• Journal of the Korean Institute of Telematics and Electronics
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• v.17 no.4
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• pp.45-52
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• 1980

In order to eliminate the phase errors caused by the finite GB product of operational amplifiers, novel integnator circuits are proposed. These circuits are characterized by their positive phase error angles and integrator selectivity. The positive sign of the Q and of the circuits compensates the negative selectivity and phase error angles, inherent in the integrated operational amplifiers. Miller inverting intergrator of a biquad circuit realized by Thomas is replaced by the proposed circuit and the band-pass frequency response of the modified biquad network is experimentally analyzed. A considerable improvement is recognized to such extent that the center frequency of the band-pass filter is allowed to be shifted up to 20KHz, which has been infeasible with conventional biquad networks.

• Journal of the Korea Safety Management & Science
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• v.16 no.1
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• pp.69-77
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• 2014

The environment and requirements of modern war fields have been affected and thus changed by a variety of issues. To this end, the development of safety-critical weapon systems frequently need to meet those changes even in the operational phase. The necessity of the changes may be due to the preparation for mass-production or the request originated from the user military forces. To meet such a need can be even tougher in the development of safety-critical weapon systems since the integration of the requirements for both systems design and systems safety would make it troublesome. To handel the matter in this paper, utilization of architecture DB is proposed. Specifically, the situation in demand has first been analyzed and then a problem-solving process to accommodate the design changes has been constructed. In doing so, the concept of the aforementioned integration is particularly focused on the functional architecture, which could be a core concept of our approach to solving the problem. The result of a case study demonstrating the method studied using a computer-aided systems engineering tool is also presented.

• Proceedings of the Korea Society of Information Technology Applications Conference
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• 2005.11a
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• pp.143-146
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• 2005

The software reliability growth depends on the testing time because the failure rate varies whether it is long or not. On the other hand, it might be difficult to reduce failure rate for most of the cases are not available for debugging during operational phase, hence, there are some literatures to study that the failure rate is uniform throughout the operational time. The failure rate reduces and the reliability grows with time regardless of debugging. As a result, the products reliability varies with the time duration of these products in point of customer view. The reason of this is that it accumulates the products experience, studies the exact operational method, and then finds and takes action against the fault circumstances. I propose the simple model to represent this status in this paper.

• Translational and Clinical Pharmacology
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• v.26 no.3
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• pp.115-117
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• 2018

This tutorial explains the basic principles of mechanistic ligand-receptor interaction model, which is an operational model of agonism. A growing number of agonist drugs, especially immune oncology drugs, is currently being developed. In this tutorial, time-dependent ordinary differential equation for simple $E_{max}$ operational model of agonism was derived step by step. The differential equation could be applied in a pharmacodynamic modeling software, such as NONMEM, for use in non-steady state experiments, in which experimental data are generated while the interaction between ligand and receptor changes over time. Making the most of the non-steady state experimental data would simplify the experimental processes, and furthermore allow us to identify more detailed kinetics of a potential drug. The operational model of agonism could be useful to predict the optimal dose for agonistic drugs from in vitro and in vivo animal pharmacology experiments at the very early phase of drug development.

• Proceedings of the Korea Society for Simulation Conference
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• 2001.10a
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• pp.325-328
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• 2001

This paper introduces a new technique to extract eigenvalues of the gain and phase offsets and to compensate them automatically in transducerless sampling RTU. It discusses in detail the cause of the offsets, describes the principles of gain and phase compensation, establishes the algorithm to extract eigenvalues. The process of using the compensated measurements is also illustrated in the paper. This technique enhances the operational speed, simplifies the operational complexity, and improves the capability of transducerless sampling in RTU.

• Proceedings of the KIPE Conference
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• 1998.07a
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• pp.193-196
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• 1998

A new excitation method of switched reluctance motor drive is described in this paper. This excitation method produces reluctance torque by mutual action between two phases as well as conventional self reluctance torque due to two phase excitation at a time. In other words, the change of self inductance and mutual inductance are used to produce torque. This paper suggests the operational principle, the mechanism of torque product of switched reluctance motor with two phase excitation. The acoustic noise characteristics of two phase excitation method are described against that of conventional excitation method.

