Fixed Period Of Time Research Articles

Railway development from the Japanese occupation period to the present – using Kaohsiung city as an example​​​​​​​​

ABSTRACTThis study intended to discuss the interactive influence of the emergence, transformation and decline of the railway in Kaohsiung Port on urban development, the population, the activities and the economy in the region during the period of 1895–2010, from the perspectives of urban planning, railway development, population and industry. This study used the crossover analysis method, and used the factors of railway development and urban planning, within a fixed time period, to explore the chain dependence relationship among the industry, the population, the regional economy and the railway stations in Kaohsiung city. This study found that urban planning, economic development, railway development and industry have an interactive influence on the overall urban development. Urban planning promotes the rapid growth of the population, and economic development propels the growth and shaping of the regional economy, thus increasing employment opportunities. In addition, the railway development process moves forward with urban development.

Dynamical behavior of a new oncolytic virotherapy model based on gene variation

Oncolytic virotherapy is an experimental treatment of cancer patients. This method is based on the administration of replication-competent viruses that selectively destroy tumor cells but remain healthy tissue unaffected. In order to obtain optimal dosage for complete tumor eradication, we derive and analyze a new oncolytic virotherapy model with a fixed time period $τ $ and non-local infection which is caused by the diffusion of the target cells in a continuous bounded domain, where $τ $ is assumed to be the duration that oncolytic viruses spend to destroy the target cells and to release new viruses since they enter into the target cells. This model is a delayed reaction diffusion system with nonlocal reaction term. By analyzing the global stability of tumor cell eradication equilibrium, we give different treatment strategies for cancer therapy according to the different genes mutations (oncogene and antioncogene).

Studying the capture of stochastic events using radar and a mobile robot

Moving sensors, vehicular devices and mobile robots can monitor larger areas than fixed sensors do during a fixed time period. However, the benefits of adopting vehicular devices, moving sensors and robots are not well understood. In this paper, our goal is to understand the benefits better. We model intrusion detection processes via a radar and a mobile sensor/robot (or a vehicular device) mathematically. We also consider using a pair of moving sensors or robots together, and we study their detection quality. We compare the robot detection and the radar detection in terms of intrusion loss probability and the expected capture time. Our studies help to understand the benefits of understanding mobility coverage.

Electrospun API-loaded mixed matrix membranes for controlled release

The development of biocompatible membrane materials capable of delivering active pharmaceutical ingredients (APIs) over a fixed time period offers significant advantages to the pharmaceutical and biomedical industries alike.

A ruin theoretic design approach for wireless cellular network sharing with facilities

AbstractWith the rise of cheap small cells in wireless cellular networks, there are new opportunities for third party providers to service local regions via sharing arrangements with traditional operators. In fact, such arrangements may be particularly desirable for large facilities—such as stadiums, universities, and mines—as they already need to cover property costs, and often have fiber backhaul and efficient power infrastructure. In this paper, we propose a network‐sharing arrangement between large facilities and traditional operators. Our network‐sharing arrangement consists of two aspects: leasing of data access and spectrum from traditional operators; and service agreements with users. As a consequence of the incorporation of the user service agreements into the sharing arrangement, financial as well as physical resource constraints need to be accounted for. This introduces a new dimension into wireless network resource allocation, which requires a new evaluation framework. To this end, we develop a framework based on ruin theory, where the key metric is the probability that the facility is insolvent within a fixed time period. We then investigate the effect of initial capital and physical layer parameters on the ruin probability, which provides insight into the robustness of the network‐sharing arrangement to varying conditions.

