• International Journal of Computer Science & Network Security
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• v.21 no.8
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• pp.65-70
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• 2021

Waste accumulation is becoming a significant challenge in most urban areas and if it continues unchecked, is poised to have severe repercussions on our environment and health. The massive industrialisation in our cities has been followed by a commensurate waste creation that has become a bottleneck for even waste management systems. While recycling is a viable solution for waste management, it can be daunting to classify waste material for recycling accurately. In this study, transfer learning models were proposed to automatically classify wastes based on six materials (cardboard, glass, metal, paper, plastic, and trash). The tested pre-trained models were ResNet50, VGG16, InceptionV3, and Xception. Data augmentation was done using a Generative Adversarial Network (GAN) with various image generation percentages. It was found that models based on Xception and VGG16 were more robust. In contrast, models based on ResNet50 and InceptionV3 were sensitive to the added machine-generated images as the accuracy degrades significantly compared to training with no artificial data.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.1
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• pp.133-151
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• 2019

In order to achieve faster content distribution speed and stronger fault tolerance, a P2P peer can connect to multiple peers in parallel and receive chunks of the data simultaneously. A critical issue in this environment is selecting a set of nodes participating in swarming sessions. Previous related researches only focus on performance metrics, such as downloading time or the round-trip time, but in this paper, we consider a new performance metric which is closely related to the network and propose a peer selection algorithm that produces the set of peers generating optimal worst link stress. We prove that the optimal algorithm is practicable and has the advantages with the experiments on PlanetLab. The algorithm optimizes the congestion level of the bottleneck link. It means the algorithm can maximize the affordable throughput. Second, the network load is well balanced. A balanced network improves the utilization of resources and leads to the fast content distribution. We also notice that if every client follows our algorithm in selecting peers, the probability is high that all sessions could benefit. We expect that the algorithm in this paper can be used complementary to existing methods to derive new and valuable insights in peer-to-peer networking.

• ETRI Journal
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• v.45 no.4
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• pp.615-626
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• 2023

Under limited transmission conditions, many factors affect the efficiency of video transmission. During the flight of an unmanned aerial vehicle (UAV), frequent network switching often occurs, and the channel transmission condition changes rapidly, resulting in low-video transmission efficiency. This paper presents an efficient video coding flow for UAVs working in the 5G nonstandalone network and proposes two bit controllers, including time and spatial bit controllers, in the flow. When the environment fluctuates significantly, the time bit controller adjusts the depth of the recursive codec to reduce the error propagation caused by excessive network inference. The spatial bit controller combines the spatial bit mask with the channel quality multiplier to adjust the bit allocation in space to allocate resources better and improve the efficiency of information carrying. In the spatial bit controller, a flexible mini graph is proposed to compute the channel quality multiplier. In this study, two bit controllers with end-to-end codec were combined, thereby constructing an efficient video coding flow. Many experiments have been performed in various environments. Concerning the multi-scale structural similarity index and peak signal-to-noise ratio, the performance of the coding flow is close to that of H.265 in the low bits per pixel area. With an increase in bits per pixel, the saturation bottleneck of the coding flow is at the same level as that of H.264.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.1
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• pp.159-169
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• 1994

A multichannel optical slotted ring network is designed using a wavelength division multiplexing(WDM) technique and photonic packet switching devices. The electronics speed bottleneck is removed out of the ring, which allows utilization of the full bandwidth for the optical fiber transmission medium. The ring channel adopts a slotted ring concept with a destination cell remove strategy for the eing access mechanism. The slot size in the ring is selected as the same as that of ATM based cell in order to be used as B-ISDN Access Networks. In this paper, we devised a mathematical method to measure the average transfer delay characteristics of the network. The analytical method turned out to yield accurate results over a broad range of parameters in comparison to simulation results. From the study, we observed the average transfer delay of the network as the network parameters vary.

• Journal of Digital Convergence
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• v.10 no.4
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• pp.265-270
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• 2012

The subscriber access network is cause of the bottleneck phenomenon because equipment and infrastructure were not originally designed for busty high-bandwidth traffic between MAN(Metro Area Network) and LAN(Local Area Network). Whether riding on shorter copper drops or optical fiber, Ethernet is emerging as the future broadband protocol of choice, offering plug and play simplicity, and low cost. EPON(Ethernet Passive Optical Network) combines point-to-multipoint optical infrastructure with low-cost high-bandwidth Ethernet. The future broadband access network will be a combination of point-to-point and point-to-multipoint Ethernet, optimized for transporting IP data, as well as time critical voice and video. EPON is being considered as a novel communications infrastructure for next-generation broadband access network for the convergence of low-cost Ethernet equipment and low-cost fiber infrastructure. But, EPON has a problem with duplex multimedia services. It is the insufficiency of bandwidth for upstream. Because all ONUs use a shared transmission media for upstream. In this paper, we addressed the problem of upstream bandwidth in EPONs. We presented a wavelength division EPON supporting QoS in the differentiated services framework.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.12
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• pp.2340-2352
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• 1994

