• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.93-93
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• 2010

In this talk, I will introduce a reactive force field (ReaxFF) molecular dynamics (MD) simulation. In contrast to common MD simulations with empirical FFs, we can predict chemical reactions (bond breaking and formation) in large scale systems with the ReaxFF simulation where all of the ReaxFF parameters are from quantum mechanical calculations such as density functional theory to provide high accuracy. Accordingly, the ReaxFF simulation provides both accuracy of quantum mechanical calculations and description of large scale systems of atomistic simulations at the same time. Here, I will first discuss a theory in the ReaxFF including the differences from other empirical FFs, and then show several applications for studying chemical reactions of SiHx radicals on Si surfaces, which is an important issue in Si process.

• Molecules and Cells
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• v.25 no.3
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• pp.428-437
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• 2008

To identify transcriptional markers for beef traits related to meat tenderness and moisture, we measured the transcriptome of the Longissimus dorsi skeletal muscle in 10 Korean native cattle (KNC). We analyzed the correlation between the beef transcriptome and measurements of four different beef traits, shear force (SF), water holding capacity (WHC), cooking loss (CL), and loin eye area (LEA). We obtained non-overlapping and unique panels of genes showing strong correlations (${\mid}r{\mid}$ > 0.8) with SF, WHC, CL, and LEA, respectively. Functional studies of these genes indicated that SF was mainly related to energy metabolism, and LEA to rRNA processing. Interestingly, our data suggested that WHC is influenced by protein metabolism. Overall, the skeletal muscle transcriptome pointed to the importance of energy and protein metabolism in determining meat quality after the aging process. The panels of transcripts for beef traits may be useful for predicting meat tenderness and moisture.

• Transactions of The Korea Fluid Power Systems Society
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• v.3 no.1
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• pp.1-6
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• 2006

A servo actuator with a valve using MR (Magneto-Rheological) fluid is proposed for fluid control systems. The MR fluid is well known as a functional fluid whose apparent viscosity is controlled by the applied magnetic field strength. The pressure in the MR cylinder can be controlled by the applied magnetic field strength. Good points of the MR cylinder are more simple, compact and reliable structure than a conventional oil hydraulic cylinder. The experimental results show that the MR cylinder could be used as a servo actuator.

• Journal of Institute of Control, Robotics and Systems
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• v.12 no.8
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• pp.798-804
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• 2006

To overcome the limited relative uncertainty and work range of the existing planar stage and the bulk structure of the contact-less motor for rotation, the novel operating principle to realize the precise rotation is suggested. It uses the two-axial vector forces, normal force and thrust force, of three-induction type of axial motors located $120^{\circ}$ apart, resulting in the contact-free rotation of the mover. Firstly in this paper, the magnetic forces across the air gap are modeled and simulated under the various conditions. It clarifies the feasible range of the derived solution. And the algorithm compensating the strong cross couple between the forces and the control inputs; generally AC magnitude and slip frequency, is given to realize the independent control of six axes. Finally, for the successfully implemented system, the round test and the micro step test results are given.

• Structural Engineering and Mechanics
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• v.90 no.6
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• pp.531-542
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• 2024

This study proposes a ground anchor using electromagnetic induction and utilizes an extended structure using hinges and links and mounting and sensing using electromagnets. The aim is to secure the anchor force, excluding grout, and to secure various sensing capabilities, including ground behavior. We propose a design based on the drilling diameter of 150 mm, and the materials used were STS304 and Aluminum 6061-T6. Computerized analysis was performed to confirm structural safety and functional implementation. The pull-out experiment was conducted by simulating the bedrock environment on a model earthwork as an experiment to check whether anchor force was generated by the insertion and tension of the anchor. The environmental pollution of grout, the difficulty of removing strands, and the inability to check whether the anchor is seated, which were pointed out as disadvantages of the existing ground anchor, were solved. Therefore, this study suggest that it can be effectively utilized as a secure and monitored anchoring solution in eco-friendly construction practices, including the installation of landslide prevention barriers.

