고속전철 추진 시스템의 미끄럼 방지 제어기법에 관한 연구

황돈하,김동희,노채균,심광열,조규판,정원영 영남대학교 공업기술연구소 1999 工業技術硏究所論文集 Vol.27 No.2

Induction motor drive with PWM inverter control has been developed for Korean High Speed Railways. To improve traction performance, the anti-slip control(ASC) to recover adhesion must be considered. This paper describes a novel hybrid anti-slip control method for the induction motor drive. By introducing the vector control for drive system, quick response of the motor torque can be achieved when wheels are going to slip. A hybrid control scheme by mixing two conventional control methods (slip velocity feedback control and slip detection pattern control) for wheel slip and re-adhesion is proposed. This control method is simulated by motor drive, train load, and friction-creep models. The train running simulation results based on induction motor vector control with PWM inverter show that good re-adhesion characteristics are obtained.

인조대리석 위생기의 주형생산방법 개선을 통한 생산성 향상사례 연구 : 인조대리석의 욕조 및 세면기를 중심으로 Focusing on the Cultured Marble Washbasin & Bathtub

황규일,황규천,이재하 남서울대학교 경영연구센타 2002 경영연구 Vol.4 No.-

This study focus on the development of new molding ways of the cultured marble washbasin & bathtub to produce higher quality goods. On looking back upon the past 30 years in the market of the washbasin & bathtub, our product quality level was below the standard and the production facility was largely imported goods. And the inferior quality leads to the unsatisfaction of customer. But the leading companies are have been concentrated their effort on the productivity and quality improvement. In this study, we introduced the success case of ‘BACHE’ which gained productivity improvement by developing the molding process.

智異山의 高度別 鳥類 分布에 관한 生態學的 硏究

河慶三,咸奎晃 慶南大學校 附設 基礎科學硏究所 1994 硏究論文集 Vol.6 No.-

A writer inquire into community structure of birds living in the Mt. Chiri area by 12 times from October 15, 1988 to September 25, 1989, and came to a conclusion of 'below' 1. Birds living in the Mt. Chiri area were found out 70 species, 26 families, 10 order. 2. The areas of Distribution by altitude: 1) The area of 'A'(below 850 m above sea level) was 1,053 birds, 60 species. 2) The area of 'B'(from 850 m to 1,450 m) was 493 birds, 35 species. 3) The area of 'C'(from 1,450 m to 1,915 m) was 51 birds, 10 species. 3. Dominant species in the inquiry area was Crow Tit, paradoxornis webbiana (14.92%), and next was Long-tailed Tit, Aegithalos caudatus(7.21%), Varied Tit, Parus varius (5.58%) and Marsh Tit, Parus palustris(5.52%). 4. Seasonal distribution was Resident(73.18%), Summer visitor(9.96%), Winter visitor(12.21%) and Passage Migrant(4.26%). 5. Individuals groups more the 10 individuals were 27 species in A area(38.57%) , 14 species in B area(40.00%) and 2 species in C area(20.00%). And more than 50 individuals wore 6 species in A area(41.12%), 2 species in B area(37.72%) and not species in C area. 6. Diversity was 2.792 in A area, 2.184 in B area and 0.611 C area and the lower was altitude, the higher was diversity. 7. Species incidence was following the order of Brambling, Fringilla montifringilla (40.00), Rustic Bunting, Emberiza rustca(18.50), Crow Tit, Paradoxornis webbiana (19.83) and Yellow-throated Bunting, Emberiza elegans(16.40).

ATM네트윅과의 접속을 위한 MAN을 이용한 사용자 - 망 인터페이스 설계

최황규,최경,서주하,김화종,이상희 江原大學校 産業技術硏究所 1991 産業技術硏究 Vol.11 No.-

In this paper the functional requirements of a B-ISDN access network based on MAN are investigated . Firstly, criteria of designing access network for the B-ISDN is studied. Secondly, the types of subscribers and their service requirements are defined. Thirdly, various artchitectures of CPNs(Customer Premises Networks) are considered and their characteristics are studied, Finally, the interworking funtions of a DQDB MAN as an access network are investigated.

