• Proceedings of the KIEE Conference
• /
• 2006.07c
• /
• pp.1621-1622
• /
• 2006

This paper presents the effect of driving waveform for piezoelectric bend mode inkjet printhead with optimized mechanical design. Experimental and theoretical studies on the applied driving waveform versus jetting characteristic s were performed. The inkjet head has been designed to maximize the droplet velocity, minimize voltage response of the actuator and optimize the firing frequency to eject ink droplet. The head design was carried out by using mechanical simulation. The printhead has been fabricated with Si(100) and SOI wafers by MEMS process and silicon direct bonding method. To investigate how performance of the piezoelectric ceramic actuator influences on droplet diameter and droplet velocity, the method of stroboscopy was used. Also we observed the movement characteristics of PZT actuator with LDV(Laser Doppler Vibrometer) system, oscilloscope and dynamic signal analyzer. Missing nozzles caused by bubbles in chamber were monitored by their resonance frequency. Using the water based ink of viscosity of 4.8 cps and surface tension of 0.025N/m, it is possible to eject stable droplets up to 20kHz, 4.4m/s and above 8pL at the different applied driving waveforms.

• Proceedings of the Korea Contents Association Conference
• /
• 2007.11a
• /
• pp.396-400
• /
• 2007

Linking of the national R&D information between different ministries is a difficult task because they were all constructed independently. A standard infrastructure for the dissemination of such R&D information is required. This paper suggests a distributed integration method for the effective linking, gathering and integration of national R&D information. R&D management institutes designated by each ministry will gather and manage all the R&D information produced using the budget by the ministry and the information required for the integrated management of national R&D will be gathered from this information. Standardization of the R&D information, linking procedure and the construction method for the data linking software will be defined in this paper. The usage of R&D information will be processed more effectively to maximize the utiliation and productivity of national R&D activities.

• Journal of Technology Innovation
• /
• v.24 no.1
• /
• pp.1-24
• /
• 2016

This study examined 142 electronic components, video, audio, and communications equipment manufacturers (KSIC 32) out of all the SMEs that responded to the Survey on Technology of the Small and Medium Enterprises in both 2005 and 2007 and empirically analyzed how the external resources utilization and the absorptive capability affected the management and the innovation performance in two years as well as how the absorptive capability moderated these relationships. According to the results of analysis, the external resources utilization, as measured by the technology collaboration and the governments R&D subsidies, did not have a significant impact on performance whereas R&D investment showed a positive (+) influence on the sales and R&D personnel ratio, negative (-). On the other hand, the moderating effect of absorptive capability varied by measurement method and independent variables. That is, when a technology collaboration takes place, the performance improved with the increase of R&D investment but R&D personnel ration had an opposite effect. The companies whose performance improved as the government R&D subsidies increase are those with low R&D investment or high R&D personnel ratio. These results demonstrate that the SME's external resources utilization cannot replace the internal and that the absorptive capability needs to be accumulated to maximize the effectiveness of external resources utilization. Also, the technology collaboration requires SME's aggressive investment in R&D and the government R&D subsidies turn out to be more helpful for the companies that already have the R&D personnel but have been unable to develop their own technology due to insufficient funds. This study has limitations in that it was conducted within the limited industry categories and samples, but has overcome those of the existing researches by identifying causal relationships through the use of longitudinal data.

• Microbiology and Biotechnology Letters
• /
• v.36 no.1
• /
• pp.28-33
• /
• 2008

The expression vector (pWHM3-TR1R2) for sprT gene encoding Streptomyces griseus trypsin (SGT) followed by two regulatory genes, sgtR1 and sgtR2, was introduced into Streptomyces lividans TK24 and Streptomyces griseus IFO 13350. Various media with different compositions were used to maximize the productivity of SGT in the recombinant trains. he SGT productivity was best when the transformant of S. lividans TK24 was cultivated in R2YE medium (0.74 unit/mL) at 5 days of cultivation. C5/L (0.66 unit/mL) medium also gave a good productivity, but Livid (0.08 unit/mL) and NDSK (0.06 unit/mL) yielded poor productivities. S. griseus IFO 13350/pWHM3-TR1R2 produced SGT by 1.518 unit/mL (C5/L), 1.284unit/mL (R2YE),0.932 unit/mL (NDSK), and 0.295 unit/mL (Livid) at 7 days of cultivation, which was much higher than those from S. lividans TK24/TR1R2. The SGT protein was purified from the culture broth of S. griseus IFO 13350/pWHM3-TR1R2 in C5/L to homogeneity via ammonium sulfate fractionation, and CM-sepharose and SP-sepharose column chromatographies. The specific activity of purified SGT was 69,252 unit/mg, and the final purification fold and recovery yield were 6.5 and 1.4%, respectively.

• Journal of Advanced Navigation Technology
• /
• v.24 no.3
• /
• pp.184-191
• /
• 2020

Avionics System Integration Laboratory is the integrated test environment for integration and verification of avionics systems. When real equipment can not be used in the laboratory for various reasons, software models should be needed. Because there hasn't been any standardized method for the models so that it is difficult to reuse the developed models, the need for a framework to develop the avionics software models was emerged. We adopted DEVS(discrete event system specification) formalism as the standardized modeling method for the avionics software models. Due to DEVS formalism is based on event-driven algorithm, it doesn't accord a legacy system which has sequential and periodic algorithms. In this paper, we propose real-time event-driven modeling and simulation method for SIL to overcome these restrictions and to maximize reusability of avionics models through the analysis of the characteristics and the limitations of avionics models.

