• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.3B
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• pp.143-152
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• 2007

In order to provide new value-added services such as a policy-based routing and the quality of services in next generation network, the Internet routers need to classify packets into flows for different treatments, and it is called a packet classification. Since the packet classification should be performed in wire-speed for every packet incoming in several hundred giga-bits per second, the packet classification becomes a bottleneck in the Internet routers. Therefore, high speed packet classification algorithms are required. In this paper, we propose an efficient packet classification architecture based on a hierarchical binary search fee. The proposed architecture hierarchically connects the binary search tree which does not have empty nodes, and hence the proposed architecture reduces the memory requirement and improves the search performance.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.23 no.6
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• pp.1554-1561
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• 1998

When the superposition of realtime traffic and non-realtime traffic is applied to the ATM network, the successive cell loss(block loss) is more influential on the quality of service (QoS) of two traffic streams than the single loss in case of bursty traffic. Block loss can be identified as an important performance measure because of delay-oriented policy for realtime traffic. In this paper, we consider the system with the two-level overload control reducing of the recurrence of shut-down periods and develop a recursive algorithm to obtain both block loss and cell loss probabilities of both traffic. We can see that it gives the more precise and diverse investigations on performance analysis of queuing strategy.

• Journal of Communications and Networks
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• v.16 no.2
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• pp.183-192
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• 2014

This paper proposes a payment-based power control scheme using non-cooperative game with a novel pricing function in cognitive radio networks (CRNs). The proposed algorithm considers the fairness of power control among second users (SUs) where the value of per SU' signal to noise ratio (SINR) or distance between SU and SU station is used as reference for punishment price setting. Due to the effect of uncertainty fading environment, the system is unable to get the link gain coefficient to control SUs' transmission power accurately, so the quality of service (QoS) requirements of SUs may not be guaranteed, and the existence of Nash equilibrium (NE) is not ensured. Therefore, an alternative iterative scheme with sliding model is presented for the non-cooperative power control game algorithm. Simulation results show that the pricing policy using SUs' SINR as price punishment reference can improve total throughput, ensure fairness and reduce total transmission power in CRNs.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.7
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• pp.1614-1620
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• 2009

The overlay multicast that has been recently presented as an alternative for the IP multicast has been getting much persuasion by the system resource and the network bandwidth and the advancement of the network cost. we propose a overlay multi_casting network policy for efficient multimedia services with P2P join scheduling. In order to evaluate the performance of proposed scheme, We test the performance of multi_casting nodes with average join count, the maximum guaranteed waiting time and buffer starvation ratio with similar techniques. The result of simulation shows improved about 15${\sim}$20% of performance.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.11
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• pp.5357-5381
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• 2018

Cloud computing offers a wide range of on-demand resources over the internet. Utility-based resource allocation in cloud data centers significantly increases the number of cloud users. Heavy usage of cloud data center encounters many problems such as sacrificing system performance, increasing operational cost and high-energy consumption. Therefore, the result of the system damages the environment extremely due to heavy carbon (CO2) emission. However, dynamic allocation of energy-efficient resources in cloud data centers overcomes these problems. In this paper, we have proposed Energy and Service Level Agreement (SLA) Aware Resource Allocation Heuristic Algorithms. These algorithms are essential for reducing power consumption and SLA violation without diminishing the performance and Quality-of-Service (QoS) in cloud data centers. Our proposed model is organized as follows: a) SLA violation detection model is used to prevent Virtual Machines (VMs) from overloaded and underloaded host usage; b) for reducing power consumption of VMs, we have introduced Enhanced minPower and maxUtilization (EMPMU) VM migration policy; and c) efficient utilization of cloud resources and VM placement are achieved using SLA-aware Modified Best Fit Decreasing (MBFD) algorithm. We have validated our test results using CloudSim toolkit 3.0.3. Finally, experimental results have shown better resource utilization, reduced energy consumption and SLA violation in heterogeneous dynamic cloud environment.

• Journal of Digital Convergence
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• v.11 no.12
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• pp.353-359
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• 2013

The search method that web services offers has its limitations. The search service considers only functional factors based on the client's preferences. In order to improve the web service search - which alone only considers functional factors - our research introduces an execution phase which performs both functional and non-functional factors by utilizing WSDL and matching information. Our research studies the architecture of both the service selecting method and the selecting process to help determine the best service solution for the client. We do so, taking into consideration the client's preferences. Our research also studies selecting methods for the best overall service. This service not only considers the matching of functional factors provided by the web service's selecting process, but it is also accommodating by matching the information as defined by the client. This paper research can offer the best quality service preferred by any end-user. Again, this is done by utilizing web services that considers the user's non-functional factors identified by the web service's selecting process and also by extracting matching information.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.11A
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• pp.859-866
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• 2003

