• Journal of the Korea Institute of Information Security & Cryptology
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• v.19 no.2
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• pp.63-74
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• 2009

In 2005, Wang et al. discovered devastating collision attacks on the main hash functions from the MD4 family. After the discovery of Wang, many analysis results on the security of existing hash-based cryptographic schemes are presented. At CRYPTO'07, Fouque, Leurent and Nguyen presented full key-recovery attacks on HMAC/NMAC-MD4 and NMAC-MD5[4]. Such attacks are based on collision attacks on the underlying hash function, and the most expensive stage is the recovery of the outer key. At EUROCRYPT'08, Wang, Ohta and Kunihiro presented improved outer key recovery attack on HMAC/NMAC-MD4, by using a new near collision path with a high probability[2]. This improves the complexity of the full key-recovery attack on HMAC/NMAC-MD4 which proposed by Fouque, Leurent and Nguyen at CRYPTO'07: The MAC queries decreases from $2^{88}$ to $2^{72}$, and the number of MD4 computations decreases from $2^{95}$ to $2^{77}$. In this paper, we propose improved outer key-recovery attack on HMAC/NMAC-MD4 with $2^{77.1246}$ MAC queries and $2^{37}$ MD4 computations, by using divide and conquer paradigm.

• Journal of Information Technology Services
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• v.6 no.2
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• pp.177-188
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• 2007

Policy-based Network Management (PBNM) has been presented as a paradigm for efficient and customizable management systems. The approach chosen is based on PBNM systems, which are a promising and novel approach to network management. These systems have the potential to improve the automation of network management processes. The Internet Engineering Task Force (IETF) has also used policy concepts and provided a framework to describe the concept as the Policy Core Information Model (PCIM) and its extensions. There are policy conflicts among the policies that are defined as the policy information model and they are not easily and effectively detected and resolved. In this paper, we present the brief description of PBNM and illustrate the concepts of policy core information model and its policy implementation for a network security. Especially we describe our framework for detecting and resolving the policy conflicts for network security.

• The Korean Journal of Physiology and Pharmacology
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• v.10 no.5
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• pp.223-229
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• 2006

The emerging concept of the 'neurovascular unit' may enable a powerful paradigm shift for neuroscience. Instead of a pure focus on the 'neurobiology' of disease, an opportunity now exists to return to a more integrative approach. The neurovascular unit emphasizes that signaling between vascular and neuronal compartments comprise the basis for both function and dysfunction in brain. Hence, brain disorders are not just due to death of neurons, but instead manifested as cell signaling perturbations at the neurovascular interface. In this mini-review, we will examine 3 examples of this hypothesis: neurovascular mechanisms involved in the thrombolytic therapy of stroke, the crosstalk between neurogenesis and angiogenesis, and the link between vascular dysfunction and amyloid pathology in Alzheimer's disease. An understanding of cell-cell and cell-matrix signaling at the neurovascular interface may yield new approaches for targeting CNS disorders.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.6
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• pp.209-220
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• 2014

Compressive Sensing (CS) is a new signal acquisition paradigm which enables sampling under Nyquist rate for a special kind of signal called sparse signal. There are plenty of CS recovery methods but their performance are still challenging, especially at a low sub-rate. For CS recovery of natural images, regularizations exploiting some prior information can be used in order to enhance CS performance. In this context, this paper addresses improving quality of reconstructed natural images based on Dantzig selector and smooth filters (i.e., Gaussian filter and nonlocal means filter) to generate a new regularization called smooth residual error regularization. Moreover, total variation has been proved for its success in preserving edge objects and boundary of reconstructed images. Therefore, effectiveness of the proposed regularization is verified by experimenting it using augmented Lagrangian total variation minimization. This framework is considered as a new CS recovery seeking smoothness in residual images. Experimental results demonstrate significant improvement of the proposed framework over some other CS recoveries both in subjective and objective qualities. In the best case, our algorithm gains up to 9.14 dB compared with the CS recovery using Bayesian framework.

• Fire Science and Engineering
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• v.34 no.4
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• pp.125-134
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• 2020

This paper aimed to statistically analyze the impact of fire needs not considered in previous reports based on preventive and preparedness strategies of fire administration and fire budget.. The panel data came from 16 metropolitan councils from 2008 to 2018 and was statistically analyzed based on the preventive measures of the fire administration (agreement for building permission, specific target for fire-fighting, public use facilities, and special fire inspection [SFI]), preparedness of the fire administration (fire safety education [FSE]), response of the fire administration (mobilization for fire suppression [MFS] and mobilization for ambulance service [MAS]), and fire budget. In the results, SFI, FSE, and MFS had a significant negative influence on the fire budget. Meanwhile, MAS had a significant positive effect on the fire budget (p < 0.01). These results reflect public policy in Korea; there has been a paradigm shift in fire administration: from disaster acceptance (focusing on recovery) to disaster response (focusing on field response) to disaster preparedness (focusing on preparedness).