ANTICANCER DRUGS AS PROSPECTIVE EFFLUX PUMP INHIBITORS FOR SALMONELLA TYPHI PRODUCE CONFLICTING RESULTS IN IN SILICO AND IN VITRO STUDIES

<p><strong>Objective: </strong>Anticancer drugs paclitaxel and vinblastine were tested for their potential as efflux pump inhibitors for <em>Salmonella</em> Typhi-based on <em>in silico</em> and <em>in vitro</em> studies.</p><p><strong>Methods: </strong>Three-dimensional protein models of AcrAB-TolC of <em>Salmonella</em> Typhi were generated by online server PHYRE-2. The quality of 3D structures was assessed by PROCHECK, SWISS MODEL. Docking analysis of anticancer drugs with AcrA, AcrB and TolC subunits were performed after refining the homology models with Modrefiner. <em>Salmonella</em> Typhi (<em>S</em>. Typhi) efflux pump activity was measured by ethidium bromide (EtBr) cartwheel and semi-automated fluorometry methods respectively. Fluorescence intensity in bacterial colonies was measured under different treatment conditions (with or without drugs) on Muller Hinton agar (MHA) plates containing EtBr in cartwheel assay. EtBr efflux assay was determined following the loading of bacteria with EtBr and fluorescence was recorded over fixed time period with the help of fluorescent spectrophotometer. The results obtained were compared with the control.</p><p><strong>Results: </strong>Efflux pump inhibitor (EPIs) activity of paclitaxel and vinblastine determined by EtBr cartwheel assay registered no activity whereas semi-automated fluorescent assay revealed marginal activity when compared to control.</p><p><strong>Conclusion: </strong>We report the conflicting result of <em>in silico</em> and <em>in vitro</em> studies in predicting the antimicrobial effect of mainstream anticancer drugs as efflux pump inhibitors for <em>Salmonella</em> Typhi.</p>

On some new dependence models derived from multivariate collective models in insurance applications

Consider two different portfolios which have claims triggered by the same events. Their corresponding collective model over a fixed time period is given in terms of individual claim sizes and a claim counting random variable N. In this paper, we are concerned with the joint distribution function (df) F of the largest claim sizes . By allowing N to depend on some parameter, say , then is for various choices of N a tractable parametric family of bivariate dfs. We investigate both distributional and extremal properties of . Furthermore, we present several applications of the implied parametric models to some data from the literature and a new data-set from a Swiss insurance company (Data-set can be downloaded here http://dx.doi.org/10.13140/RG.2.1.3082.9203.)

Insurance Applications of Some New Dependence Models Derived from Multivariate Collective Models

Consider two different portfolios which have claims triggered by the same events. Their corresponding collective model over a fixed time period is given in terms of individual claim sizes $(X_i,Y_i), i\ge 1$ and a claim counting random variable $N$. In this paper we are concerned with the joint distribution function $F$ of the largest claim sizes $(X_{N:N}, Y_{N:N})$. By allowing $N$ to depend on some parameter, say $\theta$, then $F=F(\theta)$ is for various choices of $N$ a tractable parametric family of bivariate distribution functions. We present three applications of the implied parametric models to some data from the literature and a new data set from a Swiss insurance company. Furthermore, we investigate both distributional and asymptotic properties of $(X_{N:N,Y_{N:N})$.

Insight into solute and microbial transport in heap (bio)leaching systems using residence time distribution

Residence time distribution experiments were performed using chemical and microbial tracers to elucidate solution transport mechanisms within low grade, agglomerated ore beds. Multiple, fixed bed, mini-column reactors were packed with representative grab samples of low grade ore. The tracers were introduced to the ore bed in three ways: as a pulse added with the irrigant, included during agglomeration of the ore, and introduced by submerging the ore bed in tracer solution for a fixed time period. These methods of tracer introduction allowed for the characterisation of flow interchange in packed bed systems, under unsteady state conditions. Dispersion and diffusion of solution through the ore beds were characterised based on the resulting residence time distribution curves. Distinct stagnant and flowing regions within the agglomerated ore bed were observed. Flow characteristics provided information regarding solution exchange between the fast flowing and largely stagnant liquid phases. Increased retention times of both the solute and micro-organisms were noted when the tracer was agglomerated onto the ore surface. This was followed by an increase in solute transport rate from the ore surface driven by concentration gradient.

