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Fast Squaring in TypeI All One Polynomial Field
Hidehiro Kato,Yasuyuki Nogami,Yoshitaka Morikawa 대한전자공학회 2008 ITC-CSCC :International Technical Conference on Ci Vol.2008 No.7
In this paper, the authors propose a fast squaring on all one polynomial field and show some simulation results with characteristic p = 256-bit prime and extension degree k ∈ {2, 4, 6, 10, 12} implemented on a PentiumIV (2.6㎓) using the C programming language. The computer simulations showed that, on average, the proposed algorithm accelerated about 30% in Fp² , 12% in Fp⁴ and 6% in Fp? compared to the conventional squaring.
Cyclic Vector Multiplication Algorithm Based on a Special Class of Gauss Period Normal Basis
Hidehiro Kato,Yasuyuki Nogami,Tomoki Yoshida,Yoshitaka Morikawa 한국전자통신연구원 2007 ETRI Journal Vol.29 No.6
This paper proposes a multiplication algorithm for Fpm, which can be efficiently applied to many pairs of characteristic p and extension degree m except for the case that 8p divides m(p–1). It uses a special class of type-〈k, m〉 Gauss period normal bases. This algorithm has several advantages: it is easily parallelized; Frobenius mapping is easily carried out since its basis is a normal basis; its calculation cost is clearly given; and it is sufficiently practical and useful when parameters k and m are small.
Clinical Value of CT-Guided Needle Biopsy for Retroperitoneal Lesions
Yuki Tomozawa,Yoshitaka Inaba,Hidekazu Yamaura,Yozo Sato,Mina Kato,Takaaki Kanamoto,Makoto Sakane 대한영상의학회 2011 Korean Journal of Radiology Vol.12 No.3
Objective: The purpose of this study was to investigate retrospectively the clinical procedural performance of CT-guided needle biopsy for retroperitoneal lesions. Materials and Methods: CT-guided needle biopsy was performed in 74 consecutive patients (M:F = 44:30; mean age, 59.7 years) with retroperitoneal lesions between April 1998 and June 2009. The target lesion ranged from 1.5 to 12.5 cm in size. The biopsy access path ranged from 3.5 to 11.5 cm in depth. A biopsy specimen was obtained using an 18-gauge core needle under a CT or CT-fluoroscopy guidance and with the patient under local anesthesia. The histopathological diagnoses from the biopsies were obtained. The diagnostic confirmation of the subtype of lymphoma was evaluated. Results: Satisfactory biopsy samples were obtained in 73 (99%) of 74 patients and a pathological diagnosis was made in 70 (95%) of 74 patients. Sixty three lesions were malignant (45 lymphomas, nine primary tumors, nine lymph node metastases) and seven were benign. The subtype of lymphoma was specified in 43 (96%) of 45 patients who were diagnosed with lymphoma. Analysis of the value of CT-guided biopsy in this series indicated 63 true positives, zero false positive, six true negatives and five false negatives. This test had a sensitivity of 93%, a specificity of 100% and an accuracy of 93%. No major complications were seen and minor complications were noted in seven patients (five with local hematomas, two with transient pain at the puncture site). Conclusion: CT-guided needle biopsy for retroperitoneal lesions is highly practical and useful, and particularly for determining the subtypes in patients with lymphoma. Objective: The purpose of this study was to investigate retrospectively the clinical procedural performance of CT-guided needle biopsy for retroperitoneal lesions. Materials and Methods: CT-guided needle biopsy was performed in 74 consecutive patients (M:F = 44:30; mean age, 59.7 years) with retroperitoneal lesions between April 1998 and June 2009. The target lesion ranged from 1.5 to 12.5 cm in size. The biopsy access path ranged from 3.5 to 11.5 cm in depth. A biopsy specimen was obtained using an 18-gauge core needle under a CT or CT-fluoroscopy guidance and with the patient under local anesthesia. The histopathological diagnoses from the biopsies were obtained. The diagnostic confirmation of the subtype of lymphoma was evaluated. Results: Satisfactory biopsy samples were obtained in 73 (99%) of 74 patients and a pathological diagnosis was made in 70 (95%) of 74 patients. Sixty three lesions were malignant (45 lymphomas, nine primary tumors, nine lymph node metastases) and seven were benign. The subtype of lymphoma was specified in 43 (96%) of 45 patients who were diagnosed with lymphoma. Analysis of the value of CT-guided biopsy in this series indicated 63 true positives, zero false positive, six true negatives and five false negatives. This test had a sensitivity of 93%, a specificity of 100% and an accuracy of 93%. No major complications were seen and minor complications were noted in seven patients (five with local hematomas, two with transient pain at the puncture site). Conclusion: CT-guided needle biopsy for retroperitoneal lesions is highly practical and useful, and particularly for determining the subtypes in patients with lymphoma.
