Dual tone multi frequency

Jarak pengendalian yang sangat jauh, target/aktuator yang sulit dijangkau, serta pembangunan jaringan pengendali yang sulit dan mahal, menjadi beberapa masalah dalam sistem pengendalian jarak jauh. Contohnya adalah dalam pengendalian komputer-komputer pada papan iklan digital/digital signage yang kerap disimpan di tempat-tempat yang sulit dijangkau, seperti di atas jembatan penyebrangan, di persimpangan jalan, dan sebagainya. Perusahaan pengelola kerap melakukan penonaktifan alat guna menghemat energi, namun belum ada alat yang memadai untuk mengendalikannya. Oleh karena itu, pengendalian dengan menggunakan jaringan telepon baik kabel maupun selular menjadi solusi yang tepat. Selain lingkup kendali yang sangat luas, telepon juga sangat mudah dioperasikan. Rangkaian aplikasi yang dikembangkan pada penelitian ini menggunakan dual tone multi frequency yang dibangkitkan melalui penekanan tombol telepon yang dijadikan data input pengendali mikrokontroller. Data frequency diubah menjadi data digital, lalu data tersebut dijadikan input pengendali mikrokontroller. Mikrokontroller kemudian mengendalikan komputer melalui relay dan port serial. Hasil percobaan menunjukan bahwa aplikasi yang dikembangkan ini mampu mematikan dan menghidupkan komputer serta perangkat lunak aplikasi pada komputer dari jarak jauh. Kata kunci : dual tone multi frequency, tele-control, kendali dengan phone.

This exhaustive research report details the engineering design, theoretical foundations, and implications of a novel dual-frequency radiofrequency (RF) Paul trap developed for the co-confinement of particles with vastly disparate charge-to-mass ratios, a critical prerequisite for antihydrogen synthesis and tests of CPT invariance. Conventional single-frequency traps are obstructed by the extreme mass disparity between constituents like the electron and the calcium ion proxy (a ratio of approximately 73,000:1). The engineered solution, based on the AntiMatter-on-a-Chip (AMOC) project, superimposes a 1.6 GHz fast RF field for electron confinement and a 2 MHz slow RF field for ion confinement, achieving kinematic decoupling. The theoretical framework expands classical Mathieu stability and pseudopotential theory using Floquet and Hill equations to define the bounded motion. The physical apparatus employs a miniaturized, planar printed circuit board (PCB) architecture featuring a coplanar waveguide λ/2 resonator on a low-loss Rogers 4350B substrate. Empirical validation successfully demonstrated stable, decoupled co-confinement of electrons and Ca+ ions for up to 10 milliseconds. This technology mitigates the inherent spatial mismatch of precursor plasmas in single-frequency traps and offers a decentralized, room-temperature alternative to high-field Penning traps, enabling the future synthesis and high-precision spectroscopy of antihydrogen in quiet, laboratory-scale environments.

This document specifies an Internet standards track protocol for the Internet community, and requests discussion and suggestions for improvements. Please refer to the current edition of the "Internet Official Protocol Standards " (STD 1) for the standardization state and status of this protocol. Distribution of this memo is unlimited. Copyright Notice Copyright (c) 2009 IETF Trust and the persons identified as the

Eighteenth century authors’ fascination with the figure of the nun is attested by its presence in the literary landscape. This presence has led us to question the social stakes behind its protean representations. Utilization of this figure is far from being insignificant as it often appears to be strategic, and above all, is highly rooted in the social and political context of the century. Although the tactical use of nuns as characters is extensive throughout the eighteenth century, it is even more prominent in the last two decades due to the wake of revolutionary events. During that time a radicalization of certain traits in the representations of nuns is especially perceivable. Exploration of a heterogeneous corpus emphasizes the implications of the social imagination of the nun in the evolution of revolutionary discourse, and in the final decision to close the convents in 1792. Antagonistic characterization of nuns in some eighteenth-century literature is symptomatic of the spir...

