An exploratory study of the impact of antipatterns on class change- and fault-proneness

Antipatterns are poor design choices that are conjectured to make object-oriented systems harder to maintain. We investigate the impact of antipatterns on classes in object-oriented systems by studying the relation between the presence of antipatterns and the change- and fault-proneness of the classes. We detect 13 antipatterns in 54 releases of ArgoUML, Eclipse, Mylyn, and Rhino, and analyse (1) to what extent classes participating in antipatterns have higher odds to change or to be subject to fault-fixing than other classes, (2) to what extent these odds (if higher) are due to the sizes of the classes or to the presence of antipatterns, and (3) what kinds of changes affect classes participating in antipatterns. We show that, in almost all releases of the four systems, classes participating in antipatterns are more change-and fault-prone than others. We also show that size alone cannot explain the higher odds of classes with antipatterns to underwent a (fault-fixing) change than other classes. Finally, we show that structural changes affect more classes with antipatterns than others. We provide qualitative explanations of the increase of change- and fault-proneness in classes participating in antipatterns using release notes and bug reports. The obtained results justify a posteriori previous work on the specification and detection of antipatterns and could help to better focus quality assurance and testing activities.     

Health resort treatment of eye diseases caused by ischemia]

The authors discuss the results of ophthalmodynamometric tests used for the assessment of cerebro-retinal vessels reactivity following carbon dioxide baths and "peat collars". An analysis of systemic and local blood pressure in the ophthalmic artery measured with Weigelin and Lobstein technique enables to assess changes in blood pressures following a/m balneologic procedures. It was found that blood pressure does not change parallelly due to the mechanism of cerebral autoregulation. Transient decrease in blood pressure in the ophthalmic artery is produced by the dilatation of the internal carotid artery indicating a potent vasodilating action of carbon dioxide.     

环磺酮代谢物合成工艺研究

针对环磺酮代谢物开展制备工艺研究.以环磺酮为原料,经拜耳-维利格氧化重排等反应制备得到3个代谢物,含量均大于98.5％,满足用于农药登记、农残质检等领域的应用,极具社会应用价值.     

Effect of Polyhexamethylene Biguanide in Combination with Undecylenamidopropyl Betaine or PslG on Biofilm Clearance

Hospital-acquired infection is a great challenge for clinical treatment due to pathogens’ biofilm formation and their antibiotic resistance. Here, we investigate the effect of antiseptic agent polyhexamethylene biguanide (PHMB) and undecylenamidopropyl betaine (UB) against biofilms of four pathogens that are often found in hospitals, including Gram-negative bacteria Pseudomonas aeruginosa and Escherichia coli, Gram-positive bacteria Staphylococcus aureus, and pathogenic fungus, Candida albicans. We show that 0.02% PHMB, which is 10-fold lower than the concentration of commercial products, has a strong inhibitory effect on the growth, initial attachment, and biofilm formation of all tested pathogens. PHMB can also disrupt the preformed biofilms of these pathogens. In contrast, 0.1% UB exhibits a mild inhibitory effect on biofilm formation of the four pathogens. This concentration inhibits the growth of S. aureus and C. albicans yet has no growth effect on P. aeruginosa or E. coli. UB only slightly enhances the anti-biofilm efficacy of PHMB on P. aeruginosa biofilms. However, pretreatment with PslG, a glycosyl hydrolase that can efficiently inhibit and disrupt P. aeruginosa biofilm, highly enhances the clearance effect of PHMB on P. aeruginosa biofilms. Meanwhile, PslG can also disassemble the preformed biofilms of the other three pathogens within 30 min to a similar extent as UB treatment for 24 h.     

短开路耦合谐振器加载的宽带带通滤波电路

提出了一种基于短开路耦合器加载的宽带带通滤波电路. 该滤波电路通过在输入和输出端口之间,并连加载短路耦合微带谐振器和开路耦合微带谐振器实现5个传输极点和3个传输零点的带通选择特性. 对所提出的短开路耦合谐振器进行了奇偶模理论分析,揭示了其传输零极点形成的物理机理. 最后,对所提出的滤波电路进行了加工测试. 测试结果表明,所提出的宽带滤波电路能够在2.0～4.2 GHz频率范围内实现 3 dB 带通传输,工作相对带宽为73%,仿真和实测结果吻合较好.     

开绕组永磁同步电机系统有限集模型预测控制研究

提出了一种用于开绕组永磁同步电机(OW-PMSM)的快速模型预测控制方法,与传统模型预测电流控制(MPCC)相比,在不影响性能的情况下减少了预测的次数和时间.为了提高OW-PMSM的转速响应和抗负载扰动性,提出了单环模型预测控制(MPC),将速度环MPC和电流环MPC组合一起同时进行模型预测控制.仿真结果表明所提出方法能够有效降低算法复杂度和改善系统控制性能.     

开放式计算机数控系统的构建

文章首先指出了研究多轴数控加工技术的重要现实意义和深远意义.对CNC的开放性、开放标准、系统建模、实时性进行了分析研究,在此基础上创新性地提出了一种基于WinCE和DSP的开放式CNC的构建方案.     

基于无线网络的制造业物料配送系统的设计*

针对制造业传统物料配送系统存在的缺点,基于业务流程再造的理念,运用无线局域网技术设计了全新的物料配送系统。该系统能够对配送流程进行优化,提高了配送效率,有效地解决了配送不及时所造成的生产速度瓶颈问题。     

Ensemble deep transfer learning driven by multisensor signals for the fault diagnosis of bevel-gear cross-operation conditions

The existing intelligent fault diagnosis techniques of bevel gear focus on single-sensor signal analysis under the steady operation condition. In this study, a new method is proposed based on ensemble deep transfer learning and multisensor signals to enhance the fault diagnosis adaptability and reliability of bevel gear under various operation conditions. First, a novel stacked autoencoder(NSAE) is constructed using a denoising autoencoder, batch normalization, and the Swish activation function. Second, a series of source-domain NSAEs with multisensor vibration signals is pretrained. Third, the good model parameters provided by the source-domain NSAEs are transferred to initialize the corresponding target-domain NSAEs. Finally, a modified voting fusion strategy is designed to obtain a comprehensive result. The multisensor signals collected under the different operation conditions of bevel gear are used to verify the proposed method. The comparison results show that the proposed method can diagnose different faults in an accurate and stable manner using only one target-domain sample, thereby outperforming the existing methods.     

HFSS仿真在微波技术课程教学中的应用

为提升微波技术课程质量与教学效果,激发学员学习兴趣,提出将HFSS仿真应用于微波技术课程教学.首先对课程教学进行了分析;然后给出了HFSS仿真在课程教学中的应用方法;最后运用课堂中列举仿真实例方式,给出微波网络知识点教学的实施,并对其教学效果进行反馈调查.教学案例表明,HFSS仿真在微波技术课程教学中的应用提高了学员学习兴趣,加深了对知识的理解,从而有助于教员更好地教与学员更好地学.