가정학습 가이드를 통한 산수과 학력향상 : 국민학교 산수과 2학년을 중심으로 Forcarized in the 2nd Year Grade in the Elementary School, the Arithematic Course

강용길,이상규 晋州敎育大學校 科學敎育硏究所 1981 科學敎育硏究 Vol.7 No.-

Streptococcus에 대한 chlorhexidine dihydrochloride와 불화나트륨의 효과

강인성,양규호,최남기,김선미,오종석 大韓小兒齒科學會 2004 大韓小兒齒科學會誌 Vol.31 No.2

Chlorhexidine dihydrochloride와 불화나트륨은 구강 내 세균을 억제하고 치태의 형성을 억제하기 위하여 많이 사용되고 있는 물질이다. 그러나 구강에는 여러 종류의 세균들이 상주하며 이들 물질에 대한 감수성도 다르다. 본 연구에서는 chlorhexidine dihydrochloride와 불화나트륨에 의해 Streptococcus mutans의 인공치태 형성이 억제되었을 때 Streptococcus mutans, Streptococcus sobrinus, Streptococcus oralis, Streptococcus salivarius의 증식에 미치는 이들 물질의 영향을 관찰하여 다음과 같은 결과를 얻었다. Streptococcus mutans를 8시간 배양하면 와이어에 형성된 인공치태 무게는 106.1±18.1㎎이었으나, 1.0μM chlorhexidine dihydrochloride를 첨가하면 5.1±1.5㎎으로 감소되었다(p<0.05). 이 때 배양액의 흡광도도 감소되었다. Streptococcus sobrinus의 배양액 흡광도는 감소되었으나 Streptococcus oralis에서는 감소되지 않았고 Streptococcus salivarius에서는 배양 8시간에 감소되었다가 배양 24시간에 대조군과 차이가 없었다. 배지에 3.0 mM 불화나트륨을 첨가하여 Streptococcus mutans를 8시간 배양하면 와이어에 인공치태 무게는 26.7±8.3㎎으로 감소되었다(p<0.05). 이 때 배양액의 흡광도도 감소되었다. Streptococcus sobrinus와 Streptococcus oralis에서의 배양액의 흡광도도 감소되었으나 Streptococcus salivarius에서는 거의 감소되지 않았다. 이상의 결과는 Streptococcus mutans의 인공치태 형성을 억제하는 chlorhexidine dihydrochloride와 불화나트륨 농도에서 Streptococcus의 여러 종의 감수성이 각각 다르다는 것을 시사하였다. Chlorhexidine dihydrochloride and sodium fluoride have been used as agents inhibiting the replication of oral bacteria and the formation of dental plaque. There are various kinds of bacteria with different sensitivity against these agents. In this study, chlorhexidine dihydrochloride and sodium fluoride were studied about their effects on the replication of Streptococcus mutans, Streptococcus sobrinus, Streptococcus oralis and Streptococcus salivarius at their concentrations inhibiting the formation of artificial plaque by Streptococcus mutans. When Streptococcus mutans was cultured for 8 hours in the media added with l.0μM chlorhexidine dihydrochloride, the weight of formed artificial plaque was decreased to 5.1 ±1.5mg compared with 106.1±18.1mg of the control(p〈0.05). At the same time, the optical density of cultured media was decreased. The optical density of cultured media was slightly decreased in Streptococcus sobrinus. but was not decreased in Streptococcus oralis. The optical density of Streptococcus salivarius was decreased at 8 hours-incubation, was not decreased at 24 hours-incubation. When Streptococcus mutans was cultured for 8 hours in the media added with 3.0 mM sodium fluoride. the weight of formed artificial plaque was decreased to 26.7i8.3 mg(p〈0.05). At the same time. the optical density of cultured media was decreased. The optical density of cultured media was decreased in Streptococcus sobrinus and Streptococcus oralis, but was slightly decreased in Streptococcus salivarius. These results suggest that at the concentration of chlorhexidine dihydrochloride and sodium fluoridehe inhibiting the formation of artificial plaque by Streptococcus mutans, different species of genus Streptococcus show the different sensitivity against these agents.

