• IEMEK Journal of Embedded Systems and Applications
• /
• v.5 no.1
• /
• pp.7-17
• /
• 2010

ITS(Intelligent Transport System) as things are used for Broadcast service using TDMB/TPEG/NAVI rather than personal seamless service. It is attaching weight to Traffic information gathering, Charging, Settlement service. This research is applied to improve DCCP(Datagram Congestion Control Protocol) which has function as protecting data and preserving message boundary. The improving method is like that we solve data trust in UDP because Connection and Transmission overhead in UDP is less than in TCP. We fix the data loss which is generated from unordered delivery section of IP base wireless service by using DCCP protocol. We guarantee of connection with OBE(On-Board Equipment) and reliance about transmission of data by complement to mapping table and multi-hoping. Finally, We evaluate the performance about transmission of IP based data. We constructed a test-bed near research center for this test.

• Journal of the Korea Society of Computer and Information
• /
• v.21 no.1
• /
• pp.79-84
• /
• 2016

In this paper, we propose reliable message transmission scheme based on CoAP, considering the constrained feature of IoT device, such as low power, the limited memory size and low computing capacity. Recently, the various kinds of application protocol has been studied to support IoT environments. In particular, CoAP protocol was developed as application protocol for IoT at the IETF core WG. However, because CoAP protocol is deigned to be used in constrained node, this protocol uses UDP at transport layer. Thus, data loss may occur frequently in network congestion environments. The proposed scheme, in this paper, is to overcome the problem of frequent data loss with low overhead. Also it includes the function which is to minimize the data loss in sleep mode of IoT device.

• Industrial Engineering and Management Systems
• /
• v.11 no.4
• /
• pp.299-309
• /
• 2012

This paper introduces some of the developments related to the handling equipment in container terminals and various new conceptual handling systems that have been proposed during the last several decades. The basic ideas behind the previous equipment improvements are analyzed to identify future directions that can be used for devising new handling systems. The handling systems in the container terminals include a quayside handling system, transport system, and yard system. In response to the deployment of mega-sized vessels for container transportation systems, productivity improvement has become one of the most urgent issues in the container terminals. This paper analyzes the previous improvements made for achieving higher productivity in the three subsystems of container handling. Some conceptual handling systems are introduced including the linear motor conveyance system (LMCS), automated storage and retrieval systems (AR/RS), overhead grid rail (GRAIL), SPEEDPORT, SuperDock, the automated container system by ZPMC (ACS-ZPMC), and AUTOCON.

• Smart Structures and Systems
• /
• v.11 no.5
• /
• pp.555-567
• /
• 2013

An Remote Corrosion Monitoring (RCM) system consists of an anode with low potential, the metallic structures against corrosion, an electrode to provide reference potential, and a data-acquisition system to ensure the potential difference for anticorrosion. In more detail, the data-acquisition (DAQ) system monitors the potential difference between the metallic structures and a reference electrode to identify the correct potential level against the corrosion of the infrastructures. Then, the measured data are transmitted to a central office to remotely keep track of the status of the corrosion monitoring (CM) system. To date, the RCM system is designed to achieve low power consumption, so that it can be simply powered by batteries. However, due to memory effect and the limited number of recharge cycles, it can entail the maintenance fee or sometimes cause failure to protect the metallic structures. To address this issue, the low-overhead energy harvesting circuitry for the RCM systems has designed to replenish energy storage elements (ESEs) along with redeeming the leakage of supercapacitors. Our developed energy harvester can scavenge the ambient energy from the corrosion monitoring environments and store it as useful electrical energy for powering local data-acquisition systems. In particular, this paper considers the energy harvesting from potential difference due to galvanic corrosion between a metallic infrastructure and a permanent copper/copper sulfate reference electrode. In addition, supercapacitors are adopted as an ESE to compensate for or overcome the limitations of batteries. Experimental results show that our proposed harvesting schemes significantly reduce the overhead of the charging circuitry, which enable fully charging up to a 350-F supercapacitor under the low corrosion power of 3 mW (i.e., 1 V/3 mA).

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.14 no.9
• /
• pp.3639-3662
• /
• 2020

The network capability to accomplish its functions in a timely fashion under failures and attacks is known as survivability. Ad hoc routing protocols have been studied and extended to various domains, such as Intelligent Transport Systems (ITSs), Unmanned Aerial Vehicles (UAVs), underwater acoustic networks, and Internet of Things (IoT) focusing on different aspects, such as security, QoS, energy. The existing solutions proposed in this domain incur substantial overhead and eventually become burden on the network, especially when there are fewer attacks or no attack at all. There is a need that the effectiveness of these routing protocols be analyzed in the presence of Denial of Service (DoS) attacks without any intrusion detection or prevention system. This will enable us to establish and identify the inherently stable routing protocols that are capable to survive longer in the presence of these attacks. This work presents a DoS attack case study to perform theoretical analysis of survivability on node and network level in the presence of DoS attacks. We evaluate the performance of reactive and proactive routing protocols and analyse their survivability. For experimentation, we use NS-2 simulator without detection or prevention capabilities. Results show that proactive protocols perform better in terms of throughput, overhead and packet drop.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.35 no.2
• /
• pp.143-148
• /
• 2011

