• Applied Biological Chemistry
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• v.23 no.2
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• pp.123-130
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• 1980

Thiamine derivatives of thiamine tetrahydrofurfuryl disulfide (TTFD) and thiamine propyl disulfide (TPD) were obtained in a good yield and purity by use of thiothiamine $(SB_1)$ and also described in details for the preparing sodium tetrahydrofurfuryl thiosulphate (Bunte's salt) with and without KI. The optimum reaction conditions for the preparation of TTFD was set in which the Box-Wilson plan was applied. The reaction conditions are as follows; 1. pH value of aqueous solution of thiol type of $B_1{\cdot}HCl;12.09$ 2. Quantity of Bunte's salt (to $B_1{\cdot}HCl\;20G$); 35.01g 3. Reaction temperature; $15.59^{\circ}C$ Studies on ultraviolet absorption were made at various pH and showed that the absorption maxima are shifted with change of pH. The absorption maxima are at $244{\sim}246nm,\;234{\sim}235nm$ in TTFD, and $245{\sim}246nm,\;233{\sim}235nm$ in TPD. The structure was proved by the infrared spectral evidence. Quantitative determination was studied.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.19 no.4
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• pp.373-378
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• 2006

We report on plasma damage free-sputtering technologies for organic light emitting diodes (OLEDs), organic thin film transistor (OTFT) and flexible displays by using a box cathode sputtering (BCS) method. Specially designed BCS system has two facing targets generating high magnetic fields ideally entering and leaving the targets, perpendicularly. This target geometry allows the formation of high-density plasma between targets and enables us to realize plasma damage free sputtering on organic layer without protection layer against plasma. The OLED with Al cathode prepared by BCS shows electrical and optical characteristics comparable to OLED with thermally evaporated Mg-Ag cathode. It was found that OLED with Al cathode layer prepared by BCS has much lower leakage current density ($1{\times}10^{-5}\;mA/cm^2$ at -6 V) than that $(1{\times}10^{-2}{\sim}-10^0\;mA/cm^2)$ of OLED prepared by conventional DC sputtering system. This indicates that BCS technique is a promising electrode deposition method for substituting conventional thermal evaporation and DC/RF sputtering in fabrication process of organic based optoelectronics.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.11a
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• pp.53-54
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• 2005

We report on plasma damage free-sputtering technologies for organic light emitting diodes (OLEDs), organic thin rim transistor (OTFT) and flexible displays by using a box cathode sputtering (BCS) method. Specially designed BCS system has two facing targets generating high magnetic fields ideally entering and leaving the targets, perpendicularly. This target geometry allows the formation of high-density plasma between targets and enables us to realize plasma damage free sputtering on organic layer without protection layer against plasma. The OLED with top cathode prepared by BCS shows electrical and optical characteristics comparable to OLED with thermally evaporated Mg-Ag cathode. It was found that TOLED with ITO or IZO top cathode layer prepared by BCS has much lower leakage current density ($1\times10^{-5}$ mA/cm2 at -6V) than that ($1\times10^{-1}\sim10^{\circ}mA/cm^2$)of OLED prepared by conventional DC sputtering system. This indicates that BCS technique is a promising electrode deposition method for substituting conventional thermal evaporation and dc/rf sputtering in fabrication process of organic based optoelectronics.

• Journal of The Korean Society of Agricultural Engineers
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• v.47 no.2
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• pp.55-61
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• 2005

This study was performed to evaluate fluidity of super flow concrete using recycled coarse aggregate. The unit weight was $2,246{\sim}2,344\;kg/m^3$, the unit weights of these concrete were decreased with increasing the content of fly ash and recycled coarse aggregate. The slump flow was $58{\sim}63\;cm$, the Box type passing was $3.4{\sim}6.8\;cm$, respectively. The L type compacting was excellent in the fly ash content $10\%\;and\;20\%$, but, it was showed in good in the fly ash content $30\%$. The super flow concretes using recycled coarse aggregate were improved by substitution in the range of less than the fly ash content $20\%$ and recycled coarse aggregate content $75\%$. This recycled coarse aggregate can be used for super flow concrete.

• Publications of The Korean Astronomical Society
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• v.7 no.1
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• pp.189-205
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• 1992

Paper I (김강민외. 1991) 에서 만든 초증감처리 장치를 보완하여 실용적으로 천체관측에 이용할 수 있도록 초증감처리 장치를 완성하였다. 초증감처리 장치의 주된 보완 내용으로는 진공처리조의 오븐 기능의 보완, 굽기통 (baking box) 사용, 농도쐐기마스크의 교체 및 현상의 균질도를 높이기 위한 자동현상기의 준비등이다. 8 % 수소 혼합가스를 채운 굽기처리에 의한 시험적인 초증감처리 결과, 일정한 초증감처리 시간에 대해 굽기온도를 높게 할수록 감도증가량은 커졌으며, IIIa-J 의 경우 $4.8\;{\sim}\;15.3$ 배, 103a-0 의 경우 $1.5\;{\sim}\;2.1$ 배의 감도증가를 보였다. 이 때의 안개농도는 0.1 이하의 낮은 값을 보였다.

