• Journal of the Korean Society for Heat Treatment
• /
• v.24 no.5
• /
• pp.262-270
• /
• 2011

Carbide precipitation and dissolution behavior at various temperatures during heat treatment has been studied in STD11 cold working die steel through confocal scanning laser microscopy; dilatometry; and X-ray diffraction analysis. The equilibrium phase diagram and phase fractions with temperature were calculated using a FactSage program. Confocal laser microscopic observation revealed that ${\alpha}$ to ${\gamma}$ transformation temperature is near $800^{\circ}C$; M7C3 carbides melt at $1245^{\circ}C$; and the melting temperature of STD11 is near $1370^{\circ}C$. XRD results indicated that the M23C6 carbides dissolve in the matrix if austenitized at over $1030^{\circ}C$; while the M7C3 carbides remain up to $1200^{\circ}C$ although their amount decreases. The calculated equilibrium phase diagram showed good agreement with experimental results on carbide dissolution and phase transformation temperatures.

• The Journal of Asian Finance, Economics and Business
• /
• v.7 no.11
• /
• pp.479-489
• /
• 2020

The purpose of this paper is to uncover whether and how contextual factors (information exchange, participation, trust in management, and training), relate to resistance to change. It also explores the mediating effect of perceived impact of change on the relations between contextual factors and resistance to change. This study is conducted in several manufacturing plants in food processing industry in Vietnam, which is implementing a top-down large-scale change - Lean transformation, adopting Total Productive Maintenance (TPM) program, to be specific. The findings suggest that all four contextual factors are negatively associated with resistance to change, in which training had the strongest impact. Also, the perceived change impact partially mediates the relationships between the four contextual factors and resistance to change. The practical implications of this paper are that employees who receive adequate, timely and useful information relating to change are less likely to show opposing behaviors towards change. Fostering trust in management among employees, and employee involvement in decision-making, also have a significant influence when addressing employee resistance to change. Employees who are well-trained, well-equipped with tools and knowledge about the change, are less likely to resist as they view the benefits of changes more significant than the risks.

• The Transactions of the Korea Information Processing Society
• /
• v.6 no.2
• /
• pp.307-314
• /
• 1999

In this paper, we study on the transformation technique of sequential programs for the purpose of 'exploiting parallelism' and 'improving locality'. Based on the analysis of loop procedures of sequential programs with the factor of dependency and locality, two transformation techniques of loop distribution and loop fusion are applied to them. Transformed programs can be easily expressed as a parallel program wit thread notation, having coarse-grain parallelism and improved locality. This means that those transformations can be useful tools for optimizing and automatic-parallelizing compiler construction. Application of those techniques to SPEC95 on a solaris machine with four SPARC processors show an improvement of execution time.

• Korean Journal of Geomatics
• /
• v.2 no.1
• /
• pp.83-89
• /
• 2002

The cadastral maps as many as about 750,000 map sheets to cover 34,751,000 parcels of land of Korea, are being digitalized. The problem of shrinkage-expansion of the paper cadastral maps has to be resolved for the new digital maps, where the nodes and vertices of the parcel boundaries are represented by coordinates. The photo coordinate refinement techniques, two dimensional projective transformation and local area transformation as in the reseau grid method, were introduced for this distortion correction. Using the fact that original maps drawn on the plane tables in field from 1910 to 1918 have grid lines and have been preserved well, a strategic flow to apply the refinement techniques to the digital maps with the original maps as controls was developed. To accommodate the presence or absence of the original maps and grid lines, and different scales and sizes of the maps, the strategy was implemented by a computer program package. Various distortions and corrections were simulated and errors were evaluated. The RMS errors in the corrected digital maps were allowable, thus, the method developed in this study was to be applicable for the digital cadastral maps.

• Journal of Practical Engineering Education
• /
• v.9 no.1
• /
• pp.85-90
• /
• 2017

The contemporary South Korean landscape is characterised by a massive display of modern apartment buildings. They are omnipresent in their monotonous manifestation and represent the dream of the Korean population. Serial mass housing is a typology that has had a great diffusion all over the world, but how has modern housing developed in South Korea? To this end, what are the resulting local adaptations?. This paper retraces these key evolutional aspects. Methodologically, it draws on a scholarly literature review as well as on-site photographic surveys, developed in connection with an educational program at the Korea Tech University. The result is the analysis of both the urban and architectural transformation from the early modernisation period to the present condition of contemporary housing. A historical background introduces Korean traditional urban houses, to be used as a context to describe the contemporary modern city that has developed since the 1960s. The main emphasis is then placed on the urbanisation process that fully matured during the 1980s together with a focus on the mass housing typology as the main pivot in the urban transformation. Finally, the paper will draw a parallel between modern Western theories and Korean applications.

