• Journal of the Institute of Electronics Engineers of Korea TC
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• v.43 no.5 s.347
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• pp.84-93
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• 2006

Ethernet-PON is an emerging access network technology that provides a low-cost method of deploying optical access lines between OLT and ONUs. It has a point-to-multipoint and multipoint-to-point architecture in downstream and upstream direction, respectively. Therefore, downstream packets are broadcast from an OLT toward all ONUs sithout collision. On the other hand, since alt ONUs share a common channel, the collision may be occurred for the upstream transmission. Therefore, earlier efforts on Ethernet-PON have been concentrated on an upstream MAC protocol to avoid collision. But it is needed to control downstream traffic in practical access network, where the network provider limits available bandwidth according to the number of users. In this paper, we propose a traffic control scheme for supporting the fairness of the downstream bandwidth. The objective of this algorithm is to guarantee the fairness of ONUs while maintaining good performance. In order to do this, we define the service probability that considers the past traffic information for downstream, the number of tokens and the relative size of negotiated bandwidth. We develop the simulation model for Ethernet-PON to evaluate the rate-limiting algorithm by using AWESIM. Some results are evaluated and analyzed in terms of defined fairness factor, delay and dropping rate under various scenario.

• Journal of Trauma and Injury
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• v.33 no.1
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• pp.1-12
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• 2020

Purpose: Despite recent developments in the management of trauma patients in South Korea, a standardized system and guideline for trauma treatment are absent. Methods: Five guidelines were assessed using the Appraisal of Guidelines for Research and Evaluation II instrument. Results: Restrictive volume replacement must be used for patients experiencing shock from trauma until hemostasis is achieved (1B). The target systolic pressure for fluid resuscitation should be 80-90 mmHg in hypovolemic shock patients (1C). For patients with head trauma, the target pressure for fluid resuscitation should be 100-110 mmHg (2C). Isotonic crystalloid fluid is recommended for initially treating traumatic hypovolemic shock patients (1A). Hypothermia should be prevented in patients with severe trauma, and if hypothermia occurs, the body temperature should be increased without delay (1B). Acidemia must be corrected with an appropriate means of treatment for hypovolemic trauma patients (1B). When a large amount of transfusion is required for trauma patients in hypovolemic shock, a massive transfusion protocol (MTP) should be used (1B). The decision to implement MTP should be made based on hemodynamic status and initial responses to fluid resuscitation, not only the patient's initial condition (1B). The ratio of plasma to red blood cell concentration should be at least 1:2 for trauma patients requiring massive transfusion (1B). When a trauma patient is in life-threatening hypovolemic shock, vasopressors can be administered in addition to fluids and blood products (1B). Early administration of tranexamic acid is recommended in trauma patients who are actively bleeding or at high risk of hemorrhage (1B). For hypovolemic patients with coagulopathy non-responsive to primary therapy, the use of fibrinogen concentrate, cryoprecipitate, or recombinant factor VIIa can be considered (2C). Conclusions: This research presents Korea's first clinical practice guideline for patients with traumatic shock. This guideline will be revised with updated research every 5 years.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.9
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• pp.3472-3480
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• 2010

The Clustering technology of Energy efficiency wireless sensor network gets the energy efficiency by reducing the number of communication between sensor nodes and sink node. In this paper, First analyzed on the clustering technique of the distributed clustering protocol routing scheme LEACH (Low Energy Adaptive Clustering Hierarchy) and HEED (Hybrid, Energy-Efficient Distributed Clustering Approach), and based on this, new energy-efficient clustering technique is proposed for the cause the maximum delay of dead nodes and to increase the lifetime of the network. In the proposed method, the cluster head is elect the optimal efficiency node based on the residual energy information of each member node and located information between sink node and cluster node, and elected a node in the cluster head since the data transfer process from the data been sent to the sink node to form a network by sending the energy consumption of individual nodes evenly to increase the network's entire life is the purpose of this study. To verify the performance of the proposed method through simulation and compared with existing clustering techniques. As a result, compared to the existing method of the network life cycle is approximately 5-10% improvement could be confirmed.

