• 제목/요약/키워드: tolerance limit

검색결과 207건 처리시간 0.022초

표면처리된 Al 5083-H131 합금의 고속 충격 거동에 관한 연구 (A Study on the fracture behavior of surface treated Al 5083-H131 alloy under the high velocity impact)

  • 손세원;김희재;홍성희;황도연
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 1997년도 추계학술대회 논문집
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    • pp.820-824
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    • 1997
  • In order to investigate the effect of surface treatment(Anodizing) and rolling in Al 5083-H131 alloy, ballistic testing was conducted. Ballistic resistance of these materials. was measured by protection ballistic limit(V$_{50}$), a statical velocity with 50% probability for incomplete penetration. Fracture behaviors and ballistic tolerance, described by penetration modes, are observed respectfully, resulting from V$_{50}$ test and Projectile Through Plates(PTP) test at velocities greater than V$_{50}$. PTP tests were conducted with 0$^{\circ}$obliquity at room temperature were also conducted with projectiles that were able to achieve near or complete penetration during PTP tests. Resistance to penetration, and penetration modes of Al 5052-H34 alloy, compared to those of Al 5083-H131 alloy.alloy.

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대게, Chionoecetes opilio 유생의 형태 및 수온별 성장 (Morphology of Snow Crab, Chionoecetes opilio Larvae and Larval Growth at Different Water Temperatures)

  • 임영수;이종관;이종하;이복규;허성범
    • 한국양식학회지
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    • 제14권1호
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    • pp.51-56
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    • 2001
  • At 5$^{\circ}C$ incubation of the brooded eggs of the snow crab, Chionoecetes opilio lasted for 297 days; freshly hatched prezoea molted to become the first zoea in one hour. Length (from the tip of the rostral spines to the tip of the dorsal spines) of the first and second zoeae measured 4.8 and 6.4mm, respectively. Experimental rearing of the larvae at 5, 10, 15 and 2$0^{\circ}C$ indicated that the upper limit of thermal tolerance is 15$^{\circ}C$, as all the reared larvae succumbed at 2$0^{\circ}C$. Intermolt period from the first the first zoea to the second was 57, 32 and 23 days at 5, 10 and 15$^{\circ}C$, respectively and that of the second zoea was 52, 29 and 90 days, respectively. Largest number of larvae survived at 1$0^{\circ}C$.

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시판한우 부산물 중 미량금속 함량의 비교조사 (Study on Comparison of the Amount of Trace Metals in Edible Viscera)

  • 엄애선;장정옥;고영수
    • 한국식품조리과학회지
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    • 제9권3호
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    • pp.195-197
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    • 1993
  • This study investigated the contamination of trace metals on edible visceras : tongue, intestine, lung, testis, gira, blood, liver, stomach, and kidney. The edible visceras were selected at random from ten markets in Seoul. The edible visceras underwent freeze drying prior to analysis. The contents of arsenic, cadmium, cobalt, chromium, copper, magnases, molybdenum, lead, and zinc were detected by ICP(Inductively Coupled Plasma Spectrophotometry). The results showed that the levels of trace metals in all the samples fall within the tolerance limit and cadmium in lung tended to be high(>0.1 ppm). Therefore, we may study and investigate continuously on the food contamination of heavy metals for the public health.

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네트워크 시스템 생존성 : 소프트웨어 재활기법을 이용한 TCP의 프레임워크 (Network System Survivability: A Framework of Transmission Control Protocol with Software Rejuvenation Methodology)

  • Khin Mi Mi Aung;Park, Jong-Sou
    • 한국정보보호학회:학술대회논문집
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    • 한국정보보호학회 2003년도 하계학술대회논문집
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    • pp.121-125
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    • 2003
  • In this paper, we propose a framework of Transmission Control Protocol with Software Rejuvenation methodology, which is applicable for network system survivability. This method is utilized to improve the survivability because it can limit the damage caused by successful attacks. The main objectives are to detect intrusions in real time, to characterize attacks, and to survive in face of attacks. To counter act the attacks' attempts or intrusions, we perform the Software Rejuvenation methods such as killing the intruders' processes in their tracks, halting abuse before it happens, shutting down unauthorized connection, and responding and restarting in real time. These slogans will really frustrate and deter the attacks, as the attacker can't make their progress. This is the way of survivability to maximize the deterrence against an attack in the target environment. We address a framework to model and analyze the critical intrusion tolerance problems ahead of intrusion detection on Transmission Control Protocol (TCP).

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Dead cell phagocytosis and innate immune checkpoint

  • Yoon, Kyoung Wan
    • BMB Reports
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    • 제50권10호
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    • pp.496-503
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    • 2017
  • The human body loses several billions of cells daily. When cells die in vivo, the corpse of each dead cell is immediately cleared. Specifically, dead cells are efficiently recognized and cleared by multiple types of neighboring phagocytes. Early research on cell death focused more on molecular mechanisms of cell death regulation while the cellular corpses were merely considered cellular debris. However, it has come to light that various biological stimuli following cell death are important for immune regulation. Clearance of normal dead cells occurs silently in immune tolerance. Exogenous or mutated antigens of malignant or infected cells can initiate adaptive immunity, thereby inducing immunogenicity by adjuvant signals. Several pathogens and cancer cells have strategies to limit the adjuvant signals and escape immune surveillance. In this review, we present an overview of the mechanisms of dead cell clearance and its immune regulations.