MODELLING AND SIMULATION OF VOLUMETRIC RAINFALL FOR A CATCHMENT IN THE MURRAY–DARLING BASIN

We discuss modelling and simulation of volumetric rainfall in a catchment of the Murray–Darling Basin – an important food production region in Australia that was seriously affected by a recent prolonged drought. Consequently, there has been sustained interest in development of improved water management policies. In order to model accumulated volumetric catchment rainfall over a fixed time period, it is necessary to sum weighted rainfall depths at representative sites within each sub-catchment. Since sub-catchment rainfall may be highly correlated, the use of a Gamma distribution to model rainfall at each site means that catchment rainfall is expressed as a sum of correlated Gamma random variables. We compare four different models and conclude that a joint probability distribution for catchment rainfall constructed by using a copula of maximum entropy is the most effective.

Moroccan wind farm potential feasibility. Case study

The subject of this paper is the elaboration of a methodology to study the technical feasibility of a wind farm potential. The implementation of this methodology allows a comparison between the wind resourcesoftwo different sites in Morocco. One site is located inthe region of Essaouira, whereasthe other one is located in the region of Safi. The comparison is based on real wind data collected from two masts at the heights of 30, 50, and 60m. Each of the masts is installed at one of the mentioned potential sites over a fixed time period, lasting fifteen months for the first site, and eight months for the second one. The aim is the determination of the most applicable site presenting a good potential for a statistical study in order to predict long-term wind behaviors. Thus, the geographical situation study of the chosen site including topography, roughness and obstacles, is carried out. Furthermore, the wind resource using data, generated by the measuring masts, is evaluated. Finally, the areas which present great wind potential are located and the wind farm turbine locations are optimized by using the WAsP software.

The set-up of an international agreement on the conservation and sustainable use of geologically scarce mineral resources

For more than a century, the use of mineral resources has increased exponentially with annual growth percentages of between 4% and 6%. While for most mineral resources, depletion is not an issue, for some mineral resources the current level of extraction is likely to pose a problem for future generations. Depletion of a mineral resource means that its enriched deposits will have been extracted, and consequently it will become much more expensive for future generations to continue to use these minerals. While technology may reduce some of the adverse effects of depletion, future generations may be deprived of potential innovations for which these specific materials would be essential. The question arises as to how the currently unsustainable extraction of mineral resources can be decreased to safeguard them for future generations. It is submitted that it is unlikely that market forces alone will sufficiently impact the prices of minerals to resolve the unsustainable use of certain minerals timely enough. In this article, it is posited that an international agreement on the conversation and sustainable use of geologically scarce minerals is necessary. The agreement will recognize that the geological scarcity of mineral resources differs between different minerals. It will therefore make a selection of priority minerals, determine how far the extraction rate of these substances must be reduced and decide on a fixed time period within which the extraction must decrease from the current rate to a sustainable rate. The design of such an agreement will be based on two basic principles contained in existing international environmental agreements: (1) the inter-generational equity principle and (2) the principle of conservation of natural resources. Furthermore, the obligatory reduction of the extraction of mineral resources will affect the sovereign rights of resource countries to exploit their own resources. Therefore, any international agreement should make arrangements to ensure resource countries are adequately compensated for their loss of income.

A two-storage multi-item inventory model with hybrid number and nested price discount via hybrid heuristic algorithm

The purpose of this paper is to study a multi-item two warehouse inventory model with a nested discount on unit cost and inventory costs over a fixed time period. The concept of hybrid number and a new type of price discount have been applied in formulating an inventory control system having two separate storage facilities (owned-OW and rented-RW warehouses) due to limited capacity of OW. Here, demand rate is a linear function of selling price and time. The stocks at rented warehouse (RW) are transported to the owned warehouse (OW) following bulk-release rule. So, the mathematical model of the system becomes a constrained non-linear mixed-optimization problem. Here, taking the advantage of the randomness of multi-objective genetic algorithm with varying population (MOGAVP), for the first time, an algorithm has been proposed for the solution of multi-item two-warehouse inventory problems with nested price breaks. The optimum results are compared with MOGAVP and hybrid heuristic algorithm (HA). The optimal shipments, lot size of the two warehouses, shipment size and maximum profit are determined by maximizing the profit function. Finally optimal decision is made using above mentioned MOGAVP. Performance of the proposed MOGAVP on the model with respect to a standard MOGA and HA are compared.

