• Journal of the Korea Computer Graphics Society
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• v.28 no.2
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• pp.21-28
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• 2022

ASTC is one of the standard texture formats supported in OpenGL ES 3.2 and Vulkan 1.0 (and later versions), and it has been increasingly used on mobile platforms (Android and iOS). ASTC's most important feature is the block size configuration, thereby providing a trade-off between compression quality and rates. With the higher number of textures, however, it is difficult to manually determine the optimal block sizes of each texture. To solve the problem, we present a new approach based on PSNR values to automatically determine the ASTC block size. A brute-force approach, which compresses a texture on all block sizes and compares the PSNR values of the compressed textures, can increase the compression time by up to 14 times. In contrast, our three-step approach minimizes the compression-time overhead. According to our experiments on a texture set including 64 various textures, our method determined the block sizes from 4×4 to 12×12 and reduced the size of compressed files by 68%.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.23 no.3
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• pp.13-18
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• 2023

As the number of mobile applications increases rapidly, the overhead of swapping in smartphone memory systems keeps increasing. Unlike desktop or server systems, the basic setting of smartphones does not support swapping, so applications are killed when available memory is exhausted. This is because swapping in smartphones incurs excessive storage I/O overhead. In this article, we propose a swapping policy for smartphones, which significantly reduces storage I/Os. The proposed policy categorizes mobile applications based on their functional characteristics, and controls the number of applications to be swapped based on application priorities and memory situations. Measurement experiments with Android reference devices show that the proposed swapping policy dramatically reduces the overhead of swapping in various mobile applications.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.5
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• pp.1871-1890
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• 2021

The transition toward a contactless society has been rapidly progressing owing to the recent COVID-19 pandemic. As a result, the IT environment of organizations and enterprises is changing rapidly; in particular, data security is expanding to the private sector. To adapt to these changes, organizations and companies have started to securely transfer confidential data to residential PCs and personally owned devices of employees working from home or from other locations. Therefore, organizations and companies are introducing streaming data services, such as the virtual desktop infrastructure (VDI) or cloud services, to securely connect internal and external networks. These methods have the advantage of providing data without the need to download to a third terminal; however, while the data are being streamed, attacks such as screen shooting or capturing are performed. Therefore, there is an increasing interest in prevention techniques against screen capture threats that may occur in a contactless environment. In this study, we analyze possible screen capture methods in a PC and a mobile phone environment and present techniques that can protect the screens against specific attack methods. The detection and defense for screen capture of PC applications on Windows OS and Mac OS could be solved with a single agent using our proposed techniques. Screen capture of mobile devices can be prevented by applying our proposed techniques on Android and iOS.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.3
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• pp.131-137
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• 2014

The advent of various smart devices like smart phones and tablets has triggered the changes in information systems of medical centers. Especially, diversifying devices of clients and the need for N-Screen services increase necessities for sharing effectively information in medical centers. However, developing and managing clients for each OS like iOS and Android cost high and make it hard to provide seamless service through multi devices. Also, in the aspect of security it is necessary to share information between clients and health information systems. In this paper, we develop a smart health information client based real-time health information sharing framework. The developed client is based on hybrid app, that enables to share information in real time between N devices through health information sharing framework and to adopted to developments of various clients.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.5
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• pp.731-742
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• 2022

PIPO is the latest domestic lightweight block cipher announced in ICISC'20, which is characterized by being lightweight to facilitate implementation on IoT with limited resources. In this paper, PIPO 64/128-bit and 64/256-bit were implemented using web-based languages such as Javascript and WebAsembly. Two methods of performance evaluation were conducted by implementing bitsice and TLU, and the performance was compared by implementing Looped written using for statements and Unrolled written for statements. It performs performance evaluations in various web browsers such as Google Chrome, Mozilla Firefox, Opera, and Microsoft Edge, as well as OS-specific environments such as Windows, Linux, Mac, iOS, and Android. In addition, a performance comparison was performed with PIPO implemented in C language. This can be used as an indicator for applying PIPO block cipher on the web.

