Situated Testimony: Forensic Architecture’s Memory Objects

“Forensic Architecture” describes both the research agency, founded in 2011, as well as its investigative method and aesthetic practice. As an emerging discipline, forensic architecture exploits the relation between space, material, and memory. My aim in this article is to consider how the agency’s “memory objects”—aestheticized virtual renderings of their investigations—operate as testimonial objects, evidentiary archives, and simulated sites of conscience. I attend to one “memory object” in particular, a film titled “Drone Strike Investigation Case no. 2: Mir Ali, North Waziristan, 4 October 2010; The Architecture of Memory,” an investigation which the U.N. Special Rapporteur on Counter Terrorism and Human Rights commissioned Forensic Architecture to undertake. This article suggests that this virtual “memory object” troubles the status of both the human witness and the physical landscape to which it refers.

Establishment of the Optimal Common Data Model Environment for EMR Data Considering the Computing Resources of Medical Institutions

Electronic medical record (EMR) data vary between institutions. These data should be converted into a common data model (CDM) for multi-institutional joint research. To build the CDM, it is essential to integrate the EMR data of each hospital and load it according to the CDM model, considering the computing resources of each hospital. Accordingly, this study attempts to share experiences and recommend computing resource-allocation designs. Here, two types of servers were defined: combined and separated servers. In addition, three database (DB) setting types were selected: desktop application (DA), online transaction processing (OLTP), and data warehouse (DW). Scale, TPS, average latency, 90th percentile latency, and maximum latency were compared across various settings. Virtual memory (vmstat) and disk input/output (disk) statuses were also described. Transactions per second (TPS) decreased as the scale increased in all DB types; however, the average, 90th percentile and maximum latencies exhibited no tendency according to scale. When compared with the maximum number of clients (DA client = 5, OLTP clients = 20, DW clients = 10), the TPS, average latency, 90th percentile latency, and maximum latency values were highest in the order of OLTP, DW, and DA. In vmstat, the amount of memory used for the page cache field and free memory currently available for DA, OLTP, and DW were large compared to other fields. In the disk, DA, OLTP, and DW all recorded the largest value in the average size of write requests, followed by the largest number of write requests per second. In summary, this study presents recommendations for configuring CDM settings. The configuration must be tuned carefully, considering the hospital’s resources and environment, and the size of the database must consider concurrent client connections, architecture, and connections.

Refresh Rate Identification Strategy for Optimal Page Replacement Algorithms for Virtual Memory Management

Operating system offers a service known as memory management which manages and guides primary memory. It moves processes between disk and main memory during the execution back and forth. The process in which we provisionally moves process from primary memory to the hard disk so the memory is available for other processes. This process is known as swapping. Page replacement techniques are the methods by which the operating system concludes which memory pages to be swapped out and write to disk, whenever a page of main memory is required to be allocated. There are different policies regarding how to select a page to be swapped out when a page fault occurs to create space for new page. These Policies are called page replacement algorithms. In this paper the strategy for identifying the refresh rate for ‘Aging’ page replacement algorithm is presented and evaluated. Keywords: Aging algorithm, page replacement algorithm, refresh rate, virtual memory management.

Securing Interruptible Enclaved Execution on Small Microprocessors

Computer systems often provide hardware support for isolation mechanisms such as privilege levels, virtual memory, or enclaved execution. Over the past years, several successful software-based side-channel attacks have been developed that break, or at least significantly weaken, the isolation that these mechanisms offer. Extending a processor with new architectural or micro-architectural features brings a risk of introducing new software-based side-channel attacks. This article studies the problem of extending a processor with new features without weakening the security of the isolation mechanisms that the processor offers. Our solution is heavily based on techniques from research on programming languages. More specifically, we propose to use the programming language concept of full abstraction as a general formal criterion for the security of a processor extension. We instantiate the proposed criterion to the concrete case of extending a microprocessor that supports enclaved execution with secure interruptibility. This is a very relevant instantiation, as several recent papers have shown that interruptibility of enclaves leads to a variety of software-based side-channel attacks. We propose a design for interruptible enclaves and prove that it satisfies our security criterion. We also implement the design on an open-source enclave-enabled microprocessor and evaluate the cost of our design in terms of performance and hardware size.

Signals for antigen-independent differentiation of memory CD8+ T cells

Conventional CD8+ memory T cells develop upon stimulation with foreign antigen and provide increased protection upon re-challenge. Over the past two decades, new subsets of CD8+ T cells have been identified that acquire memory features independently of antigen exposure. These antigen-inexperienced memory T cells (TAIM) are described under several names including innate memory, virtual memory, and memory phenotype. TAIM cells exhibit characteristics of conventional or true memory cells, including antigen-specific responses. In addition, they show responsiveness to innate stimuli and have been suggested to provide additional levels of protection toward infections and cancer. Here, we discuss the current understanding of TAIM cells, focusing on extrinsic and intrinsic molecular conditions that favor their development, their molecular definitions and immunological properties, as well as their transcriptional and epigenetic regulation.