This paper investigated the use of ultrasound irradiation to treat real mixed industrial wastewater under various conditions, including single and dual frequencies, variable wastewater strengths, and different operating conditions, including flow rates/residence times. This work is important to evaluate the organics' removal efficiency and to identify operational control bottlenecks under actual wastewater conditions. The highest removal efficiencies were 69.5% and 31.9% for COD and TOC, respectively, for the high-strength wastewater, which were found to occur at 16 kHz frequencies and 500 ml/min flow rate. The removal efficiencies were slightly less in the case of medium-strength wastewater (66.7 and 25.3% for COD and TOC, respectively). They were found to occur at dual frequencies of 16/20 kHz and 1500 and 1000 ml/min, respectively. For the low-strength wastewater, the efficiencies reached 78.6 and 9.1% for COD and TOC, respectively, at the same frequency and flow rates as the medium-strength wastewater. These findings demonstrated the effectiveness of dual frequency in medium-to low-strength wastewater. Among the organics monitored, chloroform (CHCl3), tetrachloroethene (C2Cl4), 1,4 dichlorobenzene (C6H4Cl2), and dichloromethane (CH2Cl2) exhibited variable removal, and in some cases, the removal was found to be negative, indicating intermediary products as a result of incomplete oxidation of organics. Besides the frequency and flow rate, it was found that the concentration of metals and organics are mostly positive influencers on organics removal. At the same time, TDS and pH have mixed effects, but they positively influence organics' removal at higher flows in a few instances. Additionally, as the residence time decreased, the concentration of organics and the pH negatively influenced organics removal.

Using insider sources from the Dreyfuss firm, hands-on examination of artifacts, and recently available digital resources, the authors dispel three myths about Henry Dreyfuss’s work for the Bell System, proving that (1) previously uncredited Bell System designer George Lum, not Dreyfuss, designed the Western Electric model 302, (2) an Ericsson phone did not inspire the 302 design, and (3) Dreyfuss did not use anthropometric measurements in his telephone work. The colorful and occasionally tension filled history of Dreyfuss and associates’ design of the 500, Princess, Trimline, and some Design Line phones clarifies human and technical aspects of his design process.

A dual-frequency measurement is employed in conjunction with an innovative Ifree filtering technique for mitigating the primary sources of Ifree influence on ground-based augmentation systems (GBAS) to safeguard the reliability of GBAS. The protective level achieved through the conventional Gaussian overbounding approach that are considered as much conventional technique. This adherence to tradition results in decreased reliability and a higher likelihood of false alarms. In contrast, the utilization of the Ifree algorithm contributes to reducing errors associated with dualfrequency measurements. This paper proposes the overbounding process according to Bayesian Gaussian mixture model (GMM) for maintaining Ifree-based GBAS range error. The Bayesian GMM is utilized for singlefrequency model errors to examine the ambiguity estimations. The Monte Carlo (MC) simulation is established for defining estimated GMM assurance level accuracy which is attained through the general estimation method. Then, the last Bayesian GMM which is utilized for overbounding Ifree error distribution is investigated. According to the property of convolution invariance, the vertical protection in position field is determined without presenting difficult numerical calculations.

A heterogeneous three-dimensional (3-D) stacked apparatus is provided that includes multiple layers arranged in a stacked configuration with a lower layer configured to receive a board-level voltage and one or more upper layers stacked above the lower layer. The heterogeneous 3-D stacked apparatus also includes multiple tiles per layer, where each tile is designed to receive a separately regulated voltage. The heterogeneous 3-D stacked apparatus additionally includes at least one layer in the one or more upper layers with voltage converters providing the separately regulated voltage converted from the board-level voltage.

A heterogeneous three-dimensional (3-D) stacked apparatus is provided that includes multiple layers arranged in a stacked configuration with a lower layer configured to receive a board-level voltage and one or more upper layers stacked above the lower layer. The heterogeneous 3-D stacked apparatus also includes multiple tiles per layer, where each tile is designed to receive a separately regulated voltage. The heterogeneous 3-D stacked apparatus additionally includes at least one layer in the one or more upper layers with voltage converters providing the separately regulated voltage converted from the board-level voltage.

