Combined Optimal Dispatch of Thermal Power Generators and Energy Storage Considering Thermal Power Deep Peak Clipping and Wind Energy Emission Grading Punishment

Peak load and wind energy emission pressure rise more as wind energy penetration keeps growing,which affects the stabilization of the PS(power system).This paper suggests integrated optimal dispatching of thermal power generators and BESS(battery energy storage system)taking wind energy emission grading punishment and deep peak clipping into consideration.Firstly,in order to minimize wind abandonment,a hierarchical wind abandonment penalty strategy based on fuzzy control is designed and introduced,and the optimal grid-connected power of wind energy is determined as a result of minimizing the peak cutting cost of the system.Secondly,considering BESS and thermal power,the management approach of BESS-assisted virtual peak clipping of thermal power generators is aimed at reducing the degree of deep peak clipping of thermal power generators and optimizing the output of thermal power generators and the charging and discharging power of BESS.Finally,Give an example of how this strategy has been effective in reducing abandonment rates by 0.66% and 7.46% individually for different wind penetration programs,and the daily average can reduce the peak clipping power output of thermal power generators by 42.97 and 72.31 MWh and enhances the effect and economy of system peak clipping.

Posterior reversible encephalopathy syndrome following uneventful clipping of an unruptured intracranial aneurysm:A case report

BACKGROUND Posterior reversible encephalopathy syndrome(PRES)is characterized mainly by occipital and parietal lobe involvement,which can be reversible within a few days.Herein,we report a rare case of PRES that developed after craniotomy for an unruptured intracranial aneurysm(UIA).CASE SUMMARY A 59-year-old man underwent clipping surgery for the treatment of UIA arising from the left middle cerebral artery.Clipping surgery was performed uneventfully,and he regained consciousness quickly immediately after the surgery.At the 4th hour after surgery,he developed a disorder of consciousness and aphasia.Magnetic resonance imaging revealed cortical and subcortical T2/FLAIR hyperintensities in the parietal,occipital,and frontal lobes ipsilaterally,without restricted diffusion,consistent with unilateral PRES.With conservative treatment,his symptoms and radiological findings almost completely disappeared within weeks.In our case,the important causative factor of PRES was suspected to be a sudden increase in cerebral perfusion pressure associated with temporary M1 occlusion.CONCLUSION Our unique case highlights that,to our knowledge,this is the second report of PRES developing after craniotomy for the treatment of UIA.Surgeons must keep PRES in mind as one of the causes of perioperative neurological abnormality following clipping of an UIA.

关于平面Clipping随机场的若干性质

讨论了平面随机场关于水平 μ 的 clipping 随机场的各向同性,齐性,独立性和可分性的若干结果.

脉冲噪声环境中基于clipping方法的鲁棒LPFT及其重排算法

为了更好地处理脉冲噪声环境中的时变信号,本文提出了基于clipping方法的鲁棒局部多项式傅里叶变换(LPFT)及其重排算法。首先利用clipping方法对信号中掺杂的脉冲噪声进行抑制,得到较好的信号时频分布表示,然后将重排算法与该鲁棒LPFT相结合,以提高信号的时频聚集性。通过实验仿真可以看出,与基于中值滤波器的鲁棒LPFT相比,基于clipping方法的鲁棒LPFT同样能对被脉冲噪声干扰的信号给出较好的时频表示,而且其瞬时频率估计的最小均方误差(MSE)较低,计算量较小。并且,本文在基于clipping方法的鲁棒LPFT对掺杂脉冲噪声的信号进行处理的基础上,利用重排算法与其结合,有效增强了信号的时频聚集性。因此基于clipping方法的鲁棒LPFT及其重排算法是一种高效的处理脉冲噪声干扰信号及提高信号时频聚集性的方法。

