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.

Comprehensive genomic analyses with 115 plastomes from algae to seed plants: structure, gene contents, GC contents, and introns

Eun‑Chae Kwon,Jong‑Hwa Kim,Nam‑Soo Kim 한국유전학회 2020 Genes & Genomics Vol.42 No.5

Background Chloroplasts are a common character in plants. The chloroplasts in each plant lineage have shaped their own genomes, plastomes, by structural changes and transferring many genes to nuclear genomes during plant evolution. Some plastid genes have introns that are mostly group II introns. Objective This study aimed to get genomic and evolutionary insights on the plastomes from green algae to flowering plants. Methods Plastomes of 115 species from green algae, bryophytes, pteridophytes (spore bearing vascular plants), gymnosperms, and angiosperms were mined from NCBI organelle genome database. Plastome structure, gene contents and GC contents were analyzed by the in-house developed Phyton code. Intronic features including presence/absence, length, intron phases were analyzed by manually in the annotated information in NCBI. Results The canonical quadripartite structures were retained in most plastomes except of a few plastomes that had lost an invert repeat (IR). Expansion or reduction or deletion of IRs resulted in the length variation of the plastomes. The number of protein coding genes ranged from 40 to 92 with an average 79.43 ± 5.84 per plastome and gene losses were apparent in specific lineages. The number of trn genes ranged from 13 to 33 with an average 21.19 ± 2.42 per plastome. Ribosomal RNA genes, rrn, were located in the IRs so that they were present in a duplicate except of the species that had lost one of the IR. GC contents were variable from 24.9 to 51.0% with an average 38.21 ± 3.27%, indicating bias to high AT contents. Plastid introns were present in 18 protein coding genes, six trn genes, and one rrn gene. Intron losses occurred among the orthologous genes in different plant lineages. The plastid introns were long compared with the nuclear introns, which might be related with the spliceosome nuclear introns and self-splicing group II plastid introns. The trnK-UUU intron contained the maturase encoding matK gene except in the chlorophyte algae and monilophyte ferns in which the trnK-UUU was lost, but matK retained. There were many annotation artefacts in the intron positions in the NCBI database. In the analysis of intron phases, phase 0 introns were more frequent than those of phase 2 and 3 introns. Phase polymorphism was observed in the introns of clpP which was derived from nucleotide insertion. Plastid trn introns were long compared to the archaeal or eukaryotic nuclear tRNA introns. Of the six plastid trn introns, one was at the D loop and other five were at the anticodon loop. The insertion sites were conserved among the trn genes in archaea, eukaryotic nuclear and plastid tRNA genes. Conclusions Current study refurbrished the previous findings of structural variations, gene contents, and GC contents of the chloroplast genomes from green algae to flowering plants. The study also included some noble findings and discussions on the plastome introns including their length variations and phase variation. We also presented and corrected some false annotations on the introns in protein coding and tRNA genes in the genome database, which might be confirmed by the chloroplast transcriptome analysis in the future.