잉어치어(稚魚)와 금붕어에 대한 folpet의 급성(急性) 및 아급성독성(亞急性毒性)에 관한 연구 (Acute and subacute toxicity of folpet to fingerings of common carp, Cyprinus carpio and goldfish, Carassius auratus)

  • 허강준;이영순;임윤규
    • 대한수의학회지
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    • 제34권2호
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    • pp.369-374
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    • 1994
  • The acute and subacute toxicity of fungicide folpet was evaluated in fingerings of common carp, Cyprinus carpio and goldfish, Carrassius auratus. Dipping of fishes for acute toxicity was performed for a period of 24h, and the TLm value(median tolerance limit) was 1.52 ppm in common carp and 1.45 ppm in goldfish. Severe damages were observed in various organs and among them, clubbing of gill lamella, lytic degeneration and vacuolation of liver cells, and epithelial edema of renal tubules were relatively prominent. The most significant changes were hyperbasophilic foci of liver cells in subacute toxicity test and these can imply the possibility of hepatocarcinogenecity of folpet.

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직교배열표를 이용한 승객보호장구의 설계 (Design Recommendations of the Occupant Protection Systems Using Orthogonal Arrays)

  • 임재문;박경진
    • 한국자동차공학회논문집
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    • 제7권8호
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    • pp.208-215
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    • 1999
  • Using the orthogonal arrays and the occupant analysis software based on the multi-body dynamics , two interactive design algorithms are proposed to improve the initial design of the occupant protection systems. Algorithm 1 sequentially moves the narrow design space within the upper and the lower design limit. Algorithm 2 sequentially reduces the relatively wide design space. Each design algorithm is composed of two levels . The first level is to improve the characteristics of the crash performance considering the noise factors. In order to obtain the robust design, the second level reduces the variations the noise factors. In order to obtain the robust design, the second level reduces the variations due to the tolerance of the design variable. To utilize the algorithm 1, HIC(Head Injury Criterion) , 3 msec criterion value of the chest acceleration and the femur load decreased by 27.4%, 10.4% and 55.8%, respectively. To utilizer the algorithm 2 , the results decreased by 38.0%, 10.5% and 3.0% , respectively.

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한국산업표준(KS)에 따른 로크웰 경도 시험기의 불확도 산정에 관한 연구 (A Study on the Evaluation of Uncertainty of Rockwell Hardness C Scale According to the Korean Industrial Standards(KS))

  • 방건웅;탁내형
    • 열처리공학회지
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    • 제13권3호
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    • pp.163-169
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    • 2000
  • Recently, uncertainty of hardeness became a major concem for the people working on the laboratory evaluation and accreditation. It is required to indicate uncertainty of hardness tester on the report after calibration. In addition to this, uncertainty of certified hardness reference block is also required to indicate on the certification sheet. Method on the evaluation of uncertainty in hardness measurement is agreed only recently for Rockwell hardness C scale. In this paper, a preliminary calculation of uncertainty based on type B evaluation has been made for hardness testers which satisfies the requirements of Korean Standards. It was found that the tolerance limit of mean value specified in KS should be increased to be compatible with the calculated uncertainty.

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고배속 CD-ROM Drive의 진동댐퍼 설계에 관한 연구 (A study on the design of vibration damper for high speed CD-ROM drives)

  • 장승환;김현석;최진경;이대길
    • 대한기계학회논문집A
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    • 제22권4호
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    • pp.939-952
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    • 1998
  • Rubber dampers are widely used to damp out vibrations generated in many mechanical elements because of the excellent damping characteristics of rubber. The damping characteristics of rubber is much dependent on temperature and frequency, which, in some cases, limit the effectiveness of rubber dampers. In this study, in order to increase the damping properties and axial and cross stiffnesses of rubber vibration dampers which are used in recording and regenerating devices, solid cores were inserted with interference tolerance in the rubber dampers. The damping characteristics of the rubber dampers with cores were investigated by experimentally and numerically using finite element method with respect to the interference tolerance, the core roughness, the materials of the core and the environmental temperature. From the experimental and theoretical investigations, it was found that the core in the rubber increased both the damping and stiffness of the damper. Also, it was found that the damping and stiffness of the rubber damper were much dependent on the temperature and frequency. Using the results of the experimental and theoretical investigations, the optimum design method for the cored rubber damper for recording and regenerating devices was developed.

Recent Trend of Residual Pesticides in Korean Feed

  • Jeong, Jin Young;Kim, Minseok;Baek, Youl-Chang;Song, Jaeyong;Lee, Seul;Kim, Ki Hyun;Ji, Sang Yun;Lee, Hyun-Jeong;Oh, Young Kyun;Lee, Sung Dae
    • 한국초지조사료학회지
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    • 제38권3호
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    • pp.156-164
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    • 2018
  • Pesticide application in agriculture provides significant benefits such as protection from disease, prevention of harmful insects, and increased crop yields. However, accurate toxicological tests and risk assessments are necessary because of many related adverse effects associated with pesticide use. In this review, we discuss and analyze residual pesticides contained in livestock feed in Korea. A pesticide residue tolerance standard for livestock feed has not been precisely established; so, risk assessments are required to ensure safety. Standards and approaches for animal criteria and appropriate methods for evaluating residual pesticides are discussed and analyzed based on technology related to animal product safety in Korea. The safety of livestock feed containing pesticides is assessed to establish maximum residue limits relative to pesticides. Analysis of residual pesticides in milk, muscle, brain, and fat was performed with a livestock residue test and safety evaluation of the detected pesticide was performed. Efficacy of organic solvent extraction and clean-up of feed was verified, and suitability of the instrument was examined to establish if they are effective, rapid, and safe. This review discussed extensively how pesticide residue tolerance in livestock feed and hazard evaluation may be applied in future studies.