• Title/Summary/Keyword: tail

Search Result 2,721, Processing Time 0.028 seconds

Stochastic Properties of Life Distribution with Increasing Tail Failure Rate and Nonparametric Testing Procedure

  • Lim, Jae-Hak;Park, Dong Ho
    • Journal of Applied Reliability
    • /
    • v.18 no.3
    • /
    • pp.220-228
    • /
    • 2018
  • Purpose: The purpose of this study is to investigate the tail behavior of the life distribution which exhibits an increasing failure rate or other positive aging effects after a certain time point. Methods: We characterize the tail behavior of the life distribution with regard to certain reliability measures such as failure rate, mean residual life and reliability function and derive several stochastic properties regarding such life distributions. Also, utilizing an L-statistic and its asymptotic normality, we propose new nonparametric testing procedures which verify if the life distribution has an increasing tail failure rate. Results: We propose the IFR-Tail (Increasing Failure Rate in Tail), DMRL-Tail (Decreasing Mean Residual Life in Tail) and NBU-Tail (New Better than Used in Tail) classes, all of which represent the tail behavior of the life distribution. And we discuss some stochastic properties of these proposed classes. Also, we develop a new nonparametric test procedure for detecting the IFR-Tail class and discuss its relative efficiency to explore the power of the test. Conclusion: The results of our research could be utilized in the study of wide range of applications including the maintenance and warranty policy of the second-hand system.

On the Tail Series Laws of Large Numbers for Independent Random Elements in Banach Spaces (Banach 공간에서 독립인 확률요소들의 Tail 합에 대한 대수의 법칙에 대하여)

  • Nam Eun-Woo
    • The Journal of the Korea Contents Association
    • /
    • v.6 no.5
    • /
    • pp.29-34
    • /
    • 2006
  • For the almost certainly convergent series $S_n=\sum_{i=1}^nV-i$ of independent random elements in Banach spaces, by investigating tail series laws of large numbers, the rate of convergence of the series $S_n$ to a random variable s is studied in this paper. More specifically, by studying the duality between the limiting behavior of the tail series $T_n=S-S_{n-1}=\sum_{i=n}^{\infty}V-i$ of random variables and that of Banach space valued random elements, an alternative way of proving a result of the previous work, which establishes the equivalence between the tail series weak law of large numbers and a limit law, is provided in a Banach space setting.

  • PDF

Complement-mediated tail degradation of Neodiplostomum seoulense cercariae

  • Park, Yun-Kyu;Hwang, Myung-Ki;Jung, Yun-Jung
    • Parasites, Hosts and Diseases
    • /
    • v.44 no.2 s.138
    • /
    • pp.127-131
    • /
    • 2006
  • The furcocercus cercariae of Neodiplostomum seoulense (Digenea: Neodiplostomidae) penetrate the skins of tadpoles and shed their tails. The speculated mechanism of this tail loss was physical efforts required to produce a vigorous zigzag motion during skin penetration; no other mechanism has been proposed. We examined the relationship between the host serum and cercarial tail loss. Cercariae of N. seoulense were collected from experimentally infected Segmentina hemisphaerula, and lots of 300 cercariae were cultured in medium 199 contained several types of sera. Cercarial tail degradation was induced in all media, but all the cercariae cultured except those cultured in media containing fetal bovine serum (FBS) died within 48 hr. After 72 hr cultivation in media containing FBS, cercarial tail degradation was induced in 67.0%; in continuous cultivation 13.3% of larvae survived for 7 days. Tail degradation did not occur in the absence of serum and when serum was heat inactivated at $56^{\circ}C$ for 30 min. The addition of 20 mM ethylenediaminetetraacetic acid (EDTA) blocked cercarial tail degradation completely. Moreover, the addition of 20 mM $MgCl_2$ restored tail degradation blocked by EDTA. These results suggest that the alternative complement pathway is related with the N. seoulense cercarial tail degradation induced by serum.