• Journal of Korea Entertainment Industry Association
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• v.13 no.8
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• pp.143-150
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• 2019

Playing musical instruments has long been a hobby enjoyed by many, whether amateur or professional. However, a lot of long and arduous practice is required if one wants to acquire the skills of musical artist and truly enjoy the pleasure of playing. This repetitive and tedious practice is often a hindrance to the process of learning a musical instrument, and numerous educators have put a lot of research and effort into making the process easier and more fun for students. In addition, various media practice tools are being developed to keep the students engaged and having fun. The core elements of this content primarily include controlling the speed of backing tracks in accordance with the skill level of students and providing a backing ensemble that enables them to enjoy the fun of playing. This paper studies and compares various MIDI playback techniques capable of controlling speed and pitch in smartphone applications. Modern applications of these techniques are seen in music educational contents, as well as entertainment contents. It also discusses the development and launching of Upbeat, a drum-loop metronome that automatically increases speed by applying different techniques to its respective smartphone operating systems, Android OS and iOS.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.05a
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• pp.281-283
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• 2013

In this paper, we have presented the implementation plan for the Server interface and how to implement the Client GUI interface of a form you can use Android considerations and ERP Interface methods available in mobile devices, with iOS. It provides in the form of Web services using TCP / IP, how to handle the data, communication of Client and Server in mobile devices, coordination of ERP that can be used in mobile devices by presenting how to send in XML format it presented a new method which can be performed more efficiently.

• Korea Science and Art Forum
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• v.21
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• pp.31-43
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• 2015

Information and Communications Technology (ICT) is one of the technologies which represent the core value of the creative economy. It has served as a vehicle connecting the existing industry and corporate infrastructure, developing existing products and services and creating new products and services. In addition to the ICT, new devices including big data, mobile gadgets and wearable products are gaining a great attention sending an expectation for a new market-pioneering. Further, Internet of Things (IoT) is helping solidify the ICT-based social development connecting human-to-human, human-to-things and things-to-things. This means that the manufacturing-based hardware development needs to be achieved simultaneously with software development through convergence. The essential element the convergence between hardware and software is OS, for which world's leading companies such as Google and Apple have launched an intense development recognizing the importance of software. Against this backdrop, the status-quo of the software market has been examined for the study of the present report (Korea Evaluation Institute of Industrial Technology: Professional Design Technology Development Project). As a result, the software platform-based Google's android and Apple's iOS are dominant in the global market and late comers are trying to enter the market through various pathways by releasing web-based OS and similar OS to provide a new paradigm to the market. The present study is aimed at finding the way to utilize a smart content by which anyone can be a developer based on OS responding to such as social change, newly defining a smart content to be universally utilized and analyzing the market to deal with a rapid market change. The study method, scope and details are as follows: Literature investigation, Analysis on the app market according to a smart classification system, Trend analysis on the current content market, Identification of five common trends through comparison among the universal definition of smart content, the status-quo of application represented in the app market and content market situation. In conclusion, the smart content market is independent but is expected to develop in the form of a single organic body being connected each other. Therefore, the further classification system and development focus should be made in a way to see the area from multiple perspectives including a social point of view in terms of the existing technology, culture, business and consumers.

• Proceedings of the Korean Society of Computer Information Conference
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• 2014.01a
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• pp.333-334
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• 2014

유니티3D는 게임 회사에서 가장 많이 사용하고 있는 게임 엔진 중의 하나이다. 다양한 장르의 게임을 쉽고 간편하게 개발 할 수 있고, 또한 개발비를 절약 할 수 있는 장점을 가지고 있다. 다양한 플랫폼 지원으로 인해 iOS(iPhone Operating System) 환경, 안드로이드(Android) 환경에 맞도록 최적화 하여 플랫폼 전환도 가능하다. 본 논문은 유니티3D에서 강점인 NGUI(Next-Gen UI)의 사용방법과 설계에 대한 방법을 통해서, 사용자 인터페이스 개발에 쉽게 접근 할 수 있는 방법에 대해 소개한다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.10
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• pp.4191-4203
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• 2015

WebView is a vital component in smartphone platforms like Android, Windows and iOS that enables smartphone applications (apps) to embed a simple yet powerful web browser inside them. WebView not only provides the same functionalities as web browser, it, more importantly, enables a rich interaction between apps and webpages loaded inside the WebView. However, the design and the features of WebView lays path to tamper the sandbox protection mechanism implemented by browsers. As a consequence, malicious attacks can be launched either against the apps or by the apps through the exploitation of WebView APIs. This paper presents a critical attack called Supplementary Event-Listener Injection (SEI) attack which adds auxiliary event listeners, for executing malicious activities, on the HTML elements in the webpage loaded by the WebView via JavaScript Injection. This paper also proposes an automated static analysis system for analyzing WebView embedded apps to classify the kind of vulnerability possessed by them and a solution for the mitigation of the attack.