In this paper, the Automated Actuarial Loss Reserving Model is developed and extended using machine learning. The traditional actuarial reserving techniques are no longer compatible with the increase in technological ...In this paper, the Automated Actuarial Loss Reserving Model is developed and extended using machine learning. The traditional actuarial reserving techniques are no longer compatible with the increase in technological advancement currently at hand. As a result, the development of the alternative Artificial Intelligence Based Automated Actuarial Loss Reserving Methodology which captures diverse risk profiles for various policyholders through augmenting the Micro Finance services, Auto Insurance Services and Both Services lines of business on the same platform through the computation of the Comprehensive Automated Actuarial Loss Reserves (CAALR) has been implemented in this paper. The introduction of the four further types of actuarial loss reserves to those existing in the actuarial literature seems to significantly reduce lapse rates, reduce the reinsurance costs as well as expenses and outgo. As a matter of consequence, this helps to bring together a combination of new and existing policyholders in the insurance company. The frequency severity models have been extended in this paper using ten machine learning algorithms which ultimately leads to the derivation of the proposed machine learning-based actuarial loss reserving model which remarkably performed well when compared to the traditional chain ladder actuarial reserving method using simulated data.展开更多
We consider intrinsic gate capacitance variations due to random dopants in the nanometer metal oxide semi- conductor field effect transistor （MOSFET） channel. The variations of total gate capacitance and gate transc...We consider intrinsic gate capacitance variations due to random dopants in the nanometer metal oxide semi- conductor field effect transistor （MOSFET） channel. The variations of total gate capacitance and gate transcapacitances are investigated and the strong correlations between the trans-capacitance variations are discovered. A simple statistical model is proposed for accurately capturing total gate capacitance variability based on the correlations. The model fits very well with the Monte Carlo simulations and the average errors are -0.033% for n-type metal-oxide semiconductor and -0.012% for p-type metal-oxide semiconductor, respectively. Our simulation studies also indicate that, owing to these correlations, the total gate capacitance variability will not dominate in gate capacitance variations.展开更多
The idea of application from DNA information organization for providing the next generation super-computers has been proposed by lessons learned from nature. Thus, molecular environment of reserving information was co...The idea of application from DNA information organization for providing the next generation super-computers has been proposed by lessons learned from nature. Thus, molecular environment of reserving information was considered as succeeding generation of a mother-board project containing some subcategories with various applications. MERI, constructed based on the binary coding system using DNA synthesizer machine, enables retrievable reading of molecular structures using DNA sequencer machine. It has high capacity for reservation of information about 1.212 × 1011 Kb/cm2 with long-term stability. It can be used in various fields of science and technology regarding its high capacity, small size and safety measures.展开更多
“Treating vitality”and“ reserving vitality”are very important manipulations during acupuncture treatment of diseases.“Treating vitality” comprises adjusting and treating both the acupuncture doctor＇s and the pa...“Treating vitality”and“ reserving vitality”are very important manipulations during acupuncture treatment of diseases.“Treating vitality” comprises adjusting and treating both the acupuncture doctor＇s and the patient＇s vitality; while “reserving vitality” demands the acupuncture doctor carefully to experience the sensations of ＇excess＇ or ＇deficiency＇ under the needle, wait for the arrival of qi, observe the patient＇s responses, and then perform reducing or reinforcing needling manipulations in accordance with the state of excess-or deficiency-syndrome. “Treating vitality”and “reserving vitality” impenetrate the whole process of acupuncture treatment all along. Through years＇ clinical practice, the author of the present paper discusses the functions of the two aspects in every stage of acupuncture treatment, including before acupuncture, during needle insertion, during retention and withdrawal of the needle. The purpose of this paper is to explain the clinical significance of treating and reserving vitality and arouse many acupuncture doctors＇attention.展开更多
Of seventy-one patients with rectal cancer after radical resection retaining the anus, 15 developed local recurrence with a recurrence rate of 21.1%. Local recurrence was correlated with improper safety margin from th...Of seventy-one patients with rectal cancer after radical resection retaining the anus, 15 developed local recurrence with a recurrence rate of 21.1%. Local recurrence was correlated with improper safety margin from the lower edge of cancer to the anal end. There was statistical significant difference between 3 cm or more and 2 cm or less. The local recurrence was also related to the pathologic stage, histologic differentiation and implant of free cancer cells. It is suggested that the surgical indication of saving the anus be strict and without stretching, the safety margin from the lower edge of cancer to the anal end should not be less than 2 cm in early rectal cancer and not less than 4 cm in advanced lesions. During the operation, no touching tumor technique, thorough rinsing of the peritoneal cavity and pre- or post-operative radiotherapy are important for prevention of local recurrence. Early local recurrent rectal cancer can be detected by periodic examinations.展开更多
