Simulated fault injection: a methodology to evaluate fault tolerantmicroprocessor architectures

A simulation-based fault-injection methodology for validating fault-tolerant microprocessor architectures is described. The approach uses mixed-mode simulation (electrical/logic analysis), and injects transient errors in run-time to assess the resulting fault-impact. To exemplify the methodology, a fault-tolerant architecture which models the digital aspects of a dual-channel, real-time jet-engine controller is used. The level of effectiveness of the dual configuration with respect to single and multiple transients is measured. The results indicate 100% coverage of single transients. Approximately 12% of the multiple transients affect both channels; none result in controller failure since two additional levels of redundancy exist     

Modeling of power supply noise in large chips using the circuit-based finite-difference time-domain method

In this paper, a multilayered on-chip power distribution network consisting of two million passive elements has been modeled using the finite-difference time-domain (FDTD) method. In this method, a branch capacitor has been used. The use of the branch capacitor is important for simulating multilayered power grids. In addition, a method for including the CMOS inverter characteristics into the FDTD simulation has been presented. As an example of the application of this method, an H-tree clock network was simulated to compute the power supply noise distribution across an entire chip. Various scenarios with varying decoupling capacitances, load capacitances, number of clock buffers, and rise times have been analyzed to demonstrate the importance of circuit nonlinearity on power supply noise. Also, a method has been presented for analyzing package and board planes. Based on the methods presented, the interaction between chip and package has been discussed for capturing the resonant behavior that is otherwise absent when each section of the system is analyzed separately.     

Channel width dependence of hot electron injection program/hot hole erase cycling behavior in silicon-oxide-nitride-oxide-silicon (SONOS) memories

The channel width dependence of hot electron injection program/hot hole erase cycling behavior in silicon-oxide-nitride-oxide-silicon (SONOS) memories is investigated. While the trapped charge profile-dependent overerasure is observed in 10-μm-wide device, it is suppressed in 0.22-μm-wide device. Both the overerasure suppression and gradual positive threshold voltage shift in narrow device are explained as an elevated hot hole injection efficiency followed by more pronounced redistribution of the hole profile in the channel-center and the suppression of the lateral migration of injected holes in the channel-edge, by combining the measured endurance characteristics and TCAD simulation results. Main physical mechanisms are three-dimensional distribution of the electric field by gate/drain voltage, increasing interface states, and their trapped charge with cycling in the channel-edge.     

Effect of salt concentration and temperature of storage water on the physicochemical properties of fish proteins

Biochemical and physical properties of fish proteins from damaged (filleted and skinned) and undamaged (free of trauma or broken skin) Pacific whiting were investigated during chilling in various salt concentrations at 0.7 to ?1.1 °C. The increase of pH and moisture content were suppressed when chilling water contained higher concentration of NaCl. Conductivities of damaged fish were maximal after 24 h storage, but those of undamaged fish continuously increased throughout 72 h. K-values increased, but rapidly increased at lower salt concentrations. Puncture force and deformation were very low when chilled water contained higher concentration of salt (2–3 g/100 ml). Gel colors were also negatively affected as the concentration of salt increased for chilling water. Our study suggest Pacific whiting may be stored at 0–2 °C, but at 0–1 g/100 ml salt concentration.     

Development of method to model surface of reflowed square microlens for image sensor

A numerical method to model the surface of a reflowed square micro- lens is proposed to improve the simulation accuracy of photosensitivity for an image sensor. To verify the proposed method, a reflowed square microlens with base size of 4.8 x 4.8 mum and sag height of 1.55 mum was fabricated and the modelling accuracy was compared and analysed.     

Development and analysis of LOCA sequences for severe accident risk database

Although a Level 2 PSA has been performed for the Korean Standard Power Plants (KSNPs), and that it considered the necessary sequences for an assessment of the containment integrity and source term analysis. In terms of an accident management, however, more cases causing severe core damage need to be analyzed and arranged systematically for an easy access of the results. At present, KAERI is intensively calculating the severe accident sequences for various initiating events and generating a database for the accident progression including thermal hydraulic and source term behaviors. The developed database (DB) system includes a graphical display for a plant and equipment status, previous research results by a knowledge-based technique, and the expected plant behavior. The plant model used in this paper is oriented to the cases of LOCAs related to severe accident phenomena and thus can simulate the plant behaviors of a severe accident. Therefore, the developed system may play a central role as an information's source during the decision-making for a severe accident management, and be used as a training simulator for a severe accident management.     

Effect of Hydration Time and Salt Addition on Gelation Properties of Major Protein Additives

Gelation properties of 4 major protein additives were measured with and without salt during various hydration times. As hydration time increased, stress and strain of beef plasma and egg white gradually decreased regardless of salt. Unsalted whey proteins did not form a gel until the hydration time reached 48 h. Stress values of salted beef plasma with no hydration were significantly high. Soy protein isolate did not form a measurable gel at 9% concentration regardless of the presence of salt under rheological instruments, however its denaturation temperature was detected under DSC. Effect of salt on gel color was more pronounced with whey protein concentrate.     

Synthesis and structural properties of lithium titanium oxide powder as-synthesized by two step calcination process

A two-step calcination synthesis, considering the potential for mass production, of lithium titanium oxide powder was carried out to fabricate a single Li₄Ti₅O₁₂ phase, which is useful for anode electrode material of Li-based rechargeable battery as well as an electrode for supercapacitor. The final composition is controlled by adding more TiO₂ powder into powder gained at one calcination process during the two calcination process. We investigated the influence of excess TiO₂ on the structural characteristics of lithium titanium oxide synthesized by the two-step calcination method. X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR) measurements showed that the as-synthesized powder had a spinel crystal structure as well as A composition of 4: 5: 12. In addition, a high resolution transmission electron microscopy (HRTEM) analysis revealed that the fabricated powder exhibited a single crystalline phase formation. These results indicated that the powder synthesized in the one-step calcination process showed coexistence crystalline phases, which are the Li₄Ti₅O₁₂ and Li_2.39Ti_3.4O₈ phase. However, in the two-step calcination process, the powder synthesized showed the single crystalline Li₄Ti₅O₁₂ phase. A very uniform grain size of the as-synthesized powder was shown in a field emission scanning electron microscopy (FESEM). These results suggested that the two-step calcination process can be used for synthesis of single crystalline Li₄Ti₅O₁₂ powder with uniform grain shape and provide motivation to pursue mass production of lithium titanium based oxide powder for bulk type batteries.