• Journal of KSNVE
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• v.11 no.3
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• pp.471-476
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• 2001

This paper focuses on the numerical prediction of airflow-induced sound in DVD drives. As a first step, computational fluid dynamics (CFD) is conducted to evaluate flow field characteristics due to the high-speed disk rotation, and to support the acoustic analysis. Acoustic analogy based on Ffowcs Wi1liams-Hawkings (FW-H) equation is adopted to predict aeroacoustic noise patterns. The integral solution for quadrupole volume source is included to identify the turbulence noise generated inside the DVD tray. The strength of sound pressure revel with respect to rotating speed is discussed to meet upfront demand on the high fidelity product development. The present study also focuses on the noise directivity and examines how much the sound noise is sensitive to change in rotating speed. Near-field noise is strongly affected by the flow field characteristic, which is caused by the complex shape of the tray. For a mid-field, the quadrupole noise play as a counterpart of thickness noise or loading noise, so it generates different sound noise Patterns compared with those in the near field.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.9
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• pp.1587-1592
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• 2010

In this paper, the beneficial effects of IHD deployments on the society were investigated, which is one of the enabling technologies related to the AMI investments. By focusing on the energy use reduction due to the feedback information from IHD, various favorable effects can be induced and quantified. The societal benefits should make a reasonable contribution to ensure that IHD should be prerequisite to the AMI deployments. In future, the quantification methodology would be applied to characterize and estimate the time-varying rate based demand response programs.

• Health Policy and Management
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• v.3 no.2
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• pp.27-80
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• 1993

It is widely known that patients' utilization pattern for medical care facilities and the patientflow are influenced by multi-factors, such as demographic characteristics, structural characteristics of society, socio-psychological characteristics(value, attitude, norms, culture, health behavior, etc.), economic characteristics(income, medical price, relative price, physician induced demand, etc.), geographical accessibility, systematic characteristics(health care delivery system, payment methods for physician fees, form of health care security, etc.), and characteristics of medical facilities(reliability, quality of medical care, convenience, kindness, tec.). This study was conducted to research the mechanism of patient-flow according to changes of health care system(implementation of national health insurance, health care referral system and regionalization of health care utilization, etc.) and characteristics of medical facilities(ownership of hospital, characteristics of medical services, non-medical characteristics, etc.). In this study, the fact could be ascertained that the patient-flow had been influenced by changes of health care system and characteristics of medical facilities.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.10a
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• pp.229-234
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• 2000

As the level of earthquake intensity in Korea is considered to be moderate, some structures or structural elements may be subjected to the reduced ductility demand, in contrast to the structures in high seismicity, due to the large inherent strength induced by gravity loads. New Zealand Standard(NZS) deals with there structures within the category of structures of limited ductility. This paper briefly reviews the applicability of the code, regarding limited ductility, for frame strucures which are commonly used as the office building structural system. The difference of the loading condition is considered. Details of the plastic hinge region are compared between NZS and Korean standard.

• Journal of Advanced Marine Engineering and Technology
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• v.16 no.4
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• pp.50-59
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• 1992

The paper presents a digital speed control approach of induction motor systems by using a digital servo control method and a well-known second order differential equation as model. The basic concept of using the modeling equation stated in the above is induced from the control theory stand point such that we can describe usually the motor system connected by inverter, generator and load etc, just as a mechanical system to be controlled. The concept does not demand us the complicated vector-based modeling equation adopted in the traditional methods for the speed control of induction motor. Futhermore, the proposed speed control system can be treated as a single input and single output system. The effectiveness of the servo control system obtained by the above-mentioned design concept is illustrated by the experimental results in the presence of both step reference changes and load variations. It is observed from the experimental results that the steady state-error of the experimental set up becomes zero after some regulation time and the induction motor system is robust in spite of reference signal changes and load variations.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2006.04a
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• pp.741-748
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• 2006