거대 뇌동맥류의 수술적 치료 : 증례 보고 A Case Report

성연상,도종웅,강재규,김기욱,김상진 최신의학사 1990 最新醫學 Vol.33 No.12

복막유착의 원인 규명과 예방을 위한 실험적 연구

강대영,송규상,노승무,조준식,이태용 충남대학교 의과대학 지역사회의학연구소 1999 충남의대잡지 Vol.26 No.1

Postoperative peritoneal adhesion is the most common cause of intestinal obstruction, and intestinal obstruction is one of the most difficult problems in abdominal surgery. In this experimental study for developing peritoneal adhesion model and its prevention, we divided rats into 5 groups; the talc powder treated group, the cotton-fluff treated group, the talc+fluff treated group, the ischemia group and the control group. There were 16 rats in each group. We made incisions on the midabdomen of the rats and administered talc powder, cotton fluff and talc powder+fluff into the peritoneal cavity respectively. In the ischemia group, we clamped the root of superior mesenteric artery for two minutes to induce ischemia on the small bowel of the rat. We counted the number of the peritoneal adhesive sites in peritoneal cavity on the 7th, 14th , 21st and 42nd postoperative day after peritoneal adhesion induced operation, and observed the characters of the adhesion state. The average number of the peritoneal adhesions were 1.25 per one rat in the talc powder group, 1.44 in the fluff group, 1.31 in the talc+fluff group and 1.31 in the ischemia group compared with 0.94 per one rat in the control group performed sham operation. 91.6% of the all adhesions were observed on the peritoneum of the previous incision sites and only 8.4% of the adhesions were adhered to the peritoneal surface of non-incision sites. The data of this study suggest that peritoneal injury and inflammatory reaction is the major cause of peritoneal adhesion. Also this study indicates that foreign bodies can develop peritoneal adhesion, but the effect is much lower than that of peritoneal injury with inflammatoty reaction.

시간-주파수 분포를 이용한 레이다 신호해석 및 처리에 관한 연구

강상만,김중규 成均館大學校 科學技術硏究所 1995 論文集 Vol.46 No.2

본 논문에서는 Time Frequency Distribution(TFD)을 이용한 새로운 레이다 신호처리 알고리즘을 제시한다. 신호를 시간과 주파수 영역에 대해서 동시에 해석하는 방법입 TFD를 이용하여 레이다 신호처리의 궁극적인 목표인 time delay(range)와 frequency shift(velocity)를 찾아내는 것이 그 목적이다. 능동적 레이다의 경우, 레이다 신호의 특성상 송신신호에 대한 정확한 정보를 가지고 있다는 점에 착안하여 송·수신 신호간에 correlation을 취한 새로운 신호에 대해서 TFD를 취해 주는 Correlated TFD(CTFD) 알고리즘을 제안한다. CTFD알고리즘을 통해서 전파의 송·수신 경로에 더해지게 되는 잡음성분의 영향을 감소시키는 효과를 얻을 수 있다. 따라서 보다 정확한 detection이 가능하게 된다. 그러나 TFD는 많은 계산 과정을 필요로 하기 때문에 현재의 기술로는 실시간 처리가 어려운 상황이다. 그래서 실시간 처리를 위한 방법으로 correlation과 TFD를 병행하여 time delay와 frequency shift를 독립적으로 찾아내는 보다 빠른 알고리즘 또한 제시한다. 본 논문에서 제시한 알고리즘의 타당성을 보이기 위해 -30dB ∼ 30dB 까지의 SNR을 갖는 additive white Gaussian noise(AWGN) 상황을 가정하여 기존의 방법과의 비교를 통한 실험결과를 제시한다. We propose a new algorithm for radar signal analysis and processing using the Time Frequency Distribution(TFD) by which the radar signal can be analyzed both in time and frequency domains simultaneously. The objective is to estimate the time delay and frequency shift between the transmitted signal and. the received signal, which is the typical goal of a radar system. The proposed algorithm is a Correlated TFD(CTFD) in the sense that it computes the time -frequency distribution of the cross-correlation between the transmitted and the received signals. Here, we consider an active radar system for which the signal characteristics are completely known a priori. By taking the TFD of the cross -correlation function rather than the radar signal itself, the effect of channel noise could be reduced significantly. One of the drawbacks for TFD method is that it involves a lot of computations, and thus can hardly be implemented in real time. To achieve the desired goal, i.e. estimation of time delay and frequency shift, in less time than the conventional TFD method, we propose a modified processing scheme which independently implements the correlation and the TFD methods for estimating the time delay and the frequency shift respectively. Finally in order to show the feasibility of our proposed scheme, we give some numerical results for an additive white Gaussian noise(AWGN) environment where the signal to noise ranges from -30 dB to 30 dB, and compared the result with conventional TFD methods.

