Increase In Total Cost Research Articles

A novel approach to developing effective maritime regulations: The case of LNG cargo filling limits

ABSTRACT This paper introduces a novel approach to resolving a part of the fundamental problems encountered in the current practice of maritime regulatory frameworks. The novelty of the proposed method lies in a detailed and structured process that can examine and verify the appropriateness of a particular regulation in terms of integrating economic, environmental and safety impacts. Through its built-up database of approximately 440 LNG carriers in the world, the excellence of the proposed approach has been demonstrated by investigating the suitability of a controversial regulation related to the LNG cargo filling limit set forth in “the International code for the construction & Equipment of Ships carrying liquefied gases in Bulk.” A series of case studies have confirmed 169 LNG carriers currently are subjected to being placed under this issue. In this study, we identified ships’ key characteristics which would contribute to the increase in total costs associated with economic, environmental and safety impacts and presented the threshold between the opportunity costs and the severity of the regulation. The research findings have provided a managerial insight that may increase the reliability of maritime regulations by applying this pragmatic/analytical regulatory framework model developed in this research.

Low carbon transition of China's electric and heating sector considering reliability: A modelling and optimization approach

China has pledged for their carbon emissions to have peaked by 2030 and to achieve carbon neutrality by 2060. However, this requires restructuring of their entire energy system. This study establishes a bottom-up low-carbon transition model for electric and heating coupled systems. The power system's adequacy with high penetration of renewable energy is considered via an iterative calculation approach, the layout of the power and heat system and the future of coal power under carbon emission constraints are discussed. Different from other research, our results show that the capacity of coal power would further increase to support a reliable transition of power system towards a higher proportion of renewable electricity, and the current target of 1200 GW of wind and solar in 2030 is not enough to achieve rapid carbon reductions, and would result in an extra 1.6 to 2.2 billion t CO2 emitted compared to 2020. Achieving 50% of non-fossil electricity generation by 2030 is feasible, and the target needs to be raised to 1660 to 1850 GW at only 3% increase of total cost. Not building new coal power plants would result in a huge expansion of electricity storage in China, which is hard to realize because of extremely high investment cost.

Economic and Energy Performance of Heating and Ventilation Systems in Deep Retrofitted Norwegian Detached Houses

The aim of this study was to evaluate the life-cycle costs (LCC) and energy performance of different heating and ventilation systems (HVAC) in deep-energy renovation of Norwegian detached houses. Eight different HVAC combinations based on heat pumps are compared using two case buildings, with different performance levels for the building envelope. The case buildings are small wooden dwellings without a hydronic heating system, which is representative of existing Norwegian detached houses. The insulation level had only a limited effect on the relative performance of the various HVAC combinations. Many solutions with medium and higher investments have a payback time close to the technical lifetime. Uncertainty regarding investment costs is important and affects the relative performance between HVAC combinations. Electricity prices also have a decisive influence on the relative performance. Solutions with lower investment costs often lead to low total costs but higher energy use. However, solutions with medium investment cost lead to a significant reduction in energy use and only a minor increase in total costs. Improving the cost-effectiveness of these technologies (reduced investment costs, grants, increased electricity price) would unlock large energy-saving potential. The lack of hydronic distribution systems in existing Norwegian buildings is a barrier to implementing air-to-water and ground-source heat pumps. For the investigated cases, the current government subsidies in Norway do not seem large enough to make investments in deep-energy renovation profitable.

Stable Metabolic Control but Increased Demand for Professional Support in Children with Type 1 Diabetes in the Past Ten Years in Bern/Switzerland: A Quality Control Study.

