• Journal of the Korea Institute of Building Construction
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• v.20 no.5
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• pp.449-457
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• 2020

Due to the improvement of living standards and avoidance of the 3D industry, it is difficult to find young and competent domestic workers at construction sites, and most foreign workers are contributing to the replacement, but the quality is still deteriorating due to lack of skilled workers and aging. Precast method is a method that make members in factory and assembles them on site, which can be expected to improve labor force and quality. This study is intended to provide basic data for the development of hang-type PC beams that can be applied to the determination of the field application of developed PC beams. The U-type connecting material is installed on both ends of the hang-up PC beam, and the role of the U-type connecting material is very important because it is a simple construction method through the U-type connecting material. In addition, the performance of the U-type connecting material will determine the performance of the hang-type PC beam as the final destruction occurs in the hang-type PC beam. The material properties of U-type connecting material were identified through structural experiments, and the end test corresponding to the partial experiment was conducted based on the material test results identified. Finally, the final design value of PC beams was proposed through structural experiments for application to the site.

• Korean Journal of Construction Engineering and Management
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• v.19 no.1
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• pp.65-73
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• 2018

Since unfair trading practices between participants in construction project are common, the government has enforced several policies and systems to prevent or minimize the unfair trading practices in construction industry. However, not much attention has been paid to figure out which policies or acts are working or not. This paper analyzed the effectiveness of the policies and acts which are being implemented to prevent unfair trading practices and provided several suggestions to improve the performance of those acts. Survey was conducted to industry experts to collect data regarding their perceptions on those policies and acts. Then the effectiveness of the policies and acts were analyzed in terms of their importance and performance through IPA (Importance-Performance Analysis) based on the survey result. It was found through IPA that execution related acts such as investigation, exposure, and punishment for unfair trading practice have shown low effectiveness in entire construction process and dispute arbitration and mediation related center operated by authority showed low performance too. To improve the effectiveness of those acts, dispute arbitration system improvement, investigation & reporting system consolidation and enhancement practical binding force of punishment and penalty were suggested. Most of all, rules and culture for fair trading should become more established in construction industry by preventing conflict among participants through active communication.

• Convergence Security Journal
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• v.16 no.6_1
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• pp.3-13
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• 2016

We take it for granted that strong sides defeat weaker counterparts, while predicting the outcome of the battles. But in modern war, we can find plenty of evidence that weak sides won against the strong. This phenomenon can be understood logically by the fourth-generation war theory. the North Korean does not give up its unification strategy, which is unification by force, even though its inferior power. It is continuing various political, social and military levels of provocations toward both the international community and South Korea. Recently, North Korea did nuclear test, launched ICBM test, provoked the DMZ, and expecting to continue the provocations of the fourth-generation war level. We have to understand the nature of North Korea's fourth-generation war threats and provocations that it is focusing on. Based on this, have a new understanding of the value of the Homeland Defense Reservists as fundamental measures as the fourth-generation war threat and supplement related systems. We can firmly refuse the balance of power and power shift of the Korean Peninsula through improved Homeland Defense Reservists. As the expected North Korea's the fourth-generation war threats, our Homeland Defense Reservists is a firm will of conduct war, and political-social-economic-military means, it is possible to display as the best alternative.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.31 no.5
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• pp.275-282
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• 2018

Using isogeometric analysis(IGA) gives more accurate results for higher order mode in eigenvalue problem than using the finite element method(FEM). This is because the FEM has $C^0$ continuity between elements, whereas IGA guarantee $C^{P-1}$ between elements for p-th order basis functions. In this paper, a mode based reduced model is constructed by using IGA and dynamic behavior analysis is performed using this advantage. Craig-Bampton(CB) method is applied to construct the reduced model. Several numerical examples were performed to compare the eigenvalue analysis results for various order of element basis function by applying the IGA and FEM to simple rod analysis. We have confirmed that numerical error increases in the higher order mode as the continuity between elements decreases in the IGA by allowing internal knots multiplicity. The accuracy of the solution can be improved by using the IGA with high inter-element continuity when high-frequency external force acts on the reduced model for dynamic behavior analysis.

• BMB Reports
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• v.41 no.12
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• pp.846-851
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• 2008

This study was conducted to identify marbling-related candidate genes in M. longissimus dorsi of high- and low-marbled Hanwoo. The longissimus dorsi muscles were selected for gene expression from eight Hanwoo steer carcasses based on crude fat content. In the analysis of variance, gene expression of five candidate genes, FABP4, SCD, $PPAR\gamma$, Titin and Nebulin was determined to be significantly different between high- and low-marbled Hanwoo steers (P < 0.0001). The Pik-4 and CaMK II genes were also shown to have a significant effect on crude fat content (P < 0.01). In the analysis of the differential expression between high- and low marbled groups, FABP4 gene expression was approximately 2 times higher in the high marbled group relative to the low marbled group. However, the $PPAR\gamma$ and SCD gene were highly expressed in the low marbled group. In addition, Titin and Nebulin were highly expressed in the low marbled group when placed under relatively high shear force. Finally, the Pik-4 and CaM K II gene also displayed a high expression pattern in the low marbled group.

