• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.6
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• pp.1103-1108
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• 2016

The development of a variety of sensor technology, users smart phone, the use of motion recognition apparatus such as a console game machines is increasing. It tends to user needs motion recognition-based input device are increasing. Existing motion recognition mouse is equipped with a modified form of the mouse button on the outside and serves as a wheel mouse left and right buttons. Existing motion recognition mouse is to manufacture a small, there is a difficulty to operate the button. It is to apply the motion recognition technology the motion recognition technology is used only pointing the cursor there is a limit. In this paper, use of MEMS-based motion recognition sensor, the body of the two-point operation data by recognizing the operation of the (thumb and forefinger) and generating a control signal, followed by studies on the generated control signal to a wireless transmitting computer input device.

• Journal of the Korea Convergence Society
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• v.8 no.1
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• pp.7-12
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• 2017

In this paper, we proposed an electronic attendance-absence recording system using a smartphone that does not require separate BLE(Bluetooth Low Energy) devices and infrastructure by using BLE advertisement technology of smartphone. The existing BLE-based electronic attendance-absence recording system requires a BEL device to be attached to each classroom for services and a separate technology to identify the devices attached to the classroom. Also, due to the interference with each other, sometimes an error occurred in the electronic connection. In this paper, we propose a system to solve the problems about time, place and cost, which is a disadvantage of the conventional Bluetooth beacon system. BLE advertising function of the smartphone that the user is using without BLE device, it is possible to construct infrastructure for electronic attendance-absence recording system. In order to evaluate the effectiveness of the proposed system, we designed the system structure and operation flow and constructed the system using the smart phone in actual used.

• Korean journal of communication and information
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• v.67
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• pp.62-87
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• 2014

The purpose of this study is to understand the social and cultural implication of the activities of taking 'selfies' and the use of Social Network Service(SNS)s through the personal story of a 20s female researcher. She analyzes her own digital photography activities based on the experience of the use of Cyworld photo albums for three years and the use of pictures in iPhone album for fifteen months. The other researcher(40s male) cooperates to answer the questions about how to understand the digital photography activities. We understand the digital photography activities including digital cameras, social network services and smart phones as acts of personal identity configuration and acts of making the personal documentary. As a result, digital photos are used more for archive purpose rather than for document purpose. Also, we found that the digital photography activities can be understood as the interactions between human and non-human actors in the perspective of Actor-Network Theory (ANT).

• Journal of Biosystems Engineering
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• v.36 no.4
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• pp.279-284
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• 2011

Protected vegetable production area is greater than 26% of the total vegetable production area in Korea, and portion of protected production area is increasing for flowers and fruits. To secure stable productivity and profitability, continuous and intensive monitoring and control of protected crop production environment is critical, which is labor- and time-consuming. Failure to maintain proper environmental conditions (e.g., light, temperature, humidity) leads to significant damage to crop growth and quality, therefore farmers should visit or be present close to the production area. To overcome these problems, application of remote monitoring and control of crop production environment has been increasing. Wireless monitoring and control systems have used CDMA, internet, and smart phone communications. Levels of technology adoption are different for farmers' needs for their cropping systems. In this paper, potential of wireless remote monitoring of protected agricultural environment using CDMA SMS text messages was reported. Monitoring variables were outside weather (precipitation, wind direction and velocity, temperature, and humidity), inside ambient condition (temperature, humidity, $CO_2$ level, and light intensity), irrigation status (irrigation flow rate and pressure), and soil condition (volumetric water content and matric potential). Scenarios and data formats for environment monitoring were devised, tested, and compared. Results of this study would provide useful information for adoption of wireless remote monitoring techniques by farmers.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.66 no.4
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• pp.242-246
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• 2017

In this study, it was investigated about optical simulation in high brightness and high uniformity general lighting using glass light guide plate. And we adopt edge-light emission type light plate. Edge-light type lighting has been used LCD application, especially note PC or smart phone backlight unit. Because it had the good properties such as slim shape and light weight. We thought this type was suitable for general lighting application such as wall attached type or ceiling mount type. But many of edge-light type lighting had problems. It called slanted output light rays. That was main key parameter how could control the direction of output light rays. We investigated the solution of this problems, using ray tracing method, we recognized the major fact of the solution relied on the geometric structure of diffusing dot shape. We set the conditions of aspect ratio in diffusing dot shape such as 0.5 to 1. And, at first, we designed diffusing dots shape based on the results of optical simulation and made specimen. as above condition, and acquired good result in confirming dots shape such as the value of the output rays's peak angle was around 75 degrees. And good light distribution characteristics were measured by slated spectro-radiometer. It was shown that the effective ways of designing light distribution characteristics using optical simulation such as ray tracing linear method for making general lighting using glass light guide plate.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.26 no.1
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• pp.81-91
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• 2016

Nowadays, electronic device is in a close relationship with human life. Above all, the use of wireless electronic devices such as smart phone, tablet pc, and wireless keyboard is increasing owing to the high convenience and portability. Furthermore, according to the increasing use of sensitive personal and financial information from the electronic device, various attacks for stealing information are being reported. In this paper we do an analysis of 27MHz wireless keyboard vulnerability and set up an analysis environment. Moreover, we make an experiment and show that there are real vulnerabilities. An experimental result will be used for safety analysis and vulnerability verification of wireless electronic devices.