This publication describes systems and techniques for a computing device that includes multiple touch screens that enables a user to cause the computing device to update the graphical user interface (GUI) being outputted by a first touch screen of the computing device by providing gesture input at a second touch screen of the computing device. For example, a mobile computing device, such as a foldable smartphone, may include two touch screens that can be folded up to 360 degrees so that the two touch screens face away from each other in a back-toback position. When such a mobile computing device is being used by a user, a first touch screen may face towards the user while a second touch screen may face away from the user. As the first touch screen of the mobile computing device outputs content that is viewable by the user, the user may interact with the second touch screen of the mobile computing device, such as by providing or performing touch input (e.g., gesture input) at the second touch screen to cause the mobile computing device to change, modify, or update the content outputted by the first touch screen. For example, the user may perform a gesture input at the second touch screen that causes the mobile computing device to zoom in and/or out of content displayed at the first touch screen. By enabling the user to interact with the second touch screen of the mobile computing device to change, modify, or update the content outputted by the first touch screen of the mobile computing device, the mobile computing device allows the user to interact with the computing device via touch-based input without the user's finger occluding the user's view of content being outputted by the first touch screen of the computing device.

An on-chip CMOS preamplifier for direct signal readout from an electret capacitor microphone has been designed with high immunity to common-mode and supply noise. The Gm-Opamp-RC based high impedance preamplifier helps to remove all disadvantages of the conventional JFET based amplifier and can drive a following switched-capacitor sigma-delta modulator in order to realize a compact digital electret microphone. The proposed chip is designed based on 0.18 µm CMOS technology, and the simulation results show 86 dB of dynamic range with 4.5 µVrms of input-referred noise for an audio bandwidth of 20 kHz and a total harmonic distortion (THD) of 1% at 90 mVrms input. Power supply rejection ratio (PSRR) and common-mode rejection ration (CMRR) are more than 95 dB at 1 kHz. The proposed design dissipates 125 µA and can operate over a wide supply voltage range of 1.6 V to 3.3 V.

A dual-frequency measurement is employed in conjunction with an innovative Ifree filtering technique for mitigating the primary sources of Ifree influence on ground-based augmentation systems (GBAS) to safeguard the reliability of GBAS. The protective level achieved through the conventional Gaussian overbounding approach that are considered as much conventional technique. This adherence to tradition results in decreased reliability and a higher likelihood of false alarms. In contrast, the utilization of the Ifree algorithm contributes to reducing errors associated with dualfrequency measurements. This paper proposes the overbounding process according to Bayesian Gaussian mixture model (GMM) for maintaining Ifree-based GBAS range error. The Bayesian GMM is utilized for singlefrequency model errors to examine the ambiguity estimations. The Monte Carlo (MC) simulation is established for defining estimated GMM assurance level accuracy which is attained through the general estimation method. Then, the last Bayesian GMM which is utilized for overbounding Ifree error distribution is investigated. According to the property of convolution invariance, the vertical protection in position field is determined without presenting difficult numerical calculations.

Controlling a robot wirelessly for surveillance application is possible with several methods such as Infrared remote control Radio frequency (RF) remote control, Bluetooth, Wi-Fi, etc. But the controls of these communication methods are limited to certain areas, and also the compatibility of these wireless modules with popular microcontrollers leads to complicated to design of the system. To overcome these difficulties, a Dual Tone Multi-Frequency (DTMF) based surveillance control robot is presented here. Using a mobile phone, it generates a tone combination of a high and low frequencies, from keypad. These frequencies can be decoded into binary sequence. Tone from DTMF encoder is given to the DTMF decoder. The decoder s decodes the incoming tone to binary data. The motors will rotate as per the binary codes. The design of an unmanned vehicle proposed here does not make use of any microcontroller. The transmitter used, is a handheld mobile phone. For transmitting live video, droid camera application is used. Applications of this system includes surveillance of hazardous environments, military, rescue operation, recreation and hobby purpose

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Facial expression recognition (FER) has good applications in different aspects of day-today life. But not yet realized due to unavailability of effective expression recognition techniques. This paper discusses the application of Gabor filter based feature extraction by using feed-forward neural networks (classifier) for recognition of four different facial expressions from still pictures of the human face. The study presented here gives simple method in facial expression recognition. The study presented here gives 72.50% recognition of facial expression for the entire database of JAFEE. In this study the Japanese Female Facial Expression (JAFFE) database used which contains expressers that expressed expressions.