Improvement and Operation of a Helicopter Tail-Fan Performance Test System (헬리콥터 테일팬 시험장치 개조 및 운용)

  • Lee, Je-Dong;Song, Keun-Woong;Kang, Hee-Jung;Sim, Jung-Wook;Kim, Seung-Bum
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • 2005.11b
    • /
    • pp.41-44
    • /
    • 2005
  • This paper described improvement and operation of a 'Tail-Fan' anti-torque performance test system KARI (Korea Aerospace Research Institute) developed a 'Tail-Fan' anti-torque system of a helicopter and a performance test-rig to test the performance of the Tail-Fan. The test-rig was improved for full rotating test in 4300rpm(100%). Machinery and hydraulic parts ware changed to reduce vibration and to increase safety. To find the operation rotating speed for the performance test, vibration test were carried out rising accelerometers on tail gear box. The performance test conditions of the Tail-Fan to avoid a resonance were found from vibration test results. The Tail-Fan operation tests were performed safely frier to carry out performance test.

  • PDF

Preparation of Red Ginseng Extract Rich in Acidic Polysaccharide from Red Tail Ginseng Marc Produced After Extraction with 70% Ethyl Alcohol (홍미삼 알콜 추출박을 이용한 산성다당체 다량 함유 홍삼 엑기스 제조)

  • 도재호;이종원
    • Journal of Ginseng Research
    • /
    • v.20 no.1
    • /
    • pp.60-64
    • /
    • 1996
  • In this study, we investigated the appropriate conditions to extract acidic polysaccharide and to prepare red ginseng extract being rich in acidic polysaccharide from red tail ginseng marc produced after manufacturing alcoholic extract from red tail ginseng. Amount of acidic polysaccharide in red tail ginseng marc was about 11%. The best condition for the extraction of acidic polysaccharide from the marc was using of 3~5 mg of $\alpha$-amylase/g residue/15 ml of distilled water, and the amount of acidic polysaccharide in water extract of the residue treated with $\alpha$-amylase was about 27%. So, it is possible to manufacture red ginseng extract being rich in acidic polysaccharide using water extract of red tail ginseng alcoholic residue as extraction solvent. From the above results, we suggest that red tail ginseng residue produced by manufacturing alcoholic extract of red tail ginseng has high potencies in the utilization of waste material.

  • PDF

A study on talc Production of Ginseng Extracts 2. Production of extracts from tail ginseng (인삼엑기스 제조에 관한 연구, 제2보. 미삼엑기스 제조)

  • 조규성;김해중;임무현;주현규;이석건
    • Journal of Ginseng Research
    • /
    • v.4 no.1
    • /
    • pp.8-14
    • /
    • 1980
  • In order to establish effective production o( ginseng extracts from tail ginseng, the tail ginseng was soaked in the different concentration and the amount of ethanol, and iii course of the time and duration of the extraction. The yield of ginseng extract, proximate chemical components and its saponin pattern were investigated. The results obtained are as follows: 1. The amount of tail ginseng extracts decreased in accordance with the increment of ethanol concentration. The yield of the extracts were 50.86%, 44.42%, 37.82%, 35.52% and 33.42% extracted by water.30%. 50%, 70%, and 90% ethanol, respectively. 2. The reasonable proportion of tail ginseng and solvent (35% ethanol) u·as 1 : 4 (42.68%)∼1 : 6 (45.92%) 3. The yield of tail ginseng extract increased according to the extraction time, but it was the most suitable that the tail ginseng extracted for 5 hour (43.32%)∼10 hour (45.60%). 4. The chemical composition and viscosity of tail ginseng extract was decreased but it's transmittance was increased, and the saponin pattern of T.L.C. showed same tendency in the course of extraction time.

  • PDF

Aerial Application using a Small RF Controlled Helicopter (V) - Tail Rotor System - (소형 무인헬기를 이용한 항공방제기술(V) -테일 로터부의 구성-)

  • Koo, Y.M.;Seok, T.S.
    • Journal of Biosystems Engineering
    • /
    • v.32 no.4
    • /
    • pp.230-236
    • /
    • 2007
  • In this study, a tail rotor system for an agricultural RF controlled helicopter was developed and tested. This study concluded the mechanical development of the 'Agro-heli' by completing the tail rotor system and its radio console. The RF control system was closely related with the tail system for the control of flying attitude. The thrust of the tail system balance off the reaction torque, created by the main rotor. Lifting tests with and without the tail system were compared for estimating the consumption of power. The tail system would use $4{\sim}5%$ of the total power which was in an acceptable range. Flying performance and attitude was visually inspected. It showed reliable and safe control during the distance flying trials and could be adapted for utilization in aerial applications. Aerial application using an RF controlled agricultural helicopter may make precise and timely spraying possible.