• Journal of Korean Academy of Nursing
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• v.50 no.4
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• pp.583-598
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• 2020

Purpose: This study was to investigate the operational status of the midwifery birthing centers (MBCs) and midwives' job status (Phase 1) and to develop midwifery practice guidelines (MPG) (Phase 2) in Korea. Methods: In the first phase, the subjects were 15 midwives who operated 11 of 14 MBCs that were opened as of August 2018. The questionnaire consisted of items to measure the operational status of the MBC and midwives' job status. In the second phase, the MPG was developed from literature review, interviews with five midwives opening their MBCs, surveys with 74 midwives, and a validity evaluation conducted by seven experts. Results: The distribution of operating MBCs was five in Gyunggi-do, two each in Seoul and Incheon, one each in Busan, Chungcheongbuk-do, Gyeongsangbuk-do, Gyeongsangnam-do and Jeju-do. The mean age of midwives was 54.3 and all were female. In 2017, a total of 762 births including 81 homebirths were performed by midwives. The job performance was highest in the order of neonatal care 3.81, childbirth care 3.56, and postpartal care 3.53, respectively. The MPG included seven areas of prenatal care, childbirth care, postpartal care, neonatal care, primary health care, law/ethics, and administration, with 56 tasks and 166 task elements. Conclusion: This study provides the valid basic data for the operational status of the MBC and the midwives' job status. The MPG describes the midwife's job and may be used as basic data for preparing policies for the development of midwifery practice in Korea.

• Journal of the Korean Society of Systems Engineering
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• v.4 no.1
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• pp.35-43
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• 2008

Generally, in analysis of reliability of Design and Development Phase, reliability of electrical components is analyzed based on standards such as MIL-HDBK-217F, Bellcore Issue 4,5,6 by analyzing stress of architectural side (Power, Voltage, Current and quality level of components) of weapon system and stress of operational side (operational environment, operational temperature, Operational Profile). But the reliability of mechanical components is analyzed based on the data book of failure history of mechanical parts called NPRD-95(Nonelectronic Parts Reliability Data-95) without any analysis of above stress. However, even if it's the same mechanical parts, it might have different failure rate(fatigue, wear, corrosion) during operation depending on how weary(stress : pressure, vibration, temperature during operation) the parts are. Therefore, analyzing reliability using just data book can cause big difference in reliability instead of analyzing based upon stressfulness that parts might have, operational concept, and other various factors. Thus, This paper will guide the way of predicting reliability by organizing ways of predicting reliability for system organization and adopt ing NSWC-98/LE1(Naval Surface Warfare Center-98/LE1) for mechanical components.

• Journal of the Korea Institute of Military Science and Technology
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• v.16 no.3
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• pp.295-303
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• 2013

The Operational Mode Summary/Mission Profile(OMS/MP) is a document which describes how a system or training device will be used in wartime and/or peacetime at the time it is field with focus on the future. OMS/MP is also typically used for the RAM goal setting in an early phase of weapon system development. This paper provides OMS/MP and RAM goal of the Next-MILSATCOM which is following military satellite system after ANASIS. We propose operational concepts, user-side OMS/MP model and RAM goal.

• Transactions on Electrical and Electronic Materials
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• v.2 no.4
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• pp.1-6
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• 2001

In this paper, a 1.5 V high-gain high-frequency CMOS complementary operational amplifier is presented. The input stage of op-amp is designed for supporting the constant transconductance on the Input stage by consisting of the parallel-connected rail-to-rail complementary differential pairs. And consisting of the class-AB rail-to-rail output stage using the concept of elementary shunt stage and the grounded-gate cascode compensation technique for improving the low PSRR which was a disadvantage in the general CMOS complementary input stage, the load dependence of open loop gain and the stability of op- amp on the output load are improved, and the high-gain high-frequency operation can be achieved. The designed op-amp operates perfectly on the complementary mode with the 180° phase conversion for a 1.5 V supply voltage, and shows the DC open loop gain of 84 dB, the phase margin of 65°, and the unity gain frequency of 20 MHz. In addition, the amplifier shows the 0.1 % settling time of .179 ㎲ for the positive step and 0.154 ㎲ for the negative step on the 100 mV small-signal step, respectively, and shows the total power dissipation of 8.93 mW.