• Journal of Internet Computing and Services
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• v.15 no.6
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• pp.107-115
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• 2014

Recently, increased use of the internet resulted in generation of large and diverse types of data due to increased use of social media, expansion of a convergence of among industries, use of the various smart device. We are facing difficulties to manage and analyze the data using previous data processing techniques since the volume of the data is huge, form of the data varies and evolves rapidly. In other words, we need to study a new approach to solve such problems. Many approaches are being studied on this issue, and we are describing an effective design and development to build indexing engine of big data platform. Our goal is to build a system that could effectively manage for huge data set which exceeds previous data processing range, and that could reduce data analysis time. We used large SNMP log data for an experiment, and tried to reduce data analysis time through the fast indexing and searching approach. Also, we expect our approach could help analyzing the user data through visualization of the analyzed data expression.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.9 no.6
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• pp.136-150
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• 2010

Due to the effect of indoor coverage problem, the QoS of the indoor users will be degraded dramatically, with the number of indoor users. The femto cell is a popular solution for such problems. Since the price of the femto base station is usually cheap enough, one can sets up huge number of base stations in a small indoor area to reduce the size of communication cell. In this way, the QoS of the indoor users can be improved significantly. Moreover, the data rate can also be increased. However, how to decide an ideal transmitting power according to the surrounding radio environment is not a trivial problem, that still has not been addressed well. If the transmit power of femto base station is too large, the interference to the macro users will be increased. Conversely, if the transmit power of femto base station is too small; the coverage of femto base station will be reduced. To address this problem, we propose a power configuration method in femto base station using Genetic Algorithm by investigating a new fitness function. Furthermore, we adopt the weighted sum approach to improve the user performance in different modes. The simulation results show that the proposed power configuration method can not only improves the downlink SINR, but also enhance the channel capacity for both the Macro cell systems and Femto cell systems compared with some conventional methods.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.1
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• pp.179-187
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• 2014

The underlay protocol is a cognitive radio method in which secondary or cognitive users use the same frequency without affecting the quality of service (QoS) for the primary users. In addition, because of the broadcast characteristics of the wireless environment, some nodes, which are called eavesdropper nodes, want to illegally receive information that is intended for other communication links. Hence, Physical Layer Security is applied considering the achievable secrecy rate (ASR) to prevent this from happening. In this paper, a performance analysis of the amplify-and-forward scheme under an interference constraint and Physical Layer Security is investigated in the cooperative communication mode. In this model, the relays use an amplify-and- forward method to help transmit signals from a source to a destination. The best relay is chosen using an opportunistic relay selection method, which is based on the end-to-end ASR. The system performance is evaluated in terms of the outage probability of the ASR. The lower and upper bounds of this probability, based on the global statistical channel state information (CSI), are derived in closed form. Our simulation results show that the system performance improves when the distances from the relays to the eavesdropper are larger than the distances from the relays to the destination, and the cognitive network is far enough from the primary user.

• Journal of Distribution Science
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• v.14 no.12
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• pp.107-118
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• 2016

Purpose - In today's markets, new technologies such as social network systems and user generated contents have provided consumers with access to unlimited amounts of information and an ability to communicate with other consumers in the world. Specially, the massive of the internet and the development of online communities and interactive platforms offer the potential to cocreate with a large number of consumers. Significant changes in marketplace suggest that simply being consumer oriented is not enough, so firms must learn from and collaborate with consumers to create values that meet their individual and dynamic needs. In these sense, emergent perspectives in marketing highlight new opportunities for co-opting consumers as a means to define and cocreate value through their engagement. Although the importance of consumer co-creation with firms, the current literature lacks the respond to two questions: (1) who are the most competent consumers for creating the values with firm? and (2) what are the stimulaters to help the consumers engage for co-creation? To this answer the question, this research investigate how to structure consumer motivations to encourage consumers to be more engaged for co-creation and what drives a consumer to get involved to respond to a call for co-creation. Research design, data, and methodology - To empirically test the hypotheses, a survey was conducted among consumers who had experienced the co-creation including upstream, downstream, autonomous, and sponsored co-creation with the firms. We collected a total of 343 responses. After we excluded 37 questionnaire because of incomplete responses, a total of 306 questionnaire remained. Working with a sample of 306 responses in Seoul and Kwangju, hierarchical moderated regression is employed to test research hypotheses. Results - The results indicated that consumer creativity and emergent nature are positively related to engagement in co-creation including upstream, downstream, autonomous, and sponsored co-creation. Also, the relationships between consumer creativity/emergent nature and engagement in co-creation were moderated by intrinsic motivation in case of upstream and downstream co-creation. Finally, interaction effects between consumer creativity/emergent nature and extrinsic motivation were not significant. Conclusions - These results suggest that marketing managers have to consider the consumer personality such as creativity and emergent nature and stimulate the intrinsic motivation of consumer to achieve the co-creation project successfully.

