• 제목/요약/키워드: Falling Time

검색결과 522건 처리시간 0.03초

마찰식 박피마늘 선별기 개발 (Development of A Friction Type Garlic Separator)

  • 박재복;김종태
    • Journal of Biosystems Engineering
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    • 제19권3호
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    • pp.185-193
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    • 1994
  • Both the wet and dry types of garlic peeling machines are being presently used in domestic garlic processing factory, but the dry type is more popular than the wet type because of higher peeling efficiency. The peeling efficiency of these machines is estimated 50 to 80%, depending on the difference in garlic varieties, physical properties and moisture content of garlic samples. If the peeling time is increased in order to improve the peeling efficiency, the damage on the surface of peeled garlic and the consumption of electric power are also increased. This study was carried out to solve these problems in garlic peeling operation and to obtain the optimun design factor for the friction type separator. The results are summarized as follows : 1. The average friction coefficients of peeled and unpeeled garlic samples were 0.91 and 0.51. respectively, for the acrylic plate, and 0.96 and 0.51, respectively, for the stainless plate. 2. For the inclined acrylic pipe with the pipe length 90 cm, the inclined angle $39^{\circ}$ and the pipe diameter 45-55 mm, the falling time of peeled garlic samples was 0.2 sec, faster than unpeeled garlic samples. 3. For the inclined stainless pipe with the pipe length 90 cm, the inclined angle $34^{\circ}$, $39^{\circ}$ and the pipe diameter pipe 35 mm, the falling time of peeled garlic samples was 0.7 sec, slower than that with the pipe diameter 47mm. 4. The stainless pipe with the pipe length 80~90 cm, the inclined angle $39^{\circ}{\sim}40^{\circ}$ and the pipe diameter 40~50 mm was the most suitable as the material of friction pipe. 5. Experimental garlic peeling machine is composed of garlic sample feeding device, friction stainless pipe and hopper. The peeling efficiency was 81 to 96%, and the separating capacity, 600 gr/min.

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임베디드 모듈 기반 지능형 영상감시 시스템의 최적화에 관한 연구 (A Study on Optimization of Intelligent Video Surveillance System based on Embedded Module)

  • 김진수;김민구;반성범
    • 스마트미디어저널
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    • 제7권2호
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    • pp.40-46
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    • 2018
  • 기존 사건 사고를 예방하기 위한 감시 시스템은 한 사람이 여러 대의 CCTV를 감시할 경우 22분 후에는 95%를 발견하지 못하는 문제점이 있다. 이를 해결하기 위해 비정상적인 상황이 발생할 경우 알림을 주는 컴퓨터 기반 지능형 영상감시 시스템에 대한 연구가 이루어지고 있지만, 소비전력 및 비용 등의 단점이 있어 실제 환경에서 활용하기에는 어려움이 있다. 이에 대한 대책으로 소형 디바이스 기반 지능형 영상감시 시스템에 대한 연구가 진행되고 있다. 본 논문에서는 침입자 검출, 화재 검출, 배회 낙상 검출을 수행하는 임베디드 모듈 기반 지능형 영상감시 시스템을 구현한다. 또한, 실시간 처리를 위해 알고리즘 및 임베디드 모듈 최적화 방법을 적용한다. 임베디드 모듈 기반 지능형 영상감시 시스템을 라즈베리파이에 구현하였으며, 알고리즘 처리 시간은 최적화 전 라즈베리파이 0.95초, 최적화 후 라즈베리파이 0.47초로 최적화 전 후 비교 결과 50.52% 처리 시간이 감소되었다. 따라서, 임베디드 모듈 기반 지능형 영상감시 시스템의 실시간 구동 가능성을 확인하였다.

GPS 오차를 고려한 항만 내 낙하물 사고위험 알고리즘 보정 방법론 개발 (Methodology of Calibration for Falling Objects Accident-Risk-Zone Approach Detection Algorithm at Port Considering GPS Errors)

  • 손승오;김현서;박준영
    • 한국ITS학회 논문지
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    • 제19권6호
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    • pp.61-73
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    • 2020
  • IoT 디바이스로부터 수집된 위치정보를 활용한 실시간 위치센싱 기술은 항만 등 다양한 산업현장에서 활용되고 있다. 그러나 GPS 센서의 특성상 오차는 항상 존재하며, 이를 활용하는 사고위험 검지 알고리즘은 오차의 고려가 필수적이다. 본 연구는 GPS 오차를 고려한 항만 내 낙하물 사고위험 구역 접근검지 알고리즘의 보정 방법론을 제안한다. IoT 디바이스로부터 수집된 GPS 오차 데이터를 확률변수로 하는 확률밀도함수를 추정하였으며 알고리즘의 검증을 위해 미시적 시뮬레이션을 활용하였다. 검증 결과 알고리즘은 디바이스의 위치오차 1m, 5m에 따라 검지 정확도가 각각 93%, 77%로 나타났다. 본 연구는 향후 디바이스의 성능을 고려한 유효 위험범위 설정 및 안전관리에 중요한 역할을 할 수 있을 것으로 기대된다.

