• Proceedings of the Korean Society of Computer Information Conference
• /
• 2021.07a
• /
• pp.207-208
• /
• 2021

본 논문에서는 스마트 폰의 가속도(Accelerometer) 센서와 GPS 센서 및 Kakao Map, Kakao OPEN API 기반을 이용하여 아동, 기저질환자 및 노약자 등의 사용자들이 위험한 상황에 노출되었을 때 자동으로 구조 요청 서비스를 제공하는 낙상 감지 애플리케이션을 설계하고 구현한다. 이 애플리케이션은 사용자의 낙상, 넘어짐 등을 감지하여 보호자에게 SMS 및 카카오톡으로 구조 요청 메시지를 자동으로 전송한다. 안드로이드의 가속도 센서는 사용자의 가속도 및 각도를 계산하여 낙상 및 넘어짐을 감지하고, GPS 센서를 통해 사용자의 현재 위치를 카카오 맵에 표시하고, 구조 요청 메시지를 자동으로 전송함으로써 사용자가 긴급한 상황에서 구출되도록 한다.

• Journal of the Semiconductor & Display Technology
• /
• v.22 no.2
• /
• pp.120-127
• /
• 2023

Recently, metaverse has attracted great attention worldwide with the development of related technologies and the demand for on-tact systems. The ideal metaverse should constitute a virtual world more similar to the realistic society with physical interactions. However, there are many constraints when we construct a virtual world using the existing commercialized metaverse platform. In this paper, we design and implement a university campus-based metaverse which minimizes the constraints, and create a virtual environment maps very similar to the real-world using Unity engine, Photon cloud and Playfab SDK for multi-user accessible to virtual world as a personal avatar. Also, this work includes attractive interaction based on exchange between users. Lastly, we illustrate our implemented metaverse works on Android phone, and it works without difficulty in terms of performance.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.9
• /
• pp.25-31
• /
• 2020

In this study, for the safe use of a portable ultrasonic skin-beauty device, an android app was developed to show the irradiation locations of focused ultrasound to a user through augmented reality (AR) and enable stable self-surgery. The utility of the app was assessed through testing. While the user is making a facial treatment with the beauty device, the user's face and the ultrasonic irradiation location on the face are detected in real-time with a smart-phone camera. The irradiation location is then indicated on the face image and shown to the user so that excessive ultrasound is not irradiated to the same area during treatment. To this end, ML-Kit is used to detect the user's face landmarks in real-time, and they are compared with a reference face model to estimate the pose of the face, such as rotation and movement. After mounting a LED on the ultrasonic irradiation part of the device and operating the LED during irradiation, the LED light was searched to find the position of the ultrasonic irradiation on the smart-phone screen, and the irradiation position was registered and displayed on the face image based on the estimated face pose. Each task performed in the app was implemented through the thread and the timer, and all tasks were executed within 75 ms. The test results showed that the time taken to register and display 120 ultrasound irradiation positions was less than 25ms, and the display accuracy was within 20mm when the face did not rotate significantly.

• KIPS Transactions on Software and Data Engineering
• /
• v.10 no.10
• /
• pp.421-428
• /
• 2021

The High Efficiency Image File Format (HEIF) is an MPEG-developed image format that utilizes the video codec H.265 to store still screens in a single image format. The iPhone has been using HEIF since 2017, and Android devices such as the Galaxy S10 have also supported the format since 2019. The format can provide images with good compression rates, but it has a complex internal structure and lacks significant compatibility between devices and software, making it not popular to replace commonly used JPEG (or JPG) files. However, despite the fact that many devices are already using HEIF, digital forensics research regarding it is lacking. This means that we can be exposed to the risk of missing potential evidence due to insufficient understanding of the information contained inside the file during digital forensics investigations. Therefore, in this paper, we analyze the HEIF formatted photo file taken on the iPhone and the motion photo file taken on the Galaxy to find out the information and features contained inside the file. We also investigate whether or not the software we tested support HEIF and present the requirement of forensic tools to analyze HEIF.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.22 no.4
• /
• pp.827-839
• /
• 2012

