• Proceedings of the Materials Research Society of Korea Conference
• /
• 2012.05a
• /
• pp.58.2-58.2
• /
• 2012

Heavy hydrocarbon reforming is a core technology for "Dirty energy smart". Heavy hydrocarbons are components of fossil fuels, biomass, coke oven gas and etc. Heavy hydrocarbon reforming converts the fuels into $H_2$-rich syngas. And then $H_2$-rich syngas is used for the production of electricity, synthetic fuels and petrochemicals. Energy can be used efficiently and obtained from various sources by using $H_2$-rich syngas from heavy hydrocarbon reforming. Especially, the key point of "Dirty energy smart" is using "dirty fuel" which is wasted in an inefficient way. New energy conversion laboratory of KAIST has been researched diesel reforming for solid oxide fuel cell (SOFC) as a part of "Dirty energy smart". Diesel is heavy hydrocarbon fuels which has higher carbon number than natural gas, kerosene and gasoline. Diesel reforming has difficulties due to the evaporation of fuels and coke formation. Nevertheless, diesel reforming technology is directly applied to "Dirty fuel" because diesel has the similar chemical properties with "Dirty fuel". On the other hand, SOFC has advantages on high efficiency and wasted heat recovery. Nippon oil Co. of Japan recently commercializes 700We class SOFC system using city gas. Considering the market situation, the development of diesel reformer has a great ripple effect. SOFC system can be applied to auxiliary power unit and distributed power generation. In addition, "Dirty energy smart" can be realized by applying diesel reforming technology to "Dirty fuel". As well as material developments, multidirectional approaches are required to reform heavy hydrocarbon fuels and use $H_2$-rich gas in SOFC. Gd doped ceria (CGO, $Ce_{1-x}Gd_xO_{2-y}$) has been researched for not only electrolyte materials but also catalysts supports. In addition, catalysts infiltrated electrode over porous $La_{0.8}Sr_{0.2}Ga_{0.8}Mg_{0.2}O_3-{\delta}$ and catalyst deposition at three phase boundary are being investigated to improve the performance of SOFC. On the other hand, nozzle for diesel atomization and post-reforming for light-hydrocarbons removal are examples of solving material problems in multidirectional approaches. Likewise, multidirectional approaches are necessary to realize "Dirty energy smart" like reforming "Dirty fuel" for SOFC.

• Journal of Digital Convergence
• /
• v.13 no.7
• /
• pp.367-372
• /
• 2015

Smartphone game market, smart phone appeared on the market and soon developed rapidly, generation change is happening. Generally, Smartphone games are only short-lived super cell's Clash of Clans is gaining popularity for over two years. So Clash of Clans this game with hold most characteristic elements of the defense and plunder on the subject analyzed the fun factor. In order to analyze the defense and plunder elements were prepared Clash of Clans and Kings of Thieves in cases. Two of the cases, depending on the fun theory Preparation, A sense of space, A solid core machanic, A range of challenge, A range of abilities required to solve the encounter and Skill required in using the abilities were evaluated in the fun factor analysis of defense and plunder elements.

• Elastomers and Composites
• /
• v.44 no.2
• /
• pp.98-105
• /
• 2009

The cochlea of the inner ear has two core components, basilar membrane and hair cells. The basilar membrane disperses incoming sound waves by their frequencies. The hair cells are on the basilar membrane, and they are the sensory receptors generating bioelectric signals. In this paper, a biomimetic technology using ZnO piezoelectric nano-pillar was studied as the part of developing process for artificial cochlea and novel artificial mechanosensory system mimicking human auditory senses. In particular, ZnO piezoelectric nano-pillar was fabricated by both low and high temperature growth methods. ZnO piezoelectric nano-pillars were grown on solid (high temperature growth) and flexible (low temperature growth) substrates. The substrates were patterned prior to ZnO nano-pillar growth so that we can selectively grow ZnO nano-pillar on the substrates. A multi-physical simulation was also conducted to understand the behavior of ZnO nano-pillar. The simulation results show electric potential, von Mises stress, and deformation in the ZnO nano-pillar. Both the experimental and computational works help characterize and optimize ZnO nano-pillar.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.37 no.9
• /
• pp.47-54
• /
• 2000

We designed asynchronous event logic library with 0.25um CMOS technology and interface chip for heterogeneous system with high-speed asynchronous FIFO operating at 1.6GHz. Optimized asynchronous standard cell layouts and Verilog models are designed for top-down design methodology. A Method for mitigating a design bottleneck when it comes to tolerate clock skew is described. This communication scheme using clock control circuits, which is used for the free of synchronization failures, is analyzed and implemented. With clock control circuit and FIFO, high-speed communication between synchronous modules operating at different clock frequencies or with asynchronous modules is performed. The core size of implemented high-speed 32bit-interface chip for heterogeneous system is about $1.1mm{\times}1.1mm$.

• Journal of the Korean GEO-environmental Society
• /
• v.9 no.3
• /
• pp.29-34
• /
• 2008

A large diameter sampler was developed to take undisturbed samples from not only soft ground but also sandy and weathered ground. The large diameter sampler which was developed in Korea Institute of Construction Technology(KICT-type large diameter sampler) was manufactured based on the principle of triple core barrel sampling. A specially designed cutting device was used to cut and contain various kinds of samples in the sampler during a sampling and retrieval procedure. By adjusting the stiffness of the spring located at the top of the sampler, the distance between the cutting shoe and auger can be controlled in accordance with the ground condition. In order to investigate the applicability of the developed sampler and compare the quality of the samples taken by the sampler with that by the traditional thin-walled tube sampler, samples were taken at various sites according to the ground condition. And a series of laboratory tests such as the unconfined compress ion test, triaxial compression test, oedometer test, large diameter Rowe cell consolidation test (D: 150 mm) were performed. The test results showed that the samples by the KICT-type large diameter sampler show higher quality than the samples by the thin-walled tube sampler. And the validity and applicability of the developed KICT-type large diameter sampler was confirmed accordingly.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2002.05a
• /
• pp.257-260
• /
• 2002

