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In order to evaluate the sound signal sensitivity of subjective auditory features, understand the process of human sound signal recognition, guide machine recognition of sound signal and noise reduction, this study constructed eight sound signals by changing waveform composition, frequency and amplitude of the sound signals. Twelve subjects were asked to evaluate the subjective auditory features of eight sound signals, such as loudness, sharpness, associativity, sweetness and pleasure, as well as the differences of each sound signal with others. It showed that the sound signals were different in sharpness, associativity, sweetness and pleasure, but only associativity could predict the difference of the sound signals, other subjective auditory features could not effectively distinguish of eight sound signals. However, a single subjective characteristic of the sound signals might not sufficiently discriminate them, two or more subjective perceptual features of sound signals might effectively classify them, with subjective sharpness and associativity being the most sensitive features to sound signals discrimination.

Command and control system operators have the characteristics of long time and high workload. Forms are an important part of the human-computer interaction interface of the command and control system. A reasonable color scheme will not only reduce user fatigue, but also improve operation performance. Therefore, this experiment focuses on the effects of the three color schemes on the user's operating fatigue and performance under the light source of the command and control cabin. The research results show that the improved interface shows better ergonomics and subjective preferences of form filling tasks. The above research results provide data support for the design of the man-machine interaction interface one the subsequent command and control system.

Due to the special task condition, sailors of oceangoing vessels have to conduct monotonous tasks in environment isolated from outside information. During a long voyage, such isolated environment may lead to the decline of the sailors’ physical and mental state and decrease in task motivation, which may directly influence the health and capability of sailors, and even result in human error and task failure. The purpose of this study was to investigate how sailors’ athletic ability changes under the long-time isolated condition. In the experiment, participants worked in a lab module isolated from outside for a period of time. The participants should not only finish the tasks on the watch, but also conduct regular physical fitness tests with professional equipment, including hand muscle strength, upper limb muscle strength, lung capacity, body flexibility, body balance and coordination. By analyzing the data collected at different time points during the experiment, comparison and significance analysis were conducted to evaluate the changes in the athletic ability of the subjects in the long-time isolated environment. Generally, the strength of upper limb muscle, body flexibility, and body balance and coordination slightly decreased. However, the fine muscle strength of the hands increased significantly. This phenomenon may relate to the handicap of wide body movement in isolated narrow space. More influence factors should be considered in future studies.

Objective: The current study aimed to explore how did the long voyage affect the mental status in the experimental environment and construct a quantitative relation model of the mental status during a long voyage. Method: To investigate participants’ mental health state during a long simulated long voyage, 12 participates were equally divided into three groups and were instructed to live in a simulated sailing cabin. The cabin provided a narrow and closed space and a social isolation environment. Symptom checklist-90 (SCL-90), Minnesota Multiphasic Personality Inventory-2 (MMPI-2) were adopted to evaluate participates’ anxiety, depression, somatic symptoms and sleep, fatigue and stress status respectively before and after the long voyage. The positive effect and negative affect schedule (PANAS) was used to investigate the daily change of positive and negative emotions in the whole simulated voyage period. These three measurements reveal the change of mental status from different perspectives before, during, after a long voyage. Results: The pretest scores of somatization were lower than the post-test scores of somatization on SCL-90.The post-test T-scores of depression and paranoia were significantly higher than those of pretest(P < 0.05) on MMPI. The change of the positive emotion could be described as a quadratic polynomial model, and the change of the negative emotion could be described as a cubic polynomial model. Conclusions: The long voyage had a significant influence on participants’ state of mind and mood, which resulted in increased negative emotion and declined positive emotion, and brought out depression and Paranoia. The positive and negative emotions showed different trends during the long term simulated voyage and different starting times of recovery, but the time of positive emotions recovering to the level of baseline after the voyage was very close to the recovery time of negative emotions after the voyage.

Aiming at the long-term voyage demand of ships, a long voyage simulated experiment was carried out in the self-developed experimental chamber in this study, to probe the crews’ alertness changing and the optimal performing opportunity of alertness maintenance measures during the simulated long voyage. The results showed that the fatigue level of the subjects increased and the alertness decreased during the simulated long voyage. Participants’ alertness had begun to decay from the second stage of the simulated voyage, and they were unable to maintain their alertness as same as the general people’s level after the first two stages of the simulated voyage. It means that alertness maintenance measures need to be carried out from the start of the voyage and execute intensive intervention before (preventive intervention) or on (immediate intervention) the second stage end to reduce safety problems caused by increased fatigue and decreased alertness.

Long-term isolation and rotating watch-keeping schedule in extended voyage might impact seafarers’ risk-taking propensity. The present study aimed to explore how seafarer’s risk-taking propensity varies with the prolonged voyage. 12 subjects were recruited to commit a prolonged “voyage” in a self-developed maritime chamber simulator. They lived and worked together following a rotating watch-standing schedule. Social isolation was realized by cutting off the communication between inside and outside world. Balloon Analogue Risk Task (BART) and Sensation Seeking Scale V (SSSV) were adopted as behavioral and self-assessed measures of risk-taking. Participants completed these two assessments before the “voyage” (baseline), at five different time points during the “voyage” and after the “voyage” (post-voyage). Number of explosions and adjusted number of pumps, which represent the riskiness on BART, decreased with the ongoing of the voyage, though the magnitude of the declination is small in size. Accordingly, the scores on SSS and its four subscales, especially the thrill and adventure seeking (TAS) subscale, also declined with the voyage. The results implicated that the sleep deprivation caused by the rotating shift and the stimulation deprivation caused by isolation together would reduce people’s riskiness in decision making and the willingness to engage in high-risk and sensational activities as the prolonged voyage going on.

In this research, three experiments were conducted to investigate the consistency of information processing in visual and auditory working memory tasks. On this basis, the comprehensive exploration and verification for the fatigue classification were carried out in the visual and auditory channels. It is shown from the experiments that: (1) Similar accuracy can be obtained in information processing of visual and auditory channels, however, processing time of auditory channel was longer than that of visual channel when the working memory capacity is 3 (for the N-back test); (2) the working memory task with the duration of 5 min, 30 min and 60 min can be utilized to induce low-level, medium-level and high-level fatigue respectively, which has been verified through the experiment III comprehensively; (3) there were some differences in information processing between visual channel and auditory channel, and it is more likely to accumulate fatigue for visual channel than that for auditory channel.