A decision support system for demand and capacity modelling of an accident and emergency department

© 2019 Operational Research Society.Accident and emergency (A&E) departments in England have been struggling against severe capacity constraints. In addition, A&E demands have been increasing year on year. In this study, our aim was to develop a decision support system combining discrete event simulation and comparative forecasting techniques for the better management of the Princess Alexandra Hospital in England. We used the national hospital episodes statistics data-set including period April, 2009 – January, 2013. Two demand conditions are considered: the expected demand condition is based on A&E demands estimated by comparing forecasting methods, and the unexpected demand is based on the closure of a nearby A&E department due to budgeting constraints. We developed a discrete event simulation model to measure a number of key performance metrics. This paper presents a crucial study which will enable service managers and directors of hospitals to foresee their activities in future and form a strategic plan well in advance.Peer reviewe

Demand and Capacity Modelling of Acute Services Using Simulation and Optimization Techniques

The level of difficulty that hospital management have been experiencing over the past decade in terms of balancing demand and capacity needs has been at an unprecedented level in the UK. Due to shortage of capacity, hospitals are unable to treat patients, and in some cases, patients are transferred to other hospitals, outpatient referrals are delayed, and accident and emergency (A&E) waiting times are prolonged. So, it’s time to do things differently, because the current status quo is not an option. A whole hospital level decision support system (DSS) was developed to assess and respond to the needs of local populations. The model integrates every component of a hospital (including A&E, all outpatient and inpatient specialties) to aid with efficient and effective use of scarce resources. An individual service or a specialty cannot be assumed to be independent, they are all interconnected. It is clear from the literature that this level of generic hospital simulation model has never been developed before (so this is an innovative DSS). Using the Hospital Episode Statistics and local datasets, 768 forecasting models for the 28 outpatient and inpatient specialties are developed (to capture demand). Within this context, a variety of forecasting models (i.e. ARIMA, exponential smoothing, stepwise linear regression and STLF) for each specialty of outpatient and inpatient including the A&E department were developed. The best forecasting methods and periods were selected by comparing 4 forecasting methods and 3 periods (i.e. daily, weekly and monthly) according to forecast accuracy values calculated by the mean absolute scaled error (MASE). Demand forecasts were then used as an input into the simulation model for the entire hospital (all specialties). The generic hospital simulation model was developed by taking into account all specialties and interactions amongst the A&E, outpatient and inpatient specialties. Six hundred observed frequency distributions were established for the simulation model. All distributions used in the model were based on age groups. Using other inputs (i.e. financial inputs, number of follow ups, etc.), the hospital was therefore modelled to measure key output metrics in strategic planning. This decision support system eliminates the deficiencies of the current and past studies around modelling hospitals within a single framework. A new output metric which is called ‘demand coverage ratio’ was developed to measure the percentage of patients who are admitted and discharged with available resources of the associated specialty. In addition, a full factorial experimental design with 4 factors (A&E, elective and non-elective admissions and outpatient attendance) at 2 levels (possible 5% and 10% demand increases) was carried out in order to investigate the effects of demand increases on the key outputs (i.e. demand coverage ratio, bed occupancy rate and total revenue). As a result, each factor is found to affect total revenue, as well as the interaction between elective and non-elective admissions. The demand coverage ratio is affected by the changes in outpatient demands as well as A&E arrivals and non-elective admissions. In addition, the A&E arrivals, non-elective admissions and elective admissions are most important for bed occupancy rates, respectively. After an exhaustive review of the literature we notice that an entire hospital model has never been developed that combines forecasting, simulation and optimization techniques. A linear optimization model was developed to estimate the required bed capacity and staff needs of a mid-size hospital in England (using essential outputs from forecasting and forecasting-simulation) for each inpatient elective and non-elective specialty. In conclusion, these results will bring a different perspective to key decision makers with a decision support tool for short and long term strategic planning to make rational and realistic plans. This hospital decision support system can become a crucial instrument for decision makers for efficient service in hospitals in England and other parts of the world

Fabrication and characterization of semiconductor core optical fibers for mid-infrared transmission

