• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.6
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• pp.1497-1508
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• 1993

Real-time mobile robot controllers usually have been designed focused on control theory without paying attention to the importance of system integration. This paper demonstrates that autonomous mobile robots require a real-time controller with a wide range of capabilities in addition to control theory. An architectural frame work supporting these capabilities has been designed in actual hardware environments. Individual modules such as a path planner, a path tracking controller, position estimators, wheel controllers and other cruical elements have been successfully integrated into the control system using this frame work. The overall performance of the system was investigated via a series of tracking experiments with a prototype mobile robot named LCAR deveoped in the laboratory. The context of the research involves the architecture, its implementation and experimental results.

• Convergence Security Journal
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• v.10 no.4
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• pp.39-48
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• 2010

In a complex, secure IT system environment there will be groups of data that be segregated from one another, yet reside on the same system. Users of the system will have varying degrees of access to specific data. The Configuration Management(CM) of the information architecture, the physical architecture, user privileges and application security policies increases the complexity for operations, maintenance and security staff. This pager describes(current work to merge the capabilities of a network CM toll with those of a Computer Aided System Engineering(CASE) tool. The rigour of Systems Engineering(SE) modelling techniques can be used to deal with the complexities of multi-level information security. The SE logical and physical models of the same system are readily tailorable to document the critical components of both the information architecture and physical architecture that needs to be managed. Linking a user-friendly, physical CM tool with the extended capabilities of a CASE tool provide the basis for improved configuration management of secure IT systems.

• The Journal of the Korea Contents Association
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• v.4 no.2
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• pp.43-49
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• 2004

SIP Caller Preference is an useful function that allows a caller to express preferences about request handling in servers. It can also feat appropriate call processing according to the callee capabilities. However, only the category of the media is considered as a criteria for target selection in the caller preference. In this case, if the callee's media information such as codec is different from the caller, an additional re­negotiation occurs for SIP call setup. Therefore, in this paper, we have suggested an extended caller preference to solve this problem. In our SIP based VoIP system, a network sewer uses detailed media informations for media stream in the session to select the target for SIP call setup. The sewer gives higher priority to the candidate which do not require re-negotiation for call setup, so that an effective call setup can be achieved in our system.

• Journal of IKEEE
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• v.25 no.3
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• pp.571-577
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• 2021

This paper describes ISO/TR 4804, an international standard to describe how to design and verify autonomous cars to ensure safety and cybersecurity. Goals of ISO/TR 4804 are (1) positive risk balance and (2) avoidance of unreasonable risk. It also 12 principles of safety and cybersecurity to achieve these goals. In the design procedures, it describes (1) 13 capabilities to achieve these safety and cybersecurity principles, (2) hardware and software elements to achieve these capabilities, and (3) a generic logical architecture to combine these elements. In the verification procedures, it describes (1) 5 challenges to ensure safety and cybersecurity, (2) test goals, platforms, and solutions to achieve these challenges, (3) simulation and field operation methods, and (4) verification methods for hardware and software elements. Especially, it regards deep neural network as a software component and it describe design and verification methods of autonomous cars.

• Korean Journal of Organic Agriculture
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• v.28 no.4
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• pp.505-534
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• 2020

The purpose of this study is to explore the key elements of the regional innovative milieu by analyzing the role of regional innovative elements and case organizations that promoted the emergence of 'Songakdongnesaramdeul (the people of the Songak town),' and to present pertinent policy implications. For the purpose, this study set the "Songakdongnesaramdeul," a residential community organization founded for regional innovation to revitalize the village community, as a case organization from the perspective of regional innovation system theory. The result of the study showed that creating an innovative milieu through the creation of various innovation elements to revitalize the village community is crucial. Especially, this study confirmed that the existence of regional development organizations is the key element of the innovative milieu. such as case organization that contributes to regional development while promoting interaction between actors, common learning and systemization, and new value creation activities. The implications derived through the study can be summarized in four points. First, a variety of means to promote the formation of subjects in response to the public debate of the village agenda is needed. Second, it is highly important to create innovative elements, for example, organizations and programs, resources, and spaces that promote regional innovation. Third, forming a close network between various innovative resources existing in the region and establishing regional capabilities that allow to mobilize and utilize such innovative resources are important. Fourth, the establishment of a promotion mechanism such as a case organization is suggested as a major task, to revitalize the village community. Specifically, forming and revitalizing numerous private-based community organizations with regional developmental capabilities to establish local governance also has significant importance. In this vein, based on the point of view of the regional innovation system theory, the establishment of regional policies to construct a regional innovation milieu, such as creating innovative elements that can actively promote the regeneration of the village community and establishing a promotion system, can be presented as major tasks.