• Journal of the Korean School Mathematics Society
• /
• v.9 no.4
• /
• pp.539-556
• /
• 2006

Tessellations are the pattern of iterations of geometric transformation. We can find them in the works of Escher, the famous Dutch artist. Also, We can find the beauty of tessellations in traditional Korean house doors, old Korean architecture, palace walls, and so forth. In this article, the figures of patterns we present are a pig, a frog, Tchiucheonwhang (the mascot of Korean football supporters), and figures by Escher, using the computer geometric program, GSP (Geometer's Sketchpad). We wanted to investigate the gender differences on students' achievement and disposition toward mathematics in constructing tessellations. The results indicated that if students were supported with well prepared instructional materials which helped students make their own figures, female students in particular would be more interested in learning geometric transformation.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.33 no.2
• /
• pp.145-152
• /
• 2009

SGBEM(Symmetric Galerkin Boundary Element Method)-FEM alternating method has been proposed by Nikishkov, Park and Atluri. In the proposed method, arbitrarily shaped three-dimensional crack problems can be solved by alternating between the crack solution in an infinite body and the finite element solution without a crack. In the previous study, the SGBEM-FEM alternating method was extended further in order to solve elastic-plastic crack problems and to obtain elastic-plastic stress fields. For the elastic-plastic analysis the algorithm developed by Nikishkov et al. is used after modification. In the algorithm, the initial stress method is used to obtain elastic-plastic stress and strain fields. In this paper, elastic-plastic J integrals for three-dimensional cracks are obtained using the method. For that purpose, accurate values of displacement gradients and stresses are necessary on an integration path. In order to improve the accuracy of stress near crack surfaces, coordinate transformation and partitioning of integration domain are used. The coordinate transformation produces a transformation Jacobian, which cancels the singularity of the integrand. Using the developed program, simple three-dimensional crack problems are solved and elastic and elastic-plastic J integrals are obtained. The obtained J integrals are compared with the values obtained using a handbook solution. It is noted that J integrals obtained from the alternating method are close to the values from the handbook.

• 제어로봇시스템학회:학술대회논문집
• /
• 2005.06a
• /
• pp.1183-1188
• /
• 2005

In this paper, we propose a 3D automated measuring system which measures the mandibular movements and the reference plane of the jaw movements. In diagnosis and treatment of the malocclusions, it is necessary to estimate the mandibular movements and the reference plane of the jaw movements. The proposed system is configured with double stereo-cameras, PC, two moving pattern plates(MPPs), two fixed pattern plates(FPPs) and one orbital marker. The virtual pattern plate is applied to calculate the homogeneous transformation matrices which describe the coordinates systems of the FPP and MPP with respect to the world coordinates system. To estimate the parameters of the hinge axis, the Euler's theorem is applied. The hinge axis points are intersections between the FPPs and the hinge axis. The coordinates of a hinge axis point with respect to the MPP coordinates system are set up to fixed value. And then, the paths of the jaw movement can be calculated by applying the homogeneous transformation matrix to fixed hinge axis point. To examine the accuracy of the measurements, experiments of measuring the hinge axis points and floating paths of them are performed using the jaw motion simulator. As results, the measurement errors of the hinge axis points are within reasonable boundary, and the floating paths are very similar to the simulator's moving path.

• The Journal of the Korea Contents Association
• /
• v.13 no.2
• /
• pp.488-497
• /
• 2013

The purpose of the study was to investigate the relationship between the degree of participation and flow for participants in ground, water, and air leisure sports-based tourism activities. A total of 437 participants' data was employed for the analyses (one-way ANOVA and multiple regression analysis) using SPSS Win 18.0 program. Main findings are as follows; First, there were differences in clear goals, transformation of time, loss of self-consciousness, challenge-skill balance, autotelic experience, unambiguous feedback, and sense of control out of flow dimensions based on types of leisure sports-based tourism activities. Second, participation period and frequence had positive effects on flow. Specifically, period had an influence on challenge-skill balance. clear goals: frequence had an effect on challenge-skill balance, transformation of time, clear goals, autotelic experience, unambiguous feedback, and sense of control: intensity had an influence on transformation of time and autotelic experience.

• Journal of Plant Biotechnology
• /
• v.47 no.1
• /
• pp.66-72
• /
• 2020

Alstroemeria plants were transformed by using an improved particle-gun-mediated transformation system. Friable embryogenic callus (FEC) induced from the leaves with axil tissues of Alstroemeria plant was used as the target tissue. Also, FEC was transformed with the bar gene was used as a selectable marker. In the case of plasmid pAHC25, 7.5% of the twice-bombarded FEC clumps showed blue foci, whereas the clumps with single bombardment showed only 2.3%. Additionally, a 90° rotation with double bombardment led to a higher frequency (6 times) of luciferase gene expression in PBL9780 than the control treatment. After 8 weeks of bombardment, more than 60 independent transgenic lines were obtained for pAHC25 and nearly 150 independent transgenic lines were obtained for PBL9780, all of which were resistant to PPT and demonstrated either GUS or luciferase activity. Regarding effect of osmotic treatment (0.2 M mannitol) with 7 different periods, the highest transient gene expression was obtained in 8 h before and 16 h after transformation in both pAHC25 and PBL9780. Compared with the control, at least three times more GUS foci and photons were observed in this treatment. With respect to different combinations of mannitol and sorbitol with 8 h before and 16 h after transformation, high numbers of transient and stable transgene expressions were observed in both 0.2 M mannitol and 0.2 M sorbitol used in the osmotic pre-culture. This combination showed the highest transformation efficiency in both pAHC25 (8.5%) and PBL9780 (14.5%). In the control treatment, only 10% of the FEC clumps produced somatic embryos. However, by using 0.2 M mannitol and 0.2 M sorbitol, the frequency of somatic embryos increased to 36.5% (pAHC25) and 22.9% (PBL9780). Of the somatic embryos produced, at least 60% germinated. Approximately 100 somatic embryos from these 210 independent transgenic lines from 2 plasmids developed into shoots, which were then transferred to the greenhouse. PCR analysis confirmed the presence of the bar gene. This is the report on the production of transgenic Alstroemeria plants by using particle bombardment with a high efficiency, thereby providing a new alternative for the transferring of gene of interests in Alstroemeria in the breeding program in the future.