• 제목/요약/키워드: slippery

검색결과 140건 처리시간 0.022초

항공기 착륙거리의 여유분 산정에 관한 연구 (A Study on the Allowances of Aircraft Landing Distance)

  • 노건수;김웅이
    • 한국항행학회논문지
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    • 제17권3호
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    • pp.279-284
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    • 2013
  • 운항의 여러 단계 중 착륙단계에서 조종사들이 많은 부담을 느낀다. 이는 조종사들이 항공기 속도를 줄이고 접지하여 완전히 정지하는 동안 착륙안전에 영향을 미치는 여러 요소가 있기 때문이다. 만일 착륙하는데 활주로길이가 충분하다면 부담이 적을 수도 있다. 그러나 항상 그런 경우만 있는 것은 아니다. 따라서 착륙성능이 제한범위 내에 있는지 아닌지를 확인할 필요가 있다. 필요착륙거리는 시험비행 조종사에 의해 실증되어진 실제착륙거리에다가 항공사의 평균적인 조종사들을 위한 여유분을 포함한 것이다. FAR의 AFM(항공기 비행규정) 인가는 건조 및 습윤 활주로에서 수동착륙을 기반으로 한다. 기타 다른 활주로 조건에서는 인가가 필요하지 않다. JAR에서는 빙설/윤활활주로에서도 정해진 여유분을 포함시키도록 규정하고 있다. 자동착륙은 인가사항이 아니므로 실제착륙거리만 제공된다. 본 논문에서는 각 활주로 조건에서 포함된 거리 여유분을 분석하고자 한다. 또한 특정한 활주로 조건에서 여유분이 규정되어 있지 않은 경우 대안을 제시하고자 한다.

설문조사를 통한 우리나라 연안복합어선의 조업 실태 (Operating status of Korean coastal composite fishing boats by the questionnaire survey)

  • 황보규;장호영;김민선
    • 수산해양기술연구
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    • 제54권4호
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    • pp.324-332
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    • 2018
  • We conducted a questionnaire survey to analyze the current status of the coastal composite fisheries, as well as the improvement point in designing a new type coastal composite fishing boat suitable for Korean fishing environments from April to August 2017. The questionnaire composed of 20 questions about the features of the coastal composite fishing boat and fishing work. The survey sites were selected to cover all parts of the country by considering the geographical position. The significance testing for the response results was accessed by ${\chi}^2$ test and ANOVA. The results revealed that more than half (59.1%) of the fishermen operated one day per voyage and operating alone topped with 22.5% in the number of crews, followed by 2 persons (20.3%) and 5 persons (22.1%). The navigation devices had a high rate of installation and GPS plotter ranked first in the devices. In addition, fish finder ranked first in fishing equipment, followed by net hauler. The most inconvenient work that they felt during the fishing operation was fish handing at 49.8% and other general fishing works like setting and hauling line, deck cleaning accounted for about 25%. The hardest work was the accident by ropes wrapped around propeller and the engine trouble came in second. The most inconvenient facilities to the present design of fishing boat was wheelhouse (76.7%), followed by fish hold (38.5%), and deck (35.1%). Furthermore, inconvenient points related to the movement of fishing gear, noise and vibration of engine, slippery deck and small fish hold exceeded 50%.

Long-Haul Truck Driver Training Does Not Meet Driver Needs in Canada

  • Malkin, Jennifer;Crizzle, Alexander M.;Zello, Gordon;Bigelow, Philip;Shubair, Mamdouh
    • Safety and Health at Work
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    • 제12권1호
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    • pp.35-41
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    • 2021
  • Introduction: Training standards for long-haul truck drivers (LHTD) are rapidly evolving in Canada, yet the opinions of the drivers themselves have not been adequately considered. The purpose was to survey LHTD on their work training history and to examine LHTD perceptions of driver training and licensing protocols. Methods: LHTD were recruited across two Western Canadian provinces from seven different truck stops. The sample completed 207 surveys and 67 semi-structured interviews. Results: The average age of the participants was 52.5 ± 11.5 years (range 24-79); 96% were men. Approximately 33% of the LHTD had at least one crash. Those who did not receive formal driver training were significantly more likely to crash than those who had received training. Participants stated that current training standards are inadequate for the industry, particularly for new drivers. According to participants, entry-level curriculums should consist of both classroom and practical training, as well as on-road observation with a senior mentor. LHTD reported that many new drivers are not equipped to drive in various contexts and settings (e.g., mountains, slippery roads). Conclusions: LHTD are not confident in the current training guidelines for novice truck drivers. Revisions to the training curriculum and standardization across Canada should be considered. Practical Application: A federal mandatory entry-level training program is needed in Canada to ensure that all new LHTD ascertain the necessary skills to drive safely. Such a program requires government involvement and input from LHTD to facilitate appropriate licensure and consistent training for all drivers.