Transmission in the mid-infrared (2-15 µm) spectrum has many applications, including biomedical surgery, chemical detection, and countermeasures in defense systems, among others. This highlights the necessity of a suitable fiber for the mid-infrared (mid-IR) spectral range. Although fluoride and chalcogenide glasses have shown promise of relatively low transmission losses, they are prone to devitrification at room temperature leading to performance degradation. Semiconductors, such as germanium and silicon have low theoretical losses in the mid-IR spectral range, and are stable at room temperature, making semiconductor-core fibers worthy of exploration for mid-IR transmission. In this study, germanium (Ge)-core, borosilicate glass-cladded; silicon (Si)-core, silica-cladded; and Si-Ge alloy-core silica-cladded fibers were drawn in laboratory-made mini draw towers using the rod-in-tube method at a relatively low temperature of 1000◦C for borosilicate glass drawing and 1760◦C for silica drawing. 3 mm outer diameter core-drilled germanium and silicon rods were placed in borosilicate and silica glass tubes as preforms for the germanium-core and silicon-core fibers, respectively. 1.9 mm outer diameter core drilled germanium rods and 2 mm inner diameter, 3 mm outer diameter core drilled silicon tubes were placed concentrically in silica tubes as preforms of silicon-germanium alloy fibers. The core/cladding area ratio was controlled by adding concentric borosilicate/silica tubes to increase the preform diameter. Depending on the drawing speed and initial core/cladding diameter ratio, fibers with core diameters of 10-200 µm with cladding diameters of 130-500 µm, as well as canes with core diameters of 300-350 µm and cladding diameters of 1.3-1.4 mm were drawn. The drawn fibers were characterized by scanning/transmission electron microscopy (S/TEM), energy dispersive x-ray spectroscopy (EDX), x-ray diffraction (XRD) and electron backscatter diffraction (EBSD). It was found that there was minimal diffusion of oxygen and silicon from the cladding to the core in the Ge-core fibers. In the Si-core and Si-Ge alloy-core fibers, around 3 at % oxygen were found in the core, presumably due to enhanced diffusion at the higher drawing temperature of the silica-clad fibers. Optical characterization of the Ge canes, carried out using Fourier transform infrared spectroscopy (FTIR) in the 1.3-16 µm wavelength range, showed similar transmission characteristics, albeit with increased losses, over the entire wavelength range as the core drilled unprocessed germanium rod, even though the germanium core had undergone melting and re-solidification during the fabrication process. The transmission losses in the fibers were measured using two quantum cascade lasers, and were found to average 5.1 dB/cm for Ge-core fibers and 18.3 dB/cm for Si-core fibers in the 5.8-6.2 µm range. Transmission loss of Si-Ge alloy fibers was found to be 75 dB/cm at 6.1 µm. The higher losses of Si-Ge fibers can be attributed to compositional fluctuation in the core, due to the rapid cooling rate during fiber drawing. High temperature annealing of the fibers following by slow cooling homogenized the fiber core, and reduced the transmission losses to 28 dB/cm, but also introduced cracks. Non-linear properties of Ge-core fibers and canes were investigated using femtosecond pump-probe spectroscopy. Unprocessed 3 mm diameter rods exhibited the same detuning oscillations as 770 and 358 µm Ge-core canes and a 132 µm Ge-core fiber, indicating that the non-liner properties of the semiconductor cores were preserved during processing

THE PERCEPTIONS OF INCREASED STUDENT LOAN DEBT ON THE COLLEGE CHOICE AND ENROLLMENT OF RURAL LOW-INCOME STUDENTS

The purpose of this phenomenological study was to gain an understanding of the college choice experience of rural low-income students and how their potential use of student loans influenced their college choice decisions. In order to conduct this research study, in-depth, semi-structured interviews were used as the primary data source. Additional data sources included demographic surveys, a site visit, online resources, and meeting with key informants. The primary research question used to guide this study included: * How do rural, low-income students describe their experiences with their college choice process? The following secondary questions included in this study were: * How do rural low-income students perceive and describe their experiences in making college choice decisions in reference to their perception of accepting debt in the form of student loans? * What types of social and cultural capital did rural low-income students describe as influencing their college choice decisions? The questions were posed to explore the lived experiences of participants with their college choice process. The main themes that emerged from the data were the following: a) Reasons for selected college choice, b) Perceptions of loans, c) Role of money, and d) Resources used in the college choice process. The findings were interpreted and situated in the context of the extant literature and the conceptual base of this work. Implications for policy and practice, study limitations, recommendations for future study, and the conclusion were also presented

EOQ in a Just in Time (JIT) World: An Empirical Analysis of the Impact of EOQ Variables on Operating Profit: The Case of Nigerian Bottling Company Plc

