• Journal of Electrical Engineering and Technology
• /
• v.9 no.5
• /
• pp.1739-1745
• /
• 2014

Prediction of fault-prone modules continues to attract researcher's interest due to its significant impact on software development cost. The most important goal of such techniques is to correctly identify the modules where faults are most likely to present in early phases of software development lifecycle. Various software metrics related to modules level fault data have been successfully used for prediction of fault-prone modules. Goal of this research is to predict the faulty modules at design phase using design metrics of modules and faults related to modules. We have analyzed the effect of pre-processing and different machine learning schemes on eleven projects from NASA Metrics Data Program which offers design metrics and its related faults. Using seven machine learning and four preprocessing techniques we confirmed that models built from design metrics are surprisingly good at fault proneness prediction. The result shows that we should choose Naïve Bayes or Voting feature intervals with discretization for different data sets as they outperformed out of 28 schemes. Naive Bayes and Voting feature intervals has performed AUC > 0.7 on average of eleven projects. Our proposed framework is effective and can predict an acceptable level of fault at design phases.

• Smart Media Journal
• /
• v.6 no.1
• /
• pp.54-60
• /
• 2017

Recently, broadcasting companies have been faced with changes in social environment, particularly, the emergence of new media, including the internet, cable TV and DMB, and in the political environment, such as convergence in broadcasting and communications media. To cope with these changes, broadcasting companies are showing increasing interest in building new broadcasting information systems. This study presents how to develop a web-based broadcasting information system for the small and medium-sized broadcasting company. For developing the system, the study describes system configuration, business function relationship diagrams and business flow diagrams, entity relationship diagrams, major programs, and graphic user interfaces. The newly developed web-based broadcasting information system is expected to increase business productivity to a significant extent through faster decision-making and business execution in and out of the company.

• Journal of Technology Innovation
• /
• v.3 no.1
• /
• pp.213-236
• /
• 1995

Advanced Manufacturing Technology(AMT), a comprehensive collection of new technologies for the efficiency and flexibility of manufacturing systems has received a growing attention recently, AMT consists of various industrial and technological components, homogeneous in some aspects while heterogeneous in others. Thus, it is difficult but necessary task to construct a classification framework in which the relationship among individual technologies are depicted in a meaningful fashion. In this, paper, we propose a hierarchical framework in which the objective and criteria of classification are decomposed into three level: industrialization, development and application of AMT. At the first and highest level, the main interest is to "industrialize" AMT. The major actors at this level are policy makers(public sector) and top management(private sector) and the primary classification criterion is the interrelationship between industry and technology. At the middle level exist system engineers whose main objective is to "develop" new technologies and/or systematize individual technologies. At the final and bottom level, shop floor managers need to "apply" AMT in order to enhance the efficiency and flexibility of manufacturing process. It should be stressed that, as a whole, the above three levels should be interactively linked to that each level contributes to the balanced development of AMT.

• Journal of Preventive Medicine and Public Health
• /
• v.39 no.2
• /
• pp.105-109
• /
• 2006

The Korean Society of Preventive Medicine has undergone continuous development, after overcoming the difficult early years, in the 59 years since its establishment in 1947. It has repeatedly upgraded its quality and quantity of research with the first journal edition in 1968 and the continuous increase in publication numbers, scientific articles, joint research projects, intra-field exchanges and participation in various international scientific activities. In the future, we should gather a more extensive collection of opinions regarding the introduction of clinical preventive medicine specialists and prepare for the establishment of a training program for clinical specialists into a preventive medicine residency course. Moreover, we should raise interest in the importance of protecting individual information and maintaining medicine ethics. It's impossible to develop academic activities without cooperation. We need such cooperation with basic medical approaches across a wide range of fields. Furthermore, we should strengthen our cooperation with aspects of clinical and drug epidemiology in many fields including public health, statistics, and dietetics. Finally, we should raise the level of international cooperation with many countries, including North Korea, to prevent diseases and promote health. Preventive medicine is a science in which practice is as important as theory. We must aim to nurture preventive medicine specialists who practice in many areas of society with the goal of preventing diseases, promoting health, improving fertility, and securing healthy elderly life for individuals and the entire population. To this end, we will endeavor to promote both theoretical and practical components of academic development.

• Journal of Advanced Navigation Technology
• /
• v.8 no.2
• /
• pp.155-162
• /
• 2004

Recently, significant interest is shown to creation rather inexpensive global systems communications on base of Low-Earth-Orbit Satellite Networks (LEOSN). One of problems of design and creation LEOSN is development of the stream control methods and estimation it's efficiency in such networks. The given problem is complicated, that the topology of the satellite networks varies in time. It essentially hinders the analytical decision of the given problem. An effective way of overcoming of these difficulties is simulation modeling. For realization of research experiments on learning the information streams routing algorithms in LEOSN a special program complex SANET was developed. In the given paper principles of development of LEOSN simulation models and architecture of the manager by the process of a simulation modeling of the unit are considered. Methods of promotion of modeling time and architecture of a simulator complex offered in the article allow to boost essentially efficiency of simulation analysis and to ensure simulation modeling of the satellite networks consisting of several hundreds space vehicles.