인영촌구비교맥진(人迎寸口比較脈診)에 관한 연구 (A Study on Comparative Pulse Diagnosis of Renying Pulse(人迎脈) and Cunkou Pulse(寸口脈))

  • 윤창열
    • 대한한의학원전학회지
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    • 제32권4호
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    • pp.35-46
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    • 2019
  • Objectives : While Comparative Pulse Diagnosis of Renying pulse(人迎脈) and Cunkou pulse(寸口脈) is one of the three major pulse diagnostic methods in "Huangdineijing" along with Three Positions and Nine Indicators Pulse Diagnosis(三部九候脈診法) and Cunkou Pulse Diagnosis(寸口脈診法), it has died out in later periods. This study aims to examine this lost method. Methods : Annotations of "Huangdineijing" were examined along with descriptions of the author's own experience. Results & Conclusions : Renying is the Renying(人迎) point from the Stomach Channel(ST), while Cunkou is the Taiyuan(太淵) point from the Lung Channel(LU). These two points are compared in order to determine the deficiency and excess of the Zangfu(臟腑). Normal pulses(平脈) are Soft(軟脈) or Moderate(緩脈), while Stirred pulses(躁脈) are Stringy(弦脈), Tight(緊脈), Slippery(滑脈) or Long(長脈). If the Renying is once active where Shaoyang pulse is active, purge the Gallbladder and supplement the Liver. If there is Stirred pulse, purge the Triple Burner and supplement the Pericardium. If the Renying is twice active where Taiyang pulse is active, purge the Bladder and supplement the Kidney. If there is Stirred pulse, purge the Small Intestine and supplement the Heart. If the Renying is three times active, where Yangming pulse is active, purge the Stomach and supplement the Spleen. If there is Stirred pulse, purge the Large Intestine and supplement the Lung. If the Cunkou is once active where the Jueyin pulse is active, purge the Liver and supplement the Gallbladder. If there is Stirred pulse, purge the Pericardium and supplement the Triple Energizer. If the Cunkou is twice active where the Shaoyin pulse is active, purge the Kidney and supplement the Bladder. If there is stirred pulse, purge the Heart and supplement the Small Intestine. If the Cunkou is three times active where the Taiyin pulse is active, purge the Stomach and supplement the Spleen. If there is Stirred pulse, purge the Lung and supplement the Large Intestine.

가정편의식 패키지 디자인에 대한 사용자 평가 연구 (A Study on User Evaluation about Package Design of Home Meal Replacement)

  • 양근영
    • 디자인융복합연구
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    • 제18권1호
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    • pp.49-60
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    • 2019
  • 이 연구는 고령화 사회 및 개인핵가족사회에 진입하는 우리나라의 현 상황에서 가정편의식 제품을 편리하게 사용할 수 있는 디자인에 대하여 알아보고자 한다. 연구방법으로 첫째, 가정편의식 이론적 고찰로서 문헌자료 및 선행연구조사를 하였다. 둘째, 디자인 조사로서 가정편의식 디자인 사례 분류를 하였다. 셋째, 실제 사용하는 이용자를 대상으로 사용자 평가 및 감성평가 조사를 실시하였다. 제품 디자인 감성평가에 의한 요인분석 결과 3개의 대표 요인으로 분류되어졌다. 1요인은 "형태적 감성", 2요인은 "기능적 감성", 3요인은 "심리적 감성"으로 연구자에 의한 대표 감성언어 명칭을 3가지로 부여하였다. 가정편의식 패키지 디자인으로 다음과 같이 제작되어져야할 것이다. 첫째, 용기를 들때 대부분 비닐용기로 되어져있어 미끄러지고 떨어뜨리기 쉽기 때문에 용기에 그립감을 주어 잘 떨어뜨리지 않게 한다. 둘째, 손목이나 손가락 힘이 약한 고령자를 위하여 쉽게 뜯을 수 있게 제작 한다. 또한, 색상과 관련하여 차가운 한색계열 색상보다는 따뜻한 난색 계열색상을 이용하여 제공한다.

