Lower Systemic Capacity Research Articles

Optimal sizing of grid connected multi-microgrid system using grey wolf optimization

Renewable distributed energy resources (DERs) offer a promising and environmentally sustainable solution for providing energy. Nowadays, there has been significant attention in wind, solar Photovoltaic (PV), and hydrogen-based fuel cell (FC) systems due to their ability to provide cost-effective energy to replace conventional generations. However, the intermittent nature of renewable energy sources presents challenges and operational issues for fully renewable energy systems. To address this, integrating energy storage systems and effectively managing uncertainties related to both load and generation resources are crucial for mitigating such challenges. This paper proposes a hybrid grid-connected PV-wind-FC generation-based Multi-microgrid (MMG) system integrated with a Battery Energy Storage System (BESS) to meet the entire load demand of the adopted MMG-based IEEE 14-bus system. The aim is to ensure cost-effectiveness and enable energy trading with the main grid by optimizing system configurations. The study incorporates stochastic analysis to handle uncertainties related to load, meteorological data, and energy prices to optimize the configuration of DERs and BESS in the MMGs. A Grey Wolf Optimization (GWO) algorithm is employed to determine the optimal sizing of the proposed grid-connected MMG. The proposed algorithm has reduced the NPC from $431.796 million to $428.832 million and LCOE to 0.267$/kWh when load and generation data uncertainty and dynamic energy price has considered. The robustness of the proposed approach is evaluated by comparing results with those obtained using Particle Swarm Optimization (PSO) and JAYA algorithms. The GWO method demonstrates superior performance, resulting in lower total Net Present Cost (NPC), lower system capacity, and a lower Levelized Cost of Energy (LCOE) compared to its counterparts. Moreover, the GWO algorithm exhibits the fastest convergence, indicating its accuracy and robustness compared to PSO and JAYA algorithms.

Implementation strategies to build mental health-care capacity in Malawi: a health-economic evaluation

Depression is a major contributor to morbidity and mortality in sub-Saharan Africa. Due to low system capacity, three in four patients with depression in sub-Saharan Africa go untreated. Despite this, little attention has been paid to the cost-effectiveness of implementation strategies to scale up evidence-based depression treatment in the region. In this study, we investigate the cost-effectiveness of two different implementation strategies to integrate the Friendship Bench approach and measurement-based care in non-communicable disease clinics in Malawi. The two implementation strategies tested in this study are part of a trial, in which ten clinics were randomly assigned (1:1) to a basic implementation package consisting of an internal coordinator acting as a champion (IC-only group) or to an enhanced package that complemented the basic package with quarterly external supervision, and audit and feedback of intervention delivery (IC + ES group). We included material costs, training costs, costs related to project-wide meetings, transportation and medication costs, time costs related to internal champion activities and depression screening or treatment, and costs of external supervision visits if applicable. Outcomes included the number of patients screened with the patient health questionnaire 2 (PHQ-2), cases of remitted depression at 3 and 12 months, and disability-adjusted life-years (DALYs) averted. We compared the cost-effectiveness of both packages to the status quo (ie, no intervention) using a micro-costing-informed decision-tree model. Relative to the status quo, IC + ES would be on average US$10 387 ($1349-$17 365) more expensive than IC-only but more effective in achieving remission and averting DALYs. The cost per additional remission would also be lower with IC + ES than IC-only at 3 months ($119 vs $223) and 12 months ($210 for IC + ES; IC-only dominated by the status quo at 12 months). Neither package would be cost-effective under the willingness-to-pay threshold of $65 per DALY averted currently used by the Malawian Ministry of Health. However, the IC + ES package would be cost-effective in relation to the commonly used threshold of three times per-capita gross domestic product per DALY averted. Investing in supporting champions might be an appropriate use of resources. Although not currently cost-effective by Malawian willingness-to-pay standards compared with the status quo, the IC + ES package would probably be a cost-effective way to build mental health-care capacity in resource-constrained settings in which decision makers use higher willingness-to-pay thresholds. National Institute of Mental Health.

