광디스크 드라이브에서의 클램핑의 유연성의 영향

김홍렬(Hongryul Kim) 대한기계학회 2002 대한기계학회 춘추학술대회 Vol.2002 No.5

This study examined the influence of transverse clamping flexibility on discs of optical disc drives. Since optical<br/> discs should be separable from drives, discs cannot be clamped rigidly and usually a magnet is used to clamp discs. This<br/> ‘non-rigid’ clamping method reduces the natural frequencies and critical speed of rotating discs. Even larger magnetic<br/> force is desirable to clamp disc in optical disc drives, it is limited by other design factors. Natural frequencies of optical<br/> disc cannot be predicted by traditional methods, which assume that the disk is clamped perfectly. In this paper, the more<br/> accurate values of natural frequencies and critical speed are calculated using finite elements method with flexible<br/> clamping model, which adds the effect of transverse fle xibility on clamping part in optical disc drive. The predicted<br/> natural frequencies and critical speed for rotating disc with this method show very good agreement with experimental<br/> measurements. Also, other vibration phenomena in optical disc drives are also studied through experiments.

선택적 Cyclooxygenase-2 억제제인 Celecoxib가 상이한 Cylooxygenase-2 발현량을 가진 인간 암세포주들에 대하여 유도하는 방사선 감수성 증진 작용

표홍렬(Hongryull Pyo),신유근(You Keun Shin),김현석(Hyun Seok Kim),성진실(Jinsil Seong),서창옥(Chang Ok Suh),김귀언(Gwi Eon Kim) 대한방사선종양학회 2003 Radiation Oncology Journal Vol.21 No.3

목 적: Cyclooxygenase-2 (COX-2)를 과발현하는 A549 인간폐암세포주와 발현하지 않는 MCF-7 인간 유방암 세포주에서 선택적 COX-2 억제제인 celecoxib의 방사선 감수성 증진 작용을 관찰하고자 하였다. 대상 및 방법 : A549 세포와 MCF-7 세포에 대해서 방사선 혹은 방사선과 celecoxib를 병용 투여한 후에 clonogenic radiationsurvival실험을 시행하였다.같은 실험을 각각 10%와 1%의 FBS를 포함한 배지에서 반복하였다.각 세포에 방사선과 celecoxib를 동시 혹은 단독 투여한 후에 각 실험 그룹의 세포사멸을 측정하였다. 결 과: 약물 투여기간 동안 10%의 혈청을 포함한 배지조건에서 배양된 A549 세포에서는, 3 0μM과 50μM 농도의celecoxib가 투여된 상태에서 surviving fraction=0.1에서의 Radiation enhancement ratio (RER)가 각각 1.58과 1.81로 celecoxib가 A549 세포의 방사선 감수성을 증가시켰다. 이러한 방사선 감수성의 증가는 세포를 1%의 혈청을 포함한 배지에서 배양하였을때는 소실되었다. MCF-7 세포에서는 10%와 1% 혈청을 포함한 각각의 배지조건 하에서 celecoxib에 의한 방사선 감수성의 변화가 관찰되지 않았다. A549와 MCF-7 세포의 각 그룹에서 세포사멸을 측정한 결과 celecoxib와 방사선이 병용 투여되었을 때 유도되는 세포사멸은 상호 상승적이지 않은 것으로 나타났다. 결 론: COX-2 선택적 억제제인 celecoxib는 COX-2를 과발현하는 A549 세포에서 선택적으로 방사선 감수성을 증진시켰으며, 저 농도의 혈청을 포함한 배지조건에서는 이러한 효과가 소실되었다. COX-2를 발현하지 않는 MCF-7 세포주에서는 celecoxib에 의해서 방사선 감수성이 변화되지 않았으며, 이러한 celecoxib의 방사선 감수성 증진 작용 기전에 세포 사멸은 관여하지 않는 것으로 보인다. Purpose To investigate the modulation of radiosensitivity by celecoxib, a selective cyclooxygenase-2 (COX-2) inhibitor, on cancer cells over-and under-expressing COX-2. Materials and Methods: A clonogenic radiation survival analysis was performed on A549 human lung and MCF-7 human breast cancer cell lines incubated in both 1 and 10% fetal bovine serum (FBS) containing media. The apoptosis in both cell lines was measured after treatment w ith radiation and/or celecoxib. Results Celecoxib enhanced the radiation sensitivity of the A 5 49 cells in the medium containing the 10% FBS, with radiation enhancement ratios of 1.58 and 1.81 respectively, at surviving fractions of 0.1, with 30M and 50M celecoxib. This enhanced radiosensitivity disappeared in the medium containing the 1% FBS. Celecox ib did not change the radiation sensitivity of the MCF-7 cells in either media. The induction of apoptosis by celecoxib and radiation was not synergistic in either cell line. Conclusion Celecoxib, a selective COX-2 inhibitor, preferentially enhanced the effect of radiation on COX-2 over-expressing cancer cells compared to the cells with a low expression, and this effect disappeared on incubation of the cells during drug treatment in the medium with suboptimal serum concentration. Apoptosis did not appear to be the underlying mechanism of this radiation enhancement effect due to celecoxib on the A549 cells. These findings suggest radiosensitization by a selective COX-2 inhibitor is COX-2 dependent.

