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      • KCI등재

        한우에 있어서 유전체 육종가 추정

        이승환,김형철,임다정,당창권,조용민,김시동,이학교,이준헌,양보석,오성종,홍성구,장원경,Lee, Seung Hwan,Kim, Heong Cheul,Lim, Dajeong,Dang, Chang Gwan,Cho, Yong Min,Kim, Si Dong,Lee, Hak Kyo,Lee, Jun Heon,Yang, Boh Suk,Oh, Sung Jong,Hong, S Institute of Agricultural Science 2012 Korean Journal of Agricultural Science Vol.39 No.3

        Genomic breeding value (GEBV) has recently become available in the beef cattle industry. Genomic selection methods are exceptionally valuable for selecting traits, such as marbling, that are difficult to measure until later in life. One method to utilize information from sparse marker panels is the Bayesian model selection method with RJMCMC. The accuracy of prediction varies between a multiple SNP model with RJMCMC (0.47 to 0.73) and a least squares method (0.11 to 0.41) when using SNP information, while the accuracy of prediction increases in the multiple SNP (0.56 to 0.90) and least square methods (0.21 to 0.63) when including a polygenic effect. In the multiple SNP model with RJMCMC model selection method, the accuracy ($r^2$) of GEBV for marbling predicted based only on SNP effects was 0.47, while the $r^2$ of GEBV predicted by SNP plus polygenic effect was 0.56. The accuracies of GEBV predicted using only SNP information were 0.62, 0.68 and 0.73 for CWT, EMA and BF, respectively. However, when polygenic effects were included, the accuracies of GEBV were increased to 0.89, 0.90 and 0.89 for CWT, EMA and BF, respectively. Our data demonstrate that SNP information alone is missing genetic variation information that contributes to phenotypes for carcass traits, and that polygenic effects compensate genetic variation that whole genome SNP data do not explain. Overall, the multiple SNP model with the RJMCMC model selection method provides a better prediction of GEBV than does the least squares method (single marker regression).

      • KCI등재

        비납계 0.98 (Na<sub>0.44</sub>K<sub>0.52</sub>)Nb<sub>0.84</sub>O<sub>3</sub>-0.02Li<sub>0.04</sub> (Sb<sub>0.06</sub>Ta<sub>0.1</sub>)O<sub>3</sub>-0.5 mol%CuO 세라믹스의 전기적, 구조적 특성

        이승환,남성필,이성갑,이영희,Lee, Seung-Hwan,Nam, Sung-Pill,Lee, Sung-Gap,Lee, Young-Hie 한국전기전자재료학회 2011 전기전자재료학회논문지 Vol.24 No.2

        The 0.98 ($Na_{0.44}K_{0.52})Nb_{0.84}O_3-0.02Li_{0.04}$ ($Sb_{0.06}Ta_{0.1})O_3-0.5$ mol%CuO ceramics have been fabircated by ordinary sintering technique and the effect of various calcination method on the electrical propertis and microstructure have been studied. It was observed that the various calcination method influenced the elelctrical properties and structural properties of the 0.98NKN-0.02LST-0.5 mol%CuO ceramics with the optimum piezoelectric constant ($d_{33}$) and electromechanical coupling factor ($k_p$) at room temperature of about $155{\rho}C/N$ and 0.349, respectively, from 0.98NKN-0.02LST-0.5 mol%CuO ceramics sample. The curie temperature ($T_c$) of this ceramic was found at $440^{\circ}C$. The 0.98NKN-0.02LST-0.5 mol%CuO ceramics are a promising lead-free piezoelectric ceramics.

      • SCOPUSKCI등재

        표준 항암화학요법에 실패한 진행성 비소세포폐암에서 ZD1839 ($Iressa^{TM}$)의 효과

        이승환,김덕룡,이상대,이종신,박연희,류백렬,김흥태,박선후,김봉석,김철현,이재철,Lee, Seung Whan,Kim, Duck Ryung,Lee, Sang Dae,Lee, Jong Sin,Park, Yeon Hee,Ryoo, Baek-Yeol,Kim, Heung Tae,Park, Sunhoo,Kim, Bong Seog,Kim, Cheol Hyeon,Lee, 대한결핵및호흡기학회 2004 Tuberculosis and Respiratory Diseases Vol.57 No.2