Introduction Lower HbA1c targets and increasingly complex diabetes management with substantially increasing costs dominate today's type 1 diabetes therapy in children and adolescents. Objective To evaluate metabolic control in children and adolescents with type 1 diabetes and assess associated factors, evaluate determinants for frequency of healthcare contacts, and compare actual with historical data. Method This cross-sectional observational study collected data on 178 children and adolescents with type 1 diabetes treated at the University Children's Hospital in Bern. Results Mean HbA1c was 7.9% (63 mmol/mol), 33.1% (59/178) of children reached the target of HbA1c < 7.5% (<59 mmol/mol), and 18.0% (32/178) had an HbA1c value < 7.0% (<53 mmol/mol). Compared to historical data, stable HbA1c levels appeared with a doubled proportion of individuals using insulin pumps. Metabolic control was worse with a longer duration of diabetes and younger age at diagnosis but better when parents came from a Western European country. Age at the consultation, use of diabetes technology and native language influenced the number of healthcare contacts. Younger patients, patients using CSII, and patients without an official Swiss language as mother tongue had more consultations with a healthcare professional than older and native language individuals. Conclusion The metabolic targets in childhood and adolescent type 1 diabetes are still unmet despite a shift towards more technology. Our study documents a higher demand for support and supervision in specific patient groups. An investment to increase healthcare contacts could help combat the increase in total diabetes cost and significantly improve metabolic control.

Evolution of healthcare costs for lower urinary tract symptoms associated with benign prostatic hyperplasia.

With the ubiquity of lower urinary tract symptoms due to benign prostatic hyperplasia (LUTS/BPH) in older men, costs related to this highly prevalent disease are likely significant but not well defined. With this study, we hoped to define costs related to LUTS/BPH care. We utilized the Optum© de-identified Clinformatics® Data Mart Database (CDM) for privately insured male enrollees aged 40-64years with LUTS/BPH (N ≈ 100,300 annually) and the Centers for Medicare and Medicaid Services Medicare 5% Sample for male beneficiaries aged 65 + years with LUTS/BPH (N ≈ 147,800 annually). Annual LUTS/BPH-related expenditures from 2004 to 2013 were age standardized and calculated overall and by age and service location. The Medicare cohort demonstrated a 23% increase in total costs over the study period with a 28% decrease in CDM costs. Decreases in inpatient hospital charges (45% for Medicare, 55% for CDM) were offset by increasing hospital-based outpatient fees (120% for Medicare, 87% for CDM). Overall, we estimated a total cost of at least $1.9 billion for treatment of men with LUTS/BPH for 2013. Per person expenditures increased with age within cohorts with an average per-person cost of $269 (CDM) and $248 (Medicare) in 2013. The distribution of healthcare expenditures for LUTS/BPH shifted across practice settings from 2004 to 2013, with increasing outpatient relative to inpatient expenditures. Total direct costs for LUTS/BPH in 2013 were at least $1.9 billion, not accounting for indirect costs or certain unmeasured populations.

Experimental study on the inclined solar still with single-axis solar tracking: thermo-economic approach

ABSTRACT The solar-energy sector is growing fast and expected to continue. Inclined solar still (ISS) is one of the promising techniques used in the solar desalination field. Adding a single-axis solar tracking system to the ISS will increase its yield and efficiency. Consequently, the total device cost will be increased. Does it worth? To answer this question, an experimental investigation of the ISS without and with a single-axis solar tracking system was conducted and evaluated. Thermo-economic analysis was developed and evaluated. Results showed that adding a single-axis solar tracking to the inclined solar still increased its productivity and efficiency by 26% and 25.4%, respectively, with an increase in the system total cost by 39.2%. The payback period of the extra cost due to adding the solar tracking system is estimated in the range between 0.9 and 1.1 years. Thus, using a solar tracking for inclined solar still is thermally and economically beneficial due to the increase of the device performance and the reduction of the required land area by almost 26% to produce the same freshwater amount which means a lot of money-saving.

