• Journal of Engineering Education Research
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• v.26 no.1
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• pp.3-11
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• 2023

The purpose of this study is to develop Raspberry Pi-based CanSat instruction materials for liberal arts classes to be used in university space education. The educational satellite simulation program is developed by applying the ADDIE program consisting of analysis, design, development, execution, and evaluation of 15 lessons per semester. The usefulness of the instruction materials is evaluated by a validity test of a total of 6 experts. The proposed materials are applied to 100 college students from various majors. To analyze the impact on creative problem-solving ability, a questionnaire is conducted before and after class, and as a result, it is confirmed that there is a significant improvement in all areas after class. The class satisfaction survey is conducted for a total of 10 questions, and the average score is 4.41 out of 5, which is high. In conclusion, the proposed instruction materials make it possible to achieve successful space education using Raspberry Pi and improve creative problem-solving ability in universities.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.37 no.1
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• pp.79-90
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• 2014

The Purpose of this study is to empirically examine the impact of various internal and external innovation activities of SMEs on their innovation performances in the field of electronics and communication industry. Drawing upon the literature review, internal and external innovation activities are defined and conceptualized, and independent, dependent and moderator variables are developed. We have used survey-based data for this study from the survey of technology innovation activities in manufacturing industry, which was conducted by the Science and Technology Policy Institute (STEPI) in 2010. The main result of this study shows that there were no significant differences in the impact of innovation activities on market performance according to the size of SMEs. On the other hands, we found that there were significant differences in the impact of innovation activities on technological innovation performance according to the size of SMEs. Therefore, in order to make high technological innovation performance, companies in the field of electronics and communication industry need to properly implement the internal and external innovation activities by considering their size.

• Journal of information and communication convergence engineering
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• v.10 no.4
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• pp.372-377
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• 2012

In this paper, we propose an implementation of a real-time operating system for the two-wheel mobile robot. With this implementation, we have the ability to control the complex embedded systems of the two-wheel mobile robot. The advantage of the real-time operating system is increasing the reliability and stability of the two-wheel mobile robot when they work in critical environments such as military and industrial applications. The real-time operating system which was ported to this implementation is open systems and the corresponding interfaces for automotive electronics (OSEK/VDX). It is known as the set of specifications on automotive operating systems, published by a consortium founded by the automotive industry. The mechanical design and kinematics of the two-wheel mobile robot are described in this paper. The contributions of this paper suggest a method for adapting and porting OSEK/VDX real-time operating system to the two-wheel mobile robot with the differential drive method, and we are also able to apply the real-time operating system to any complex embedded system easily.

• Journal of information and communication convergence engineering
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• v.14 no.4
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• pp.207-214
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• 2016

In this paper, we propose a radial reference map-based location fingerprinting technique with constant spacing from an access point (AP) to all reference points by considering the minimum dynamic range of the received signal strength indicator (RSSI) obtained through an experiment conducted in an indoor environment. Because the minimum dynamic range, 12 dBm, of the RSSI appeared every 20 cm during the training stage, a cell spacing of 80 cm was applied. Furthermore, by considering the minimum dynamic range of an RSSI in the location estimation stage, when an RSSI exceeding the cumulative average by ${\pm}6dBm$ was received, a previously estimated location was provided. We also compared the location estimation accuracy of the proposed method with that of a conventional fingerprinting technique that uses a grid reference map, and found that the average location estimation accuracy of the conventional method was 21.8%, whereas that of the proposed technique was 90.9%.

• Journal of Practical Engineering Education
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• v.5 no.2
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• pp.109-115
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• 2013

In this paper, a teaching assistant system using computer vision is presented. Using the proposed system, lecturers can utilize various lecture contents such as lecture notes and related video clips easily and seamlessly. In order to do transition between different lecture contents and control multimedia contents, lecturers just draw pre-defined symbols on the board without pausing the class. In the proposed teaching assistant system, a feature descriptor, so called shape context, is used for recognizing the pre-defined symbols successfully.

