Takefuji Yoshiyasu

Fourier analysis can provide policymakers useful information for analysing the pandemic behaviours. This paper proposes a Fourier analysis approach for examining the cycle length and the power spectrum of the pandemic by converting the number of deaths due to coronavirus disease 2019 in the US to the frequency domain. Policymakers can control the pandemic by using observed cycle length whether they should strengthen their policy or not. The proposed Fourier method is useful for analysing waves in other medical applications.

This paper reports an illogical policy on smart highway management in Japan. Heavy snow in Japan on Dec. 17 in 2020 revealed the failed link in the current policy between the smart highway management and weather forecast. Weather forecast information is supposed to be used in controlling the gates in highway for mitigating stranded vehicles by heavy snowfalls, blizzards, freezing rain or sleet, dense fog, high winds, and other weather-related phenomena respectively. However, more than several thousand vehicles were stranded every winter on the smart highway in Japan. This paper examines what is wrong and what should be fixed in the current highway policy in Japan.

Keio is a leading research university where 33,436 students are currently registered with 3,140 faculty members. The university system was cracked in September 2020 by malicious crackers where it is composed of the internet-connected-integrated database across the administrative and academic units. The cracked system was completely down, so that all courses from October 1 to October 7 in 2020 were canceled except my courses. The minimum survival system using private mail servers functioned, and my online courses were successfully held. This article shows my story of how to build a resilient secured education system for online lectures against malicious attacks during the pandemic.

In human's cooperative behavior, there are some strategies: a passive behavioral strategy based on others’behaviors and an active behavioral strategy based on the objective-first. However, it is not clear how to acquire a meta-strategy to switch those strategies. In this study, we conduct a collision avoidance experiment with agents taking multiple strategies in a grid-like corridor to see whether subject's behavior changes when agent's strategy changes. We compare the behavior selected by the subjects with the behavior of the agents acquired by reinforcement learning. The experimental results show that subjects can read the change in strategy from the behavior of the oncoming agent.

Adam (Adaptive Moment Estimation) is one of the promising techniques for parameter optimization of deep learning. Because Adam is an adaptive learning rate method and easier to use than Gradient Descent. In this paper, we propose a novel randomized search method for Adam with randomizing parameters of beta1 and beta2. Random noise generated by normal distribution is added to the parameters of beta1 and beta2 every step of updating function is called. In the experiment, we have implemented binary tree-structured LSTM and adam optimizer function. It turned out that in the best case, randomized hyperparameter tuning with beta1 ranging from 0.88 to 0.92 and beta2 ranging from 0.9980 to 0.9999 is 3.81 times faster than the fixed parameter with beta1 = 0.999 and beta2 = 0.9. Our method is optimization algorithm independent and therefore performs well in using other algorithms such as NAG, AdaGrad, and RMSProp.

Mitochondria are the largest source of reactive oxygen species (ROS) and are intracellular organelles that produce large amounts of the most potent hydroxyl radical (·OH). Molecular hydrogen (H2) can selectively eliminate ·OH generated inside of the mitochondria. Inflammation is induced by the release of proinflammatory cytokines produced by macrophages and neutrophils. However, an uncontrolled or exaggerated response often occurs, resulting in severe inflammation that can lead to acute or chronic inflammatory diseases. Recent studies have reported that ROS activate NLRP3 inflammasomes, and that this stimulation triggers the production of proinflammatory cytokines. It has been shown in literature that H2 can be based on the mechanisms that inhibit mitochondrial ROS. However, the ability for H2 to inhibit NLRP3 inflammasome activation via mitochondrial oxidation is poorly understood. In this review, we hypothesize a possible mechanism by which H2 inhibits mitochondrial oxidation. Medical applications of H2 may solve the problem of many chronic inflammation-based diseases, including coronavirus disease 2019 (COVID-19).

In human’s cooperative behavior, there are two strategies: a passive behavioral strategy based on others’ behaviors and an active behavioral strategy based on the objective-first. However, it is not clear how to acquire a meta-strategy to switch those strategies. The purpose of the proposed study is to create agents with the meta-strategy and to enable complex behavioral choices with a high degree of coordination. In this study, we have experimented by using multi-agent collision avoidance simulations as an example of cooperative tasks. In the experiments, we have used reinforcement learning to obtain an active strategy and a passive strategy by rewarding the interaction with agents facing each other. Furthermore, we have examined and verified the meta-strategy in situations with opponent’s strategy switched.

Background: Fake meat industry is expected to grow and to be worth $140 billion by 2030. Alternative protein can be produced by plant or microbe. Animal-free dairy protein can be produced by fermentation in microflora.Scope and approach: In order to improve the real production, many companies are focusing on fermentation for animal-free meat, eggs, and dairy respectively.Key findings and conclusions: However, their production capabilities, efficiencies, and costs are not available in public respectively. This paper reports briefly what is going on in sustainable protein alternatives.

