the characteristics of PM were investigated using samples collected in Guangzhou during 27-29 April, 2009. In addition, the mass concentration and chemical composition during a normal non-dust period (12-14 May, 2009) were compared with those in dust period. The results show that the concentration of PM10during the dust episode (0.231 mg m−3) was twice higher than that in the non-dust episode (0.103 mg m−3). Chemical analysis showed that concentrations of metal elements, enrichment factors of metal elements, and soluble ions during the dust episode were very different from those of non-dust. The total concentration of metal elements content in PM10 was 53.5 μg m−3 in the dust episode, which is about two times higher than that in non-dust episode (28.5 μgm−3). Increases in concentrations of Na, Ti, Zn, Cu, and Cr ranged from zero to 100% during the dust episode. However, the enrichment factors in non-dust episode were higher than that in dust-storm period,indicating that the above five chemicals originated mainly from local sources in Guangzhou. The concentrations of K, Mg, Al, Fe, Mn, V,and Co increased by over 100% in the dust episode, indicating their origins of remote sources. In the dust period, some water-soluble ions increased in PM10, but the main components in PM10 were SO42−,NO3− and NH4+. At last, we assessed the sources of dusts by analyzing synoptic situation and back trajectories of air mass in Guangzhou, and demonstrated that the main source of the dust storm was from Mongolia.

Control Algorithm of Static Loading Test for Wind Turbine Blades Based on Fuzzy Theory

Zhang Leian,Huang Xuemei,Yuan Guangming 보안공학연구지원센터 2015 International Journal of Smart Home Vol.9 No.4

In the process of full-scale static loading test of wind turbine blades, the loading forces all had relatively strong coupling effect, which seriously affected the accuracy of the test result. In order to eliminate this effect, firstly, a vertical static loading device for 10MW wind turbine blades was established and the coupling rule of loading force was obtained. Then, a control algorithm was put forward based on fuzzy theory. This algorithm took the error of loading force, error’s change rate as the input variables and the opening degree of proportional valve as the output variable. A control strategy based on this algorithm was constructed. In the end, the static device took the max flapwise of aeroblade5.0-62 wind turbine blade as example to conduct loading test. The result suggested the algorithm in this paper could ensure that the loading forces on five nodes always kept uniform changing and the control errors were respectively less than±2KN, ±2KN,± 2KN,± 2KN and±1KN. When in the 100% phase, the loading force could be finely maintained at the set value. The statistical results showed that the error rates of loading force with control algorithm were smaller than those without control algorithm. The test results verified the feasibility of control strategy applying to full-scale static loading test for wind turbine blades.

Continuous Passaging of a Recombinant C-Strain Virus in PK-15 Cells Selects Culture-Adapted Variants that Showed Enhanced Replication but Failed to Induce Fever in Rabbits

( Chao Tong ),( Ning Chen ),( Xun Liao ),( Xuemei Yuan ),( Mengjiao Sun ),( Xiaoliang Li ),( Weihuan Fang ) 한국미생물생명공학회(구 한국산업미생물학회) 2017 Journal of microbiology and biotechnology Vol.27 No.9

Classical swine fever virus (CSFV) is the etiologic agent of classical swine fever, a highly contagious disease that causes significant economic losses to the swine industry. The lapinized C-strain, a widely used vaccine strain against CSFV, has low growth efficiency in cell culture, which limits the productivity in the vaccine industry. In this study, a recombinant virus derived from C-strain was constructed and subjected to continuous passaging in PK-15 cells with the goal of acquiring a high progeny virus yield. A cell-adapted virus variant, RecCpp80, had nearly 1,000-fold higher titer than its parent C-strain but lost the ability to induce fever in rabbits. Sequence analysis of cell-adapted RecC variants indicated that at least six nucleotide changes were fixed in RecCpp80. Further adaption of RecCpp80 variant in swine testicle cells led to a higher virus yield without additional mutations. Introduction of each of these residues into the wild-type RecC backbone showed that one mutation, M979R (T3310G), located in the C-terminal region of E2 might be closely related to the cell-adapted phenotype. Rabbit inoculation revealed that RecCpp80+10 failed to induce fever in rabbits, whereas RecCpp40₊₁₀ caused a fever response similar to the commercial C-strain vaccine. In conclusion, the C-strain can be adapted to cell culture by introducing specific mutations in its E2 protein. The mutations in RecCpp80 that led to the loss of fever response in rabbits require further investigation. Continuous passaging of the C-strain-based recombinant viruses in PK-15 cells could enhance its in vitro adaption. The non-synonymous mutations at 3310 and 3531 might play major roles in the enhanced capacity of general virus reproduction. Such findings may help design a modified C-strain for improved productivity of commercial vaccines at reduced production cost.

Transcriptome Sequencing Reveals the Potential Mechanisms of Modified Electroconvulsive Therapy in Schizophrenia

Wanhong Peng,Qingyu Tan,Minglan Yu,Ping Wang,Tingting Wang,Jixiang Yuan,Dongmei Liu,Dechao Chen,Chaohua Huang,Youguo Tan,Kezhi Liu,Bo Xiang,Xuemei Liang 대한신경정신의학회 2021 PSYCHIATRY INVESTIGATION Vol.18 No.5

Objective Schizophrenia (SCZ) is one of the most common and severe mental disorders. Modified electroconvulsive therapy (MECT) is the most effective therapy for all kinds of SCZ, and the underlying molecular mechanism remains unclear. This study is aim to detect the molecule mechanism by constructing the transcriptome dataset from SCZ patients treated with MECT and health controls (HCs).Methods Transcriptome sequencing was performed on blood samples of 8 SCZ (BECT: before MECT; AECT: after MECT) and 8 HCs, weighted gene co-expression network analysis (WGCNA) was used to cluster the different expression genes, enrichment and protein-protein interaction (PPI) enrichment analysis were used to detect the related pathways.Results Three gene modules (black, blue and turquoise) were significantly associated with MECT, enrichment analysis found that the long-term potentiation pathway was associated with MECT. PPI enrichment p-value of black, blue, turquoise module are 0.00127, <1×10^-16 and 1.09×10^-13, respectively. At the same time, EP300 is a key node in the PPI for genes in black module, which got from the transcriptome sequencing data.Conclusion It is suggested that the long-term potentiation pathways were associated with biological mechanism of MECT.