• 제목/요약/키워드: Center Pillar

검색결과 107건 처리시간 0.025초

성형효과를 고려한 해석을 통한 차체 측면구조의 충돌 및 진동 성능평가 (Evaluation of Crashworthiness and NVH Performances of Side Structure with Finite Element Analysis considering Stamping Effects)

  • 김세호;김기풍;최원호
    • 한국자동차공학회논문집
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    • 제16권5호
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    • pp.119-127
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    • 2008
  • In this paper, the influence of the stamping effect is investigated in the performance analysis of a side structure. The analysis covers the performance evaluation such as the crashworthiness and NVH. Stamping analyses are carried out for the center pillar and the side sill made of high strength steels. Then, numerical simulations are carried out in order to identify the stamping effect on the crashworthiness, the natural frequency and the normal mode. The result shows that the analysis of the side structure considering the forming history leads to a different result from that without considering the forming effect. The variation of the system response fully reveals effects of thinning and hardening of members on the performance prediction of vehicle parts. The analysis results demonstrate that the design of auto-body members should be carried out considering the stamping history for accurate assessment of various performances.

Porcine epidemic diarrhea virus: an update overview of virus epidemiology, vaccines, and control strategies in South Korea

  • Guehwan Jang;Duri Lee;Sangjune Shin;Jeonggyo Lim;Hokeun Won;Youngjoon Eo;Cheol-Ho Kim;Changhee Lee
    • Journal of Veterinary Science
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    • 제24권4호
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    • pp.58.1-58.25
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    • 2023
  • Porcine epidemic diarrhea virus (PEDV) has posed significant financial threats to the domestic pig industry over the last three decades in South Korea. PEDV infection will mostly result in endemic persistence in the affected farrow-to-finish (FTF) herds, leading to endemic porcine epidemic diarrhea (PED) followed by year-round recurrent outbreaks. This review aims to encourage collaboration among swine producers, veterinarians, and researchers to offer answers that strengthen our understanding of PEDV in efforts to prevent and control endemic PED and to prepare for the next epidemics or pandemics. We found that collaboratively implementing a PED risk assessment and customized four-pillar-based control measures is vital to interrupt the chain of endemic PED in affected herds: the former can identify on-farm risk factors while the latter aims to compensate for or improve weaknesses via herd immunity stabilization and virus elimination. Under endemic PED, long-term virus survival in slurry and asymptomatically infected gilts ("Trojan Pigs") that can transmit the virus to farrowing houses are key challenges for PEDV eradication in FTF farms and highlight the necessity for active monitoring and surveillance of the virus in herds and their environments. This paper underlines the current knowledge of molecular epidemiology and commercially available vaccines, as well as the risk assessment and customized strategies to control PEDV. The intervention measures for stabilizing herd immunity and eliminating virus circulation may be the cornerstone of establishing regional or national PED eradication programs.

SGAFC1180 TRIP강재의 저항 점용접성 평가 (Evaluation of Resistance Spot Weldability of SGAFC1180 Steel)

  • 신석우;이종훈;김대환;박상흡
    • 한국산학기술학회논문지
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    • 제18권12호
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    • pp.644-649
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    • 2017
  • 자동차 산업에서는 환경 문제와 국제 유가 상승 등으로 인한 차량 경량화에 대한 요구가 증대되고 있다. 이에 따라 알루미늄 합금과 특수 소재 등이 차량 중량을 줄이는데 활용되고 있지만 비용과 강도 측면에서 철강소재를 극복하기 에는 여전히 많은 어려움이 있다. 따라서 강도와 성형성이 좋은 AHSS(Advanced High Strength Steel) 소재의 적용이 증가하고 있다. 특히 운전자 보호를 위한 안전 규제가 강화되면서 센터필러 (Center Pillar), 루프레일 (Roof Rail) 부분에 1.2GPa급 초고강도 강재의 적용이 점차 늘어나고 있으며 이종강재에 대한 자동차 차체 적용 또한 점차 증가하고 있다. 본 연구에서는 SGAFC1180 1.2t 강재의 저항 점용접성 및 용접부의 특성을 파악하였다. 시뮬레이션을 이용하여 너깃의 생성 및 성장 거동을 관찰하였으며 예측 성능은 오차율 10% 이내에서 유사한 경향을 나타내었다. 또한 이러한 거동이 공정변수인 동저항에 미치는 영향을 파악하였고 전단인장강도 및 너깃 직경과의 상관관계를 고찰하였다. 본 연구를 통하여 동저항의 패턴을 인식하여 패턴의 형태에 따라 용접 상태를 분류하고 용접 품질을 판단하는 시스템도 제안할 수 있을 것으로 사료된다.

