• Journal of the Korea Society of Computer and Information
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• v.17 no.9
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• pp.65-73
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• 2012

The traditional text-based password is vulnerable guessing, dictionary attacks, keyloggers, social engineering, stole view, etc. these vulnerability effect more serious problem in a mobile environment. In this study, By using the pattern number to enter the password of an existing four-digit numeric password, User easily use to new password system. The technology on pattern based numerical password authorization proposed in this paper would intensify the security of password which holds existing 10 numbers of cases by authorizing a user and would not invade convenience of use by providing high security and making users memorize only four numbers like old method. Making users not have inconvenience and raising complexity, it would have a strength to an shoulder surfing attack of an attacker. So I study password system that represents the shape-based of number. I propose the new password system to prevent peeking attacks and Brute-force attack, and this proposal is to review the security and usability.

• Korean Institute of Interior Design Journal
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• v.27 no.3
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• pp.49-61
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• 2018

Korea achieved compressed growth through rapid industrialization. However, the housing policy of this period was driven by the provision of large scale public rental housing and redevelopment of residential areas, resulting in community collapse and social exclusion. Meanwhile, Korean society needs new housing types and management methods as housing demand varies due to low birthrate, aging, and growing numbers of single-person households. Therefore, in order to realize social integration community that solves these problems by themselves, it is necessary to plan housing that can enhance community in residential space. In this reason, the purpose of this study is to derive the characteristics of social integration plan of community housing which is supplied mainly in the metropolitan area. Accordingly, the subjects of this study were housing cases designed to enhance social integration by promoting community activation in Seoul and Gyeonggi-do. The results of this study are as follows: First, it is necessary to flexibly apply the type and range of community housing. Second, It is needed to have a housing plan considering various characteristics of resident community. Third, social integrated community housing requires not only physical planning, but also mechanism to operate it.

• Korean Journal of Construction Engineering and Management
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• v.4 no.4 s.16
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• pp.114-122
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• 2003

Dynamic and fragmented characteristics are two of the most significant factors that distinguish the construction industry from other industries. Previous forecasting techniques have failed to solve the problems derived from the above characteristics, and do not provide considerable support This paper deals with providing a more precise forecasting by applying Case-based Reasoning (CBR). The newly developed model in this study enables project managers to forecast monthly expenditures with less time and effort by retrieving and referring only projects of a similar nature, while filtering out irrelevant cases included in database. For the purpose of accurate forecasting, the choice of the numbers of referring projects was investigated. It is concluded that selecting similar projects at $5{\~}6{\%}$ out of the whole database will produce a more precise forecasting. The new forecasting model, which suggests the predicted values based on previous projects, is more than just a forecasting methodology; it provides a bridge that enables current data collection techniques to be used within the context of the accumulated information. This will eventually help all the participants in the construction industry to build up the knowledge derived from invaluable experience.

• Advances in pediatric surgery
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• v.7 no.2
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• pp.147-156
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• 2001

Membership qualifications and recognition of the subspecialty training programs by the Korean Association of Pediatric Surgeons(KAPS) have been determined by criteria based on the number of neonatal and total pediatric surgical cases registered, since 1989 (Index cases). The numbers are based on a survey of the 14 founding members of the society by Jung et al. in 1987. The current survey is to review the present status of the index cases from 1997 to 1999 among 36 members of the KAPS. Two surveys were undertaken for this study. In the first survey, cases were collected by the registration form, composed of neonatal(N), important pediatric surgical cases (I), tumor and other similar operations(T) and other common pediatric surgical cases(O). Thirty members responded. and the result was discussed at the Topic Discussion section of the 15th Annual Congress of KAPS, 2000. The second survey analyzed additive data, proposed during discussion at the Congress. Twenty-three members responded. This report is the analysis of the both surveys. The average numbers of the cases/year/surgeon of N, I, T, O and total were 19.5, 51.8, 9.5, 77.1 and 356.5. respectively. The number of index cases(N+I+T)/year/surgeon was 80.8. The ratio of (N+I+T)/total cases was 0.3. Seventeen of 30 members have more than 20 cases of N per year. Twelve members have more than 150 cases, and 13 do more than 100 cases of I per year. Fourteen members have more than 10 cases of T per year. Nineteen and 10 members experienced more than 150 and 100 of index cases(N+I+T) per year. A new list of the index cases and coding system are proposed for the future regular update.

