Negative-bias Temperature Instability 및 Hot-carrier Injection을 통한 중수소 주입된 게이트 산화막의 신뢰성 분석

이재성,Lee, Jae-Sung 한국전기전자재료학회 2008 전기전자재료학회논문지 Vol.21 No.8

This paper is focused on the improvement of MOS device reliability related to deuterium process. The injection of deuterium into the gate oxide film was achieved through two kind of method, high-pressure annealing and low-energy implantation at the back-end of line, for the purpose of the passivation of dangling bonds at $SiO_2/Si$ interface. Experimental results are presented for the degradation of 3-nm-thick gate oxide ($SiO_2$) under both negative-bias temperature instability (NBTI) and hot-carrier injection (HCI) stresses using P and NMOSFETs. Annealing process was rather difficult to control the concentration of deuterium. Because when the concentration of deuterium is redundant in gate oxide excess traps are generated and degrades the performance, we found annealing process did not show the improved characteristics in device reliability, compared to conventional process. However, deuterium ion implantation at the back-end process was effective method for the fabrication of the deuterated gate oxide. Device parameter variations under the electrical stresses depend on the deuterium concentration and are improved by low-energy deuterium implantation, compared to conventional process. Our result suggests the novel method to incorporate deuterium in the MOS structure for the reliability.

소프트웨어 재활기법에 기반한 주-여분 서버 시스템의 작업전이 시간 분석

이재성,박기진,김성수,Lee, Jae-Sung,Park, Kie-Jin,Kim, Sung-Soo 한국정보처리학회 2001 정보처리학회논문지 A Vol.8 No.2

인터넷의 급속한 확산으로 인하여, 컴퓨터 시스템의 규모 및 복잡도가 점차 증가하고 있으며, 컴퓨터 시스템에 대한 높은 수준의 가용도 요구 조건을 충족시키기 위해, 하드웨어적.소프트웨어적 결함 허용 기법에 대한 연구가 활발하다. 소프트웨어 재활 기법은 서버에 탑재된 소프트웨어의 장시간 가동에 따른 소프트웨어 노화 현상을 다루고 있으며, 서버에서 실행중인 소프트웨어의 수행을 고의적으로 멈춘 후에 결함 발생 가능성이 낮은 초기 상태에서 이를 다시 가동시키는 소프트웨어적 결함 예방 방법의 일종이라 볼 수 있다. 본 연구에서는 주-여분 서버 시스템에서의 작업전이 시간이 소프트웨어 재활에 미치는 영향을 연구하였으며, 가용도 분석을 통해서 작업전이 시간이 재활 정책을 결정함에 있어서 중요한 요소임을 발견하였다. As the rapid growth of Internet, computer systems are growing in its size and complexity. To meet high availability requirements for the systems, one usually uses both hardware and software fault tolerance techniques. To prevent failures of computer systems from software-aging phenomenon that come from long mission time, we adopt software rejuvenation method that stops and restarts the software in the servers intentionally. The method makes the systems clean and healthy state in which the probability of fault occurrence is very low. In this paper, we study how switchover time affects software rejuvenation of primary-backup server systems. Through experiments, we find that switchover time is an essential factor for deciding the rejuvenation policy.

10 V 이하의 프로그래밍 전압을 갖는 Ta2O5/SiO2 로 구성된 안티휴즈 소자

이재성,오세철,류창명,이용수,이용현 ( Jae Sung Lee,Seh Chul Oh,Chang Myung Ryu,Yong Soo Lee,Yong Hyun Lee ) 한국센서학회 1995 센서학회지 Vol.4 No.3

This paper presents the fabrication of ametal-insulator-metal(MIM) antifuse structure consisting of insulators sandwiched between top electrode, Al, and bottom electrode, TiW and additionally studies on antifuse properties depending on the condition of insulator. The intermetallic insulators, prepared by means of sputter, comprised of silicon oxide and tantalum oxide. In such an antifuse structure, silicon oxide layer is utilized to decrease the leakage current and tantalum oxide layer, of which the dielectric strength is lower than that of silicon oxide, is also utilized to lower the breakdown voltage near 10V. Finally sufficient low leakage current, below InA, and low programming voltage, about 9V; could be obtained in antifuse device comprising Al/Ta₂O₃(10nm)/SiO₂=(10nm)/TiW structure and OFF resistance of 3.65㏁ and ON resistance of 7.26Ω could be also obtained. This Ta₂O₃/ SiO₂= based antifuse structures will be promising for highly reliable programmable device.

