Negotiating on location, timing, duration, and participant in agent-mediated joint activity-travel scheduling     

Huiye Ma  Nicole Ronald  Theo A. Arentze  Harry J. P. Timmermans 《Journal of Geographical Systems》2013,15(4):427-451

Agent-based simulation has become an important modeling approach in activity-travel analysis. Social activities account for a large amount of travel and have an important effect on activity-travel scheduling. Participants in joint activities usually have various options regarding location, participants, and timing and take different approaches to make their decisions. In this context, joint activity participation requires negotiation among agents involved, so that conflicts among the agents can be addressed. Existing mechanisms do not fully provide a solution when utility functions of agents are nonlinear and non-monotonic. Considering activity-travel scheduling in time and space as an application, we propose a novel negotiation approach, which takes into account these properties, such as continuous and discrete issues, and nonlinear and non-monotonic utility functions, by defining a concession strategy and a search mechanism. The results of experiments show that agents having these properties can negotiate efficiently. Furthermore, the negotiation procedure affects individuals’ choices of location, timing, duration, and participants.  相似文献   

Mafic magmas from Mount Baker in the northern Cascade arc,Washington: probes into mantle and crustal processes     

Nicole?E.?MooreEmail author  Susan?M.?DeBari 《Contributions to Mineralogy and Petrology》2012,163(3):521-546

Five mafic lava flows located on the southern flank of Mount Baker are among the most primitive in the volcanic field. A comprehensive dataset of whole rock and mineral chemistry reveals the diversity of these mafic lavas that come from distinct sources and have been variably affected by ascent through the crust. Disequilibrium textures present in all of the lavas indicate that crustal processes have affected the magmas. Despite this evidence, mantle source characteristics have been retained and three primitive endmember lava types are represented. These include (1) modified low-K tholeiitic basalt (LKOT-like), (2) typical calc-alkaline (CA) lavas, and (3) high-Mg basaltic andesite and andesite (HMBA and HMA). The Type 1 endmember, the basalt of Park Butte (49.3–50.3 wt% SiO₂, Mg# 64–65), has major element chemistry similar to LKOT found elsewhere in the Cascades. Park Butte also has the lowest overall abundances of trace elements (with the exception of the HREE), indicating it is either derived from the most depleted mantle source or has undergone the largest degree of partial melting. The Type 2 endmember is represented by the basalts of Lake Shannon (50.7–52.6 wt% SiO₂, Mg# 58–62) and Sulphur Creek (51.2–54.6 wt% SiO₂, Mg# 56–57). These two lavas are comparable to calc-alkaline rocks found in arcs worldwide and have similar trace element patterns; however, they differ from each other in abundances of REE, indicating variation in degree of partial melting or fractionation. The Type 3 endmember is represented by the HMBA of Tarn Plateau (51.8–54.0 wt% SiO₂, Mg# 68–70) and the HMA of Glacier Creek (58.3–58.7 wt% SiO₂, Mg# 63–64). The strongly depleted HREE nature of these Type 3 units and their decreasing Mg# with increasing SiO₂ suggests fractionation from a high-Mg basaltic parent derived from a source with residual garnet. Another basaltic andesite unit, Cathedral Crag (52.2–52.6 wt% SiO₂, Mg# 55–58), is an Mg-poor differentiate of the Type 3 endmember. The calc-alkaline lavas are least enriched in a subduction component (lowest H₂O, Sr/P_N, and Ba/Nb), the LKOT-like lavas are intermediate (moderate Sr/P_N and Ba/Nb), and the HMBA are most enriched (highest H₂O, Sr/P_N and Ba/Nb). The generation of the LKOT-like and calc-alkaline lavas can be successfully modeled by partial melting of a spinel lherzolite with variability in composition of slab flux and/or mantle source depletion. The HMBA lavas can be successfully modeled by partial melting of a garnet lherzolite with slab flux compositionally similar to the other lava types, or less likely by partial melting of a spinel lherzolite with a distinctly different, HREE-depleted slab flux.  相似文献   

How to assess hydromorphology? A comparison of Ukrainian and German approaches     

Nicole Scheifhacken  Ulrike Haase  Lesya Gram-Radu  Roman Kozovyi  Thomas U. Berendonk 《Environmental Earth Sciences》2012,65(5):1483-1499

Recently, the Ukrainian Western Bug water authorities developed a national field survey to assess the quality of river habitats. The Ukrainian government already cooperates with EU member states along transboundary rivers and also orientates itself towards the European Water Framework Directive (WFD). As a future application for EU membership is feasible, the water authorities started to implement WFD criteria into their national survey schemes including the assessment of rivers’ hydromorphology. This article compares two different hydromorphological survey methods to identify similarities and differences of the classification approaches with regard to the conformity of obtained outputs with the WFD demands. The field surveys, the Ukrainian (UA-FS) and the German (LAWA-FS), were applied in parallel on 14 river sections along the Western Bug River and parts of its tributaries. Results show a wide range of conformity, but also several differences between and gaps within all methods. The UA-FS generally lacks the idea of reference condition in rivers’ hydromorphology and the definition of different stream types or near-natural land uses. The UA-FS and the LAWA-FS approaches are similar with respect to their incorporated compartments and most main parameters, but differ in definition and interpretation of specific functional units and single parameters. Greatest similarities down to single parameters exist in aspects of land use, bank vegetation, currents diversity, and within-stream variation of water depths. Differences include the assessment and interpretation of lateral erosion, sinuosity, type and depth of profile, substrate diversity, as well as special structures of bank and riverbed. Overall, the LAWA-FS is more conservative in its rating than the UA-FS. Still, UA-FS can be regarded as an important improvement for a systematic and reliable monitoring of river hydromorphology in the Ukraine that will help to successfully engage with both the integrated water resources management and the WFD harmonisation process in the future.  相似文献   

