• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제10권10호
• /
• pp.4933-4956
• /
• 2016

Use-After-Free (UAF) is a common lethal form of software vulnerability. By using tools such as Web Browser Fuzzing, a large amount of samples containing UAF vulnerabilities can be generated. To evaluate the threat level of vulnerability or to patch the vulnerabilities, automatic deduplication and exploitability determination should be carried out for these samples. There are some problems existing in current methods, including inadequate pertinence, lack of depth and precision of analysis, high time cost, and low accuracy. In this paper, in terms of key dangling pointer and crash context, we analyze four properties of similar samples of UAF vulnerability, explore the method of extracting and calculate clustering eigenvalues from these samples, perform clustering by fast search and find of density peaks on a large number of vulnerability samples. Samples were divided into different UAF vulnerability categories according to the clustering results, and the exploitability of these UAF vulnerabilities was determined by observing the shape of class cluster. Experimental results showed that the approach was applicable to the deduplication and exploitability determination of a large amount of UAF vulnerability samples, with high accuracy and low performance cost.

• 대한수학회논문집
• /
• 제16권4호
• /
• pp.679-690
• /
• 2001

Doubly stochastic matrices are n$\times$n nonnegative ma-trices whose row and column sums are all 1. Convex polytope $\Omega$$_{n}$ of doubly stochastic matrices and more generally (R,S), so called transportation polytopes, are important since they form the domains for the transportation problems. A theorem by Birkhoff classifies the extremal matrices of , $\Omega$$_{n}$ and extremal matrices of transporta-tion polytopes (R,S) were all classified combinatorially. In this article, we consider signed version of $\Omega$$_{n}$ and (R.S), obtain signed Birkhoff theorem; we define a new class of convex polytopes (R,S), calculate their dimensions, and classify their extremal matrices, Moreover, we suggest an algorithm to express a matrix in (R,S) as a convex combination of txtremal matrices. We also give an example that a polytope of signed matrices is used as a domain for a decision problem. In this context of finite reflection(Coxeter) group theory, our generalization may also be considered as a generalization from type $A_{*}$ n/ to type B$_{n}$ D$_{n}$. n/.

• 영미문화
• /
• 제14권1호
• /
• pp.287-310
• /
• 2014

While Janis Joplin is generally known as a hippie rock star of an untimely death to Korean audience, she is more strongly evoked in the image of blues mama in American context. Blues, definitely based on African-American vernacular tradition, is defined as a matrix, which is "a point of ceaseless input and output, a web of intersecting, crisscrossing impulses always in productive transit," to borrow Houston A. Baker's expression. This article explores how her life and music can be understood in blues tradition, especially in terms of personal and social transgression for which she was criticized, focusing on her blues performance. First of all, born and growing up in southern Texas between 1940s and 1960s, she expressed her innate suspicion against segregation and white supremacy, actively embracing rich black musical heritage of the area. Second, against the normative social and moral expectation of a middle class white woman to be a suburban housewife, she sought her own desire, whether it was professional ambition or sexual possibility. Third, beyond the selling image of a heterosexually lascivious blues mama, she dared to be a homosexual and bisexual, while it was not publically acknowledged. Along with her alcohol and drug dependence, such transgressions against normative social expectation were not made without her inner conflict, leaving a trace of trauma, hesitation, and the blues. While she was "buried alive in the blues," as a sacrifice at the altar of the 1960s, she still remains "alive" provoking "fire inside of everyone of us."

• 공학교육연구
• /
• 제22권5호
• /
• pp.29-36
• /
• 2019

Here we analyze a case of redesigned course named "Prospect of Nuclear Engineering" as an example of student-entered education which came to the fore of university education innovation. This course was reformed from lecture-based to student-centered class by changing the context as follows: Stimulating students by addressing various problems or episodes behind scientific and mathematical concepts in the history; Offering experimental project to perceive the importance of differential equations; Exploring the research status and issues of nuclear engineering and the ways of attacking them by discipline; Discussing the public acceptance of nuclear power plants. Small group activities using 'small group discussion' and 'peer-learning' have been applied in this course to enhance students' critical and creative ability. In the survey, students rated highly in the fact that they could actively interact with the peers and that they could think for themselves through 'small group discussion' and 'peer-learning' which is not just the way of conveying knowledge.

• 한국컴퓨터정보학회논문지
• /
• 제11권4호
• /
• pp.27-33
• /
• 2006

향후 도래하는 유비쿼터스 환경에서는 모든 전자기기가 유/무선 통신망으로 연결되어 사용자는 언제 어디서나 원하는 정보에 접근할 수 있을 것으로 본다. 특히, u-러닝(Ubiquitous-Learning)은 교육학적인 측면뿐 아니라 어디서나 접근할 수 있다는 유비쿼터스적인 측면을 통해 학습의 효과를 보다 향상시킬 수 있어야 한다. 현재까지 추진된 u-러닝의 연구로는, PDA를 이용하여 학습 컨텐츠를 야외에서 학습하거나 원격지 모바일 환경의 학생들을 교실 수업에 참여시키는 스마트교실 등을 들 수가 있는데, 기존의 연구들에서는 학습자의 상호작용이나 협동학습 등의 교육학적인 속성과 유비쿼터스의 환경적 속성을 만족시키지 못하고 있다. 따라서 본 연구에서는 대학 등을 대상으로 어디서나 교실 환경에 참여하는 유비쿼터스 환경에 적합하면서도 교육학적인 면을 만족시키는 모바일 교실 프레임워크를 제안하고자 한다.

