• Title/Summary/Keyword: frequency multiplication

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Implementation of a pipelined Scalar Multiplier using Extended Euclid Algorithm for Elliptic Curve Cryptography(ECC) (확장 유클리드 알고리즘을 이용한 파이프라인 구조의 타원곡선 암호용 스칼라 곱셈기 구현)

  • 김종만;김영필;정용진
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.11 no.5
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    • pp.17-30
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    • 2001
  • In this paper, we implemented a scalar multiplier needed at an elliptic curve cryptosystem over standard basis in $GF(2^{163})$. The scalar multiplier consists of a radix-16 finite field serial multiplier and a finite field inverter with some control logics. The main contribution is to develop a new fast finite field inverter, which made it possible to avoid time consuming iterations of finite field multiplication. We used an algorithmic transformation technique to obtain a data-independent computational structure of the Extended Euclid GCD algorithm. The finite field multiplier and inverter shown in this paper have regular structure so that they can be easily extended to larger word size. Moreover they can achieve 100% throughput using the pipelining. Our new scalar multiplier is synthesized using Hyundai Electronics 0.6$\mu\textrm{m}$ CMOS library, and maximum operating frequency is estimated about 140MHz. The resulting data processing performance is 64Kbps, that is it takes 2.53ms to process a 163-bit data frame. We assure that this performance is enough to be used for digital signature, encryption & decryption and key exchange in real time embedded-processor environments.

Comparison of Bone Scan Findings with Collagenase Activities in Patients with Breast Cancer (유방암 환자에서 종양조직내 Collagenase 활성도와 골스캔과의 비교)

  • Kim, Hyun-Jeong;Kim, Chang-Guhn;Kim, Seon-Gu;Lim, Hyung-Guhn;Choi, See-Sung;Roh, Byung-Suk
    • The Korean Journal of Nuclear Medicine
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    • v.30 no.3
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    • pp.332-337
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    • 1996
  • Purpose : It has been known that the activity of extracellular matrix degradative enzymes such as collagenase correlate well with the metastatic potential of various tumor cells in experimental study. This study was aimed at comparing the activities of type IV collagenase with bone scan findings in patients with breast cancer. Materials and Methods : We retrospectively correlated bone scan findings with the results of immunohistochemical staining for 92kDa, 72kDa type IV collagenase in 28, and 30 patients with metastatic breast cancer, respectively, as well as 23, and 27 patients with primary breast cancer, respectively. The immunohistochemical staining was performed with tissue specimens obtained from primary or metastatic breast tumor lesions. The amounts of the enzyme were graded from 0 to 4 and scored by multiplication with the percentage of tumor cells. The confidence of bone scan interpretation for metastasis was also scored from 1 to 5 with increasing probability. Results : There was a significant difference in enzyme scores between patients with and without metastasis. In patients with primary breast cancer group, the frequency of patients with enzyme score of less than 170 were 96%(26/27) and 100%(26/26) with 92kDa and 72kDa collagenase, respectively. In contrast, in patients with metastatic breast cancer group, the frequency of patients with enzyme score of more than 200 were 93%(28/30) and 87%(26/30) with 92kDa and 72kDa collagenase, respectively. All patients with each enzyme score of less than 170 show no active bony metastasis, however, there were variable bone scan findings in patients with each enzyme score of more than 200. Conclusion : Bone scan is useful to confirm, localize or follow up of bony metastasis in patients with each enzyme scores of more than 200. Acitve metastatic lesions were hardly seen on the bone scintigraphy in patients with collagenase scores of less than 170.

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Elimination of Grapevine fleck virus from infected grapevines 'Kyoho' through meristem-tip culture of dormant buds (휴면아 경정 배양법을 통한 포도 '거봉' 에서 Grapevine fleck virus의 제거)

  • Kim, Mi Young;Cho, Kang Hee;Chun, Jae An;Park, Seo Jun;Kim, Se Hee;Lee, Han Chan
    • Journal of Plant Biotechnology
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    • v.44 no.4
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    • pp.401-408
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    • 2017
  • Herein, we report the meristem-tip culture from dormant buds of grape 'Kyoho' single-infected with Grapevine fleck virus (GFkV), which is phloem-limited and transmitted by graft inoculation. We produced GFkV-free shoots without thermo- or chemotherapy using meristem-tip explants approximately 0.3 mm (73 explants) and 0.8 mm long (five explants) including shoot apical meristem, 2-5 leaf primordia, and 1-4 uncommitted primordia from dormant buds of the infected woody cuttings (stored at $4^{\circ}C$). Explants were cultured on Murashige and Skoog (MS) medium supplemented with 3% sucrose, 3.0 mg/L benzyladenine (BA) and 0.1 mg/L indole-3-butyric acid (IBA). After 16 weeks of culture, shoot (10-mm long) regeneration frequency achieved from 0.3-mm explants was 4.1% and that obtained from 0.8-mm explants was 40.0%. Virus-free efficiency (expressed as the percentage of RT-PCR negative shoots regenerated) from 0.3- and 0.8-mm explants was 100% and 50%, respectively. Following in vitro multiplication, RT-PCR assays revealed identical results to assays of the first regenerated shoots. Our new methodological approach could be applied for eliminating other viruses in grapevines, as well as for producing virus-free plants in many other deciduous tree species, including fruit trees.

