• 스마트미디어저널
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• 제8권4호
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• pp.25-32
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• 2019

인터넷의 발달로 많은 정보에 쉽게 접근할 수 있게 되었지만, 이에 따라 악의적인 목적을 가진 프로그램의 침입 경로가 다양해졌다. 그리고 전통적인 시그니처 기반 백신은 변종 및 신종 악성코드의 침입을 탐지하기 어렵기 때문에 많은 사용자들이 피해를 입고 있다. 시그니처로 탐지할 수 없는 악성코드는 분석가가 직접 실행시켜 행위를 분석해 볼 수 있지만, 변종의 경우 대부분의 행위가 유사하여 비효율적이라는 문제점이 있다. 본 논문에서는 변종이 대부분의 행위가 유사하다는 것에 착안하여 기존 악성코드와의 행위 유사성을 이용한 탐지 방법을 제안한다. 제안 방법은 변종들이 공통적으로 가지는 행위 대상과 유사한 행위 대상을 갖는 프로그램을 탐지하는 것이다. 1,000개의 악성코드를 이용해 실험한 결과 변종의 경우 높은 유사도를 보이고, 아닐 경우 낮은 유사도를 보여 행위 유사도로 변종을 탐지할 수 있음을 보였다.

• Archives of Plastic Surgery
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• 제50권4호
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• pp.384-388
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• 2023

Gorlin-Goltz syndrome, also known as nevoid basal cell carcinoma syndrome, is an autosomal dominant disease characterized by multisystemic developmental defects caused by pathogenic variants such as patched-1 (PTCH1) gene variants and/or SUFU gene variants. The presence of either two main criteria or one major and two minor criteria are required for the diagnosis of Gorlin-Goltz syndrome. Recently, a major criterion for molecular confirmation has also been proposed. In this article, we report the case of an 80-year-old male who was admitted at our department for multiple brown-to-black papules and plaques on the entire body. He was diagnosed with Gorlin-Goltz syndrome with clinical, radiologic, and pathologic findings. While the diagnosis was made based on the clinical findings in general, confirmation of the genetic variants makes an ideal diagnosis and suggests a new treatment method for target therapy. We requested a genetic test of PTCH1 to ideally identify the molecular confirmation in the hedgehog signaling pathway. However, no pathogenic variants were found in the coding region of PTCH1, and no molecular confirmation was achieved.

• 대한영상의학회지
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• 제85권3호
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• pp.488-504
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• 2024

정상 변이란 일반적으로 무증상이며 우연히 발견되는 영상 소견을 의미하며, 병적 상태와 유사한 소견을 보일 수 있다. 소아 뼈의 정상 변이를 인지하기 위해서는 장관 골 및 이차 골화 중심의 발달 과정에 대한 이해가 필요하다. 정상 변이의 다양한 영상의학적 소견에 익숙해진다면 불필요한 추가 영상 검사 및 잘못된 진단과 치료를 방지할 수 있다. 본 종설에서는 성장하는 소아의 뼈에서 보이는 정상 변이들의 특징적인 영상 소견과 이를 병적 상태와 구별하기 위한 방법들에 대해서 논의하고자 한다.

• 충청수학회지
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• 제24권2호
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• pp.141-146
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• 2011

Kou et al. presented a class of new variants of Ostrowski's method in their paper (J. of Comput. Appl. Math., 209(2007), pp.153-159) whose title is "Some variants of Ostrowski's method with seventh-order convergence". They proposed an incorrect error equation, although they showed a correct seventh-order of convergence. The main objective of this note is to establish the correct error equation of the method and confirm its validity via concrete numerical examples.

• Biotechnology and Bioprocess Engineering:BBE
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• 제4권1호
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• pp.12-16
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• 1999

Xenorhabdus nematophilus sp., an insect-pathogenic bacterium, was newly isolated from Korean entomopathogenic nematode of Steinernema carpocapsae, which can be used as a useful bioinsecticide. Primary and secondary form variants of Xenorhabdus nematophilus were observed when cultured in vitro. Primary form variants adsorbed bromothymol blue, while secondary form did not. However, many other characters of two variants were very similar. The variants were all rod-shaped and cell size was highly variable ranging from 0.5 by 2.0 ${\mu}$m to 1.0 by 5.0 ${\mu}$m. Both produced highly toxic substances and killed the insect larva within 20∼38 hr, indicating that insect pathogenicity of Xenorhabdus is not directly associated with its phase variation. In addition, cell-free culture supernatant of Xenorhabdus was sufficient to kill the insect larva by injecting it ito insect hemolymph; however, cell-harboring culture broth was more effective for killing the insect. The use of Xenorhabdus nematophilus may provide a potential alternative to Bacillus thuringiensis (Bt) toxins.

