ABSTRACT
A parallel computation method for large-size Fresnel computer-generated hologram (CGH) is reported. The method was introduced by us in an earlier report as a technique for calculating Fourier CGH from 2D object data. In this paper we extend the method to compute Fresnel CGH from 3D object data. The scale of the computation problem is also expanded to 2 gigapixels, making it closer to real application requirements. The significant feature of the reported method is its ability to avoid communication overhead and thereby fully utilize the computing power of parallel devices. The method exhibits three layers of parallelism that favor small to large scale parallel computing machines. Simulation and optical experiments were conducted to demonstrate the workability and to evaluate the efficiency of the proposed technique. A two-times improvement in computation speed has been achieved compared to the conventional method, on a 16-node cluster (one GPU per node) utilizing only one layer of parallelism. A 20-times improvement in computation speed has been estimated utilizing two layers of parallelism on a very large-scale parallel machine with 16 nodes, where each node has 16 GPUs.
ABSTRACT
A method has been proposed to reduce the communication overhead in computer-generated hologram (CGH) calculations on parallel and distributed computing devices. The method uses the shifting property of Fourier transform to decompose calculations, thereby avoiding data dependency and communication. This enables the full potential of parallel and distributed computing devices. The proposed method is verified by simulation and optical experiments and can achieve a 20 times speed improvement compared to conventional methods, while using large data sizes.
ABSTRACT
BACKGROUND: The weight-loss effect of team medical care in which counseling is provided by clinical psychologists was investigated in an university hospital obesity (OB) clinic. Nutritional and exercise therapy were also studied. In our previous study, we conducted a randomized, controlled trial with obese patients and confirmed that subjects who received counseling lost significantly more weight than those in a non-counseling group. The purpose of this study was to identify the psychological characteristics assessed by ego states that promote behavior modification by obese patients. METHODS: 147 obese patients (116 females, 31 males; mean age: 45.9 +/- 15.4 years) participated in a 6-month weight-loss program in our OB clinic. Their psychosocial characteristics were assessed using the Tokyo University Egogram (TEG) before and after intervention. The Wilcoxon signed rank test was used to compare weight and psychological factors before and after intervention. Multiple regression analysis was used to identify factors affecting weight loss. RESULTS: Overall, 101 subjects (68.7%) completed the program, and their data was analyzed. The subjects mean weight loss was 6.2 +/- 7.3 kg (Z = 7.72, p < 0.01), and their mean BMI decreased by 2.4 +/- 2.7 kg/m2 (Z = 7.65, p < 0.01). Significant differences were observed for the Adult (A) ego state (0.68 +/- 3.56, Z = 1.95, p < 0.05) and the Free Child (FC) ego state (0.59 +/- 2.74, Z = 2.46, p < 0.01). The pre-FC ego state had a significant effect on weight loss (beta = 0.33, p < 0.01), and a tendency for changes in the A ego state scores to affect weight loss (beta = - 0.20, p = 0.06) was observed. CONCLUSION: This study of a 6-month weight-loss program that included counseling by clinical psychologists confirmed that the A ego state of obese patients, which is related to their self-monitoring skill, and the FC ego state of them, which is related to their autonomy, were increased. Furthermore, the negative aspects of the FC ego state related to optimistic and instinctive characteristics inhibited the behavior modification, while the A ego state represented objective self-monitoring skills that may have contributed to weight loss.
ABSTRACT
We reexamined the Japanese version of the 20-item Toronto Alexithymia Scale, a self-report sc ale for measuring alexithymic characteristics, by comparing the scores on three factors and the total scores with variables of the Rorschach in a sample of 40 (originally 48) Japanese college students. Based on prior studies, our aims were to further validate the 20-item Toronto Alexithymia Scale by comparing its scores with those on a projective technique. We also investigated whether sociocultural factors, such as repression of hostility. are associated with scores on the 20-item Toronto Alexithymia Scale (especially Factor 3). None of the seven Rorschach Alexithymia Variables were significantly related to the factors and total scores of the 20-item Toronto Alexithymia Scale. However, scores for Factor 1 (difficulty identifying feelings) of the 20-item Toronto Alexithymia Scale correlated positively with scores on Sum C' (reserved responses to emotional stimuli) and Adj es (stimulus demand), suggesting that individuals who score high for Factor 1 experience gloomy, depressive feelings but in constricted ways. Scores for Factor 3 (externally oriented thinking) correlated positively with the D scores (stress tolerance) and negatively with m (situational stress) responses, suggesting that Factor 3 may reflect a psychological defense that enhances stress tolerance. There was a nonsignificant negative correlation between Factor 1 and Factor 3 scores, but, unlike our hypothesis. Factor 3 was neither related to AG (aggression) nor S (space responses reflecting oppositional tendency), indices of aggression or hostility in the Rorschach Comprehensive System. It may be that the 20-item Toronto Alexithymia Scale and the Rorschach measure quite different aspects of personality, but further research is necessary.