연시조의 현대적 계승과 종장 운용의 특성 -이병기의 연시조를 중심으로-

권정은 ( Jung Eun Kwon ) 한국시가학회 2010 韓國 詩歌硏究 Vol.29 No.-

이 논문은 가람 이병기의 연시조를 대상으로 그 종장 구성의 특성을 살펴봄으로써 현대 시조가 전통적인 양식을 계승하면서도 어떻게 현대적인 미감을 효과적으로 표현할 수 있었는지 탐색하고자 했다. 연시조는 일찍이 사대부 시조로서의 확고한 지위를 누리면서 조선시대에 지속적으로 창작되었는데, 현대시조에서도 그 가치를 크게 인정받으며 재등장 했다. 하지만 현대시조 직전의 개화기시조의 경우를 보면 연시조를 배제한 단형시조를 위주로 하면서 종장의 마지막 어구를 생략하는 가운데 당대의 급진적이고 현실적인 내용을 담아냈다. 그런데 막상 개화기시조를 이은 현대시조는 정반대의 형태를 보임으로써 외형상으로서는 오히려 중세로 회귀한 듯한 인상을 주게 되었는데, 그럼에도 불구하고 실상 종장의 운용 양상을 살펴본 결과 사정이 다르다는 것을 알 수 있었다. 우선 초, 중장과 종장의 연결 구조를 볼 때 기존의 고시조와는 달리 종장이 분리되지 않고 문법적으로 연결되는 것을 확인할 수 있었다. 아울러 비록 공식적인 율격이 잘 지켜 지기는 했지만 의미상으로는 고시조와 같은 종결을 통한 완결이 아닌 개방성을 지향하는 것을 알 수 있었다. 이러한 개방성은 심리적 발산을 근거로 상황을 연속적으로 제시함으로써 시인의 감성이 보다 자유롭게 표현될 수 있는 여지를 마련했던 것이다. 그래서 결과적으로 고시조의 종장이 긴장을 강화함으로써 종결을 유도했던 반면에, 현대시조의 종장은 표면적으로는 전통적인 정형시로서의 틀은 그대로 유지하고 있었지만 종장의 개방성을 허용함으로써 현대시조가 보다 강화된 서정시로서 재탄생하는 데에 일조했던 것을 확인할 수였었다. This paper aims at examining the stanzaic si-jo of Lee Byoung-gi(l891~1986), specially having an emphasis on the last line. Lee is representative poet for contemporary si-jo of early 20th century in that time so many famous poet likes Choe, Nam-sun or Lee, eun-sang strived to show Korean beauty in si-jo, Korean traditional lyric poem. Among these poets, Lee Byoung-gi is specailly famous for reflecting natural life without exaggerated emotion in his stanzaic si-jo. Stanzaic si-jo is the connection of short type normal si-jo which made with three lines under the same theme. It drove from early Jo-seon dynasty though, this stanzaic form had a key to realize modern feeling in Lee`s si-jo. To investigate that kinds of value, this paper specially focus on the composition of concluding line in Lee`s works. Generally concluding line of si-jo performed the convergence of theme and tends to be independent. But in the case of Lee`s, last(third) line is closely connect with second line in both side of grammar and meaning. Even though basically last line of Lee`s obeys the perfect traditional rules of versification, apart from that rule, it constructed new poetic order. Most of all, the third line of Lee`s are not independent from first & second line. This situation is strange in the virtue of common si-jo, but from this variated from Lee can made his si-jo more sensitive. Lee`s concluding line is not close but open and among this openness separated individual work of stanzaic form linked naturally under the same emotion and theme. And all of these feature allow si-jo to correspond to 20th new modern complicated era.

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.

청주시 토지이용의 특성과 공간구조적 해석

권상준,이은엽 淸州大學校 都市·地域開發硏究所 1996 都市·地域開發硏究 Vol.2 No.-

This study focus on the issue that the urban land uses are neither fixed nor rigid even though the contex of urban character is corelated to the social, historical and cultural bad ground. This study find on the spatial structure transition corelated to the characterized land uses that could show the biogentic and energenic integrations of the urban functions. The findings of the transition abstract as follow: a. The trend of the residential areas in Chongju can be represented as a simple formular Yi=13.85+(1.99×Xi). b. The trend of the commerical areas in Chongju can be represented as a simple formular Yi=-3.42+ (1.99×Xi). c. The trend of the indurstrial areas in Chongju can be represented as a simple formular Yi=2.44+(0.762×Xi). d. The trend of the open space areas in Chongju can be represented as a simple formular Yi=250.3+(-4×Xi).