메타 검색에서 외래어 질의 정제 효과

이재성,Lee, Jae-Sung 한국정보처리학회 2008 정보처리학회논문지B Vol.15 No.2

문서에서 외래어가 일관되게 사용되지 않고 여러 이형태로 사용되고 있기 때문에, 정확한 질의어 일치를 지원하는 검색 시스템에서 외래어 질의로 문서를 검색하는데 어려움이 많다. 본 논문에서는 하나의 외래어로 질의할 경우, 원 질의어와 같은 뜻의 다양한 이형태 외래어 질의로 자동 확장하고 정제하여 더 많은 관련 문서를 손쉽게 검색할 수 있는 메타 검색 방법을 제안한다. 이 방법은 1차로 원 질의어에서 다양한 외래어 이형태를 통계적 방법으로 확장하고, 2차로 그 결과를 각 검색 엔진에게 질의하여 일정 개수 이상의 질의어가 문서에 나타났는지, 원 질의어의 문맥과 유사한 문맥에서 그 질의어가 쓰였는지를 비교하여, 같은 뜻의 유효한 외래어를 판별해 내고 이를 이용하여 검색할 수 있도록 한다. 실험 결과, 기준점으로 쓰인 1차로 만든 이형태로 검색했을 때 F값은 평균 38%이었으나, 제안된 방법인 2차로 정제된 질의어로 검색했을 때의 F값은 평균 81%로 매우 향상된 결과를 보였다. Foreign word transliterations are not consistently used in documents, which hinders retrieving some important relevant documents in exact term matching information retrieval systems. In this paper, a meta search method is proposed, which expands and refines relevant variant queries from an original input foreign word transliteration query to retrieve the more relevant documents. The method firstly expands a transliteration query to the variants using a statistical method. Secondly the method selects the valid variants: it queries each variant to the retrieval systems beforehand and checks the validity of each variant by counting the number of appearance of the variant in the retrieved document and calculating the similarity of the context of the variant. Experiment result showed that querying with the variants produced at the first step, which is a base method of the test, performed 38% in average F measure, and querying with the refined variants at the second step, which is a proposed method, significantly improved the performance to 81% in average F measure.

듀얼 반사판을 이용한 광대역 보우타이 슬롯 안테나

이재성,이상우,Lee Jae-Sung,Lee Sang-Woo 한국정보통신학회 2006 한국정보통신학회논문지 Vol.10 No.8

In this paper, we have fabricated and tested a broad band bow-tie slot antenna with dual reflector. If we put 1/2 length thin and long slot on a wide metal plate, the slot antenna radiates efficient and strong radio wave as same as 1/2 dipole antenna does. we made with bow-tie form slot which has wider broad band than normal rectangular slot. At first, we made and test a single reflector slot antenna. To enlarge the broad band, we inserted another reflection plate between the slot antenna and reflection plate. After the test, we could have known that the low band(VSWR<2.0) has about $22%(793MHz\sim992MHz)$, high band(VSWR<2.0) has about 61% (1626MHz\sim3064MHz). 이 논문은 듀얼 반사판을 이용한 광대역 보우타이 슬롯 안테나를 제작 실험 했다. 슬롯 안테나는 넓은 도체판에 약 1/2 길이의 가늘고 긴 슬롯을 뚫게 되면 반파장 다이폴과 마찬가지로 효율이 좋고 강한 전파가 복사된다[1] 이 논문에서는 보통 사각 슬롯 보다 대역폭이 넓은 보우타이 형태의 슬롯으로 제작하였다. 먼저 단일 반사판 슬롯 안테나를 제작 실험 측정하였으며 제작된 단일 반사판 슬롯 안테나에 또 하나의 반사판을 슬롯 안테나와 반사판 사이에 삽입함으로서 대역폭을 확장하였다. 제작 실험 결과 VSWR<2.0 이하인 Low Band 대역폭은 약 $22%(793MHz\sim992MHz)$ 대역폭을 가졌으며 High Band 대역폭은 약 $61%(1626MHz\sim3064MHz)$의 대역폭을 가짐을 실험을 통해 알 수 있었다.

