복잡한 ULSI 배선 구조 생성을 위한 토포그래피 모델링 및 시뮬레이션

權五燮,원태영,尹錫仁,金演泰,尹林澤 대한전자공학회 2002 電子工學會論文誌-SD (Semiconductor and devices) Vol.39 No.4

A dynamically-allocated topographical model, so-called cell advancing model, has been developed modifying the cell model. Memory requirements are reduced by dynamically allocating completed topography and material information only at surface cells, and setting other cells as a material index. In this paper, this model is presented and verified with applications to etching process by using the analytic model and Monte Carlo model for the incident ion flux, deposition process, and process integration. In case of DRAM cell fabrication process with 5,440,500(130×155×270) cells takes about 22MB memory to represent the topography. 본 논문에서는 반도체 공정 중, 토포그래피 시뮬레이션을 수행함에 있어서, 기존의 셀 모델을 수정하여, 소요되는 메모리의 양을 최소화하는 셀 전진 모델을 개발하였다. 셀 전진 모델은, 전체 시뮬레이션 영역은 물질 정보만으로 나타내지며, 표면의 셀들만으로 리스트가 구성되고, 리스트에 표면 진화 계산에 필요한 정보가 저장된다. 개발된 시뮬레이터는 해석적 모델과 몬테카를로 모델을 이용하여 식각 공정에 있어서 입사 이온 분포가 계산되며, 단위 공정뿐만아니라 공정 순서도에 따라 적층 캐패시터 또는 디램 셀(DRAM cell) 제조 공정과 같은 통합 공정을 수행한다. 개발된 시뮬레이터를 이용하여 디램 셀 제조 공정 시뮬레이션을 수행하였을 경우에, 소요된 셀은 5,440,500(130×155×270)개였고, 메모리 양은 22MB에 불과하였다.

낙동강하구에서의 미생물 다양성과 환경변화에 따른 내성한계

권오섭,하영칠,홍순우 한국미생물학회 1987 미생물학회지 Vol.25 No.3

To determine the characteristics of heterotrophic bacterial community in estuarine ecosystem, water and sediment samples were taden from Naktong estuary. All isolates were compared with 73 characters and described by cluster analysis. With same characters, 30 reference strains were able to divide into approximate species level at 80% similarity (S value). Diversity indices ($H^{1}$) of sediment column isolates were higher than water column isolates. The bacterial community commonly appeared in water and sediment column was reduced with going to downstream. Tolerance indices for temperature (Pt) and salinity (Ps) were also higher in sediment isolates than in water isolates. The bacterial community in sediment column is believed to be composed with diverse populations compared to water column and maintains its stability against various environmental changes with high physiological tolerances.

낙동강 하구에서의 Aeromonas hydrophila의 분포와 특성

권오섭 인제대학교 1989 仁濟論叢 Vol.5 No.2

Samples from four stations of Naktong Estuary had been taken, to scrutinize the effects of environmental parameters on the distribution of Aeromonas hydrophila. The density of Aeromonas spp. was corelated with heterotrophic bacteria, available nitrogen, fecal coliform bacteria, and temperature. Cluster analysis was performed with the results of forty two morphological and biochemical characteristics of the 161 isolates, and three mayor groups and two minor groups were identified. The first three groups exhibited different distribution pattern at each station. Group 1 was isolated from all stations. Group 2 was isolated from relatively polluted stations (St. 1 and 2). Group 3 was isolated from less polluted stations (St. 3 and 4). These three groups were different from MR reaction and gas production from glucose.

돼지에 있어 일당증체량과 등지방두께에 대한 선발지수

권오섭,김성훈,정흥우,박영일 ( O . S . Kwon,S . H . Kim,H . W . Chung,Y . I . Park ) 한국축산학회 1986 한국축산학회지 Vol.28 No.10

Selection index for average daily gain and backfat thickness was derived from the genetic and phenotypic parameters estimated on the basis of the data from 3,369 heads of Yorkshires, Durocs, Hampshires and Landraces tested from March, 1984 to August, 1985. The results obtained in this study are summarized as follows; 1. The heritabilities of average daily gain estimated were 0.369, 0.470, 0.318 and 0.367, respectively, in Yorkshires, Durocs, Hampshires and Landraces and the average heritability was 0.381. The heritabilities of backfat thickness estimated were 0.404, 0.662, 0.565 and 0.892, respectively, in Yorkshires, Durocs, Hampshires and Landraces and the average heritability was 0.631. 2. The genetic correlations between average daily gain and backfat thickness were 0.238, 0.425, -0.132 and 0.079, respectively, in Yorkshires, Durocs, Hampshires and Landraces and the average genetic correlation was 0.152. The phenotypic correlations between average daily gain and backfat thickness, were 0.147, 0.321, 0.020 and 0.147, respectively, in Yorkshires, Durocs, Hampshires and Landraces and the average phenotypic correlation was 0.159. 3. The selection index derived from the estimated parameters and economic weights based on the data from market survey on the price of the products was I₁= =X₁+ 6.52X₂ and the index from the economic weights based on the regression analysis of the price of the breeding stocks was I₂= =X₁+ 2.94X₂. (X₁= backfat thickness(㎝), X₂=average daily gain(㎏))

