• Title/Summary/Keyword: T-tail

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On Asymptotic Properties of Bootstrap for Autoregressive Processes with Regularly Varying Tail Probabilities

  • Kang, Hee-Jeong
    • Journal of the Korean Statistical Society
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    • v.26 no.1
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    • pp.31-46
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    • 1997
  • Let $X_{t}$ = .beta. $X_{{t-1}}$ + .epsilon.$_{t}$ be an autoregressive process where $\mid$.beta.$\mid$ < 1 and {.epsilon.$_{t}$} is independent and identically distriubted with regularly varying tail probabilities. This process is called the asymptotically stationary first-order autoregressive process (AR(1)) with infinite variance. In this paper, we obtain a host of weak convergences of some point processes based on bootstrapping of { $X_{t}$}. These kinds of results can be generalized under the infinite variance assumption to ensure the asymptotic validity of the bootstrap method for various functionals of { $X_{t}$} such as partial sums, sample covariance and sample correlation functions, etc.ions, etc.

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Mechanical Development of an Unmanned Helicopter for Precise Small-scaled ULV Aerial Application - Conceptual Design and Prototype - (저투입 소필지 정밀 살포용 무인헬리콥터의 기체개발 - 기체요소의 개념설계 및 시작기 -)

  • Koo, Y.M.;Seok, T.S.;Shin, S.K.;Lee, C.S.;Kang, T.G.
    • Journal of Biosystems Engineering
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    • v.33 no.2
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    • pp.94-100
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    • 2008
  • Present chemical application method using a power sprayer has been labor intensive, costly and ineffective. Therefore, a small agricultural unmanned helicopter was suggested to replace the conventional spray system. In this study, conceptual design for developing the helicopter and a consequential prototype were reported. The overall conceptual design was initiated by deciding the type of agricultural helicopter, as the single rotor helicopter with a tail system. As the first step of the designing, an air-cooled, 2-stroke engine was selected and a prototype transmission was designed by determining the rotating speed of main rotor shaft. A 'pusher' type tail rotor system was adapted to balance the reaction torque and reduce the power use. The tail boom length was designed to avoid the rotating trajectory of the main rotor. The RF console consisted of the engine control, attitude control, and emergency control modules. Assembling the prototype concluded the mechanical development of the agricultural helicopter.

Direct approximations for t percentage points (t 분포 퍼센트점의 직접근사공식)

  • 김현철;송규문;허문렬
    • The Korean Journal of Applied Statistics
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    • v.2 no.1
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    • pp.48-53
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    • 1989
  • In contrast to the customary approximations based on standard normal percentage points, direct approximations involve simple functions of parameters (such as degrees of freedom and tail area of the t distributions). This article used techniques of exploratory data analysis following Hoaglin to develop direct approximations for percentage points in the commonly used portions of upper tail of the t distribution with small to moderate numbers of degrees of freedom. These approximations are convenient to use and they compare favorably in accuracy with the popular approximations based on standard normal percentage points such as Peiser's. They can be used as an initial value generator in algorithms for getting more accurate percentage points.

Vision-Based Camber and Optimal Cutting Line Detection Algorithm for Hot-Rolling Process (열연 공정에서의 영상을 이용한 캠버 및 최적 절단선 검출 알고리즘)

  • Kong, Nam-Wong;Moon, Jung-Hye;Park, Poo-Gyeon
    • Proceedings of the KIEE Conference
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    • 2007.10a
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    • pp.155-156
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    • 2007
  • This paper presents the vision-based camber and optimal cutting line detection algorithm for hot-rolling process. It is important to measure the camber of head and tail part of strips because many problems are caused by the camber in the hot-rolling process. The hot-rolling process has time constraints. The camber detection algorithm of head and tail parts requires fast and less complex for satisfying time constraints. The proposed algorithm consists of two parts: measurement of the camber in the head and tail part of strips and decision part of the optimal cutting line of hot-rolled strip. First, we obtain the camber value of the strip from the difference between the real center line and the center line of head, tail part. Second, the head and tail part of strips isn't suitable for strips connections. Therefore, the cutting process is needed in the hot-rolling process. The optimal cutting line is determined by the head and tail images obtained from cameras. The algorithm is applied into the vision system with two area cameras, Matrox image processing board and host PC for verification.

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Percutaneous Pig-tail Catheter Drainage in the Management of Lung Abscesses (폐농양의 치료에 Pig-tail 도관을 통한 경피적 배농)

  • Lee, Y.C.;Lee, Y.S.;Rhee, Y.K.
    • Tuberculosis and Respiratory Diseases
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    • v.40 no.2
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    • pp.153-157
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    • 1993
  • Background: Patients with pyogenic lung abscess who do not respond to medical therapy are usually candidates for thoracotomy with pulmonary resection. Percutaneous tube drainage, used routinely and with good results before the antibiotic era, has nearly been forgotten. Methods: We treated 8 patients who had poor cadidates for a lobectomy and didn't respond to medical management. A pig-tail catheter (6 to 10 Fr.) was inserted into the abscess under the fluoroscopic guidance. Results: All patients brought about dramatic clinical responses with prompt closure of cavity and radiographic improvement. Conclusion: Percutaneous pig-tail catheter drainage provides excellent clnical results with ease and safety, and avoids unnecessary loss of functioning lung parenchyma. But lobectomy should be considered in patients who major life-threatening bleeding or massive pulmonary necrosis.