SAN ANTONIO TRANSPORTATION PLANNING SYSTEM: MAPPING INFRASTRUCTURE CAPACITY AND COORDINATION

Abstract Ride Connect Texas and its partnering agencies seek to develop an expanded senior mobility management system supported by a One Call One Click transportation planning system. Its purpose is to enhance on-demand transportation system coordination and the application of technology, providing consumers, service providers, and mobility managers with direct access to comprehensive transportation information. GIS mapping is used to help develop a spatial awareness of the transportation challenges among older people and individuals with a disability and the current system capacity. Interviews with transit, non-transit, and health and human service agencies will reveal factors that influence coordination among providers and opportunities for capacity expansion. Surveys and focus groups of older adults and individuals with disability will show differentiating characteristics of riders and transportation needs and challenges. GIS mapping will allow us to geocode these findings relative to the user’s street address and zip code, illustrating variations in specialized client needs, service availability, travel behavior, and available amenities for basic daily living. Mapping will identify gaps in transportation services, hot zones revealing high user demand and low system capacity, and the ability to reduce fragmentation of service through seamless technology-based coordination. The mapping element informs the measurement of a community’s transportation system capacity for this user group. The value proposition of this tool is its ability to help any community measure its readiness toward developing a comprehensive implementation strategy for coordinated demand response transportation, including resource mobilization strategies, capacity augmentation, phasing of the system, and implementation timeline.

Routine child immunizations in India during the COVID-19 pandemic

Disruptions in health service delivery and utilization during the COVID-19 pandemic may have caused many children worldwide to not receive vital preventative health services. We investigate the pandemic’s effects on routine childhood vaccinations in India, which has the world’s largest child immunization program. Using data from the Government of India’s health management information system and interrupted time series analyses, we estimate district-level changes in routine child vaccinations during the pandemic relative to typical monthly vaccinations in the pre-pandemic period. Our results indicate there were significant reductions in child vaccinations during the pandemic, with declines being extremely large in April 2020 when a strict national lockdown was in place. For example, district-level administration of the final required dose in the polio series declined by about 60% in April 2020 relative to the typical monthly vaccination levels observed prior to the pandemic. Vaccinations subsequently increased but largely remained below levels observed before the outbreak of COVID-19. Additional declines in vaccinations occurred in 2021 during the second wave of COVID-19 infections in India. Heterogeneity analyses suggest that vaccinations declined the most in districts with the strictest lockdowns and in districts with low health system capacity at baseline. There is a vital need for corrective actions, such as catch-up vaccination campaigns, to limit the deleterious consequences that will arise for the children who missed routine immunizations during the COVID-19 pandemic.

Where did it hit harder? Understanding the geography of excess mortality during the COVID-19 pandemic.

The health impact of the COVID‐19 pandemic across OECD (Organisation for Economic Co‐operation and Development) and European regions has been strikingly uneven. In 2020, excess mortality rates in the hardest‐hit regions were, on average, 17 percentage points higher than those in the least affected regions of the same country. This paper shows that low health system capacity, followed by population density, air pollution, the share of elderly people, and low institutional quality were associated with higher excess mortality during the first year of the pandemic. Finally, reduced home‐to‐work mobility, following governments' COVID‐19 responses, was associated with lower excess mortality 2 months after implementation of the measures.

The Determinants of the Low COVID-19 Transmission and Mortality Rates in Africa: A Cross-Country Analysis.

Background: More than 1 year after the beginning of the international spread of coronavirus 2019 (COVID-19), the reasons explaining its apparently lower reported burden in Africa are still to be fully elucidated. Few studies previously investigated the potential reasons explaining this epidemiological observation using data at the level of a few African countries. However, an updated analysis considering the various epidemiological waves and variables across an array of categories, with a focus on African countries might help to better understand the COVID-19 pandemic on the continent. Thus, we investigated the potential reasons for the persistently lower transmission and mortality rates of COVID-19 in Africa.Methods: Data were collected from publicly available and well-known online sources. The cumulative numbers of COVID-19 cases and deaths per 1 million population reported by the African countries up to February 2021 were used to estimate the transmission and mortality rates of COVID-19, respectively. The covariates were collected across several data sources: clinical/diseases data, health system performance, demographic parameters, economic indicators, climatic, pollution, and radiation variables, and use of social media. The collinearities were corrected using variance inflation factor (VIF) and selected variables were fitted to a multiple regression model using the R statistical package.Results: Our model (adjusted R-squared: 0.7) found that the number of COVID-19 tests per 1 million population, GINI index, global health security (GHS) index, and mean body mass index (BMI) were significantly associated (P < 0.05) with COVID-19 cases per 1 million population. No association was found between the median life expectancy, the proportion of the rural population, and Bacillus Calmette–Guérin (BCG) coverage rate. On the other hand, diabetes prevalence, number of nurses, and GHS index were found to be significantly associated with COVID-19 deaths per 1 million population (adjusted R-squared of 0.5). Moreover, the median life expectancy and lower respiratory infections rate showed a trend towards significance. No association was found with the BCG coverage or communicable disease burden.Conclusions: Low health system capacity, together with some clinical and socio-economic factors were the predictors of the reported burden of COVID-19 in Africa. Our results emphasize the need for Africa to strengthen its overall health system capacity to efficiently detect and respond to public health crises.

