• Korean Chemical Engineering Research
• /
• v.47 no.6
• /
• pp.747-754
• /
• 2009

In this study, adsorption isotherms of o-DCB(ortho-dichlorobenzene) on an activated carbon heated at $1000^{\circ}C$ for 24 hours were obtained by experiment and were predicted by using molecular simulation. The initial molecular structure of the activated carbon was designed on the basis of its molecular formula and functional groups ratio measured experimentally. Then, the molecular structure was optimized using the COMPASS(condensed-phase optimized molecular potentials for atomistic simulation studies) force field. The particle porosity, specific surface area, and particle density obtained from the optimized molecular structure of activated carbon were compared with those experimental data. The errors between experimental data and simulation results of the particle porosity, specific surface area, and particle density were shown as 7.6, 3.8, and 2.8%, respectively. Adsorption isotherms constants of o-DCB are calculated by the GCMC(grand canonical Monte Carlo) method in the optimized molecular structure of activated carbon. The simulation result of the adsorption isotherms showed an error of under 3%, compared to that of experimental data. Adsorption isotherms, adsorption heat and pore diffusivity of 2,3,7,8-TCDD(tetrachlorodibenzo-p-dioxin) was finally obtained in the same molecular structure of the activated carbon as used for o-DCB. Thus, adsorption characteristics of persistent organic pollutants on activated carbon, which are not easy to experimentally evaluate, are predicted by the molecular simulation.

• The Journal of Korean Academy of Prosthodontics
• /
• v.30 no.1
• /
• pp.25-42
• /
• 1992

The purpose of this study was to analyze the magnitude and distribution of stress using a photoelastic model from a unilateral distal extention removable partial dentures with five kinds of the direct retainers, that is, the bilaterally designed bar clasp of the cross-arch lingual bar and the unilaterally designed bar clasp, circumferential clasp, mini-Dalbo attachment, and telescope retainer. A photoelastic model for mandible was made of the epoxy resin(PL-1) and hardner (PLH-1) with the acrylic resin teeth used and was coated with plastic cement-1 at the lingual surface of the model, and then five kinds of removable partial dentures were set, A unilateral vertical load of about 16Kg was applied on the first molar and the stress pattern of the photoelastic model under each condition was analyzed by the reflective circular polariscope. The following results were obtained: 1. The conventional removable partial denture with the bilaterally cross arch lingual bar produced the most favorable stress distribution on the residual ridge and supporting structure of abutment teeth than the unilaterally designed removable partial dentures. 2. The unilaterally designed removable partial denture with the bar clasp produced the stress distribution on the residual ridge, except sligtly higher stress concentration on the supporting structure of the abutment teeth, similar to the conventional removable partial denture with the bilaterally designed cross arch lingual bar. 3. On the unilaterally designed removable partial dentures, the bar clasp produced greater stress distribution on the residual ridge and supporting structure of the abutment teeth than the circumferential clasp. 4. On the unilaterally designed removable partial dentures, the mimi-Dalbo attachment produced relatively higher stress concentration on the residual ridge, but produced lesser stress concentration on the supporting structure of the abutment teeth than the other direct retainers. 5. On the unilaterally designed removable partial dentures, the telescope retainer produced uniform stress distribution on the residual ridge, but produced higher stress concentration at the root apex of the terminal abutment tooth than the other direct retainers. 6. On the unilaterally designed removable partial dentures the circumferential clasp and telescope retainer produced slightly higher stress concentration on the residual ridge and supporting structure of the abutment teeth than the bar clasp and mini- Dalbo attachment.

• Journal of Korean Orthopaedic Sports Medicine
• /
• v.6 no.1
• /
• pp.33-37
• /
• 2007

Purpose: The harvest of hamstring tendon is technically demanding because of the inadequate identification of hamstring tendon separation and accessory tendon of semitendinosus tendon. We conducted therefore conducted an anatomic study, aiming at the anatomic knowledge for graft harvest. Materials and Methods: 20 human cadaveric knees (10 cadavers) were used for the study. The location of tendon separation in conjoined tendon and accessory tendon of semitendinosus tendon were described and recorded. Results: The location of tendon separation of conjoined tendon was average $39.68{\pm}9.97mm$ vertically and $18.57{\pm}2.91mm$ horizontally from the tibial spine. We found that the accessory structure of the semitendinosus tendon was mostly fascia-like structure(17 knees), the tendinous structure, 3 cases which was straightly located 15cm from the tibial crest. Conclusion: We propose that the expected incision for hamstring tendon harvest is centered on the inferior 40mm, medial 20mm from the tibial spine. The accessory structure of the semitendinosus tendon was mostly found of fascia-like structure.

