Rank one chaos in a switch-controlled Chua's circuit

In this paper, we study the existence of strange attractors in a switch-controlled Chua's circuit. This circuit is obtained from the original Chua's circuit by adding externally controlled switches to it in such a way to modulate the system state variables. This investigation is conducted from the perspective of a recent chaos theory of rank one maps. The externally controlled switches are used for the purposes of realizing the general settings of the theory. Both synchronous and asynchronous switch control schemes providing periodic kicks in various directions are investigated, and their effects on the resulting chaotic attractors are discussed. The results of the numerical simulations presented are in close agreement with the expectations of the theory.     

Les Disparités d'alphabétisation et de scolarisation en Turquie

The struggle against illiteracy is a problem of great importance in Turkey as in many other countries. In Turkey the democratisation and secularisation of education have been a difficult process. Despite strong educational efforts in recent years, the country still presents various forms of inequality, such as considerable disparities between women and men, between town and country and between different regions. Unequal socio-economic, cultural and educational development, and attachment to cultural traditions are some of the factors that influence these inequalities. At the same time, Turkey is confronted by the sore problem of the education of linguistic minorities (especially the Kurds), who are not officially recognised as the cultural policy of Turkey aims to assimilate them. Thus, in the 1920s the Kurdish language was forbidden along with all languages other than Turkish, the official national language.     

真空预压技术对软粘土物理与力学属性影响的试验研究

研制了一套新三轴试验仪,该仪器能将堆载和真空加载在土样上,在固结进行中能同时监控超孔隙水压力、轴向应变(沉降)与体积应变.并根据浙江省温州市原状软粘土进行了固结试验,软粘土的天然含水率是72.5%.试验结果发现,真空预压、堆载预压或真空堆载联合预压3类加固方式中,粘土的固结特性没有明显差异.研究表明3种加固方法改变了软土的一些物理属性并改善了它的力学属性.     

Information security landscape and maturity level: Case study of Malaysian Public Service (MPS) organizations

Information protection is of paramount importance in today's world. From information involving the highest level of government administration and national security, to information existing at the level of the private company in the form of trade secrets or personal data, all are under the constant threat of being compromised. In this study, the researchers attempt to evaluate the information security maturity level and provide clear thoughtful analysis of the information security landscapes of the Malaysian Public Service (MPS) organizations. This study uses convenience sampling and the required data collected from 970 targeted individuals through a self-administrated survey. In addition, a survey questionnaire is utilized to gauge the security landscape and to further understand the occurrence of incidents, the sources of attack, and the types of technical safeguard. Findings revealed that the highest security incidents experienced by the MPS were spamming (42%), followed by attacks of malicious codes (41%). Twenty-five percent of incidents originated from within the organizations, 15% originated from outside, and 11% were from a mixture of internal and external sources. Also, it shows that 49% of incidents were from sources unknown to the respondents. The top most deployed safeguards by the MPS were found to be firewalls (95%), followed by anti-virus software (92%), and access control to information system (89%). Findings on the maturity level show that 61% of respondents are at Level 3, followed by 21% at Level 2 where the information security processes are still considered an Information and Communication Technology (ICT) domain. At the higher end of the continuum lies 13% for Level 4 and 1% at Level 5.     

对发展关中平原循环农业的认识与实践

循环农业是近年来提出的一种新的农业发展理念,其理论框架及支撑其理论体系的实践例证尚处于争鸣与建构中。陕西关中平原作为历史悠久的传统农业区,过去几十年来已建立起以冬小麦-夏玉米轮作制为特征的集约化农业生产,目前存在的最大问题是作物秸秆大都不能以合理方式返还农田。本文基于对关中地区农业发展现状的分析与思考,紧紧围绕循环农业所倡导的“4R”原则,提出以田块尺度的秸秆还田为主要纽带,以期连通农田生态系统中物质和能量的循环链,建立关中平原地区秸秆资源高效利用的农业循环生产模式和体系,为该区域农业可持续发展提供理论和现实依据。     