Association between traffic related air pollution exposure and direct health care costs in Northern California

BackgroundTraffic related air pollution (TRAP) is associated with a complex and diverse array of health effects. It is unknown whether these effects may be reflected by higher health care costs. ObjectivesEvaluate the association between TRAP exposure and direct health care costs in an elderly population. MethodsThis multi-ethnic population-based cohort of 25,684 elderly subjects, served by Kaiser Permanente Northern California (KPNC), were followed between 2013 and 2017. Hyperlocal long-term pollutant concentrations for nitrogen dioxide [NO2], nitric oxide [NO], and black carbon [BC] were measured at a resolution of 30 m using repeated street-level mobile measurements and linked to residential addresses. Health care utilization and costs were derived from KPNC databases and were used to calculate individual annual total health care, inpatient, outpatient, and emergency room (ER) and pharmacy costs. The associations between TRAP exposures and health care costs were evaluated using generalized estimating equation models adjusted for age, sex, race, BMI, smoking, SES and comorbidities. Subgroup analyses and interaction models were used to assess differences among specific susceptible population subgroups. ResultsAn IQR difference (10.1 ppb vs 4.2 ppb) in NO2 concentration was associated with a 3% (95% CI: -1%, 6%), 22% (95% CI:11%, 35%), and 5% (95% CI:1%, 8%) increase in annual total health care, ER and outpatient costs in the baseline model. Associations with black carbon showed similar patterns but were smaller in magnitude. Among those with cardiovascular diseases, an IQR increase in NO2 was associated with a 7% (95% CI: 1%, 13%) increase in total annual health care cost and 23% (95% CI: 17%, 29%) increase in ER costs. DiscussionHigher long-term TRAP exposure was associated with higher direct annual health care cost in this elderly cohort. Those with existing cardiovascular disease had particularly strong associations between TRAP exposure and direct annual health care costs.

Seismic Resilience Assessment Strategy for Social and Sustainability Impact Evaluation on Transportation Road Network: A Seismic Liquefaction-Induced Damage Application

Transport networks play a critical role for living communities, as they facilitate the exchange of people and goods and foster economic growth. Improving their resilience against seismic hazards, among which liquefaction is by far one of the most significant and complex, is consistent with most of the Sustainable Development Goals pinpointed by the United Nations’ Agenda. In this paper, an original methodological framework, combining innovative Geo-statistical approaches to analyze soil properties, prediction models for soil liquefaction, and calibrated transport demand models providing the social and economic cost associated with seismic-induced road damages and closures within a renewed Geographical Information Systems (GIS) workspace, is proposed. In particular, based on traditional risk assessment evaluation, an innovative approach to evaluate the exposure in terms of economic loss due to lack of accessibility is presented. The methodology is applied to a district area in northern Italy that underwent a recent seismic event that caused several soil liquefaction phenomena. Results provided by a sensitivity analysis on a stochastic (return period) basis are derived: as the seismic intensity increases, the total social costs increase, but the trend of the rates due to traffic delays and the loss of accessibility are irregular. Although further simulation scenarios need to be undertaken, the proposed methodology seems to provide an effective planning tool to evaluate preventive strategies aimed at improving the resilience of transport networks against liquefaction risk.

Analysis of cost and outcomes in bony versus soft tissue midface free flap reconstruction.

Outcomes and cost of soft tissue versus bony midface free flap reconstruction (MR) with and without virtual surgical planning (VSP) were evaluated. Retrospective review of MR including ischemic time (IT), operative duration (OD), length of stay (LOS), and total cost (TC). Eighty-one soft tissue and 76 bony MR (VSP=23) were reviewed. Bony MR was used for higher complexity defects (p=0.003) and was associated with higher IT (p < 0.001), OD (p < 0.001), LOS (p=0.032), and TC (p < 0.001). VSP was associated with a mean 111.2 ± 37.9minute reduction in OD (p=0.004) compared to non-VSP bony flaps. VSP was associated with higher itemized cost, but no increase in TC (p=0.327). Bony MR was used for higher complexity MR and was associated with increased TC, LOS, OD, and IT. VSP shortened OD with no significant increase in TC.

Robotic-Assisted Versus Manual Unicompartmental Knee Arthroplasty: A Time-Driven Activity-Based Cost Analysis.

