• The Korean Journal of Nuclear Medicine
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• v.25 no.1
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• pp.37-45
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• 1991

Infarct size is a major determinant of prognosis after acute myocardial infarction. Up to date, however, clinically available tests to estimate this size have not been sufficiently accurate. Twelve lead electrocardiogram and wall motion abnormality measurement are not quantitative, and creatine phophokinase (CPK) measurement is inaccurate in the presence of reperfusion or right ventricular infarction. Methods have been developed to localize and size acute myocardial infarcts with agents that are selectively sequestered in areas of myocardial damage, but previously used agents have lacked sufficient specificity. Antibodies that bind specifically only to damaged myocardial cells may resolve this problem and provide an accurate method for noninvasively measuring infarct size. We determined the accuracy with which infarcted myocardial mass can be measured using single photon emission computed tomography (SPECT) and radiolabeled antimyosin antibodies. Seven patients with acute myocardial infarction and one stable angina patient were injected with 2 mCi of Indium-111 labeled antimyosin antibodies. Planar image and SPECT was performed 24 hours later. None of the patients had history of prior infarcts, and none had undergone reperfusion techniques prior to the study, which was done within 4 days of the attack. Planar image showed all infarct patients to have postive uptakes in the cardiac region. The location of this uptake correlated to the infarct site as indicated by electrocardiography in most of the cases. The angina patient, however, showed no such abnormal uptake. Infarct size was determined from transverse slices of the SPECT image using a 45% threshold value obtained from a phantom study. Measured infarct size ranged from 40 to 192 gr. There was significant correlation between the infarct size measured by SPECT and that estimated from serial measurements of CPK (r=0.73, p<0.05). These date suggest that acute myocardial infarct size can be accurately measured from SPECT Indium-111 antimyosin imaging. This method may be especially valuable in situations where other methods are unreliable, such as early reperfusion technique, right ventricular infarct or presence of prior infarcts.

• Journal of Information Technology and Architecture
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• v.10 no.1
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• pp.79-91
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• 2013

This paper proposes a systematic methodology that could be used to decide which one shows the best performance among space filling curves (SFCs) in applying lower-dimensional transformations to histogram sequences. A histogram sequence represents a time-series converted from an image by the given SFC. Due to the high-dimensionality nature, histogram sequences are very difficult to be stored and searched in their original form. To solve this problem, we generally use lower-dimensional transformations, which produce lower bounds among high dimensional sequences, but the tightness of those lower-bounds is highly affected by the types of SFC. In this paper, we attack a challenging problem of evaluating which SFC shows the better performance when we apply the lower-dimensional transformation to histogram sequences. For this, we first present a concept of spatial locality, which comes from an intuition of "if the entries are adjacent in a histogram sequence, their corresponding cells should also be adjacent in its original image." We also propose spatial locality preservation metric (slpm in short) that quantitatively evaluates spatial locality and present its formal computation method. We then evaluate five SFCs from the perspective of slpm and verify that this evaluation result concurs with the performance evaluation of lower-dimensional transformations in real image matching. Finally, we perform k-NN (k-nearest neighbors) search based on lower-dimensional transformations and validate accuracy of the proposed slpm by providing that the Hilbert-order with the highest slpm also shows the best performance in k-NN search.

• Korean Security Journal
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• no.22
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• pp.65-90
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• 2010

Recently, alarmed by the frequent international terrorism or safety accidents, the host countries of world sports events are focusing on security activities for the sake of the participants, facilities, events and competitions. They are alarmed because in case any happenings like international terrorism or safety accident, the contest itself can be criticized to be a failure as much as the international reliability of the host nation may well crash. We can see that any failure in coping with terrorism or safety matters can lead to a nation-wise crisis in the case of Indonesia where the October 12th of 2002 terrorist bomb attack in Bali damaged the image of the nation followed by the similar case in Philippine (Oct. 20th, 2002) where the same terrorist attack dramatically scared away the tourists to the nation. Korea is scheduled to hold the World Championship in Athletics in Daegu Metropolitan City in 2011. Also, it is slated to host various world sports events such as Yeosu International Exposition and Incheon Asian Games. In these contexts, this study analyzes counter-terrorism cases related with the recent international sports events that have been organized in a variety of manners in the era of globalization. This study aims to show alternatives for the safety management in these events. In other words, it is focusing on giving directions to the safety policies of the nation -which may become the future hub of north-east Asia and the world - for more perfect guard and defense, and counter-terrorism activities in all the conferences, sports events and international festivals where any private defense and guard companies are allowed to cooperate with the police force or public security agencies.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.40 no.4
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• pp.193-205
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• 2003

There has been so many research activities about robot soccer system in the many research fields, for example, intelligent control, communication, computer technology, sensor technology, image processing, mechatronics. Especially researchers research strategy for attacking in the field of strategy, and develop intelligent strategy. Then, soccer robots cannot defense completely and efficiently by using simple defense strategy. Therefore, intention extraction of attacker is needed for efficient defense. In this thesis, intention extractor of soccer robots is designed and developed based on FMMNN(Fuzzy Min-Max Neural networks ). First, intention for soccer robot system is defined, and intention extraction for soccer robot system is explained.. Next, FMMNN based intention extractor for soccer robot system is determined. FMMNN is one of the pattern classification method and have several advantages: on-line adaptation, short training time, soft decision. Therefore, FMMNN is suitable for soccer robot system having dynamic environment. Observer extracts attack intention of opponents by using this intention exactor, and this intention extractor is also used for analyzing strategy of opponent team. The capability of developed intention extractor is verified by simulation of 3 vs. 3 robot succor simulator. It was confirmed that the rates of intention extraction each experiment increase.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.12 no.6
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• pp.629-635
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• 2019