Corrosion at the top of a distillation column is a common problem in refineries and chemical plants. In particular, severe damage has been inflicted in refineries by corrosive materials such as hydrogen sulfide and chlorine. Therefore, the mechanism of the corrosion occurring at the top of a distillation column has been analyzed, and a model for forecasting the corrosion rate has been developed. Four major materials were selected for modeling: $H_2S$, $CO_2$, $H^+$ and $Cl^-$. These were selected by taking into consideration their effect on the corrosion rate. Studies on the transport phenomenon and reaction engineering for this model were carried out, and the reliability of the model was verified on the basis of the data measured at a real refinery.

• Journal of KIISE:Information Networking
• /
• v.36 no.1
• /
• pp.34-42
• /
• 2009

In this paper, we propose a practical hybrid transport error control scheme to provide SVC video streaming service over error-prone IP networks. Many error control mechanisms for various video coding standards have been proposed in the literature. However, there is little research result which can be practically applicable to the multilayered coding structure of SVC(the scalable extension of H.264/AVC). We present a new hybrid transport error control scheme that efficiently combines layered Forward Error Correction(FEC) and Automatic Repeat Request(ARQ) for better packet-loss resilience. In the proposed hybrid error control, we adopt ACK-based ARQ instead of NACK-based ARQ to maximize throughput which is the amount of effective data packets delivered over a physical link per time unit. In order to prove the effectiveness of the proposed hybrid error control scheme, we adopt NIST-Net network emulator which is a general-purpose tool for emulating performance dynamics in IP networks. It is shown by simulations over the NIST-Net that the proposed hybrid error control scheme shows improved packet-loss resilience even with much less number of overhead packets compared to various conventional error control schemes.

• Journal of Broadcast Engineering
• /
• v.16 no.3
• /
• pp.520-529
• /
• 2011

In this paper, we propose the extension of the MPEG-2 Transport Stream (TS) header for efficient adaptation of multi-layer coded video such as scalable video coding (SVC) and multiview video coding (MVC) in the HTTP streaming. First of all, the limit of the existing TS in terms of flexible adaptation of multi-layer video is investigated, and the signaling by extending TS header is proposed to provide efficient adaptation in a TS level. The proposed extension utilizes the private data field in the adaptation field of TS header to signal scalability and/or view information, which enable us to support diverse adaptation that suits underlying constraints of client capabilities, network conditions and user preferences. In short, the extension enables adaptation of scalable video with full scalability as well as view selection of multiview video in a TS level while keeping backward compatibility with the existing TS syntax/semantics. The performance of the proposed extension is compared with the existing adaptation using PID (packet ID) in terms of efficiency and complexity of adaptation. Furthermore, the increase of TS overhead caused by proposed extension is analyzed and an extension scheme to minimized the overhead is proposed.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.10 no.8
• /
• pp.851-860
• /
• 2015

Transport Social Overhead Capital refers to public utilities necessary for a nation's basic economic activities, and is divided into roads, railway, subway, ports and so on. It is important to be able to provide these SOC in the right place at the right time to enhance productivity and competitiveness of a nation. In this study, correlation and factor analysis on countries' socioeconomic and transport indicators were performed in order to understand the need for expansion of SOCs including railway, and to identify the impact they have on national competitiveness(productivity). As a result, GDP showed high correlativity(0.59~0.99) with factors such as population, land area, extension of available railroad, and road extension. Specifically, through the analysis of Russia's urban transport system and comparison between socioeconomic indices and SOCs of OECD countries, it was examined that how increasing transport infrastructure investments could enhance national competitiveness. In conclusion, opening new Light Rail greatly affects the growth of GDP followed by the increasing extension of available railroad. Furthermore, if available railroad extension is increased by 10 % from 2014, assuming high speed tram is opened, GDP will likely increase by 21.6%.

• Journal of the Korea Convergence Society
• /
• v.7 no.4
• /
• pp.25-32
• /
• 2016

When using reliable multicast protocol over air links, the multicast packets lost in the air link cause the initiation of retransmission request packets and the implosion of retransmission packets, which deteriorate multicast session performance. This paper proposes on the efficient reliable multicast mechanism in wireless networks utilizing the Agents. In this paper we show the design of a retransmission agent which improves the performance of reliable multicast sessions in wireless network. The main idea is to cache reliable multicast packets at the base station and perform local retransmissions across the wireless link. MATLAB has been used to simulate and to get performance results for signaling overhead and processing delay through the comparison of the proposed agent model to the Multicast File Transfer Protocol. It has been proven from the simulation results that the proxy module make pass trials shorter in Multicast File Transfer Protocol.