用于降低OFDM系统峰均功率比的PTS-Clipping联合算法

基于IEEE 802.16d协议的OFDM传输系统,研究了峰均功率比(PAPR)较高的原因,在现有PARR降低算法的基础上,深入研究了算法之间的最佳联合准则,比较了两种可行的联合算法PTS-Clipping和Clipping-PTS之间的性能差异,得出了算法联合时的最佳级联顺序。Matlab仿真结果表明,PTS-Clipping是较优的联合算法,能够最大限度地利用现有算法的优势,在很好地降低PAPR的同时,又不会引入很大的计算量和限幅噪声。另外,本文得出的最佳联合准则具有通用性,适用于其他PAPR降低算法之间的联合。

Clipping Alters the Response of Biomass Production to Experimental Warming: A Case Study in an Alpine Meadow on the Tibetan Plateau, China

Predicting how human activity will influence the response of alpine grasslands to future warming has many uncertainties.In this study, a field experiment with controlled warming and clipping was conducted in an alpine meadow at three elevations（4313 m, 4513 m and 4693 m） in Northern Tibet to test the hypothesis that clipping would alter warming effect on biomass production.Open top chambers（OTCs） were used to increase temperature since July,2008 and the OTCs increased air temperature by approximately 0.9o C ~ 1.8o C during the growing in2012.Clipping was conducted three times one year during growing season and the aboveground parts of all live plants were clipped to approximately 0.01 m in height using scissors since 2009.Gross primary production（GPP） was calculated from the Moderate-Resolution Imaging Spectroradiometer GPP algorithm and aboveground plant production was estimated using the surface-measured normalized difference vegetation index in 2012.Warming decreased the GPP, aboveground biomass（AGB） and aboveground net primary production（ANPP） at all three elevations when clipping was not applied.In contrast, warming increased AGB at all three elevations, GPP at the two lower elevations and ANPP at the two higher elevations when clipping was applied.These findings show that clipping reduced the negative effect of warming on GPP, AGB and ANPP, suggesting that clipping may reduce the effect of climate warming on GPP, AGB and ANPP in alpine meadows on the Tibetan Plateau, and therefore, may be a viable strategy for mitigating the effects of climate change on grazing and animal husbandry on the Tibetan Plateau.

Analysis of wave clipping effects of plain reservoir artificial islands based on MIKE21 SW model

Plain reservoirs are shallow, and have low dams and widespread water surfaces.Therefore, wind-wave-induced damage to the dam is one of the important factors affecting the safety of the reservoir.To improve upon unsatisfactory plain reservoir wave-clipping schemes, a numerical method is proposed to predict and analyze waves in the reservoir in the presence of artificial islands, constructed from dredged sediment.The MIKE21 SW model is applied to a specific plain reservoir for finding the optimal artificial island parameters.The simulated wave height attenuation results are seen to agree well with empirically predicted values.Thus, the validity and reliability of the numerical model are established.Artificial islands at suitable locations in the reservoir can attenuate the wave heights by approximately 10%e30%, which justifies the efficacy of the clipping scheme making use of dredging and island construction.

Signal Clipping at Transmitter and Receiver of O-OFDM for VLC under Optical Power Constraint

Visible light communications(VLC)is considered as an effective supplement technology for next-generation(6G)communications due to its abundant spectrum,high power efficiency and easy deployment.Optical orthogonal frequency division multiplexing(O-OFDM)is a common technology to obtain further promotion.In this paper,two typical O-OFDM schemes direct current biased O-OFDM(DCO-OFDM)and asymmetrically clipped O-OFDM(ACO-OFDM)are analyzed in terms of signal clipping at both transmitter and receiver under the constraints of maximum optical power and non-negative optical power.And effective electrical SNR models after signal clipping are proposed and verified by link simulation.Then a noise cancellation scheme is proposed based on received signal clipping and is proved to bring a significant gain for ACO-OFDM.By system simulation,we find that under a certain optical power limitation,most users can achieve above 4 Gbps in indoor scenario when modulation bandwidth of the light emit diode(LED)or laser diode(LD)is 1 GHz.Therefore,it can be expected that the throughput could reach tens Gbps when the LED/LD modulation bandwidth is increased and multiple LEDs/LDs are deployed.

