IIR 적응필터를 이용한 오차보상 능동소음제어

권기룡,박남천 慶南大學校 附設 工業技術硏究所 1993 硏究論文集 Vol.11 No.-

본 논문에서는 능동소음제어를 위하여 오차보상 RNLMS(recursive normalize least mean square)알고리듬(CRNLMS)을 제안하였다. 이 CRNLMS(error compensated RNLMS)알고리듬에서는 수렴속도를 빠르게 하기 위하여 입력소음과 오차소음의 전력에 따라 가변수렴인자를 사용하였다. 또한, 정상상태오차를 최소화하기 위하여 오차경로에서 소음발생기를 사용하지 않고 소음오차를 더욱 작아지도록 보상하는 보조시스템을 사용하였다. 시스템의 성능을 입증하기 위하여 기존의 적응디지틀필터인 RLMS(recursive LMS) 및 RNLMS알고리듬과 비교하였다. 컴퓨터 시뮬레이션 결과, 제안한 CRNLMS 알고리듬의 소음레벨은 RLMS 및 RNLMS알고리듬의 것보다 평균 12㏈ 및 3㏈ 정도 더 큰 감쇄효과가 있음을 확인하였다. In this paper, an error compensated RNLMS algorithm(CRNLMS) is proposed for an active noise control. This CRNLMS algorithm use the variable convergence factor according to the input and error noise power to fast convergence speed. And it uses an error compensated auxiliary system, which reduces error noise without random noise generator in error path, to minimize steady state error. To demonstrate the performance of the system, the p개posed CRNLMS algorithm is compared with the conventional ones, the RLMS and the RNLMS algorithms. The computer simulation results for each algirithm show that the noise level of the proposed CRNLMS algorithm is reduced about 12㏈ and 3㏈ as compared with the RLMS and RNLMS algorithms, respectively.

Ethylcinnamate에 對한 Iso-propylmercaptan의 親核性 添加反應에 關한 反應速度論的 硏究

權奇星,李天培,成洛道 圓光大學校 1977 論文集 Vol.11 No.-

ethylcinnamate에 대한 iso-propylmercaptan의 친핵성 첨가반응 속도상수를 측정하여 넓은 pH 범위에서 잘맞는 반응속도식을 얻었다. 이 식에 의하면 pH 6.5 이하에서는 iso-propylmercaptan과 iso-propylmercaptide ion의 첨가가 경쟁적으로 일어난다. pH 10이상에서는 ethylcinnamate에 iso-propylmercaptide ion의 첨가만이 일어남을 알수 있다. 그러므로 본 실험에서 구한 반응속도식으로부터 실험측정값과 계산 값(이론 값)이 여러 pH를 통하여 잘 맞기 때문에 넓은 pH범위내에서 일어나는 친핵성 첨가반은 mechanism을 잘 설명할 수 있었다. The rate constants of nucleophilic addition reaction of iso-propylmercaptan to ethylcinnamate were determined at various pH and a rate equation which can be applied overwide pH range was obtained; ?? The rate equation reveals that below pH 6.5 the reaction is initiated by addition of iso-propylmercaptan molecule, from pH 6.5 to 10.0 iso-propylmercaptan and iso-propylmercaptide ion are competitively added. Above pH 10.0 the addition reaction of iso-propylmercaptide ion occurs. From these rate equation, we found that observed data accorded satisifactorily with theoretical value over various pH range. Hence, the mechanism of nucleophilic addition reaction over wide pH range can be fully explained.

조직과 문화의 관점에서 접근한 한국형 지식경영 모델 : IMF 사태에 대한 사례 분석을 중심으로 A case study of the IMF stand-by arrangement in Korea

전기정,현우식,장승권 한국생산성학회 1999 生産性論集 Vol.13 No.3

Using the knowledge management perspective, this study investigates the top level decision making process, which brought the financial crisis in Korea at late 1997. To analyze the characteristics of a Korean knowledge management, this study applies knowledge spaces for meta-knowledge, formalhformal organizations, and cultural spaces. Implicit knowledge and the role of informal organizations are regarded to be relatively more important in Korean knowledge management models. It, then, suggests the introduction of meta-knowledge mechanisms for the fluent circulation of knowledge.