With today’s uncertain economy, companies are searching for alternative methods to keep ahead of their competitors by effectively driving sales and by cost reduction. Big manufacturing companies – as well as other companies, do not stand a chance in today’s environment if they do not have an appropriate inventory control model intact. The Economic Order Quantity (EOQ) and Just in Time (JIT) have been used for many years, but yet some companies have not taken advantage of it. An Economic order quantity could assist in deciding what would be the best optimal order quantity at the company’s lowest price. Similarly JIT focuses on providing customers with stocks at the right time and with the right quantity thereby reducing in process inventory and carrying costs and maximizing profits at the same time (Gonzalez and Gonzalez, 2010). All these in place in any organization are known as its inventory management system which invariable needs to be as efficient as possible in other to reduce costs and translate in profit maximization. In recent times there has been a clarion call to abandon EOQ model in place of JIT.  Perhaps this is because of the perceived benefits of JIT which includes:  time reduction as well as improved flow of goods from warehouse to shelves which in turn leads to regular replenishment of stock amongst others.  However, one might be tempted to ask: is this call for abandonment justifiable? Using JIT does it actually reduce costs as well as lead to profit maximization in the organization?. This study looks at the relevance of EOQ Variables – Cost of goods purchased and overheads in impacting on the profitability of the firm. In doing this,  the relationship of increase in cost of goods purchased against Operating profit  as well as increase in Overhead against Operating profit  of  manufacturing  companies in Nigeria were compared. Using Nigerian Bottling Company (NBC) Plc as a case study, Twenty – Nine (29) Years financial statements (1980-2009) were analyzed and the relationships between these variables were compared using regression analysis.  It was found out that there is a relationship amongst these variables in NBC PLC.  This paper thereafter, suggests that rather than abandon EOQ for JIT, they should complement each other for effective inventory management and ultimately lead to profit maximization. Keywords: Economic Order Quantity (EOQ), EOQ Variables, Just In Time (JIT), Nigerian Bottling Company Plc and Regression Analysis

Relationship between exchange rates and foreign trade: Case of Turkey

Türkiye'nin dış ticaret hacmi son yıllarda önemli gelişmeler kaydetmiştir. Ancak bu gelişme neticesinde ticaret açığı da önemli oranda artmıştır. Son yıllarda esnek kur rejimi ile birlikte Türk Lirası'nın değerlenmesi de ortaya çıkmıştır. Ülkenin ticaret hacmi beklenmedik biçimde hızla artmıştır. Bu durum, dış ticaretin döviz kurlarından etkilenip etkilenmediği sorusunu da gündeme getirmiştir. Para biriminin değerlenmesi yabancı malları daha ucuz hale getirerek ithalatı körüklerken, aynı zamanda daha çok ithal girdilere dayanan sektörlerin de ihracat potansiyelinin artmasını sağlamaktadır. Bu çalışmada Türkiye'nin dış ticaret açığının döviz kurlarındaki değişime duyarlılığı incelenmektedir. Araştırma sonuçları uzun devalüasyon dönemlerine karşın, dış ticaret açığının artma eğilimi gösterdiği görülmektedir. Buna göre döviz kuru politikasının olumlu bir dış ticaret dengesi kuramadığı söylenebilir. Dış ticaret hacimlerinin döviz kurlarındaki değişimlere cevap veremediği de görülmektedir. Türkiye'nin ithalatındaki hızlı artış iç piyasadaki talebin yüksek seyretmesi ile ilişkili olmasına karşın, ihracattaki artış dış pazar sayısındaki artış ve bu pazarlardaki ekonomik büyümelerle ilişkilidir.Relationship Between Exchange Rates and Foreign Trade: Case of Turkey Foreign trade volume of Turkey has indicated a significant improvement in last years. This fact also led to increase of trade deficit. In recent period, there occurred revaluation of Turkish Lira thanks to floating exchange regime. Export volume has exceeded expectations. On the other hand, all these facts give rise to debates if export volume is affected by real exchange rates. Revaluation of Turkish Lira also promotes import volume since it leads to cheap foreign goods. However, it also promotes export strength of industries which dependent on import of raw or intermediary materials. This study evaluates the sensitivity of Turkish trade deficit to fluctuations in real exchange rates. Result of the study reveals that despite longer devaluation periods, trade deficit has a tendency to constantly grow up. In this framework, it can be argued that foreign exchange policy could not establish a positive trade balance. It is also seen that trade volume could not react to fluctuations in exchange rates. Although import figures of Turkey are associated with that high domestic demand, increase in exports can be related to increase in the number of export markets and economic growth in those markets

An innovative approach to game-based learning in nursing education: Virtual gaming simulation: Hemşirelik eğitiminde oyun temelli öğrenmede yenilikçi bir yaklaşım: Sanal oyun simülasyonu

