• 한국자동차공학회논문집
• /
• 제18권5호
• /
• pp.50-55
• /
• 2010

In recent years, the development of fuel cell vehicles has further accelerated because of environmental problem and petroleum resources shortage. The fuel cell vehicles have the stack which converts fuel to electricity. The stack is usually mounted by bush to isolate the vibration of chassis and body. This paper analyzed the vibratory characteristics of stack and chassis, body system. The wheel forces of fuel cell vehicle are measured to estimate the road load data. And the paths of vibration from wheel to stack are analyzed by CAE. According to the test and CAE results, the improvement of stack vibration are evaluated.

• Genomics & Informatics
• /
• 제5권1호
• /
• pp.24-29
• /
• 2007

Computational virtual screening has become an essential platform of drug discovery for the efficient identification of active candidates. Moleculardocking, a key technology of receptor-centric virtual screening, is commonly used to predict the binding affinities of chemical compounds on target receptors. Despite the advancement and extensive application of these methods, substantial improvement is still required to increase their accuracy and time-efficiency. Here, we evaluate several advanced structure-based virtual screening approaches for elucidating the rank-order activity of chemical libraries, and the quantitative structureactivity relationship (QSAR). Our results show that the ensemble-average free energy estimation, including implicit solvation energy terms, significantly improves the hit enrichment of the virtual screening. We also demonstrate that the assignment of quantum mechanical-polarized (QM-polarized) partial charges to docked ligands contributes to the reproduction of the crystal pose of ligands in the docking and scoring procedure.

• 한국국방경영분석학회지
• /
• 제24권2호
• /
• pp.170-186
• /
• 1998

The purposes of this paper are applying the IDEF(Integrated DEFinition), which was selected for standard methodology of CALS(Computer-aided Acquisition and Logistic Support) process modeling, to the acquisition process of the weapon system to activate DEfense CALS of the acquisition and management business of weapon system on Defense Planning and Management System and developing a AS-IS model which is usable and that the analysis of process problems results in. On this paper, We diagrammed the function of the acquisition and management of weapon system by using IDEF0 and presented AS-IS model. This paper focused on the development of AS-IS model which can put to practical use to find the problems of current acquisition and management process of weapon system and the embodiment of national defense CALS system. So more detailed analysis of current system and additional studies about TO-BE model would be the future research area.

• 한국자동차공학회논문집
• /
• 제18권4호
• /
• pp.74-78
• /
• 2010

Turbocharger in the application to a diesel engine was widely used in automobile industries for the improvement of engine performance. To comply with stringent emission standards, ball bearing turbocharger has been developed by applying new emission reduction technology. Up to date turbocharger has been proved as an essential part of diesel engines by demonstrating its improved engine performance, fuel efficiency and reduced emission as well. In this research, the performance of the ball bearing turbocharger was compared by the conventional journal bearing type turbocharger. The results shows that ball baring turbocharger was proved to be 10~13% higher fuel efficiency and 30% less average emission than journal bearing turbocharger.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2001년도 하계학술대회 논문집 A
• /
• pp.419-421
• /
• 2001

The large distribution automation system for metropolitan city was developed in KEPCO just recently. This system has many functions for remote control and data acquisition, and it will be linked the other computer aided system such as NDIS(new distribution automation system) and SCADA(supervisory control and data acquisition) to construct the database of DAS(distribution automation system).

• Computers and Concrete
• /
• 제4권1호
• /
• pp.1-18
• /
• 2007

Over the past decades, an enormous amount of effort has been expended in laboratory and field studies on concrete durability estimation. The results of this research are still either widely scattered in the journal literature or mentioned briefly in the standard textbooks. Moreover, the theoretical approaches of deterioration mechanisms with a predictive character are limited to some complicated mathematical models not widespread in practice. A significant step forward could be the development of appropriate software for computer-based estimation of concrete service life, including reliable mathematical models and adequate experimental data. In the present work, the basis for the development of a computer estimation of the concrete service life is presented. After the definition of concrete mix design and structure characteristics, as well as the consideration regarding the environmental conditions where the structure will be found, the concrete service life can be reliably predicted using fundamental mathematical models that simulate the deterioration mechanisms. The prediction is focused on the basic deterioration phenomena of reinforced concrete, such as carbonation and chloride penetration, that initiate the reinforcing bars corrosion. Aspects on concrete strength and the production cost are also considered. Field observations and data collection from existing structures are compared with predictions of service life using the above model. A first attempt to develop a database of service lives of different types of reinforced concrete structure exposed to varying environments is finally included.

• Journal of Information Processing Systems
• /
• 제17권5호
• /
• pp.972-988
• /
• 2021

At present, DevOps environments are getting popular in software organizations due to better collaboration and software productivity over traditional software process models. Software artefacts in DevOps environments are vulnerable to frequent changes at any phase of the software development life cycle that create a continuous integration continuous delivery pipeline. Therefore, software artefact traceability management is challenging in DevOps environments due to the continual artefact changes; often it makes the artefacts to be inconsistent. The existing software traceability related research shows limitations such as being limited to few types of artefacts, lack of automation and inability to cope with continuous integrations. This paper attempts to overcome those challenges by providing traceability support for heterogeneous artefacts in DevOps environments using a prototype named SAT-Analyser. The novel contribution of this work is the proposed traceability process model consists of artefact change detection, change impact analysis, and change propagation. Moreover, this tool provides multi-user accessibility and is integrated with a prominent DevOps tool stack to enable collaborations. The case study analysis has shown high accuracy in SAT-Analyser generated results and have obtained positive feedback from industry DevOps practitioners for its efficacy.

