• Journal of Welding and Joining
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• v.22 no.6
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• pp.50-56
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• 2004

MlAB(magnetically impelled arc butt) welding is a sort of pressure welding method by melting two pipe sections with high speed rotating arc and upsetting two pipes in the axial direction. The electro-magnetic force, the driving force of the arc rotation, is generated by interaction of arc current and magnetic field induced from the magnetic flux generator in the welding system. In this study, an openable coil system for the generation of magnetic flux and a 3-dimensional numerical model for analyzing the electro-magnetic field were proposed. Through the fundamental numerical analyses, a magnetic concentrator was adopted for smoothing the magnetic flux density distribution in the circumferential direction. And then a series of numerical analysis were performed for investigating the effect of system parameters on the magnetic flux density distribution in the interested welding area.. Numerical quantitative analyses showed that magnetic flux density distribution generated from the proposed coil system is mainly dependent on the exciting current in the coil and the position of coil or concentrator from the pipe outer surface. And the gap between pipe ends and arc current are also considered as important factors on arc rotating behavior.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.10a
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• pp.442-445
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• 2003

In this study, we developed the 40 J-class MPC(magnetic pulse compression) system for exciting excimer laser and investigated the optimal conditions of each stage of MPC circuit. This system consists of a DC power supply, a pulse transformer and four saturable inductors. The number of turns of saturable inductors at each stage of MPC circuit are 140, 25, 5, 1 and the optimal storage capacitance of each stage are 34 nF, 28.9 nF, 22.1 nF, respectively. In the improvement MPC system, we have obtained an output voltage of 43 kV, a current of 8.25 kA and a pulse duration of 360 ns. Also, the maximum pulse compression ratio of 77.7 and the current gain of 71.7 were obtained.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.48 no.12
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• pp.671-678
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• 1999

In this study, it has been aimed that the accuracy of position control be increased by microstep drive to the 2 phase 8 pole HB type prototype of linear pulse motor of which winding are applied sine wave current and the vibration and noise in the lower speed region be decreased. The fixed off-time method which controls the exciting current bandwidth, was applied to the microstep current controller. When the LPM was driven 1/8 microstep its accuracy of position was 0.109[mm] (=tooth pitch 3.5[mm] ). Also, the elimination method of harmonics in the static thrust force is proposed. It was confirmed that the position error range of the prototype LPM was $\pm$0.2[mm].

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.9 no.1
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• pp.23-33
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• 2023

Prostate cancer ranks as the world's second most frequently diagnosed cancer among men, and is responsible for the fifth highest number of cancer-related deaths in this population. The development of effective diagnostic and therapeutic approaches for prostate cancer remains a major challenge in the field of oncology. Over the past few years, the prostate-specific membrane antigen (PSMA) has raised as a hopeful tracer for the diagnosis and treatment of prostate cancer.Various radioisotopes, such as ¹³¹I, ^99mTc, ⁶⁸Ga, and ¹⁷⁷Lu, have been used to label PSMA analogues, with varying degrees of success. Among these, ⁶⁸Ga-PSMA-11 and ¹⁷⁷Lu-PSMA-617 have emerged as the most promising radioligands for clinical use. Recently, researchers have been exploring the use of other radioisotopes, such as ²¹¹At, ⁸⁹Zr, ^64/67Cu, and ^203/212Pb, for the labeling of PSMA-targeted radioligands. These radioisotopes have unique properties that may offer advantages over existing radioligands, such as longer half-lives, higher specific activities, and different emission profiles. Efforts are currently underway to develop these radiopharmaceuticals and make them more widely available for clinical use. These exciting developments highlight the potential of PSMA-targeted radioligands for the diagnosis and treatment of prostate cancer, and provided significant implications for the management of this disease in the future. The current study aims to provide a comprehensive summary of the latest research and clinical applications of radiolabeled PSMA inhibitors for diagnoses and therapy of prostate cancer, emphasizing the exciting developments in the field and their potential impact on clinical practice.

• Proceedings of the KIEE Conference
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• 2005.11b
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• pp.261-263
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• 2005

In the extra and ultra high voltage system, the coupling capacitor voltage transformer (CCVT) measures the primary voltage with a small scale of voltage transformer (VT). However, the CCVT generates errors caused by the hysteresis characteristics of iron core and by the ferroresonance, inevitably. This paper proposes a compensation algorithm for the secondary voltage of a CCVT considering the hysteresis characteristics of an iron core. The proposed algorithm calculates the seconda교 current of a VT by summing the current flowing the ferroresonance circuit and the burden current; it estimates the secondary voltage of a VT; then the core flux is calculated by integrating of the secondary voltage of a VT, then estimates the exciting current using ${\lambda}-i$ characteristic of the core. The method calculates a primary voltage of a VT considering the estimated primary current. Finally, the correct voltage is estimated by compensating the voltage across the inductor and capacitor. The performance of the proposed algorithm was tested in a 345kV transmission system. The test results show that the proposed method can improve the accuracy of the seconda교 voltage of a CCVT.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.5
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• pp.44-54
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• 2010

