Towards a conjoint-based, context-dependent model of task allocation in activity settings: Some numerical experiments     

Aloys Borgers  Frank Hofman  Maarten Ponjé  Harry Timmermans 《Journal of Geographical Systems》2001,3(4):347-367

 None of the currently developed activity-based models of transport demand explicitly models task allocation among household members. To fill this gap, the present paper suggests to complement activity-based models of activity scheduling with a context-dependent model of task allocation. That is, it is assumed that the allocation of tasks within households is partly based on such contextual variables as the amount of time a member has to spend on mandatory activities and car availability. In particular, the paper advocates a conjoint-based approach, based on an assignment task as opposed to the traditional ranking, rating or choice response formats. By definition, an assignment task involves a combinatorial explosion of choice alternatives, implying that additional operational decisions to estimate the context-dependent model are required. This study presents the results of various numerical experiments, conducted to better understand the impacts of those decisions on the degree of bias in the parameter estimates of the choice model. The results of these simulations indicate that under particular assumptions, the development and estimation of a conjoint-based, context-dependent model of task allocation within households is feasible. Received: March 1999 / Accepted: June 2001  相似文献   

论徐连经济带建设   总被引：1，自引：0，他引：1  

沈正平 《地域研究与开发》1997,16(4):15-20

通过对徐连经济带在全省，淮海经济区中经济地位的分析，与省内宁镇扬，苏锡常两区的比较，找出本带经济中存在的问题及原因，提出加快其经济发展所拥有的优势区位，优越的自然条件和重要意义，并就点轴开理论本带建设布局中的应用进行了探讨。  相似文献   

大震震中参数及时测定在救灾中的意义     

阎志德 《山西地震》1992,(4):24-27

从测震学的角度,审视了大震参数快速测定的方法,讨论了为保证测定参数所需能完整记录大地震的仪器配套问题。叙述了适用于城市救灾的高技术救灾器械的研制问题。  相似文献   

Vertical distribution of Artemisia halodendron root system in relation to soil properties in Horqin Sandy Land, NE China     

YongQing Luo  XueYong Zhao  JiePing Ding  Tao Wang 《寒旱区科学》2016,8(5):411-418

Root distribution plays an important role in both vegetation establishment and restoration of degraded land through influencing soil property and vegetation growth. Root distribution at 0~60 cm depth of A. halodendron was investigated in Horqin Sandy Land. Soil organic carbon (SOC) and nitrogen (SN) concentration as well as carbon and nitrogen in root biomass and necromass were measured. Root length density (RLD) was estimated. Total root biomass, necromass and the RLD at 0~60 cm depth was 172 g/m², 245 g/m², and 368 m/m², respectively. Both biomass and necromass of A. halodendron roots decreased with soil depth, live roots were mainly at 0~20 cm (76% of biomass and 63% of root length), while 73% of the necromass was within 0~30 cm depth. N concentration of roots (biomass and necromass) was about 1.0% and 1.5%, respectively. There were significant differences in SOC concentration between soil layers, but insignificant for SN. Soil C/N ratio decreased with depth (P<0.05). C and N storage for belowground system at 0~60 cm decreased markedly with depth; 41.4% of C and 31.7% of N were allocated to the 0~10 cm layer. Root bio- and necromass together contained similar amount of C to that of the soil itself in the top layer. N stock was dominated by soil nitrogen at all depths, but more so in deeper layers. It is clear that differentiating between soil layers will aid in interpreting A. halodendron efficiency in soil restoration in sandy land.  相似文献   

RTK测量中基准站的设置问题     

翟翠允  段凌燕  耿志军  薄振龙  贾黎君  张军 《海洋测绘》2007,27(3):63-65

介绍了GPS单点定位及RTK的工作原理,并结合基本原理,对RTK测量中基准站的设置方法进行说明,并着重分析1 n RTK测量中,n台手簿在基准站设置中容易进入的误区,并结合实验数据进行了分析说明,找出错误原因,最后得出基准站正确的设置方法。  相似文献   

Life history of a short-lived squid (Sepioteuthis australis): resource allocation as a function of size, growth, maturation, and hatching season     

Pecl  Gretta T.; Moltschaniwskyj  Natalie A. 《ICES Journal of Marine Science》2006,63(6):995-1004

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Sustainable energy transition in developing countries: the role of energy aid donors     