        배 경 : 비소세포폐암에서 2차 항암화학요법에 대한 치료반응과 역할은 아직 정립되어 있지 못한 실정이다. 한편, 최근 개발된 ZD1839는 상피세포성장인자 수용체 억제제로서 악성 고형 종양, 특히 비소세포폐암에서 항종양효과를 보이는 것으로 알려져 있다. 저자들은 기존의 표준 항암화학요법에 실패한 진행성 비소세포폐암 환자들을 대상으로 ZD1839를 투여하여 그 반응 및 안전성을 평가하고자 하였다. 대상 및 방법 : 원자력병원에서 비소세포폐암으로 조직학적 진단을 받고 임상 병기 IIIB 이상인 환자들 중에서 1차 이상의 항암화학요법을 시행 받은 후 치료실패로 판정된 환자들을 대상으로 2002년 1월부터 2003년 9월까지 ZD1839를 투여 하였다. 투여 용량은 하루 250 mg이었고, 반응 및 부작용을 평가하기 위해 1개월 간격으로 흉부 방사선 검사 및 외래 추적 검사를 실시하였다. 이 환자들 중 반응 및 독성의 평가가 가능하였던, 1개월 이상 투여 받은 83명의 환자들을 대상으로 하였다. 환자들의 중앙 연령은 59(33-76)세였고, 임상 병기는 IIIB가 12명, IV가 71명이었으며, ECOG 전신수행상태는 0-1이 10명, 2는 42명, 3은 31명이었다. ZD1839 투여일수는 중앙값이 90일이었다. 결 과 : ZD1839 투여 후 부분 반응은 12명(14.5%), 불변은 31명(37.3%), 진행은 40명(48.2%)이었고, 전체 생존기간과 병의 진행까지 기간의 중앙값은 각각 9.2 개월과 3.1 개월이었다. ZD1839의 부작용으로는 피부 발진을 보인 환자가 25명(25.8%)으로 가장 많았으며, 구토 및 설사를 보인 환자가 15(15.5%), 비정상적 간효소수치 상승 및 혈소판 감소를 보인 환자가 각각 1명(1.03%)이었다. Performance status 0, 1인 전신 상태와 선암종을 가진 환자군에서 반응률 및 생존률이 통계적으로 유의한 증가를 보였다. 결 론 : 기존의 항암화학요법에 실패한 일부 진행성 비소세포폐암 환자들에서 ZD1839 투여는 비교적 높은 반응률을 보였으며 부작용은 비교적 경미하였다. 향후 보다 대규모의 연구 결과에 대한 추시가 필요할 것으로 생각된다. Background : The role of second-line chemotherapy in the treatment of advanced non-small cell lung cancer (NSCLC) is known to be limited. Recently, ZD1839, the small molecule epidermal growth factor receptor-tyrosine kinase inhibitor, has been developed and has shown anti-tumor activity in patients with solid malignant tumors including lung cancer. We evaluated the response rate and toxicities of ZD1839 in patients with advanced NSCLC which has progressed after previous chemotherapy. Patients and Methods : We examined 83 patients with advanced NSCLC treated with ZD1839 for more than 1 month in Korea Cancer Center Hospital during the period from January 2002 to September 2003. All the patients were enrolled in the international expanded access program (EAP) with ZD1839 by AstraZeneca. The administered dose of ZD1839 was 250 mg once daily. Chest radiography and laboratory tests were followed-up. We evaluated the response rate, median survival, and toxicity after treatment. Results : Median age of the patients was 59 years (range 33-76). The most predominant cell type was adenocarcinoma and the most stage of the patients was IV. ECOG performance status was as follows; grade 0-1 in 10, grade 2 in 42, and grade 3 in 31 patients. Partial response was achieved in 12 patients (14.5%). Median overall survival was 9.2 (range 1.3-21.6+) months and median time to progression was 3.1 (range 1-21.2+) months. The most common adverse effect of ZD1839 was skin eruption which developed in 25 patients (25.8%). Significantly higher response rate and survival was found in patients with adenocarcinoma or good performance status. Conclusion : ZD1839 showed modest activity and tolerable toxicity in the treatment for patients with NSCLC which has progressed after previous chemotherapy.

