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视频点播中用户行为分析

视频点播中用户行为分析

作者： m. RIZWAN arif 中国科学技术大学

学位级别：硕士

视频点播(VoD)服务已经成为在线娱乐产业的一个重要部分。然而,在实现VOD服务上仍然有许多挑战,尤其是带宽、存储和数据传输已经成为影响在供应商向客户提供VOD服务的主要问题。本工作的目的在于通过对用户点播行为的研究,帮助服务商了... 详细信息

视频点播(VoD)服务已经成为在线娱乐产业的一个重要部分。然而,在实现VOD服务上仍然有许多挑战,尤其是带宽、存储和数据传输已经成为影响在供应商向客户提供VOD服务的主要问题。本工作的目的在于通过对用户点播行为的研究,帮助服务商了解用户需求,从而设置更加合适的服务策略和服务模式,以将数据高效传输给用户,提高用户的满意度。本文采用了中国电信在江苏省开展IPTV商业运行的实际用户行为数据,并着重研究了与点播时长、到达率、离开率和系统并发率有关的工作负载特性。本文主要工作有：1.建立SQL数据库,并将从江苏电信获得的运行数据在数据库中进行复原,并编写SQL程序进行分析。2.研究了用户点播时长的分布,针对电影和电视剧的结果稍有不同,电影类的用户观看时长大多是短时间的(1-5分钟内);电视剧类的会话时长多为一个正常电视剧集长度(40-50分钟)。总体来说,用户行为态度是急躁的。3.研究了用户到达率和离开率,两者是相似的,均有明显的规律性：从0点到6点,用户到达/离开率逐步下降到最低值;6点到11点,到达/离开率会慢慢提升到平均值;11点到14点到达/离开率会再次提升到更高值;14点到18点间又降低;然后开始上升,20点到23点半是全天的最高值,随后开始下降。4.最后研究了系统并发率。在以小时为考察单位考察每天的系统并发情况时,由模型可以看出早晨、午休和傍晚时用户访问量增加。更多的用户访问发生在晚上8点,在2个小时后达到峰值,之后在第二天早上3点多开始减到最低值。而将上述考察周期改为一周作为观察窗口,则一周中,周末的系统并发量最高。通过上述研究可以发现,VOD服务的用户行为具有一定的模式,后继可以对系统通过上述模型,进一步研究其服务策略的设置,从而提高系统的服务质量。

关键词： VOD系统单播系统多播系统宽带管理

Efficacy of interferon alpha-2b and lamivudine therapy for chronic hepatitis B in children

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中华医学杂志(英文版) 2003年第4期 114-117页

作者： Bahar arif,Iscan Selim,Karademir Ferhan,Gocmen Ismail Department of Pediatrics GmmA Haydarpaa Training Hospital Kadiky Department of Pediatrics GmmA Haydarpaa Training Hospital Kadiky Department of Pediatrics GmmA Haydarpaa Training Hospital Kadiky Department of Pediatrics GmmA Haydarpaa Training Hospital Kadiky Istanbul 81327 Turkey Istanbul 81327 Turkey Istanbul 81327 Turkey Istanbul 81327 Turkey

To evaluate the efficacy of interferon (IFN) alpha-2b and lamivudine therapy in children with chronic hepatitis B virus (HBV) infection method Ten children who developed chronic hepatitis B infection received IFN alpha-2b 10 million international units (IU)/m 2 body surface area, subcutaneously three times a week for six months IFN+lamivudine therapy began to be used in the cases who were unresponsive to IFN treatment Results Among 27 HBsAg (+) subjects in this study, interferon treatment was given to 11 subjects who developed chronic hepatitis One case was excluded from the study due to detection of Herpes type 1 encephalitis At the end of six months of follow-up, complete response was obtained in three (30%) patients and partial response in four (40%) patients, whereas no response was detected in three (30%) patients Fifty percent of the cases experienced serological response, 70% biochemical response, and all (100%) had histological response In three cases started concomitant IFN+lamivudine therapy, HBV-DNA became negative at the second month of treatment Conclusions IFN-alpha and lamivudine can be used for the treatment of chronic hepatitis B infection in children

