• 제목/요약/키워드: C-obstacles

검색결과 139건 처리시간 0.026초

수직통로를 극복하기 위한 협소구역 이동용 다관절 로봇 설계 (Design of Articulated Mobile Robot to Overcome Vertical Passages in Narrow Space)

  • 이지수;김성현;양현석;박노철
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2005년도 춘계학술대회 논문집
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    • pp.806-811
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    • 2005
  • The robot to search and rescue is used in narrow space where human cannot approach. In case of this robot, it can overcome obstacles such as wrecks or stairs etc. Also, this robot can do various locomotion for each object. In this reason, an articulated robot has advantages comparing with one module robot. However, the existing articulated robot has limits to overcome vertical passages. For expanding contacted territory of robot, a novel mechanism is demanded. In this paper, the novel mechanism of articulated mobile robot is designed for moving level ground and vertical passages. This paper proposes to change wheel alignment. The robot needs two important motions for passing vertical passages like pipe. One is a motion to press wheels at wall for not falling into gravity direction. The other is a motion that wheels contact a vertical direction of wall's tangential direction for reducing loss of force. The mechanism of the robot focused that two motions can be acted to use just one motor. Length of each link of robot is optimized that wheels contact a vertical direction of wall's tangential direction through kinematic modeling of each link. The force of pressing wall of robot is calculated through dynamic modeling. This robot composes four modules. This mechanism is confirmed by dynamic simulation using ADAMS program. The articulated mobile robot is elaborated based on the results of kinematic modeling and dynamic simulation.

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Immunotherapy with methyl gallate, an inhibitor of Treg cell migration, enhances the anti-cancer effect of cisplatin therapy

  • Kim, Hyunseong;Lee, Gihyun;Sohn, Sung-Hwa;Lee, Chanju;Kwak, Jung Won;Bae, Hyunsu
    • The Korean Journal of Physiology and Pharmacology
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    • 제20권3호
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    • pp.261-268
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    • 2016
  • $Foxp3^+$ $CD25^+CD4^+$ regulatory T (Treg) cells are crucial for the maintenance of immunological self-tolerance and are abundant in tumors. Most of these cells are chemo-attracted to tumor tissues and suppress anti-tumor responses inside the tumor. Currently, several cancer immunotherapies targeting Treg cells are being clinically tested. Cisplatin is one of the most potent chemotherapy drugs widely used for cancer treatment. While cisplatin is a powerful drug for the treatment of multiple cancers, there are obstacles that limit its use, such as renal dysfunction and the development of cisplatin-resistant cancer cells after its use. To minimize these barriers, combinatorial therapies of cisplatin with other drugs have been developed and have proven to be more effective to treat cancer. In the present study, we evaluated the effect of the combination therapy using methyl gallate with cisplatin in EL4 murine lymphoma bearing C57BL/6 mice. The combinatorial therapy of methyl gallate and cisplatin showed stronger anti-cancer effects than methyl gallate or cisplatin as single treatments. In Treg cell-depleted mice, however, the effect of methyl gallate vanished. It was found that methyl gallate treatment inhibited Treg cell migration into the tumor regardless of cisplatin treatment. Additionally, in both the normal and cisplatin-treated tumor-bearing mice, there was no renal toxicity attributed to methyl gallate treatment. These findings suggest that methyl gallate treatment could be useful as an adjuvant method accompanied with cisplatin therapy.

생태-문화-환경교육을 위한 적합지(장소) 분석과 결정 요인 - <논 생태계와 쌀 문화>의 생활 밀착형 환경 인식론 - (Proper Space and Its Conditions for Ecology-Culture(connected)-Environmental Education)

