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Data storage is one of the hottest discussion topics in today’s connected world. The amount of data growth is expected to be exponential, while budget and space remain constricted. Since the transformation of storage device from planar NAND to 3D V-NAND [1], the areal density of semiconductor storage devices has continuously evolved and has surpassed the density of magnetic hard drives. By providing the largest storage capacity in the smallest footprint, 3D V-NAND has been leading the data center revolution in recent years. However, 3D-technology scaling faces several technical challenges [2]. (1) As the number of WL stacks increases the channel-hole etch process becomes a limit, since the total WL-mold height increases. (2) Interference between cells increases since the distance between WLs becomes smaller. (3) Faster data transfer speeds are required to support higher IO bandwidth.

This paper studies computing the l ∞ -induced norm of multi-input/multi-output (MIMO) linear time-invariant (LTI) discrete-time systems, which is called the l 1 analysis problem. Because such a computation involves an infinite-dimensional matrix, this paper employs a truncation idea to approximately deal with the l 1 analysis problem. More precisely, this paper develops two methods for computing the l ∞ -induced norm, in which upper bounds and lower bounds of the l ∞ -induced norm are derived on the truncated treatment. Furthermore, it is shown that the gaps between the computed upper and lower bounds converge to 0 at an exponential rate of N, where N is the truncation parameter. Finally, a numerical exampled is provided to demonstrate the effectiveness of the developed computation methods.

This paper describes the design of the lower limb wearable robot. When we design the wearable exoskeleton robot for rehabilitation, the major issue to be considered is the need for the robot and the patient to act mutually. The movement of the robot should be similar to the human's movement because they will move at the same time when the human wears the exoskeleton. Therefore, the robot should have the similar number of joint with the human Based on the concept, we developed the lower limb exoskeleton, KUEX-R. KUEX-R was designed to assist a patient who needs help when the patient walks and stands up. Since the degree of freedom that the human need to walk straight is at least five degree of freedoms (DOFs) per a leg, KUEX-R has ten actuated joints including the hip and the ankle roll joints. The location of the actuators and the length of the links were determined based on the wearer's comfortability.

In this paper, robust attitude determination based on the indirect extended Kalman filter is proposed. For the nano-satellite, there are only two vectors of magnetic vector and sun vector for vector measurement without redundant sensors. Accordingly, the three-axis attitude determination using conventional algorithm is impossible when one of the vectors is not available. The proposed attitude determination method uses propagation based on satellite attitude dynamics. The gyro measurements are used for a measurement, and angular rates are estimated by measurements and control inputs. Thus the attitude propagation shows much smaller error than conventional attitude update in the simulation results.

Nowadays energy efficiency in power electronics has been drawn a more attention as the worldwide energy crisis was raised up. To achieve high efficiency, thermal engineering in the design and construction of power conversion modules (or Intelligent Power Modules) are crucial in their rating and applications because the operation temperature or junction temperature (which is a maximum temperature rise in the die at a given power dissipation) gives strong impacts on reliability, performance and efficiency. A module with a low thermal resistance can afford the operation at the high power densities for the same temperature rise or lower temperatures for fixed power densities. To build an efficient power module having lower thermal resistance, substrate having a high thermal conductivity as well as good electrical isolation and reliability should be selected as a packaging platform. In this paper, the novel substrate technology which is so called ‘Copper Bonded Metal Substrate’ technology has been developed for intelligent power module (IPM) applications. Without the assistance of an adhesive material, the copper is directly bonded to the dielectric layers which have a high thermal conductivity and low-CTE (Coefficient of Thermal Expansion). These properties make CBM substrate technology a strongest contender for a packaging platform in power module applications. Electrical and thermal characteristics of the CBMTM substrate have been investigated as well. Owing to the structural continuity of CBM™ structure, as well as the high thermal conductivity of dielectric layer which is up to ∼5 W/m-K, the retardation of thermal resistance in the interface between the copper layer and base plate has been minimized. And computational simulation and experimental measurement of the thermal resistance of the functional power module which adopt the CBM™ substrate have been conducted. In addition, electrical insulating properties are enough to be affordable for a high voltage operation (over 700 Vrms) of the power modules with a low leakage current (< 300 nA). The obtained results in which CBM™ substrate has high heat dissipating capability and high insulating properties have been proven for CBM™ technology to be suitable for power module applications.

This paper presents a high dimming ratio LED driver for automotive lighting applications which require avoiding EMI radiation. In order to accomplish a high dimming ratio LED driver, the preloading inductor current methodology is proposed for the power stage of the proposed circuit to achieve the fast transient response time during the LED load switching. The proposed circuit receives the input voltage of 12V and generates the output voltage of 30V with the load current of 350mA. The chip is implemented with 0.35um BCDMOS process, and the die area is 2.35 × 2.35 mm2. Measurement results illustrate that the proposed LED drive system features the minimum rising time as small as 240ns and the corresponding dimming ratio becomes 2000∶1 at the dimming frequency of 1KHz. The maximum power conversion efficiency of the chip is measured to be 93.72%.

To improve spectrum utilization, cognitive radio attempts to use temporarily unoccupied spectrum which is referred to spectrum hole in cognitive radio. In this paper, we introduce novel spectrum management algorithms for cognitive radio. We introduce a heuristic matching algorithms which is named cost minimized matching. The heuristic algorithm proposed in this paper outperforms the general random matching algorithm with respect to the expected number of handovers and handover probability fairness. Also, the spectrum hole reservation algorithm minimizes service dropping while using optimum amount of resource, and it realizes seamless service by eliminating delay generated due to spectrum change. Performance analysis and computer simulations validate the efficiency of the proposed algorithms. The proposed algorithms can be efficiently used in cognitive radio systems.

To reduce handover overhead such as signaling overhead and latency, optimal handover algorithm is needed for mobile multi-hop relay (MMR) systems. This article proposes a novel handover method that reduces inter-cell handover but increases intra-cell handover events, because inter-cell handover has more overhead in view of the system and gives more latency time to users rather compared to intra-cell handover. Therefore, in the proposed scheme, intra-cell handover is encouraged instead inter-cell handover using adaptive hysteresis level. Intra-cell handover performs based on higher hysteresis level than inter-cell handover. This paper also presents hierarchical relay station ID (RS ID) concept for IEEE 802.16j standard. And, additional method using MOB_NBR-ADV message is proposed in case that hierarchical ID could not be used. This proposed algorithm can decrease handover signaling overhead, latency, and unnecessary handovers called ping-pong effect as well. Also, the proposed algorithm is backward compatible with mobile station (MS). Performance analysis and simulation validate the efficiency of the proposed algorithm.