• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.24 no.2
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• pp.127-132
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• 2024

Recently, secondary batteries, commonly known as rechargeable batteries, find widespread applications across various industries. Particularly valued for their compact and lightweight characteristics, they play a crucial role in diverse portable electronic devices such as smartphones, laptops, and tablets, offering high energy density and efficient charge-discharge capabilities. Moreover, they serve as vital components in electric vehicles and contribute significantly to the field of renewable energy as part of Energy Storage Systems(ESS). However, despite advancements in this technology, issues such as reduced lifespan, cracking, damage, and even the risk of fire can arise due to excessive charging and discharging of secondary batteries. To address these challenges, Battery Management System(BMS) are employed to protect against overcharging and improve overall performance. Nevertheless, understanding the protective range settings of BMS using lithium-ion batteries, the most commonly used secondary batteries, and lead-acid batteries can be challenging. Therefore, this paper aims to utilize a battery charge-discharge tester and simulator to investigate the charging and discharging characteristics of lithium-ion batteries and lead-acid batteries, addressing the associated challenges of reduced lifespan, cracking, damage, and fire hazards in secondary batteries.

• Journal of Convergence Society for SMB
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• v.2 no.1
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• pp.51-58
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• 2012

Android platform is a powerful operating system developed on Linux 2.6 Kernel, and provides many features such as comprehensive libraries, a multimedia environment, and powerful interface for phone applications. Since Android is an open operating system, which can be installed in any vendors's equipments. Current smartphones as well as netbooks, navigations, car PCs, tablet PCs, Industrial PCs are used in various fields. It is difficult a lot that to mount to other devices on the Android platform or new devices. In this Paper, The process that data that occurred from a hardware was passed to the highest application and Android platform system for managing hardware devices were analyzed. Building Android & driver compilation environment, How to support the protocol for the use of WiFi in the kernel, How to Mount a WiFi device in the kernel, Device driver registration for the Android platform, WiFi Management Service Daemon (wpa_supplicant) and IP allocation services daemon (dhcpcd) registration, How to create a socket for communication between the daemon (wpa_supplicant) and HAL have been presented. In the experiment using the proposed method, WiFi devices were mounted on the Android platform in the X-86 & ARM family. Understanding the whole process of control flow in Android hierarchy is very important to porting a new device on it. The process included in this paper can help technicians who might encounter the obstacles in their porting works.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.10
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• pp.602-608
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• 2020

Development of Internet technology and the spread of various smart devices provide a convenient computing environment for people, which is becoming common thanks to the Internet of Things (IoT). However, attacks by hackers have caused various problems, such as leaking personal information or violating privacy. In the IoT environment, various smart devices are connected, and network attacks that are used in the PC environment are occurring frequently in the IoT. In fact, security incidents such as conducting DDoS attacks by hacking IP cameras, leaking personal information, and monitoring unspecified numbers of personal files without consent are occurring. Although attacks in the existing Internet environment are PC-oriented, we can now confirm that smart devices such as IP cameras and tablets can be targets of network attacks. Through performance evaluation, the proposed protocol shows 11% more energy efficiency on servers than RSA, eight times greater energy efficiency on clients than Kerberos, and increased efficiency as the number of devices increases. In addition, it is possible to respond to a variety of security threats that might occur against the network. It is expected that efficient operations will be possible if the proposed protocol is applied to the IoT environment.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.10
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• pp.7071-7077
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• 2015

In recently, the demand of cover-glass is increased because smart phone, tablet pc, and electrical device has become widely used. The display of mobile device is enlarged, so it is necessary to have a high strength against the external force such as contact or falling. In fabrication process of cover-glass, a grinding process is very important process to obtain high strength of glass. Conventional grinding process using a grinding wheel is caused such as a scratch, chipping, notch, and micro-crack on a surface. In this paper, polishing system using a abrasive film was developed for a grinding of mobile cover-glass. To evaluate structural stability of the designed system, finite element model of the polishing system is generated, and multi-body dynamic analysis of abrasive film polishing machine is proposed. As a result of the analysis, stress and displacement analysis of abrasive film polishing system are performed, and using laser displacement sensor, structural stability of abrasive film polishing system is confirmed by measuring displacement.

• Smart Media Journal
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• v.10 no.2
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• pp.76-83
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• 2021

With the development and use of smart devices such as smartphones and tablets increases, the mobile application market based on mobile devices is growing rapidly. Mobile application users write reviews to share their experience in using the application, which can identify consumers' various needs and application developers can receive useful feedback on improving the application through reviews written by consumers. However, there is a need to come up with measures to minimize the amount of time and expense that consumers have to pay to manually analyze the large amount of reviews they leave. In this work, we propose to collect delivery application user reviews from Google PlayStore and then use machine learning and deep learning techniques to classify them into four categories like application feature advantages, disadvantages, feature improvement requests and bug report. In the case of the performance of the Hugging Face's pretrained BERT-based Transformer model, the f1 score values for the above four categories were 0.93, 0.51, 0.76, and 0.83, respectively, showing superior performance than LSTM and GRU.

