• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.75-78
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• 2014

MLCC is one of the most frequently used component in high-tech device like smart phone. Because of dynamic characteristic of piezoelectric materials which is main ingredient of MLCC, its vibration leads to acoustic noise from pcb. To solve this problem at minimal cost, company has to change only the main noise-generating MLCC to low noise-generating MLCC. To find the main noise source, this study approached to solution from a vibration point of view. From mode shapes of pcb at particular frequencies, two groups can be obtained; MLCCs soldered at where maximum deformation occurs and where anti-phase with respect to the other group appears. When the MLCC belongs to 1st group does not working, amplitude at where maximum deformation occurs decreases compared to when all MLCCs are working. This tendency also appears in noise measurement. This analysis can be put to use in various fields where require noise reduction or noise source identification.

• Journal of Digital Contents Society
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• v.16 no.6
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• pp.943-950
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• 2015

In this study, we propose an annotation system exhibits a secondary role using augmented reality in the exhibition environment. Common methods that utilize the description of the picture or photo booklet or audio device to the exhibition and in the form of viewing the exhibits while people describe method is used. We are using augmented reality technology, in addition to these conventional methods to provide a variety of information about the exhibits utilizing text, photos, video and audio of the multimedia medium. Where visitors can use a smart phone in hand deulgoseo, the exhibition becomes a secondary role by applying the Augmented Reality technology in tablet-based devices.

• Journal of Korea Society of Digital Industry and Information Management
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• v.10 no.1
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• pp.47-53
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• 2014

LTE-Advanced is the evolved version of LTE which is currently in progress at the 3GPP. At present, as the number of smart phone users is rapidly increasing, the demand for ever more capacity is driven largely by video usage and high quality data communication and so on, this let more researchers study about LTE-A all over the world. LTE-A aims to achieve improved service and communication quality over 3G system at the aspect of throughput, peak data rate, latency, and spectral efficiency. Among various features in LTE-A, the multi-user MIMO(MU-MIMO), in which the base station transmits several streams to multiple receivers, has expected to give better quality for system. In this paper, we investigate performances of various types of downlink receivers with fixed number of antennas. we first review the development process from LTE to LTE-A. Second we introduce TM9 which is adopted in Rel.10 for MU-MIMO system, including the MU-MIMO system model and the explanation on the algorithm used in system. We also have brief introduction about sub-blocking in turbo decoding, finally we compare the performance between the uncoded case and coded case which is using turbo encoding.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.1
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• pp.217-223
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• 2012

Time synchronization problems is very important in everyday life and a variety of industries, In this paper, we developed PLB(Power Line Broadcasting) system which broadcast time information to each device through power line modems. In our system, the smartphone synchronized to GPS time is used as a time source and we propose, develop and evaluate a relay system to solve the difficulties of long-distance transmission of power line modem technology.

• Journal of Korean Institute of Industrial Engineers
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• v.36 no.3
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• pp.146-153
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• 2010

The purposes of this are (1) to present representative five hand dimensions by measurement year, (2) to investigate hand characteristics based on relative ratios of varying hand dimensions and (3) to compare Korean hand dimensions to other countries' data. Comparing to those of 1979, statures of 2004 increased by 3.0~3.5%, while males' hand dimensions of hand length, medius finger length, hand circumference, hand breadth and hand thickness decreased by 2.0~5.0%. Ratios of hand dimensions to those of medius finger were not significantly different depending upon age group and gender, but were significantly different depending upon races of Korean and American. Hand lengths of Koreans were shorter by about 4.0% than those of Japanese irrespective of gender, while the other compared dimensions for Koreans were larger than those of Japanese. Hand dimensions used in this study of Koreans were generally smaller that those of Americans. It is recommended from this study that when designing hand relevant things including glove, computer keyboard, smart phone key pad, etc., the different hand characteristics found in this study be fully reflected to develop competitive products.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.10a
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• pp.643-644
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• 2018