In Deep Learning models derivative is implemented by error back-propagation which enables the model to learn the error and update parameters. It can find the global (or local) optimal points of parameters even in the complex models taking advantage of a huge improvement in computing power. However, deliberately generated data points can 'fool' models and degrade the performance such as prediction accuracy. Not only these adversarial examples reduce the performance but also these examples are not easily detectable with human's eyes. In this work, we propose the method to detect adversarial datasets with random noise addition. We exploit the fact that when random noise is added, prediction accuracy of non-adversarial dataset remains almost unchanged, but that of adversarial dataset changes. We set attack methods (FGSM, Saliency Map) and noise level (0-19 with max pixel value 255) as independent variables and difference of prediction accuracy when noise was added as dependent variable in a simulation experiment. We have succeeded in extracting the threshold that separates non-adversarial and adversarial dataset. We detected the adversarial dataset using this threshold.

• Korean Security Journal
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• no.51
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• pp.11-35
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• 2017

The third industrial revolution, characterized by factory automation and informatization, are moving toward the fourth industrial revolution which is the era of superintelligence and supernetworking through rapid technology innovation. The most important resources in the fourth industrial revolution are information or data since the most of industrial and economic activities will be affected by information in the fourth industrial revolution. Therefore we can expect that more information will be utilized, shared and transfered through the networks or systems in real time than before so the significance of information management and security will also increase. As the importance of information resource management and security which is the core of the fourth industrial revolution increases, the threats on information security are also growing so security incidents such as data breeches and accidents take place more often. Various and thorough solutions are highly needed to protect information resources from security risks because information accidents or breaches seriously damage brand image and cause huge financial damage to organization. The purpose of this study is to research general trends on data breaches and accident that can be serious threat of information security. Also, we will provide resonable solutions to protect data from nine attack patterns or other risk factors after figuring out each characteristic of nin attack patterns in data breaches and accidents.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.29 no.4
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• pp.859-866
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• 2019

Cybersecurity attack targeting a specific user is rising in number, even enterprises are trying to strengthen their cybersecurity. Network segmentation environment where public network and private network are separated could block information coming from the outside, however, it is unable to control outside information for business efficiency and productivity. Even if enterprises try to enhance security policies and introduce the network segmentation system and a solution incorporating CDR technology to remove unnecessary data contained in files, it is still exposed to security threats. Therefore, we suggest a system that uses file format conversion to transmit a secure file in the network separation environment. The secure file is converted into an image file from a document, as it reflects attack patterns of inserting malicious code into the document file. Additionally, this paper proposes a system in the environment which functions that a document file can keep information for incident response, considering forensic readiness.

• The Journal of the Convergence on Culture Technology
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• v.10 no.3
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• pp.413-420
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• 2024

After Friedrich Nietzsche's advocacy of nihilism, many literary works, dramas, and films have depicted aspects of human psychology associated with nihilism. Animation, too, has been used to convey nihilism, with narratives infused with nihilistic themes produced as both TV series and theatrical animations. Particularly, animation, as a visual medium capable of realizing any imaginative image unlike other media, possesses distinctive characteristics from live-action cinematography and differs from comics in its temporal properties. Hence, this study aims to analyze how Nietzsche's defined three stages of nihilism are represented within animation characters and how they construct various scenarios, using the anime "Attack on Titan" as a case study. The research unfolds by first examining Nietzsche's types of nihilism and the three stages through a review of literature, while also investigating the portrayal of nihilism in mass media and considering the unique attributes of animation. Secondly, building upon the literature review, the analysis interprets the narrative and constructed world of the chosen case study from a nihilistic perspective, examining four major characters through the stages of passive nihilism, active nihilism, and eternal recurrence. The findings demonstrate that the anime conveys two messages regarding negation and affirmation of one's life and existence, thereby offering viewers an opportunity to deeply contemplate human existence. This study is considered significant as it examines how Nietzschean nihilism is portrayed within the popular entertainment medium of animation.

• Journal of the Institute of Convergence Signal Processing
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• v.4 no.2
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• pp.46-52
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• 2003

In this paper, the wavelet watermarking algorithm based on adaptive weight MASK processing as a watermark embedded-method for Copyright Protection of Digital contents is Proposed. Because watermark induce as a noise of original image, the watermark size should be limited for preventing quality losses and embedding watermark into images. Therefore, it should be preserve the best condition of the factors, robustness, capacity and visual quality. Tn order to solve this problem, we propose watermarking embedded method by applying adaptive weight MASK to the algorithm and optimize its efficiency. In that result, the watermarked images are improved about external attack. Specifically, correlation coefficient has over 0.8 on both modifications of brightness and contrast. Also, correlation coefficient of wavelet compression of embedded watermark last by over 0.65.

• Journal of KIISE:Computing Practices and Letters
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• v.7 no.3
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• pp.220-228
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• 2001

Digital watermarking is a technique for the purpose of protecting the ownership of the image by embedding invisible watermarks in a digital imnge. To guarantee the security of the digital watermarking scheme for copyright protection, it is required to satisfy some requirements robustness and perceptual invisibility which provided by the location of embedded bits, the public watermarking algorithm, and the hidden use of the key, which can protect unauthorized accesses from illegal users. For this, in this paper we propose a new copyright watermarking scheme, which is based on one-way hash functions using RSA functions and modular operations. RSA functions are widely used in cryptographic systems. Our watermarking scheme is robust against LSB(Jeast significant bit) attacks and gamma corresction attack, and is also perceptually invisible. We demonstrate the characteristics of our proposed watermarking scheme through experiments.