• Journal of Advanced Navigation Technology
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• v.23 no.5
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• pp.333-338
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• 2019

Satellite communication is not used by many people like mobile communication, but it is a necessary technology for public service and communication services, such as providing the Internet in military, disaster, remote education and medical services, island areas, and infrastructure vulnerable areas. However, most communication modems have problems with two-way communication with server as IP addresses are assigned to floating IP that change every time they communicate with the network. In this paper, we used the Raspberry Pi as the controller of the terminal device to communicate the network through the satellite modem and the PPP protocol, and to solve the problem of the modem with the floating IP, we used the text message function of the satellite modem. Through this process, two-way data links using the Thuraya geostationary orbit satellite were implemented.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.10
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• pp.15-23
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• 2016

To support the telematics and infotainment services, vehicle-to-everything (V2X) communication requires a robust and reliable network. To do this, the 3rd Generation Partnership Project (3GPP) has recently developed V2X communication. For reliable communication, accurate channel estimation should be done. However, because vehicle speed is very fast, radio channel is rapidly changed with time. Therefore, it is difficult to accurately estimate the channel. In this paper, we propose the new linear minimum mean square error (LMMSE) channel interpolation scheme based on the Long Term Evolution (LTE) sidelink system in vehicle-to-vehicle (V2V) environments. In our proposed reduced decision error (RDE) channel estimation scheme, LMMSE channel estimation is applied in the pilot symbol, and then in the data symbol, smoothing and LMMSE channel interpolation scheme is applied. After that, time and frequency domain averaging are applied to obtain the whole channel frequency response. In addition, the LMMSE equalizer of the receiver side can reduce the error propagation due to the decision error. Therefore, it is possible to detect the reliable data. Analysis and simulation results demonstrate that the proposed scheme outperforms currently conventional schemes in normalized mean square error (NMSE) and bit error rate (BER).

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.12
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• pp.2905-2910
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• 2015

CW Radar Sensors can be categorized into Single and Dual by its IF output type. Dual IF type is used for detecting the direction of moving objects. However, Dual IF type has more complicated circuitry than Single IF type and higher cost due to more parts required. In this paper, we propose an algorithm for Single IF type CW radar sensors to detect the direction of moving objects. It performs FFT on signals created at IF output when an object moves and determines approach, stop and recede according to amplitude variations. In order to verify the algorithm, a function generator is used to create a virtual signal and confirmed that it accurately detects the directions according to amplitude variations.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.12
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• pp.2968-2974
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• 2014

When lighting has installed indoor, we control lighting using human-detecting sensors for people who pass at night and places that are lack of quantity of light. However, malfunction can be caused by positions of inappropriate sensors, and in the case of passages of big buildings, it is a problem that even after a person pass, light apparatuses are turned on for a long time. In this paper, we propose lighting control system based on location positioning for energy saving that control lighting in accordance with passers's position through indoor location positioning. This system use the fingerprinting technology that is one of the location positioning technologies and RSSI data that is collected by a smart device. Using those, it can turn on only lightings that are included in the positioned location and reduce unnecessary power consumption. As a result of experiment, on condition that four people were existing and illumination was 308 lux, we assured reduction effect of 49 Wh.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.1
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• pp.20-26
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• 2019

Due to the human influence of particulate matter, various studies are being conducted to predict it using past data measured in the atmospheric environment monitoring network. However, it is difficult to precisely set the measurement environment and detailed conditions of the previously designed predictive model, and it is necessary to design a new predictive model based on the existing research results because of the problems such as the missing of the weather data. In this paper, as a previous study for particulate matter prediction, the conformity of the algorithm for particulate matter prediction was evaluated by designing the prediction model through the multiple linear regression and the artificial neural network, which are machine learning algorithms. As a result of the prediction performance comparison through RMSE, 18.13 for the MLR model and 14.31 for the MLP model, and the artificial neural network model was more conformable for predicting the particulate matter concentration.