• Title/Summary/Keyword: 후사경

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Robust Optimization of the Automobile Rearview Mirror for Vibration Reduction (승용차용 후사경의 진동 저감을 위한 강건최적설계)

  • 황광현;이광원;박경진
    • Transactions of the Korean Society of Automotive Engineers
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    • v.7 no.6
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    • pp.198-206
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    • 1999
  • An automobile outside rear view mirror system has been analyzed and designed to reduce vibration with a finite element model. model analysis is conducted for the calculation of natural frequencies. harmonic analysis is utilized to estimate the displacements of the glass surface under dynamic loads. The model is verified with the vibration experiment of the parts and the assembled body. The structure of the mirror system is optimized for the robustness defined by the Taguchi concept. At first, many potential design variables are defined. Final design variables are selected based on the amount of contribution on the objective function. That is, sensitive variables are chose. The SN ratio in the Taguchi method is replaced by an objective function with the mean and the standard deviation of the quality characteristic. The defined objective function is appropriate in the structural design in that the vibration displacements are minimized while the robustness is improved.

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The Development of the Korean Motor Vehicle Safety Standards for Motorcycles : Exterior Rear-View Mirror and Tire (국내 이륜자동차 안전기준 개발 : 후사경과 타이어)

  • Yong, Boojoong;Yong, Geejoong;Shin, Jaeho;Ryu, Kihyeon
    • Journal of Auto-vehicle Safety Association
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    • v.8 no.3
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    • pp.16-21
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    • 2016
  • As motorcycles are getting more widely used recently, motorcycle accidents are gradually increased every year. Although most accidents are caused by human factors, the importance of motor vehicle safety standards cannot be underestimated indeed. A variety of regulations related to motorcycle safety have been issued in many countries such as EU, U.S., and Australia, etc. In order to harmonize the international safety standards, it is necessary to develop or enhance the Korean Motor Vehicle Safety Standards (KMVSS) for motorcycles. In this study, motorcycle safety standards for an exterior rear-view mirror and a tire are investigated. Actual test procedures are expected in sequential studies according to the results provided herein. Also, the findings in this paper can be utilized to ensure the KMVSS for a safer driving.

건강과 자연농업-제181호

  • Korea Organic Farming Association
    • THE HEALTH and ORGANIC FARMING
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    • no.181
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    • pp.1-24
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    • 2002
  • 2002년 지회장단 연찬회 개최/작금의 마늘사태에 대한 현명한 해법은?/친환경농업은 반드시 성공해야/믿어봐 ! 야채의 힘을/수입개방 피해 직접보상... 도입 붐/"2002 새농민상" 회우 5쌍 선정/농협 "이달의새농민" 수상자대만연수기Ⅱ/유기농업에의한과수(단감) 재배/8월중 농사정보/아시아 유기농업 발전추이/후사리움균(Fusarium)에 의한 토양 병해와 대책/친환경농법에 새우를 이용/미생물을 이용한 토양병해 방제/제5회충남유기농업인대회성료

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건강과 자연농업-제182호

  • Korea Organic Farming Association
    • THE HEALTH and ORGANIC FARMING
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    • no.182
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    • pp.1-24
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    • 2002
  • 사상 유례없는 태풍 '루사' 피해복구에 총력을!!/지구의 미래는 유기농업뿐이다!/헤어리벳치 실증재배기술 요약/내년 농업예산 삭감.축소편성 '파장'/아주 편리한 신개념 고추건조방법이란?/전국 친환경농업 품평.전시회/GMO (유전자변형식품) 이란무엇인가?/유기농업에의한 양계/9월중 농사정보/당신도 무병장수를 꿈꾸는가?/후사리움균(Fusarium)병의 방제법/영국의 유기농업 농가의 소득손실?/미생물의 질병방제 기작/영천시 유기농업 한마음대회 성료

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Analysis of the flow field around an automobile with Chimera grid technique (Chimera 격자기법을 이용한 자동차 주위의 유동장 해석)

  • An, Min-Gi;Park, Won-Gyu
    • Journal of computational fluids engineering
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    • v.3 no.2
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    • pp.39-51
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    • 1998
  • This paper describes the analysis of flow field around an automobile. The governing equations of the 3-D unsteady incompressible Navier-Stokes equations are solved by the iterative time marching scheme. The Chimera grid technique has been applied to efficiently simulate the flow around the side-view mirror. To validate the capability of simulating the flow around a ground vehicle, the flows around the Ahmed body with 12.5$^{\circ}$ and 30$^{\circ}$ of slant angles are simulated and good agreements with experiment and other numerical results are achieved. To validate Chimera grid technique, the flow field around a cylinder was also calculated. The computed results are also well agreed with other numerical results and experiment. After code validations, the flow phenomena around the ground vehicle are evidently shown. The flow around the side-view mirror is also well simulated using the Chimera grid technique.