고추의 열풍건조특성(熱風乾燥特性) (The Characteristics of Hot Air Drying of Red Pepper)

  • 전재근;김공환
    • Applied Biological Chemistry
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    • 제17권1호
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    • pp.42-48
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    • 1974
  • 고추 건조방법(乾燥方法)의 개선(改善) 및 건조특성(乾燥特性)을 알기 위하여 원형(原形) 및 절단(切斷)고추에 대(對)하여 온도(溫度)및 풍속(風速)의 영향을 조사(調査)하고 고추 건조기작(乾燥機作)을 고찰(考察)하였다. 1) 원형(原形)고추 건조곡선(乾燥曲線)의 특징(特徵)은 건조초기(乾燥初期)에는 어느정도(程度)의 settling down period를 가졌고 그이 후 제일(第一), 이기(二期) 감율건조기(減率乾燥期)를 보였으나 저온건조(低溫乾燥)일수록 항속건조양상(恒速乾燥樣相)을 띠어 임계수분함량(臨界水分含量)에 이르는, 시간(時間)이 최저온도(最低溫度)인 $55^{\circ}C$에서 15시간(時間)이나 되었다. 2) 절단(切斷)고추의 건조곡선(乾燥曲線)에서는 건조속도(乾燥速度)의 변화(蠻化)가 급격(急激)하였다. 3) 절단(切斷)고추의 건조방법(乾燥方法)은 원형건조(原形乾燥)에 비해 보다 효과적(效果的)이어서 각(各) 건조온도(乾燥溫度)에서 모두 약(約) 2배(倍) 이상(以上)의 건조시간(乾燥時間)을 단축(短縮)할 수 있었다. 4) 원형(原形) 및 절단건조(努斷乾燥) 모두 건조속도상수(乾燥速度常數)(k)값은 일정(一定)하지않고 시간(時間)에따라 변화(變化)하였으나 양건조방법(兩乾燥方法)에서 k값의 시간(時間)에 대(對)한 변화양상(變化樣相)이 구별(區別)되었다. 5) 건조속도상수(乾燥速度常數) k 값을 일정(一定)한 평균치(平均値)로 택(擇)할 경우, 원형건조(原形乾燥)에 대(對)하여는 $M-M_e/M_o-M_e=e^{-0.118t}$식(式는)이 절단건조(切斷乾燥)에 대(對)하여는 $M-M_e/M_o-M_e=e(-0.342t^{0.128})$식(式)이 적용되었다.

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내진테이블의 중량물 낙하 충격실험 (Weight Drop Impact Tests of Earthquake-Proof Table)

  • 엄태성;허석재;박태원;이상현
    • 한국지진공학회논문집
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    • 제22권7호
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    • pp.369-378
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    • 2018
  • Full-scale seismic retrofit of old and deteriorated masonry buildings requires a lot of cost and time. In such buildings, installing an emergency evacuation space can be considered as an alternative. In this study, requirements of the earthquake-proof table used as an emergency evacuation space for buildings hit by earthquake are investigated. Load conditions required for the table, including the impact effects due to building debris drop, are explained. To investigate the impact effects in more detail, weight drop test is performed for an prototype earthquake-proof table. In the test, the weight of the falling object and free fall height were considered as the main test parameters. The results showed that the duration of impact is very short (0.0226~0.0779sec), and thus the impact forces increase to 15.8~45.2 times the weight of the falling object. Based on these results, design considerations and performance verification criteria of the earthquake-proof table as an emergency evacuation space are given.

Motion Estimation-based Human Fall Detection for Visual Surveillance

  • Kim, Heegwang;Park, Jinho;Park, Hasil;Paik, Joonki
    • IEIE Transactions on Smart Processing and Computing
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    • 제5권5호
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    • pp.327-330
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    • 2016
  • Currently, the world's elderly population continues to grow at a dramatic rate. As the number of senior citizens increases, detection of someone falling has attracted increasing attention for visual surveillance systems. This paper presents a novel fall-detection algorithm using motion estimation and an integrated spatiotemporal energy map of the object region. The proposed method first extracts a human region using a background subtraction method. Next, we applied an optical flow algorithm to estimate motion vectors, and an energy map is generated by accumulating the detected human region for a certain period of time. We can then detect a fall using k-nearest neighbor (kNN) classification with the previously estimated motion information and energy map. The experimental results show that the proposed algorithm can effectively detect someone falling in any direction, including at an angle parallel to the camera's optical axis.