• Hwankyungkyoyuk
• /
• v.15 no.1
• /
• pp.1-17
• /
• 2002

The aim of this study is to establish an object of environmental education in liberal arts, and to develop a teaming program and search for the most effective environmental teaching method. At first this study analyzed the current situations and problems of the present environmental education in the liberal arts. As a result of this analysis, I found that, most of environmental educations have been conducted mainly by an approach of natural science, inevitably they should have limits in which students can't have holistic view in solve the environmental problem. Due to the fact that, many students were attending lectures, teaching methods were limited in the forms lecture and video tapes. As I applied educational programs with various teaching methods for students in order to change cognition and value toward environment, I found that there was no significant difference of cognition even after applying the programs. This may be interpreted as, most students already had very sound and sustainable environmental view. But some programs with teaching method using role play, debate, cyber-debate lead students to have interest in environments, thus actively participating in the class. These methods, taking into consideration, the hundreds of enrolled students, seem to pose a problem in actual application. The most important matter is, how to develop a cognition and value toward environment into environmental behavior. Therefore, in the future, aim is to study what determines the factors for causing environmental behavior from a cognition and value of the environment, and a development of programs in this regard will be necessary.

• Elastomers and Composites
• /
• v.56 no.3
• /
• pp.136-151
• /
• 2021

Biomass lignin, a waste produced during the paper and bio-ethanol production process, is a cheap material that is available in large quantities. Thus, the interest in the valorization of biomass lignin has been increasing in industrial and academic areas. Over the years, lignin has been predominantly burnt as fuel to run pulping plants. However, less than 2% of the available lignin has been utilized for producing specialty chemicals, such as dispersants, adhesives, surfactants, and other value-added products. The development of value-added lignin-derived co-products should help make second generation biorefineries and the paper industry more profitable by valorizing lignin. Another possible approach towards value-added applications is using lignin as a component in plastics. However, blending lignin with polymers is not simple because the polarity of lignin molecules results in strong self-interactions. Therefore, achieving in-depth insights on lignin characteristics and structure will help in accelerating the development of lignin-based products. Considering the multipurpose characteristics of lignin for producing value-added products, this review will shed light on the potential applications of lignin and lignin-based derivatives on polymeric composite production. Moreover, the challenges in lignin valorization will be addressed.

• Journal of Powder Materials
• /
• v.26 no.2
• /
• pp.156-165
• /
• 2019

Over the last decade, the next generation's ultra-high-temperature materials as an alternative to Nickel-based superalloys have been highlighted. Ultra-high-temperature materials based on refractory metals are one of several potential candidates. In particular, molybdenum alloys with small amounts of silicon and boron (Mo-Si-B alloys) have superior properties at high temperature. However, research related to Mo-Si-B alloys were mainly conducted by several developed countries but garnered little interest in Korea. Therefore, in this review paper, we introduce the development history of Mo-Si-B alloys briefly and discuss the properties, particularly the mechanical and oxidation properties of Mo-Si-B alloys. We also introduce the latest research trends of Mo-Si-B alloys based on the research paper. Finally, for domestic research related to this field, we explain why Mo-Si-B alloys should be developed and suggest the potential directions for Mo-Si-B alloys research.

• BioChip Journal
• /
• v.12 no.4
• /
• pp.294-303
• /
• 2018

Shear stress occurs in flowing liquids, especially at the interface of a flowing liquid and a stationary solid phase. Thus, it occurs inside the artery system of the human body, where it is responsible for a number of biological functions. The shear stress level generally remains less than $70dyne/cm^2$ in the whole circulatory system, but in the stenotic arteries, which are constricted by 95%, a shear stress greater than $1,000dyne/cm^2$ can be reached. Methods of researching the effects of shear stress on cells are of large interest to understand these processes. Here, we show the development of a microfluidic device for generating shear stress gradients. The performance of the shear stress gradient generator was theoretically simulated prior to experiments. Through simple manipulations of the liquid flow, the shape and magnitude of the shear stress gradients can be manipulated. Our microfluidic device consisted of five portions divided by arrays of micropillars. The generated shear stress gradient has five distinct levels at 8.38, 6.55, 4.42, 2.97, and $2.24dyne/cm^2$. Thereafter, an application of the microfluidic device was demonstrated testing the effect of shear stress on human umbilical vein endothelial cells.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.67 no.12
• /
• pp.1729-1734
• /
• 2018

Recently, interest in environmentally friendly transportation systems has been increasing, and study on railway systems has been aggressively conducted. Therefore, lots of studies have been done in railway advanced countries to improve performance of PWM converter. The research on the PWM converter for railway vehicle was mainly carried out on the converter mounted on railway vehicle such as the high-speed railway and metropolitan railway. In also, a lot of study has been carried out to improve converter performance installed in the ground. The high-capacity transform used in this paper converted from AC 22.9kV to AC 590V. The converter changed from AC 590V to DC 950V. In general, in the case of rectifier, the DC power supply system has a negative impact on inverter control characteristics because it can not avoid the pulsating component. In this study, it was performed current control for high-capacity converter using Matlab Simulink. The PWM converter is normally performed through the voltage and current at starting mode, powering mode, and braking mode. In the light-load test and the on-line test, we have studied for the PWM converter characteristics. Using this research, we have founded that the converter has excellent performance.