• IEIE Transactions on Smart Processing and Computing
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• v.4 no.3
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• pp.169-172
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• 2015

Dalvik is a virtual machine (VM) that is designed to run Java-based Android applications. A trace-based just-in-time (JIT) compilation technique is currently employed to improve performance of the Dalvik VM. However, due to runtime compilation overhead, the trace-based JIT compiler provides only a few simple optimizations. Moreover, because each trace contains only a few instructions, the trace-based JIT compiler inherently exploits fewer optimization and parallelization opportunities than a method-based JIT compiler that compiles method-by-method. So we propose a new method-based JIT compiler, named DEX2C, in order to improve performance by finding more opportunities for both optimization and parallelization in Android applications. We employ C code as an intermediate product in order to find more optimization opportunities by using the GNU C Compiler (GCC), and we will detect parallelism by using the Intel C/C++ parallel compiler and the AESOP compiler in our future work. In this paper, we introduce our DEX2C compiler, which dynamically translates Dalvik bytecodes (DEX) into C code with method granularity. We also describe a new method-based JIT interface in the Dalvik VM for the DEX2C compiler. Our experiment results show that our compiler and its interface achieve significant performance improvement by up to 15.2 times and 3.7 times on average, in Element Benchmark, and up to 2.8 times for FFT in Smartbench.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.25 no.1
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• pp.31-37
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• 2015

As the forms of cyberattacks become diverse, there has been reported another case of exploiting vulnerabilities revealed while processing either a document or multimedia file that was distributed for attacking purpose, which would replace the traditional method of distributing malwares directly. The attack is based upon the observation that the softwares such as document editer or multimedia player may reveal inherent vulnerabilities on some specific inputs. The fuzzing methods that provide invalid random inputs for test purpose could discover such exploits. This paper suggests a new fuzzing method on document applications that could work in mobile environments, in order to resolve the drawback that the existing methods run only in PC environments. Our methods could effectively discover the exploits of mobile applications, and thus could be utilized as a means of dealing with APT attacks in mobile environments.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.25 no.4
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• pp.817-827
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• 2015

In this modern society, people are having a close relationship with smartphone. This makes easier for hackers to gain the user's information by installing the malware in the user's smartphone without the user's authority. This kind of action are threats to the user's privacy. The malware characteristics are different to the general applications. It requires the user's authority. In this paper, we proposed a new classification method of user requirements method by each application using the Principle Component Analysis(PCA) and Probabilistic K-Nearest Neighbor(PKNN) methods. The combination of those method outputs the improved result to classify between malware and general applications. By using the K-fold Cross Validation, the measurement precision of PKNN is improved compare to the previous K-Nearest Neighbor(KNN). The classification which difficult to solve by KNN also can be solve by PKNN with optimizing the discovering the parameter k and ${\beta}$. Also the sample that has being use in this experiment is based on the Contagio.

• Journal of the Korea Society of Computer and Information
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• v.25 no.11
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• pp.17-25
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• 2020

In this paper, we deal with a system that provides temperature, humidity and fine dust data around infants to parents through Arduino and Raspberry Pi. It controls the operation of the mobiles remotely through applications. Android applications can perform the following functions. First, the infant's surrounding temperature, humidity and fine dust data are received. Second, mobile controls the smart mobile remotely. Third, recording and playing the voices of parents and enhancing the convenience of parenting. Through the experiment of measuring the operating time of the remote control module, it was confirmed that the application can quickly access the system. Existing products on the market do not provide environmental information around the infants and application that has various functions. The system covered in this paper is expected to improve child-rearing convenience by providing parents environmental information around infants, remotely controllable function and convenient functions of the application.

