• 제목/요약/키워드: free fall

검색결과 228건 처리시간 0.024초

FreeCAD를 이용한 셀카봉 모델링

  • 성광원;김영기
    • 한국CDE학회지
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    • 제21권2호
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    • pp.50-60
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    • 2015
  • Corresponding to the high consumption rate of the selfie stick for cell phone camera, the design of the product is becoming diverse. However, relatively low cost selfie stick models are not strong enough to stand the weight of the cell phone. This results into a bending of the stick or the accidental fall of the cell phone by the failure of the holding unit. As a solution to the problem, design of selfie stick that is structurally strong enough to stand the weight of the cell phone with the minimum weight for the portability is proposed in this paper.

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추락에 의한 손상으로 응급실로 내원한 환자의 임상적 고찰 (A Clinical Study of Free-Fall Patients in Emergency Department)

  • 이재광;최종필;박성수;박준석
    • Journal of Trauma and Injury
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    • 제18권2호
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    • pp.155-160
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    • 2005
  • Background: Falls are a major cause of emergency room visits. Injury secondary to falls is a largely preventable public health problem. This study helps to better understand the epidemiology of falls from height, then develops prevention strategies. Methods: We reviewed the medical records of 192 patients admitted to the emergency department of Konyang university hospital with a history of falls from January 2004 to December 2004. Collected data included the patient's age, gender, height of fall and method, outcome of management, Injury Severity Score(ISS). Results: According to the characteristics of height of fall, the ISS was higher when the patient fell from height of 2 meters or more($13.79{\pm}12.17$) than not($8.13{\pm}9.25$)(p<0.05). There were positive correlation between mean age and ISS(p<0.001, r=0.7). To gender, ISS was higher in the male group($12.73{\pm}11.78$) than the female group($8.48{\pm}10.00$)(p<0.05). Conclusion: Falls often results from multiple concurrent problems including environmental and behavioral factors. This study suggests that we need to improve the occupational environment, especially above 2meters, for decreasing injuries of fall from heights. Also we consider the prevention of children from injuries of fall from heights.

저온과 Polyamine 처리에 의한 봄무우와 가을무우 자엽과 상배축에서 당류와 총 아미노산 분석에 관한 연구 (Analysis of sugars and total amino acids-content of young spring and fall-radish cotyledons and hypocotyls by cold and polyamine-treatments)

  • 조봉희;박선영
    • 분석과학
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    • 제9권4호
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    • pp.325-330
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    • 1996
  • 몸무우의 자엽에 저온과 polyamine(PA)을 처리하면 세포내의 환원당과 설탕의 농도가 증가되었고, 가을무우의 자엽에 저온처리를 하면 환원당과 설탕의 농도가 증가되나, 저온과 PA를 동시에 처리하면 세포내에 당류의 농도가 증가되지 않았다. 몸무우 자엽에서는 저온처리에 의해 총 아미노산의 농도는 증가되나, 가을무우에서는 증가되지 않았다. 이 결과는 저온에 예민한 봄무우는 세포내의 삼투조절에 의하여 적응하며, 봄무우와 가을무우 사이에 생리 및 생화학적인 대사가 다름을 보여 주었다. 저온에 예민한 봄무우에서 PA는 저온처리와 함께 상승효과를 보이나, 저온 스트레스에 강한 가을무우에서는 PA 처리로 상승효과를 나타내지 못함은 처음 보고 하는 결과이다.

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넘어짐(전도) 재해예방 안전기준 개정(안) 연구 (A study of improvement on safety regulation for slip, trip and fall prevention)