• Honam Mathematical Journal
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• v.37 no.3
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• pp.339-352
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• 2015

We aim at giving explicit expressions of $${\sum_{m,n=0}^{{\infty}}}{\frac{{\Delta}_{m+n}(-1)^nx^{m+n}}{({\rho})_m({\rho}+i)_nm!n!}$$, where i = 0, ${\pm}1$, ${\ldots}$, ${\pm}9$ and $\{{\Delta}_n\}$ is a bounded sequence of complex numbers. The main result is derived with the help of the generalized Kummer's summation theorem for the series $_2F_1$ obtained earlier by Choi. Further some special cases of the main result considered here are shown to include the results obtained earlier by Kim and Rathie and the identity due to Bailey.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.3116-3121
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• 2007

In this paper, the inverse shape design is introduced using the permeable wall boundary condition. Inverse shape design defines the blade shape for the prescribed Mach numbers or pressure distribution on its surface. It calculates the normal mass flux from the difference between the calculated and prescribed pressure at the surface. A new geometry can be achieved after applying the quasi one-dimensional continuity equation from the leading edge to the trailing edge. For validation of this method, two test cases are studied. The first test case of inverse shape design illustrates the cosine bump with a strong shock. After seven geometry modifications, the shock-free bump geometry can be obtained. The second example concerns the redesign of a transonic turbine cascade. The initial isentropic Mach distribution has a peak on the upper surface. The target isentropic Mach number distribution was imposed smoothly. The peak of Mach distribution has disappeared at the final geometry. This proposed inverse design method has proven to be an efficient and robust tool in turbomachinery design fields.

• Journal of the Korean Mathematical Society
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• v.54 no.2
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• pp.479-491
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• 2017

We investigate the zeros of Epstein zeta functions associated with positive definite quadratic forms with rational coefficients in the vertical strip ${\sigma}_1$ < ${\Re}s$ < ${\sigma}_2$, where 1/2 < ${\sigma}_1$ < ${\sigma}_2$ < 1. When the class number h of the quadratic form is bigger than 1, Voronin gave a lower bound and Lee gave an asymptotic formula for the number of zeros. Recently Gonek and Lee improved their results by providing a new upper bound for the error term when h > 3. In this paper, we consider the cases h = 2, 3 and provide an upper bound for the error term, smaller than the one for the case h > 3.

• International journal of advanced smart convergence
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• v.10 no.2
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• pp.10-14
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• 2021

Today people adopt various contents from their mobile devices which lead to numerous platforms. As technology of 5G, IOT, and smart phone develops, the number of people who create, edit, collect, and share their own videos, photos, and articles continues to increase. As more contents are shared online, the numbers of data being stolen continue to increase too. To prevent these cases, an authentication method is needed to encrypt the content and prove it as its own content. In the report, we propose a few methods to secure various misused content with secondary security. A unique private key is designed when people create new contents through sending photos or videos to platforms. The primary security is to encrypt the "Private Key" with a public key algorithm, making its data-specific "Timeset" that doesn't allow third-party users to enter. For the secondary security, we propose to use Message Authentication Codes(MACs) to certify that we have produced the content.

• Korean Journal of Mathematics
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• v.32 no.2
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• pp.285-295
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• 2024

In this work, we consider the function $${\Psi}(z)=\frac{z}{\ln(1+z)}=1+\sum\limits_{n=1}^{\infty}\,G_nz^n$$ whose coefficients G_n are the Gregory coefficients related to Stirling numbers of the first kind and introduce a new subclass ${\mathcal{G}}^{{\lambda},{\mu}}_{\Sigma}(\Psi)$ of analytic bi-univalent functions subordinate to the function Ψ. For functions belong to this class, we investigate the estimates for the general Taylor-Maclaurin coefficients by using the Faber polynomial expansions. In certain cases, our estimates improve some of those existing coefficient bounds.

• Journal of Korean Neurosurgical Society
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• v.29 no.12
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• pp.1600-1605
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• 2000

Objective : World Health Organization and International Labour Organization, in June 8, 1999, requested that working conditions should be reformed ethically right and economically solid for 2.7 billion world labour force. The purpose of this study is to request compensable surgical therapeutic options and to suggest the renewal in cognizance criteria for worker's compensation, especially in spondylolisthesis. Methods : Regarding spondylolisthesis, we obtained data from Korea Labor Welfare Corporation(KLWC). Spinal disease occurrence incidences and medical fees of National Federation of Medical Insurance(NFMI) were analysed. The compensated 122 spinal instrumented cases included 117 male and 5 female patients, aged from 23 to 72 years old(mean : $45{\pm}9.85$). We compared Korean and Foreign Workers Compensation Law. Results : Numbers of herniated nucleus pulpus(78 cases), spinal fractures(34 cases) and dislocations(4 cases) were claimed after spinal interbody fusion operation and were compensated. These compensated degenerative diseases, work related illness, occurred in the course of work. A case of 52-year old spondylolisthesis patient with Disability Grade 8 was compensated by KLWC, according to its occurrence at work by accident. With exception of trauma at work by accident, current cognizance criteria were too narrow to be compensable, especially in surgical therapeutic option, for worker's spondylolisthesis. Conclusion : Considering both worker's compensation law and clinical pathologic progress, we believe that spondylolisthesis should be regarded as a compensable occupation related disease if and when aggravates rapidly in the course of work. We suggest a new cognizance standard to KLWC for labour welfare and proper worker's compensation.