• 제목/요약/키워드: Threshold Effect

검색결과 1,513건 처리시간 0.029초

멀티웨이블릿 변환영역에서 계수정규화를 이용한 Soft-Threshold 기법의 영상신호 잡음제거 (Image Signal Denoising by the Soft-Threshold Technique Using Coefficient Normalization in Multiwavelet Transform Domain)

  • 김재환;우창용;박남천
    • 융합신호처리학회논문지
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    • 제8권4호
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    • pp.255-265
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    • 2007
  • 웨이블릿 축소 기법으로 영상신호의 잡음을 제거할 때, 웨이블릿 계수들이 상관관계를 갖는 경우 잡음제거 효과가 저하된다. 멀티웨이블릿 변환된 계수 들은 사전 필터의 영향으로 상관관계를 갖게 된다. 이러한 문제점을 해결하기위해 V Sterela에 의해 Universal 경계 값 적용을 위한 사전 필터를 새로 설계하거나 가중 값을 적용하는 기법이 제시되었다. 본 논문에서는 멀티웨이블릿 변환 영역에서 웨이블릿 축소 기법의 잡음제거 효과를 향상시키기 위해, 대역의 계수를 추정된 잡음편차로 나누는 계수 정규화기법을 Universal, SURE 및 GCV 경계 값에 적용하여 잡음을 제거하는 시도를 하였다. 각 경계 값들에 대한 PSNR을 비교하여 이 기법의 실용성을 확인하였다.

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Development of the RE indirect-heating LPE furnace and the effect of impurity in YIG film on the MSSW properties

  • Fujino, M.;Fujii, T.;Sakabe, Y.
    • 한국결정성장학회지
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    • 제12권6호
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    • pp.288-291
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    • 2002
  • We developed a new RF indirect-heating LPE furnace. The thermal gradient of our newly developed furnace is less than that of direct heating, and is as gentle as that of the resistance-heating LPE furnace. With this new furnace, the heating and/or cooling is faster than that of the resistance-heating furnace. Impurity-doped YIG film was grown from a $PbO-B_{2}O_{3}$, based flux on a (111) GGG substrate. To study the effect of the impurities on the MSSW threshold power and the saturation response time, we used two microstrip lines to excite and propagate the MSSW at 1.9 GHz. The MSSW threshold power and saturation response time was found to be related to the $\Delta$H.

SM40C 강의 열처리가 피로균열전파속도에 미치는 영향 (The Effect of Heat Treatment on the Fatigue Crack Propagation in SM40C Steel)

  • 금창훈;권숙인
    • 열처리공학회지
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    • 제3권2호
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    • pp.37-44
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    • 1990
  • The effect of the microstructural change on the near threshold fatigue crack growth rate in SM40C steel has been studied using the ${\Delta}K$ decreasing method. Below the total strain amplitude of 0.56%, cyclic softening occured, whereas above this value cyclic hardening occurred in the pearlitic lamellar structure. However, in the spherodized structure the cyclic hardening solely occurred. The crack growth rate in the near-threshold region was decreased with increasing prior austenite grain size and this was due to surface roughness. The crack growth rate of the spherodized structure was lower than that of the pearlite lamellar structure and the ${\Delta}K_{th}$ of the former was higher than that of the latter. It was understood that the crack propagates preferentially through the ferrite phase. The intergranular facets in the near-threshold region appeared in the spherodized structure.

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Two-Sided Mirror: An Analysis of Inflation's Dual Impact on China's Economic Growth

  • Ke Chen;Jongheuk Kim
    • East Asian Economic Review
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    • 제28권2호
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    • pp.175-219
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    • 2024
  • This study investigates the impact of inflation rate fluctuations on economic growth in China, with a particular focus on potential non-linear characteristics. The global economic impact of the COVID-19 pandemic notably heightens the study's relevance. The research that the unidirectional causal relationship from inflation to economic growth in China first strengthens and then weakens over time. Furthermore, there is an inflation rate threshold effect on economic growth, identified at 2%. Below this threshold, inflation positively influences economic growth, whereas above it, the impact turns negative. This finding underscores the importance of balancing economic growth with inflation control in the formulation of monetary policy.

과적응 감소를 위한 주성분 분석 및 독립성분 분석을 이용한 MLLR 화자적응 알고리즘 개선 (Improvement of MLLR Speaker Adaptation Algorithm to Reduce Over-adaptation Using ICA and PCA)

  • 김지운;정재호
    • 한국음향학회지
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    • 제22권7호
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    • pp.539-544
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    • 2003
  • 본 논문은MLLR (Maximum Likelihood Linear Regression)를 화자 적응시 과적응 방지를 위해 트리 구조에서 HHM 파라메타의 변환을 결정하는 점유 문턱값 (occupation threshold)의 영향을 감소하는 방법에 대해 기술한다. 데이터의 특징을 잘 나타내는 주성분 분석과 독립성분 분석을 통해 모델 혼합성분의 상관관계를 줄이고 상대적으로 데이터의 분포가 적은 축을 삭제함으로써 적은 적응데이터에 의한 과적응의 영향을 감소시켰다. 점유 문턱값을 작게 설정함으로써 변환함수의 수를 증가시켰을 경우, 기존의 MLLR 알고리즘은 과적응에 의해 화자 독립 모델보다 낮은 인식률을 나타내는 반면, 제안한 MLLR알고리즘은 화자 독립 모델의 성능에 비해 평균 2%이상 인식율 향상을 나타내었다.

