• 한국정보디스플레이학회:학술대회논문집
• /
• 2007.08b
• /
• pp.1093-1095
• /
• 2007

This paper reviews the state of the art of critical processes and proposes novel structures of an integrated device comprising LCD and OLED backlight that increases the compactness and decreases the assembly time of hand-held mobile display units like the hand-sets of mobile phones

• 한국초전도학회:학술대회논문집
• /
• v.14
• /
• pp.35-35
• /
• 2004

• Proceedings of the Korean Magnestics Society Conference
• /
• 2005.06a
• /
• pp.34-35
• /
• 2005

• Tuberculosis and Respiratory Diseases
• /
• v.78 no.4
• /
• pp.455-458
• /
• 2015

Excessive dynamic airway collapse (EDAC) is a disease entity of excessive reduction of the central airway diameter during exhalation, without cartilage collapse. An 80-year-old female presented with generalized edema and dyspnea at our hospital. The patient was in a state of acute decompensated heart failure due to pneumonia with respiratory failure. We accordingly managed the patient with renal replacement therapy, mechanical ventilation and antibiotics. Bronchoscopy confirmed the diagnosis of EDAC. We scheduled extubation after the improvement of pneumonia and heart condition. However, extubation failure occurred due to hypercapnic respiratory failure with poor expectoration. Her EDAC was improved in response to high flow nasal oxygen therapy (HFNOT). Subsequently, the patient was stabilized and transferred to the general ward. HFNOT, which generates physiologic positive end expiratory pressure (PEEP) effects, could be an alternative and effective management of EDAC. Further research and clinical trials are needed to demonstrate the therapeutic effect of HFNOT on EDAC.

• Journal of Welding and Joining
• /
• v.25 no.4
• /
• pp.35-41
• /
• 2007

In kinetic spraying process, the critical velocity is an important criterion which determines the deposition of a feedstock particle onto the substrate. In other studies, it was experimentally and numerically proven that the critical velocity is determined by the physical and mechanical properties and the state of materials such as initial temperature, size and the extent of oxidation. Compared to un-oxidized feedstock, oxidized feedstock required a greater kinetic energy of in-flight particle to break away oxide film during impact. The oxide film formed on the surface of particle and substrate is of a relatively higher brittleness and hardness than those of general metals. Because of its physical characteristics, the oxide significantly affected the deposition behavior and critical velocity. In this study, in order to investigate the effects of oxidation on the deposition behavior and critical velocity of feedstock, oxygen contents of Al feedstock were artificially controlled, individual particle impact tests were carried out and the velocities of in-flight Al feedstock was measured for a wide range of process gas conditions. As a result, as the oxygen contents of Al feedstock increased, the critical velocity increased.

• Journal of The Korean Association For Science Education
• /
• v.33 no.1
• /
• pp.144-160
• /
• 2013

This study is a proposal, which is the trial to explicate, in neurology, on how critical thinking as a creative method of sciences functions. The creative methods of sciences, even at present, are mostly the hypothetical insistences concerning with the logical processes of researches suggested from the philosophers of science; Popper, Kuhn, Hempel, or Lakatos. These insistences do excavate what process or approach can be scoped out of scientists' creativity. I call the tendency or approach of the researches, "Process Approach of Creativity (PAC)". From my view point, any PAC trial does not concern with how creative theories can actually be invented. On the other hand, this study is focused on the philosophical thinking abilities of scientists who invented new great theories. They mostly had some experiences to study philosophy while studying their science fields, thus had critical thinking abilities on their studies. From my point of view, critical thinking in philosophy raised questions as to their fundamental and basic (old) concepts and principles, and thus gave them new creative theories. I will try to explain this from the point of neurophilosophy. From the perspectives coming from "the state space theory of representation" of Paul & Patricia Churchland, the pioneers of neurophilosphy, the "creative theories" are the networks of topographic maps giving new comprehensive explanations and predictions. From these perspectives, I presuppose that the attitude of critical questioning revises the old networks of maps with back-propagation or feedback, and thus, is the generative power of searching new networks of maps. From the presupposition, I can say, it is important that scientists reflect on the basic premises in their academic branches for issuing out extraordinary creativity. The critical attitude of philosophy can make scientists construct the maps of new conceptual scheme by shaking the maps of the old basic premises. From this context, I am able to propose "Critical Thinking Approach of Creativity (CTAC)".

