• Journal of Institute of Control, Robotics and Systems
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• v.7 no.11
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• pp.927-932
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• 2001

When people write a character with a pen stably, proper compliance planning is necessary. In this paper, after investigating the property of character writing task, we propose a fundamental grasp model for character writing and also analyze compliance characteristics for effective character writing using multi-fingered hands. For this, the general stiffness relation of multi-fingered hand is firstly described. Next, we investigate the grasp configurations for grasping a pen and then, we analyze the conditions of the specified stiffness matrix in the operational space to successfully and more effectively achieve the given character writing task. Through the analysis, an effective grasp modeling for successful character writing is shown. And also, we conclude that the operational compliance characteristics should be properly planned for character writing, stably and precisely.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.05a
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• pp.510-513
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• 2003

The paper represents the stability of a rotor system with the squeeze film damper (SFD) using an electromagnet. The electromagnet is installed in the inner damper of the SFD. The proposed SFD has basically property of a conventional SFD and variable damping property according to variation of the applied electric current. Therefore, when the applied current controlled, the whirling vibration of the rotor system can be effectively reduced in a wide operational speed range. In the present work, the performance of the SFD was experimentally investigated according to changing the magnetic field strength. When the applied current increased, the whirling amplitude greatly reduced and the damping ratio also increased.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.13 no.6
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• pp.484-489
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• 2003

The paper represents stability of a rotor system with the squeeze film damper (SFD) using an electromagnet. The electromagnet is installed in the inner damper of the SFD. The proposed SFD has basically the property of a conventional SFD and variable damping property according to variation of the applied electric current. Therefore, when the applied current Is controlled, the whirling vibration of the rotor system can be effectively reduced in a wide operational speed range. In the present work, the performance of the SFD was experimentally investigated according to changing the magnetic field strength. As the applied current increased, damping ratios increased, while whirling amplitudes greatly reduced.

• Proceedings of the KIEE Conference
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• 1988.11a
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• pp.36-41
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• 1988

Analog and Digital Speed Control Systems have mutually complementary properties. Analog System has good dynamic characteristics and moderate steady-state accuracy and can be implemented economically with operational a ampliers. Digital System, on the contray, has good static accuracy, but relatively poor dynamic property. So, a hybrid system which uses both digital and analog control can have good static and dynamic characteristics. In this paper, it is shown that a simple digital controller can improve steady-state accuracy of existing analog control system satisfactorily, and some design criteria are presented also.

• ETRI Journal
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• v.29 no.6
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• pp.811-813
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• 2007

We report on a ridge waveguide laser diode with laterally tapered waveguides fabricated in a single growing step using a double patterning method. In this structure, nearly constant output power is obtained with the change of the lower tapered waveguide width, and the facet power ratio of 1.4 to 1.5 is observed over the current range. The asymmetric facet power property is also investigated.

• Honam Mathematical Journal
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• v.35 no.4
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• pp.607-623
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• 2013

Operational properties of cubic sets are first investigated. The notion of cubic subsemigroups and cubic left (resp. right) ideals are introduced, and several properties are investigated. Relations between cubic subsemigroups and cubic left (resp. right) ideals are discussed. Characterizations of cubic left (resp. right) ideals are considered, and how the images or inverse images of cubic subsemigroups and cubic left (resp. right) ideals become cubic subsemigroups and cubic left (resp. right) ideals, respectively, are studied.

• Honam Mathematical Journal
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• v.34 no.2
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• pp.289-295
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• 2012

In this note we prove the space (A, ${\parallel}.{\parallel}$) is a Banach space and ${\parallel}ab{\parallel}{\leq}{\parallel}a{\parallel}{\parallel}b{\parallel}$ for $a,b{\in}A$ where $A:=\{a:=(a_t)_{t{\in}G}:{\sum}_{t{\in}G}{\parallel}a_t{\parallel}_t<{\infty}\}$, $G=\mathbb{N}^*$. Also we show some property in (A, ${\parallel}.{\parallel}$).

