The Computer Algebra Systems in Mathematics Education : A Review of Recent Research

Kwon, Oh-Nam,Shin, Eun-Ju,Shon, Bo-Kyung 이화여자대학교 교과교육연구소 2001 East west education Vol.18 No.-

This study examines the potential role for Computer Algebra Systems(CAS) in such an educational context, particularly their potential to get students more engaged in the learning of mathematics as well as to reduce the "strangle hold" of prerequisite algebraic skills, in courses such as functions, introductory calculus. What is the present status of and near-future outlook for computer algebra in Korean secondary schools? The answer that arises from this review of available fact is: bright with promise, but still dim. Several recent developments have set the stage for an acceleration in the dissemination rate for CAS to high schools. However, this review of some past and present conditions indicates that many years will pass before computer algebra is impacting high school mathematics as much as hand-held calculators are doing now.

해마 theta리듬과 pyramidal neuron의 세포내 특성과의 상관관계

권오흥,조진화,남순현,김현정,최병주,김영진,이만기 大韓小兒齒科學會 1998 大韓小兒齒科學會誌 Vol.25 No.4

Eledctrophysiological phenomena of pyramidal cells in the CAI area of the dorsal hippocampus were recorded from and filled with neurobiotin in anesthetized rats. The electropharmacological properties of membrane as well as the cellular-synaptic generation of rhythmic slow activity (theta)were examined. The intracellular response characteristics of these pyramidal cells were distinctly different from responses of inteneurons. Pyramidal cells had a high resting membrane potential, a low input resistance, and a large amplitude action potential. A afterhyperpolarization was followed a single action potential. Most of pyramidal cells did not display a spontaneous firing. Pyramidal cells displayed weak inward rectification and anodal break excitation. The slope of the frequency-current relation was 53.4 Hz/nA for the first interspike interval and 15.9 Hz/nA for the last intervals, suggesting the presence of spike frequency adaptation. Neurobiotin-filled neurons showed pyramidal morphology. Cells were generally bipolar dendritc processes ramifying in stratum lacunosum-moleculare, radiatum, and oriens. Commissural stimulation discharged pyramidal cells, followed by excitatory and inhibitory postsynaptic potentials (EPSPs and IPSPs). The frequency of theat-related membrane potential oscillation was voltage-independent in pyramidal neurons. At strong depolarization levels (less than 30 mV) pyramidal cells emitted sodium spike oscillation, phase-locked to theta. The observations provide direct evidence that theta-related rhythmic hyperpolarization of principal cells is brought by the rhythmically discharging interneurons. Furthermore, the findings in which interneurons were also paced by rhythmic inhibitory postsynaptic potentials during theta suggest that they were periodically hyperpolarized by their GABAergic septal afferents.

Bacillus cereus에 있어서 Phospholipase C활량에 관한 몇가지 계면활성제의 영향

권오용,윤희주,한수자 충남대학교 자연과학연구소 1987 忠南科學硏究誌 Vol.14 No.2

This study demonstrates the effects of four detergents and three on the activity change of phospholipase C which is prepared from the cultural broth of Bacillus cereus. This assay of phospholipase C activity was carried out with phosphatidylcholine micelles which were mixed with the detergents and sterols, with increase a molar ratio of these compounds to phosphatidylcholine. Phospholipase C was highly activated at 0.5 molar ratio of Tween 80-mixed micelles. In the case of Triton X-100, it was activated at higher molar ratio indicated 1.0. Sodium dodecyl sulfate was more effective than that of the other detergents at lower molar ratio. However sodium deoxycholate-mixed micelles increased the activity more 7 times than that of the control group. This maximum activation was occurred at 2.5 molar ratio and the turbidity was gradually decreased. Cholesterol and ergosterol increased the activity until molar ratio reached up to 0.9. But the activity was higher at 0.3 molar ratio for stigmasterol. Consequently, it was indicated that phospholipase C was activated with the supplement of detergents until the mixed micelles made a number of small and spherical shape.

상황인지 기반 최적화가 가능한 개인화된 모바일 웹서비스 구축을 위한 다중에이전트 접근법에 관한 연구

권오병,이주철 한국경영과학회 2004 經營 科學 Vol.21 No.3

Recently the usage of mobile devices which enable the accessibility to Internet has been dramatically increased. Most of the mobile services. however, so far tend to be simple such as infotainment service. In order to fully taking advantage of wireless network and corresponding technology, personalized web service based on user's context could be needed. Meanwhile, optimization techniques have been vitally incorporated for optimizing the development and administration of electronic commerce. However, applying context-aware optimization mechanism to personalized mobile services is still very few. Hence, the purpose of this paper is to propose a methodology to incorporate optimization techniques into personalization services. Multi agent-based web service approach is considered to realize the methodology. To show the feasibility of the methodology proposed in this paper, a prototype system, CAMA-myOpt(Context-Aware Multi-Agent system for my Optimization), was implemented and adopted in mobile comparative shopping.

