Jinman Jung

A capsaicin-receptor antagonist, capsazepine, reduces inflammation-induced hyperalgesic responses in the rat: evidence for an endogenous capsaicin-like substance.

In the present study, the presence of an endogenous capsaicin-like substance and the role of capsaicin receptors in nociception during inflammation were assessed using Fos immunohistochemistry and the paw-withdrawal test in rats. Intradermal injection of carrageenan in the hind-paw produced inflammation in the foot pad, increased the number of cells exhibiting Fos-like immunoreactivity in the dorsal horn of the spinal cord, and decreased the paw-withdrawal latency. Intradermal injection of capsazepine, a capsaicin-receptor antagonist, significantly reduced the number of cells exhibiting Fos-like immunoreactivity, significantly increased the paw-withdrawal latency, but did not decrease inflammation induced by carrageenan injection. Intradermal injection of capsaicin or formalin also increased Fos-positive neurons. Capsaicin- or formalin-induced Fos expression was reduced in both cases by pretreatment of capsazepine, but to a much lesser extent for formalin. The capsazepine inhibition of carrageenan inflammation-induced hyperalgesic responses strongly suggests that an endogenous capsaicin-like substance is released in inflamed tissues and produces nociceptive neural impulses by acting on capsaicin receptors present on sensory neurons. Furthermore, our results indicate that capsaicin receptors take part only in generating nociceptive signals in sensory neurons, but not in activating the inflammation-promoting cells.

Protecting Android applications with steganography-based software watermarking

In this paper, we propose a steganography-based software watermarking scheme to protect Android applications from software piracy. Considering the resource limitations in mobile devices, it is difficult to apply previous software watermarking schemes in mobile applications. To decrease the watermarking overhead in a watermarking scheme, such as a slowdown in the execution of applications after embedding a watermark, we proposed a different approach that applies steganography-based techniques in software watermarking. The proposed scheme embeds watermarks by reordering the sequence of instructions in the basic blocks in Dalvik executable files.

A Smart Checkpointing Scheme for Improving the Reliability of Clustering Routing Protocols

In wireless sensor networks, system architectures and applications are designed to consider both resource constraints and scalability, because such networks are composed of numerous sensor nodes with various sensors and actuators, small memories, low-power microprocessors, radio modules, and batteries. Clustering routing protocols based on data aggregation schemes aimed at minimizing packet numbers have been proposed to meet these requirements. In clustering routing protocols, the cluster head plays an important role. The cluster head collects data from its member nodes and aggregates the collected data. To improve reliability and reduce recovery latency, we propose a checkpointing scheme for the cluster head. In the proposed scheme, backup nodes monitor and checkpoint the current state of the cluster head periodically. We also derive the checkpointing interval that maximizes reliability while using the same amount of energy consumed by clustering routing protocols that operate without checkpointing. Experimental comparisons with existing non-checkpointing schemes show that our scheme reduces both energy consumption and recovery latency.

Design and Implementation of μ-Webpage based on QR Code

QR(Quick Response) Code has been developed to provide greater storage capacity and more functionality compared to 1D bar codes. With the emergence of increasingly mobile devices equipped with cameras such as smart-phones and tablets, QR codes have become very popular and more important in mobile businesses. Typically, most QR codes are used as a URL link for redirecting users to webpages. However, the URL based QR codes are required to be connected over the internet and to be run a server. This can incur unnecessary traffics in the Internet. Furthermore, it is not suitable for the country lagging behind others in its network infrastructure. In this paper, we propose a server-less -webpage to provide mobile web services and be optimized for the capabilities and limitations of QR Code. We have implemented the -webpage in Android, and the results showed that the proposed mechanism can provide web-services without requiring extra servers or incurring mobile traffic data compared to the URL-based QR Codes.