Nursing education includes cognitive, affective and psychomotor learning areas that enable students to take on certain roles. Reasons such as limited clinical applications, patients' reluctance to have students practice and the low number of teaching staff negatively affect the development of students. For this reason, technological developments are integrated into the nursing education curriculum and it is tried to provide knowledge and skills to students in a safer and more effective way. Game-based learning is becoming more and more common in the education of nursing students who grow up in the age of technology. Game-based learning provides permanence in knowledge, supports active learning and increases student satisfaction. Recently, one of the applications involving technology in nursing education is virtual game simulation. Virtual game simulation is a 2D (two-dimensional) virtual computer game involving simulated real people, allowing students to actively participate in a clinical scenario. Virtual simulation games are designed with realistic scenarios for students to experience the clinical environment, improve their self-confidence, critical thinking and clinical decision making skills. The aim of this article is to explain virtual game simulation, which is a new approach in game-based learning in nursing education, and research on the subject. ​Extended English summary is in the end of Full Text PDF (TURKISH) file.   Özet Hemşirelik eğitimi öğrencilere belirli rolleri üstlenmelerini sağlayacak düzeyde bilişsel, duyuşsal ve psikomotor öğrenim alanlarını içermektedir. Sınırlı klinik uygulamalar, hastaların öğrencilere uygulama yaptırmak istememesi ve öğretim elemanı sayısının az olması gibi nedenler ise öğrencilerin gelişimini olumsuz etkilemektedir. Bu nedenle yaşanan teknolojik gelişmeler hemşirelik eğitim müfredatına entegre edilerek öğrencilere bilgi ve beceri öğretimi daha güvenli ve etkin bir şekilde sağlanmaya çalışılmaktadır. Teknoloji çağında yetişen hemşirelik öğrencilerinin eğitiminde oyun temelli öğrenme giderek yaygınlaşmaktadır. Oyun temelli öğrenme, bilgide kalıcılığı sağlayarak aktif öğrenmeyi desteklemekte ve öğrenci memnuniyetini artırmaktadır. Son zamanlarda hemşirelik eğitiminde teknolojiyi içeren uygulamalardan biri sanal oyun simülasyonudur. Sanal oyun simülasyonu, öğrencilerin klinik bir senaryoya aktif katılımını sağlayan, simüle edilmiş gerçek insanları içeren 2D (iki boyutlu) bir sanal bilgisayar oyunudur. Sanal simülasyon oyunları gerçeğe yakın senaryolar ile öğrencilerin klinik ortamı deneyimlemesi, özgüvenlerinin, eleştirel düşünme ve klinik karar verme becerilerinin geliştirilmesi amacıyla tasarlanmıştır. Bu makalenin amacı, hemşirelik eğitiminde oyun temelli öğrenmede yeni bir yaklaşım olan sanal oyun simülasyonunu ve konu ile ilgili yapılan araştırmaları açıklamaktır

Effect of Moderate Static Magnetic Field on Human Bone Marrow Mesenchymal Stem Cells: a Preliminary Study For Regenerative Medicine

