• Journal of information and communication convergence engineering
• /
• v.19 no.3
• /
• pp.175-179
• /
• 2021

Enhancing the reliability of the system is important for recent system-on-chip (SoC) designs. This importance has led to studies on fault diagnosis and tolerance. Fault-injection (FI) techniques are widely used to measure the fault-tolerance capabilities of resilient systems. FI techniques suffer from limitations in relation to environmental conditions and system features. Moreover, a hardware-based FI can cause permanent damage to the target system, because the actual circuit cannot be restored. Accordingly, we propose a simulation-based FI framework based on the Verilog Procedural Interface for measuring the failure rates of SoCs caused by soft errors. We execute five benchmark programs using an ARM Cortex M0 processor and inject soft errors using the proposed framework. The experiment has a 95% confidence level with a ±2.53% error, and confirms the reliability and feasibility of using proposed framework for fault analysis in SoCs.

• Journal of the Optical Society of Korea
• /
• v.18 no.6
• /
• pp.720-731
• /
• 2014

There are many kinds of optical systems to widen a field of view. Fisheye lenses with view angles of 180 degrees and omni-directional systems with the view angles of 360 degrees are recognized as proper systems to widen a field of view. In this study, we proposed a new optical system to overcome drawbacks of conventional omni-directional systems such as a limited field of view in the central area and difficulties in manufacturing. Thus we can eliminate the undesirable reflection components of the omni-directional system and solve the primary drawback of the conventional system. Finally, tolerance analysis using Zernike polynomial coefficients was performed to confirm the productivity of the new optical system. Furthermore, we established a method of optical axis alignment and compensation schemes for the proposed optical system as a result of tolerance analysis. In a sensitivity calculation, we investigated performance degradation due to manufacturing error using Code V(R) macro function. Consequently, we suggested compensation schemes using a lens group decentering. This paper gives a good guidance for the optical design and tolerance analysis including the compensation method in the extremely wide angle system.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.27 no.9
• /
• pp.1597-1606
• /
• 2003

Static analysis using hybrid finite element(FE) method has been applied to characterize the influence of position, runout and thickness errors of the sun, ring and planet on the bearing forces and critical tooth stress. Some guidelines for tolerance control to manage critical stress and bearing forces are deduced from the results. Carrier indexing error planet assembly and planet tooth thickness error are most critical to reduce planet bearing force and maximize load sharing as well as to reduce critical stresses. Sun and carrier bearing forces due to errors increase several times more than those of normal condition.

• Journal of the Korean Society for Precision Engineering
• /
• v.25 no.5
• /
• pp.69-76
• /
• 2008

Inner diameter of bearing race is automatically measured by complete inspection system after grinding process. Contact type three points supporting method is widely applied to automatic inner diameter measurement because of its excellent stability. However, the geometric consideration regarding three points supporting method is not sufficient. In this study, the error equation from geometric error analysis of three points supporting method is found. The effect of factors in the error equation is also investigated. The error equation is linear for difference of diameter in sample and master on range of tolerance. An error becomes more and more larger, when the distance of two supporting balls or the diameter of supporting ball are increased. In the result, some considerations are proposed for measurement of inner diameter by the three points supporting method.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.13 no.8
• /
• pp.3470-3476
• /
• 2012

In this study, for cadastral surveying specified in current relevant legislation, regulations of allowable error tolerance and applicable equipments, accuracy in the relevant regulations and applicable regulations were comprehensively studied. Based on them, the objective was to develop performance standard for cadastral surveying equipments satisfying allowable error tolerance of cadastral surveying specified in the special law for cadastral re-survey. The study results are as follows. By comparing current legislation for performance and allowable error tolerance of applicable equipments with provisions of the special law for cadastral re-survey, analyzed were where performance of equipments needs to be improved on cadastral re-survey project. Based on them, as primary control point surveying and detail surveying were separated, performance standard of equipments were presented. Results of this study may be utilized as basic materials for supply and demand program of surveying equipments on establishment of the basic plan for cadastral re-survey project.

