• 제목/요약/키워드: Rough Ground

검색결과 91건 처리시간 0.031초

수면이론(睡眠理論)의 발전사(發展史)에 관(關)한 연구(硏究)(I) (춘추시기이전(春秋時期以前)~남북조대(南北朝代)까지) (A Study on sleep and sleep-related-dysfunctions(I) -Based on the traditional medical classic-)

  • 이영석;하홍기;김기욱
    • 대한한의학원전학회지
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    • 제24권4호
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    • pp.9-21
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    • 2011
  • Mankind spends a third of it's lifetime sleeping. Sleep deficiency can cause several psychological and physical complications - as well as death - if prolonged over extended periods. Therefore, sleep is a substantial part of life and essential to the preservation of human-life. In modern society, human-beings are having more difficulty with sleep than ever before. Consequently, the need for medical research on sleep has increased as well. There are no studies in current western medicine that focuses entirely on sleep alone. However, there have been ongoing research by traditional eastern medicine on sleep and sleep-related-dysfunctions since ancient times which has yielded diverse results. Undertaken a study of the sleep and sleep-related-dysfunction in traditional medicine of East-asia, I have summarized my studies into the following. 1. From ancient china to the age of the warring state(戰國時代) - ground on few data that we can get - humans have a simple and rough cognizance of sleep and sleep-related- dysfunction. But people are little removed from shamanism yet. 2. After Han(漢) dynasty, in "Huang Di Nei Jing(黃帝內經)" and "Shang Han Lun(傷寒論)" and "Jin Gui Yao Lue(金匱要略)", people present a basic physiology and pathology of sleep. 3. The theory has improved repeatedly in quality and quantity through "Zhen Jiu Jia Yi Jing(針灸甲乙經)" of Huang Fu Mi(皇甫謐) of Jin(晉) dynasty, "Bei Ji Qian Jin Yao Fang(備急千金要方)" of Sun Si Miao(孫思邈) of Tang(唐) dynasty to "Tai Ping Sheng Hui Fang(太平聖惠方)" of Song(宋) dynasty.

공간구문론을 이용한 자하 하디드 뮤지엄 건축의 공간구조 분석 (Analysis of the Spatial Structure of Zaha Hadid's Museum using Space Syntax)

  • 국진선;조자연
    • 한국실내디자인학회논문집
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    • 제22권5호
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    • pp.311-319
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    • 2013
  • Buildings of the de-constructive tendency beyond definite forms are being constructed in countries with economic power, technical skills and open culture because they require social conditions to accommodate those buildings as well as a lot of construction expenses. Frank Gehry and Zaha Hadid can be chosen as the representative architects of de-constructivism series who are currently working hard. Though both of them are architects belonging to the de-constructivism category, their works show different construction due to the differences in architectural philosophy and working ways. Gehry consider Architect as a fine art and enjoy (sculpture) three-dimensional structure work through Rough Model. With increasing demand for landmark atypical buildings, Hadid has been frequently awarded in the recent series of International Competitions and deals with a lot of cultural works. Affected by absolutism, Hadid showed various diagonal lines in her early construction and works based on the theme of dynamics such as lightness, gliding and light contact with the ground etc. Hadid's Architecture which worked under the theme of dynamic contains a variety of diagonal lines that might cause the viewers to have difficulty on spatial awareness, thus It is known that Hadid's Architecture has lower efficiency on the Circulation and difficulty on spatial cognition compared to the typical museum. According to the research findings of the previous paper that space understanding of viewers on Frank Gehry Museum consisting of complicated planes is generally better than that of them on a typical museum, the purpose of this study is to find out the Circulation efficiency and spatial cognition of Hadid Museum by explaining the space structure of dynamic Hadid Museum and the difference compared to typical museum.

