• Journal of architectural history
• /
• v.13 no.3
• /
• pp.7-19
• /
• 2004

This study is to comprehend the interior space of the Royal Palace in the 15th Century, the early years of Joseon Dynasty. The subject of this study is limited to the center of the Royal Palace, that is Jeongjeon(正殿, the royal audience chamber) and Haengrang(行廊, which encloses Jeongjeon on four sides and has many rooms). It is very important to understand the usage of the interior space because the architectural space consists of the space unified by the organic function of the interior and the exterior space. But there are few studies on the interior space of Jeongjeon and Haengrang at the Royal Palace. Therefore, the purpose of this study is to understand the interior space of those buildings. The result of this study is following. Haengrang has several uses such as a night duty room, a storehouse, a government office or a banquet hall etc. So the interior spaces were finished with various methods that were suitable for the use of each room, and the material of the floor were the ground, Maru(the wooden floor) or Ondol(the Korean traditional heating system) There were held many kinds of ceremonies in Jeongjeon, and the government officials could not enter the inside of that building and took part in the ceremony on the front court of Jeongjeon, except the men performing the ceremony. But the high ranking officials could enter the inside when King gave a banquet and there, they prostrated themselves before King. They sat down with their legs crossed on the ground floor instead of sitting on a chair. When King held tea ceremony with Chinese envoys in Jeongjeon, they sat on Gyoui(交倚, a kind of armchair). Then, the government officials performing the ceremony in Jeongjeon prostrated himself around the King and the Chinese envoys and others stood around them.

• Advances in nano research
• /
• v.7 no.3
• /
• pp.209-221
• /
• 2019

Graphene, with impressive electronic properties, have high potential in the microelectronic field. However, graphene itself is a zero bandgap material which is not suitable for digital logic gates and its application. Thus, much focus is on graphene nanoribbons (GNRs) that are narrow strips of graphene. During GNRs fabrication process, the occurrence of defects that ultimately change electronic properties of graphene is difficult to avoid. The modelling of GNRs with defects is crucial to study the non-idealities effects. In this work, nearest-neighbor tight-binding (TB) model for GNRs is presented with three main simplifying assumptions. They are utilization of basis function, Hamiltonian operator discretization and plane wave approximation. Two major edges of GNRs, armchair-edged GNRs (AGNRs) and zigzag-edged GNRs (ZGNRs) are explored. With single vacancy (SV) defects, the components within the Hamiltonian operator are transformed due to the disappearance of tight-binding energies around the missing carbon atoms in GNRs. The size of the lattices namely width and length are varied and studied. Non-equilibrium Green's function (NEGF) formalism is employed to obtain the electronics structure namely band structure and density of states (DOS) and all simulation is implemented in MATLAB. The band structure and DOS plot are then compared between pristine and defected GNRs under varying length and width of GNRs. It is revealed that there are clear distinctions between band structure, numerical DOS and Green's function DOS of pristine and defective GNRs.

• Applied Microscopy
• /
• v.49
• /
• pp.3.1-3.7
• /
• 2019

Graphene, which is one of the most promising materials for its state-of-the-art applications, has received extensive attention because of its superior mechanical properties. However, there is little experimental evidence related to the mechanical properties of graphene at the atomic level because of the challenges associated with transferring atomically-thin two-dimensional (2D) materials onto microelectromechanical systems (MEMS) devices. In this study, we show successful dry transfer with a gel material of a stable, clean, and free-standing exfoliated graphene film onto a push-to-pull (PTP) device, which is a MEMS device used for uniaxial tensile testing in in situ transmission electron microscopy (TEM). Through the results of optical microscopy, Raman spectroscopy, and TEM, we demonstrate high quality exfoliated graphene on the PTP device. Finally, the stress-strain results corresponding to propagating cracks in folded graphene were simultaneously obtained during the tensile tests in TEM. The zigzag and armchair edges of graphene confirmed that the fracture occurred in association with the hexagonal lattice structure of graphene while the tensile testing. In the wake of the results, we envision the dedicated preparation and in situ TEM tensile experiments advance the understanding of the relationship between the mechanical properties and structural characteristics of 2D materials.

• Advances in nano research
• /
• v.15 no.5
• /
• pp.385-399
• /
• 2023

Hexagonal boron nitride (h-BN), commonly referred to as Boron Nitride Nanoribbons (BNNRs), is an electrical insulator characterized by high thermal stability and a wide bandgap semiconductor property. This study delves into the electronic properties of two BNNR configurations: Armchair BNNRs (ABNNRs) and Zigzag BNNRs (ZBNNRs). Utilizing the nearest-neighbour tight-binding approach and numerical methods, the electronic properties of BNNRs were simulated. A simplifying assumption, the Hamiltonian matrix is used to compute the electronic properties by considering the self-interaction energy of a unit cell and the interaction energy between the unit cells. The edge perturbation is applied to the selected atoms of ABNNRs and ZBNNRs to simulate the electronic properties changes. This simulation work is done by generating a custom script using numerical computational methods in MATLAB software. When benchmarked against a reference study, our results aligned closely in terms of band structure and bandgap energy for ABNNRs. However, variations were observed in the peak values of the continuous curves for the local density of states. This discrepancy can be attributed to the use of numerical methods in our study, in contrast to the semi-analytical approach adopted in the reference work.