This study proposes a novel approach for estimating automobile insurance loss reserves utilizing Artificial Neural Network (ANN) techniques integrated with actuarial data intelligence. The model aims to address the ch...This study proposes a novel approach for estimating automobile insurance loss reserves utilizing Artificial Neural Network (ANN) techniques integrated with actuarial data intelligence. The model aims to address the challenges of accurately predicting insurance claim frequencies, severities, and overall loss reserves while accounting for inflation adjustments. Through comprehensive data analysis and model development, this research explores the effectiveness of ANN methodologies in capturing complex nonlinear relationships within insurance data. The study leverages a data set comprising automobile insurance policyholder information, claim history, and economic indicators to train and validate the ANN-based reserving model. Key aspects of the methodology include data preprocessing techniques such as one-hot encoding and scaling, followed by the construction of frequency, severity, and overall loss reserving models using ANN architectures. Moreover, the model incorporates inflation adjustment factors to ensure the accurate estimation of future loss reserves in real terms. Results from the study demonstrate the superior predictive performance of the ANN-based reserving model compared to traditional actuarial methods, with substantial improvements in accuracy and robustness. Furthermore, the model’s ability to adapt to changing market conditions and regulatory requirements, such as IFRS17, highlights its practical relevance in the insurance industry. The findings of this research contribute to the advancement of actuarial science and provide valuable insights for insurance companies seeking more accurate and efficient loss reserving techniques. The proposed ANN-based approach offers a promising avenue for enhancing risk management practices and optimizing financial decision-making processes in the automobile insurance sector.展开更多
The concept of the brain cognitive reserve is derived from the well-acknowledged notion that the degree of brain damage does not always match the severity of clinical symptoms and neurological/cognitive outcomes.It ha...The concept of the brain cognitive reserve is derived from the well-acknowledged notion that the degree of brain damage does not always match the severity of clinical symptoms and neurological/cognitive outcomes.It has been suggested that the size of the brain(brain reserve) and the extent of neural connections acquired through life(neural reserve) set a threshold beyond which noticeable impairments occur.In contrast,cognitive reserve refers to the brain's ability to adapt and reo rganize stru cturally and functionally to resist damage and maintain function,including neural reserve and brain maintenance,resilience,and compensation(Verkhratsky and Zorec,2024).展开更多
For stochastic loss reserving,we propose an individual information model(IIM)which accom-modates not only individual/micro data consisting of incurring times,reporting developments,settlement developments as well as p...For stochastic loss reserving,we propose an individual information model(IIM)which accom-modates not only individual/micro data consisting of incurring times,reporting developments,settlement developments as well as payments of individual claims but also heterogeneity among policies.We give over-dispersed Poisson assumption about the moments of reporting developments and payments of every individual claims.Model estimation is conducted under quasi-likelihood theory.Analytic expressions are derived for the expectation and variance of outstanding liabilities,given historical observations.We utilise conditional mean square error of prediction(MSEP)to measure the accuracy of loss reserving and also theoretically prove that when risk portfolio size is large enough,IIM shows a higher prediction accuracy than individ-ual/micro data model(IDM)in predicting the outstanding liabilities,if the heterogeneity indeed influences claims developments and otherwise IIM is asymptotically equivalent to IDM.Some simulations are conducted to investigate the conditional MSEPs for IIM and IDM.A real data analysis is performed basing on real observations in health insurance.展开更多
Elk are seen at the Tian’ezhou National Nature Reserve for Elk in Shishou,Hubei Province,on 27 November 2025.The reserve’s elk population has risen from just 64 in the 1990s to more than 4,500 today.
CHINA.Dinghu Mountain National Nature Reserve.Located in Zhaoqing,Guangdong Province,Dinghu Mountain National Nature Reserve is a pristine natural sanctuary spanning 1,133 hectares within the low mountain ranges of th...CHINA.Dinghu Mountain National Nature Reserve.Located in Zhaoqing,Guangdong Province,Dinghu Mountain National Nature Reserve is a pristine natural sanctuary spanning 1,133 hectares within the low mountain ranges of the Dayunwu Mountains.展开更多
Dune barrier systems represent highly sought-after coastal landscapes for tourism and urban development around the world.However,a century ago,they were considered hazardous environments due to their great dynamic nat...Dune barrier systems represent highly sought-after coastal landscapes for tourism and urban development around the world.However,a century ago,they were considered hazardous environments due to their great dynamic nature.As a result,stabilization practices were considered necessary.The systematic introduction of fast-growing exotic trees helped stabilize the sand,making it easier for tourism urbanization to take place,but also leading to erosion processes.This paper aims to assess long-term changes in vegetation cover over a large temperate barrier in Argentina.This complex region includes urban resorts,afforestation zones,and protected areas.A GIS-based geospatial analysis was conducted using a large satellite database(>350 images),and the future evolution of the vegetation was modeled.The results revealed two primary spatiotemporal patterns associated with a gradual expansion of vegetation cover,accompanied by a concurrent reduction in sandy areas.In 1986,the dune area comprised 75%more surface than vegetation,whereas in 2021,it represented 60%less than vegetation.Furthermore,the 2050 scenario suggests a potential 40%reduction of dunes in certain areas.It is necessary to enhance management actions aimed at maintaining dune mobility and ensuring local and regional sediment balance.Long-term management strategies must focus on restoring native plant communities and controlling invasive species,and avoiding new dune fixation initiatives based on the introduction of exotic species.展开更多