Preliminary Interlaboratory Trial for ISO/DIS 12010: Determination of Short Chain Polychlorinated Alkanes (SCCP) in Water     

Sabine Geiß  Nicole Lettmann  Aurélien Rey  Herbert Lepper  Birgit Körner  Silvio Mais  Theodor Prey  Bettina Hilger  Moana Engelke  Stephan Lebertz  Claudine Chatellier  George Sawal  Dirk Löffler  Tom Schillings 《洁净——土壤、空气、水》2011,39(6):537-542

A first preliminary interlaboratory trial was planned to prepare ISO/DIS 12010: Water quality – determination of short chain polychlorinated alkanes (SCCP) in water – method using GC/MS and electron capture negative ionisation (ECNI). The task was to determine the sum of short chain polychlorinated n‐alkanes with carbon chain lengths of C₁₀–C₁₃ and a chlorine content between 49 and 67% in water by GC‐ECNI‐MS and quantification by multiple linear regression described in ISO/DIS 12010 as the compulsory method. Distributed samples were obtained from a real water extract spiked with a target concentration of 0.4 µg/mL sum of SCCP, i.e. the environmental quality target level according to the Water Framework Directive. The interlaboratory trial included the calibration, a column chromatographic clean up, a concentration step and an integration of chromatographic unresolved humps as well as the quantification with multiple linear regression. Reproducibility standard deviations between 21.5 and 22.9% were achieved by 17 participating laboratories from four countries. The method outlined no significant difference of the results between the standard solution and a real water matrix extract. On the basis of this succeeded preliminary interlaboratory trial the final interlaboratory trial for validation of ISO 12010 was prepared in autumn 2010.  相似文献   

Geological evolution of the West Luzon Basin (South China Sea,Philippines)     

Jashar?ArfaiEmail author  Dieter?Franke  Christoph?Gaedicke  Rüdiger?Lutz  Michael?Schnabel  Stefan?Ladage  Kai?Berglar  Mario?Aurelio  Jennie?Montano  Nicole?Pellejera 《Marine Geophysical Researches》2011,32(3):349-362

Interpretation of deep 2-D multi-channel seismic data sheds insights into the geological evolution of the West Luzon Basin, Philippines. This basin is a sediment-filled trough that is located between the island of Luzon and the outer arc high of the west Luzon subduction zone. High-amplitude, low-frequency reflection bands mark the acoustic basement. The basement, at about 6 s (TWT), is dissected by normal faults with some of them being inverted in a later phase of deformation. The sedimentary successions, overlying the basement are stratified with partly chaotic structures and discontinuous reflectors. Five regional unconformities separate major stratigraphic units. Grid calculations of our seismic data reveal variations in the sedimentation pattern of the basin with a shift of the deposition centre from east to west and backwards during formation. A distinct bottom-simulating reflector is commonly observed. Because the northern boundary of the continental fragments to the South of the West Luzon Basin is unclear we speculate that the basin may be (partly) underlain by continental crust. The continental crust was affected by rifting prior to and during the opening of the South China Sea and the basin was overprinted at a later stage by a forearc structural setting when subduction was initiated.  相似文献   

Ability of beach users to identify rip currents at Pensacola Beach, Florida   总被引：3，自引：2，他引：1  

Nicole Caldwell  Chris Houser  Klaus Meyer-Arendt 《Natural Hazards》2013,68(2):1041-1056

Quasi-permanent rip current hot spots at Pensacola Beach, Florida, pose a significant hazard to beach users, largely because the hot spots are located at or close to the primary access points. While an increase in the number of lifeguards has led to a decrease in the number of drownings since 2004, the number of rescues and contacts has increased to over a 30,000 year. Despite warning signs at access points along the beach, it is not clear whether beach users are able to identify a rip channel or an active rip current. To assess beach users’ knowledge of rip currents and their ability to identify rip channels and currents, 97 surveys were conducted between June and September of 2010 at Pensacola Beach. Beach users were asked to identify rip channels in oblique photographs taken on green, yellow and red flag days when the potential for rip currents is low, medium and high, respectively. A majority of participants suggested that they could identify a rip channel or current (if present), but less than 20 % of beach users were able to identify the rip channels and currents. The majority of participants identified heavy surf areas as the location of the rips versus the relatively flat water of the current or the darker color water of the channel. Results further suggest that most beach users, and particularly local participants, are overconfident in their ability to identify rip channels and currents. The focus of beach users on heavy surf as an indication of the rip current potential and the overconfidence in identifying a rip channel or current affects the spatial distribution of beach users and to some degree the location of rescues and drownings. While it can be quite difficult for the average beach user to identify rip channels and active rip currents, the results of the study suggest a need for further education efforts to reduce the rip hazard, particularly in areas where lifeguards are not permanently stationed.  相似文献