The Study of Returns to Private Investment in Higher Education from the Point of Employment

The quantitative methods are used to compare the difference of vocation and employment between the university graduates and high school graduates, which including the secondary school graduates. And the following four respects are involved to describe the impact of higher education to employment: the relative concentration degree, the difference of vocation, the weekly working time and the working industry. So we come to the conclution from the aspect of employment that private investment gets not only great market returns but also nonmarket returns. Key words: higher education; private investment; non-market returns; employment Résumé: Les méthodes quantitatives sont utilisées pour comparer les différences dans la vacation et dans le type de travail entre les diplômés des universités et les diplômés des collèges, y compris les écoles secondaires. Les quatre aspects suivants sont impliqués pour décrire l’impact d’une éducation supérieure sur l’emploi : le degré de concentration relatif, les différences de vocation, les heures de travail hebdomadaires, et le type de l’industrie dans lequelle ils travaillent. Du point de vue de l’emploi, nous arrivons à la conculsion que l’investissment privé peut obtenir non seulement des rendements du marché mais aussi des rendements qui ne proviennent pas du marché. Mots-Clés: enseignement supérieur; investissement supérieur; rendements qui ne proviennent pas du marché; emplo

Data-Driven 3D Placement of UAV Base Stations for Arbitrarily Distributed Crowds

In this paper, we consider an Unmanned Aerial Vehicle (UAV)-assisted cellular system which consists of multiple UAV base stations (BSs) cooperating the terrestrial BSs. In such a heterogeneous network, for cellular operators, the problem is how to determine the appropriate number, locations, and altitudes of UAV-BSs to improve the system sumrate as well as satisfy the demands of arbitrarily flash crowds on data rates. We propose a data-driven 3D placement of UAV-BSs for providing an effective placement result with a feasible computational cost. The proposed algorithm searches for the appropriate number, location, coverage, and altitude of each UAV-BS in the serving area with the maximized system sumrate in polynomial time so as to guarantee the minimum data rate requirement of UE. The simulation results show that the proposed approach can improve system sumrate in comparison with the case without UAV-BSs.Comment: 6 pages, 3 figures, accepted by 2019 IEEE Global Communications Conference: Wireless Communications (Globecom2019 WC

Irreversibility at macromolecular scales in the flake graphite of the lithium-ion battery anode.

Charging a commercial lithium-ion battery intercalates lithium into the graphite-based anode, creating various lithium carbide structures. Despite their economic importance, these structures and the dynamics of their charging-discharging transitions are not well-understood. We have videoed single microcrystals of high-quality, natural graphite undergoing multiple lithiation-delithiation cycles. Because the equilibrium lithium-carbide compounds corresponding to full, half, and one-third charge are gold, red, and blue respectively, video observations give direct insight into both the macromolecular structures and the kinematics of charging and discharging. We find that the transport during the first lithiation is slow and orderly, and follows the core-shell or shrinking annuli model with phase boundaries moving at constant velocities (i.e. non-diffusively). Subsequent lithiations are markedly different, showing transport that is both faster and disorderly, which indicates that the initially pristine graphite is irreversibly and considerably altered during the first cycle. In all cases deintercalation is not the time-reverse of intercalation. These findings both illustrate how lithium enters nearly defect-free host material, and highlight the differences between the idealized case and an actual, cycling graphite anode

Out-of-hospital Cardiac Arrest in the Elderly

SummaryBackgroundTo investigate the characteristics of out-of-hospital cardiac arrest (OHCA) in the elderly, we retrospectively studied a 6-month series of cases in an emergency department (ED) of a medical center in northern Taiwan.MethodsThere were 145 OHCA cases sent to our ED from January 1, 2007 to June 30, 2007. Of these, 28 traumarelated and five pediatric cases were excluded, and 112 cases were eventually enrolled into our study. The 112 cases were divided into an elderly group (≥ 65 years) of 81 cases and a non-elderly group of 31 cases. There were 64 males and 48 females (male/female ratio, 1.33:1) aged 24–99 years. We collected the laboratory data and made comparisons between the elderly and non-elderly group in arterial blood gas, hemoglobin, potassium, glucose, and troponin I. We used the statistical software SPSS version 11.5.0 (SPSS Inc., Chicago, IL, USA) with t test analysis. The clinical significance was set at p < 0.05.ResultsReturn of spontaneous circulation (ROSC) occurred in 46 cases (41%) after standard resuscitation by advanced cardiac life support. The elderly group had a higher ROSC rate than the non-elderly group, but this was not significant (44% vs. 32%; p = 0.335). The elderly group had less acidosis, less hypercapnia, less hyperkalemia, less hyperglycemia and a higher rate of elevated troponin I than the non-elderly group, but the differences were not significant. The elderly group had significantly lower hemoglobin levels than the non-elderly group (10.52 ± 3.04 vs. 12.6 ± 3.32g/dL; p = 0.003). The glucose levels of the ROSC group were significantly higher than the non-ROSC group in the elderly (230.14 ± 130.4 vs. 195.1 ± 147.7mg/dL; p = 0.049). In the group of acute coronary syndrome (ACS)-related OHCA, the ROSC rate in the elderly group was significantly higher than that of the non-elderly (54.2% vs. 40%; p = 0.014). The elderly group had a slightly lower rate of survival than the non-elderly group (7.4% vs. 9.7%; p = 0.159).ConclusionThe elderly OHCA cases had an anemic status. The elderly had a higher ROSC rate in cases with relative hyperglycemia and ACS-related OHCA. This finding provides us with the theory of trialing administration of glucose water during resuscitation in OHCA cases

Ruptured Aortic Aneurysm Presenting as a Stridor

SummaryStridor is an abnormal, high-pitched, whining breathing sound caused by a blockage in the throat or larynx that is usually heard in children. We describe an unusual case of an 81-year-old man brought to our emergency department with sudden onset of dyspnea and shortness of breath. Stridor could be heard without a stethoscope. We found a huge mass over the left upper chest on chest radiography, suggesting an aortic aneurysm. We believed that these symptoms were caused by a huge thoracic aortic aneurysm with trachea/bronchi compression. Chest computed tomography confirmed the diagnosis