  • 김정수
    • 대한안전경영과학회:학술대회논문집
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    • 대한안전경영과학회 2013년 춘계학술대회
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    • pp.19-29
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    • 2013
  • Slips and falls are associated with many occupational injuries in Korea. It is also estimated that slipping are major contributors to slip, trip and fall injury burden. So "LOCAL RULE ON OCCUPATIONAL SAFETY AND HEALTH STANDAR D" must be improved, especially article 3(prevention of slip, trip and fall). The primary purpose of the present study is to determine if, and to what extent, the standard could be improved in present environment. In order to fulfill our objective, the another regulation in Korea and foreign countries were investigated and reviewed. Many kind of standard, mandatory documents and guideline were also reviewed. And then, regulations, standard, guideline etc. reviewed were compared with each others. The article 3 was revised as below. 1. The floors of the traffic route in workplace shall have no hole or slope, or be uneven or slippery so as, in each case, to expose employees to slip, trip and fall risk, except if adequate measures have been taken to prevent a employees falling. 2. The employer shall design, install and fix the drain for effective drainage if fluid contaminants were frequently occurred. So far as is reasonably practicable, An employer shall keep the workplace clean, sanitary, and dry so that employees won't have any risk to tripping or slipping at the workplace. 3. To facilitate cleaning, every floor, workplace, and passageway shall be, so far as is reasonably practicable, kept free from protruding objects, splinters, holes, etc. Also, some criteria was developed in this study. Standard and criteria developed in this study will help to prevent slip, trip, and fall injuries.

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산지, 성장조건 및 계절별 미꾸라지의 정미성분 비교 (Comparison of the Taste Compounds of Loach Differing in the Local, Growing Condition and Season)

  • 김희연;신재욱;심규창;박희옥;장영미;김현숙;허종화
    • 한국식품과학회지
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    • 제32권4호
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    • pp.772-787
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    • 2000
  • In this study, evaluation on the loaches from the various sources was carried out in respect of their taste compounds. The samples were classified by local, season and growing condition and evaluated in terms of composition, the refuse, contents of nucleotides and their related compounds, total and free amino acid, organic acid and fatty acid. Evaluation on the compositions revealed the fact that, in terms of the local, the imported loach contain a low level of fat and high level of ash, in comparison with Korean loach; in terms of growing condition, cultured loach contains a high level of fat and low level of moisture, in comparison with wild loach; and in terms of the season, the summer loach contains less moisture than the fall loath; but as for the contents of other component, the summer loach was superior. As for the refuse, the imported loach had a greater refuse than the Korean loach. In the growing condition, the wild loach had lower value than the cultured loach. There was no substantial difference in each season. Also nucleotide and these related compounds were detected in all of the samples, while ATP was not found. The content levels of such detected compound did not show a substantial difference in each condition. However, generally, the imported loach was poor in such compound and all of the samples were high in IMP. The samples were high in total amino acids. The local and growing conditions showed no substantial difference, while in the season, the summer loach had a higher content of total and essential amino acid than the fall loach. As for the contents of free amino acids, similar distribution of the composition was shown in each sample, even though there was little difference in their constituents. Also, total content of free amino acid varied with the conditions of the samples. As for total content of organic acid and the distribution of the composition, there was a little difference between each condition. In the season and growing condition, the summer loach was high in organic acid. As for the distribution of the fatty acid compositions, there was no substantial difference between each condition and each sample. In the case of the wild loach, the summer loach was high in ${\omega}-3$ polyunsaturated fatty acid and the fall loach was high in essential fatty acid. Similarly, in the case of the imported loach, the summer loach was high in ${\omega}-3$ polyunsaturated fatty acid and the fall loach was high in essential fatty acid.

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자유낙하식 콘관입시험 시스템의 거동특성을 반영한 신호저장용 트리거 개발 (Development of Trigger for Signal Storage Reflecting the Behavior Characteristics of the Free-Fall Cone Penetration Test System)

  • 강현;신창주;권오순;장인성;백승재;서정민;원성규
    • 한국산학기술학회논문지
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    • 제21권10호
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    • pp.16-22
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    • 2020
  • 한국해양과학기술원은 해저 표층지반의 특성을 원활하게 획득할 수 있는 자유낙하식 콘관입시험 시스템(Free-Fall Cone Penetration system, FFCPT)을 개발하고 있다. FFCPT를 통해 신호를 원활하게 획득하기 위해서는 전체 시험 시간동안 지속적으로 저장하는 방법 또는 사용자가 정의하는 시간 동안만 저장하는 방법이 고려될 수 있다. 효율적으로 데이터를 저장하고 관리하기 위해서는 사용자가 정의하는 시간 동안만 데이터를 저장하는 것이 유리하다. FFCPT는 낙하관성력을 최대한 확보하기 위해 회수용 와이어를 제외한 낙하에 방해되는 구성품이 최대한 배제되어 있다. 따라서 외부 보조장치를 활용한 데이터 저장 및 종료 시점 정의가 어렵다. 이에 FFCPT에 내부에 탑재된 센서를 통해 획득되는 신호를 이용하여 기본 거동을 분석하였고, 그 중 수심센서를 이용한 데이터 저장 시작과 종료를 인식할 수 있는 트리거 방식을 제안하였다. 수심 값의 3초와 0.03초 이동평균 차를 이용하여 낙하 시작 및 종료 시점을 판단하도록 하였다. 개발된 FFCPT를 이용하여 실해역 실험을 수행하였고, 트리거가 정상작동하여 원하는 데이터를 확보할 수 있었다.

