Ferrocenylmethyl Benzoate류의 가용매분해에 대한 반응속도론적 연구

홍순영,김창석,원성준 漢陽大學校 自然科學硏究所 1996 自然科學論文集 Vol.15 No.-

여러 가지 p- 혹은 m- 치환 ferrocenylmethyl benzoate를 합성하였다. 이들 에스테르의 가용매 분해반응 속도를 여러 혼합비의 methanol, ethanol, acetone 및 1,4-dioxane 수용액에서 pH metric method로 측정하였다. 반응 속도는 용매의 유전상수가 클수록 빠르고 Kirkwood-Onsager 관계식에 잘 맞았다. Grunwald-Winstein 식을 적용시킬 때 substrate parameter m 값이 0.5 -0.6으로 나타나며 aprotic solvent에서 보다 protic solvent에서 약간 더 크게 나타났다. 이들 가용매 분해반응은 전자 끄는 치환기에 의해 촉진되며 Hammett 반응 상수가 +0.622 (80% EtOH)와 +0.882 (80% 1,4-dioxane)로 나타났다. 또한 이들 반응에 관여하는 몇 가지 활성화 parameter를 산출하였다. 이상의 반응 속도론적 연구결과로부터 이들 에스테르의 가용매 분해반응은 ?? (alkyl-oxygen fission)과 ?? (acyl-oxygen fission)의 혼합과정으로, 그러나 ??쪽이 약간 우세한 과정으로 진행한다는 사실을 알 수 있었다. Several ferrocenylmethyl p-or m- substituted benzoates were synthesized. Rates of solvolysis of these esters in aqueous methanol, ethanol, acetone or 1,4-dioxane of various compositions were measured by a pH metric method. Rates of reaction were increased with increasing dielectric constant of solvent and these reactions obeyed Kirkwood-Onsager equation well. Substrate parameter (m) derived from Grunwald-Winstein equation was found to be 0.4-0.6 in these solvolyses, and the value (m) in protic solvent was slightly larger than that in aprotic solvent. Reactions were accelerated by electron-withdrawing substituents and Hammett substituent constants (ρ) of +0.622 (in 80% EtOH) and +0.882 ( in 80% 1, 4-dioxane) were obtained. Some activation parameters relevant to these reactions were also calculated. From the observed kinetics, it was concluded that ferrocenylmethyl benzoates solvolyze by a combination of ?? (alkyl-oxygen fission) and ?? (acyl-oxygen fission) pathways, in which ?? mode predominates slightly over ?? mode.

신경회로망을 이용한 원공 결함 패턴 인식에 관한 연구

홍순혁,이동우,허건,조석수,주원식 동아대학교 생산기술연구소 2000 生産技術硏究所硏究論文集 Vol.5 No.1

Ultrasonic inspection of defects has been focused on the existence of defect in structural material and need has much time and expenses in inspecting all the coordinates (x, y) on material surface. Neural networks is information processing system modeling human brain and can have an application to coordinates (x, y) of defects by multi-point inspection method. Ultrasonic inspection modeling is optimized by neural networks which makes defect echo, back-wall echo and ultrasonic transducer units of input layer and absolute and relative coordinates of defects and defect pattern units of output layer. This method can predict coordinates (x, y) of defects within engineering estimated mean error Ψ.