• Journal of Internet Computing and Services
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• v.20 no.5
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• pp.95-104
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• 2019

Various kinds of devices are used for the Internet of Things (IoT) service, and IoT devices mainly use communication technology that uses the frequency of the unlicensed band. There are several types of communication technology in the unlicensed band, but WiFi is most commonly used. Devices used for IoT services vary in computing resources from devices with limited capabilities to smartphones and provide services over wireless networks such as WiFi. Most IoT devices can't perform complex operations for network control, thus they choose a WiFi access point (AP) based on signal strength. This causes a decrease in IoT service efficiency. In this paper, an intelligent AP system that can efficiently control the WiFi connection of the IoT devices is implemented. Based on the network information measured by the IoT device, the access point learns using a feed forward neural network algorithm, and predicts a network connection state to control the WiFi connection. By controlling the WiFi connection at the AP, the service efficiency of the IoT device can be improved.

• Journal of Digital Convergence
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• v.20 no.4
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• pp.353-366
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• 2022

The study sets out to examine the relationship between the effects of government support, network capability, and knowledge sharing on the effects of innovative behavior on innovation performance. As digital-based networks and knowledge sharing activities are rapidly becoming common in the era of the spread of Covid-19, 357 questionnaires were analyzed for incumbent employees and the research hypotheses are verified using SPSS 24 and smart PLS 3 to prove the relationships between variables. As a result of the study, it is found that innovation performance increased when government support, network capability, and knowledge sharing increased. Innovative behavior is found to significantly mediate the relationship between network capability, knowledge sharing, and innovation performance, and government support was found to have a significant effect on network capabiltiy. Therefore, in order to induce innovative actions that are important in creating innovative results, various programs to enhance the network capabilities of entrepreneurs and promote knowledge sharing should be required as government support policies. This will serve as a driving force for entrepreneurs to voluntarily develop and implement ideas more flexibly and freely, thereby enhancing competitiveness through innovative growth of companies and industries. In other words, this study verified the effectiveness of government support in the network capability to help create innovative results by inducing innovative behavior along with knowledge sharing activities, and comprehensively demonstrated the relationship between factors in the overall structure.

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

• Journal of Navigation and Port Research
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• v.44 no.5
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• pp.382-391
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• 2020

In line with the trend of global transport volume which has increased rapidly over the years, internal transportation in seaports is always conducted with high frequency. Thus, there is always much potential for traffic jams as well as high transportation costs and emissions. Many efforts have been initiated to streamline the inter-terminal container transport (ITT) through the development of automated vehicles and equipment as well as using private transport facilities to overcome these limitations. The purpose of this paper to develop a framework to design, analyze, and validate the efficiency of a new ITT system in a port area based on the monorail network and automatic vehicles. First, the number of shuttles and loaders was determined depending on the transport demand scenario. Next, a simulation model was applied to evaluate the system performance as well as gain more insight into the working process of the ITT system. Finally, by setting goals for the performance indicators, the results showed that the system was highly efficient with 100% of the containers delivered to their destination on time. Besides, a series of other performance tracking was provided to provide insight into the system's capabilities.

• The Journal of the Korea Contents Association
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• v.12 no.4
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• pp.10-19
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• 2012

Seamless streaming of multimedia content that ensures Quality of Service over heterogeneous networks has been a desire for many multimedia services, for which the multimedia contents should be adapted to usage environments such as network characteristics, terminal capabilities, and user preferences. Scalability in video coding is a good feature to meet the requirement of heterogeneous networks. In this paper, we propose a dynamic adaptation scheme of H.264/AVC SVC bit-stream using the MPEG-21 Digital Item Adaptation (DIA) tool. MPEG-21 DIA framework provides systematic solutions in choosing an adaptation operation to given conditions and supports interoperable video adaptation. The experiment results show that the proposed adaptation scheme provides QoS-enabled delivery and consumption of SVC with time-varying constraints of network, terminal, and user preference, in a robust and efficient way. In particular, the proposed adaptation scheme is proved to work well with very low delay under the condition that the variation rate of the given network bandwidth is upto 62%.