중학교 과학 교과서 분별 증류 실험의 비교 분석 및 개선

柳五鉉,崔文永,宋周眩,권정근,白盛惠,朴國泰 한국교원대학교 과학교육연구소 2001 청람과학교육연구논총 Vol.11 No.1

이 연구의 목적은 제 6차 교육과정에 의한 중학교 1학년 과학 교과서 분별 증류 실험의 문제점을 파악하고, 중학생들이 분별 증류 실험을 능률적으로 수행할 수 있는 실험 방법을 제시하고자 하는 것이다. 이를 위한 첫 번째 단계로서 현재 사용되고 있는 8종의 과학 교과서를 분별 증류 실험 장치와 액체 혼합물의 종류에 따라 6가지로 분류하였다. 두 번째 단계로서 액체 혼합물을 가열 방법에 따라 직접가열과 물 중탕 가열로 나누어 교과서 실험과정에 따라 같은 실험을 세 번 실시하였다. 세 번째 단계로서 실험 결과의 문제점을 해결하기 위한 대안 실험을 실시하였다. 대안 실험에서는 알코을 램프로 직접가열 하는 방법과 기름 중탕으로 가열하는 방법, 그리고 가열 맨틀을 사용하여 가열하는 방법을 사용하였다. 연구결과, 가지 달린 둥근 플라스크를 직접 가열하는 실험 결과가 가지 달린 시험관을 물 중탕으로 가열하는 실험 결과보다 이론적인 결과에 근접하였다. 그리고 가지 달린 둥근 플라스크를 직접 가열하는 실험에서 플라스크 윗 부분을 보온해 주는 실험이 보온하지 않은 실험보다 실험 결과가 더 나았다. 대안 실험에서는 액체 혼합물의 증류 온도 증가를 보면서 가열 맨틀의 가열 온도를 을려 준 실험의 결과가 이론적인 결과에 가장 가까웠다. 이러한 연구 결과로부터 가지 달린 시험관을 물 중탕으로 가열하는 분별 증류 실험 장치는 탐구실험 수업에 부적절한 것이므로 개선이 요구되며, 중학교 과학실 여건을 고려할 때, 액체 혼합물의 증류 온도 증가를 보면서 가열 맨틀의 가열 온도를 변화시키는 분별 증류 실험이 가장 능률적인 방법임을 알 수 있었다. The purpose of this study was to find out the problems on the fractional distillation experiments in the middle school science textbooks based on the 6th curriculum and to suggest an efficient experiment method for the middle school students. The first step was the classification of the experiments in 8 science textbooks according to heating apparatus and liquid mixtures. The second step was doing each experiment 3 times followed by the experimental process in the textbooks. The third step was developing the alternative experiments for solving the problems found in the second step. The heating method used in the alternative experiments were direct heating, oil bath, and heating mantle. The results of the second step showed that the direct heating experiment of branched round flask was more close to the theoretical prediction than the experiment of water bath heating of branched test tube. Also the direct heating experiment of thermally insulated branched round flask was better than the result of the experiment which was not insulated. The results of the third step showed that the experiment using heating mantle regulated heating power by observing the temperature of distillate gave the closest result to the theoretical prediction. From the above results, it is concluded that the experiment using branched test-tube with water bath heating is not adequate for the fractional distillation and an alternative experiment using insulated branched round flask with heating mantle regulated heating power during experiment is recommended.

배추(Brassica campestris L. var. pekinensis Makino)의 cDNA library 구축 및 상동성 비교

안주미,권오병,전봉균,이풍연,이정민,권무식 성균관대학교 생명과학자원연구소 1995 生命資源科學硏究 Vol.2 No.1

Expressed sequence tag(EST) has a good value to discover a new gene or to study its structure. Some 20 ESTs were generated to obtain new genetic resources of chinese cabbage(Brassian campestris L. var. pekinensis Makino). Poly A+ RNAs were isolated from 10-day-old seedlings grown at 25℃ under the day light. cDNA gene bank was constructed using λ ZAP /cDNA synthesis /Giga Pack Gold Packing kit. About a million clones were able to obtain from the library. All the clones examined so far had insert DNAs. Nucleotide compositions of randomly selected clones were determined by the Sanger mthod. The DNA sequences were compared with those deposited in the GenePept and GenBank database to figure out nucleotide homologies. Two ESTs showed significant similarities to the enlisted sequences. They are chloroplast GADPH subunit of Arabidopsis thaliana and carbonic anhydrase of A. thaliana. The full DNA sequences of the two clones are being determined. The cDNA gene bank constructed. in this experiment will being used to isolate more genes induced by the light in the plant.

