• Journal of The Korean Association For Science Education
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• v.19 no.3
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• pp.448-460
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• 1999

Worksheets with various levels are major instructional material in open classroom, but sometimes they have been arbitrarily developed in elementaryschools. Especially, pedagogical elements of science course seem to have been neglected in developing science learning papers. To solve these problems, a model of worksheets was developed considering the contextual nature of science knowledge and educational constructivism. The frame of this model is composed of inquiry skill and context, which are two dimensions of each learning task. The level of each worksheet was determined by the level of inquiry skills and the familiarity of contexts.

• Child Health Nursing Research
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• v.21 no.2
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• pp.115-122
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• 2015

Purpose: The purpose of this study was to validate the Korean version of the TNO-AZL Preschool Children Quality of Life (TAPQOL) questionnaire for children aged 18-60 months. Methods: The participants were 223 mothers of healthy children from nurseries and kindergartens, and 54 mothers of hospitalized children from a university children's hospital in Korea. Data were collected in 2011. Principal component factor analysis and known-groups method were used to confirm construct validity, and internal consistency was used to determine reliability. Results: According to the factor analysis, 11 factors with an eigenvalue over 1 were extracted, and these factors explained 73.5% of the variance. All dimensions except two had Cronbach's alpha coefficients greater than .7. The mean TAPQOL scores of the hospitalized group were significantly lower than those of the healthy group (p=.001) for all four functions (physical, emotional, social, and cognitive). Conclusion: The TAPQOL showed acceptable validity and reliability, and can be used to measure children's health-related quality of life in Korea, and can be considered for use in other Asian countries.

• 제어로봇시스템학회:학술대회논문집
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• 1988.10b
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• pp.794-797
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• 1988

G. Binnig and H. Rohrer introduced the Scanning Tunneling Microscope (STM) in 1982 and developed it into a powerful and not to be missed physical tool. Scanning tunneling Microscopy is a real space surface imaging method with the atomic or subatomic resolution in all three dimensions. The tip is scanned over the surface by two piezo translators mounted parallel (X-piezo and Y-piezo) to the surface and perpendicular to each other. The voltage applied to the third piezo (Z-piezo) translator mounted perpendicular to the surface to maintain the tunneling current through the gap at a constant level reflects then the topography of the surface. The feed back control loop for the constant gap current is designed using the automatic control technique. In the designing process of the feed back loop, the identification of the gap dynamics is very complex and has difficulty. In this research, using some suitable test signals, the system dynamics of the gap including the Z-piezo are investigated. Especially, in this paper, a system model is proposed for the gap and Z-piezo series system. Indicial response is used to find out the model. The driving voltage of the Z-piezo and the tunneling current are considered as input and output signals respectively.

• ETRI Journal
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• v.31 no.1
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• pp.51-61
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• 2009

We present a unified explanation of the internationalization strategies of major mobile network operators (MNOs). We have developed a framework that analyzes the strategies of major international MNOs in terms of the relationship between their degree of involvement in international business operations and the degree of equity participation. The results show a positive association between these two dimensions as expected, but they also reveal some exceptional cases in which certain MNOs are actively involved in the business operations of other foreign MNOs, even with minor (or zero) equity investments. In this paper, we argue that the strategic actions of the major MNOs which are the largest shareholders of foreign MNOs are in an equilibrium status because these major MNOs derive maximum benefit from full or considerable management control and active involvement. Finally, we predict that latecomers (MNOs who are just about to enter foreign telecommunications markets) may adopt an incremental investment approach because most developed markets and deregulated emerging markets with growth potential are already preempted by major MNOs. Therefore, the window of opportunity for internationalization in those markets is currently small.

• The Journal of Bigdata
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• v.4 no.1
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• pp.83-97
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• 2019

With sensor and communication technology development, spatial data related to business activities is exploding. Spatial data is now evolving into atypical data about space over three dimensions, away from two-dimensional geographic data. In addition to the Fourth Industrial Revolution, which connects the virtual space with the real space, there is a great opportunity for companies to utilize it. The analysis of recent overseas cases shows that it is possible to analyze customized services by understanding the situation of customers and objects located in the space, to manage risk, and furthermore to innovate business processes by analyzing spatial data. In the future, business innovation that combines spatial data from various sources and real-time analysis of relationships and situations between people and objects in space is expected to expand in all business fields.