Clarifying the mechanisms through which coal mining affects groundwater storage(GWS)variations is crucial for water resource conservation and sustainable development.The Ordos Mining Region in China,a key energy base ...Clarifying the mechanisms through which coal mining affects groundwater storage(GWS)variations is crucial for water resource conservation and sustainable development.The Ordos Mining Region in China,a key energy base in China with significant strategic importance,has undergone intensive coal mining activities that have substantially disrupted regional groundwater circulation.This study integrated data from the Gravity Recovery and Climate Experiment Satellite(GRACE)and Famine Early Warning Systems Network(FEWS NET)Land Data Assimilation System(FLDAS)models,combined with weighted downscaling methodology and water balance principles,to reconstruct high-resolution(0.01°)terrestrial water storage(TWS)and GWS changes in the Ordos Mining Region,China from April 2002 to December 2021.The accuracy of GWS variations were validated through pumping test measurements.Subsequently,Geodetector analysis was implemented to quantify the contributions of natural and anthropogenic factors to groundwater storage dynamics.Key findings include:1)TWS in the study area showed a fluctuating but overall decreasing trend,with a total reduction of 8901.11 mm during study period.The most significant annual decrease occurred in 2021,reaching 1696.77 mm.2)GWS exhibited an accelerated decline,with an average annual change rate of 44.35 mm/yr,totaling a decrease of 887.05 mm.The lowest annual groundwater storage level was recorded in 2020,reaching 185.69 mm.3)Precipitation(PRE)contributed the most to GWS variation(q=0.52),followed by coal mining water consumption(MWS)(q=0.41).The interaction between PRE and MWS exhibited a nonlinear enhancement effect on GWS changes(0.54).The synergistic effect of natural hydrological factors has a great influence on the change of GWS,but coal mining water consumption will continue to reduce GWS.These findings provide critical references for the management and regulation of groundwater resource in mining regions.展开更多
Objective To evaluate the association of GGN repeat polymorphism of androgen receptor(AR)with ovarian reserve and ovarian response in controlled ovarian stimulation(COS).Methods This genetic association study was cond...Objective To evaluate the association of GGN repeat polymorphism of androgen receptor(AR)with ovarian reserve and ovarian response in controlled ovarian stimulation(COS).Methods This genetic association study was conducted among a total of 361 women aged≤40 years with basal FSH≤12 U/L undergoing the GnRH-agonist long protocol for COS in a university affiliated IVF center.GGN repeat in the AR gene was analyzed with Sanger sequencing.The primary endpoint was the number of antral follicle counts(AFCs),and the secondary endpoints were stimulation days,total dose of gonadotropin(Gn)used,total number of retrieved oocytes,ovarian sensitivity index,and follicular output rate.Results The GGN repeat in exon 1 of the AR gene ranged from 13 to 24,and the median repeat length was 22.Based on the genotypes(S for GGN repeats<22,L for GGN repeats≥22),the patients were divided into 3 groups:SS,SL,and LL.Generalized regression analysis indicated that the number of AFCs in group SS was significantly lower than those in group SL(adjusted β=1.8,95%CI:0.2-3.4,P=0.024)and group LL(adjusted β=1.5,95%CI:0.2-2.7,P=0.021).No significant difference was observed in the number of AFCs between group SL and group LL(P>0.05).Generalized regression analysis indicated no significant differences in ovarian stimulation parameters among the 3 groups,either before or after adjusting for confounding factors(P>0.05).Conclusion GGN repeat length on the AR gene is associated with AFC but not with ovarian response in Chinese women,indicating that AR gene polymorphisms may affect ovarian reserve.展开更多
CHINA Gaoligongshan National Natural Reserve Rising to over 4,000 metres above sea level in western Yunnan Province,Gaoligong Mountain forms part of the southern Hengduan Mountain Range and is renowned for its rich bi...CHINA Gaoligongshan National Natural Reserve Rising to over 4,000 metres above sea level in western Yunnan Province,Gaoligong Mountain forms part of the southern Hengduan Mountain Range and is renowned for its rich biodiversity and vibrant cultural landscape.Encompassing a vast protected area across the Tengchong and Baoshan regions,the Gaoligongshan National Natural Reserve is a secluded ecological treasure trove.In April 2000,the reserve joined the UNESCO World Network of Biosphere Reserves.展开更多
The pioneering work of China’s Zhejiang Province in biosphere preservation and restoration,as well as its green development of residential areas around its nature reserves,made it the ideal location to host the 5th W...The pioneering work of China’s Zhejiang Province in biosphere preservation and restoration,as well as its green development of residential areas around its nature reserves,made it the ideal location to host the 5th World Congress of Biosphere Reserves and share China’s achievements in this field with the world.展开更多
