• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.3
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• pp.770-776
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• 2021

Positioning systems have been actively researched and developed over the past few years and have been used in many applications. This paper presents a method to determine a location in a large space using a sensor system consisting of an accelerometer and a single-axis gyroscope. In particular, to consider usability, a sensor device was loosely worn on the waist so that the experimental data could be used in practical applications. Based on the experimental results of circular tracks with radiuses of 1m and 3m, in this paper, an algorithm using the threshold of rotation angle was proposed and applied to the experimental results. A tracking experiment was performed on the grid-pattern track model. For raw sensor data, the average deviation between the final tracking point and the target point was approximately 15.2 m, which could be reduced to approximately 4.0 m using an algorithm applying the rotation angle threshold.

• Journal of the Semiconductor & Display Technology
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• v.21 no.3
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• pp.101-104
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• 2022

Mist-CVD is known to have advantages of low cost and high productivity compared to ALD and PECVD methods. It is capable of reacting to the substrate by misting an aqueous solution using ultrasonic waves under vacuum-free conditions of atmospheric pressure. In particular, Ga₂O₃ is regarded as advanced power semiconductor material because of its high quality of transmittance, and excellent electrical conductivity through N-type doping. In this study, Computational Fluid Dynamics were used to predict the uniformity of the thin film on a large-area substrate. And also the deposition pattern and uniformity were analyzed using the flow velocity and particle tracking method. The uniformity was confirmed by quantifying the deposition cross section with an FIB-SEM, and the consistency of the uniformity prediction was secured through the analysis of the CFD distribution. With the analysis and experimental results, the match rate of deposition area was 80.14% and the match rate of deposition thickness was 55.32%. As the experimental and analysis results were consistent, it was confirmed that it is possible to predict the deposition thickness uniformity of Mist-CVD.

• Journal of KIISE:Software and Applications
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• v.29 no.8
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• pp.555-564
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• 2002

Design patterns are used to utilize well-defined design information. As using these design patterns, we can get re-use in object-oriented paradigm, decrease the time of development and improvement the quality of software. Although these design patterns are widely used among practice, most of design patterns information is manually used, inconsistent and its utilization could be very low. Because the design patterns information that a designer applies does not appear in software, it is sometimes difficult to track them. In this paper, we propose a tool support for design pattern-oriented software development. This tool supports design pattern management, software design and automatic source code generation. The design pattern management has the function for storing, managing and analyzing the existing design pattern and registering new design pattern. The software design has the function for software design with UML and automatically generate design pattern elements. By using this design information, this system can automatically generate source code. In the result to include the tracking design pattern element that is not Included In the existing CASE tools into design information, we can build the stable and efficient system that provides to analyse software, manage design pattern and automatically generate source code.

• Journal of Intelligence and Information Systems
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• v.22 no.1
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• pp.1-18
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• 2016

Owing to the extensive use of Web media and the development of the IT industry, a large amount of data has been generated, shared, and stored. Nowadays, various types of unstructured data such as image, sound, video, and text are distributed through Web media. Therefore, many attempts have been made in recent years to discover new value through an analysis of these unstructured data. Among these types of unstructured data, text is recognized as the most representative method for users to express and share their opinions on the Web. In this sense, demand for obtaining new insights through text analysis is steadily increasing. Accordingly, text mining is increasingly being used for different purposes in various fields. In particular, issue tracking is being widely studied not only in the academic world but also in industries because it can be used to extract various issues from text such as news, (SocialNetworkServices) to analyze the trends of these issues. Conventionally, issue tracking is used to identify major issues sustained over a long period of time through topic modeling and to analyze the detailed distribution of documents involved in each issue. However, because conventional issue tracking assumes that the content composing each issue does not change throughout the entire tracking period, it cannot represent the dynamic mutation process of detailed issues that can be created, merged, divided, and deleted between these periods. Moreover, because only keywords that appear consistently throughout the entire period can be derived as issue keywords, concrete issue keywords such as "nuclear test" and "separated families" may be concealed by more general issue keywords such as "North Korea" in an analysis over a long period of time. This implies that many meaningful but short-lived issues cannot be discovered by conventional issue tracking. Note that detailed keywords are preferable to general keywords because the former can be clues for providing actionable strategies. To overcome these limitations, we performed an independent analysis on the documents of each detailed period. We generated an issue flow diagram based on the similarity of each issue between two consecutive periods. The issue transition pattern among categories was analyzed by using the category information of each document. In this study, we then applied the proposed methodology to a real case of 53,739 news articles. We derived an issue flow diagram from the articles. We then proposed the following useful application scenarios for the issue flow diagram presented in the experiment section. First, we can identify an issue that actively appears during a certain period and promptly disappears in the next period. Second, the preceding and following issues of a particular issue can be easily discovered from the issue flow diagram. This implies that our methodology can be used to discover the association between inter-period issues. Finally, an interesting pattern of one-way and two-way transitions was discovered by analyzing the transition patterns of issues through category analysis. Thus, we discovered that a pair of mutually similar categories induces two-way transitions. In contrast, one-way transitions can be recognized as an indicator that issues in a certain category tend to be influenced by other issues in another category. For practical application of the proposed methodology, high-quality word and stop word dictionaries need to be constructed. In addition, not only the number of documents but also additional meta-information such as the read counts, written time, and comments of documents should be analyzed. A rigorous performance evaluation or validation of the proposed methodology should be performed in future works.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.869-875
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• 2009