A Review on Deadly Nipah Virus - Prevalence and its Management

NiV is an emerging infectious disease caused by infected bats from the family of Paramyxoviridae. From its secretions the disease can be spread to humans or through close contact with infected humans. NiV was detected for the first time in 1998 in Malaysia. NiV have broad species tropism and potential that may evolve life threatening respiratory and/ or neurologic disease in humans and as well as in animals which make them important trans-boundary biological threats. The disease presented mainly as acute encephalitis with a short incubation period of less than two weeks (4 to 18 days), with the main symptoms of fever, headache and giddiness followed by coma. The major involvement of the lung and brain in NiV infection often manifested as an acute severe respiratory syndrome, encephalitis etc. In case of Henipavirus the diagnosis of infection is mainly based on the details of contact with diseased animals, evidence of encephalitis and or pneumonia, with serologic evidence of infection using Enzyme Linked Immunosorbant (EIA) assay testing or polymerase chain reaction. The anti-viral drug Ribavirin is a well-known first line treatment strategy for suspected viral infections of unknown etiology. Based on a study conducted to discover whether combining monotherapeutic treatments with Ribavirin and Chloroquine would result in any protection indicative of favourable drug-drug interactions when treatment were initiated with lethal inoculums of NiV. The reason for multiple outbreaks may be due to low healthcare system capacity and robust surveillance strategy contributes to it. Multidisciplinary and multiple facet approach is vital in preventing the emergence of NiV. It is crucial to undertake rigorous research for developing vaccines and medicines to prevent and treat NiV.

The Determinants of the Low COVID-19 Transmission and Mortality Rates in Africa: A Cross- Country Analysis

Background: More than one year after the beginning of the international spread of COVID- 19, the reasons explaining its apparently lower reported burden in Africa is still to be fully elucidated. Few studies previously investigated the potential reasons explaining this epidemiological observation using data at the level of a few African countries. However, an updated analysis considering the various epidemiological waves and variables across an array of categories, with a focus on African countries might help to better understand the COVID-19 pandemic on the continent. Thus, we investigated the potential reasons for the persistently lower transmission and mortality rates of COVID-19 in Africa. Methods: Data were collected from publicly available and well-known online sources. Cumulative numbers of COVID-19 cases and deaths per one million population reported by African countries up to February 2021 were used to estimate the transmission and mortality rates of COVID-19, respectively. Covariates were collected across several data sources: clinical/diseases data, health system performance, demographic parameters, economic indicators, climatic, pollution and radiation variables, and use of social media. Collinearities were corrected using variance inflation factor (VIF) and selected variables were fitted to a multiple regression model using the R statistical package. Results: Our model (adjusted R-squared: 0.7) found that the number of COVID-19 tests per one million population, GINI index, global health security (GHS) index and mean body mass index (BMI) were significantly associated (P<0.05) with COVID-19 cases per one million population. No association was found with the median life expectancy, proportion of rural population and BCG coverage rate. On the other hand, diabetes prevalence, number of nurses and GHS index were found to be significantly associated with COVID-19 deaths per one million population (adjusted R-squared of 0.5). Moreover, the median life expectancy and lower respiratory infections rate showed a trend towards significance. No association was found with BCG coverage or communicable disease burden. Conclusions: Low health system capacity, together with some clinical and socio-economic factors were predictors of the reported burden of COVID-19 in Africa. Our results emphasise the need for Africa to strengthen its overall health system capacity to efficiently detect and respond to public health crises.

