Samsung

About: Samsung is a company organization based out in Seoul, South Korea. It is known for research contribution in the topics: Layer (electronics) & Signal. The organization has 134067 authors who have published 163691 publications receiving 2057505 citations. The organization is also known as: Samsung Group & Samsung chaebol.

Hypervision Across Worlds: Real-time Kernel Protection from the ARM TrustZone Secure World

Abstract: TrustZone-based Real-time Kernel Protection (TZ-RKP) is a novel system that provides real-time protection of the OS kernel using the ARM TrustZone secure world. TZ-RKP is more secure than current approaches that use hypervisors to host kernel protection tools. Although hypervisors provide privilege and isolation, they face fundamental security challenges due to their growing complexity and code size. TZ-RKP puts its security monitor, which represents its entire Trusted Computing Base (TCB), in the TrustZone secure world; a safe isolated environment that is dedicated to security services. Hence, the security monitor is safe from attacks that can potentially compromise the kernel, which runs in the normal world. Using the secure world for kernel protection has been crippled by the lack of control over targets that run in the normal world. TZ-RKP solves this prominent challenge using novel techniques that deprive the normal world from the ability to control certain privileged system functions. These functions are forced to route through the secure world for inspection and approval before being executed. TZ-RKP's control of the normal world is non-bypassable. It can effectively stop attacks that aim at modifying or injecting kernel binaries. It can also stop attacks that involve modifying the system memory layout, e.g, through memory double mapping. This paper presents the implementation and evaluation of TZ-RKP, which has gone through rigorous and thorough evaluation of effectiveness and performance. It is currently deployed on the latest models of the Samsung Galaxy series smart phones and tablets, which clearly demonstrates that it is a practical real-world system.

Low complexity precoding for large millimeter wave MIMO systems

Abstract: Millimeter wave (mmWave) systems must overcome heavy signal attenuation to support high-throughput wireless communication links. The small wavelength in mmWave systems enables beamforming using large antenna arrays to combat path loss with directional transmission. Beamforming with multiple data streams, known as precoding, can be used to achieve even higher performance. Both beamforming and precoding are done at baseband in traditional microwave systems. In mmWave systems, however, the high cost of mixed-signal and radio frequency chains (RF) makes operating in the passband and analog domains attractive. This hardware limitation places additional constraints on precoder design. In this paper, we consider single user beamforming and precoding in mmWave systems with large arrays. We exploit the structure of mmWave channels to formulate the precoder design problem as a sparsity constrained least squares problem. Using the principle of basis pursuit, we develop a precoding algorithm that approximates the optimal unconstrained precoder using a low dimensional basis representation that can be efficiently implemented in RF hardware. We present numerical results on the performance of the proposed algorithm and show that it allows mmWave systems to approach waterfilling capacity.

Are Firm-Specific Advantages Location-Specific Too?

Abstract: Much of the research on the role of firm-specific advantages on firms' subsidiary ownership preferences has been undertaken in the context of advanced-country multinationals, specifically U.S. MNCs. Research has found that U.S. firms derive ownership advantages from their size, experience, and technological and marketing superiority. Perhaps having operated in the most-developed and sophisticated home market, many U.S. firms generate unique skills that give them absolute advantages over firms in almost all foreign host locations. Developing-country MNCs do not have absolute ownership advantages similar to those of the U.S. firms. The relevance of a particular firm-specific characteristic for a developing-country MNC may be contingent not only upon the home-country characteristics, as in the case of U.S. MNCs, but also upon host-country characteristics. This study investigates the subsidiary ownership preferences among Korean MNCS and finds that the influence of three firm-specific advantages—technological intensity, product differentiation and capital intensity—on subsidiary ownership levels is contingent upon whether the subsidiary is located in a relatively less-developed or a more-developed country as compared to the home country. Although some authors have suggested that the influence of firm-specific advantages may be contingent upon the characteristics of both home- and host-country locations, empirical investigations to this effect have been nonexistent.

Degrees of Freedom of the MIMO Y Channel: Signal Space Alignment for Network Coding

Abstract: In this paper, we study a network information flow problem for a multiple-input-multiple-output (MIMO) Gaussian wireless network with three users each equipped with M antennas and a single intermediate relay equipped with N antennas. In this network, each user intends to convey independent messages for two different users via the intermediate relay while receiving two independent messages from the other two users. This is a generalized version of the two-way relay channel for the three-user case. We will call it a "MIMO Y channel." For this MIMO Y channel, we show that the capacity is 3M log(SNR) + o(log(SNR)) if N ≥ ⌈3M/2⌉ by using two novel signaling techniques, which are signal space alignment for network coding, and network-coding-aware interference nulling beamforming.