자간증과 성장지연에 이환된 태아에서 심박동의 불안정성과 자율신경계 조절에 대한 연구

이미라,강윤덕,염명걸,오재원,김창렬,김남수,박은영,김종화 한국소아심장연구회 2004 소아심장 Vol.8 No.1

화학양론 조성의 뮬라이트 합성거동과 입자형상에 미치는 전구체 pH의 영향

이재언,김재원,정연길,장중철,조창용,Lee, Jae-Ean,Kim, Jae-Won,Jung, Yeon-Gil,Chang, Jung-Chel,Jo, Chang-yong 한국재료학회 2002 한국재료학회지 Vol.12 No.7

Stoichiometric mullite ($3Al_2$$O_3$. $2SiO_2$) precursor sol has been prepared by sol-gel method. The effects of the precursor pH and sintering temperature on the synthesizing behavior and morphology of mullite have been studied. Mullite precursor sol was prepared by dissolution of aluminum nitrate enneahydrate (Al($NO_3$)$_3$.9H$_2O) into the mixture of silica sol. Precursor pH of the sols was controlled to acidic condition ($PH\leq$ 1~1.5) and to basic condition ($pH\geq$8.5~9). The synthesized aluminosilicate sols were formed under 20 MPa pressure after drying at $150^{\circ}C$ for 24 hours, and then sintered for 3hours in the temperature range of $1100~1600^{\circ}C$. From TGA/DTA analysis, total weight loss in the aluminosilicate gel of the acidic sample was (equation omitted) 56% and that of the basic sample was (equation omitted) 85%, indicating that the synthesizing temperature of mullite phase for acidic and basic samples was above $1200^{\circ}C$ and $1300^{\circ}C$, respectively. The morphologies of the synthesized mullite were fine and needle-like (or rod-like) for acidic sample, and granular for basic sample that has been sintered above $1300^{\circ}C$. It was found that the morphology of mullite particle was predominantly governed by precursor pH and sintering temperature.

조선업의 심출작업에 종사하는 비정형 근로자에 대한 근골격계질환 분석

구본언,박근상,김창한,Koo, Bon-Ean,Park, Keun-Sang,Kim, Chang-Han 대한인간공학회 2007 大韓人間工學會誌 Vol.26 No.2

In shipbuilding industry, musculoskeletal disorders increase rapidly since 2001. Musculoskeletal disorders was occurred the number of 735 in 2003 and the number of 479 on the whole in 2002 and is increased. About this, it is in progress actively that a lot of research services for problem grasping and technology seminar for prevention of musculoskeletal disorders of shipbuilding industry with KOSHIPA (The Korea Shipbuilding Association) in the center in 2002. But, it is actuality that the research is in many difficulties by absence of basic data in shipbuilding industry that most un-standardization work forms. Therefore, this study analyzed present condition of musculoskeletal disorders to shipbuilding industry that most un-standardization work forms. Also, we analyzed on the subject of the Centering-work that appearance extremely much musculoskeletal disorders.

5ZrSiO₄-xCaCO₃ 혼합계에서 CaCO₃첨가량이 CaZrO₃와 m-ZrO₂의 합성 및 미세구조변화에 미치는 영향

김재원,이재언,조창용,이재현,정연길,Kim, Jae-Won,Lee, Jae-Ean,Jo, Chang-Yong,Lee, Je-hyun,Jung, Yeon-Gil 한국재료학회 2003 한국재료학회지 Vol.13 No.9