管群의 流動과 熱傳達에 관한 數値解釋

姜濚珪,朴祥奎 全北大學校 1992 論文集 Vol.34 No.-

The fluid flow and heat transfer in tube bank in crossflow are important in relation to several types of heat exchangers. Numerous experimental studies have been reported previously. Recently, several numerical studies based on the finite difference and the finite element methods have been published. The present study represents the numerical predication of laminar flow and heat transfer in an in-line tube bank at low Reynolds number. The conservation equations of stream function, vorticity and energy were solved numberically using the finite difference method by Gosman et al. Calcurations were carried out for pitch-to-diameter ratios (1.2∼1.5)×(1.2∼1.5), Reynolds number Re = 50∼300, and the Prandtl number Pr=0.7∼15, under the condition of uniform heat flux. This paper presents the characteristic variations of local and mean heat transfer coefficients, pressure drop and friction coefficients, stream-line, isovorticity and isothermal contours, with arrangement, Reynolds and Prandtl numbers.

후두와 종양에서의 무언증 : 증례 보고 A Case Report

성연상,강재규,도종웅,김기욱,김상진 최신의학사 1991 最新醫學 Vol.34 No.1

전화망을 이용한 화자 식별에 관한 연구

강현규,고광현,양성일,권영헌 漢陽大學校 工學技術硏究所 1999 工學技術論文集 Vol.8 No.1

본 논문은 전화기 음성에 대하여 하이브리드 모델을 이용한 화자 식별 시스템에 대한 관한 연구이다. 전화음성 녹음을 위하여 전화기로부터 음성을 채집할 수 있는 장비의 설계와 화자 식별을 위한 하이브리드 인식기의 설계를 하였다 화자식별을 위하여 설계한 하이브리드 화자 인식기는 일반적으로 사용되고 있는 HMM과 DTW를 사용하여 구성하였다. 인식기의 성능을 판단하기 위한 실험은 다음의 두 가지 경우에 대하여 수행하였다. 시스템에 등록되어 있는 화자의 시스템 접근 허용과 비 등록 화자의 등록된 화자의 키워드 도용에 따른 시스템 거부에 관해 검토하였다. 키워드는 화자의 이름을 사용하였고 시스템에 사용된 특징 파라메터는 15차 켑스트럼(CEP), 10차 line spectrum pairs(LSP), 10개 대역으로 나뉘어진 주파수 대역별 에너지값(FB)을 사용하였다. 세 가지 특징 파라메터들과 인식기를 조합한 실험 결과를 누적하여 인식여부를 결정하도록 하였다. 개별적 시스템에서 발생되는 오인식을 하이브리드 모델을 이용한 본 시스템에서는 좋은 결과를 얻을 수 있었으며, 이로부터 전화기 음성을 이용하여 원격시스템에서 사용자를 확인할 수 있는 신뢰성 있는 사용자 확인 시스템이 제안된다. This paper is concerning a study on speaker verification system(SVS) over telephone network. For speater verification using telephone network, we design a hybrid-recognizer model composed of conventional methods (such as HMM, DTW) with a telephone recording system. We analyze the system performance as follows, access approval for a registered speaker using a correct keyword, and access denial for a registered or non-registered speaker using a keyword of other registered. speakers. Speaker's name is used as the keyword. We use three classes of feature vectors; line spectrum pairs(LSP), cepstrum(CEP), and filter bank energy(FB). The hybrid-recognizer model using these three features yields six results with respect to feature and recognizer. Though a single system makes some recognition error, this speaker verification system using the hybrid model gives good results in the experiment. and we suggest a reliable user verification system to remote system over telephone network.

