촉매를 이용한 이산화탄소 고정화 및 고리형 카보네이트 합성반응에 대한 계산화학적 해석

안혜영(Hye Young An),김민경(Min-Kyung Kim),정희철(Hui Cheol Jeong),엄기헌(Ki Heon Eom),원용선(Yong Sun Won) 한국청정기술학회 2016 청정기술 Vol.22 No.1

본 연구에서는 이론화학 또는 분자모델링이라 불리는 계산화학을 기존에 연구된 촉매반응 실험결과를 해석하는 데 접목시켜 보았다. 온실효과의 주범인 이산화탄소를 에폭사이드와 반응을 통해 고정화하고 카보네이트를 생성하는 반응을 선택하였는데 이 반응은 활성화 에너지(55~59 kcal/mol)가 높아 촉매의 사용이 불가피하다. 많은 기존 연구들 중에 ZIF-90/ionic liquid immobilized ZIF-90 (IL-ZIF-90), polystyrene-supported quaternized ammonium salt, KI/KI-glycine, dimethylethanolamine (DMEA)를 촉매로 사용한 경우에 대해 반응의 각 단계를 계산하여 반응의 경로를 예측하고 단계별로 구한 에너지를 바탕으로 에너지도를 구성함으로써 실험결과를 열역학적으로 해석하였다. ZIF-90/IL-ZIF-90과 KI/KI-glycine의 경우는 실험적으로 후자들이 상대적으로 높은 수율을 얻었는데 계산 결과 활성화에너지가 낮아진 이유가 아니라 전자들의 경우 반응 중간체가 높은 에너지를 가져 반응물로 되돌아가는 역반응에 의해 정반응의 진행이 방해를 받은 것으로 밝혀졌다. DMEA를 촉매로 사용하였을 경우는 활성화 에너지를 ~42 kcal/mol로 낮춰줌으로써 금속이나 할로겐염 없이도 촉매의 활성이 잘 일어남을 증명하였다. 폴리스티렌(polystyrene)으로 지지된 quaternized 암모늄염 촉매의 경우 클러스터 가정을 사용하여 계산을 진행하였으며 암모늄염의 -NH기와 에폭사이드의 O 원자 사이의 상호작용의 가능성을 확인할 수 있는 반응경로를 제시하였다. In this study, a computational chemistry methodology called as molecular modeling was been applied to explain several experiment results mechanistically. The reaction chosen for this study was to remove carbon dioxide, known as a primary greenhouse gas, by an epoxide via the carbon dioxide fixation to produce carbonates. This reaction inherently needs the use of catalysts because it has a significantly high activation barrier (55~59 kcal/mol). Among various types of catalysts, we studied in zeolitic imidazolate framework 90 (ZIF-90)/ionic liquid immobilized ZIF-90 (IL-ZIF-90), polystyrene-supported quaternized ammonium salt, KI/KI-glycine, and dimethylethanolamine (DMEA). First, probable reaction pathways were proposed based on calculated energetics by computational chemistry. The energetics was then used for the thermodynamic interpretation on the activity of catalysts. In the case of ZIF-90/IL-ZIF-90 and KI/KI-glycine, IL-ZIF-90 and KI-glycine showed better yields compared to their counterparts. The calculation proposed interesting results that it is not from the lowering of activation energy but from the unstable intermediates of ZIF-90 and KI-glycine. For DMEA, the calculated activation energy was ~42 kcal/mol, much lower than that of the non-catalytic reaction. A possible reaction pathway was located to confirm the interaction between -NH group from ammonium and oxygen from epoxide for polystyrene-supported quaternized ammonium salt.

비선형 특성의 근사 선형화를 이용한 도립 진자 시스템의 안정화 제어

안기형,최부귀 동아대학교 공과대학 부설 한국자원개발연구소 1994 硏究報告 Vol.18 No.1

When we design a stabilizing controller for a nonlinear system, we usually linearizing the system, and then utilize linear control theory. Thus the performance of the closed loop system depends on the linearizing method used in the controller design. The state space linearization by feedback and nonlinear coordinate transformation is an effective method of control design for a certain class of nonlinear system, but it is not applicable to all systems. In this paper, we proposed approximate feedback linearization method using the differential geometric theory. First, the inverted pendulum system is transformed into the approximate feedback linearized model by nonlinear state feedback. Secondly, the linear controller is designed using the pole placement method for the approximate feedback linearized model. The simulation results are also shown to verify the proposed method.