Under the current IN(Intelligent Network) Architecture, most of their function were performed in SSP(Service Switching point), so the provision or modification of service was limited. To over come these limitation, the structure of 'AIN(Advanced Intelligent Network)' emerged. In this paper, SSP for AIN structure is designed and its performance is evaluated. In other words, the requirements for AIN service implementation are specified on the basis of ITU-T Recommendations. From these requirments and TDX-10 Exchange architecture, the SSP for AIN structure is designed, and its performance is analyzed through the method of simulation and analytical modeling. As a conclusion of this paper, when the system is operated as a standard model, the maximum throughput is 1,270,000 BHCA for Free Phone Service and 1,190,000 BHCA for Credit Call Service. The processors in INS(Interconnection Network Subsystem) are proved to be bottleneck elements. To enhance the performance, several suggestions such as processor and link speedup, and other D_bus service policy are proposed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.12
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• pp.2450-2460
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• 2015

Recently, as interest in IoT (Internet of Things) increase, research and standardization of a new protocol which reflects the characteristics of IoT has progressed. Among them, RPL(IPv6 for Low-Power Lossy Network) is a standardized routing protocol for IoT. RPL utilizes DIO (DODAG Information Object) messages which is flooded from the sink node to the whole network for path establish and maintenance. However, in large scale networks, not only a long time is required to propagate the DIO message to the whole networks but also a bottleneck effect around the sink node is occurred. Multi-sink based approaches which take advantage of reducing routing overhead and bottleneck effect are widely used to solve these problems. In this paper, we define 'unnecessary path update problems' that may arise when applying the RPL protocol to the multi sink based IoT networks and propose two methods namely Routing Metric based Path Update Decision method and Immediate Successor based Path Update Decision method for selective routing update.

• Journal of KIISE
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• v.42 no.10
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• pp.1268-1279
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• 2015

In order to manage a large number of devices connected to the Internet of Things (IoT), the Internet Engineering Task Force (IETF) proposed the IPv6 Routing Protocol for Low Power and Lossy Networks (RPL). The route of the RPL network is generated through the use of an Objective Function (OF) that is suitable for the service that is required for the IoT network. Since the route of the RPL network is conventionally simply chosen only by considering the link quality between the nodes, it is sensible to seek an OF that can also provide better Quality of Service (QoS). In previous studies, the end-to-end delay might possibly be sub-optimal because they only deal with problems related to the reduction of energy consumption and not to the link quality on the path to the sink node. In this study, we propose a scheme that reduces the end-to-end delay but also gives full consideration to both the quality on the entire route to the destination and to the expected lifetime of nodes with bottlenecks from heaped traffic. Weighting factors for the proposed scheme are chosen by experiments and the proposed scheme can reduce the end-to-end delay and the energy consumption of previous studies by 20.8% and 10.5%, respectively.

• Journal of Korea Multimedia Society
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• v.12 no.3
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• pp.409-418
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• 2009

Providing Quality-of-Service (QoS) guarantee requires for each router on the path of a traffic flow not to violate the flow's delay budget allocated to itself. Since the amount of load being offered to the router is determined by the budget, some imbalance in load among routers on the path may be alleviated by means of adjusting the budget. The equal allocation applied to the resource reservation protocol (RSVP) is simple to implement, but it has the drawback of a poor resource utilization. A load balancing method in which the delay budget being allocated to a router depends on its load state was developed to improve the drawback, but it's too complex to apply to the RSVP. This paper proposes an intra-path load balancing method not only applicable to the RSVP but also more effective in improving the drawback. The proposed method first partitions the end-to-end delay bound of a flow to routers by the RSVP and then let them adjust their budgets according to both the bottleneck state of the path and their links' bandwidth availabilities. The results of the simulation applying the proposed method to an evaluation network showed that the proposed method may provide the gain of 4 ${\sim}$ 17 % compared to that in the legacy one in terms of the number of maximally admittable flows.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.9C
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• pp.1345-1351
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• 2004

Due to the overwhelming importance the Internet gained nowadays, more and more sophisticated security services are requested. However many applications such as Internet Banking, Home Trading System, Electronic Medical Recede, electronic commerce, etc. are related to non-repudiation. Non-repudiation services are one of these new security requirements. ill comparison to other security issues, such as privacy or authenticity of communications, non-repudiation has not been studied intensively. Informally, we say that a protocol is fair if at the end of the protocol execution either originator receives a non-repudiation of receipt evidence and recipient receives a non-repudiation of origin evidence or none of them receives any valid evidence. The most non-repudiation protocols rely on a trusted third party(TIP) that has to intervene during each protocols run. the TIP may create a communication bottleneck. ill this paper, we suggest the digital signature recorder that guarantees fairness logically and supplies minimal network bottleneck to be composed verification server physically.