• Journal of Advanced Navigation Technology
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• v.15 no.5
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• pp.865-870
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• 2011

MD-64 is a 64-bit block cipher suitable for the efficient implementation in hardware environments such as WSN. In this paper, we propose a related-key amplified boomerang attack on the full-round MD-64. The attack on the full-round MD-64 requires $2^{45.5}$ related-key chosen plaintexts and $2^{95}$ MD-64 encryptions. This work is the first known cryptanalytic result on MD-64.

• International Journal of Internet, Broadcasting and Communication
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• v.11 no.3
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• pp.41-48
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• 2019

The Management Discussion and Analysis(MD&A) provides investors with an opportunity to gain insight into the company from a manager's perspective and enables short-term and long-term analysis of the business. And MD&A is an important channel through which companies and investors can communicate, providing a useful source of information for analyzing financialstatements. MD&A is measured by the quality of disclosure and there are many previous studies on the usefulness of disclosure information. Therefore, it is very important for the financial analyst who is the representative information user group in the capital market that MD&A Disclosure Quality is measured in real-time in combination with IT information technology and provided timely to financial analyst. In this study, we propose a method that real-time data is converted to digitalized data by combining MD&A disclosure with IT information technology and provided to financial analyst's information environment in real-time. The real-time information provided by MD&A can help the financial analysts' activities and reduce information asymmetry.

• Journal of Korean Society for Quality Management
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• v.50 no.4
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• pp.735-749
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• 2022

Purpose: The purpose of this study is to investigate whether the Management Discussion and Analysis (MD&A) has an impact on auditors' audit efforts. MD&A is a means of disclosure that provides information about a company from the management's perspective in financial reporting. The MD&A is a standardized format of nonfinancial information that can be useful for the stake-holders. The auditors have incentives to utilize the nonfinancial information contained in the MD&A for their decision-making. We posit that the MD&A disclosure quality is associated with the level of audit efforts. Methods: We hand-collect the disclosure data from the Financial Supervisory Service of Korea (the Korean SEC). Results: By employing two measures of audit efforts, we document evidence that the quality of MD&A is associated with both audit hours and audit fees. Conclusion: It implies that the auditors perform intensive audit work for companies with high-quality disclosure of MD&A. The study contributes to the literature by providing the first approach to examine the association between the MD&A disclosure and audit efforts.

• Journal of the Korean Mathematical Society
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• v.46 no.6
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• pp.1179-1192
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• 2009

In this note we give a new generalization of the notions of $Pr{\ddot{U}}fer$ domain and PvMD which uses quasi semistar invertibility, the "quasi P$\star$MD", and compare them with the P$\star$MD. We show in particular that the problem of when a quasi P$\star$MD is a P$\star$MD is strictly related to the problem of the descent to subrings of the P$\star$MD property and we give necessary and sufficient conditions.

• Journal of Korea Multimedia Society
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• v.12 no.1
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• pp.1-15
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• 2009

This paper presents an assignment method of the multidimensional type inheritance indexes (MD-TIXs) to support the processing of XML queries in XML databases. MD-TIX uses a multidimensional index structure for efficiently supporting nested predicates that involve both nested element and type inheritance hierarchies. In this paper, we have analyzed the strategy of the query processing by using the MD-TIXs, and presented an assignment method of the MD-TIXs in the framework of complex queries, containing conjunctions of nested predicates, each one involving an Xpath having target types or domain types substitution. We first consider MD-TIX operations caused by updating of XML data-bases, and the use of the MD-TIXs in the case of a query containing a single nested predicate. And then, we consider the assignments of the MD-TIXs in the framework of more general queries containing nested predicates over overlapping paths that have common subpaths.