PCBs의 혐기성 분해에 관한 연구

권오섭 인제대학교 낙동강환경연구소 1993 심포지움(인제대학교 부설 환경연구소 발표논문집) Vol.- No.2

Reductive dechlorination by sediment microorganisms was investigated using Aroclors and individual congeners. Dechlorination was concentration-dependent and this dependence was congener-specific. The Cl removed was determined by the pattern of Cl substitution on the biphenyl ring rather than the substition position with respect to the biphenyl link. Dechlorination was compeletly inhibited under denitrifying condition, but partly inhibited under sulfidogenic conditions when compared to methanogenic conditions, 2-bromoethane sulfonate had no effect on dechlorination, indicating methanogens were not required. CO_2/H_2 enhanced the dechlorination of 2, 3, 4-chlorobiphenyl (CBP) and altered the pathway compared to CO_2 or N_2. Biphenyl enrichment altered Aroclor 1254 dechlorination by primarily inhibiting the removal of p-Cl. The inhibition of p-dechlorination was in fact due primarily to the inability to further dechlorinate 2, 4, 4' -CBP. Dechlorination activity was site-specific; the pathway and produccts of dechlorination of sediment microorganisms from St. Lawrence River were significantly different from those observed with Hudson River organisms.

Altered Gut Microbiota Composition in Rag1-deficient Mice Contributes to Modulating Homeostasis of Hematopoietic Stem and Progenitor Cells

권오섭,이승원,김지혜,김혜강,이승우 대한면역학회 2015 Immune Network Vol.15 No.5

Hematopoietic stem and progenitor cells (HSPCs) can produce all kind of blood lineage cells, and gut microbiota that consists of various species of microbe affects development and maturation of the host immune system including gut lymphoid cells and tissues. However, the effect of altered gut microbiota composition on homeostasis of HSPCs remains unclear. Here we show that compositional change of gut microbiota affects homeostasis of HSPCs using Rag1−/− mice which represent lymphopenic condition. The number and proportions of HSPCs in Rag1−/− mice are lower compared to those of wild types. However, the number and proportions of HSPCs in Rag1−/− mice are restored as the level of wild types through alteration of gut microbiota diversity via transferring feces from wild types. Gut microbiota composition of Rag1−/− mice treated with feces from wild types shows larger proportions of family Prevotellaceae and Helicobacterceae whereas lower proportions of family Lachnospiraceae compared to unmanipulated Rag1−/− mice. In conclusion, gut microbiota composition of lymphopenic Rag1−/− mice is different to that of wild type, which may lead to altered homeostasis of HSPCs.

건식 식각 공정 시뮬레이션을 위한 효율적인 그림자 테스트 알고리즘과 토포그래피 진화에 대한 연구

권오섭,반용찬,원태영,Kwon, Oh-Seop,Ban, Yong-Chan,Won, Tae-Young 대한전자공학회 1999 電子工學會論文誌, D Vol.d36 No.2

In this paper, we report 3D-simulations of a plasma etching process by employing cell-removal algorithm takes into account the mask shadow effect os well as spillover errors. The developed simulator haas an input interface to take not only an analytic form but a Monte Carlo distribution of the ions. The graphic user interface(GUI) was also built into the simulator for UNIX environment. To demonstrate the capability of 3D-SURFILER(SURface proFILER), we have simulated for a typical contact hole structure with 36,000($30{\times}40{\times}30$) cells, which takes about 20 minutes with 10 Mbytes memory on sun ultra sparc 1. as an exemplary case, we calculated the etch profile during the reactive ion etching(RIE) of a contact hole wherein the aspect ratio is 1.57. Furthermore, we also simulated the dependence of a damage parameter and the evolution of topography as a function of the chamber pressure and the incident ion flux. 본 논문에서는 플라즈마 건식 식각 공정을 모의 실험하기 위하여 셀 제거 방법을 적용하여 개발한 시뮬레이터의 성능을 보고한다. 마스크의 기하학적 형상에 의한 그림자 효과(shadow effect)를 고려하기 위한 알고리즘과, 오차의 누적을 막기 위한 알고리즘을 새로이 적용하였다. 입사하는 이온의 분포를 계산하기 위해서 해석적 모델과 몬테 카를로 방법을 모두 적용하였다. 또한 사용자가 유닉스(UNIX) 환경에서 공정 조건을 편리하게 입력할 수 있도록 그래픽 사용자 환경(graphic user interface, GUI)을 개발하였다. 개발된 3D-SURFILER(SURface proFILER)의 성능을 검증하기 위한 콘택 홀(contact hol) 구조의 시뮬레이션에서 셀의 수를 36,000($30{\times}40{\times}30$)으로 설정하여 시뮬레이션하였을 때 SUN ULTRA 1 시스템에서 약 10Mbyte의 메모리가 사용되었으며, 시뮬레이션 시간을 20분이었다. 종횡비(aspect ratio)가 1.57인 콘택 홀 구조에서 반응성 이온 식각(reactive ion etching, RIE)을 시뮬레이션하였으며, 이온의 증속 식각의 정도를 나타내는 손상 계수의 변화와 압력이 600mTorr일 때의 이온의 입사 분포에 의한 토포그래픽(topography) 진화를 시뮬레이션하였다.