• Journal of Korea Technology Innovation Society
• /
• v.12 no.3
• /
• pp.614-637
• /
• 2009

To enhance the efficiency of national R&D programs, it is the most important thing to establish the optimized evaluation system. This is because the distorted evaluation could be an obstacle to select the best suited research team and lead the desirable research result. In current evaluation process of national R&D program, it is the most frequently used method for eliminating an evaluator's biased view to exclude both the maximum and minimum scores. However, there are several limitations in this stereotype method. Therefore, this study analyzes some real cases to derive the problems from the stereotype method and then recommends the complementary alternatives which can enhance the reliability of the evaluation system for national R&D programs. The results acquired from this study seem to be helpful to increase the agreement of the applicants on the evaluation results and ultimately to maximize the efficiency of national R&D program. In addition, they can be applied to various field with respect to the methodology for ranking decision.

• BMB Reports
• /
• v.32 no.1
• /
• pp.86-91
• /
• 1999

The sprT gene encoding Streptomyces griseus trypsin (SGT) was introduced into Streptomyces lividans TK24 and Streptomyces lividans 1326 to study which strain would be better to overexpress the extracellular proteinase. Various media with different compositions were also used to maximize the productivity of SGT in heterologous hosts. The SGT productivity was best when the transformants of S. lividans TK24 and 1326 were cultivated in R2YE medium, and their relative trypsin activity of the culture broth measured with an artificial chromogenic substrate, N-${\alpha}$-benzoyl-DL-arginine-${\rho}$-nitroanilide, were 382 units/ml and 221 units/ml, respectively. They produced high levels of SGT in GYE medium but relatively lower than those in R2YE medium, and negligible amount of SGT was produced in Ferm, RASF, LIVID, and NDSK media. Considering non-SGT associated activity in Pronase powder, it was estimated that the transformant of S. lividans TK24 can produce SGT in R2YE 3.5 times more than the amount by S. griseus 10137 from which the sprT gene had been originated. The growth of S. lividans reached the maximum level of cell mass at 5 d of culture, but SGT production started in the stationary phase of cell growth and kept increasing until the ninth day of culture in R2YE medium, but in GYE media the productivity reached at the maximum level at 7 d of cultivation.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.31 no.10A
• /
• pp.943-951
• /
• 2006

Multi-input-multi-output (MIMO) systems are considered to improve the capacity and reliability of next generation mobile communication. However, the multiple RF chains associated with multiple antennas are costly in terms of size, power and hardware. Antenna selection is a low-cost low-complexity alternative to capture many of the advantages of MIMO systems. We proposed new joint Tx/Rx antenna selection algorithm with low complexity. The proposed algorithm is a method selects $L_R{\times}L_T$ channel matrix out of $L_R{\times}L_T$ entire channel gain matrix where $L_R{\times}L_T$ matrix selects alternate Tx antenna with Rx antenna which have the largest channel gain to maximize Frobenius norm. The feature of this algorithm is very low complexity compare with Exhaustive search which have optimum capacity. In case of $4{\times}4$ antennas selection out of $8{\times}8$ antennas, the capacity decreases $0.5{\sim}2dB$ but the complexity also decreases about 1/10,000 than optimum exhaustive search.

• Asian-Australasian Journal of Animal Sciences
• /
• v.22 no.1
• /
• pp.131-138
• /
• 2009

Among rumen microbes, bacteria play important roles in the biological degradation of plant fiber due to their large biomass and high activity. To maximize the utilization of fiber components such as cellulose and hemicellulose by ruminant animals, the ecology and functions of rumen bacteria should be understood in detail. Recent genome sequencing analyses of representative fibrolytic bacterial species revealed that the number and variety of enzymes for plant fiber digestion clearly differ between Fibrobacter succinogenes and Ruminococcus flavefaciens. Therefore, the mechanism of plant fiber digestion is also thought to differ between these two species. Ecology of individual fibrolytic bacterial species has been investigated using pure cultures and electron microscopy. Recent advances in molecular biology techniques complement the disadvantages of conventional techniques and allow accurate evaluation of the ecology of specific bacteria in mixed culture, even in situ and in vivo. Molecular monitoring of fibrolytic bacterial species in the rumen indicated the predominance of F. succinogenes. Nutritive interactions between fibrolytic and non-fibrolytic bacteria are important in maintaining and promoting fibrolytic activity, mainly in terms of crossfeeding of metabolites. Recent 16S rDNA-based analyses suggest that presently recognized fibrolytic species such as F. succinogenes and two Ruminococcus species with fibrolytic activity may represent only a small proportion of the total fibrolytic population and that uncultured bacteria may be responsible for fiber digestion in the rumen. Therefore, characterization of these unidentified bacteria is important to fully understand the physiology and ecology of fiber digestion. To achieve this, a combination of conventional and modern techniques could be useful.

• Smart Structures and Systems
• /
• v.16 no.6
• /
• pp.1023-1047
• /
• 2015

In this study, the optimal location of the MR fluid segments in a partially treated laminated composite sandwich plate has been identified to maximize the natural frequencies and the loss factors. The finite element formulation is used to derive the governing differential equations of motion for a partially treated laminated composite sandwich plate embedded with MR fluid and rubber material as the core layer and laminated composite plate as the face layers. An optimization problem is formulated and solved by combining finite element analysis (FEA) and genetic algorithm (GA) to obtain the optimal locations to yield maximum natural frequency and loss factor corresponding to first five modes of flexural vibration of the sandwich plate with various combinations of weighting factors under various boundary conditions. The proposed methodology is validated by comparing the natural frequencies evaluated at optimal locations of MR fluid pockets identified through GA coupled with FEA and the experimental measurements. The converged results suggest that the optimal location of MR fluid pockets is strongly influenced not only by the boundary conditions and modes of vibrations but also by the objectives of maximization of natural frequency and loss factors either individually or combined. The optimal layout could be useful to apply the MR fluid pockets at critical components of large structure to realize more efficient and compact vibration control mechanism with variable damping.