• Journal of the Korean Society of Physical Medicine
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• v.13 no.3
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• pp.19-25
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• 2018

PURPOSE: Most gait assessment tools are expensive and require controlled laboratory environments. Tri-axial accelerometers have been used in gait analysis as an alternative to laboratory assessments. Many smartphones have added an accelerometer, making it possible to assess spatio-temporal gait parameters. This study was conducted to confirm the reliability and validity of a smartphone-based accelerometer at quantifying spatio-temporal gait parameters of stroke patients when attached to the body. METHODS: We measured gait parameters using a smartphone accelerometer and gait parameters through the GAITRite analysis system and the reliability and validity of the smartphone-based accelerometer for quantifying spatio-temporal gait parameters for stroke patients were then evaluated. Thirty stroke patients were asked to walk at self-selected comfortable speeds over a 10 m walkway, during which time gait velocity, cadence and step length were computed from smartphone-based accelerometers and validated with a GAITRite analysis system. RESULTS: Smartphone data was found to have excellent reliability ($ICC2,1{\geq}.98$) for measuring the tested parameters, with a high correlation being observed between smartphone-based gait parameters and GAITRite analysis system-based gait parameters (r = .99, .97, .41 for gait velocity, cadence, step length, respectively). CONCLUSION: The results suggest that specific opportunities exist for smartphone-based gait assessment as an alternative to conventional gait assessment. Moreover, smartphone-based gait assessment can provide objective information about changes in the spatio-temporal gait parameters of stroke subjects.

• Journal of the Korean Society of School Health
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• v.26 no.2
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• pp.124-131
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• 2013

Purpose: This study was designed to identify the relationship between smartphone addiction and psychiatric symptoms and the difference in severity of psychiatric symptoms by the degree of smart phone addiction in order to raise awareness of mental health problem. related to smartphone addiction in college students. Methods: Two hundreds and thirteen university student survey data was collected from December 5th to 9th of 2011 in South Korea using smartphone Addiction Scale, and the Symptom Checklist-90-Revision that was translated with korean for the psychiatric symptoms. Results: Respondents were classified as upper addicted (25.3%) and lower addicted group (28.1%). Addicted scores were positively correlated with psychiatric symptom scores. Obsessive-compulsive score was the most highly correlated with addiction scores. There were significant different in psychiatric symptom scores by the groups. Upper groups was 1.76 times higher than lower in total psychiatric scores. The addicted group used smartphone significantly longer per day and more satisfied with than lower addicted group. Conclusion: Although the smartphone was first introduced not so long ago, the addiction rate is exponentially increasing in students. The results proved that there is an inevitable correlation between the smartphone addiction and the severity of psychiatric symptoms.

• Journal of KIISE:Computing Practices and Letters
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• v.16 no.5
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• pp.621-625
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• 2010

This paper presents a hand motion tracking method for hand gesture interface using a camera in mobile devices such as a smart phone and PDA. When a camera moves according to the hand gesture of the user, global optical flows are generated. Therefore, robust hand movement estimation is possible by considering dominant optical flow based on histogram analysis of the motion direction. A continuous hand gesture is segmented into unit gestures by motion state estimation using motion phase, which is determined by velocity and acceleration of the estimated hand motion. Feature vectors are extracted during movement states and hand gestures are recognized at the end state of each gesture. Support vector machine (SVM), k-nearest neighborhood classifier, and normal Bayes classifier are used for classification. SVM shows 82% recognition rate for 14 hand gestures.

• The Journal of the Korea Contents Association
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• v.14 no.12
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• pp.950-958
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• 2014

According to the rapid spreading of smart phone, the use of social network service(SNS) is also increasing rapidly. Social network service(SNS) which plays an important role in customer relationship management and brand management is becoming more important. This study aims to find out if differences exist in the perceptions of service quality and the consumer behaviors between Korean and Chinese consumers using SNS. In order to achieve the objectives of the study, the literatures of service quality and consumer behavior theory is reviewed. And based on the literature reviews, dimensions related to service quality and consumer behavior are derived and T-test is used to identify the differences. According to the analysis, significant differences exist in the perceptions of service quality and consumer behaviors between Korean and Chinese consumers using SNS. The results not only provide theoretical evidences for further SNS study but also provide practical evidences for companies in their overseas expansion.