Synthesizing behavior and microstructural evolution of $CaZrO_3$and $m-ZrO_2$in a thermal reaction process of $ZrSiO_4$-$xCaCO_3$mixtures, where x is 7 and 19, were investigated to determine the addition amount of CaO in CaO:$ZrO_2$:$SiO_2$ternary composition. CaZrO$_3$-Ca$_2$SiO$_4$precursor prepared by the mixture of $ZrSiO_4$and CaCO$_3$in aqueous suspending media was controlled to the acidic (pH=4.0) condition with HCI solution to enhance the thermal reaction. The addition amount of dispersant into the $ZrSiO_4$-$xCaCO_3$slip increased with increasing mole ratio of $CaCO_3$, which was associated with the viscosity of slip. Decarbonation reaction was activated with an increase of the addition amount of $CaCO_3$, showing different final temperatures in $ZrSiO_4$-$7CaCO_3$and $ZrSiO_4$-$19CaCO_3$mixtures as about 980 and 116$0^{\circ}C$, respectively, for finishing decarbonation reaction. The grain morphology was changed to spherical shape for all samples with an increase of sintering temperature. The grain size and phase composition of the synthesized composites depended on the mixture ratio of Zrsi04 and CacO3 powders, indicating that the main crystals were m-ZrO2 ($\leq$3 $\mu\textrm{m}$) and $CaZrO_3$ ($\leq$ 7 $\mu\textrm{m}$) in $ZrSiO_4$</TEX$>-7CaCO_3$and $ZrSiO_4$-$19CaCO_3$mixtures, respectively.

수용성 매체에서 뮬라이트의 합성거동 및 입자형상에 미치는 염 및 전구체 pH의 영향

정연길,이재언,신영일,김재원,조창용,Jung, Yeon-Gil,Lee, Jae-Ean,Shin, Young-Ill,Kim, Jae-Won,Jo, Chang-Yong 한국재료학회 2003 한국재료학회지 Vol.13 No.4

The effects of the salt and the precursor pH on the synthesizing behavior and the morphology of mullite have been studied. Two kinds of mullite precursor sols were prepared by the dissolution of two kinds of salt (aluminum nitrate enneahydrate, Al($NO_3$)$_3$ㆍ$9H_2$O; type I and aluminum sulfate 14∼18 water, (SO$Al_4$)$_3$$\cdot$$14∼18H_2$O; type II) into the mixture of colloidal silica sol, respectively. Precursor pH of the sols was controlled to the acidic (pH= 1.5∼2) and basic (pH= 8.5∼9) conditions. The co-products with nitrate and sulfate were completely eliminated at $500^{\circ}C$ and $850^{\circ}C$, respectively, which was confirmed by TG/DTA results. The synthesizing temperature of mullite phase was found to be above $1200^{\circ}C$ for pH= 1.5∼2 and above $1300^{\circ}C$ for pH= 8.5∼9 in type I. However, in type II, the synthesizing temperature of mullite was decreased to $850^{\circ}C$ for pH= 1.5∼2 and $1100^{\circ}C$ for pH= 8.5∼9. The grain size of the mullite synthesized at pH= 8.5∼9 was larger than that at pH= 1.5∼2 in overall heat-treated temperatures, showing smaller grain size in type II. Aspect ratio of the mullite grains was more increased at pH= 1.5∼2 than pH= 8.5∼9 in type I, showing similar aspect ratio at both pH conditions in type II. It was found that the synthesizing temperature and grain size were predominantly governed by the initial precursor pH and decomposition of the salt, with minor effect on the grain morphology.

멀티레벨 변조방식에서 LDPC 복호 알고리즘

이인기,정지원,최덕군,최은아,장대익,오덕길,Lee In-Ki,Jung Ji-Won,Choi Duk-Gun,Choi Ean-A,Chang Dae-Ig,Oh Duk-Gil 한국통신학회 2005 韓國通信學會論文誌 Vol.30 No.6C

8PSK 이상의 멀티 레벨 변조 방식에서는 LDPC 복호를 위해서는 수신 심볼의 Inphase와 Quadrature 성분을 이용하여 각각의 비트로 분리하여야 하며, 성능은 각각의 비트의 거리와 관계가 있기 때문에 분리 하는 방식이 성능에 영향을 미치게 된다. 따라서 본 논문에서는 기존의 유클리디언 거리를 이용하여 분리하는 방식을 분석하고 이는 하드웨어 구현 관점에서 많은 계산량을 필요로 하기 때문에 약간의 성능 감소를 가지더라도 섹터를 이용하는 방식을 제안한다. 또한 DVB-S2에서는 BC(Backward Compactible) 모드를 제공한다. BC 모드에서는 변조방식이 계층적 변조 방식인데 즉 변조시 심볼의 위상이 non-uniform 하게 분포되는데 본 연구에서는 non-uniform한 위상 분포에서 각각 인접한 심볼의 위상의 각도에 따른 LDPC 성능을 분석하였다. For LDPC decoding, received symbols are splitted bit by bit based using the received in-phase and quadrature components. The method of bit-splitting is affected on decoding performance because its method depend on distance over symbol constellation. Therefore this paper propose the bit split method using the sector information with sacrifice a little performance loss compared to Euclidean distance method. Futhermore DVB-S2 specification supports BC(Backward Compactible) mode which using the hierarchical modulation method, this paper also analyze the decoding performance according to deviation angle of 8PSK constellation for various LDPC coding rates.