Polystyrene Beads를 사용한 경량 폴리머 시멘트 모르타르의 기초적 성질

연규석,신영수,이윤수,이기원,황진하 강원대학교 부설 석재복합신소재 제품연구센터 2000 석재연 논문집 Vol.5 No.-

polystyrene beads를 사용한 경량 시멘트 모르타르의 성질을 개선하기 위해 EVA혼화용 폴리머를 첨가한 모르타르를 제조하여, 물리ㆍ역학적 성질을 살펴보았던 바 polystyrene beads 골재 재부의 공극 때문에 높은 공기량을 보였고, 플로우 값은 폴리머-시멘트비 10%에서 가장 높은 값을 나타냈다. 또한 폴리머-시멘트비가 증가할수록 압축강도와 휨강도는 증가하였고, 시멘트-경량골재비가 낮을수록 압축강도는 증가하였으나, 휨감도에는 크게 영향을 주지 않았다. The objective of this study was to improve performance of lightweight polymer cement mortars by treating with redispersible polymer powders. Lightweight polymer-cement mortars were prepared with respect to different polymer-cement ratios, and tested for water absorption, specific gravity, flexural and compressive strengths, workability and freeze-thaw resistance. Manufactured lightweight polymer-cement mortars in this study showed lower specific gravity and lower thermal diffuseness than ordinary cement mortars. Water absorption, specific gravity, flexural, compressive strengths and workability were measured according to appropriate KS test methods. As a results, the optimum mix ratios for cement-aggregate, polymer-cement, and water-cement were found to be 1:3, 10% and 30%, respectively.

내후성 폴리머 콘크리트의 제조 및 특성연구

연규석,김기성,이기원,황진하 강원대학교 석재복합신소재제품연구센터 2001 석재연 논문집 Vol.6 No.-

본 연구에서는 불포화 폴리에스터 수지비율을 변수로 하는 자외선 흡수제 첨가유ㆍ무 시편에 대한 Xenon lamp, 52±3℃, 실내습도 50±5%, 시험체 걸이 직경 20inches의 조건의 내후성 시험기로 각각 100, 200, 400, 800, 1600 시간 인공촉진열화 시킨 시편의 색차변화를 측정하여 불포화 폴리에서터 수지량 및 자외선 흡수제의 첨가에 의한 열화특성을 고찰하였다. 그 결과 100% 불포화 폴리에스터 수지량 및 자외선 흡수제의 첨가에 의한 열화특성을 고찰하였다. 그 결과 100% 불포화 폴리에스터 수지 시편과 상대적으로 수지비율이 큰 폴리머 페이스트에서는 자외선 조사시간에 따른 큰 색차변화 및 자외선 첨가에 의한 열화방지 효과를 확인 할 수 있었고 불포화 폴리에스터 수지비율이 상대적으로 작은 폴리머 모르타르에서는 자외선 조사에 의한 색차변화 및 자외선 흡수제 첨가에 의한 열화방지가 그리 크지 않음을 확인할 수 있었다. 이러한 것은 야외에 설치되는 폴리머 모르타르(콘크리트) 제품은 자외선에 의한 열화가 그리 크지 않음을 보여주는 결과이기도 하다. This study was to investigate the characteristics of deterioration of polymer concrete due to wethering Two sets of specimens with a various mixing ratio of unsaturated polyester resin, UV absorber added and not-added, were artificially exposed by the weathering test machine to ultraviolet (UV) radiation 100, 200, 400, 800 and 1600 hours under the conditions that the temperature was set by Xenon lamp at 52±3℃, the chamber humidity at 50±5%, and specimen rack diameter 20 inches to measure the color change to examine the characteristics of deterioration. Color difference increased as the exposure time to UV radiation increased, but decreased 20-30%, comparing to the case of non-absorber added, as the ultraviolet absorber was added. On the other hand, the effect of addition of ultraviolet absorber decreased as addition of aggregate increase. Thus, the effect of addition of ultraviolet absorber was a little on the polymer concrete containing aggregate, Especially, increment of color difference in polymer mortar specimen was lower than that of polymer resin and polymer paste specimen, when the resin volume for specimen mixture proportion was below 30%, as fine aggregate increased. As a result, outdoor-installed polymer concrete product is believed to be hardly affected by ultraviolet radiation.

세그멘트기법을 이용한 프랙탈 영상 부호화에 대한 연구

서주하,최황규,조철희 江原大學校 産業技術硏究所 1995 産業技術硏究 Vol.15 No.-

Fractal coding is a promising method for image compression, but it has not lived up to its promise as low bit-rate image compression scheme. The existing algorithms for finding self-mapping contractive transforms are computationally expensive and offer a poor rate-quality tradeoff. In this paper, we propose a segment based fractal coding. We classify the range blocks into shade, midrange or edge blocks, and segment edge block along the edge. And we apply midrange coding scheme for each segment. Our experiments show that our method gives better rate-qualty trade of than current fractal block coding methods.

