Visible to the public Pattern Locks, 2014

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Pattern Locks, 2014

Pattern locks are best known as the access codes using a series of lines connecting dots.  Primarily familiar to Android users, research into pattern locks shows promise for many more uses.  The research cited here was presented in 2014.

Ishizaki, K.; Daijavad, S.; Nakatani, T., "Transforming Java Programs For Concurrency Using Double-Checked Locking Pattern," Performance Analysis of Systems and Software (ISPASS), 2014 IEEE International Symposium on, pp.128,129, 23-25 March 2014. doi: 10.1109/ISPASS.2014.6844469
Abstract: Java provides a synchronized construct for multi-core programming with many workloads. However, naïve use of the synchronized construct causes performance scalability problems due to lock contention. One of the sources of lock contentions is a synchronized collection class. There are known concurrency code patterns to alleviate lock contentions such as a Concurrent Collection (CC), Read-Write Lock (RWL), and Double-Checked Locking (DCL). To date, there is no algorithm to transform a program using DCL. This paper describes steps on how to rewrite synchronized blocks using DCL.
Keywords: Java; concurrency control; parallel programming; CC; DCL; Java programs; RWL; concurrency code patterns; concurrent collection; double-checked locking pattern; lock contention; multicore programming; performance scalability problems; read-write lock; synchronized block rewriting; synchronized construct; Concurrent computing; Java; Libraries; Programming; Scalability; Synchronization; Transforms (ID#: 15-5634)


Zongwei Zhu; Xi Li; Hengchang Liu; Cheng Ji; Yuan Xu; Xuehai Zhou; Beilei Sun, "A Thread Behavior-Based Memory Management Framework on Multi-core Smartphone," Engineering of Complex Computer Systems (ICECCS), 2014 19th International Conference on, pp. 91, 97, 4-7 Aug. 2014. doi: 10.1109/ICECCS.2014.21
Abstract: Memory management systems have significantly affected the overall performance of modern multi-core smartphone systems. Android, as one of the most popular smartphone operating systems, adopts a global buddy system with the FCFS (first come, first served) principle for memory allocation, and releases requests to manage external fragmentations and maintain the memory allocation efficiency. However, extensive experimental study on thread behaviors indicates that memory external fragmentation is no longer the crucial bottleneck in most Android applications. Specifically, a thread usually allocates or releases memory in bursts, resulting in serious memory locks and inefficient memory allocation. Furthermore, the pattern of such bursting behaviors varies throughout the life cycle of a thread. The conventional FCFS policy of Android buddy system fails to adapt to such variations and thus suffers from performance degradation. In this paper, we propose a novel memory management framework, called Memory Management Based on Thread Behaviors (MMBTB), for multi-core smartphone systems. It adapts to various thread behaviors through targeted optimizations to provide efficient memory allocation. The efficiency and effectiveness of this new memory management scheme on multicore architecture is proved by a theoretical emulation model. Our experimental studies on the real Android system show that MMBTB can improve the efficiency of memory allocation by 12%-20%, confirming the theoretical analysis results.
Keywords: Android (operating system);multiprocessing systems; smart phones; storage management; Android applications; Android buddy system; FCFS; MMBTB; first come first served principle; global buddy system; memory allocation; memory external fragmentation; memory management based on thread behaviors; memory management systems; multicore architecture; multicore smartphone systems; smartphone operating systems; thread behavior-based memory management framework; Androids; Humanoid robots; Instruction sets; Libraries; Memory management; Multicore processing; Resource management; Android; behaviors; memory management; smartphone; thread (ID#: 15-5635)


Thatmann, D., "Distributed Authorization In Complex Multi Entity-Driven API Ecosystems," Signal Processing and Communication Systems (ICSPCS), 2014 8th International Conference on, pp. 1, 9, 15-17 Dec. 2014. doi: 10.1109/ICSPCS.2014.7021072
Abstract: In certain business sectors adapting to modern and cost reducing technologies and service models can be still a challenge. This especially applies for health care related SME, such as hospitals, where cost reduction runs counter the need of being compliant to legal regulations and where the access control has to struggle against a diverse landscape of health care equipment accompanied by dynamic and complex role models. Outsourcing data storage and data processing seems not to reduce the complexity, rather bears the risks of reduced data availability, loss or abuse of data and can increase legal compliance risks and concerns. Since this applies for many SMEs, a common platform, such as an ecosystem, can help to lower the entrance barrier by regaining helpful management functionalities, standardized basic services and therefore push the adoption to modern cost reducing service consumption scenarios. In this paper a generic design pattern for realizing distributed authorization in an API ecosystem is presented. The pattern is applied within a research project, which aims to develop an ecosystem for trading and consuming services within demanding business sectors and reduce lock-in effects for both, service providers and consumers. The concept of Distributed Authorization is applied in a new complex multi entity use-case, where access policies for RESTful APIs can be designed flexible under consideration of service providers' and consumers' requirements which are enforced by a central trusted 3rd party provider.
Keywords: application program interfaces; authorisation; API ecosystem; SME; access control; complex multientity-driven API ecosystems; data processing; distributed authorization; generic design pattern; health care equipment; hospitals; outsourcing data storage; trading; Authorization; Contracts; Ecosystems; Logic gates; Monitoring; Servers (ID#: 15-5636)


