A CSMA/CA based MAC protocol for hybrid Power-line/Visible-light communication networks:Design and analysis

Hybrid Power-line/Visible-light Communication(HPVC)network has been one of the most promising Cooperative Communication(CC)technologies for constructing Smart Home due to its superior communication reliability and hardware efficiency.Current research on HPVC networks focuses on the performance analysis and optimization of the Physical(PHY)layer,where the Power Line Communication(PLC)component only serves as the backbone to provide power to light Emitting Diode(LED)devices.So designing a Media Access Control(MAC)protocol remains a great challenge because it allows both PLC and Visible Light Communication(VLC)components to operate data transmission,i.e.,to achieve a true HPVC network CC.To solve this problem,we propose a new HPC network MAC protocol(HPVC MAC)based on Carrier Sense Multiple Access/Collision Avoidance(CSMA/CA)by combining IEEE 802.15.7 and IEEE 1901 standards.Firstly,we add an Additional Assistance(AA)layer to provide the channel selection strategies for sensor stations,so that they can complete data transmission on the selected channel via the specified CSMA/CA mechanism,respectively.Based on this,we give a detailed working principle of the HPVC MAC,followed by the construction of a joint analytical model for mathematicalmathematical validation of the HPVC MAC.In the modeling process,the impacts of PHY layer settings(including channel fading types and additive noise feature),CSMA/CA mechanisms of 802.15.7 and 1901,and practical configurations(such as traffic rate,transit buffer size)are comprehensively taken into consideration.Moreover,we prove the proposed analytical model has the solvability.Finally,through extensive simulations,we characterize the HPVC MAC performance under different system parameters and verify the correctness of the corresponding analytical model with an average error rate of 4.62%between the simulation and analytical results.

A Contrastive Analysis of English and Chinese Idioms About Color Words & Their Cultural Connotations

There are many idioms related to color words in English and Chinese.The use of color words in idioms adds beauty and vividness to the language.Due to the cultural differences,“color idioms”have gained different cultural connotations with the development of English and Chinese languages.It is of great significance to accurately understand and grasp the meanings and differences of color-related idioms in Chinese and English.This paper intends to analyze and expound the cultural connotations of English and Chinese idioms related to several widely used basic color words with the aim of helping English learners know and use the idioms about color words better.

Contrastive Analysis:A Phonetic Case

This paper is to make a comparison on Chinese and English sounds under contrastive analysis with the consideration of that Chinese teachers of English would be better able to foresee their students' difficulty and consequently be better able to do their teaching plan in practice.

Contrastive Analysis of Conversational Implicature between English and Chinese

Implicature is a universal feature of human communication.In conversations,it is common to see examples of something unsaid but communicated.After introducing the theory of conversational impilcature and its four maxims,this paper presents English and Chinese examples to compare their conversational implicature,and finds conversational implicature exists in both Chinese and English conversation.

A Study of E-C and C-E Translation in the Light of Lexical Contrastive Analysis and Cultural Differences

The essay briefly illustrates E-C and C-E Translation strategies in the light of lexical similarity and differences of Lexical Contrastive Analysis, and explores lexical translation skills under the theory of Cultural Differences.

我国学前教育高质量发展的多组态路径——基于DPSIR框架的模糊集定性比较分析(fsQCA)

文章基于DPSIR框架设计评价指标体系对区域学前教育高质量发展水平进行评价,以熵权-TOPSIS计算指标权重和综合得分,结合模糊集定性比较分析(fsQCA)进行组态路径分析。研究发现:(1)我国学前教育高质量发展水平呈现由东向西递减的趋势,除东部外,中部与西部区域学前教育高质量发展水平均值均低于全国均值;(2)基于DPSIR框架的区域学前教育发展系统驱动学前教育高质量发展具有“多重并发”与非对称性的特点;(3)存在两条高水平组态路径与3条非高水平组态路径,多条组态路径殊途同归,且高水平组态与非高水平组态处于非对称状态;(4)东部、中部与西部组态路径存在一定差异,三大区域学前教育高质量发展均离不开状态因子与响应因子的支持。为此,要完善机制体制建设,为学前教育发展提供保障;因地制宜制定发展策略,以协同路径驱动学前教育高质量发展;聚焦区域重点,以重点发展引领区域学前教育高质量发展。

Log Anomaly Detection Based on Hierarchical Graph Neural Network and Label Contrastive Coding

