Interactive Collision Detection for Deformable Models Using Streaming AABBs

Xinyu Zhang,Kim, Y.J. IEEE Computer Society 2007 IEEE transactions on visualization and computer gr Vol.13 No.2

<P>We present an interactive and accurate collision detection algorithm for deformable, polygonal objects based on the streaming computational model. Our algorithm can detect all possible pairwise primitive-level intersections between two severely deforming models at highly interactive rates. In our streaming computational model, we consider a set of axis aligned bounding boxes (AABBs) that bound each of the given deformable objects as an input stream and perform massively-parallel pairwise, overlapping tests onto the incoming streams. As a result, we are able to prevent performance stalls in the streaming pipeline that can be caused by expensive indexing mechanism required by bounding volume hierarchy-based streaming algorithms. At runtime, as the underlying models deform overtime, we employ a novel, streaming algorithm to update the geometric changes in the AABB streams. Moreover, in order to get only the computed result (i.e., collision results between AABBs) without reading back the entire output streams, we propose a streaming en/decoding strategy that can be performed in a hierarchical fashion. After determining overlapped AABBs, we perform a primitive-level (e.g., triangle) intersection checking on a serial computational model such as CPUs. We implemented the entire pipeline of our algorithm using off-the-shelf graphics processors (GPUs), such as nVIDIA GeForce 7800 GTX, for streaming computations, and Intel Dual Core 3.4G processors for serial computations. We benchmarked our algorithm with different models of varying complexities, ranging from 15K up to 50K triangles, under various deformation motions, and the timings were obtained as 30~100 FPS depending on the complexity of models and their relative configurations. Finally, we made comparisons with a well-known GPU-based collision detection algorithm, CULLIDE and observed about three times performance improvement over the earlier approach. We also made comparisons with a SW-based AABB culling algorithm and observed about two times improvement</P>

Effects of Moral Judgement on Information Ethics of Gifted Students in Computer Science

권대용 IEEE Computer Society 2013 2013 IEEE 37th Annual Computer Software and Applic Vol.1 No.1

Activity Probability-Based Performance Analysis and Contention Control for IEEE 802.11 WLANs

Choi, Junsu,Byeon, Seongho,Choi, Sunghyun,Lee, Kwang Bok IEEE Computer Society 2017 IEEE TRANSACTIONS ON MOBILE COMPUTING Vol.16 No.7

<P>In this paper, we develop a contention window (CW) control scheme for practical IEEE 802.11 wireless local area networks (WLANs) that have node heterogeneity in terms of the traffic load, transmission rate, and packet size. We introduce activity probability, i.e., the probability that a node contends for medium access opportunities at a given time. We then newly develop a performance analysis model that enables analytic estimation on the contention status including the collision probability, collision time, back-off time, and throughput with comprehensive consideration of node heterogeneity. Based on the newly developed model, we derive the theoretically ideal contention status, and develop a CW control scheme that achieves the ideal contention status in an average sense. We perform extensive NS-3 simulations and real testbed experiments for evaluation of both the proposed performance analysis model and CW control scheme. The results show that the proposed model provides accurate prediction on the contention status, and the proposed CW control scheme achieves considerable throughput improvement compared to the existing schemes which do not comprehensively consider node heterogeneity.</P>

Overcoming IoT Language Barriers Using Smartphone SDRs

Park, Yongtae,Kuk, Seungho,Kang, Inhye,Kim, Hyogon IEEE Computer Society 2017 IEEE TRANSACTIONS ON MOBILE COMPUTING Vol.16 No.3

<P>In the Internet of Things (IoT) era, smartphones are expected to frequently interact with IoT devices and even facilitate various IoT applications. Due to limited roles, energy constraints, etc., however, IoT devices may use mission-tailored or proprietary wireless protocols that smartphones do not speak natively. In this paper, we propose a novel approach to the wireless 'language barrier' problem between the smartphones and IoT devices of the future. We first demonstrate that smartphones have become powerful enough to process software defined radio (SDR) for some known wireless protocols. Moreover, we show that the SDRs can be packaged as 'apps' and be downloaded from app stores for OS-independent deployment. Second, we show different SDR protocols on the smartphone can concurrently run through a shared RF to serve multi-tasked applications on it as might happen in diversified IoT environments. For proof-of-concept, we implement a prototype architecture that has all the SDR logic and supporting middleware on an Android smartphone which uses a USRP as the simple RF-end. Finally, we demonstrate that IEEE 802.11p and IEEE 802.15.4 SDRs on a smartphone, respectively, communicate with a ZigBee sensor mote, a ZigBee smart lightbulb, and a commercial Wireless Access in Vehicular Environment (WAVE) device, concurrently.</P>

3D Finger CAPE: Clicking Action and Position Estimation under Self-Occlusions in Egocentric Viewpoint

Youngkyoon Jang,Seung-Tak Noh,Hyung Jin Chang,Tae-Kyun Kim,Woontack Woo IEEE Computer Society 2015 IEEE transactions on visualization and computer gr Vol. No.