Applications of multislice CT angiography in the surgical clipping and endovascular coiling of intracranial aneurysms

Prompt diagnosis and therapy of aneurysms are critical for patients with nontraumatic subarachnoid hemorrhage （SAH）.The aim of our study was to assess the clinical usefulness of multislice computed tomography angiography （CTA） in the surgical and endovascular treatment of intracranial aneurysms.A total of 195 cases with 206 intracranial aneurysms underwent CTA.Fifty （24%） aneurysms underwent surgical clipping while 156 （76%） aneurysms underwent endovascular coiling.In the five missed aneurysms at digital substraction angiography and the nine aneurysms with mass intracerebral hematomas,surgical treatment was successfully performed based on 16-slice CTA alone,and the other 36 aneurysms were clipped on the main basis of the CTA.The intraoperative findings correlated well with the CTA findings and all aneurysms were clipped successfully.Sixteen-slice CTA image information has been shown to determine the choice of aneurysm therapy and assist the surgical and endovascular treatment of intracranial aneurysms.

Outcomes of early physiotherapy in patients with cerebral aneurysms treated by surgical clipping or endovascular embolization

Early physiotherapy was given to 124 patients with ruptured or unruptured cerebral aneurysms who were treated by surgical clipping or endovascular embolization.Patients were divided into four groups according to their Hunt and Hess grade at admission and aneurysm treatment modality： Group 1,Hunt and Hess grade≤II and surgical clipping;Group 2,Hunt and Hess grade≤II and endovascular embolization;Group 3,Hunt and Hess grade≥III and surgical clipping;Group 4,Hunt and Hess grade≥III and endovascular embolization.Level of consciousness was evaluated using the Glasgow Coma Scale,functional status using the Glasgow Outcome Scale,level of the mobility using the Mobility Scale for acute stroke patients,and independence in activities of daily living using the Barthel Index.After early physiotherapy,the level of consciousness and functional status improved significantly in Groups 1,3,and 4;mobility improved significantly in all groups;and independence in activities of daily living improved significantly in Groups 1 and 3.At discharge, Groups 1 and 2 had better functional status than Groups 3 and 4.Level of consciousness,functional status,mobility and independence in activities of daily living improved after early physiotherapy. These findings suggest that early physiotherapy improved the prognosis of patients with cerebral aneurysms who were treated by surgical clipping or endovascular embolization.Patients with a worse clinical status at presentation had a poorer functional status at discharge.The outcome of physiotherapy was not affected by whether surgical clipping or endovascular embolization was chosen for treatment of the aneurysm.

A Strategy of Signal Detection for Performance Improvement in Clipping Based OFDM System

In this paper,the supervised Deep Neural Network(DNN)based signal detection is analyzed for combating with nonlinear distortions efficiently and improving error performances in clipping based Orthogonal Frequency Division Multiplexing(OFDM)ssystem.One of the main disadvantages for the OFDM is the high Peak to Average Power Ratio(PAPR).The clipping is a simple method for the PAPR reduction.However,an effect of the clipping is nonlinear distortion,and estimations for transmitting symbols are difficult despite a Maximum Likelihood(ML)detection at the receiver.The DNN based online signal detection uses the offline learning model where all weights and biases at fully-connected layers are set to overcome nonlinear distortions by using training data sets.Thus,this paper introduces the required processes for the online signal detection and offline learning,and compares error performances with the ML detection in the clipping-based OFDM systems.In simulation results,the DNN based signal detection has better error performance than the conventional ML detection in multi-path fading wireless channel.The performance improvement is large as the complexity of system is increased such as huge Multiple Input Multiple Output(MIMO)system and high clipping rate.

