더블 팬터그래프형 매니퓰레이터의 설계 및 수평위치제어

홍대선,신중호,정원지,김성철 國立 昌原大學校 産業技術硏究所 1998 産技硏論文集 Vol.12 No.-

In this paper, a double pantograph type manipulator activated by two slider joints is proposed for a fuel handling machine in atomic power plants. The manipulator consists of two parallelogrammic structures considered as simplified 2-DOF linkage systems. The linkage motion is controlled in such a manner that the joint rates of two linkages are constant and the movement of end-effector is horizontal, because the constant joint rates have advantages for the stable movement of the system. In addition, the static deflection of the proposed mechanism was analyzed using a transfer-stiffness matrix method.

평탄 지역과 경계선 지역에 따른 적응형 필터를 이용한 스패클 잡음 제거에 관한 연구

홍승범,백중환 한국항공대학교 1996 論文集 Vol.34 No.-

본 논문에서는 경계선을 보호하면서 잡음을 제거하는 전 처리 방식을 제안한다. 초음파 영상은 과립(顆粒) 형태의 스패클 잡음에 의하여 열화된다. 스패클 잡음은 곱형 잡음(multiplicative noise)의 형태로서 신호에 독립(signal independent)적이며, 공간상에서 상관적이다. 우리가 제시한 방식인 이종형 필터는, 본 논문에서는 AWF(Adaptive Window Filter)로 부름, 스패클의 성질을 이용하여 제작하였다. 구성 형태는 에지 영역에서는 평균 필터를 이용하였고, 잡음 영역(flat region)에서는 Log필터를 이용하였다. 두 영역을 구별하는 방법은 기존에 제시된 통계적 연산 방식(국부 평균과 표준편차) 대신에 공간 영역 상에서 국부 창(3x3 subwindow)에서 얻어지는 기울기를 이용하여 두 영역을 구별할 수 있다. 제안된 필터의 성능 평가는 향상 지수 (??)와 스패클 지수(SI)에 의해 잡음의 제거 정도를 평가 하였다. In this paper, we propose a pre-processing method which removes noise while preserves the edges. The ultrasonic images are corrupted by the granular pattern noise-a speckle noise. the speckle exists in a types of coherent imaging systems, the speckle is the signal independent and multiplicative noise. In this paper, we derive a filter, called the AWF(Adaptive Window Filter), from the nature of the speckle. The filter is made of the MEAN Filter in the edge region and LOG Filter in the flat or noise region. To make a distinction between edge and flat region, we calculate the inclination around the subwindow(3x3) instead of computing the local statistics of pixels (such as local mean M and standard deviation ?). According to the obtained region, edgeregion is performed by the mean filter and flat region by the Log filter. Performance of the proposed filter is evaluated by the Enhanced Factor (??) and the Speckle Index(SI).

주파수 응답 함수를 이용한 평면 밀링에서의 채터 예측

홍성욱,박중윤,김현수,박재현,박창용 金烏工科大學校 産業技術開發硏究院 1999 産業技術開發硏究 Vol.15 No.-

The present paper investigates the chatter stability of a milling spindle-workpiece system in face milling process. To this end, a new method using frequendy response function is adopted for predicting the chatter vibration. A compliant workpiece is used to make the spindle-workpiece system easily exposed to chatter vibration. The entire experimental procedure, including measurement of frequency response function and cutting coefficients, is demonstrated. The experimental result shows that the chatter stability prediction method using frequendy response function is of great use in face milling process.

Dielectric Resonator의 Microwave Q-factor 측정에서 Cavity 재질의 영향

김홍오,김명중 忠州大學校 2012 한국교통대학교 논문집 Vol.47 No.-

The effects of cavity material on the Q-factor measurement of microwave dielectric materials were studied by HFSS simulation. TE01δ mode resonant frequency was determined from the electric and magnetic field patterns and the loaded Q-factor was calculated from 3dB bandwidth of S21 spectrum. When the cavity metal materials were Cu, steel and Au cavity, the level of Q-factor was similar. However, Q-factor was significantly decreased when the Cu metal was oxidized to CuO.

