15,332 research outputs found

    How Design Plays Strategic Roles in Internet Service Innovation: Lessons from Korean Companies

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    In order to survive in the highly competitive internet business, companies have to provide differentiated services that can satisfy the rapidly changing users’ tastes and needs. Designers have been increasingly committed to achieving user satisfaction by generating and visualizing innovative solutions in new internet service development. The roles of internet service design have expanded from a narrow focus on aesthetics into a more strategic aspect. This paper investigates the methods of managing design in order to enhance companies’ competitiveness in internet business. The main research processes are to: (1) explore the current state of internet service design in Korea through in-depth interviews with professional designers and survey questionnaires to 30 digital design agencies and 60 clients; (2) compare how design is managed between in-house design groups and digital design agencies though the case studies of five Korean companies; and (3) develop a taxonomy characterizing four roles of designers in conjunction with the levels of their strategic contributions to internet service innovation: visualist, solution provider, concept generator, and service initiator. In addition, we demonstrate the growing contributions of the strategic use of design for innovating internet services, building robust brand equity, and increasing business performance. Keywords: Design Management; Internet Business; Internet Service Design; Digital Design; Digital Design Agency; In-House Design Group, Case Study</p

    Duality for nonlinear filtering

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    This thesis is concerned with the stochastic filtering problem for a hidden Markov model (HMM) with the white noise observation model. For this filtering problem, we make three types of original contributions: (1) dual controllability characterization of stochastic observability, (2) dual minimum variance optimal control formulation of the stochastic filtering problem, and (3) filter stability analysis using the dual optimal control formulation. For the first contribution of this thesis, a backward stochastic differential equation (BSDE) is proposed as the dual control system. The observability (detectability) of the HMM is shown to be equivalent to the controllability (stabilizability) of the dual control system. For the linear-Gaussian model, the dual relationship reduces to classical duality in linear systems theory. The second contribution is to transform the minimum variance estimation problem into an optimal control problem. The constraint is given by the dual control system. The optimal solution is obtained via two approaches: (1) by an application of maximum principle and (2) by the martingale characterization of the optimal value. The optimal solution is used to derive the nonlinear filter. The third contribution is to carry out filter stability analysis by studying the dual optimal control problem. Two approaches are presented through Chapters 7 and 8. In Chapter 7, conditional Poincar\'e inequality (PI) is introduced. Based on conditional PI, various convergence rates are obtained and related to literature. In Chapter 8, the stabilizability of the dual control system is shown to be a necessary and sufficient condition for filter stability on certain finite state space model.Comment: Ph.D. Thesis of the autho

    On forward-backward SDE approaches to continuous-time minimum variance estimation

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    The work of Kalman and Bucy has established a duality between filtering and optimal estimation in the context of time-continuous linear systems. This duality has recently been extended to time-continuous nonlinear systems in terms of an optimization problem constrained by a backward stochastic partial differential equation. Here we revisit this problem from the perspective of appropriate forward-backward stochastic differential equations. This approach sheds new light on the estimation problem and provides a unifying perspective. It is also demonstrated that certain formulations of the estimation problem lead to deterministic formulations similar to the linear Gaussian case as originally investigated by Kalman and Bucy. Finally, optimal control of partially observed diffusion processes is discussed as an application of the newly proposed estimators

    Intensifying Gated Exclusiveness of Apartment Complex Boundary Design in Seoul, Korea

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    The proliferation of private residential development is evident worldwide. In Seoul, these developments have distinctive spatial and morphological characteristics. Originally, government housing policies drove the construction of apartment complexes to ensure massive housing supply. Over time, development shifted, becoming more market-driven, aimed at the middle class, and built by the private sector. During the late 1990s, an increase in luxury high-rise apartment complexes increased, reflecting a tendency to live in a socioeconomically homogeneous community and propelling the proliferation of self-contained gated communities. To understand the continually increasing exclusive nature of apartment complexes in Seoul, we examine two areas with apartment complexes of different periods and development methods: Mok-dong, where the 1980s ‘Housing Site Development’ resulted in the simultaneous construction of multiple apartment complexes according to a single master-plan, and Geumho-dong, a neighbourhood transforming by apartment complexes under ‘Housing Redevelopment’ from the 1980s to the present. The research focused on 28 complexes, and measured the surrounding vertical borders, pedestrian paths, and roadways, and access control. Tracing these features over time, we investigated the increasingly exclusive nature and decreasing public nature of apartment complexes, consequences of development for physical and social space during different periods, and degree of public or private intervention

    Combined Striatum, Brain Stem, and Optic Nerve Involvement due to Mycoplasma pneumoniae in an Ambulatory Child

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    In children, Mycoplasma pneumoniae encephalitis has been characterized by acute onset of an encephalopathy associated with extrapyramidal symptoms and symmetric basal ganglia with or without brain stem involvement on magnetic resonance imaging. Our case, showing unilateral optic neuritis, ophthalmoplegia, no extrapyramidal symptoms, and typical striatal involvement on magnetic resonance imaging, broadens the spectrum of varying clinical manifestations of childhood M. pneumoniae-associated encephalopathy

    Past, Present and Future Molecular Approaches to Improve Yield in Wheat

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    This chapter addresses the development and use of molecular markers for yield enhancement in wheat. Since their key goal for breeding is to maximize yield, extensive efforts have been made toward the improvement of yield. Agronomic traits related to yield, yield-related, disease resistance, and abiotic stresses are considered to be quantitative traits (QTLs), also known as complex traits, because they are controlled by numerous genes and are affected by environmental factors. Researchers have been studying such traits in the past decades for the development of molecular markers which can be used in various wheat breeding studies mainly involving restriction fragment length polymorphism (RFLP), simple sequence repeat (SSR), single nucleotide polymorphism (SNP), random amplified polymorphic DNA (RAPD), and amplified fragment length polymorphism (AFLP). Furthermore, the advent of next-generation sequencing (NGS) has accelerated the discovery of agronomically important genes. All of the technologies have enabled great advances for increasing the productivity of wheat. Here, the past history of first-generation sequencing, present status of second-generation sequencing, and future potential of translational genomics linked to the yield will be discussed

    Structural, electrical and multiferroic properties of Nb-doped Bi7Fe3Ti3O21 thin films

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    The effects of donor Nb5+-ion doping on the structural, electrical, and multiferroic properties of an Aurivillius Bi7Fe3Ti3O21 thin film were investigated. Incorporation of Nb5+-ions into the Ti4+-sites of the Bi7Fe3Ti3O21 thin film resulted in a substantial improvement of its electrical and multiferroic properties. From the study of the electrical properties, the Bi7Fe3Ti2.94Nb0.06O21+δ thin film exhibited a low leakage current density of 5.11×10-6 A/cm2at 100 kV/cm, which was about one order of magnitude lower than that of the untreated Bi7Fe3Ti3O21 thin film. The ferroelectric P -E hysteresis loops of the Bi7Fe3Ti2.94Nb0.06O21+δthin film showed a large remnant polarization (2Pr) of 20.6 μC/cm2 at 630 kV/cm whereas the 2Pr value measured for the untreated Bi7Fe3Ti3O21 thin film was 3.5 μC/cm2at 318 kV/cm. Furthermore, a well-saturated magnetic hysteresis loop with an enhanced magnetization was observed for the Bi7Fe3Ti2.94Nb0.06O21+ δthin film at room temperature
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