The cost-effectiveness of robotic-assisted unicompartmental knee arthroplasty (RA-UKA) remains unclear. Time-driven activity-based costing (TDABC) has been shown to accurately reflect true resource utilization. This study aimed to compare true facility costs between RA-UKA and conventional UKA. We identified 265 consecutive UKAs (133 RA, 132 conventional) performed at a specialty hospital in 2016-2020. Itemized facility costs were calculated using TDABC. Separate analyses including and excluding implant costs were performed. Multiple regression was performed to determine the independent effect of robotic assistance on facility costs. Due to longer operative time, RA-UKA patients had higher personnel costs and total facility costs ($2,270 vs $1,854, P < .001). Controlling for demographics and comorbidities, robotic assistance was associated with an increase in personnel costs of $399.25 (95% confidence interval [CI] $343.75-$454.74, P < .001), reduction in supply costs of $55.03 (95% CI $0.56-$109.50, P= .048), and increase in total facility costs of $344.27 (95% CI $265.24-$423.31, P < .001) per case. However, after factoring in implant costs, robotic assistance was associated with a reduction in total facility costs of $235.87 (95% CI $40.88-$430.85, P < .001) per case. Using TDABC, overall facility costs were lower in RA-UKA despite a longer operative time. To facilitate wider adoption of this technology, implant manufacturers may negotiate lower implant costs based on volume commitments when robotic assistance is used. These supply cost savings appear to offset a portion of the increased costs. Nonetheless, further research is needed to determine if RA-UKA can improve clinical outcomes and create value in arthroplasty.

Lifetime medical costs attributable to sickle cell disease among nonelderly individuals with commercial insurance

AbstractSickle cell disease (SCD) is a severe monogenic disease associated with high morbidity, mortality, and a disproportionate burden on Black and Hispanic communities. Our objective was to estimate the total healthcare costs and out-of-pocket (OOP) costs attributable to SCD among commercially insured individuals over their nonelderly lifetimes (0 to 64 years of age). We constructed a retrospective cohort of individuals with diagnosed SCD using Truven Health Marketscan commercial claims data from 2007 through 2018, compared with matched control subjects from the Medical Expenditure Panel Survey. We estimated Kaplan-Meier sample average costs using previously reported survival curves for SCD and control subjects. Individuals with SCD (20 891) and control subjects (33 588) were included in our analysis. The SCD sample had a mean age of 25.7 (standard deviation, 17.4) years; 58.0% were female. Survival-adjusted costs of SCD peaked at age 13 to 24 years and declined at older ages. There was no significant difference in total medical costs or OOP costs between the sexes. SCD-attributable costs over 0 to 64 years of age were estimated to be $1.6 million (95% confidence interval [CI], $1.3M-$1.9M) and $1.7 million (95% CI, $1.4M-$2.1M) for females and males with SCD, respectively. The corresponding OOP estimates were $42 395 (95% CI, $34 756-$50 033) for females and $45 091 (95% CI, $36 491-$53 691) for males. These represent a 907% and 285% increase in total medical and OOP costs over control subjects, respectively. Although limited to the commercially insured population, these results indicate that the direct economic burden of SCD is substantial and peaks at younger ages, suggesting the need for curative and new medical therapies.

Inferior outcomes associated with emergency department presentation for head and neck cancer surgery☆

PurposeHead and neck cancer (HNC) patients frequently require care through emergency departments (ED) due to lack of access or symptom acuity, however, the frequency and implications of this occurrence have not been delineated. ObjectiveTo determine the association between emergency department admission of HNC surgery with length of stay (LOS) and total costs (TC). MethodsA cohort of 12,920 adult HNC patients admitted to acute care hospitals receiving ablative surgery during index admission was identified using the New York State Inpatient Database from 2006 to 2016. Outcomes included LOS, TC, 90-day complications, and inpatient mortality. ResultsEight percent of the cohort was admitted through the ED, which increased over the study period from 6.52% (95% CI: 5.05–7.99) to 17.0% (95% CI: 14.9–19.1). ED admission was associated with a longer LOS (11 days longer, 95% CI 10.3–11.7) and higher mean TC ($43,197) versus non-ED admission ($19,010), with a mean difference of $24,191 (95% CI 20,713–27,669). After controlling for covariates, ED admission was associated with an 81.6% (95% CI 76.8–86.5) and 80.4% (95% CI 70.5–90.8) increase in LOS and TC, respectively, and decreased survival with a hazard ratio of 1.97 (95% CI 1.60–2.42). ConclusionsRates of ED admission for HNC diagnoses requiring surgical intervention during index admission are rising and associated with longer LOS higher TC, more postoperative complications, and increased inpatient mortality after accounting for patient and facility differences. Striving for high-quality HNC cancer care demands addressing barriers to care that contribute to patients relying on the ED for access.