• Journal of Sensor Science and Technology
• /
• v.9 no.1
• /
• pp.1-8
• /
• 2000

One of today's very critical and sensitive accurate accelerometer which can be used higher temperature than $200^{\circ}C$ and corrosive environment, is particularly demanded for automotive engine. Because silicon is a material of large temperature dependent coefficient, and the piezoresistors are isolated with p-n junctions, and its leakage current increase with temperature, the performance of the silicon accelerometer degrades especially after $150^{\circ}C$. In this paper, The temperature characteristic of a accelerometer using silicon on insulator (SOI) structure is studied theoretically, and compared with experimental results. The temperature coefficients of sensitivity and offset voltage (TCS and TCO) are related to some factors such as thermal residual stress, and are expressed numerically. Thermal stress analysis of the accelerometer has also been carried out with the finite-element method(FEM) simulation program ANSYS. TCS of this accelerometer can be reduced to control the impurity concentration of piezoresistors, and TCO is related to factors such as process variation and thermal residual stress on the piezoresistors. In real packaging, The avarage thermal residual stress in the center support structure was estimated at around $3.7{\times}10^4Nm^{-2}^{\circ}C^{-1}$ at sensing resistor. The simulated ${\gamma}_{pT}$ of the center support structure was smaller than one-tenth as compared with that of the surrounding support structure.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2010.03a
• /
• pp.16-16
• /
• 2010

GaN-based light-emitting diodes (LEDs) are attracting great interest as candidates for next-generation solid-state lighting, because of their long lifetime, small size, high efficacy, and low energy consumption. However, for general illumination applications, the external quantum efficiency of LEDs, determined by the internal quantum efficiency (IQE) and the light extraction efficiency, must be further increased. The IQE is determined by crystal quality and epitaxial layer structure and high value of IQE more than 70% for blue LEDs have been already reported. However, there is much room for improvement of light extraction efficiency because most of the generated photons from active layer remain inside LEDs by total internal reflection at the interface of semiconductor with air due to the high refractive index difference between LEDs epilayer (for GaN, n=2.5) and air (n=1). The light confining in LEDs will be reabsorbed by the metal electrode or active layer, reducing the efficacy of LEDs. Here, we present the first demonstration of enhanced light extraction by forming a MgO nano-pyramids structure on the surface of vertical-LEDs. The MgO nano-pyramids structure was successfully fabricated at room temperature using conventional electron-beam evaporation without any additional process. The nano-sized pyramids of MgO are formed on the surface during growth due to anisotropic characteristics between (111) and (200) plane of MgO. The ZnO layer with quarter-wavelength in thickness is inserted between GaN and MgO layers to increase the critical angle for total internal reflection, because the refractive index of ZnO (n=1.94) could be matched between GaN (n=2.5) and MgO (n=1.73). The MgO nano-pyramids structure and ZnO refractive-index modulation layer enhanced the light extraction efficiency ofV-LEDs with by 49%, comparing with the V-LEDs with a flat n-GaN surface. The angular-dependent emission intensity shows the enhanced light extraction through the side walls of V-LEDs as well as through the top surface of the n-GaN, because of the increase in critical angle for total internal reflection as well as light scattering at the MgO nano-pyramids surface.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.12 no.9
• /
• pp.1575-1583
• /
• 2008

Wireless sensor network has merit of low-power, low-cost and self-organization network, so there are many researches substituted for existing wire network. As structure reinforcement work need a high accuracy, many sensors are installed in structure and connected with data logger for monitoring. However this wire data logger method takes a long time to install wires and installed wires obstruct to work. Additionally, wire data logger method represent sensor data by only numeric and graph, it is not able to support a rapid decision-making for working. To resolve wiring problem and support decision-making, we designed and implemented the monitoring system based in wireless sensor network. For verifying performance, accuracy and availability, we simulated and tested our system in real field. Consequently, wireless sensor network method is easier to install and deploy than wire data logger method, user is able to monitor instinctively and overall by 3D representation of structure and sensors, and it show not only accuracy but also performance for many sensors.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.32 no.3
• /
• pp.155-164
• /
• 2019