Safety is a big issue in the construction sites. For safe and secure management, tracking locations of construction resources such as labors, materials, machineries, vehicles and so on is important. The materials, machineries and vehicles could be controlled by computer, whereas the movement of labors does not have fixed pattern. So, the location and movement of labors need to be monitored continuously for safety. In general, Global Positioning System(GPS) is an opt solution to obtain the location information in outside environments. But it cannot be used for indoor locations as it requires a clear Line-Of-Sight(LOS) to satellites Therefore, indoor location monitoring system could be a convenient alternative for environments such as tunnel and indoor building construction sites. This paper presents a case study to investigate feasibility of Wi-Fi based indoor location monitoring system in construction site. The system is developed by using fingerprint map of gathering Received Signal Strength Indication(RSSI) from each Access Point(AP). The signal information is gathered by Radio Frequency Identification (RFID) tags, which are attached on a helmet of labors to track their locations, and is sent to server computer. Experiments were conducted in a shield tunnel construction site at Guangzhou, China. This study consists of three phases as follows: First, we have a tracking test in entrance area of tunnel construction site. This experiment was performed to find the effective geometry of APs installation. The geometry of APs installation was changed for finding effective locations, and the experiment was performed using one and more tags. Second, APs were separated into two groups, and they were connected with LAN cable in tunnel construction site. The purpose of this experiment was to check the validity of group separating strategy. One group was installed around the entrance and the other one was installed inside the tunnel. Finally, we installed the system inner area of tunnel, boring machine area, and checked the performance with varying conditions (the presence of obstacles such as train, worker, and so on). Accuracy of this study was calculated from the data, which was collected at some known points. Experimental results showed that WiFi-based indoor location system has a level of accuracy of a few meters in tunnel construction site. From the results, it is inferred that the location tracking system can track the approximate location of labors in the construction site. It is able to alert the labors when they are closer to dangerous zones like poisonous region or cave-in..

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.4
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• pp.811-819
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• 2017

A behavior pattern analysis algorithm based on descriptors consists of information of a moving object and temporal histogram is proposed. Background learning is performed first for detecting, tracking and analyzing moving objects. Each object is identified using an association of the center of gravity of objects and tracked individually. A temporal histogram represents a motion pattern using positions of the center of gravity and time stamp of objects. The characteristic and behavior of objects are figured out by comparing each coordinates of a position history in the histogram. Behavior information which is comprised with numbers of a start and end frame, and coordinates of positions of objects is stored and managed in the linked list. Descriptors are made with the stored information and the video retrieval algorithm is designed. We confirmed the higher retrieval accuracy compare with conventional methods.

• Journal of the Korean Institute of Intelligent Systems
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• v.22 no.3
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• pp.319-327
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• 2012

In this paper, we present a sign language recognition model which does not use any wearable devices for object tracking. The system design issues and implementation issues such as data representation, feature extraction and pattern classification methods are discussed. The proposed data representation method for sign language patterns is robust for spatio-temporal variances of feature points. We present a feature extraction technique which can improve the computation speed by reducing the amount of feature data. A neural network model which is capable of incremental learning is described and the behaviors and learning algorithm of the model are introduced. We have defined a measure which reflects the relevance between the feature values and the pattern classes. The measure makes it possible to select more effective features without any degradation of performance. Through the experiments using six types of sign language patterns, the proposed model is evaluated empirically.

• The Journal of the Korea institute of electronic communication sciences
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• v.17 no.3
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• pp.423-432
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• 2022

This paper addresses the safety concern that the SOH of batteries in electric vehicles decreases sharply when drivers change or their driving patterns change. Such a change can overload the battery, reduce the battery life, and induce safety issues. This paper aims to present the SOH as the changes on a dashboard of an electric vehicle in real-time in response to user pattern changes. As part of the training process I used battery data among the datasets provided by NASA, and built models incorporating linear regression and ARIMA, and predicted new battery data that contained user changes based on previously trained models. Therefore, as a result of the prediction, the linear regression is better at predicting some changes in SOH based on the user's pattern change if we have more battery datasets with a wide range of independent values. The ARIMA model can be used if we only have battery datasets with SOH data.

• Journal of the Korean Solar Energy Society
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• v.26 no.2
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• pp.69-77
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• 2006

Photovoltaic is an attractive technology to remote power applications, because of its reliability, low maintenance, and zero fuel requirements. In this paper represents residential PV system based on BESS(battery energy storage system) for managing the electric power, a pattern of daily operation considering the load characteristics of the house, the generation characteristics of PV power, and utility power leveling. For apply to control algorithm, we consider the load on monthly power consumption trend and daily usage pattern. As for the control of the proposed system, to increase the conversion efficiency of the PV power, bidirectional converter is used for MPPT and SPWM inverter. An experimental system is implemented, and some experimental results are provided to demonstrate the effectiveness of the proposed system.

• Journal of Korean Elementary Science Education
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• v.31 no.4
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• pp.501-512
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• 2012

The purpose of this study was to identify the differences in eye movement pattern shown in classification activities between the gifted and regular students in elementary schools. The subjects for the research consisted of five gifted students in the special education center for the gifted at Seoul National University of Education and five students at D regular elementary schools. SMI (Senso Motoric Instruments)' iView $X^{TM}$ RED 120 Hz was used in order to collect eye movement data. Results were as follows. There were difference patterns between the gifted and the regular student in question identification, attribute observation, and criteria generation process. Gifted students minimized unnecessary cognitive overload and took advantage of cognitive economic efficiency. Regular students have a lot of cognitive burden because they did not grasp the essential information.