Benzo(a)pyrene에 의해 유도된 간기능 장해에 미치는 세신 추출액의 영향

정영건,권오진,윤수홍,이송애,이주영 효성여자대학교 부설 한국환경위생연구소 1993 환경위생연구 Vol.3 No.1

탄소화합물의 불완전 연소 및 열분해에 의해 생성되는 다환방향족 탄화수소로 간 실질세포에서 cytochrome P_450에 의해 산화되는 간장해 물질인 benzo(a)pyrene으로 유도한 rats의간독성 발현에 미치는 세신 수침액의 예방 및 치료 효과를 실험한 결과 세신 수침액의 투여는B(a)P 투여로 현저하게 증가된 혈청 및 간장의 transaminase 활성을 유의성 있게 감소시켰으며 그효과는 조직에서 보다 우세하였다. 그러나 세신 수침액이 B(a)P투여로 증가한혈청 total cholesterol과 phospholipid 함량을 감소시킬 수는 있었지만 그 효과는 약하여 지질대사에는 세신의 작용이 미미할 것으로 보인다. Effects of Asiasari Radix, which is herbal drug used frequentlyin the oriental prescriptions, water extract on the liver-protective activities wereinvestigated in the rats. Asiasari Radix water extract, when administered intothe gastric intubation, produced liver-protective effect against benzo(a)pyreneinduced liver damage. The results obtained from enzyme assay, measurement of serum and liveralanine aspartate aminotransferase(AST, ALT) and lipid composition indicatedthat Asiasari water extract showed significant liver-protective activities againstbenzo(a)pyrene-induce hepatotoxicity.

천연자원을 이용한 간기능 증진제 개발 연구 : Benzo(a)pyrene에 의해 유도된 간기능 장해에 미치는 익모초 추출액의 영향 The Effect of Leonuri Herba on Benzo(a)pyrene Induced Hepatotoxicity

정영건,권오진,윤수홍,박은주 효성여자대학교 부설 한국환경위생연구소 1994 환경위생연구 Vol.4 No.1

Benzo(a)pyrene으로 유도한 rats의 간독성 발현에 미치는 익모초 수침액의 예방 및 치료효과를 실험한 결과 익모초 수침액의 투여는 B(a)P투여로 현저하게 증가된 혈청 및 간장의 AST, ALT, LDH, ALP 활성을 유의성 있게 감소시켰고 B(a)P 투여로 변화한 혈청 지질함량에 약간의 회복도를 보이기는 하나 현저한 차이는 없었다. 즉 익모초의 투여는 B(a)P에 의한 간독성 발현을 효소적으로 유의성 있게 감소시켰으며 그 효과는 전처리가 후처리에 비해 우수하다. The present study was undertaken to compare the pharmacological activity of crude Leonuri Herba reported with the clinical uses in the oriental medicine. Crude Leonuri Herba used for the treatment of gynecologic condition, irregular menstration, parturition hemaostater and diuretics. Therefore we tested the effects of Leonuri Herba water extract on the liver-protective activities in the rats. The results obtained from liver microsomal enzyme assay, measurement of serum and liver alanine aspartate aminotransferase and lipid accumulation indicated that Leonuri Herba extract showed significant liver-pro-tective activities against benzp(a)pyrene poisoning.

MPEG-2 비디오 디코더(MP@HL)의 상위 레벨 설계에 관한 연구

박준호,오주환,천성권 경운대학교 산업기술연구소 2002 産業技術硏究論文誌 Vol.5 No.1(A)

In this paper, high level of MPEG-2 video MP@HL decoder is designed and follows ISO/IEC 13818-2 standard specification. MPEG-2 video decoder consists of system processign board, slice processign board, and motion processing board, which is compatible with MPEG-TS and MPEG layer-2. Each board represents schematic level design and external interface.

Benzo(a)pyrene에 의해 유도된 간기능장해에 미치는 자근 추출액의 영향

윤수홍,박은주,오관현,정영건,권오진 효성여자대학교 부설 한국환경위생연구소 1994 환경위생연구 Vol.4 No.1

민간에서 주로 사용되는 약용식물들 중 간독성의 발현 저해 및 간기능 보호효과가 우수한 약물을 찾아 임상적인 약효를 밝혀보고자 하는 실험 과정으로 탄소화합물의 불완전 연소 및 열분해에 의해 생성되는 간장해 물질인 benzo(a)pyrene 으로 유도한 rats 의 간독성 발현에 미치는 자근 수침액의 예방 및 치료효과를 실험한 결과 자근 수침액의 투여는 B(a)P 투여로 현저하게 증가된 혈청 및 간장의 AST, ALT, LDH, ALP 활성을 유의성있게 감소시켰고, B(a)P투여로 증가한 혈청 total cholesterol 및 phospholipid 함량 역시 감소시킬 수 있었으나 그 효과는 현저하지 않았다. 즉, 자근 수침액의 투여는 B(a)P에 의한 간독성 발현을 유의성 있게 감소시켰으며 그 효과는 전처리가 후처리에 비해 우수하였다. The present study was undertaken to compare the pharmacologicalactivities of cn de Lithospermi Radix reported with the clinical uses in the orientalmedicine. Crude Lithospermi Radix uesd for the treatment of burn, eczema,blister, diuretic, scarlet fever and septicemia as antipyretic, antidotic and antiph-logistics. Therefore we tested the effects of Lithospermi Radix water extracton the liver-protective activities in the rats. The results obtained from enzymeassay, measurement of serum and liver alanine·aspartate aminotransferase(ALT, AST) and lipid composition indicated that Lithospermi Radix water extractshowed significant liver-protective activities against benzo(a)pyrene-induced he-patotoxicity.