885 research outputs found
Freight Rates and Productivity Gains in British Tramp Shipping 1869-1950
The standard source for pre-WWII global freight rate trends is the Isserlis British tramp shipping index. We think it is flawed, and that its sources offer vastly more information than the Isserlis aggregate contains. The new data confirm the precipitous decline in nominal freight rates before the World War I, but it also extends the series to the 1940s. Furthermore, our new series is linked to the post-World War II era (documented by David Hummels), so that we can be more precise about what has happened over the very long run. We also create route-specific deflators by using the prices of commodities transported. Previous scholars have deflated their nominal freight rate indices by a price index that includes tradables not carried on all routes and non-tradables not carried on any route. Our deflated indices offer a more effective measure of the contribution of declining freight rates to commodity-price convergence across trading regions. Using the pricedual method and new indices for factor prices, we then calculate total factor productivity growth pre-war and interwar for five global routes. Finally, we identify the sources of the total factor productivity growth.
Quantum Revivals in Periodically Driven Systems close to nonlinear resonance
We calculate the quantum revival time for a wave-packet initially well
localized in a one-dimensional potential in the presence of an external
periodic modulating field. The dependence of the revival time on various
parameters of the driven system is shown analytically. As an example of
application of our approach, we compare the analytically obtained values of the
revival time for various modulation strengths with the numerically computed
ones in the case of a driven gravitational cavity. We show that they are in
very good agreement.Comment: 14 pages, 1 figur
Relationship between Human Resource Management Practices and Perceived Performance of Employees in Jordanian Hospitals
The relationship between human resource management (HRM) practices and organizational performance is an important topic in the organizational sciences, but little research examining this relationship in hospital settings has been conducted. This study aims to quantify the effects of HRM practices on employee performance in 5 hospitals in Jordan. A descriptive survey design was used, wherein data was collected from all the staff of each hospital using questionnaires. The data were analyzed using descriptive statistics and correlation and regression analyses. The results demonstrate that HRM practices have an impact on performance, that Jordanian hospitals do not have effective HRM practices, and that compensation has the greatest impact on increasing an employee’s level of performance. Keywords: Jordanian Hospitals, human resource management practices, hospital performance
Desain dan Pengembangan Backend Aplikasi Bantucari Menggunakan Microservices
BantuCari merupakan aplikasi untuk membantu seseorang apabila sedang kehilangan barang maupun menemukan barang. Aplikasi yang baik tentunya harus memiliki backend yang mumpuni. Salah satu cara untuk memnuhi backend mumpuni yakni dengan mengimplementasikan layanan microservices. Salah satu cara untuk membuktikan dengan pengujian stress test menggunakan aplikasi Apache JMeter dan dibandingkan dengan services lainnya seperti VPS dan Shared Hosting. Dengan menggunakan parameter response time, troughput, sent, receive dan error untuk mengetahui keunggulan microservices. Dan hasil yang didapatkan pada penelitian ini dengan penerapan microservices dan pengujian dengan skenario yang ditentukan, arsitektur microservices lebih unggul dibandingkan dengan layanan yang lainnya
On the degree conjecture for separability of multipartite quantum states
We settle the so-called degree conjecture for the separability of
multipartite quantum states, which are normalized graph Laplacians, first given
by Braunstein {\it et al.} [Phys. Rev. A \textbf{73}, 012320 (2006)]. The
conjecture states that a multipartite quantum state is separable if and only if
the degree matrix of the graph associated with the state is equal to the degree
matrix of the partial transpose of this graph. We call this statement to be the
strong form of the conjecture. In its weak version, the conjecture requires
only the necessity, that is, if the state is separable, the corresponding
degree matrices match. We prove the strong form of the conjecture for {\it
pure} multipartite quantum states, using the modified tensor product of graphs
defined in [J. Phys. A: Math. Theor. \textbf{40}, 10251 (2007)], as both
necessary and sufficient condition for separability. Based on this proof, we
give a polynomial-time algorithm for completely factorizing any pure
multipartite quantum state. By polynomial-time algorithm we mean that the
execution time of this algorithm increases as a polynomial in where is
the number of parts of the quantum system. We give a counter-example to show
that the conjecture fails, in general, even in its weak form, for multipartite
mixed states. Finally, we prove this conjecture, in its weak form, for a class
of multipartite mixed states, giving only a necessary condition for
separability.Comment: 17 pages, 3 figures. Comments are welcom
A Note on Normal Forms of Quantum States and Separability
We study the normal form of multipartite density matrices. It is shown that
the correlation matrix (CM) separability criterion can be improved from the
normal form we obtained under filtering transformations. Based on CM criterion
the entanglement witness is further constructed in terms of local orthogonal
observables for both bipartite and multipartite systems.Comment: 8 page
Adapted LZW Protocol for ECG Data Compression
خوارزمية الـ(LZW) هي واحدة من طرق ضغط البيانات المستخدمة في عدة تطبيقات كضغط بيانات تخطيط القلب الكهربائي( ECG) لتقليل حجمها مما يسهل عملية نقلها عبر الشبكة. بما ان بيانات الـ(ECG) الخاصة بالمرضى تنقل عبر الشبكة طول الوقت لذلك ظهرت الحاجة الى تقليل حجمها من اجل ضمان وصولها بالسرعة الممكنة لقاعدة البيانات. في هذه البحث نحن نهتم بطريقة الـ (LZW) التي هي واحدة من اهم واشهر طرق ضغط البيانات وقد اقترحنا بروتوكول لتحسين الطريقة التي تعتمدها خوارزمية الـ(LZW) في خزن المؤشرات الخاصة بالبيانات المضغوطة. البروتوكول المقترح يمكن ان يقلل حجم المؤشر لخوارزمية الـ(LZW). تم اعتماد خمس عينات اخذت من بنك المعلومات الخاص بـ(Physionet) لغرض اختبار البروتوكول المقترح. وقد اظهرت نتائج الاختبارت العملية ان البروتوكول المقترح يعطي نسبة ضغط افضل لبيانات الـ(ECG) مقارنة بطريقة الـ(LZW) الاصلية.Lempel–Ziv–Welch (LZW) is a data compression method, which is adopted by many applications likes Electrocardiography (ECG) data to reduce the size of transferred data. Because of the ECG data moves over the network all the time, which means there is a need to reduce its size to improve the network performance. In this paper, we concerned with the LZW method, which is one of the important and famous data compression method. We propose a protocol to improve the way in which the LZW saving an index for the compressed data. The proposed protocol could reduce the size of the index in LZW method. Five samples data groups provided by Physionet are used for evaluation. The experimental result shows that the proposed protocol can give best compression ratio compared with the original method
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