Established in 1958,Xishuangbanna National Nature Reserve is one of China’s first protected areas.Covering about 2,435 square km,it is the country’s largest tropical primeval forest and one of the world’s most biol...Established in 1958,Xishuangbanna National Nature Reserve is one of China’s first protected areas.Covering about 2,435 square km,it is the country’s largest tropical primeval forest and one of the world’s most biologically diverse regions.In 1993,it became part of the UNESCO World Biosphere Reserve Network,reflecting its global ecological significance.展开更多
Background Non-invasive computed tomography angiography(CTA)-based fractional flow reserve(CT-FFR)could become a gatekeeper to invasive coronary angiography.Deep learning(DL)-based CT-FFR has shown promise when compar...Background Non-invasive computed tomography angiography(CTA)-based fractional flow reserve(CT-FFR)could become a gatekeeper to invasive coronary angiography.Deep learning(DL)-based CT-FFR has shown promise when compared to invasive FFR.To evaluate the performance of a DL-based CT-FFR technique,DeepVessel FFR(DVFFR).Methods This retrospective study was designed for iScheMia Assessment based on a Retrospective,single-center Trial of CTFFR(SMART).Patients suspected of stable coronary artery disease(CAD)and undergoing both CTA and invasive FFR examinations were consecutively selected from the Beijing Anzhen Hospital between January 1,2016 to December 30,2018.FFR obtained during invasive coronary angiography was used as the reference standard.DVFFR was calculated blindly using a DL-based CTFFR approach that utilized the complete tree structure of the coronary arteries.Results Three hundred and thirty nine patients(60.5±10.0 years and 209 men)and 414 vessels with direct invasive FFR were included in the analysis.At per-vessel level,sensitivity,specificity,accuracy,positive predictive value(PPV)and negative predictive value(NPV)of DVFFR were 94.7%,88.6%,90.8%,82.7%,and 96.7%,respectively.The area under the receiver operating characteristics curve(AUC)was 0.95 for DVFFR and 0.56 for CTA-based assessment with a significant difference(P<0.0001).At patient level,sensitivity,specificity,accuracy,PPV and NPV of DVFFR were 93.8%,88.0%,90.3%,83.0%,and 95.8%,respectively.The computation for DVFFR was fast with the average time of 22.5±1.9 s.Conclusions The results demonstrate that DVFFR was able to evaluate lesion hemodynamic significance accurately and effectively with improved diagnostic performance over CTA alone.Coronary artery disease(CAD)is a critical disease in which coronary artery luminal narrowing may result in myocardial ischemia.Early and effective assessment of myocardial ischemia is essential for optimal treatment planning so as to improve the quality of life and reduce medical costs.展开更多
The Yangtze finless porpoise(Neophocaena asiaeorientalis asiaeorientalis)is distributed in the main stream of the middle and lower reaches of the Yangtze River,as well as in Dongting and Poyang lakes.Currently,the mos...The Yangtze finless porpoise(Neophocaena asiaeorientalis asiaeorientalis)is distributed in the main stream of the middle and lower reaches of the Yangtze River,as well as in Dongting and Poyang lakes.Currently,the most crucial conservation approach involves the establishment and management of both in-situ and ex-situ nature reserves.Since the 1990s,seven nature reserves have been established in the middle and lower reaches of the Yangtze River,covering nearly one-third of its main stream.Additionally,two nature reserves,one in the Dongting Lake and another in the Poyang Lake,have been set up;and three ex-situ nature reserves have been established in three oxbows respectively in Hunan,Hubei,and Anhui provinces.Through measures such as improving the ecological environment quality within the reserves,regulating human activities,and conducting continuous monitoring,the finless porpoise population showed a slight increase in 2022 for the first time.The ex-situ population has continued to grow,with four individuals being released back into the main stream of the Yangtze River after undergoing reintroduction training in 2023.Based on the population development lasting for over three decades,and predictions of future ecological changes,orderly establishment and scientific management of nature reserves have played a key role in and will remain an important basis for the sustaining growth of the finless porpoise population.展开更多
CHINA Tarim Populus Euphratica National Nature Reserve Located along the northern edge of the Taklimakan Desert in Xinjiang,the Tarim Populus Euphratica National Nature Reserve lies in the middle reaches of the Tarim ...CHINA Tarim Populus Euphratica National Nature Reserve Located along the northern edge of the Taklimakan Desert in Xinjiang,the Tarim Populus Euphratica National Nature Reserve lies in the middle reaches of the Tarim River-the longest inland river in China-within Bayingolin Mongol Autonomous Prefecture.Established in 1983 and upgraded to a national reserve in 2006,it covers an area of about 395,420 hectares,including a core,bu!er,and experimental zone.The reserve features alluvial plains and desert terrain,with elevations ranging from 800 to 940 metres.The landscape consists of river floodplains,ancient riverbeds,and oasis margins,forming a remarkable ecological mosaic shaped by the Tarim River and its tributaries.The region experiences a typical temperate continental desert climate-dry,hot,and windy with scarce rainfall.展开更多