• Journal of KIISE:Information Networking
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• v.36 no.6
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• pp.492-504
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• 2009

The delivery of multimedia that efficiently adapts its bit-rate to changing network characteristics and conditions is one of the important challenging tasks in the design of today's real-time multimedia streaming systems such as IPTV, Mobile IPTV and so on. In these work, the primary focus is on network congestion, to improve network stability and inter-protocol fairness. However, these existing works have problems which do not support QoE (Quality of Experience), because they did not consider essential characteristics of contents playback such as the media continuity. In this paper, we propose a novel rate control scheme for improving the QoE of multimedia streaming service in the Internet congestion, called NCAR (Network and Client-Aware Rate control), which is based on network-aware congestion control and client-aware flow control scheme. Network-aware congestion control of the NCAR offers an improving reliability and fairness of multimedia streaming, and reduces the rate oscillation as well as keeping high link utilization. Client-aware flow control of NCAR offers a removing the media discontinuity and a suitable receiver buffer allocation, and provides a good combination of low playback delay. Simulation results demonstrate the effectiveness of our proposed schemes.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.41 no.10
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• pp.1-9
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• 2004

User-Perceived application-level performance is a key to the adoption and success of CDMA 2000. To predict this performance in advance, a detailed end-to-end simulation model of a CDMA network was built to include application traffic characteristics, network architecture, network element details, and protocol features. We assess the user application performance when a Radio Access Network (RAN) and a Core Network (CN) adopt different transport architectures such as ATM and If. For voice Performance, we found that the vocoder bypass scenario shows 8% performance improvement over the others. For data packet performance, we found that HTTP v.1.1 shows better performance than that of HTTP v.1.0 due to the pipelining and TCP persistent connection. We also found that If transport technology is better solution for higher FER environment since the IP packet overhead is smaller than that of ATM for web browsing data traffic, while it shows opposite effect to small size voice packet in RAN architecture. Though simulation results we showed that the 3G-lX EV system gives much better packet delay performance than 3G-lX RTT, the main conclusion is that end-to-end application-level performance is affected by various elements and layers of the network and thus it must be considered in all phases of the technology evolution process.

• The Transactions of the Korea Information Processing Society
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• v.7 no.8
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• pp.2484-2496
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• 2000

High speed switches have been developing to interconnect a large number of nodes. It is important to analyze the switch performance under various conditions to satisfy the requirements. Queueing analysis, in general, has the intrinsic problem of large state space dimension and complex computation. In fact, The petri net is a graphical and mathematical model. It is suitable for various applications, in particular, manufacturing systems. It can deal with parallelism, concurrence, deadlock avoidance, and asynchronism. Currently it has been applied to the performance of computer networks and protocol verifications. This paper presents a framework for modeling and analyzing ATM switch using stochastic activity networks (SANs). In this paper, we provide the ATM switch model using SANs to extend easily and an approximate analysis method to apply A TM switch models, which significantly reduce the complexity of the model solution. Cell arrival process in output-buffered Queueing A TM switch with finite buffer is modeled as Markov Modulated Poisson Process (MMPP), which is able to accurately represent real traffic and capture the characteristics of bursty traffic. We analyze the performance of the switch in terms of cell-loss ratio (CLR), mean Queue length and mean delay time. We show that the SAN model is very useful in A TM switch model in that the gates have the capability of implementing of scheduling algorithm.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.10
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• pp.5867-5870
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• 2013