경쟁기업 확인을 위한 탐색적 연구

안봉근,주기중 啓明大學校 産業經營硏究所 2004 經營經濟 Vol.37 No.1

Confirmation of competitors and knowledge on their strategies are required to establish an effective and efficient strategical competitive edge of a company. This paper presents an integrative model to identify competitors on the theoretical grounds of resources-based, supply-based and demand-based views. Also methodologies of balance score card and some statistical models are suggested to apply and validate the integrative model.

공동주택 지하구조물에 적용되는 방수재의 환경적 열화요인과 부위별 필요성능에 관한 연구-설문조사를 중심으로-

안기원 ( An Ki-won ),강효진 ( Kang Hyo-jin ),오규환 ( Oh Kyu Hwan ),김수연 ( Kim Soo-yeon ),오상근 ( Oh Sang-keun ) 한국건축시공학회 2017 한국건축시공학회 학술발표대회 논문집 Vol.17 No.2

In this study, a survey was conducted to investigate the environmental degradation factors of specific areas in residential apartment underground structures an`d the required performance attributes for waterproofing material. Based on the survey, it was concluded that joint displacement of concrete is the highest cause for problems, and the required performance was determined to high wet surface adhesion performance for waterproofing materials.

아산시 신정호소의 수질오염 현황 및 부영양화 저감 방안

박종안,이종화,장봉기 순천향대학교 기초과학연구소 1998 순천향자연과학연구 논문집 Vol.4 No.1

This study was conducted to estimate the amount of water pollution load, water quantity and quality of inflow stream, status of water pollution and reduction of eutrophication in the Sinjung lake in Asan city. Inflow of branch to Sinjung lake have two streams, one is Cho-sa stream which are Ki-san bridge and Cho-sa bridge and the other is Hwang-san stream. Number of sampling points for water quality are 23 in the Sinjung lake and it's sediment of bottom from March to July, 1997. Water quality had been tested pH, dissolved oxygen(DO), chemical oxygen demand(COD), suspended solid(SS), total nitrogen(T-N), total phosphorus(T-P), E.coli group, and spring out test for sediment are total nitrogen, total phosphorus and heavy metals(Fe, Pb, Cd). The results were as follows; Amounts of pollution load were highest at Cho-sa stream. The ratio of livestock wastewater was occupied with the above 90% of total water pollution load. Mean daily inflow of Cho-sa stream and Hwang-san stream were 34,092㎥ and 25,524㎥, respectively. In mean level of inflow water quality, COD, SS, T-N, T-P and E. coli group were 16.96㎎/ℓ, 50.3㎎/ℓ, 5.85㎎/ℓ, 0.51㎎/ℓ and 4,096/100㎖, respectively. Water quality of inflow was worst at the point of Ki-san bridge in Cho-sa stream. Mean level of DO, COD, SS, T-N, T-P and E. coli group were 6.43㎎/ℓ, 17.11㎎/ℓ, 194.0㎎/ℓ, 5.96㎎/ℓ, 0.56㎎/ℓ and 2,191/100㎖, respectively at Sinjung lake. These are higher than class V by environmental water quality standards for lake. Spring out level of T-N, T-P, Fe and Pb in sediment of Sinjung lake were 326.6ppm, 17.9ppm, 624.2ppm and 2.65ppm, respectively.