An Improvement of Twisted Ate Pairing Using Integer Variable with Small HammingWeight
Yumi Sakemi,Hidehiro Kato,Yasuyuki Nogami,Yoshitaka Morikawa 대한전자공학회 2008 ITC-CSCC :International Technical Conference on Ci Vol.2008 No.7
Barreto?Naehrig (BN) curve has been introduced as a pairing-friendly elliptic curve over prime field Fp which has embedding degree 12. Characteristic and Frobenius trace are given as polynomials of integer variable χ. This paper proposes an improvement of Miller’s algorithm of twisted Ate pairing with BN curve by χ of small hamming weight. Then, in order to show the efficiency of the proposed method, twisted Ate pairings with BN curve of order r ? 2¹?? and r ? 2²?⁴ are simulated and it is shown that these twisted Ate pairings are carried out with 7.21 milliseconds and 16.5 milliseconds by Pentium4 (3.6㎓), respectively.
Efficient Exponentiation in Extensions of Finite Fields without Fast Frobenius Mappings
Yasuyuki Nogami,Hidehiro Kato,Kenta Nekado,Yoshitaka Morikawa 한국전자통신연구원 2008 ETRI Journal Vol.30 No.6
This paper proposes an exponentiation method with Frobenius mappings. The main target is an exponentiation in an extension field. This idea can be applied for scalar multiplication of a rational point of an elliptic curve defined over an extension field. The proposed method is closely related to so-called interleaving exponentiation. Unlike interleaving exponentiation methods, it can carry out several exponentiations of the same base at once. This happens in some pairing-based applications. The efficiency of using Frobenius mappings for exponentiation in an extension field was well demonstrated by Avanzi and Mihailescu. Their exponentiation method efficiently decreases the number of multiplications by inversely using many Frobenius mappings. Compared to their method, although the number of multiplications needed for the proposed method increases about 20%, the number of Frobenius mappings becomes small. The proposed method is efficient for cases in which Frobenius mapping cannot be carried out quickly.
Extension Field for Ate Pairing with Freeman Curve
Kenta Nekado,Hidehiro Kato,Masataka Akane,Yasuyuki Nogami,Yoshitaka Morikawa 대한전자공학회 2008 ITC-CSCC :International Technical Conference on Ci Vol.2008 No.7
Recently, pairing-based cryptographies such as ID-based cryptography and group signature have been studied. For fast pairing calculation, not only pairing algorithms but also arithmetic operations in extension field must be efficiently carried out. The authors consider efficient arithmetic operations of extension field for Ate pairing especially with Freeman curve.