암 등록사업의 현황과 추진방향 (Cancer Registration in Korea: The Present and Furtherance)

  • 안윤옥
    • Journal of Preventive Medicine and Public Health
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    • 제40권4호
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    • pp.265-272
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    • 2007
  • It was not until 1975 that cancer registration was initiated in Korea; voluntary registration of cancer patients of training hospitals throughout the country began under the auspices of the Korean Cancer Society(KCS). However, an official cancer registration, the Korea Central Cancer Registry(KCCR), began on July 1st, 1980. Forty-five training and two non-training hospitals throughout the country initiated registration of patients in whom neoplasms had been found. Data related to case information specified are to be sent to the KCCR at the National Medical Center(it moved at National Cancer Center in 2000). The initial cancer registration of KCS was merged to the KCCR in 1980. Although the KCCR covers most all the large training hospitals in Korea, it cannot provide incidence data. It is, however, the only of its kind in the world, being neither hospital nor population based. The first population based cancer registry(PBCR) was launched in a small county, Kangwha(it has around 80,000 inhabitants), by Yonsei University Medical College in 1983. All data were collected by active methods, and incidence statistics for 1986-1992 appeared in Vol VII of the CI5. Another PBCR, Seoul Cancer Registry(SCR), started in 1991. It was supported by a civilian foundation, the Korean Foundation for Cancer Research. The basic idea of case registration of SCR was the incorporation of KCCR data to PBCR, e. g. dual sources of case registration, i.e., from the KCCR and also including cases diagnosed in small hospitals and other medical facilities. Assessing completeness and validity of case registration of SCR, the program and methodology used by the SCR was later extended to other large cities and areas in Korea, and the PBCR in each area was established. Cancer incidence statistics of Seoul for 1993-1997, Busan for 1996-1997, and Daegu for 1997-1998, as well as Kangwha for 1993-1997, appeared eventually in Vol VIII of the CI5. The Korean or 'pillar' model for a PBCR is a new one. The KCCR data file is a reliable basis, as a pillar, for a PBCR in each area. The main framework of the model for such a registry is the incorporation of a KCCR data file with data from additionally surveyed cases; the data related to cancer deaths, medical insurance claims, and visit-and surveillance of non-KCCR medical facilities. Cancer registration has been adopted as a national cancer control program by Korean government in 2004 as the Anti-Cancer Act was enacted. Since then, some officers have tried to launch a nation-wide PBCR covering whole country. In the meantime, however, cancer registration was interrupted and discontinued for years due to the Privacy Protection Law, which was solved by an amendment of the Anti-Cancer Act in 2006. It would be premature to establish the nation-wide PBCR in Korea. Instead, continuous efforts to improve the completeness of registration of the KCCR, to progress existing PBCRs, and to expand PBCRs over other areas are still to be devoted. The nation-wide PBCR in Korea will be established eventually with summation of the PBCRs of the Korean model.

운룡주(雲龍柱) 보물 앙부일구의 특성과 제작 기술 (Characteristics and Manufacturing Technology of the Angbuilgu Treasure with Plate Pillars Decorated with a Dragon in Clouds)