  • 김태경
    • 한국환경교육학회지:환경교육
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    • 제23권3호
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    • pp.62-81
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    • 2010
  • We are easily supposed to think that outdoor EE can help make Eco-Sense, furthermore 'Eco' means nature and natural resource itself. Relatively we are likely to think indoor EE is something theoretical or knowledge-oriented. It comes from our strong beliefs going into nature would be best choice for feeling Eco-mind. But every place in our daily life could be space for finding Eco-feeling(mind), as far as the relation to life in there. No life without ecological relation, so firstly we need to be rethink Eco-feeling could be enough trained in daily life, our EE trends that have distinguished between indoor and outdoor should be rearranged, going there is just for when we unavoidably need to go for outdoor experience. So I focus on two special causes bringing out these biases, 1st Environmental management-thinking, which has been passed over this trend under the name of training environmentally responsible citizen through Awareness, Knowledge, Skill and Attitudes. 2nd important cause is cultural metaphors, which means our thinking is fixed into some patterns, losing cultural thinking diversity, although eco-culture in our daily life has been figured our daily life out as ecological phenomenon hermeneutically. To illustrate this problematic trends, this paper will introduce theories of Bateson G. and Bowers C.A. mainly, who insist fixed pattern-thinking bound for environmental management could be obstacles to make students see and have Ecological intelligence in their mind throughout daily life. This paper will focus on how to feel Eco-mind in our daily life through cultural experience. Representative way for this is to research on rice paddy eco-system and rice culture.

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가리비의 조형성을 이용한 한지직물 의상 디자인 연구 (A Study on the Fashion Design of Hanji(Korean traditional paper) Textile Using the Formative Features of Scallop)

  • 권민정;유금화
    • 한국의상디자인학회지
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    • 제13권3호
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    • pp.149-163
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    • 2011
  • Hanjisa(Korean paper yarn), a new material made from the traditional Korean paper, has been developed through local R&D efforts, reflecting the current trend highly valuing environmental friendly. This new material is considered suitable for the 21C lifestyle and culture pursuing improved quality of human life and the environment. Therefore, this study aims to widely make known the originality and functions of the environmentally friendly Korean paper yarn, as well as to increase its commercial value. Furthermore, a new category of apparel design is presented by studying painting dyeing based on transformational tuck techniques and wax resist dyeing with formative features of repeated lines and rhythms of shells in order to implement three-dimensional and decorative artistic expressions. The texture of the Korean cotton paper yarn was particularly suitable to employ tuck and dyeing techniques Which express formative features of shell. Also, the material was useful for expressing the three-dimensional feelings with repeated curves and cross sections of shells. Moreover, paraffin resist dyeing and stitch techniques were used in order to avoid monotony and the images of shells visually materialized. Through the results stated above, this study could explore how to overcome obstacles to globalization of the Korean modern apparel such as its uniqueness, limit of materials or absense of internationality by applying modern design to the Korean paper fabrics. In the future, it is expected that more manufactures could produce and supply the new materials so as to make widely known the originality of the Korean paper fabrics and develop the material into a popular organic product fitting the modern lifestyle.

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Limit-cycle 항법의 동역학적 안정성 분석 (Analysis of Dynamic Stability of Limit-cycle Navigation Method)

  • 김동한;강수혁;이은진;고국원;남상엽
    • 전자공학회논문지 IE
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    • 제46권3호
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    • pp.33-41
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    • 2009
  • 본 논문에서는 Limit-cycle 항법의 안정성을 분석하고 path follwer를 제안한다. Limit-cycle 항법은 2차 비선형 함수의 특징을 이용하며, 빠른 이동로봇의 움직임을 제어하기 위해 제안되어졌다. Limit-cycle의 수렴반경과 방향을 조절하여 충돌 없이 장애물을 회피하고, 목표점에 도달할 수 있다. 하지만 지금까지 Limit-cycle 항법의 안정성은 연구되어지지 않았다. 따라서 본 논문에서는 이러한 안정성을 분석하고, Limit-cycle 항법을 로봇축구에 적용하여, 시뮬레이션과 실제 실험에서 제안된 방법을 검증한다.

