• Journal of the Korea Computer Graphics Society
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• v.26 no.1
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• pp.7-15
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• 2020

In the process of visualizing a point set representing a smooth manifold surface, global illumination techniques can be used to render a realistic scene with various effects of lighting. Thanks to the continuous demand for ray tracing and the development of graphics hardware, dedicated GPUs and programmable pipeline for ray tracing have been introduced in recent years. In this paper, real-time global illumination rendering is studied for a point-set model using ray-tracing GPUs. We apply the moving least-squares (MLS) method to approximate the point set to a smooth implicit surface and render it using global illumination by performing massive ray-intersection tests with the surface and generating shading effects at the intersection point. As a result, a complicated point-set scene consisting of more than 0.5M points can be generated in real-time.

• KSBB Journal
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• v.31 no.4
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• pp.193-199
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• 2016

Global warming caused from the heavy consumption of fossil fuel is one of the biggest problems to be solved. Biofuel has been gained more attention as an alternative to reduce the consumption of fossil fuel. Recently, butanol produced from the genus Clostridium has been considered as one of the promising alternatives for gasoline, fossil based fuel. Nevertheless, the lack of the genome-engineering tools for the genus Clostridium is the major hurdle for the economic production of butanol. More recently, genome engineering tools have been developed for metabolic engineering of butanol-producing Clostridium species, which includes genome scale network model and genome editing tools on the basis of mobile group II introns and CRISPR/Cas system. In this study, the genome engineering tools for butanol-producing Clostridium species have been reviewed with a brief future perspective.

• Korean Journal of Poultry Science
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• v.28 no.2
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• pp.143-153
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• 2001

Using bioinformatic tools for searching the massive genome databases, it is possible to Identify new genes in few minutes for initial discoveries based on evolutionary conservation, domain homology, and tissue expression patterns, followed by further verification and characterization using the bench-top works. The development of high-density two-dimensional arrays has allowed the analysis of the expression of thousands of genes simultaneously in the humans, mice, rats, yeast, and bacteria to elucidate the genes and pathways involved in physiological processes. In addition, rapid and automated protein identification is being achieved by searching protein and nucleotide sequence databases directly with data generated from mass spectrometry. Recently, analysis at the bio-chemical level such as biochemical screening and metabolic profiling (Biochemical genomics) has been introduced as an additional approach for categorical assignment of gene function. To make advantage of recent achievements in computational approaches for facilitated gene discoveries in the avian model, chicken expression sequence tags (ESTs) have been reported and deposited in the international databases. By searching EST databases, a chicken heparanase gene was identified and functionally confirmed by subsequent experiments. Using combination of sub-tractive hybridization assay and Genbank database searches, a chicken heme -binding protein family (cSOUL/HBP) was isolated in the retina and pineal gland of domestic chicken and verified by Northern blot analysis. Microarrays have identified several host genes whose expression levels are elevated following infection of chicken embryo fibroblasts (CEF) with Marek's disease virus (MDV). The ongoing process of chicken genome projects and new discoveries and breakthroughs in genomics and proteomics will no doubt reveal new and exciting information and advances in the avian research.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.8
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• pp.897-904
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• 2012

The rifling design problem has continuous-type shape variables and an integral number of riflings. In addition, it requires considerable time for analysis because its behavior should be described by a nonlinear finite element model (FEM). Therefore, this study presents an efficient design process for rifling based on a design of experiment (DOE) approach. First, Bose's orthogonal array is used to represent 25 runs for four design variables including three shape variables and one integer variable. Then, nonlinear FE analyses are performed. Next, to minimize the bullet resistance without affecting the bullet velocity and bullet rotational angle immediately before a bullet leaves the gun barrel, a what-if design is performed. In the proposed what-if design, a functional including the design objective and constraints is constructed and effect analysis is performed by using the functional. It is found that the new design obtained from the what-if design shows better results than the current one.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.4
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• pp.287-297
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• 2020

The research aims to investigate the impact levels of determinants on the loyalty of accountants to FDI firms underlying investment management in Thanglong Industrial Park in Hanoi, Vietnam. We conducted a questionnaire consisting of 31 observation variables with a 5-point Likert scale. Independent variables were measured from 1 "without effect" to 5 "strongly". The method of data collection was done through the survey and subjects are accountants in FDI firms doing business in Thanglong Industrial Park in Hanoi. After checking the information on the votes, there are 120 questionnaires with full information for data entry and analysis, This study employs Cronbach's Alpha test, and regression model. The results show that seven determinants including Working environment, The characteristics of working; Training, promotion prospects and development; Income, Personal characteristic, Collective work together and The method of leading had positive relationships with the loyalty of accountants. Based on the findings, some recommendations are given related to such determinants to improve the loyalty of accountants of FDI firms in general and FDI firms in Thanglong Industrial Park in Hanoi in particular. With which, those firms can enhance performance, reduce financial strain, saving on investment in the recruiting process of new staff, increase profitability to ensure investment management.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.25 no.6
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• pp.520-528
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• 1992