• 한국해양공학회지
• /
• 제35권2호
• /
• pp.131-140
• /
• 2021

The paper deals with comparative study of various surrogate models based approximate optimization in the structural design of the passive type deck support frame under design load conditions. The passive type deck support frame was devised to facilitate both transportation and installation of 20,000 ton class topside. Structural analysis was performed using the finite element method to evaluate the strength performance of the passive type deck support frame in its initial design stage. In the structural analysis, the strength performances were evaluated for various design load conditions. The optimum design problem based on surrogate model was formulated such that thickness sizing variables of main structure members were determined by minimizing the weight of the passive type deck support frame subject to the strength performance constraints. The surrogate models used in the approximate optimization were response surface method, Kriging model, and Chebyshev orthogonal polynomials. In the context of numerical performances, the solution results from approximate optimization were compared to actual non-approximate optimization. The response surface method among the surrogate models used in the approximate optimization showed the most appropriate optimum design results for the structure design of the passive type deck support frame.

• Mass Spectrometry Letters
• /
• 제9권4호
• /
• pp.91-94
• /
• 2018

Bilin tetrapyrroles are metabolic products of the breakdown of porphyrins within a species. In the case of mammals, these bilins are formed by the catabolism of heme and can be utilized as either biomarkers in disease or as an indicator of human waste contamination. Although a small subset of bilin tandem mass spectrometry reports exist, limited data is available in online databases for their fragmentation. The use of fragmentation data is important for metabolomics analyses to determine the identity of compounds detected within a sample. Therefore, in this study, the fragmentation of bilins generated by positive ion mode electrospray ionization is examined by collision-induced dissociation (CID) as a function of collision energy on an FT-ICR MS. The use of the FT-ICR MS allows for high mass accuracy measurements, and thus the formulas of resultant product ions can be ascertained. Based on our observations, fragmentation behavior for hemin, biliverdin and its dimethyl ester, phycocyanobilin, bilirubin, bilirubin conjugate, mesobilirubin, urobilin, and stercobilin are discussed in the context of the molecular structure and collision energy. This report provides insight into the identification of structures within this class of molecules for untargeted analyses.

• 대한치과의사협회지
• /
• 제57권3호
• /
• pp.162-168
• /
• 2019

Composite resin restorations in posterior teeth are increasing due to the aesthetic needs of patients and the development of materials. This trend will accelerate in line with domestic insurance policies. However, resin composites generate stresses due to their contraction during the polymerization process. To reduce the polymerization shrinkage stress of resin composites, incremental layering technique has been recommended for decades. This technique reduces stress at the cavity wall interface and allows a more efficient light curing of the material. Bulk-fill resin composites have been designed to simplify the restorative technique because they can be placed into cavities in a single increment of 4-5mm. The simplification of the operative procedures is desirable in clinical daily practice. In this context, bulk-fill resin composites are an attractive alternative for posterior restorations. However, a clearer understanding of the clinical performance of this relatively new class of materials in comparison to conventional resin composites is required. Based on previous studies, the aim of the current review was to present the clinical criteria for the use of bulk-fill composites in direct restorations of posterior teeth.

• 비교문화연구
• /
• 제38권
• /
• pp.461-500
• /
• 2015

This study aims to investigate the effective method to improve the competence of the Vocabulary by the image and listening towards the ELF. In the first part, we observed the problems and point improvement on learning vocabulary based on learner survey. In the second part, we analyzed two remarkable studies: - consistent and adapt method, communicational context - method based on the lexical, morphological semantical, notional and thematic field Then we proposed effective methods that are applicable to the vocabulary's learning in the class : - learning vocabulary by combining the words - learning vocabulary based on the meaning field - learning vocabulary as concrete characters - learning vocabulary by the descriptive character - learning vocabulary with the type "who am I?" - learning vocabulary by listening For teachers, one of the difficulties to the conduct of vocabulary course is that learners take passive position. Specifically, it is the teachers who play an important role because it runs in the direction of the course. However, learners do not show the active attitude for vocabulary lessons despite the course to take to improve their vocabulary skills. Therefore, teachers must prepare course materials that can both improve the competence of the vocabulary of learners and cause their interest or desire on the current vocabulary. This is why teachers should exploit various materials depending on the skill level of the learner vocabulary.

• 대한상한금궤의학회지
• /
• 제13권1호
• /
• pp.81-98
• /
• 2021

Objective : We explored the meaning of "Pyo (表)" in Gangpyeong-Shanghanlun through two cases. Methods : We analyzed the original form of 表 and its context in Shanghanlun. We also analyzed 2 clinical cases of bipolar disorder treated with Mahwang-tang (麻黃湯) according to the newly deduced definition of 表. Results : 表 can be interpreted as "pursuing something high-class seen from the outside." Both cases had various psychological symptoms including insomnia, mood swings, anxiety, and depression. We determined that the diseases in both cases occurred when 表 had not been achieved. We also found that 麻黃湯 can improve psychological status. Conclusions : 表 is different from "surface," which is the most widely used definition. After diagnosing these two patients with bipolar disorder using the Diagnostic and Statistical Manual of Mental Disorders (5^th edition), we found that symptoms could be improved by administration of 麻黃湯 (46條). Although its potential for neuropsychiatric diagnosis has been suggested through etymological interpretation of 表 and analysis of two cases, more advanced clinical studies are needed in the future.