关键词： Hepatitis B · interferon · children · hepati tis B virus · lamivudine

modelling the Soil Loss in the Watershed of the Chaddad Wadi in Terms of Both Rockiness and Soil Slaking Indexes

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International Journal of Geosciences 2020年第3期11卷 100-124页

作者： Naima Azaiez arif King Khalid University Abha KSA Preparatory Institute for Literary Studies and Human Sciences of Tunis I (IPELSHT) Tunis Tunisia Research Laboratory: “Biogeography Applied Climatology and Environmental Dynamics” (BICADE) Faculty of Arts and Humanities of Manouba Manouba Tunisia

Currently we are at a phase where morphogenesis is gaining more prominence and dimension regarding the pedogenesis. The numerous multidisciplinary studies on the soil showed that the erosive action as well as the various problems that result from it, bring out a very serious state of soil degradation in the semi-arid field [1]-[9]. Several attempts have established to set empirical and experimental methods for a quantitative estimation of soil loss caused by diffuse erosion. In this perspective, this research intends to track soil losses in the watershed of the Chaddad wadi, the average-flowing stream of the Nebhana wadi belonging to the lower semi-arid field. The main stream and its tributaries drain an area of 26.5 km2 from the eastern slopes of Ejhaf mountain (517 m) and Fartout mountain (476 m), as well as the southern slope of Ediour mountain (405 m). The dividing line of the waters with the Khalfallah wadi and Bel Assoued wadi is caused by rows of hills with an altitude ranging between 220 m and 306 m such as the hills of Sidi Salah and those of Es-Souida and Ain Fres. The Wischmeier Equation will be improved by two corrective parameters: the rockiness on the one hand and the soil slaking index on the other, aiming to develop and optimize the potential of this empirical model. This application allowed overcoming some of the limitations that came with the Wischmeier equation, which is primarily designed for an application within different physical conditions on the scale of a land plot. This research is an opportunity to make a detailed contribution to the potential sensitivity of the watershed to water erosion. A good demarcation of the physical anthropogenic framework of the erosive action will provide substantial support in terms of soil protection and the stabilization of watersheds emitting sediments.

关键词： Drainage Density Index of Soil Slaking Crust Sheet Erosion Stoniness Index USLE

亲水性介孔碳负载Ru纳米粒子催化海藻油低温水相加氢脱氧制烷烃

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Chinese Journal of Catalysis 2020年第8期41卷 1174-1185页

作者：林凯赵晨华东师范大学化学与分子工程学院上海市绿色化学与化工过程绿色化重点实验室上海200062 华东师范大学崇明生态研究院上海200062

将微藻油等能源载体加工成有价值的燃料和化学品具有广阔的应用前景.由于从藻类细胞中分离固有水非常困难,因此以水相为溶剂适合含水微藻油的转化.而制备耐水且水热稳定的催化剂非常重要,因为许多载体容易被蒸汽破坏.其中,碳材料相当稳... 详细信息