[Objectives]To analyze the composition of lycophytes and ferns in Yunzhongshan Nature Reserve,Fujian Province.[Methods]This study examined the composition of lycophytes and ferns in Yunzhongshan Nature Reserve through...[Objectives]To analyze the composition of lycophytes and ferns in Yunzhongshan Nature Reserve,Fujian Province.[Methods]This study examined the composition of lycophytes and ferns in Yunzhongshan Nature Reserve through field investigations and specimen identification,supplemented by a review of relevant literature.[Results]A total of 84 species of lycophytes and ferns were identified,encompassing 55 genera and 29 families.This included 14 species of lycophytes distributed across 8 genera and 3 families,as well as 70 species of ferns belonging to 47 genera and 26 families.Polypodiaceae and Selaginella were the dominant family and genus,respectively,while oligospecific families and monotypic genera were significant components of lycophytes and ferns in the region.The distribution types of these families were primarily cosmopolitan and tropical.The Germline differentiation degree(SD)was 3.34,and the proportion of rare or endangered species among lycophytes and ferns was 8.33%.[Conclusions]Yunzhongshan Nature Reserve possesses a diverse array of lycophyte and fern species.This study offers valuable scientific insights that can inform efforts related to the conservation of biodiversity,resource utilization and development,species introduction,and system evolution of lycophytes and ferns within the reserve.展开更多
文摘In this paper, the Automated Actuarial Loss Reserving Model is developed and extended using machine learning. The traditional actuarial reserving techniques are no longer compatible with the increase in technological advancement currently at hand. As a result, the development of the alternative Artificial Intelligence Based Automated Actuarial Loss Reserving Methodology which captures diverse risk profiles for various policyholders through augmenting the Micro Finance services, Auto Insurance Services and Both Services lines of business on the same platform through the computation of the Comprehensive Automated Actuarial Loss Reserves (CAALR) has been implemented in this paper. The introduction of the four further types of actuarial loss reserves to those existing in the actuarial literature seems to significantly reduce lapse rates, reduce the reinsurance costs as well as expenses and outgo. As a matter of consequence, this helps to bring together a combination of new and existing policyholders in the insurance company. The frequency severity models have been extended in this paper using ten machine learning algorithms which ultimately leads to the derivation of the proposed machine learning-based actuarial loss reserving model which remarkably performed well when compared to the traditional chain ladder actuarial reserving method using simulated data.
基金Supported by the National Natural Science Foundation of China under Grant Nos 61271064,61571171 and 61302009the Zhejiang Provincial Natural Science Foundation of China under Grant No LZ12F01001
文摘We consider intrinsic gate capacitance variations due to random dopants in the nanometer metal oxide semi- conductor field effect transistor （MOSFET） channel. The variations of total gate capacitance and gate transcapacitances are investigated and the strong correlations between the trans-capacitance variations are discovered. A simple statistical model is proposed for accurately capturing total gate capacitance variability based on the correlations. The model fits very well with the Monte Carlo simulations and the average errors are -0.033% for n-type metal-oxide semiconductor and -0.012% for p-type metal-oxide semiconductor, respectively. Our simulation studies also indicate that, owing to these correlations, the total gate capacitance variability will not dominate in gate capacitance variations.
文摘The idea of application from DNA information organization for providing the next generation super-computers has been proposed by lessons learned from nature. Thus, molecular environment of reserving information was considered as succeeding generation of a mother-board project containing some subcategories with various applications. MERI, constructed based on the binary coding system using DNA synthesizer machine, enables retrievable reading of molecular structures using DNA sequencer machine. It has high capacity for reservation of information about 1.212 × 1011 Kb/cm2 with long-term stability. It can be used in various fields of science and technology regarding its high capacity, small size and safety measures.
文摘“Treating vitality”and“ reserving vitality”are very important manipulations during acupuncture treatment of diseases.“Treating vitality” comprises adjusting and treating both the acupuncture doctor＇s and the patient＇s vitality; while “reserving vitality” demands the acupuncture doctor carefully to experience the sensations of ＇excess＇ or ＇deficiency＇ under the needle, wait for the arrival of qi, observe the patient＇s responses, and then perform reducing or reinforcing needling manipulations in accordance with the state of excess-or deficiency-syndrome. “Treating vitality”and “reserving vitality” impenetrate the whole process of acupuncture treatment all along. Through years＇ clinical practice, the author of the present paper discusses the functions of the two aspects in every stage of acupuncture treatment, including before acupuncture, during needle insertion, during retention and withdrawal of the needle. The purpose of this paper is to explain the clinical significance of treating and reserving vitality and arouse many acupuncture doctors＇attention.
文摘Of seventy-one patients with rectal cancer after radical resection retaining the anus, 15 developed local recurrence with a recurrence rate of 21.1%. Local recurrence was correlated with improper safety margin from the lower edge of cancer to the anal end. There was statistical significant difference between 3 cm or more and 2 cm or less. The local recurrence was also related to the pathologic stage, histologic differentiation and implant of free cancer cells. It is suggested that the surgical indication of saving the anus be strict and without stretching, the safety margin from the lower edge of cancer to the anal end should not be less than 2 cm in early rectal cancer and not less than 4 cm in advanced lesions. During the operation, no touching tumor technique, thorough rinsing of the peritoneal cavity and pre- or post-operative radiotherapy are important for prevention of local recurrence. Early local recurrent rectal cancer can be detected by periodic examinations.