In this study, the soil-structure interaction(SSI) effect on the seismic response of LNG storage tanks was investigated according to the type of foundation. For this purpose, a typical of LNG storage tank with a diameter of 71m, which is constructed on a 30m thick clay layer over bedrock was selected, and nonlinearity of the soil was taken into account by the equivalent linearization method. Four different types of foundations including shallow foundation, piled raft foundation, and pile foundations(surface and floating types) were considered. In addition, the effect of soil compaction in group piles on seismic response of the tank was investigated. The KIESSI-3D, which is a SSI analysis package in the frequency domain, was used for the SSI analysis. Stresses in the outer tank, and base shear and overturning moment in the inner tank were calculated. From the comparisons, the following conclusions could be made: (1) Conventional fixed base seismic responses of outer tank and inner tank can be much larger than those of considering the SSI effect; (2) The influence of SSI on the dynamic response of the inner tank and the outer tank depends on the foundation types; and (3) Change in the seismic response of the structure by soil compaction in the piled raft foundation is about 10% and its effect is not negligible in the seismic design of the structure.

• Journal of Popular Narrative
• /
• v.27 no.3
• /
• pp.53-94
• /
• 2021

This article pays attention to the gender representation of an abominable male abject that reveal class polarization in the movie Parasite. I seeks to read a new aspect of emotional politics in which a precariat man becomes a male patriarch while representing himself with an abhorrent position. Parasite shows a reversal of daughter and son responsible for parents, contrary to the existing family narrative. They teaches the parents' generation how to survive neoliberal that their place is created only when they take away others' place. However, after losing this prospect, Ki-woo confesses to his father that he is sorry first. Ki-taek also attempted to identify Dong-ik with the patriarch, but this male solidarity collapsed by class and committed murder in sudden anger. As a result, Gi-taek goes down to the hateful status of a stinking underground life, and Ki-woo receives a message of ethical reflection from his isolated father. The film gives the father and son the noble status of ethical fighter who fought against the structure of class polarization, especially the ending epilogue and narration emphasizing the ethical responsibility and mutual solidarity between father and son. In this process, the voices of female characters are gradually omitted, blurring gender screening for male characters. Parasite reveals the political reenactment strategy of precariat men in the age of neoliberalism, which is ethical subject by claiming to be a class abject himself. And representing the hate with gender-selecting, it is beautifying the responsible ethics of the patriarch.

• Journal of the Korean Society of Costume
• /
• v.58 no.10
• /
• pp.78-94
• /
• 2008

Contemporary fashion is experiencing a rise in design that combines heterogeneous things, or goes beyond the roles, boundaries, and meanings of existing things. This can be described as a 'heterogeneous fusion' that is different in character from the mixed use of heterogeneous materials, borrowed designs, and exaggeration of the silhouette that have been practices in fashion design, or the non-structure, deconstruction, and recombination that have existed since the age when post-structuralism was a central philosophy. This 'fusion' causes a 'confusion' of the generally accepted mental principle of 'one sense reacting to one stimulus', and breaks the boundary between the various senses, causing confusion in the senses of the individual, and leading him or her to experience unfamiliar feelings. In this process, all information received from external sources is not perceived as it is seen, but rather is perceived through a fusion of the individual's motivations, the environment in which it is perceived, the resulting change in emotion, and the individual's past memories. The combination of these heterogeneous elements visually accepted, or such a non-territorial combination acts as a 'fusion of senses' in the individual's perception, which causes confusion in the homeostasis of perception, and a change in emotion, and serves as a factor that causes the information to be stored in the memory for a long time. In parallel with deconstruction or non-structure, the 'heterogeneous fusion' found in modern fashion is taking root as a representative creative trend, and is represented in various forms such as the mixed use of subjects and materials, non-territorial borrowing, fusion with animal forms, fusion with non-physical geometry, and fusion with heterogeneous hair decoration.

• Journal of the Korean GEO-environmental Society
• /
• v.14 no.8
• /
• pp.45-51
• /
• 2013

In the construction site of underground buildings which have severe environment such as dust, noise, vibration, the technology of rescue the builders in the construction site when accident occurs by tracking the location of the builders and express the mission of supervisor smoothly. In this study, in order to acquire the location information of the builders in the construction site of underground buildings by using MEMS INS and air pressure sensor, we firstly performed the field test in construction site, analyzed the location and the elevation accuracy based on the detected results, and then verified its practicality and rationality after all. As a result, we could acquire worker's position-accuracy within 10m in horizontal direction and 4m in vertical direction. Therefore we could judge availability in construction fields of underground structure.