스핀들 회전축계의 기전 연성 해석을 이용한 모바일 HDD의 자유 낙하 특성 및 감지에 관한 연구 (Characterization and Detection of a Free-falling State of a Mobile HDD Using the Electromechanical Analysis in a Rotating Spindle System)

  • 박상진;장건희;김철순;한재혁
    • 한국소음진동공학회논문집
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    • 제16권1호
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    • pp.12-18
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    • 2006
  • This research investigates the electromechanical characteristics of a spindle motor in a free-falling mobile hard disk drive before unexpected shock. Electromechanical simulation includes a time-stepping finite element analysis of the magnetic field in a speed controlled brushless DC motor and dynamic analysis of the stationary and rotating part linked by the fluid dynamic bearing under the free-falling condition. Analysis results show that the dynamic characteristics of the rotating spindle system during free-falling state have an effect on the relative motion between the stationary and rotating part of HDD. It results from the variation of reaction force in the bearing area due to the gravity force exerted on the rotating part of HDD, and the free-falling condition can be detected by observing the signal of the spindle motor and disk-head interface without using an accelerometer.

스핀들 회전축계의 기전 연성 해석을 이용한 모바일 HDD의 자유 낙하 특성 및 감지에 관한 연구 (Characterization and Detection of a Free-Falling State of a mobile HDD Using Electromechanical Analysis in Rotating Spindle System)

  • 박상진;장건희;김철순;한재혁
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2005년도 추계학술대회논문집
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    • pp.324-329
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    • 2005
  • This research investigates the electromechanical characteristics of a spindle motor in a free-falling mobile hard disk drive before unexpected shock. Electromechanical simulation includes a time-stepping finite element analysis of the magnetic field in a speed controlled brushless DC motor and dynamic analysis of the stationary and rotating part linked by fluid dynamic bearing under the free-failing condition. Analysis results show that the dynamic characteristics of the rotating spindle system during free-falling state have an effect on the relative motion between the stationary and rotating part of HDD. It results from the variation of reaction force in the bearing area due to the gravely force exerted on the rotating part of HDD, and the free-failing condition can be detected by observing the signal of the spindle motor and disk-head interface without using the accelerometer.

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FreeCAD를 이용한 셀카봉 모델링 (Modeling of selfie stick using FreeCAD)

  • 성광원;김영기
    • EDISON SW 활용 경진대회 논문집
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    • 제4회(2015년)
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    • pp.428-441
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    • 2015
  • Corresponding to the high consumption rate of the selfie stick for cell phone camera, the design of the product is becoming diverse. However, relatively low cost selfie stick models are not strong enough to stand the weight of the cell phone. This results into a bending of the stick or the accidental fall of the cell phone by the failure of the holding unit. As a solution to the problem, design of selfie stick that is structurally strong enough to stand the weight of the cell phone with the minimum weight for the portability is proposed in this paper.

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가시화 기법을 사용한 자유낙하하는 반구모델의 자세각 및 항력계수 측정 (Attitude Angle and Drag Coefficient Measurements of Free-Falling Hemisphere Using a Visualization Technique)

  • 송하균;이성민;이종국;박기수
    • 한국항공우주학회지
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    • 제45권8호
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    • pp.619-626
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    • 2017
  • 마하수 6 조건에서 반구 모델에 대해 자세각의 변화에 따른 항력계수를 연구하였다. 충격파 터널에서 실험이 진행되었으며 지지대 유동 간섭을 최소화하기 위해 자유낙하 기법을 사용하였다. 자유낙하하는 반구 모델의 자세와 항력계수를 측정하기 위해 계단식 모듈과 전자석을 이용한 자유낙하 기법을 구축하였고 초고속 카메라를 통한 shadowgraph 기법을 사용하였다.