Chemical Changes of Dredged Soil in Kojima Lake from the Viewpoint of Soil Reaction

While dredged soil is increasing, the processing problem isn't solved. So it is expected to use effectively as the soil material. Although, to use dredged soil, the chemical characteristic must be grasped. It is because acidification cause material (pyrite) can be contained in dredged soil. It causes sulfulic ions when it touches air and has the possibility to become acidification. In this experiment, dredged soil in Kojima Lake was made clear that it contained in pyrite and acidified under the oxidation condition. Accordingly, when using dredged soil as ground resources, it is necessary to use as the soil material such as filling-up reclamation under the deoxidization condition

Cutting Dynamics Associated with Vibration Normal to Cut Surface

Investigation into the dynamics of the metal cutting process has been carried out using a new experimental method to identify the cutting stiffness without directly measuring the dynamic cutting force. Comparing obtained data to the theoretical formula, it has been determined that the theoretical model proposed by Das and Tobias in 1967 is valid with respect to the inner modulation effect. Effects of cutting conditions, wave length of chatter mark, and built-up edge formation on the onset of the regenerative-type self-excited chatter are also investigated

Active Suppression of Chatter by Programed Variation of Spindle Speed

By a programed variation of the spindle speed of machine tools, it is possible to control the onset of regenerative-type self-excited chatter, which restricts the maximum depth of cut allowable in rough cutting operations. This paper presents a theoretical basis of this phenomenon, together with experimental proofs demonstrated in turning operations

Effects of mask fitness and worker education on the prevention of occupational dust exposure

To decrease the incidence of pneumoconiosis, we examined dust protective mask performance and its relation to pulmonary function as well as the effects of worker education on the proper wearing of masks. One hundred and seventy-eight workers from 15 factories subject to dust exposure participated in this study. All participants were interviewed to obtain relevant personal information and underwent both a mask leakage and a pulmonary function test. The mask leakage was expressed as a percentage, with under 10% leakage indicating that the dust protective mask worked efficiently. In addition, 23 workers from 2 factories were educated on how to wear masks properly. The average mask leakage was 24.3%, and 58% of workers wore ineffective masks. Though pulmonary function was almost normal, the percent vital capacity (%VC) tended to be lower depending on the mask leakage. Mask education, which was very easy and took only a short time, dramatically decreased average mask leakage from 32.1% to 10.5% (p0.001). Educating workers to wear masks properly might prevent the worsening of pulmonary function in response to dust exposure. Appropriate mask fitness by education could be useful in preventing the development of pneumoconiosis.</p

High-Precision Control of Ball-Screw-Driven Stage Based on Repetitive Control Using n-Times Learning Filter

Abstract-This paper presents a novel learning control method for ball-screw-driven stages. In recent years, many types of friction models that are based on complicated equations have been studied. However, it is difficult to treat friction models with equations because the level of precision that is associated with real friction characteristics and parameter tuning are difficult to achieve. In contrast, repetitive perfect tracking control (RPTC) is a repetitive control technique that achieves high-precision positioning. In this paper, we propose the use of RPTC with n-times learning filter. The n-times learning filter has a sharper rolloff property than conventional learning filters. With the use of the n-times learning filter, the proposed RPTC can converge tracking errors n times faster than the RPTC with the conventional learning filter. Simulations and experiments with a ball-screw-driven stage show the fast convergence of the proposed RPTC. Finally, the proposed learning control scheme is combined with data-based friction compensation, and the effectiveness of this combination is verified for the x-y stage of a numerically controlled machine tool. Index Terms-n-times learning, perfect tracking control, repetitive control, zero-phase low-phase filter

履修カルテシステムの分析による教職課程指導室業務の検証（4）－教職履修カルテ自己評価レーダーチャートの活用ー

「履修カルテの分析による教職課程指導室の業務の検証（3）」において、履修カルテの自己評価のレーダーチャートの作成による学生の自己分析の結果について報告した［3］。本報告は、2018 年度教職実践演習履修者のレーダーチャートによる自己分析の実践報告である。2017 年度の結果と比較して、レーダーチャートの形状から見た傾向は概ね一致しており、（1）育成事項II は概ね評価が高い（2）育成項目III、IV は全体的に評価が低い傾向があると言える。しかし、レーダーの大きさは2018 年度の方が大きく、3 年次の評価より4 年次の評価の方が低いという評価の逆転はほとんど起きていない。そこで、学生作成したレーダーチャートを調査してみると、評価の逆転が起きている学生は多数いることが分かった。にもかかわらず、全体でみると評価の逆転がみられない。本報告では、これらの要因も含め考察する

A case of laparoscopic surgery for endometrial cancer in a patient previously treated with a transvaginal mesh procedure for pelvic organ prolapse

Transvaginal mesh (TVM) surgery is an effective treatment option for women with pelvic organ prolapse (POP). Because the TVM procedure preserves the uterus, it is possible for endometrial cancer to occur at a later date. We herein present the first report of such an endometrial cancer, diagnosed well after TVM surgery for POP, and the use of laparoscopic surgery to conduct a simple total hysterectomy to treat it. Keywords: endometrial cancer, laparoscopic surgery, pelvic organ prolapse, transvaginal mes