호중구감소증 환자에서의 기관-기관지 아스페르길루스증 1예

권재철,송명준,김기조,오유경,김성용,박선희,최수미,이동건,이석,신완식,김춘추 대한감염학회 2004 감염과 화학요법 Vol.36 No.1

저자들은 급성 림프구성 백혈병 환자에서 항암치료 후 호중구감소증이 지속되는 상태에서 침습성 아스페르길루스증의 드문 형태인 치명적인 아스페르길루스 기관기관지염을 경험하고 문헌고찰과 함께 증례를 보고하는 바이다. Tracheobronchial aspergillosis is an uncommon clinical form of invasive aspergillosis, particularly found in patients with AIDS and in lung transplant recipients than in other immunocompromised patients. The rapidity of the disease progression can result in fatal airway obstruction in a short period of time that the patient may need emergency tracheostomy without knowing the cause of the obstruction. We describe a case of fatal tracheobronchial aspergillosis which developed in a 43-year-old female patient with acute lymphoblastic leukemia. Dyspnea and stridor developed on the 20th day after 2nd consolidation chemotherapy, which was during the prolonged neutropenic period. Airway narrowing was observed on the computed tomograph scan of neck and emergency tracheostomy was performed. Infiltration with aspergillus hyphae was found in the tracheal ring and bronchial mucosa. Despite the use of amphotericin B, the patient died of bleeding and airway obstruction.

α-Bromobenzaldehyde-p-nitrophenylhydrazone의 알카리 가수분해 반응 메카니즘

권기성,이천배,박문규,성낙도 충남대학교 기초과학연구소 1980 연구논문집 Vol.1 No.-

The rate constants for the hydrolysis of the derivatives of α-bromobenzaldehyde-p-nitro-phenylhydrazone (p-H, p-OCH_3, p-Cl, p-NO_2) at various pH have been determined by UV spectrophotometry in 50% dioxane at 25℃ and the following rate equations which can be applied over wide pH range were obtained. i. e. α-bromobenzaldehyde-p-nitrophenylhydrazone; kobs.=1.25×10 exp (-7) + 7.92×10 exp (-11)/〔H^+〕+1.51×10 exp (-7) α-bromo-p-chlorobenzaldehyde-p-nitrophenylhydrazone; kobs.=1.06×10 exp (-7) + 1.08×10 exp (-10)/〔H^+〕+1.45×10 exp (-7) α-bromo-p-methoxybenzaldehyde-p-nitrophenylhydrazone; kobs.=1.79×10 exp (-7) + 1.40×10 exp (-10)/〔H^+〕+4.08×10 exp (-7) α-bromo-p-nitrobenzaldehyde-p-nitrophenylhydrazone; kobs.=7.10×10 exp (-8) + 2.89×10 exp (-10)/〔H^+〕+2.37×10 exp (-7) Below pH 2, the rate of hydrolysis of α-bromobenzaldehyde-p-nitrophenylhydrazone is accelerated by electron-donating group (ρ=-0.91). Above pH 5, however, this reaction is slowded down by electron-attracting group (ρ=0.37). From the rate equation and the effect of solvent and substituent upon the rate of reaction, below pH 2, the hydrolysis proceed through SN_1 mechanism. Above pH 5, the hydrolysis proceed through 1.3-dipolar ion mechanism. And in the range of pH 2∼5 these two reactions occur competitively.

가솔린엔진의 실린더 溫度特性에 關한 硏究

윤영춘,권기린 濟州大學校工科大學産業技術硏究所 1996 尖端技術硏究所論文集 Vol.7 No.2

The purpose of this study is to prevent the stick. scuffing. scratch between piston and cylinder in advance, to obtain data for duration test in actual engine operation. Therefore, temperature gradient in peripheral and axial distribution of cylinder bore were measured in use of 800cc class gasoline engine. The results obtained are summarized as follows ; 1) The maximum reaction force by overlap is 101.97kg. The skirt length at that position is 10mm from skirt upper. 2) The rear side temperature of top dead center is 142℃ in peripheral distribution, it is about 20℃ higher than thrust, anti-thrust, front side temperature. 3) The rear side temperature of bottom dead center is 125℃ in axial distribution, whereas the rear side of midway position temperature is 120℃. 4) The temperature of cylinder wall is about 20∼30℃ higher than temperature of cooling water. 5) The temperature of cylinder wall at top dead center in use of SAE ?? lubricating oil is 16℃ higher than SAE 20 at 6000rpm.

