• Title/Summary/Keyword: Primary resolution

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The Choice of a Primary Resolution and Basis Functions in Wavelet Series for Random or Irregular Design Points Using Bayesian Methods

  • Park, Chun-Gun
    • Communications for Statistical Applications and Methods
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    • 제15권3호
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    • pp.379-386
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    • 2008
  • In this paper, the choice of a primary resolution and wavelet basis functions are introduced under random or irregular design points of which the sample size is free of a power of two. Most wavelet methods have used the number of the points as the primary resolution. However, it turns out that a proper primary resolution is much affected by the shape of an unknown function. The proposed methods are illustrated by some simulations.

NEW SELECTION APPROACH FOR RESOLUTION AND BASIS FUNCTIONS IN WAVELET REGRESSION

  • Park, Chun Gun
    • Korean Journal of Mathematics
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    • 제22권2호
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    • pp.289-305
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    • 2014
  • In this paper we propose a new approach to the variable selection problem for a primary resolution and wavelet basis functions in wavelet regression. Most wavelet shrinkage methods focus on thresholding the wavelet coefficients, given a primary resolution which is usually determined by the sample size. However, both a primary resolution and the basis functions are affected by the shape of an unknown function rather than the sample size. Unlike existing methods, our method does not depend on the sample size and also takes into account the shape of the unknown function.

Primary Angle-Closure Glaucoma in a Maltipoo Dog

  • Jiwoo Park;Manbok Jeong
    • 한국임상수의학회지
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    • 제40권3호
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    • pp.221-224
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    • 2023
  • A two-year-old spayed female Maltipoo dog was presented with a two-month duration of glaucoma in the right eye. On the first presentation, menace response and dazzle reflex were absent in the right eye, but it was present in the left eye. Slit-lamp biomicroscopy showed buphthalmia, mild corneal edema, and conjunctival and episcleral hyperemia in the right eye. The intraocular pressures were 70 mmHg and 30 mmHg in the right and left eyes, respectively. On the gonioscopic and high-resolution ultrasound examinations, both the iridocorneal angle and ciliary cleft were completely closed in the right eye. However, gonioscopy revealed an opened iridocorneal angle even with some broader base of pectinate ligament fiber, but high-resolution ultrasound showed a narrowed ciliary cleft and increased contact of the iris base with the limbal cornea in the left eye. Based on these results, a diagnosis of primary angle-closure glaucoma was made in both eyes. This case report highlighted the importance of evaluating the ciliary cleft with high-resolution ultrasound as a critical diagnostic and prognostic role in canine glaucoma.

High Spontaneous Resolution Rates of Severe Primary Vesicoureteral Reflux and Minimal Development of New Renal Scars

  • Cha, Jihei;Lee, Seung Joo
    • Childhood Kidney Diseases
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    • 제20권1호
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    • pp.18-22
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    • 2016
  • Purpose: The previous reports regarding VUR resolution were not precise due to early frequent surgical intervention. We evaluated the spontaneous resolution (SR) rate and the incidence of new renal scars in primary VUR, focusing on severe reflux. Methods: Medical records of 334 patients with primary VUR who were on medical prophylaxis without surgery for 1 to 9 years, were retrospectively reviewed. Medical prophylaxis was initiated with low-dose antibiotic prophylaxis or probiotics. Radioisotope cystourethrography was performed every 1 to 3 years until SR of reflux. New renal scar was evaluated with follow-up $^{99m}Tc$ DMSA renal scan. Results: The SR rates decreased as VUR grades were getting higher (P=0.00). The overall and annual SR were 58.4% and 14.9%/yr in grade IV reflux and 37.5% and 9.3%/yr in grade V reflux. The median times of SR were 38 months in grade IV reflux and 66 months in grade V reflux. The probable SR rates in grade IV and V reflux were 7.8% and 8.9% in the 1st year, 46.0% and 30.8% in the 3rd year and 74.4% and 64.4% in the 5th year. The incidences of new renal scars between low to moderate reflux and severe reflux showed no significant difference (P=0.32). Conclusion: The SR rates of severe primary VUR were higher than previously reported and most new renal scars were focal and mild.

