共查询到20条相似文献,搜索用时 62 毫秒
1.
2.
面向接收机冲突的多址接入(ROMA)是一种高效的适用于多波束自适应阵列天线的调度协议,但它无法保证具有不同时延要求的报文传输的服务质量。针对此问题,在原始ROMA的基础上提出了一种多时延限制的调度算法(MDRS)。通过在调度接入过程中插入子时隙,比较发送端报文时延信息,调度发送节点的传输顺序,使得时延限制更严格的报文优先发送,从而提高了不同时延等级的报文的传输成功率。最后,通过仿真验证了MDRS的性能:与原始ROMA相比,所提算法在多时延限制的发送端调度中表现出了更好的吞吐量和传输成功率。 相似文献
3.
4.
传统的短波令牌协议(HFTP)调度方式单一,在没有数据传送时,信道资源会被各节点间的令牌传递所占用,且令牌在通信质量较差时易丢失。基于此,提出一种多信道的分簇式短波令牌协议(CHFTP),通过以通信质量评估为标准的分簇算法和基于预约的动态令牌调度,减小了令牌丢失的概率和令牌传递、处理的开销,并给出了仿真分析。仿真结果表明,该协议的端到端平均时延和网络吞吐量明显优于短波令牌协议,CHFTP的平均时延最多可减少75%,网络吞吐量最多可增加66.7%,适合在短波通信网络中使用。 相似文献
5.
以仿真为主要手段研究了自组织网中基于AODV的路由算法的性能 ,比较了采用全网泛洪方式和限制泛洪半径方式下的网络性能。改进了现有调度策略 ,并仿真了其对端到端时延的影响。仿真结果表明 ,采用限制泛洪半径方式的网络性能明显好于全网泛洪方式 ,而改进型调度策略也能够进一步有效提高网络性能 相似文献
6.
UxDMA算法是一种高效的集中式算法,是用于时分多址、频分多址和码分多址信道分配的统一算法。在UxDMA的基础上,利用多波束天线的多波束形成能力,针对低时延定向ad hoc网络提出了一种集中式调度算法——CLSM(Centralized Low-delay Scheduling Algorithm Based on Multi-beam Antennas)。CLSM通过不同时延等级限制的报文来比较着色后发送链路的优先级,优先选择高优先级链路传输。通过仿真验证了CLSM的性能:与UxDMA相比,该算法在多时延限制的发送端调度中表现出了更好的吞吐量和时延性能。 相似文献
7.
为了提高集中式认知网络的吞吐量,提出了基于信任度的吞吐量优化算法。该算法在主用户充分保护的前提下,以认知用户的吞吐量为目标函数,融合中心采用双门限值对本地感知结果进行融合。从理论上证明了吞吐量是全局漏检概率的增函数,当全局漏检概率等于门限值时,吞吐量达到最大值。并利用牛顿迭代法求出单节点概率,然后采用遍历法可得到认知用户吞吐量最大值。仿真结果表明,当信噪比为-14 dB时认知用户融合优化算法相对“AND准则”“OR准则”以及“HALF准则”归一化吞吐量分别提高了0.62、0.3和0.09。 相似文献
8.
9.
10.
针对采用时隙ALOHA算法的无线Ad Hoc网络,考虑数据包到达的动态性与数据包传输的随机性,以最大化吞吐量为目标,同时满足数据队列稳定性,构建了关于接纳控制与竞争接入的随机优化问题。由于在时隙ALOHA算法中数据包传输的最优概率取决于无线Ad Hoc网络中数据队列非空的活跃节点数,提出了一种基于活跃节点数预测的时隙ALOHA算法。该算法要求无线Ad Hoc网络中的所有发送节点实时地侦听通信信道的忙闲状态,计算基于信道状态的活跃节点数条件期望,从而动态地预测无线Ad Hoc网络在不同时刻的活跃节点数,达到网络节点依据局部网络状态信息自适应地优化数据包传输概率的目的。仿真结果表明,所提算法能够有效估计无线Ad Hoc网络在每个时隙的活跃节点数,从而显著提升网络吞吐量并且降低数据包的平均排队时延。 相似文献
11.
美国国际贸易法院判定美国商务部对河北兴茂轮胎有限公司非公路用轮胎“双反”措施不当案评述 总被引:1,自引:0,他引:1
美国进口商和中国出口商不满美国商务部对来自中国的某些非公路用轮胎实施反倾销和反补贴税的裁定,向美国国际贸易法院提出起诉。美国国际贸易法院裁定,美国法律没有明确规定反倾销税法是否可适用于非市场经济国家;本案中美国商务部做的"双反"裁定,在方法上不合理。本文在介绍该案的基本案情、归纳法院推理和判决的基础上,对该案涉及的法律问题做了简要评论。 相似文献
12.
In this study, we evaluate how the effect of customers' experiences on revisit intention for non-indigenous restaurants can be moderated by economic distance (ED), cultural distance (CD) and global-connectedness distance (GD) between the country of origin for a given non-indigenous restaurant and the customer’s resident country. Surveys were conducted in seven countries across three continents, and the levels of ED, CD and GD between Korea and the seven countries were used as moderators. The findings suggest that the types of food and staff are two elements that should be emphasized in countries that are relatively close to Korea. Conversely, elements like the atmosphere of the restaurant and word of mouth should be emphasized in countries that have greater distances from Korea. Of the three distances considered in the study, GD had the strongest moderating effect on the relationship between customers’ experiences and their intentions to return to the restaurant. As a whole, the results imply that ED, CD and GD are important points of reference when considering prior experience while selecting a target country based on the strength of the restaurant’s experience management. 相似文献
13.