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Formalin Pretreatment Attenuates Tail-Flick Inhibition Induced by ${\beta}$-Endorphin Administered Intracerebroventricularly or Intrathecally in Mice

  • Han Ki-Jung;Choi Seong-Soo;Shim Eon-Jeong;Seo Young-Jun;Kwon Min-Soo;Lee Jin-Young;Lee Han-Kyu;Suh Hong-Won
    • Archives of Pharmacal Research
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    • v.28 no.2
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    • pp.227-231
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    • 2005
  • We examined the effect of the subcutaneous (s.c.) pretreatment of formalin into both hind paws of mice on the antinociception induced by the intracerebroventricularly (i.c.v.) or intrathecally (i.t.) administration of ${\beta}$-endorphin using the tail-flick test. Pretreatment with formalin ($5\%$) for 5 h had no affect on the i.c.v. administered ${\beta}$-endorphin-induced tail-flick response. However, pretreatment with formalin for 40 h attenuated the tail-flick inhibition induced by i.c.v. administered ${\beta}$-endorphin. This antinociceptive tolerance to i.c.v. ${\beta}$-endorphin continued up to 1 week, but to a lesser extent. Pretreatment with formalin for 5 and 40 h significantly reduced the i.t. ${\beta}$-endorphin-induced inhibition of the tail-flick response, which continued up to 1 week. The s.c. formalin treatment increased the hypothalamic pro-opiomelanocortin (POMC) mRNA level at 2 h, but this returned to the basal level after 40 h. Our results suggest that the increase in the POMC mRNA level in the hypothalamus appears to be involved in the supraspinal or spinal ${\beta}$-endorphin-induced antinociceptive tolerance in formalin-induced inflammatory pain.

Combustion Characteristics of HCNG Burner System with Tail Gas Addition (HCNG용 버너시스템에서 Tail Gas 첨가 시 연소특성)

  • Han, J.O.;Lee, J.S.;Kim, H.T.;Kim, S.M.;Lee, Y.C.;Kim, Y.C.;Hong, S.H.
    • Journal of the Korean Society of Combustion
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    • v.20 no.2
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    • pp.36-39
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    • 2015
  • The combustion characteristics of metal fiber burner fueled natural gas with tail gas produced from reforming process were analyzed on the point of flame stability and excess air conditions. Also, it was analyzed the effect of energy efficiency improvement due to decrease the fuel input in reforming system by using residue gases. As a results, it was confirmed that tail gas including hydrogen, CO and $CO_2$ could be directly injected without any change of air control system in natural gas burner and also energy efficiency was increased up to 30% maintained stable combustion.

Naloxone Reversal of He-Ne Laser Stimulation Induced Analgesia in Rat (헬륨 -네온 레이저자극으로 유발된 흰쥐 진통작용의 날록손 반전)

  • Lee Jae-Hyoung;Song In-Yong;Choi Eun-Yong
    • The Journal of Korean Physical Therapy
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    • v.8 no.1
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    • pp.15-20
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    • 1996
  • The purpose of this study were to 1) determine the analgesic effect of 632.8 nm of helium-neon (He-Ne) laser stimulation on acupuncture point in rat and 2) determine the reversal of analgesic effect by naloxone injection. Eighteen Sprague-Dawley rats were devided into three groups : control (n=6) : laser (n=6), laser stimulation at $3.58\;J/cm^2$ ; and naloxone (n=6), 1 mg/kg of naloxone chloride inject into peritoneum before laser stimulation at $3.63J/cm^2$. Tail-flick latency were measured pretreat and posttreat with hot plate $(55^{\circ}C)$. Data were analyzed using one-way ANOVA and paired t-teat for tail-flick latency. No significant change was noted in the tail-flick latency in either control or naloxone groups. But significant increased in tail-flick latency in taller group. The results suggest that He-Ne laser induced analgesic effect, and endogenous opioids may be involved in He-Ne laser induced analgesia.

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ON CONVERGENCE OF SERIES OF INDEPENDENTS RANDOM VARIABLES

  • Sung, Soo-Hak;Volodin, Andrei-I.
    • Bulletin of the Korean Mathematical Society
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    • v.38 no.4
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    • pp.763-772
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    • 2001
  • The rate of convergence for an almost surely convergent series $S_n={\Sigma^n}_{i-1}X_i$ of independent random variables is studied in this paper. More specifically, when S$_{n}$ converges almost surely to a random variable S, the tail series $T_n{\equiv}$ S - S_{n-1} = {\Sigma^\infty}_{i-n} X_i$ is a well-defined sequence of random variables with T$_{n}$ $\rightarrow$ 0 almost surely. Conditions are provided so that for a given positive sequence {$b_n, n {\geq$ 1}, the limit law sup$_{\kappa}\geqn | T_{\kappa}|/b_n \rightarrow$ 0 holds. This result generalizes a result of Nam and Rosalsky [4].

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