Holey, A.; Zhai, A., "Lightweight Software Transactions on GPUs," Parallel Processing (ICPP), 2014 43rd International Conference on, pp. 461, 470, 9-12 Sept. 2014. doi: 10.1109/ICPP.2014.55
Abstract: Graphics Processing Units (GPUs) provide an attractive option for extracting data-level parallelism from diverse applications. However, some applications, although possess abundant data-level parallelism, exhibit irregular memory access patterns to the shared data structures. Porting such applications to GPUs requires synchronization mechanisms such as locks, which significantly increase the programming complexity. Coarse-grained locking, where a single lock controls all the shared resources, although reduces programming efforts, can substantially serialize GPU threads. On the other hand, fine-grained locking, where each data element is protected by an independent lock, although facilitates maximum parallelism, requires significant programming efforts. To overcome these challenges, we propose to support software transactional memory (STM) on GPU that is able to achieve performance comparable to fine-grained locking, while requiring minimal programming efforts. Software-based transactional execution can incur significant runtime overheads due to activities such as detecting conflicts across thousands of GPU threads and managing a consistent memory state. Thus, in this paper we illustrate three lightweight STM designs that are capable of scaling to a large number of GPU threads. In our system, programmers simply mark the critical sections in the applications, and the underlying STM support is able to achieve performance comparable to fine-grained locking.
Keywords: data structures; graphics processing units; multi-threading; parallel processing; storage management; transaction processing; GPU threads; GPUs; STM; application porting; coarse-grained locking; consistent memory state management; data-level parallelism; graphics processing units; irregular memory access patterns; programming complexity; shared data structures; software transactional memory; software transactions; software-based transactional execution; synchronization mechanisms; Graphics processing units; Instruction sets; Parallel processing; Programming; Reactive power; System recovery; GPUs; parallel programming; software transactional memory (ID#: 15-5637)


Rybnicek, M.; Lang-Muhr, C.; Haslinger, D., "A Roadmap To Continuous Biometric Authentication On Mobile Devices," Wireless Communications and Mobile Computing Conference (IWCMC), 2014 International, pp. 122, 127, 4-8 Aug. 2014. doi: 10.1109/IWCMC.2014.6906343
Abstract: Mobile devices nowadays contain a variety of personal or even business-related information that is worth being protected from unauthorized access. Owners of such devices should use a passcode or unlock pattern to secure such important assets, but since these techniques are being perceived as annoying barriers, locked devices are not standard. But even if such authentication mechanisms are used, they are very easy to circumvent. Biometric methods are promising applications to secure mobile devices in an user-friendly, discreet way. Based on embedded sensors like gyroscope, accelerometer or microphones, which are state-of-the-art sensors for mobile devices, behavioral biometric approaches appear even more attractive for user verification than physiological methods like fingerprints or face recognition. So far many biometric approaches have been presented. After a short overview of relevant representatives, we discuss these methods based on their applicability and limitations. Our findings are summarized and presented as a roadmap to provide a foundation for future research.
Keywords: biometrics (access control); mobile handsets; security of data; authentication mechanisms; continuous biometric authentication; mobile devices; Accelerometers; Authentication; Electronic mail; Feature extraction; Mobile handsets; Tactile sensors; Bring your own Device; Continuous Biometrics; Mobile Security (ID#: 15-5638)


Articles listed on these pages have been found on publicly available internet pages and are cited with links to those pages. Some of the information included herein has been reprinted with permission from the authors or data repositories. Direct any requests via Email to for removal of the links or modifications to specific citations. Please include the ID# of the specific citation in your correspondence.