海外投資 지역에 따른 韓國 企業의 國際 經營 戰略에 관한 比較 硏究 : 對中國市場 및 對유럽市場의 直接投資에 대한 實證分析

박기안,김달현 韓獨經商學會 1997 經商論叢 Vol.15 No.1

<Abstract> Comparative Study on the Direct Investment Strategies of Korean Industry in China and in European Countries Prof. Ki-An Park/Prof. Daljyun Kim(Kyung Hee University) China and European countries after 1991 are regarded as the greatest market for Korean Firms. Korean Firms will have great opportunity to participate in and benefit from these markets. Korean Firms wish to enter these markets or expand and improve their existing positions there. This paper empirically examines the direct investment strategies in China and the European countries and identify the determinants of performances of Korean firms, in order to make some strategy suggestions regarding the modus of direct investment to be used by Korean firms in China and European countries. This study analyzed the direct investments of Korean Industry in China and European countries. It, therefore, was hypothesized that investing in foreign markets which maintain a high level of market potential, firms prefer to choose good motivations and circumstances. Results of empirical test based on 98 firms support the research hypotheses. Korean firms' investments in China seem to be motivated by the following factors, which are listed in the order of significance: ①to secure low-cost labor, ② to make use of market potential in China, ③ to establish a foothold for entry and favorable location to enter the third country market. Out of these results, one can infer that Korean firms' direct investment strategies in China attach more weight to developing international advantages rather than securing new markets and advanced technologies. As the important determinants for the selection of production sites in China, Korean firms identified the following factors, i.e. lower labor cost of skilled forces in host country, larger local market size and its favorable conditions. Direct Investments in Europe are aimed at assisting Korean firms already in the world market which are unable to strengthen their competitive position independently to enhance their market competitiveness with their own technology and other resources. Under the foreign direct investment in Europe, Korean firms with foreign and Korean partner will establish joint ventures in concerted efforts, joint production and exchange of parts and components and joint sales of goods produced by the partners, share technology and management experiences etc. The basic objective of direct investments in China and Europe is to reduce prime costs, to expand market, and to raise the productivity. Yet, the location decision of Korean firms appears to be different from what the theory says. Namely, the ownership-specific advantages seem to matter little for the Korean firm's choices of host country. Otherwise, market size and the other favorable conditions in the market were among the factors influential in their choice of location. These criteria, that is, low labor cost in China and good labor management in Europe and market size potential of the host country is closely related with the exportled direct investment types of Korean firms in China and Europe. This is because they seem to be greatly concerned about expansion of market and favorable circumstances in host countries. Generally speaking, Korean firms in any host country readily make use of location merits of host country Korean firms should enter full-scale operation to grapple with Chinese and European markets. Particularly some obstacles turn out to warrant special attentions, namely insufficient infrastructure and difficulty in securing the raw material in China. To no lesser degree, in case of threefold important difficulties, Korean firms in China are concerned with the problems of difficulty in local financing and a heavy burden of taxation, as well as competition from third country. But contrary to predicted expectation in the case of tabor management in China labor disputes are more frequent than in Europe. In China there are still many restraining factors which hinder rapid development of foreign direct investment due to the nature of China and its market. More specifically, the internal structure of the economy in China must be completely realigned along with market liberalization and the implementation of economic reform policies, This is no doubt a result of the stage of economic development attained by China. On the other hand, distinctively less headaches are caused by difficulty in securing the raw material as well as infrastructure in Europe. Comparing the difficulties in China with that in Europe, fundamental differencies in legal frameworks and commercial practices are particularly eye-catching. In China, the Korean firms want to go to guarantee the recruitment of the labor of low cost for the labor-intensive industry, This case is distinguished from the motives for Foreign Direct Investment in European countries by Korean firms. Korean firms in China and Europe are the market seekers. They go to the host countries to protect and develop their markets and they also want to serve growing market as well. Production efficiency seekers want to recruit the skilled labor of lower cost in China and want to cooperate with partners in Europe. The cooperation lies in boosting of competitiveness in the world market. Korean companies remain generally cautious when considering investment in foreign countries because of various risks. Differences in legal frameworks and commercal practices with the host countries pose as a challenge for Participating companies. In pursuing to promote the direct investment, existing problems in investment should be scrutinized so that amicable solutions are sought in a logical and rational fashion. Along these lines, procedures must be readjusted and developed to accommodate the needs of the partner countries involved through fostering a climate conducive to the entry and profitable operation of foreign or joint-venture enterprises, developing an adequate infrastructure to support manufacturing activities, and framing and implementing investment legislation with fairness and impartiality.

혈중납이 흰쥐의 Microsomal Cytochrome P-450 Monooxygenase 활성도에 미치는 영향

박기현,장성근,윤영안,김기웅,박종안 순천향대학교 1993 논문집 Vol.16 No.3

In rats treated with lead nitrate and/or red ginseng extract mixture we observed a change in the level of hepatic cytochrome P-450 and electron transport system for P-450 dependent reaction, and content of Zincprotoporphyrin(ZPP) and Hemoglobin(Hb) in whole blood. The content of cytochrome P-450 and ?? , and the activity of ECHEase, AHHase and NADPH-cytochrome C(p-450) reductase were slowly decreased according to the dosage of lead nitrate. On the other hand, the activity of ?? reductase was increased according to the dosage of lead nitrate, but in case of treatment with red ginseng mixture, this enzyme activity was slightly decreased. In whole blood, the content of hemoglobin and ZPP were not shown any critival change but lead content increased according to dosage of lead nitrate. These results suggest that content and activity of cytochrome P-450-dependent monoxygenase may be dependent on specificity of substrates, and the acute exposure of lead nitrate and red ginseng extract mixture was not affected any biological significance.