System logs are essential for detecting anomalies,querying faults,and tracing attacks.Because of the time-consuming and labor-intensive nature of manual system troubleshooting and anomaly detection,it cannot meet the actual needs.The implementation of automated log anomaly detection is a topic that demands urgent research.However,the prior work on processing log data is mainly one-dimensional and cannot profoundly learn the complex associations in log data.Meanwhile,there is a lack of attention to the utilization of log labels and usually relies on a large number of labels for detection.This paper proposes a novel and practical detection model named LCC-HGLog,the core of which is the conversion of log anomaly detection into a graph classification problem.Semantic temporal graphs(STG)are constructed by extracting the raw logs’execution sequences and template semantics.Then a unique graph classifier is used to better comprehend each STG’s semantic,sequential,and structural features.The classification model is trained jointly by graph classification loss and label contrastive loss.While achieving discriminability at the class-level,it increases the fine-grained identification at the instance-level,thus achieving detection performance even with a small amount of labeled data.We have conducted numerous experiments on real log datasets,showing that the proposed model outperforms the baseline methods and obtains the best all-around performance.Moreover,the detection performance degrades to less than 1%when only 10%of the labeled data is used.With 200 labeled samples,we can achieve the same or better detection results than the baseline methods.

基于CRISPR/Cas系统的纸基分析在快速检测食源性致病菌中的应用

由食源性致病菌引起的食品安全事件严重影响人类健康,开发针对食源性致病菌的快速检测技术十分必要。成簇间隔短回文重复序列(clustered regularly interspaced short palindromic repeats,CRISPR)及相关蛋白(CRISPR-associated protein,Cas)是原核生物的适应性免疫系统,具有特异性识别并切割核酸序列的功能。纸基分析方法作为一种简便性好、成本低廉的分析检测工具,在快速检测领域展现出良好的前景。因此,将CRISPR/Cas系统的高效识别能力和纸基分析方法的简便性相结合可实现对食源性致病菌的快速灵敏检测。本文简要介绍了CRISPR/Cas系统用于核酸检测的概况,对第二类单Cas效应蛋白系统的特点及原理进行概述,重点综述基于CRISPR/Cas系统的试纸分析、侧向流动分析和纸基微流控装置在检测食源性致病菌方面的应用,并讨论了CRISPR/Cas系统结合纸基分析建立检测方法的优势、当前的挑战及未来的发展前景。

Leveraging Vision-Language Pre-Trained Model and Contrastive Learning for Enhanced Multimodal Sentiment Analysis

Multimodal sentiment analysis is an essential area of research in artificial intelligence that combines multiple modes,such as text and image,to accurately assess sentiment.However,conventional approaches that rely on unimodal pre-trained models for feature extraction from each modality often overlook the intrinsic connections of semantic information between modalities.This limitation is attributed to their training on unimodal data,and necessitates the use of complex fusion mechanisms for sentiment analysis.In this study,we present a novel approach that combines a vision-language pre-trained model with a proposed multimodal contrastive learning method.Our approach harnesses the power of transfer learning by utilizing a vision-language pre-trained model to extract both visual and textual representations in a unified framework.We employ a Transformer architecture to integrate these representations,thereby enabling the capture of rich semantic infor-mation in image-text pairs.To further enhance the representation learning of these pairs,we introduce our proposed multimodal contrastive learning method,which leads to improved performance in sentiment analysis tasks.Our approach is evaluated through extensive experiments on two publicly accessible datasets,where we demonstrate its effectiveness.We achieve a significant improvement in sentiment analysis accuracy,indicating the supe-riority of our approach over existing techniques.These results highlight the potential of multimodal sentiment analysis and underscore the importance of considering the intrinsic semantic connections between modalities for accurate sentiment assessment.

The Application of Contrastive Analysis to Vocabulary Teaching in Middle School

Learning a language must begin with learning pronunciation,vocabulary and grammar.Among these three factors,vo cabulary is of great importance.By putting the method of the Contrastive Analysis theories into practice,this thesis presents the necessity and significance of Contrastive Analysis in practical teaching.

A Contrastive Analysis of Same-Topic News Reports in Chinese and American Mainstream Media

Based on ideational,interpersonal,and textual metafunctions in systemic functional linguistics(SFL),a contrastive analysis is carried out on two same-topic news reports of Chinese and American main stream media.Two reports from the People’s Daily and CNN are analyzed in terms of the lexical-grammatical systems(transitivity,mood and modality,and theme)realizing the three corresponding metafunctions to compare Chinese and American media reports on the same event.Results show that the two reports deploy different transitivity processes,but indicate similarity in the uses of mood and thematic choices.There are also respective preferences for reporting the sametopic news:CNN focuses on the whole process of the incident,the report being relatively objective and fair without obvious emotional bias,while the report of People’s Daily is relatively comprehensive,analyzing the incident from various angles,and playing a positive role in guiding public opinion.

