Relationship between the content of expansible 2:1 type clay minerals in paddy soils and the amount of ammonium nitrogen in the ponding water by a laboratory experiment

From the viewpoint of ammonium-nitrogen (N) transportation from paddy fields to rivers, estimation of ammonium-N in the ponding water is important for soil management to reduce N outflow from paddy fields. The relationship between the content of expansible 2:1 type clay minerals (i.e. smectite and vermiculite) and the amount of ammonium-N in the ponding water was investigated by a laboratory incubation experiment. Eighteen soils including fifteen alluvial soils and three volcanic ash soils from northeastern Japan were used; the clay content in soils was 116-476g kg^; the content of expansible 2:1 type clay minerals in soils was 0-395g kg^. The experimental condition corresponded to the condition of paddy fields just before transplanting, where readily available N fertilizer was incorporated to plow layers (0.15m) at a rate 5g N m^ as basal fertilizer and submerged water depth was 0.06m. The concentration and the amount of ammonium-N in the ponding water was 1.4-7.5mg L^ and 0.08-0.45g m^. The amount of ammonium-N significantly related to the amount of clay in the calculated plow layer with a depth of 0.15m (R^2=0.42). On the other hand, the amount of expansible 2:1 type clay minerals in the calculated plow layer more strongly related to ammonium-N than the amount of clay (R^2=0.55). These results were attributed to the fact that expansible 2:1 type clay minerals have larger amount of negative charge site per clay and higher selectivity in ammonium adsorption than other clay minerals. From these results it was considered that paddy soils rich in clay fraction or expansible 2:1 type clay minerals could adsorb larger ammonium and mitigate ammonium-N runoff through the ponding water.Original Pape

Effects of available nitrogen and ammonium adsorption of plow layer on nitrogen uptake and yield of paddy rice (Oryza sativa L.)

Effects of available nitrogen (N) and ammonium adsorption of plow layer (PL) on N uptake and brown rice yield were investigated for seven soils. The experiment was conducted in a single paddy field under same conditions except for soils. Rice plants were grown in frames, which the seven different soils (four alluvial paddy soils and three andic paddy soils) were repacked. Not only a small percolation condition (i.e. original subsoil (OS) plot) but also an increased percolation condition was treated by the replacement of subsoil with sand (i.e. sandy subsoil (SS) plot). Percolation rate was lower in clayey smectitic (1-2mm day^) than in sandy and andic (5-9mm day^) soils in the SS plots. In the OS plots, percentage of exchangeable ammonium-N in total soil ammonium N was 89-96% in all soils at 11 days after transplanting (DAT), and was higher in soils with the large ammonium adsorption of PL. Soil ammonium-N at 40 DAT (i.e. at active-tillering stage), N uptake at harvest and brown rice yield were explained by the available N of PL in the OS plots. It is considered that the difference of ammonium adsorption of PL did not strongly affect them, because of its small variation and the small percolation. In the SS plots, the soil ammonium-N at 40 DAT was explained by the ammonium adsorption and the available N of PL. It is considered that soil ammonium-N was much protected from leaching and denitrification in soils with the large ammonium adsorption of PL. However, the total N uptake and the brown rice yield were effectively explained by the available N of PL, and the ammonium adsorption of PL was not selected as an important parameter. It is considered that the ammonium adsorption of PL did not strongly affect the N uptake after maximum tillering stage. The ammonium adsorption of PL did not significantly related to recovery rate of fertilizer N both in the OS and SS plots because of the small variation in the ammonium adsorption of PL among soils.Original Pape

Our activities after the ISMS certificated

情報化推進センターは，平成24年3月に情報セキュリティマネジメントシステム(ISMS)を取得した．これは，我々が管理・運用する情報システムを，適切に運用するための活動及び体制を国際標準規格の下で確立するプロジェクトであった．ISMSを取得した時点では，その物理的な適用範囲は情報化推進センター棟に限定しており，本来含めるべき情報化推進センター蔵本分室を適用外としていた．今回，適用外としていた蔵本分室を適用範囲に含めるため，ISMSの変更審査を受審(変更審査は9月)するため活動を行ったので，その事例を紹介する