The disclosed embodiments relates to a crowdsourcing directory system. The crowdsourcing directory system is configured for identifying and comparing one or more of a plurality of crowdsourcing platforms based on a plurality of attributes associated with each of the plurality of crowd Sourcing platforms. The crowdsourcing directory system then recommends a set of crowdsourcing platforms from the one or more crowdsourcing platforms based on values of the plurality of attributes. The crowdsourcing directory system also maintains a repository of information pertaining to the plurality of crowdsourcing platforms. In an embodiment, the repository may be updated by implementing software adap tors configured to extract various information pertaining to the plurality of crowdsourcing platforms.

A time-multiplexed digitally-programmable switched-capacitor (SC) variable equalizer which allows the realization of arbitrary frequency responses is presented. The circuit performs the same operation as a cascade of N secondorder programmable equalizers, where N is also the multiplexing order. Except the storing capacitors, the rest of the circuitry is shared for all individual equalizer functions (channels), resulting in silicon area savings higher than 60% with respect to a direct circuit implementation for N = 4. The impact on circuit performance of crosstalk effects is discussed. Experimental results of a 3-V timesharing SC equalizer architecture fabricated in a CMOS 1.2 m technology are given for different values of the multiplexing order. The circuit has been designed to be incorporated in a programmable hearing aid device.

A CMOS mixed-mode fully-differential signal processor (VERDI), that constitutes the core of a hearing aid system, is introduced. Its characteristics (frequency response, compression level, and output sound pressure level) are wireless controlled by means of dual tone multi-frequency (DTMF) encoded signals transmitted by an external unit. A system description is provided, and the implementation and experimental results of the key components (preamplifier, antialiasing filter, automatic gain control, filter section, output amplifier, and DTMF receiver/decoder) are covered in more detail. The circuit has been fabricated in a conventional 1.2 pm CMOS n-well process and operates from a single 1.3 V battery, although a d d d c converter is required. It consumes typically less than 1 mA and occupies 28 mm2 of silicon. The dynamic range is larger than 66 dB for the maximum input signal (54 mVrms = 108 dB SPL) .

MobilED started as an international collaborative project to facilitate and support teaching and learning through the creation and support of learning environments using mobile technology. This paper provides an overview of the theoretical underpinning and reflects on the project methodology. We discuss and analyse what worked and what didn't work. Problems encountered such as navigation and entry to schools with set curricula and limited time are articulated and some contextualised recommendations are made.

Socio-economic development in South Africa poses a variety of challenges, such as bridging communication gaps, providing access to information, dealing with pockets of technological and functional illiteracy, and addressing widespread poverty. South Africa is thus a prototypical example of a developing world nation –

Science Real & Relevant: 2nd CSIR Biennial Conference, CSIR International Convention Centre Pretoria, 17 & 18 November 2008, pp 1 Skilful dialogue design in an interactive voice response system has facilitated the effective use of a telephone-based health information syatem ny caregivers to HIV/AIDS-infected childern in Botswana. The intended users, caregivers, can access information over telephone line in their local language. This uniqueness necessitates the design of a system to meet specific concerns and decisions, which will ensure its usefulness and usability to its intended users. This document describes both context and content design of the dialogue system.

A method for generating an interactions explorer for a user interface prototype comprising detecting one or more proto typing actions while a user creates a user interface prototype, adding the one or more prototyping actions to an interaction hierarchy and generating an interactive visual depiction of the interaction hierarchy.

Access to information and communication is one of the most important needs in any population group. It is generally challenging for people in the developing world to access information because the tools and the technologies used to access information are prohibitively expensive and also require training prior to operating such tools [13]. This restrains those who are either poor, illiterate, or without computer skills from accessing information. We carried out two case studies of contrasting Interactive Voice Response (IVR) systems. The research compared the eraction modality between Dual-Tone Multi-Frequency (DTMF) and speech-enabled IVR modalities and correlated the results with learnability of the different modalities in the milieu of the two systems. The targeted users are oral users of Southern Africa with diverse literacy levels but nevertheless numerically literate and accustomed to the telephone.