A mathematical model of tumor growth and its response to single irradiation.

BackgroundMathematical modeling of biological processes is widely used to enhance quantitative understanding of bio-medical phenomena. This quantitative knowledge can be applied in both clinical and experimental settings. Recently, many investigators began studying mathematical models of tumor response to radiation therapy. We developed a simple mathematical model to simulate the growth of tumor volume and its response to a single fraction of high dose irradiation. The modelling study may provide clinicians important insights on radiation therapy strategies through identification of biological factors significantly influencing the treatment effectiveness.MethodsWe made several key assumptions of the model. Tumor volume is composed of proliferating (or dividing) cancer cells and non-dividing (or dead) cells. Tumor growth rate (or tumor volume doubling time) is proportional to the ratio of the volumes of tumor vasculature and the tumor. The vascular volume grows slower than the tumor by introducing the vascular growth retardation factor, θ. Upon irradiation, the proliferating cells gradually die over a fixed time period after irradiation. Dead cells are cleared away with cell clearance time. The model was applied to simulate pre-treatment growth and post-treatment radiation response of rat rhabdomyosarcoma tumors and metastatic brain tumors of five patients who were treated with Gamma Knife stereotactic radiosurgery (GKSRS).ResultsBy selecting appropriate model parameters, we showed the temporal variation of the tumors for both the rat experiment and the clinical GKSRS cases could be easily replicated by the simple model. Additionally, the application of our model to the GKSRS cases showed that the α-value, which is an indicator of radiation sensitivity in the LQ model, and the value of θ could be predictors of the post-treatment volume change.ConclusionsThe proposed model was successful in representing both the animal experimental data and the clinically observed tumor volume changes. We showed that the model can be used to find the potential biological parameters, which may be able to predict the treatment outcome. However, there is a large statistical uncertainty of the result due to the small sample size. Therefore, a future clinical study with a larger number of patients is needed to confirm the finding.Electronic supplementary materialThe online version of this article (doi:10.1186/s12976-016-0032-7) contains supplementary material, which is available to authorized users.

A Continuous Health Monitoring System for Photovoltaic Array Using Arduino Microcontroller

In this paper new technique is developed to monitor the health status of the PV panels in the array. For finding the health status short circuit current is measured continuously over a fixed time period. This technique can classify the health status into four categories such as Healthy, Low Fault, Medium Fault and High Fault. By this classification faulty operation can be rectified and power generation may be improved. In case of high faults, PV panels can be protected. The cost requirement for the implementation is very low. The proposed technique is implemented in MATLAB Simulation and hardware. The array considered in this paper is 2 × 2 Series Parallel.

Optimal burn-in procedure for mixed populations based on the device degradation process history

Burn-in is a method of ‘elimination’ of initial failures (infant mortality). In the conventional burn-in procedures, to burn-in an item means to subject it to a fixed time period of simulated use prior to actual operation. Then, the items which failed during burn-in are just scrapped and only those which survived the burn-in procedure are considered to be of satisfactory quality. Thus, when the items are subject to degradation phenomena, those whose degradation levels at the end of burn-in exceed a given failure threshold level are eliminated. In this paper, we consider a new burn-in procedure for items subject to degradation phenomena and belonging to mixed populations composed of a weak and a strong subpopulation. The new procedure is based on the ‘whole history’ of the degradation process of an item periodically observed during the burn-in and utilizes the information contained in the observed degradation process to assess whether the item belongs to the strong or weak subpopulation. The problem of determining the optimal burn-in parameters is considered and the properties of the optimal parameters are derived. A numerical example is also provided to illustrate the theoretical results obtained in this paper.

