• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.12
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• pp.4385-4399
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• 2021

The Internet of Things (IoT) eHealth systems composed by Wireless Body Area Network (WBAN) has emerged recently. Sensor nodes are placed around or in the human body to collect physiological data. WBAN has many different applications, for instance health monitoring. Since the limitation of the size of the battery, besides speed, reliability, and accuracy; design of WBAN protocols should consider the energy efficiency and time delay. To solve these problems, this paper adopt the end-edge-cloud orchestrated network architecture and propose a transmission based on reinforcement algorithm. The priority of sensing data is classified according to certain application. System utility function is modeled according to the channel factors, the energy utility, and successful transmission conditions. The optimization problem is mapped to Q-learning model. Following this online power control protocol, the energy level of both the senor to coordinator, and coordinator to edge server can be modified according to the current channel condition. The network performance is evaluated by simulation. The results show that the proposed power control protocol has higher system energy efficiency, delivery ratio, and throughput.

• Childhood Kidney Diseases
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• v.28 no.2
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• pp.51-58
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• 2024

Patients with chronic kidney disease (CKD) bear a significant financial burden and face numerous complications and higher mortality rates. The progression of CKD is associated with glomerular injury caused by glomerular hyperfiltration and oxidative stress. Factors such as uncontrolled hypertension, elevated urine protein levels, anemia, and underlying glomerular disease, contribute to CKD progression. In addition to conservative treatment, several medications are available to combat the progression of CKD to end-stage kidney disease. Renin-angiotensin-aldosterone system blockers could slow the progression of CKD by reducing glomerular hyperfiltration, lowering blood pressure, and decreasing inflammation. Mineralocorticoid receptor antagonists inhibit the mineralocorticoid receptor signaling pathway, thereby attenuating inflammation and fibrosis. Sodium-glucose cotransporter 2 inhibitors exhibit protective effects on the kidneys and against cardiovascular events. Tolvaptan, a selective vasopressin V2-receptor antagonist, decelerates the rate of increase in total kidney volume and deterioration of kidney function in patients with rapidly progressive autosomal dominant polycystic kidney disease. The protective effects of AST-120 remain controversial. Due to a lack of evidence regarding the efficacy and safety of these medications in children, it is imperative to weigh the benefits and adverse effects carefully. Further research is essential to establish the efficacy and safety profiles in pediatric populations.

• Journal of the Institute of Convergence Signal Processing
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• v.12 no.3
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• pp.157-162
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• 2011

This study is about implementing wireless transferring system in pre-hospital cardiopulmonary resuscitation(CPR). Also, this study includes monitoring based feedback between patient and hospital to increase the survival rate of emergency patient by developing the performance of cardiopulmonary resuscitation in pre-hospital. It minimizes the loss of flow rate or gastric inflation through the space between the airway and the esophagus, which enables the inspiration-expiration rate to be measured more precisely. Due to these reasons this study applied ET insertion based respiratory sensor to measure flow rate. The main indices of artificial ventilation are justified from minute respiration(V), end-tidal $CO_2(E_TCO_2)$, and tracheal pressure($P_{tr}$). The simulation is performed to verify the bandwidth and delay time of transport network for in-hospital monitoring even as transporting images and voice information simultaneously. The total bandwidth is 815 kbps, and WLAN (IEEE 802.11x) is used as communication protocol. The network load is under 1.5% and the transmit delay time is measured under 0.3 seconds.

• Journal of the Korea institute for structural maintenance and inspection
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• v.15 no.1
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• pp.148-158
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• 2011

As critical infrastructure, bridges play an indispensable role in facilitating the distribution of goods. When bridges reach their end of useful life or get damaged by natural disasters such as earthquakes or storms, they have to be removed and reconstructed. When bridges in service need to be reconstructed, user costs occur from vehicle detours and traffic congestions, and social costs occur from noise and dust during construction periods. However, these user and social costs are not considered during reconstruction and the evaluation methods of those costs are vague. Thus, there is lack of appropriate bridge types that consider these costs. Therefore, this paper identifies the social overhead costs that occur during bridge reconstruction, which is also called, users' socioeconomic values. Next, it proposes a method to evaluate user costs during bridge reconstruction, and appraises the method. User costs are evaluated based on traffic information, social and material volumes including the bridge's daily traffic volume, peak hours, detour distance and time. In addition, time delay costs due to traffic operational costs and bridge reconstruction are also taken into consideration.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.10a
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• pp.434-437
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• 2010

