• The Journal of the Korea Contents Association
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• v.11 no.5
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• pp.148-156
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• 2011

Recently, an introduction of the cloud computing causes rapid changes in every aspect of the internet environments including hardware, operating systems, applications, and their services. As the cloud computing environment based on SaaS are being developed to a form in which web platform technology and web cloud services are converged. The digital library system also has been being developed to a service model optimized to SaaS based cloud computing environment, which are different from ASP technology. From the web interface point of view, user customization of the SaaS based cloud computing environment is the most important fact. Therefore, this research work suggests a customized web interface considering usability and accessibility so that enterprises and individual users can be able to do an effortless internet browsing under the cloud computing environment. For this purpose, usability tests were carried out as the user customized web interface design were developed and applied to the LinkSaaS website. This paper work lastly presents an UI environment on which customized interface design for individual users can be formulated.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.42 no.4
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• pp.871-878
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• 2017

As the interest of things to the Internet increases, the market of IoT grows larger and devices and protocols related with IoT are evolving.As these IoT devices and protocols evolve, There was a problem with interoperability. As a result, market and standard of IoT are confused, and communication between objects and objects is being hindered by different platforms. Currently, various IoT platforms are being developed and interoperability with heterogeneous platforms is under study, but the protocols used on each platform are limited and designed to have no generalized structure. Therefore, in this paper, we analyze services of HTTP, CoAP, and MQTT protocols, which are typical in the Internet market, and design services that enable selective protocol communication. We also design resources that apply the RESTful API to generalize platform usage. and We implemented the platform through database modeling for quick processing and safety of the collected data. Through this process, devices communicating with different protocols can be interworked on one platform and We propose a "generalized selective protocol based Internet object data collecting platform" that can be applied to various protocols.

• Journal of KIISE:Computing Practices and Letters
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• v.11 no.3
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• pp.224-234
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• 2005

As the network-related technology develops the number of both Internet users and the usage are explosively increasing. The networking traffic is increasing in the campus as the networking system inside universities, following the trend, adds more nodes and various networking services. Nonetheless, the quality of services for users has been degraded. Accordingly, core problems, which can cause troubles for network management, design and expansion of the network, and the cost policy, has appeared. To effectively cope with the problems with analyses a great number of technicians, tools, and budget are needed. However, it is not possible for mid and small-sized colleges to spend such a high expenditure for professional consulting. To reduce the cost and investment creating the optimized environment, the analyses on the replacement of the tools, changing the network structure, and performance analysis about capacity planning of networking is necessary. For this reason, in this paper, framework-based performance management tools are used for all steps that are related to the subject of the analysis for the network management. As the major research method, the current data in detailed categories are collected, processed, and analyzed to provide the solution for the problems. As a result we could manage the network, server, and application more systematically and react efficiently to errors and degrading of performance that affect the networking tasks. Also, with the scientific and organized analyses the overall efficiency is upgraded by optimizing the cost for managing the operation of entire system.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.5
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• pp.25-38
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• 2013

Future wireless systems will be required to support the increasingly nomadic lifestyle of people. This support will be provided through the use of multiple overlaid networks which have very different characteristics. Moreover, these networks will be required to support the seamless delivery of today's popular desktop services, such as web browsing, interactive multimedia and video conferencing to the mobile devices. Thus one of the major challenges in the design of these mobile systems will be the provision of the quality of service (QoS) guarantees that the applications demand under this diverse networking infrastructure. We believe that it is necessary to use resource reservation and adaptation techniques to deliver these QoS guarantee to applications. However, reservation and pre-configuration in the entire service region is overly aggressive, and results in schemes that are extremely inefficient and unreliable. To overcome this, the mobility pattern of a user can be exploited. If the movement of a user is known, the reservation and configuration procedure can be limited to the regions of the network a user is likely to visit. Our proposed Proxy-UMP is not sensitive to increase of the search cost than other schemes and shows that the increasing rate of total cost is low as the SMR increases.

• Journal of the HCI Society of Korea
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• v.7 no.2
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• pp.49-56
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• 2012

The camera-based mobile applications such as color, pattern and object reading can improve the living quality of blind people. However currently available camera-based applications are uncomfortable for the blind, since these applications do not reflect accessibility requirements of the blind especially on touch screen. We investigated accessibility requirements about rapidly growing camera-based mobile applications on touch screen devices for the blind. In order to identify accessibility requirements, we conducted a usability testing for color reading applications with three different types of interfaces on Android OS. The results of the usability testing were as follows: (1) users preferred short depth of menu hierarchy, (2) the initial audio help was more useful than just-in-time help, (3) users needed both manual and automatic camera shooting modes although they preferred manual to automatic mode, (4) users wanted the OS supported screen reader function to be turned off during the color reading application was running, and (5) users required tactile feedback to identify touch screen boundary. We designed a new user interface for blind people by applying the identified accessibility requirements. From a usability testing of the new user interface with 10 blind people, we showed that the identified accessibility requirements were very useful accessibility guidelines for camera-based mobile applications.

