129 research outputs found
Electricity Market Impacts of Low-carbon Energy Transition in the Nordic-Baltic Region
The Baltic countries Estonia, Latvia and Lithuania are well connected to the Nordic countries Finland and Sweden on the electricity market, yet in a different position facing the transition to a low-carbon electricity system. While especially Sweden is a large electricity producer and net exporter, the Baltic countries suffer from a lack of capacity, which makes them highly dependent on trade. In addition, the present electricity mix of Estonia is very carbon intensive compared to the Nordic countries. There is a debate regarding nuclear power in Sweden. This paper explores four possible solutions for a Nordic-Baltic electricity system: with and without nuclear power in Sweden and with the current transmission network, as well as with a considerably expanded network. The impact on electricity mix, electricity prices, carbon dioxide intensity and import dependence in the Baltic countries from the EU transition to electricity systems with very low carbon dioxide emissions is investigated. The electricity and district heat market model Enerallt is used to quantify electricity prices, electricity trade and system costs. The results show that the development of the transmission network affects electricity prices and especially electricity trade in the Baltic countries. With transmission expansion, the demand weighted average prices in the Baltic countries increase from 62 €/MWh to 65 €/MWh and 70 €/MWh with and without nuclear power in Sweden, respectively. If transmission is expanded, phasing out nuclear power in Sweden can increase the revenue from electricity export by over 100% for the Baltic countries. However, significant new investment in wind power is required
Phase-based Ranging in Narrowband Systems with Missing/Interfered Tones
The growth in the number of low-cost narrow band radios such as Bluetooth low
energy (BLE) enabled applications such as asset tracking, human behavior
monitoring, and keyless entry. The accurate range estimation is a must in such
applications. Phase-based ranging has recently gained momentum due to its high
accuracy in multipath environment compared to traditional schemes such as
ranging based on received signal strength. The phase-based ranging requires
tone exchange on multiple frequencies on a uniformly sampled frequency grid.
Such tone exchange may not be possible due to some missing tones, e.g.,
reserved advertisement channels. Furthermore, the IQ values at a given tone may
be distorted by interference. In this paper, we proposed two phase-based
ranging schemes which deal with the missing/interfered tones. We compare the
performance and complexity of the proposed schemes using simulations,
complexity analysis, and two measurement setups. In particular, we show that
for small number of missing/interfered tones, the proposed system based on
employing a trained neural network (NN) performs very close to a reference
ranging system where there is no missing/interference tones. Interestingly,
this high performance is at the cost of negligible additional computational
complexity and up to 60.5 Kbytes of additional required memory compared to the
reference system, making it an attractive solution for ranging using
hardware-limited radios such as BLE
Marching toward implementation of an ultra-high density dynamic perfusion process
Please click Additional Files below to see the full abstract
Array Configuration Effect on the Spatial Correlation of MU-MIMO Channels in NLoS Environments
In this paper, three different base-station antenna (BSA) configurations are compared in terms of inter-user spatial correlation in a two dimensional (2D) non-line-of-sight (NLoS) environment. The three configurations are: (i) a regular uniform linear array (ULA); (ii) a periodic sparse array; and (iii) an aperiodic sparse array. Electromagnetic modeling of the NLoS channel is proposed where scatterers are considered as resonant dipoles confined in clusters of scatterers (CoSs). While the probability of facing highly correlated user-equipments (UEs) in a multi-user multiple-input multiple-output (MU-MIMO) system is decreasing as the richness of mutipath increases, the sparsity (increased inter-element spacing) is seen to be capable of reducing this probability as well. This is due to the larger spatial variations experienced by the sparse array. Moreover, the results show that further improvement can be achieved by deploying an aperiodic distribution of antenna elements into the sparse antenna aperture
Insulin adherence in patients with diabetes: Risk factors for injection omission
Aims The purpose of this study was to evaluate adherence to insulin therapy in patients with diabetes. The underlying factors affecting insulin injection omission among patients with type 1 or 2 diabetes were also investigated. Methods This cross-sectional study has been conducted on 507 patients with diabetes. Adherence to insulin therapy was measured by the 8-Item Moriskey Medication Adherence Scale (MMS) and the autocompliance method. Furthermore, socio-demographic, disease and injection-related barriers to insulin injection were assessed. Results Based on the Morisky Green test, 14.3 and 28.8 of patients with type 1 and 2 diabetes respectively had low adherence to insulin therapy. However, almost all patients were adherent according to the autocompliance method. Different factors showed a significant association with insulin compliance in both groups. Conclusions The current study suggests acceptable adherence to insulin therapy among patients with type 1, and poor adherence in patients with type 2, diabetes. Our findings regarding barriers with significant effect on insulin adherence may be useful to identify patients at risk for low compliance, and to guide the design of proper strategies to improve adherence and the consequential clinical outcomes. © 2014 Primary Care Diabetes Europe. Published by Elsevier Ltd. All rights reserved