농민의 작업환경별 노동부담 경감방안에 관한 연구(I) -겨울철 비닐하우스에서 상추재배 작업을 중심으로- (A Study for Farmers to Reduce Work Load on the Different Working Conditions (part I) - Cultivating Lettuce in the Winter Greenhouse -)

  • 김명주;최정화
    • 한국농촌생활과학회지
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    • 제8권2호
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    • pp.111-117
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    • 1997
  • In this study we tried to give a decision on propriety of working conditions, to present ideas on reducing work loads. and to grope for efficiency of agricultural works. For this we examined the actual conditions of working environment, farmer's clothes, working posture, working methods, working time, resting state, fatigue recovery methods during cultivating lettuce in the winter greenhouse. And Ive improved harmful factors that affect farmer's health by considering results of previous study and farmer's subjective sensation. And we measured, compared, and analyzed the farmer's work loads before and after improvement. The results of this study are as follows ; 1. According to examine the actual conditions of cultivating lettuce in the winter greenhouse, farmers have experienced physical and mental chronic fatigue on the basis of the hot and humid crops-centered working environment, the rough ground condition, inconsistent arrangement of working stand and sorter, heavy-weared habits. and unsuitable working posture. 2. When we improved harmful factors that affect farmer's health, conformed the positive effects on important work efficiency index such as heart rate, electromyovolume, body temperature, and microclimate inside clothing and work loads were decreased by improving the hot and humid working environment, eliminating the hillock and obstacles of working path. deliver way, arranging the working stand and sorter consistantly, decreasing the clothing weight, improving the working postures and methods as using assistant appliances, alloting the working time and sequence effectively and presenting the light gymnastic exercises and rest for fatigue restoration.

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장애물 패턴을 이용한 자율이동로봇의 예측주행 및 충돌회피 알고리즘 개발 (Development of an Algorithm for Predictable Navigation and Collision Avoidance Using Pattern Recognition of an Obstacle in Autonomous Mobile Robot)

  • 이민철;김범재;이석
    • 한국정밀공학회지
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    • 제17권7호
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    • pp.113-123
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    • 2000
  • In the navigation for a mobile robot, the collision avoidance with unexpected obstacles is essential for the safe navigation and it is independent of the technique used to control the mobile robot. This paper presents a new collision avoidance algorithm using neural network for the safe navigation of the autonomous mobile robot equipped with CAN and ultrasonic sensors. A tracked wheeled mobile robot has a stability and an efficiency to move on a rough ground. And its mechanism is simple. However it has difficulties to recognize its surroundings. Because the shape of the tracked wheeled mobile robot is a square type, sensor modules are generally located on the each plane surface of 4 sides only. In this paper, the algorithm using neural network is proposed in order to avoid unexpected obstacles. The important character of the proposed algorithm is to be able to detect the distance and the angle of inclination of obstacles. Only using datum of the distance and the angle, informations about the location and shape of obstacles are obtained, and then the driving direction is changed. Consequently, this algorithm is capable of real time processing and available for a mobile robot which has few sensor modules or the limited sensing range such as a tracked wheeled mobile robot. Effectiveness of the proposed algorithm is illustrated through a computer simulation and an experiment using a real robot.

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북태평양 중부 해산어장에 있어서 저층 트롤의 어획실태 (Fishing investigation of trawl fisheries in sea mount of central northern Pacific)

  • 김영승;오택윤;조삼광;최석관;고정락;양원석
    • 수산해양기술연구
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    • 제41권3호
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    • pp.179-187
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    • 2005
  • This study was conducted in order to the experiment of bottom trawl fisheries in the sea mount of central northern pacific($30^{\circ}-40^{\circ}N$, $170^{\circ}-175^{\circ}E$), during the period of July 1 to August 25, 2004 by commercial trawl ship. Fishing experiment was carried out by bottom trawl, with the codend of 110mm mesh size. The number of 101 test fishing was done in the sea mount of central northern pacific during 56 days and the total catches were 198,593kg as 18 fish species, and CPUE/day and catches/day were 8.3 hours towing time and 3,546kg. Catch ratio according to each fishing ground was higher with the order of B, C, and E, and catches for B was 7,171.0kg during the towing time of 13.2 hours. Main target species were Pseudopentaceros richardsoni and Beryx splendens, there was 14.9% of damage ratio for fishing gears on catching the target fishes inhabiting on the rough sea bottom. Catches by water depth was the order of 300m below, 301-350m, 451-500m and 351-400m. It is thought that there was no problem on the mesh size because most of fishes caught from the experimental fishing was 30cm over.