将微藻油等能源载体加工成有价值的燃料和化学品具有广阔的应用前景.由于从藻类细胞中分离固有水非常困难,因此以水相为溶剂适合含水微藻油的转化.而制备耐水且水热稳定的催化剂非常重要,因为许多载体容易被蒸汽破坏.其中,碳材料相当稳定,具有高的比表面积.然而,它们具有高度的憎水性,亲水性较差,因此很难与水中的反应物接触.本文中,我们合成了以高度亲水性介孔碳为载体的钌/碳催化剂,用于催化微藻油在低温(140℃)下一锅法于水相中定量加氢脱氧成烷烃.首先以淀粉和氯化锌为原料,在氮气中一步煅烧制备了介孔炭.其中,淀粉用作碳源,氯化锌则作为活化的路易斯酸和脱水剂.所得碳具有高的比表面积和孔体积,使得Ru纳米粒子具有较高的分散性.XPS表征表明,Ru/AC在286.5 e V处有一个与杂原子结合的sp^2碳峰,表明催化剂上存在C-OH基团.值得注意的是,Ru/C-ZnCl2催化剂在286.5 e V时的峰值比Ru/AC催化剂的峰值更强,显示Ru/C-ZnCl2表面有更多的C-OH键.FTIR光谱研究表明,两种催化剂分别在3400和1530 cm^-1处出现对应于O-H拉伸和C=C键的振动峰.有趣的是,Ru/C-ZnCl2催化剂在1092 cm^-1处显示出强且宽的峰证实了羟基的存在.但在Ru/AC催化剂中没有观察到该峰.催化剂的热重分析显示,在低于100℃、120-579℃和580℃的温度下分别出现三个峰,分别对应于脱水(表面水分)、去除含氧基团和载体分解.Ru/C-ZnCl2催化剂的失重率(13%)是Ru/AC(3%)的4倍,与FTIR测试结果一致,表明Ru/C-ZnCl2催化剂上的羟基含量较高.XPS、IR和TGA结果表明,碳材料表面富含羟基.另一方面,对Ru/C-ZnCl2和Ru/AC催化剂进行了与水的接触角实验,通过比较Ru/C-ZnCl2和Ru/AC与水的不同作用角,进一步证实了Ru/C-ZnCl2比Ru/AC具有更好的亲水性.我们认为,碳材料相对于有机相优选地与水相接触,提高了基底的可接近性.同样,亲水性碳材料由于其水相容性而更适合于水相反应.催化剂对硬脂酸的反应结果显示,Ru/AC催化剂转化率为100%,硬脂醇收率52%,正庚烷收率43%,酯收率3%.而Ru/C-ZnCl2催化剂的硬脂酸转化率为100%,正庚烷产率为88%,正十八烷产率为12%.原位FTIR研究了模型化合物丁酸在两种钌/碳催化剂上的吸附和加氢脱氧作用.实验结果表明,丁酸在Ru/C-ZnCl2催化剂上显现了1720 m-1处丁酸的羰基振动峰,这是由于其多孔性和对丁酸的吸附.相比之下,Ru/AC催化剂在1720 cm^-1处未见出峰显示对丁酸的弱吸附.总之,在硬脂酸的串联加氢和脱羰反应中,亲水性介孔和亲水性Ru/C-ZnCl2催化剂的动力学模拟和在水中的原位红外监测均显示出比商用Ru/AC催化剂优越的性能.本文设计的水热碳材料是一种高活性、环境友好、可持续、可循环利用的材料,在水热条件下的加氢反应中表现出很好的应用潜力.

关键词：海藻油硬脂酸十七烷亲水性碳材料加氢脱氧 Ru/C催化剂

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Genome Characteristics of the Cyclophragma Undans Nucleopolyhedrovirus: A Distinct Species in Group Ⅰ of Alphabaculovirus

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Virologica Sinica 2018年第4期33卷 359-368页

作者： Zheng Zhu Jun Wang Qianran Wang Feifei Yin Xiaoping Liu Dianhai Hou Lei Zhang Haizhou Liu Jiang Li Basil m. arif Hualin Wang Fei Deng Zhihong Hu manli Wang State Key Laboratory of Virology and China Center for Virus Culture Collection Wuhan Institute of Virology Chinese Academy of Sciences Wuhan 430071 China Canadian Forest Service Great Lakes Forestry Centre Sault Ste Marie ON P6A 2E5 Canada

