Deep Neural Networks for Semiparametric Frailty Models via H-likelihood

For prediction of clustered time-to-event data, we propose a new deep neural network based gamma frailty model (DNN-FM). An advantage of the proposed model is that the joint maximization of the new h-likelihood provides maximum likelihood estimators for fixed parameters and best unbiased predictors for random frailties. Thus, the proposed DNN-FM is trained by using a negative profiled h-likelihood as a loss function, constructed by profiling out the non-parametric baseline hazard. Experimental studies show that the proposed method enhances the prediction performance of the existing methods. A real data analysis shows that the inclusion of subject-specific frailties helps to improve prediction of the DNN based Cox model (DNN-Cox)

Subject-specific Deep Neural Networks for Count Data with High-cardinality Categorical Features

There is a growing interest in subject-specific predictions using deep neural networks (DNNs) because real-world data often exhibit correlations, which has been typically overlooked in traditional DNN frameworks. In this paper, we propose a novel hierarchical likelihood learning framework for introducing gamma random effects into the Poisson DNN, so as to improve the prediction performance by capturing both nonlinear effects of input variables and subject-specific cluster effects. The proposed method simultaneously yields maximum likelihood estimators for fixed parameters and best unbiased predictors for random effects by optimizing a single objective function. This approach enables a fast end-to-end algorithm for handling clustered count data, which often involve high-cardinality categorical features. Furthermore, state-of-the-art network architectures can be easily implemented into the proposed h-likelihood framework. As an example, we introduce multi-head attention layer and a sparsemax function, which allows feature selection in high-dimensional settings. To enhance practical performance and learning efficiency, we present an adjustment procedure for prediction of random parameters and a method-of-moments estimator for pretraining of variance component. Various experiential studies and real data analyses confirm the advantages of our proposed methods

Implementation of the submarine diving simulation in a distributed environment

ABSTRACTTo implement a combined discrete event and discrete time simulation such as submarine diving simulation in a distributed environment, e.g., in the High Level Architecture (HLA)/Run-Time Infrastructure (RTI), a HLA interface, which can easily connect combined models with the HLA/RTI, was developed in this study. To verify the function and performance of the HLA interface, it was applied to the submarine dive scenario in a distributed environment, and the distributed simulation shows the same results as the stand-alone simulation. Finally, by adding a visualization model to the simulation and by editing this model, we can confirm that the HLA interface can provide user-friendly functions such as adding new model and editing a model

Investigation of the physicochemical features and mixing of East/Japan Sea Intermediate Water: An isopycnic analysis approach

We present spatial distributions of the mixing ratio and properties of the East/Japan Sea Intermediate Water (ESIW) at its core density layer (σθ = 27.2–27.3) based on high-quality hydrographic data observed in the East/Japan Sea (EJS) during summer 1999. ESIW is defined as a source water type showing minimum salinity and maximum dissolved oxygen concentration. ESIW plays an important role in supplying dissolved oxygen and transporting anthropogenic carbon into the intermediate/deep layers in EJS. Studying the ESIW formation and distribution processes may provide insights on EJS\u27s shallow- to mid-depth thermohaline circulation and recent ocean changes. Here, we combine the previously estimated mixing ratio of ESIW, based on Optimum Multi-Parameter (OMP) analysis, and its physicochemical properties, such as pressure, dissolved oxygen, and phosphate, interpolated onto several isopycnic surfaces (σθ = 27.20, 27.25, and 27.30). The physicochemical properties of ESIW show steep north-south gradients across the subpolar front at 40–41°N. Higher dissolved oxygen concentrations (≥335 μmol kg–1) of ESIW are found in the western Japan Basin particularly off the Primorye coast, indicating a potential source region. The spatial and depth distributions of apparent oxygen utilization (AOU) on the ESIW isopycnic surfaces indicate that the subduction of ESIW occurs at 131–133°E (Ulleung Basin) across the subpolar front to the south. The density layer of ESIW shoals near the Korean coast in the Ulleung Basin, implying a potential link to coastal upwelling. The relative age of ESIW at its core layer is estimated from the oxygen utilization rate and AOU. The correlation between the pCFC12 and relative ages, and AOU estimated at 90% surface water oxygen saturation condition suggests a decadal-scale ventilation of ESIW (≤24 years). Younger waters at the ESIW coexist with the high-salinity intermediate water at the same density layer in the eastern Japan Basin. Our analysis suggests that ESIW is sensitive to climate forcing and an important shallow- to mid-depth thermohaline circulation component of EJS