Decisions on sailing frequency and ship type in liner shipping with the consideration of carbon dioxide emissions

To find the optimal sailing frequency and optimal ship type of container liner operation under low carbon environment, a mixed integer nonlinear programming model is proposed, in which the ship load capacity constraint is considered. The objective of the proposed model is to minimize voyage total cost consisting of carbon dioxide emissions cost, voyage shipping cost(fuel costs, port charges, operating costs) as well as shipper’s inventory cost in a certain operation period. It is shown from theoretical analysis that the proposed model can be solved by Kuhn–Tucker condition and Enumeration method. A numerical example is given to demonstrate the effectiveness of the proposed model, and analyze the impacts of carbon tax levels, fuel prices, ship size and the sailing frequency on total cost and environmental cost. The results show that as the size of the ship increases, the ship total cost decreases first and then increases, the percentage of carbon emission cost in total ship cost increases. As the sailing frequency increases, the ship total cost decreases first and then increases, the percentage of carbon emission cost in total ship cost decreases. The results indicate that the shipping companies can improve economic performance and environment performance simultaneously by employing reasonable sailing frequency and ship type decisions.

Optimal Planning of Integrated Energy System Considering Convertibility Index

Nowadays, developing an integrated energy system (IES) is considered as an effective pattern to improve energy efficiency and reduce energy supply costs. This study proposes a new index—convertibility index (CI)—to quantitatively assess the flexibility of the IES regarding the energy conversion processes between different energy flow types. Based on the CI constraint, a planning problem is modeled as a bi-level optimization problem. To solve the proposed bi-level problem, a hybrid genetic algorithm (GA)—MILP algorithm—is developed. A case study is carried out to verify the effectiveness of the proposed method. The results show that the total cost of the IES will increase with the CI constraint. For a given case study, the total cost increases by 26.2% when the CI decreases to 0.7 and increases by 3.7% when the CI increases to 1.6. Sensitivity analysis shows that the total numbers and capacities of conversion devices show an overall increasing trend with the increase in the CIs. Meanwhile, the total cost decreases quickly at first and then slightly increases, which, in a whole, shows a “Nike” shape. With different CI constraints, the IES MW per CI ranges from 31.8 to 37.5 MW, and the average cost increase is 2.229 million yuan (2.1%/0.1 CI).

Trends in resource utilization and cost of illness in patients with active epilepsy in Germany from 2003 to 2020.