  • 윤용현;민병희;김상혁
    • 헤리티지:역사와 과학
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    • 제56권4호
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    • pp.24-37
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    • 2023
  • 본 연구는 2022년에 새롭게 보물로 지정된 앙부일구의 재질과 외형적 특징을 분석하였다. 국립고궁박물관, 국립경주박물관과 성신여자대학교박물관의 세 기관에서 소장하고 있는 보물 앙부일구는 그 재질, 규격, 형태(외형), 은상감 등 제작기법이 쌍둥이처럼 비슷하다. 이 세 점의 앙부일구은 구리: 아연: 납이 90.6: 6.0: 1.8의 비율인 황동으로 제작되어 있다. 이 성분비는 82.2: 3.7: 11.8의 조성비를 가지고 있는 보물 제845호 앙부일구와 분명한 차이를 보인다. 새 보물 앙부일구에서 반구의 받침부분은 용의 문양이 수직기둥에 그려지고 구름의 문양이 기둥의 날개를 형성하여, 반구 지평환에 각각 리벳과 은땜으로 결합되어 있다. 이러한 운룡주(雲龍柱)의 문양은 조선 후기 제작된 다양한 앙부일구 받침대 중에서도 가장 뛰어난 조형미를 보여주고 있다. 앙부일구에 새겨진 북극고도는 1713년 이후에 제작되었음을 알 수 있는데, 실제 제작은 19세기 진주 강씨 앙부일구 전문제작자의 활동 시기에 근접할 것으로 추정된다. 본 연구가 2022년 지정 보물 앙부일구의 재질과 외형적 특징을 분석함으로써 근대 과학기기의 과학기술사적 고찰을 견인할 수 있기를 기대한다.

악성 혼합종의 임상적 고찰 (Malignant Mixed Tumor of Salivary Glands: A Clinical Study)

  • 오경균;이국행;이종호;심윤상
    • 대한두경부종양학회지
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    • 제9권2호
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    • pp.227-233
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    • 1993
  • For malignant neoplasms of salivary tissues. two of the better determinants of progosis are histologic classification and size of the neoplasm. Proper management of these tumors requires an accurate diagnosis by the pathologist and correct interpretation by the surgeon. Malignant mixed tumors account for between 3 and 13 precent of all cancers of the salivary glands and 2 percent of all tumors in these locations. The typical history of these tumors is that of slowly growing mass demonstrating a sudden increase in growth. The duration of onset of the tumor mass and the diagnosis of malignancy has been demonstrated to be 10 to 18 years. The risk of malignat transformation of a benign mixed tumor increases with the duration of the tumor. We analyzed retrospectively 13 cases of malignant mixed tumor who visited from Jan. 1985 to Dec. 1992. Mean age of the patients was 56.5 years. The origin of tumors were parotid gland 7 cases, submandibular gland 2 cases, and minor salivary gland 4 cases(palate 3 cases, tonsil pillar 1 case). According to the criteria of the AJCC on staging, stage I was 1 case, stage II 1 case, stage III 2 cases, and stage IV 9 cases. Histopathologically, carcinma ex pleomorphic adenoma were 12 cases and the true malignant mixed tumor was 1 case. The major treatment modalities were curative surgery, and radiation therapy followed. In conclusion, aggressive therapy of combined surgery and postoperative radiation therapy is required for these lesions, and patients with known or suspected benign tumor should be encouraged to undergo surgery early on in their disease to avoid malignant degeneration at a later dete.

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신설터널의 위치에 따른 기존 병렬터널의 영향 분석 (Analysis of the influence of existing parallel tunnels according to the location of the new tunnel)

  • 윤지석;김한얼;남경민;정예림;조재은;유한규
    • 한국터널지하공간학회 논문집
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    • 제24권2호
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    • pp.193-215
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    • 2022
  • 최근 지상구조물이 포화상태에 이르렀고 증가하는 교통난과 환경문제를 해결하기 위한 방안으로 터널과 같은 지하구조물을 활용한 지하화 건설이 각광 받고 있다. 그러나 증가하는 지하구조물로 인해 지속적인 지하화 개발을 위해서는 근접 시공이 불가피한 상황이다. 새로운 지하구조물을 근접 시공할 시 기존구조물에 미치는 영향으로 인해 안정성이 취약해져 붕괴를 일으킬 수 있다. 따라서 기존구조물의 안정성을 분석하는 것은 필수적으로 고려해야 하는 사항이다. 본 연구에서는 지하구조물인 병렬터널의 하부에 신설터널을 굴착하여 근접시공으로 인한 기존 병렬터널에 미치는 영향을 수치해석을 사용하여 분석하였다. 변위조절모델(Displacement Control Model, DCM)을 이용하여 시공 시 발생하는 지반손실률을 세 가지(0.5%, 1.0%, 1.5%)로 모사하였다. 필라 중심을 기준으로 신설터널이 위치하는 거리를 5 m, 6 m, 7 m, 8 m, 9 m로 설정하고 각 거리별로 간격을 5가지(0D1, 0.37D1, 0.75D1, 1.13D1, 1.5D1)로 설정하였다. 일반적으로 지반손실률이 증가하고 거리가 근접할수록 최대변위, 각변위가 증가하였고 필라의 안정성을 평가하는 강도/응력비 또한 감소하였다. 결과적으로 신설터널과 필라 중심과의 거리가 5 m, 간격이 0D1, 지반손실률이 1.5%인 경우 기존 병렬터널의 안정성이 가장 취약한 것으로 나타났다.

