MaRMI-III: a methodology for component-based development

This study, supported by the Korea Ministry of Information and Communication, contributed to advancing the paradigm of software component-based development by developing a detailed process, techniques, and guidelines for making the most of component technologies. The outcome was a new CBD methodology named Magic and Robust Methodology Integrated III (MaRMI-III). MaRMI-III is now considered as a standard development methodology for using component technologies in Korea. To date, more than 100 Korean software development companies have adopted the methodology developed in this study

Performance of a prototype active veto system using liquid scintillator for a dark matter search experiment

We report the performance of an active veto system using a liquid scintillator with NaI(Tl) crystals for use in a dark matter search experiment. When a NaI(Tl) crystal is immersed in the prototype detector, the detector tags 48% of the internal K-40 background in the 0-10 keV energy region. We also determined the tagging efficiency for events at 6-20 keV as 26.5 +/- 1.7% of the total events, which corresponds to 0.76 +/- 0.04 events/keV/kg/day. According to a simulation, approximately 60% of the background events from U, Th, and K radioisotopes in photomultiplier tubes are tagged at energies of 0-10 keV. Full shielding with a 40-cm-thick liquid scintillator can increase the tagging efficiency for both the internal K-40 and external background to approximately 80%.Comment: Submitted to Nuclear Instruments and Methods in Physics Research Section

Crystallization and preliminary crystallographic studies of an antimicrobial protein from Pharbitis nil

An antimicrobial protein from seeds of Pharbitis nil (Pn-AMP) which shows an antifungal activity towards several agriculturally important plant pathogens has been crystallized in the presence of equimolar N-acetylglucosamine with sodium citrate as precipitant. The crystal belongs to the hexagonal space group P6(1)22 (or P6(5)22), with unit-cell parameters a = b = 29.33 (5), c = 133.44 (12) Angstrom. Native data were collected using a crystal at 100 K to a resolution of 1.78 Angstrom.open2

Exact solutions of a restricted ballistic deposition model on a one-dimensional staircase

Surface structure of a restricted ballistic deposition(RBD) model is examined on a one-dimensional staircase with free boundary conditions. In this model, particles can be deposited only at the steps of the staircase. We set up recurrence relations for the surface fluctuation width $W$ using generating function method. Steady-state solutions are obtained exactly given system size $L$. In the infinite-size limit, $W$ diverges as $L^\alpha$ with the scaling exponent $\alpha=\frac{1}{2}$. The dynamic exponent $\beta$ $(W\sim t^\beta)$ is also found to be $\frac{1}{2}$ by solving the recurrence relations numerically. This model can be viewed as a simple variant of the model which belongs to the Kardar-Parisi-Zhang (KPZ) universality class $(\alpha_{KPZ}= \frac{1}{2} , \beta_{KPZ}=\frac{1}{3})$. Comparing its deposition time scale with that of the single-step model, we argue that $\beta$ must be the same as $\beta_{KPZ}/(1-\beta_{KPZ})$, which is consistent with our finding.Comment: 19 pages, REVTEX, 5 figures upon request, INHA-PHYS-94-00

A Study to Improve the Crash Performance of Plastic Materials Considering the Strain Rate and Fracture Characteristic

The numerical simulation of structural parts made from plastics is becoming increasingly important nowadays. The fact that almost any structural requirement can be combined in a lightweight, durable and cost effective structure is the driving force behind its widespread application. More and more structural relevant parts are being constructed and manufactured from plastics. It is difficult accurately to predict the reliability according to finite element analysis, because plastics materials show the complex material behaviour. Thus, it is demanded for reliable and obvious methods to design these parts and to predict their material behaviour. For the finite element simulations of polymeric materials mathematical models are needed which cover all the phenomena of the material. In this paper, it is possible to describe accurately the mechanical behaviour of thermoplastic materials using a new constitutive model termed as SAMP-1(Semi- Analytical Model for Polymers) in LS-dyna. We performed the high speed tension tests (strain rate: 0.001/s, 0.1/s, 1/s, 50/s, 100/s) for the characterisation of the plastics material. Also, the parameters of the SAMP-1 model were identified by using multidirectional mechanical tests such as uniaxial tension, simple shear, and compression tests. As validation purpose, the SMAP-1 model was compared to the existing models for predicting the stress-strain behaviour in the test specimens and the dynatup impact test