This study was undertaken to calculate epilepsy-related direct, indirect, and total costs in adult patients with active epilepsy (ongoing unprovoked seizures) in Germany and to analyze cost components and dynamics compared to previous studies from 2003, 2008, and 2013. This analysis was part of the Epi2020study. Direct and indirect costs related to epilepsy were calculated with a multicenter survey using an established and validated questionnaire with a bottom-up design and human capital approach over a 3-month period in late 2020. Epilepsy-specific costs in the German health care sector from 2003, 2008, and 2013 were corrected for inflation to allow for a valid comparison. Data on the disease-specific costs for 253 patients in 2020 were analyzed. The mean total costs were calculated at €5551 (±€5805, median = €2611, range = €274-€21667) per 3months, comprising mean direct costs of €1861 (±€1905, median = €1276, range = €327-€13158) and mean indirect costs of €3690 (±€5298, median = €0, range = €0-€11925). The main direct cost components were hospitalization (42.4%), antiseizure medication (42.2%), and outpatient care (6.2%). Productivity losses due to early retirement (53.6%), part-time work or unemployment (30.8%), and seizure-related off-days (15.6%) were the main reasons for indirect costs. However, compared to 2013, there was no significant increase of direct costs (-10.0%), and indirect costs significantly increased (p<.028, +35.1%), resulting in a significant increase in total epilepsy-related costs (p<.047, +20.2%). Compared to the 2013study population, a significant increase of cost of illness could be observed (p=.047). The present study shows that disease-related costs in adult patients with active epilepsy increased from 2013 to 2020. As direct costs have remained constant, this increase is attributable to an increase in indirect costs. These findings highlight the impact of productivity loss caused by early retirement, unemployment, working time reduction, and seizure-related days off.

Fracture-related infection of the patella: Treatment options and outcome

BackgroundFracture-related infection (FRI) after the operative management of patella fractures is a serious complication that can result in prolonged hospitalization, multiple revision procedures and permanent functional impairment. Till today, treatment modalities and outcome of FRI of the patella are not well described. Therefore, the main objective of this retrospective cohort study was to evaluate treatment options, functional outcome and healthcare costs related to FRI of the patella. MethodsThis study evaluated 111 consecutive patients that were surgically treated for patella fractures, at the department of trauma surgery of the University Hospitals Leuven (Belgium), between January 2015 and April 2020. Patients were excluded if they (1) were younger than 18 years at the time of injury or (2) died during follow up. The minimal follow-up for all patients was 18 months. ResultsDuring the 5-year study period, 107 patients with 108 patella fractures were included. A total of 10 patients were diagnosed with an FRI (9.3%). Four of these were treated with a DAIR approach and three patients underwent implant removal or exchange. Finally, three patients were treated with total patellectomy. Out of the 10 patients, two were diagnosed with a recurrence of infection. Overall, we observed substantial lower scores for all Knee Injury and Osteoarthritis Outcome Score subscales in the FRI group, compared to a reference population. Moreover, our study shows that direct hospital-related healthcare costs of FRI of the patella were nine times higher compared to non-FRI cases. ConclusionsFRI of the patella is a challenging complication and recurrence of infection not uncommon. Although multiple treatment modalities exist, a multidisciplinary patient-specific approach is crucial. An early or delayed onset infection can be managed with a DAIR approach, but only when the construct is stable and the soft tissue coverage adequate. In patients with an FRI, implant removal is preferred when the fracture has healed. A total patellectomy can be used as a salvage procedure in complex cases with acceptable functional results. Overall, FRI of the patella leads to both a negative impact on the functional status of the patient and a ninefold increase in total healthcare costs.

A goal programming model for the optimization of log logistics considering sorting decisions and social objective

Log logistics include sorting, processing, and transporting of logs from their place of harvest to demand locations. These activities account for a significant portion of the total log procurement costs; therefore, attempts were made in previous studies to optimize some aspects of log logistics. However, operational details, such as sorting decisions, truck compatibility requirements, and social objectives, are often disregarded in the optimization literature. Incorporating these details into the model makes the results more realistic and applicable. To address these gaps, a bi-objective mixed-integer programming model is developed in this paper to optimize log logistics. The first objective is to minimize total logistics costs, and the second objective is to provide a balanced workload for trucking contractors. The bi-objective model is solved using the goal programming approach. The model is applied to log logistics of a large Canadian forest company, where trucking contractors use heterogeneous fleet of trucks to carry various log sorts from cutblocks to sort yards for sorting. The planning horizon is 4 weeks with daily decisions. The goal programming model generates balanced workloads for the contractors with less than 0.4% increase in total costs compared to the single objective model where only the total cost is minimized.