차량주행 환경에서 다중라이다센서를 이용한 효과적인 검출 시스템 개발 (A Development of Effective Object Detection System Using Multi-Device LiDAR Sensor in Vehicle Driving Environment)

  • 권진산;김동순;황태호;박현문
    • 한국전자통신학회논문지
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    • 제13권2호
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    • pp.313-320
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    • 2018
  • 자동차의 자율주행 기술이 확대되면서 '눈'의 역할을 하는 센서가 점차 중요시되고 있다. 최근 차량에 장착되는 라이다 센서는 채널이 많을수록 피사체에 반사된 신호 또한 풍부해짐에 따라 장애물, 지형, 차량 등 주변 환경 탐색의 정확도가 높아진다. 하지만, 라이다 센서는 채널 증가에 따른 열배 이상 가격의 차이가 있으며, 이러한 가격적인 문제로 보급형 차량보다는 고가의 차량에만 부분적으로 사용되고 있다. 본 연구는 저 가격의 16 채널의 라이다를 복수개로 구성하여 동시에 신호를 수집 처리하여 하나의 입체공간으로 융합하고 이를 나타낼 수 있게 함으로써 64 채널의 라이더와 같은 효과를 나타낼 수 있게 하였다. 이를 통해서 차량 심미성의 개선과 함께 보급화를 위한 기반을 제공할 수 있다.

Identification of Subspecies-specific STS Markers and Their Association with Segregation Distortion in Rice(Oryza sativa L.)

  • Chin, Joong-Hyoun;Kim, Jung-Hee;Jiang, Wenzhu;Chu, Sang-Ho;Woo, Mi-Ok;Han, Longzhi;Brar, Darshan;Koh, Hee-Jong
    • Journal of Crop Science and Biotechnology
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    • 제10권3호
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    • pp.175-184
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    • 2007
  • Two subspecies, japonica and indica, have been reported in rice, which differ in several ecotypic traits. However, reproductive barriers in hybrid progenies between subspecies have been major obstacles in breeding programs using inter-subspecific hybridization. As the first step to elucidate the reproductive barriers, we developed subspecies-specific(SS) STS markers in this study. A total of 765 STS primers were designed through comparing DNA sequences at every $2{\sim}3$cM interval between japonica and indica rices, which are available at Web DBs such as IRGSP, NCBI, TIGR, and GRAMENE, and tested for subspecies-specificity using 15 indica and 15 japonica varieties of diverse origin. Of them, 67 STS markers were identified as SS STS markers and their subspecies-specificity scores were estimated. The SS markers were dispersed throughout the genome along chromosomes. Of them, 64 SS markers were mapped on an RIL population derived from a Dasanbyeo(indica)/TR22183(japonica) cross. Genomic inclination of RILs was evaluated based on the genotyping with different types of markers. Association test between markers and segregation distortion revealed that segregation distortion might not be the cause of generating SS markers. The SS markers will be applicable to estimate the genomic inclination of varieties or lines and to study the differentiation of indica and japonica, and ultimately to breed true hybrid rice varieties in which desirable characters from both subspecies are recombined.

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X-선 회절 패턴 측정과 투과 전자 현미경을 이용한 구리 나노분말의 수소 환원 처리 시 발생하는 미세조직 변화 및 치밀화 시편의 물성 분석 (Analysis of the Change in Microstructures of Nano Copper Powders During the Hydrogen Reduction using X-ray Diffraction Patterns and Transmission Electron Microscope, and the Mechanical Property of Compacted Powders)

  • 안동현;이동준;김우열;박이주;김형섭
    • 한국분말재료학회지
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    • 제21권3호
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    • pp.207-214
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    • 2014
  • In this study, nano-scale copper powders were reduction treated in a hydrogen atmosphere at the relatively high temperature of $350^{\circ}C$ in order to eliminate surface oxide layers, which are the main obstacles for fabricating a nano/ultrafine grained bulk parts from the nano-scale powders. The changes in composition and microstructure before and after the hydrogen reduction treatment were evaluated by analyzing X-ray diffraction (XRD) line profile patterns using the convolutional multiple whole profile (CMWP) procedure. In order to confirm the result from the XRD line profile analysis, transmitted electron microscope observations were performed on the specimen of the hydrogen reduction treated powders fabricated using a focused ion beam process. A quasi-statically compacted specimen from the nano-scale powders was produced and Vickers micro-hardness was measured to verify the potential of the powders as the basis for a bulk nano/ultrafine grained material. Although the bonding between particles and the growth in size of the particles occurred, crystallites retained their nano-scale size evaluated using the XRD results. The hardness results demonstrate the usefulness of the powders for a nano/ultrafine grained material, once a good consolidation of powders is achieved.

