• Nano
• /
• v.13 no.12
• /
• pp.1850138.1-1850138.6
• /
• 2018

Two-dimensional (2D) or layered materials have a great potential for applications in energy storage, catalysis, optoelectronics and gas separation. Fabricating novel 2D or quasi-2D layered materials composed of relatively abundant and inexpensive atomic species is an important issue for practical usage in industry. Here, we suggest the layer-structured AlOOH (Boehmite) as a promising candidate for such applications. Boehmite is a well-known layer-structured material and a single-layer can be exfoliated from the bulk boehmite by breaking the interlayer hydrogen bonding. We study atomic and electronic band structures of both bulk and single-layer boehmite, and also obtain the single-layer exfoliation energy using first-principles calculations.

• Journal of Communications and Networks
• /
• v.8 no.2
• /
• pp.144-150
• /
• 2006

A serious problem with traditional 'command & control' spectrum management techniques is that they do not easily accommodate new technologies and new services. This paper describes the necessary principles of flexible-use spectrum rights which may allow a wide variety of spectrum uses in a single general-purpose band. Based on the electrospace description of the radio spectrum, these principles allow general aggregation or division of licensed electrospace regions via secondary markets, providing rules for how regulatory limits change under aggregation or division. These flexible-use principles limit transmitter behaviors that tend to create a more difficult operating environment for receivers, while making receivers responsible for handling any remaining interference. The author shows how flexible-use principles could provide a basis for real-world flexible-use frequency bands.

• Journal of the military operations research society of Korea
• /
• v.5 no.2
• /
• pp.15-25
• /
• 1979

Single-period inventory problems such as the newspaper boy problem having quadratic cost functions for both shortages and overage are examined to determine the optimal order level under various principles of choice such as minimum expected cost, aspiration level, and minimax regret. Procedures for finding the optimum order levels are developed for both continuous and discrete demand patterns.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
• /
• v.2B no.4
• /
• pp.207-213
• /
• 2002

The paper introduces a switched reluctance motor drive system based on an 80C31 and an Intel 80C 196KB single-chip microprocessor control. Advance schemes are used in turn-on and turn-off angles with the power converter's main switches during traction and regenerative braking. The principles of traction speed control and braking torque control are given. The hardware and software patterns in the 80c31 and the Intel 80C196KB single-chip microprocessor control system are also presented.

• Journal of Interdisciplinary Genomics
• /
• v.5 no.2
• /
• pp.24-28
• /
• 2023

Chromosomal microarray (CMA) is primarily recommended for detecting clinically significant copy number variants (CNVs) in the genetic diagnosis of developmental delay, intellectual disability, autism, and congenital malformations. Prenatal CMA is recommended when a fetus has major congenital malformations. The main principles of CMA can be divided into array comparative genomic hybridization and single-nucleotide polymorphism arrays. In the current CMA platforms, these two principles are combined, and detection of genetic abnormalities including CNVs and absence of heterozygosity is facilitated. In this review, I described practical assessment of CMA testing regarding to laboratory management of CMA, interpretation of CNVs, and special considerations for comprehensive genetic counseling.

• Proceedings of the Optical Society of Korea Conference
• /
• 1988.06a
• /
• pp.33-36
• /
• 1988

The distributed feedback dye laser is a source of single picosecond pulses tunable in a very wide wavelength range. Operational principles, experimental arrangements, and recent applications are reviewed.

• The Journal of the Acoustical Society of Korea
• /
• v.42 no.5
• /
• pp.452-459
• /
• 2023

Acoustic tweezers represent an exceptionally versatile and adaptable collection of instruments that harness the intrinsic power of sound waves to manipulate a wide spectrum of bioparticles, ranging from minuscule extracellular vesicles at the nanoscale to more substantial multicellular organisms measuring in millimeters. This field of research has witnessed remarkable progress over the course of the past few decades, primarily in the domain of Single Beam Acoustic Tweezers (SBAT) which utilizes a single element transducer for its operation. Initially conceived as a method for particle trapping, SBAT has since evolved into an advanced platform capable of achieving precise translation of cells and organisms. Recent groundbreaking advancements have significantly enhanced the capabilities of SBAT, unlocking new functionalities such as particle/cell separation and controlled deformation of single cells. These advancements have propelled SBAT to the forefront of bioparticle/cell manipulation, gathering attention within the scientific community. This review explores the core principles of SBAT and how sound waves affect bioparticles/cells. We aim to build a strong conceptual foundation for understanding advancements in this field by detailing its principles and methodologies.

• Proceedings of the KIPE Conference
• /
• 1998.07a
• /
• pp.418-422
• /
• 1998

A new single stage AC/DC converter based on the forward converter is proposed. The proposed converter offers both the high power factor and the direct conversion from ac line to dc output voltage. Also, the proposed converter reduces the diode conduction loss, so improves the overall efficiency of the converter, compared with other alternatives. The principles of operation and the simulation results of the proposed converter are presented. A 100 W prototype was built and tested to show the potential of applications of the proposed converter.

• Proceeding of EDISON Challenge
• /
• 2014.03a
• /
• pp.409-411
• /
• 2014

Based on the first-principles computations, the nature of the microscopic geometry of the molecule-electrode contacts was addressed. The single-molecule junction was prepared by connecting hexanediothiolate (HDT) to Au(111) electrodes via one, two, and three Au adatoms having coordination number of one (CN1), two (CN2), and, three (CN3), respectively. The contact atomic structure and energy of the stretched Au-HDT-Au junction was observed. The analysis revealed that the contact geometry with lowest coordination number (CN1) is energetically more stable than CN2 and CN3.

• Journal of the Korean Society for Precision Engineering
• /
• v.25 no.1
• /
• pp.51-62
• /
• 2008