• 한국신재생에너지학회:학술대회논문집
• /
• 2010.06a
• /
• pp.251.2-251.2
• /
• 2010

Plant biomass has been proposed to be an alternative source for petroleum-based chemical compounds. Especially, phenolic chemical compounds can be obtained from lignin by chemical depolymerization processes because lignin consists of complex aromatic polymer such as trans-p-coumaryl, coniferyl and sinapyl alcohols, etc. Phenolic chemical compounds from lignin were usually produced in super critical water. However, we applied Near-critical water (NCW) system because NCW is known as a good solvent for lignin depolymerization. Organic matter like lignin can be solved in NCW system and the system has a unique acid-base property without conventional non-eco-friendly chemicals such as sulfuric acid and sodium hydroxide. In this work, we tried to optimize the NCW depolymerization system by adjusting the processing variables such as reaction time, temperature and pressure. Moreover, the amount of additional phenol was optimized by changing the molar ratio between water and phenol. Phenol was used as capping agent to prevent re-polymerization of active fragment such as formaldehyde. Alkali-lignin was used as a starting material and characterized by a Solid State 13C-NMR, FT-IR and EA (Elemental Analysis). GC-MS analysis confirmed that o-cresol, p-cresol, anisole and 4-hydroxyphathalic acid were the main product and they were quantitatively analyzed by HPLC.

• Structural Engineering and Mechanics
• /
• v.40 no.4
• /
• pp.563-581
• /
• 2011

Many novel materials, developed in recent years, have obvious properties with different modulus of elasticity in tension and compression. The ratio of their tensile modulus to compressive modulus is as high as five times. Nowadays, it has become a new trend to study the mechanical properties of these bimodular materials. At the present stage, there are extensive studies related to the strength analysis of bimodular structures, but the investigation of the buckling stability problem of bimodular rods seems to cover new ground. In this article, a semi-analytical method is proposed to acquire the buckling critical load of bimodular slender rod. By introducing non-dimensional parameters, the position of neutral axis of the bimodular rod in the critical state can be determined. Then by combining the phased integration method, the deflection differential equation of bimodular pin-ended slender rod is deduced. In addition, the buckling critical load is obtained by solving this equation. An example, which is conducted by comparing the calculation results between the three of the methods including the laboratory tests, numerical simulation method and the method we developed here, shows that the method proposed in the present work is reliable to use. Furthermore, the influence of bimodular characteristics on the stability is discussed and analyzed.

• Journal of Power Electronics
• /
• v.18 no.2
• /
• pp.588-603
• /
• 2018

This paper presents the idea of a smart load that can adjust the input power flow based on the intermittent power available from RESs (Renewable Energy Resources) to regulate the line voltage, and draw a constant power from the grid. To this effect, an innovative power flow controller is presented based on a Resistive ES (Electric Spring) in combination with a PEAT (Power Electronics based Adjustable Transformer), which can effectively shape the load power flow at the subnetwork level. With a PEAT incorporated in the step down transformer at the grid side, the proposed controller can supply non-critical loads through local RESs, and the critical loads can draw a relatively constant power from the grid. If there is an abundance of power produced by the RESs, the controller can supply both non-critical loads and critical loads through the RES, which significantly reduces the power demand from the grid. The principle, practicality, stability analysis, and controller design are presented. In addition, simulation results show that the power flow controller performs well in shaping the load power flow at the subnetwork level, which decreases the power demand on the grid. Experimental results are also provided to show that the controller can be realized.

• 유체기계공업학회:학술대회논문집
• /
• 2006.08a
• /
• pp.227-230
• /
• 2006

The method of mass flow rate measurement using a critical nozzle is well established in the flow satisfying ideal gas law. However, in the case of measuring high-pressure gas flow, the current method shows invalid discharge coefficient because the flow does not follow ideal gas law. Therefore an appropriate equation of state considering real gas effects should be applied into the method. The present computational study has been performed to give an understanding of the physics of a critical nozzle flow for high-pressure hydrogen gas and find a way for the exact mass flow prediction. The two-dimensional, axisymmetric, compressible Navier-Stokes equations are computed using a fully implicit finite volume method. The real gas effects are considered in the calculation of discharge coefficient as well as in the computation. The computational results are compared with the previous experimental data and predict well the measured mass flow rates. It has been found that the discharge coefficient for high-pressure hydrogen gas can be corrected properly adopting the real gas effects.