선천성 식도 폐쇄의 수술 후 경과 및 장기 예후 (The Long-term Outcome of Esophageal Atresia)

  • 정재홍;김혜은;이석구;서정민
    • Advances in pediatric surgery
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    • 제14권2호
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    • pp.117-124
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    • 2008
  • Children who underwent reparative operations for esophageal atresia (EA) with or without tracheoesophageal fistula (TEF), are confronted with many gastrointestinal or respiratory problems, especially during the early years of life. We reviewed the medical records of 50 patients who underwent repairs of EA with or without TEF at the Division of Pediatric Surgery, Samsung Medical Center, from December 1994 to December 2005. Current status of children was accessed by telephone-interview, but only 27 of them were accessible. Of 50 patients, 3 patients (6 %) were type A, 45 patients (90 %) were type C, and 2 patients (4 %) were type E. The mean interval between primary operation and interview was 5.5 years. The incidences of growth retardation (<10 percentile of height/weight) were 39 % and 21 % during the first 5 years after repairs, respectively. The incidences of dysphagia or gastroesophageal reflux and recurrent respiratory infections were 33 % and 39 %, respectively. However, these problems were likely to improve as the children grew. The incidences of growth retardations (<10 percentile of height/weight) were 11 % and 11 % for the children more than five years postoperative. The incidences of dysphagia or gastroesophageal reflux and recurrent respiratory infections were 22 % and 22 %, respectively. Children with EA with or without TEF are faced with many obstacles. Close observation and adequate treatment for delayed postoperative complications are necessary to improve the quality of life for these children.

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Genotyping of Agaricus bisporus Strains by PCR Fingerprints

  • Min, KyongJin;Oh, YounLee;Kang, HeeWan
    • 한국균학회소식:학술대회논문집
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    • 한국균학회 2014년도 추계학술대회 및 정기총회
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    • pp.41-41
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    • 2014
  • Agaricus bisporus, commonly known as the button mushroom, is the most widely cultivated species of edible fungi. Low frequency of recombination ratio and homokaryotic or monokaryotic spore on meiotic basidia form obstacles for breeding programs. Since the first hybrid varieties for white button mushrooms were released in Europe, new varieties released afterwards were either identical of very similar to these first hybrids on morphologies. Therefore, different DNA markers have been used to define unique varieties of A. bisporus strains. Aim of this study is to assess the genetic diversity of different A. bisporus strains in Korea. Twelve UFP (Universal fungal primer, JK BioTech. Ltd), 12 simple sequence repeat (ISSR) and 30 SSR primers were used to assess genetic diversity of monokaryotic and dikaryotic Agaricus bisporus strains including other 19 Agaricus spp. Of them, four UFP, four SSR primers, $(GA)_8T$, $(AG)_8YC$, $(GA)_8C$ and $(CTC)_6$ and seven SSR markers produced PCR polymorphic bands between the Agaricus species or within A. bisporus strains. PCR polymorphic bands were inputted for UPGMA cluster analysis. Forty five strains of A. bisporus are genetically clustered into 6 groups, showing coefficient similarity from 0.75 to 0.9 among them. In addition, genetic variations of monokaryotic and dikaryotic Agaricus bisporus strains were partially detected by PCR technologies of this study. The varieties, Saea, saedo, Saejeong and Saeyeon that have recently been developed in Korea were involved in the same group with closely genetic relationship of coefficient similarity over 0.96, whereas, other strains were genetically related to A. bisporus strains that were introduced from USA, Eroupe and Chinese.

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