Yozo Sato,Shigeru Matsushima,Yoshitaka Inaba,Tsuyoshi Sano,Hidekazu Yamaura,Mina Kato,Yasuhiro Shimizu,Yoshiki Senda,Tsuneo Ishiguchi 대한영상의학회 2015 Korean Journal of Radiology Vol.16 No.3
To retrospectively evaluate relative enhancement (RE) in the hepatobiliary phase of gadoxetic acid disodium-enhanced magnetic resonance (MR) imaging as a preoperative estimation of future remnant liver (FRL) function in a patients who underwent portal vein embolization (PVE). In 53 patients, the correlation between the indocyanine green clearance (ICG-K) and RE imaging was analyzed before hepatectomy (first analysis). Twenty-three of the 53 patients underwent PVE followed by a repeat RE imaging and ICG test before an extended hepatectomy and their results were further analyzed (second analysis). Whole liver function and FRL function were calculated on the MR imaging as follows: RE x total liver volume (RE Index) and FRL-RE x FRL volume (Rem RE Index), respectively. Regarding clinical outcome, posthepatectomy liver failure (PHLF) was evaluated in patients undergoing PVE. Indocyanine green clearance correlated with the RE Index (r = 0.365, p = 0.007), and ICG-K of FRL (ICG-Krem) strongly correlated with the Rem RE Index (r = 0.738, p < 0.001) in the first analysis. Both the ICG-Krem and the Rem RE Index were significantly correlated after PVE (r = 0.508, p = 0.013) at the second analysis. The rate of improvement of the Rem RE Index from before PVE to after PVE was significantly higher than that of ICG-Krem (p = 0.014). Patients with PHLF had a significantly lower Rem RE Index than patients without PHLF (p = 0.023). Relative enhancement imaging can be used to estimate FRL function after PVE.
How to Generate a Secure Composite Order Ordinary Pairing-friendly Curve of Embedding Degree 3
Yasuyuki Nogami,Kazushi Nishii,Yumi Sakemi,Hidehiro Kato,Yoshitaka Morikawa 대한전자공학회 2009 ITC-CSCC :International Technical Conference on Ci Vol.2009 No.7
This paper proposes an efficient method for generating secure composite order ordinary pairing?friendly elliptic curves of embedding degree 3. It averagely takes about 22 minutes on Core 2 Duo (3.0㎓).
Sasaki, Yusuke,Hamaguchi, Tetsuya,Yamada, Yasuhide,Takahashi, Naoki,Shoji, Hirokazu,Honma, Yoshitaka,Iwasa, Satoru,Okita, Natsuko,Takashima, Atsuo,Kato, Ken,Nagai, Yushi,Taniguchi, Hirokazu,Boku, Nari Asian Pacific Journal of Cancer Prevention 2016 Asian Pacific journal of cancer prevention Vol.17 No.2
Background: It is well known that peritoneal carcinomatosis (PC) from colorectal cancer (CRC) is associated with a poor prognosis. However, data on the prognostic significance of modern chemotherapy containing bevacizumab, cetuximab or panitumumab are not available. Materials and Methods: This retrospective review concerned 526 patients with metastatic CRC who were classified into two groups according to the presence or absence of PC, and were treated with systemic chemotherapy, with or without bevacizumab or anti-EGFR antibodies. The genetic background, in particular KRAS, BRAF, and PIK3CA gene mutations, and overall survival (OS) were compared between the two groups. Results: The median OS values were 23.3 and 29.1 months for PC and non-PC patients, respectively (hazard ratio [HR]=1.20; p=0.17). Among all patients, tumor location, number of metastatic sites and BRAF mutation status were significant prognostic factors, whereas the presence of PC was not. In the PC group, chemotherapy with bevacizumab resulted in a significantly longer OS than forchemotherapy without bevacizumab (HR=0.38, p<0.01), but this was not the case in the non-PC group (HR=0.80, p=0.10). Furthermore, the incidence of the BRAF V600E mutation was significantly higher in PC than in non-PC patients (27.7% versus 7.3%, p<0.01). BRAF mutations displayed a strong correlation with shorter OS in non-PC (HR=2.26), but not PC patients (HR=1.04). Conclusions: Systemic chemotherapy, especially when combined with bevacizumab, improved survival in patients with PC from CRC as well as non-PC patients. While BRAF mutation demonstrated a high frequency in PC patients, but it was not associated with prognosis.