Cooperative Enhancement of Radiosensitivity After Combined Treatment of 17-(Allylamino)-17-Demethoxygeldanamycin and Celecoxib in Human Lung and Colon Cancer Cell Lines

Kim, Young-Mee,Pyo, Hongryull Mary Ann Liebert 2012 DNA and cell biology Vol.31 No.1

도로터널 환기설계시 적정 차량항력계수 결정에 관한 연구

이창우(Changwoo Lee),조홍률(Hongryul Cho),박홍채(Hongchae Park) 한국유체기계학회 2006 유체기계 연구개발 발표회 논문집 Vol.- No.-

Quantifying the drag forces exerted by vehicles is critical for road tunnel ventilation safety design due to the high ratios they account for. Vehicle-induced forces occupy as much as 32~100% of the total ventilation forces acting inside tunnel, while in safety design, drag forces is in the range of 28 to 65% of the mechanical pressure required for the emergency fan. The method adopted in local design guidelines for determining the drag coefficient does not take into account the effects of slip streaming despite of the recommendation by PIARC. This paper aims at analyzing the effects of slip streaming on drag coefficient by varying vehicle type, blockage ratio, inter-vehicle distance and relative air velocity. A total of 192 cases in 4 different target tunnels with 4 levels of service, 2 types of vehicle, 6 different relative air velocities were numerically studied with SOLVENT. Some of the significant results can be summarized as follows: (1) If the inter-vehicle distance is kept constant, drag coefficient remains almost constant with relative air velocity of 5.0~28.3㎧. (2) Effects of slip streaming become more prominent, as traffic density increases and inter-vehicle distance gets shorter. Reduction of drag coefficient reaches 23~39%. However, differences in reduction ratios are not significant among the different vehicle types . (3) In the case of heavy vehicles, reduction in drag coefficient due to decreasing inter-vehicle distance shows linear relationship, while the relationship is not statistically significant for small vehicles. (4) Drag coefficient of small vehicles noticeably increases with higher blockage ratio under the relative air velocity of 5.0~28.3㎧ and the blockage ratio of 1.8~3.6%. However, the trend in heavy vehicles is not consistent, as drag coefficient increases up to the blockage ratio of 7.% and unexpectedly decreases thereafter. (5) The drag coefficient suggested by current local guidelines must be interpreted as its upper limit, and the suggested method for coefficient derivation should be reappraised.

Different Cell Cycle Modulation by Celecoxib at Different Concentrations

Kim, Young-Mee,Pyo, Hongryull Mary Ann Liebert 2013 Cancer Biotherapy & Radiopharmaceuticals Vol.28 No.2

시계열 유전자 발현 데이터의 스트레스 특이 반응 유전자 검출 및 스트레스 예측 알고리즘 개발

강동원(Dongwon Kang),안홍렬(Hongryul Ahn),이상선(Sangseon Lee),정우석(Woosuk Jung),김선(Sun Kim) 한국정보과학회 2018 한국정보과학회 학술발표논문집 Vol.2018 No.6

Design and Implementation of an ONS Test-bed

Xun, Lu,Piao, Chunjie,Hongryul Yoon,Park, Sangwee,Choung, Jaeuk 대구대학교 정보통신연구소 2004 情報通信硏究 Vol.3 No.1

This paper presents a design and implementation of an ONS test-bed. It provides EPC naming and Web services with respect to EPCTM code currently under standardization. The goal of this research is to investigate the feasibility and complexity of the EPC network. The prototype can be used to verify the concept of the EPC network by providing experimental setup for domestic researchers and engineers.

