• The KIPS Transactions:PartC
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• v.9C no.6
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• pp.875-882
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• 2002

The active packets unlike traditional IP packets should be executed at each active node along their path. To execute the active program at each active node, the active packets for an active program should go through the same active nodes and all packets are delivered without any loss. This paper presents the new active engine for every active packet which execute an active program to be routed through the same intermediate active nodes and to be delivered reliably. Proposed active engine requires fewer changes to existing IP protocols and guarantees the reliable delivery of the active packets. Moreover, even if the sender does not have any information about the intermediate nodes every active packet is routed through the same intermediate active nodes. The simulation results show that proposed active engine achieves an efficient transmission with high data delivery and low communication overhead compared with the other existing transmission protocols.

• Smart Structures and Systems
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• v.6 no.5_6
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• pp.661-673
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• 2010

This paper presents recent developments in an extremely compact, wireless impedance sensor node (the WID3, $\underline{W}$ireless $\underline{I}$mpedance $\underline{D}$evice) for use in high-frequency impedance-based structural health monitoring (SHM), sensor diagnostics and validation, and low-frequency (< ~1 kHz) vibration data acquisition. The WID3 is equipped with an impedance chip that can resolve measurements up to 100 kHz, a frequency range ideal for many SHM applications. An integrated set of multiplexers allows the end user to monitor seven piezoelectric sensors from a single sensor node. The WID3 combines on-board processing using a microcontroller, data storage using flash memory, wireless communications capabilities, and a series of internal and external triggering options into a single package to realize a truly comprehensive, self-contained wireless active-sensor node for SHM applications. Furthermore, we recently extended the capability of this device by implementing low-frequency analog-to-digital and digital-to-analog converters so that the same device can measure structural vibration data. The compact sensor node collects relatively low-frequency acceleration measurements to estimate natural frequencies and operational deflection shapes, as well as relatively high-frequency impedance measurements to detect structural damage. Experimental results with application to SHM, sensor diagnostics and low-frequency vibration data acquisition are presented.

• Physical Therapy Rehabilitation Science
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• v.11 no.4
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• pp.430-435
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• 2022

Objective: This study was conducted to investigate the effect of active movement with skin mobilization on range of motion, pain, and rating of perceived exertion in patients diagnosed with axillary web syndrome after axillary lymph node dissection. Design: A Case report Methods: It was performed on 7 patients diagnosed with axillary web syndrome after lymph node dissection. The subjects experienced a decrease in the range of joint motion and pain in movement when raising their arms in their daily lives, and complained of discomfort. The active range of motion, numeric rating scale, and modified Borg scale of shoulder joint flexion were measured, and the differences after active movement with skin mobilization were compared. Results: All subjects increased by 24.9 degree on average in active range of motion after active movement with skin mobilization intervention. There was no pain in the maximum range of joint motion measured before intervention, and rating of perceived exertion was significantly reduced. Conclusions: Active movement with skin mobilization can be a very useful way to help improve and treat axillary web syndrome, and it is recommended for improving the function and quality of life of axillary web syndrome patients. and It is also believed that it can be used steadily at home through the education of patients and families.

• Journal of Korean Institute of Industrial Engineers
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• v.41 no.2
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• pp.220-224
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• 2015

The DCF (Dcistributed Coordination Function) and PCF (Point Coordination Function) are the basic MAC (Medium Access Control) protocols of IEEE 802.11 wireless LANs. According to the DCF, each node performs the exponential backoff algorithm before the transmission of its data frame. Each node doubles the backoff waiting time before the transmission of its data frame whenever it detects the transmission collision with other nodes. Therefore, as the number of the active nodes having the data frames to transmit increases, the overall MAC performance of the DCF decreases. On the other hand, according to the PCF, each node is granted the transmission opportunity by which the PCF transmission is possible without the collision with other nodes. Therefore, as the number of the active nodes increases, the MAC performance of the PCF increases, In this paper, considering the tradeoff of MAC performance between the DCF and PCF, a hybrid MAC protocol is proposed to enhance the performance of IEEE 802.11 wireless LANs.

