• 전자공학회논문지 IE
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• 제46권2호
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• pp.33-45
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• 2009

본 논문은 실제적인 제약, 컴퓨팅 시간 지연, 양자화를 고려하여 퍼지 모델을 기초로 한 제어기를 트럭-트레일러 타입의 모바일 로봇의 귀환 제어기에 적용하여 설계하였다. 퍼지 귀환 제어기의 출력은 단위 샘플링 시간동안 지연되므로 이를 예측하여 설계하였다. 시간 지연을 고려한 해석 및 디자인 문제는 제안된 제어기가 샘플링 시간과 동기되어 있기 때문에 쉽게 해결된다. 또한 퍼지 제어기 구조 개발 시 양자화가 이루어지기 때문에 안정성 있는 해석이 가능하고 양자화 이외에 발생하는 사소한 문제도 역시 안정함을 보여주므로, 양자화한 시스템은 일반적으로는 극단적인 수렴을 한다. 실험결과에서 제안된 시스템의 효율성이 증명됨을 볼 수 있다.

• Journal of Microbiology and Biotechnology
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• 제31권7호
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• pp.956-966
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• 2021

To prevent the outbreak of infectious diseases that inflict huge economic and social losses, domestic livestock farms and related facilities have introduced automatic and semiautomatic disinfectant solution-spraying systems for vehicles. However, the facility standards and specifications vary by manufacturer, and no scientific performance evaluation has been conducted. The puropose of this study is to develop physical and biological evaluation methods. Physical and biological appraisals were conducted using two types of disinfection facilities (tunnel- and U-type) and two types of vehicles (passenger car, truck). Water-sensitive paper was used to evaluate the physical performance values for the disinfection facilities. In addition, to assess their biological performance, carriers containing low-pathogenic avian influenza virus were attached to vehicles, and the viral reduction was measured after the vehicles moved through the facility. The tunnel-type had rates of coverage in the range of 70-90% for the passenger car and 60-90% for the truck. At least 4-log virus reduction after spraying for 1-5 min was shown for both vehicles. For the U-type facility evaluation, the coverage rates were in the range of 60-90% for the passenger car and at least 90% for the truck. More than 4-log viral reduction was estimated within a spraying time of 5 min. To reduce viruses on the surface of vehicles by at least 4 log within a short period, the disinfectant solution should cover at least 71% of the pathogens. In conclusion, we were able to assess the physical and biological performance criteria for disinfection facilities aboard transportation vehicles.

• 한국철도학회논문집
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• 제11권6호
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• pp.588-595
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• 2008

본 연구는 우리나라 화주의 수송수단 선택특성을 파악하는 목적으로 수행하였다. 모형의 형태는 개별행태모형이며 SP 자료를 이용하였다. SP 조사는 실험설계를 통해 준비하였다. 고려한 요인은 수송시간, 수송비용, 서비스 수준이다. 연구에서 도출된 시사점은 철도수송의 수요를 증대시키기 위해서는 수송비용을 감소시키는 전략이 가장 효과적이라는 것이다. 화물 품목별로 설명하면, 컨테이너는 수송비용의 감소와 더불어 수송시간을 단축시키고 서비스 수준을 개선할 때 공로수송에 비하여 경쟁력을 확보할 수 있는 것으로 평가되었다. 반면에 양회와 철강 등 벌크화물은 다른 요소보다 수송비용을 인하하는 정책이 효과적이다.

• 대한지역사회영양학회지
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• 제24권1호
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• pp.47-59
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• 2019

Objectives: Young athletes require adequate nutrition to maintain their athletic performance, growth and health. This study examined the status and needs of nutrition management and meal services for student athletes among the athlete's parents. Methods: The subjects were parents of elementary, middle, and high school athletes (n=323) from 18 schools participating mainly in the Sports Food Truck. The questionnaire included general characteristics, status and needs on nutrition management and meal service for student athletes, and satisfaction with the Food Truck. The survey was done during 2018. The data were analyzed according to the school groups using a ${\chi}^2-test$ or ANOVA. Results: Approximately 45% of subjects had difficulty in the nutrition management of athletes, and 87.1% had not received nutrition education. Approximately 74% wanted nutrition education held for athletes, and mainly wanted topics on nutrition management for health and eating for athletic performance. The preferred methods were lectures and cooking activity. The responses on the necessity of nutrition education for athletes, desired education topics, and desired times for education differed significantly according to the school groups (p<0.05). Most subjects also wanted nutrition information mainly through SNS. In the athlete's meal, breakfast and snacks were highlighted as the meal to supplement. Approximately 90.3% responded that providing a meal service is necessary. The subjects preferred snacks before/after exercise and dinner if a meal service was provided. They preferred Korean food, followed by snacks, and a dish meal. As the meal type, the subjects wanted the Food Truck and packed meal. The responses on necessity of a meal service (p<0.05), preferred food (p<0.001), and meal type (p<0.001) in the meal service differed significantly according to the school groups. Approximately 43% were satisfied with the Food Truck and 50.8% responded as average. They made suggestions for the Food Truck in terms of foods, operations and frequency. Conclusions: Based on the study results, nutrition education and meal service may support nutrition for student athletes considering the needs of the parents according to the school groups.