      • KCI등재

        ZnO와 CuO 첨가에 따른 NKN-LST 세라믹스의 압전 특성

        이승환,이성갑,이영희,Lee, Seung-Hwan,Lee, Sung-Gap,Lee, Young-Hie 한국전기전자재료학회 2011 전기전자재료학회논문지 Vol.24 No.8

        Additions (ZnO, CuO) doped $0.98(Na_{0.5}K_{0.5})NbO_3-0.02Li(Sb_{0.17}Ta_{0.83})O_3$ (0.98NKN-0.02LST-x) lead free piezoelectric ceramics have been fabricated by ordinary sintering technique. The effects of additions doping on the dielectric, piezoelectric, and ferroelectric properties of the ceramics were mainly investigated. X-ray diffraction of the sample appeared orthorhombic phase. The specimen doped with additions exhibits enhanced electrical properties ($d_{33}$= 153 pC/N). These results indicate that the 0.98NKN-0.02LST-x ceramics is a promising candidate for lead-free piezoelectric ceramics for applications such as piezoelectric actuators, harmonic oscillator and so on.

      • 병원종사자의 VDT증후군 자각증상과 건강영향에 관한 연구

        이승환,정병곤,이규찬,이광철,배성복,Lee, SeungHwan,Jeong, Byeong Gon,Lee, Gyu Chan,Lee, Gwang Cheol,Bae, Seong Bock 대한핵의학기술학회 2012 핵의학 기술 Vol.16 No.2

        Purpose : This study aims to examine hospital employees' subjective symptoms of VDT syndrome (Video display terminal syndrome) and figure out their effects on health conditions and correlations. Materials and Methods : This study used a structured self-administering questionnaire and gained data from 125 subjects. The questionnaire consists of total 62 questions, and they went through real number, percentage, ${\chi}^2$-terst, t-test, one-way ANOVA, and logistic regression analysis. Results : Regarding the difference in the types of subjective symptoms of VDT syndrome by jobs, there was statistically significant difference in ophthalmic symptoms, systemic symptoms, and musculoskeletal symptoms. About the correlation between the subjective symptom points of VDT syndrome by the types of symptoms, there was statistically significant correlation all in skin trouble, backache, upper limb muscle pain, lower limb muscle pain, fatigue in the head and eyes, and depression or anxiety disorders. There was significant correlation between the subjective symptom points of VDT syndrome and subjective health conditions. Conclusion : Hospital employees' subjective health conditions had significant correlation with subjective symptom points of VDT syndrome. This result shows that as radiologists' and also other hospital employees' working conditions change into VDT environment, VDT syndrome gradually appears more and more. This implies that it is needed to designate not only radiologists but also all the other hospital employees as jobs exposed to the working environment of VDT syndrome and provide preventive measures, education, and publicity for it afterwards.

      • PET/CT 검사에서 Stomach의 추가 촬영을 줄이기 위한 수분 섭취의 유용성

        이승환,배성복,정병곤,이규찬,이광철,배원규,Lee, Seung-Hwan,Bae, Seong-Bok,Jeong, Byeong-Gon,Lee, Gyu-Chan,Lee, Gwang-Cheol,Bae, Won-Gyu 대한핵의학기술학회 2011 핵의학 기술 Vol.15 No.1

