• Journal of Korea Multimedia Society
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• v.21 no.8
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• pp.837-848
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• 2018

Monitoring technology of machining has a long history since unmanned machining was introduced. Despite the long history, many researchers have presented new approaches continuously in this area. Sound based machine fault diagnosis is the process consisting of detecting automatically the damages that affect the machines by analyzing the sounds they produce during their operating time. The collected sound is corrupted by the surrounding work environment. Therefore, the most important part of the diagnosis is to find hidden elements inside the data that can represent the error pattern. This paper presents a feature extraction methodology that combines various digital signal processing and pattern recognition methods for the analysis of the sounds produced by tools. The magnitude spectrum of the sound is extracted using the Fourier analysis and the band-pass filter is applied to further characterize the data. Statistical functions are also used as input to the nonlinear classifier for the final response. The results prove that the proposed feature extraction method accurately captures the hidden patterns of the sound generated by the tool, unlike the conventional features. Therefore, it is shown that the proposed method can be applied to a sound based automatic diagnosis system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.7
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• pp.492-498
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• 2016

It is well known that since abrupt faults in induction motors tend to lead to subsequent faults and deterioration of the drive apparatus, motor faults may lead to several operating restrictions, such as security problems and economic loss. A lot of research has been done in the area of diagnosis to detect machine faults and to prevent catastrophic hazards in the motor drive system. This paper presents a new method of motor current signature analysis in which the DC-link current of the inverter-driven induction motor system, where a single current sensor is employed instead of three AC current sensors, is measured, and fast Fourier transform analysis is performed. This proposed method makes it possible to easily discern and clearly separate the motor fault current signature from the normal operation current flowing through the stator and rotor windings.

• Journal of the Korea Convergence Society
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• v.11 no.2
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• pp.109-116
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• 2020

Social media is growing rapidly as a means of promoting artists' artworks and a channel for sales. However, since social media is not fundamentally a platform designed for trading, it has various limitations that make it difficult to ensure trust and security in carrying out transactions. In this paper, it is proposed interoperability between social media and blockchain-based smart contract system that can record and preserve the artist's profile, information related to artworks and details of the contract on the blockchain. The proposed interoperability allows artwork trading participants on social media to maintain mutual trust and to conduct the contract transparently. Also, the proposed interoperability consists of an API provided by the social media developer or an open source API without having to modify existing social media. This study is expected to contribute to the growth of the art trading market on social media by complementing the art trading practices on social media.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.5
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• pp.99-104
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• 2016

The walking exercise can alleviate stress and also it can improve health fortheir lifetime. Recent development in Information and Communication Technologies (ICT) has laid the foundation for Internet of Things (IoT) to become the future technology. IoT has many applications in industry automation, security, smart homes and cities, education, health etc. In personal health-care domain, IoT is mainly used for monitoring fitness condition by observing current activity of individual. In this paper, we have proposed a novel IoT based personal wellness care system. Proposed system not only keep track of current fitness level but also provide future activity prediction based on history data along with standard recommendations. Predicted activity helps in motivating the individual to achieve the desired fitness level. Initially, we consider only walking activity for testing purpose and later, other types of activities/exercise will be captured for improved health care support.

• Journal of Korea Multimedia Society
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• v.21 no.4
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• pp.450-463
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• 2018

Sound based machine fault diagnosis is the process consisting of detecting automatically the damages that affect the machines by analyzing the sounds they produce during their operating time. The collected sounds being inevitably corrupted by random disturbance, the most important part of the diagnosis consists of discovering the hidden elements inside the data that can reveal the faulty patterns. This paper presents a novel feature extraction methodology that combines various digital signal processing and pattern recognition methods for the analysis of the sounds produced by the drills. Using the Fourier analysis, the magnitude spectrum of the sounds are extracted, converted into two-dimensional vectors and uniformly normalized in such a way that they can be represented as 8-bit grayscale images. Histogram equalization is then performed over the obtained images in order to adjust their very poor contrast. The obtained contrast enhanced images will be used as the features of our diagnosis system. Finally, principal component analysis is performed over the image features for reducing their dimensions and a nonlinear classifier is adopted to produce the final response. Unlike the conventional features, the results demonstrate that the proposed feature extraction method manages to capture the hidden health patterns of the sound.

