Optimization of Detector Movement Algorithm Using Decision Trees Analysis for Radiation Source Identification Based on 4π Gamma Imaging

Path-Planning System for Radioisotope Identification Devices Using 4π Gamma Imaging Based on Random Forest Analysis

“…For rapidly identifying radiation sources using 4π gamma imaging, the images should be obtained from multiple positions that are suitable for obtaining the intensity and position information of the sources. In a previous study, we developed a detector movement algorithm for a single radiation source [13]. The first priority in the algorithm is that the detector is moved to the direction with the highest intensity in the 4π gamma image, and the second one is that the detector is moved away from the direction with the highest intensity in the image and toward the direction with the next-higher intensity in the image.…”

“…In this study, we investigated a path-planning system for detector movement. An integrated simulation model [13] that estimates the location and intensity of a single gamma source from gamma images at arbitrary positions around the source was used to develop the path-planning system. To obtain gamma images in the simulation, a 3D multipixel array CdTe detector was assumed as a 4π gamma imager.…”

“…The output data were analyzed using RF, a machine learning model. First, to find the features in this RF analysis, the features in the decision tree analysis that were examined in our previous study [13] were selected as the candidates. Figure 2 where A and B are the first and second measurement points, respectively, C is the midpoint of line segment AB, Gest is the point closer to point C between the weighted centers of the estimated areas of sources #1 and #2, and Gpos is the weighted center of the three points A, B, and Gest.…”

“…The output data were analyzed using RF, a machine learning model. First, to find the features in this RF analysis, the features in the decision tree analysis that were examined in our previous study [13] were selected as the candidates. Figure 2 Assuming that the source is identified when G est is estimated within ±1 m of the true source location and the estimated source intensity is estimated within ±75% of the true source intensity, the objective function in the RF analysis was set as "detected" (i.e., "1") or "not detected" (i.e., "0").…”

“…In autonomous source identification by a 4π Compton imager mounted on a robotic vehicle, it is necessary to optimize the measurement procedure, i.e., the measurement positions around the target sources. For this purpose, we proposed a detector movement algorithm for a single source [13,14]. In this study, we developed a path-planning system for radioisotope identification devices by using 4π gamma imaging based on random forest (RF) analysis.…”