        암 환자의 영상에서 stomach의 병변과 분비물을 구분하기란 쉽지 않다. 이 연구의 목적은 검사 전 충분한 수분 섭취로 stomach의 병변과 분비물의 분별력을 높임으로서 추가 촬영을 줄이기 위하여 시행하였고 본 연구는 총 228명의 암 환자로 2010년 8월 18일부터 2010년 9월10일까지 진행하였으며, 2010년 8월 18일부터 2010년 8월 31일까지는 수분섭취 제한환자가 115명이었고, 2010년 9월 1일부터 2010년 9월 10일까지는 촬영 직전 수분을 500 cc 정도 섭취한 후 검사를 진행한 환자로 113명이었다. 이 검사를 시행한 결과 전체 암 환자 228명을 대상으로 촬영 수분 섭취 제한 환자는 총 115명이고, 이중 추가 촬영이 없는 환자가 89명이었고, stomach 추가 촬영을 진행한 환자가 13이었으며, 기타 추가 촬영을 진행한 환자는 13명이었다. 그리고 촬영 직전 수분을 500 cc 정도 섭취한 후 검사를 진행한 환자 113명 중 추가 촬영이 없는 환자가 109이었고, stomach 추가 촬영을 진행한 환자가 1명이었으며, 기타 추가 촬영을 진행한 환자는 3명에 해당하였다. 이와 같은 결과로도 수분을 500 cc 정도 섭취하고 검사를 진행한 환자에게서 추가 촬영이 줄었음을 알 수 있었으나, 정확한 유의성을 알기 위하여 pearson의 chi-square test를 시행한 결과 유의확률이 0.05보다 작은 0.001이었으므로 두 집단은 유의한 관련성이 있음을 알 수 있고 최소 기대빈도가 6.94로서 5보다 작은 기대빈도가 없었으므로 pearson의 정확한 검정을 할 필요는 없었고, 위의 연구로 인하여 물을 검사 직전 약 500 cc 정도 섭취하고 촬영을 진행하면 stomach 추가 촬영을 현저히 줄일 수 있으며 기타 추가 촬영 또한 줄일 수 있음을 알 수 있었고 검사 지연 시간 또한 줄일 수 있을 것으로 사료된다. Purpose: With the introduction of PET since 1994, test methods have made rapid progress. Accordingly, the studies on the diagnosis and treatment of cancer as well as treatment response evaluation PET test are useful. However, it is difficult to divide stomach lesions and secretion. The purpose of this study is to reduce additional shooting by dividing lesions and secretion of stomach. Materials and Method: This study aiming at total 228 cancer patients was conducted from Aug 18 to Sep. 10, 2010. Among them, 115 patients had a test without water intake before shooting from Aug. 8 to 31 and 113 had a test after drinking 500 cc water right before shooting from Sep. 1 to 10 The Discovery ST PET/CT (GE Healthcare, USA) was used, and pearson's chi-square test was conducted to analyze significance through SPSS (Ver.18). Results: Among the total 228 cancer patients, there were 115 who had a test without water intake before shooting, 89 who had no double additional shooting, 13 who had stomach additional shooting and 13 who had other additional shooting. In addition, 109 had no additional shooting among 113 who had a test after taking 500 cc water, 1 had stomach additional shooting and 3 had other additional shooting. According to the findings above, the patients who had a test without water intake show reduced additional shooting, but for more exact significance, pearson's Chi-square test was carried out and the significance percentage was 0.001 that is smaller than 0.05, which means two groups have a significant relationship. As the minimum expectation frequency was 6.94 and there was no expectation frequency smaller than 5, so that it doesn't need to carry out pearson's exact verification. Conclusion: The above analysis has found that if one drinks 500cc water before the test, not only stomach additional shooting but also other additional shooting can be dramatically reduced, and test delay can be also reduced.

      • 지능형 U-Car에서 IEEE 802.11b을 이용한 차량 내 데이터 무선 랜 전송 성능 분석

        이승환,허수정,박용완,이상신,이동학,유재황,Lee Seung-Hwan,Heo Soo-Jung,Park Yong-Wan,Lee Sang-Shin,Lee Dong-Hahk,Yu Jae-Hwang 대한전자공학회 2006 電子工學會論文誌-TC (Telecommunications) Vol.43 No.9

        본 논문에서는 지능형 차량을 위한 차량네트워크를 IEEE 802.11b 무선 랜을 사용하여 구현하였을 때 간섭신호와 차량에서 발생하는 노이즈에 의한 영향을 확인하고 시스템의 안정성 여부를 판단한다. 무선 랜의 AP와 ME간의 통신을 지능형 차량의 차량 네트워크의 중앙 제어기와 센서, ECU, 구동계 장치 간의 통신이라고 가정하였을 때 다른 차량에서 사용하는 무선 차량 네트워크의 신호가 간섭으로 작용할 수 있다. 또한 차량 내부에서 발생하는 자동차 노이즈 또한 무선 차량 네트워크 시스템에 영향을 줄 수 있다. 본 연구에서는 외부 차량에서 송신된 신호가 다른 차량에게 간섭으로 작용하였을 패 간섭 수신신호의 세기에 따른 BER(Bit Error Rate)를 확인하였고 차량 내부에서 발생하는 차량 노이즈의 종류를 항상 영향을 주는 White type과 특정 시간에만 영향을 미치는 Spark type 노이즈로 구분하여 시스템에 주는 BER 영향을 확인하였다. 이를 통해 지능형 차량을 구성하기 위한 무선 차량 네트워크를 IEEE 802.11b 무선 랜으로 구현하였을 때 시스템의 안정성을 시뮬레이션을 통하여 확인하였다. In this paper, we analyze the performance of IEEE 802.11b WLAN communication between access point(AP) and mobile equipment(ME) in 2.4 GHz band with noise and interference factors. WLAN communication at in-vehicle environment is assumed as the communication between main vehicle controller and electronic device such as sensor, ECU (Electrical Control Unit) in vehicle on telematics field for implementing wireless vehicle control system. Received interference level from other system's mobile equipment in the same band and automobile noise from each part of vehicle can be the main factors that can cause increasing error rate of control signal. With these (actors, we focus on the Eb/No the BER performance of WLAN for analyzing the characteristic of interference factors by the measured bit error rate.