OTF 정밀측위를 위한 신속한 미지정수 결정방법 (A Fast Integer Ambiguity Resolution Method For Precise Positioning On- The-Fly)

  • 이대규;성태경
    • 제어로봇시스템학회논문지
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    • 제10권5호
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    • pp.458-463
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    • 2004
  • This paper presents a fast IA(integer ambiguity) resolution method that determines the IA within short epochs with guaranteed reliability. Based on the fact that the search volume and the cost function are influenced by the selection of primary IAs in the plane intersection method, an IA resolution method is proposed that evaluates IA candidates repeatedly in an epoch with different combinations of primary IAs. In order to guarantee the reliability of the resolved IA with a certain probability, an inequality condition for selecting differencing operator is derived. Experiment results show that the proposed method consistently provides the true IA estimates within short time.

SIMS glancing anlge을 적용한 tunnel oxide 내 Nitorgen 깊이 분해능 향상 연구

  • 이종필;최근영;김경원;김호정;한오석
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2011년도 제40회 동계학술대회 초록집
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    • pp.41-41
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    • 2011
  • Flash memory에서 tunnel oxide film은 electron tunnelling 현상을 이용하여 gate에 전하를 전달하는 통로로 사용되고 있다. 특히, tunnel oxide film 내부의 charge trap 현상과 불순물이 소자 특성에 직접적인 영향을 주고 있어, 후속 N2O/NO 열처리 공정에서 SiO2/Si 계면에 nitrogen을 주입하여 tunnel oxide film 특성을 개선하고 있다. 따라서 N2O/NO 열처리 공정 최적화를 위해서는 tunnel oxide film 내 N 농도와 분포에 대한 정확한 평가가 필수적이다[1]. 본 실험에서는 low energy magnetic SIMS를 이용하여 N2O로 열처리된 tunnel oxide film 내의 N농도를 보다 정확하게 평가하고자 하였다. 사용된 시료는 Si substrate에 oxidation 이후 N2O 열처리를 진행하여 tunnel oxide를 형성시켰으며, 분석 impact energy는 surface effect최소화와 최상의 depth resolution 확보를 위해 250eV를 사용하였으며, matrix effect와 mass interference를 방지하기 위해 MCs+ cluster mode[2]로 CsN signal를 검출하였다. 실험 결과, 특정 primary beam 입사각도에서 nitrogen depth resolution 저하 현상이 발생하였고, SIMS crater 표면이 매우 거칠게 나타났다. 이에, Depth resolution 저하 현상을 개선하기 위해 극한의 glancing 입사각 조건으로 secondary extraction voltage 변화를 통해 depth resolution이 개선되는 최적의 impact energy와 primary beam 입사각 조건을 확보하였다. 그 결과 nitrogen의 depth resolution은 1.6nm의 depth resolution을 확보하였으며, 보다 정확한 N 농도와 분포를 평가할 수 있게 되었다.

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A TRADE OFF STUDY OF LIGHTWEIGHT PRIMARY MIRROR FOR SPACEBORNE TELESCOPE

  • LEE Haeng-Bok;Choi Se-Chol
    • 한국우주과학회:학술대회논문집(한국우주과학회보)
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    • 한국우주과학회 2005년도 한국우주과학회보 제14권2호
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    • pp.149-152
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    • 2005
  • High-resolution telescope from space comprises electro-optical imagery with a ground resolution tying within the range of 1 to 5 meters. According to information documented in the literature up to now, most primary mirrors verified and flown in optical space missions have been lightweighted made from Zerodur, ULE, beryllium, SiC or aluminium. A trade off study was performed to determine as a &lightweighted& by factors like backside cell pattern, rib thickness, face thickness, mirror fixation device location and material and so on based on structural performance for primary mirror in submeter class spaceborne telescope.

