scholarly journals Research and Design of Java Timing Processing Method

2021 ◽  
Vol 2066 (1) ◽  
pp. 012034
Author(s):  
Weiwen He
Keyword(s):  
Programming Languages ◽  
Time Sequence ◽  
Processing Method ◽  
Test Results ◽  
Improved Method ◽  
Root Cause ◽  
Military Applications ◽  
Correct Execution ◽  
Research And Design ◽  
Execution Order

Abstract There are differences among programming languages. In contrast to C/C++ in Linux, standard Java timer has some issues, such as uncontrollable execution order, unpredictable start moment and running duration, when it’s applied to handle dense timing tasks. So it could not be directly used by some military applications with strict requirements on time sequence. In this paper, its root cause is analyzed, and then an improved method based on queue and delay feedback is presented, as well as its implementation flow chart. The test results show that, this method is able to not only ensure the correct execution order, but also reduce the uncontrollable delay. So it could satisfy the time sequence demand of military applications.

Analysis Approach on DMOS Transistor Vth Mismatch Due to Trapped Charges

2015 ◽  
Author(s):  
Hashim Ismail ◽  
Ang Chung Keow ◽  
Kenny Gan Chye Siong
Keyword(s):  
Failure Analysis ◽  
Threshold Voltage ◽  
Gate Oxide ◽  
Analysis Approach ◽  
Test Results ◽  
Root Cause ◽  
Switching Event ◽  
Output Transistor ◽  
Event Based ◽  
Trapped Charge

Abstract An output switching malfunction was reported on a bridge driver IC. The electrical verification testing revealed evidence of an earlier over current condition resulting from an abnormal voltage sense during a switching event. Based on these test results, we developed the hypothesis that a threshold voltage mismatch existed between the sense transistor and the output transistor. This paper describes the failure analysis approach we used to characterize the threshold voltage mismatch as well as our approach to determine the root cause, which was trapped charge on the gate oxide of the sense transistor.

scholarly journals Full Aperture CO2Laser Process to Improve Laser Damage Resistance of Fused Silica Optical Surface

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Wei Liao ◽  
Chuanchao Zhang ◽  
Xiaofen Sun ◽  
Lijuan Zhang ◽  
Xiaodong Yuan
Keyword(s):  
Damage Threshold ◽  
Fused Silica ◽  
Processing Temperature ◽  
Test Results ◽  
Optical Surface ◽  
Improved Method ◽  
Damage Resistance ◽  
Scanning Velocity ◽  
High Laser ◽  
Laser Flux

An improved method is presented to scan the full-aperture optical surface rapidly by using galvanometer steering mirrors. In contrast to the previous studies, the scanning velocity is faster by several orders of magnitude. The velocity is chosen to allow little thermodeposition thus providing small and uniform residual stress. An appropriate power density is set to obtain a lower processing temperature. The proper parameters can help to prevent optical surface from fracturing during operation at high laser flux. S-on-1 damage test results show that the damage threshold of scanned area is approximately 40% higher than that of untreated area.

Failure Investigation of 1st Stage Buckets From Frame 3002, 10 MW Gas Turbine Unit

2011 ◽  
Author(s):  
Girish M. Shejale ◽  
David Ross
Keyword(s):  
Gas Turbine ◽  
Test Results ◽  
High Carbon ◽  
High Carbon Content ◽  
Metallurgical Investigation ◽  
Root Cause ◽  
Failure Investigation ◽  
Surface Failure ◽  
Grain Boundary Embrittlement ◽  
Industrial Gas Turbine

The 1st stage buckets in Frame 3002, 10 MW industrial gas turbine experienced premature failures. The buckets failed unexpectedly much earlier than the designed bucket life. Bucket material is Inconel 738, with platinum-aluminized coating on the surface. Failure investigation of the buckets was performed to know the root cause of the failure. The failure investigation primarily comprised of metallurgical investigation. The results of the metallurgical investigation were co-related with the unit operational history. This paper provides an overview of 1st stage buckets investigation. The metallurgical investigation performed concluded prime failure mechanism due to high carbon content of bucket material and improper heat treatment. The bucket coating was initially damaged during the first loading and fracture occurred due to grain boundary embrittlement in short span of service. The metallurgical tests performed included Visual inspection, Scanning Electron Microscopy (SEM), Energy Dispersive Analysis of X-ray (EDS), Chemical analysis, Tensile test and Hardness survey. The test results, discussions and conclusions are presented in this paper.

scholarly journals Determination of Tiamulin in Type C Medicated Swine Feeds Using High Throughput Extraction with Liquid Chromatography