• The Journal of Advanced Prosthodontics
• /
• 제10권1호
• /
• pp.65-72
• /
• 2018

PURPOSE. The aim of this in vitro study was to investigate the fracture resistance under chewing simulation of implant-supported posterior restorations (crowns cemented to hybrid-abutments) made of different all-ceramic materials. MATERIALS AND METHODS. Monolithic zirconia (MZr) and monolithic lithium disilicate (MLD) crowns for mandibular first molar were fabricated using computer-aided design/computer-aided manufacturing technology and then cemented to zirconia hybrid-abutments (Ti-based). Each group was divided into two subgroups (n=10): (A) control group, crowns were subjected to single load to fracture; (B) test group, crowns underwent chewing simulation using multiple loads for 1.2 million cycles at 1.2 Hz with simultaneous thermocycling between $5^{\circ}C$ and $55^{\circ}C$. Data was statistically analyzed with one-way ANOVA and a Post-Hoc test. RESULTS. All tested crowns survived chewing simulation resulting in 100% survival rate. However, wear facets were observed on all the crowns at the occlusal contact point. Fracture load of monolithic lithium disilicate crowns was statistically significantly lower than that of monolithic zirconia crowns. Also, fracture load was significantly reduced in both of the all-ceramic materials after exposure to chewing simulation and thermocycling. Crowns of all test groups exhibited cohesive fracture within the monolithic crown structure only, and no abutment fractures or screw loosening were observed. CONCLUSION. When supported by implants, monolithic zirconia restorations cemented to hybrid abutments withstand masticatory forces. Also, fatigue loading accompanied by simultaneous thermocycling significantly reduces the strength of both of the all-ceramic materials. Moreover, further research is needed to define potentials, limits, and long-term serviceability of the materials and hybrid abutments.

• 대한치과기공학회지
• /
• 제41권4호
• /
• pp.271-278
• /
• 2019

Purpose: To quantify the effect of the crystallization process on lithium disilicate ceramic crowns that are fabricated using a computer-aided design/computer-aided manufacturing(CAD/CAM) system, and to determine whether they are clinically acceptable by comparing values before and after the crystallization process. Methods: The maxillary first molar was selected as the abutment for the experiments. Ten working models were prepared. Marginal and internal gap of 4 groups of lithium disilicate crowns(n=10) fabricated with conventional method. Comparison was performed using the silicone replica technique and 3D superimposition analysis. The marginal and internal gaps of the restoration were measured before and after the crystallization process of this prosthesis. The average value of each part(the average of values measured before and after the crystallization) was statistically analyzed using paired t-test(α=0.05). Results: The results from the second phase of this research, which compared the average value of the gap between the marginal and internal fits of the lithium disilicate single crown before and after the crystallization process, indicated that the marginal gap was larger and the internal gap was smaller after the crystallization process, and this difference was statistically significant (P<0.05) in all the parts evaluated. Conclusion: While the shrinkage that occurs during crystallization does affect the marginal and internal fit of the prosthesis, it cannot be concluded to be a major effect because the resultant distortion was within the clinically acceptable range.

• 디자인학연구
• /
• 제13권4호
• /
• pp.145-154
• /
• 2000

교육의 성과는 합리적인 교과 운영의 방법에 의해서 달성된다고 할 수 있다. 따라서 짧은 기간 내에 학생들의 전문성을 갖추어야 하는 전문대학의 교육은 더욱 효과적인 교육방법이 요구되어지며, 전공과정에서 채택하고 있는 각 교과목의 운영은 학생들의 전문성을 책임질 수 있도록 계획되어져야 하는 것이다. 전공에서의 각 교과목은 학생들의 전문성을 형성하기 위한 교육목표에 밀접한 인과요인으로 작용하기 때문에 각 교과목에서의 교육성과달성은 교육자의 중대한 연구부분으로 인식되게 된다. 이러한 문제 인식을 바탕으로 진행한 본 연구는 산업디자인 학과에서 채택하고 있는 두 개의 교과목(공간디자인/컴퓨터응용디자인)을 연계하여 교육함으로써 두 교과목의 상호관계성에 대한 학생들의 이해의 폭을 넓히고 학습의 집중도를 유발함으로써 각 교과목의 교육 목표를 동시에 달성하는 방법론적인 접근을 하였다. 본 교과 운영의 방법을 통해서 학생들은 두 교과목이 목표로 하는 디자인 지식과 표현기술의 습득은 물론 디자인 전개 과정을 기획하고 전개하는데 자신감을 갖게 됨으로써 교과목 연계를 통한 교육적 효과를 확인하였다.