적응 알고리즘을 이용한 DS/CDMA 간섭제거

문병현,손준일,이채욱 대구대학교 과학기술연구소 1998 科學技術硏究 Vol.5 No.2

A DS/CDMA receiver with adaptive filter has more benefit than conventional DS receiver, such as near-far problem, multiuser interference rejection and artificial jamming. Usually in the CDMA receiver, filter length is same as spreading sequence length. So the more PN sequence length, the more number of calculation is needed for convergence. Recently, partial update algorithm like SNLMS or SBNLMS is proposed to resolve this problem. But these algorithms have defect that convergence is slow because of partial updating. We propose the effective adaptive algorithm for DS/CDMA multiuser interference rejection and show the correlation between the number of block and convergence in selective coefficient update algorithm.

우울증 관련 평가도구의 개관

조현주,채정호,전태연 大韓神經精神醫學會 2007 신경정신의학 Vol.46 No.2

Objective : Since a lot of assessment tools for depression have been developed and used, it is difficult to choose the proper and optimal instruments for the purpose of their usage, In order to maximize the effectiveness of assessment for depression, this paper reviewed the characteristics and specific features of currently using tools. Method : The domestically and internationally using assessment tools for depression were reviewed and classified by litera-hire search and clinical experience. Results : Methods of assessment, selecting guides and characteristics of assessment tools for depression were presented. Conclusion : This paper would provide helpful guidelines for selecting the assessment tools. We suggest that it is needed to develop the assessment tools for depression that reflects Korean specific culture and custom.

인체의 수동적 전기특성 계측법 개발

이현철,윤재현,박형준 원광대학교 공업기술개발연구소 2003 工業技術開發硏究誌 Vol.23 No.-

In this study, a system for the method measuring of passive electrical properties in the human body was developed. The system was composed of the stimulating part for input with voltage(about 2[㎷]) and of the measuring part for measurement of electrical properties in human body. As a result of this experiment, the frequency characteristic of each subject represent that the electrical properties goes up in spite of a constant stimulate-voltage according to frequency (l[㎐]-50[㎑]) increment. Namely, the amplitude of stimulate-signal was not reflected but frequency was reflected on the measured results. This result be estimated that the proposed system is able to measure the passive electrical properties of human body. Also, it would be estimated neural signal propagation directions by using the method developed in this study was measured passive electrical properties in each part of body.

Fe-Cr-Si과 Fe-Cr-Pt 합금의 고온 cyclic 산화거동에 관한 연구

임채선,조현준,최송천,이동복 成均館大學校 科學技術硏究所 1994 論文集 Vol.45 No.1

To investigate the cyclic oxidation behavior of Fe-Cr-Si and Fe-Cr-Pt alloys, both (82-94)wt% Fe-(5-15)wt% Cr--(1-3)wt% Si and (82-94)wt% Fe--(5-15)wt% Cr-(1--3) wt%Pt alloys were cyclically oxidized in air at 1000 and 1250℃. By the addition of Si or Pt, the oxidation resistance of Fe-Cr alloys was generally increased with the most pronouncing effects observed in Fe-15wt%Cr containing alloys. After oxidation, on the surface of Fe-Cr--Si alloys, complex oxide layers of Fe_20_3/Fe-Cr spinel/Si-rich oxide were formed, which provides the necessary oxidation resistance. Especially, Fe-15wt%Cr-3wt%Si alloys had best oxidation resistance because the inward diffusion of oxygen was considerably deterred owing to the formation of the protective inner Si0_2 layer from the initial oxidation stage. In Fe-Cr-Pt alloys, oxidation resistance was obtained by forming protective Cr_2 O_3 layers below initially formed outer Fe_2 0_3, layers. However, Fe-Cr-Pt alloys showed decreased oxidation resistance at 1250℃ compared with Fe-Cr-Si alloys.