Background: Cervical cancer is the second most common cancer among Malaysian women with an ASR of 17.9 and a mortality rate of 5.6 per 100,000 population in 2008 (GLOBOCAN, 2008). The 5 year prevalence was estimated to be 14.5 per 100,000 population. As the second most common cancer affecting productive females, cervical cancer imposes an impact to the socioeconomic aspect of the country. However, the poor uptake of cervical cancer screening is a major problem in detecting early pre-cancerous lesions and thus, delay in initiating treatment for cervical cancer. Realizing the urgency to increase the uptake of PAP smear, besides enhancing the promotion of PAP smear screening for women above 35 years old, the call-recall system for pap smear screening had been piloted in one of the suburban districts which aimed to improve regular participation of women for cervical and breast cancer screening. This is of public health importance as identifying the best feasible option to increase patient's respond to participate in the screening program effectively in our setting will be helpful in implementing an organized regular population based screening program tailored to our setting. The pilot program of cervical cancer screening in Klang was an opportunity to assess different options in recalling patients for a repeat pap smear to increase their participation and adherence to the program. Methods and Results: This was a population based randomized control trial. Women aged 20-65 years in the population that matched the inclusion and exclusion criteria were re-called for a repeat smear. There are four different intervention groups; letter, registered letters, short messages services (SMS) and phone calls where 250 subjects were recruited into each group. Samples were generated randomly from the same population in Klang into four different groups. The first group received a recall letter for a repeat smear similar to the one that has been given during the first invitation. The intervention groups were either be given a registered letter, an SMS or a phone call to re-call them. The socio-demographic data of the patients who came for uptake were collected for further analysis. All the groups were followed up after 8 weeks to assess their compliance to the recall. Conclusions: The study will provide recommendations about the most effective methods for recall in a population based pap smear screening program on two outcomes: i) patients response; ii) uptake for repeat pap smear.

• Journal of Advanced Marine Engineering and Technology
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• v.40 no.7
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• pp.613-621
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• 2016

This research connected network equipment, including CCTV, PAGA, IP-PBX, and Legacy, in order to enable the operation and configuration of internal IP-based network equipment in maritime plants and vessels, both in the field and from remote places, and to allow for the support of remotely controlling such equipment. It also realized an operating program for the integrated network equipment management system to enable the monitoring and control of equipment status, operation condition, and notifications from distant places. By applying the operating program to satellite stations and vessels sailing on the sea, a performance test was conducted to evaluate data loss and transmission/reception delay in the communication section between the land and vessels. As a result, this research verified the normal operation of CCTV control and of real-time monitoring and control of the network equipment, including PAGA, IP-PBX, and Legacy under the FBB and MVSAT environments. It was observed that the transmission of CCTV video images with a large volume of data as well as the transmission and reception of voice data were found to be slightly delayed, indicating the need to develop technology to compress and convert data for real-time transmission and reception.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.10a
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• pp.477-481
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• 2007

The emergency patient who occurs from the place where it is various the control which is quick must come to accomplish in Ubiquitous environment. In the body of the patient or the old person the organism signal sensor about under attaching condition of the patient at real-time about under the monitor ring about under disposing the control which is quick against the emergency patient does to become accomplished at the case real-time when the above will get in the body of the patient or the old person. Using ZigBee (802.15.4) system base on Shor wireless communication protocol because of complement wireless of hospital. This system use ZigBee (802.15.4) system to get for electrocardiogram, blood pressure and pulse bio-sensors. This paper constructs Bio-Sensor communication monitoring system and transmission rate and the delay which it follows possibility and node occurrence rate of wireless sensor network construction hour transmission session it leads and it verifies the effectiveness.

• The KIPS Transactions:PartC
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• v.11C no.3
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• pp.379-386
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• 2004

The WAP 2.0 system is a newly proposed wireless communication system by the WAP Forum for interoperability across Internet environment and the system takes charge of communication between WAP terminals and existing origin Web servers. The purpose of this paper is 1) to construct a WAP 2.0 proxy proposed by the WAP Forum and 2) to improve the WAP Proxy in order to increase communication efficiency between wired and wireless communication objects. The Improved WAP proxy constructed in this study provides links between wired and wireless communication environments using the split-TCP concept. However, unlike the split-TCP connection, The improved WAP proxy maintains TCP's end-to-end semantics and reduces overhead by avoiding operations as much as possible on the upper protocol layer. In addition, The improved WAP proxy supports SACK(Selective Acknowledgement ) option and Timestamp option for speedy re-transmission which leads to reduction of performance degradation. After constructing the improved WAP proxy under Linux environment, experiments have been taken. The experimental results show that, compared with the experiments when a WAP proxy proposed by the WAP Forum is used, both data transmission delay time and data transmission size decrease to show that communication efficiency is increased. In particular, as packet missing ratio Increases, data transmission size decreases, which demonstrates that the improved WAP proxy is very effective for performance improvement in wireless communication environment.