This paper describes a design of cryptographic processor that implements the AES (Advanced Encryption Standard) block cipher algorithm“Rijndael”. To achieve high throughput rate, a sub-pipeline stage is inserted into the round transformation block, resulting that the second half of current round function and the first half of next round function are being simultaneously operated. For area-efficient and low-power implementation the round transformation block is designed to share the hardware resources in encryption and decryption. An efficient scheme for on-the-fly key scheduling, which supports the three master-key lengths of 128-b/192-b/256-b, is devised to generate round keys in the first sub-pipeline stage of each round processing. The cryptoprocessor designed in Verilog-HDL was verified using Xilinx FPGA board and test system. The core synthesized using 0.35-${\mu}{\textrm}{m}$ CMOS cell library consists of about 25,000 gates. Simulation results show that it has a throughput of about 520-Mbits/sec with 220-MHz clock frequency at 2.5-V supply.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.30 no.4
• /
• pp.246-252
• /
• 2017

Pulverized $FeS_2$ (pyrite) gives different discharge test results with as-received $FeS_2$ electrodes. The as-received $FeS_2$ electrode shows three voltage plateaus during the discharge test. However, the ball-milled $FeS_2$ electrode shows two voltage plateaus. To interpret this result, the effect of $FeS_2$ particle size on electrochemical reactions is investigated by unit cell discharge tests, SEM and XRD. As a result, it is found that the transition reaction product ($Li_2+xFe+xS_2$) of $FeS_2$ explains the difference. The as-received $FeS_2$ reacts according to three reaction steps ($FeS_2{\rightarrow}Li_3Fe_2S_4{\rightarrow}Li_2+xFe_1+xS_2{\rightarrow}LiFe_2S_4$). However, ball-milled $FeS_2$ reacts without the $Li_2+xFe_1+xS_2$ stage. In this study, this result is explained by the difference in electrochemical reaction mechanism. The as-received $FeS_2$ has a larger radius than the ball-milled $FeS_2$. Therefore, the lithium ion has to diffuse into the $FeS_2$ unreacted core, and $Li_2+xFe_1+xS_2$, the transition reaction product of as-received $FeS_2$, is formed during this stage.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.39 no.11
• /
• pp.33-43
• /
• 2002

This paper describes a design of cryptographic processor that implements the AES (Advanced Encryption Standard) block cipher algorithm "Rijndael". To achieve high throughput rate, a sub-pipeline stage is inserted into a round transformation block, resulting that two consecutive round functions are simultaneously operated. For area-efficient and low-power implementation, the round transformation block is designed to share the hardware resources for encryption and decryption. An efficient on-the-fly key scheduler is devised to supports the three master-key lengths of 128-b/192-b/256-b, and it generates round keys in the first sub-pipeline stage of each round processing. The Verilog-HDL model of the cryptoprocessor was verified using Xilinx FPGA board and test system. The core synthesized using 0.35-${\mu}m$ CMOS cell library consists of about 25,000 gates. Simulation results show that it has a throughput of about 520-Mbits/sec with 220-MHz clock frequency at 2.5-V supply.

• Nuclear Engineering and Technology
• /
• v.15 no.4
• /
• pp.267-279
• /
• 1983

An analytical system has been established for scrutinizing both uranium- and plutonium-fueled lattices moderated by light water. This system consists of two primary codes. One is a unit cell program called KICC, which has theoretical foundation on the models of GAM and THERMOS incorporated with appropriate approximate treatments for various phenomena, whereas the other is a multi-dimensional diffusion-depletion program entitled KIDD. The adequacy of this system is verified by performing extensive benchmark calculations on a variety of critical experiments. The average value of effective multiplication factors for the selected nineteen UO$_2$ critical experiments of heterogeneous lattice structure is calculated to be 1.0006 with a standard deviation of 0.0039. Power distributions have also been calculated for some critical experiments fueled with both uranium and plutonium of varying concentrations. The maximum percentage difference between the measured and calculated power distributions appears to be less than 5%. This result, together with the previously reported result, illustrates that the KICC/KIDD system is a very effective tool for the analysis of a light water reactor core.

• Molecules and Cells
• /
• v.39 no.4
• /
• pp.286-291
• /
• 2016

Epstein-Barr virus (EBV) is the prototypical ${\gamma}$-herpesvirus and an obligate human pathogen that infects mainly epithelial cells and B cells, which can result in malignancies. EBV infects these target cells by fusing with the viral and cellular lipid bilayer membranes using multiple viral factors and host receptor(s) thus exhibiting a unique complexity in its entry machinery. To enter epithelial cells, EBV requires minimally the conserved core fusion machinery comprised of the glycoproteins gH/gL acting as the receptor-binding complex and gB as the fusogen. EBV can enter B cells using gp42, which binds tightly to gH/gL and interacts with host HLA class II, activating fusion. Previously, we published the individual crystal structures of EBV entry factors, such as gH/gL and gp42, the EBV/host receptor complex, gp42/HLA-DR1, and the fusion protein EBV gB in a postfusion conformation, which allowed us to identify structural determinants and regions critical for receptor-binding and membrane fusion. Recently, we reported different low resolution models of the EBV B cell entry triggering complex (gHgL/gp42/HLA class II) in "open" and "closed" states based on negative-stain single particle electron microscopy, which provide further mechanistic insights. This review summarizes the current knowledge of these key players in EBV entry and how their structures impact receptor-binding and the triggering of gB-mediated fusion.