금은화(金銀花)가 Bleomycin에 의한 폐섬유화(肺纖維化)에 미치는 영향(影響)

이재성,정희재,정승기,이형구,Lee Jae-Sung,Jung Hee-Jae,Jung Sung-Ki,Rhee Hyung-Goo 대한한방내과학회 2004 大韓韓方內科學會誌 Vol.25 No.1

Objective : Idiopathic Lung Fibrosis(IPF) is chronic fibrotic interstitial pneumonia. The pathogenesis is unclear. Lonicerae Flos is known to prevent the inflammation and reinforce the immune system. The effects of Lonicerae Flos on bleomycin-induced lung fibrosis is evaluated. Material and Methods: Lonicerae Flos extract was given to the Normal rats, control(bleomycin) rats everyday and treated(bleomycin and lonicerae flos) rats 21.0 mg per body weight 109 for 14 days. 14 days after, we observed the change of leukocyte count and percentage of IFN-gamma and IL-4 in BALF. and that of Semiquantative histological index(SHI). Results : Compared to control rats, Lonicerae Flos decreased leukocyte count(P<0.01) lymphocyte, neutrophil percentage(P<0.05), SHI(P<0.01), IFN-gamma and IL-4(P<0.05) in Treated rats. Otherwise, macrophage percentage was increased(P<0.01) in Treated rats. Conclusion : This study showed that Lonicerae Flos reduced the change of inflammatory cells and cytokines in bleomycin-induced lung fibrosis and reduced the fibrosis of tissue. And, we needed many other distinct researches on lung fibrosis.

H2 15O 양전자단층촬영술을 이용한 뇌기능 지도 작성 ( II ) - 작업 기억의 지도 작성

이재성,이동수,이상건,남현우,김석기,박광석,정재민,정준기,이명철 ( Jae Sung Lee,Dong Soo Lee,Sang Kun Lee,Hyun Woo Nam,Seok Ki Kim,Kwang Suk Park,Jae Min Jeong,June Key Chung,Myung Chul Lee ) 대한핵의학회 1998 핵의학 분자영상 Vol.32 No.3

Purpose: To localize and compare the neural basis of verbal and visual human working memory, we erforrned functional activation study using H2O PET. Materials and MethoDs: Repeated H213O PET scans with one control and three different activation tasks were performed on six right-handed narmal volunteers. Each activation task was composed of 13 matching trials. On each trial, four targets, a fixation dot and a probe were presented sequentially and subjects task was to press a response button to indicate whether or nat the probe was one of the previous targets. Short meaningful Korean words, simple drawings and monochromic pictures of human faces were used as matching objects for verbal or visual memory. All the images were spatially normalized and the differences between control and activation states were statistically analyzed using SPM96. Results: Statistical analysis of verbal memory activation with short words showed activation in the left Broca's area, premotor cortex, cerebellum and right cingulate gyrus. In verbal memory with simple drawings, activation was shown in the larger regions including where activated with short words and left superior temporal cortex, basal ganglia, thalamus, prefrontal cortex, anterior portion of right superior temporal gyrus and right infero-lateral frontal cortex. On the other hand, the visual memory task activated predominantly right-sided structures, especially inferior frontal cortex, supplementary motor cortex and superior parietal cortex. Conclusion: The results are :consistent with the hypothesis of the laterality and dissociation of the verbal and visual workmg memory from the invasive electrophysiological studies and emphasize the pivotal role of frontal cortex and cingulate gyrus in working memory system. (Korean J Nucl Med 1998;32:238-49)

