Labeled sequent calculus for justification logics

Justification logics are modal-like logics that provide a framework for reasoning about justifications. This paper introduces labeled sequent calculi for justification logics, as well as for combined modal-justification logics. Using a method due to Sara Negri, we internalize the Kripke-style semantics of justification and modal-justification logics, known as Fitting models, within the syntax of the sequent calculus to produce labeled sequent calculi. We show that all rules of these systems are invertible and the structural rules (weakening and contraction) and the cut rule are admissible. Soundness and completeness are established as well. The analyticity for some of our labeled sequent calculi are shown by proving that they enjoy the subformula, sublabel and subterm properties. We also present an analytic labeled sequent calculus for $\mathsf{S4LPN}$ based on Artemov–Fitting models.     

A Highly Selective Chemosensor for Cu2+ Based on a Diarylethene Linking an Aminoquinoline Unit

A new diarylethene derivative containing an aminoquinoline unit was synthesized and its structure was determined by single crystal X‐ray diffraction analysis. Its properties such as photochromism, fluorescent switches and detection for metal ions were measured. The results indicated that the closed‐ring of the diarylethene was highly selective toward Cu²⁺ with an obvious absorption decrease and color changes from blue to colorless, even in the presence of other metal ions. The binding constant for the closed isomer of this new diarylethene and Cu²⁺ was 2.0×10⁴ L·mol^?1 and the limit of detection for Cu²⁺ was calculated to be lower than that in drink water. Finally, a logic circuit was constructed by using the absorption intensity as the output signal with the inputs of the combinational stimuli of light and Cu²⁺.     

Lineal DNA logic gate for microRNA diagnostics with strand displacement and fluorescence resonance energy transfer

Designing molecular logic gates to operate programmably for molecular diagnostics in molecular computing still remains challenging. Here, we designed a novel linear DNA logic gates for microRNA analysis based on strand displacement and fluorescence resonance energy transfer (FRET). Two labeled strands closed each other produce to FRET through hybridization with a complementary strand to form a basic work unit of logic gate. Two indicators of heart failure (microRNA-195 and microRNA-21) were selected as the logic inputs and the fluorescence mode was used as the logic output. We have demonstrated that the molecular logic gate mechanism worked well with the construction of YES and AND gates.     

含手性亚胺侧基聚苯乙烯衍生物的设计及其在酸碱诱导下的手光响应性质

以N-(2-羟基-1-萘基)亚甲基-(S)-α-苯基乙胺为模型分子,考察了脱质子前后该手性Schiff碱溶液手光性质的变化,利用DFT计算探讨手光信号反转机理.结果表明,手光反转源于分子内氢键的断裂与形成及伴随的C—C单键旋转所引起的构象转变,且前后2种构象处于拟对映关系.这一发现意味着通过单键旋转操控分子构象转变可作为构建手性开关的一种有效途径.在此基础上设计、合成了苯乙烯型手性功能单体(VNP)及相应的光学活性聚合物.由于邻位基团的协同效应,聚合物的手光性质对酸碱刺激表现出比单体更灵敏的响应性和可重复性.当循环加入H+和OH-时,聚合物溶液的CD信号(382 nm处的Cotton效应)以"ON"-"OFF"方式发生可逆转变,以此为输出信号可无损耗重复至少5次,实现了通过酸碱调控的无损输出的新型聚合物基手性开关.此外,基于该手性开关体系构建了典型的"禁阻"(IHIBIT)分子逻辑门.     

Non decomposable connectives of linear logic

This paper studies the so-called generalized multiplicative connectives of linear logic, focusing on the question of finding the “non-decomposable” ones, i.e., those that cannot be expressed as combinations of the default binary connectives of multiplicative linear logic, ⊗ (times) and ⅋ (par). In particular, we concentrate on generalized connectives of a surprisingly simple form, called “entangled connectives”, and prove a characterization theorem giving a criterion for identifying the undecomposable entangled ones.     

CLEW: The Generation of Pharmacophore Hypotheses Through Machine Learning

Abstract

The paper describes the program CLEW, which utilizes learning and geometrical fitting to discover pharmacophores from a set of active and inactive compounds. The program first divides the compounds into similar classes. It then utilizes machine learning to derive a set of rules that relate structure to activity for each class. Then it finds the common features among all classes. These common features are used by a geometrical fitting program that tries to a 3D fit between these features between minimized conformations for every active molecule in every class. Such a fit is used to infer a pharmacophore.     

Static and dynamic analysis of an all-optical inverter based on a Vertical Cavity Semiconductor Optical Amplifier (VCSOA)

We report the static and dynamic properties of an all-optical inverter based on an 850 nm Vertical Cavity Semiconductor Optical Amplifier (VCSOA). The inverter exhibits low switching power requirements (~ 15 μW), large on/off contrast ratio (> 11 dB), and high speed operation (~ 1.4 GHz). Large and small signal measurements show that the speed of operation and the on/off contrast ratio improve with increased bias current. This holds important prospects for the development of VCSOA-inverters for high-speed, low-power optical logic applications. Finally, a theoretical model of the VCSOA-inverter has been employed giving good agreement with experiments.     

Polarization encoded all-optical quaternary successor with the help of SOA assisted Sagnac switch

The application of multi-valued (non-binary) signals can provide a considerable relief in transmission, storage and processing of large amount of information in digital signal processing. Optical multi-valued logical operation is an interesting challenge for future optical signal processing where we can expect much innovation. A novel all-optical quaternary successor (QSUC) circuit with the help of semiconductor optical amplifier (SOA)-assisted Sagnac switch is proposed and described. This circuit exploits the polarization properties of light. Different logical states are represented by different polarization state of light. Simulation result confirming described method is given in this paper. Proposed all-optical successor circuit can take an important and significant role in designing of all-optical quaternary universal inverter and modulo arithmetic unit (addition and multiplication).     

A new approach to all-optical half-adder by utilizing semiconductor optical amplifier based MZI wavelength converter

Semiconductor optical amplifier (SOA) has already been established itself as a strong all-optical switching element for conducting super fast optical operations. Many all optical logic operations have been proposed by the use of SOA. Here in this paper the authors proposed a new method of implementing all-optical frequency encoded logic operations and half-adder by the use of SOA as well as Mach Zehnder interferometer. The advantage of frequency encoding has been strongly exploited here.     

Design of ultra compact all-optical XOR and AND logic gates with low power consumption

We propose a novel ultra-compact all-optical XOR and AND logic gates without using nonlinear optics. In order to realize these devices, we adopt photonic crystal waveguides (PCWs) based on multi-mode interference devices. Numerical results show that the operating bandwidth of the ON to OFF logic-level contrast ratio of not less than 6.79 dB is 35 nm for XOR logic gate and 9 nm for AND logic gate. Proposed logic gates have the potential to be key components for an optical packet switching system due to their small feature sizes and low power consumption.