Optimal efficiency control of synchronous reluctance motor(SynRM) is very important in the sense of energy saving and conservation of natural environment because the efficiency of the SynRM is generally lower than that of other types of AC motors. This paper is proposed a novel efficiency optimization control of SynRM considering iron loss using multi adaptive fuzzy learning controller(AFLC). The optimal current ratio between torque current and exciting current is analytically derived to drive SynRM at maximum efficiency. This paper is proposed an efficiency optimization control for the SynRM which minimizes the copper and iron losses. There exists a variety of combinations of d and q-axis current which provide a specific motor torque. The objective of the efficiency optimization control is to seek a combination of d and q-axis current components, which provides minimum losses at a certain operating point in steady state. The control performance of the proposed controller is evaluated by analysis for various operating conditions. Analysis results are presented to show the validity of the proposed algorithm.

• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.923-925
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• 2002

The existing contactless inductive coupler has many problems because of its large volume and high level of exciting current, so a new contactless inductive coupler is being required under the circumstances and the load requirement. For a contactless inductive coupler in the manufacturing equipment of semiconductor, the coupler's efficiency is low because of its small magnetic inductance and large leakage inductance. Moreover, the high frequency switching to increase energy density per unit volume increases the iron loss and the eddy current loss, so it must be considered deeply when selecting core materials. Therefore, this paper presents core materials and shape to improve the performance of the contactless inductive coupler according to the coil positions.

• BMB Reports
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• v.43 no.7
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• pp.451-460
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• 2010

Starting with the first publication of lacZ gene fusion in 1980, reporter genes have just entered their fourth decade. Initial studies relied on the simple fusion of a promoter or gene with a particular reporter gene of interest. Such constructs were then used to determine the promoter activity under specific conditions or within a given cell or organ. Although this protocol was, and still is, very effective, current research shows a paradigm shift has occurred in the use of reporter systems. With the advent of innovative cloning and synthetic biology techniques and microfluidic/nanodroplet systems, reporter genes and their proteins are now finding themselves used in increasingly intricate and novel applications. For example, researchers have used fluorescent proteins to study biofilm formation and discovered that microchannels develop within the biofilm. Furthermore, there has recently been a "fusion" of art and science; through the construction of genetic circuits and regulatory systems, researchers are using bacteria to "paint" pictures based upon external stimuli. As such, this review will discuss the past and current trends in reporter gene applications as well as some exciting potential applications and models that are being developed based upon these remarkable proteins.

• Journal of Advanced Marine Engineering and Technology
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• v.23 no.3
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• pp.346-351
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• 1999

This paper is a research for removing the hunting which came about during the parallel running of the alternators which four-pole six-phase have the converter with twelve diodes to rectify all the waves. Druing the parallel running the hunting came about under the period of 0.2-0.3{sec} not when it's load was the resistance but the capacity at the rpm band 1575[rpm] 1690[rpm] This hunting in our judgement was not come about from the general hunting causes which have been already known to but the special example. And so we checked that the hunting came about or not as per the changes of the rpm exciting current load current and converter and converter output voltage and the following facts were revealed. -The hunting occured during the constant voltage charging where r. p. m band is from 1575[rpm] to 1690[rpm] - The hunting did not came about during the constant power charging in which there was the large difference between the converter output voltage and the battery voltage. -The hunting did not came about in the low rpm band. We could see from the above facts that the existence of the hunting inducing point at the con-stant voltage charging band was the direct cause of the hunting. After trying every possible means to remove the hunting inducing point we could know that the modification of the synchronous generator is suitable for he purpos in view of the small engine room.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.49 no.1
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• pp.1-8
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• 2000

Switched reluctance motor(SRM) has simple magnetic structure, and requires simple power electronic driving circuit. It is very useful for wide range adjustable speed drive system. But, SRM drive generates large vibration and acoustic noise because it is commutated individually by step pulse m.m.f of each phase pole. In the vibration and acoustic noise characteristics. The considerable vibration and noise is induced by radial deforming of stator, so the frequency of dominant vibration and noise is coincident with the frequency of natural mode frequency of mechanical structure. This radial vibration force is generated in the phase commutation region. This paper suggests the new electromagnetic structure of SRM with auxiliary commutation winding which is excited by direct current. This phase and commutation winding are coupled magnetically between one phase winding and the other. Therefore, the switch-off phase current is absorbed by the another phase winding. By this interaction of phase and commutation winding in commutation mechanism, vibration and noise is reduced. And this reduction effect is examined by the test of prototype machine. As a result, SRM with DC exciting commutation winding is very useful to reduce vibration and acoustic noise.