관상동맥질환의 중증도와 혈중지질치 및 아포지단백과의 상관관계

임현주,황종현,류재근,정병천,조용근,채성철,전재은,박의현 慶北大學校 醫科大學 1997 慶北醫大誌 Vol.38 No.1

목적 : 관상동맥질환의 위험인자로서 혈청지질 및 혈장 지단백에 대한 관심이 높아지고 있고 또 아포지단백이 관상동맥 질환을 일으키는데 다른 지질보다 더 중요하다는 연구가 많이 발표되고 있으나 우리나라에서는 아포지단백에 대한 연구가 그리 많지 않은 편이다. 이에 저자등은 혈중지질치와 새로운 위험인자로 알려지고 있는 아포지단백치를 측정하고 이들과 관상동맥질환 중증도와의 상관 관계를 알아보았다. 대상 및 방법 : 관상동맥질환이 의심되어 관상동맥조영술을 실시한 69명의 환자를 대상으로 하였으며 12시간 이상 공복후 혈청을 채취하여 총콜레스테롤, 중성지방, HDL-콜레스테롤, 아포지단백 AI (ape AI), 아포지단백 B (ape B)를 측정하였다. 관상동맥조영상 50%이상의 협착이 있는 혈관의 수 (lesion number), 최대협착을 합한 값 (lesion score), 각 분절의 최대협착을 합한 값 (total score), 가장 심한 협착 값 (peak stenosis) 등으로 관상동맥 중증도를 알아본 다음 이들과 혈청지질치, 아포지단백과의 상관 관계를 비교해 보았다. 상관 관계는 Spearman's correlation coefficient를 구하였다. 결과 : 관상동맥질환의 중증도와 각 지질치 간의 상관 관계를 비교해 보았을때 lesion number와 관계있는 것은 연령 (r=0.2789), 중성지방치 (r=0.2829)이며 lesion score와 관계있는 것은 연령(r=0.2911), 중성지방치0 (r=0.3316), 총콜레스테롤과 HDL-콜레스테롤의 비 (r=0.2361), apo B 치(r=0.2759), apo AI과 apo B의 비 (-0.3154)로 나타났다. Total score는 연령 (r=0.3100), 총콜레스테롤치 (r=0.2452), 중성지방치 (r=0.3022), 총콜레스테롤과 HDL-콜레스테롤의 비 (r=0.2770), apo B치 (r=0.2927), apo AI과 apo B의 비 (r=-0.3408)와 연관이 있었고 peak stenosis는 중성지방 치(r=0.3305), ape B 치 (r=0.2968), apo AI과 apo B의 비 (r=-0.3977)와 관계가 있었다. 연령으로 조정하여 partial correlation을 좌면, 관상동맥조영술상 중증도는 중성지방치 (r=0.3408), apo B 치(r=0.2877), apo AI과 apo B의 비 (r=-0.3460)와 유의한 상관 관계가 있었다. 이중 ape AI과 ape B의 비는 lesion score (r=-0.2640), total score (r=-0.3057), peak stenosis (r=-0.3460)와 유의한 상관관계를 보였다. 결론 : 이상의 결과로 보아 apo B치 그리고 apo AI과 apo B의 비가 관상동맥 중증도의 예견인자로 다른 혈중 지질 치보다 더 유용하다는 것을 알 수 있었다. Objectives : Recently, it was reported that the measurements of apolipoprotein levels may be valuable in the clinical assessment of coronary artery disease severity. However there are a few reports regarding to the relationship between coronary artery disease severity and apolipoprotein levels in Korea. Thus, we measured serum lipid and apolipoprotein levels and studied the relationship between coronary artery disease severity and serum lipids and apolipoproteins levels. Subjects and Methods : The 69 patients who underwent coronary angiography to evaluate chest pain were subjected to this study. We measured the levels of serum cholesterol, triglycerides, HDL cholesterol, apolipoprotein AI(apo AI) and apolipoprotein B(Apo B) and measured the severity of coronary artery disease by lesion number, lesion score, total score and peak stenosis. Then, we studied the relationship between coronary artery disease severity and apolipoproteins and calculated the correlation coefficient. Results : The results were as follows. There are significant correlation(r=0.3) between age, triglycerides, apo B levels, apo AI/B ratio and coronary artery disease severity. In controlling for age, tyiglycerides, apo B levels and apo AI/B ratio shows significant correlation(r=0.3) with coronary artery disease severity. Especially, apo AI/B ratio shows significant correlation(r=0.3) with lesion number, total score and peak stenosis. Conclusion : These results suggest that the apo B levels and the ratio of apo AI/B can be used as significant independent predictor for coronary artery disease severity rather than other serum lipid levels.