The invention relates to a method for monitoring user activity on mobile devices and a method for analyzing user activity at a server. Further, a computer program product comprising one or more computer readable media having computer executable instructions for performing the steps of at least one of the aforementioned methods is provided. BACKGROUND OF THE INVENTION [0002] Mobile computing devices, as smartphones or tablets for example, are giving the possibility to easily browse the Internet, process emails or make phone calls at any place. Due to their increased attractiveness more and more people start using such devices creating a large market for service and network providers, application developers, and marketing specialists. Since these devices provide comprehensive functionalities to their users, the complexity of some applications and services is too high to be handled by an average user. Helping the user managing this complexity is a hard task since users are often not able to describe the exact technical situation that is causing problems. [0003] Especially mobile phones have become the central computing and communication devices today. Since August 2006, more mobile phones than inhabitants are registered in Germany. As the capabilities of these devices increase, they are not simple voice-centric handsets any more. They represent one step towards realizing Mark Weiser's vision of ubiquitous computing (Mark Weiser, The computer for the 21st century, Scientific American, 265(3):94-104, September 1991). In this vision, it is described that classical computers will be replaced by small, intelligent, distributed, and networked devices that will be integrated into everyday objects and activities. This replacement can be already observed in shops and warehouses using tags for monitoring and controlling items. The evolution of mobile devices, in particular smartphones, can be seen as part of this vision since they represent a possibility for making use of technical and computational capabilities in a mobile context. Smartphone is a commonly used term for describing current comprehensive mobile phones, although no global industry definition exists. A common understanding of this term is that these devices provide state-of-the-art technical characteristics as well as software development environments that allow creation of third-party applications. [0004] With the increasing capabilities of mobile devices, more and more people start using mobile devices such as smartphones or tablets. Remote-capabilities for helping the user managing the complexity of some applications on such mobile devices are generally limited due to the lack of solutions being supported by the op

In this paper, an indoor localization system making use of LEDs, is proposed and demonstrated in the space of 100 cm  118.5 cm  128.7 cm. Different LED lamps transmitted signals with different central frequencies and the identities (IDs) of the transmitters are encoded on the envelopes of the transmitted signals. At the receiver side, the finite impulse response (FIR) filters are applied to discriminate the signals from different lamps. The IDs could be successfully decoded and the received signal strength (RSS) from each transmitter could be achieved. The experimental results show that the average positioning errors of x-scale and y-scale are 1.76 cm and 2.20 cm, respectively.

The OpenPhone project aims to design an Interactive Voice Response (IVR) health information system that enables people who are caregivers for HIV/AIDS infected children to access relevant information by using a telephone in their native language of Setswana in Botswana. The system lowers accessibility barriers since it is accessible to illiterate users and the community of the blind. The design utilizes usability engineering methodology in order to ascertain that the end product is usable, efficient, effective and satisfactory to the targeted users who are predominantly females, ranging from semi-literate to illiterate adults but nevertheless numerically literate. The paper describes the methodologies that were used to obtain information from the target user population. Based on the information gathered, we are now able to begin the initial design of the OpenPhone system.

Access to literacy is critical to children's futures, but formal education may be insufficient for fostering early literacy, especially in low-resource contexts. Educational technologies used at home may be able to help, but it is unclear whether or how children (and families) will use such technologies at home in rural communities, particularly in low-literate families. In this paper, we investigate these questions with a voice-based literacy technology deployed with families in 8 rural communities in Côte d'Ivoire for 4 months. We use interviews and observations with 37 families to investigate motivations, methods, and barriers for rural families' engagement with a literacy technology accessible via feature phones. We contribute insights into how families view digital literacy as a learning goal, leverage networks of supporters, and over time, transition from explicit to implicit support for children's learning.

Information access by low literate users is a hard problem. Critical information, such as in the field of healthcare, can often mean the difference between life and death. In our research, we have developed and tested various spoken language interface prototypes with low literate community health worker. In this paper, we present results from our research that show that well-designed speech interfaces are preferable to touch-tone equivalents. Additionally, we show that it is especially important to localize the system's spoken language output for low literate users.