삼일열 말라리아에 합병된 비장 파열 1예

홍경욱,이정아,김원진,박철민,권혜리,박혜원,엄중식 대한감염학회 2007 감염과 화학요법 Vol.39 No.5

국내의 토착형 말라리아는 삼일열 말라리아로, 1993년부터 재유행이 시작되었다. 말라리아의 중요한 합병증으로 드물지만 비장 파열이 있는데, 이는 주로 삼일열 말라리아에 의해서 발생되며, 국내에서는 1999년 말라리아에 의한 비장 파열로 비장 절제술을 시행한 예가 보고된 바 있다. 현재까지는 비장 파열이 있을 때 비장 절제술이 일차적인 치료로 되어 있으나, 비장 절제술 후의 감염 위험성이 크므로, 활력 징후가 불안정하거나, 출혈이 지속되는 소견이 보이지 않으면 가급적 보존적 치료를 하는 것이 추천된다. 저자들은 비장 파열이 동반된 말라리아 환자에서 비장 절제술을 시행하지 않고 보존적 치료로 호전된 예를 경험하여 보고하는 바이다. Plasmodium vivax has been the predominant Plasmodium species in the Republic of Korea and reemerged in 1993. Spontaneous rupture of malarial spleen is a rare but important complication associated with P. vivax infection. Only one case of spontaneous rupture of malarial spleen was reported in Korea in 1999. Splenectomy is still accepted as the treatment of choice in cases of spontaneous rupture of the spleen. But, considering increased risk of postsplenectomy infecion, splenectomy should be reserved for those patients with severe rupture or those with continued or recurrent bleeding. And conservative treatment should be considered in selected, closely monitored patients. We report a patient with P. vivax malaria who developed a spontaneous splenic rupture and was improved by conservative treatment.

프로세스 중심의 ERP 구축 방법론에 관한 연구

홍현기,안중호 한국경영과학회 1998 經營 科學 Vol.15 No.2

부분적으로 일정한 자기장의 영향을 받는 보의 동적해석에 관한 연구

홍성욱,박중윤 金烏工科大學校 1992 論文集 Vol.13 No.-

This paper presents the dynamic analysis of a beam subjected to a piecewise uniform magnetic field. The objective of this study is to test the applicability of a passive magnetic damper in the suppression of structural vibration. The fundamental idea of the passive magnetic damper is that a moving conductor experiences viscous damping force when subjected to a magnetic field, due to internal current loss induced by electromotive force. The dynamic equation of the system is formulated by using the Green function method and finite element modeling technique. Simulation of the system is also performed to discuss the pros and cons of the passive magnetic damper in the suppression of a beam vibration.

