N. Asada

We determined model ages of mare deposits on the farside of the Moon on the basis of the crater frequency distributions in 10-meter-resolution images obtained by the Terrain Camera on SELENE (Selenological and Engineering Explorer) (Kaguya). Most mare volcanism that formed mare deposits on the lunar farside ceased at approximately 3.0 billion years ago, suggesting that mare volcanism on the Moon was markedly reduced globally during this period. However, several mare deposits at various locations on the lunar farside also show a much younger age, clustering at approximately 2.5 billion years ago. These young ages indicate that mare volcanism on the lunar farside lasted longer than was previously considered and may have occurred episodically.

An artificial neural network approach was applied to the differential diagnosis of interstitial lung diseases. The neural network was designed to distinguish between nine types of interstitial lung diseases on the basis of 20 items of clinical and radiographic information. A data base for training and testing the neural network was created with 10 hypothetical cases for each of the nine diseases. The performance of the neural network was evaluated by means of receiver operating characteristic analysis. The decision performance of the neural network was high; it was comparable to that of chest radiologists and superior to that of senior radiology residents. The preliminary results strongly suggest that the neural network approach has potential utility in the computer-aided differential diagnosis of interstitial lung diseases.

The Spectral Profiler (SP) onboard the Japanese SELENE (KAGUYA) spacecraft is now providing global high spectral resolution visible‐near infrared continuous reflectance spectra of the Moon. The reflectance spectra of impact craters on the farside of the Moon reveal lithologies that were not previously identified. The achievements of SP so far include: the most definite detection of crystalline iron‐bearing plagioclase with its characteristic 1.3 μ m absorption band on the Moon; a new interpretation of the lithology of Tsiolkovsky crater central peaks, previously classified as “olivine‐rich,” as mixtures of plagioclase and pyroxene; and the lower limit of Mg number of low‐Ca pyroxene found at Antoniadi crater central peak and peak ring which were estimated through direct comparison with laboratory spectra of natural and synthetic pyroxene samples.

This paper describes a calibration method of zoom lens systems to eliminate the photometric distortion due to vignetting. A novel camera model including the variable cone is proposed to account for the marginal intensity reduction observed in images. Using the theoretical model, we first show that the serious distortion due to vignetting appears when using a zoom lens that has open aperture and long focal length. Then we present the calibration method to estimate the intensity reduction from the lens parameters of zoom and iris. The experimental results demonstrate the validity of our theoretical model and the effectiveness of the photometric calibration of zoom lens systems.