• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.28 no.6
• /
• pp.701-708
• /
• 2004

This paper discusses applicability of the enhanced reference stress method to estimate J-integral along the semi-elliptical surface crack front. It is found that angular variations of normalized J­integral are strongly dependent on the geometry, loading mode and loading magnitude. As application of the reference stress approach to semi-elliptical surface cracks implies proportional increases in the normalized J-integral, the present results pose a question in applicability of the reference stress approach. However, investigation of the error in the estimated J-integral in the present work suggests that the enhanced reference stress approach, recently proposed by authors, provides an effective engineering tool fur estimating crack driving force along the semi-elliptical surface crack front.

• Journal of computational fluids engineering
• /
• v.11 no.3 s.34
• /
• pp.52-58
• /
• 2006

A numerical investigation is made of air flow in a spinner equipment used for cleanning and drying flat display panels. A unique feature of the spinner under question is the placement of a torus plate cover over the rotating plate. The turbulent flow is driven by rotation of a large disk and suction by the exhaust system connected to vacuum chamber. The flow is modelled as an axisymmetric two-dimensional flow and computation is conducted by using the FLUENT package with a version of k-$\varepsilon$ turbulence model. The required capacity of the exhaust system is assessed numerically. The usefulness of the cover in controlling air flow circulation is examined. A computational trouble shooting is attempted to resolve the problem of panel rising which occurred in real experiment.

• English Language & Literature Teaching
• /
• v.9 no.spc
• /
• pp.39-60
• /
• 2003

The purpose of the present classroom research is to investigate teacher talk in the primary English classroom with special reference to teacher questions. The analysis of the recorded teacher questions reveals that the teacher asks a carefully structured sequence of questions leading to the clear pedagogical goals she has set: to encourage students to correct themselves; to find out what students know; to personalize the task; and to elicit culture talk. It is also shown that her use of display questions is supportive of learning; the teacher provides feedback in a way which is as communicative as possible in the context of the classroom and which facilitates the attainment of the pedagogical purposes. All these findings suggest that we consider how teacher talk may perform communicative functions in the classroom context rather terms defining communicative teacher talk purely in terms of the norms of communication outside the classroom.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 2005.05a
• /
• pp.394-397
• /
• 2005

In korea, the power consumption is increasing every year because of economic growth, requiring of convenience and delightfulness condition. As increasing power consumption, Private Use is steadily increasing and the rate of electrical accident is increasing. Therefore we research the electrical safety culture of our people by the survey of electrical safety. The subject to investigation is possessor, occupier of Private Use and electrical safety manager. This paper will be used to base data for the protection of electrical accident and facility accident at Private Use

• Asia pacific journal of information systems
• /
• v.26 no.1
• /
• pp.124-142
• /
• 2016

Companies operating in social network platforms continue to improve and expand their marketing techniques. This study examines the practice of "gating", which involves virtual barriers between social network users and company content. Gates demand mandatory user endorsements, in the form of a Facebook "Likes", Twitter "retweets" etc., to gain access to company content, such as coupons and rewards,. Gating practices demand a mandatory endorsement before any content consumption takes place. Thus, while user endorsements are assumed to arise voluntarily from trusted known sources, gating practices would appear to violate this assumption. However, whether this violation lessens the effectiveness of gating practices still requires empirical validation. We investigate this question through the use of a unique panel data set that includes data on "like" endorsements obtained from a number of real-world Facebook business pages. Results of the study show that gating practices are effective for endorsement solicitation; however, gates may interfere with more traditional marketing activities.

• Communications of the Korean Mathematical Society
• /
• v.9 no.2
• /
• pp.285-291
• /
• 1994

This paper is a contribution to the study of the isomorphism problems for algebras. Among the isomorphism problems, that of global determination is investigated here. That is, our investigation of the problems is concerned with the question whether two algebras are isomorphic when their globals are isomorphic. The answer is not always affirmative. The counterexample, due to E. M. Mogiljanskaja, is the class of all infinite semigroups. But T. Tamura and J. Shafer [6] proved that the class of all groups is globally determined and announced the same result for the class of rectangular bands. Vazenin [7] proved that for any set X, the transformation semigroup $T_{X}$ must be isomorphic to any semigroup S for any P(S)$\simeq$P($T_{X}/TEX>).(omitted)

• BMB Reports
• /
• v.29 no.4
• /
• pp.380-385
• /
• 1996

Ovomucoid third domain is a serine proteinase inhibitor protein which consists of 56 amino acid residues. A fifty picosecond molecular dynamics (MD) simulation was carried out for ovomucoid third domain protein with 5 $\AA$ layer of water molecules. A comparison of main chain atoms in the MD averaged structure with the crystal structure showed that most of the backbone structures are maintained during the simulation. Investigation of the intramolecular hydrogen bondings indicated that most of the interactions between main chain atoms were conserved, whereas those between side chains were reorganized for the period of the simulation. Especially, the side chain interactions around the scissile bond of reactive site P1 (Met18) were found to be more extensive for the MD structures. During the simulation, hydrogen bonds were maintained between the side chains of Glu19 and Arg21 as well as those of Thr17 and Glu19. Extensive side chain interactions observed in the MD structures may shed light on the question of why protein proteinase inhibitors are strong inhibitors for proteinases rather than good substrates.

• Journal of Biomedical Engineering Research
• /
• v.26 no.4
• /
• pp.251-255
• /
• 2005

When the extracorporeal shock wave lithotriptor is operated, sounds can be heard. Then that might be a question about the location where the sounds come from. For the purpose of investigating the fact, we identify the location of the sounds radiated using one hydrophone. In order to carry out the experiment, it is needed to obtain direct waves from objects. Therefore, we present an experimental method to reduce reflected waves for obtaining direct waves only. The experimental results show the amplitude of waves can be attenuated about 28dB due to a silicon rubber plate of 8.5mm attached at the bottom. This is a quantified result that can expect to obtain the direct waves using the proposed method. Then, we carried out the experiment for the sound source location. From the experimental results, we can undoubtedly present a fact that the sounds are radiated from the objects to be shot due to shock waves.

• Tribology and Lubricants
• /
• v.11 no.5
• /
• pp.93-98
• /
• 1995

To increase the information storage density in magnetic disk files, the head, the headdisk spacing must be reduced. This has motivated the investigation of alternatives to the conventional air-lubricated head-disk interface (HDI), which operates at a spacing of about 100 nm. One such alternative under consideration is the liquid-lubricated bearing. To properly model the HDI with a liquid bearing it is necessary to incorporate the theological properties of liquid lubricants at high shear rates. These rheological properties themselves are most easily measured within the HDI. Recently, some question has arisen in the literature concerning the interpretation of the frictional data acquired in this manner. In this study analytical and numerical solutions of the Reynolds eqn. are applied to the starved, liquid lubricated HDI to provide some validation of the rheological data reported the author and coworkers (Streator et al., 1994). Results of the analysis highlight the importance of the inlet taper region in determining the equilibrium configuration of the starved HDI even when only a small fraction of its length is wetted by the lubricant.

• Fire Science and Engineering
• /
• v.21 no.1 s.65
• /
• pp.29-36
• /
• 2007

This study has grasped weakness factor fire safety and way aspect of fire analyzing hazardous material accident, and has investigated how by legal present kind and scale of hazardous material work that must assign hazardous material safety supervisor are prescribed. We have proposed efficient lecturing education time analyzing about validity and efficiency of education time about hazardous material safety supervisor lecturing education with question investigation to people who take hazardous material safety supervisor lecturing education that manage in korea fire safety association.