디지털 환경에서의 도서관 자원공용

권은경 大邱大學校 社會科學硏究所 1999 社會科學硏究 Vol.6 No.1

전자출판과 인터넷의 결합은 디지털정보의 생산 뿐만 아니라 네트워크 출판을 가능하게 하였다. 정보검색 표준 프로토콜인 Z39.50의 구현으로 네트워크로 연결된 타 도서관의 OPAC시스템을 쉽게 탐색할 수 있게 되어 도서관 이용자들이 언제 어디서나 필요한 정보를 탐색하고 접근할 수 있다는 디지털도서관의 꿈이 이루어지는 듯이 보인다. 현실적으로 아직은 인쇄매체가 정보전달 매체적 주류를 형성하고 있고, 디지털정보가 점차 증가한다 하더라도 상당히 오랜 기간 이원화된 정보이용 체제가 지속될 것으로 예측된다. 본 논문은 이러한 과도기적 상황하에서 효과적인 자원의 공동 이용 방법에 관하여 고찰하였다. 먼저 디지털환경 이전의 도서관 자원공용 방법과 파생된 문제점을 살펴보았다. 그리고 자원공용의 필요성을 날로 심각하게 일깨우는 요인으로 최근의 출판량의 증가와 가격인상, 상대적인 구입자료의 감소 추세, 그리고 연구방법의 변화를 분석하였다. 미국에서 비교적 최근에 조직되고 있는 OhioLINK, CIC 등은 전통적 자원공용에서 발생하는 인쇄매체 상호대차의 비효율성을 극복하고 디지털정보를 공동으로 이용하기 위한 지역적 콘소시움이다. 회원도서관의 장서에 대한 용이한 OPAC탐색, 간편한 온라인 대출 신청, 신속하고도 신뢰할 수 있는 물리적 접근의 제공은 인쇄매체의 공용에 전환점을 마련하였고, 디지털정보에 대한 공동 이용 계약은 회원도서관에 비용절감의 효과와 함께 더 많은 정보에의 접근을 가능하게 하였다. 디지털기술은 서지적 접근과 상호대차 매카니즘을 개선하여 소장자료에 대한 접근을 크게 향상시켰으나 접근은 소장을 전제로 해서만 가능한 것이므로 장서 수집을 위한 협력이 지속적으로 요구된다. 그러므로 도서관은 소장과 접근이 균형을 이룬 복합적이고도 전략적인 자원공용 패러다임을 개발하여야 할 것이다.

유아를 위한 절제·절약 프로그램의 적용사례 연구

권미량,김은주 부산대학교 영유아보육연구소 2002 영유아보육연구 Vol.8 No.-

This program developed, implemented, and evaluated "moderation and saving activities" for early childhood facilities. This program had conducted in children who from 3 to 5 years old in H child care center, from March, 2001 to February, 2002. This program was implemented with daily activities and education activities. daily activities consist of the following ; using furniture longer, saving education material, saving clothes in daily life, saving food, managing garage market. education activities consist of following ; role play, children's story, children's story play, shop play, mathematics activities, cooking activity, language activity, project activity, trip activity. This program was evaluated positively by the children, teachers, and parents. The children had formed saving habit and gotten sharing life style. They could have thoughts of rotation and sharing. The teacher could get the idea of economy with sharing and reusing and the idea of education thinking material and life. The parents could lower desire for purchasing and form economic family life style. Through this program, there were chances of interactions between parents and children, parents and teachers and gave effect of increasing communication with a community.

한국의 재활의료 전달체계

권혁철,정영일,남은우 高神大學校 保健科學硏究所 1993 보건과학연구소보 Vol.3 No.-

This study was carried out for reorientation of Rehabilitation Service Delivery System (RSDS) through reviewing reference and observing field practice. The most important results are as follows: 1. The current rehabilitation facility for handicapped persons can be classified into four categories : (a) those for physically disabled persons, (b) those for mentally disturbed persons, (c) those for visually disturbed persons, and (d) those for acoustic and speech disturbed persons. The nationwide number of rehabilitation facilities is 101 of those, 43.5% is for physically disabled persons and 32.9% is for mentally disturbed persons. 2. A small number of circulating rehabilitation centers for physically disability are being run by comprehensive rehabilitation centers since 1992. 3. The hospitals are self-supporting only 20% of their operational costs, and the rest of the operational costs comes from federal tax(40%) and local tax(40%). 4. The number of handicapped persons in Taegu and Kyungpook province is estimated to be about 50,000, but only 20 percent out of them ws registered. The rehabilitation facilities located in this area receives 69% of their operational costs from central government. This figure is higher than the national average of 64.6%. 5. Although RSDS is different from other medical delivery system, nonetheless, it should be developed as a sub-system of national health care delivery system. Its development should also be in accordance with the need of local community. Therefore we suggest the development policy for the development of RMDS must consider the following points.; First, all rehabilitation-related medical systems should be integrated unde ra single comprehensive system so that handicapped persons may easily obtain better service available. Second, rehabilitation programs based on local community should be rejuvenated. In addition to in-patient service, development of intermediate facilities and programs connecting home and society should be encouraged. Third, rehabilitation medical services should be more specialized. Also, more emphasis should be given to team approach to rehabilitation medical services. Fourth, a comprehensive rehabilitation information system should be developed so that handicapped persons may have easy access to public welfare facilities, and the central government should formulate a comprehensive long-term plan for the rehabilitation system.