• Transactions of Materials Processing
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• v.12 no.1
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• pp.3-10
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• 2003

The formation of surface defects associated with Jotting in injection molding is related to the geometries of cavity and fate, operational conditions and the rheological properties of polymer. In this study we have examined jetting phenomena in injection molding process for the throe kinds of PCs which have different molecular weights and structures, PBT and PC/ABS alloy with several injection speeds. We have used various cavity shapes those are tensile, flexural and impact test specimens with various gates and cavity thicknesses. Through this study we have observed that the jetting is related to the dic swell of material. This means that the jotting is strongly affected by the elastic flow property rather than the viscous flow property in viscoelastic characteristics of molten polymer. Different resins have different elastic properties, and elastic flow behavior depends on the shear rate of flow, i.e. injection speed. Large die swell would eliminate jetting however, the retardation of die swell would stimulate jetting. In the point of mole design, reducing the thickness ratio of cavity to gate can reduce or eliminate jetting regardless of amount of elasticity of polymer melt.

• Korean Journal of Heritage: History & Science
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• v.53 no.4
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• pp.274-291
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• 2020

This year is the 50th anniversary of the adoption by UNESCO in 1970 of the Convention on the Means of Prohibiting and Preventing the Illicit Import, Export, and Transfer of Ownership of Cultural Property (the '1970 Convention'). Since its ratification of the 1970 Convention in 1983, the Republic of Korea has domestically implemented the Convention through its Cultural Heritage Protection Act, which was first enacted in 1962. This is a different form of implementation than is normally used for other UNESCO Conventions on cultural heritage, in that the Republic of Korea has recently adopted special acts to enforce the 2003 Convention for the Safeguarding of Intangible Cultural Heritage and the 1972 Convention concerning the Protection of the World Cultural and Natural Heritage. In addition, the 1970 Convention has been developed further through the introduction of new Operational Guidelines in 2015 for the concrete enforcement of the Convention, which has provided momentum for the Republic of Korea to analyze its current national legislation related to the 1970 Convention as well as consider its amendment in the future. Overall, the Cultural Heritage Protection Act of the Republic of Korea effectively reflects the duties of States Parties under the 1970 Convention. These include measures to introduce export certificates, prohibit the import of stolen cultural property, return other state parties' cultural property, and impose penalties or administrative sanctions in the event of any infringements. Indeed, the Republic of Korea's implementation of the 1970 Convention was introduced as an example of good practice at the Meeting of State Parties in 2019. However, changes in the illegal market for cultural property and development of relevant international law and measures imply that there still exists room for improvement concerning the legal implementation of the 1970 Convention at the national level. In particular, the Operational Guidelines recommend States Parties to adopt legal measures in two respects: detailed criteria for due diligence in assessing bona-fide purchasers, referring to the 1995 UNIDROIT Convention on Stolen or Illegally Exported Cultural Objects, and measures to address the emerging issue of illegal trade in cultural property on internet platforms. Amendment of the Cultural Heritage Protection Act and other relevant laws should be considered in order to duly reflect these issues. Taking that opportunity, concrete provisions to facilitate international cooperation in respect of the implementation of the 1970 Convention could be introduced as well. Such measures could be expected to strengthen the Republic of Korea's international legal cooperation to respond to the changing environment regarding illicit trafficking of cultural property and its restitution.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.64 no.4
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• pp.220-230
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• 2015

Rolling stock RAMS is a field of engineering which integrates reliability, availability, maintainability and safety (RAMS) characteristics into an inherent product design property through rolling stock system engineering process. It is implemented to achieve operational objectives successfully, and recently the RAMS has become a rapidly growing engineering discipline because it has a great potential to ensure safety and improve cost effectiveness. However, the Korean rolling stock industry has not yet implemented RAMS management in the rolling stock engineering process, despite the issue having been addressed since the introduction of the KTX. Thus, this paper discusses the processes, methods and techniques for RAMS assessment in three parts. Firstly, it outlines a process of the overall RAMS performance assessment for achieving technical RAMS design criteria. Secondly, it discusses a process for assessing the operational RAM and allocating the RAM. This paper also proposes a model for assessing safety-based risk management, which includes five analytic techniques for identifying the causes and consequences of a system failure. Finally, a case example is provided for the risk assessment of the pneumatic braking device.