5,092 research outputs found
A Comparative Study of Optimization- and Rule-Based Control for Microgrid Operation
As local renewable energy based generation units
are being deployed worldwide, distribution grids are facing integration
challenges. Here, microgrids provide a solution, by allowing
intentional islanding and connection to the public distribution
grid depending upon its current state. Microgrids may consist of
loads, generation units and storages which can be operated as
a single controllable entity. This paper investigates two control
approaches for cost-efficient operation of grid-connected microgrids:
optimization- and rule-based control. For optimizationbased
control, a model predictive control algorithm with mixed
integer linear programming formulation is used. A case study
for a microgrid in an office building consisting of distributed
generation units and different storage units is presented to assess
the performance of the two control approaches. The simulation
results show the effectiveness of the optimization-based approach
and a potential for lower microgrid operating costs compared to
the rule-based approach
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Population History and Gene Divergence in Native Mexicans Inferred from 76 Human Exomes.
Native American genetic variation remains underrepresented in most catalogs of human genome sequencing data. Previous genotyping efforts have revealed that Mexico's Indigenous population is highly differentiated and substructured, thus potentially harboring higher proportions of private genetic variants of functional and biomedical relevance. Here we have targeted the coding fraction of the genome and characterized its full site frequency spectrum by sequencing 76 exomes from five Indigenous populations across Mexico. Using diffusion approximations, we modeled the demographic history of Indigenous populations from Mexico with northern and southern ethnic groups splitting 7.2 KYA and subsequently diverging locally 6.5 and 5.7 KYA, respectively. Selection scans for positive selection revealed BCL2L13 and KBTBD8 genes as potential candidates for adaptive evolution in Rarámuris and Triquis, respectively. BCL2L13 is highly expressed in skeletal muscle and could be related to physical endurance, a well-known phenotype of the northern Mexico Rarámuri. The KBTBD8 gene has been associated with idiopathic short stature and we found it to be highly differentiated in Triqui, a southern Indigenous group from Oaxaca whose height is extremely low compared to other Native populations
Channel-Hot-Carrier degradation of strained MOSFETs : A device level and nanoscale combined approach
Strained MOSFETs with SiGe at the source/drain regions and different channel lengths have been studied at the nanoscale with a conductive atomic force microscope (CAFM) and at device level, before and after channel-hot-carrier (CHC) stress. The results show that although strained devices have a larger mobility, they are more sensitive to CHC stress. This effect has been observed to be larger in short channel devices. The higher susceptibility of strained MOSFETs to the stress has been related to a larger density of defects close to the diffusions, as suggested by CAFM data
Recovery of the MOSFET and circuit functionality after the dielectric breakdown of ultra-thin high-k gate stacks
The reversibility of the gate dielectric breakdown in ultra-thin high-k dielectric stacks is reported and analyzed. The electrical performance of MOSFETs after the dielectric recovery is modeled and introduced in a circuit simulator. The simulation of several digital circuits shows that their functionality can be restored after the BD recovery
Estimation of Individual Micro Data from Aggregated Open Data
In this paper, we propose a method of estimating individual micro data from
aggregated open data based on semi-supervised learning and conditional
probability. Firstly, the proposed method collects aggregated open data and
support data, which are related to the individual micro data to be estimated.
Then, we perform the locality sensitive hashing (LSH) algorithm to find a
subset of the support data that is similar to the aggregated open data and then
classify them by using the Ensemble classification model, which is learned by
semi-supervised learning. Finally, we use conditional probability to estimate
the individual micro data by finding the most suitable record for the
probability distribution of the individual micro data among the classification
results. To evaluate the performance of the proposed method, we estimated the
individual building data where the fire occurred using the aggregated fire open
data. According to the experimental results, the micro data estimation
performance of the proposed method is 59.41% on average in terms of accuracy.Comment: 7 page
Current-limiting and ultrafast system for the characterization of resistive random access memories
Experimental verification of memristor-based material implication NAND operation
Memristors are being considered as promising devices for highly dense memory systems as well as the potential basis of new computational paradigms. In this scenario, and in relation with data processing, one of the more specific and differential logic functions is the material implication logic also named as IMPLY logic. Many papers have been published in this framework but few of them are related with experimental works using real memristor devices. In the paper authors show the verification of the IMPLY function by using Ni/HfO2/Si manufactured devices and laboratory measurements. The proper behavior of the IMPLY structure (2 memristors) has been shown. The paper also verifies the proper operation of a two-step IMPLY-based NAND gate implementation, showing the electrical behavior of the circuit in a cycling operation. A new procedure to implement a NAND gate that requires only one step is experimentally shown as well
Incidence of hypohidration in athletes and sedentary male adults with intellectual disability
El presente estudio descriptivo de tipo transversal se diseñó para
determinar el nivel de hidratación de deportistas con discapacidad intelectual y
su comparación con adultos sedentarios con la misma discapacidad.
