Interpretation of the variability of the <i>β</i> Cephei star <i>λ</i> Scorpii. I. The multiple character

We derive accurate values of the orbital parameters of the close binary β Cephei star λ Scorpii. Moreover, we present the first determination of the properties of the triple system to which λ Scorpii belongs. Our analysis is based on a time series of 815 high-resolution spectra, covering a timespan of 14 years. We find a close orbit of 5d.9525days (e=0.26) and a wide orbit of approximately 1082d days (e=0.23). The orbital parameters of the triple star and a spectrum synthesis lead us to conclude that the system is composed of two early-type B stars and a low-mass pre-main-sequence star rather than containing an ultra-massive white dwarf as claimed before. Our proposed configuration is compatible with population synthesis. The radial velocity variations of the primary allow us to confirm the presence of at least one pulsation mode with frequency 4.679410 c d-1 which is subject to the light-time effect in the triple system. A detailed analysis of the complex line-profile variations is described in a subsequent paper

Addition of 24‐hour heart rate variability parameters to the Cardiovascular Health Study stroke risk score and prediction of incident stroke: The Cardiovascular Health Study

Background Heart rate variability (HRV) characterizes cardiac autonomic functioning. The association of HRV with stroke is uncertain. We examined whether 24‐hour HRV added predictive value to the Cardiovascular Health Study clinical stroke risk score (CHS‐SCORE), previously developed at the baseline examination. Methods and Results N=884 stroke‐free CHS participants (age 75.3±4.6), with 24‐hour Holters adequate for HRV analysis at the 1994–1995 examination, had 68 strokes over ≤8 year follow‐up (median 7.3 [interquartile range 7.1–7.6] years). The value of adding HRV to the CHS‐SCORE was assessed with stepwise Cox regression analysis. The CHS‐SCORE predicted incident stroke (HR=1.06 per unit increment, P=0.005). Two HRV parameters, decreased coefficient of variance of NN intervals (CV%, P=0.031) and decreased power law slope (SLOPE, P=0.033) also entered the model, but these did not significantly improve the c‐statistic (P=0.47). In a secondary analysis, dichotomization of CV% (LOWCV% ≤12.8%) was found to maximally stratify higher‐risk participants after adjustment for CHS‐SCORE. Similarly, dichotomizing SLOPE (LOWSLOPE <−1.4) maximally stratified higher‐risk participants. When these HRV categories were combined (eg, HIGHCV% with HIGHSLOPE), the c‐statistic for the model with the CHS‐SCORE and combined HRV categories was 0.68, significantly higher than 0.61 for the CHS‐SCORE alone (P=0.02). Conclusions In this sample of older adults, 2 HRV parameters, CV% and power law slope, emerged as significantly associated with incident stroke when added to a validated clinical risk score. After each parameter was dichotomized based on its optimal cut point in this sample, their composite significantly improved prediction of incident stroke during ≤8‐year follow‐up. These findings will require validation in separate, larger cohorts. Keywords: autonomic nervous system, clinical stroke risk model, heart rate variability, prediction, predictors, risk prediction, risk stratification, strok

Integrated chance constraints: reduced forms and an algorithm

We consider integrated chance constraints (ICC), which provide quantitative alternatives for traditional chance constraints.We derive explicit polyhedral descriptions for the convex feasible sets induced by ICCs, for the case that the underlying distribution is discrete. Based on these reduced forms, we propose an efficient algorithm for this problem class. The relation to conditional value-at-risk models and (simple) recourse models is discussed, leading to a special purpose algorithm for simple recourse models with discretely distributed technology matrix. For both algorithms, numerical results are presented.

ALM model for pension funds : numerical results for a prototype model

A multistage mixed-integer stochastic programming model is formulated for an Asset Liability Management problem for pension funds. Since these models are too difficult to solve for realistically sized problems, a heuristic is described. Numerical results for several instances of a prototype model are presented and discussed.