The Cyclophragma undans nucleopolyhedrovirus(Cyun NPV), a potential pest control agent, was isolated from Cyclophragma undans(Lepidoptera: Lasiocampidae), an important forest pest. In the present study, we performed detailed genome analysis of Cyun NPV and compared its genome to those of other Group Ⅰ alphabaculoviruses. Sequencing of the Cyun NPV genome using the Roche 454 sequencing system generated 142,900 bp with a G + C content of 45%. Genome analysis predicted a total of 147 hypothetical open reading frames comprising 38 baculoviral core genes, 24 lepidopteran baculovirus conserved genes, nine Group Ⅰ Alphabaculovirus conserved genes, 71 common genes, and five genes that are unique to Cyun NPV. In addition, the genome contains 13 homologous repeated sequences(hrs). Phylogenetic analysis groups Cyun NPV under a distinct branch within clade ‘‘a'' of Group Ⅰ in the genus Alphabaculovirus. Unlike other members of Group Ⅰ, Cyun NPV harbors only nine of the 11 genes previously determined to be specific to Group Ⅰ ***, the Cyun NPV lacks the tyrosine phosphatase gene and the ac30 gene. The Cyun NPV F-like protein contains two insertions of continuous polar amino acids, one at the conventional fusion peptide and a second insertion at the pretransmembrane domain. The insertions are likely to affect the fusion function and suggest an evolutionary process that led to inactivation of the F-like protein. The above findings imply that Cyun NPV is a distinct species under Group Ⅰ Alphabaculovirus.

关键词：染色体分析核心基因特征害虫控制森林害虫重复序列种系发生进化过程

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Robots in Cancer Surgery: A Boon or Bane

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Journal of Cancer Therapy 2020年第12期11卷 803-823页

作者： Yusuf Jamal Abdulrahman m. Alshahrani Jamal m. arif Feras m. Almarshad Faculty of medicine Ternopil National Medical University Ternopil Ukraine Department of Internal medicine College of Medicine Shaqra University Shaqra KSA Department of Biochemistry College of Medicine Shaqra University Shaqra KSA

It is an ongoing task to keep exploring and applying the best available technology to alleviate the pain and sufferings of the cancer patients. Since the discovery of robotic surgery, da Vinci surgical systems have played a special and significant role in cancer surgeries worldwide, however, surgeons are still skeptical with the clinical and oncological outcomes which are almost comparable to the laparoscopic approach in several cancers. many meta-analyses using mostly retrospective studies indicated significant advantage of robotic surgery over laparoscopic or open surgery approaches for various cancers, however, scarcity of technically sound robot savvy surgeons and quality multicentered, multinational, coordinated, random clinical trials had not done justice to the positives of robotic surgery which were quite often suppressed by the negative factors like operative cost and oncological outcomes. Nevertheless, robotic surgery approach has been clinically accepted for hysterectomy and prostatectomy. This overview briefly discusses the comparative approaches (open, laparoscopic, robotic assisted) and their clinical outcomes in the surgery of various cancers.

关键词： Da Vinci Robotic Surgery Laparoscopic Surgery Cancers Oncologic Outcomes

Effect of sucrose and potassium nitrate on biomass and saponin content of Talinum paniculatum Gaertn. hairy root in balloon-type bubble bioreactor

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Asian Pacific Journal of Tropical Biomedicine 2015年第12期5卷 1027-1032页

作者： Yosephine Sri Wulan manuhara Alfinda Novi Kristanti Edy Setiti Wida Utami arif Yachya Laboratory of Plant Tissue Culture Biology Department Faculty of Science and Technology Airlangga University Laboratory of Organic Chemistry Chemistry Department Faculty of Science and Technology Airlangga University Laboratory of Plant Tissue Culture Biology Department Faculty of Mathematics and Natural Sciences PGRI Adi Buana University