NIPS(Network Intrusion Prevention System) is in line at the end of the external and internal networks which performed two kinds of action: Signature-based filtering and anomaly detection and prevention-based on self-learning. Among them, a signature-based filtering is well known to defend against attacks. By using signature-based filtering, intrusion prevention system passing a payload of packets is compared with attack patterns which are signature. If match, the packet is discard. However, when there is packet delay, it will increase the required pattern matching time as the number of signature is increasing whenever there is delay occur. Therefore, to ensure the performance of IPS, we needed more efficient pattern matching algorithm for high-performance ISP. To improve the performance of pattern matching the most important part is to reduce the number of comparisons signature rules and the packet whenever the packets arrive. In this paper, we propose an improve signature hashing-based pattern matching method. We use tuple pruning algorithm with Bloom filters, which effectively remove unnecessary tuples. Unlike other existing signature hashing-based IPS, our proposed method to improve the performance of IPS.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.5
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• pp.2144-2165
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• 2016

In a vehicular ad hoc network, the communication links are unsteady due to the rapidly changing topology, high mobility and traffic density in the urban environment. Most of the existing geographical routing protocols rely on the continuous transmission of beacon messages to update the neighbors' presence, leading to network congestion. Source-based approaches have been proven to be inefficient in the inherently unstable network. To this end, we propose an opportunistic beaconless packet forwarding approach based on a modified handshake mechanism for the urban vehicular environment. The protocol acts differently between intersections and at the intersection to find the next forwarder node toward the destination. The modified handshake mechanism contains link quality, forward progress and directional greedy metrics to determine the best relay node in the network. After designing the protocol, we compared its performance with existing routing protocols. The simulation results show the superior performance of the proposed protocol in terms of packet delay and data delivery ratio in realistic wireless channel conditions.

• Electronics and Telecommunications Trends
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• v.34 no.6
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• pp.51-60
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• 2019

As a way to further expand and enable the 5G ecosystem, the $3^{rd}$ Generation Partnership Project (3GPP) is considering the development of a 5G new radio (NR)-based non-terrestrial network (NTN). These NTNs are expected to provide ubiquitous 5G services to user's equipment (especially, in Internet of Things/machine-type communications (IoT/MTC) public safety, and critical communications) by extending service coverage to areas not covered by 5G terrestrial networks. To this end, this NTN is developing scenarios to provide 5G services using spaceborne vehicles, such as geosynchronous and low-Earth orbit satellites, and airborne vehicles, such as unmanned aircraft systems, including high-altitude pseudo-satellites. In addition, various technologies are being studied to satisfy new requirements not considered in 5G NR, such as long propagation delay time, large cell coverage, large Doppler effect, and base station movement. In this paper, we present the scenarios, requirements, technical issues and solutions, and standardization planning for NR-based NTN in 3GPP.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.6 no.3
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• pp.386-392
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• 2002

Internet telephony is an application that transmits voice data for conversation. Therefore it must provide high sound quality. However while audio packets are transferred through the network, they are affected by delay variations and jitters, which could result in poor sound quality of the receiving end does not have an appropriate jitter buffer to overcome network factors. This thesis introduces a buffer management algorithm that could be used to provide better sound quality for Internet phone terminals. This algorithm actively responds to both the compression algorithms that are used by the terminals, as well as to the received data to provide an improvement in sound quality. In order to verify the effectiveness of the proposed algorithm, we experimented in variance network settings. The results show that the proposed algorithm improves on the performance of the conventional buffer management algorithm.

• Journal of Communications and Networks
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• v.13 no.3
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• pp.286-297
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• 2011

A novel converged optical network unit (ONU)-base station (BS) architecture has been contemplated for next-generation optical-wireless networks. It has been demonstrated through high quality studies that data traffic carried by both wired and wireless networks exhibit self-similar and long range dependent characteristics; attributes that classical teletraffic theory based on simplistic Poisson models fail to capture. Therefore, in order to apprehend the proposed converged architecture and to reinforce the provisioning of tightly bound quality of service (QoS) parameters to end-users, we substantiate the analysis of the QoS behavior of the ONU-BS under self-similar and long range dependent traffic conditions using custom queuing which is a common queuing discipline. This paper extends our previous work on priority queuing and brings novelty in terms of presenting performance analysis of the converged ONU-BS under realistic traffic load conditions. Further, the presented analysis can be used as a network planning and optimization tool to select the most robust and appropriate queuing discipline for the ONU-BS relevant to the QoS requirements of different applications.

• The Bulletin of The Korean Astronomical Society
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• v.38 no.1
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• pp.43.1-43.1
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• 2013

We present here the preliminary results of the fast variability of AGN radio light curves. The shortest time scale of minute in AGN light curves is needed to probe the AGN activity for a few reasons; First, to check if there is any kind of shortest time scale activity. Secondly, to find out what high frequency end of AGN spectra look like. For the last, to see the time delay at several wavelength bands and the change of the spectral index with time. The observation was conducted with three KVN(Korea VLBI Network) antennas with single dish cross scan mode. In order not to lose the target at any given time, whenever one station needs to observe the calibrator, the other station is on the target. Though the detailed data reduction is still going on, there might exist varying feature in the radio light curve. The more fine calibration will be done in near future and another good data set is ready for the reduction.