• Strategy21
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• s.40
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• pp.5-36
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• 2016

Recently, the Japanese government revised the three guidelines of its security policy, the National Security Strategy(NSS), the National Defense Program Outline and Midterm Defense Buildup Plan, exceptionally at one time. This means Japan has been seeking the new strategy and strengthening military power considering changing regional security environment. Moreover, Japan revised the security laws for the right to collective self-defense, which authorized the use of force even when Japan is not under attack. Also, Japan renewed the Guidelines for Japan-U.S. Defense Cooperation in twenty years, and has expanded JSDF's scope of activity to a worldwide level. These changes imply Japan would constantly seek to build military forces focusing on naval forces. Because Japan's naval forces, the JMSDF is the means that allow Japan to use its force at anywhere overseas and expand its roles and missions in international society by the basis of the right to collective self-defense. This research will analyze Japan's new maritime strategy and trend of force development and eventually look for the implication on our maritime security These days, Japan has perceived Chinese rapid increase of naval power and pursuing of maritime hegemony as a grave threat. In response to this, Japan is designing new maritime strategy, which are "remote islands defense and recapture" and proactively develop a new type of naval forces to accomplish this new strategy. The Japan's "remote island defense and recapture strategy" is to harden its defensive posture in Nansei islands which correspond to China's 1st island chain for chinese A2/AD strategy and directly encounter with China and to protect its own dominium and maritime interest while supporting US national strategy in East Asia. Japan continues to build compact, multi-functional ship to accomplish "remote island defense and recapture strategy" and keep strengthening its maritime power projection capability to include build of new amphibious ship, and large, multi-functional ship which can provide effective C2. These changes imply that Japan is shifting its strategy from passive and defensive to proactive and aggressive way and continues to pursue naval buildup.The implication of Japan's new maritime strategy and naval buildup needs to be observed carefully and we need to keep developing naval power required to protect our maritime sovereignty and interest.

• Korean Journal of Mathematics
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• v.6 no.1
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• pp.27-46
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• 1998

We are concerned with an optimal control problem governed by a Poisson equation in which body force acts like a control parameter. The cost functional to be optimized is taken to represent the error from the desired observation and the cost due to the control. We recast the problem into the mixed formulation to take advantage of the minimax principle for the duality method. The existence of a saddle point for the Lagrangian shall be shown and the optimality system will be derived therein. Finally, to attain an optimal control, we combine the optimality system with an operational technique. By achieving the gradient of the cost functional, a convergent algorithm based on the projected gradient method is established.

• The Journal of the Korean dental association
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• v.54 no.6
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• pp.438-446
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• 2016

Severe tooth wear may cause the pathologic change of the TMJ and masticatory muscles, unesthetic facial appearance, pathogenic pulp and occlusal disharmony. Treating patients with severely worn dentition often requires full mouth rehabilitation with increasing vertical dimension. Proper diagnosis and treatment planning are important for esthetic and functional definitive restorations and the long term stability of the neuromuscular system and the TMJ. In this case, 66 year-old female presented with generalized worn dentition. Based on assessment, pathologic destruction of teeth structure on entire dentition was caused by masticatory force and diet habit without loss of vertical dimension. Subsequently, 3 mm increase of vertical dimension that based on incisor for tooth restoration and esthetic improvement was determined. After 8 weeks stabilization period with temporary fixed prostheses, definitive prostheses were fabricated. After 6 months follow up period, satisfactory outcomes were attained both functional and esthetic aspects through this procedure.

• Molecules and Cells
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• v.41 no.1
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• pp.45-49
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• 2018

Autophagy is a lysosome-dependent degradation process that is essential for maintaining cellular homeostasis. In recent years, more studies have focused on the late stages of autophagy. Our group discovered and studied the terminal step of autophagy, namely autophagic lysosome reformation (ALR). ALR is the process that regenerates functional lysosomes from autolysosomes, thus maintaining lysosome homeostasis. ALR involves clathrin-mediated membrane budding from autolysosomes, elongation of membrane tubules along microtubules with the pulling force provided by the motor protein KIF5B, proto-lysosome scission by dynamin 2, and finally maturation of proto-lysosomes to functional lysosomes. In this review, we will summarize progress in unveiling the molecular mechanisms underlying ALR and its potential pathophysiological roles.

• Journal of the Korean Institute of Telematics and Electronics
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• v.24 no.6
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• pp.1068-1073
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• 1987

Traditional circuit partitioning algorithm using the cluster development method, which is suitable for such applications as single chip floor planning or multiple layer PCB system placement, where the clusters are formed so that inter-cluster nets are localized within the I/O connector pins, may not be appropriate for the functiona block placement in truly 3-D electronic modules. 3-D hybrid IC is one such example where the inter-layer routing as well as the intra-layer routing can be maximally incorporated to reduce the overall circuit size, cooling requirements and to improve the speed performance. In this paper, we propose a new algorithm called MBE(Minimum Box Embedding) for the layer assignment of each functional block in 3-D hybrid IC design. The sequence of MBE is as follows` i) force-directed relaxation in 3-D space, ii) exhaustive search for the optimal orientation of the slicing plane and iii) layer assignment. The algorithm is first explaines for a 2-D reduced problem, and then extended for 3-D applications. An example result for a circuit consisting of 80 blocks has been shown.