• Journal of Convergence Society for SMB
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• v.2 no.1
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• pp.19-24
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• 2012

In this paper, we propose the battery life time extension method in the multi-interface terminal by using the state information in an optical wireless integrated network architecture. When the bottlenecks occurs in the network, the terminal receives data packets via multipath. However, the battery life time is rapidly reduced because the power consumption of the terminal is bigger than single interface. For reducing the power consumption in the multi-interface terminal, the Optical Line Terminal (OLT) confirms whether the bottleneck phenomenon is occurred or not. And the network state information is transmitted to the terminal. The terminal turns one of the interfaces off to reduce the power consumption. In order to estimate the performance, we compare the power consumption between single and dual interfaces.

• Convergence Security Journal
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• v.8 no.1
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• pp.1-7
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• 2008

The hacking method came to be more complicated, became program ant it was automated. That is hacking trend of recent times. Before, The password crack, catch root authority is trend of hacking which uses the vulnerability of server. Hacker attack network or all of domain not some host. Web application system at hacking technique develops and improve transmitted data through the network shows many vulnerability. The massive data are transmitted through the network without encipherment filtering. It will be able to bring about the neck of a bottle actual condition which is serious in security system because of the network where the user comes to be many it leads and the data which is delivered comes to be many. In this paper, we propose web application system to prevent overload from bottleneck in encipherment system. It can solve security key trust problem in encoding and decoding with public key infrastructure.

• Journal of the Korea Computer Industry Society
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• v.2 no.9
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• pp.1163-1174
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• 2001

A general goal of the ATM(Asynchronous Transfer Mode) network is to support connections across various networks. ABR service using EPRCA(Enhanced Proportional Rate Control Algorithm) switch controls traffics in ATM network. EPRCA switch, traffic control method uses variation of the ACR(Allowed Cell Rate) to enhance the utilization of the link bandwidth. However, in ABR(Available Bit Rate) service, different treatments are offered according to different RTTs(Round Trip Times) of connections. To improve the above unfairness, this paper presents ABR DELAY mechanism, in which three reference parameters for cell delay are defined, and reflect on the messages of RM(Resource Management) cells. To evaluate our mechanism, we compare the fairness among TCP connections between ABR DELAY mechanism and ABR RRM mechanism. And also we execute simulations on a simple ATM network model where six TCP connections and a background traffic with different RTTs share the bandwidth of a bottleneck link. The simulation results, based on TCP goodput and efficiency, clearly show that ABR DELAY mechanism improves the fairness among TCP connections.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.3B
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• pp.204-211
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• 2012

Wireless Mesh Network (WMN) has drawn much attention due to wide service coverage with low system cost. However, WMN suffers from high bit error rate, which provides different link capacity among wireless mesh routers. The conventional routing metrics select the path based on link quality. The link with the best quality is preferred as the data transmission path, and they becomes the bottleneck links, which leads to network performance degradation. In this paper, we propose a routing metric that considers the available bandwidth and the number of nodes suffering congestion in the path. Through computer simulations, we verified that the proposed routing metric outperforms the existing routing metrics in terms of average transmission delay, packet loss, system throughput.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.2A
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• pp.153-164
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• 2010

In this paper, we propose a multi-channel MAC protocol to improve the channel efficiency and network performance in wireless ad hoc networks. There are two main problems encountered in designing multi-channel MAC protocols. The first problem is the rendezvous problem and the second is multi-channel hidden node problem. In order to solve these problems, most of previous researches that have considered multi-channel MAC protocols use a common control channel to exchange control packets. However, they have a bottleneck problem at common control channel as increasing the number of data channels. The proposed MAC protocol solves the multi-channel hidden node problem using a TDMA scheme and increases the network throughput because transmitting and receiving data at the same time is possible. Also, since there is no common control channel, the network does not suffer from the common control channel saturation problem. Moreover, it achieves energy savings by allowing nodes that are not involved in communication to go into sleep mode. Simulation results show that the proposed MAC protocol improves the network throughput and channel efficiency and provides energy savings.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.1
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• pp.183-189
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• 2018

This paper proposes distributed file placement and coverage expansion techniques for mitigating the traffic bottleneck in backhaul for small-cell networks. In order to minimize the backhaul load with limited memory space, the proposed scheme controls the coverage and file placement of base station according to file popularity distribution and memory space of base stations. In other words, since the cache hit ratio is low when there is small memory capacity or widespread file popularity distribution, the base stations expand its coverage and cache different set of files for the user located in overlapped area to exploit multiple cached file sets of base stations. Our simulation results show that the proposed scheme outperforms the conventional cache strategy in terms of network throughput when there is small memory capacity or widespread file popularity distribution.

