Acoustic echo cancellation for full-duplex voice transmission on fading channels

This paper discusses the implementation of an adaptive acoustic echo canceler for a hands-free cellular phone operating on a fading channel. The adaptive lattice structure, which is particularly known for faster convergence relative to the conventional tapped-delay-line (TDL) structure, is used in the initialization stage. After convergence, the lattice coefficients are converted into the coefficients for the TDL structure which can accommodate a larger number of taps in real-time operation due to its computational simplicity. The conversion method of the TDL coefficients from the lattice coefficients is derived and the DSP56001 assembly code for the lattice and TDL structure is included, as well as simulation results and the schematic diagram for the hardware implementation

A simple implementation of the Viterbi algorithm on the Motorola DSP56001

As systems designers design communication systems with digital rather than analog components to reduce noise and increase channel capacity, they must have the ability to perform traditional communication algorithms digitally. The use of trellis coded modulation as well as the extensive use of convolutional encoding for error detection and correction requires an efficient digital implementation of the Viterbi Algorithm for real time demodulation and decoding. Digital signal processors are now fast enough to implement Viterbi decoding in conjunction with the normal receiver/transmitter functions for lower speed channels on a single chip as well as performing fast decoding for higher speed channels, if the algorithm is implemented efficiently. The purpose of this paper is to identify a good way to implement the Viterbi Algorithm (VA) on the Motorola DSP56001, balancing performance considerations with speed and memory efficiency

Fundamental study of underfill void formation in flip chip assembly

Flip Chip in Package (FCIP) has been developed to achieve the assembly process with area array interconnects. Particularly, a high I/O count coupled with finer pitch area array interconnects structured FCIP can be achieved using no-flow underfill assembly process. Using the assembly process, a high, stable yield assembly process recently reported with eutectic lead-tin solder interconnections, 150 µm pitch, and I/O counts in excess of 3000. The assembly process reported created a large number of voids among solder interconnects in FCIP. The voids formed among solder interconnections can propagate, grow, and produce defects such as solder joint cracking and solder bridging. Moreover, these voids can severely reduce reliability performance. Indeed, many studies were conducted to examine the void formation in FCIP. Based on the studies, flip chip geometric design, process conditions, and material formulation have been considered as the potential causes of void formation. However, the present research won't be able to identify the mechanism of void formation, causing a lot of voids in assembly process without consideration of chemical reaction in the assembly process with a fine-pitch, high I/O density FCIP. Therefore, this research will present process technology necessary to achieve high yields in FCIP assemblies using no-flow underfills and investigate the underlying problem of underfill void formation in these assemblies. The plausible causes of void formation will be investigated using experimental techniques. The techniques will identify the primary source of the void formation. Besides, theoretical models will be established to predict the number of voids and to explain the growth behavior of voids in the FCIP. The established theoretical models will be verified by experiments. These models will validate with respect to the relationship between process parameters to achieve a high yield and to minimize voids in FCIP assemblies using no-flow underfill materials regarding process as well as material stand points. Eventually, this research provides design guideline achieving a high, stable yield and void-free assembly process.Ph.D.Committee Chair: Baldwin, Daniel; Committee Member: Colton, Jonathan; Committee Member: Ghiaasiaan, Mostafa; Committee Member: Moon, Jack; Committee Member: Tummala, Ra

Minimum interference channel assignment for multicast in multi-channel multi-radio wireless mesh networks

Wireless mesh networks (WMNs) have emerged as a key technology for next-generation wireless networking. In a WMN, wireless routers provide multi-hop wireless connectivity between hosts in the network and also allow hosts to access the Internet via the gateway nodes. Wireless routers are typically equipped with multiple radios operating on different channels to increase network throughput. Multicast is a form of communication that delivers data from a source to a set of destinations simultaneously. It is used in a number of applications such as distributed games, distance education, and video conferencing. In this work, we address the channel assignment problem for multicast in multi-radio multi-channel WMNs. In a multi-radio multi-channel WMN, when two nearby nodes transmit on the same channel, they will interfere with each other and cause throughput decrease. Thus, an important goal for multicast channel assignment is to reduce the interference among the tree nodes. We have developed a Minimum Interference Channel Assignment (MICA) algorithm for multicast that accurately models the interference relationship between pairs of multicast tree nodes using the concept of interference factor and assigns channels to tree nodes to minimize interference within the multicast tree. Simulation results show that MICA achieves higher throughout and lower end-to-end packet delay compared with an existing channel assignment algorithm named MCM. In addition, MICA achieves much lower throughput variation among the destination nodes than MCM

