• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.4
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• pp.470-476
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• 2019

The pattern locking technique applied to smart phones is a locking technique that many people use conveniently. However, the safety of pattern locking techniques is very low compared with other techniques. The pattern locking technique is vulnerable to a shoulder surfing attack, which is based on the user's input and can be interpreted by looking at the movement of the shoulder, and the smudge attack is also vulnerable due to fingerprint drag marks remaining on the mobile phone pad. Therefore, in this paper, we want to add a new security method to check the pressed time by using a thread in the pattern locking scheme to secure the vulnerability. It is divided into short, middle, and long click according to the pressing time at each point. When dragging using the technique, security performance enhances $3^n$ tiems. Therefore, even if dragging in the same 'ㄱ' manner, it becomes a completely different pattern depending on the pressing time at each point.

• Journal of the Korea Society of Computer and Information
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• v.25 no.12
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• pp.119-126
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• 2020

In this paper, we design and implement a product information guidance system Based on BLE beacons. This system is designed to provide various functions such as contactless entrance service through mobile ticket, seat guidance service, event push service, content push service, and public service. This system consists of three modules: a beacon recognition module, a server linkage module, and a content transmission module. The beacon recognition module implements a function of transmitting a specific ID of a nearby beacon when a customer with a smartphone approaches the available service area. The server linkage module recognizes the beacon ID value, transfers it to the server, and implements the function to check the location of the server having the ID. The content transmission module implements a function of transmitting event or service information set at a corresponding location to a smartphone. The beacon-based product information guidance system implemented in this paper has the advantage of being able to quickly and easily implement various product information guidance systems.

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.6
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• pp.1241-1248
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• 2019

In this paper, an auxiliary device was implemented to help blind people more safely from obstacles or risk factors while walking. The ultrasonic sensors detect obstacles in the front, so that the noise gap and the vibration intensity of the buzzer can be heard differently by distance and angle, and so the situation can be perceived by pedestrians. When the ambient light becomes darker than the light intensity set using the CdS resistance value of the light sensor, the LED automatically turns on, makes it easier for pedestrians to recognize the position of the auxiliary device through buzzer if the pedestrian misses the aid using the gyro sensor's slope. Moreover, the location and situation of the blind were transmitted to the caregiver to check safety and behavior using GPS and Bluetooth.

• KIPS Transactions on Software and Data Engineering
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• v.3 no.3
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• pp.109-118
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• 2014

Code refactoring focuses on enhancing the maintainability of software to extend its lifetime. However as software applications were varied and the range of its usage becomes broaden, there are some efforts to improve software qualities like performance or reliability as well as maintainability using code refactoring techniques. Recently, as low-energy software has become one of critical issues in mobile environment, developing energy efficient software through code refactoring becomes an important one. Therefore this paper has its goal to investigate whether the existing refactoring techniques can support energy efficient software generation or not. That is to say, the existing code refactoring techniques can cause the minus of energy efficiency because they did not considered the energy consumption in their refactoring process. This paper experiments and analyzes to check whether the M. Fowler's code refactoring techniques can support the energy efficient software generation or not. Our research result can give to software developer some informations about energy-efficient refactoring techniques, and can support the development of software that has high maintainability and good energy efficiency.

• Journal of Practical Engineering Education
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• v.14 no.1
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• pp.99-108
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• 2022

As the demand for kiosks increases, more users complain of discomfort. Accordingly, a kiosk that enables easy menu selection and order by producing a voice-based interactive service is produced and provided in the form of a web. It implements voice functions based on the Annyang API and SpeechSynthesis API, and understands the user's intention through Dialogflow. And discuss how to implement this process based on Rest API. In addition, the recommendation system is applied based on collaborative filtering to improve the low consumer accessibility of existing kiosks, and to prevent infection caused by droplets during the use of voice recognition services, it provides the ability to check the wearing of masks before using the service.