Optimal operation of multi‐vector energy storage systems with fuel cell cars for cost reduction

Combined borehole (BH) heat storage systems, batteries and power-to-gas system have the potential to shift load, reduce carbon emissions, provide hydrogen for fuel cell cars and save energy costs for end customers on an extended scale. This study proposes an optimal operation strategy for a local multi-vector energy storage system, which includes batteries, BH thermal storage, the power to the gas system and the fuel cell cars system. These storage systems can be divided into the short-term storage system and inter-seasonal storage system or low capacity storage system and high capacity storage system. The optimisation problem is divided into a two-stage framework, (i) the first stage optimisation is seasonal optimisation, which gives an approximate optimal operation plan for BH heat storage systems in the following year; (ii) the second stage develops a day-ahead robust optimal plan for all storage systems. Finally, the algorithm will return to seasonal optimisation to update the operation plan for BH heat storage systems to make results more accurate. The test case of eight nodes illustrates that the combined energy system of photovoltaic, heat pump power to gas, BH and batteries can provide hydrogen to fuel cell cars and significantly save power costs for customers with the optimal operation.

A decentralized prediction market platform based on blockchain and masternode technologies

Prediction market can help to trade the outcome of events, which is very useful for risk hedging, especially when people are making business ventures. However, the traditional prediction market is centralized, which means the platform is completely controlled by just one person or team. This centralization has bad influence on the platform to obtaining trust from massive users. So it is important for the prediction market industry to decentralize the traditional platform into a decentralized one, and get its control from few person and give it back to a lot of people in the prediction market community. Blockchain is a very promising technology to make it true as it is a popular decentralizing technology. However, existing blockchain technologies like Bitcoin or Ethernum bring about new problems like high energy consumption, expensive fee, and very low system capacity, which is not suitable for the current prediction market. To solve these problems, we propose to combine masternode technology together with blockchain to serve as a decentralized node, and each masternode is deployed and running on an edge server in mobile edge network. The network of master-nodes serves together as the decentralized prediction market platform. As we know, it is not easy to run a masternode. So the number of masternodes is much less than the number of complete nodes of the blockchain. As a result, it is easier to reach the consensus among these masternodes. Theoretical analysis and experimental results show that our proposed method is useful.

Preplant Irrigation Effectiveness and Crop Yield and Water Productivity in the United States: A Review

Soil moisture content early growing season is determinant for crop season planning mainly a decision on planting date. In the region where off season or early season precipitation does not much the conditions for seed germination and plant growth/ development, preplant irrigation is applied to meet these conditions. Also, under limited water availability or low system capacity to meet crop water requirement at peak evapotranspiration, preplant irrigation could be applied to store water within the crop root zone. However, its efficiency or effectiveness depends on the soil type and soil water storage efficiency. This review explored the advantages and disadvantages of the practice and its impact on crop yield and water productivity using summaries of different researches conducted mostly in the United States and other regions. The consideration of applying preplant irrigation should be examined regarding soil type, crop management practices, tillage and residue management, irrigation technique, actual precipitation pattern and forecast, crop choice to optimize the preplant irrigation practice for system sustainability.

Challenges Facing the Implementation of Pico-Hydropower Technologies

840 million people living in rural areas across the world lack access to electricity, creating a large imbalance in the development potential between urban and rural areas. Pico-hydropower offers a cost-effective way of accessing electricity, where the resource exists. This paper discusses and critically examines several challenges that remain in implementing pico-hydropower systems, such as local manufacturing, maintenance and repair of turbines, low-head solutions, dealing with variation in the water flow between seasons, the ability to deal with income generating loads and low system power and capacity factor. The solutions to many of these problems exist; several low head turbine systems are appearing on the market, and new power electronic packages are able to improve the system capacity factor. Some turbines are now being designed for local construction using design for manufacturing rules, so only basic workshop tools and process are required to build turbine systems and components, and enabling turbines to be locally repaired. Through the commercialisation and implementation of these solutions, the proliferation of pico-hydropower systems can take place providing low cost sustainable electricity for remote communities, but this requires a stronger emphasis in social awareness and policy. Three critical enabling factors for the success of pico-hydropower projects are identified through this analysis: understanding the local context, financial sustainability and stakeholder awareness.

