Analysis on Factors Causing Project Delays in Road and Highways Sector in India Using Relative Ranking Index Technique

On-time completion of road infrastructure projects is a critical goal.When projects were not completed on schedule and real construction progress is slower than expected,the inconvenience and disruption to business access increases.On time completion is linked to economic and social welfare,as well as safety.Construction delays continue to be a typical occurrence,despite the need of prompt completion.A literature study is conducted in this context in order to learn more about the causes and factors that contribute to delays.Following a thorough review of the literature,it was determined that a questionnaire survey is the most effective and trustworthy way for gathering information about the causes and quantifying delays caused by emergent factors.The Relative Importance Index(RII)method was used to analyze the data,and the reasons for the delay were prioritized according to their importance.This study focuses on the emergent concerns/causes and reasons of concern in road infrastructure projects,as well as how to priorities these issues sequentially during the planning stage.This study survey can assist construction companies doing business in India in understanding the essential or sensitive issues that require special attention in order to conduct their businesses smoothly in this country while employing appropriate project management practices.

Comparative regeneration status in a natural forest and enrichment plantations of Chittagong (south) forest division, Bangladesh

The natural regeneration of the tree species in pure natural forest stand and enrichment plantations of Baraitali Forest of Chittagong (South) Forest Division, Bangladesh was studied by stratified random quadrat method during April 2002 to November 2002. Totally 100 plots of 3 m X 3 m in size represents a total of 64 regenerating tree species from natural forest with an average seedlings of 24767/hm2, while only 40 regenerating tree species were recorded from enrichment plan-tations with an average seedlings of 18633/hm2. Maximum regeneration in natural forest was found with Castanopsis spp. (2200 seedlings/hm2) followed by Glochidion lanceolarium (2183 /hm2) whereas, in enrichment plantations maximum regen-eration was found with Dipterocarpus gracilis (2117/hm2) followed by Anogeissus acuminata (2000/hm2). For natural forest, highest relative density was found for Castanopsis spp (8.88%), relative frequency for Glochidion lanceolarium (7.36%), rela-tive abundance for Syzygium spp. (3.79%) and Importance Value Index were recorded with Glochidion lanceolarium (18.24%). The corresponding values for enrichment plantations were highest with Dipterocarpus gracilis (11.36%), Glochidion lanceo-larium (9.71%), Dipterocarpus gracilis (5.92%), Glochidion lanceolarium (23.32%) respectively. Stem per hectare of some common trees with their seedlings and saplings in both the natural stands and enrichment plantations showed that only Dip-terocarpus gracilis successfully recruited in both sites but recruitment was higher in natural forest. Like many other primary rain forests, the Baraitoli forest typically has both substantial seedlings and soil seed bank from which regeneration may occur. The naturally regenerated seedlings are quite dense but it could not reach the pole stage due to human interference.

Assessment of Tree Diversity and Abundance in Rashad Natural Reserved Forest, South Kordofan, Sudan

This study aims to estimate the tree diversity status of Rashad Forest Reserves in the Rashad locality of the South Kordofan State of Sudan. For data collection, eight sample plots (20 × 20 m) were taken randomly, and parameters were determined: trees species diversity, composition, relative density, dominance, important value index, and species richness in the Rashad forest reserve. The results show that a total of 237 and 56 tree species, including 22 families, have been identified in the study area. Fabaceae family and species numbers have the highest number of 13 species in 8 genera, followed by Combretaceae with 8 species belonging to 3 different genera, Malvaceae with 5 species belonging to 4 different genera, Apocynaceae with 3 species belonging to 3 different genera. The Arecaceae, Burseraceae, Capparaceae, Euphorbiaceae, Meliaceae, and Rubiaceae families each had two species, and all the other 11 families had one species each. Among the 56 different tree species found within the reserve. The results also indicated that Tamarindus indica L. and Ziziphus spina-christi (L.) Desf. had the highest relative density and dominance of 4.64% and 11% respectively. Adansonia digitata L., Grewia villosa Willd, Vepris nobilis (Delile) Mziray had density and dominance of 4.80% and 9%. Followed by Anogeissus leiocarpa (DC.) Guill. & Perr, Adansonia digitata L., Catunaregam nilotica (Stapf) Tirveng. (Syn: Xeromphis nilotica (Stapf) Keay, Vangueria madagascariensis J. F. Gmel. with 3.38% and 8%, respectively. Eleven species recorded the least relative dominance of 0.42%. Shannon-Weiner diversity index (H’) value stood at 3.82. And as diversity indices varied with location depending on the species available within an ecological zone, Rashad forest reserve is blessed with a moderate diversity index.