The objective of this study was to determine how school principals and nutrition coordinators see their roles in the management of school nutrition programmes for learners from disadvantaged communities. Design: In this qualitative study, a single case study design was used to collect data through open-ended questionnaires, followup interviews and field notes. Subjects and setting: Principals and nutrition coordinators at five primary schools and three secondary township schools in Alexandra. Results: The findings highlight the importance of school nutrition programmes in contributing to a healthy learning environment. Principals and nutrition coordinators were clear about their management roles and responsibilities in the programme. The biggest challenges were the work overload of nutrition coordinators, a lack of training and inadequate food delivery. Conclusion: Based on the findings, the study recommends the implementation of a training programme for school principals and nutrition coordinators on time and human resource management to assist them in balancing teaching time and the management of food handlers, the appointment of a nutrition coordinator and collaboration with non-government organisations, volunteers and businesses to assist schools. Finally, this study reveals that the struggle for environmental justice to address shortage of nutritious food to feed needy learners remains valid and that school nutrition programmes, if managed properly, can make a crucial contribution in this regard.

Information access by low literate users is a hard problem. Critical information, such as in the field of healthcare, can often mean the difference between life and death. In our research, we have developed and tested various spoken language interface prototypes with low literate community health worker. In this paper, we present results from our research that show that well-designed speech interfaces are preferable to touch-tone equivalents. Additionally, we show that it is especially important to localize the system's spoken language output for low literate users.

The full range of possibilities for spoken-language technologies (SLTs) to impact poor communities has been investigated only partially, despite what appears to be strong potential. Voice interfaces raise fewer barriers for the illiterate, require less training to use, and are a natural choice for applications on cell phones, which have far greater penetration in the developing world than PCs. At the same time, critical lessons of existing technology projects in development still apply and require careful attention. We suggest how to expand the view of SLT for development, and discuss how its potential can realistically be explored.

This specification standardizes three media types-application/xml, application/xml-external-parsed-entity, and application/xml-dtd-for use in exchanging network entities that are related to the Extensible Markup Language (XML) while defining text/xml and text/ xml-external-parsed-entity as aliases for the respective application/ types. This specification also standardizes the '+xml' suffix for naming media types outside of these five types when those media types represent XML MIME entities. Status of This Memo This is an Internet Standards Track document. This document is a product of the Internet Engineering Task Force (IETF). It represents the consensus of the IETF community. It has received public review and has been approved for publication by the Internet Engineering Steering Group (IESG). Further information on Internet Standards is available in Section 2 of RFC 5741. Information about the current status of this document, any errata, and how to provide feedback on it may be obtained at http://www.rfc-editor.org/info/rfc7303.

India is primarily an agricultural country, with agriculture providing all of the country's resources. Even in the modern era of
industrialization, agriculture remains the most important factor in determining the country's economic progress. Agriculture also
contributes for 8.56 percent of the overall exports of the country.

A technique for generating component usage statistics involves associating components with blocks of a stream enabled application. When the streaming application is executed, block requests may be logged by Block ID in a log. The frequency of component use may be estimated by ana lyzing the block request log with the block associations.

This brief introduces four different structures for implementing a continuous-time common-mode feedback (CMFB) network for fully differential (FD) amplifiers. The proposed circuits use bulk-driven MOS transistors, thus representing a lowvoltage realization of their gate-driven counterparts. The CMFB circuits were included in a 1.5-V FD buffer implemented in standard 0.35-µm CMOS technology. Experimental results illustrate the performance of the proposed schemes, demonstrating their suitability to operate with a low supply voltage. Index Terms-Bulk-driven MOS transistors, CMOS analog integrated circuits, common-mode feedback (CMFB), fully differential amplifiers, low-voltage. T HE OVERALL performance of analog and mixed-mode systems may be improved by adopting a fully differential (FD) implementation. The use of this approach entails several well-known advantages, such as the extension of the dynamic range, the ideal cancellation of even-order harmonics, and the reduction of the effects of undesired noises coming from the supplies, which may be considered as common-mode (CM) signals . Nevertheless, there are also disadvantages associated to the use of FD circuits. The duplication of most parts of the circuit leads to area and power consumption increase. Moreover, an additional network, referred to as CM feedback (CMFB) circuit, must be used to control the CM component of the output signal [1]-[4]. Some approaches have been reported in order to avoid the need for a CMFB loop in FD circuits [5]- . However, all the proposed techniques have their own benefits and drawbacks. The conventional block diagram of a FD amplifier including a CMFB loop is shown in Fig. . The amplifier output voltages, V + out and V - out , are fed to a CM detector. This block provides a signal, V s , which monotonously tracks the amplifier output CM voltage V out,CM = (V + out + V - out )/2. This signal is compared to a reference voltage, V ref , by means of an error amplifier whose Manuscript