• The Journal of the Acoustical Society of Korea
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• v.42 no.5
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• pp.395-401
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• 2023

Sound Event Detection (SED) aims to identify not only sound category but also time interval for target sounds in an audio waveform. It is a critical technique in field of acoustic surveillance system and monitoring system. Recently, various models have introduced through Detection and Classification of Acoustic Scenes and Events (DCASE) Task 4. This paper explored how to design optimal parameters of DenseNet based model, which has led to outstanding performance in other recognition system. In experiment, DenseRNN as an SED model consists of DensNet-BC and bi-directional Gated Recurrent Units (GRU). This model is trained with Mean teacher model. With an event-based f-score, evaluation is performed depending on parameters, related to model architecture as well as model training, under the assessment protocol of DCASE task4. Experimental result shows that the performance goes up and has been saturated to near the best. Also, DenseRNN would be trained more effectively without dropout technique.

• Journal of KIISE:Computing Practices and Letters
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• v.6 no.4
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• pp.421-429
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• 2000

In present, ATM integrated switching system has been developed to a mixed modules that complexed switching system including maintenance, operation based on B-ISDN/LAN service and plug-in module, , which runs on workstation computer system. Meanwhile, workstation has HMI operation system feature including file system management, time management, graphic processing, TMN agent function. The workstation has communicated with between ATM switching module and clients. This computer system architecture has much burden messages communication among processes or processor. These messages communication consume system resources which are socket, message queue, IO device files, regular files, and so on. Therefore, in this paper we proposed new performance modeling with this system architecture. We will analyze the system bottleneck and improve system performance. In addition, in the future, the system has many additional features should be migrated to workstation system, we need previously to evaluate system bottleneck and redesign it. In performance model, we use queueing network model and the simulation package is used PDQ and C-program.

• Proceedings of the Korea Contents Association Conference
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• 2004.11a
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• pp.327-332
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• 2004

USB(Universal Serial Bus) is one of the most popular communication interfaces. When USB is used in an extended range, especially configurating In-home network by connecting multiple digital devices each other, USB interface uses the bandwidth in the way of TDM(Time Division Multiplexing) so that the bottleneck of bus bandwidth can be brought. In this paper, the more effective usage of bus bandwidth to overcome this situation is introduced. Basically, in order to realize the system for transferring realtime moving picture data among digital information devices, we analyze USB transfer types and Descriptors and introduce the method to upgrade detailed performance of Isochronous transfer that is one of USB transfer types. In the case that Configuration descriptor of a device has Interface descriptor that has two AlternateSetting, if Isochronous transfers are not processed smoothly due to excessive bus traffic, the application of the device changes AlternateSetting of the Interface descriptor and requires a new configuration by SetInterface() request. As a result of this adaptive configuration, the least data frame rate is guaranteed to a device that the sufficient bandwidth is not alloted. And if the bus traffic is normal, the algorithm to return to the original AlteranteSetting is introduced. this introduced method resolve the bottleneck of moving picture transfer that can occur in home network connected by multiple digital devices.

• The KIPS Transactions:PartC
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• v.12C no.2 s.98
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• pp.301-308
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• 2005

According to banking online transaction grows very rapidly, guarantee validity about business transaction has more meaning. To offer guarantee validity about banking online transaction efficiently, certificate status verification system is required that can an ieai-time offer identity certification, data integrity, guarantee confidentiality, non-repudiation. Existing real-time certificate status verification system is structural concentration problem generated that one node handling all transactions. And every time status verification is requested, network overload and communication bottleneck are occurred because ail useless informations are transmitted. it does not fit to banking transaction which make much account of real response time because of these problem. To improve problem by unnecessary information and structural concentration when existing real-time certificate status protocol requested , this paper handle status verification that break up inspection server by domain. This paper propose the method of real~time certificate status verification that solves network overload and communication bottleneck by requesting certification using really necessary Reduction information to certification status verification. And we confirm speed of certificate status verification $15\%$ faster than existing OCSP(Online Certificate Status Protocol) method by test.