• Proceedings of the KIPE Conference
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• 2015.07a
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• pp.193-194
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• 2015

In this paper, the solid state pulsed power modulator developed in KERI, which is based on IGBT technologies are overviewed. During last ten years, several kinds of solid state modulators were developed in KERI such as IGBT stacks with step up transformer, full IGBT stack based marx generator, modified IGBT marx generator and high repetitive solid state modulator. Basic principle of the design is described and each pros and cons are compared. KERI's solid state pulsed power modulators has lot of advantages for industrial pulsed power application focused on everlasting life cycle and high repetitive, and shows superior arching protection ability.

• Current Optics and Photonics
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• v.2 no.5
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• pp.431-435
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• 2018

A modified setup of a CMD technique for high power coherent beam combining was presented to address an issue of low damage threshold of electro-optic modulators. The feasibility of the modified setup was demonstrated by combining eight fiber beams, and it was successfully performed with ${\lambda}/44$ of residual phase error and 100 Hz of control bandwidth. It is expected that the modified CMD setup facilitates ultra-high power coherent beam combination without a limitation caused by the low damage threshold of electro-optic modulators.

• Archives of Pharmacal Research
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• v.24 no.6
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• pp.473-484
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• 2001

There is clearly a need for novel breast cancer chemopreventive agents with enhanced potency and specificity with tittle or no side effects. To this end, several new chemical moieties have been synthesized or isolated from natural sources. In this reviewal we have described some agents currently in use or under development for treatment or prevention of breast cancer, as well as our own strategies for the discovery of natural product modulators of estrogen biosynthesis and function. In particulars bioassay-guided fractionation of active plant extracts is a unique method for identifying agents with novel mechanisms of action, some of which should be useful for prevention of human cancer. Further, with the advent of combinatorial chemistry and high throughput screening, even greater progress may now be expected with natural product leads.

• Current Optics and Photonics
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• v.5 no.4
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• pp.466-476
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• 2021

Frequency-multiplication technology based on microwave photonic principles can be used to generate microwave and millimeter wave signals with a wide frequency tuning range. However, the existing cascaded external modulation frequency-tupling scheme needs to ensure the phase coherence of the modulated Radio Frequency (RF) signal, while the phase modulation directly limits the frequency tuning range of the external modulation frequency multiplication. In this paper, a novel approach for generating an incoherent frequency 12-tupling signal with cascade modulation is proposed. The structure of cascaded dual-parallel Mach-Zehnder modulators can generate a frequency 12-tupling signal. The proposed structure uses no filter or phase control of the RF driving signal. Microwave photonic frequency-tupling was realized under incoherent conditions. Software simulations and experiments validated the proposed structure and proved that it can generate frequency 12-tupling microwave signals under incoherent conditions. Both the frequency range and reliability of the frequency-tupling system has been improved by the proposed structure.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2022.06a
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• pp.359-360
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• 2022

In light of the unprecedented occupational health and safety concerns that have been raised in the wake of the COVID-19 pandemic, the importance of seafarers' mental health has been significantly underlined. Despite the fact that there has been a significant amount of research on the psychological threats of seafarers' mental health, mutual cooperative actions on this issue have not been properly coordinated among seafarers' relevant bodies and stakeholders in APEC region. This paper introduces the APEC SEN's initiatives that have been undertaken to improve the mental health of seafarers, in collaboration with medical professionals, seafarers' unions, maritime administrations, and other stakeholders, through the development of training programmes and materials for both seafarers and modulators, resulting in a more effective approach to mental healthcare promotion.

• Journal of Institute of Convergence Technology
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• v.13 no.1
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• pp.7-12
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• 2023

The built-in motor with an integrated magnetic gear can realize high torque without a separate reduction device. In this paper, the main design parameters of the magnetic gear constituting the magnetic geared motor are derived and the sensitivity analysis results according to these design parameters are discussed. In particular, processing and assembly issues of modulators sandwiched between rotating bodies are discussed, and loss and magnetic force characteristics of various types of modulators are introduced. Since the modulator, which plays a key role in converting the torque of the magnetic gear, is desirable to have a separate form, it is inevitable to add a non-magnetic support to add torsional stiffness according to high-speed rotation, so the effect of this is also analyzed.

• Proceedings of the Korean Vacuum Society Conference
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• 1998.06a
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• pp.85-85
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• 1998

• 한국정보디스플레이학회:학술대회논문집
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• 2002.08a
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• pp.939-942
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• 2002

The optically addressed and electrically addressed spatial phase only light modulators without pixelized structures have been developed. A sufficient phase modulation capability and a high diffraction efficiency of these devices are useful for practical applications.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1998.11a
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• pp.44-51
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• 1998

• Archives of Pharmacal Research
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• v.11 no.1
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• pp.1-6
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• 1988

The use of blue cotton for detecting polycyclic aromatic mutagens in environmental samples (foods, human excretions, river water, etc) is reviewed. Since the invention of blue cotton has its origin in studies of mutagen modulators, these studies are also briefly reviewed.