A Mobility-Aware Efficient Routing Scheme for Mobile Sensor Networks

In mobile sensor networks, a variety of dynamic environmental conditions affect performance. Node movement caused by the network environment or by mobile entities makes the sensors particularly vulnerable to route failures, which in turn affects the efficiency and reliability of these networks. Therefore, mobility is an important factor in the design of a routing protocol for mobile sensor networks. In this paper, we propose a mobility-aware efficient routing called MAER, in which sensor nodes make use of mobile information to select the most appropriate routing behavior. The proposed method integrates proactive and reactive routing components efficiently using a sink cluster that consists of underlying multiple static or slow sensor nodes. The cluster provides the stable paths between less mobile entities efficiently. Our scheme also uses mobile information to evaluate and select alternative paths during a route discovery process, thus allowing sensor nodes dynamically to adapt to varying mobile networks. We evaluate the performance of MAER using a simulation by comparing it to the most popular standard for WSN, AODV. The results of the simulation show that our scheme outperforms AODV in mixed mobile sensor networks.

Impact of Mobility on Routing Energy Consumption in Mobile Sensor Networks

Mobility in mobile sensor networks causes frequent route breaks, and each routing scheme reacts differently during route breaks. It results in a performance degradation of the energy consumption to reestablish the route. Since routing schemes have various operational characteristics for rerouting, the impact of mobility on routing energy consumption shows significantly different results under varying network dynamics. Therefore, we should consider the mobility impact when analyzing the routing energy consumption in mobile sensor networks. However, most analysis of the routing energy consumption concentrates on the traffic condition and often neglects the mobility impact. We analyze the mobility impact on the routing energy consumption by deriving the expected energy consumption of reactive, proactive, and flooding scheme as a function of both the packet arrival rate and topology change rate. Routing energy consumption for mobile sensor networks is analytically shown to have a strong relationship with sensor mobility and traffic conditions. We then demonstrate the accuracy of our analysis through simulations. Our analysis can be used to decide a routing scheme that will operate most energy efficiently for a sensor application, taking into account the mobility as well as traffic condition.

SWICOM: An SDR-Based Wireless Communication Gateway for Vehicles

A wide range of emerging and promising wireless communication protocols are rapidly being introduced into vehicles. They are commonly used for in-car infotainment, telematics, and safety applications. However, adopting new wireless communications into vehicles requires them to be equipped with the corresponding hardware devices. This hardware dependency incurs extra costs to customers to deploy and maintain wireless services in vehicles. To alleviate this problem, this paper proposes a novel wireless communication gateway for vehicles that is called the software-defined radio (SDR)-based wireless communication gateway (SWICOM). It exploits the SDR technology that uses software running on a generic hardware platform to perform signal processing instead of dedicated hardware. The SWICOM can thus integrate multiple wireless hardware devices into a single generic wireless gateway device, which improves flexibility, adaptability, and connectivity of wireless communications. We built its prototype implementation and performed measurements to quantify its run-time performance. The worst-case execution time (WCET) analysis is also given using synchronous data flow (SDF) graphs. All entire results clearly show the viability of the SWICOM.

Virtual protocol stack interface for multiple wireless sensor network simulators

We present VPSI, which is a Virtual Protocol Stack Interface for wireless network simulators. VPSI provides two features; 1) a unified programming interface for developing network protocols, and 2) separation of simulator engine and the network protocols. By using VPSI, developers do not need to understand multiple different simulator engines. We implemented and adapted VPSI on existing well-known simulation packages, and we observed that VPSI works well with different wireless network simulators.

Concurrency control scheme for key-value stores based on InfiniBand

Using InfiniBand technologies, the performance of key-value stores can be greatly improved because of RDMA features and the ultra-low latency of InfiniBand. However, maximizing the benefits of InfiniBand for key-value stores is still challenging because of the data consistency problem between RDMAs and CPU-aware memory accesses. In this paper, we propose a concurrency control scheme to utilize the RDMA features of InfiniBand in key-value stores. The proposed scheme efficiently handles the race conditions among GET and PUT operations on the key-value store.

Enhancing lookup performance of key-value stores using cuckoo hashing

Recently, many studies have been conducted on key-value store as a platform for distributed storage services. A key-value store manages data as key-value pairs using hash tables. In this paper, we propose a hybrid hash table management technique to improve the performance of single nodes in a key-value store. The proposed scheme uses cuckoo hashing and separate chaining at the same time. Using this hybrid hashing scheme, cuckoo hashing and separate chaining offset the respective disadvantages while preserving the advantages of both. Experiments show that the proposed scheme is much faster than the hash table with separate chaining for temporal locality workloads.