산화법에 의한 N-치환 히드라존의 합성

이기창,권순자,양천회 明知大學校 産業技術硏究所 1983 産業技術硏究所論文集 Vol.2 No.-

In acetone-ammonia system with amines, N-Substituted hydrazone was synthesized by the oxidation of hydrogenperoxide. The results are as follows : 1. The yield of phenylhydrazone was increased and that of azone decreawed with increasing the aniline added. 2. The excess of aniline was unfarorable for preparation of both azine and hydrazone. 3. Similar behavior was observed for t-butylamine to afford acetone t-butylhydrazone and azine, while cyclohexylamine resulted in the exclusive formation of 2-cyclohexyl-3, 3-dimethyloxaziridine.

通度寺 進入空間을 통해서 본 傳統景觀의 現代的 受容에 관한 考察

鄭基浩,韓炳權,全美璟 成均館大學校 科學技術硏究所 1992 論文集 Vol.43 No.1

Traditional landscapes were effected on the characteristics of nature and culture and have created distinct landscapes, while todays such attributes are becoming obscure as technology. In aspect of the contermperary applications of traditional landscapes, the cognitive qualities of observers was researched, which is about the components of entrance space in Tongdo Teple by phenomenological approach. The results of this can be summarized as follows : 1. Old components were not perceived and effected on the behavior of observers. 2. Cognitive qualities were varied from the attributes of space in and out. 3. Artificial features that related to contemporary life were perceived easily. As there were old and contemporary features to gether, the existence of old things is to be obscure relatively.

수술실 오염도감소를 위한 수술실공조시스템에 대한 연구

김천숙,박은정,강규식,김지은,안기량,권진형,유시현,주영철,권순정 순천향의학연구소 2004 Journal of Soonchunhyang Medical Science Vol.10 No.1

Background: The OR(operating room) should provide an optimum environment that is safe for the patient and the working personnel. The air ventilation system of OR has been studied to decrease the contamination of air. We investigated the flow and contamination of the air in OR at our hospital. Method: Cultures in OR were made and the number of bacteria and fungi were calculated. A two-dimensional model for the cross-section of an operation room is developed for the CFD (computational fluid dynamics) analysis. The characteristics of air flow in the empty operation room and in the occupied operation room are calculated by using a CFD program. Results: The current air ventilation system of our hospital does not deliver the clean air to the operating site efficiently in occupied OR. Conclusions: We suggested a new location of air ventilation system which improves air venting with little increase of the cost of equipment.

수용성 Polymer-metal Complex의 형성과 중합 개시제로서의 활용성에 관한 연구(Ⅰ)

맹기석,송해영,권오승,황명천,황택성 충남대학교 공업교육연구소 1983 論文集 Vol.6 No.2(B)

The formation of Water-Soluble Poly(Methacrylic acid) (PMA) and poly (acrylamide) (PAAm)-Cu(II) complexes was achieved at various PH. The structures and the optimum conditions for the formation of complexes have been determined through UV, IR and viscosity measurements. In addition, it was found that they can be used as an initiator for vinyl type monomers. Formed polymer-metal complexes are the most stable at around PH=7 and therefore give rise to maximum absorbance in UV spectrum. As PH is increased the conformation of polymer-metal complexes has become more compact. This can be explained in terms of decreasing viscosity with increasing PH. It was also observed that the function as an initiator of the polymer-metal complexes is very active at around PH=7 and the complexes can polymerize vinyl type monomers up to 10% Conversion. These results can explain the fact that the stable complexes were formed at around PH=7 and the formed complexes can be used as good initiators.