A sliding puzzle is a combination puzzle where a player slide pieces along certain routes on a board to reach a certain end-configuration. In this paper, we propose a novel measurement of complexity of massive sliding puzzles with paramodulation which is an inference method of automated reasoning. It turned out that by counting the number of clauses yielded with paramodulation, we can evaluate the difficulty of each puzzle. In experiment, we have generated 100 * 8 puzzles which passed the solvability checking by countering inversions. By doing this, we can distinguish the complexity of 8 puzzles with the number of generated with paramodulation. For example, board [2,3,6,1,7,8,5,4, hole] is the easiest with score 3008 and board [6,5,8,7,4,3,2,1, hole] is the most difficult with score 48653. Besides, we have succeeded to obverse several layers of complexity (the number of clauses generated) in 100 puzzles. We can conclude that proposal method can provide a new perspective of paramodulation complexity concerning sliding block puzzles.

Hydrogen (H2 ) is promising as an energy source for the next generation. Medical applications using H2 gas can be also considered as a clean and economical technology. Since the H2 gas based on electrolysis of water production has potential to expand the medical applications, the technology has been developed in order to safely dilute it and to supply it to the living body by inhalation, respectively. H2 is an inert molecule which can scavenge the highly active oxidants including hydroxyl radical (·OH) and peroxynitrite (ONOO− ), and which can convert them into water. H2 is clean and causes no adverse effects in the body. The mechanism of H2 is different from that of traditional drugs because it works on the root of many diseases. Since H2 has extensive and various effects, it may be called a “wide spectrum molecule” on diseases. In this paper, we reviewed the current medical applications of H2 including its initiation and development, and we also proposed its prospective medical applications. Due to its marked efficacy and no adverse effects, H2 will be a next generation therapy candidate for medical applications.

Generally, negation-limited inverters problem is known as a puzzle of constructing an inverter with AND gates and OR gates and a few inverters. In this paper, we introduce a curious new result about the effectiveness of two powerful ATP (Automated Theorem Proving) strategies on tackling negation limited inverter problem. Two resolution strategies are UR (Unit Resulting) resolution and hyper-resolution. In experiment, we come two kinds of automated circuit construction: 3 input/output inverters and 4 input/output BCD Counter Circuit. Both circuits are constructed with a few limited inverters. Curiously, it has been turned out that UR resolution is drastically faster than hyper-resolution in the measurement of the size of SOS (Set of Support). Besides, we discuss the syntactic and semantic criteria which might causes considerable difference of computation cost between UR resolution and hyper-resolution.

Science (eLetter, 27 Sept. 2020) https://science.sciencemag.org/content/369/6511/1553/tab-e-letters

Super typhoon Hagibis on October 12, 2019, in Japan revealed that the current dam control policy has the fatal defect. The current dam policy should be updated for saving humans. Human-induced flood should be avoided by the weather prediction.

Tree-structured LSTM is promising way to consider long-distance interaction over hierarchies. However, there have been few research efforts on the hyperparameter tuning of the construction and traversal of tree-structured LSTM. To name a few, hyperparamters such as the interval of state initialization, the number of batches for normalization have been left unexplored specifically in applying batch normalization for reducing training cost and parallelization. In this paper, we propose a novel recursive algorithm for traversing batch normalized tree-structured LSTM. In proposal method, we impose the constraint on the recursion algorithm for the depth-first search of binary tree representation of LSTM for which batch normalization is applied. With our constrained recursion, we can control the hyperparameter in the traversal of several tree-structured LSTMs which is generated in the process of batch normalization. The tree traversal is divided into two steps. At first stage, the width-first search over models is applied for discover the start point of the latest tree-structured LSTM block. Then, the depth-first search is run to traverse tree-structured LSTM. Proposed method enables us to explore the optimized selection of hyperparameters of recursive neural network implementation by changing the constraints of our recursion algorithm. In experiment, we measure and plot the validation loss and computing time with changing the length of internal of state initialization of tree-structured LSTM. It has been turned out that proposal method is effective for hyperparameter tuning such as the number of batches and length of interval of state initialization of tree-structured LSTM.

There are unknown and known attacks against the consensus algorithms used in blockcliain. Detection and protection mechanisms must be embedded in blockchain applications for protecting vulnerabilities of known consensus algorithms.

Reproducibility problems have delayed the advancement of Science. The chemical resistance of synthetic sapphires and quartz (glassware) was measured to quantize the dissolution of solid laboratory instruments. Glassware laboratory instruments have been used for many years in chemical/biomedical experiments. The choice of laboratory instruments is important for successful experiments since they may be dissolved in chemical. The chemical resistance is compared between synthetic polycrystalline sapphires, synthetic monocrystalline sapphire, and quartz (glassware) where tested chemicals include HCL, HNO3, HF, HF/HNO3, H3PO4, H2SO4, and NaOH respectively. For high reproducibility, the result suggests that we should use the high chemical resistant laboratory instruments including synthetic polycrystalline/monocrystalline sapphires, instead of glassware.