저수축형 폴리머 콘크리트의 제조 및 물리·역학적 특성

연규석,이윤수,최동순,정경현,황진하 강원대학교 부설 석재복합신소재 제품연구센터 2000 석재연 논문집 Vol.5 No.-

본 연구에서는 폴리머 콘크리트의 수축저감을 목적으로 수지량, 수축저감제함량과 S/a 비등을 변화시켜 경화수축의 변화와 강도 특성을 실험적으로 구명하였다. 경화수축량은 수치량이 105%일 때 보다 11.5%일 때, 즉 수지량이 증가할수록 커짐을 알 수 있었다. 수축저감제의 첨가에 따른 경화수축량은 감소함을 알 수 있었다. B10.5-SR10일 경우 수축저감제가 첨가되지 않았을 때 보다 약 30%, B10.5-SR20 일 경우 약 53%, B11.5-SR10일 경우 약 31%, B11.5-SR20 일 경우 약 47% 정도의 수축저감의 효과를 볼 수 있었다. S/a 비에 따른 경화 수축챨ㅇ은 S/a 60일 때 가장 적은 값을 보였으며, S/a 50, S/a 40 일때는 S/a60 일 때 가장 적은 값을 보였으며, S/a 50, S/a 40일 때는 S/a 60일 때 보다 각각 10%, 30% 정도 수축량이 증가함을 알 수 있었다. 압축 및 휨 강도특성은 수지량이 증가할수록 높아지고, 수축저감제의 첨가량이 증가할수록 낮아짐을 알 수 있었다. S/a 비에 따른 강도 특성은 압축강도와 휨강도 모두 S/a 비가 60일 때 가장 큰 값을 보였으며, S/a 비가 50,40 순으로 감소하였다. Many different polymer based concrete materials are known today, but the large setting or hardening shrinkage of polymer concrete is a problem to overcome in their practical applications. The setting shrinkage reaches about five to ten times the drying shrinkage of ordinary cement concrete, i.e, 50 to 60 ×10^4. This paper deals with a reduction in the hardening shrinkage of unsaturated polyester resin concrete which is treated with respect to shrinkage-reducing agent content, S/a ratio and catalyst content, and tested for length change during hardening, and flexural and compressive strengths. It is shown that the change of shrinkage-reducing agent content and S/a ration the length change of the unsaturated polyester resin concrete during hardening.

인터넷 기반 실시간 멀티미디어 서비스 시스템의 구현 및 성능 분석

최황규,서주하 강원대학교 정보통신연구소 1998 정보통신논문지 Vol.2 No.-

In this paper, we present the impelmentation and experimental analysis of a real time multimedia service system. The system can play the MPEG video/audio and text caption on the Internet environment in real time. The software feedback mechanism is adopted for client/server synchronization, QoS control. and system adaptiveness. Our experimental study shows that the system performs very well in the Internet environment.

lacZ 유전자를 이용한 Bacillus subtilis 유전체에서의 promoter 부위 탐색

이하규,황혜진,김지환 가톨릭대학교 자연과학연구소 2007 자연과학논문집 Vol.28 No.-

Bacillus subtilis는 GRAS균주로서 최근에 유전공학 식품과 약품 재료로 많이 이용된다. 본 연구에서는 B. subtilis에서의 expression system을 만들기 위해 B. subtilis의 genomic DNA에서 promoter 서열을 검색하였다. lacZ 유전자를 가지는 상업용 TA cloning vector에서 이 promoter를 제거하고 B. subtilis의 DNA 단편으로 이 부위를 대체했다. 재조합 plasmid library를 DH5a에 형질전환 시켰다. 형질전환 후 X-gal 분석을 통하여 blue colony를 골라내어 삽입된 단편의 서열을 분석하였다. Plasmid 서열분석을 통해 promoter로 추정되는 4개의 서열을 얻었다. IPTG test를 통해 이 서열들의 유도성 여부를 확인했다. On-line software program인 BPROM(http://www.softberrt.com)을 이용하여 추정된 4개의 서열들이 promoter 특이 보존성 서열을 가지고 있음을 확인했다. 이러한 서열들은 B. subtilis의 promoter로서 가능성을 가짐에 따라, 향후 유전자 발현 실험을 통해 promoter 활성을 검증 하는 등의 연구가 수행되어야 할 것이다. Bacillus subtilis is one of the GRAS bacteria, and it's application for production of genetic engineered food and drug material is increasing in recent days. In this study, for the construction of expression system in B. subtilis, we screened promoter sequences in the bacterial genomic DNA. Using the commercial TA cloning vector containing lacZ gene, we removed its promoter and replaced it with Bacillus DNA fragments. This recombinant plasmid library was transferred to DH5a strain. Based on the X-gal assay after the transformation, blue colonies were selected and their plasmids were sequenced in the replaced region. 4 sequences were recruited as candidate promoters. We confirmed the induction of these sequences by IPTG test. On-line software program, BPROM, was showed all of these sequences have promoter-specific conserved sequences. We suggest these sequences are probable promoter of B. subtilis, and it should be further studied for applicational development.