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영아기 일차성 방광요관역류의 임상적 특성과 자연 소실율 (The Clinical Characteristics of Infantile Primary Vesicoureteral Reflux and Its Spontaneous Resolution Rate)

  • 최윤성;김지혜;심윤희;이승주
    • Childhood Kidney Diseases
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    • 제11권1호
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    • pp.83-91
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    • 2007
  • 목적 : 소아기 일차성 방광요관역류는 대부분 요로감염 후에 진단되고, 여아에서 흔하며 역류와 신반흔의 정도가 다양하고 심한 역류에서는 자연 소실율이 낮다. 반면 최근에 태아 수신증으로부터 진단된 신생아기 일차성 방광요관역류는 남아에서 흔하고, 역류와 신반흔의 정도가 심하며 심한 역류에서도 자연 소실율이 높은 점 등 상반된 특징이 보고되어 있다. 본 연구의 목적은 신생아기와 소아기의 이행기인 영아기 일차성 방광요관역류의 임상적 특성과 자연 소실율을 후향적으로 조사하여 비교하고자 하였다. 방법 : 1995년 1월부터 2004년 5월까지 이화여자대학교 의과대학 부속 목동병원에서 요로감염 치료 후에 일차성 방광요관역류로 진단된 영아에서 매년 동위원소 배뇨성 방광요도조영술로 3년간 추적 조사가 가능하였던 96명을 대상으로 하였다. 대상아의 연령은 $4.7{\pm}3.8$개월(남아 $4.2{\pm}3.5$개월, 여아 $5.6{\pm}4.8$개월)로 성별에 따른 유의한 차이는 없었다. 임상적 특성으로 성별, 역류의 정도, 신반흔의 정도 등을 조사하였고, 자연 소실율과 관련된 요인을 분석하였다. 결과 : 영아기 일차성 방광요관역류는 남아가 76명(79.2%), 여아가 20명(20.8%)으로 남아에서 유의하게 많았고(P<0.05) 역류성 요관도 남아가 99단위(77.3%), 여아가 29단위(22.7%)로 남아에서 유의하게 많았다(P<0.05). 역류 등급의 분포는 성별에 따라 유의한 차이가 없었다. 신반흔의 동반율은 남아 31.3%(31/99), 여아 17.2%(5/29)로 성별에 따른 유의한 차이는 보이지 않았으나, 위축신의 동반율은 남아에서 17.2%(17/99)로 여아 3.4%(1/29)에 비하여 유의하게 높았다(P<0.05). 역류성 요관의 3년 누적 자연 소실율은 89.1% (114/128)로 매우 높았으며 성별과 역류의 등급에 따른 유의한 차이는 없었다. 단 첫해, 중증 역류성 요관(3-5등급)의 자연 소실율이 남아에서 46.2%로, 여아의 7.1%에 비하여 유의하게 높았고(P<0.05) 정상 신장을 동반한 경우의 자연 소실율이 76.6%로 위축신을 동반한 경우의 20%에 비하여 유의하게 높았다(P<0.05). 결론 : 영아기 일차성 방광요관역류는 남아에서 많았고 특히 남아에서 위축신의 동반율이 높았다. 3년 누적 자연 소실율은 매우 높았고 중증 역류와 위축신을 동반한 경우에도 높았다. 즉, 영아기 일차성 방광요관역류는 위축신을 동반한 심한 역류에서도 수술요법보다 내과적 치료가 우선적으로 권장된다.

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A Note on A Bayesian Approach to the Choice of Wavelet Basis Functions at Each Resolution Level

  • Park, Chun-Gun
    • Journal of the Korean Data and Information Science Society
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    • 제19권4호
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    • pp.1465-1476
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    • 2008
  • In recent years wavelet methods have been focused on block shrinkage or thresholding approaches to accounting for the sparseness of the wavelet representation for an unknown function. The block shrinkage or thresholding methods have been developed in both of classical methods and Bayesian methods. In this paper, we propose a Bayesian approach to selecting wavelet basis functions at each resolution level without MCMC procedure. Simulation study and an application are shown.

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