별'에 대한 초등학교 교사와 학생들의 幼年的 槪念과 核心 信念 비교

오준형,채동현 경북대학교 사범대학 부속 중등교육연구소 2004 중등교육연구 Vol.52 No.1

This article presents the results which investigated elementary school students' and teachers' conceptions about the stars. Samples consisted of one hundred forty eight 5th-grade students, one hundred seventy four 6th-grade students, and thirty eight primary science teachers. Research method was paper-pencil test. Their responses to these questions revealed considerable apparent naive conceptions. and the study results proved that the items showing a high response rate of teachers' childhood concept also resulted in a high response rate of students' naive concept. A great of this apparent inconsistency could be explained by assuming that the students used, a naive core belief of the stars other than a target scientific concept of the stars. And, elementary school students and teachers often held a different naive core beliefs based on their other experiences rather than scientific theories. this paper was also discussed the core beliefs that elementary school students and teachers held to overcome these naive conceptions.

혈관내피세포-U937세포의 부착에 미치는 Eicosapentaenoic Acid의 효과

김은지,전재은,임현주,차성철,정의룡,조용근,조용근 경북대학교 병원 1998 경북대학교병원의학연구소논문집 Vol.2 No.1

연구배경: 역학적연구에서 어류의 섭취가 많은 집단에서 관상동맥질환의 빈도가 낮은 것이 보고되었고, 이것은 어류에 많이 함유된 불포화지방산(polyunsaturated fatty acid) 특히 eicosapentaenoic acid 때문으로 생각되어지고 있다. 본 연구에서는 동맥경화증 발생의 초기단계로 여겨지는 단핵구와 혈관내피세포 사이의 adhesion에 미치는 다불포화지방산의 영향을 in vitro system에서 관찰하고자 하였다. 방 법: 제대정맥에서 얻은 혈관내피세포를 배양하여 96 well에 옮기고 25, 50, 100, 200 ㎛ 농도의 eicosapentaenoic acid(EPA)를 6시간 동안 처리한 U937세포를 부착시켜 adhesion assay를 시행하였다. 혈관내피세포를 자극하기 위해서는 lipopolysaccharide(LPS)를 well당 100 ng씩을 투여하였다. 음성대조군으로는 LPS로 자극하지 않은 혈관내피세포에 EPA처리를 하지 않은 U937세포로 adhesion assay한 성적을 사용했고, 양성대조군으로는 LPS로 자극한 혈관내피세포에 EPA처리를 하지 않은 U937세포로 adhesion assay한 성적을 사용했다. 그리고 EPA(3.3 mM)을 5㎛ CuSO4 및 300 ㎛ asscorbic acid와 혼합하여 섭씨 37도에서 16시간 두어 산화-EPA를 만들어 같은 실험을 반복하였다. 결 과: U937세포에 25, 50, 100, 200 ㎛의 EPA로 6시간 처리하였을 때 U937세포의 생존율은 99% 이상이었다. 혈관내피세포를 LPS로 자극했을 때 adhesion assay에서 혈관내피세포에 붙는 U937세포의 수는 현저히 증가하였다. 그러나 EPA를 U937세포에 25, 50, 100, 200 ㎛의 농도로 6시간 처리 후에 lipopolysac-charide를 처리한 제대정맥 내피세포에 부착(adhesion)시켰을 때 처리한 EPA의 각 농도에 따른 부착된 U937세포의 수는 통계적으로 유의한 차이를 나타내지 못했다. EPA처리가 부착된 U937세포의 수에 영향을 미치지 못하였다. 결 론: EPA는 U937세포에 영향을 미쳐 혈관내피세포-U937 세포부착을 감소시키지는 못하였다. 