文摘This study proposes a novel approach for estimating automobile insurance loss reserves utilizing Artificial Neural Network (ANN) techniques integrated with actuarial data intelligence. The model aims to address the challenges of accurately predicting insurance claim frequencies, severities, and overall loss reserves while accounting for inflation adjustments. Through comprehensive data analysis and model development, this research explores the effectiveness of ANN methodologies in capturing complex nonlinear relationships within insurance data. The study leverages a data set comprising automobile insurance policyholder information, claim history, and economic indicators to train and validate the ANN-based reserving model. Key aspects of the methodology include data preprocessing techniques such as one-hot encoding and scaling, followed by the construction of frequency, severity, and overall loss reserving models using ANN architectures. Moreover, the model incorporates inflation adjustment factors to ensure the accurate estimation of future loss reserves in real terms. Results from the study demonstrate the superior predictive performance of the ANN-based reserving model compared to traditional actuarial methods, with substantial improvements in accuracy and robustness. Furthermore, the model’s ability to adapt to changing market conditions and regulatory requirements, such as IFRS17, highlights its practical relevance in the insurance industry. The findings of this research contribute to the advancement of actuarial science and provide valuable insights for insurance companies seeking more accurate and efficient loss reserving techniques. The proposed ANN-based approach offers a promising avenue for enhancing risk management practices and optimizing financial decision-making processes in the automobile insurance sector.
文摘The concept of the brain cognitive reserve is derived from the well-acknowledged notion that the degree of brain damage does not always match the severity of clinical symptoms and neurological/cognitive outcomes.It has been suggested that the size of the brain(brain reserve) and the extent of neural connections acquired through life(neural reserve) set a threshold beyond which noticeable impairments occur.In contrast,cognitive reserve refers to the brain's ability to adapt and reo rganize stru cturally and functionally to resist damage and maintain function,including neural reserve and brain maintenance,resilience,and compensation(Verkhratsky and Zorec,2024).
基金This work was supported by the Natural Science Foundation of China(71771089)the Shanghai Philosophy and Social Sci-ence Foundation(2015BGL001)+1 种基金the National Social Science Foundation Key Program of China(17ZDA091)China Scholarship Council(201906140045)。
文摘For stochastic loss reserving,we propose an individual information model(IIM)which accom-modates not only individual/micro data consisting of incurring times,reporting developments,settlement developments as well as payments of individual claims but also heterogeneity among policies.We give over-dispersed Poisson assumption about the moments of reporting developments and payments of every individual claims.Model estimation is conducted under quasi-likelihood theory.Analytic expressions are derived for the expectation and variance of outstanding liabilities,given historical observations.We utilise conditional mean square error of prediction(MSEP)to measure the accuracy of loss reserving and also theoretically prove that when risk portfolio size is large enough,IIM shows a higher prediction accuracy than individ-ual/micro data model(IDM)in predicting the outstanding liabilities,if the heterogeneity indeed influences claims developments and otherwise IIM is asymptotically equivalent to IDM.Some simulations are conducted to investigate the conditional MSEPs for IIM and IDM.A real data analysis is performed basing on real observations in health insurance.
文摘Elk are seen at the Tian’ezhou National Nature Reserve for Elk in Shishou,Hubei Province,on 27 November 2025.The reserve’s elk population has risen from just 64 in the 1990s to more than 4,500 today.
文摘CHINA.Dinghu Mountain National Nature Reserve.Located in Zhaoqing,Guangdong Province,Dinghu Mountain National Nature Reserve is a pristine natural sanctuary spanning 1,133 hectares within the low mountain ranges of the Dayunwu Mountains.
基金supported by the Ministry of Science,Technology and Innovation of Argentina trough the project“Topografía,escurrimiento superficial y monitoreo de playas en el Partido de Villa Gesell,provincia de Buenos Aires”(Impact.AR N°106-RESOL-2022-224-APN-SACT#MCT)by the Nacional Council of Scientific and Technical Research(CONICET)through the project“Impactos de la reversión del nivel del mar en Buenos Aires,Argentina”(PIP 21/2311220200100041CO-RESOL-2021-1639-APN-DIR#CONICET)。
文摘Dune barrier systems represent highly sought-after coastal landscapes for tourism and urban development around the world.However,a century ago,they were considered hazardous environments due to their great dynamic nature.As a result,stabilization practices were considered necessary.The systematic introduction of fast-growing exotic trees helped stabilize the sand,making it easier for tourism urbanization to take place,but also leading to erosion processes.This paper aims to assess long-term changes in vegetation cover over a large temperate barrier in Argentina.This complex region includes urban resorts,afforestation zones,and protected areas.A GIS-based geospatial analysis was conducted using a large satellite database(>350 images),and the future evolution of the vegetation was modeled.The results revealed two primary spatiotemporal patterns associated with a gradual expansion of vegetation cover,accompanied by a concurrent reduction in sandy areas.In 1986,the dune area comprised 75%more surface than vegetation,whereas in 2021,it represented 60%less than vegetation.Furthermore,the 2050 scenario suggests a potential 40%reduction of dunes in certain areas.It is necessary to enhance management actions aimed at maintaining dune mobility and ensuring local and regional sediment balance.Long-term management strategies must focus on restoring native plant communities and controlling invasive species,and avoiding new dune fixation initiatives based on the introduction of exotic species.