한영 혼용문에서 괄호 안 대역어구의 자동 인식

이재성,서영훈,Lee, Jae-Sung,Seo, Young-Hoon 한국정보처리학회 2002 정보처리학회논문지B Vol.9 No.4

한영 혼용문에서 번역된 전문용어 등을 사용할 때, 이해를 돕기 위해 그 뒤의 괄호 안에 원어 풀이를 함께 쓰는 경우가 많다. 본 논문에서는 괄호가 사용된 구가 대역어구 관계인지를 판단하고, 어느 범위까지 대역어구인지를 기본사전을 이용하여 확률적으로 계산하고 인식하는 방법을 제시한다. 특히, 사전에 표제어로서 혹은 대역어로서 존재하지 않는 단어들을 처리하기 위해 음운유사도 일치, 대역어 부분일치의 방법과 복합어 처리를 위해 부분일치 방법을 새로 제안하였다. 각 방법들을 단계별로 실험하여 0.4F값$(\alpha$를 0.4로 설정한 F값)으로 측정한 결과, 기본 실험 방법인 사전 대역어 완전일치방법의 경우 23.8%인데 비해, 대역어 부분일치와 음운유사도 일치를 흔합한 방법이 75.9%, 복합어 처리를 추가한 방법이 77.3%의 값을 보여 성능이 최고 3.25배 향상되었다. In Korean-English mixed documents, translated technical words are usually used with the attached full words or original words enclosed with parenthesis. In this paper, a collective method is presented to recognize and extract the translation phrases with using a base translation dictionary. In order to process the unregistered title words and translation words in the dictionary, a phonetic similarity matching method, a translation partial matching method, and a compound word matching method are newly proposed. The experiment result of each method was measured in F-measure(the alpha is set to 0.4) ; exact matching of dictionary terms as a baseline method showed 23.8%, the hybrid method of translation partial matching and phonetic similarity matching 75.9%, and the compound word matching method including the hybrid method 77.3%, which is 3.25 times better than the baseline method.

활성탄에 의한 CFC - 113 의 흡착특성에 미치는 Presorbed Water 의 영향

이재성,전해수,조성용,이윤용 ( Jae Sung Lee,Hai Soo Chun,Sung Yong Cho,Youn Yong Lee ) 한국화학공학회 1996 화학공학의이론과응용 Vol.2 No.1

한약(韓藥)이 임신중(妊娠中) 태아(胎兒)에 미치는 영향(影響) ( I ) - 동의보감중(東醫寶鑑中) 임신병(妊娠病) 치료(治療)에 사용(使用)된 처방(處方) 및 약물(藥物)에 관(關)한 연구(硏究) -

이재성,장준복,송병기,Lee, Jae-Sung,Jang, Jun-Bock,Song, Byoung-Key 대한한의학회 1998 대한한의학회지 Vol.19 No.2

Medication used during pregnancy may affect the growth of fetus and maintenance of pregnancy so that it may cause fetal deformity or abortion. Before 1940 it was recognized that only genetic factor could affect the incidence of fetal deformity and the teratogen was protected by placenta barrier. But since the report that Thalidomide caused phocomelia was announced in l962 and 1962, it was acknowledged that the placenta barrier was imperfect. In oriental medical care, there were so many prescription used during pregnancy for nausea, threatened abortion, recurrent spontaneous abortion and it was acknowledged that those medication did not harm both maternity and fetus. Most of them are composed of the material that was not classified as prohibition during pregnancy. But we thought that it should be demonstrated through objective methods that these materials do not affect the incidence of fetal deformity or abortion and have the effect of preventing abortion and maintenance of pregnancy. As the first step of that study we researched 78 prescription and each materials, their kinds and using frequency, used for illness and symptoms during pregnancy written in Dongeuibokam(東醫寶鑑) so that we got to know the tendency about what materials are used for each illness and symptoms.