The Operation and Vibration Characteristics of Tail-Fan Performance Test System (테일팬 성능시험장치의 운용과 진동특성)

  • Song, Ken-Woong;Kim, Jun-Ho;Kang, Hee-Jung;Rhee, Wook;Sim, Jung-Wook
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • 2004.11a
    • /
    • pp.508-512
    • /
    • 2004
  • This paper described operation and vibration characteristics of 'Tail-Fan' performance test system. KARI(Korea Aerospace Research Institute) developed 'Tail-Fan' system as a kind of helicopter anti-torque system(ATS) and designed ATS performance test-rig for Tail-Fan system performance test. Test-rig consists of driving parts, supporting parts and rotating parts. For Tail-Fan system performance tests, firstly, test-rig operation tests were carried out for verification of design specifications. Secondly, natural frequencies of fan blade and test-rig were measured respectively. Lastly, to find the operation rotating speed for performance tests, vibration tests using accelerometers on tail gear box(TGB) were carried out. Through the fanplot and vibration test results, Tail-Fan performance test conditions to avoid a resonance were found and performance tests were well done safely.

  • PDF

Korean Head-Tail POS-Tagger by using Transformer (Transformer를 이용한 한국어 Head-Tail 품사 태거)

  • Kim, Jung-Min;Suh, Hyun-Jae;Kang, Seung-Shik
    • Annual Conference on Human and Language Technology
    • /
    • 2021.10a
    • /
    • pp.544-547
    • /
    • 2021
  • 한국어의 품사 태깅 문제는 입력 어절의 형태소 분석 후보들로부터 통계적으로 적절한 품사 태그를 가지는 후보들을 찾는 방식으로 해결하여 왔다. 어절을 형태소 단위로 분리하고 품사를 부착하는 기존의 방식은 품사태그 정보를 딥러닝 feature로 사용할 때 문장의 의미를 이해하는데 복잡도를 증가시키는 요인이 된다. 본 연구에서는 품사 태깅 문제를 단순화 하여 한 어절을 Head와 Tail이라는 두 가지 유형의 형태소 토큰으로 분리하여 Head와 Tail에 대해 품사를 부착한다. Head-Tail 품사 태깅 방법을 Sequence-to-Sequence 문제로 정의하여 Transformer를 이용한 Head-Tail 품사 태거를 설계하고 구현하였다. 학습데이터로는 KCC150 말뭉치의 품사 태깅 말뭉치 중에서 788만 문장을 사용하고, 실험 데이터로는 10만 문장을 사용하였다. 실험 결과로 토큰 정확도는 99.75%, 태그 정확도는 99.39%, 토큰-태그 정확도는 99.31%로 나타났다.

  • PDF

Nutritional Characteristics of Water Extract from Kangaroo Tail. (캥거루 꼬리의 영양학적 특성)

  • Ha, Soon-Ok;Park, In-Hye;Lee, Yong-Seok;Kim, Jae-Kyu;Chung, Soo-Yeol;Choi, Yong-Lark
    • Journal of Life Science
    • /
    • v.18 no.7
    • /
    • pp.958-962
    • /
    • 2008
  • To get the nutritional data of hot water extract from imported kangaroo tails, research was done about contents of collagen, chondroitin sulfate, protein, fat, mineral ions, and conjugated linoleic acid (CLA) in tails. Collagen content of sulfuric acid digested sample was way higher at bones than meats in both kangaroo tail and cow tail. Comparing kangaroo tail and cow tail, meat of kangaroo tail have 1.7 times higher collagen content than that of cow tail. Content of collagen in bone parts of kangaroo tail was also higher 1.2 times than that of cow tail. Meat sample of kangaroo tail (liquid extraction) have 1.3 times higher content of muco-polysaccharide than that of cow tail. In the born part, kangaroo tail was 2.4 times higher than cow tail in its content of muco-polysaccharide. The CLA content of the kangaroo tail showed the content that was higher than 0.9% of the cow tail for 4.9% and showed about 5.3 times high ratios. Especially in kangaroo tail, a band with high content of CLA was found between C18:1 and C18:2.