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Lane Spare Widths Reflecting Vehicles' Rearview Mirror Widths and Lateral Wheel Paths (차량의 후사경 폭과 횡방향 이격거리를 반영한 차로여유폭 산정)

  • Yoo, Hye-Min;Han, Man-Seob;Oh, Heung-Un
    • International Journal of Highway Engineering
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    • v.16 no.1
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    • pp.41-48
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    • 2014
  • PURPOSES : The lane width of the domestic highway is 3.5 ~ 3.6m and it has been designed nationwide. However, the distribution of the average vehicle widths, rearview mirror widths and lateral wheel paths by region appear different. Then, lane spare widths may differ by region followingly. Thus, the flexible design of freeway lane widths is required. METHODS : The methodologies of this paper are as follows. First, vehicle widths rearview mirror widths lateral wheel paths of vehicles driven four national expressways were measured. Second, lane spare widths by vehicle widths were calculated. Third, lane spare widths reflecting rearview mirror widths were calculated by using interval estimation. Additionally, lane spare widths reflecting vehicles lateral wheel paths were calculated. RESULTS : The results of this paper are as follows. First, lane spare widths by vehicle widths ranges 0.83 to 0.95m. Second, lane spare widths reflecting rearview mirror widths ranges 0.518 to 0.747m at the confidence interval 95%. Third, lane spare widths reflecting vehicles' lateral wheel paths ranges -0.022 to 0.322m at the curved sections and the confidence interval 95%. CONCLUSIONS : It may be concluded that the present lane spare widths are relatively narrow at the curved section. Thus, there is a need to consider expanded lane widths at the curved sections. Additionally, there is a need to consider flexible design of lane widths by various conditions.

A Study do parts of So-yin-In and So-yang-In (소음인(少陰人)·소양인편(少陽人篇)의 표병(表病)·이병(裏病)에 대한 고찰考察(표이음양승강(表裏陰陽升降)을 중심으로))

  • Lee, Eui-Ju;Song, Il-Byeong
    • Journal of Sasang Constitutional Medicine
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    • v.8 no.1
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    • pp.43-56
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    • 1996
  • As considering a study of the So-um-In and So-yang-In desease, I know each of Extra-disease (表病) and Intra-disease (裏病). I takes serious view of the Extra-Intra-Um-Yang-Up-Down (表裏陰陽升降). I try to join costitutional disease to the parts of human body, which base on the theory on Sa-sang constituional Medicine. And I make some diagrams of them. They could be summerized as follows. 1.The Extra-qi (表氣) is four-viscera (四臟) and four back parts of hurman body (後四海). The Intra-qi (裏氣) is four-digestive organs (四腑) and four fore parts of human body (前四海). 2. It is important that Yang-qi (陽氣) go up at So-um-In Extra-disease (少陰人 表病) and Um-qi (陰氣) go down at So-yang-In Extra-disease (少陽人 表病). And It is important that Um-qi (陰氣) go down at So-um-In Intra-disease (少陰人 裏病) and Yang-qi of Large Intestine (大關局) go up at So-yang-In Intra-disese (少陽人 裏病). 3. Looking into the Extra-disease, ◈ Sin-Yang-Gon-Yiel (腎陽困熱) and Ha-Cho-Chuk-Hyel (下篇蓄血) of So-um-In disease are the disease that Yang-qi don't go up from the buttock. So-Yang-sang-Pung (少陽傷風) of So-yang-In disease is the disease that Um-qi don't go down from the upper back. ◈ Yui-Ga-Sil (胃家室) of So-um-In disease is the disease that Yang-qi don't go up from the lower abdomen Gyel-Hung (結胸) of So-yang-In disease is the disease that Um-qi don't go down from the thorax. ◈ Mang-Yang (亡陽) of So-um-In disease is the disease that Yang-qi don't go up from Intra-qi so it go out to the Extra-qi. Mang-Um (亡陰) of So-yang-In disease is the disease that Um-qi don't go down from the Extra-qi so it go into the Extra-qi. ◈ Dea-Jang-Pa-Han of So-um-In disease and Sim-Ha-Gyel-Hung (心下結胸) of So-yang-In desease are half of Extra-qi and Inrea-qi. 4. Looking into the Intra-disease, ◈ The Intra-disease of So-um-In is Tae-um symtom (太陰證) and So-um symtom (少陰證). The So-um symtom is more severe than Tae-um symtom because a cold wave of Large Intestine (大腸冷氣) involve a warm wave of Stomach (胃局). ◈ The Intra-disease of So-yang-In is not to go up Yang-qi of Large Intestine. Deficit of Yang-qi from Large Intestine which go up at Stomach is more sever than deficit of Yang-qi from Stomach which go up at extremes.