• Journal of Korea Multimedia Society
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• v.9 no.6
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• pp.742-749
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• 2006

In the network-based game where it uses the Internet infrastructure, the implementation is possible with the various methods. Such Applications are developed in the multi-tired architecture. There are many cases for the server to be separated from the hardware or the software. In this case, a lot of applications make the distributed process possible and are made as the multi-tiered architecture to develop the reusability of the existing software module. Especially, it is mostly general to separate for the case of a database server to a new tier. One of the important points of multi-tiered server side applications is security and because of this, it is difficult to share the related data about the design skill. Using design patterns, it gives help in reusing the existing written-code for the design of the game that needs a lot of money and time. Design Patterns are related to the software reuse. For the development of more efficient games, if well-defined design patterns are provided to the developers, then it would make more easy advanced game API and make possible the framework for the game development based on the API Through the analysis of the general network-based game currently servicing in the Internet, in this paper, we discuss how to implement a business logic tier using database system among the server side architectures. The main objective of this article is to show an efficient APIs(Application Programming Interfaces) design method which can be used to manage the data that must be saved to the database system among the packets that client/server have to be exchange.

• Proceedings of the KOSOMBE Conference
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• v.1989 no.05
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• pp.75-76
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• 1989

The blood bank is a field of clinical pathology which requires the most accuratemaintenanceofrecording. Because the mistake in it is directly related to a patient's life. So, the computerization of the blood bank is urgent to maintain a log blook arid to compare the patient's current data with past result. We developed the blood bank management program using 32 bit minicomputer. This is composed of 4 parts; a management of routine test result, special test result, the blood issue and statistics. The management of routine test result handles the patient's information and blood typing and compares above results with the past one of same patient. The management of special test result are for special immunohematologic tests like an irregular antibody, Coombs' test, and etc. Blood issue part records the type of the blood bag, component, and the name of issuer. Statistic part are made to get statistics of each day and each month by the blood type, and the type the blood component. The program is secured by the maintenance of operator's operation history and thu provision of the security code to each operator, without which no one can enter the system and after the content. So the stability and reliability of the data is obtained. This program will be upgraded for bar-code using system in the near future.

• Journal of KIISE:Computer Systems and Theory
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• v.32 no.10
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• pp.491-498
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• 2005

The Denial of Service(DoS) attacks, which are done by consuming all of the computing or communication resources necessary for the services, are known very difficult to be protected from. TCP has drawbacks in its connection establishment for possible DoS attacks. TCP maintains the state of each partly established connection in the connection queue until it is established completely and accepted by the application. The attackers can make the queue full by sending connection requests repeatedly and not completing the connection establishment steps for those requests. In this paper, we have designed and implemented the extended TCP for preventing from SYN Flood DoS attacks. In the extended TCP, the state of each partly established connection is not maintained in the queue until the connection is established completely. For the extended TCP, we have modified the 3-way handshake procedure of TCP and implemented the extended TCP in the Linux operating system. The test result shows $0.05\%$ delay more than original TCP, but it shows that the extended TCP is strong for SYN Flood attacks.

• Journal of Digital Contents Society
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• v.10 no.3
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• pp.433-439
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• 2009

With the help of fast growing popularization of internet, all areas of e-Health have expanded rapidly; such that people have become interested in digital personal health record and its management. This paper examined the characteristics of personal health record and made the analysis of the structure of Google Health, the internet-based personal health record system. Google Health allows you to store and manage all of your health information, import medical records from hospitals and pharmacies, share your health records, and explore online health services. This examples represents not only a significant change of current medical systems but also enables to estimate the future stream of it. As a result, this paper, in the areas of e-Health which will be expanded in various service areas, may give you a greater sense of importance of personal health record and will eventually provide more complemental structure of future personal health record through comparative studies on the strength and weakness of it.

• Journal of Convergence for Information Technology
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• v.10 no.7
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• pp.41-48
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• 2020

Recently, the spreading business of AMI (Advanced Metering Infrastructure) remote metering systems in various regions of the country has been activated, and it provides various metering functions such as two-way communication and security plan functions for power demand management. Current AMI system is difficult to analyze based on the existing RDB(Relational Database) due to the increase in the size of new internal IoT devices and networks. This study proposes a new GDB(Graph Database) based failure analysis method that utilizes existing RDB data. It analyzes the correlation of new failure patterns through accumulated data such as internal thresholds and status values. As a result of GDB-based simulation, it was confirmed that RDB can predict to a new obstacle pattern that was difficult to analyze.