• Journal of Korean Institute of Industrial Engineers
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• v.21 no.3
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• pp.357-369
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• 1995

Wafer fabrication process is the most important and critical process in semiconductor manufacturing. The process is very complicated and hard to establish an efficient schedule due to its complexity. Furthermore, several performance indices such as due dates, throughput, cycle time and workstation utilizations are to be considered simultaneously for an efficient schedule, and some of these indices have negative correlations in performances each other. We develop an efficient heuristic scheduling algorithm; Hybrid Input Control Policy and Hybrid Dispatching Rule. Through numerical experiments, it is shown that the proposed Hybrid Scheduling Algorithm gives better performance compared with existing algorithms.

• Proceedings of the KIEE Conference
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• 1991.11a
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• pp.96-100
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• 1991

In the classical Preisach model for hard magenets, there break out several problems which are the asymmetry and negative domains of the distribution functions and the contradiction of the congruency. In this paper, generalized hysteresis model is proposed by applying the molecular field theory to the classical Preisach model. And it is showed that the problems above are solved by the generalized hysteresis model. The experiments are compared with the simulations and we got acceptible results.

• Tribology and Lubricants
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• v.16 no.6
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• pp.469-476
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• 2000

The effect of particulate contamination on the friction and wear between a negative-pressure picoslider/tri-pad nanoslider and laser-textured disk was studied. Particles of different concentration were injected at the head-disk interface consisting of disks with various textures and slider types at different speed. Durability increased and coefficient of friction decreased as the disk speed increased in a contaminated environment. Frictional characteristics and durability in the data Bone were better than those in the laser-textured zone. It was also found that durability of head-disk interface (HDI) decreased as the particle concentration increased. The interface durability with a picoslider was better than that with a nanoslider at any condition in a contaminated environment. Based on the test results, mechanisms were proposed to explain the reasons why durability with a picoslider was superior to that with a nanoslider.

• Proceedings of the KIEE Conference
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• 2008.10b
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• pp.151-152
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• 2008

Laser has been applied in various diagnostic and therapeutic medical fields. For last few decades, medical low-level laser devices have been introduced in market, but they have limitations which cannot convey enough energy to deep layer of tissues for diagnostic or therapeutic purposes. To address the issue, there have been many studies of using physical and chemical methods; it is one of ways to apply negative or positive pressure to tissue. However, it is hard to apply desired pressure on tissues continuously when practical laser devices arc used. In this study, we introduce a low-level laser probe which allows maintain pressure on skin tissue. Consequently, we are confident that the pressure probe for low-level laser treatment should be a useful tool in order to deliver sufficient energy for practical uses.

• Tribology and Lubricants
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• v.16 no.4
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• pp.247-252
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• 2000

As the demand for higher areal recording densities requires a lower flying height of the slider, the variation of the flying height of the slider during drive operation becomes of great concern. The variation of the flying height is closely related with the slider design parameters such as air bearing shape, cavity depth, shallow step depth, crown, camber, pitch offset, roll offset, gram load, and so on. The objective of this work is to optimize the cavity depth and the shallow step depth, which are the control factors in air bearing design, using Robust Design method. It was found that the shallow step depth was statistically significant in affecting the variation of flying height, therefore the level of the shallow step depth should be chosen to minimize the variation of flying height.

• Journal of Plant Biology
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• v.28 no.3
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• pp.253-259
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• 1985

The results of the conducted experiment obtained basic data on seed germination for Phragmites communis and Atriplex gmelini were; Seed germination was not influenced till 0.5% NaCl, but at over 1.0% NaCl it dropped remarkably. The germination limit fro degree of NaCl was 2.0% in Phragmites communis. Atriplex gemelini was 2.5% and in accordance with the increase of the degree of NaCl. Germination speed showed a negative correlation being highly significant and the germination period lengthened. Compared with growing top plants, growth of roots was largely influenced by a high degree of NaCl. In accordance with the rise of temperature, the germination rate, and speed of both plants remarkably increased and the germination period was shortened. Ubride of Atriplex gmelini was germinated at the early days of picking but was not as the passing of the period. The seeds also did not germinated likewise Ubride. By a seedcoat breaking germination became 81%. During 20 min soaking treatment in conc H2SO4 seed germination possibility of 63% was known to be hard. Adequate soaking time in conc H2SO4 was 17.5 min.