Real-Time Energy Storage Management With Renewable Integration: Finite-Time Horizon Approach

We consider the design of cost-effective management of energy storage with renewable integration for load supply. We take a finite time horizon approach and formulate the control optimization problem aimed at minimizing the system cost over a fixed time period. Recognizing the unpredictable and nonstationary stochastic nature of system dynamics, we assume unknown arbitrary dynamics of renewable generation, load, and electricity pricing in formulating our problem. Furthermore, we incorporate detailed battery operation cost into the system cost. Different from the infinite time horizon problems in existing works, the coupling of control decisions over time, due to finite battery capacity, is more challenging to manage. We develop a special technique to tackle the technical challenges in solving the problem. Through problem modification and transformation, we are able to apply Lyapunov optimization to design a real-time control algorithm that relies only on the current system dynamics. The proposed control solution has a closed-form expression and thus is simple to implement. Through analysis, the proposed algorithm is shown to have a bounded performance gap to the optimal noncausal $T$ -slot lookahead control policy. Simulation studies show the effectiveness of our proposed algorithm as compared with two alternative real-time and noncausal algorithms.

Effect of the Lookback Period's Length Used to Identify Incident Acute Myocardial Infarction on the Observed Trends on Incidence Rates and Survival: Cardiovascular Disease in Norway Project.

In studies using patient administrative data, the identification of the first (incident) acute myocardial infarction (AMI) in an individual is based on retrospectively excluding previous hospitalizations for the same condition during a fixed time period (lookback period [LP]). Our aim was to investigate whether the length of the LP used to identify the first AMI had an effect on trends in AMI incidence and subsequent survival in a nationwide study. All AMI events during 1994 to 2009 were retrieved from the Cardiovascular Disease in Norway project. Incident AMIs during 2004 to 2009 were identified using LPs of 10, 8, 7, 5, and 3 years. For each LP, we calculated time trends in incident AMI and subsequent 28-day and 1-year mortality rates. Results obtained from analyses using the LP of 10 years were compared with those obtained using shorter LPs. In men, AMI incidence rates declined by 4.2% during 2004 to 2009 (incidence rate ratio, 0.958; 95% confidence interval, 0.935-0.982). The use of other LPs produced similar results, not significantly different from the LP of 10 years. In women, AMI incidence rates declined by 7.3% (incidence rate ratio, 0.927; 95% confidence interval, 0.901-0.955) when an LP of 10 years was used. The decline was statistically significantly smaller for the LP of 5 years (6.2% versus 7.3%; P=0.02) and 3 years (5.9% versus 7.3%; P=0.03). The choice of LP did not influence trends in 28-day and 1-year mortality rates. The length of LP may influence the observed time trends in incident AMIs. This effect is more evident in older women.

Burn-in Procedure Based on a Dependent Covariate Process

Burn-in is a method of ‘elimination’ of initial failures (infant mortality). In the conventional burn-in procedures, to burn-in a component or a system means to subject it to a fixed time period of simulated use prior to actual operation. Then those which fail during the burn-in procedure are scrapped and only those which survived the burn-in procedure are considered to be of satisfactory quality. Thus, in this case, the only information used for the elimination procedure is the lifetime of the corresponding item. In this paper we consider a new burn-in procedure which additionally employs a dependent covariate process in the elimination procedure. Through the comparison with the conventional burn-in procedure, we show that the new burn-in procedure is preferable under commonly satisfied conditions. The problem of determining the optimal burn-in parameters is also considered and the properties of the optimal parameters are derived. A numerical example is provided to illustrate the theoretical results obtained in this paper.

Burn-in Procedure Based on a Dependent Covariate Process

Burn-in is a method of ‘elimination’ of initial failures (infant mortality). In the conventional burn-in procedures, to burn-in a component or a system means to subject it to a fixed time period of simulated use prior to actual operation. Then those which fail during the burn-in procedure are scrapped and only those which survived the burn-in procedure are considered to be of satisfactory quality. Thus, in this case, the only information used for the elimination procedure is the lifetime of the corresponding item. In this paper we consider a new burn-in procedure which additionally employs a dependent covariate process in the elimination procedure. Through the comparison with the conventional burn-in procedure, we show that the new burn-in procedure is preferable under commonly satisfied conditions. The problem of determining the optimal burn-in parameters is also considered and the properties of the optimal parameters are derived. A numerical example is provided to illustrate the theoretical results obtained in this paper.