따라서 EPA에 의한 혈관내피세포-단핵구 부착 억제 효과는 EPA의 단핵구에 미치는 영향에 의하지는 않는 것으로 생각되나 추후 더 많은 연구가 필요하리라 생각된다. Background : Epidemiological studies have shown correlation between low incidence of coronary heart disease and high consumption of fish products. It has been suggested that this may be due to the high content of polyunsaturated fatty acids of the n-3 fatty acid group in fish oil. In animal studies eicosapentaenoic and (EPA) inhibited attachment of monocytes to the arterial endothlium. Method : Adhesion assay was performed on the endothelial cells of the human umbilical vein with 25, 50, 100, 200 ㎛ EPA-treated U937 cells. The endothelial cells were activated with lipopoysaccharide (LPS). The adhesion assay was repeated with oxidized EPA. EPA was oxidized with CuSO4 and ascorbic acid. Result : Viability of U937 cells were not afected by concentrations up to 200 ㎛ of EPAand oxidized EPA. LPS treatment of endothelium notably increased the number of U937 cells attached to endothelial cells on the adhesion assay. However, treatment of EPA, native or oxidized, to U937 cells did not afect the number of U937 cells attached to LPS activated endothelial cells. Conclusion : EPA treatment, native or oxidized, of U937 cells did not affect U937 cell-endothlial cell adhesion. This suggests that inhibition of monocyte-endothlial cells ◎attachment by EPA is not due to the effects of EPS on monocytes.(Korean Circulatin J 1998;28(4):606-610)

Roxythromycin-tylosin-furaltadone 합제의 닭 유래 세균에 대한 시험관내 항균효과

김지영,채미경,윤효인,서상희,박배근,김현수,전무형 충남대학교 수의과대학 동물의과학연구소 2003 動物醫科學硏究誌 Vol.11 No.-

In vitro antimicrobial susceptibility of roxythromycin (Rx), tylosin (Tyl), erythromycin (EM) and furaltadone (Fur) was studied, either by the single type or the combinated type of Rx-Tyl-Fur (RTF) against E. co1i (30 strains), Staph. aureus (20 strains) and Mycoplasma gallisepticum (5 strains) that are the major pathogens in poultry farm. The paper disk diffusion and MIC tests were applied. In screening test by paper disk diffusion method, the single types of antibiotics showed the sensitivity against 55 strains of bacteria in order of Fur, EM, Rx and Tyl. The combinated RTF showed the higher rate of sensitivity (80∼83.3% at 64㎍/disk, 60-75% at 32㎍/disk) and wider range of growth inhibiting zone (19.6±3.7-24.8±4.7mm) than those of the single drugs. In MIC test, the sensitivity against the 55 strains appeared in order of Fur. EM, Rx and Tyl as similar to those of paper disk diffusion method. The MIC ranges of RTF were 0.125∼16㎍/ml for E. coli, 0.25∼16㎍/ml for Staph. aureus and 1-8㎍/ml for Myco. gallisepticum, showing evidently lower than those of the single types. The MIC_(50) and MIC_(90) of RTF were estimated l∼4㎍/ml and 8∼16㎍/ml, respectively, and remarkably lower than those of the single drugs.

