Detection and categorization of severe cardiac disorders based solely on pulse interval measurements

Cardiac disorders are common conditions associated with a high mortality rate. Due to their potential for causing serious symptoms, it is desirable to constantly monitor cardiac status using an accessible device such as a smartwatch. While electrocardiograms (ECGs) can make the detailed diagnosis of cardiac disorders, the examination is typically performed only once a year for each individual during health checkups, and it requires expert medical practitioners to make comprehensive judgments. Here we describe a newly developed automated system for alerting individuals about cardiac disorders solely based on pulse interval measurements. For this purpose, we examined two metrics of heart rate variability (HRV) and analyzed 1-day ECG recordings of more than 1,000 subjects in total. We found that a newly introduced metric of local variation was more efficient than conventional HRV metrics for detecting premature contraction, and furthermore, that a suitable combination of the old and new metrics resulted in much superior detectability particularly for atrial fibrillation, which requires more attention. Even with a 1-minute recording of pulse intervals, our new detection system had a diagnostic performance even better than that of the conventional analysis method applied to a 1-day recording.

An Elegant Method of Analysis for the BJT Amplifiers using Floating Admittance Matrix

The Floating Admittance Matrix (FAM) is an elegant, neat, illustrative, and simplified technique for analyzing all configurations of the BJT amplifiers, starting with the maneuvering of the FAM of the phase-splitter circuit. The conventional analysis method requires a small-signal equivalent circuit, and then conventional tools, either KCL, KVL, or Thevenin, Norton, etc., are used for the analysis. The researcher has to guess which conventional tool suites better than the other for any particular circuit, whether active or passive. The proposed technique is equally ell useful for all circuits. In the FAM method, once the device matrix is known rest of the circuit can be embedded in it by inspection. The sum property of this matrix provides a check to know whether FAM has been written correctly to proceed further.

Compression with unified and accessible byte blocks to enhance management and analyses of UKBB-scale genotypes

Whole-genome sequencing projects of millions of persons contain enormous genotypes, entailing a huge memory burden and time overhead during computation. Here, we introduce Genotype Blocking Compressor (GBC), a method for rapidly compressing large-scale genotypes into a fast-accessible and highly parallelizable format. We demonstrate that GBC has a competitive compression ratio to help save storage space. Furthermore, GBC is the fastest method to access and manage compressed large-scale genotype files (sorting, merging, splitting, etc.). Our results indicate that GBC can help resolve the fundamental problem of time- and space-consuming computation with large-scale genotypes, and conventional analysis would be substantially enhanced if integrated with GBC to access genotypes. Therefore, GBC's advanced data structure and algorithms will accelerate future population-based biomedical research involving big genomics data.

PERBANDINGAN DEFORMASI DINDING PADA BASEMENT METODE TOP-DOWN DENGAN ANALISIS CONSTRUCTION STAGE DAN ANALISIS KONVENSIONAL