2002 ◽  
Vol 85 (3) ◽  
pp. 533-540 ◽  
Author(s):  
Douglas B Moore ◽  
Nancy L Britton ◽  
Robert L Smallidge ◽  
Ken L Riter
Keyword(s):  
Liquid Chromatography ◽  
Mobile Phase ◽  
Test Results ◽  
Improved Method ◽  
Mobile Phase Composition ◽  
Significance Level ◽  
Paired Sample ◽  
Recovery Study ◽  
Type C

Abstract An improved method for extraction and analysis of tiamulin is presented to address issues that arose during routine analysis of Type C medicated swine feeds under the current U.S. Food and Drug Administration-Center for Veterinary Medicine (FDA-CVM) approved method. The issues included the need for higher sample throughput and the ability to accommodate a wider variety of feed matrixes. Changes to the FDA-CVM approved method include reduced sample size and solvent volumes, phosphate buffering of tartaric acid, centrifugation, and use of a new liquid chromatography column and adjusted mobile phase composition. A paired sample study was performed to compare performance of the new and existing methods. The paired sample study showed no statistical difference between sample means of paired sets of 17 samples analyzed by both methods (t = 1.95 at 0.05 significance level, p = 0.068). A recovery study showed the method precision to be 2.06% (coefficient of variation) with an average standard recovery of 95.8%. Ruggedness test results indicated good overall ruggedness of the method.

scholarly journals Finite-element analysis and structure optimization of X-O composite seal of cone bit

2020 ◽  
Vol 12 (5) ◽  
pp. 168781402091868
Author(s):  
Shuang Jing ◽  
Anle Mu ◽  
Yi Zhou ◽  
Ling Xie
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Structural Parameters ◽  
Structure Optimization ◽  
Seal Ring ◽  
Test Results ◽  
Element Analysis ◽  
Root Cause ◽  
Sealing Performance ◽  
Distribution Of Stress

The seal is the key part of the cone bit. To reduce the failure probability, a new seal was designed and studied. The sealing performance and structure optimization of the X-O composite seal was analyzed and compared by finite-element analysis. The stress and contact pressure were analyzed to establish the main structural parameters that affect sealing performance and the direction of the structural optimization. By optimizing these structural parameters, including the height, and the radial and axial arc radii, an optimized structure is obtained. The results show that (1) the X-O composite seal can meet the seal requirement, the excessive height of the X seal ring is the root cause of the uneven distribution of stress, pressure, and distortion. (2) A new seal structure is obtained, the distribution of pressure and stress is reasonable and even, and the values of stress and pressure are reduced to avoid distortion and reduce the wear. Finally, the field test results of the X-O composite seal of cone bit showed that the service life of the bit bearing increased by 16% on average and the drilling efficiency increased by 11% on average compared with the original cone bit with the O seal ring.

Dynamic Research and Design on SINS Damping System in Vehicle

2011 ◽  
Vol 328-330 ◽  
pp. 1679-1683
Author(s):  
Jie Li ◽  
Rui Ping Tao ◽  
Jun Liu ◽  
Wei Chen
Keyword(s):  
Vibration Isolation ◽  
Inertial Navigation ◽  
Vibration Damping ◽  
Test Results ◽  
Characteristic Analysis ◽  
Isolation System ◽  
Vibration Isolation System ◽  
System Vibration ◽  
Research And Design ◽  
Damping Model

For the vibration noise problem of strap-down inertial navigation system in the vehicle, a better vibration damping system was designed. Based on the vibration characters of the vehicle environment, a vibration damping model fitted the SINS in the vehicle was presented; and then the mechanism of vibration damping system was designed especially; and then the design of vibration damping system was verified by using of the dynamic characteristic analysis, On the basis of the above analysis, the overall structure of actual vibration isolation system was built, and then the test for the vibration isolation system was made, the results show that the micro-isolation system for the SINS system vibration and noise has a better inhibition effect, and the applicability and the dependability of the vibration damping system is verified by the test results, which provides reference basis for the design of the strap-down inertial navigation damping system in the land vehicle and provides techniques for the better application of SINS in other fields.

scholarly journals Analysis and Disposal of Typical Breakdown Failure for Resin Impregnated Paper Bushing in the Valve Side of HVDC Converter Transformer

Energies ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 4303 ◽  
Author(s):  
Hao Tang ◽  
Guangning Wu ◽  
Ming Chen ◽  
Jiang Deng ◽  
Xining Li
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Fault Current ◽  
Special Device ◽  
Test Results ◽  
The Finite Element Method ◽  
Load Current ◽  
High Voltage Direct Current ◽  
Root Cause ◽  
Current Characteristics

