• Proceedings of the Korean Geotechical Society Conference
• /
• 2010.03a
• /
• pp.1376-1381
• /
• 2010

In this study, we dealt with an analysis and development of measurement systems for tunnel and slope structures under a high velocity. Deterioration of tunnel and slope structures becomes a critical issue in regard to both safety and economic concerns. Deterioration itself is inevitable, but condition assessment technology and nondestructive evaluation techniques could provide solutions to ensure public safety by means of detecting damage before serious and expensive degradation consequences occur. We reviewed the existing monitoring and maintenance systems of slopes and tunnels and more advanced directions, especially for highways under high-speed vehicles.

• Proceeding of KASS Symposium
• /
• 2008.05a
• /
• pp.89-94
• /
• 2008

This paper deals with the method of self-equilibrium stress mode analysis of cable dome structures. From the point of view of analysis, cable dome structure is a kind of unstable truss structure which is stabilized by means of introduction of prestressing. The prestress must be introduced according to a specific proportion among different structural member and it is determined by an analysis called self-equilibrium stress mode analysis. The mathematical equation involved in the self-equilibrium stress mode analysis is a system of linear equations which can be solved numerically by adopting the concept of Moore-Penrose generalized inverse. The calculation of the generalized inverse is carried out by rank factorization method. This method involves a parameter called epsilon which plays a critical role in self-equilibrium stress mode analysis. It is thus of interest to investigate the range of epsilon which produces consistent solution during the analysis of self-equilibrium stress mode.

• Tuberculosis and Respiratory Diseases
• /
• v.78 no.3
• /
• pp.149-155
• /
• 2015

Extracorporeal life support (ECLS) is a type of cardiopulmonary bypass. It is an artificial means of supplying oxygen and removing $CO_2$ on behalf of damaged lungs while patients are recovering from underlying diseases. Recently, the use of ECLS is rapidly increasing as this machine becomes smaller, less invasive and easier to use. In addition, the improvement of clinicians' technique and outcome is increasing their application to patients with acute respiratory distress. In this regard, the purpose of this review is to introduce the physiological principles, risk factors, and advantages of ECLS, clinical rationale for using ECLS, ventilatory strategy during ECLS, which are still causing different opinions, the weaning from ECLS, and the use of anticoagulant.

• International Commerce and Information Review
• /
• v.11 no.1
• /
• pp.465-484
• /
• 2009

Since the launch of the GATT system, one of the most controversial topics in trade liberalization has been the conflict between culture and trade. The sticking point has been the necessity of cultural exceptions in trade rules. Some countries do not wish to allow further exceptions to basic principles even in cultural industry, while many other countries make their efforts to obtain "cultural safety valve." The latter group asserts that it is indispensable for the protection of cultural identity, whereas the former seems to doubt the truth of the assertion. That is because cultural policy measure possibly constitute a means of arbitrary or unjustifiable discrimination between countries, or a disguised barriers to trade in cultural products. Unfortunately, cultural exceptions still remain unresolved in the WTO, the successor to the GATT. This paper is to review the history and rules of multilateral trading system on cultural industry, address the critical issues to deal with in the DDA negotiations, and lastly provide some perspectives on the appropriate shape of the cultural safety valve.

• Progress in Superconductivity and Cryogenics
• /
• v.7 no.1
• /
• pp.25-31
• /
• 2005

Since the discovery of the high temperature superconductors many researches have been performed for the practical applications of superconductivity technologies in various fields. As results, significant progress has been achieved. Especially, Superconducting Fault Current Limiter (SFCL) offers an attractive means In limit fault current in power systems. HTS resistive type SFCL is based on the ultra fast transition from the superconducting (non resistive) state to the normal (resistive) state by overstepping the critical current density, In this study, the simulation method of resistive type superconducting fault current limiter using EMTDC is proposed and the developed EMTDC model of SFCL is applied to the modeled power network using the Parameters of real system.