定期船 海運의 運賃決定要因과 安定化方案에 관한 硏究

박호건,안기명 한국해운물류학회 2002 해운물류:이론과실천 Vol.- No.3

정기선 해상운송과 관련 운임 결정에 있어서 경제 이론적, 경영 과학적 접근방법과 카르텔 형태인 해운동맹 등을 통하여 인위적이고 물리적인 방법 하에 적정운임 결정을 도출하려는 연구가 이루어져 왔으나 현대조선 기술의 발달과 단위당 비용 절감을 통해 규모의 경제를 실현하고져 계속되는 초대형 컨테이너 선박의 건조는 제한된 정기선 시장에 만성적인 선복 공급 과잉이 되어 극심한 경쟁으로 기존 운임시장이 교란되어 원가이하의 운임 수입으로 해운기업들의 통폐합 또는 존폐문제로 귀결되고 있으며, 더욱이 정기선 시장의 불안정과 운임의 극심한 편차는 궁극적으로 안정된 국제 상품 교역에 위해 요소로 작용하고 있는바 이와 관련 정기선 시장의 운임에 영향을 미치는 요인을 실증 분석하여 그 대책과 방안을 제시하여 정기선 시장의 질서 유지와 운임 안정화를 도모하는데 연구목적을 두고져한다. The global liner shipping markets have changed significantly since year 1990 especially in containerized liner freights. The number of liner containers has increased steadily to about 6-12 percent every year and KMI forecasted global container movements in year 2002 as 248 million TEU showing 142% up on 103 million TEU in year 1992. As well, the number of container vessels and its loading capacity have increased drastically for the purpose of contributing to the increase in worldwide demand for liner freights and the existence of economies of vessel size. KMI reported that the global loading capacity of container fleets will be estimated as 5.5 million TEU showing 150% up on 2.2 million TEU in year 1992 and the size of vessel to be ordered by global carriers become bigger and larger to Post/Super panamax model of 6,000-8,000 TEU capacity as fifth to seventh generation type. Ultimately, the trend to more and larger ships has been accompanied by strong growth in available liner capacity. Most of trade routes have been oversupplied with ship slots and reported that the surplus ratio of ship's slots will be around 24.5% in year 2002 and further estimated excess capacity of 30-40% in the Trans- pacific and the Europe trade. Eventually, such excess capacity in liner shipping is a result of increased competition among the carriers, in which appears to have led to a quest for lower freight rates and lower costs. In turn the liner market has been extremely unstabilized by intense and unfair competition each other and the profitability of liner carries become poor and lower and such low profits may be a force driving toward strategies involving alliances, mergers and building bigger ships in an effort to capture economics of scale and scope. To make it worse, some of carriers having financial difficulties have finally gone to the bankruptcy. Accordingly, the primary objective of this thesis is to explain the determinant of the freight rates theoretically and practically and to find out how to take an appropriate measures to be stabilized for liner markets and liner freight rates through the introduction of institutional and systematical approaches to the liner shipping industry.

18세기 범신론 논쟁: 야코비의 스피노자의 가르침에 관한 편지들(1785)

