• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.27 no.2
• /
• pp.236-242
• /
• 2003

Thermal bubbles find their diverse application areas in the MEMS (MicroElectroMechanial Systems) technology, including bubble jet printers, microactuators, micropumps, etc.. Especially, microactuators and micropumps, which use a microbubble growing by a controlled heat input, frequently involve mechanical and thermal interaction of the bubble with a solid structure, such as a cantilever beam and a membrane. Although the concept is experimentally verified that an internal pressure of the bubble can build up high enough to deflect a thin solid plate or a beam, the physics of the entire process have not yet been thoroughly explored. This work reports the experimental study of the growth of a thermal bubble while deflecting a thin cantilever beam. A physical model is presented to predict the elastic response of the cantilever beam based on the experimental measurements. The scaling law constructed through this work can provide a design guide for micro- and nano-systems that employ a thermal bubble for their actuation/pumping mechanism.

• Proceedings of the Korean Nuclear Society Conference
• /
• 1997.05a
• /
• pp.45-50
• /
• 1997

The conventional MOX fuel shows adverse controllability in view of its neutronic characteristics such as decreased soluble boron worth and effective delayed-neutron fraction compared to the UO$_2$ fuel. In order to mitigate these disadvantages, we devised a new concept of the hybrid UO$_2$-MOX fuel pellet with dual structure such that its outer annular section contains. UO$_2$ fuel and its inner cylindrical bar contains MOX fuel. The lattice physics code HELIOS was used to evaluate the neutronic characteristics of three different types of fuel pellets ; UO$_2$ fuel pellet, MOX fuel pellet, and hybrid UO$_2$-MOX fuel pellet. Results show that the hybrid UO$_2$-MOX fuel pellet generally has intermediate neutronic tendency between UO$_2$ fuel and MOX which could diminish the problems arising from the use of the conventional MOX fuel.

• Korean Institute of Interior Design Journal
• /
• no.25
• /
• pp.18-25
• /
• 2000

Architecture and music have reflected many changes occurring in a greater cultural realm. Specially, the concept of time and space formed from relativistic physics becomes the basis of cultural awareness, and a method to understand the world. Therefore, this study aims to suggest the possibility to integrate architecture and music, based on the close relationship between architecture and music of the 20th century focusing on time and space. Resultantly, in this study, interrelationship between architecture and music is elucidated by proving both the spatiality of music and the temporality of architecture, and such possibility to integrate the two realms helps understand the reality.

• Journal of Information Display
• /
• v.12 no.3
• /
• pp.135-139
• /
• 2011

This paper presents the directly obtained rotational viscosity values of E7, which includes pentylcyanobiphenol, heptylcyanobiphenol, 4-cyano-4'-n-octyloxy-1,1'-biphenyl, and 4-cyano-4"-n-pentyl-1,1',1"-terphenyl, at various tempe using molecular dynamics computer simulation. The director mean squared displacement was achieved from the squared displacement of the mean director using the concept of the mean director of various nematic liquid crystals. The calculated values were compared with the experiment results that predicted a good agreement. Additional points that must be considered for further study are also discussed.

• IE interfaces
• /
• v.17 no.spc
• /
• pp.79-89
• /
• 2004

Supply Chain (SC) can balance demands with supply activities as executing Supply Chain Planning (SCP). The fluctuated demands, however, will break the balance between demand and supply. It means that the present SCP is useless in responding the changed demands. Thus it is necessary for SCP to be updated with changed demands. We call this procedure as Supply Chain Replanning. However, the existing measures for SC can not deal with the balance between supply and demand so that they can not detect effectively the timing of replanning. For this reason, a new performance measure, Balancing Point, is developed using momentum, a concept of Physics. It can treat the balance between supply and demand. Also, a replanning method based on Balancing Point is proposed. The proposed method is more effective than the existing replanning method, periodic replanning method and net inventory method.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2013.02a
• /
• pp.670-670
• /
• 2013

The concept of a fusion-driven transmutation reactor based on LAR (Low Aspect Ratio) tokamak as a neutron source is studied based on ITER physics and technology. The radial build of transmutation reactor components are self-consistently determined by coupling the systems analysis with radiation transport analysis and an optimal configuration of a transmutation reactor for aspect ratio, A in the range of 1.5 to 2.0 is found. The performance of a transmutation reactor is investigated and shows that a transmutation reactor with a neutron source producing fusion power less than 150 MW can destroy the transuranic actinides contained in the spent fuels produced from more than two 1 GWe PWRs with production of the fission power being greater than 2 GW.

• Korean Institute of Interior Design Journal
• /
• v.23 no.3
• /
• pp.92-99
• /
• 2014

Quantum theory of Niels Bohr received the Nobel Prize in Physics was rooted to the Oriental thought 'Yin-Yang and the Five Elements 陰陽五行', and architect Frank Lloyd Wright is also known as Lao Tzu's thoughts on the best architectural theory. Thus, the western architecture and oriental thought is very similar to the concept development. On the basis of this fact, the architectural philosophy of Mies van der Rohe is closely contact with Lao Tzu's Taoism, that is 'The greatest has no boundary 大象無形, Tao Te Ching chap.41' or 'The way to be is not to be 有道者 不處, Tao Te Ching chap.24'. Hence the aim of this thesis is to investigate the interrelation between the German architect Mies van der Rohe's 'almost nothing' and the Chinese philosopher Lao Tzu's 'Taoism'.

• Bulletin of the Korean Mathematical Society
• /
• v.57 no.4
• /
• pp.945-956
• /
• 2020

We introduce the concept of S-exchange rings to unify various subclass of exchange rings, where S is a subset of the ring. Many properties on S-exchange rings are obtained. For instance, we show that a ring R is clean if and only if R is left U(R)-exchange, a ring R is nil clean if and only if R is left (N(R) - 1)-exchange, and that a ring R is J-clean if and only if R is left (J(R) - 1)-exchange. As a conclusion, we obtain a sufficient condition such that clean (nil clean property, respectively) can pass to corners and reprove that J-clean passes to corners by a different way.

• Proceedings of the Polymer Society of Korea Conference
• /
• 2006.10a
• /
• pp.186-186
• /
• 2006

We report a new architecture for high efficiency polymer solar cells introducing a new concept of 'optical spacer' with new material. By implementing a novel solution-based titanium oxide ($TiO_{x}$) layer between the active layer and the electron collecting Al electrode, we invented a way to increase ${\sim}50\;%$ in power conversion efficiency compared to conventional polymer solar cells. Now the new devices exhibit ${\sim}6\;%$ power conversion efficiency, which is the highest value reported to date for a polymer based photovoltaic cell. The $TiO_{x}$ layer increases the efficiency by modifying the spatial distribution of the light intensity inside the device, thereby creating more photogenerated charge carriers in the bulk heterojunction layer.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.11 no.1
• /
• pp.81-86
• /
• 2016

Three hundred years ago, the fractional differential equation that is one of concept of fractional calculus released. Now, many researchers continue to try best effort applying into the control engineering, mathematics and physics. In this paper, the dynamics equation which is represented by Van der Pol, represent integer order and fractional order that having real order. Then this paper performs the comparisons between integer and real order as time series and phase portrait according to variation of parameter value for real order.