Recently indoor and outdoor location tracking systems are operated in different ways. The indoor positioning method uses WiFi and BLE beacon positioning, and the outdoor positioning uses GPS and PDR. In this paper, it is a device to measure position by using it. It is used to check whether it is indoors or outdoors when measuring based on a smart phone, A automatic conversion method is needed. When using GPS in the room, it is difficult to distinguish the floor or space. We propose a method to solve this problem.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.4C
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• pp.321-328
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• 2012

The Mobile device like smart phone is a small computing device and easy to carry around. The Mobile devices are wildly being used as desktop personal computer and can served individual services. Because of compatibility of applications working on mobile devices are not good, so developer need to develop it that match changes in platform fetures. In this paper, we design and implementate ubiquitous healthcare monitoring system that can be runs on many different platforms using HTML5 as a standard web development language and jQuery as a javascript library. Ubiquitous healthcare monitoring system is runs on on many different platforms like mobile platforms and desktop web browsers.

• Spatial Information Research
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• v.19 no.1
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• pp.83-91
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• 2011

The route finding analysis is an essential geo-related decision support tool in a LBS(Location based Services) and previous researches related to route guidance have been mainly focused on route guidances for vehicles. However, due to the recent spread of personal computing devices such as PDA, PMP and smart phone, route guidance for pedestrians have been increasingly in demand. The pedestrian route guidance is different from vehicle route guidance because pedestrians are affected more surrounding environment than vehicles. Therefore, pedestrian path finding needs considerations of factors affecting walking. This paper aimed to extract factors affecting walking and charting the factors for application factors affecting walking to pedestrian path finding. In this paper, we found various factors about environment of road for pedestrian and extract the factors affecting walking. Factors affecting walking consist of 4 categories traffic, sidewalk, network, safety facility. We calculated weights about each factor using analytic hierarchy process (AHP). Based on weights we calculated scores about each factor's attribute. The weight is maximum score of factor. These scores of factor are used to optimal pedestrian path finding as path finding cost with distance, accessibility.

• Journal of Korean Clinical Health Science
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• v.7 no.2
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• pp.1289-1297
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• 2019

Purpose: The purpose of this study was to investigate occupational therapy at M college in Changwon and the impact of smart phone use on the school life of college students and to help them find ways to further develop in the future. Methods; Data collection was conducted using questionnaires, and the questionnaires consisted of 152 total questions with 15 interpersonal questions, 23 problem solving skills, 43 self-efficacy, 16 class participation scale, and 55 self-directed learning scale. It was conducted to first and second graders of M college and conducted a survey through the corresponding academic year from March 26, 2019 to March 29, 2019 to retrieve 120 questionnaires and use them for analysis. The collected data were analyzed using SPSS. Statistic 20.0. Results: Studies show that "school life satisfaction" is usually the highest at 53 percent. The "smartphone user motivation" was the highest with 50.8 percent, while the "most frequently used feature on smartphones" was the highest with 57.5 percent on SNS. Satisfaction after using a smartphone was the highest with 49.2 percent, while 41.7 percent said it would be easier to acquire and utilize information in the areas of satisfaction. Conclusion: Smartphone addiction, interpersonal relationships, problem-solving skills, self-efficacy, participation in classes, and self-control learning items are not only affected by one part, but also by the other.

• Journal of the Korean Solar Energy Society
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• v.31 no.6
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• pp.72-77
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• 2011

The purpose for installation of offshore weather station is a measurement of wind resources and so on. If weather station is operated, it will be possible to analysis for wind resource and arrangement of wind farm by using measured data. In this paper, we carried out the development of offshore wind resource measurement system for measuring offshore wind resource. Also, In order to monitor for real-time wind data with 1 Hz, we installed the wireless transmission system. All wind characteristic data are sent to the server PC through the this system is connected outport of DataLogger. Transmitted wind data were used in order to look at in the Web-page and tablet PC on a real time basis in a graph. In this paper, we will introduce about the wind resource measurement and remote monitoring system that is the result of study.