Participaron 22 deportistas federados que realizan el mismo programa de
entrenamiento además de 22 adultos sedentarios ajustados en sexo, edad y
cociente de inteligencia. Los parámetros ensayados fueron la densidad urinaria
determinada mediante refractómetro así como la ingesta diaria de líquido adlibitum.
Este protocolo fue aprobado por un Comité de Ética Institucional.
Tan solo 6 deportistas (21,6%) presentaron valores de euhidratación
frente a 9 (40,9%) de los participantes sedentarios incluidos en el grupo control.
Las únicas diferencias significativas respecto a la ingesta de líquidos se
estableció precisamente entre deportistas y sedentarios con euhidratación.
Se concluye que los deportistas con discapacidad intelectual se
encuentran en riesgo de deshidratación que podría explicarse, al menos en
parte, por una insuficiente ingesta hídricaThe current study was designed to determine hydration status of well-trained,
male athletes with ID. A secondary purpose was to compare these results with
hydration status of sedentary young adults with ID.
A total of 22 athletes with ID volunteered for this cross-sectional, descriptive
study. The control group included 22, age, sex and IQ-matched sedentary
adults with ID. Main outcome measurements were urine specific gravity (USG)
and daily fluid intake for three consecutive days.
With regard to athletes with ID, it was found that 5 participants (21,7%) stayed
significantly hypohydrated, 12 athletes (52,2%) appeared hypohydrated and 6
participants (26,1%) stayed euhydrated. In fact, a significantly lower percentage
of athletes was euhydrated when compared to sedentary matched adults with
ID (26,1vs.40,9%;χ2=5,67;p<001).
In conclusion, athletes with ID are at increased risk of dehydration that may be
explained, at least in part, given that ad-libitum fluid consumption was
insufficien
Testing behavioral interventions to optimize participation in a population-based colorectal cancer screening program in Catalonia
The aim of the study was to measure the effect of three cost-neutral behavioral interventions on participation compared to the standard invitation letter in a population-based colorectal cancer screening program in 2014. For that purpose, a four-arm randomized field trial was conducted among 5077 individuals aged 50 to 69 years. Over an 8-week period, each week was randomly allocated to the intervention or the control conditions. Individuals assigned to the intervention conditions additionally received a prompt to write down the date to pick up the screening test in a pharmacy. Two of the three intervention groups also included an additional paragraph in the invitation letter on either: 1) the high proportion of individuals participating regularly (social norms condition) or 2) the importance of regular participation (benefit condition). We measured screening participation before and after receiving a reminder letter six weeks after the screening invitation. An overall 8.0 percentage point increase in CRC screening was achieved as a direct result of receiving a reminder letter; however none of the intervention strategies influenced participation. The only significant difference was found for newly invited individuals. There, participation rates decreased from 34.9% to 24.2% when the invitation mailing mentioned the importance of regular participation (OR: 0.60; 95% CI: 0.38-0.95). While none of the intervention strategies improved participation rates we found that praising the benefit of regular screening may discourage individuals who have never been invited before as the continuous behavior may be perceived as a large request. Nevertheless, the reminder letter boosted participation rates independently of the intervention assigned
Ownership and control in a competitive industry
We study a differentiated product market in which an investor initially owns a controlling stake in one of two competing firms and may acquire a non-controlling or a controlling stake in a competitor, either directly using her own assets, or indirectly via the controlled firm. While industry profits are maximized within a symmetric two product monopoly, the investor attains this only in exceptional cases. Instead, she sometimes acquires a noncontrolling stake. Or she invests asymmetrically rather than pursuing a full takeover if she acquires a controlling one. Generally, she invests indirectly if she only wants to affect the product market outcome, and directly if acquiring shares is profitable per se. --differentiated products,separation of ownership and control,private benefits of control
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