dc electrokinetic transport of cylindrical cells in straight microchannels

Electrokinetic transport of cylindrical cells under dc electric fields in a straight microfluidic channel is experimentally and numerically investigated with emphasis on the dielectrophoretic (DEP) effect on their orientation variations. A two-dimensional multiphysics model, composed of the Navier–Stokes equations for the fluid flow and the Laplace equation for the electric potential defined in an arbitrary Lagrangian–Eulerian framework, is employed to capture the transient electrokinetic motion of cylindrical cells. The numerical predictions of the particle transport are in quantitative agreement with the obtained experimental results, suggesting that the DEP effect should be taken into account to study the electrokinetic transport of cylindrical particles even in a straight microchannel with uniform cross-sectional area. A comprehensive parametric study indicates that cylindrical particles would experience an oscillatory motion under low electric fields. However, they are aligned with their longest axis parallel to the imposed electric field under high electric fields due to the induced DEP effect.     

An integrated group decision-making process for supplier selection and order allocation using multi-attribute utility theory and linear programming

Supplier selection is a complex multi-criteria problem including both quantitative and qualitative factors. In order to select the best suppliers it is necessary to make a trade-off between these factors, some of which may be in conflict and may also be uncertain. In this problem if suppliers have capacity or other different constraints, two problems will exist: which suppliers are best and how much should be purchased from each selected supplier.In this paper an integrated approach of multi-attribute utility theory (MAUT) and linear programming (LP) is proposed for rating and choosing the best suppliers and defining the optimum order quantities among selected ones in order to maximize total additive utility. A numerical example is proposed to illustrate an application of the proposed method.     

Normal delivery induced stress alters glutathione peroxidase and TNF-α in elderly primigravidas mononuclear cells

To probe the glutathione peroxidase (GPx) activity coupled to ROS and TNF-α levels in younger versus elderly primigravidas. Monocytes were isolated from blood of young and elderly primigravidas after 12 hrs, 24 hrs and 14 days postpartum. Age-matched healthy female donors served as controls. Thereafter, the above monocytes were subjected to evaluation of GPx activity, levels of pro-inflammatory cytokine TNF-α and reactivity/specificity towards anti-TNF-α antibody. Suppression in GPx activity with simultaneous enhancement of TNF-α levels in monocytes was observed after 12 hrs and 24 hrs of spontaneous labor pain-induced maternal delivery through normal vaginal route. Conversely, an enhancement of GPx activity and decrease in TNF-α levels were observed on day 14 of postpartum, thereby indicating reversal of the impaired neutralizing mechanisms. The antioxidant network combating ROS was stronger in younger primigravidas. Capability of TNF-α and ROS suppression was somewhat lesser in elderly primigravidas even 14 days of postpartum via normal vaginal route. The capability of GPx activity enhancement with simultaneous suppression in ROS and TNF-α, decreases in elderly primigravidas. This may act as one of the important parameters leading to a variety of complications encountered by elderly primigravidas.     

Optimized sliding mode current controller for power converters with non-minimum phase nature

This paper proposes a unified method to design an optimized type of the hysteresis modulation-based sliding mode current controller for non-minimum phase power converters in continuous conduction mode. The traditional sliding mode controlled converters have a slow transient voltage response at heavy loads, a large overshoot at light loads and during abrupt output resistance variations. To solve these problems, an optimized feedback control scheme is used according to the output resistance to adjust the coefficients of the controller. The basic idea of this controller is to suggest a new way for reduction of the sensitivity function amplitude of the closed loop system. The presented approach is developed for three basic DC/DC converters; i.e. boost, buck-boost and quadratic boost converters. Generally, the certain advantages of the suggested control approach are: (i) a fast transient response can be achieved in heavy load conditions, (ii) the voltage overshoot can be effectively reduced during load variations; (iii) the transient voltage overshoot can be eliminated in light load conditions; (iv) the closed loop control sensitivity can be reduced and therefore, the performance specification of a control system can be improved compared with the conventional sliding mode current control. To show the reliability of the suggested control scheme, simulations and experimental results for the derived systems are developed. Several conditions are performed to confirm the effectiveness of the proposed controller.