Objective:To increase biomass and saponin production in hairy root culture of Talinum paniculatum Gaertn.(***)in balloon-type bubble bioreactor(BTBB).methods:Hairy roots which were collected from leaf explants of *** were infected by Agrobacterium rhizogenes strain *** hairy roots were cultivated at400 m L murashige and Skoog liquid medium without growth regulator(mS0)in1 000 m L *** BTBB had 2 g hairy roots as initial inoculum and these cultures were treated with various concentrations of sucrose(3%,4%,5%,6%w/v)and potassium nitrate(0.5,1.0,1.5 and 2.0 strength of mS medium).Cultures were maintained for *** and dry weights of hairy roots at the end of culture were ***:Various concentrations of sucrose influenced the biomass accumulation of hairy *** biomass was reached by mS medium supplemented with 6%sucrose and it was approximately threefold higher than *** supplemented with potassium nitrate at 2.0 strength of mS0 could increase biomass accumulation of hairy roots until 0.14 g dry weight and it was almost threefold higher than ***,the maximum saponin content was obtained by mS medium supplemented with 5%sucrose and 2.0 strength potassium nitrate of ***:Based on this research,those conditions can be used to produce biomass and saponin of hairy root of *** in the large scale.

关键词： Talinum paniculatum Gaertn. Saponin Hairy root Liq

Challenges of Internal and External Variables of Consumer Behaviour towards mobile Commerce

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International Journal of Communications, Network and System Sciences 2015年第13期8卷 578-596页

作者： arif Sari Pelin Bayram Department of management Information Systems Girne American University Kyrenia Cyprus Department of Business management Girne American University Kyrenia Cyprus

The mobile Commerce (m-commerce) becomes very powerful tool in the competitive business markets. Companies started to use this technology to attract their customers and catch their attention. Usage of mobile commerce applications spreaded around different countries and became very popular. Different communication protocols and security techniques are designed for business use of m-commerce. mobile Commerce, likewise the e-commerce brought significant difference in the market. People start to use this technology by feeling the freedom of having transactions at anywhere and anytime. However, consumers face lot of difficulties while using this technology which is consumer-based or service provider based. This research exposes the impact of determinants that influences mobile commerce application users’ attitudes by classifying and investigating the internal and external variables in a case study of Cyprus Research Centre.

关键词： m-Commerce Internal Variables External Variables Consumer Behaviour

Does Health Literacy Predict Preventive Lifestyle on metabolic Syndrome? A Population-Based Study in Sarawak malaysia

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Open Journal of Preventive medicine 2018年第6期8卷 169-182页

作者： S. Froze m. T. arif R. Saimon Department of Community medicine and Public Health Faculty of Medicine and Health Sciences Universiti Malaysia Sarawak Kota Samarahan Malaysia

Poor health literacy (HL) is a risk factor for developing metabolic syndrome. In malaysia, about 93% of adults’ population has limited HL—a huge prevalence yet understudied phenomenon. This study aims to determine the predictors of preventive lifestyles on metabolic syndrome among adult population in Sarawak are timely. This was a population-based study, conducted from September 2016 till December 2017 using a multistage stratified sampling method. Health Literacy Scale and Simple Lifestyle Indicator Questionnaire were used to measure health literacy and preventive lifestyles respectively. Analysis of Variance and logistic regression were used to analyze the data. A total of 743 respondents were involved in this study with half of them have acceptable score for health literacy (m = 46.9, SD = 6.3) and good preventive lifestyles (m = 7.3, SD = 1.4). Critical health literacy was a significant influence of preventive lifestyles. The malay ethnic group has the highest scores for both critical health literacy [F (3, 739) = 17.82, p p = 0.025]. The other Native groups scored the lowest for critical health literacy. Individual with higher score of critical health literacy tend to perform physical activities. Gender, education level, distance of health facilities, critical health literacy and employment status were identified as predictors for preventive lifestyle in this study. Health literacy is a key to preventive lifestyle behaviors in metabolic syndrome among adult population in Sarawak. Future program should focus on improving HL status with specific program targeting ethnic minorities.

关键词： Health Literacy metabolic Syndrome Preventive Lifestyle Sarawak