This paper presents analysis, diagnosis and disposal with a typical internal breakdown failure of the resin impregnated paper (RIP) valve side bushing in high voltage direct current (HVDC) converter transformer. Based on the analysis of fault current characteristics at the time of the RIP valve side bushing failure, and field test results of insulation parameters, a method of diagnosing typical breakdown failures of valve side bushings is proposed. Through disassembly inspection of the internal overheating and arcing traces on the failure bushing, the root cause of this typical breakdown failure is found, which is upper axial flashover along the RIP condenser/SF6 interface caused by the abnormal contact of two current-carrying conductive tubes. Temperature distribution inside the bushing with an abnormal contact resistance between the copper conductive tube and aluminum conductive tube under different load current is simulated by using the finite element method. An special device is also developed for repairing defective bushing on-site, and 75 bushings with conductive contact defects have been repaired on the premise of not pushing converter transformers away from the valve hall and even without pulling out defective bushings.

Mobile Instant Messaging in the Workplace: Research and Design

2014 ◽  
Vol 556-562 ◽  
pp. 6336-6339 ◽  
Author(s):  
Wei Dong
Keyword(s):  
Mobile Communication ◽  
System Architecture ◽  
Instant Messaging ◽  
Mobile Internet ◽  
Workplace Communication ◽  
Internet Services ◽  
Test Results ◽  
Work Efficiency ◽  
Message Exchange ◽  
Research And Design

The last decade has seen a significant popularity of instant messaging and its main usage is for recreational purposes. However, instant messaging can also be utilized in the workplace and by utilizing such tools more efficiency of workplace communication can be achieved. For this purpose, in this paper we conduct research on mobile instant messaging in the workplace. Mobile Internet services based communication is chosen because mobile communication is playing an important role in today's communication system. First, the system architecture of a mobile instant messaging is presented. Some main functionality, such as message exchange and file transmission, are elaborated. Then, based on this architecture, an android-based messaging client and a Linux-based server are developed. Finally, the instant messaging software is tested in a real mobile communication network and test results show that the software works well. As mobile Internet services become increasingly important, the instant messaging tool developed in this paper will be utilized in the workplace as a communication means and will improve work efficiency greatly in the future.

Studies on Scroll Compressor Noise Improvement

2014 ◽  
Vol 694 ◽  
pp. 504-508
Author(s):  
Qing Miao ◽  
Yan Ru Men ◽  
Jin Xiang Wu ◽  
Xiang Gou
Keyword(s):  
Intensity Distribution ◽  
Noise Level ◽  
Sound Intensity ◽  
Specific Method ◽  
Test Results ◽  
Scroll Compressor ◽  
Root Cause ◽  
Additional Weight ◽  
Noise Characteristics ◽  
Noise Test

As the environment and customer are sensitive to compressor noise from refrigeration air condition system, it’s necessary to reduce noise level for scroll compressor to compete with piston one in this field. In this paper, we studied one way to detect noise resource and reduce noise level for scroll compressor; analyzed its vibration and noise characteristics; got the sound intensity distribution on the surface of compressor; performed the model test of the main part by using hammer strike and gained their intrinsic frequents. At last, by comparing the scroll compressor noise test results, sound intensity distribution, and intrinsic frequents, it was confirmed that upper shell resonation is the root cause to increase the noise. Also we gave a specific method, adding additional weight to upper shell, to avoid resonation. It’s proved to be efficient after test check.

EMD Based on Time-Sequence and Window Function and its Application in Diagnosis of Machinery Faults

2013 ◽  
Vol 470 ◽  
pp. 353-356
Author(s):  
Ren Ze Luo ◽  
Peng Cao ◽  
Yuan Hua Fu ◽  
Ya Bin Huang ◽  
Qing Yang
Keyword(s):  
Signal Analysis ◽  
Moving Average ◽  
Time Sequence ◽  
Window Function ◽  
Autoregressive Moving Average ◽  
End Effect ◽  
Improved Method ◽  
Mode Decomposition ◽  
Time Varying Parameter ◽  
The Impact

To solve the end effect occurring in empirical mode decomposition adopted in the course of decomposition, we propose an improved method on the basis of time-sequence analysis and cosine window function. First, the ARMA (Autoregressive Moving Average) of time-varying parameter is adopted to extend signals, and thus the extended data can be smoothly connected with the original signal at the end. Second, the extended signals are processed with cosine window, so that the extended errors will exert no impact on the existing data. Finally, the signals processed as above mentioned will be decomposed with EMD to confine the end effect to the ends of the signal. The simulation and fault signal analysis prove that the proposed method can effectively reduce the impact of the end effect and be applied in rotating machinery fault diagnosis.

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