A Contrastive Analysis of Conditionals in English and Moroccan Arabic: Potential problems when learning English conditionals by Moroccan EFL learners

Learning to handle hypothetical situations in a new language is always difficult(Catford,et al.,1974).This rule holds true for Moroccan Arabic(henceforth MA)speakers learning English because grammatical devices in the two languages differ in almost all equivalent situations.For instance,while English verb forms are used to indicate tense in conditional sentences,MA uses them to indicate aspect.Adopting the typology of conditional constructions suggested by Dancygier(1999)and Dancygier&Sweetser(2005),this study provides a contrastive analysis of conditionals in English and MA to predict the possible errors EFL/ESL learners are likely to make while learning English.The analysis shows that the main discrepancy between English conditionals and MA conditionals lies in the verb form used by the two systems.Accordingly,if EFL/ESL learners are influenced by verb form in their L1,they are likely to face some challenges while learning English conditionals.That is,they are likely to use the past tense in the protases of English predictive conditionals and generic conditionals since the perfective form of the verb is used in the protases of these two types in MA.Concerning the protases of English non-predictive conditionals,Moroccan EFL/ESL learners are likely to use either the past tense or the present tense since both the perfective and the imperfective forms of the verb are possible in the protases of MA non-predictive conditionals.However,due to the fact that the perfective form is the prototypical form in the protases of conditionals in MA,EFL/ESL learners are likely to use the past tense more often than the present tense.The analysis also shows that EFL/ESL learners tend to use the present tense in the apodoses of English conditionals since the prevalent form in the apodoses of MA conditionals is the imperfective.

茶树OSCA基因家族的鉴定及表达分析

钙通透性阳离子通道蛋白(OSCA)在植物调节高渗胁迫中发挥着重要作用。为了解OSCA基因家族在茶树响应干旱胁迫中的作用,本研究基于茶树全基因组数据对OSCA基因家族进行鉴定,分析CsOSCAs基因和蛋白结构以及启动子顺式作用元件,并对CsOSCAs在茶树不同组织、不同抗旱性品种间和干旱胁迫下的表达模式进行分析。结果表明:茶树基因组包含12个OSCA基因家族成员,分别命名为CsOSCA1~CsOSCA12;CsOSCAs基因编码的氨基酸序列长度为667~831 bp,蛋白分子量在76630.55~93563.99 kDa之间,等电点在6.15~9.33之间,含有9~12个跨膜结构域,均含有特征保守结构域DUF221,根据系统进化关系可以分为4个亚族;10个CsOSCAs基因定位于茶树7条染色体上,2个CsOSCAs基因定位于未锚定染色体的contig上;CsOSCAs基因编码的蛋白二级结构含有32%~38%的跨膜结构和60%~68%的α-螺旋;CsOSCAs基因具有组织表达特异性,CsOSCA2、CsOSCA3、CsOSCA11、CsOSCA12基因在干旱敏感的品种CN98中的表达量显著高于其他2个耐旱品种,9个基因响应PEG胁迫,其中CsOSCA2、CsOSCA3、CSOSCA5、CsOSCA8、CsOSCA10和CsOSCA12受干旱胁迫强烈诱导;进一步分析启动子顺式作用元件显示,6个基因含有干旱诱导响应元件,11个基因含有脱落酸响应元件。由此推测茶树OSCA基因家族在茶树响应干旱胁迫中发挥着重要的作用,此研究为茶树OSCA基因功能分析与茶树抗逆性研究提供参考。

Identification and Validation of Novel Biomarkers Related to the Calcium Metabolism Pathway in Hypertension Patients Based on Comprehensive Bioinformatics Methods

