Effect of Mokhyangsungi-tang(MHS) on antioxidative ability in human intestinal epithelial cells

김지웅,김우환,김원일,Kim, Ji-Woong,Kim, Woo-Hwan,Kim, Won-Ill The Society of Internal Korean Medicine 2001 大韓韓方內科學會誌 Vol.22 No.3

목적 : 본 연구는 목향순기탕(木香順氣湯)이 인간의 장관상피세포 계열인 Caco-2 세포에서 항산화작용을 증진시키는 효과가 있는지 검증하기 위한 실험이다. 방법 : 배양된 인간장관 세포계열인 Caco-2 세포에서 세포의 사망은 trypan blue의 소실정도에 의해 평가했으며 $H_2O_2$는 표본산화제로 사용되었다. 결과 : $H_2O_2$에서 노출된 세포들은 용량에 비례하여 세포 사망하는 결과를 보였다. 목향순기탕(木香順氣湯)은 $H_2O_2$에 의해 유발된 세포사망을 방지하였고, 0.05-1%의 농도범위에 걸쳐서 효과가 극대화되었다. 목향순기탕(木香順氣湯)과 강력한 항산화제인 DPPD는 $H_2O_2$에 의해 억제된 SOD의 활성에는 영향을 주지는 못했다. 그러나 $H_2O_2$에 의해 유발된 catalase, glutathione peroxidase, hydroperoxide 탈취효소의 활성이 감소되는 것을 억제하였다. 또한 $H_2O_2$에 의해 유발된 glutathione의 감소는 목향순기탕(木香順氣湯)과 DPPD에 의해 억제되었다. 목향순기탕(木香順氣湯)은 $H_2O_2$에 의해 유발된 ATP의 소실을 회복시켰지만 DPPD는 ATP 소실을 회복시키지 못하였다. 결론 : 이러한 결과로 볼 때 Caco-2세포에서 목향순기탕이 세포사망을 억제하는 것은 다른 기전을 통하여 항산화작용을 하는 것으로 볼 수 있다. 따라서 본 연구는 목향순기탕(木香順氣湯)이 반응성산소기에 의해 유발된 인체 위장관질환의 치료에 사용할 수 있을 가능성을 제시하고 있다.

HILS를 활용한 전투차량의 반능동 현수장치 적용에 관한 연구

김지웅,김문준,이은준,이경훈,우관제,Kim, Chi-Ung,Kim, Moon-June,Rhee, Eun-Jun,Lee, Kyoung-Hoon,Woo, Kwan-Je 한국군사과학기술학회 2010 한국군사과학기술학회지 Vol.13 No.6

There have been a lot of efforts on the improvement for the ride comfort and handling stability of the combat vehicles. Especially most of vehicles for military purpose have bad inertial condition and severe operating condition such as the rough road driving, and need a high mobility in the emergency status. It is necessary to apply the controlled suspension system in order to improve the vehicle mobile stability and ride comfort ability of crews. A feasibility study is performed on the application of the semi-active suspension system with a magneto-rheological controlled shock absorber for a $6{\times}6$ combat vehicle. First, the dynamic simulation model of the vehicle including the control model for the semi-active suspension system was executed. Based on this model, a hardware-in-the-loop simulation(HILS) system which has a semi-active suspension controller hardware was constructed. After full vehicle simulations were performed in virtual proving courses with this system, the semi-active suspension system was proven to give better ride comfort and handling stability in comparison with the conventional passive suspension system.

어도비포토샵 프로그램을 이용한 anaglyphic 입체영상 제작법

김지웅,이세정,유임주,Kim, Jee-Woong,Lee, Se-Jeong,Rhyu, Im-Joo 한국현미경학회 2007 Applied microscopy Vol.37 No.2

The objects of the nature have three dimensional (3-D) parameters. The 3-D profiles are embedded on the photographs and microscopic images. To understand 3-D configuration, stereo pair image with thick section is frequently employed. The perception of 3-D images is possible with the aid of stereoscopic glasses, although the expert can perceive 3-D images without the glasses. Anaglyphic stereo images are constructed by various softwares from commercial and freeware. Here we would like to present an easy anaglyphs construction method with Adobe $Photoshop^{(R)}$ based on tilting paired images from high voltage electron microscope. The anaglyphic stereo images constructed revealed the same 3-D perception with conventional stereoscopy. We could zoom in/out the anaglyph image digitally to investigate the detail configuration by real time. This method is expected to contribute to understanding complex structures 3 dimensionally.

