106 research outputs found

    Stability Optimization of Positive Semi-Markov Jump Linear Systems via Convex Optimization

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    In this paper, we study the problem of optimizing the stability of positive semi-Markov jump linear systems. We specifically consider the problem of tuning the coefficients of the system matrices for maximizing the exponential decay rate of the system under a budget-constraint. By using a result from the matrix theory on the log-log convexity of the spectral radius of nonnegative matrices, we show that the stability optimization problem reduces to a convex optimization problem under certain regularity conditions on the system matrices and the cost function. We illustrate the validity and effectiveness of the proposed results by using an example from the population biology

    On input-to-state stability verification of identified models obtained by Koopman operator

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    This paper proposes a class of basis functions for realizing the input-to-state stability verification of identified models obtained from the true system (assumed to be input-to-state stable) using the Koopman operator. The formulated input-to-state stability conditions are in the form of linear matrix inequalities. We also present extensions to relax the imposed restrictions on the basis functions. A numerical example is provided to demonstrate the efficacy of the proposed results

    Model Rute dan Peta Interaktif Posyandu di Kota Semarang Menggunakan Geolocation dan Haversine Berbasis Mobile Android

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    Users of mobile phones with android operating system is increasing from year to year as more affordable. Thisgives the potential use of mobile phones as a means of disseminating information. As the capital of Central Java,Semarang has a variety of health care facilities which include Posyandu is always used by the surroundingcommunity. However, not all locations Posyandu known by the public because they lack information about thelocation. It is necessary for the navigation application Posyandu in Semarang. The purpose of this research ishow to design the application model and the location of Posyandu in real time with the geolocation methods andformulas Haversine. The method used is the Systems Development Life Cycle. System analysis model using UseCase Diagrams, Activity Diagrams, Sequence Diagrams and Class Diagrams. Results of this research is theapplication of navigation map based on Android mobile can provide information about the existence of thelocation, route and distance Posyandu. Results of this application is important for people who need drivingdirections Posyandu location. With this application is expected the results will help the public to obtaininformation and the location of the neighborhood health center (posyandu) in the city of Semarang can be met

    The Central Domain of MCPH1 Controls Development of the Cerebral Cortex and Gonads in Mice

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    MCPH1 is the first gene identified to be responsible for the human autosomal recessive disorder primary microcephaly (MCPH). Mutations in the N-terminal and central domains of MCPH1 are strongly associated with microcephaly in human patients. A recent study showed that the central domain of MCPH1, which is mainly encoded by exon 8, interacts with E3 ligase βTrCP2 and regulates the G2/M transition of the cell cycle. In order to investigate the biological functions of MCPH1’s central domain, we constructed a mouse model that lacked the central domain of MCPH1 by deleting its exon 8 (designated as Mcph1 -Δe8). Mcph1 -Δe8 mice exhibited a reduced brain size and thinner cortex, likely caused by a compromised self-renewal capacity and premature differentiation of Mcph1 -Δe8 neuroprogenitors during corticogenesis. Furthermore, Mcph1 -Δe8 mice were sterile because of a loss of germ cells in the testis and ovary. The embryonic fibroblasts of Mcph1 -Δe8 mice exhibited premature chromosome condensation (PCC). All of these findings indicate that Mcph1 -Δe8 mice are reminiscent of MCPH1 complete knockout mice and Mcph1 -ΔBR1 mice. Our study demonstrates that the central domain of MCPH1 represses microcephaly, and is essential for gonad development in mammals

    United States Consumers’ Landscaping Expenditures: A Case of Garden and Lawn Care Services and Equipment

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    The economic downturns of 2007–09 and the COVID-19 pandemic affected most industries in the United States, including landscape services and equipment sales, and provoked both short-term disruptions and long-term changes. To understand how the landscaping industry has responded, we investigated patterns of consumer expenditures on landscape services and equipment from 2009 through 2021 using a representative sample of 76,895 US households. We categorized US households as detached single-family residents and townhouse residents to more fully articulate the factors that turned potential consumers into purchasers and the factors that affected purchasers’ expenditures. We used a double-hurdle model to identify key factors that drive consumer demand for landscape services and equipment over time, including social-demographics, geographic characteristics, housing conditions, year and seasonal trends, and the COVID-19 pandemic. We found that during the studied period, the demand for landscape services declined in terms of both the percentage of consumers purchasing the services and the purchasers’ average expenditures, while the demand for do-it-yourself (DIY) equipment remained relatively unchanged. In response to the COVID-19 pandemic, the percentage of consumers who purchased landscape services increased, while the expenditures on landscape services decreased in 2020 and then began to rebound in 2021, but not enough to reverse the overall downward trend. In contrast, purchases of DIY equipment were relatively stable in response to the COVID-19 pandemic and mainly relied on current consumers

    Relationships between Landscape Patterns and Hydrological Processes in the Subtropical Monsoon Climate Zone of Southeastern China

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    With rapid economic development, extensive human activity has changed landscape patterns (LPs) dramatically, which has further influenced hydrological processes. However, the effects of LPs changes on hydrological processes, especially for the streamflow–sediment relationship in the subtropical monsoon climate zone, have not been reported. In our study, 10 watersheds with different sizes in the subtropical monsoon climate zone of southeastern China were chosen as the study area, and the effect of the 14 most commonly used landscape metrics (LMs) on 4 typical hydrological indices (water yields (WY), the runoff coefficient (RC), the soil erosion modulus (SEM), and the suspended sediment concentration (SSC)) were analyzed based on land use maps and hydrological data from 1990 to 2019. The results reveal that the LP characteristics within the study area have changed significantly. The number of patches and landscape shape indices were significantly positively correlated with watershed size (p &lt; 0.01). For most watersheds, the largest patch index was negatively correlated with WY, RC, and SEM, and the perimeter area fractal dimension was positively correlated with WY, RC, SEM, and SSC. The effects of several LMs on the hydrological indices had scale effects. WY/RC and the interspersion and juxtaposition index were negatively correlated in most larger watersheds but were positively correlated in most smaller watersheds. Similar results were found for Shannon’s diversity/evenness index and SEM. In general, an increase in a small patch of landscape and in landscape diversity would increase WY, the fragmentation of LPs would result in more soil erosion, and LPs would affect the relationship between streamflow and sediment yield. As a result, a proper decrease in landscape fragmentation and physical connectivity in the subtropical monsoon climate zone of southeastern China would benefit soil erosion prevention. These results enhance the knowledge about the relationship between LPs and hydrological processes in the subtropical monsoon climate zone of southeastern China and benefit local water and soil conservation efforts.</p
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