급식소에서 제공되는 비가열조리 음식의 위해요인 분석과 HACCP 적용 후 위생개선효과 (Microbiological Hazard Analysis of Non-Heating Process Menus Served at Foodservice Operations and Hygienic Improvements by Implementing HACCP)

  • 이미라;김혜영
    • 한국식품조리과학회지
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    • 제23권5호
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    • pp.749-760
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    • 2007
  • The purpose of this study was to evaluate the microbiological quality of non-heat-processed foods and the effects of HACCP implementation. Here, cabbage salad and cucumber&onion salad were selected and we investigated HA(Hazard Analysis) by checking microbiological quality, time and temperature, pH, and water activity at each processing stage. Thus, the receiving of spices and dressings, washing and sterilizing, cutting, cooking, and serving stages were all considered CCPs. Before implementing HACCP, microbial analysis showed that standard plate counts and coliform counts were higher than standard levels in most of the raw ingredients of each menu, as well as during the production process. The microbiological quality of the utensils and employee's hands used during cooking indicated levels requiring direct management. Evaluations of falling bacteria-in the foodservice establishment work areas ranged from $2{\sim}12CFU/plate$. However, after HACCP implementation, microbiological levels improved to standard levels fly sanitation education. Also, the number of falling bacteria were lower than before implementing HACCP. Therefore, it is essential the foodservice operations make efforts to implement HACCP, so that microbiological hazard levels are lowered and hygienic status improved.

건설업에서 떨어짐의 사망재해 원인 분석 (A study on the causal analysis of death accidents by the falls in the construction sites)

  • 신운철;정성춘;이로나
    • 대한안전경영과학회지
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    • 제16권4호
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    • pp.63-69
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    • 2014
  • The large-sized, complex, and multi-storied construction industry caused the increasing construction amount together with insufficient skilled workers to increase the probability of occurring accident, resulting in the most construction accidents next to manufacturing industry. Death accidents have risen to serious level, compared construction industry with manufacturing industry along the numbers of workers. Due to the main feature of one-time industry receiving orders, open-air dispersed production activity and the long-complex production process, the continuous efforts to prevent and manage safety accidents were made but the results were of no effect. They didn't deeply analyze the falling accidents that consist of half death accidents in construction industry. This study has classified in detail Missteps, Slip, Trip, Unstability and the others on the basis of gait characteristics, occurrence types, frequency and intensity of death accidents. This study suggested the effective methods on the construction safety management according to the causes of falling accidents. This study will be expect to be used as the basic data in the procedure and the program of safety management.

마늘 분말을 첨가한 소맥분의 리올로지 특성에 관한 연구 (Study on the Rheology Characteristics of Flour Containing Garlic Powder)

  • 정윤경;이현자;이현주
    • 동아시아식생활학회지
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    • 제19권6호
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    • pp.1025-1031
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    • 2009
  • This study was conducted to investigate the effects of garlic powder on medium and cake flours using falling number and RVA tests, as well as alveograms and farinograms. The garlic powder was added to the medium and cake flour bases at 2 and 4%, respectively. Falling numbers increased with the addition of garlic powder. The peak viscosity of the medium flour containing 2% garlic powder was highest while that made with 4% garlic powder showed a decrease in peak viscosity. The addition of garlic powder increased the set-back value, thus the garlic powder did not have an anti-retrogradation effect. The alveographic P values of the treatment were lower than that of the control, but the L value was not significantly different. On the farinogram, water absorption was decreased in the flours containing garlic powder and development time was increased. In conclusion, the addition of 2% garlic powder is recommended to improve the volume and stability of cake.

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벤젠의 점성도에 대한 온도와 압력의 영향 (Effect of Temperature and Pressure on the Viscosity of Benzene)

  • 김정림;경진범;유미현
    • 대한화학회지
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    • 제37권12호
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    • pp.1003-1009
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    • 1993
  • 여러 온도와 압력에서 벤젠의 점성도를 결정하여, 액체 벤젠의 점성도에 미치는 온도와 압력의 영향에 대하여 연구하였다. 여러 온도와 압력으로 유지되고 있는 일정한 밀도의 벤젠 속에서 공 낙하 시간을 측정함으로써 벤젠의 점성도를 산출할 수 있었다. 그 결과로부터 벤젠의 비부피에 미치는 온도와 압력의 영향, 자유부피에 미치는 온도와 압력의 영향에 대해서 알아보았으며, 결론적으로 벤젠의 점성도에 대한 온도와 압력의 영향을 온도와 압력의 변화에 따르는 자유부피의 변화에 의하여 고찰하였다.

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