DergiPark: 806802trkjnatStatic Magnetic Field (SMF) is one of the biophysiological stimulants which modulates physiological processes in different cell lines. Mesenchymal stem cells (MSCs) are important biological tools for regenerative medicine. Although it is known that SMFs cause a change in cellular membrane polarization, oxidative product concentrations, gene expression patterns and cell propagation rates, depending on exposure time and intensity, their effects on MSCs have not been properly explained yet. In this study, MSCs derived from human bone marrow were treated with moderate 328 mT SMF by using cylindric Neodymium Iron Boron (Nd2Fe14B) magnets to investigate its influence on orientation, proliferation rates and morphologies. Results showed that the treated cells gained more homogenous orientation than the non-treated cells, however SMF influence did not significantly change proliferation rates. The cells were grown under both chemically osteogenic induction and SMF to observe the osteogenic differentiation and biomineralization. Alkaline phosphatase (ALP) activity decreased significantly in the cells treated with SMF compared to the control groups. Alizarin Red S staining showed that mineralization also decreased in the cells. The results showed that an easily produced moderate SMF can be a useful physical stimulant to control the fate of MSC both in vitro and in vivo. Statik Manyetik Alan (SMA), farklı hücre hatlarında fizyolojik süreçleri düzenleyen biyofizyolojik uyarıcılardan biridir. Mezenkimal kök hücreler (MKH’ler) rejeneratif tıp için önemli biyolojik araçlardır. SMA'ların yoğunluğuna ve süresine göre hücre membran polarizasyonunu, oksidatif ürün konsantrasyonlarını, gen ekspresyon modellerini ve hücre çoğalma oranlarını değiştirdiği bilinmesine rağmen, MKH'ler üzerindeki SMA etkileri henüz tam olarak açıklanmamıştır. Bu çalışmada, insan kemik iliği kaynaklı MKH'ler, silindirik Neodimyum Demir Bor (Nd2Fe14B) mıknatıslar kullanılarak orta derecede 328 mT SMA etkisinde bırakıldı ve hücrelerin oryantasyonu, çoğalma oranı ve osteojenik farklılaşma potansiyelleri incelendi. Sonuçlar, tedavi edilen hücrelerin, tedavi edilmeyen hücrelerden daha homojen bir yönelim kazandığını, ancak SMF etkisinin çoğalma oranlarını önemli ölçüde değiştirmediğini gösterdi.MKH’ler, osteojenik farklılaşmayı ve biyomineralizasyonu gözlemlemek için hem kimyasal olarak osteojenik indüksiyon hem de SMA altında büyütüldüğünde, Alkalin Fosfataz (ALP) aktivitesi kontrol gruplarına kıyasla önemli ölçüde azaldı. Alizarin Red S boyaması, uyarılan hücrelerde mineralleşmenin de azaldığını gösterdi. Sunulan sonuçlar, kolayca üretilen orta düzeyde bir SMA'nın in vitro veya in vivo olarak MKH kaderini kontrol etmek için yararlı bir fiziksel uyarıcı olabileceğinin altını çizmektedir

Prediction of Undrained Shear Strength by the GMDH-Type Neural Network Using SPT-Value and Soil Physical Properties

This study presents a novel method for predicting the undrained shear strength (c(u)) using artificial intelligence technology. The c(u) value is critical in geotechnical applications and difficult to directly determine without laboratory tests. The group method of data handling (GMDH)-type neural network (NN) was utilized for the prediction of c(u). The GMDH-type NN models were designed with various combinations of input parameters. In the prediction, the effective stress (sigma(v)'), standard penetration test result (N-SPT), liquid limit (LL), plastic limit (PL), and plasticity index (PI) were used as input parameters in the design of the prediction models. In addition, the GMDH-type NN models were compared with the most commonly used method (i.e., linear regression) and other regression models such as random forest (RF) and support vector regression (SVR) models as comparative methods. In order to evaluate each model, the correlation coefficient (R-2), mean absolute error (MAE), and root mean square error (RMSE) were calculated for different input parameter combinations. The most effective model, the GMDH-type NN with input parameters (e.g., sigma(v)', N-SPT, LL, PL, PI), had a higher correlation coefficient (R-2 = 0.83) and lower error rates (MAE = 14.64 and RMSE = 22.74) than other methods used in the prediction of c(u) value. Furthermore, the impact of input variables on the model output was investigated using the SHAP (SHApley Additive ExPlanations) technique based on the extreme gradient boosting (XGBoost) ensemble learning algorithm. The results demonstrated that using the GMDH-type NN is an efficient method in obtaining a new empirical mathematical model to provide a reliable prediction of the undrained shear strength of soils.Chungnam National University; National Research Foundation of Korea (NRF) - Korea government (MSIT) [NRF2022R1C1C1011477]This work was supported by research fund of Chungnam National University and National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (No. NRF2022R1C1C1011477)

Poverty and Ignorance as Correlates of Youths Social Restiveness Behaviour in Rivers and Bayelsa States of Nigeria: Implication for Counselling

This study investigates poverty, ignorance and gender as correlates of youths social restiveness behavior in Bayelsa and Rivers States of Nigeria. Two research questions and two hypotheses were formulated to guide the study. Correlational research design was used for the study. The population consists of all youths (male and female) from ten local government areas of Bayelsa and Rivers states of Nigeria (5 local government areas from Bayelsa and 5 local government areas from Rivers respectively) estimated to be about 5000 youths. The sample size of 500 youths was used for the study selected through purposive random sampling technique from the selected local government areas. Researcher self made questionnaire titled “Youth Social Restiveness Behaviour Questionnaire (YSRBQ) was used for data collected from the subjects. Regression analysis statistics was used to answer and analyze the two research questions and two hypotheses formulated for the study at 0.05 level of significance. The result shows that poverty and ignorance are significant predictors of youth social restiveness behaviour though, poverty is stronger. Gender was not significant. Conclusions were reached, implication for counselling made and recommendations stated