基金Under the National Key R&D Program Key Project(No.2021YFC3201201)National Natural Science Foundation of China(No.52360032)+2 种基金Basic Scientific Research Business Fee Project of Colleges And Universities Directly Under the Inner Mongolia Autonomous Region(No.JBYYWF2022001)Development Plan of Innovation Team of Colleges And Universities in Inner Mongolia Autonomous Region(No.NMGIRT2313)the Innovation Team of‘Grassland Talents’。
文摘Clarifying the mechanisms through which coal mining affects groundwater storage(GWS)variations is crucial for water resource conservation and sustainable development.The Ordos Mining Region in China,a key energy base in China with significant strategic importance,has undergone intensive coal mining activities that have substantially disrupted regional groundwater circulation.This study integrated data from the Gravity Recovery and Climate Experiment Satellite(GRACE)and Famine Early Warning Systems Network(FEWS NET)Land Data Assimilation System(FLDAS)models,combined with weighted downscaling methodology and water balance principles,to reconstruct high-resolution(0.01°)terrestrial water storage(TWS)and GWS changes in the Ordos Mining Region,China from April 2002 to December 2021.The accuracy of GWS variations were validated through pumping test measurements.Subsequently,Geodetector analysis was implemented to quantify the contributions of natural and anthropogenic factors to groundwater storage dynamics.Key findings include:1)TWS in the study area showed a fluctuating but overall decreasing trend,with a total reduction of 8901.11 mm during study period.The most significant annual decrease occurred in 2021,reaching 1696.77 mm.2)GWS exhibited an accelerated decline,with an average annual change rate of 44.35 mm/yr,totaling a decrease of 887.05 mm.The lowest annual groundwater storage level was recorded in 2020,reaching 185.69 mm.3)Precipitation(PRE)contributed the most to GWS variation(q=0.52),followed by coal mining water consumption(MWS)(q=0.41).The interaction between PRE and MWS exhibited a nonlinear enhancement effect on GWS changes(0.54).The synergistic effect of natural hydrological factors has a great influence on the change of GWS,but coal mining water consumption will continue to reduce GWS.These findings provide critical references for the management and regulation of groundwater resource in mining regions.
文摘Objective To evaluate the association of GGN repeat polymorphism of androgen receptor(AR)with ovarian reserve and ovarian response in controlled ovarian stimulation(COS).Methods This genetic association study was conducted among a total of 361 women aged≤40 years with basal FSH≤12 U/L undergoing the GnRH-agonist long protocol for COS in a university affiliated IVF center.GGN repeat in the AR gene was analyzed with Sanger sequencing.The primary endpoint was the number of antral follicle counts(AFCs),and the secondary endpoints were stimulation days,total dose of gonadotropin(Gn)used,total number of retrieved oocytes,ovarian sensitivity index,and follicular output rate.Results The GGN repeat in exon 1 of the AR gene ranged from 13 to 24,and the median repeat length was 22.Based on the genotypes(S for GGN repeats<22,L for GGN repeats≥22),the patients were divided into 3 groups:SS,SL,and LL.Generalized regression analysis indicated that the number of AFCs in group SS was significantly lower than those in group SL(adjusted β=1.8,95%CI:0.2-3.4,P=0.024)and group LL(adjusted β=1.5,95%CI:0.2-2.7,P=0.021).No significant difference was observed in the number of AFCs between group SL and group LL(P>0.05).Generalized regression analysis indicated no significant differences in ovarian stimulation parameters among the 3 groups,either before or after adjusting for confounding factors(P>0.05).Conclusion GGN repeat length on the AR gene is associated with AFC but not with ovarian response in Chinese women,indicating that AR gene polymorphisms may affect ovarian reserve.
文摘CHINA Gaoligongshan National Natural Reserve Rising to over 4,000 metres above sea level in western Yunnan Province,Gaoligong Mountain forms part of the southern Hengduan Mountain Range and is renowned for its rich biodiversity and vibrant cultural landscape.Encompassing a vast protected area across the Tengchong and Baoshan regions,the Gaoligongshan National Natural Reserve is a secluded ecological treasure trove.In April 2000,the reserve joined the UNESCO World Network of Biosphere Reserves.
文摘The pioneering work of China’s Zhejiang Province in biosphere preservation and restoration,as well as its green development of residential areas around its nature reserves,made it the ideal location to host the 5th World Congress of Biosphere Reserves and share China’s achievements in this field with the world.
文摘Established in 1958,Xishuangbanna National Nature Reserve is one of China’s first protected areas.Covering about 2,435 square km,it is the country’s largest tropical primeval forest and one of the world’s most biologically diverse regions.In 1993,it became part of the UNESCO World Biosphere Reserve Network,reflecting its global ecological significance.