ABSTRACT In basement construction with the top-down approach, excavation and slab installation work are carried out in stages. However, not all geotechnical applications can simulate construction stages, hence this effect has been ignored by many engineers in practice. Therefore, in this study, the effect of basement construction stages is analyzed using MIDAS GTS NX. In the program, two different analyses are performed. The first analysis is the construction stage analysis that simulates construction stages. As a comparison, a conventional analysis is performed which doesn't simulate construction stages. The two analysis results are compared. This analysis focuses mainly on the wall deformation. The modeling consists of 5 excavation stages (17 meters deep) and a diaphragm wall (36 meters deep). The walls are given 5 layers of slab reinforcements. In the first excavation stage, the maximum wall deformation results in both analyses show slightly different results (the construction stage analysis result is 8% greater than that of conventional analysis). However, in the final excavation stage, a significant difference is shown (the construction stage analysis result is 37% greater than that of conventional analysis). These results indicate that the effect of construction stages should not be neglected, especially in multi-story basements with top-down construction.ABSTRAK Pada konstruksi basement dengan metode top-down, pekerjaan penggalian dan pemasangan pelat dilakukan secara bertahap. Namun, tidak semua aplikasi geoteknik dapat mensimulasikan tahapan konstruksi sehingga pengaruhnya sering diabaikan oleh banyak insinyur dalam praktiknya. Maka, pada penelitian ini dilakukan analisis pengaruh tahapan konstruksi basement menggunakan aplikasi MIDAS GTS NX. Pada program, akan dilakukan dua analisis yang berbeda. Pertama, dilakukan analisis construction stage yang mensimulasikan tahapan konstruksi. Sebagai perbandingan, dilakukan analisis konvensional yang tidak mensimulasikan tahapan konstruksi. Kedua hasil analisis dibandingkan. Analisis ini lebih berfokus pada deformasi yang terjadi pada dinding diafragma. Pemodelan terdiri dari 5 tahap galian dengan kedalaman 17 meter dan dinding diafragma dengan kedalaman 36 meter. Dinding diberi perkuatan pelat sebanyak 5 lapis. Pada galian tahap pertama, hasil deformasi maksimum dinding pada kedua analisis menunjukkan hasil yang tidak jauh berbeda (hasil analisis construction stage lebih besar 8% dibandingkan hasil analisis konvensional). Tetapi pada galian tahap akhir, hasil deformasi maksimum dinding pada kedua analisis menunjukkan perbedaan signifikan (hasil analisis construction stage lebih besar 37% dibandingkan hasil analisis konvensional). Hasil ini menunjukkan bahwa pengaruh tahapan konstruksi sebaiknya tidak diabaikan khususnya pada basement bertingkat banyak dengan metode top-down.

Estimating Fair Market Value of Petroleum Assets in Nigeria: A Risk-Based Approach

Many independent Nigerian oil & gas companies have emerged over the last decade out ofthe divestments of ageing petroleum assets by multinational oil companies. Thesetransactions are marked by pervasive cases of overvaluation and huge gap in offers that leadto unnecessarily high acquisition costs. Petroleum analysts around the world adopt the Discounted Cashflow Analysis method forestimating present value of future oil production revenues. Unfortunately, project economicsusing conventional analysis does not de-risk the reserves components appropriately oraccount for the excess and political risk premiums. Even when analysts derive the NetPresent Value from conventional evaluation, say at discount rates of say 10% or 15%, theyface the dilemma of extracting offer price from that figure. Some post a conservative offerbased on 50% NPV, while others throw in all the NPV in a scheme to win the bid at all cost. Some also start by guesstimating value by rule of thumb and then offer the NPV that is leftbehind. The decision to offer a given percentage of the NPV is entirely subjective and variesamongst investors and as such does not depict a logical perception of market value, or therisks thereof. Furthermore, by omitting political risk, buyers are invariably ignoring the mostcrucial risk of all. The adoption of different bases of reserves tend to compound the problemby yielding NPVs that are few and far between each other. They are usually based on un-risked ‘proved plus probable’ (2P) reserves, which is highly speculative and unrealistic forvaluation. For the first time, the concerns of high purchase price and offer gaps were debuggedleveraging the new Risk-Based Valuation approach which is based on a modified Discounted Cashflow model. A research deeply investigates the problems first by reconstructing originaltransaction to identify the root causes. Furthermore, the study concludes that buyers arepaying on average 4 times the value and that regulating reserves base is fundamental inorder to minimize offer gaps that sometimes tend to a billion dollars for large deals. Thus, the Risk-Based Discounted Cashflow Analysis technique can help prevent overpricing orunderpricing of Nigerian assets, minimize offer gaps in the market as well as account for theimpact of political risks (or its mitigation) in valuation.

Interpretation of pressure interference tests for wells connected by a large hydraulic fracture

Shale formations are being exploited in several places around the world. Thus, an adequate characterization of such formations is recommended. In this work, two interpretation methodologies—TDS technique and conventional analysis—are implemented for determining the fracture permeability, from interference tests, between two wells connected by a large hydraulic fracture. Therefore, equations have been developed for both interpretation techniques and tested with synthetic examples. The estimated fracture permeabilities closely match the values initially used for the simulation of the tests.