Size Analysis of CdSe/ZnS Quantum Dots in Aqueous Solution by Using Laser-Induced Breakdown Detection

김지웅,박승한,Dae-Kyu Kim,Jason Han,윤종일,최중길,제구철,Thomas Fanghanel 한국물리학회 2006 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.49 No.1

CdSe/ZnS quantum dots (QDs) coated with mercaptoacetic acid (MAA) in an anqueous solution are investigated by means of highly sensitive laser-induced breakdown detection (LIBD). In particular, a size distribution analysis of QDs dispersed in ultra pure water is performed as a function of time until a steady state is reached. Freshly prepared CdSe/ZnS-MAA QDs are found to initially exist as relatively large (25.0 ± 1.2 nm) agglomerates that slowly disperse over days to small (6.5 ± 0.2 nm), but stable, single particles. These results of increasing breakdown probability with increasing particle density amply demonstrate that LIBD can be a promising analytical technique for size analysis of nanoparticle formation and stability.

부호화 효율을 고려한 고속 인터/인트라 모드 결정 알고리즘

김지웅,김용관,Kim, Ji-Woong,Kim, Yong-Kwan 한국통신학회 2007 韓國通信學會論文誌 Vol.32 No.8c

H.264/AVC 비디오 부호화 표준은 부호화 효율을 향상시키기 위하여 기존의 부호화 표준들과는 다른 새로운 부호화 기법들을 사용한다. 그러나 새로이 채택된 여러 기법들로 인해 H.264/AVC 표준 부호기의 복잡도는 극단적으로 증가하게 되었다. 특히 율-왜곡 최적화 기법에 의한 H.264/AVC의 인터/인트라 모드 결정 방법은 부호기의 복잡도를 증가시키는 가장 큰 원인 중 하나이다. 본 논문에서는 매크로블록 모드 결정 과정의 복잡도 감소 및 전체 부호화 효율 측면에서 우수함을 나타내는 데 주안점을 두며, 이에 대한 고속 매크로블록 모드 결정 알고리즘을 제안한다. 제안한 알고리즘을 적용한 실험 결과, 고속 움직임 추정/보상과 결합한 경우 최대 80%의 부호화 시간을 감소시켰으며, 평균 $8{\sim}10%$의 비트율을 감소시키는데 반해 PSNR의 변화량은 미미하여 전체 부호화 효율 또한 상승시킬 수 있었다. For the improvement of coding efficiency, the H.264/AVC video coding standard employs new coding tools compared with existing coding standards. However, due to these new coding tools, the complexity of H.2641AVC encoder is greatly increased. Specially, Inter/Intra mode decision method of H.264/AVC using RDO(rate-distortion optimization) technique is one of the most complex parts in H.264/AVC. In this paper, we focus on the complexity reduction in macroblock mode decision considering coding efficiency. From the simulation results, the proposed algorithm reduce the encoding time by maximum 80% of total, and reduce the bitrate of the overall sequences by $8{\sim}10%$ on the average compared with existing coding methods.

N-Carbamoylglycine 및 N-Salicylideneaniline과 Metal ions들에 의한 발광 세기의 변화

김지웅,김영해,Kim, Ji Ung,Kim, Yeong Hae 대한화학회 2002 대한화학회지 Vol.46 No.6

We have used PET chemosensors in the determination of N-carbamoylglycine. When N-carbam-oylglycine reacts with complex already made by the fluorophore and metal ion, the luminescence intensity can be changed and this phenomenon can be utilized in quantification. We used three metal ions, $Zn^{2+}$, $Ni^{2+}$, $Cu^{2+}$ and in order to investigate selectivity an acetic acid was used. $Ni^{2+}$ ion showed change in the eT mechanism by the anions. $Cu^{2+}$ ion showed the ability to distinguish N-carbamoylglycine from an acetic acid and it is noteworthy that $Zn^{2+}$ ion can change luminescence sensitively according to concentration. 본 실험은 N-Carbamoylglycine의 농도 결정에 PET sensor를 응용한 것이다.N-Carbamoylglycine이 금속 이온에 리간드로 작용하면서 착물을 만들고 있는 fluorophore의 luminescence intensity를 변화시킬수 있고 이를 통해 농도결정에 이용할 수 있다. 사용한 금속이 온은 $Ni^{2+}$, $Cu^{2+}$ 그리고 $Zn^{2+}$이며 비교대상으로 아세트산을 사용하여 선택성을 확인하였다. $Ni^{2+}$ 이온은 음이온 리간드에 의해서 eT mechanism 변화를 보여주었으며 , $Cu^{2+}$이온은 아세트산과 N-Carbamoylglycine을 구별하는 선택성을 가지고 있으며, $Zn^{2+}$이온은 매우 예민한 luminscence intensity 변화를 일으키는 것으로 나타났다.