In order to establish the standard conditions for thermal sterilization of foods, a microcomputer based $F_o-value$ measuring system was developed upon the basis of the time-temperature profile in food. $F_o-value$ was calculated simultaneously from the time-temperature profile, and described as integrated lethality during the whole sterilization process. The accuracy of system was evaluated by the analysis of thermal diffusivity of the model solid food, Alaska pollack surimi. The $F_o-value$ could be measured precisely under the different sterilizing conditions as the varied time and temperature. The practical thermal diffusivities from various sterilizing conditions agreed well to the values predicted by some experimental equations suggested in the literatures. The differences were within the range of $\pm12\%$.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.2
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• pp.146-156
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• 2012

In-flight icing remains as one of the most persistent hazards for aircraft operations. The effect of icing on aircraft performance and safety has to be evaluated during the development and airworthiness certification process. The scaling method is a procedure to determine the scaled test conditions in icing wind tunnels in order to produce the same result as when the reference model is exposed to the desired cloud conditions. In this study, a scaling program is developed to provide an easy-to-use tool to the aero-icing community. The Olsen and Ruff 4th methods are employed for this purpose and the velocity is calculated by matching the dimensionless Weber number. To validate the program, the results are compared with the NASA scaling results. The scaling examples based on FAR (Federal Aviation Regulation) Part 25 Appendix C are also presented. Finally, a validation study using a state-of-the-art icing simulation code FENSAP-ICE is presented.

• Journal of Biosystems Engineering
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• v.28 no.4
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• pp.305-314
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• 2003

The ROPS of an agricultural tractor is designed to protect its driver when the tractor overturns. Although the current OECD tests to determine whether the ROPS meets the requirements of the OECD regulation are desirable, they need long time to test. We experimental time and effort by using CAE. We conducted a finite element analysis for the ROPS design of a Dae-Dong tractor cabin in an attempt to reduce the design and manufacturing time. This study shows the interpretative skill using MARC(v.2000) for designing ROPS and difference between the results of testing and FEA. Design process is generally divided into two phases: a concept and a detail design. The concept design uses simple analysis to predict structural behavior, whereas the detail design involves a finite element analysis performed by the results of the concept design. This study focused on the detail design and used Patran(v.2000r2) and MARC(v.2000) of the MSC software corporation. The model consisted of 4812 elements and 4582 nodes. Four tests. specified in the OECD standards, were performed: (1) longitudinal loading test (2) rear crushing test (3) side loading test (4), and front crushing test. Independent analyses were also performed for each test, along with a sequential analysis. When compared, the results of the independent and sequential analyses were found to be similar to the test results.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.2
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• pp.1234-1249
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• 2017

One of the difficulties developers encounter in maintaining tasks of a large-scale software system is the updating of suitable libraries on time. Developers tend to miss or make mistakes when searching for and choosing libraries during the development process, or there may not be a stable library for the developers to use. We present a novel approach for helping developers modify software easily and on time and avoid software failures. Using a tool previously built by us called GPES, we collected information of projects, such as abstract syntax trees, tokens, software metrics, relations, and evolutions, for our experiments. We analyzed the contexts of source codes in existing projects to predict changes automatically and to recommend suitable libraries for the projects. The collected data show that researchers can reduce the overall cost of data analysis by transforming the extracted data into the required input formats with a simple query-based implementation. Also, we manually evaluated how the extracted contexts are similar to the description and we found that a sufficient number of the words in the contexts is similar and it might help developers grasp the domain of the source codes easily.

• Journal of the Society of Naval Architects of Korea
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• v.30 no.1
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• pp.94-103
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• 1993

This study deals with an investigation on the tip vortex generated by an elliptic wing with section shapes of NACA 0020. The flow structure on the wing surface is investigated by using tufts test as well as observing the cavitation pattern. The surface pressure on a foil surface is measured to complement the visualized flow field. Results show that a strong spanwise pressure gradient is a definite contributor on the formation of tip vorex, and the fluids from both sides contribute to the evolutionary process of tip vortex. On the other hand, a series of experiments are conducted to investigate the detailed structure of tip-vortex at various angles of attack. The tip-vortex formation and development are observed by producing a cavitation, and then by a laser sheet technique in conduction with a dye injection method. The shape of tip-vortex and the distance between a vortex core and the trailing vortex sheet are found to vary with the angle of attack. Overall features of tip flow are evaluated to complement the vortex model based on inviscid theory.