A health economics study of long-acting injectable once-monthly paliperidone palmitate in schizophrenia: a one-year mirror-image study in China

Schizophrenia is ranked among the top 25 leading causes of disability worldwide in 2013 which resulting in social and economic burden. By observing patients with schizophrenia one year before and after switching from oral antipsychotics (OAPs) to once-monthly paliperidone palmitate (PP1M), we can better understand the change of total costs in schizophrenic patients, including direct costs and indirect costs, after switching treatment patterns.A total of 100 schizophrenic (ICD-10) patients from Shandong Mental Health Center were collected from December 2016 to June 2019. Treatment modalities, health care resource utilization and costs were compared before and after switching directly from oral antipsychotics to PP1M.Of the 82 patients included in the main analyses, treatment with PP1M resulted in an increase in direct costs of 31.92% (P < 0.01), an increase in medicine costs of approximately 142% (P < 0.01), and a reduction in hospital costs of 68.15% (P > 0.05). There was no significant increase in total costs (P = 0.25), while 31.92% increase in direct costs (P < 0.01), and 35.62% decrease in indirect costs (P < 0.01) after conversion to PP1M. Compared with before administration of PP1M, patients with ≥ 1 inpatient stay in 1 year Pre-PP1M treatment with OAPs (n = 32) had a 20.16% decrease in direct costs (P < 0.01), a 144% increase in medicine costs (P < 0.01), and a significant 72.02% decrease in hospital costs (P < 0.01). The observed reduction in the number of hospitalizations (t = 2.56, P ≤ 0.01) and inpatient stays (t = 1.73, P < 0.05) and after transition to PP1M resulted in a reduction in hospitalization costs (P < 0.01).Switching from OAPs to PP1M decreased the household workforce burden without increasing clinical healthcare costs. Direct costs were significantly reduced in patients with ≥ 1 inpatient stay in 1 year pre-PP1M treatment with OAPs after the switch, which decreased by improving adherence to therapy and reducing the number and length of hospital stays, suggesting that those patients may benefit after switching to PP1M.

Integrated capacity configuration and control optimization of off-grid multiple energy system for transient performance improvement

The off-grid multiple energy system offers a promising way for energy supply due to its advantages of independency, multi energy co-generation, high efficiency and local utilization of renewable energy. A key issue of the off-grid multiple energy system is the operating performance during the dynamic transition because it is isolated from the utility grid. The conventional steady-state configuration methods ignore the significant impact of configuration scheme on the transient performance of the multiple energy system, which can easily lead to poor dynamic performance, thus are not suited for the off-grid multiple energy system with high penetration of intermittent renewable energy. It is necessary to consider the closed-loop dynamic control behavior of the system early in the configuration stage. To this end, this paper proposes a novel integrated capacity configuration and control optimization method of the multiple energy system, in which both the economic costs and closed-loop dynamic performance are fully considered. The multi-parametric programming is applied to construct a design-perceptive predictive tracking controller to bridge the gap between configuration and dynamic operation of the system. Case study on a typical off-grid combined heat and power multiple energy system shows that the proposed approach can reduce the dynamic thermal and electrical deviations of the multiple energy system by 84.45% and 28.11% respectively at the expense of only 1.86% increase of total economic costs. In-depth validations are carried out under extreme weather conditions and low carbon requirements, which further demonstrate the effectiveness and applicability of the proposed approach.

The effects of physician retirement on patient outcomes: Anticipation and disruption

The physician retirement rate in the United States is increasing as the population ages. I use an event study model allowing for anticipation to evaluate the effects of primary care physician (PCP) retirement on elderly adults’ health care utilization and quality of care. I find that, despite moderate anticipatory effects, PCP retirement results in an approximately $572 increase in total Medicare costs per beneficiary in the first 1.5 years post-retirement and an over 10% increase in detection of new chronic conditions. Heterogeneity analyses show that the increase in costs is disproportionately driven by the retirement of solo practitioners; Medicare beneficiaries with a retired PCP practicing in states with mandatory physician departure notice experience less disruption in care; and beneficiaries living in primary care health professional shortage areas experience greater disruption in care.