• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.22 no.3
• /
• pp.127-133
• /
• 2012

To achieve low-cost and high-efficiency of thin-film solar cells applications, the sol-gel method that can be coated on a large area substrate, obtain homogeneous thin films of high purity was used. We studied structural and optical characteristics versus annealing temperature of $Cu_2ZnSnS_4$ which has kesterite structure by substitution low-cost sulfur (S) instead of high-cost selenium (Se). By analyzing XRD patterns, main peak was observed at $2{\theta}=28.5^{\circ}$ when Zn/Sn ratio is 0.8/1.2. And when we observed kesterite structure which has orientation of (112) direction, the more annealing temperature increase the bigger strength of (112) direction is. $Cu_2ZnSnS_4$ thin film showed characteristics of kesterite structure at $550^{\circ}C$. And when we calculated lattice constant, a = 5.5047 and $c=11.014{\AA}$ as same JCPDS (Joint Committee on Powder Standards) data measured. We measured optical transmittance to analyze optical characteristics. Optical transmittance was lower than 65 % at visible ray (${\lambda}=380{\sim}770nm$).

• Journal of the Korea Convergence Society
• /
• v.9 no.9
• /
• pp.31-39
• /
• 2018

In this paper, we proposed a license plate detection method based on contour extraction that adapts to environmental changes. The proposed method extracts contour lines using DoG (Difference of Gaussian) to remove unnecessary noise parts in the contour extraction process. Binarization was applied in ugly outline images, and erosion and dilation operations were used to emphasize the contour of the character part. Then, only the outline of the ratio of the characters of the plate was extracted through the ratio of the width and height of the characters. And the case where the outline is the longest is estimated by estimating the characters of the license plate. For the experiment, we applied 130 image data to license plate on the front of the vehicle, oblique environment, and environment images with various backgrounds. I also experimented with motorcycle images of different license plate patterns. Experimental results showed that the detection rate of the oblique image was 93% and that of the various background environment was 70% in the motorcycle image but 98% in the front image.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.18 no.10
• /
• pp.274-280
• /
• 2017

The smart-car industry has emerged as the important variable that will decide the future industrial contour of the automotive industry, together with commercialization of electronic vehicles, connected cars, infotainment, telematics, and the autonomous/self-driving car. This study analyzes the strategic position of platform companies and car manufacturers that would determine the future of the smart-car market. The findings of this study show that despite the entry barriers in industrial factors, such as economies of scale, the industrial infrastructure, and global production networks, and technical factors like exclusive head-sector information, car manufacturers may be deprived of their industrial leadership by platform companies with map and user data, big data capabilities, and user interface experience if they lag behind ICT innovation. This insight is based on the emerging importance of software and platforms, and the simplification of car structures, proven by the successful commercialization of electronic vehicles. This study complements existing studies mainly focused on technical aspects of the smart-car industry by examining the strategic dimensions of platform companies and their approach to the future smart-car market by comparing them with existing car manufacturing multinationals.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.24 no.2
• /
• pp.173-178
• /
• 2014

In this study, we introduce ASM-based face recognition classifier and its design methodology with the aid of 2-dimensional 2-directional hybird preprocessing algorithm. Since the image of face recognition is easily affected by external environments, ASM(active shape model) as image preprocessing algorithm is used to resolve such problem. In particular, ASM is used widely for the purpose of feature extraction for human face. After extracting face image area by using ASM, the dimensionality of the extracted face image data is reduced by using $(2D)^2$hybrid preprocessing algorithm based on LDA and PCA. Face image data through preprocessing algorithm is used as input data for the design of the proposed polynomials based radial basis function neural network. Unlike as the case in existing neural networks, the proposed pattern classifier has the characteristics of a robust neural network and it is also superior from the view point of predictive ability as well as ability to resolve the problem of multi-dimensionality. The essential design parameters (the number of row eigenvectors, column eigenvectors, and clusters, and fuzzification coefficient) of the classifier are optimized by means of ABC(artificial bee colony) algorithm. The performance of the proposed classifier is quantified through yale and AT&T dataset widely used in the face recognition.

• Journal of Korean Society for Geospatial Information Science
• /
• v.12 no.4 s.31
• /
• pp.53-60
• /
• 2004

Congestion index is needed for quantifying congestion level for various areas. So far, the index has been calculated based on multiple vehicle data for specified time interval. Such being the case, it was costly to build it and the usage of it was focused on policy development and evaluation rather than on traffic information provision. This study focuses on a development on a single vehicle based congestion index which can be a representative value for link congestion level and link speed information at the same time for dual purposes of traditional usages and information provision. A new term has been added for representing real time based arterial congestion level and it has been verified on a real time basis. The index was based on single vehicle GPS data and seemed to be cost effective in deriving the index. With the help of the index, the traffic information contents can be diversified in a constructive way in providing real time traffic information for ITS area and in using congestion level determination for traditional transportation areas.

