Kyoung Park

The handwave bluetooth skin conductance sensor

HandWave is a small, wireless, networked skin conductance sensor for affective computing applications. It is used to detect information related to emotional, cognitive, and physical arousal of mobile users. Many existing affective computing systems make use of sensors that are inflexible and often physically attached to supporting computers. In contrast, HandWave allows an additional degree of flexibility by providing ad-hoc wireless networking capabilities to a wide variety of Bluetooth devices as well as adaptive biosignal amplification. As a consequence, HandWave is used in a variety of affective computing applications such as games, tutoring systems, experimental data collection, and augmented journaling. This paper describes the novel design attributes of this handheld sensor, its development, and various form factors. Future work includes an extension of this approach to other biometric signals of interest to affective computing researchers.

Room temperature observation of single electron tunneling effect in self-assembled metal quantum dots on a semiconductor substrate

We report on the observation of room-temperature single electron tunneling phenomena in a metal-insulator-metal-semiconductor double-junction structure. The nanosized Ag dots were self-assembled on a Sb-terminated Si(100) surface, and the Coulomb gap and staircases were observed in the local current–voltage (I–V) measurements using scanning tunneling microscopy. The I–V characteristics exhibiting the single electron tunneling behavior vary significantly with the variation of the measurement position within the same Ag droplet. These phenomena are well described by the tip-dot(Ag)-Si double-junction picture.

Effects of atomistic defects on coherent electron transmission in Si nanowires: Full band calculations

The effects of atomistic imperfections on coherent electron transmission in Si[100] quantum wires a few nanometers wide are investigated using a tight-binding Green function approach. We find a significant suppression in the electron transmission by atomistic imperfections in these extremely narrow wires. Multiple conductance peaks or oscillations can be easily developed by the presence of only several vacancy defects, which can lead to a finite zero-conductance region around the subband edge. Several substitutional defects and surface dangling bonds generally result in decreased, oscillatory conductances with more significant effects found in narrower wires.

GEOMETRICALLY INDUCED MULTIPLE COULOMB BLOCKADE GAPS

We have theoretically investigated the transport properties of a ring-shaped array of small tunnel junctions, which is weakly coupled to the drain electrode. We have found that the long range interaction together with the semi-isolation of the array bring about the formation of stable standing configurations of electrons. The stable configurations break up during each transition from odd to even number of trapped electrons, leading to multiple Coulomb blockade gaps in the the

SECONDARY COULOMB BLOCKADE GAP IN A FOUR-ISLAND TUNNEL-JUNCTION ARRAY

I-V

Internet Protocol Engine in TCP/IP Offloading Engine

characteristics of the system.

Linux/SimOS - a simulation environment for evaluating high-speed communication systems

In the ring-shaped tunnel-junction array with four islands, the secondary Coulomb blockade gap in a low bias-voltage range is observed in the I-V characteristics. We attribute its appearance to the unique topology of the array which induces up to two electrons to get trapped inside. We have analyzed the formation and destruction of the gap in terms of detailed single-electron tunneling processes. The negative differential resistance behavior when the thermal and quantum fluctuations are present is also studied.

Effective digital IO pin modeling methodology based on IBIS model

As the network works in high speed, TCP/IP protocol loads on the host CPU. Recently, TOE (TCP/IP Offload Engine) which processes TCP/IP on a network adapter instead of host CPU is rising up to the network market to solve the CPU burden. This paper is the design of TCP/IP offloading Engine in lGbps network. Especially, our engine is fully offloaded for TCP/IP using two embedded processor and Internet protocol also designed in hardware circuit level. In this paper, we show the hardware design of the Internet protocol and the role of IP in TOE. The manufactured chip can show the satisfaction for high speed network over lGbps.

Band gap tunability of molecular beam epitaxy grown lateral composition modulated GaInP structures by controlling V/III flux ratio

This paper presents Linux/SimOS, a Linux operating system port to SimOS, which is a complete machine simulator from Stanford. The motivation for Linux/SimOS is to alleviate the limitations of SimOS, which only supports proprietary operating systems. The contributions made in this paper are two-fold: First, the major modifications that were necessary to run Linux on SimOS are described. Second, a detailed analysis of the UDP/IP protocol and M-VIA is performed to demonstrate the capabilities of Linux/SimOS. The simulation study shows that Linux/SimOS is capable of capturing all aspects of communication performance, including the effects of the kernel, device drivers, and network interface.

AMBA based multiprocessor system

IBIS (I/O buffer information specification) model is widely used in signal integrity analysis of on-board high-speed digital systems. IBIS model is converted equivalent SPICE behavioral model when used board-level simulations. It is important to represent accurately output buffers switching characteristics converting IBIS model to SPICE behavioral model. This paper proposes a new modeling algorithm to represent output buffers switching characteristics in IBIS model. The accuracy of the proposed algorithm has verified through SPICE simulation with other behavioral models.