• The Journal of the Korea institute of electronic communication sciences
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• v.7 no.1
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• pp.53-60
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• 2012

In this paper, an improved algorithm of distributed QoS is proposed for real-time networks. This algorithm like a delay-constrained unicast routing(DCUR) algorithm uses either least-cost(LC) path or least-delay(LD) path of an active node, but when there is a loop, this algorithm is quite different from DCUR in choosing the link between the active node and the previous node to replace the original loop path. And this algorithm makes the construction of the paths more efficiently.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.12 no.2
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• pp.135-145
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• 2002

Active networks represent a new approach to network architecture. Nodes(routers, switches, etc.) can perform computations on user data, while packets can carry programs to be executed on nodes and potentially change the state of them. While active networks provide a flexible network iufrastructure, they are more complex than traditional networks and raise considerable security problems. Nodes are Public resources and are essential to the proper and contract running of many important systems. Therefore, security requirements placed upon the computational environment where the code of packets will be executed must be very strict. Trends of research for active network security are divided into two categories: securing active nodes and securing active packets. For example, packet authentication or monitoring/control methods are for securing active node, but some cryptographic techniques are for the latter. This paper is for transferring active packets securely between active nodes. We propose a new method that can transfer active packets to neighboring active nodes securely, and execute executable code included in those packets in each active node. We use both public key cryptosystem and symmetric key cryptosystem in our scheme

• Proceedings of the Korea Information Processing Society Conference
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• 2002.04a
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• pp.381-384
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• 2002

This paper describes the motivation, design and performance of bi-active Load balancer in Linux Virtual Server. The goal of bi-active Load balancer is to provide a framework to build highly scalable, fault-tolerant services using a large cluster of commodity servers. The TCP/IP stack of Linux Kernel is extended to support three IP load balancing techniques, which can make parallel services of different kinds of server clusters to appear as a service on a single IP address. Scalability is achieved by transparently adding or removing a node in the cluster. and high availability is provided by detecting node or daemon failures and reconfiguring the system appropriately. Extensive simulation reveals that the proposed approach improves the reply rate about 20% compared to earlier design.

• The Journal of the Korea Contents Association
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• v.6 no.7
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• pp.69-78
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• 2006

In this paper, we presents the efficiency and a transmission quality of the system which is composed of the optical elements from physical layer of the active optical ring network. For a simulation it will use the Transmissionmaker WDM and it will be able to observation a optical transmission quality of the optical transmission system. The active optical network is composed of two rings(main ring and sub-ring). It measures the BER(Bit Error Rate) quality which it follows node number from the sub ring and physical distance of the node. Performance analysis from the physical layer becomes the standard of the plan for the efficiency optimization of the active optical ring network. Consequently it will be able to compose the efficient optical transmission system which reflects the physical distance, a traffic demand quantity of each node and a number of users from actual network.

• IEMEK Journal of Embedded Systems and Applications
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• v.5 no.4
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• pp.234-242
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• 2010

Two-way ranging methods such as TWR and SDS-TWR have been considered for many ranging systems because these methods are useful in the absence of synchronization. To estimate the location of a mobile node, complicated ranging procedures consisting of ranging frames between an anchor node and the mobile node are performed. Supporting multiple mobile nodes such as a few hundreds or thousands and several anchor nodes, the ranging procedures have the fatal disadvantage of processing delay and inefficient traffic bandwidth. On the other hand, the one-way ranging method is simple and fast, but susceptible to network synchronization. In this paper, we propose a method to modify asynchronous ranging equations to establish exact frequency or frequency offset, a method to estimate frequencies or frequency offsets, and a method to establish post-facto synchronization with anchor nodes. The synchronization for a node pair is adapted using instantaneous time information and corresponding difference of distances can be determined. We evaluate the performance of TWR, SDS-TWR and proposed ranging algorithms.

• Structural Engineering and Mechanics
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• v.39 no.3
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• pp.339-360
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• 2011

In the h-type adaptive analysis, when an element is refined or subdivided, new nodes are added. Among them are the transition nodes which are the corner nodes of the new elements formed by subdivision and, simultaneously, the mid-side nodes of the adjacent non-subdivided elements. To secure displacement compatibility, the slave-node approach in which the DOFs of a transition node are constrained by those of the adjacent nodes had been used. Alternatively, transition elements which possess the transition nodes as active mid-side/-face nodes can be used. For C0 plate analyses, the conventional slave-node constraints and the previously derived ANS transition elements are implemented. In both implementations, the four-node element is the ANS element. With reference to the predictions of the transition elements, the slave-node approach not only delivers erroneous results but also fails the patch test. In this paper, the patch test failure is resolved by developing a set of new constraints with which the slave-node approach surpasses the transition-element approach. The accuracy of the slave-node approach is further improved by developing a hybrid four-node element in which the assumed moment and shear force modes are in strict equilibrium.