• ETRI Journal
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• 제22권4호
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• pp.25-31
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• 2000

Design of secure and efficient public-key encryption schemes under weaker computational assumptions has been regarded as an important and challenging task. As far as ElGamal-type encryption schemes are concerned, some variants of the original ElGamal encryption scheme based on weaker computational assumption have been proposed: Although security of the ElGamal variant of Fujisaki-Okamoto public -key encryption scheme and Cramer and Shoup's encryption scheme is based on the Decisional Diffie-Hellman Assumption (DDH-A), security of the recent Pointcheval's ElGamal encryption variant is based on the Computational Diffie-Hellman Assumption (CDH-A), which is known to be weaker than DDH-A. In this paper, we propose new ElGamal encryption variants whose security is based on CDH-A and the Elliptic Curve Computational Diffie-Hellman Assumption (EC-CDH-A). Also, we show that the proposed variants are secure against the adaptive chosen-ciphertext attack in the random oracle model. An important feature of the proposed variants is length-efficiency which provides shorter ciphertexts than those of other schemes.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권6호
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• pp.2835-2850
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• 2016

RSA is a public key cryptosystem that is currently the most popularly used in information security. Development of RSA variants has attracted many researchers since its introduction in 1978 by Ron Rivest, Adi Shamir, and Leonard Adleman. In this paper, we propose an algebraic structure for RSA and show that the proposed structure covers all known RSA variants. The usefulness of the proposed structure is then proved by showing that, following the structure we can construct a RSA variant based on the Bergman ring. We compare the original RSA and its variants from the point of view of factoring the modulus to determine why the original RSA is widely used than its variants.

• Genomics & Informatics
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• 제17권4호
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• pp.46.1-46.7
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• 2019

The implications of germline de novo variants (DNVs) in diseases are well documented. Despite extensive research, inconsistencies between studies remain a challenge, and the distribution and genetic characteristics of DNVs need to be precisely evaluated. To address this issue at the whole-genome scale, a large number of DNVs identified from the whole-genome sequencing of 1,902 healthy trios (i.e., parents and progeny) from the Simons Foundation for Autism Research Initiative study and 20 healthy Korean trios were analyzed. These apparently nonpathogenic DNVs were enriched in functional elements of the genome but relatively depleted in regions of common copy number variants, implying their potential function as triggers of evolution even in healthy groups. No strong mutational hotspots were identified. The pathogenicity of the DNVs was not strongly elevated, reflecting the health status of the cohort. The mutational signatures were consistent with previous studies. This study will serve as a reference for future DNV studies.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 2004년도 춘계공동학술대회 논문집
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• pp.409-412
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• 2004

Today, meta-heuristic algorithms have been much attention by researcher because they have the power of solving combinational optimization problems efficiently. As the result, many variants of a meta-heuristic algorithm (e.g., simulated annealing) have been proposed for specific application domains. However, there are few efforts to classify them into a unified software framework, which is believed to provide the users with the reusability of the software, thereby significantly reducing the development time of algorithms. In this paper, we present an object-oriented framework to be used as a general tool for efficiently developing variants of simulated annealing algorithm. The interface classes in the framework achieve the modulization of the algorithm, and the users are allowed to specialize some of the classes appropriate for solving their problems. The core of the framework is Algorithm Configuration Pattern (ACP) which facilitates creating user-specific variants flexibly. Finally, we summarize our experiences and discuss future research topics.

• 소성∙가공
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• 제19권7호
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• pp.416-422
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• 2010

The $\{10\bar{1}2\}$ twinning characteristics, such as active twin variants, volume fraction of twins with strain, twin morphology, twin texture and angle relationship between twins, were dependent on the activation mode (i.e., tension parallel to the caxis or compression perpendicular to the c-axis). The selection criterion of active twin variants was governed by the Schmid law. This activation of selected twin variants depending on the activation mode consequently caused a totally different plastic deformation behavior in two activation modes. The differences in the deformation characteristics, such as flow stress and work hardening rate, between both activation modes were explained in relation with activation stresses for slips and twinning, relative activities of twinning and slips during plastic deformation, grain refining effect by twin boundaries (Hall-Petch effect), and twinning-induced change in activities of slips.