1674369
An integrated source coding and congestion control framework for video streaming in the Internet
We describe a framework for video transmission over the Internet that features the coordinated operation of an application-layer video source coding algorithm and a transport-layer rate control mechanism. The proposed video coding scheme operates on a progressively encoded video stream and provides graceful resilience to network packet drops. The robustness is enabled through a generalized multiple description (MD) coding strategy, architectured as an adaptive array of packet-erasure correction codes. The video coding algorithm is matched to an efficient and reactive rate control mechanism that minimizes the fluctuation of rate and uses the profile of past losses to adjust the rate in a TCP-friendly manner. While the two constituent algorithms identified above are interesting in their own right, a key feature of this work is the integration of these algorithms in a simple framework that seeks to maximize the expected delivered video quality at the receiver through coordinated adaptation of the two components. We present simple simulation results to illustrate the utility of our approach.
6972987
Scalable service differentiation in a shared storage cache
Motivated by the need to enable easier data sharing and curb rising storage management costs, storage systems are becoming increasingly consolidated and thereby shared by a large number of users and applications. In such environments, service differentiation becomes increasingly important. Since caching is a fundamental and pervasive technique employed to improve the performance of storage systems, providing differentiated services from a storage cache is a crucial component of the entire end-to-end QoS solution. In this paper we discuss a QoS architecture for a shared storage proxy cache which can provide long-term hit rate assurances to competing classes. The proposed architecture consists of three components: (a) per-class feedback controllers that track the performance of each class, (b) a fairness controller that allocates excess resources fairly in the case when all goals are met, and (c) a contention resolver that decides cache allocation in the case when at least one class does not meet its target hit rate. We compare the performance of various feedback per-class controllers, and provide guidelines for designing QoS mechanisms for such a dynamic environment.
11059176
Policy-based validation of SAN configuration
Historically, storage has been directly connected to servers for fast local access and easy configuration. In recent years, storage area networks (SANs) have defined an alternative storage paradigm that allows storage to be shared among servers using fast interconnects. One of the key challenges of SAN management is the large number of configuration problems that are encountered in a typical SAN deployment. These configuration problems can be addressed by SAN management software. However, hard-coding the SAN configuration rules into the management software is not a viable option since it is not possible to easily modify or replace old configuration rules and specify new policies and guidelines. In this paper, we propose a novel policy-based SAN configuration validation system that can be used to specify, store, and evaluate configuration policies for SANs. We also introduce five new operators for collection policies that are useful for evaluating a wide variety of practical SAN configuration policies found in practice. The policy-based SAN configuration checking approach proposed in this paper is discussed within the context of device interoperability constraints. However, this approach is extensible as it can also be used to enforce performance, reliability, and security-related configuration constraints.
6735701
Dependency algebra: a theoretical framework for dependency management in real-time control systems
The large and complex dependency relationship between software components is at the root of system instability. A seemingly minor fault can propagate along dependency chains and bring down the system. Therefore, the first step in the development of a robust system is the management and control of dependency relations between software components. The two contributions of this paper are: 1) a refinement of the commonly used failure semantics in the context of a real time control system; 2) the development of a dependency algebra. Component dependency relationships can be described in terms of a set of refined failure semantics mappings, enabling differentiation and comparison of different relationships and designs. The system-wide evaluation and tracking of these dependency relationships are performed using dependency algebra.
2700489
An efficient algorithm for predictive continuous nearest neighbor query processing and result maintenance
Predictive continuous nearest neighbor queries are concerned with finding the nearest neighbor objects for some future time period according to the current object and query locations and their motion information. Existing continuous query processing algorithms are not efficient enough, requiring multiple dataset lookups to evaluate the query results throughout the duration of a continuous query. More importantly, the complete result for the whole query time interval is only available at the moment when all object motion updates have been examined, based on which adjustment of the query result is made. In this paper, we propose an algorithm which requires only one dataset lookup to deliver a complete predictive result. We then apply a differential update technique to maintain the query results incrementally in the presence of object location and motion updates.
16838706
Hangul, the Korean Writing System, and its Computational Treatment
In this paper I will describe how the efficiency of the Hangul writing system can be transferred to its coding on computers. I will also review the encodings of Hangul by the precomposed Hangul code set of KSC 5601, a combinational Hangul code set, and ISO 2022, and their applications to the development of Hangul pro grams for sorting, editing, and processing Korean text. I then conclude with remarks on the merger efforts of the Unicode standard and ISO DIS 10646 on Hangul.
11611370
A component model for building systems software
OpenCOM v2 is our experimental language-independent component-based systems-building technology. OpenCOM offers more than merely a component-based programming model. First, it is a runtime component model and supports dynamic runtime reconfiguration of systems (i.e. one can load, unload, bind, and rebind components at runtime). Second, it explicitly supports the deployment of the model in a wide range of ‘deployment environments’ (e.g. operating systems, PDAs, embedded devices, network processors). Third, it allows the particularities of different deployment environments to be selectively hidden from/ made visible to the OpenCOM programmer without inherent performance overhead.
24310355
Component-Based Online Learning for Face Detection and Verification
Component detectors can accurately locate facial components, and component-based approaches can be used to build detectors that can handle partial occlusions. This paper proposes a face detection and verification method using component-based online learning. The main difference from previously reported component-based approaches is the use of online learning, which is ideal for highly repetitive tasks. This results in faster and more accurate face detection, because system performance improves with continued use. Further, uncertainty is added by calculating the standard deviation of face components and their relations.