The operation of switched-capacitor (SC) circuits with periodical nonuniform individual sampling (PNIS) is introduced. The basic idea consists in a time averaged control of the effective rate of charge delivered by any given SC structure. In this way, the equivalent resistance of each SC branch in a circuit is individually controlled by programming the number of clock pulses in which it is active in a predetermined period of time. It is shown that this additional design degree of freedom provides a very wide programmability range in all response parameters. A second-order SC filter programmable by PNIS has been designed and fabricated in conventional CMOS technology. Experimental results are in good agreement with theoretical ones, and demonstrate the effectiveness and versatility of the proposed technique for low-frequency applications.

A CMOS mixed-mode fully-differential signal processor (VERDI), that constitutes the core of a hearing aid system, is introduced. Its characteristics (frequency response, compression level, and output sound pressure level) are wireless controlled by means of dual tone multi-frequency (DTMF) encoded signals transmitted by an external unit. A system description is provided, and the implementation and experimental results of the key components (preamplifier, antialiasing filter, automatic gain control, filter section, output amplifier, and DTMF receiver/decoder) are covered in more detail. The circuit has been fabricated in a conventional 1.2 pm CMOS n-well process and operates from a single 1.3 V battery, although a d d d c converter is required. It consumes typically less than 1 mA and occupies 28 mm2 of silicon. The dynamic range is larger than 66 dB for the maximum input signal (54 mVrms = 108 dB SPL) .

Access to literacy is critical to children's futures, but formal education may be insufficient for fostering early literacy, especially in low-resource contexts. Educational technologies used at home may be able to help, but it is unclear whether or how children (and families) will use such technologies at home in rural communities, particularly in low-literate families. In this paper, we investigate these questions with a voice-based literacy technology deployed with families in 8 rural communities in Côte d'Ivoire for 4 months. We use interviews and observations with 37 families to investigate motivations, methods, and barriers for rural families' engagement with a literacy technology accessible via feature phones. We contribute insights into how families view digital literacy as a learning goal, leverage networks of supporters, and over time, transition from explicit to implicit support for children's learning.

This paper presents a System on Chip (SOC) based high-density carrier class Voice over Internet Protocol (VoIP) media gateway. The design exploits three levels of parallelism namely HW/SW partitioning, multiprocessing and instruction level parallelism. The system facilities the carrier class service providers to transform channels on PSTN network to IP network, enabling the consumers to enjoy several value added services, such as voice, data, fax and video all through a uniform network at lower cost. The SoC implements a high-density media gateway switch for carrier class VoIP applications. The solution is synthesized to operate at 266 MHz handling up to OC-3 data rate port density equivalent to 2016 simultaneous calls on a single chip and it can be cascaded to support OC-12 and OC-48 rate port density on single board in different configurations. On each channel the SoC supports up to 128 ms tail length G.168 compliant Line Echo Cancellation (LEC), Voice Activity Detection (VAD), Comfort Noise Generation (CNG) and Discontinuous Transmission (DTX), Dual Tone Multi Frequency (DTMF) detection and generation, variety of G.xxx Voice Codecs, V.17 Fax and V.34 Data modem standards and MPEG4 Video compression/decompression algorithms. The solution is compared with the existing architectures and commercial products; it offers 3x to 10x cost, size, power and port density performance improvements with IP and PSTN internetworking support. The media gateway system based on the presented architecture has been used to develop IP-based Automatic Call Distribution (ACD) by etel Pvt. Ltd and installed in Telephone Inquiry Exchange of Pakistan Telecom and its variants are being tested by Buraq Telecom for installation in their service network 1 .