Pressure and reciprocal rate transient analysis for finite-conductivity vertical fractured hydrocarbon wells under trilinear flow

Hydraulic well fracturing has been an important practice for well stimulation along the history of the hydrocarbon industry. Therefore, accurate and practical assessment of the fracturing job should be of importance. Interpretation of well pressure and rate test data in vertical finite-conductivity fractured hydrocarbon wells by the TDS methodology and conventional analysis are presented in this paper. The accuracy and practicality of the developed equations are successfully tested with synthetical examples and a field case.

Ship Collision Analysis of Double Hull Structures in Various Ship Types

This paper elaborates the impact characteristics of double hull structures in various ship types including bulk carrier, container ship, LNG carrier and oil tanker. Their own structural configurations, such as the strengthened topside tank in the container ship, affect the crashworthiness of double hull structures in ship collisions. Two striking bows are modeled so as to evaluate the crashworthiness of the double hull structures. The calculations are performed using LS-DYNA to assess the impact characteristics of four struck ships. The ship collision analysis also discusses the assumption of rigid bow in conventional analysis and its effect on the evaluation of side structural crashworthiness. The numerical force-displacement responses and absorbed energy-displacement curves of various ships are compared. The comparison aims to reveal the discrepancy of the crashworthiness of the four typical double hull structures. It is of importance to analyze their structural characteristics for the design of crashworthy structures.

The SMRI-NIRS technology: development, validation and benefit

The Sugar Milling Research Institute NPC (SMRI) has developed a simple to use near-infrared spectroscopy (NIRS) transmission-based analysis method as an alternative to conventional methods for analysis of sugarcane factory stream samples. The technology provides rapid, simultaneous analysis of refractometric dry substance (rds), polarimetric sugar, sucrose, glucose, fructose, conductivity ash contents as well as colour and pH for all streams and additionally, dry solids for final molasses and eliminates the need for sample clarification chemicals. The analyte prediction equations were developed using conventional results of samples from 14 South African factories, analysed at SMRI using SANAS/ISO17025 accredited test methods, and NIRS scans of the same samples using up to 16 different NIRS instruments. The NIRS analyte prediction equations were validated against more than 1,500 independent factory samples that had been analysed by conventional methods of analysis, including samples from factories outside South Africa. The reproducibility of the NIRS results were equivalent to existing conventional analysis reproducibility values (juice and final molasses) and previously undocumented values determined for this study for conventional raw house analysis methods. Correlation coefficients of greater than 0.97 were recorded for all major analytes and greater than 0.9 for minor analytes when predicted results were compared against conventional results. A maintenance protocol was also developed to ensure that the prediction equations remain robust and can account for sample matrix variations that can occur from season to season. The SMRI-NIRS technology was installed at all 14 South African factories and found to be robust and give equivalent results to conventional methods of analysis.

Rapid detection of inter-clade recombination in SARS-CoV-2 with Bolotie

The ability to detect recombination in pathogen genomes is crucial to the accuracy of phylogenetic analysis and consequently to forecasting the spread of infectious diseases and to developing therapeutics and public health policies. However, in case of the SARS-CoV-2, the low divergence of near-identical genomes sequenced over a short period of time makes conventional analysis infeasible. Using a novel method, we identified 225 anomalous SARS-CoV-2 genomes of likely recombinant origins out of the first 87,695 genomes to be released, several of which have persisted in the population. Bolotie is specifically designed to perform a rapid search for inter-clade recombination events over extremely large datasets, facilitating analysis of novel isolates in seconds. In cases where raw sequencing data was available, we were able to rule out the possibility that these samples represented co-infections by analyzing the underlying sequence reads. The Bolotie software and other data from our study are available at https://github.com/salzberg-lab/bolotie.