금속관 내부의 음압유량 향상을 위한 기하학적 디자인 및 SLIPS 윤활 (Geometrical Design and SLIPS Lubrication for Enhancement of Negative-pressure-driven Internal Flow Rate in Metal Pipes)

  • 김동근;장창환;김성재;김대겸;김산하
    • Tribology and Lubricants
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    • 제37권6호
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    • pp.253-260
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    • 2021
  • Metal pipes are used in a wide range of applications, from plumbing systems of large construction sites to small devices such as medical tools. When a liquid is enforced to flow through a metal pipe, a higher flow rate is beneficial for higher efficiency. Using high pressures can enhance the flow rate yet can be harmful for medical applications. Thus, we consider an optimal geometrical design to increase the flow rate in medical devices. In this study, we focus on cannulas, which are widely used small metal pipes for surgical procedures, such as liposuction. We characterize the internal flow rate driven by a negative pressure and explore its dependence on the key design parameters. We quantitatively analyze the suction characteristics for each design variable by conducting computational fluid dynamics simulations. In addition, we build a suction performance measurement system which enables the translational motion of cannulas with pre-programmed velocity for experimental validation. The inner diameter, section geometry, and hole configuration are the design factors to be evaluated. The effect of the inner diameter dominates over that of section geometry and hole configuration. In addition, the circular tube shape provides the maximum flow rate among the elliptical geometries. Once the flow rate exceeds a critical value, the rate becomes independent of the number and width of the suction holes. Finally, we introduce a slippery liquid-infused nanoporous surface (SLIPS) coating using nanoparticles and hydrophobic lubricants that effectively improves the flow rate and antifouling property of cannulas without altering the geometrical design parameter.

Landslide risk zoning using support vector machine algorithm

  • Vahed Ghiasi;Nur Irfah Mohd Pauzi;Shahab Karimi;Mahyar Yousefi
    • Geomechanics and Engineering
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    • 제34권3호
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    • pp.267-284
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    • 2023
  • Landslides are one of the most dangerous phenomena and natural disasters. Landslides cause many human and financial losses in most parts of the world, especially in mountainous areas. Due to the climatic conditions and topography, people in the northern and western regions of Iran live with the risk of landslides. One of the measures that can effectively reduce the possible risks of landslides and their crisis management is to identify potential areas prone to landslides through multi-criteria modeling approach. This research aims to model landslide potential area in the Oshvand watershed using a support vector machine algorithm. For this purpose, evidence maps of seven effective factors in the occurrence of landslides namely slope, slope direction, height, distance from the fault, the density of waterways, rainfall, and geology, were prepared. The maps were generated and weighted using the continuous fuzzification method and logistic functions, resulting values in zero and one range as weights. The weighted maps were then combined using the support vector machine algorithm. For the training and testing of the machine, 81 slippery ground points and 81 non-sliding points were used. Modeling procedure was done using four linear, polynomial, Gaussian, and sigmoid kernels. The efficiency of each model was compared using the area under the receiver operating characteristic curve; the root means square error, and the correlation coefficient . Finally, the landslide potential model that was obtained using Gaussian's kernel was selected as the best one for susceptibility of landslides in the Oshvand watershed.

패싱, 경계와 차이의 서사 -제임스 W. 존슨과 넬라 라선 (Boundaries and Differences in the Narrative of Passing: James W. Johnson and Nella Larsen)

  • 강희
    • 영어영문학
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    • 제53권2호
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    • pp.307-333
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    • 2007
  • When W. E. B. Du Bois says that "the problem of the twentieth century is the problem of the color line," such a statement clearly recognizes the significance of the issue of racial identity, a cultural phenomenon called 'passing.' Both Johnson in The Autobiography of an Ex-Colored Man and Larsen in Passing confront this issue. Both novels, using the metaphor of passing, not only trace the racial anxiety and race politics of the time but also expose the unstable landscape of the established social and cultural boundaries of racial identity. Mapping out multiple meanings and various dimensions of passing, this paper argues how Johnson's and Larsen's narratives display the ambivalence of color line while they at the same time complicate, problematize, and destabilize the mainstream racial boundaries and differences. It furthers to delineate how the two writers, with difference, deal with the problem of passing, the significance of racial identity, and black middle class values along with its intraracial differences. Rather than draw a clear definition of and a definitive closure on passing narrative, this paper focuses on its complexities and undecidability, challenging every dimension of its established significations. It also explores the complex dynamic between passing act and individual identity, for passing here is not just a racially signified term but extends its significance to the other factors of identity, such as class and even sexuality. Johnson and Larsen open up a site for a newly emergent, modern racial identity for black middle class in the twentieth century American urban spaces. Both writers, illuminating the subversive and slippery nature of language in their passing narrative, clearly herald new, different forms of Afro-American writings and themes for the different century they face.

