Ground state of the spin-1/2 chain of green dioptase at high fields

The gem-stone dioptase Cu6Si6O18.6H2O has a chiral crystal structure of equilateral triangular helices consisting of Cu-3d spins. It shows an antiferromagnetic order with an easy axis along c at TN = 15.5 K under zero field, and a magnetization jump at HC = 13.5 T when the field is applied along c-axis. By 29Si-NMR measurements, we have revealed that the high-field state is essentially the two sub-lattice structure, and that the component within ab-plane is collinear. The result indicates no apparent match with the geometrical pattern of helical spin chain.Comment: SCES2013, Hongo, Toky

ASCII Art Classification Model by Transfer Learning and Data Augmentation

In this study, we propose an ASCII art category classification method based on transfer learning and data augmentation. ASCII art is a form of nonverbal expression that visually expresses emotions and intentions. While there are similar expressions such as emoticons and pictograms, most are either represented by a single character or are embedded in the statement as an inline expression. ASCII art is expressed in various styles, including dot art illustration and line art illustration. Basically, ASCII art can represent almost any object, and therefore the category of ASCII art is very diverse. Many existing image classification algorithms use color information; however, since most ASCII art is written in character sets, there is no color information available for categorization. We created an ASCII art category classifier using the grayscale edge image and the ASCII art image transformed from the image as a training image set. We also used VGG16, ResNet-50, Inception v3, and Xception’s pre-trained networks to fine-tune our categorization. As a result of the experiment of fine tuning by VGG16 and data augmentation, an accuracy rate of 80% or more was obtained in the “human” category

Secret Handshake: Strong Anonymity Definition and Construction

Secret handshake allows two members in the same group to authenticate each other secretly. In previous works of secret handshake schemes, two types of anonymities against the group authority (GA) of a group G are discussed: 1)Even GA cannot identify members, namely nobody can identify them (No-Traceability), 2)Only GA can identify members (Traceability). In this paper, first the necessity of tracing of the identification is shown. Second, we classify abilities of GA into the ability of identifying players and that of issuing the certificate to members. We introduce two anonymities Co-Traceability and Strong Detector Resistance. When a more strict anonymity is required ever for GA, the case 2) is unfavorable for members. Then, we introduce Co-Traceability where even if A has GAs ability of identifying members or issuing the certificate, A cannot trace members identification. However, if a scheme satisfies Co-Traceability, GA may be able to judge whether handshake players belong to the own group. Then, we introduce Strong Detector Resistance where even if an adversary A has GAs ability of identifying members, A cannot make judgments whether a handshaking player belongs to G. Additionally, we propose a secret handshake scheme which satisfies previous security requirements and our proposed anonymity requirements by using group signature scheme with message recovery

Red fluorescent cAMP indicator with increased affinity and expanded dynamic range

cAMP is one of the most important second messengers in biological processes. Cellular dynamics of cAMP have been investigated using a series of fluorescent indicators; however, their sensitivity was sub-optimal for detecting cAMP dynamics at a low concentration range, due to a low ligand affinity and/or poor dynamic range. Seeking an indicator with improved detection sensitivity, we performed insertion screening of circularly permuted mApple, a red fluorescent protein, into the cAMP-binding motif of PKA regulatory subunit Iα and developed an improved cAMP indicator named R-FlincA (Red Fluorescent indicator for cAMP). Its increased affinity (Kd = 0.3 μM) and expanded dynamic range (860% at pH 7.2) allowed the detection of subtle changes in the cellular cAMP dynamics at sub-μM concentrations, which could not be easily observed with existing indicators. Increased detection sensitivity also strengthened the advantages of using R-FlincA as a red fluorescent indicator, as it permits a series of applications, including multi-channel/function imaging of multiple second messengers and combinatorial imaging with photo-manipulation. These results strongly suggest that R-FlincA is a promising tool that accelerates cAMP research by revealing unobserved cAMP dynamics at a low concentration range

Security of Practical Cryptosystems Using Merkle-Damgard Hash Function in the Ideal Cipher Model

