Simulation of the flocculation process using both inorganic and polymer flocculants is very difficult because there are many factors that influence the process. In this study, a model that enables the visual understanding of the qualitative trends of the flocculation system using both inorganic and polymer flocculants is proposed. It is a simplified onedimensional model that expresses flocculation under various additive manners of the flocculant. Various kinds of thought experiments as well as experimental runs with model flocculants were carried out based on the model; the results demonstrate that the model can express many empirical qualitative trends of flocculation.

Since there are many factors which in uence the process of occulation by polymer occulant, the scienti c understanding of the occulation mechanism is still under discussion. We have proposed a simple bridging model which expresses occulation under various additive manners of the occulant and enables the understanding of qualitative trends of the occulation system. In the present study, from the simulated results based on the model and experimental data, we obtained the following knowledge: 1) the intermittent addition of polymer occulant gives better and reproducible turbidity removal; 2) the optimum dosage, which results in maximum turbidity removal in a given manner of addition, increases as the number of doses under the intermittent addition increases; 3) at a given amount of primary particles, the reproducibility at the optimum dosage of the 1-time dose is the worst among all results, irrespective of the additive manner. It could, therefore, be concluded that all these ndings are originating from the di erence of probability of bridging formation among particles under various additive manners.

Objective: To develop the Gait Ability Assessment for hemiplegics (GAA), and to verify its validity and inter-rater reliability. Methods: We developed the GAA, a new method for the assessment of gait ability. Next, we examined the inter-rater reliability of GAA by assessing gait ability of post-stroke patients by two physical therapists. Then, we verified the validity of GAA by comparing with the existing assessments methods comprising Functional Ambulation Categories (FAC), Functional Independence Measure (FIM)-walk, maximum walking speed, motor subscore of the FIM (FIM-M), and total score of affected-side motor function of the Stroke Impairment Assessment Set (SIAS-L/E). Results: Regarding the inter-rater reliability of GAA, κ coefficient was 0.76 and weighted κ coefficient was 0.96. The correlation coefficients between GAA scores and existing assessment methods were: 0.95 for FAC scores, 0.95 for FIM-walk scores, 0.82 for maximum walking speed, 0.89 for FIM-M, and 0.61 for SIAS-L/E, all of which showed a significant correlation (p<0.01). Conclusion: GAA has high inter-rater reliability as well as high validity as a gait ability assessment method, suggesting that it can be applied to research and clinical settings.

From 2020, programming is a compulsory subject in elementary schools in Japan. Since many schools are using block-based programming languages and environments as teaching materials, the number of students who have already learned block-based programming is expected to increase. To help such learners of block-based programming shift to text-based programming languages, we have designed and implemented a programming learning environment named TABLET. We have designed TABLET as a syntax-directed system that focuses on making the learner aware of the syntax of the target text-based language. To this end, TABLET incorporates two programming behaviors: deriving blocks for non-terminal symbols of the target language and writing program code directly with text. TABLET synchronizes these two behaviors to make it easier for the learner to grasp the correspondence between block-based programs and text-based programs. TABLET can be used for many target text-based languages as long as the syntax can be given as a set of Backus-Naur Form (BNF) rules. Thus, TABLET is general enough to capably generating blocks for the language and to enable the both programming behaviors. We conducted evaluation experiments with second-year undergraduate students. We found that TABLET made it easier for the students to grasp the correspondence between the block-based and text-basd programs and to understand the syntax of the target language.