• The Journal of the Convergence on Culture Technology
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• v.8 no.5
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• pp.377-383
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• 2022

In today's modern society, along with the 4th industrial revolution, digitalization is rapidly progressing from everyday life to the entire industry. In the field of education, support is being provided at the government level, such as the dissemination of digital devices to create a digital educational environment, and the use of digital devices is remarkably increasing at the level of individual students as well. In the fashion design education field of universities, the number of students using tablet PCs and applications such as iPads is increasing and the scope of its application is expanding, from design concept setting and idea generation to design sketches in the early fashion design process, as well as diagramming and portfolio work. For fashion design sketching, it was found that students mainly use Procreate or Clip Studio applications with iPad. Therefore, by identifying the differentiated functions and characteristics of Procreate and Clip Studio, and examining design sketch examples using them, the possibility of effective use of iPad applications was presented and problems were also examined. Through this study, it is intended to provide basic data for fashion design education that can increase students' interest and achievement by using the iPad application.

• Journal of the Institute of Electronics and Information Engineers
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• v.54 no.4
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• pp.16-21
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• 2017

In this paper, a Small-sized and planer resonator design of Magnetic Resonance - Wireless Power Transfer(MR-WPT) were proposed for practical applications of mobile devices, such as a laptop, a smart-phone and a tablet pc. The proposed MR-WPT system were based on four coil MR-WPT and designed as a transmitter part (Tx) and a receiver part (Rx) both are the same shape with the same loop and resonator. There are four different spiral coil type of resonators with variable of line length, width, gap and turns in $50mm{\times}50mm$ size. The both of top and bottom side of substrate(acrylic; ${\varepsilon}_r=2.56$, tan ${\delta}=0.008$) ere used to generate high inductance and capacitance in limited small volume. Loops were designed on the same plane of resonator to reduce their volume, and there are three different size. The proposed MR-WPT system were fabricated with two acrylic substrate plane of Tx and Rx each, the Rx and Tx loops and resonators were fabricated of copper sheets. There are 12 combinations of 3 loops and 4 resonators, each combination were measured to calculate transfer efficiency and resonance frequency in transfer distance from 1cm to 5cm. The measured results, the highest transfer efficiency was about 70%, and average transfer efficiency was 40%, on the resonance frequency was about 6.78 MHz, which is standard band by A4WP. We proposed small-sized and planer resonator of MR-WPT and showed possibility of mobile applications for small devices.

• KIPS Transactions on Software and Data Engineering
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• v.2 no.8
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• pp.555-564
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• 2013

Innovative evolution in mobile devices along with recent spread of Tablet PCs and Smart Phones makes a new change not only in individual life but also in enterprise applications. Especially, in the case of medium-large mobile applications for large enterprises which generally takes more than 3 months of development periods, importance and complexity increase significantly. Generally Agile-methodology is used for a development process for the medium-large scale mobile applications, but some issues arise such as high dependency on skilled developers and lack of detail development directives. In this paper, S-MADP (Smart Mobile Application Development Process) is proposed to mitigate these issues. S-MADP is a service oriented development process extending a object-oriented development process, for medium-large scale mobile applications. S-MADP provides detail development directives for each activities during the entire process for defining services as server-based or client-based and providing the way of reuse of services. Also, in order to support various user interfaces, S-MADP provides detail UI development directives. To evaluate the performance of S-MADP, three mobile application development projects were conducted and the results were analyzed. The projects are 'TBS(TB Mobile Service) 3.0' in TB company, mobile app-store in TS company, and mobile groupware in TG group. As a result of the projects, S-MADP accounts for more detailed design information about 'Minimizing the use of resources', 'Service-based designing' and 'User interface optimized for mobile devices' which are needed to be largely considered for mobile application development environment when we compare with existing Agile-methodology. Therefore, it improves the usability, maintainability, efficiency of developed mobile applications. Through field tests, it is observed that S-MADP outperforms about 25% than a Agile-methodology in the aspect of the required man-month for developing a medium-large mobile application.

• Journal of Digital Convergence
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• v.12 no.9
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• pp.379-385
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• 2014

N-Screen era is held due to the cloud computing technology which access to contents anytime, anywhere without any persistent. In the broadcast industry, this broadcast contents is rapidly serviced by variety of media devices such as PC, Smart phone, Tablet, App, IPTV. To Increase the usefulness and usability of the platform, same brand identity have to be maintain by devices and integrated guide which can encompass a variety of media are needed. This study tries to figure out the need of New Media Style Guide to keep brand identity in a variety of new media beyond previously Web style guide which limited in the Web pages. First, Integrated Guide GEL of BBC's and Web style guide of KBS was analyzed. Through the analysis it was found that the limitations and problem of the current web style guide and then suggested the improvement direction. In addition, this study tried to find which design elements should be made for new media style guides through in-depth interview with practitioners who work in broadcast media industry for more than three years. Through the research it was understood the current status of integrated brand identity and found a way to improve forward to new media platforms of KBS.

• The Journal of Society for e-Business Studies
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• v.22 no.1
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• pp.89-106
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• 2017

In advanced mobile devices environment, the market share of mobile application has been increased. Among various mobile services, Location-based Service (LBS) is an important feature to increase user motivation related to purchase intention on mobile. However, individual privacy has also increased as an important problem for invasion of privacy and information leakage while too many LBS based applications (App) rapidly launched in the App market. In this study, we focused on perceived values of LBS App users who use Apps related to recommending best restaurants in China and South Korea. The purpose of this study is to identify important factors for perceived value when users provide personal information for LBS service provider. The result of this study is follows: perceived value can increase while LBS customers can more control self-information and information useability. Also information ability of users affected perceived values for LBS Apps. Also users' app user ability and perceived value were effects on privacy revenue. In addtion, perceived weakness of users and perceived value increased privacy threat.