135 research outputs found
Prediction of Commuterâs Daily Time Allocation
This paper presents a model system to predict the time allocation in commutersâ daily activity-travel pattern. The departure time and the arrival time are estimated with Ordered Probit model and Support Vector Regression is introduced for travel time and activity duration prediction. Applied in a real-world time allocation prediction experiment, the model system shows a satisfactory level of prediction accuracy. This study provides useful insights into commutersâ activity-travel time allocation decision by identifying the important influences, and the results are readily applied to a wide range of transportation practice, such as travel information system, by providing reliable forecast for variations in travel demand over time. By introducing the Support Vector Regression, it also makes a methodological contribution in enhancing prediction accuracy of travel time and activity duration prediction
Examination of staggered shifts impacts on travel behavior: a case study of Beijing, China
Staggered shifts is one of the popular TDM (Transportation Demand Management) policies, which can reduce commute travel volume during the AM and PM peak periods, and relieve traffic congestion. In order to make effective staggered shifts program, it is necessary to examine the effect of the program on commute travel behavior. This paper takes Beijing (China) as an example to evaluate the validity of staggered shifts policy. Based on data investigation, the commute travel behavior and the commutersâ preference for staggered shifts are analyzed. This paper makes four staggered shifts programs, and develops a commute departure time choice model with Multinomial Logit method to predict the influence of the programs on commute departure time, and develops a commute travel duration model to analyze the influence of the programs on commute travel time. Departure time prediction shows that Program B can reduce the traffic volumes in 6:30â8:30 period by 15.24%, and commute travel duration analysis indicate that Program B can reduce the home-to-work travel time by 21.73%. Therefore, Program B is proven to be the best staggered shifts program for Beijing. The results of this paper can provide valuable information on how to develop an effective staggered shifts program
Zhongjing: Enhancing the Chinese Medical Capabilities of Large Language Model through Expert Feedback and Real-world Multi-turn Dialogue
Recent advances in Large Language Models (LLMs) have achieved remarkable
breakthroughs in understanding and responding to user intents. However, their
performance lag behind general use cases in some expertise domains, such as
Chinese medicine. Existing efforts to incorporate Chinese medicine into LLMs
rely on Supervised Fine-Tuning (SFT) with single-turn and distilled dialogue
data. These models lack the ability for doctor-like proactive inquiry and
multi-turn comprehension and cannot always align responses with safety and
professionalism experts. In this work, we introduce Zhongjing, the first
Chinese medical LLaMA-based LLM that implements an entire training pipeline
from pre-training to reinforcement learning with human feedback (RLHF).
Additionally, we introduce a Chinese multi-turn medical dialogue dataset of
70,000 authentic doctor-patient dialogues, CMtMedQA, which significantly
enhances the model's capability for complex dialogue and proactive inquiry
initiation. We define a refined annotation rule and evaluation criteria given
the biomedical domain's unique characteristics. Results show that our model
outperforms baselines in various capacities and matches the performance of
ChatGPT in a few abilities, despite having 50x training data with previous best
model and 100x parameters with ChatGPT. RLHF further improves the model's
instruction-following ability and safety.We also release our code, datasets and
model for further research
Climate change and its influence on the Karst groundwater recharge in the Jinci Spring Region, Northern China
Due to climate change and human activities over the last fifty years, the spring flow
volume of karst groundwater has sharply diminished in China. Climate change is one of the critical
factors that initiates a series of karst hydrogeologic and water ecological environmental problems,
because the precipitation shows a decreasing trend while the temperature shows an increasing trend.
The Jinci Spring is one of the largest, most famous springs in northern China. This study employed
data from the Taiyuan Meteorological Station and ten precipitation stations in and around the Jinci
Spring region as well as the runoff data gathered from two hydrological monitoring stations during
1960-2012. The sliding average method and the Mann-Kendall test were used to analyze the variation
tendency of precipitation, temperature, and land evaporation in this area. Finally, the following
were calculated: the varying pattern of the karst groundwater recharge amount and the response
of the recharge amount to precipitation, land evaporation, and river runoff by quantitative analysis.