Optical Code Division Multiple Access for FTTH system

Many multiple access techniques have been proposed and demonstrated to provide flexible solutions for FTTH network configurations. The performance of this system suffers because of the correlation properties that contribute to a high level of Multiple Access Interference (MAI), low system capacity (users), and lower transmission rate. In this paper, we have proposed Optical CDMA (OCDMA) as a configuration solution for FTTH networks to improve the performance of this type of network. Full Text: PDF References. Z. Mateusz, M. Mariusz, On cost of the uniformity in FTTH network design, Conference on Transparent Optical Networks (2017), 87-90 CrossRef CEDRIC F. LAM, Passive Optical Networks- Principles and Practice, first ed., British Library, USA, 2007. DirectLink M.K. Abdullah, W.T. P'ng, P.W. Lau, E.R. Tee, FTTH access network protection using a switch, Asia Pacific Conference on Communications (APCC), 3(2003) 1219–1222. CrossRef J. Ronnakorn, S. Napat, L. Somkiat, Design and implement of GPON-FTTH network for residential condominium, Conference on Computer Science and Software Engineering, (2017), 333-339. CrossRef M. BOUREGAA, M. CHIKH-BLED, Comparative Study of Optical Unipolar Codes for Incoherent DS-OCDMA system, International Journal of Hybrid Information Technology, 6 (2013) 225-236. CrossRef M. BOUREGAA, M. CHIKH-BLED, The performance of a DS-OCDMA system using Orthogonal Optical Codes (OOC), European Scientific Journal, 9 (2013), 322-335 CrossRef M. Iwase, Y. Ishikawa, T. Komatsu, J. Kasahara, N. Hattori, M. Miura, N. Nakamura, K. Odaka, Optical transceiver modules for gigabit Ethernet PON FTTH systems, Furukawa Review, 28 (2005) 8-10. DirectLink

Dual-Connectivity Prevenient Handover Scheme in Control/User-Plane Split Networks

A control/user (C/U) plane-split network, where macro- and microevolved Node Bs (eNBs) are responsible for C/U-planes, respectively, is a potential 5G solution to address the problems experienced by high-speed railway communication systems such as frequent handovers (HOs), low system capacity, and low data rate. The C-plane transition occurs during an intermacro eNB HO to reduce the frequency of HOs. However, the intermacro-eNB HO in a C/U-plane-split network is prone to handover failures (HOFs) and long service interruption time similar to the traditional long-term evolution-advanced (LTE-A) HO without improvements because it is similar to an LTE-A HO between macro-eNBs from the perspective of C-plane transition. In this paper, we realize a C/U-plane-split network using the LTE-A dual-connectivity (DC) technique and propose a dc-based prevenient HO (PHO) scheme to improve the robustness of the intermacro-eNB HO. The proposed scheme specifically is an a priori method and uses the transmit diversity based on the dc technique to reduce the risk of HOFs and the long service interruption time. Further, we first develop the analytical expressions for HO performance for PHO and LTE-A HO, where HOFs are aligned with the LTE-A specifications such that they are defined as the association between the radio link monitor and HO processes. The analytical results are verified against simulation results. Through simulations, we compare PHO with LTE-A HO and the representative schemes of the previous literature in a variety of mobility performance metrics (such as the averages of the successful HO rate, the HOF rate, the radio link failure rate, the ping-pong rate, and the service interrupt time). The results confirm that the proposed scheme achieves superior performance in the key metrics of the successful HO rate and service interrupt time.

Generator maintenance scheduling based on the risk of power generating unit failure

A power utility’s ability to satisfy energy demand can be influenced significantly by unexpected breakdowns of power generating units. In most cases, such unexpected failures are also much more expensive to repair than taking planned preventative maintenance action. It has been found, especially in developing countries, that maintenance of often ageing power generating units is neglected due to high energy demand and low system capacity. The typical objectives pursued in the design of power generating unit maintenance schedules do not take these difficulties into account. A new scheduling criterion is therefore proposed in this paper. The occurrences of power generating unit failures may be estimated using methods from reliability theory in which the aim is typically to quantify the probability of a system completing its intended function for a specific duration of time. Based on this theory, our new scheduling objective seeks to maximise the probability of no power generating units in the power system failing during the scheduling window, weighted by the rated power generating capacity of each unit. The feasibility and effectiveness of this new objective is analysed by applying it, in conjunction with an exact solution approach, to two well-known generating maintenance scheduling test systems.

