Discrete-time systems

In this article we introduce digital control and contrast it with analog control. Traditionally, control systems have been designed using analog techniques. But today, because of the explosive growth of digital technology, controllers are typically implemented as programmable digital hardware or as programs on digital computers. The concepts and techniques for analysis and design of digital controllers are the central concerns of this article. In this part we introduce discrete-time signals and provide examples. We also describe discrete-time systems in terms of difference equations and look at their solutions via transform methods.     

Discrete-time systems

In this part we analyze the discrete-time systems and suggest some intuitive design procedures. We survey the state-of-the-art digital control systems.     

Fabrication of rigid microstructures with thiol-ene-based soft lithography for continuous-flow cell lysis

In this work, we introduce a method for the soft-lithography-based fabrication of rigid microstructures and a new, simple bonding technique for use as a continuous-flow cell lysis device. While on-chip cell lysis techniques have been reported previously, these techniques generally require a long on-chip residence time, and thus cannot be performed in a rapid, continuous-flow manner. Microstructured microfluidic devices can perform mechanical lysis of cells, enabling continuous-flow lysis; however, rigid silicon-based devices require complex and expensive fabrication of each device, while polydimethylsiloxane (PMDS), the most common material used for soft lithography fabrication, is not rigid and expands under the pressures required, resulting in poor lysis performance. Here, we demonstrate the fabrication of microfluidic microstructures from off-stoichiometry thiol-ene (OSTE) polymer using soft-lithography replica molding combined with a post-assembly cure for easy bonding. With finite element simulations, we show that the rigid microstructures generate an energy dissipation rate of nearly 10⁷, which is sufficient for continuous-flow cell lysis. Correspondingly, with the OSTE device we achieve lysis of highly deformable MDA-MB-231 breast cancer cells at a rate of 85%, while a comparable PDMS device leads to a lysis rate of only 40%.     

Subtypes of ADH2 gene in alcoholics

Alocholism is the multifactorial disease influenced by genetic environmental interaction and genetic variation of the genes may be associated with alcohol dependence due to its modified function in behavioral and physiological responses. In the present study, genetic variation was detected in the subtypes of gene, coding for the alcohol metabolizing enzyme Alcohol Dehydrogenase 2 (ADH2). Blood samples were collected from the alcoholic and non alcoholic subjects and genotyping was performed using PCR-RFLP (Polymerase Chain Reaction-Restriction Fragment Length Polymorphism), analysis to determine genetic polymorphisms in the ADH2 gene subtypes. The three subtypes of ADH2 gene (ADH2.1, ADH2.2 and ADH2.3) were found in both alcoholics (Family History Positive and Family History Negative) as well as non alcoholics.     

Knowledge, attitudes, and beliefs about HIV/AIDS among Hindu students from a government women's college of South India

The purpose of the study was to determine the attitudes of Hindu students from a government women's college of South India toward people with AIDS, to assess their beliefs about HIV/AIDS, to determine their knowledge level about HIV/AIDS and to determine how they gain information about HIV/AIDS. The sample consisted of four hundred female students at a government funded Women's University in Southern India who participated in an AIDS survey research project. Participants completed a survey asking about their knowledge, attitudes and beliefs about HIV/AIDS. Results indicated that a majority of the participants learned about HIV/AIDS from reading material while some learned about HIV/AIDS from school classes, and only a few learned from family members. Thirty-nine percent had never communicated to any one about HIV/AIDS. The results indicated that the majority of Indian women in this study did not know about explicit sexual behaviors which transmit the virus. The study also showed that those Indian women university students, by and large, are accepting of people with AIDS but still have fears of getting HIV/AIDS. This data suggest a need to increase educational efforts at the university. It was suggested that counselors take responsibility for helping this population of Indian women become self advocates, particularly in a society which permits men to have multiple sexual relationships. Educators and counselors working with this population must initiate programs that impart accurate and specific knowledge to these female college students and begin to address the multiple psychosocial issues related to HIV/AIDS.     

Coverage of the Surgical Strike on Television News in India

On 29 September 2016, the Indian army conducted a surgical strike along the India–Pakistan border. The mainstream news media in India followed the event with assertive nationalistic rhetoric. What was supposed to be a covert military operation against terrorism became morphed into political rhetoric aggravated by the unwarranted jingoism of television news channels and social media. The coverage of the strike on television news is typically characterized by a confluence of militant nationalist discourses, and the ideologically imbued labelling of specific communities. Within this context, drawing from the close reading of the coverage, this article analyses how Indian television news sustains the construction of a fictive “we”, conflated with the government policies and military strategies, and speaks for a supposedly homogeneous national consensus that also consciously obscures the dissent through minority voices. The article emphasizes the relationship between communities, formal politics, and the supposedly non-political spaces and practices of news media in India.     

Enhancing the government service experience through QR codes on mobile platforms

Digital government is universally gaining acceptance as the public becomes more technologically advanced. It is critical for the government to embrace new technology for minimizing costs and maximizing utility of services to the taxpayers. While administrative services have been easily ported to the digital world, there are still many important citizen-centric services that have not yet been effectively migrated. Quick Response codes (QR codes) provide a means to effectively distribute many different varieties of information to the public. We propose to integrate QR code systems and corresponding smartphone applications into existing government services with the goal of providing a new level of interactivity for the public. We illustrate this through two case studies, examining the National Park Services and the Mobile Environmental Information Services (MENVIS). The focus is on developing a QR code waypoint system for park navigation, as well as incentivizing park use through gamification of site attractions. The system provides increased safety for park goers, disseminates information more effectively and accurately, and improves feedback.