취업대비 기사자격증 취득을 위한 효과적 학습지도 방안에 관한 연구

홍순욱,윤상원,서용성 永同大學校 1997 硏究論叢 Vol.3 No.1

지난 2년간 STC를 수행하면서 경험한 바에 의하면, 기사시럼을 준비하기 위하여 시중에서 구입한 연습 문제집에 실린 일부 문제들이 내포한 모호성 때문에 많은 학생들이 어려움을 겪고 있다는 것을 알게 되었다. 이는 학생들이 전공지식을 학습하는데 있어서 비효율을 초래하는 주요 요인들 가운데 하나일 것이다. 본 논문은 학생들이 스스로 자신들의 지식을 확장하고 조직화할 수 있도록 「기출문제 수정출제법(PRST)」이라는 새로운 개념을 도입함으로써 그와 같은 부정적인 효과를 최소화하려는 구체적인 노력을 보여주고 있다. PRST는 5단계로 구성되어 있는데, 이를 통하여 학생들과 지도교수는 모호성을 제거하고 문제를 개선하는 작업을 함께 하게 된다. 이를 위하여 시스템적 접근의 관점에서 Dick의 모형을 채택하는데, 이 모형은 교수설계를 위한 기본틀을 제공해 주며, 본 연구에서 다룰 하나의 기능은 그러한 교수설계 모형 가운데 일부가 된다. 교수설계 모형에 있어서 8개의 기능 가운데, 일련의 개선된 연습 문제들을 제작하는 것이 학생들에게 우선적으로 도움이 될 것이라는 관점에서 수업교재의 개발이라는 기능이 가장 긴급하다고 판단되었다. 본 연구의 목적에 부합하는 적절한 연구의 방향과 범위를 결정하기 위하여 기존 문제들에 대한 사전 조사연구가 수행되었다. 그리고 두 과목에 대한 연습 문제집의 제작과 학생들의 학습 동기부여를 위하여 여름방학 STC기간에 PRST가 시험적으로 적용되었다. 제작된 연습 문제집 가운데 하나가 문제집의 양호도라는 측면에서 6개의 7점 Likert척도로 학생들에 의하여 인지적으로 평가되었다. 그 결과, 새로 구성된 연습 문제집이 기존의 연습 문제집보다 여러 각도에서 더 양호하다고 판정된다. 이것은 통계적 적용상의 한계에도 불구하고, 본 연구에서 제안된 PRST 뿐만 아니라 제작된 연습문제집의 질적 부분의 타당성은 최소한 뒷받침된다는 것을 의미한다고 하겠다. By what we have experienced in STC for the last two years, we can see that a number of students have been suffering from the ambiguities of some problems contained in exercise books which are available at the market for preparing the National Certificate of Engineering. This seems one of the primary factors that bring on inefficiencies in learning expertise. This paper reports our concrete efforts to minimize such a negative force by introducing a new concept of「process for Revise of Sample Test(PRST)」, so that students can be able to organize and expand their knowledge in a good manner. PRST consists of five stages that enable students and the instructor work together on improving problems by getting rid of ambiguities. From the viewpoint of systems approach, Dick's model is adopted to provide a framework for an instructional design which designates a function we deal with in this study. Among the eight functions in the model, the development of class material is considered to be most urgent in that it would be of highly benefit to students to make series of improved exercise problems. Preliminary investigation of existing problems is conducted to figure out right direction and scope for the purpose of our research. PRST is, then, tentatively applied during the summer STC not only to produce exercise books for two different subjects, but to motivate students. One of the produced exercise books is examined perceptively by students in terms of goodness using six seven-point Likert scales. The result shows that the newly constructed exercise book is, on the perception basis, likely to be better than existing books. This implies that the quality of the produced book, as well as the proposed PRST, is validated at least positively in spite of statistical limitation.

Pyridine 촉매하의 Cyclohexene의 Ozonolysis

홍원표,양현수,장자순,김철규 忠南大學校 産業技術硏究所 1988 산업기술연구논문집 Vol.3 No.2

Terminally functionalized molecules are essential building block for the formation of polymers by polycondensation reactions. It is the major goal of this research to establish new routes for the preparation of such molecules by selective oxidation reaction of cyclohexene, using ozone as an oxydizing agent. To this purpose, it has been explored, whether the usual course of the ozonolysis of olefins can be modified with the help of specific catalyst in order to introduce the desired functional groups. In particular, the ozonolysis of cyclohexene in hydrocarbon solvents and in the presence of pyridine has been tested with the goal of preparing molecules containing one aldehyde and one carboxylic acid group. Ozonolysis of cyclohexene in hydrocarbon solvents such as methylene chloride and pentane can be guided by catalysis with pyridine, such that the reactions afford desired molecules. In this manner, pyridine catalized ozone oxidation converted cyclohexene into the corresponding 6-oxohexanoic acid(45.87%), adipaldehyde(14.68%), and polymeric ozonide(39.45%), via the ω-formyl carbonyl oxides in CH₂Cl₂at 0℃.