간 세포암에서 VEGF, TGF-β1, b-FGF 발현의 의의

김성용,남충현,주종우,채만규,백무준,이문수,김형철,안현철,김홍수,김창진,김창호 순천향의학연구소 2001 Journal of Soonchunhyang Medical Science Vol.7 No.1

Purpose: Angiogenesis is important for the proliferation and the metastasis of solid tumors. The growth of a solid tumor is widely recognized to depend on the process of neovascularrozation. Without angiogenesis, tumors cease to grow beyond even a few milimeters in diameter. It has been shown that tumor vascular density is an independent prognostic marker in several types of human tumors and is known to correlate with poor prognosis. To date, many angiogenic factors have been identified, such as transforming growth factor-α(TGF-α), transforming growth factor-β(TGF-β), fibroblast growth factor family(FGF), vascular endothelial growth factor(VEGF), platelet derived endothelial cell growth factor(PD-ECGF), tumor necrosis factor-α(TNF-α), and angiogenin. Hepatocellular carcinoma(HCC) is the second most common tumor in Korean males and is known as a typical hypervascular tumor with frequent portal vein invastion. The authors identified the expreesion of VEGF, TGF-β1, and b-FGF in HCC specimens and evaluated the relationship between these growth factors and the clinicopathologic characteristics of HCC. Method: We reviewed the medical records of 30 patients who were diagnosed as hepatocellular carinoma treated with hepatic resection between January 1994 and December 1998 in Soonchunhyang University Chunan Hospital. The selection of the cases was decided according to the condition of paraffin block fixation. The prognostic factors such as age, sex, tumor size, concentration of serum α-fetoprotein, presence of liver cirrhosis, presence of tumor emboli in portal vein, TMN stage, amount of transfusion during the operation, hepatitis B virus(HBV) infection, and Edmonson-Steiner(E-S) grade were investigated. Relationship between the prognostic factors and the immunopathologic expression of the TGF-β1, b-FGF, and VEGF was examined. Result: Thirty patients (24 males, 6 females) were included in the current study. The patient's mean age was 50.6 years and the age ranged from 36 to 65 years. The mean size of the tumor was found to be 5.2cm. All the patients were follewed up for 7 to 63 months. Child's classification A patients were 23(76.7%)cases, B patients were 7(23.3%)cases, and C was none. Immunohistochemical staining of HCC tumor mass in VEGF expression patients were 17(56.7%), b-FGF expression patients were 10(33.3%), and TGF-β1 expression patients were 10(33.3%). VEGF expression or more than one positive expression among the three factors correlated with tumor size and the stage of HCC but did not correlated with other clinicopathological characteristics. TGF-β1 and b-FGF did not correlate with any clinicopathological characteristics. Conclusion: The results suggest that the expression of VEGF or more than one positive expression among the three factors in HCC cells may be a significant prognostic factor of HCC.

급성하벽심근경색에서 전흉부유도 ST절 하강의 의의

정병천,배호상,곽동훈,김영태,배용학,황종현,임현주,류재근,조용근,채성철,전재은,박의현 慶北大學校 醫科大學 1997 慶北醫大誌 Vol.38 No.2