• Carbon letters
• /
• v.11 no.2
• /
• pp.102-106
• /
• 2010

In this work, the effect of aminized multi-walled carbon nanotubes (NH-MWNTs) on the mechanical interfacial properties of epoxy nanocomposites was investigated by means of fracture toughness, critical stress intensity factor ($K_{IC}$), and impact strength testing, and their morphology was examined by scanning electron microscope (SEM). It was found that the incorporation of amine groups onto MWNTs was confirmed by the FT-IR and Raman spectra. The mechanical interfacial properties of the epoxy nanocomposites were remarkably improved with increasing the NH-MWNT content. It was probably attributed to the strong physical interaction between amine groups of NH-MWNTs and epoxide groups of epoxy resins. The SEM micrographs showed that NH-MWNTs were uniformly embed and bonded with epoxy resins, resulted in the prevention of the deformation and crack propagation in the NH-MWNTs/epoxy nanocomposites.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2008.11a
• /
• pp.369-370
• /
• 2008

This paper describes the electric field distribution of high voltage polymer bushing with inner field shaper designs. The field control can be achieved by means of the designs of such internal field shaper. But high electric stress occurred between field shaper and central conductor by the closely space. In accordance, the floating and ring shield designs was importance for electric stress grading at critical parts of the bushing. The bushing has a central conductor, and internal ring shield or floating shield, gaps are formed between field shaper and ring shield. Accordance equipotential lines extend through gaps. Maxwell 2D simulator based on the boundary element method was also introduced in order to verify the reliability of the polymer bushing.

• 제어로봇시스템학회:학술대회논문집
• /
• 2002.10a
• /
• pp.46.5-46
• /
• 2002

As device dimension shrinks down to sub 100nm, it is increasingly important to monitor plasma states. Plasma etching is a key means to fine patterning of thin films. Many parameters are involved in etching and each parameter has different impact on process performances, including etch rate and profile. The uniformity of etch responses should be maintained high to improve device yield and throughput. The uniformity can be measured on any etch response. The most difficulty arises when attempting to characterize etched profile. Conventionally, the profile has been estimated by measuring the slope or angle of etched pattern. One critical drawback in this measurement is that this is unable to cap...

• Journal of Institute of Control, Robotics and Systems
• /
• v.5 no.2
• /
• pp.123-130
• /
• 1999

In discrete-time controlled system, sampling time is one of the critical parameters for control performance. It is useful to employ different sampling rates into the system considering the feasibility of measuring system or actuating system. The systems with the different sampling rates in their input and output channels are named multirate system. Even though the original continuous-time system is time-invariant, it is realized as time-varying state equation depending on multirate sampling mechanism. By means of the augmentation of the inputs and the outputs over one period, the time-varying system equation can be constructed into the time-invariant equation. The two multirate formulations have some trade-offs in the simplicity to construct the controller, the control performance. It is good issue to determine the suitable formulation in consideration of performance of them. In this paper, the two categories of multirate formulations will be compared in terms of the linear quadratic (LQ) cost function. The results are used to select the multirate formulation and the sampling rates suitable to the desired control performance.

• Journal of Institute of Control, Robotics and Systems
• /
• v.5 no.2
• /
• pp.131-138
• /
• 1999

In discrete-time controlled system, sampling time is one of the critical parameters for control performance. It is useful to employ different sampling rates into the system considering the feasibility of measuring system or actuating system. The systems with the different sampling rates in their input and output channels are named multirate system. Even though the original continuous-time system is time-invariant, it is realized as time-varying state equation depending on multirate sampling mechanism. By means of the augmentation of the inputs and the outputs over one Period, the time-varying system equation can be constructed into the time-invariant equation. In this paper, an alternative time-invariant model is proposed, the design method and the stability of the LQG (Linear Quadratic Gaussian) control scheme for the realization are presented. The realization is flexible to construct to the sampling rate variations, the closed-loop system is shown to be asymptotically stable even in the inter-sampling intervals and it has smaller computation in on-line control loop than the previous time-invariant realizations.