• Journal of the Korea Institute of Information Security & Cryptology
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• v.23 no.1
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• pp.11-18
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• 2013

In order to prevent tampering and reverse engineering of executive code, this paper propose a new tamper resistant software mechanism. This paper presents a cryptographic MAC function and a relationship which has its security level derived by the importance of code block instead of by merely getting the encryption and decryption key from the previous block. In this paper, we propose a cryptographic MAC function which generates a dynamic MAC function key instead of the hash function as written in many other papers. In addition, we also propose a relationships having high, medium and low security levels. If any block is determined to have a high security level then that block will be encrypted by the key generated by the related medium security level block. The low security block will be untouched due to efficiency considerations. The MAC function having this dynamic key and block relationship will make analyzing executive code more difficult.

• Journal of the Korean Regional Science Association
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• v.36 no.2
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• pp.3-12
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• 2020

Recently, metropolitanization and suburbization have been occurring mainly in large cities, and spatial miss-match between residential and employment areas has increased. Spatial miss-match is different in the metropolitan cities and other metropolitan cities in Korea. Seoul and other metropolitan cities have grown to become centers of business functions, while other metropolitan cities have been transformed into residential function centers. Accordingly, The reverse commuting phenomenon is occurring in the rural metropolitan. The reverse commuting phenomenon limits the employment opportunities of specific classes among urban residents, and cause various problems such as environmental pollution and traffic congestion. Therefore, many studies on spatial mismatch and reverse commuting have been conducted, but a number of studies have been conducted on the Seoul metropolitan area, and research on other metropolitan areas is insufficient. The purpose of this study is to analyze the cause of the commuting phenomenon in the metropolitan area of the non-metropolitan area by considering spatial mismatch and understanding the reverse commutation situation in the local metropolitan area. This study is analyzed by a multi-level model and suggests the need for management of industrial location and expansion of residence in suburban.

• Clinics in Shoulder and Elbow
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• v.14 no.1
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• pp.125-133
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• 2011

Purpose: The purpose of the present article is to help orthopedic surgeons better understand the function and performance of reverse total shoulder arthroplasty, and also to help them perform the most proper surgical technique for reconstruction. Materials and methods: In this article, the specific technical aspects and pitfalls of reverse total shoulder arthroplasty were reviewed in depth. Additionally, the current issues relevant to the reverse total shoulder arthroplasty such as scapular notching and restoration of active external rotation were discussed. Results and conclusion: An understanding of the biomechanics of reverse total shoulder arthroplasty and the technical details and pitfalls of its implantation are critical in order to provide the best functional outcome without increasing the risk of complications.

• Korean Journal of Culture and Social Issue
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• v.21 no.1
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• pp.45-66
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• 2015

This study explored the moderating effects of social supports (family support, home friends support, foreign friends support) and cultural identity (home identity, foreign identity) on the relationships of reverse culture shock and subjective well-being. Participants were 157 returnees who left home-country prior to the age of 19 and resided in the foreign-country for more than three years. The results of hierarchical regression analyses on two-way interaction effect between reverse culture shock and each hypothesized moderator (e.g., family support, home friends support, foreign friends support, home identity, foreign identity) indicated that reverse cultural shock and subjective well-being was negatively related and their relationship was moderated only by family support. Specifically, the relationship between reverse culture shock and subjective well-being was weaker when the level of family support was higher. Subsequently, three-way interaction among reverse culture shock, one of the social support factors, and one of the cultural identity factors was investigated using hierarchical regression analyses. The results showed that the three-way interaction among reverse culture shock, family support, and home identity was significant. The slope difference tests yielded that the relationship between reverse culture shock and subjective well-being was stronger when both levels of family support and home identity were lower compared to when either level of family support or home identity was higher. These results imply that environmental factors such as family support and intrapsychic factor such as home identity might function as a buffer against the negative consequences of reverse culture shock experience.

• Kyungpook Mathematical Journal
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• v.49 no.3
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• pp.563-572
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• 2009

In this paper, by introducing some parameters and using the way of weight function, a new integral inequality with a best constant factor is given, which is a relation between Hilbert's integral inequality and a Hilbert-type inequality. As applications, the equivalent form, the reverse forms and some particular inequalities are considered.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.36 no.10
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• pp.713-718
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• 1987

A new method for the modeling of non-ideal dc-dc converters whose switching times are finite is proposed. The effects of finite turn-on, turn-off times, delay time, storage time, reverse recovery process on the system stability, dc transfer function and efficiency are investigated. It is verified how system poles are changed and how dc transfer function and efficiency are decreased by non-ideal switching.

• Kyungpook Mathematical Journal
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• v.50 no.2
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• pp.281-288
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• 2010

By introducing some parameters and using the way of weight function and the technic of real analysis and complex analysis, a new Hilbert-type integral inequality with a best constant factor and a combination kernel involving two mean values is given, which is an extension of Hilbert's integral inequality. As applications, the equivalent form and the reverse forms are considered.

• Communications of the Korean Mathematical Society
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• v.34 no.2
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• pp.573-583
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• 2019

This article studies the monotonicity, log-convexity of the modified Lommel functions by using its power series and infinite product representation. Some properties for the ratio of the modified Lommel functions with the Lommel function, sinh and cosh are also discussed. As a consequence, $Tur{\acute{a}}n$ type and reverse $Tur{\acute{a}}n$ type inequalities are given. A Rayleigh type function for the Lommel functions are derived and as an application, we obtain the Redheffer-type inequality.

• Kyungpook Mathematical Journal
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• v.54 no.1
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• pp.1-9
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• 2014

We build new Hilbert-type integral inequalities in the whole plane with the non-homogeneous kernel involving some parameters and the best constant factors. We also consider their reverse.

• Kyungpook Mathematical Journal
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• v.49 no.2
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• pp.393-401
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• 2009

By introducing a parameter and estimating the weight coefficient, we obtain a new Hilbert-type integral inequality with a composite kernel and a best constant factor. As applications, we also consider its equivalent forms and reverse forms.