• The Journal of Asian Finance, Economics and Business
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• v.5 no.4
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• pp.67-72
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• 2018

The purpose of this study is to investigate the effect of quality of management discussion and analysis (MD&A) disclosure on stock price crash risk. The MD&A can be seen to reflect the management's intention on public announcement and reveals directly what the management says to communicate with outside investors. A firm's high-quality MD&A implies the management's commitment to communicating with the market, not allowing the managers to have incentives to hoard unfavorable news, which if revealed to the public, may lead to downward stock price corrections, damaging corporate values. The high-quality MD&A is, thus, likely to reduce the stock price crash risk. We use a logistic regression to test whether MD&A influences crash risk using listed companies in the Korean Stock Exchange (KSE) stock market between 2010 and 2013. Findings of the empirical test show that the higher the quality of MD&A, the less likely crash risk appears, implying that the MD&A disclosed adequately can be one of the factors mitigating firm's stock price crash risk. This study has implications as it presents the MD&A disclosure as a factor influencing stock price crash risk and suggests voluntary disclosure as well as mandatory disclosure acts as a variable that explains the risk of stock price crash.

• The Journal of Engineering Geology
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• v.11 no.3
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• pp.269-278
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• 2001

We describe the calculation of thermal expansion coefficients of $\alpha$-quartz, muscovite and albite using a MD simulation method. The selection of interatomic potentials is important for the MD calculation, and we used the 2-body interatomic potential function. The coefficients are calculated using a differential operation of the temperature dependence of the lattice constant obtained from the NPT-ensemble molecular dynamics simulation. Reasonable agreement is found between the analytical results and measured data.

• Journal of Information Technology Services
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• v.22 no.4
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• pp.21-35
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• 2023

Software as Medical Devices (SaMD) is a growing category of medical devices that are composed of software to perform one or more medical purposes. SaMD is less likely to cause physical harm compared to conventional medical devices, particularly medical electrical equipments, and may be more vulnerable to privacy issues. This difference was acknowledged and resulted in introducing new regulation guidance specifically for cybersecurity of SaMD. It guides stakeholders of SaMD what to consider in what context in terms of cybersecurity. This study examines the current guidance of how cybersecurity is considered for SaMD by analyzing current medical device standards, then suggest which concept or details beyond current medical device standards may be applicable through analysis of international standards documents published for software in general.

• Journal of Internet Computing and Services
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• v.7 no.1
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• pp.39-47
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• 2006

The evaluation of MDx family hash functions such as MD5 is difficult because the design background or a generalized model is unknown. In this paper, an approximated model is proposed to generalize hash functions. The diffusion of a input difference is tested by an approximated model for MD5. The results show that MD5 does not provide perfect diffusion, so MD5 is weak against some attacks. We propose a multiple chaining pattern which provides perfect diffusion in approximated model of hash function without extra calculation or memory. And We show the probability of differential characteristics of our proposal.

• The korean journal of orthodontics
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• v.41 no.3
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• pp.184-190
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• 2011

Objective: The purpose of this study was to investigate the relationship between the enamel thickness of proximal surfaces and the morphologic features of mandibular incisors. Methods: Mesiodistal/faciolingual (MD/FL) index, MD width, and height of contour width/cervical width ratio were measured in 40 incisors extracted from Koreans. For determining the height of contour width/cervical width ratio, the cervical width was measured as the distance between proximal cementoenamel junctions. Then, the labial surface was ground to the height of the contour level to measure enamel thickness. Pearson correlation analysis was used to investigate the correlation between enamel thickness and morphologic features. Results: Enamel thickness was $0.75{\pm}0.07mm$ per side, and MD width was $5.56{\pm}0.40mm$. Enamel thickness and MD width were significantly correlated. However, a significant relationship was not observed between enamel thickness and MD/FL index or the height of contour width/cervical width ratio. Conclusions: The results suggest that enamel thickness is affected only by MD width. Therefore, if the MD width is the same for mandibular incisors with a large MD/FL index or triangular shape and mandibular incisors with normal shape, then the limit of enamel reduction for reproximation will be the same.