• Information Systems Review
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• v.14 no.2
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• pp.117-140
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• 2012

It is hard, but important to evaluate and select a new service model for the public sector, accompanying unexpectable risk. The purpose of this study is to build and develop the evaluation framework of public projects and to present a project evaluation system which is more rational and methodical. The evaluation framework has been developed by calculating the evaluation criteria and weights resulted from an interview with an expert group and Analytic Hierarchy Process(AHP). Moreover, market-oriented characteristics, technology-oriented characteristics, service development capabilities and policy-oriented characteristics were predominantly chosen as the evaluation items. The re-evaluation of the app development support programs was conducted to check the feasibility as an evaluation system influencing the performance of firms. The result of an evaluation system proposed by this study showed better evaluation performance than previous ones, better predicting the actual business performance. Currently, though the policies of the public sectors and support programs focus on the outcome and performance management, the result of this study shows the importance of project selections. Also, implications of the study are discussed.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.13 no.10
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• pp.1089-1097
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• 2002

In this paper, the novel shipboard Active Phased Array Antenna(APAA) system for maritime mobile satellite communications is introduced. The antenna uses novel technologies like wide range hybrid tracking, single antenna elements with both of Rx and Tx, asymmetrical array structure, interference isolation between Rx and Tx, and error correction method from frequency scan effect. The antenna has single aperture for both of Rx and Tx with 32 $\times$ 4 two-dimensional array. The antenna has two beams. Its frequencies are 7.25 ~ 7.75 GHz for Rx and 7.9 ~ 8.4 GHz for Tx. The antenna gains are 35.4 dBi for Rx and 35.7 dBi for Tx, those are 54 % of efficiency. The electrically steering ranges are $\pm$35$^{\circ}$ of elevation direction and $\pm$4$^{\circ}$ of azimuth direction. The mechanical control ranges at hybrid tracking capability are continuous 360$^{\circ}$ of azimuth direction and $\pm$10$^{\circ}$ of elevation direction. The antenna has 2.2$^{\circ}$ of 3 dB beamwidth, -14 dB of sidelobe level, and 21 dB of cross-pol suppression. The antenna performance was measured by near field measurement set. Its system performance was tested on the ship motion simulator and with the satellite transponder simulator. The test result showed that its tracking error was within -3 dB from its peak gain under motion condition. The antenna system was tested by real modulated Direct Broadcasting Satellite(DBS) signals to check its communication processing function.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.11A
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• pp.921-928
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• 2003

This paper propose a new design of directional couplers with the high directivity. The directional coupler is used to check and verify the power, frequency and antenna reflection of a signal at transmission station for the mobile communications. The performance index of the directional coupler is to which the coupling is strong to reduce the effect on the transmitted power and the directivity is high to suppress the interference of the reflected signals and reduce the nor in the communication. Then, the architectures to gain the high directivity and the studies to get the strong coupling have been proposed However, the conventional architectures lot the high directivity and strong coupling have the directivity by about 20㏈ and the difficulty to achieve the higher directivity than 40㏈ suitable for IMT-2000 [1]. This paper proposes an architecture of the directional coupler which is based on the grounding composed of the strip lines and the comparison results with the conventional directional couplers. The comparison results show that the proposed directional coupler has the directivity more than 40 ㏈ and is adequate for the 2.05GHz IMT-2000

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.4
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• pp.533-538
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• 2017

In this thesis, the ambulatory aid mechanism was implemented so that blind people could be safer at risk of walking outdoors. Using ultrasonic sensors, the obstacles can be detected when the distance between the obstacle is within 50 cm of the obstacle. If the light sensor becomes less than 25 lux, the LED will automatically turn on and help the safety of the visually impaired and the security of sight of the peripheral walkers. Color recognition sensors increase the rate of recognition of yellow color by the detection distance is 1cm, it vibrated when yellow light was detected. Using GPS with 7.3 m of error range, the guardian was able to check the location of the visually impaired.

• Journal of Digital Contents Society
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• v.18 no.3
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• pp.443-455
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• 2017

This study is a follow-up study of Smart-phone Application Content Development for the Measurement and Management of Adolescents' Depression(J. S. Park et al., 2016), that designing and implementing a smart-phone application based on cognitive behavioral therapy. This app facilitates analysis of depressive symptoms, and a simple, continuous self-check. Through this, the app will allow for continuous management of the psychological states by avoiding one-off or comprehensive analysis and diagnosis of depression, unlike previous app. We also aim to make a connection to the practical counseling services. To achieve this goal, we examined not only existing studies on youth depression, but also mobile applications related to depression.