In this paper, we designed the bandwidth allocation scheme with priority consideration for upstream channel access of EthernetPON. The objective of our scheme is to control the multi services in more effective way according to their CoS(Class of Service) or QoS(Quality of Service). The designed scheme considers transmission priority in the both side of OLT and ONU. In the OLT's view, the Two-step scheduling algorithm is applied with which we can support multiple bandwidth allocation policies simultaneously, i.e. SBA for the time-sensitive, constant rate transmission services and DBA for the best-effort services. This Two-step scheduling algorithm reduces the scheduling complexity by separating the process of transmission start time decision from the process of grant generation. In the ONU's view, the proposed scheme controls 8 priority queues of the 802.1d recommended 8 service classes. Higher priority queue is serviced in prior during the allowed GATE time from OLT. The OPNET modeling and simulation result compares the performance of each bandwidth allocation policy with SBA or DBA only approach.

• The KIPS Transactions:PartC
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• v.14C no.1 s.111
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• pp.27-38
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• 2007

IPv6 has appeared for solving the address exhaustion of IPv4 and for guaranteeing the problems of security and QoS. It occurs the unexpected new attacks of IPv6 as well as the existing attacks of IPv4 because of the increasing address space to 128bits and the address hierarchies for efficient network management and additions of the new messages between nodes and routers like neighbor discovery and auto address configuration for the various comfortable services. For the successful transition from IPv4 to IPv6, we should get the secure compatibility between IPv4 hosts or routers working based on secure and systematic policy and IPv6. Network manager should design security technologies for efficient management in IPv4/IPv6 co-existence network and IPv6 network and security management framework designation. In this paper, we inspected the characteristics of IPv4 and IPv6, study on security requirement for efficient security management of various attacks, protocol, service in IPv4/IPv6 co-existence and IPv6 network, and finally suggest integrated solution about security vulnerability of IPv6 network in considering of analysis of IPv6 system, host and application, IPv6 characteristics, modified CGA(MCGA).

• Journal of Preventive Medicine and Public Health
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• v.56 no.5
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• pp.467-474
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• 2023

Objectives: Diabetes mellitus (DM) is a serious public health issue that places a heavy financial, social, and health-related burden on individuals, families, and healthcare systems. Self-reported health-related quality of life (HRQoL) is extensively used for monitoring the general population's health conditions and measuring the effectiveness of interventions. Therefore, this study investigated HRQoL and associated factors among patients with type 2 DM at a primary healthcare center in Indonesia. Methods: A cross-sectional study was conducted in Klaten District, Central Java, Indonesia, from May 2019 to July 2019. In total, 260 patients with DM registered with National Health Insurance were interviewed. HRQoL was measured with the EuroQol Group's validated Bahasa Indonesia version of the EuroQoL 5-Dimension 5-Level (EQ-5D-5L) with the Indonesian value set. Multivariate regression models were used to identify factors influencing HRQoL. Results: Data from 24 patients were excluded due to incomplete information. Most participants were men (60.6%), were aged above 50 years (91.5%), had less than a senior high school education (75.0%), and were unemployed (85.6%). The most frequent health problems were reported for the pain/discomfort dimension (64.0%) followed by anxiety (28.4%), mobility (17.8%), usual activities (10.6%), and self-care (6.8%). The average EuroQoL 5-Dimension (EQ-5D) index score was 0.86 (95% confidence interval [CI], 0.83 to 0.88). In the multivariate ordinal regression model, a higher education level (coefficient, 0.08; 95% CI, 0.02 to 0.14) was a significant predictor of the EQ-5D-5L utility score. Conclusions: Patients with diabetes had poorer EQ-5D-5L utility values than the general population. DM patients experienced pain/discomfort and anxiety. There was a substantial positive relationship between education level and HRQoL.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.2
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• pp.634-645
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• 2014

VoIP (Voice over Internet Protocol) is a technology of transmitting and receiving voice and data over the Internet network. As the telecommunication industry is moving toward All-IP environment with growth of broadband Internet, the technology is becoming more important. Although the early VoIP services failed to gain popularity because of problems such as low QoS (Quality of Service) and inability to receive calls as the phone number could not be assigned, they are currently established as the alternative service to the conventional wired telephone due to low costs and active marketing by carriers. However, VoIP is vulnerable to eavesdropping and DDoS (Distributed Denial of Service) attack due to its nature of using the Internet. To counter the VoIP security threats efficiently, it is necessary to develop the criterion or the model for estimating the information security level of VoIP service providers. In this study, we developed reasonable security indicators through questionnaire study and statistical approach. To achieve this, we made use of 50 items from VoIP security checklists and verified the suitability and validity of the assessed items through Multiple Regression Analysis (MRA) using SPSS 18.0. As a result, we drew 23 indicators and calculate the weight of each indicators using Analytic Hierarchy Process (AHP). The proposed indicators in this study will provide feasible and reliable data to the individual and enterprise VoIP users as well as the reference data for VoIP service providers to establish the information security policy.