낙동강 하구생태계의 환경변화에 따른 종속영양세균의 생리학적 특성

권오섭 한국미생물학회 1992 미생물학회지 Vol.30 No.3

낙동강 하구언 건설에 따른 하구생태계의 변화를 파알하기 위하여 축조 전후의 환경인자와 종속 영양세균의 생리적 특성을 요인분석에 의해 비교하였다. 하구언 축조 후 해수유입의 영향이 급격히 감소하였으며, 축조 전 50.7% 를 차지하던 영양물질의 과다와 관련된 환경변수가 축조후 77.1%로 증가하였다.하구언 축조 전 환경변수와 종속영양세균의 생리적 특성 사이에 밀접한 관련성을 나타냈으며, 축조 후에도 종속영양세균의 생리적 특성이 영양물질의 과다와 관련된 형질로 대부분 해석되어 환경변화와 분포 미생물의 생리적 특성 사이의 관련성을 나타내었다. 그러나 하구언 축조에 따른 해수유입의 차단에도 불구하고 분리균주의 생리적 특성에 의한 요인분석의 3번째 쥬요인이 호염성 형질로 해석되어 작동강 하구의 환경변화에 따른 종속영양세균의 형질이 아직 완전 안정화되지 않은 것으로 사료된다. Environmental parameters and physiological characteristics of heterotrophic bacterial isolates were compared by factor analysis to investigate the influences of river barrage construction on the ecosystem of Naktong River Estuary. Aftcr the construction of river barrage, the influence of seawater was no longer significant. ant1 the influences of nutrients loading were increased from 50.7% to 77.1% of the environmental variances before and after the construction, respectively. The interpretations of features of bacterial physiological characteristics were closely related to environmental parameters as the results of factor analysis. But. differing from the environmental variances. it was found that the halophilic feature was the third factor of bacterial characteristics after the construction of river barrage. This suggests that the stability of Naktong estuarine ecosystem and heterotrophic bacterial characteristics are not established till now.

농축배양 시료를 이용한 trichlorophenols의 혐기성 분해

송성주,권오섭 인제대학교기초과학연구소 1998 자연과학 Vol.2 No.-

2, 3, 4-trichlorophenol (TCP)에 8∼17개월 적응시킨 장림하수처리장의 혐기성 소화조 슬럿지와 김해시 쓰레기매립장 침출수를 사용하여 몇 가지 TCPs의 환원형 탈염소반응 및 환경요인의 영향을 연구하였다. 비적응 시료에 비해 적응 시료의 TCPs 분해는 지체기의 단축으로 빠른 분해 속도를 나타냈으며, 2, 3, 4-TCP는 초기부터 빠른 분해를 보인 반면 2, 3, 6-TCP나 2, 4, 6-TCP는 9일 정도의 지체기를 나타냈다. TCPs의 혐기성 분해에 미치는 head space gas의 H2 조성비와 혐기성 대사저해제의 영향은 접종시료에 따라 다르게 나타났다. CO₃²-, SO₄²-, NO₃-를 전자수용체로 황산염환원 조건에서 다소 느리게 분해되었다. 2, 3, 4-TCP에서는 2, 3-DCP, 2, 3, 5-TCP에서는 2, 5-DCP, 2, 3, 6-TCP에서는 2, 3,-DCP, 2, 4, 6-TCP에서는 2, 4,-DCP가 주된 부산물로 검출되었으며, monochlorophenols와 phenol도 적은 양이지만 지속적으로 검출되었다. Anaerobic inocula of the anaerobic digester sludge from Jangrim municipal wastewater treatment plant and the leachate from Kimhae landfill site were enriched with 2, 3, 4-trichlorophenol (TCP) for a period of 8∼17 months. As compared with the unacclimated samples, the anaerobic degradation rates of TCPs by the acclimated samples were fast. The degradation of 2, 3, 4-TCP occurred without a lag period, but 2, 3, 6-TCP and 2, 4, 6-TCP had a lag period of 9 days each. The effects of headspace gas composition and inhibitors of anaerobic metabolisms such as methanogen and sulfate reduction were not so significant and varied with the kinds of inoculum. Anaerobic biodegradation of TCPs occurred under methanogenic, sulfidogenic, and denifrifying conditions were occurred. Major dechlorination by-products of 2, 3, 4-, 2, 3, 5-, 2, 3, 6-, and 2, 4, 6-TCPs were 2, 3,-, 2, 5-, 2, 3,-, and 2, 4-DCPs, respectively, and small amounts of monochlorphenols and phenol were also detected.

3D-SURFILER ; Topography Simulator for Plasma Etching Process

권오섭,원태영 대한전자공학회 1998 대한전자공학회 학술대회 Vol.1998 No.1