Cell Partitioning Antenna System Performance in Multi-User Scenarios for mmWave Communications
Fixed-beam, high-gain antenna systems can be used for a finer partitioning of the currently used cell-sectoring. This partitioning has the benefit of reducing the number of users seen per antenna beam, which reduces interference. Furthermore, the high antenna gain allows for a high effective isotropic radiated power while keeping the transmit power low. In this paper, we study the performance of such a fixed-beam, high gain antenna system design for millimeter-wave mobile communications. The antenna system is designed to keep the inter-sector interference in a multi-site scenario low. The performance is analyzed for single- and multi-user environments. In single-input single-output mode, the 50th percentile of the signal-to-interference-plus-noise ratio lies between 12.5 dB to 39.7 dB if 3 to 0 interferers are present, respectively. For multiple-input multiple-output transmission using zero-forcing, the signal-to-interference-plus-noise ratio increases and the 50th percentile ranges from 36.1 dB to 43.3 dB if 3 to 0 interferes are present, respectively. By using maximum ratio transmission, the best performance is achieved with no interferers present, while a plunge in performance is observed with interferers. Furthermore, the study revealed that the narrow beam antenna system can also provide a clear signal separation for small spatial separations. In the given example, the signal-to-interference-plus-noise ratio is larger than 32.1 dB with 11 active antenna elements, where 2.8 meters separate the users. Hence, the paper shows that the cell-partitioning antenna systems provide coverage in the desired area while keeping the inter-sector interference low, and the considered transmission techniques can be used for situation optimized mobile communication links
Trade-off Curves and Elasticity Analysis in Multi Fuel Options System and Combined Problem
Recent environmental concerns and policies have reformulated the traditional economic dispatch problem by including the emission impacts in the mathematical model. The combined economic and emission dispatch problem is a multi-objective non-linear optimization problem. This paper presents a method to consider the fuel costs and environmental emissions simultaneously. The -constraint method for bi-objective optimization has been used to generate Pareto front. Furthermore, trade-off curves have been developed for different types of emission. The elasticity of cost with respect to the emission (say, emission elasticity) has been estimated for all Pareto optimal points and different types of emissions that provides invaluable information for the system operator to run the system with sufficient flexibility subject to technical constraints while the operator has multi fuel options. Moreover, the emission elasticity is effective tool for competition in the electricity market. The Iranian Electricity Market is considered as empirical evidence.
Keywords: Combined economic-emission dispatch, Emission elasticity, Iranian electricity market, Multi objective optimization model, ε-Constraint.
JEL Classifications: C6, F64, P48,
Medication Errors in an Emergency Department in a Large Teaching Hospital in Tehran
Medication errors have important effects on increased length of hospitalization, increased
mortality and costs. We assessed the incidence of medication errors and characterize the error
types in an emergency department in a large teaching hospital in Tehran. We also investigated
the effect of Emergency Department pharmacists on patient safety with regard to recovery
of potentially harmful medication errors. The study was conducted in the 24 bed emergency
department from February to March, 2010 at a 600-bed teaching hospital. Two hospital
pharmacists and two clinical pharmacy residents observed care provision and collected data on
medication errors. Demographic data, type of medication error, the recorded stage of error, date
and time of occurrence and report, who made the error, probability of error were recorded from
medical records. We used chi-squared and independent sample t- tests for analyzing the data.
We recorded 203 medication errors during 180 hours. The incidence of medication errors
was 50.5% at various levels in the emergency department. Significant difference in age means
was seen between the patients with and without medication errors. Seventy four point nine
percent of errors were recorded as definitely an error. Most recorded errors were made by
nurses (44.5%) and occurred in administrating stage (63.6%). Given that the rate of the errors
was relatively high, it seems that the presence of clinical pharmacist can be beneficial
- …