In order to know the influence of impacting pose on the sound discreteness of a single pistachio , the sounds of the closed and open pistachio during impacting were recorded, and the 100-times data for each type on the same condition were analyzed including the discreteness of spectrum and statistical parameter. The discreteness of spectrum was evaluated by the angular separation between each sample signal with its average and variation coefficient, ant that of statistical parameter was then assessed by its variation coefficient, represented by energy, entropy and zero-cross rate, respectively. Moreover, the variation coefficient of the parameter was defined as the standard deviation over the average. The results were demonstrated as follows. Firstly, we found that for the open pistachio, angular separation was 30.94°, and the variation coefficient was 16.56%. What is more, the statistical parameter’s variation coefficient were 38.33%, 2.30%, 20.00%, and its average were 11.20, 4.39, 63.43 for energy, entropy and zero-cross coefficient, respectively. Sencondly, it was found that, for closed pistachio, the angular separation was 20.52°, the variation coefficient was 25.11%, the statistical parameter’s variation coefficient were 18.36%, 2.27%, 13.08%, and its average were 6.08,4.28,62.94 for energy entropy and zero-cross coefficient, respectively. Thus we could get the conclusions that the random impact pose could have an influence on impact sound signal discretely.Furthermore, the discreteness of open pistachio was higher than the closed ones. Lastly, The random impact pose was also found making spectrum and statistics parameter discretely in a limit range, so it was possible to sort open and closed pistachios using the parameters of larger differences on average whereas smaller value on variation coefficient.

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[1] 应义斌, 韩东海. 农产品无损检测技术[M]. 北京: 化学工业出版社, 2005: 164-174.
[2] 梅亚敏, 郭敏. 基于碰撞声信号的农产品品级检测技术综述[J]. 西北农林科技大学学报, 2013, 41(4): 213-219.
[3] PEARSON T C. Detection of pistachio nuts with closed shells using impact acoustics[J]. Applied Engineering in Agriculture, 2001, 17(2): 249-253.
[4] CETIN A E, PEARSON T C, TEWFIK A H. Classification of closed and open-shell pistachio nuts using voice-recognition technology[J]. Transaction of ASAE, 2004, 47(2): 659-664.
[5] MAHMOUD Omid, ASGHAR Mahmoudi, MOHAMMAD H Omid. An intelligent system for sorting pistachio nut varieties[J]. Expert Systems with Applications, 2009, 36: 11 528-11 535.
[6] MAHMOUD Omid. Design of an expert system for sorting pistachio nuts through decision tree and fuzzy logic classifier[J]. Expert Systems with Applications, 2011, 38: 4 339-4 347.
[7] ONARAN I, PEARSON T C, YARDIMCI Y, et al. Detection of underdeveloped hazelnuts from fully developed nuts by impact acoustics [J]. Information & Electrical Technologies Division of ASABE, 2006, 49(6): 1 971-1 976.
[8] KHALIFA S, KOMARIZADEH M H, TOUSI B. An intelligent system for grading walnuts based on acoustic emission and neural [J]. Journal of Food Agriculture and Environment, 2011, 9(1): 132-135.
[9] KHALESI S, MAHMOUDI A, HOSAINPOUR A, et al. Detection of walnut varieties using impact acoustics and artificial neural networks (ANNs) [J]. Modern Applied Science, 2012, 6(1): 43-49.
[10] 杨红卫. 小麦品质分析的信号处理方法研究[D]. 郑州: 解放军信息工程大学, 2005: 44-46.
[11] 杨丽. 基于信号处理的小麦品质声学检测方法研究[D]. 郑州: 河南工业大学, 2007: 21-27.
[12] 张丽娜. 基于BP神经网络的小麦碰撞声信号分类[J]. 电子设计工程, 2013, 21(7): 163-168.
[13] 臧富瑶, 冯涛, 王晶, 等. 基于撞击声的开心果分拣模型研究[J]. 食品与机械, 2015, 31(2): 157-160.
[14] 刘华平. 语音信号端点检测方法综述及展望[J]. 计算机应用研究, 2008, 25(8): 2 278-2 283.
[15] 宋知用. MATLAB在语音信号分析与合成中的应用[M]. 北京: 北京航空航天大学出版社, 2013: 117-122, 159.



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