• 한국자동차공학회논문집
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• 제8권4호
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• pp.121-129
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• 2000

this paper develops a computational model for the turning maneuver analysis of a cabover type heavy truck. The model having 42 degree-of-freedom is developed using ADAMS. Leaf springs used in the front and rear suspension systems are modeled by dividing it three links and joining them with joints. Force and displacement relationship showing nonlinear hysteric characteristics of the leaf spring is measured and modeled with an exponential function. A velocity and force relationship of a shock absorber is measured and modeled with a spline function. And a stabilizer bar is modeled using ADAMS beam element to consider a twisting and bending effect. To verify the developed model an actual vehicle test is performed in the double lane change course with 50kph and 60kph vehicle velocity. In the actual vehicle test lateral acceleration roll angle and yaw rate are measured, The tendency and peak-to-peak values of the actual vehicle test and simultion results are compared each other.

• 한국소음진동공학회논문집
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• 제15권6호
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• pp.731-737
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• 2005

This paper evaluates dynamic performance of a cab over type large-sized truck for estimating the effects of frame's torsional characteristics using a computer model. The computer model considers two mounting methods of frame, flange mounting and web mounting. Frame is modeled by finite elements using MSC/NASTRAN In order to consider the flexibility of frame. The torsional test of the frame is conducted In order to validate the modeled finite element model. A load cell is used to measure the load applied to the frame. An angle sensor is used to measure the torsional angle. An actuator is used to apply a load to the frame. To estimate the effects of frame's torsional characteristics on dynamic performance, simulations are performed with the flange mounting and web mounting frame. Simulation results show that the web mounting frame's variations of roll angle, lateral acceleration, and yaw rate are larger than the flange mounting frame's variations, especially in the high velocity and the second part of the double lane course.

• 한국안전학회지
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• 제28권4호
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• pp.33-37
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• 2013

A forklift truck, commonly used for transporting heavy materials in manufacturing industries, etc., is a useful machine. However accidents occur frequently during the operation of the machine. In order to prevent accidents it is necessary to examine the current safety regulations on a forklift truck. Because the regulations have not revised for a long time, they do not reflect the rapidly changing environment of industries. Proposed revision of standard on articles for forklift trucks was presented after analysing the causes of occurred injuries, comparing domestic standards with international standards and examining the survey results. We analyzed the safety regulation articles and the injuries according to the type of work conducted with forklift. The major differences in safety regulations between Korea and the major foreign countries were investigated. The opinions of field workers on the safety regulations were surveyed using e-mail or interview. As a result, it was found that preventing workers from contacting with the forklift is very important. To prevent accident due to movement of a stopped forklift, actions are necessary to prevent slip of a forklift. Also supervision is required to make workers fasten safety belt and to prohibit workers from using a forklift for undesignated purpose.

• 한국자동차공학회논문집
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• 제14권2호
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• pp.194-201
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• 2006

Roof-fairing and deflector system have been used on heavy-duty trucks to minimize aerodynamic drag force not only for driving stability of the truck but also for energy saving by reducing the required driving power of the vehicle. In this study, a numerical simulation was carried out to see aerodynamic effect of the drag reducing device on the model vehicle. Drag and lift force generated on the five different models of the drag reducing system were calculated and compared them each other to see which type of device is efficient on the reduction of driving power of the vehicles quantitatively. An experiment has been done to see airflow characteristics on the model vehicles. Airflow patterns around the model vehicles were visualized by smoke generation method to compare the complexity of airflow around drag reducing device. From the results, the deflector systems(Model 5,6) were revealed as a better device for reduction of aerodynamic drag than the roof-fairing systems(Model 2,3,4) on the heavy-duty truck and it can be expected that over 10% of brake power of an engine can be saved on a tractor-trailer by the aerodynamic drag reducing device at normal speed range($80km/h{\sim}$).

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 춘계학술대회논문집
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• pp.332-339
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• 2006

A leaf spring suspension has been widely used since it can carry big load and simplicity. But one major drawback is the poor ride performance because of the friction in the system and the high stiffness coefficient. To overcome these, air spring suspension can be used. The air spring suspension system can improve the ride of the heavy vehicle significantly and also it can adjust the height to the loading and unloading. A truck with the leaf suspension system is modified with the air suspension system and the performance of the vehicle is compared using the suggested method. The existing leaf suspension can be replaced with the air suspension system to improve the performance.

• 한국안전학회지
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• 제25권6호
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• pp.103-108
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• 2010

In this study, tank truck incidents of road transport of hazardous materials to experimental investigated the potential fire hazard. Real scale fire was to perform experiments for on this qualitative and quantitative data collection and analysis. Particularly affected by radiant heat from the flames caused and damage estimates range investigated accordingly. Flame temperature, internal temperature of tank and emitted radiation from the flames was investigated. The flame of light oil spill caused a fire at a temperature of about $300^{\circ}C$ high in comparison with the methanol by combustion of diesel and methanol, according to the difference, the flame duration changes varies depending on the Burning rate, amount of radiant heat flux from light oil fire was 4 times increases compared with fire of methanol. Depending on spill locations(kinds of road surfaces, absorbing rate) and the longer the duration of the flame important factors for the internal temperature of tank truck rise was found. Dirt roads than paved road accident in a fire caused by leakage of hazardous was could the higher the damaged. Therefor, Fire suppression activities should be required in particular to be around.