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Recent updated diagnostic methods for esophageal motility disorders (식도의 운동장애에 관한 최신지견)

  • Yoon, Seok-Hwan
    • Journal of radiological science and technology
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    • v.27 no.4
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    • pp.11-16
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    • 2004
  • Classification of esophageal motility disorders not yet finalized and is still ongoing as the new disorders are reported, and the existing classification is changed or removed. In terms of radiology, the primary peristalsis does not exist, and the lower end of the esophagus show the smooth, tapered, beak-like appearance. The esophageal motility disorder, which mostly occurs in the smooth muscle area, show the symptoms of reduction or loss (hypomotility) or abnormal increase (hypermotility) of peristalsis of the esophagus. It is important to understand the anatomy and physiology of the esophagus for the appropriate radiological method and diagnosis. Furthermore, the symptom of the patient and the manometry finding must be closely referred for the radiological diagnosis. The lower esophageal sphincter can be normally functioning and open completely as the food moves lower. Sperandio M et al. argues that the name diffuse esophageal spasm must be changed to distal esophageal spasm (DES) as most of the spasm occurs in the distal esophagus, composed of the smooth muscle. According to Ott et al., usefulness of barium method for diagnosing the esophageal motility disorder is Achalasia 95%, DES 71% and NEMD 46%, with the overall sensitivity of 56%. However, excluding the nutcracker esophagus or nonspecific disorder which cannot be diagnosed with the radiological methods, the sensitivity increases to 89%. Using videofluoroscopy and 5 time swallows, the average sensitivity was over 90%. In conclusion, the barium method is a simple primary testing method for esophageal motility test. Using not only the image but also the videofluoroscopy with good knowledge of the anatomy and physiology, it is believed that the method will yield the accurate diagnosis.

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The Comparison of $45^{\circ}$ and $55^{\circ}$ Anteroposterior Oblique View for Observating the Intervertebral Foramen (경추 추간공 관찰을 위한 촬영법의 고찰)

  • Jeon, Ju-Seob;Eun, Sung-Jong;Kim, Hye-Ran;An, Seung-Hyun;Choi, Nam-Kin;Kim, Young-Keun
    • Journal of radiological science and technology
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    • v.28 no.2
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    • pp.91-95
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    • 2005
  • The cervical spine of anteroposterior oblique view is essential to observe the intervertebral foramen(IVF). The morphologic changes of IVFs were proved to be abnormal with nerve roots and peripheral structures. The purpose of this study is to evaluate the effective projection angle for observing the IVFs in the Korean adults. In a prospective clinical study of 100 normal persons, $45^{\circ}$, $50^{\circ}$ and $55^{\circ}$ oblique views were compared by measuring the maximal transverse diameter of all the cervical IVFs. $45^{\circ}$ oblique views provided slightly better visualization of upper cervical level(C2-C3, C3-C4, C4-C5), but the lower cervical level(C5-C6, C6-C7, C7-T1) of IVF transverse diameters were substantially increased on the $55^{\circ}$ AP oblique projection. In the comprasion of mean differences between 8 obese person(BMI > 25) and 58 normal person(18.5 < BMI < 22.9) proved to be statistically not significant. Consequently this study shows that $55^{\circ}$AP oblique(tube angle $15^{\circ}$cephalad) view is optimal for evaluating the lower cervical IVFs.

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