A Folksonomy Ranking Framework: A Semantic Graph-based Approach (폭소노미 사이트를 위한 랭킹 프레임워크 설계: 시맨틱 그래프기반 접근)

  • Park, Hyun-Jung;Rho, Sang-Kyu
    • Asia pacific journal of information systems
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    • v.21 no.2
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    • pp.89-116
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    • 2011
  • In collaborative tagging systems such as Delicious.com and Flickr.com, users assign keywords or tags to their uploaded resources, such as bookmarks and pictures, for their future use or sharing purposes. The collection of resources and tags generated by a user is called a personomy, and the collection of all personomies constitutes the folksonomy. The most significant need of the folksonomy users Is to efficiently find useful resources or experts on specific topics. An excellent ranking algorithm would assign higher ranking to more useful resources or experts. What resources are considered useful In a folksonomic system? Does a standard superior to frequency or freshness exist? The resource recommended by more users with mere expertise should be worthy of attention. This ranking paradigm can be implemented through a graph-based ranking algorithm. Two well-known representatives of such a paradigm are Page Rank by Google and HITS(Hypertext Induced Topic Selection) by Kleinberg. Both Page Rank and HITS assign a higher evaluation score to pages linked to more higher-scored pages. HITS differs from PageRank in that it utilizes two kinds of scores: authority and hub scores. The ranking objects of these pages are limited to Web pages, whereas the ranking objects of a folksonomic system are somewhat heterogeneous(i.e., users, resources, and tags). Therefore, uniform application of the voting notion of PageRank and HITS based on the links to a folksonomy would be unreasonable, In a folksonomic system, each link corresponding to a property can have an opposite direction, depending on whether the property is an active or a passive voice. The current research stems from the Idea that a graph-based ranking algorithm could be applied to the folksonomic system using the concept of mutual Interactions between entitles, rather than the voting notion of PageRank or HITS. The concept of mutual interactions, proposed for ranking the Semantic Web resources, enables the calculation of importance scores of various resources unaffected by link directions. The weights of a property representing the mutual interaction between classes are assigned depending on the relative significance of the property to the resource importance of each class. This class-oriented approach is based on the fact that, in the Semantic Web, there are many heterogeneous classes; thus, applying a different appraisal standard for each class is more reasonable. This is similar to the evaluation method of humans, where different items are assigned specific weights, which are then summed up to determine the weighted average. We can check for missing properties more easily with this approach than with other predicate-oriented approaches. A user of a tagging system usually assigns more than one tags to the same resource, and there can be more than one tags with the same subjectivity and objectivity. In the case that many users assign similar tags to the same resource, grading the users differently depending on the assignment order becomes necessary. This idea comes from the studies in psychology wherein expertise involves the ability to select the most relevant information for achieving a goal. An expert should be someone who not only has a large collection of documents annotated with a particular tag, but also tends to add documents of high quality to his/her collections. Such documents are identified by the number, as well as the expertise, of users who have the same documents in their collections. In other words, there is a relationship of mutual reinforcement between the expertise of a user and the quality of a document. In addition, there is a need to rank entities related more closely to a certain entity. Considering the property of social media that ensures the popularity of a topic is temporary, recent data should have more weight than old data. We propose a comprehensive folksonomy ranking framework in which all these considerations are dealt with and that can be easily customized to each folksonomy site for ranking purposes. To examine the validity of our ranking algorithm and show the mechanism of adjusting property, time, and expertise weights, we first use a dataset designed for analyzing the effect of each ranking factor independently. We then show the ranking results of a real folksonomy site, with the ranking factors combined. Because the ground truth of a given dataset is not known when it comes to ranking, we inject simulated data whose ranking results can be predicted into the real dataset and compare the ranking results of our algorithm with that of a previous HITS-based algorithm. Our semantic ranking algorithm based on the concept of mutual interaction seems to be preferable to the HITS-based algorithm as a flexible folksonomy ranking framework. Some concrete points of difference are as follows. First, with the time concept applied to the property weights, our algorithm shows superior performance in lowering the scores of older data and raising the scores of newer data. Second, applying the time concept to the expertise weights, as well as to the property weights, our algorithm controls the conflicting influence of expertise weights and enhances overall consistency of time-valued ranking. The expertise weights of the previous study can act as an obstacle to the time-valued ranking because the number of followers increases as time goes on. Third, many new properties and classes can be included in our framework. The previous HITS-based algorithm, based on the voting notion, loses ground in the situation where the domain consists of more than two classes, or where other important properties, such as "sent through twitter" or "registered as a friend," are added to the domain. Forth, there is a big difference in the calculation time and memory use between the two kinds of algorithms. While the matrix multiplication of two matrices, has to be executed twice for the previous HITS-based algorithm, this is unnecessary with our algorithm. In our ranking framework, various folksonomy ranking policies can be expressed with the ranking factors combined and our approach can work, even if the folksonomy site is not implemented with Semantic Web languages. Above all, the time weight proposed in this paper will be applicable to various domains, including social media, where time value is considered important.