• Journal of Advanced Navigation Technology
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• v.14 no.5
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• pp.684-690
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• 2010

Recently, the NG(Next Generation) system is studied for supporting convergence of various services and multi mode of single terminal. And a demand of user for taking the various services is getting increased, for supporting these services, many systems being able to transmit a large message have been appeared. In the NG system, it has to be supporting the CDMA and WCDMA besides the tele communication systems using OFDM method with single terminal An intergrated system can be improved with adopting of SoC technique. For adopting SoC technique on the intergrated terminal, we have to solve the non linear problem of HPA(High Power Amplifier). Nonlinear characteristic of HPA distorts both amplitude and phase of transmit signal, this distortion cause deep adjacent channel interference. We adopt a polynomial pre-distortion technique for this problem. In this paper, a noble modem design for NG mobile communication service and a method using polynomial pre-distorter with PAPR technique for counterbalancing nonlinear characteristic of the HPA are proposed.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.10a
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• pp.292-295
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• 2003

This paper presents the architecture and its function of Tool server. MPEG-21 will enable all-electronic creation, delivery and trade of digital multimedia content and transparent usage of various content types on network device. Therefore, we can provide access to information and services from almost anywhere at anytime with various terminals and networks. In order to support multimedia delivery chain that contains content creation, production, delivery and consumption, we need some elements to identify, describe, manage and protect the contents. Thus, we define Digital Item Processing(DIP), Digital Item Adaptation(DIA) server and Tool server as primary objects of MPEG-21 multimedia framework. DIP provides a function which creates and consumes Digital Item(DI) as a kind of a digital object by user. DIA server adapts the original DI to the usage environment description sent from the terminal and transmits the adapted DI to the terminal. Tool sewer searches for a tool requested from DIP or DIA and downloads the best tool to DIP or DIA server. In this paper, we present how Tool server is organized and is used among 2 primary objects. The paper is structured as following: Section 1 briefly describes why MPEG-21 is needed and what MPEG-21 wants. We see the basic architecture of tool server and its functionality by each module in section 2. Section 3 explains a scenario that tool server transmits tool to DIP or DIA. The paper concludes in section 4.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.8
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• pp.1735-1742
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• 2011

Now a days, as a mass-storage USB becomes comfortable to carry, function of USB is being developed fast. However, there is a problem that the personal information which is stored in USB could be exposed being used with negative purpose without other certification process. This paper suggests OTP(One-Time Password)-based certification protocol of USB to securely protect personal information stored in USB without additional certification information. The proposed OTP based certification protocol of USB not only demands low calculations but also prevents physical approach of USB of other network and does not allow unnecessary service access of user because it conducts simple action and uses one-way hash function. Therefore, communication overhead and service delay is improved. In the experiment, the proposed protocol compares and evaluates throughput of certification server according to the numbers of USB and delay time of packet certification with a device(USB driver) which simply save device and a device(USB Token) which can calculate by oneself. As a result, it is improved as the number of 12.5% in the certification delay time on average and is improved as the number of 10.8% in the throughput of certification server according to the numbers of USB.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.48 no.10
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• pp.773-782
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• 2020

The development of joint FE models for deep learning neural network (DLNN)-based hybrid FEA is presented. Material models of bolts and bearings in the front axle of tractor, showing complex behavior induced by various tightening conditions, were replaced with DLNN models. Bolts are modeled as one-dimensional Timoshenko beam elements with six degrees of freedom, and bearings as three-dimensional solid elements. Stress-strain data were extracted from all elements after finite element analysis subjected to various load conditions, and DLNN for bolts and bearing were trained with Tensorflow. The DLNN-based joint models were implemented in the ABAQUS user subroutines where stresses from the next increment are updated and the algorithmic tangent stiffness matrix is calculated. Generalization of the trained DLNN in the FE model was verified by subjecting it to a new loading condition. Finally, the DLNN-based FEA for the front axle of the tractor was conducted and the feasibility was verified by comparing with results of a static structural experiment of the actual tractor.

• Journal of Broadcast Engineering
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• v.16 no.2
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• pp.350-359
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• 2011

Fast developments of broadcasting technologies since 1990s enabled not only High Definition Television service providing high quality audiovisual contents at home but also mobile broadcasting service providing audiovisual contents to high speed moving vehicle. Terrestrial Digital Multimedia Broadcasting (T-DMB) is one of the technologies developed for mobile broadcasting service, which has been successfully commercialized. One of the major technical breakthroughs achieved by T-DMB in addition to robust vehicular reception is an adoption of framework based on MPEG-4 System. It naturally enables integrated interactive data services by using Binary Format for Scene (BIFS) technology for scene description and representation of graphics object and Object Descriptor Framework representing multimedia service components as objects. T-DMB interactive data service has two fundamental limitations. Firstly, graphic data for interactive service should be always overlaid on top of a video not to be rendered out of it. Secondly, data for interactive service is only received by broadcasting channel. These limitations were considered as general in broadcasting systems. However, they are being considered as hard limitations for personalized data services using location information and user characteristics which are becoming widely used for data services of smart devices in these days. In this paper, the architecture of T-DMB hybrid data service is proposed which is utilizing broadcasting network, wireless internet and local storage for delivering BIFS data to overcome these limitations. This paper also presents hybrid BIFS technology to implement T-DMB hybrid data service while maintaining backward compatibility with legacy T-DMB players.

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