• Applied Chemistry for Engineering
• /
• v.31 no.5
• /
• pp.526-531
• /
• 2020

Manganese ions contained in water phase are acting as a toxic substance in the human body and also known to affect the nervous system. In particular, effective treatment technology is required since manganese removal is difficult due to its high solubility in a wide pH range. In this study, Prinus densiflora bark was chemically modified with hydrogen peroxide, and the modified adsorbent was used for removing manganese ions in an aqueous solution. The modified adsorbent showed high removal capacity of 82.1 and 56.2%, respectively, at conditions of 5 and 10 mg/L manganese ions. Also, the adsorption isotherm from the data was applied to the theoretical equation. As a result, the adsorption behavior of manganese ions was better suited to the Langmuir than Freundlich model, and it was also found from kinematics that the pseudo-second order kinetic model was more suitable. In addition, the changes of Gibbs free energy indicated that the adsorption reaction became more spontaneously with increasing temperature. Consequently, these experimental results may be used as a water treatment technology which can efficiently treat manganese ions contained in water.

• Journal of Digital Convergence
• /
• v.11 no.3
• /
• pp.415-426
• /
• 2013

Smart work has recently introduced as a way to solve problems such as greenhouse gas emissions, low birth rate and aging as well as to improve productivity. Because of development of ICT infrastructure and the proliferation of smart devices, the mobile office has the most commonly used within types of smart work in Korea. But the adoption of the mobile office in small businesses is only half of that of large corporations. The security issue appears to be one of the biggest obstacles to the introduction of smart work in small businesses. Therefore, the purpose of this study is to analyze the information security factors that should be considered when the mobile office is introduced to small businesses. By analyzing the previous studies, the information security factors of the mobile office are classified 5 groups composed of 24 factors. 5 groups are terminals, applications and platforms, networks, servers and users. According to the survey result using AHP, 'User' was drawn to the most important group, and 'Data Encryption', 'Wireless LAN Control' and 'Terminal Recovery When Leaving' were drawn to the important information security factors of the mobile office among 24 factors.

• Journal of the Korean Chemical Society
• /
• v.60 no.1
• /
• pp.69-81
• /
• 2016

The purpose of this study was to find out the validation of instructional strategies using the Advanced Laboratory Equipment (ALE class) by investigating science high school students’ perception on ALE in chemistry classrooms and to consider the need for development of teaching materials on ALE class. 7 sessions of ALE including experiments with innovative equipment were developed and applied to 21 students in D Science High School. At the end of the sessions, questionnaire was given to the students. We also collected qualitative data by interviewing 9 students who participated in the questionnaire. We analyzed the data collected by In-depth interviews and students’ experimental reports. The result showed that ALE class was effective to enhance students’ understanding of learning concepts because the experimental time was shortened in real time data processing. Some students showed creative performance on solving scientific problems by using everyday materials in experimental process and developed perceptions of practical inquiry. Through this process, students’ positive attitudes and interests in science and heuristic inquiry skills were also enhanced. Developing ALE lesson materials will be helpful for students to understand science and technology and the domain of science in broader contexts.

• Journal of rehabilitation welfare engineering & assistive technology
• /
• v.7 no.1
• /
• pp.51-58
• /
• 2013

As it is changing into aging society, rehabilitation, welfare and sports industry markets are being expanded fast. Especially, the field of vital signals interface to control welfare instruments like wheelchair, rehabilitation ones like an artificial arm and leg and general electronic ones is a new technology field in the future. Also, this technology can help not only the handicapped, the old and the weak and the rehabilitation patients but also the general public in various application field. The commercial bio-signal measurement instruments and interface systems are complicated, expensive and large-scaled. So, there are a lot of limitations for using in real life with ease. this thesis proposes a wireless transmission interface system that uses EMG(electromyogram) signals and a control module to manipulate hardware systems with portable size. We have designed a hardware module that receives the EMG signals occurring at the time of wrist movement and eliminated noises with filter and amplified the signals effectively. DSP(Digital Signal Processor) chip of TMS320F2808 which was supplied from TI company was used for converting into digital signals from measured EMG signals and digital filtering. We also have used PCA(Principal Component Analysis) technique and classified into four motions which have right, left, up and down direction. This data was transmitted by wireless module in order to display at PC monitor. As a result, the developed system obtains recognition success ratio above 85% for four different motions. If the recognition ratio will be increased with more experiments. this implemented system using EMG wrist direction signals could be used to control various hardware systems.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.40 no.1
• /
• pp.152-164
• /
• 2015

A rapid development of semiconductors, sensors and mobile network technologies has enable that the embedded device includes high sensitivity sensors, wireless communication modules and a video processing module for vehicular environment, and many researchers have been actively studying the smart car technology combined on the high performance embedded devices. The vehicle is increased as the development of society, and the risk of accidents is increasing gradually. Thus, the advanced driver assistance system providing the vehicular status and the surrounding environment of the vehicle to the driver using various sensor data is actively studied. In this paper, we design and implement the smart vehicular camera device providing the V2X communication and gathering environment information. And we studied the method to create the metadata from a received video data and sensor data using video analysis algorithm. In addition, we invent S-ROI, D-ROI methods that set a region of interest in a video frame to improve calculation performance. We performed the performance evaluation for two ROI methods. As the result, we confirmed the video processing speed that S-ROI is 3.0 times and D-ROI is 4.8 times better than a full frame analysis.