• Applied Biological Chemistry
• /
• v.36 no.1
• /
• pp.38-44
• /
• 1993

1) OBT7 mutant was isolated by W light-butanol tolerance from Clostridium saccharoperbutylacetonicm ATCC 13564 (N1-4 strain). The mutant produced 16.5 g/l (1.4-fold increase) of n-butanol, 4.65 g/l (1.5-fold increase) of acetone, and 21.5 g/l of total solvent. It was suggested that clostridial bacteria producing n-butanol does not have a poor effect on misrepair via an error-prone pathway by UV light-butanol tolerance. 2) Compared to glucose fermentation, in mannitol fermentation, OBT7 mutant did not produce acetone and acetic acid. And the ratios of n-butanol and ethanol to total solvents increased by 10.3% and 10.5%, respectively, totalling 20.8%, while the ratio of acetone was decreased by 21.2%. Also the maximum ratio of n-butanol to total solvents reached 94.8%. These results indicated that oxidized compound (acetone, acetic acid, and butyric acid) was converted to the reduced compounds (n-butanol, and ethanol). Therefore, mannitol can be used to eliminate by-products of oxidized compound.

• Transactions of the Korean Society of Machine Tool Engineers
• /
• v.18 no.1
• /
• pp.116-121
• /
• 2009

Thermosonic flip chip bonding is an important technology for the electronic packaging due to its simplicity, cost effectiveness and clean and dry process. Mechanical properties of the horn and the shank, such as the natural frequency and the amplitude, have a great effect on the bonding capability of the transverse flip chip bonding system. In this research, two kinds of study are performed. The first is the new design of the clamp and the second is the effect of tolerance parameters to the performance of the system. The clamp with a bent shape is newly designed to hold the nodal point of the flip chip. The second is the effect of the design parameters on the vibration amplitude and planarity at the end of the shank. The variation of the tolerance parameters changes the amplitude and the frequency of the vibration of the shank. They, in turn, have an effect on the quantity of the plastic deformation of the gold ball bump, which determined the quality of the flip chip bonding. The tolerance parameters that give the great effect on the amplitude of the shank are determined using Taguchi's method. Error of set-up angle, the length and diameter of horn and error of the length of the shank are determined to be the parameters that have peat effect on the amplitude of the system.

• The Transactions of the Korea Information Processing Society
• /
• v.6 no.10
• /
• pp.2618-2629
• /
• 1999

In this paper, we describe the design and implementation of the FDRA(Fault Detection Recovery based on Agent) running on distributed multimedia environment. DOORAE is a good example for distributed multimedia and multimedia distance education system among students and teachers during lecture. It has primitive service agents. Service functions are implemented with objected oriented concept. FDRA is a multi-agent system. It has been environment, intelligent agents interact with each other, either collaboratively or non-collaboratively, to achieve their goals. The main idea is to detect an error by using polling method. This system detects an error by polling periodically the process with relation to session. And, it is to classify the type of error s automatically by using learning rules. The merit of this system is to use the same method to recovery it as it creates a session. FDRA is a system that is able to detect an error, to classify an error type, and to recover automatically a software error based on distributed multimedia environment.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.45 no.11
• /
• pp.50-55
• /
• 2008

As more DSP functionalities are integrated into an embedded mobile device, power consumption and device reliability have emerged as crucial issues. As the complexity of mobile embedded designs increases very rapidly, verifying the functionality of the mobile devices has become extremely difficult. Therefore, designs with error (fault) tolerance are often required since these capabilities will enable the design to operate properly even with some existence of errors. However, designs with fault tolerance may suffer from significant power overhead since fault tolerance is often achieved by resource replication. In this paper, we propose a low power and fault tolerant MAC (multiply-and-accumulate) design. The proposed MAC design is based on multiple barrel shifters since MAC designs with barrel-shifters and adders are known to be excellent in terms of power consumption.

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.41 no.6
• /
• pp.33-41
• /
• 2004

This paper proposes a color matching 3D look-up table simplifying the complex color matching procedure between a monitor and a mobile display device. In other to perform color matching, it is necessary to process color of image in the device independent color space like CIEXYZ or CIELAB. To obtain the data of the device independent color space from that of the device dependent RGB color space, we must perform display characterizations. LCD characterization error using S-curve model is larger than tolerance error since LCD is more nonlinear than CRT. This paper improves the S-curve model to have smaller characterization error than tolerance error using the electro-optical transfer functions of X, Y, and Z value. We obtained images having higher color fidelity on mobile display devices through color matching experiments between monitor and mobile display devices. As a result of this experiments, we concluded that the color matching look-up table with 64(4${\times}$4${\times}$4) is the smallest size allowing characterization error to be acceptable.