Clipping prevents perforation in large, flat polyps

AIM To determine if prophylactic clipping of post-polypectomy endoscopic mucosal resection(EMR) mucosal defects of large,flat,right sided polyps prevents perforations.METHODS IRB approved review of all colonoscopies,and prospective data collection of grasp and snare EMR performed by 2 endoscopists between January 1,2010 and March 31,2014 in a community ambulatory endoscopy center.The study consisted of two phases.In the first phase,all right-sided,flat polyps greater than or equal to 1.2 cm in size were removed using the grasp and snare technique.Clipping was done at the discretion of the endoscopist.In the second phase,all mucosal defects were closed using resolution clips.Phase 2 of the study was powered to detect a statistically significant difference in perforation rate with 148 EMRs,if less than or equal to 2 perforations occurred.RESULTS In phase 1 of the study,2121 colonoscopies were performed.Seventy-five patients had 95 large polyps removed.There were 4 perforations in 95 polypectomies(4.2%).The perforations occurred in polyps ranging in size from 1.5 cm to 2.5 cm.In phase 2,there were 2464 colonoscopies performed.One hundred and sixteen patients had 151 large polyps removed,and all mucosal defects were clipped.There were no perforations(P=0.0016).There were no post-polypectomy hemorrhages in either phase.An average of 2.15 clips were required to close the mucosal defects.The median time to perform the polypectomy and clipping was 13 min,and the median procedure duration was 40 min.Five percent of all patients undergoing colonoscopy in our community based,ambulatory endoscopy center had flat,right sided polyps greater than or equal to 1.2 cm in size.CONCLUSION Prophylactic clipping of the mucosal resection defect of large,right-sided,flat polyps reduces the incidence of perforation.

Role of endoscopic clipping in the treatment of oesophagealperforations

With advances in endoscopic technologies,endoscopic clips have been used widely and successfully in the treatment of various types of oesophageal perforations,anastomosis leakages and fistulas. Our aim was to summarize the experience with two types of clips: The through-the-scope(TTS) clip and the over-the-scope clip(OTSC). We summarized the results of oesophageal perforation closure with endoscopic clips. We processed the data from 38 articles and 127 patients using PubM ed search. Based on evidence thus far,it can be stated that both clips can be used in the treatment of early(< 24 h),iatrogenic,spontaneous oesophageal perforations in the case of limited injury or contamination. TTS clips are efficacious in the treatment of 10 mm lesions,while bigger(< 20 mm) lesions can be treated successfully with OTSC clips,whose effectiveness is similar to that of surgical treatment. However,the clinical success rate is significantly lower in the case of fistulas and in the treatment of anastomosis insufficiency. Tough prospective randomized multicentre trials,which produce the largest amount of evidence,are still missing. Based on experience so far,endoscopic clips represent a possible therapeutic alternative to surgery in the treatment of oesophageal perforations under well-defined conditions.

Reduction of the Clipping Noise for OFDM/OQAM System

Orthogonal frequency division multiplex/offset QAM (OFDM/OQAM) has been proven to be a promising multi-carrier modulation (MCM) technique for the transmission of signals over multipath fading channels. However, OFDM/OQAM has also the intrinsic disadvantage of high peak-to-average-power ratio (PAPR) that should be alleviated. This paper focuses on the reduction of the clipping noise and out-of band radiation caused by the clipping process. The basic principle is to estimate the clipping noise and then eliminate it from the received signal. Analysis and simulation results show that, with one time iteration, the proposed method can effectively improve the bit error ratio (BER) performance.

The Line Clipping Algorithm Basing on Affine Transformation

A new algorithm for clipping line segments by a rectangular window on rectangular coordinate system is presented in this paper. The algorithm is very different to the other line clipping algorithms. For the line segments that cannot be identified as completely inside or outside the window by simple testings, this algorithm applies affine transformations (the shearing transformations) to the line segments and the window, and changes the slopes of the line segments and the shape of the window. Thus, it is clear for the line segment to be outside or inside of the window. If the line segments intersect the window, the algorithm immediately (no solving equations) gets the intersection points. Having applied the inverse transformations to the intersection points, the algorithm has the final results. The algorithm is successful to avoid the complex classifications and computations. Besides, the algorithm is effective to simplify the processes of finding the intersection points. Comparing to some classical algorithms, the algorithm of this paper is faster for clipping line segments and more efficient for calculations.

