• 대한기계학회논문집A
• /
• 제34권1호
• /
• pp.1-9
• /
• 2010

본 연구의 목적은 저속충돌에서 승용차량의 범퍼체결구조를 분석하기 위한 것이다. 차량의 손상성-수리성 향상 연구를 위해 범퍼체결구조가 서로 상이한 3개 차종에 대해 RCAR(세계자동차 수리기술위원회)의 저속충돌시험(전,후면 40% 오프셋 충돌시험) 기준을 적용하였다. 시험결과 충격흡수능력은 직사각형 단면형상을 가지고 그 부분이 범퍼레일에 삽입되는 크래시박스식의 범퍼스테이가 대부분의 차량에 적용되고 있는 다른 두 유형의 범퍼체결구조에 비해 우수하게 나타났다. 우수하게 설계된 직사각형 단면형상을 가지는 범퍼체결구조가 저속충돌사고 시 차량의 손상성-수리성을 향상시킴으로써 승객의 안전성도 강화시킬뿐만 아니라 수리비 절감에도 기여할 수 있다는 것이 본 연구에서 입증되었다.

• 한국자동차공학회논문집
• /
• 제18권1호
• /
• pp.99-104
• /
• 2010

It is a frequent occurrence in urban traffic - a low-speed collision in which one vehicle hits the back of another. The vehicles often sustain expensive damage. Bumpers can reduce this damage, but only line up so the initial contact in an impact is bumper to bumper. Then the bumpers on the colliding vehicles have to absorb the crash energy, keeping damage away from expensive sheet metal, lights, and other components. In real world accidents, Bumper mismatches in crashes are increasing, and the resulting repair costs from low-speed collisions are escalating. In this study, we investigated the bumper rail height and analyzed their effects on repair cost. Futhermore, Our 16kph front-into-rear crash tests demonstrates bumper mismatch problem.

• Journal of Mechanical Science and Technology
• /
• 제14권11호
• /
• pp.1232-1243
• /
• 2000

Motor vehicle accidents in rear impacts cause more than fifty percents of drivers to suffer from neck injuries. It is known that most neck injuries are associated with rear-end collisions at a speed lower than 32 km/h and between the Abbreviated Injury Scale (AIS) 1 and AIS 2. Two different types of low speed crash tests such as the frontal barrier and rear moving barrier crashes have been conducted by following the procedure of the Research Committee for Automobile Repairs (RCAR). The injury for the neck and the Head Injury Criteria (HIC) were measured by using the sensors mounted on dummies. We reviewed neck injures and the relationship between the neck and head injuries, and examined the deceleration of the body. Using the experimental test data at the neck, we investigated an improved neck injury criterion Nij. Also, the effects of the position of a head restraint on reducing the frequency and severity of the neck injury in rear-end collisions were investigated.

• The Plant Pathology Journal
• /
• 제29권4호
• /
• pp.471-476
• /
• 2013

Plants are frequently exposed to numerous environmental stresses such as dehydration and high salinity, and have developed elaborate mechanisms to counteract the deleterious effects of stress. The phytohormone abscisic acid (ABA) plays a critical role as an integrator of plant responses to water-limited condition to activate ABA signal transduction pathway. Although perception of ABA has been suggested to be important, the function of each ABA receptor remains elusive in dehydration condition. Here, we show that ABA receptor, pyrabactin resistance-like protein 8 (PYL8), functions in dehydration conditions. Transgenic plants overexpressing PYL8 exhibited hypersensitive phenotype to ABA in seed germination, seedling growth and establishment. We found that hypersensitivity to ABA of transgenic plants results in high degrees of stomatal closure in response to ABA leading to low transpiration rates and ultimately more vulnerable to drought than the wild-type plants. In addition, high expression of ABA maker genes also contributes to altered drought tolerance phenotype. Overall, this work emphasizes the importance of ABA signaling by ABA receptor in stomata during defense response to drought stress.

• 한국자동차공학회논문집
• /
• 제13권2호
• /
• pp.157-161
• /
• 2005

In the FY 2003, the number of registered vehicles in Korea reached 14 million, which is 7.7% increase from the previous year. The increase of number of vehicles has caused a lot of social problem with enormous costs. The social costs related to the vehicles includes environmental costs resulting from pollution and scraping of vehicles, those resulting from life-saving and repairing from car accidents and so on. There have been m any efforts to reduce the social costs in m any areas. As a part of the efforts, there are recent grow ing interests on the damageability & repairability in related industries. In this study, we investigated the cases of two different types of bum per stay. Futhermore, we analyzed their effects on damageability & repairability and reduction of repair cost. So we found that if the manufacturers design new cars with good damageability & repairability, then the total repair cost in crash will be reduced.

• 한국자동차공학회논문집
• /
• 제13권2호
• /
• pp.108-113
• /
• 2005

The damageability and repairability of similar platform type vehicles could be very concerned with design optimization. In all the vehicles crash tested, small size passenger vehicles were weakness in aspect of damageability and repairability. The most critical area appears to be repair cost considering that parts cost is the largest portion of total repair cost segments. Besides repair cost, attaching method of front sidemember and subframe are placed special importance for impact energy absorption and damageability and repairability. So in order to improve damageability and repairability of vehicle structure and body component of the monocoque type passenger vehicles, the end of front side member and front back beam should be designed with optimum level and to supply the end of front side member as a partial condition approx 300mm. The effectiveness of design concept on the 40% offset frontal impact characteristics of the passenger vehicle structure is investigated and summarized.

• 한국작물학회:학술대회논문집
• /
• 한국작물학회 2017년도 9th Asian Crop Science Association conference
• /
• pp.109-109
• /
• 2017

The core components of ABA-dependent gene expression signaling have been identified in Arabidopsis and rice. This signaling pathway consists of four major components; group A OsbZIPs, SAPKs, subclass A OsPP2Cs and OsPYL/RCARs in rice. These might be able to make thousands of combinations through interaction networks resulting in diverse signaling responses. We tried to characterize those gene functions using transient gene expression for rice protoplasts (TGERP) because it is instantaneous and convenient system. Firstly, in order to monitor the ABA signaling output, we developed reporter system named pRab16A-fLUC which consists of Rab16A promoter of rice and luciferase gene. It responses more rapidly and sensitively to ABA than pABRC3-fLUC that consists of ABRC3 of HVA1 promoter in TGERP. We screened the reporter responses for over-expression of each signaling components from group A OsbZIPs to OsPYL/RCARs with or without ABA in TGERP. OsbZIP46 induced reporter most strongly among OsbZIPs tested in the presence of ABA. SAPKs could activate the OsbZIP46 even in the ABA independence. Subclass A OsPP2C6 and -8 almost completely inhibited the OsbZIP46 activity in the different degree through the SAPK9. Lastly, OsPYL/RCAR2 and -5 rescued the OsbZIP46 activity in the presence of SAPK9 and OsPP2C6 dependent on ABA concentration and expression level. By using TGERP, we could characterize successfully the effects of ABA dependent gene expression signaling components in rice. In conclusion, TGERP represents very useful technology to study systemic functional genomics in rice or other monocots.