A cell phone is very close to the user and therefore should be considered in digital forensic investigation. Recently, the proportion of smartphone owners is increasing dramatically. Unlike the feature phone, users can utilize various mobile application in smartphone because it has high-performance operating system (e.g., Android, iOS). As acquisition and analysis of user data in smartphone are more important in digital forensic purposes, smartphone forensics has been studied actively. There are two way to do smartphone forensics. The first way is to extract user's data using the backup and debugging function of smartphones. The second way is to get root permission, and acquire the image of flash memory. And then, it is possible to reconstruct the filesystem, such as YAFFS, EXT, RFS, HFS+ and analyze it. However, this methods are not suitable to recovery and analyze deleted data from smartphones. This paper introduces analysis techniques for fragmented flash memory pages in smartphones. Especially, this paper demonstrates analysis techniques on the image that reconstruction of filesystem is impossible because the spare area of flash memory pages does not exist and the pages in unallocated area of filesystem.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.19 no.4
• /
• pp.352-358
• /
• 2013

The objective of this paper is to introduce on a mobile APP called MAMIS(Marine pollution Accident response Mobile Information System) and it's functions. MAMIS was developed by Korea Coast Guard for marine pollution responder in 2012. Users can get information on marine pollution response easily without being restricted by time and place. MAMIS can be operated by smart phones with Android OS and iOS, both of which are the most popular mobile operating systems in Korea. And it has been developed in the form of hybrid APP which combined the functions of mobile APP and mobile WEB. MAMIS is composed of 9 menus, 5 mobile-based ones and 4 web-based ones. The mobile-based menus are on substance information, clean-up skills, response measures, QR code scanning, and volunteer's safety, and the web-based ones on weather information, response equipment, clean-up materials, and SNS.

• Journal of Digital Contents Society
• /
• v.11 no.3
• /
• pp.323-330
• /
• 2010

Due to the widespread smartphones and application stores, mobile application developments are now booming again in the same manner of PC history. The smartphone software development process, however, gives much inconvenience to developers because of the heterogeneous platform APIs and hardware incompatibility between different devices. To make clear these problems, mobile web applications are being accepted as an alternative to the native smartphone applications. Mobile web applications can be developed more simply and easily than native applications by using webkit engine's html, Java script, and CSS. Additionally developers can provide a platform-independent applications since web applications are going to run on web browsers. In this paper, we develop a personal applications store running on an android phone's browsers. We can accomplish this very simply by using webkit's various APIs such as OpenID. We can find out by implementing a real web application that development of web applications can surpass the native one in cost and time period without much loss of performance.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.8 no.6
• /
• pp.847-854
• /
• 2013

This paper implements a smartphone application for sound recording and player of mobile learning. Due to its ubiquitous nature, smartphones could be used anytime anywhere, and because they combine an audio and a microphone, the application for sound recording and player that this paper suggests can be easily and cost effectively developed without additional infrastructure. This paper also explains a technique which processes data of music lyrics. The technique is built on a database technology by using SQLite, a DBMS combined in a platform of android. Thus, as long as the smartphone application for sound recording and player is developed and the mobile phone has sound source files, learners could record their own voices to the sound. Therefore, we expect the learners without additional infrastructure to enable mobile learning.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.25 no.1
• /
• pp.31-37
• /
• 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 and Communication Engineering
• /
• v.15 no.9
• /
• pp.1955-1964
• /
• 2011

With fast deployment of high-speed networks and various online services, the demand for massive content distribution is also growing fast. An approach that is increasingly visible in communication research community and in industry domain is peer-to-peer (P2P) networks. The P2P swarming technique enables a content distribution system to achieve higher throughput, avoid server or network overload, and be more resilient to failure and traffic fluctuation. Moreover, as a P2P-based architecture pushed the computing and bandwidth cost toward the network edge, it allows scalability to support a large number of subscribers on a global scale, while imposing little demand for equipment on the content providers. However, the P2P swarming burdens message exchange overheads on the system. In this paper, we propose a new protocol which provides confidentiality, authentication, integrity, and access control to P2P swarming. We implemented a prototype of our protocol on Android smart phone platform. We believe our approach can be straightforwardly adapted to existing commercial P2P content distribution systems with modest modifications to current implementations.