Since the Merkle-Damgård (MD) type hash functions are differentiable from ROs even when compression functions are modeled by ideal primitives, there is no guarantee as to the security of cryptosystems when ROs are instantiated with structural hash functions. In this paper, we study the security of the instantiated cryptosystems whereas the hash functions have the well known structure of Merkle-Damgård construction with Stam\u27s type-II compression function (denoted MD-TypeII) in the Ideal Cipher Model (ICM). Note that since the Type-II scheme includes the Davies-Meyer compression function, SHA-256 and SHA-1 have the MD-TypeII structure. We show that OAEP, RSA-KEM, PSEC-KEM, ECIES-KEM and many other encryption schemes are secure when using the MD-TypeII hash function. In order to show this, we customize the indifferentiability framework of Maurer, Renner and Holenstein. We call the customized framework ``indifferentiability with condition\u27\u27. In this framework, for some condition $\alpha$ that cryptosystem $C$ satisfies, if hash function $H$ is indifferentiable from RO under condition $\alpha$, $C$ is secure when RO is instantiated with $H$. We note the condition of ``prefix-free\u27\u27 that the above schemes satisfy. We show that the MD-TypeII hash function is indifferentiable from RO under this condition. When the output length of RO is incompatible with that of the hash function, the output size is expanded by Key Derivation Functions (KDFs). Since a KDF is specified as MGF1 in RSA\u27s PKCS $\#$1 V2.1, its security discussion is important in practice. We show that, KDFs using the MD-TypeII hash function (KDF-MD-TypeII) are indifferentiable from ROs under this condition of ``prefix-free\u27\u27. Therefore, we can conclude that the above practical encryption schemes are secure even when ROs are instantiated with (KDF-)MD-TypeII hash functions. Dodis, Ristenpart and Shrimpton showed that FDH, PSS, Fiat-Shamir, and so on are secure when RO is instantiated with the MD-TypeII hash function in the ICM, their analyses use the different approach from our approach called indifferentiability from public-use RO (pub-RO). They showed that the above cryptosystems are secure in the pub-RO model and the MD-TypeII hash function is indifferentiable from pub-RO. Since their analyses did not consider the structure of KDFs, there might exist some attack using a KDF\u27s structure. We show that KDFs using pub-RO (KDF-pub-RO) is differentiable from pub-RO. Thus, we cannot trivially extend the result of Dodis et al to the indifferentiability for KDF-MD-TypeII hash functions. We propose a new oracle called private interface leak RO (privleak-RO). We show that KDF-pub-ROs are indifferentiable from privleak-ROs and the above cryptosystems are secure in the privleak-RO model. Therefore, by combining the result of Dodis et al. with our result, we can conclude that the above cryptosystems are secure when ROs are instantiated with KDF-MD-TypeII hash functions. Since OAEP, RSA-KEM, PSEC-KEM, ECIES-KEM and many other encryption schemes are insecure in the pub-RO (privleak-RO) model, we cannot confirm the security of these encryption schemes from the approach of Dodis et al. Therefore, the result of Dodis et al can be supplemented with our result. Consequently, from the two results we can confirm the security of almost practical cryptosystems when ROs are instantiated with (KDF-)MD-TypeII hash functions

How to Prove the Security of Practical Cryptosystems with Merkle-Damgård Hashing by Adopting Indifferentiability

In this paper, we show that major cryptosystems such as FDH, OAEP, and RSA-KEM are secure under a hash function $MD^h$ with Merkle-Damgård (MD) construction that uses a random oracle compression function $h$. First, we propose two new ideal primitives called Traceable Random Oracle ($\mathcal{TRO}$) and Extension Attack Simulatable Random Oracle ($\mathcal{ERO}$) which are weaker than a random oracle ($\mathcal{RO}$). Second, we show that $MD^h$ is indifferentiable from $\mathcal{LRO}$, $\mathcal{TRO}$ and $\mathcal{ERO}$, where $\mathcal{LRO}$ is Leaky Random Oracle proposed by Yoneyama et al. This result means that if a cryptosystem is secure in these models, then the cryptosystem is secure under $MD^h$ following the indifferentiability theory proposed by Maurer et al. Finally, we prove that OAEP is secure in the $\mathcal{TRO}$ model and RSA-KEM is secure in the $\mathcal{ERO}$ model. Since it is also known that FDH is secure in the $\mathcal{LRO}$ model, as a result, major cryptosystems, FDH, OAEP and RSA-KEM, are secure under $MD^h$, though $MD^h$ is not indifferentiable from $\mathcal{RO}$

ATTED-II: a database of co-expressed genes and cis elements for identifying co-regulated gene groups in Arabidopsis

Publicly available database of co-expressed gene sets would be a valuable tool for a wide variety of experimental designs, including targeting of genes for functional identification or for regulatory investigation. Here, we report the construction of an Arabidopsis thaliana trans-factor and cis-element prediction database (ATTED-II) that provides co-regulated gene relationships based on co-expressed genes deduced from microarray data and the predicted cis elements. ATTED-II () includes the following features: (i) lists and networks of co-expressed genes calculated from 58 publicly available experimental series, which are composed of 1388 GeneChip data in A.thaliana; (ii) prediction of cis-regulatory elements in the 200 bp region upstream of the transcription start site to predict co-regulated genes amongst the co-expressed genes; and (iii) visual representation of expression patterns for individual genes. ATTED-II can thus help researchers to clarify the function and regulation of particular genes and gene networks

RESPONSE CHARACTERISTICS OF A TRAILER TYPE MULTI-CONNECTED BARGE SYSTEM IN WAVES

ABSTRACT A trailer type multi-connected barge system is a new type of ocean transportation system composed of several barges connected to each other with a mechanical connecting device and a tug ship. To design the trailer type multi-connected barge system, it is necessary to grasp the exact response characteristics of the trailer type multi-connected barge system in waves. A model basin test was conducted for the trailer type multiconnected barge system in waves. In the model basin test, the tug ship and three barges were connected to each other by the mechanical connecting device, and the tug ship towed three barges in waves. As a result, the response characteristics of the trailer type multi-connected barge system in waves were obtained. A nonlinear phenomenon of a longitudinal connecting force caused by relative pitch motions of barges was observed. A way to avoid the non-linear phenomenon and reduce the longitudinal connecting force could be found, and the realization of the trailer type multi-connected barge system was experimentally confirmed

Use of Balloon Enteroscopy in Preoperative Diagnosis of Neurofibromatosis-Associated Gastrointestinal Stromal Tumours of the Small Bowel: A Case Report

Neurofibromatosis type I (NF1) is one of the most common inheritable disorders and is associated with an increased risk of gastrointestinal stromal tumours (GISTs). However, the predominant location of these lesions in the small bowel makes them difficult to diagnose. We report the successful use of balloon enteroscopy in conjunction with conventional methods for clinical diagnosis of jejunal GISTs in a 70-year-old man with NF1 who presented with melaena. The importance of screening NF1 patients for GISTs and the complementary role of balloon enteroscopy with capsule endoscopy in such diagnoses is discussed