• Journal of Information Technology Services
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• v.16 no.2
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• pp.129-138
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• 2017

This paper is concerned with an Internet of Things (IoT)-based unmanned home-delivery box system, in which the system is developed with a prototype using a weight sensor, shock sensor, the Arduino and Raspberry-Pi of open-source hardware platforms. The developed system provides several functions such as a safe storage means, prevention of delivery-theft, and remote control of the home-delivery box, etc. Specifically, the system recognizes the arrival of goods by detecting the weight of deliveries and sends the arrived message of deliveries to the recipient' smartphone, and also controls (i.e., open and close) the locker of the unmanned home-delivery box system remotely with the smartphone. Furthermore, the developed system provides automatically a warning alarm around the unmanned home-delivery box when an external shock is applied to the home-delivery box, and sends a message on the shock to the recipient' smartphone. The major functions of the developed home-delivery box system have been verified in a realistic environment, and confirmed to work well. With the application of the developed home-delivery box system to the homes and offices where recipients are always not to stay, it is expected to significantly improve the safety of delivered goods as well as to effectively prevent the delivery operatives posing as a crime.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2019.05a
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• pp.486-487
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• 2019

Smartphones have various sensors built in. In particular, acceleration sensors are used to analyze human behavior because they can detect movement of objects. Previous studies have analyzed the behavior of people by analyzing the magnitude of acceleration sensor values. In this study, we proposed a method of detecting the motion by applying the K-average of the acceleration sensor value built in the smartphone. We proposed a method of recognizing walking and running, which is basic human behavior, by applying K-average of acceleration sensor value of smartphone.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.1
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• pp.133-138
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• 2019

The indoor navigation system using smart phone is a very important infrastructure technology for users' location based services in large indoor facilities. For this purpose, if the user can estimate the movement distance and direction by using the acceleration sensor and the gyro sensor built in the smartphone, the additional external environment is not necessary, which is a very useful technique. This paper deals with indoor navigation system technology that uses Pedestrian Dead Reckoning (PDR) technology and Kalman filter on a general smartphone and allows the user to trace the position while moving the smartphone in front of his chest. In particular, an extended Kalman filter was designed to estimate the direction of movement, and its performance was verified when walking at a constant speed.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.10a
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• pp.405-406
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• 2012

A sensor network is composed of a large number of sensor nodes which have sensing, computation and wireless communication capabilities. The sensor node sends such collected data, usually via radio transmitter, to a command center (sink) either directly or through a data concentration center (a gateway). These sensor networks can be used for various application areas such as health, military, home network, managing inventory, monitoring disaster areas and so on. Moreover, owing to the rapid growth of mobile technology, high-performance smartphones are widespread and in increasing cases are utilized as a terminal device. In this paper, we propose a home management system using smartphone and sensor networks.

• Journal of KIISE:Software and Applications
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• v.41 no.8
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• pp.586-597
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• 2014

The next generation mobile computing technology is recently attracting attention that smartphone and wearable device imbedded with various sensors are being deployed in the world. Existing activity and posture recognition research can be divided into two different ways considering feature of one's movement. While activity recognition focuses on catching distinct pattern according to continuous movement, posture recognition focuses on sudden change of posture and body orientation. There is a lack of research constructing a system mixing two separate patterns which could be applied in real world. In this paper, we propose a method to use both smartphone and wearable device to recognize activity and posture in the same time. To use smartphone and wearable sensor data together, we designed a pre-processing method and constructed recognition model mixing signal vector magnitude and orientation pattern features of vertical and horizontal. We considered cycling, fast/slow walking and running activities, and postures such as standing, sitting, and laying down. We confirmed the performance and validity by experiment, and proved the feasibility in real world.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38C no.9
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• pp.797-801
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• 2013

Visible light communication (VLC) is a rapidly growing area of research and applications, due to the potential and predicted high efficiency of bandwidth. One of the key challenges in VLC technology is the choice of devices which are going to be deployed VLC features. Smartphone rationally uses the most widely deployed visible light sensor i.e. image sensor in camera, which could be used to receive the intensity modulated data. Image sensor based VLC system would be the most deployable scenario but initially the capacity was not much attractive compared with photodetector based VLC system. Here, the spatial multiplexing is proposed in MIMO based VLC system to increase the system capacity by utilizing the property of spatial separation of optical light sources in smartphone's camera module. The active pixels of imaging plane act as the multiple receivers which could be able to use on MIMO spatial multiplexing to enhance the system performance.

• Journal of Convergence for Information Technology
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• v.7 no.4
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• pp.91-96
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• 2017

In this paper, we aim to respond efficiently to crime by using Arduino and smartphone apps in response to increasing number of house-breaking crimes. It receives the signal of the sensor installed in the house and connects it with the app of the smartphone. To use the app, you can download the app from the user's smartphone, launch the app, and operate the operation outside the home, not only inside the house, by linking the executed app. Among the sensors installed in the house, the movement detection sensor is used to enhance the security, and the gas leakage sensor and the flame detection sensor can be used to easily detect the risk of fire and to prevent the fire early. Security is further enhanced by the ability to remotely control the front door with a smartphone. After that, various sensors can be added and it can be developed as a WiFi module in addition to the Bluetooth module.

• Journal of Korea Society of Digital Industry and Information Management
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• v.11 no.4
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• pp.143-154
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• 2015

This study aims to evaluate smartphone gaming controllers. Diffusion of smartphone makes its users to play smartphone games in ease and comfort and its built-in sensors deliver new gaming experience to the users. Based on the concept how the controller system is important, the current research also implies the importance of customizing service which gives users a selection to deploy a controller. To explore the interaction effect of controllers and customizing on interactivity, flow, usability, attitude, and intention, the research constructs 3(gyroscope, wheel, and button controllers) by 2(default and customizing setting) experimental design and forty college students played Gameloft's Asphalt 8: Airborne in a within subject design. The results showed that interaction effect and customizing main effect were not found, but controller main effect was statistically significant. Button controller is superior to those other two in more detail. It implies that it is still not useful to play new types of gaming controller, and a customizing service. It suggests that smartphone games should more focus on improving optimal user experience with built-in sensor controllers.

• International journal of advanced smart convergence
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• v.10 no.4
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• pp.30-37
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• 2021

Touch sensor interface has become the most useful input device in a smartphone. Unlike keypad/keyboard interfaces used in electronic dictionaries and feature phones, smartphone's touch interfaces allow for the recognition of various gestures that represent distinct features of each application's input. In this paper, we analyze application-specific input patterns that appear in smartphone's touch interfaces. Specifically, we capture touch input patterns from various Android applications, and analyze them. Based on this analysis, we observe a certain unique characteristics of application's touch input patterns. This can be utilized in various useful areas like user authentications, prevention of executing application by illegal users, or digital forensic based on logged touch patterns.

• Journal of the Semiconductor & Display Technology
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• v.20 no.2
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• pp.51-55
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• 2021

With the recent development of various smartphone designs in the smartphone market, the use of curved cover glass has been required, and interest in curved glass production has increased. In this paper, we designed a pressurization system that simplified the size of the system using a wedge amplification mechanism for smartphone curved glass molding systems. The pressurization system consisted of a linear motor, a wedge, and a force sensor. The wedge was used to amplify the force, and the piezoelectric sensor was used to measure the force. In addition, the proposed amplification mechanism was confirmed to have an error of 1.27% through an experiment compared to the simulation, and the pressurization error of 0.76% for the pressurization profile 3,500N was verified through an experiment.