지역사회 정신의학 전공의 교육과정 실태조사

홍진표,황순찬,이영문,이선형,신나리,이종일,박종익,장동원,정인원 大韓神經精神醫學會 2008 신경정신의학 Vol.47 No.1

Objectives : There is a increasing need to recruit and retain more psychiatrists who can plan and implement organized programs to work with chronic mentally ill patients in community settings. The aim of study is to discover what training is currently in place to prepare psychiatrist for work in "community" or "public" settings. Methods : Survey questionnaires were mailed to 85 residency training directors and 10 leaders of community mental health in 2005. Response rate was 75%. Results : Academic seminar about community mental health were not administered to residents in 63% of training hospitals. Forty one out of 64 training hospitals had community mental health rotation programs, Community mental health center (50%) and day hospital (36%) were the most common type of programs. Few general hospital had affiliation with community mental health programs. The amount of time for clinical rotation varied from less than three months part time to 6 months fulltime, with most frequent form of one day per week for three month in second or third year of psychiatry residents. Conclusion : Further steps are needed to improve residency training curricula and to encourage well qualified psychiatrist to choose careers in community psychiatry.

신경회로망을 이용한 Al 2024-T3 합금의 피로손상모델에 관한 연구

홍순혁,조석수,주원식 한국공작기계학회 2001 한국생산제조학회지 Vol.10 No.4

To estimate crack growth rate and cycle ratio uniquely, many investigators have developed various kinds of mechanical parameters and theories. But, these have produced local solution space through single parameter. Neural Networks can perform pattern classification using several input and output parameters. Fatigue damage model by neural networks was used to recognize the relation between da/dN/ N/N_f, and half-value breadth ratio B/Bo, fractal dimension D_f and fracture mechanical parameters in 2024-T3 aluminium alloy. Learned neural networks has ability to predict both crack growth rate da/dN and cycle ratio N/N_f within engineering estimated mean error(5%)

정신분열병 환자에서 통계적 확률 해부학 지도를 이용한 확산텐서영상 연구 : 겉보기 확산 계수 지도를 이용한 고찰

홍순범,신용욱,김대진,문원진,정은철,이재성,박해정,권준수 大韓神經精神醫學會 2006 신경정신의학 Vol.45 No.4

Objectives : Diffusion tensor imaging (DTl) studies of schizophrenia, thus far, have mainly focused on white matter abnormalities reflected in anisotropy indices such as fractional anisotropy (FA), but recently, new implications of apparent diffusion coefficient (ADC) have been proposed. This is. to our knowledge, the first study to analyze ADC maps of schizophrenic Patients using statistical parametric anatomical mapping (SPAM). Methods : DTl was performed in 20 schizophrenic patients and an equal number of age- and sex-matched healthy controls. ADC maps were then generated, from which 98 volumes of interest were extracted using SPAM. Probability-weighted mean values of ADC were calculated from each volume of interest and compared between the two groups. Results : Significantly higher mean ADC values were observed in patients with schizophrenia compared to healthy controls in the following volumes of interest: bilateral hippocampal formation, bilateral uncus, nght thalamus, light temporal lobe white matter, right superior temporal gyrus, bilateral insula and right lateral ventricle. Conclusion : The results support the recently proposed assertion that regionally increased ADC may reflect cortical brain atrophy. In addition, a new possibility is raised that a neuropathological event involving both the gray and the white matter may also play a role.