Human Nail Clippings as a Source of DNA for Genetic Studies

Blood samples have traditionally been used as the main source of DNA for genetic analysis. How-ever, this source can be difficult in terms of collection, transportation, and long-term storage. In this study, we investigated whether human nail clippings could be used as a source of DNA for SNP genotyping, null-allele detection, and whole-genome amplification. From extracted nail DNA, we achieved amplicons up to a length of ~400 bp and >96% concordance for SNP genotyping and 100% concordance for null-allele detection compared to DNA derived from matched blood sam-ples. For whole-genome amplification, OmniPlex performed better than Multiple Displacement Amplification with a success rate of 89.3% and 76.8% for SNP genotyping and null-allele detection, respectively. Concordance was ~98% for both methods. When combined with OmniPlex whole-genome amplification, human nail clippings could potentially be used as an alternative to whole blood as a less invasive and more convenient source of DNA for genotyping studies.

Effects of clipping on dry matter production and nutrients in the fernland of Hong Kong

The dry matter production and its nutrient amounts varied significantly with time and period from April to June was a favourable season for plant growth. Dry matter production declined significantly with clipping. Especially, repeated cutting of high frequencies for the long term had a severe effect on dry matter production. However, N, P, and K amounts in dry matter production did not significantly decline because the concentrations of N, P, and K in the plants increased with clipping. Repeated cutting for long term is a reason why net primary production has been depressed in the most of upland areas of southern China.

Endoscopic clipping in the lower gastrointestinal tract

Endoscopic clipping has been established as a safe and effective method for the treatment of nonvariceal upper gastrointestinal bleeding in numerous randomized studies.Recently,clipping has been applied to various lesions in the lower gastrointestinal tract,including diverticular bleeding,postpolypectomy bleeding,and repair of perforations with successful outcomes.We review the safety and efficacy of this maneuver for the management of diseases in the lower gastrointestinal tract.

Line clipping against polygonal window algorithm based on the multiple virtual boxes rejecting

This paper presents a new algorithm for line clipping against a polygonal window by exploiting the local relationship between each line segment and the polygon. Firstly, a minimal enclosing box （MEB） of the polygon is adopted to reject the invisible line segments located outside the MEB. Secondly, a 45° rotated box is used to encode the endpoint of the line segment, and then reject a portion of the invisible segments crossing polygon comers. Finally, instead of encoding the endpoints of all line segments with respect to the polygonal window, each vertex of the polygon is encoded, taking the line segment to be clipped as reference. For efficient encoding of the polygon vertices, a new concept, termed with slope adaptive virtual box, is introduced regarding each line segment. Such a box can not only conveniently reject all totally invisible lines lying outside the MEB conveniently, but also precisely identify the edges of the polygon with which the line segment potentially intersects. With the summation of the vertex codes, it can be verified whether the line segment is separated from or potentially intersects the polygon window. Based on the product of the codes of adjacent vertices, singular cases of intersection can be solved accurately. Experimental results demonstrate the efficiency and stability of the new algorithm.

Endoscopic clipping for the secondary prophylaxis of bleeding gastric varices in a patient with cirrhosis:A case report

BACKGROUND Bleeding from gastroesophageal varices(GOV)is a serious complication in patients with liver cirrhosis,carrying a very high mortality rate.For secondary prophylaxis against initial and recurrent bleeding,endoscopic therapy is a critical intervention.Endoscopic variceal clipping for secondary prophylaxis in adult GOV has not been reported.CASE SUMMARY A 66-year-old man with cirrhosis was admitted to our hospital complaining of asthenia and hematochezia for 1 wk.His hemoglobin level and red blood cell counts were significantly decreased,and his fecal occult blood test was positive.An enhanced computed tomography of the abdomen showed GOV.The patient was diagnosed with hepatitis B cirrhosis-related GOV bleeding.A series of palliative treatments were administered,resulting in significant clinical improvement.Subsequently,an endoscopic examination revealed severe gastric fundal varices,prompting endoscopic variceal clipping.There were no further episodes of gastrointestinal bleeding.The GOV improved significantly on follow-up imaging and was confirmed as improved on endoscopy at the 5th post-operative month.CONCLUSION Our results suggest that endoscopic clipping is an inexpensive,safe,easy,effective,and tolerable method for the secondary prophylaxis of bleeding from gastric type 2 GOV.However,additional research is indicated to confirm its longterm safety and efficacy.