동해안 대문어(Enteroctopus dofleini)의 문어상자 행동 실험 (Behavioural experiments of Pacific giant octopus (Enteroctopus dofleini) to wooden octopus pot in the tank)

  • 김병관;서영일;정성재;양재형
    • 수산해양기술연구
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    • 제58권3호
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    • pp.199-204
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    • 2022
  • The Pacific giant octopus (Enteroctopus dofleini) is one of the most important species in the East Sea fishery of Korea. The annual production of Pacific giant octopus in 2021 was 3,880 metric ton between Gangwon province and Gyeongsangbuk province. Most of the fishing gears for the octopus fishery were based on behavioral properties such as thigmotaxis and chemotaxis. Wooden octopus box is also one of the fishing gears, which is application of thigmotaxis for the octopus capture in fishing industry. In this study, the tank experiments were designed to examine the behaviour and the effect of surface roughness to the infiltration of the octopus quantitatively. Three different types of octopus boxes were used for the experiments with different surface roughness on the average of 701.6 ㎛, 141.7 ㎛ and 2.09 ㎛ for each gear. 22 trials were conducted from June to September 2021. The normality of the experiments was tested using Shapiro-Wilk normality test (p-value < 0.05). The significance of results was conducted by Kruskal-Wallis rank sum test (Chi-squarded = 21, Degree of freedom = 3, p-value < 0.05). The use of wooden octopus box with rough surface was found to enhance the catch efficiency and observe infiltration behaviour of the octopus frequently.

마오리族 傳統 服飾과 文身 考察 (A Study on the Traditional Costumes and Tattoo of the Maori)

  • 황춘섭;정현주
    • 복식문화연구
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    • 제3권2호
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    • pp.241-260
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    • 1995
  • The Maori's traditional clothing materials, basic forms of dress, and the pattern and technique of tatoo were examined in the present study in order to deepen the appreciation of the cultural heritage of the Maori. The research method employed was the analysis of written materials. And a fild-trip was also made for the study. The study was limitted to the traditional culture of body adornment of the Maori including the clothing which is preserved and practicing by them at the present day, and the origin and the process of the historical development of those are not included in the scope of the present study. Followings are the results of the study: (1) By far the most widely used fiber for Maori clothing is abtained from what is commonly called New Zealand Flax. The fiber of kiekie(Freycinetia baueriana) and cabbage trees(Cordyline spp.) may also be used. The strong, long-lasting fiber of toi(cordyline indivisa) is used for a prestige warrior's cloak. Flat strips of ti kauka(Cordyline australi) are also used as thatch on rain cloaks. (2) Regardless of technique used, Maori weaving is always worked horizontally from left to right. Traditionally the work was suspended between two upright turuturu or weaving sticks. As the work progressed a second pair of uprights was used to keep the work off the ground. These uprights were moved forward as required. Because the weaver sat on the ground, the working edge was kept at a height that was comfortable to reach. No weaving tools are used, the wefts(aho) being manipulated by the fingers. The two main Maori weaving techniques are whatu aho patahi(single-pair twining) and whatu aho rua(double-pair twining). (3) The Maori wore two basic garments - a waist met and a cloak. The cloth of commoners were of plain manufacture, while those of people of rank were superior, sometimes being decorated with feather or dyed tags and decorated borders. Children ran more-or-less naked until puberty, being dressed only for special events. Some working dress consisted of nothing more than belts with leaves thrust under them. Chiefs and commoners usually went barefoot, using rough sandals on journeys over rough country (4) The adornment of men and women of rank was an important matter of tribal concern as it was in chiefly persons that prestige of the group was centred, The durable items of Maori persons adornment were either worn or carried. Ornaments of various kinds were draped about the neck or suspended from pierced earlobes. Combs decorated the head. Personal decorations not only enhanced the appearance of men and women, but many had protective magical function. The most evident personal ornament was the hei-tiki made of jade or other material. Maori weapons were treasured by their owners. They served on bottle and were also personal regalia. A man of rank was not fully dressed without a weapon in hand. Also weapons were essential to effective oratory. (5) No man or woman of rank went without some tattoo adornment except in extremely rare instances when a person was too sacred to have any blood shed. The untattooed were marked as beeing commoners of no social standing. This indelible mark of rank was begun, with appropriate rite and ritual, at puberty. And tattoo marked the person as being of a marriageable age. Maori tattoo was unlike most traditional tattoo in that its main line were 'engraved' on the face with deep cuts made by miniature bone chisels. The fill-in areas were not tattooed with cuts but with the multiple pricks of small bone 'combs' that only lightly penetrated the skin surface. The instrument of tattoo consisted of small pots of pumice or wood into which was placed a wetted black pigment made from burnt kauri gum, burnt vegetable caterpillars or other sooty materials. A bird bone chisel or comb set at right angles on a short wooden handle was dipped into the gigment, that a rod or stick was used to tap head of this miniature adze, causing penetration of the skin surface. Black pigment lodged under the skin took on a bluish tinge. A full made facial tattoo consisted of major spirals with smaller spirals on each side of the nose and sweeping curved lines radiating out from between the brows over the forehead and from the nose to the chin. The major patterns were cut deep, while the secondary koru patterns were lightly pricked into the skin.