南沙群岛西南部海域和北部湾口海域底层游泳动物多样性

根据2012—2013年在南沙群岛西南部和北部湾口海域进行的秋季和春季两个航次的调查资料,分析了这两个区域游泳动物的种类组成,计算渔获种类的相对重要性指数(IRI)、Margalef种类丰富度指数(D)、Shannon-Weiner种类多样性指数(H′)、Pielou均匀度指数(J′)和资源密度。结果表明,南海调查海域春秋两个航次的渔获物中,共鉴定出游泳动物663种,隶属于4纲36目171科374属;其中鱼类为504种,占所有渔获种类的76.0%。优势种种数较少,且季节变化较大。春季游泳动物的多样性指数高于秋季,这主要是由于春季出现大量补充群体,并且有许多种类在秋季向较深海区移动所造成的。南沙群岛西南部海域游泳动物多样性指数高于北部湾口海域,这可能是由于南沙群岛西南部海域受水温和洋流的影响较大所造成的。目前,南海北部渔业资源处于过度捕捞状态,资源结构呈现小型化和低值化。对南北海域资源调查结果进行比较发现,南沙群岛西南部海域资源相对较好。应合理开发利用该海域渔业资源,同时加强物种多样性的保护工作。

长江上游宜宾江段渔业资源现状研究

为了解长江上游宜宾江段鱼类群落结构和渔业捕捞现状及变化趋势，为物种和资源保护提供依据，该文对宜宾江段的流刺网和小钩等主要作业渔具的渔获物进行了调查，对渔获物种类组成、捕捞规格和单位捕捞努力量渔获量等进行了统计分析．结果表明：在宜宾江段共采集到鱼类49种，隶属于3目10科29属，以鲤形目和鲇形目鱼类为主．圆口铜鱼、瓦氏黄颡鱼、异鳔鳅鮀、宜昌鳅鮀和蛇鮈为该江段的优势种．采集到长江上游特有鱼类11种，占鱼类总种数的22.4％，其中一半以上的特有鱼类为偶见种．宜宾江段渔业捕捞规格普遍偏小，大部分捕捞个体体质量在100 g以下，体长在150 m m以下．该江段流刺网和小钩的单位捕捞努力量渔获量仅为每船1～2 kg／d ．宜宾江段渔业资源已严重衰退，许多特有鱼类变为偶见种，渔业捕捞渔获量偏低，捕捞规格偏小，建议采取休鱼等措施，促进物种和资源的保护．

北部湾口海域鱼类分类多样性的初步探讨

根据2012-2013年在北部湾口海域秋、春两个航次的调查数据,系统地分析了调查海域鱼类种类组成,并分别计算该海域鱼类的相对重要性指数（IRI）、分类阶元包涵指数（TINCLi）及分类多样性指数（△^＋和∧^＋）.结果显示,此次调查共捕获鱼类26目100科195属301种,其中以鲈形目鱼类占据绝对优势,两个季节同时被捕获鱼类75种.秋季优势种类数明显低于春季,且均以中小型鱼类为主,种类更替现象明显.TINCLi研究结果表明,研究海域鱼类种类组成目、科、属所分别拥有的（科、属、种）、（属、种）和（种）的平均数目分别为（3.85、7.50、11.58）、（1.95、3.01）和（1.54）,在种级水平上,该海域的鱼类分类多样性较低,分布相对集中,亲缘关系较近.北部湾口海域的△^＋和∧^＋值分别为46.34和47.82,相比较于黄渤海、东海和南沙群岛西南部海域,其△^＋值最接近于北部湾,表明二者间鱼类的亲缘关系比较近;但在大尺度范围内,该海域△^＋值并未表现出明显随纬度变化的规律.