• Journal of the Korean School Mathematics Society
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• v.5 no.1
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• pp.1-11
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• 2002

The purpose of this study is to find out if there are meaningful differences between small rural middle schools and nearby urban ones In the mathematical diagnostic evaluation. It also says how to improve students' scholastic abilities, making up a question of attitudes towards math to know the mathematical abilities lowering cause in small rural middle schools. Findings are, 1. Students must recognize that studying math is essential and be interested in it. 2. The mathematical confidence is needed. 3. A strong will of studying math hard is important. 4. Students must have a motivational triggering, while solving math problems and then checking answers for themselves. 5. Backward countries' humanistic and social environmental factors should be overcome. In conclusion, we expect the mathematical abilities improvement, making students remove the mathematical abilities lowering cause after having a learning experience suitable for the rural community instead of the negative attitudes towards math.

• English Language & Literature Teaching
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• v.18 no.2
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• pp.85-106
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• 2012

This paper examines the role of extensive reading in foreign language learning classrooms. The effects of extensive reading are shown both positive and negative as in Krashen (1999) and Spada (1997), particularly researches done in classroom setting. Extensive reading is hard to implement in foreign language classrooms due to the stringent school curricula despite its benefits in cognitive and affective domain of learners. This study searched 21 papers from research database on extensive reading researches in a classroom setting and synthesized 55 cognitive effects and 11 affective effects from these papers under investigation in a manner of quantifying their means and standard deviations to derive generalizations. Research synthesis in this manner has secured its own status of scientific investigation by providing secondary researchers with replicable methods that produce verifiable findings. The syntheses of researches show that extensive reading is effective in both literacy skills and other language skills such as listening and writing. It also shows positive effects across different age groups, but the effect sizes are different in that elementary and adults gained more positive effects than middle and high school students.

• Applied Science and Convergence Technology
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• v.24 no.6
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• pp.284-288
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• 2015

Anionic small molecules are hard to penetrate the cell membranes because of their negative charges. Encapsulation of small molecules into liposome particles can provide target specific delivery of them. In our previous study, siRNA could be efficiently encapsulated into liposome particles using an asymmetric preparation method of liposomes. In this study, the same method was applied for encapsulation of small anionic fluorescent chemicals such as calcein and indocyanine green (ICG). More than 90% fluorescent chemicals were encapsulated in the asymmetric liposome particles (ALPs). No intracellular fluorescent signal was observed in the tumor cells treated with the unmodified calcein/ALPs and ICG/ALPs, whereas the surface modification with a cell-penetrating polyarginine peptide (R8 or R12) allows cellular uptake of the ALPs. The results demonstrate that the ALPs encapsulating small anionic drugs will be useful for target-specific delivery after modification of target-specific ligands.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.12 no.2
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• pp.131-136
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• 2012

If one can find a control Lyapunov function (CLF) for a given nonlinear system, the control input stabilizing the system can be easily obtained. To find a CLF, the time derivative of an energy function should be negative definite. This procedure frequently requires a control input which is a rational function or includes an inverse function. The control input is not defined on the specific state-space where the denominator of the rational function is equal to 0 or the inverse function does not exist. In this region with singularities, the trajectory of the control system cannot be generated, which is one of the most important reasons why it is hard to make the origin of a nonlinear system be globally asymptotically stable. In this paper, we propose a smooth control law ensuring the globally asymptotic stability by means of cancelling the singularity in the control input.