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4-Post Road Simulator 를 이용한 농용 트랙터의 유연 다물체 동역학 해석 (Flexible Body Dynamics Analysis of Agricultural Tractor Using 4-Post Road Simulator)

  • 박지수;이강욱;조종윤;윤지원;신재윤
    • 대한기계학회논문집 C: 기술과 교육
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    • 제3권2호
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    • pp.83-88
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    • 2015
  • 농용 트랙터는 일반적인 도로 주행이 아닌 논 또는 밭과 같은 험지에서 작업용으로 사용한다. 때문에 정적 하중 뿐만 아니라 동적 하중이 고려된 구조 해석이 진행되어야 한다. 하지만 동적 입력 하중을 계산하기 위해서는 다양한 작업기와 하중조건을 모사해야 하기에 실제 측정에 많은 시간과 노력이 소요된다. 이러한 노력들을 줄이기 위해서 본 연구에서는 상용 자동차와 동일하게 농용 트랙터를 위한 4 축 도로하중 시뮬레이터(4-Post Road Simulator) 모델을 개발하였다. 입력하중을 검증하기 위해 사내 험로 시험장에서 차축의 가속도 값과 바디프레임의 변형률(strain)을 측정하였다. 가속도 값은 동역학 모델의 입력 하중으로 사용하고 모드 중첩 법을 포함한 동역학 해석을 수행하여 변형률을 검증하였다. 이를 통해 험로 프로파일과 유사한 거동을 나타내는 4 축 도로하중을 구할 수 있었으며 신뢰성을 검증하였다.

서로 다른 거칠기의 복합레진에 표면 강화제 도포시 표면 거칠기의 변화 (Effect of surface sealant on surface roughness of dental composite with different surface roughness)