Miguel D Ramirez 《The journal of international trade & economic development》2013,22(2):159-178
This paper addresses the important question of whether public investment spending on economic infrastructure enhances economic growth in Mexico. It estimates a Cobb-Douglas production function that includes public infrastructure capital. Using cointegration analysis, the paper estimates a vector error correction model (VECM) for the 1995?–?99 period. The results suggest that there is a long-term stable relationship among the variables included in the VECM. The evidence also indicates that both public infrastructure spending and private capital formation have a positive and highly significant effect on the rate of output growth. Finally, the impulse response functions (IRF) and the variance decompositions (VDC) of the endogenous variables in the VECM suggest that the response of private capital to public infrastructure is positive while the reverse causation is not affirmed. From a policy standpoint, the findings call into question stabilization policies that disproportionately reduce public infrastructure to meet targeted reductions in the fiscal deficit (JEL, O1, O47, O54). 相似文献
14.
Unlike previous studies which only focus on the main effect between IC and FV, this research includes PTE with the gap of resource-based view. IC is a key element in creating a competitive advantage, as it has a great influence on FV. A company may put relatively less into IC if it demonstrates higher efficiency. However, previous studies have neglected the fact that relative efficiency and IC affect FV and stock returns directly and indirectly. The research period was from 2006 to 2010 and the main research methods include HRA and DEA. The main research findings include the following. (1) There is a space for improvement in terms of the total technical efficiency. (2) PTE has a significant moderating effect between IC and FV. (3) IC and PTE have a significant influence on FV. (4) Apart from PTE and stock returns, IC and FV show significant differences within the sub-industry. 相似文献
15.
文章根据风险调整收益(RAROC)的原理,借鉴J.P.摩根的信用计量CreditMetrics模型中信用等级转移的思想,构建了应收账款回收期内受信企业信用状况转移矩阵,并据此计算出企业信用VaR值和经济资本CaR值,进而计算RAROC比值,可为企业信用销售决策提供依据。通过将RAROC方法引入企业信用风险管理体系,可以对企业经营活动进行基于风险的绩效考核和业绩评价,以期提高企业信用风险管理水平。 相似文献
16.
采用高效液相色谱(HPLC)与电感耦合等离子体质谱(ICP-MS)联用技术,建立了粉质化妆品中六价铬的测定方法。样品经0.05 mol/L氢氧化纳溶液超声振荡提取;HPLC采用Hypersil GOLD C18柱分离,以5%(v/v)甲醇-2 mmol/L四丁基硫酸氢铵水溶液(pH 4.0)作为流动相;ICP-MS测定选用碰撞池技术以消除40Ar12C对52Cr的谱学干扰。方法学研究结果表明,添加水平为0.040-2.000 mg/kg时,回收率为77.5%-107.5%,相对标准偏差(RSD)小于10%。 相似文献
17.
《International Business Review》2023,32(3):102066
In recent years, there has been an exponential increase in the amount of foreign investment by emerging market multinational enterprises (EMNEs). While it has been debated whether EMNEs strengthen or weaken the institutions in host countries they invest in, the literature has paid limited attention to how EMNE investment impacts corruption in other emerging markets, one of the most significant destinations of EMNEs. Following Hoskisson et al. (2013), we categorize two types of emerging markets as targets of EMNE investment, a) low-income emerging markets and b) middle-income emerging markets, based on their institutional and market development. Building on the theory of firm-specific advantages (FSAs) and the institutional advantage (IA) of EMNEs, we reason that EMNEs enter foreign markets in accordance to where their skills and competencies can be effectively utilized, and this impacts corruption in the host country. We make two key arguments: (1) EMNEs predominantly use their IA in low-income emerging markets, which in the long term increases corruption in the host market, and (2) EMNEs predominantly use their FSAs to gain competitive advantage in middle-income emerging markets, which decreases corruption in the host market. Empirical analysis of Chinese outward FDI from the 2008-2018 period supports our hypotheses. Our research contributes to both the literature on EMNEs and corruption. 相似文献
18.
Kim Nguyen Thuy Hang Dao 《Journal of Promotion Management》2018,24(3):398-419
ABSTRACTBuilding on social-identity theory, the research develops a model for understanding of the impact of consumer identification with a nation on consumers' brand evaluations. It posits that developing-country consumers' identification with a foreign (developed) nation influences three factors—consumer-based brand equity, consumer-based country image, and consumer-based brand credibility. The research was informed by data from 400 Vietnamese consumers in relation to two Japanese brands Sony and Honda and analyzed using structural equation modeling (SEM). The findings show that Vietnamese (developing-country) consumers prefer Japanese (developed-country) brands over domestic brands, when these consumers identify with the developed nation. 相似文献
19.
为了增强无线通信系统的抗干扰能力,设计了一种认知FrFT(分数傅里叶变换)域通信系统(
CFrFTDCS
),在变换域通信系统中采用分数傅里叶变换,并与认知无线电技术结合,给出了系统的结
构框图和工作原理,分析了系统的抗干扰性能。计算机仿真结果表明,CFrFTDCS具有较强的
抗
干扰能力,针对单音干扰、窄带干扰和Chirp干扰,CFrFTDCS的平均误码率性能比直接序列
扩频(DSSS)通信系统分别改善了约15.70 dB、13.29 dB和13.79 dB,比传统
的变换域通信系统(TDCS)分别改善了约0.18 dB、0.23 dB和3.63 dB。 相似文献
20.
供应链管理和虚拟企业是已经在世界范围所采用的概念。这些概念包括一系列管理、组织和技术问题,公司为了提高竞争能力,开拓市场机遇,建立合作联盟。供应链管理是一种集成的管理思想,从战略上整体地整合供应商和顾客。虚拟企业是一种动态的临时组织形式,不同的企业为了开拓商业机遇而通过合作弥补自身竞争力的不足。虽然他们有各自的特点,但是也有共同点。 相似文献