文摘Background Non-invasive computed tomography angiography(CTA)-based fractional flow reserve(CT-FFR)could become a gatekeeper to invasive coronary angiography.Deep learning(DL)-based CT-FFR has shown promise when compared to invasive FFR.To evaluate the performance of a DL-based CT-FFR technique,DeepVessel FFR(DVFFR).Methods This retrospective study was designed for iScheMia Assessment based on a Retrospective,single-center Trial of CTFFR(SMART).Patients suspected of stable coronary artery disease(CAD)and undergoing both CTA and invasive FFR examinations were consecutively selected from the Beijing Anzhen Hospital between January 1,2016 to December 30,2018.FFR obtained during invasive coronary angiography was used as the reference standard.DVFFR was calculated blindly using a DL-based CTFFR approach that utilized the complete tree structure of the coronary arteries.Results Three hundred and thirty nine patients(60.5±10.0 years and 209 men)and 414 vessels with direct invasive FFR were included in the analysis.At per-vessel level,sensitivity,specificity,accuracy,positive predictive value(PPV)and negative predictive value(NPV)of DVFFR were 94.7%,88.6%,90.8%,82.7%,and 96.7%,respectively.The area under the receiver operating characteristics curve(AUC)was 0.95 for DVFFR and 0.56 for CTA-based assessment with a significant difference(P<0.0001).At patient level,sensitivity,specificity,accuracy,PPV and NPV of DVFFR were 93.8%,88.0%,90.3%,83.0%,and 95.8%,respectively.The computation for DVFFR was fast with the average time of 22.5±1.9 s.Conclusions The results demonstrate that DVFFR was able to evaluate lesion hemodynamic significance accurately and effectively with improved diagnostic performance over CTA alone.Coronary artery disease(CAD)is a critical disease in which coronary artery luminal narrowing may result in myocardial ischemia.Early and effective assessment of myocardial ischemia is essential for optimal treatment planning so as to improve the quality of life and reduce medical costs.
基金supported by the National Natural Science Foundation of China(42225604,31500456,31430080)the 2023 Strategic Consultation Project of the Chinese National Committee for Man and the Biosphere,the National Key Programme of Research and Development of Ministry of Science and Technology of China(2022YFF1301603)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA23040403).
文摘The Yangtze finless porpoise(Neophocaena asiaeorientalis asiaeorientalis)is distributed in the main stream of the middle and lower reaches of the Yangtze River,as well as in Dongting and Poyang lakes.Currently,the most crucial conservation approach involves the establishment and management of both in-situ and ex-situ nature reserves.Since the 1990s,seven nature reserves have been established in the middle and lower reaches of the Yangtze River,covering nearly one-third of its main stream.Additionally,two nature reserves,one in the Dongting Lake and another in the Poyang Lake,have been set up;and three ex-situ nature reserves have been established in three oxbows respectively in Hunan,Hubei,and Anhui provinces.Through measures such as improving the ecological environment quality within the reserves,regulating human activities,and conducting continuous monitoring,the finless porpoise population showed a slight increase in 2022 for the first time.The ex-situ population has continued to grow,with four individuals being released back into the main stream of the Yangtze River after undergoing reintroduction training in 2023.Based on the population development lasting for over three decades,and predictions of future ecological changes,orderly establishment and scientific management of nature reserves have played a key role in and will remain an important basis for the sustaining growth of the finless porpoise population.
文摘CHINA Tarim Populus Euphratica National Nature Reserve Located along the northern edge of the Taklimakan Desert in Xinjiang,the Tarim Populus Euphratica National Nature Reserve lies in the middle reaches of the Tarim River-the longest inland river in China-within Bayingolin Mongol Autonomous Prefecture.Established in 1983 and upgraded to a national reserve in 2006,it covers an area of about 395,420 hectares,including a core,bu!er,and experimental zone.The reserve features alluvial plains and desert terrain,with elevations ranging from 800 to 940 metres.The landscape consists of river floodplains,ancient riverbeds,and oasis margins,forming a remarkable ecological mosaic shaped by the Tarim River and its tributaries.The region experiences a typical temperate continental desert climate-dry,hot,and windy with scarce rainfall.
基金Supported by National Key Protected Plant Investigation Project in Anxi Yunzhongshan Nature Reserve Primarily Focusing on Alsophila spinulosa,Paris polyphylla,and Angiopteris fokiensis([350524]BWZ[CS]2024003).
文摘[Objectives]To analyze the composition of lycophytes and ferns in Yunzhongshan Nature Reserve,Fujian Province.[Methods]This study examined the composition of lycophytes and ferns in Yunzhongshan Nature Reserve through field investigations and specimen identification,supplemented by a review of relevant literature.[Results]A total of 84 species of lycophytes and ferns were identified,encompassing 55 genera and 29 families.This included 14 species of lycophytes distributed across 8 genera and 3 families,as well as 70 species of ferns belonging to 47 genera and 26 families.Polypodiaceae and Selaginella were the dominant family and genus,respectively,while oligospecific families and monotypic genera were significant components of lycophytes and ferns in the region.The distribution types of these families were primarily cosmopolitan and tropical.The Germline differentiation degree(SD)was 3.34,and the proportion of rare or endangered species among lycophytes and ferns was 8.33%.[Conclusions]Yunzhongshan Nature Reserve possesses a diverse array of lycophyte and fern species.This study offers valuable scientific insights that can inform efforts related to the conservation of biodiversity,resource utilization and development,species introduction,and system evolution of lycophytes and ferns within the reserve.