• The Journal of Advanced Prosthodontics
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• v.9 no.1
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• pp.52-56
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• 2017

PURPOSE. Considering the importance of metal-ceramic bond, the present study aimed to compare the bond strength of ceramics to cobalt-chrome (Co-Cr) alloys made by casting and selective laser melting (SLM). MATERIALS AND METHODS. In this in-vitro experimental study, two sample groups were prepared, with one group comprising of 10 Co-Cr metal frameworks fabricated by SLM method and the other of 10 Co-Cr metal frameworks fabricated by lost wax cast method with the dimensions of $0.5{\times}3{\times}25\;mm$ (following ISO standard 9693). Porcelain with the thickness of 1.1 mm was applied on a $3{\times}8-mm$ central rectangular area of each sample. Afterwards, bond strengths of the samples were assessed with a Universal Testing Machine. Statistical analysis was performed with Kolmogorov-Smirnov test and T-test. RESULTS. Bond strength in the conventionally cast group equaled $74.94{\times}16.06\;MPa$, while in SLM group, it equaled $69.02{\times}5.77\;MPa$. The difference was not statistically significant ($P{\leq}.05$). CONCLUSION. The results indicated that the bond strengths between ceramic and Co-Cr alloys made by casting and SLM methods were not statistically different.

• Journal of Korea Game Society
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• v.20 no.4
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• pp.111-124
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• 2020

This paper analyzed the dialogue language of 'Maple Story' NPC from the perspective of learned optimism. Not only is NPC's language a key skill in artificial intelligence language, it also plays a big role in giving game users fun and desire to achieve. In this paper, as a result of analyzing the dialogue language of NPCs by utilizing the two key dimensions of NPC's learned optimistic explanation form: permanence and pervasiveness, the rate of characters' conversations using optimistic languages was 6%~7%. It was confirmed the important consideration in NPC artificial intelligence development.

• BMB Reports
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• v.29 no.1
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• pp.38-44
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• 1996

Taq DNA polymerase from Thermus aquaticus has been shown to be very useful in the polymerase chain reaction method, which is being used for amplifying DNA. Not only does Taq DNA polymerase have high commercial value commercial value for the polymerase chain reaction application, but it is also important in studying DNA replication, because it is apparently an homologue to E. coli DNA polymerase I, which has long been used for DNA replication study (Lawyer et ai., 1993). The crystal structure determination of Taq DNA polymerase was initiated. An X-ray diffraction pattern breaks down a crystal structure into discrete sine waves in a Fourier series. The original shape of a crystal object in terms of electron density may be represented as the sum of those sine waves with varying amplitudes and phases in three dimensions. The molecular replacement method was initially employed to provide phase information for the structure of Taq DNA polymerase. The rotation search using the program MERLOT resulted in a solution peak with 5.4 r.m.s. PC-refinement of the X-PLOR program verified the result and also optimized the orientation angles. Next, the translation search using the X-PLOR program resulted in a unique solution peak with 7.35 r.m.s. In addition, the translation search indicated $P3_121$ to be the true space group out of two possible ones. The phase information from the molecular replacement was useful in the MIR phasing experiment.

• 한국전산유체공학회:학술대회논문집
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• 2008.03a
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• pp.33-41
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• 2008

This paper is an extension of previous study[9] on a development of a divergence-free element method using a hermite interpolated stream function. Divergence-free velocity bases defined on rectangles derived herein produce pointwise divergence-free flow fields. Hence the explicit imposition of continuity constraint is not necessary and the Galerkin finite element formulation for velocities does not involve the pressure. The divergence-free element of the previous study employed hermite serendipity cubic for interpolation of stream function, and it has been noted a possible discontinuity in variables along element interfaces. This deficiency can be removed by use of a hermite bicubic interpolated stream function, which requires at each element corners four degrees-of-freedom such as the unknown variable, its x- and y-derivatives and its cross derivative. Detailed derivations are presented for both solenoidal and irrotational bases from the hermite bicubic interpolated stream function. Numerical tests are performed on the lid-driven cavity flow, and results are compared with those from hermite serendipity cubics and a stabilized finite element method by Illinca et al[7].

• Transactions of the Korean Society of Mechanical Engineers A
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• v.29 no.4 s.235
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• pp.511-517
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• 2005

Fretting fatigue is often the root cause of the nucleation of cracks at attachments of structural components. Since fretting fatigue damage accumulation occurs over relatively small volumes, the subsurface cyclic plastic strain is expected to be rather non-uniformly distributed in polycrystalline materials. The scale of the cyclic plasticity and the damage process zones is often on the order of microstructure dimensions. Fretting damage analyses using cyclic crystal plasticity constitutive models have the potential to account for the influence of size, morphology, and crystallographic orientation of grains on fretting damage evolution. Two-dimensional plane strain simulations of fretting fatigue are performed using the cyclic properties of Ti-6Al-4V. The crystal plasticity simulations are compared to an initially isotropic $J_{2}$ theory with nonlinear kinematic hardening as well as to experiments. The influence of initially isotropic versus textured microstructure in the presence of crystallographic slip is studied.