관상동맥질환 환자에서 스텐트 시술 후 재협착에 관한 연구

강진환,권영주,박상호,한대희,이상철,김명구,변정득,최병조,심규혁,온영근,현민수,김성구 순천향의학연구소 2001 Journal of Soonchunhyang Medical Science Vol.7 No.2

Background and aims : In the coronary artery disease, a rate of restenosis was much decreased by placement of coronary stent than when percutaneous transluminal coronary angioplasty has been applied, but there are still important clinical problems of restenosis. There has been many progressive studies about various factors contributed to this restenosis. So, we studied a relation between restenosis after placement of coronary stent in the coronary artery disease and many clinical factors, characteristics of stenotic lesion and procedural factors, and also assessed the restenosis rate of various coronary stents. Methods : Total 58 lesions(46 cases of patients ; man 30, woman 16) were evaluated, which has been performed a follow-up coronary angiography after 6 months (mean 188 days) since coronary stent had been placed. Various stents were implanted and assessed a relation between restenosis and many factors. Results : Of 58 lesions were target stenotic studies, there were 22 of restenotic lesions(37.9%), and the restenosis rate wes statistically significant difference in the relation with diabetes mellitus(p<0.05), group of acute myocardial infarction(p<0.05) among clinical diagnosis of ischemic heart disease(stable angina, unstable angina and acute myocardial infarction) in clinical factors and with high dilation pressure of stent(p<0.05) in procedural factors. When the rate of restenosis was evaluated among implanted stents, it was lowest in the Multilink^(®) stent and highest in the Nir Royal^(®) stent(60%). Conclusion : In this study of restenosis and various factors after placement of stents in the coronary artety disease, factors such as diabetes mellitus, group of acute myocardial infarction and a dilation pressure of stent were significant related with restenosis and the restenosis rate of Multilink^(®) stent was lowest and the highest restenosis rate was of Nir Royal^(®) stent.

삼랑진 지점의 수위-유량곡선식 개발에 관한 연구

강대석,민일규,이승휘,옥치율 東亞大學校 海洋資源硏究所 2003 硏究論文集 Vol.15 No.-

In this study, Development The Rating-Curve Formula through to enforce the discharge investigator on Samrangjin Point. As use the result, We earning rationality, Economical irrigation and establishment a water control project, the basic material of determines hydraulic capacity to design water resources structure. At the same time, We can use The Rating-curve for a high efficient Flood wamning forecast in Nak-Dong River. The result and opinion of the discharge investigator is as follow: 1. The Rating-Curve Formula is Q=(-1065.91941)+1137.237287H+4.671360913H³(1.27<H<9.57) 2. A periodical and continuously management make a routine check over a watermark. 3. When enforce the discharge inverstigator, it require many time, person and equipment. So we can get accuracy and safety working conditions by assist a new system equipment to amount of flowing water measurement. 4. We must sublate to prepare the river bed or collect aggregate as possible, for the upper and downstream section in the established point of a watermark .