Jung Eun Kim 《Climate Policy》2019,19(1):1-16

Dialogues on global climate policy are increasingly discussing the sustainable energy transition, with Goal 7 of the UN’s Sustainable Development Goals highlighting the importance of affordable and clean energy. This study looks at foreign aid as a carrier of global climate policy and examines donor behaviour in the energy sector. By examining donor behaviour when giving energy aid, one can grasp how the donor community helps recipients achieve a sustainable energy transition. A panel of donor–recipient pairs, covering 29 donors and 99 recipients, was constructed for the period between 1996 and 2013, using data from Organisation for Economic Co-operation and Development Creditor Reporting System (OECD CRS), International Energy Agency (IEA) and World Development Indicators (WDI). The pair-year panel data were empirically analysed using a two-part model to test whether energy aid donors respond to recipients’ needs with regard to renewable energy and residential electricity. The findings demonstrate that donors respond to recipients’ sustainable energy needs, both renewable and residential, when selecting recipients. Moreover, donors tend to increase the amount of aid based on renewable energy needs. The findings also highlight the significant role of international climate policy, as donors have changed their energy aid-giving patterns since the start of the Kyoto Protocol. Contrary to the common belief in the aid-giving literature, this study shows that, with regard to energy aid, donor interests are more weakly related to recipient selection than are recipient needs.

Key policy insights

• Donors are influenced by the residential energy needs of recipients when giving energy aid, which aligns with the Sustainable Development Goals.

• Donors’ energy aid-giving patterns changed between the periods before and after entry into force of the Kyoto Protocol, highlighting the significant role of international climate change policy.

• Policy makers and aid practitioners can steer donors to continue to allocate resources to the development of recipients’ energy policy and to help recipients prepare institutional structures to attract private investment in sustainable energy.

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拍卖机制在碳市场配额分配中的应用回顾和比较分析     

张文秀  邓茂芝  周剑 《气候变化研究进展》2019,15(3):246-256

配额拍卖机制在碳市场中具有重要作用。文中在综述配额拍卖机制研究进展的基础上,重点回顾拍卖机制在欧盟、美国加州和澳大利亚等具有代表性的国际碳市场中的应用情况,结合国内试点碳市场的运行情况,分析不同地区碳市场中拍卖机制的效果。研究认为,国际碳市场拍卖机制设计较为完善,在实际应用中效果良好,起到了增强市场流动性的作用,国内各试点碳市场拍卖机制仍处于探索阶段。文中从拍卖机制的要素设计、平台建设、所得资金管理等方面对全国统一碳市场配额拍卖机制设计提出建议,为全国碳市场中拍卖机制的建设提供参考。  相似文献   

全驱动船舶轨迹跟踪初始位置影响分析   总被引：1，自引：0，他引：1  

邱荷珍  王磊 《海洋工程》2015,33(4):86-93

船舶轨迹跟踪属于广义上的船舶动力定位,具体来说是船舶在规定的时间内,通过轨迹跟踪系统的控制到达原本设定的位置。以某一全驱动船舶为例,分别对预定轨迹为直线和圆进行船舶轨迹跟踪时域模拟研究,通过分析船舶时域模拟轨迹与预设轨迹的水平位置偏差与艏向角偏差研究轨迹跟踪精度,并分析船舶初始位置对轨迹跟踪的影响。研究表明,船舶初始水平位置偏离设定轨迹起点越大,船舶调整至轨迹的时间越长,但最终能回到预设轨迹上;船舶初始艏向如偏离过大,会导致船舶远离预设轨迹。在实际工程应用中,可利用动力定位将船舶定位至轨迹跟踪起点,调整船舶艏向,再开始轨迹跟踪。  相似文献   

浙江省科技资源的区域差异及其空间配置效率研究   总被引：1，自引：0，他引：1  

陈修颖  陈颖 《地理科学》2012,(4):418-425

科技资源是科技活动的基础,是创造科技成果,推动整个经济和社会发展的要素的集合。利用主成分分析法评价了浙江省各地级市科技资源的存量,并运用ArcView分析了浙江省科技资源的空间分布状况,利用数据包络分析法(DEA)评价了浙江省各地级市的科技资源配置相对效率,利用柯布-道格拉斯生产函数和索洛余值法计算了各个地级市的科技进步对于经济发展的贡献率。结果表明:①浙东北的科技资源及科技进步贡献率都要明显高于浙西南,同时浙东北、浙西南内部也存在着较大的差异。②杭州市、嘉兴市、绍兴市、金华市、舟山市和丽水市科技资源配置效率较高,而宁波市、温州市、湖州市、衢州市和台州市的科技资源配置效率相对较低。  相似文献