• Journal of the Korean Society of Combustion
• /
• v.13 no.1
• /
• pp.17-22
• /
• 2008

A partly implicit/quasi-explicit method is introduced for the solution of detailed chemical kinetics with stiff source terms based on the standard fourth-order Runge-Kutta scheme. Present method solves implicitly only the stiff reaction rate equations, whereas the others explicitly. The stiff equations are selected based on the survey of the chemical Jaconian matrix and its Eigenvalues. As an application of the present method constant pressure combustion was analyzed by a detailed mechanism of hydrogen-air combustion with NOx chemistry. The sensitivity analysis reveals that only the 4 species in NOx chemistry has strong stiffness and should be solved implicitly among the 13 species. The implicit solution of the 4 species successfully predicts the entire process with same accuracy and efficiency at half the price.

• 한국연소학회:학술대회논문집
• /
• 2012.11a
• /
• pp.67-70
• /
• 2012

Many computational fluid dynamic (CFD) simulations have treated the coal kinetics poorly due to large physical domain sizes and high computational complexity, particularly for the recent oxy-coal boilers. Furthermore, some modelers' lack of understanding of the kinetic rate model seems to worsen the simulation accuracy. This study is to suggest the importance of proper use of single-film global kinetic model generally used in CFD code to describe the oxy-fuel combustion of coal char through simple char burnout calculation.

• Journal of Microbiology and Biotechnology
• /
• v.21 no.10
• /
• pp.1069-1072
• /
• 2011

A real-time PCR assay method was established to monitor Leuconostoc spp. populations via specific amplification of the dextransucrase gene. Quantification of L. mesenteroides B-512F using both genomic DNA and cell suspensions yielded a log-linear correlation spanning approximately 5 log units. By using this method, monitoring changes of Leuconostoc spp. during sauerkraut fermentation was successfully accomplished with accuracy after inoculation of starter and sugars (sucrose and maltose).

• 한국생물공학회:학술대회논문집
• /
• 2000.11a
• /
• pp.264-265
• /
• 2000

Helicobacter pylori(H. pylori) is the causative agent of chronic gastritis and the single most important factor in peptic ulcer disease, however, the pathogenetic mechanisms underlying H, pylori infection are not well understood. Futhermore, there is a strong association between H. pylori infection and gastric cancer. Various diagnostic methods for detecting H. pylori infection are available. These can be divided into invasive methods, requiring endoscopy, and non-invasive tests, mainly 13C-urea breath tests and serologic detection of antibodies. Rapid urease test is the most recommendable endoscopic test for the diagnosis of H. pylori infection, presently. CLO test kit is the represent of rapid urease test kits. The principles of CLO test kit is that hydrolysis of urea by urease Is detected by a dye indicators showing a color change. Our device is used same principle but we improved the reaction time is more faster and positive color change is more distinctive from the color of the negative specimen. So, this kit is more reliable because it response faster and accuracy.

• Transactions of the Korean Society of Machine Tool Engineers
• /
• v.11 no.5
• /
• pp.7-14
• /
• 2002

In order to achieve high precision machine tools, the research for performance enhancement of feed drive systems is required. Development of the high speed feed drive system has been a major issue for the past few decades in machine tool indestries. Because table levitation system decrease the table weight, an effect of reaction by weight is minimized and lost motion can be removed at maximum. In case fled system is designed with drive motor, ball screw and support bearing load capacity selection, an effect of decrease of the table weight exist. So, the table weight through an effect of decrease call it into the realization of cost down. Stick-slip friction has a great influence on the contouring accuracy of CNC machine tools. In this paper table levitation system has been developed for the stick-slip in a fled drive systems.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2000.11a
• /
• pp.358-361
• /
• 2000

To reduce the leadtime for a new model according to the strict market requirements, automobile manufacturer begins to utilize 3-dimensional CAD based techniques such as DMU(Digital Mock-Up). RP(Rapid Prototyping), VE(Virtual Engineering). But, not so many satisfactory utilities have been introduced to deal with the emotional properties such as embossment on the surface of interior parts and touch from material characteristics in virtual environment. It is required to manufacture prototype parts to verify actual feeling of the passengers in real automobile. This paper suggests a methodology to enhance emotional property via embedding embossment on the surface of prototype car interior trim without deterioration of dimensional accuracy using RIM(Reaction Injection Molding) and vacuum forming method.

• Journal of Mechanical Science and Technology
• /
• v.17 no.12
• /
• pp.1912-1921
• /
• 2003

This paper presents a global mode modeling of space structures and a control scheme from the practical point of view. Since the size of the satellite has become bigger and the accuracy of attitude control more strictly required, it is necessary to consider the structural flexibility of the spacecraft. Although it is well known that the finite element (FE) model can accurately model the flexibility of the satellite, there are associated problems : FE model has the system matrix with high order and does not provide any physical insights, and is available only after all structural features have been decided. Therefore, it is almost impossible to design attitude and orbit controller using FE model unless the structural features are in place. In order to deal with this problem, the control design scheme with the global mode (GM) model is suggested. This paper describes a flexible structure modeling and three-axis controller design process and demonstrates the adequate performance of the design with respect to the maneuverability by applying it to a large flexible spacecraft model.

• Proceedings of the KSME Conference
• /
• 2008.11a
• /
• pp.1617-1622
• /
• 2008

We report a new molecular detection process which measures the changes in the plasmon resonance peaks of periodic Au nanoparticle arrays fabricated using the electron beam lithography. As the Au nanoparticle arrays are modified by the chemical reaction in solutions having various concentrations of a target molecule, both the position and intensity of the plasmon peak change in proportion to the concentration of the target molecule. We expect that the process developed in this work can be employed for fine tuning of the plasmon peak wavelength and also for the optical detection of various kinds of molecules. Moreover, this method may improve the measurement accuracy compared with existing approaches that use only one change (peak wavelength or peak intensity) as a readout value for the molecular detection.

• Proceedings of the KSME Conference
• /
• 2000.04b
• /
• pp.807-812
• /
• 2000

Chlorination dosage in water treatment plant of field is determined by chlorination demand experiment through two or three hours after raw water was sampled in inflow. It is impossible to continuously control fer real time because sampled water is adapted chlorination dosage after water treatment process had been proceeded. Therefore in this study, we will design informal chlorination demand system this designed system will be experimented as to water quality and accuracy of control in various conditions. Throughout these. experimental results, we will revise the system and revised system is enable to optimal control of chlorination dosage. Finally, We have developed chlorination demand system, which can automatically determination of chlorination dosage to be determined according to variety of raw water quality inflow in water treatment plant.

• Journal of the korean Society of Automotive Engineers
• /
• v.15 no.2
• /
• pp.53-63
• /
• 1993

A numerical modeling technique is proposed for computer simulations of high speed valve train dynamic terms in the valve spring reaction forces are calculated using linear vibration theory for given kinematic valve motions. Because the spring dynamics are analyzed before the time stepping integration, spring surge phenomena can be included without using additional computer time. In addition to that, steady state response of the valve dynamics can be obtained by just one cycle simulation. Consequently, valve train dynamics can be simulated very quickly without noticeable errors in accuracy. The experimental result prove the computer model developed here is accurate and also computationally efficient. The model is especially useful for cam profile optimizations.