Flowers of Inula japonica Attenuate Inflammatory Responses

Choi, Jeon-Hyeun,Park, Young-Na,Li, Ying,Jin, Mei-Hua,Lee, Ji-Ean,Lee, Youn-Ju,Son, Jong-Keun,Chang, Hyeun-Wook,Lee, Eun-Kyung The Korean Association of Immunobiologists 2010 Immune Network Vol.10 No.5

Background: The flowers of Inula japonica (Inulae Flos) have long been used in traditional medicine for the treatment of inflammatory diseases. In the present study, we investigated the anti-inflammatory properties of Inulae Flos Extract (IFE). Methods: The anti-inflammatory effects of IFE against nitric oxide (NO), $PGE_2$, TNF-${\alpha}$, and IL-6 release, as well as NF-${\kappa}B$ and MAP kinase activation were evaluated in RAW 264.7 cells. Results: IFE inhibited the production of NO and the expression of inducible nitric oxide synthase (iNOS) in LPS-stimulated RAW264.7 cells. In addition, IFE reduced the release of pro-inflammatory cytokines, such as TNF-${\alpha}$ and IL-6. Furthermore, IFE inhibited the NF-${\kappa}B$ activation induced by LPS, which was associated with the abrogation of $I{\kappa}B-{\alpha}$ degradation and subsequent decreases in nuclear p65 and p50 levels. Moreover, the phosphorylation of ERK, JNK, and p38 MAP kinases in LPS-stimulated RAW 264.7 cells was suppressed by IFE in a dose-dependent manner. Conclusion: These results suggest that the anti-inflammation activities of IFE might be attributed to the inhibition of NO, iNOS and cytokine expression through the down-regulation of NF-${\kappa}B$ activation via suppression of $I{\kappa}B{\alpha}$ and MAP kinase phosphorylation in macrophages.

광대역무선채널에서 다중반송파 적응변조시스템의 궤환정보 감소알고리듬

강민구,임승주,천현수,강창언,Min-Goo, Kang,Soong-Ju, Im,Hyun-Su, Cheon,Chang-Ean, Kang 통신위성우주산업연구회 2001 Joint Conference on Satellite Communications Vol.2001 No.-

본 논문에서는 다중 반송파 적응 변조기술을 적용한 무선 데이터 전송 시스템에서 궤환정보를 감소하는 알고리듬을 제안하고, 성능을 분석한다. 일반적인 직교 주파수 분할 다중화 (OFDM :orthogonal frequency division multiplexing) 방식은 모든 부반송파를 통해 전송되는 신호의 정보량을 같게 설정한다. 하지만 제안된 다중 반송파 적응 변조 시스템은 채널의 상태 또는 주어진 에러 확률에 따라 부반송파를 통해 전송되는 신호의 정보량을 다르게 함으로서 원하는 품질의 전송상태를 유지하면서도 데이터의 전송률을 최대화할 수 있다. 또한 데이터의 전송률과 전송 상태를 고정하면서 최소의 소비전력으로 전송할 수 있다. In this thesis a wireless data transmission system has been proposed and analysed that uses the multi-carrier technique with the adaptive modulation scheme. In general, the OFDM(Orthogonal Frequency Division Multiplexing) system is assigning a same amount of information to all sub-carriers in a wireless data transmission. In the proposed system, the different amount of information is assigned to each sub-carrier depending on the state of channel and the target probability of error of system. With the proposed scheme, the transmission rate can be maximized with the fixed power and the required power to transmit the information can be minimized with the target probability of error of system.