Jarak pengendalian yang sangat jauh, target/aktuator yang sulit dijangkau, serta pembangunan jaringan pengendali yang sulit dan mahal, menjadi beberapa masalah dalam sistem pengendalian jarak jauh. Contohnya adalah dalam pengendalian komputer-komputer pada papan iklan digital/digital signage yang kerap disimpan di tempat-tempat yang sulit dijangkau, seperti di atas jembatan penyebrangan, di persimpangan jalan, dan sebagainya. Perusahaan pengelola kerap melakukan penonaktifan alat guna menghemat energi, namun belum ada alat yang memadai untuk mengendalikannya. Oleh karena itu, pengendalian dengan menggunakan jaringan telepon baik kabel maupun selular menjadi solusi yang tepat. Selain lingkup kendali yang sangat luas, telepon juga sangat mudah dioperasikan. Rangkaian aplikasi yang dikembangkan pada penelitian ini menggunakan dual tone multi frequency yang dibangkitkan melalui penekanan tombol telepon yang dijadikan data input pengendali mikrokontroller. Data frequency diubah menjadi data digital, lalu data tersebut dijadikan input pengendali mikrokontroller. Mikrokontroller kemudian mengendalikan komputer melalui relay dan port serial. Hasil percobaan menunjukan bahwa aplikasi yang dikembangkan ini mampu mematikan dan menghidupkan komputer serta perangkat lunak aplikasi pada komputer dari jarak jauh. Kata kunci : dual tone multi frequency, tele-control, kendali dengan phone.

Access to literacy is critical to children's futures, but formal education may be insufficient for fostering early literacy, especially in low-resource contexts. Educational technologies used at home may be able to help, but it is unclear whether or how children (and families) will use such technologies at home in rural communities, particularly in low-literate families. In this paper, we investigate these questions with a voice-based literacy technology deployed with families in 8 rural communities in Côte d'Ivoire for 4 months. We use interviews and observations with 37 families to investigate motivations, methods, and barriers for rural families' engagement with a literacy technology accessible via feature phones. We contribute insights into how families view digital literacy as a learning goal, leverage networks of supporters, and over time, transition from explicit to implicit support for children's learning.

This research study focuses on the feasibility of using the telephone as a tool for information access in the oral communities of Southern Africa. The OpenPhone and BGR systems are used as case studies and their designs have been influenced by field studies with the targeted users. The OpenPhone project aims to design an Interactive Voice Response (IVR) health information system that enables people who are caregivers for HIV/AIDS infected children to access relevant care-giving information by using a telephone in their native language of Setswana in Botswana, Southern Africa. The BGR system allows soccer fans to access results of recently played matches in Premier Soccer League (PSL) of South Africa. Both designs utilise usability engineering methodology to ascertain that the end products are usable and satisfactory to their targeted users. We hypothesise that ignoring the socio-cultural circumstances of the intended users will lead to an ineffective design. In the present study, the first challenge is to determine which input modality is preferred by the intended users: dual tone multi frequency (DTMF) input or automatic speech recognition (ASR) input. Usability evaluation experiments were conducted with a sample of the intended users and both qualitative and quantitative analyses are used to explore the results. We have obtained additional evidence on ASR / DTMF preferences in the developing world, and we present the first evidence of the relationship between educational levels and users' interaction behaviour. We have established important findings on language preferences for numbers pronunciation which impacts how IVR systems are designed for users in the region. We also show that HCI for development research can benefit substantially from focussing on "enjoyable" applications as a testing ground for speech technology in the developing world, instead of concentrating only on serious matters such as healthcare, agriculture, public services, etc.

Access to information and communication is one of the most important needs in any population group. It is generally challenging for people in the developing world to access information because the tools and the technologies used to access information are prohibitively expensive and also require training prior to operating such tools [13]. This restrains those who are either poor, illiterate, or without computer skills from accessing information. We carried out two case studies of contrasting Interactive Voice Response (IVR) systems. The research compared the eraction modality between Dual-Tone Multi-Frequency (DTMF) and speech-enabled IVR modalities and correlated the results with learnability of the different modalities in the milieu of the two systems. The targeted users are oral users of Southern Africa with diverse literacy levels but nevertheless numerically literate and accustomed to the telephone.