셀룰로오스 아세테이트 기반 어레이 촉각 액추에이터의 제작 및 특성평가 (Fabrication and Characterization of Array Tactile Actuator Based on Cellulose Acetate)

  • 김현찬;윤성률;고현우;김재환
    • 한국정밀공학회지
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    • 제32권8호
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    • pp.743-748
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    • 2015
  • This paper reports the enhanced fabrication and characterization of a $3{\times}3$ array tactile actuator composed of cellulose acetate. The array tactile actuator, with dimensions of $15{\times}15{\times}1mm^3$, consists of 9 pillar-supported cells made from a cellulose-acetate molding. The fabrication process and performance test along with the results for the suggested actuator are explained. To improve the cell-array fabrication, a laser cut was adopted after the molding process. The displacement of the unit cell increased the input voltage and frequency. Various top masses are added onto the actuator to mimic the touch force, and the acceleration of the actuator is measured under actuation. When 2 kV is applied to the actuator, the maximum acceleration is 0.64 g, which is above the vibrotactile threshold. The actuation mechanism is associated with the electrostatic force between the top and bottom electrodes.

충돌 해석을 이용한 능동형 보행자 보호 시스템의 성능 분석 (Performance Analysis of an Active System for Pedestrian Protection Using Impact Analysis)

  • 박종선;정성범;윤용원;박경진
    • 한국자동차공학회논문집
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    • 제21권6호
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    • pp.100-107
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    • 2013
  • Although automotive safety technologies have been developed steadily, the efforts for pedestrian protection still seems to be insufficient. In a car-pedestrian accident, the structures such as the engine under a hood, the lower part of a windshield and the A-pillar are the major causes of fatal pedestrian injuries. Recently, there have been several studies on the active safety system to reduce the pedestrian injuries. The safety system consists of an active hood lift system and a pedestrian airbag. In this research, the safety performance of the active hood lift system and the pedestrian airbag is investigated by using the finite element method. The finite element model of the system is set up based on the head impact test, and the impact analyses are performed. The necessity and the usefulness of the safety system are verified.

제주향교의 조영적 특성에 관한 연구 (A Study on the Constructional Characteristics of Jeju-HyangGyo)

  • 지태승;박정근;박철민
    • 한국농촌건축학회논문집
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    • 제10권3호
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    • pp.59-66
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    • 2008
  • This study was performed to ascertain how HyangGyos based on national ideology were built in Jeju Island and what their detailed styles are. In Jeju-HyangGyo, unique architectural characteristics are shown as they have been built in an island independent from the mainland. Also up-down system was well reflected in detailed architectural styles. The main temple of Jeju-HyangGyo was built in the type of one-Chulmok(a subsidiary material of Gongpo and a piece of wood to support the eaves) of which ancon supports a purline from the center of a pillar and two-Ikgong(a piece of wood engraved to put on an ancon), but in the case of the lecture hall, its Gongpo(a piece of wood to support the eaves) was inferior in quality. In the case of Jeju abutments were used in main temples and fire walls were mostly used. In particular, their abutments are difficult to be observed in HyangGyo in the mainland. It is presumed that the abutment and the fire wall used in Jeju Island might be the best solution to protect structures from rain and moisture. To sum up, local characteristics and traditional rules were thoroughly reflected in Jeju-HyangGyos built in Jeju Island from the aspect of arrangement and detailed style. In conclusion, it is significant that architectural styles, not to mention the other aspects of Jeju culture, were suitably adapted to Jeju Island.

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