• Journal of Korean Tunnelling and Underground Space Association
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• v.19 no.6
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• pp.1029-1044
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• 2017

The Discrete Element Method (DEM) is one of the useful numerical methods to analyze the behavior of the ground formation by computing the motion and interaction using particles. The DEM has not been applied in civil engineering but also a wide range of industrial fields, such as chemical engineering, pharmacy, material science, food engineering, etc. In this study, to review a performance of the spoke-type earth pressure balance (EPB) shield TBM (Tunnel Boring Machine), the commercial software based on the DEM technology was used. An analysis of the TBM during excavation was conducted according to two pre-defined excavation conditions with the different rotation speed of a cutterhead. During the analysis, the resistant torque at the face of the cutterhead, the compressive force at the cutterhead and shield surface, the muck discharge at the screw auger were measured and compared. Upon the two kinds of excavation conditions, the applicability of the DEM analysis was reviewed as a modelling method for the TBM.

• Journal of Service Research and Studies
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• v.9 no.3
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• pp.87-99
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• 2019

Healthcare and data science are often linked through finances as the industry attempts to reduce its expenses with the help of large amounts of data. Data science and medicine are rapidly developing, and it is important that they advance together. Data science is a driving force in transition of healthcare systems from treatment-oriented to preventive care in healthcare 3.0 era. It enables customized precision-based medicine that current healthcare systems cannot facilitate, and discovers more cost-effective treatment. Currently, healthcare big data is in the reality of medical institution, public health, medical academia, pharmaceutical sector as well as insurance agency. With this motivation, the medical college of Soonchunhyang university has performed a 'healthcare data science initiative(HDSI)' since 2014. Most of domestic HDSI programs focus on short-term contents such as mentoring and sharing cases for data science. Therefore, it is difficult to provide education tailored to the level of skills and job competency required at the practical site. Soonchunhyang HDSI implemented specialized strategies for improving resilience and response to changes in the IT education of current healthcare with the emphasis on the need for systematic activation of the practical HDSI. The HDSI has been performed as a part of on industry-academic link program in CK-1. Through quantitative and qualitative analysis, this paper discussed the HDSI process, performance, achievement, and implications.

• Journal of the Optical Society of Korea
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• v.13 no.1
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• pp.8-14
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• 2009

In a laser-plasma wakefield accelerator, the ponderomotive force of an ultrashort high intensity laser pulse excites a longitudinal wave or plasma bubble in a way similar to the excitation of a wake wave behind a boat as it propagates on the water surface. Electric fields inside the plasma bubble can be several orders of magnitude higher than those available in conventional RF-based particle accelerator facilities which are limited by material breakdown. Therefore, if an electron bunch is properly phase-locked with the bubble's acceleration field, it can gain relativistic energies within an extremely short distance. Here, in the bubble regime we show the generation of stable and reproducible sub GeV, and GeV-class electron beams. Supported by three-dimensional particle-in-cell simulations, our experimental results show the highest acceleration gradients produced so far. Simulations suggested that the plasma bubble elongation should be minimized in order to achieve higher electron beam energies.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.26 no.1
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• pp.59-67
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• 2013

Complex-shaped tall building causes many structural challenges due to its structural characteristics regarding inclined members and complexed shape. This paper is aimed at development of design process using computational-platform which is effective design tool for responding frequent design changes, particularly as to overseas projects. StrAuto, a parametric structural modeling and optimizing system, provides the optimized alternatives according to design intent and realize a swift process converting a series of structural information necessary to nonlinear analytical models. The application of the process was to a 45-story hotel building in Ulanbator, Mongolia adopting shear wall and special moment frame with outrigger systems. To investigate the safety of lateral force resisting system against maximum considered earthquake(MCE), nonlinear response history analysis was conducted using StrAuto.

• Journal of The Korean Association For Science Education
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• v.16 no.4
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• pp.340-350
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• 1996

Knowledge is composed through the interaction between the concept structure already held by students and their experience, and learning can be said to be the active process of solving the cognitive conflict caused by this interaction. Therefore, this study consists in showing the effective learning method and finding out the elements which the teacher has to own, through examining several forms of pre-conception or mis-conception of the inertia, the force-equilibrium, the action and reaction, the heat, and the electric current, and then finding out their solution and studying student's change in science concepts. For this study, the types of concept on the five above-mentioned materials which students have were examined through the concept-classifying question paper, and the classes to which the class mode for the change of concepts applied, were practised in each different classroom by each different instructor - a professor, a scientist, a teacher, and two students, respectively. And the effect of the teaching strategy based on these classes, and each different instructor' influence on the change of concept in students. were examined. The result of my study is as follows; 1. Students have various types of pre-conception which are different from science concept, and these types of pre-conception tend to last even after learning in class. 2. The thoughts on the correct science concept of the high school third-grade students who learned the physics in the traditional teaching method, and the second grade students who don't learn the physics yet, were nearly equal those of the second grade students by receiving the physics class through the cognitive conflict course were greatly changed especially that students showed the distinct change on mechanics and electric current. 3. Students didn't show the remarkable change of the science concept on the five materials in the four kinds of experimental classes by each different instructor but in the part of mechanics, there was the distinct change between the class by professor and those by the students. This was due to the difference of the authority and the attitude of the concept demonstrator. 1) The authority, the kind attitude, and the responsibility of the expert played an important role in the correct concept-formation of mechanics part - especially in the case of the mis-conception caused by the intuitive belief. 2) In the class by instructor with the democratic teaching method, the change of concept took place more easily, because in his class students could discuss the subject freely, so that they might experience the thought course to give them the confidence on the science concept.