이온성 혈관조영제 Talabrix가 동맥혈관내막과 미세혈관 문합 후 혈관개폐에 미치는 영향

홍순원,김용욱,탁관철,박병윤 大韓成形外科學會 1993 Archives of Plastic Surgery Vol.20 No.1

In the free flap surgery using microvascular anastomosis, angioraphy is widely used as an integral part of preoperative plans. The necessity of angiography is well extablished. But since there exist many controversies regarding adverse effects of angiography. especially there is no concrete evidence about their effects on the patency after microvascular anastomosis, This study attempts to examine the chronological changes of the arterial intima after systemic injection of ionic contrast media sodium iothamate(Talabrix ) and to evaluate its effects on the patency of microvascular anastomosis. Fifty-nine Sprague Dawley rats were divided into 5 groups according to time interval between contrast media injection and microvascular anastomosis. The time intervals were 1 day, 3 days, 7 days, and 14 days after contrast media injection. The ionic contrast media was injected intraveneously through the tail vein. Left inguinal arteries were anastomosed under an operating microscope after the contrast media injection. After the above procedures and reviewing all the results, we can conclude that ionic angiographic dye causes reversible injuries to the vascular intima, and deteriorates patency of the microvascular anastomosis. And we suggest that a time interval more than at least 7 days to 14 days, between anguographic study and flap transfer is requested.

구연산을 첨가한 오디 설기떡의 품질 특성

홍정희,안상희,김미지,박금순,최상원,이순재 한국조리과학회 2003 한국식품조리과학회지 Vol.19 No.6

This study was carried out to investigate the characteristics of mulberry fruit seolgidduk. Four percent additions of mulberry were evaluated as the most suitable concentration for seolgidduk, in order to improve the color of gum metal gray and sour smell. Therefore, in order to improve the preference, citric acid was added. The acidity of mulberry fruit seolgidduk increased and its pH decreased significantly by increasing amount of citric acid. The moisture content of mulberry fruit seolgidduk showed no significant difference between the groups with added citric acid and the control of group. The L value decreased as the citric acid concentration increased. Color a and b (Ed-define 'a' and 'b') values increased significantly by increasing the amount of citric acid. The hardness, cohesiveness, springiness, gumminess and brittleness decreased as the citric acid was added. From the sensory evaluation, mulberry fruit seolgidduk with 0.01% citric acid added was the most preferred in taste, chewiness and overall acceptability. These results indicated that mulberry fruit seologidduk with 0.01% citric acid added showed the best quality.

木材의 硬度에 關한 硏究

洪淳一,李元用 江源大學校 林科大學 森林科學硏究所 1992 Journal of Forest Science Vol.8 No.-

This study was performed to investigate the hardness of wood related to the wood surface, sap and heartwood, early and latewood, specific gravity, annual ring width and moisture content on major Korean tree species such as Pinus koraiensis, Abies holophylla, Larix leptolepis and Quercus valiabilis. The results were summarized as follows: 1. The arithmetic mean values of wood hardness on cross section were respectively 8.0 ㎏/㎟ on Quercus valiabilis, 7.4 ㎏/㎟ on Larix leptolepis, 5.1 ㎏/㎟ on Pinus koraiensis and 4.7 ㎏/㎟ on Abies hollophylla. 2. Generally hardness of wood on cross section was greater than the others and the proportion of cross section hardness to radial was respectively 2.8 on Quercus valiabilis, 2.6 on Larix leptolepis, 3.8 on Pinus koraiensis, and 4.1 on Abies holophylla and that proportion was tend to be decrease as specific gravity increased. 3. It was recognized that the hardness of sap and heartwood was different from each of the tree species and generally heartwood hardness was somewhat greater than sapwood. 4. Generally latewood hardness with in a ring was greater than earlywood and the proportion of earlywood hardness to latewood decreased as specific gravity increased. 5. The relations between hardness of wood and specific gravity show a high positive correlation on all sample tree species. 6. The values of hardness decreased with increasing annual ring width. 7. Hardness of wood on Abies holophylla was greatest in oven dried wood and it was decreased as moisture content increased, but not changed with moisture content abve F.S.P.. The proportion of oven dried wood hardness to green are respectively 3.0 on cross, 2.4 on radial and 1.9 on tangential section.