• Smart Structures and Systems
• /
• v.5 no.3
• /
• pp.209-221
• /
• 2009

A control algorithm for seismic protection of building structures based on the theory of variable structural control or sliding mode control is presented. The paper focus in the design of sliding surface. A method for determining the sliding surface by pole assignment algorithm where the poles of the system in the sliding surface are obtained on-line, based on the frequency content of the incoming earthquake signal applied to the structure, is proposed. The proposed algorithm consists of the following steps: (i) On-line FFT process is applied to the incoming part of the signal and its frequency content is recognized. (ii) A transformation of the frequency content to the complex plane is performed and the desired location of poles of the controlled structure on the sliding surface is estimated. (iii) Based on the estimated poles the sliding surface is obtained. (iv) Then, the control force which will drive the response trajectory into the estimated sliding surface and force it to stay there all the subsequent time is obtained using Lyapunov stability theory. The above steps are repeated continuously for the entire duration of the incoming earthquake. The potential applications and the effectiveness of the improved control algorithm are demonstrated by numerical examples. The simulation results indicate that the response of a structure is reduced significantly compared to the response of the uncontrolled structure, while the required control demand is achievable.

• Journal of Korean language education
• /
• v.29 no.3
• /
• pp.117-144
• /
• 2018

The purpose of this study is to explore the linguistic elements that can promote academic literacy in terms of content-based instructions for KSL learners. In order to study the characteristics of learning languages for subjects, focus was given to the framework of systematic functional linguistics that has been extensively used in ELL teaching and learning research in the United States and Australia. History, which is taught in all classes and classified as a required course, was the subject of analysis. From the history curriculum, the elementary school level texts "Social Studies 5-2" and "Social Studies 6-1" were chosen for the analysis. Based on the results, we can come to the following conclusions. First, history textbooks are divided into narrative and analytical explanatory sub-genres based on their content, and there are differences in the factors that need to be focused on to find the main information. Second, the vocabulary of history textbooks should focus on the use of verbs which comprehend material processes. Particularly, learners should pay attention to the differences in meaning between low-frequency expressions. We hope that the results of this study will have a positive effect on history subject learning for learners in the "Adaptive Korean Course" and will help establish direction in terms of building curriculum contents for KSL learners.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.44 no.1
• /
• pp.51-59
• /
• 2021

Electronic document communication based on a digital channel is becoming increasingly important with the advent of the paperless age. The electronic document based on PDF format does not provide a powerful customer experience for a mobile device user despite replacing a paper document by providing the content integrity and the independence of various devices and software. On the other hand, the electronic document based on HTML5 format has weakness in the content integrity as there is no HTML5 specification for the content integrity despite its enhanced customer experience such as a responsive web technology for a mobile device user. In this paper, we design the Document-HTML, which provides the content integrity and the powerful customer experience by declaring the HTML5 constraint rules and the extended tags to contain the digital signature based on PKI. We analyze the existing electronic document that has been used in the major financial enterprise to develop a sample. We also verify the Document-HTML by experimenting with the sample of HTML electronic communication documents and analyze the PKI equation. The Document-HTML document can be used as an authorized electronic document communication and provide a powerful customer experience in the mobile environment between an enterprise and a user in the future.

• International Journal of Computer Science & Network Security
• /
• v.22 no.8
• /
• pp.175-186
• /
• 2022

This research article develops an Arabic books' recommendation system, which is based on the content similarity that assists users to search for the right book and predict the appropriate and suitable books pertaining to their literary style. In fact, the system directs its users toward books, which can meet their needs from a large dataset of Information. Further, this system makes its predictions based on a set of data that is gathered from different books and converts it to vectors by using the TF-IDF system. After that, the recommendation algorithms such as the cosine similarity, the sequence matcher similarity, and the semantic similarity aggregate data to produce an efficient and effective recommendation. This approach is advantageous in recommending previously unrated books to users with unique interests. It is found to be proven from the obtained results that the results of the cosine similarity of the full content of books, the results of the sequence matcher similarity of Arabic titles of the books, and the results of the semantic similarity of English titles of the books are the best obtained results, and extremely close to the average of the result related to the human assigned/annotated similarity. Flask web application is developed with a simple interface to show the recommended Arabic books by using cosine similarity, sequence matcher similarity, and semantic similarity algorithms with all experiments that are conducted.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.16 no.6
• /
• pp.1113-1120
• /
• 2021

