Proposing an Unsupervised Approach to Evaluate Essays Using IDF on Reference Data

大学入試において2020 年から記述式問題が導入されることから記述式の問題を自動で採点する手法の開発が求められている．本論では，エッセイタイプの小論文課題を対象に，課題に関連する参照データとWikipedia 全文から作成したidf を利用した事前採点不要な自動採点手法を提案する．先行研究において，日本語小論文を対象とした自動採点では，多くの事前採点が必要となり，実際の数百人規模の試験では利用することが難しいと考えられる．そこで本研究では，事前採点が不要な小論文採点手法を提案する．また，小論文の模擬試験を実施して小論文データを構築する．構築した小論文データに対して採点手法を用い，実験を行い評価する．また小論文データの人手による採点に対しても評価を行う．評価実験の結果neologd 辞書を利用した形態素解析器を用いて， idf 値を利用した形態素の一致数が，人手の評価値と相関が高いことを示す．In this paper, we describe an on-going study of developing an automatic essay-scoring system in Japanese. Essay scoring systems have already been developed and used mainly in English, while not many previous studies have been done on Japanese essay evaluations. Most of the methods and systems of automatic essay evaluation need not small number of previously human-graded essays for calibrating the parameter of regression functions or parameter of machine learning. The previous studies show the high performance for essay evaluation task, however, it must be not easy to assume large graded essays in, for example, actual tests or entrance examinations. Thus, we take a approach to evaluate Japanese essays without previously human-graded essays but with assuming reference data related to essay questions. The proposed method is a simple one, that is, evaluating the essays with co-occurrences with the reference data in their words or morphemes. In the method technical terms would be given high scores using neologd dictionary and idf values. Experimental results show that the proposed method works well in our developing Japanese mock trial writing tests. Key words automatic scoring of essays, human annotation, supportin

Amphiphilic peptide-tagged N-cadherin forms radial glial-like fibers that enhance neuronal migration in injured brain and promote sensorimotor recovery

The mammalian brain has very limited ability to regenerate lost neurons and recover function after injury. Promoting the migration of young neurons (neuroblasts) derived from endogenous neural stem cells using biomaterials is a new and promising approach to aid recovery of the brain after injury. However, the delivery of sufficient neuroblasts to distant injured sites is a major challenge because of the limited number of scaffold cells that are available to guide neuroblast migration. To address this issue, we have developed an amphiphilic peptide [(RADA)3-(RADG)] (mRADA)-tagged N-cadherin extracellular domain (Ncad-mRADA), which can remain in mRADA hydrogels and be injected into deep brain tissue to facilitate neuroblast migration. Migrating neuroblasts directly contacted the fiber-like Ncad-mRADA hydrogel and efficiently migrated toward an injured site in the striatum, a deep brain area. Furthermore, application of Ncad-mRADA to neonatal cortical brain injury efficiently promoted neuronal regeneration and functional recovery. These results demonstrate that self- assembling Ncad-mRADA peptides mimic both the function and structure of endogenous scaffold cells and provide a novel strategy for regenerative therapy

Amphiphilic peptide-tagged N-cadherin forms radial glial-like fibers that enhance neuronal migration in injured brain and promote sensorimotor recovery

名古屋市立大学博士 (医学)doctoral thesi

Evaluation of Moisture Transport Properties Based on Modelling of Silane-based Impregnation Agent Effects on Concrete Surface Layer

It is now desirable to establish a technique for long-term prediction of the effects of silane-based impregnation agent on concrete structures exposed to various environments. To meet this requirement, the purpose of this study is set to establish the model to evaluate the effect of a silane-based impregnation agent on the waterproofing properties of cementitious materials based on microscopic mechanisms. Several mortar specimens were prepared with the silane-based impregnation agent, and moisture absorption and evaporation experiments were conducted. The results showed that the application of the agent was shown to effectively inhibit the penetration of moisture into the interior of the cementitious materials. The effect of the silane-based impregnation agent was modeled in a multiscale pore structure model by applying a microscopic water-repellent effect to the pores in which no pore water was present at the time of agent coating. The analysis with proposed model showed that, as in the experiment, the moisture supply was reduced by the application of the agent, whereas the amount of moisture loss remained almost the same with and without the agent. Moreover, the analysis quantitatively showed that the water content can continue to decrease with silane treatments, even under repeated wet-dry conditions

Crystallographic characterization of the high-potential iron-sulfur protein in the oxidized state at 0.8 Å resolution

High-potential iron-sulfur protein (HiPIP) is a soluble electron carrier protein of photosynthetic bacteria with an Fe4S4 cluster. Although structural changes accompanying the electron transfer are important for understanding of the functional mechanism, the changes have not been clarified in sufficient detail. We previously reported the high-resolution crystal structures of HiPIP from a thermophilic purple bacterium Thermochromatium tepidum in the reduced state. In order to perform a detailed comparison between the structures in different redox states, the oxidized structure should also be revealed at high resolution. Therefore, in the present study we performed a crystallographic analysis of oxidized HiPIP and a structural comparison with the reduced form at a high resolution of 0.8 Å. The comparison highlighted small but significant contraction in the iron-sulfur cluster. The changes in Fe-S bond lengths were similar to that predicted by theoretical calculation, although some discrepancies were also found. Almost distances between the sulfur atoms of the iron-sulfur cluster and the protein environment are elongated upon the oxidation. Positional changes of hydrogen atoms in the protein environment, such as on the amide-hydrogen of Cys75 in the proximity of the iron-sulfur cluster, were also observed in the accurate analyses. None of the water molecules exhibited significant changes in position or anisotropy of atomic displacement parameter between the two states, while the orientations of some water molecules were differen

Crystallographic characterization of the high-potential iron-sulfur protein in the oxidized state at 0.8 A resolution

High-potential iron-sulfur protein (HiPIP) is a soluble electron carrier protein of photosynthetic bacteria with an Fe4S4 cluster. Although structural changes accompanying the electron transfer are important for understanding of the functional mechanism, the changes have not been clarified in sufficient detail. In the present study, we performed a crystallographic analysis of oxidized HiPIP and a structural comparison with the reduced form at a high resolution of 0.8 Å. The changes in Fe-S bond lengths were similar to that predicted by theoretical calculation, although some discrepancies were also found. Almost distances between the sulfur atoms of the iron-sulfur cluster and the protein environment are elongated upon the oxidation. Positional changes of hydrogen atoms in the protein environment, such as on the amide-hydrogen of Cys75 in the proximity of the iron-sulfur cluster, were also observed in the accurate analyses. None of the water molecules exhibited significant changes in position or anisotropy of atomic displacement parameter between the two states, while the orientations of some water molecules were different