• The Transactions of the Korea Information Processing Society
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• v.5 no.3
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• pp.649-661
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• 1998

If there is redeveloping into the system applying the object-oriented paradigm, productivity Improvement of software through reuse would be accomplished and maintenance cost be reduced. When a procedure-oriented system is transformed to a type applying the object-oriented paradigm, various techniques are studied to extract objects from source code automatically or semi-automatically. However, it is not easy to extract conceptuat objects when those techniques are applied, This problem entails another problem which drops the conceptual integrity of the extracted objects. In this paper, we suggest an object extraction method and tool development to resolve the problem occurring at the time when thc pr"~r"m, dcveloped through procedure-oriented is transformed to an object-oriented system. The suggested method allow to extract the desired objects using object modeling for various application domains of the real world given source code and design recovery information. During the extraction process, functionality and global variables of the source code as well as its intcrface arc rigorously analyzed. This process can enhance the conceptual integrity of the objects and make easy to construct class hierarchies.

• Journal of Convergence for Information Technology
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• v.11 no.5
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• pp.158-167
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• 2021

This work aims to explore personal coping and insight experience in mental disorder symptoms from the perspective of the parties in order to lay an empirical basis for the transition of the mental health service paradigm from a medical model to a human rights model. For this purpose, in-depth interviews with 8 persons with mental disorders were conducted and a model of practice was suggested through analysis using the grounded theory. As a result, 11 categories, 23 sub-categories and 132 concepts were identified. According to the analysis of this study, people with mental disorders have changed their perspective on symptoms through in-depth insight into their identities and symptoms as mental disorders, and discovered their own autonomous ways to cope with symptoms, managing their daily lives. Therefore, in developing a Korean alternative model for people with mental disorders, it is necessary to prepare conditions to find their own countermeasures through opportunities for insight.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.4
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• pp.173-180
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• 2014

Compressive sensing is a new signal acquisition paradigm that enables sparse/compressible signal to be sampled under the Nyquist-rate. To fully benefit from its much simplified acquisition process, huge efforts have been made on improving the performance of compressive sensing recovery. However, concerning color images, compressive sensing recovery lacks in addressing image characteristics like energy distribution or human visual system. In order to overcome the problem, this paper proposes a new group-sparsity hard thresholding process by preserving some RGB-grouped coefficients important in both terms of energy and perceptual sensitivity. Moreover, a smoothed group-sparsity iterative hard thresholding algorithm for compressive sensing of color images is proposed by incorporating a frame-based filter with group-sparsity hard thresholding process. In this way, our proposed method not only pursues sparsity of image in transform domain but also pursues smoothness of image in spatial domain. Experimental results show average PSNR gains up to 2.7dB over the state-of-the-art group-sparsity smoothed recovery method.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.3
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• pp.410-420
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• 2012

The heavy reliance on fossil fuels, especially oil and gas has triggered the global energy crisis. Continued use of petroleum fuels is now widely recognized as unsustainable because of their depleting supplies and degradation to the environment. To become less dependent on fossil fuels, current world is shifting paradigm in energy by developing alternative energy sources mainly through the utilization of renewable energy sources. In particular, bioenergy recovery from wastes with the help of microorganism is viewed as one of the promising ways to mitigate the current global warming crisis as well as to supply global energy. It has been proved that microorganism can generate power by converting organic matter into electricity using microbial fuel cells (MFCs). MFC is a bioelectrochemical device that employs microbes to generate electricity from bio-convertible substrate such as wastewaters including municipal solid waste, industrial, agriculture wastes, and sewage. Sustainability, carbon neutral and generation of renewable energy are some of the major features of MFCs. However, the MFC technology is confronted with a number of issues and challenges such as low power production, high electrode material cost and so on. This paper reviews the recent developments in MFC technology with due consideration of electrode materials used in MFCs. In addition, application of biocathodes in MFCs has been discussed.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.6
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• pp.509-515
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• 2020

TThe cooperation on disaster prevention between the two Koreas has been mostly focused on cooperation at the recovery stage, such as emergency relief supplies and equipment support. This study aims to articulate future practical development plans by analyzing disaster cooperation between North and South Korea in accordance with the changing paradigm of international disaster cooperation. Considering the specificity of inter-Korean cooperation, the Framework for Inter-Korean Disaster Prevention Cooperation was established centering on the Sendai Framework for Disaster Risk Reduction. The framework consists of understanding and sharing disaster risks, building back better, strengthening community resilience, and supporting regional disaster action plans for continuous action. Inter-Korean disaster prevention cooperation requires sharing information about North Korean disasters. It is necessary to accurately identify and support social vulnerability to North Korean disasters. Above all, it is supporting the development of disaster action plans from a humanitarian perspective needs. A medium-to-long term resilience reinforcement plan that North Korea can resolve on its own is also needed. Since North Korea is also deeply interested in international disaster cooperation, it should be based on the direction of the Sendai Framework. Considering the uniqueness of inter-Korean cooperation, a path for North Korea to actively participate in international disaster cooperation should be established.