Content Central Network (CCN) appeared to improve network efficiency by transforming IP-based network into content name-based network structures. Each router performs caching mechanism to improve network efficiency in the CCN. And the cache replacement policy applied to the CCN router is an important factor that determines the overall performance of the CCN. Therefore various studies has been done relating to cache replacement policy of the CCN. In this paper, we proposed a cache replacement policy that improves the limitations of the LFU policy. The proposal algorithm applies real-time producer popularity-based variables. And through experiments, we proved that the proposed policy shows a better cache hit ratio than existing policies.

• ETRI Journal
• /
• v.45 no.3
• /
• pp.505-517
• /
• 2023

Color, texture, and shape act as important information for images in human recognition. For content-based image retrieval, many studies have combined color, texture, and shape features to improve the retrieval performance. However, there have not been many powerful methods for combining all color, texture, and shape features. This study proposes a content-based image retrieval method that uses the combined local and global features of color, texture, and shape. The color features are extracted from the color autocorrelogram; the texture features are extracted from the magnitude of a complete local binary pattern and the Gabor local correlation revealing local image characteristics; and the shape features are extracted from singular value decomposition that reflects global image characteristics. In this work, an experiment is performed to compare the proposed method with those that use our partial features and some existing techniques. The results show an average precision that is 19.60% higher than those of existing methods and 9.09% higher than those of recent ones. In conclusion, our proposed method is superior over other methods in terms of retrieval performance.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2022.10a
• /
• pp.386-388
• /
• 2022

Recently, realistic contents using virtual reality and augmented reality are attracting attention as learning aids. 3D-based contents have the advantage of being able to observe and experience objects from various angles than 2D-based contents shown on a flat surface. In this paper, we propose a content design based on 3D model for Arduino learning in a virtual environment. The Arduino board and sensor were implemented using Blender, and a 3D-based simulator environment was constructed using the Unity engine. The proposed content uses the Arduino board and sensor implemented in 3D so that learners can easily experience the working principle of Arduino and the coding process.

• Journal of Internet Computing and Services
• /
• v.18 no.2
• /
• pp.13-20
• /
• 2017

Recently, researches to adopt Content-centric network (CCN), which is one of the promising technologies for replacing TCP/IP-based networks, to wireless networks has actively performed. However, because of erroneous and unreliable channel characteristics, there are many problems to be resolved to adopt CCN to wireless networks. This paper proposes a method to reduce content download time because nodes possess only parts of content chunks. The proposed method enables a node having parts of content chunks to request the rest of parts of content chunks to a provider before a Consumer requests the content. As a consequence, the content download time is reduced.

• Journal of Information Processing Systems
• /
• v.10 no.4
• /
• pp.543-554
• /
• 2014

It is difficult for mobile learners to maintain a high level of concentration when learning content for more than an hour while they are on the move. Despite the attention span issue, many m-learning systems still provide their mobile learners with the same content once used in e-learning systems. This has called for an investigation to identify the suitable characteristics of the m-learning environment. With this in mind, we have conducted a survey in hopes of determining the requirements for developing more suitable m-learning content. Based on the results of the survey, we have developed a content model comprised of two types: a segment type and a supplement type. In addition, we have implemented a prototype system of the content model for Apple iPhones and Android smartphones in order to investigate a feasibility study of the model application.

• International journal of advanced smart convergence
• /
• v.12 no.4
• /
• pp.154-163
• /
• 2023

With the rapid development of AI technology, ChatGPT and other AI content creation tools are becoming common, and users are becoming curious and adopting them. These tools, unlike search engines, generate results based on user prompts, which puts them at risk of inaccuracy or plagiarism. This allows unethical users to create inappropriate content and poses greater educational and corporate data security concerns. AI content detection is needed and AI-generated text needs to be identified to address misinformation and trust issues. Along with the positive use of AI tools, monitoring and regulation of their ethical use is essential. When detecting content created by AI with an AI content detection tool, it can be used efficiently by using the appropriate tool depending on the usage environment and purpose. In this paper, we collect data on AI content detection tools and compare and analyze the functions and characteristics of AI content detection tools to help meet these needs.