Seismic performance evaluation was conducted for four wind-designed concentrically braced steel highrise buildings in order to check the feasibility of designing steel highrise buildings per elastic seismic design criterion (or strength and stiffness solution) in the regions of strong wind and moderate seismicity. The pushover analysis results revealed that the wind-designed highrise buildings possess significantly increased elastic seismic capacity due to the overstrength resulting from the wind serviceability criterion. The strength demand-to-capacity study showed that, due to the wind-induced overstrength, highrise buildings with a slenderness ratio of larger than four or five can withstand elastically even the maximum considered earthquake at the performance level of immediate occupancy. Based on the analytical results of this study, practical elastic seismic design procedure for steel highrise buildings in the regions of moderate seismicity is proposed.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.28 no.1
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• pp.27-38
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• 1992

The paper presents a digital speed control approach of induction motor systems by using a digital redesign method and adopting a well known 2nd order model as the system model equation. The basic concept using the modeling equation is induced from the control theory stand point such that we can describe usually the motor system connected by inverter, generator and load etc. just as a mechanical system to be controlled. The concept does not demand us the complicated vector-based modeling equation adopted in the traditional methods for the speed control of induction motor. The effectiveness of the servo control system composed by the above mentioned design concept is illustrated by the experimental results in the presence of step reference change and generator load variation. It is observed from the experimental results that the steady state error of the experimental set up becomes zero after some regulation time and the induction motor system is robust in spite of reference signal change and load variation of generator.

• Journal of Yeungnam Medical Science
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• v.37 no.3
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• pp.159-168
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• 2020

The demand for drug-induced sedation for magnetic resonance imaging (MRI) scans have substantially increased in response to increases in MRI utilization and growing interest in anxiety in children. Understanding the pharmacologic options for deep sedation and general anesthesia in an MRI environment is essential to achieve immobility for the successful completion of the procedure and ensure rapid and safe discharge of children undergoing ambulatory MRI. For painless diagnostic MRI, a single sedative/anesthetic agent without analgesia is safer than a combination of multiple sedatives. The traditional drugs, such as chloral hydrate, pentobarbital, midazolam, and ketamine, are still used due to the ease of administration despite low sedation success rate, prolonged recovery, and significant adverse events. Currently, dexmedetomidine, with respiratory drive preservation, and propofol, with high effectiveness and rapid recovery, are preferred for children undergoing ambulatory MRI. General anesthesia using propofol or sevoflurane can also provide predictable rapid time to readiness and scan times in infants or children with comorbidities. The selection of appropriate drugs as well as sufficient monitoring equipment are vital for effective and safe sedation and anesthesia for ambulatory pediatric MRI.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.9
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• pp.1342-1351
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• 2001

Over the years, the embryo transfer industry has grown from the simple collection & transfer of embryos into an advanced field of embryo biotechnology. Currently a large demand exists for bovine oocytes and early embryos in both research and commercial settings. Bovine embryos can now be produced in-vitro. Primary oocytes collected from antral follicles of abattoir - obtained ovaries can be induced to undergo the maturation process. In-vitor maturation system, however must ensure that the resulting oocyte is capable of undergoing normal fertilization and yields a zygote competent of developing to term after embryo transfer. Sperm preparation for IVF has improved with the use of heparine. The use of co-culture system has proved beneficial in circumventing the developmental block in IVM/IVF bovine embryos.

• Proceedings of the KSME Conference
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• 2000.04b
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• pp.205-212
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• 2000

Induction motors. having axial cooling channels in stator and rotor are designed for better cooling performance. Traction motors are one of those examples. And, thermal analysis gain more attention with the Increased demand of the motors, for reliable operation and life prolongation. was Induced to effective thermal conductivity through modeling. Through. fundamental comparison experiment, heat source experiment and transient state experiment, the induction motor using inverter was examined to produce heat source with frequency level and traced to thermal variation at starting and stopping. And thermal analysis using thermal network was compared with a transient state experiment.