  • 신동아;진선주;배꽃별;황인남
    • 구강회복응용과학지
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    • 제39권4호
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    • pp.195-203
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    • 2023
  • 목적: 본 연구는 서로 다른 필러를 가지는 복합레진에서 표면 연마 정도에 따라 수종의 레진 표면 강화제(Surface sealant)를 도포했을 때 복합레진의 거칠기에 미치는 영향에 대해 연구해 보고자 한다. 연구 재료 및 방법: 미세입자형 복합레진(Metafil CX, Sun Medical Co.)과 혼합형 복합레진(AeliteTM LS posterior, Bisco)을 사용하여 직경 8 mm, 높이 4 mm의 시편을 레진당 60개씩 제작하고, 3개 군으로 나누어 주수 하에 600, 1000, 2000 grit 사포(Tamiya finishing abrasives, Tamiya Inc.)로 연마하였다. 연마된 표면의 표면 조도(Ra)값은 Surface Roughness Tester (SJ-301, Mytutoyo)를 이용해 측정하였으며 연마된 각 시편에 레진 표면 강화제인 BisCoverTM LV (Bisco), Optiguard® (Kerr), and Seal-n-ShineTM (Pulpdent)를 각각 제조사의 지시에 따라 도포하였다. 레진 표면 강화제 처리 전과 후에 시편의 표면 조도를 측정하였으며 주사전자현미경(JSM-7500, JEOL)과 원자현미경(MultiMode IV, Veeco Instruments)으로 관찰하였다. 결과: 600 grit 사포로 연마한 후 레진 표면 강화제를 처리한 군은 도포 전보다 더 낮은 표면 조도(Ra)값을 보였으나(P < 0.05), 1000, 2000 grit으로 연마한 군에서는 도포 전 후 간에 통계적으로 유의한 차이를 보이지 않았다. 레진 표면 강화제 제품 간 뚜렷한 거칠기 차이는 나타나지 않았다. SEM과 AFM으로 시편을 관찰 시 마무리와 연마 후 레진 표면에 형성된 미세한 결함이 레진 표면 강화제를 처리한 후 현저히 줄어드는 양상을 보였다. 결론: 본 연구 결과, 마무리와 연마 후 복합레진 표면이 거친 경우에는 레진 표면 강화제의 도포가 미세한 결함을 채워서 거칠기에 영향을 줄 수 있지만 복합레진 표면의 연마 상태가 우수한 경우 레진 표면 강화제의 도포가 거칠기에 크게 영향을 주지 않음을 보여준다.

비산재로부터 유용성분을 회수하는 청정부유선별공정 (Clean Flotation Process to Recycle useful Materials from Fly Ash)

  • 한광수;김둘선;이동근
    • 청정기술
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    • 제26권3호
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    • pp.177-185
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    • 2020
  • 본 연구에서는 석탄화력발전소에서 전량 폐기되고 있는 석탄재의 재활용 방안으로 석탄회의 80%를 차지하고 있는 비산재로 부터 유용성분을 회수하고 이를 산업재로 활용하기 위한 청정부유선별 공정을 개발하였다. 비산재로부터 미연탄소(unburned carbon, UC) 를 회수하기 위해 비이온성 포수제인 등유 대신에 친환경 식물성 오일인 대두유를 사용하여 등유로부터 악취 발생을 예방하였고 부유선별 후 잔류물로부터 CM (ceramic microsphere)과 CA (cleaned ash)를 분리하기 위해 황산용액을 사용하지 않고 hydro-cyclone를 사용함으로써 산성폐수를 발생시키지 않고 미립의 CM를 회수할 수 있었다. 등유를 포수제로 사용하여 UC를 분리할 때 보다 대두유를 포수제로 사용하였을 때, 대두유의 높은 점성으로 인한 UC의 흡착성 증가와 대두유에 포함된 리놀레산에 의해 부유성 향상으로 UC의 회수율이 85.8%로 높게 나타났다. 회수된 UC에 포함된 연소가능성분(combustible component, CC)은 모두 탄소성분으로 대두유를 사용하였을 때 탄소의 함량이 높게 나타났으며, 회수된 UC는 표면이 거칠면서 기공이 많아 분쇄가 쉬워 미립화로 산업용 소재로 활용할 수 있을 것이다. Hydro-cyclone을 이용한 입도선별 청정분리공정에 의해 회수된 CM과 CA는 구형 형상으로 입자들이 서로 뭉치지 않고 뚜렷하게 분리되었으며 입자의 평균직경(D50)은 5 ㎛로 미세하여 공정변경에 의한 CM의 미립화를 구현할 수 있었다.