• Proceedings of the IEEK Conference
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• 2002.07a
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• pp.164-167
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• 2002

This paper presents the design of Rijndael crypto-processor with 128 bits, 192 bits and 256 bits key size. In October 2000 Rijndael cryptographic algorithm is selected as AES(Advanced Encryption Standard) by NIST(National Institute of Standards and Technology). Rijndael algorithm is strong in any known attacks. And it can be efficiently implemented in both hardware and software. We implement Rijndael algorithm in hardware, because hardware implementation gives more fast encryptioN/decryption speed and more physically secure. We implemented Rijndael algorithm for 128 bits, 192 bits and 256 bits key size with VHDL, synthesized with Synopsys, and simulated with ModelSim. This crypto-processor is implemented using on-the-fly key generation method and using lookup table for S-box/SI-box. And the order of Inverse Shift Row operation and Inverse Substitution operation is exchanged in decryption round operation of Rijndael algorithm. It brings about decrease of the total gate count. Crypto-processor implemented in these methods is applied to mobile systems and smart cards, because it has moderate gate count and high speed.

• IEMEK Journal of Embedded Systems and Applications
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• v.7 no.3
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• pp.121-127
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• 2012

An integrated crypto engine for encryption and decryption of AES algorithm based on unified data-path architecture is efficiently designed and implemented in this paper. In order to unify the design of encryption and decryption, internal steps in single round is adjusted so as to operate with columns after row operation is completed and efficient method for a buffer is developed to simplify the Shift Rows operation. Also, only one S-box is used for both key expansion and crypto operation and Key-Box saving expended key is introduced provide the key required in encryption and decryption. The functional simulation based on ModelSim simulator shows that 164 clocks are required to process the data of 128bits in the proposed engine. In addition, the proposed engine is implemented with 6,801 gates by using Xilinx Synthesizer. This demonstrate that 40% gates savings is achieved in the proposed engine, compared to individual designs of encryption and decryption engine.

• Journal of the Korean Professional Engineers Association
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• v.45 no.6
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• pp.28-32
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• 2012

Namhae chemical is one of the largest fertilizer manufacturing company in Korea which company has operating 4 unit agitator gear boxes and producing variety kinds of fertilizer production. The gearbox operating temperature of agitator is approximated in $55^{\circ}C{\sim}90^{\circ}C$ and required to keep operating continuous without stopping. The system required high performance oil and longer oil drain interval as limited workforce in maintenance team. It was lubricated by mineral gear oil of ISO VG 320 and also need to change to new oil frequently. Namhae Chemical would expect to keep stable operating condition without shut down and consider, lower cost of operation and equipment protection.

• Research in Plant Disease
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• v.14 no.2
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• pp.127-130
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• 2008

Rhizopus soft rot caused by Rhizopus stolonifer on June, 2008 occurred on Rubus crataegifolius Bunge in the box at Jinju City Wholesale Market of Agricultural Products at Gyeongnam province in Korea. The infected fruits were rapidly water-soaked, softened, black and eventually rotted. The symptoms occurred after infecting wounds at harvest time. The colony were white to light brown, formed much sporangiospores. The optimum temperature of the fungus on potato dextrose agar was $30^{\circ}C$. Sporangiophores were $12{\sim}25{\mu}m$ in width. Sporangia were globose or hemispheric, white at first and gradually to black, and $82{\sim}195{\mu}m$ in size. Columella were hemispheric, and $70{\sim}92{\mu}m$ in size. Sporangiospores were irregular round or oval, brownishblack and $9{\sim}21{\times}7{\sim}8{\mu}m$ in size. On the basis of symptom, mycological characteristics and pathogenicity of the fungus, the causal fungus was identified as Rhizopus stolonifer. This is the first report of Rhizopus soft rot by R. stolonifer on R. crataegifolius in Korea.

• The Korean Journal of Mycology
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• v.35 no.1
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• pp.54-57
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• 2007

Rhizopus soft rot caused by Rhizopus stolonifer occurred on banana (Musa sapientum) in the box at Jinju City Wholesale Market of Agricultural Products at Gyeongnam province in Korea. The infected fruits were rapidly water-soaked, softened, blackened and eventually rotted. They were infected from wounds at harvest time. The colony of the isolate from the infected fruit was white to light brown and formed many sporangiospores. The optimum growth temperature of the fungus on potato dextrose agar was $30^{\circ}C$. Sporangiophores were $12{\sim}26\;{\mu}m$ in width. Sporangia were globose or hemispheric, white at first and changed gradually to black, and $83{\sim}195\;{\mu}m$ in size. Columella were hemispheric, and $72{\sim}125\;{\mu}m$ in size. Sporangiospores were irregular round or oval, brownish-black and $9{\sim}20{\times}7{\sim}8\;{\mu}m$ in size. On the basis of symptom, mycological characteristics and pathogenicity to banana, the causal fungus was identified as Rhizopus stolonifer. This is the first report of Rhizopus soft rot by R. stolonifer on banana in Korea.