신경회로망 제어기를 이용한 PID 파라미터 추정에 관한 연구

權重東,裵銀敬,金恩基,全基英,李承桓,吳鳳煥,李勳九,金容珠,韓慶熙 明知大學校 産業技術硏究所 2006 産業技術硏究所論文集 Vol.25 No.-

In this paper, supposed to solve these problem to PID parameters controller algorithm using ANN. In the proposed algorithm, the parameters of the controller were adjusted to reduce by on-line system the error of the speed of IM. In this process, EBPA NN was constituted to an output error value of an IM and conspired an input and output. The performance of the self-tuning controller is compared with that of the PH) controller tuned by conventional method (Ziehler-Nichols). The effectiveness of the proposed control method is verified thought the Matlab Simulink and experimental results.

Resin infiltration을 시행한 법랑질 초기 우식 병소의 특성

김은영,권민석,김신,정태성 大韓小兒齒科學會 2012 大韓小兒齒科學會誌 Vol.39 No.1

The concept of resin infiltration which was born in an innovative philosophy to arrest the incipient caries. However, the structural changes of resin infiltrated lesions have not yet explained completely. The liquid resin might contribute not only to maximizing the penetration but to deteriorating physical stability. This study was performed to examine some physical and histological features of resin infiltrated incipient carious lesions. With the specimen of resin infiltrated lesions, microhardness by nanoindentation in depth profile, morphology of resin tags were revealed after HCl dissolution, and degree of microleakage were assessed. The percentage of microhardness of surface layer and lesion body of untreated specimen to sound enamel was 64.6% and 24.6% respectively, while that of resin-infiltrated lesions was 72.1%, showing significant difference (p<0.05). The resin tags observed under SEM had relatively homogeneous length of 433(282~501) ㎛ on the average. Among 20 specimens for microleakage assessment, 13 specimens showed no leakage while 5 and 2 showed leakage into outer and inner half of lesion respectively. It was thought the infiltrant resin penetrates deeply and homogeneously into lesion body and improves its hardness with relatively good physical stability. 본 연구는 infiltrant resin을 침투시킨 초기 우식 병소의 특성을 평가하기 위해 법랑질의 깊이에 따른 경도를 측정하고, 병 소 내로의 레진 침투양상을 분석하며, 미세누출 정도를 관찰하여 다음의 결과를 얻었다. 건전 법랑질에 대한 초기 우식 법랑질의 경도 백분율은 표층(5~40 ㎛) 64.6%, 병소본체(60~350 ㎛) 24.6%였으며, infiltrant resin을 침투시킨 병소의 경도 백분율은 72.1%로 나타났다. 5~350 ㎛의 전 깊이에서, infiltrant resin을 침투시 킨 병소는 비처치 우식 병소보다 경도가 유의하게 높았지만 정상 법랑질에 비해서는 경도가 유의하게 낮았다(p<0.05). FESEM 관찰 결과 탈회된 법랑질 내부로 비교적 균일하게 침투한 레진 테그가 관찰되었으며, 침투깊이는 433 ㎛(282-501)로 측정되었다. 열순환 처리 후 13개의 치아에서 미세누출이 관찰되지 않았고, 5개에서 병소 외측 절반, 2개에서 병소 내측 절 반까지 미세누출이 관찰되었다.