목적 : 급성하벽심근경색증 환자에서 심전도상 흔히 동반되는 전흉부유도 ST절 하강의 의의를 알아보았다. 방법 : 심근경색후 24시간에서 48시간에 얻은 심전도를 기준으로 52명의 급성하벽심근경색증 환자를 전흉부유도에서 ST절의 하강이 있는 군과 없는 군으로 나누었으며 심도자, 관상동맥조영술, 심초음파도 및 방사성 핵종을 이용한 좌심구혈율 측정 등을 시행하였다. 결과 : 1) 좌심실확장기말압은 전흉부유도에서 ST절의 하강이 있는 경우에서 16.9±5.33mmHg로 없는 경우의 11.0±4.02mmHg보다 유의하게 높았다(p<0.05). 그러나 운동량 및 좌심구혈을은 흥부 유도상 ST절의 하강이 있는 경우 7.6±3.0 METs 및 53.9±9.1%로 없는 경우의 9.1±2.7 METs 및 54.6±9.5%보다 낮았으나 통계적 유의성은 없었다(p=0.180, p=0.823). 2) 관상동맥조영술상 전흉부 ST절의 하강이 동반된 군에서는 유의한 좌전하행지나 좌회선지의 협착이 있는 경우가 60.9% 및 57.9%로 ST절의 하강이 없는 군에서의 34.5% 및 7.7%와 비교해 좌관상동맥에 협착이 동반된 경우가 많았다(p=0.050, p=0.001). 3) 관상동맥조영술상 세 혈관질환의 빈도는 흉부유도상 ST절의 하강을 보인 23예에서 10예로 ST절 하강이 없었던 29예중 2예에 비하여 유의하게 많았고(P=0.007), 단 혈관질환의 빈도는 ST절의 하강을 보인 군에서 23예중 5예로 ST절 하강이 없었던 29예중 17예에 비하여 유의하게 적었다(P=0.002). 두 혈관질환의 경우에는 각각 8예와 10예로 양군간에 유의한 차이가 없었다. 4) 흉부유도상 ST절 하강의 빈도는 단 혈관질환 22예 중 5예에서, 두 혈관질환 18예중 8예, 세 혈관질환 12예 중 10예에서 관찰되어 협착이 있는 관상동맥의 수가 많을수록 ST절의 하강이 나타나는 빈도가 많음을 보였다(p=0.00308). 그러나 흉부유도상 나타난 ST절의 하강을 모두 합하여 구한 ST절 하강의 합은 협착이 있는 관상동맥의 수와 통계적인 유의성이 없었다. 5) 심초음파도상 좌심실 하벽의 벽운동은 ST절 하강을 보인 군에서는 akinesia가 83.3%, hypokinesia가 11.1%, 정상 벽운동이 5.6%로, ST절 하강이 없었던 군에서의 dyskinesia가 3.6%, akinesia가 39.3%, hypokinesia가 25.0%, 정상 벽운동이 32.1%와 비교하여 ST절의 하강이 있는 군에서 유의하게 벽운동의 장애가 빈번함을 보였다(p=0.03891). 그러나 좌심실전벽, 측벽 및 중격부위에서는 유의한 벽운동의 차이가 없었다. 결론 : 급성하벽심근경색증 환자의 전흉부유도에서 ST절의 하강이 동반되는 경우 다혈관 질환의 가능성이 높으며 좌심실확장기말압이 상승되었고 운동능력은 감소되어 있었다. 또한 심초음파도상 좌심실하벽의 벽운동장애도 심하였다. 따라서 전흉부 ST절의 하강을 동반한 급성하벽심근경색증 환자는 전흉부유도에 ST절 하강이 없는 경우보다 예후가 불량할 것으로 생각되며, 보다 적극적인 치료가 필요할 것으로 생각된다. The purpose of this study was to determine the significance of precordial ST segment depression appearing during acute inferior myocardial infarction and to assess the correlation of that with angiographic finding. 52 patients were allocated into two groups based on the existence of precordial ST segment depression : 23 patients with ST segment depression and 29 patients without ST segment depression. The extent of coronary artery disease as well as the prevalence of significant stenosis (≥70%) in left anterior descending artery were more frequent in patients showing precordial ST segment depression than in patients not showing them (p=0.050) and the result were similar in cases of left circumplex artery (p=0.001). On echocrdiographic examination of left ventricular (LV) wall motion, it showed more severely decreased inferior LV wall motion in patients showing precordial ST segment depression than in patients not showing them (p=0.03891) even though the other segment of LV wall motion didn't show the statistical difference between both groups. The other cardiac parameters such as LVEDP, exercise amount (METs) and ejection fraction were tend to showing bad profile in patients with precordial ST segment depression. From the above results, we could deduce that patients with precordial ST segment depression have relatively large infarction or concomitant left coronary artery disease, so they need more caution and intensive theraphy.