항생제 사용과 관련된 Clostridium difficile 감염증

김홍빈,김남중,최희정,오명돈,김의종,최강원 대한화학요법학회 1997 대한화학요법학회지 Vol.15 No.1

목적 : Clostridium difficile 감염증은 중요한 원내 감염중의 하나로 최근 들어 항균제 사용의 증가와 함께 그 빈도가 늘어나고 있어 Clostridium difficile 감염의 빈도 및 임상양상을 알기 위해 본 연구를 시행하였다. 방법 : 102명의 정상 성인으로부터 대변에서 Clostridium difficile 배양을 시행하였으며, 92년 3월부터 93년 9월까지 서울대학교 병원에 입원한 환자중 대변배양 검사에서 Clostridium difficile이 배양된 61명의 환자를 대상으로 병록지를 토대로 조사하였다. 결과 : 정상 성인 중 3%에서 Clostridium difficile이 분리되었다. 대상환자의 기저 질환은 악성고형종양(29%), 혈액종양(6.5%), 뇌혈관 질환(6.5%), 간경변(4.9%) 등의 순이었으며, 대상 환자의 75%에서 균이 분리되기 6주 이내에 항균제가 사용되었다. 사용된 항균제는 aminoglycoside(60.8%), 1세대 cephalosporin(56.5%), 3 세대 cephalosporin(43.4%), ampicillin(15.2%), metronidazole(15.2%), clindamycin(8.6%)의 순이었다. 흔한 증상은 설사(77%), 복통(53.8%), 오심(37%), 빈맥(25%) 등이었며, 혈액 검사상 백혈구증가증은 21.6%, 저알부민혈증은 3.03%에서 관찰되었다. 44명의 환자중 24명의 환자가 대증적 치료 후 호전되었고, vancomycin이나 metronidazole을 투여받은 17명의 환자중 15명의 환자가 증상의 호전을 보였다. 4예가 사망하였으며, 3예(4.9%)는 재발하였다. 결론 : Clostridium difficile 장염은 항균제 사용시 흔히 발생하는 질환이다. 정상 성인의 3%에서 Clostridium difficile이 분리되었다. Objective : Clostridium difficile gastrointestinal disease is an important nosocomial infection and is associated with antibiotic use. This study evaluated the incidence and clinical characteristics of Clostridium difficile infections. Methods : Stool specimens from 102 normal adults were cultured for Clostridium difficile. Sixty-one patients with Clostridium difficile isolated from stool specimens were reviewed retrospectively. The patients were seen at the Seoul National University Hospital during the period from Mar., 1592 to Sep., 1993. Results : Clostridium difficile was isolated in 3% (3/102) of normal adult Population. Underlying diseases of the patients included solid tumor(29%), hematologic malignancy(6.5%), corebrovascular disease(6.5%), and liver cirrhosis(4.9%). Antibiotics associated with Clostridium difficile infections included aminoglycosides (60.8%), first generation cephalosporin(56.5%), third generation cephalosporin(43.4%), ampicillin(15.2%), metronidazole(15.2%), and clindamycin(8.6%). In 3/4 of the cases, these antibiotics had beer) administered within 6 weeks before Clostridium difficile isolated. Associated symptoms included diarrhea(77%), abdominal pain(53.8%), nausea(37%), fever(37.7%), and tachycardia(25%). Leukocytosis and hypealbuminemia were observed in 21.6% and 30.3%. Out of 44 cases received symptomatic treatment, 54% (24/44) improved. Of 17 cases treated with metronidazole or vancomycin, 88% (15/17) improved. Four cases expired and 3 cases(4.9%)were relapsed. Conclusion : Clostridium difficile gastroenteritis is frequently associated with antibiotic treatment. Three percent of normal adult population had Clostridium difficile.

TiO₂-CaSO₄와 TiO₂-CaCO₃계의 고상반응기구 : TiO₂의 반응성 및 상형성 Reactivity of TiO₂and Phase Forming

김홍대,한인섭,유태석,정윤중 明知大學校 産業技術硏究所 1986 産業技術硏究所論文集 Vol.5 No.-

For to detect the mechanism of the product phase and the assignment of the two reactant on the solid state reaction of TiO₂ with the CaSO₄ and CaCO₃ respectively at the reaction temperature 900℃ - 1400℃, the refractive microscope, scanning electron microscope, and electron dispersive spectroscope analysis were examined. For the reaction of TiO₂ with CaSO₄ the product phase which earned is CaTiO₃perovskite and from the first, the intermediate product of TiO₂· CaO·SO₂ was formed. However, the main product phase is Ca₃Ti₂O7, which is coexisted in the product layer, at the reaction of TiO₂ with CaCO₃·TiO₂ was diffused into CaSO₄ and CaCO₃ reactant side is both two reaction. Specially, in the case of CaCO₃, the transfer of TiO₂ is rapid through the pore, which was formed with vaporization of CO₂ gas.

統計學의 過去·現在·未來

金泓中 충남대학교 경상대학부설 경영경제연구소 1984 경영논집 Vol.6 No.1