Design of optimal relay location in two-hop cellular systems

Relay stations are usually used to enhance the signal strength for the users near cell boundary, thereby extending the cell coverage. However, transmission through a relay station needs two transmission phases. The first phase is from base station to relay station, and the second one is from relay station to mobile station. Thus, using relay station may decrease system capacity due to two-phase transmission time. As a result, whether or not data are transmitted by one-hop or two-hop phases should be determined according to both signal strength and throughput. In this paper, we investigate the optimal relay location aiming to maximize system capacity. We consider two relay selection rules for determining whether two-hop transmission will be used: signal strength-oriented and throughput-oriented selection rules. We find that the signal strength-oriented two-hop transmission may yield even lower system capacity than the one-hop transmission. In the throughput-oriented scheme, the two-hop transmission can achieve higher system capacity than the one-hop transmission. By simulations, we determine the optimal relay location and show the coverage enhancement by the relaying network. Extensive simulations are performed to investigate the impacts of relay transmission power and the number of relay stations on system capacity and optimal relay location. The simulation results reveal important insights into designing a relaying network with high system capacity.

Health information technology and physician perceptions of quality of care and satisfaction

To examine across seven countries the relationship between physician office information system capacity and the quality of care. Multivariate analysis of a cross-sectional 2006 random survey of primary care physicians in seven countries: Australia, Canada, Germany, the Netherlands, New Zealand, United Kingdom, and United States. coordination and safety of care, care for chronically ill patients, and satisfaction with practice of medicine. The study finds significant disparities in the quality of health care between practices with low information system capacity and those with high technical capacity after controlling for within country differences and practice size. There were significant physician satisfaction differences with the overall experience of practicing medicine by information system level. For policy leaders, the seven-nation survey suggests that health systems that promote information system infrastructure are better able to address coordination and safety issues, particularly for patients with multiple chronic conditions, as well as to maintain primary care physician workforce satisfaction.

A comparative study of R22–E181 and R134a–E181 working pairs for a compression–absorption system for simultaneous heating and cooling applications

A comparative thermodynamic study has been carried out on R22–E181 and R134a–E181 working pairs for a vapour compression–absorption system for simultaneous heating and cooling applications. The results are obtained for a system that can be used, for example, in a dairy plant for pasteurization and chilling of milk for subsequent storage. Results show that R134a–E181 working pair gives better performance at lower solution concentration and hence at lower system capacity. At higher solution concentration and higher system capacity R22–E181 working pair is marginally better than R134a–E181 working pair. The performance trends obtained from experimental studies on a compression–absorption system working with R22–E181 are found to agree with the theoretical results, even though the actual COP is much lower than the theoretically predicted value.

분산환경하에서 해운 전자상거래 에이전트 설계 및 구현

이 본문은 선박중개시스템으로써 분산객체기술을 이용한 CORBA환경하에서 설계되고 구현되었다. 최근 각광 받고 있는 웹에서의 전자상거래 시스템이 방대해 짐에 따라 호스트 중심의 중앙 집중식 방식이 한계를 가지게 되었다. 또한 시스템의 성능 향상도 크게 요구되어졌으며, 이러한 문제들을 해결하기 위해 이종 시스템간에 프로그램을 분산시켜 부하를 줄임으로써 시스템의 성능 저하와 네트워크 병목형상을 해결하고 있다. 본 연구는 에이전트 통신언어(ACL)를 이용하여 분산된 데이터베이스에fi의 에이전트 기반 모형을 제시한다. 또한 분산된 서로 다른 운영체제, 분산된 이종의 데이터베이스에서의 정보 공유와 교환이 가능한 CORBA를 이용한 지능형 선박검색 에이전트의 모형을 구현한다. In this thesis a shipping broker agent system, which can be executed by a CORBA-based environment using the distributed object technique, CORBA is designed and implemented Nowadays, while the EC system is extensive on the web, legacy host systems have limitations and its capacity-upgrade os required. In order to solve these problems the method that distributes programs into several computer systems can reduce their loads, set low system capacity and minimize network bottleneck. In this thesis using Agent Communication Language(ACL), we propose an agent based prototype and implement an intelligent agent prototype for ships search using CORBA, which can exchange and shiare data between different systems.