Taro Ishikawa

Extraction and computational estimation of malignant microcalcification on mammography

Mammography is one of the tools in the diagnosis of breast cancer. By a new method of mammography based on the soft X-ray and the ultrafine X-ray film, the X-ray exposure is reduced and the fine internal structure of the breast can be observed. With the increase of the subjects for breast cancer, it is required to improve the accuracy and efficiency of the diagnosis. A diagnosis-supporting equipment is required which provides an image display to assist in recognition of pathological changes, and provides an objective feature evaluation. This paper considers the microcalcification which is important in the diagnosis of the early breast cancer. The microcalcification appears as opaque points on the mammograph, and when the points are concentrated locally, it is diagnosed as malignant. After the emphasis by Laplacian processing, cell division was applied. The cell with aggregated microcalcification was extracted, and the image display was made so that the feature difference between cancerous and noncancerous lesions can be recognized. To arrive at a numerical representation of the feature difference, the following parameters were considered: (1) effective distance between cells; and (2) rate of change of the number of cells with regard to the change of the threshold. As the result of processing 37 cases, including 14 benign cases and three normal cases, up to 14 of 15 malignant cases were able to be separated from other benign and normal cases, using those two parameters.

An Electronic Watt Meter for Electric Power Measurement of an Electroluminescent Cell

In the measurement of electric Power consumption, it is impossible to use the commercially available measuring instruments. The reasons are (a) that EL cell itself is of low power factor load (cosφ=0.1-0.4), (b) that the frequency range for the working of the cell is comparatively wide, (c) that the power consumption of the cell is little at present, (d) that there is a distortion in the voltage and current waveform of the cell, and so on. Therefore, the correct method of measurement of electric power has been variously studied in many quarters. In this report, there are described the materials which we have recently studied about this subject and which we submitted to the Japanese Investigation Committee on EL of Illuminating Engineering Institute and No.125 Committee of Japanese Science Promotion Conference, etc. The contents of this study are the operating principles of the instantaneous indicating type electronic watt metter, for the trial manufacture of which we spent two years, and its properties, the examples of measurement of electric power by this meter, the comparison with the other methods of measurement, the representative EL properties from an applied example of electric power measurement, etc.

Automatic Gas Filling Control System in Process of Production for Fluorescent Lamp

けい光ランプに所望の圧力で封入するためのサーボ系について検討し, グロー放電管を用いた制御方式について試作例と動作例が述べられ動作時における解析かなされている.グロー放電管において, そのガス圧は温度の関数であり, その管電圧は圧力の関数である.そこで, 同じ構造の放電管二つをブリッジに組み, その一つを基準として一方の圧力変化をこの回路で電圧変化として取り出し, これによってガス量を制御すれば任意の温度における封入圧力は基準温度における所望圧力を補正した値となる.実用上, 放電管としては, 電源, 安定抵抗等が定められると適当な大きさがある. またこれら放電管のけい光ランプに対する位置, 温度の差異によって封入圧力を補正しなければならない. それには制御電圧の時間的変化を自動記録させながら調節すると便利である.最後に動作および調節に関する理論的根拠を把握するためにこの系を電気等価回路に変換して考察を行った.