黄海中南部主要鱼种的生态位分析

根据2006年黄海中南部4个季度月(1、4、8、10月)的渔业资源调查资料,运用定性、定量的方法分析了黄海中南部鱼类群落的种类组成、时空生态位宽度、时空生态位重叠以及优势种的季节变化,以期对该海域主要鱼种的生态位特征进行分析。结果表明,4个航次总共有鱼类57种,其中冬季39种,春季42种,夏季31种,秋季40种。4个航次共有相同鱼种22种,隶属于14科20属。时空生态位宽度值大于1的10个鱼种从大到小依次为黄鱼安鱼康Lophius litulon、小黄鱼Pseudosciaenapolyactis、银鲳Pampus argenteus、七星底灯鱼Benthosema pterotum、小带鱼Trichiurus muticus、虻鲉Erisphex pottii、细纹狮子鱼Liparis tanakae、星康吉鳗Conger myriaster、白姑鱼Argyrosomusargentatus、带鱼Trichiurus haumela。这10种主要鱼类的生物量变动在黄海中南部受季节变化的影响是递增的。细纹狮子鱼与星康吉鳗的时空生态位重叠值最大,小带鱼与星康吉鳗的时空生态位重叠值最小。生态位宽度与相对重要性指数(IRI)相比,时空生态位宽度值最大的是黄鱼安鱼康,而IRI值最大的是鳀鱼,通过二者计算所得到主要鱼种在群落中的重要性排序不同。作者认为,生态位宽度与相对重要性指数(IRI)相比,能够更加全面的反映鱼类生物量在不同时间和空间尺度上的均匀度和变化情况。

砌体结构可靠性评级中权重系数的序关系法

为解决在采用特征值法求解判断矩阵过程中,由于所建立的判断矩阵往往都不是一致阵,这将不同程度的导致评价指标间权重系数排序关系错乱的问题,并且特征值法的计算量很大。为此采用序关系法,先确定评价指标重要性程度序关系,再确定相邻两个评价指标的相对重要性程度之比,最后经过简单计算就可求得权重系数。研究结果表明:计算量较特征值法成倍的减少,并且对元素或指标的个数没有限制。该方法具有保序性,不用构造判断矩阵,更无需一致性检验,减少计算量,便于应用。得出结论:将序关系法应用于结构可靠性评级中确定权重系数是非常实用和有意义的。

韭山列岛海域虾类群落结构与海洋环境因子的关系

根据韭山列岛海域2015年11月(秋)、2016年2月(冬)、5月(春)、8月(夏)的调查资料,运用相对重要性指数(index of relative importance, IRI)、冗余分析(redundancy analysis, RDA)、数量生物量曲线(Abundance-biomass comparison curve,简称ABC曲线)及W统计量(W-statistics)等方法,分析了该海域优势种虾类及其与环境因子的关系。结果表明,保护区共调查到暖温、暖水性虾类16种,隶属于8科12属;其中,各季节优势种(IRI> 1 000)变化明显。虾类相对资源密度呈春、秋季高,夏、冬季低的季节性分布。秋季主要优势种为安氏白虾(Exopalaemon annandalei)和葛氏长臂虾(Palaemon gravieri),虾类群落的分布主要受底层水温影响(r2=0.726 2,P=0.001);冬季优势种主要为鲜明鼓虾(Alpheus distinguendus)、葛氏长臂虾和日本鼓虾(Alpheus japonicus),此季节虾类的分布主要受水深的影响(r2=0.543 7,P=0.009);春季优势种为日本鼓虾和细巧仿对虾(Parapenaeopsis tenella),此时物种的分布与表层环境因子关系密切;夏季优势种以哈氏仿对虾(Parapenaeopsis hardwickii)和中华管鞭虾(Solenocera crassicornis)为主,此时研究海域环境较为稳定,环境因子整体对虾类群落的分布影响显著(P=0.008)。4个季节W统计值均小于1,其变化范围为-1.772×10-3～-2.47×10-4。秋、冬和春季数量优势度曲线高于生物量优势度曲线,表明虾类群落受干扰较为严重;而夏季两曲线相交,受干扰情况较另外3个季节有所好转。通过比较数量、生物量优势度曲线斜率,还可以推测虾类的体型大小:当相邻两排序物种在生物量优势度曲线上对应值连线的斜率大于数量优势度曲线上对应值连线的斜率时,该物种个体相对较大,反之较小。进而可推知:当物种数量足够多时,可通过比较某一物种在生物量优势度曲线和数量优势度曲线上对应处切线的斜率判断个体的相对大小。

Integration system research and development for three-dimensional laser scanning information visualization in goaf

An integration processing system of three-dimensional laser scanning information visualization in goaf was developed. It is provided with multiple functions, such as laser scanning information management for goaf, cloud data de-noising optimization, construction, display and operation of three-dimensional model, model editing, profile generation, calculation of goaf volume and roof area, Boolean calculation among models and interaction with the third party soft ware. Concerning this system with a concise interface, plentiful data input/output interfaces, it is featured with high integration, simple and convenient operations of applications. According to practice, in addition to being well-adapted, this system is favorably reliable and stable.