잣나무림의 변재부면적을 이용한 엽면적 추정에 관한 연구

주영특,김홍률,김영채 경희대학교 부설 식량자원개발연구소 1995 硏究論文集 Vol.16 No.-

우리나라의 주요 조림수종 중의 하나로서 24만 ha에 달하는 식재면적을 갖고 경제적 가치가 높은 잣나무림을 대상으로 표준목을 선정, 벌채하여 측정한 후 상대생장의 법칙과 수관사진 분석 방법을 통해 임관구조 파악과 엽면적 추정식을 개발할 목적으로 수행된 본 연구의 결과를 요약하면 다음과 같다. 1. 조사 대상임분의 입관구조 파악을 위하여 수고 각 층위의 연령별 착엽부 가지의 길이, 착엽부 가지의 건중량, 각 층위의 엽 건중량, 엽면적 등의 분포를 조사하였던 바 수고 6~7m 부위의 역지에서 공히 최대수치를 보였으며, 이를 기점으로 위 아래로 갈수록 감소하는 전형적인 침엽수림 구조를 보였다. 2. 흉고직경 및 변재부 면적과 엽중량 및 엽면적과의 관계 규명을 위해 회귀 분석을 실시한 바에 의하면 이들 모두 공히 매우 높은 상관계수를 나타내었고, 모두 직선 회귀 관계에 있음을 알 수 있었다. 3. 흉고 부위의 변재부 면적과 엽면적 간에는 Y = 0.5217 X - 14.357의 직선회귀관계와 상관계수 r = 0.9849 로 유의성을 인정할 수 있었다. Estimation equation between biomass and leaf area and DBH and sapwood area were developed using the harvesting method for Korean white pine(Pinus koraiensis) in experimental forest of Kyunghee University, Kyungki province. For this purpose, canopy structure of sample trees were investigated. There were close relationship between biomass and leaf ares, and DBH and sapwood area, respectively. Sapwood area served as a better independent variable to estimate leaf biomass and leaf area. Linear regression between leaf area(LA) and sapwood area(SA) was LA=0.5217SA-14.573(r=0.9849^(***)).

크기 및 비율 다형성 의료 이미지에서 병변 영역 세그멘테이션을 위한 이미지 데이터 정규화 및 증강 방법

송대석(Daeseok Song),안홍렬(Hongryul Ahn) 한국정보과학회 2022 한국정보과학회 학술발표논문집 Vol.2022 No.12

Degradation of Polyethylene Terephthalate (PET) Through Polyethylene Terephthalate-degradingEnzyme (PETase)

Sumin LEE,Yejin WON,Hongryul KIM,Jaewook MYUNG 한국생물공학회 2021 한국생물공학회 학술대회 Vol.2021 No.4

For many years, plastic recycling rate has been very low because the cost for plastic recycling cost is higher than for new production. As a result, plastic waste is accumulating at a staggering rate, causing various environmental pollution. After the discovery of polyethylene terephthalate (PET)-hydrolytic emzyme, biotechnological strategy to recycle PET has gained interests among stakeholders. Ideonella sakaiensis, a newly discovered bacterium in 2016, has a PET degrading enzyme called IsPETase. In this study, IsPETase has been used to degrade PET for 24 h in aerobic conditions. Each sample with different concentrations of IsPETase (20, 40, 80, and 100 mg/ml) was collected every 12 h and its compositions were analyzed via HPLC. The result indicates that PET was decomposed into terephthalic acid (TPA), which is a monomer in PET synthesis and has a potential to be upcycled into biodegradable plastics.