Polymerization of ethylene oxide using yttrium isopropoxide

Well defined poly(ethylene oxide)s were prepared using yttrium isopropoxide as an initiator. End group analysis using 1H- and 13C NMR spectroscopy revealed that only polymers with isopropyl ether and hydroxyl end groups were produced. The molecular weight is controlled by the initial amount of initiator added and low polydispersity polymer (Mw/Mn ≈ 1.1) was isolated. Sequential polymerization indicated the suitability of this initiator for macromolecular engineering

Sistem Pakar Otomatisasi Standar Baku Mutu Limbah Pertambangan Nikel Menggunakan Algoritma Supervised Mechine

Metode buka tutup pintu pembuangan limbah secara manual berdasarkan hasil uji laboratorium membutuhkan waktu relatif lama. Ketika hasil uji laboratorium menyatakan proses pembuangan harus dihentikan, limbah yang tidak memenuhi standar kelayakan sudah ikut terbuang. Tujuan dari penelitian ini adalah untuk merancang sistem pakar menggunakan algoritma Supervised Learning untuk otomatisasi standar baku limbah pertambangan nikel, algoritma ini digunakan untuk mengklasifikasikan besaran nilai kandungan unsur dalam limbah, dan digunakan untuk mengoptimalkan proses penentuan kelayakan buang limbah. Algoritma ini bekerja setelah menerima data dalam bentuk nilai-nilai kandungan unsur yang dibangkitkan oleh sebuah aplikasi simulator yang mendeteksi kadar kandungan unsur dalam air limbah. Hasil analisis tersebut digunakan untuk menentukan kelayakan pembuangan limbah. Dari 11 unsur yang dianalisis tujuh unsur memiliki bobot nilai tertinggi dalam setiap pengukuran yaitu pH, TSS, Cu, Zn, Cr(6+), Cr Total, dan Fe., sementara Support Vector Machine hanya empat unsur yang memiliki nilai bobot tertinggi dari setiap pengukuran, yaitu unsur Cd, Pb, Ni dan C

Strongly nonexponential time-resolved fluorescence of quantum-dot ensembles in three-dimensional photonic crystals

We observe experimentally that ensembles of quantum dots in three-dimensional (3D) photonic crystals reveal strongly nonexponential time-resolved emission. These complex emission decay curves are analyzed with a continuous distribution of decay rates. The log-normal distribution describes the decays well for all studied lattice parameters. The distribution width is identified with variations of the radiative emission rates of quantum dots with various positions and dipole orientations in the unit cell. We find a striking sixfold change of the width of the distribution by varying the lattice parameter. This interpretation qualitatively agrees with the calculations of the 3D projected local density of states. We therefore conclude that fluorescence decay of ensembles of quantum dots is highly nonexponential to an extent that is controlled by photonic crystals

Perancangan Sistem Informasi Perpustakaan Berbasis Clien Server pada Universitas Pejuang Republik Indonesia (UPRI) Makassar

Penggunaan teknologi informasi dewasa ini dipandang telah menjadi suatu kebutuhan yang pada saat ini dirasakan sangat penting, disamping digunakan sebagai sarana komunikasi juga sebagai sarana pertukaran informasi. Teknologi informasi telah memudahkan hampir di setiap aktivitas manusia, Tuntutan kebutuhan akan informasi dan penggunaan komputer yang semakin banyak mendorong terbentuknya sebuah jaringan komputer yang mampu melayani berbagai kebutuhan tertentu dalam waktu yang bersamaan, khususnya pada sistem pengelolaan buku dapat dilakukan dengan baik, cepat dan efesien. Dengan adanya jaringan komputer, pengelolaan informasi dapat berlangsung lebih baik lagi, sehingga kebutuhan penggunaan beberapa jaringan komputer bersama-sama semakin diperlukan. Universitas Pejuang Republik Indonesia (UPRI) Makassar dengan jarak dan gedung yang terpisah di setiap Fakultas yang dalam proses pengelolaan data buku, peminjaman buku, pengembalian buku, dan proses lainnya masih menggunakan sistem manual sehingga informasi yang diperoleh mejadi tidak efektif. Tujuan dari penelitian ini adalah merancang suatu sistem informasi perpustakaan berbasis client server pada Universitas Pejuang Republik Indonesia (UPRI) Makassar, hasil penelitian menunjukan bahwa dengan diterapkannya sistem ini diharapkan dapat membantu para dosen, staff, pustakawan, pimpinan dan mahasiswa dalam proses pendataan buku, pencarian buku, peminjaman buku serta proses lainnya di setiap Fakultas dapat dilakukan secara efektif dan efesien, dengan dibuktikan dari hasil pengujian sistem dapat disimpulkan bahwa sistem yang dirancang sudah bebas dari kelahan logik