이동로봇의 저비용 위치추정을 위한 효율적인 인공표식 배치기법

김지웅,정우진,Kim, Jiwoong,Chung, Woojin 한국전기전자학회 2013 전기전자학회논문지 Vol.17 No.4

인공표식은 이동로봇의 위치추정에서 불확실성을 감소시키기 위해 널리 사용되어 왔다. 또한, 사용되는 인공표식의 수가 증가함에 따라 위치추정 비용이 증가하기 때문에, 인공표식의 효율적 배치를 위한 연구는 핵심적인 이슈중 하나로서 여겨져 왔다. 따라서 본 논문은 운동모델과 센서모델의 불확실성 특성을 고려함으로써 인공표식들을 효율적으로 배치하기 위한 방법을 제안한다. 운동모델과 센서모델은 서로 다른 불확실성 분포를 가지기 때문에, 최종 불확실성은 두 가지 불확실성의 효율적 조합을 통해 크게 감소될 수 있다. 제안한 기법의 유용성은 시뮬레이션 결과에 의해 입증된다. Artificial landmarks have been widely used for reducing the uncertainty in localization of a mobile robot. In addition, research for efficient placement of artificial landmarks has been considered as one of the fundamental issues since the cost of localization is increased with the number of used landmarks. Therefore, this paper proposes a method in which landmarks are efficiently placed by considering the uncertainty characteristics of the motion model and the sensor model. Because two models have different uncertainty distributions, the final uncertainty can be considerably reduced through their efficient combination. The usefulness of the proposed method is demonstrated by simulation results.

단결정 실리콘 태양전지 최적 운전조건을 위한 전기적 특성 분석

김지웅,최용성,이경섭,조수영,황종선,Kim, Ji-Woong,Choi, Yong-Sung,Lee, Kyung-Sup,Cho, Soo-Young,Hwang, Jong-Sun 한국전기전자재료학회 2011 전기전자재료학회논문지 Vol.24 No.8

This paper was investigated the electrical properties for optimal operating conditions of monocrystalline silicon solar cell. The output of electricity for monocrystalline solar cell was investigated according to the distances between solar cell and halogen lamp and to the resistances by the variable resistor.

염료 흡착 조건에 따른 염료감응형 태양전지의 전기적 특성

김지웅,이경섭,최용성,Kim, Ji-Woong,Lee, Kyung-Sup,Choi, Yong-Sung 한국전기전자재료학회 2015 전기전자재료학회논문지 Vol.28 No.11

This paper is designed to find out where power reaches the highest point as the load of solar cells varies. In addition, the current and power were measured when irradiation changes, and the correlation between current and power was investigated. On top of that, experiments were conducted with the light volume kept constant and with the incoming light angle changing in order to figure out the incoming light angle that produces the most power and to conduct analyses. It was ascertained that if the load increases, the current decreases and the voltage increases. Since the power of 0.9828[W] was the highest when measurements were done, it can be said that when a load of 30[%] is applied to the solar cells, they are the most efficient.

작동 조건에 따른 PEMFC 단위 셀 모델 개발

김지웅(Jiwoong Kim),심재봉(Jaebong Sim),김예빈(Yebeen Kim),전현수(Hyunsoo Chun),장정효(Junghyo Chang),김병재(Byeongjae Kim),민경덕(Kyoungdoug Min) 한국자동차공학회 2023 한국자동차공학회 부문종합 학술대회 Vol.2023 No.5

A proton exchange membrane fuel cell (PEMFC) is an energy conversion device that converts chemical energy into electrical energy, generating water and heat as by-products of an electrochemical reaction. A fuel cell system consists of a fuel cell stack and balance of plants (BOP), and it is essential to develop a PEMFC unit cell model according to operating conditions in order to efficiently control the system. In this study, a PEMFC unit cell model was developed through the governing equation of the physical phenomena of each component of the unit cell, and the developed model was verified through comparison with PEMFC experimental data under various operating conditions (such as temperature, pressure, and relative humidity). The developed unit cell model and experimental data were shown to be in good agreement with a relative error of <3%.