• Journal of Korea Multimedia Society
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• v.16 no.9
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• pp.1089-1097
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• 2013

The applications for considering their position and daily patterns of dementia patients have been developed in an early stage even if the older patients who have weaker or serious symptoms has increased in various forms. In this paper, we develop an android-based application which displays positions and pathways of patients on maps and provide messages in the cases of dangerous situations. Guardians need to register schedules including safe areas and personal information of their patients. This system registers behavior status categorized as normal or abnormal each position which is sent to a database. In particular, the deviation status is assigned in case the patients are not within the safe areas that their guardians registered on their schedule. The wandering status is assigned in case the patients are repeatedly passed by their pathways. This smart application contains the modules such as patient position sending, guardian and patient information, patient schedule and safe zone registration, position and behavior status registration, pathway display and message sending, and rescue request. This system sends the notification and alarm service providing normal and abnormal behavior with deviation and wandering status of patients respectively.

• Journal of Advanced Navigation Technology
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• v.18 no.1
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• pp.101-106
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• 2014

Smart TV is to form a market of new industries along with the smartphone that appeared in the early 2000s. With the development of IT technology and the emergence of smart phones, user to pursue the application of high satisfaction. The smartphone has to meet the needs of the user in a variety of applications. However, Smart TV which led to a decrease in the development of a member of the application that reflect the needs of the user. Smart TV is popularized, the approach may be used instead of the application of high specification, the smart TV feel to be a smart are required to meet the needs of the user. Therefore in this paper, using the latest IT technology to provide a smart TV applications. This provides a feeling in conjunction as a system of one smart TV, smartphone, the exercise bike like to travel the distance of the actual user. For this reason to use WebOS, HTML5, Web sockets, the technology of Android.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.6
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• pp.195-200
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• 2015

As mobile equipments have been developed while we use public transport, several applications for knowing arrival informations of public transport have happened. But these only provide public traffic informations simply, these solving applications for problems and inconvenience that we ride/get off public transport do not exist. These inconveniences are occurred mainly on tagging card, when tag error or without advanced preparation are happened, these caused for delay while we use ride/get off. Also, these caused for traffic congestion. In this paper, in order to solve these problems, we use Beacon and we overcome narrow range of NFC and we implemented for Android application for decreasing delay while several people could ride/get off simultaneously.

• Journal of the Korea Convergence Society
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• v.10 no.1
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• pp.61-69
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• 2019

As smartphones become widespread, numerous applications are developed and social issues related to software copyright are emerging. Software watermarking is digital watermarking technology applied to software and is a technology that can be used to recognize copyright owners. Generally, Java language is used to develop applications on the Android environment. The Java is an object-oriented language that supports method overloading and overriding. In this paper, we propose and implement a method generation based watermarking technique. As a result of evaluating the overhead due to the watermark, it was confirmed that the increase of the executable file size and the decrease of the execution speed are not large. Using the watermarking technique proposed in this paper, it is expected that copyright information can be verified when illegal copying is suspected or actual program is stolen, and piracy attempts will be prevented in advance.

• The Journal of the Convergence on Culture Technology
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• v.4 no.2
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• pp.205-209
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• 2018

In this paper, we design and implement a political online platform using smartphones. This platform is consisted of monitoring of members of the National Assembly, monitoring of legislation, and participating in several issues. It is implemented as an AWS server, DB and an Android applications. Especially, we update the political information in real time by using Open API and Naver API. This system will be well applied to the division in discussion and sharing of thinking about legislation and political issues.

• Journal of Korea Game Society
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• v.15 no.2
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• pp.73-82
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• 2015

This study makes a proposal about Flash mobile game applications using Adobe AIR. In developing a mobile game, the developer programs in Flash ActionScript, and distributes and publishes the program using Adobe AIR so that the game can be played on an Android mobile device. In order to run the game, the player downloads and installs Android Adobe AIR onto the mobile device and sets up the published app. This study designed and implemented a mobile game application and showed that a mobile game is executed on a smart phone. This outcome may be applicable to various genres of apps. Moreover, this study analyzed the trends of mobile games, focusing on their genres and characteristics, and according to the results, most of them were mobile games using Kakao Talk. The analysis results also showed that the popularity ranking of games varied little among sites.