The results indicated that the precipitation and land evaporation amount decreased at first and then
subsequently increased. Likewise, the variation trend of the karst groundwater recharge amount
in the spring region was roughly consistent with the precipitation variation pattern. In contrast,
the temperature displayed an increasing trend. The climate change resulted in a reduction of the
karst groundwater recharge amount, and it had the greatest influence in the 1990s, which caused the
karst groundwater recharge amount to decrease 26.75 mm as compared to that of the 1960s (about
39.68% lower than that of the 1960s). The Jinci Spring had zero flow during this period. The reduction
in precipitation was one of main factors that caused the cutoff of the Jinci Spring.IS
Toward LowâTemperature ZincâIon Batteries: Strategy, Progress, and Prospect in VanadiumâBased Cathodes
Low-temperature vanadium-based zinc ion batteries (LT-VZIBs) have attracted much attention in recent years due to their excellent theoretical specific capacities, low cost, and electrochemical structural stability. However, low working temperature surrounding often results in retarded ion transport not only in the frozen aqueous electrolyte, but also at/across the cathode/electrolyte interface and inside cathode interior, significantly limiting the performance of LT-VZIBs for practical applications. In this review, a variety of strategies to solve these issues, mainly including cathode interface/bulk structure engineering and electrolyte optimizations, are categorially discussed and systematically summarized from the design principles to in-depth characterizations and mechanisms. In the end, several issues about future research directions and advancements in characterization tools are prospected, aiming to facilitate the scientific and commercial development of LT-VZIBs
Microplastic exposure represses the growth of endosymbiotic dinoflagellate Cladocopium goreaui in culture through affecting its apoptosis and metabolism
Abstract(#br)Microplastics are widespread emerging marine pollutants that have been found in the coral reef ecosystem. In the present study, using Cladocopium goreaui as a symbiont representative, we investigated cytological, physiological, and molecular responses of a Symbiodiniaceae species to weeklong microplastic exposure (Polystyrene, diameter 1.0 ÎŒm, 9.0 Ă 10 9 particles L â1 ). The density and size of algal cells decreased significantly at 7 d and 6â7 d of microplastic exposure, respectively. Chlorophyll a content increased significantly at 7 d of exposure, whereas Fv/Fm did not change significantly during the entire exposure period. We observed significant increases in superoxide dismutase activity and caspase3 activation level, significant decrease in glutathione S-transferase activity, but no change in catalase activity during the whole exposure period. Transcriptomic analysis revealed 191 significantly upregulated and 71 significantly downregulated genes at 7 d after microplastic exposure. Fifteen GO terms were overrepresented for these significantly upregulated genes, which were grouped into four categories including transmembrane ion transport, substrate-specific transmembrane transporter activity, calcium ion binding, and calcium-dependent cysteine-type endopeptidase activity. Thirteen of the significantly upregulated genes encode metal ion transporter and ammonium transporter, and five light-harvesting protein genes were among the significantly downregulated genes. These results demonstrate that microplastics can act as an exogenous stressor, suppress detoxification activity, nutrient uptake, and photosynthesis, elevate oxidative stress, and raise the apoptosis level through upregulating ion transport and apoptotic enzymes to repress the growth of C. goreaui . These effects have implications in negative impacts of microplastics on coral-Symbiodiniaceae symbiosis that involves C. goreaui
Microplastic exposure represses the growth of endosymbiotic dinoflagellate Cladocopium goreaui in culture through affecting its apoptosis and metabolism.
Microplastics are widespread emerging marine pollutants that have been found in the coral reef ecosystem. In the present study, using Cladocopium goreaui as a symbiont representative, we investigated cytological, physiological, and molecular responses of a Symbiodiniaceae species to weeklong microplastic exposure (Polystyrene, diameter 1.0 ÎŒm, 9.0 Ă 109 particles L-1). The density and size of algal cells decreased significantly at 7 d and 6-7 d of microplastic exposure, respectively. Chlorophyll a content increased significantly at 7 d of exposure, whereas Fv/Fm did not change significantly during the entire exposure period. We observed significant increases in superoxide dismutase activity and caspase3 activation level, significant decrease in glutathione S-transferase activity, but no change in catalase activity during the whole exposure period. Transcriptomic analysis revealed 191 significantly upregulated and 71 significantly downregulated genes at 7 d after microplastic exposure. Fifteen GO terms were overrepresented for these significantly upregulated genes, which were grouped into four categories including transmembrane ion transport, substrate-specific transmembrane transporter activity, calcium ion binding, and calcium-dependent cysteine-type endopeptidase activity. Thirteen of the significantly upregulated genes encode metal ion transporter and ammonium transporter, and five light-harvesting protein genes were among the significantly downregulated genes. These results demonstrate that microplastics can act as an exogenous stressor, suppress detoxification activity, nutrient uptake, and photosynthesis, elevate oxidative stress, and raise the apoptosis level through upregulating ion transport and apoptotic enzymes to repress the growth of C. goreaui. These effects have implications in negative impacts of microplastics on coral-Symbiodiniaceae symbiosis that involves C. goreaui
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