담적의 진단요소 및 증후군으로서의 가치에 대한 문헌고찰 (A Literature Study on the Diagnostic Factors and Value as a Syndrome of Damjeok)

  • 임윤서;노기환;최규호;이상현;최서형
    • 대한한의학회지
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    • 제44권3호
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    • pp.170-188
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    • 2023
  • Objectives: The purpose of this study is to investigate the diagnostic factors of Damjeok in the literature. Methods: This study used the databases of five (Mediclassics, RISS, KMbase, OASIS, CNKI) to analyze diagnostic factors of Damjeok. Literatures published by May 2023 were assessed and we classified 91 literatures dealing with diagnostic factors by 5 categories, 'characteristics', 'location', 'symptom', 'pulse wave & tongue feature', and 'eating habits & lifestyle'. Results: Damjeok is mainly formed at the stomach in the form of lump or hard seed, and it can be observed in other regions or even the whole body by its trait of floating. Damjeok mainly shows symptoms of the digestive system and also causes various symptoms associated with the respiratory system and infection, musculoskeletal system, urogenital system, neuropsychiatric system and cardiovascular system. Regarding pulse wave and tongue feature, a slippery wave and greasy coated tongue are typical features of Damjeok. Additionally, bad eating habits and a lack of exercise have been described as a factor that cause and aggravate Damjeok. Conclusions: The two most important factors in the diagnosis of Damjeok are abdominal stiffness by physical examination and digestive symptoms, and these correspond to the definition of a syndrome. Diagnostic factors based on literature evidence will provide clues to the clinical diagnosis of Damjeok syndrome.

고령자를 위한 거주지 외부환경 평가 - 대전시 거주 준고령자 이상을 대상으로 - (An Evaluation of Outdoor Living Environments for Senior Citizens - Focused on the Prospective Seniors and Senior Citizens in Daejeon -)

  • 이시영;이희정;임병호;심준영
    • 한국조경학회지
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    • 제39권4호
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    • pp.39-48
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    • 2011
  • 한국은 빠르게 고령화사회로 접어들고 있다. 이러한 시점에서 본 연구의 목적은 예비고령자들의 현 주거지의 외부환경 이용실태를 조사하고, 고령자 친화형 외부공간에 주요한 요소들을 파악하여 이들의 평가를 통해 고령자의 건강한 생활을 위한 환경요소를 파악하여 개선점을 제시하는데 있다. 연구 방법으로서 먼저 기존 선례와 관련연구의 조사를 통한 이론적 토대를 마련하고, 실증연구로서 대전에 거주하고 있는 준고령자 이상 주민의 외부환경 이용실태와 만족도에 대해 설문조사를 병행하였다. 본 연구의 결과로서 전반적으로 현 거주지의 외부환경이 큰 문제가 없이 중간 수준의 평가를 받고 있었지만, 평가요소들중 비교적 저평가된 요소들은 고령자 친화형 공간요소로 개선이 필요되어져야 할 것이다. 첫째, 산책하기 위해서 '산책길의 이용'이 가장 높았고, 한번에 1~2시간동안 외부에 머무르며, 주차된 차량이 많음이 가장 불편한 사항이었다. 둘째, 외부환경은 '보통'으로 평가되었으며, '사회성'이 기장 낮게 평가되었다. 셋째, '카트/휠체어 이용편리성', '조명에 의한 야간 식별성', '야간의 안내판 식별성'. '나무 화초 쾌적성'의 4 개 항목에서 남자가 여자보다 불만족하고 있었다. 66세 이상의 응답자들이 '바닥의 미끄러움', '계단난간', '야간의 안내판 식별성', '단지배치의 방향성' 항목에서 더 불만족하고 있었으며, '바닥 미끄러움', '야간의 안내판 식별성'의 두 개 항목에서는 80대 이상의 응답자들이 더 불만족하고 있었다. 넷째, 현 거주지 유형에 따른 평가는 22개 중 20개 항목에서 유의미한 차이가 나타나는 바, 아파트 거주자의 평가가 더 높게 나왔다. 전반적으로 현거주지 주변환경에 있어 고령자들의 입장에서 크게 문제로 대두된 것은 없다고 평가되었다. 그러나 향후 10년 내에 고령화가 더욱 진행된다고 가정할 때, 기술통계에서 낮은 점수를 받은 항목과 80세 이상의 고령자들에게 특히 불편을 야기하고 있는 낮은 평가항목에 대하여 주거환경 개선이 우선적으로 요구된다.