안윤기 ( Yoon Ki An ) 한국칸트학회 2012 칸트연구 Vol.30 No.-

스피노자의 가르침에 관해 멘델스존에게 보낸 편지들에서 야코비는 레싱이 자신과의 대화 중 본인의 스피노자주의를 고백했다는 충격적인 보고를 한다. 이로써 18세기 후반 독일 지성계를 강타한 ``범신론 논쟁``이 야기되는데, 그 논쟁의 두 주인공은 야코비와 멘델스존이었다. 논점은 몇 차례 변화를 겪는다. 초기에는 레싱이 정말로 그런 고백을 했는지 여부가 초미의 관심사였다. 왜냐하면 독일 계몽주의의 상징적 인물인 레싱이 - 무신론으로 세간에 알려진 - 스피노자주의를 고백했다는 것은, 이미 그 자체만으로도 세인(世人)의 마음을 뒤흔들 수 있을 만큼 파괴력이 있었던 스캔들이요, 따라서 레싱과 절친한 사이로 공인된 멘델스존은 이러한 사태가 벌어지는 것을 그저 앉아서만 지켜볼 수 없었다. 그렇지만 점차 이 논쟁은 누가 스피노자의 철학을 더 정확히 잘 알고 있느냐의 문제로 확산되었고, 궁극적으로는 이성의 능력 자체에 대한 이성주의의 과도한 신뢰가 야코비에 의해 의문시되었다. 야코비는 한 때 스피노자의 철학을 탐독했던 사람이다. 그러나 그는 얼마 안 가서 스피노자 철학의 위험성을 간파하고 이를 비판하게 되었다. 야코비가 스피노자의 철학에 관심을 갖게 된 이유는, 이것이 가장 이성주의의 원칙을 일관되게 관철 시키고 있었기 때문이다. 그런데 이런 일관된 체계성이야말로 비판거리였는데, 왜냐하면 거기서 발휘되는 사유는 현존에 대한 근원적 경험을 놓쳐서이다. 그가 보기에는 오직 이런 현존 경험만이 확실한 것이다. 그러니까 야코비가 체계적 사유를 비판하면서, 우리가 그 아래 감춰진 존재의 드러남을 보는 것이다. 그리하여 결국 야코비가 제안한 것은 믿음으로의 도약(salto mortale)이었다. 그는 이런 믿음을 때로는 거부할 수 없는 느낌이라고도 불렀다. 그가 목표로 했던것은, 현실이 근원적으로 드러난 모습을 그 자체로 붙드는 일이었다. 이에 비해 본다면, 사유 또는 추론을 통한 인식은 근원적 경험에 의존하는 2차적 확실성만 제공할 뿐이다. In den Briefen an Mendelssohn uber die Lehre Spinozas hat Friedrich H. Jacobi ein Gesprach mit Lessing aus dem Juli 1780 uberliefert, in dem Lessing sich zum Pantheismus Spinozas bekannte. Diese Außerung Jacobis bildete den Ausgangspunkt fur den Pantheismusstreit, der zwischen ihm und Moses Mendelssohn ausgetragen wurde. Das Zentrum des Streits hat sich doch mehrfach verschoben. Zuerst war es das Bekenntnis Lessings, das allein schon die Gemuter aufs außerste erregte und Mendelssohn zu einer Reaktion herausforderte. Im weiteren Verlauf weitete der Streit sich aus zu einer Auseinandersetzung um die Philosophie Spinozas und schließlich zu einer um den Rationalismus als solchen. Spinozas Philosophie faszinierte Jacobi, zugleich aber ist er ihr erbitterter Gegner. Im Spinozismus erkennt er das einzig konsequente System des Rationalismus an. Die Geschlossenheit aller konsequente Systeme ist es jedoch auch wiederum, die seine Kritik hervorruft, denn in ihnen schließt sich das Denken gegen die Erfahrung seines Ursprungs, d.h. die Daseinserfahrung, ab, die letztlich allein Gewißheit bringen kann. Von der Einsicht in die Gebundenheit des Geistes in den Lebenszusammenhang erhofft Jacobi sich einen Blick auf Phanomene, die dem System verschlossen bleiben, ja die eine Kritik jeglichen Systemdenkens darstellen. Deshalb schlagt Jacobi endlich einen Sprung in den Glauben (salto mortale) vor, den er auch manchmal unabweisbares Gefuhl nennt. Die Anstrengung seines Denkens zielt darauf, die ursprungliche Erschlossenheit des Wirklichen so zu fassen, dass die mittelbare Erkenntnis aus Schlussen als von ihr dependierend, als eine Gewißheit aus zweiter Hand begriffen werden kann.

포괄적인 정보시스템 성과평가모형에 관한 연구

안봉근,주기중,권해익 한국경영과학회 2004 經營 科學 Vol.21 No.2

Measuring performance of corporate information system has become one of the core issues in that development of the information system requires substantial amount of investments and the system works as a crucial leverage to enhance competitive edge. Most of the previous researches for performance of the information system have narrow and limited focus on such as the effect of user satisfaction and productivity. This paper suggests a model to measures the comprehensive performance which is classified as user scope (user involvement and satisfaction), operational scope (task productivity, task innovation, customer satisfaction, management control) and efficiency scope (financial performance), and to represent the relationship among the scopes by the path analysis model. Followings are conclusions from statistical hypothesis test of the model: (ⅰ) user involvement through user satisfaction has positive effect on all the performances in the operational scope, (ⅱ) task innovation and customer satisfaction in the operational scope has statistically significant impact on financial performance but task productivity and management control do not. This conclusion indicates that task productivity and management control has the long term effect in nature, and evaluation of the information system has managerial implication when it is measured in comprehensive performance which includes internal operational performances as well as financial performance.