Automatic generation of equations of motion for multibody system in discrete event simulation framework

AbstractIn this paper, the development of a simulation program that can automatically generate equations of motion for mutibody systems in the discrete event simulation framework is presented. The need to analyze the dynamic response of mechanical systems that are under event triggered conditions is increasing. General mechanical systems can be defined as multibody systems that are collections of interconnected rigid bodies, consistent with various types of joints that limit the relative motion of pairs of bodies. For complex multibody systems, a systematic approach is required to efficiently set up the mathematical models. Therefore, a dynamics kernel was developed to automatically generate the equations of motion for multibody systems based on multibody dynamics. The developed dynamics kernel also provides the numerical solver for the dynamic analysis of multibody systems. The general multibody dynamics kernel cannot deal with discontinuous state variables, event triggered conditions, and state triggered conditions, though. To enable it to deal with multibody systems in discontinuous environments, the multibody dynamics kernel was integrated into a discrete event simulation framework, which was developed based on the discrete event system specification (DEVS) formalism. DEVS formalism is a modular and hierarchical formalism for modeling and analyzing systems under event triggered conditions, which are described by discontinuous state variables. To verify the developed program, it was applied to an block-lifting and transport simulation, and dynamic analysis of the system is carried out

SoEasy: A Software Framework for Easy Hardware Control Programming for Diverse IoT Platforms

Many Internet of Things (IoT) applications are emerging and evolving rapidly thanks to widespread open-source hardware platforms. Most of the high-end open-source IoT platforms include built-in peripherals, such as the universal asynchronous receiver and transmitter (UART), pulse width modulation (PWM), general purpose input output (GPIO) ports and timers, and have enough computation power to run embedded operating systems such as Linux. However, each IoT platform has its own way of configuring peripherals, and it is difficult for programmers or users to configure the same peripheral on a different platform. Although diverse open-source IoT platforms are widespread, the difficulty in programming those platforms hinders the growth of IoT applications. Therefore, we propose an easy and convenient way to program and configure the operation of each peripheral using a user-friendly Web-based software framework. Through the implementation of the software framework and the real mobile robot application development along with it, we show the feasibility of the proposed software framework, named SoEasy

Renal transplantation in a patient with Bartter syndrome and glomerulosclerosis

Bartter syndrome (BS) is a clinically and genetically heterogeneous inherited renal tube disorder characterized by renal salt wasting, hypokalemic metabolic alkalosis and normotensive hyperreninemic hyperaldosteronism. There have been several case reports of BS complicated by focal segmental glomerulosclerosis (FSGS). Here, we have reported the case of a BS patient who developed FSGS and subsequent end-stage renal disease (ESRD) and provided a brief literature review. The patient presented with classic BS at 3 months of age and developed proteinuria at 7 years. Renal biopsy performed at 11 years of age revealed a FSGS perihilar variant. Hemodialysis was initiated at 11 years of age, and kidney transplantation was performed at 16 years of age. The post-transplantation course has been uneventful for more than 3 years with complete disappearance of BS without the recurrence of FSGS. Genetic study revealed a homozygous p.Trp(TGG)610Stop(TGA) mutation in the CLCNKB gene. In summary, BS may be complicated by secondary FSGS due to the adaptive response to chronic salt-losing nephropathy, and FSGS may progress to ESRD in some patients. Renal transplantation in patients with BS and ESRD results in complete remission of BS

Hutchinson-Gilford Progeria Syndrome with G608G LMNA Mutation

Hutchinson-Gilford progeria syndrome (HGPS) is a rare condition originally described by Hutchinson in 1886. Death result from cardiac complications in the majority of cases and usually occurs at average age of thirteen years. A 4-yr old boy had typical clinical findings such as short stature, craniofacial disproportion, alopecia, prominent scalp veins and sclerodermatous skin. This abnormal appearance began at age of 1 yr. On serological and hormonal evaluation, all values are within normal range. He was neurologically intact with motor and mental development. An echocardiogram showed calcification of aortic and mitral valves. Hypertrophy of internal layer at internal carotid artery suggesting atherosclerosis was found by carotid doppler sonography. He is on low dose aspirin to prevent thromboembolic episodes and on regular follow up. Gene study showed typical G608G (GGC- > GGT) point mutation at exon 11 in LMNA gene. This is a rare case of Hutchinson-Gilford progeria syndrome confirmed by genetic analysis in Korea