<P>In this paper we present a novel framework for simultaneous detection of click action and estimation of occluded fingertip positions from egocentric viewed single-depth image sequences. For the detection and estimation, a novel probabilistic inference based on knowledge priors of clicking motion and clicked position is presented. Based on the detection and estimation results, we were able to achieve a fine resolution level of a bare hand-based interaction with virtual objects in egocentric viewpoint. Our contributions include: (i) a rotation and translation invariant finger clicking action and position estimation using the combination of 2D image-based fingertip detection with 3D hand posture estimation in egocentric viewpoint. (ii) a novel spatio-temporal random forest, which performs the detection and estimation efficiently in a single framework. We also present (iii) a selection process utilizing the proposed clicking action detection and position estimation in an arm reachable AR/VR space, which does not require any additional device. Experimental results show that the proposed method delivers promising performance under frequent self-occlusions in the process of selecting objects in AR/VR space whilst wearing an egocentric-depth camera-attached HMD.</P>

Link Capacity-Energy Aware WDC for Network Lifetime Maximization

Seonghyun Kim,Sanghoon Lee IEEE Computer Society 2015 IEEE Transactions on Mobile Computing Vol. No.

<P>With the increase in flexibility and capabilities of wireless networks, the use of distributed computing over wireless network environments is being researched in order to maximize network sustainability and interoperability among distributed nodes. To this end, a new paradigm is required for optimization of a more generalized environment. This environment would include various nodes of different processing and communication abilities constrained by circuit powers and residual energy over individual dynamic wireless channels. In this paper, we present a novel strategy named link capacity-energy aware wireless distributed computing (LEA-WDC) for maximizing the lifetime of a wireless network. The major advantage of LEA-WDC is its achievement of lifetime maximization by systematically reconciling highly coupled system parameters (tasks, processing power, communication power, and residual energy) in terms of the role of nodes and the layer of each node. To attain an optimal solution, we perform unique interworking optimization via decomposition in accordance with the roles of header and slave nodes. The evaluation results of our simulation verify that the lifetime is further maximized by finding the optimal transmission power of each node according to the Shannon capacity.</P>

Adaptive Route Optimization in Hierarchical Mobile IPv6 Networks

Sangheon Pack,Xuemin Shen,Mark, J.W. IEEE Computer Society 2007 IEEE TRANSACTIONS ON MOBILE COMPUTING Vol.6 No.8

<P>By introducing a mobility anchor point (MAP), Hierarchical Mobile IPv6 (HMIP6) reduces the signaling overhead and handoff latency associated with Mobile IPv6. However, if a mobile node (MN)'s session activity is high and its mobility is relatively low, HMIPv6 may degrade end-to-end data throughput due to the additional packet tunneling at the MAP. In this paper, we propose an adaptive route optimization (ARO) scheme to improve the throughput performance in HMIPv6 networks. Depending on the measured session-to-mobility ratio (SMR), ARO chooses one of the two different route optimization algorithms adaptively. Specifically, an MN informs a correspondent node (CN) of its on-link care-of address (LCoA) if the CN's SMR is greater than a predefined threshold. If the SMR is equal to or lower than the threshold, the CN is informed with the MN's regional CoA (RCoA). We analyze the performance of ARO in terms of balancing the signaling overhead reduction and the data throughput improvement. We also derive the optimal SMR threshold explicitly to achieve such a balance. Analytical and simulation results demonstrate that ARO is a viable scheme for deployment in HMIPv6 networks.</P>

Designing Fault-Tolerant Photovoltaic Systems

Xue Lin,Yanzhi Wang,Pedram, Massoud,Jaemin Kim,Naehyuck Chang IEEE Computer Society 2014 IEEE design & test Vol.31 No.3

<P>PV systems are subject to PV cell faults, which lower the output power and shorten the lifespan of the system. This paper presents the design principles and runtime control algorithms of a fault-tolerant PV system which can detect and bypass PV cell faults in situ without any manual interventions.</P>

Feature-Modeling and Aspect-Oriented Programming: Integration and Automation

이관우 IEEE Computer Society 2009 Networking and Parallel/Distributed Computing Vol.1 No.-

Hierarchical and Controlled Advancement for Continuous Collision Detectionof Rigid and Articulated Models

Min Tang,Manocha, Dinesh,Kim, Young J. IEEE Computer Society 2014 IEEE transactions on visualization and computer gr Vol.20 No.5

<P>We present fast CCD algorithm for general rigid and articulated models based on conservative advancement. We have implemented the CCD algorithm with two different acceleration techniques which can handle rigid models, and have extended one of them to articulated models. The resulting algorithms take a few milliseconds for rigid models with tens of thousands of triangles, and a few milliseconds for articulated models with tens of links. We show that the performance of our algorithms is much faster than existing CCD algorithms for polygon-soup models and it is also comparable to competing CCD algorithms that are limited to manifold models. The preliminary version of this paper appeared in .</P>