Lost in Adaptation: Antifidelity and/in Mike De Leon’s Bilanggo sa Dilim and Bayaning 3rd World

Following the tenets of auteur criticism that proposes a film auteur to have an autonomous, original, and individual voice despite the nature of filmmaking as an art form that follows the Fordist model, this essay looks at how Mike De Leon’s artistic style has become the ordering agent for his two films: Bilanggo sa Dilim and Bayaning 3rd World. This study puts under the lens De Leon’s signature and confronts the difficulty of assigning authorship and originality within a collaborative, institutionalized medium that aims to adapt for the screen one literary and one historical material. De Leon has his own way of reclaiming an adapted work and a historical figure, and by wrestling Bilanggo sa Dilim away from the pages of the novel and by being unfaithful and transgressive in adapting Jose Rizal in Bayaning 3rd World, the filmmaker creates a space for himself and his signature in his cinematic transmediations

Cutting Across the Waves of the Web: The “Care of the Self” as an Ethical Response to Post-truth Politics in Social Media

Uttering “facts are passé” captures the spirit of post-truth. However, it often leads to addressing facts rather than why they pass off as passé. “Post-truth” was dubbed the 2016 Word of the Year due to its increased usage during the Brexit referendum and the US presidential election in the same year. The issue presses at least twenty-six countries, including the Philippines, as they face widespread disinformation and misinformation. This paper offers an overview of the social media manipulation from Samantha Bradshaw and Philip Howard, and networked disinformation in the Philippines from Jonathan Corpus Ong and Jason Vincent Cabañes. This paper also draws from the definitions of Claire Laybats, Luke Tredinnick, and Kathleen Higgins and investigates Michel Foucault’s insights on stultitia and flattery in relation tocontrolled interactivity and volatile virality. The content of post-truth is enriched by the discussion of the internet medium. Marshall McLuhan’s “the medium is the message” and “global village” are used to explore the key shifts and the unanticipated consequences that ensured post-truth’s arrival. Lastly, the Hellenistic model of self-care is explored as an ethical response to the post-truth attitude as it addresses stultitia and flattery with the exercises of mathesis and askesis

How Does LG Group Embed Enterprise Risk Management (ERM) System In Its Conglomerate Governance To Control Its Affiliated Firms' Risk Events?

This paper presents a case of enterprise risk management (ERM) embeddedness in LG Group, globalized conglomerate in Korea. Findings are differentiated from prior studies in two aspects. First, this study focuses on how ERM systems minimize the agency costs between conglomerate headquarters and its affiliated firms. Second, cases of diversified twelve affiliated firms find that COSO ERM framework are to be applied adaptively to entities’ inherent or external conditions as industry, age, management level etc. Those findings might be a practical guidance for most Asian business groups to embed ERM frameworks in conglomerate governances, filling gaps between theoretical COSO manual and practical applications.

Thermoregulated gas transport through electrospun nanofiber membranes

Thermoregulation of gas transport using electrospun fiber membranes is demonstrated experimentally for the first time. The fiber membranes comprise three layers: a middle layer of electrospun polystyrene sandwiched between two outer layers of electrospun cellulose acetate mat as supports, bonded together by hot pressing. The electrospun polystyrene layer serves as a phase change material that blocks transport of gases though the membrane when the fibers de-vitrify. The membrane exhibited a reduction in oxygen flux at temperatures in excess of 140 °C. Using a blend of polysulfone and polystyrene resulted in an upward shift of the transition temperature to 250 °C. Modeling of transport was performed to estimate the impact of the morphological properties of the membranes such as tortuosity, fiber diameter, and porosity.Philip Morris Internationa