      • KCI등재

        NKN-(1-x)BNT-xBT 세라믹스의 압전 및 유전특성

        이승환,남성필,이성갑,이영희,Lee, Seung-Hwan,Nam, Sung-Pill,Lee, Sung-Gap,Lee, Young-Hie 한국전기전자재료학회 2010 전기전자재료학회논문지 Vol.23 No.10

        In this study, piezoelectric and dielectric properties of the $(Na_{0.5}K_{0.5})NbO_3-(1-x)(Bi_{0.5}Na_{0.5})TiO_3-xBaTiO_3$ [NKN-(1-x)BNT-xBT] ceramics were investigated. The lead-free NKN-(1-x)BNT-xBT ceramics were fabricated by a conventional mixed oxide method. The results indicate that the addition of $BaTiO_3$ significantly influences the sintering, microstructure, phase transition and electrical properties of NKN-BNT ceramics. A gradual change in the piezoelectric and dielectric properties was observed with the increase of BT contents. The dielectric constant, piezoelectric constant ($d_{33}$) and electromechanical coupling factor ($k_p$) increased at the morphotropic phase boundary (MPB). The $d_{33}$=184 pC/N, $k_p$=0.38, dielectric constant=1455 with dielectric loss value of less than 1% were obtained for the NKN-0.95BNT-0.05BT ceramics sintered at $1150^{\circ}C$ for 2h. These results demonstrate that the NKN-(1-x)BNT-xBT ceramics is an attractive candidate for lead-free piezoelectric materials.

      • KCI등재

        CuO와 ZnO 첨가에 따른 NKN-BZT 세라믹스의 압전 특성

        이승환,백상돈,이동현,이성갑,이영희,Lee, Seung-Hwan,Baek, Sang-Don,Lee, Dong-Hyun,Lee, Sung-Gap,Lee, Young-Hie 한국전기전자재료학회 2011 전기전자재료학회논문지 Vol.24 No.8

        The lead-free $0.98(Na_{0.5},K_{0.5})NbO_3-0.02Ba(Zr_{0.52},Ti_{0.48})O_3$-(hereafter NKN-BZT) CuO, ZnO-doped ceramics were prepared using a conventional mixed oxide method. NKN-BZT ceramics doped CuO, ZnO have superior structural and electrical properties than pure NKN-BZT ceramics. For the NKN-BZT-ZnO ceramics sintered at $1,120^{\circ}C$, piezoelectric constant ($d_{33}$) of sample showed the optimum values of 172 pC/N. The $0.98(Na_{0.5},K_{0.5})NbO_3-0.02Ba(Zr_{0.52},Ti_{0.48})O_3$-ZnO ceramics are a promising candidate for lead-free piezoelectric materials.

      • KCI등재

        알루미늄 하부층이 탄소나노튜브의 성장 및 전계방출 특성에 미치는 영향

        이승환,곽정춘,이한성,이내성,Lee, Seung-Hwan,Goak, Jeung-Choon,Lee, Han-Sung,Lee, Nae-Sung 한국전기전자재료학회 2008 전기전자재료학회논문지 Vol.21 No.2

        We studied the effect of an Al underlayer on the growth of carbon nanotubes (CNTs) and their field emission characteristics, First of all, CNTs were grown on the Invar catalyst layers with different thickness of 1 to 10 nm, showing that the CNT length was saturated for the catalyst 5 nm or thicker. The CNTs grown on the 5-nm-thick catalyst were ${\sim}10{\mu}m$ long and ${\sim}30nm$ in diameter. Second, an Al underlayer was applied between the catalyst layer and the Ti diffusion barrier to reduce the diameters of CNTs for better field emission properties by forming spherical Al oxide particles on which smaller catalyst nanoparticles would occur. The optimal thickness of an Al underlayer underneath the 5-nm-thick catalyst was ${\sim}15nm$, producing the CNTs with the length of ${\sim}15{\mu}m$ and the diameter of ${\sim}15nm$. The field emission measurements, following the tape activation, showed that the thinner and longer CNTs gave rise to better field emission performance with the lower turn-on and threshold electric fields.

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