基于重要贡献度的中小型土石坝安全评价指标体系研究

针对中小型土石坝安全评价指标体系的研究相对缺乏的问题,采用文献统计方法分析了中小型土石坝的安全特性,总结了影响安全的主要因素,提出了"重要贡献度"遴选依据。采用德尔菲法结合灰色关联度分析法组合赋权,量化确定指标的重要贡献度。依据累积重要贡献度遴选对中小型土石坝安全评价影响大、贡献率高的优势因子,建立由两个层次,即7个一级准则、16个二级指标组成的评价指标体系。应用于实际工程案例分析,验证了本评价体系的合理性与可行性。结果表明:该方法避免了定性分析的主观随意性和定量分析的数据依赖性,构建的中小型土石坝安全评价指标体系精炼、针对性强,提高了综合安全评价的效率和可操作性,为量化和智能化的安全评价研究奠定了基础。

基于南沙群岛西南部海域探捕调查的鱼类分类多样性初步研究

根据2012—2013年秋、春两个航次在南沙群岛西南部海域探捕调查数据,系统整理了调查海域鱼类物种组成并分析其季节更替,通过计算调查海域鱼类相对重要性指数(IRI)、分类阶元包含指数(TINCLi)以及分类学多样性指数(Δ^+和∧^+),初步探讨了该海域鱼类分类多样性现状。结果显示,调查海域鱼类共有27目104科206属340种,其中鲈形目种类数目占绝对优势。当采用IRI≥500标准定义优势种时,秋季优势种有2种,春季有4种,不同季节鱼类优势种存在差异,并且主要鱼种的季节更替现象明显。分类阶元包含指数分析结果显示,鱼类物种组成中,目、科、属各分类阶元包含各低级分类阶元的平均数目分别为(3.85、7.63、12.59),(1.98、3.27)和(1.65)。调查海域Δ^+值和∧^+值分别为66.3和100.2,其中Δ^+值高于大亚湾(62.2)和北部湾(63.5),最接近于东海陆架区(65.7)。研究结果显示南沙群岛西南部海域鱼类分类多样性目前并未发生显著变化,但仍应关注人类活动对该海域鱼类多样性的影响。

中文版视功能指数量表在日常低视力白内障手术患者中的应用价值评估

目的结合校标法和分布法以计算中文版视功能指数量表(VF-11R-CN)用于日常低视力白内障人群围手术期的最小临床意义差异(MCID),基于MCID值比较不同特点人群术后视觉相关生活质量(VRQol)的改善率。方法采用横断面研究方法,纳入2018年5月至2019年6月在温州医科大学附属眼视光医院收治的术前日常低视力白内障患者98例,所有患者均接受白内障超声乳化联合人工晶状体植入术,分别于术前和术后1~3个月行VF-11R-CN量表调查,且术后调查时增加校标条目。通过天花板效应和地板效应、术前术后的得分差异和效应值来评估VF-11R-CN量表的适用性。分布法测定MCID值时采用0.5个标准差(SD)和1.96个测量标准误(SEM)进行估算,校标法测定MCID值时采用线性回归分析法进行估算。在应答者分析中计算MCID的敏感性和特异性,对不同特点人群基于MCID值的VRQol提高率进行比较。结果共85例受试者完成随访。受试者围手术期VF-11R-CN量表得分变化为(399.51±234.92)分,视力变化为(0.65±0.36)。量表术前的天花板和地板效应均为1.18%,术后地板效应为22.35%。受试者术前VF-11R-CN量表总分高于术后,差异有统计学意义(t=15.68,P<0.001),VF-11R-CN量表的效应值为1.63。基于0.5个SD和1.96个SEM的MCID估值分别为122.23分和123.10分;校标条目的得分增加1分,围手术期得分变化下降106.17分。平均化分布法和回归分析法得到的MCID值为117.17分。受试者中术后得分超过MCID值者76例,占89.41%,MCID值的灵敏度为96.67%,特异性为46.67%。不同性别间、单种眼病与多种眼病间及手术前视力(以LogMAR 1.3为界)间术后VRQol提高率差异均无统计学意义(P=0.73、0.88、0.27)。结论VF-11R-CN量表适用于中国日常低视力白内障手术人群术后生活质量的客观评估,手术的MCID估值为117.17分,MCID估值敏感性高,特异性偏低。