Background: Hypertension is a universal risk factor for cardiovascular diseases and is thus the leading cause of death worldwide. The identification of novel prognostic and pathogenesis biomarkers plays a key role in disease management. Methods: The GSE145854 and GSE164494 datasets were downloaded from the Gene Expression Omnibus (GEO) database and used for screening and validating hypertension signature genes, respectively. Gene Ontology (GO) enrichment analysis was performed on the differentially expressed genes (DEGs) related to calcium ion metabolism in patients with hypertension. The core genes related to immune infiltration were analyzed and screened, and the activity of the signature genes and related pathways was quantified using gene set enrichment analysis (GSEA). The infiltration of immune cells in the blood samples was analyzed, and the DEGs that were abnormally expressed in the clinical blood samples of patients with hypertension were verified via RT-qPCR. Results: A total of 176 DEGs were screened. GO showed that DEGs was involved in the regulation of calcium ion metabolism in biological processes (BP), actin mediated cell contraction, negative regulation of cell movement, and calcium ion transmembrane transport, and in the regulation of protease activity in molecular functions (MF). KEGG analysis revealed that the DEGs were involved mainly in the cGMP-PKG signaling pathway, ubiquitin-protein transferase, tight junction-associated proteins, and the regulation of myocardial cells. MF analysis revealed the immune infiltration function of the cells. RT-qPCR revealed that the expression of Cacna1d, Serpine1, Slc8a3, and Trpc4 was up regulated in hypertension, the expression of Myoz2 and Slc25a23 was down regulated. Conclusion: Cacna1d, Serpine1, Slc8a3, Trpc4, Myoz2 and Slc25a23 may be involved in the regulation of calcium metabolism pathways and play key roles in hypertension. These differentially expressed calcium metabolism-related genes may serve as prognostic markers of hypertension.

Accuracy and Utility of Vessel Analysis Using Non-Contrast CT for Planning Endovascular Aortic Repair

Objectives: This study aimed to determine whether errors in vascular measurements would affect device selection in endovascular aortic repair (EVAR) by comparing measurements obtained using non-contrast computed tomography (NCT) with those obtained using contrast-enhanced CT (CECT). Materials and Methods: This single-center, retrospective study included 25 patients who underwent EVAR for abdominal aortic aneurysm at our institution. A 1-mm horizontal cross-sectional slice of NCT and CECT from each patient was retrospectively reviewed. The area from the abdominal aorta to the common iliac artery was divided into four zones. A centerline was created using the NCT by manually plotting the center points. Subsequently, the centerlines were automatically extracted and manually corrected during the arterial phase of CECT. The diameter and length of each zone were measured for each modality. The mean diameters and lengths of the target vessels were compared between NCT and CECT. Results: The measurements obtained using both methods were reproducible and demonstrated good agreement. The mean differences in vessel length and diameter measurements for each segment between NCT and CECT were not statistically significant, indicating good consistency. Conclusion: NCT may be useful for preoperative EVAR evaluation in patients with renal dysfunction or allergies to contrast agents.

基于CA-Markov模型的土壤侵蚀预测分析——以宜昌市为例

本研究介绍了CA-Markov模型预测土地侵蚀的方法,分析了宜昌市2000年、2010年和2020年三期的土壤侵蚀强度空间分布数据,提出以这三期数据作为预测基准年,利用CA-Markov模型进行精度验证后来预测宜昌市2030年土壤侵蚀情况,并在此基础上分析宜昌市2030年土壤侵蚀强度空间分布及土壤侵蚀发展趋势。结果表明:宜昌市2030年土壤侵蚀情势总体向好发展,水土流失面积与强度呈现“双下降”态势,水土流失面积下降至2493.6km~2;秭归县、当阳市、兴山县等区域土壤侵蚀情势仍然不容乐观,高强度侵蚀面积出现净增长,仍是未来水土保持的工作重点。

Contrastive thematic analysis in research articles

Based on the theory of thematic complexity, a contrastive analysis on 2 sections selected from research articles-method and discussion, was conducted. The differences and similarities between the 2 sections in simple theme, multiple theme, textual theme, interpersonal theme, topical theme and thematic progression were analyzed and concluded. The author believes that the causes of the differences and similarities are the different genre features of the 2 sections and the academic features of the materials selected.

Theoretical Approaches to Error Analysis

Contrast Analysis (CA), Interlanguage(IL),cognitive approach are considered as three aspects closely related to Error Analysis (EA).Originated from CA, EA takes IL as its linguistic basis and cognitive approach as its psychological support.Comparing with CA, EA pays more attention to the learner himself rather than the linguistic forms, and error is therefore shifted from what should be avoided to the crucial approach to the exploration of the learner’s cognitive process.

A Brief Analysis of Contrastive Analysis Hypothesis

This paper makes a brief analysis on the contrastive analysis hypothesis, and it is hoped to be helpful for the English teachers.