Quantitative Measurement and Analysis to Computational Thinking for Elementary Schools in Japan

In Japan, programming education has been made compulsory in elementary schools since 2020. The Programming Education Guide (GPE) explains the purpose of programming education and the abilities that can be fostered through programming education. In addition, the “Portal Site for Programming Education Focusing on Elementary Schools” introduces various examples of programming education. However, there is little information measuring whether programming classes are effective in improving OTWP (Objective Thinking as a Way of Programming) abilities based on CT (Computational Thinking), except for reports of improvement after simple statistical analysis. Therefore, we prepared 30 CT questions, 12 basic and 18 applied, for the CT test considering four key techniques, decomposition, pattern recognition, abstraction, and algorithms, of which 14 questions were pre-test and seven questions were assessment test. In the experiment, 18 elementary school students from grades 1st to 6th were given a short workshop only once, and the analysis of the effect was done statistically, considering their habituation to the problems. The results of the experiment showed that there was no effect of the one-time workshop, unlike other reports of improvement that used simple statistical methods. It became clear that the CT ability was not improved by the short education. On the other hand, a new finding is that females may be inferior to males in three techniques: decomposition, algorithm, and abstraction

Security Impact Analysis of Degree of Field Extension in Lattice Attacks on Ring-LWE Problem

Modern information communications use cryptography to keep the contents of communications confidential. RSA (Rivest-Shamir-Adleman) cryptography and elliptic curve cryptography, which are public-key cryptosystems, are widely used cryptographic schemes. However, it is known that these cryptographic schemes can be deciphered in a very short time by Shor's algorithm when a quantum computer is put into practical use. Therefore, several methods have been proposed for quantum computer-resistant cryptosystems that cannot be cracked even by a quantum computer. A simple implementation of LWE-based lattice cryptography based on the LWE (Learning With Errors) problem requires a key length of $O(n^2)$ to ensure the same level of security as existing public-key cryptography schemes such as RSA and elliptic curve cryptography. In this paper, we attacked the Ring-LWE (RLWE) scheme, which can be implemented with a short key length, with a modified LLL (Lenstra-Lenstra-Lov\'asz) basis reduction algorithm and investigated the trend in the degree of field extension required to generate a secure and small key. Results showed that the lattice-based cryptography may be strengthened by employing Cullen or Mersenne prime numbers as the degree of field extension.Comment: accepted in COMPSAC 2023 Workshop DSML: The 1st IEEE International Workshop on Data Science & Machine Learning for Cybersecurity, IoT & Digital Forensic

A Questionnaire System with an Authentication Framework Considering Online Activities of Users

It is difficult to distribute online questionnaire adequately to those subjects who satisfy requirements of investigations. In addition, low questionnaire response rates, because of factors such as overlooking request emails and noncooperation to answer the questionnaires, sometimes annoy the investigators. Now that today’s organizational systems adopt a unified authentication framework of which logging function stores authentication records of users in federated systems, the possible solution for these problems arises by utilizing the log data and adding the questionnaire process to the framework. The present paper proposes a flow controlling mechanism arranged in a major unified authentication framework and describes how to utilize log data on the framework to select target persons for questionnaires and increase the response rates

Copyright (c)JCPDS-International Centre for Diffraction Data

ABSTRACT This paper describes the effect of renitriding for hot work die steel. We noticed a decrease of compressive residual stress on the nitrided die surface during thermal fatigue process. X-ray stress measurement was used to detect the decomposition of nitride layer on hot work die steel (H13). As a result, compressive residual stress decreased gradually during the thermal fatigue test, almost restoring to the pre-test level by renitriding. The number of cracks decreased with the frequency of test by surface removal effect of shot peening while renitriding. Comparing the renitrided specimen with non renitrided specimen (single nitride), the number of cracks had decreased. 1.INTRODUCTION On the surface of hot work die, such as die-casting die, heat cycles are applied during the operation. Then, the cracks occurred due to thermal stresses caused by thermal cycles. To extend die-casting die life, nitriding is often applied to the die surface 1) . Even with nitriding, the nitride layer is damaged by heat during the die-casting operation. Thus, if renitriding will be available with the detecting damaged layer quantitatively, extension of die life can be expected. On the other hand, high compressive residual stress about -900MPa is caused on the surface of hot work die steel (AISI-H13) by nitriding. And the reheating decreases the residual stress 2) . We noticed the compressive residual stress, and tried to detect decomposition of nitride layer in thermal fatigue process by X-ray stress measurement. And repair effect of nitride layer by renitriding with shot peening was investigated. During the thermal fatigue test, renitriding was applied several times and changes of residual stress and half-value breadth were measured. After the test, distribution of residual stress, maximum crack length and number of cracks were measured