Detection of schedule delay risk of empirical construction projects

In Ethiopian construction projects, schedule delay risk is a predominant issue because it is not properly addressed. Although several studies have been focused on the various effects of risk in construction projects, limited efforts have been made to investigate the typical and the overall schedule delay risk. In this study, our aim is to detect the typical and overall schedule delay risk throughout the construction project lifecycle, which consists of the pre-construction, construction, and post-construction stages, and compare the stages with each other. Common criteria, sub-criteria, and attributes were developed for all alternatives for the purpose of making a risk decision. The methodology that was followed integrated the multiplecriteria decision-making(MCDM) model of fuzzy analytic hierarchy process comprehensive evaluation(FAHPCE)and the relative important index(RII). Data were collected from 77 participants, who were selected through purposive sampling from different contracting organizations in Ethiopian construction projects by means of questionnaires that were distributed to experienced experts. The findings showed that there is a typical delay risk either in the type or in the level of the different construction activities.Consequently, the most influenced alternative is the construction stage because of the high-risk responsibility,resource, and contract condition related criteria. The postconstruction stage was the second most influenced stage because of the high-risk responsibility-related criteria. The pre-constructed stage was the least influenced stage that consist high-risk criteria of responsibility, resource, and contract condition related. These differences provided noteworthy information about risk mitigation in construction projects by identifying the exact risk level on specific activity to make appropriate decision.

社会主义生态文明建设的理论与实践研究(笔谈)

主持人语 随着生态危机越来越严重，党和国家对生态文明建设越来越重视，党的十七大首次提出了建设生态文明的目标和任务，党的十八大明确提出“大力推进生态文明建设”，党的十八届三中全会将“加快生态文明制度建设”列入全面深化改革的重要内容。本专题就是围绕着生态文明建设的理论和实践问题展开比较深广的探讨。

长江口及其毗邻海域鱼类群落优势种的生态位宽度与重叠

根据"北斗号"调查船2006年6月、8月和10月在长江口及其毗邻海域进行渔业资源底拖网调查的资料,通过相对重要性指数确定鱼类群落优势种,对优势种的生态位测度指标及季节变化进行分析.结果表明:3航次的优势种共有10种,它们的生态位宽度和生态位重叠指标呈现出明显的季节性变化,通过Bray-Curtis相似性聚类与非度量多维标度(MDS)分析可分为两组.第一组为鳀鱼、鳄齿鱼、发光鲷,其生态位宽度和生态位重叠指标夏季大于秋季,呈现出由夏季到秋季从长江口及其毗邻海域向外部深水区移动的趋势;第二组为带鱼、矛尾虾虎鱼、细条天竺鲷、小黄鱼、刺鲳、白姑鱼、七星底灯鱼,其生态位宽度和生态位重叠指标秋季大于夏季,呈现出由夏季到秋季从黄海南部和东海北部水域向长江口及其毗邻海域移动的趋势.这两组鱼类不同的移动趋势与其生态习性和环境因素有关.

韭山列岛自然保护区虾类优势种生态位

根据韭山列岛自然保护区2015年11月,2016年2月、5月、8月的调查资料,运用相对重要性指数(index of relative importance,IRI)、生态位宽度以及生态位重叠指数等生态指标,对调查海域的优势种虾类进行生态位特征分析,以了解该海域内虾类组成及优势种间的关系。结果表明,保护区共调查到虾类16种,隶属8科12属,均属暖温种或暖水种,其中优势种(IRI>500)有7种,隶属于4科5属;虾类相对资源量呈春秋季高,夏冬季低的季节性分布特征。除脊尾白虾(Exopalaemon carinicauda)外,优势种的时空生态位宽度值(时间生态位宽度与空间生态位宽度的乘积)均大于非优势种。日本鼓虾(Alpheus japonicus)和细巧仿对虾(Parapenaeopsis tenella)的时空二维生态位重叠值最大,表明其对资源的利用具有相似性;安氏白虾(Exopalaemon annandalei)和哈氏仿对虾(Parapenaeopsis hardwickii)的时空生态位重叠值最小,说明二者相关性低。通过计算得知,相对重要性指数(IRI)与生态位宽度对物种重要性排序结果有异:时空生态位宽度值最大的为葛氏长臂虾(Palaemon gravieri),而IRI值最高的为日本鼓虾。与相对重要性指数(IRI)相比,生态位宽度指数不仅能反映物种对资源的利用能力,还能反映物种分布是否均匀,但这两者均不能反映生物量的多少。