• Journal of Digital Contents Society
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• v.19 no.2
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• pp.251-257
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• 2018

The purpose of this study is to analyze the satisfaction and requirements of users' devices after development of tablet based AAC(Augmentative and Alternatice Communication) application for Android. The purpose of this study is to evaluate the satisfaction and the requirement of tablet - based AAC application, Were assessed using the Korea Assistive Technology Assessment Tool (KAAT). As a result of satisfaction evaluation of tablet-based smart AAC device, all the items including device, service, and everyday life showed positive response satisfying from 5 point scale to more than 4 point scale. However, it was relatively low in the items of effectiveness, manipulation and convenience. Some of the improvements in the application include the enlargement of the symbol sound and the simplicity of symbol editing. The results of the study suggest that continual updates of m Smart AAC applications, the simplicity of symbolic editing, application usage and training should be improved. The satisfaction evaluation results of this study and the feedback of potential users will be the guidelines for improving and complementing the functions of existing smart AAC devices.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.44 no.10
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• pp.7-16
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• 2007

In this paper, we introduce a new design environment for efficient multiprocessor system-on-chip design space exploration. The design environment takes a process network model as input system specification. The process network model has been widely used for modeling signal processing applications because of its excellent modeling power. However, it has limitation in predictability, which could cause severe problem for real time systems. This paper proposes a new approach that enables static analysis of a process network model by converting it to a hierarchical synchronous dataflow model. For efficient design space exploration in the early design step, mapping application to target architectures has been a crucial part for finding better solution. In this paper, we propose an efficient mapping algorithm. Our mapping algorithm supports both single bus architecture and multiple bus architecture. In the experiments, we show that the automatic conversion approach of the process network model for static analysis is performed successfully for several signal processing applications, and show the effectiveness of our mapping algorithm by comparing it with previous approaches.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.30 no.5
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• pp.895-907
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• 2020

With the recent increasing influence of multimedia content other than the text-based content, services that help to process information in content brings us great convenience. These services' representative features are searching and masking the sensitive data. It is not difficult to find the solutions that provide searching and masking function for text information and image. However, even though we recognize the necessity of the technology for searching and masking a part of the audio data, it is not easy to find the solution because of the difficulty of the technology. In this study, we propose web application that provides searching and masking functions for audio data using audio partitioning method. While we are achieving the research goal, we evaluated several speech to text conversion APIs to choose a proper API for our purpose and developed regular expressions for searching sensitive information. Lastly we evaluated the accuracy of the developed searching and masking feature. The contribution of this work is in design and implementation of searching and masking a sensitive information from the audio data by the various functionality proving experiments.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.30 no.5
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• pp.847-857
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• 2020

As IoT equipment is commercialized, Bluetooth or wireless networks will be built into general living devices such as IP cameras, door locks, cars and TVs. Security for IoT equipment is becoming more important because IoT equipment shares a lot of information through the network and collects personal information and operates the system. In addition, web-based attacks and application attacks currently account for a significant portion of cyber threats, and security experts are analyzing the vulnerabilities of cyber attacks through manual analysis to secure them. However, since it is virtually impossible to analyze vulnerabilities with only manual analysis, researchers studying system security are currently working on automated vulnerability detection systems, and Firm-AFL, published recently in USENIX, proposed a system by conducting a study on fuzzing processing speed and efficiency using a coverage-based fuzzer. However, the existing tools were focused on the fuzzing processing speed of the firmware, and as a result, they did not find any vulnerability in various paths. In this paper, we propose IoTFirmFuzz, which finds more paths, resolves constraints, and discovers more crashes by strengthening the mutation process to find vulnerabilities in various paths not found in existing tools.

• Journal of Broadcast Engineering
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• v.10 no.3
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• pp.413-421
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• 2005

As the population of HDTV is growing, among many useful features of modern set top boxes (STBs) or digital video recorders (DVRs), video browsing, visual bookmark, and picture-in-picture capabilities are very frequently required. These features typically employ reduced-size versions of video frames, or thumbnail images. Most thumbnail generation approaches generate DC images directly from a compressed video stream. A discrete cosine transform (DCT) coefficient for which the frequency is zero in both dimensions in a compressed block is called a DC coefficient and is simply used to construct a DC image. If a block has been encoded with field DCT, a few AC coefficients are needed to generate the DC image in addition to a DC coefficient. However, the bit length of a codeword coded with variable length coding (VLC) cannot be determined until the previous VLC codeword has been decoded, thus it is required that all codewords should be fully decoded regardless of their necessary for DC image generation. In this paper, we propose a method especially for fast DC image generation from an I-frame using multiple-symbol lookup table (mLUT). The experimental results show that the method using the mLUT improves the performance greatly by reducing LUT count by 50$\%$.