A Method to Detect Rogue Access Points in a Campus without Decrypting WLAN Frames

大学に無線LAN アクセスポイント（以下，AP と呼ぶ）を導入するに当り，許可を得ず接続されたAP や正規のAP を装ったAP 等の不正AP に関するセキュリティ上の課題が存在する．大学では，全学としてのネットワーク管理者（以下，全学ネットワーク管理者と呼ぶ）だけでなく，各サブネットワークごとに管理者を指定していることが多く，ネットワーク全体を把握している管理者が存在しない可能性がある．本論文では，全学ネットワーク管理者の視点で，サブネットワーク管理者との連携を追加で要することなく，検査対象AP のキャンパスネットワークへの接続の有無を判断することにより不正AP を検出する手法について提案する．提案手法では，Windows やAndroid 等のOS に導入されている，Captive Portal Detection（以下，CPD と呼ぶ）を利用する．キャンパスネットワークの上流と無線LAN 通信区間の二箇所におけるCPD 用HTTP 通信の時間差から，検査対象AP のキャンパスネットワークへの接続を確認する．なお，本手法では無線LAN での通信において，WPA2 等の復号を行わず推定している．評価実験では，提案手法によりネットワーク上流から見た各サブネットワークのIP アドレスと無線LAN クライアントが接続したAP の紐付けが可能であることを確認した

Enhanced Merge Sort- A New Approach to the Merging Process

AbstractOne of the major fundamental issues of Computer Science is arrangement of elements in the database. The efficiency of the sorting algorithms is to optimize the importance of other sorting algorithms11. The optimality of these sorting algorithms is judged while calculating their time and space complexities12. The idea behind this paper is to modify the conventional Merge Sort Algorithm and to present a new method with reduced execution time. The newly proposed algorithm is faster than the conventional Merge Sort algorithm having a time complexity of O(n log2 n). The proposed algorithm has been tested, implemented, compared and the experimental results are promising

Mobile Robot Self Localization based on Multi-Antenna-RFID Reader and IC Tag Textile

This paper presents a self-localization system using multiple RFID reader antennas and High-Frequency RFID-tag textile floor for an indoor autonomous mobile robot. Conventional self-localization systems often use vision sensors and/or laser range finders and an environment model. It is difficult to estimate the exact global location if the environment has number of places that have similar shape boundaries or small number of landmarks to localize. It tends to take a long time to recover the self-localization estimation if it goes wrong at once. Vision sensors work hard in dark lighting condition. Laser range finder often fails to detect distance to a transparent wall. In addition, the self-localization becomes unstable if obstacles occlude landmarks that are important to estimate position of the robot. Door opening and closing condition affects the self- localization performance. Self-localization system based on reading RFID-tags on floor is robust against lighting condition, obstacles, furniture and doors conditions in the environment. Even if the arrangement of the obstacles or furniture in the environment is changed, it is not necessary to update the map for the self-localization. It can localize itself immediately and is free from well-known kidnapped robot problem because the RFID-tags give global po- sition information. Conventional self-localization systems based on reading RFID-tags on floor often use only one RFID reader antenna and have difficulty of orientation estimation. We have developed a self-localization system using multiple RFID reader antennas and High-Frequency RFID-tag textile floor for an indoor autonomous mobile robot. Experimental results show the validity of the proposed methods.2013 IEEE Workshop on Advanced Robotics and its Social Impacts (ARSO) Shibaura Institute of Technology, Tokyo, JAPAN November 7-9, 201