Effects of Fascial Distortion Model and Myofascial Release on Pain Threshold in Remote Area

  • JiYoung Kim;Migyoung Kweon
    • The Journal of Korean Physical Therapy
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    • 제35권1호
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    • pp.31-35
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    • 2023
  • Purpose: This study sought to identify whether fascial therapy using myofascial release (MFR) and Fascial Distortion Model (FDM) techniques affected not only the area where treatment was being given but also remote areas connected to the treatment area by fascial continuity through comparison of the pain pressure threshold (PPT). Methods: The subjects were 16 healthy normal adults in their 20s and 30s who were divided into the MFR and FDM groups before the experiment. The PPT was measured at 4 different points on the body of the subjects. C7, T7, L5, and gastrocnemius along the superficial back line (SBL) before and after the intervention. Results: Only the FDM group subjects showed a significant increase in the PPT at T7 after the intervention. (p<0.05). In addition, the FDM group demonstrated significantly increased PPT at L5 compared to the MFR group. However, neither the FDM nor the MFR group showed a meaningful change in the PPT at the remote area in the lower leg. Conclusion: These findings showed that FDM can affect PPT more and has a positive effect on the pain threshold compared to MFR. However, neither FDM nor MFR showed any effect on the PPT in a remote area.

비휘발성 기억소자의 저항효과에 관한 연구 (A study on the impedance effect of nonvolatile memory devices)

  • 강창수
    • E2M - 전기 전자와 첨단 소재
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    • 제8권5호
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    • pp.626-632
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    • 1995
  • In this paper, The effect of the impedances in SNOSFET's memory devices has been developed. The effect of source and drain impedances measured by means of two bias resistances - field effect bias resistance by inner region, external bias resistance. The effect of the impedances by source and drain resistance shows the dependence of the function of voltages applied to the gate. It shows the differences of change in source drain voltage by means of low conductance state and high conductance state. It shows the delay of threshold voltages. The delay time of low conductance state and high conductance state by the impedances effect shows 3[.mu.sec] and 1[.mu.sec] respectively.

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초음파 적용방식에 따른 근-근막 발통점의 압통각 역치 변화 (The Change of Pressure Pain Threshold of Myofascial Trigger Points by Ultrasound Application Method)

  • 이정우;윤세원
    • 대한임상전기생리학회지
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    • 제1권2호
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    • pp.61-68
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    • 2003
  • The purpose of this study was to compare the application method of ultrasound on the alteration of pressure pain threshold of myofascial trigger points. We used thirty patients with mayofascial pain syndrome in upper trapezius. Participants classified according to each group in non noxious dose, noxious dose by the ultrasound. The test was measured continuously pre test, post-test by algometer. The following results were obtained; 1. Pressure pain threshold were significantly increased in non-noxious dose and noxious dose group(p<.001). 2. In noxious dose group, pressure pain threshold were more significantly increased than non-noxious dose group(p<.001). These results lead us to the conclusion that non-noxious dose and noxious dose were significantly increased pressure pain threshold of upper trapezius trigger points. Therefore, a further direction of this study will be to provide more evidence that noxious dose have more effect on pressure pain threshold of myofascial trigger points.

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고려수지기맥 레이저 자극의 압통 역치상승 효과 (Increasing Effect of Laser Stimulation to Koryo-Hand Acupuncture Points on Experimental Pressure Threshold)

  • 박보경;이종은;송병철;이진복;안덕현
    • 한국전문물리치료학회지
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    • 제5권2호
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    • pp.1-14
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    • 1998
  • This study was conducted to examine the increasing effects of Ga-As-Al laser Koryo-hand acupuncture on experimental pressure threshold. Forty healthy subjects (female=20. male=20) aged 21 to 30 years were randomly assigned to two treatment groups with same ratio in sex. The subjects in the experimental group (n=20) received Ga-As-Al laser stimulation, and those in the control group (n=20) received sham stimulation on appropriate Koryo-hand acupuncture points M10 on the left hand which is reflex point of upper trapezius portion. Experimental pressure threshold at the contralateral upper trapezius was determined with a pressure algometer and Galvanic Skin Response (GSR) before and after treatment. The change of pressure threshold between pretreatment and posttreatment in the experimental group was greater than that in the control group (p<0.05). The result indicates that Ga-As-Al laser Koryo-hand acupuncture increases experimental pressure threshold and suggests that it is an effective noninvasive pain management technique.

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2상계 스테인리스강 용접부의 피로크랙 전파특성 (II) -하한계치 근접에서의 전파특성- (Fatigue Crack Propagation Characteristics of Duplex-Stainless Steel Weldments (II) -Crack Propagation on Near-Threshold Region-)

  • 권종완;김상대;이택순
    • 대한기계학회논문집
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    • 제13권1호
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    • pp.115-124
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    • 1989
  • 본 연구에서는 2상계 스테인리스강의 모재,용접재 및 용접후 열처리재 3종류의 경우에 대하여 피로크랙 전파특성을 피로크랙의 하한계치 근방에서 금속조직적인 영향을 검토하기 위하여, 각 조건에 대한 피로크랙 전파속도의 하한 계치를 구하였고 피로식검후의 파단면을 주사전자현미경(SEM)으로 관찰하였다. 용접재에 대하여는 용착부 부근 용접열영향부의 입경측정, .alpha./.gamma.상의 체적비교율의 변화량 측정 및 용접재와 용접후열처리재의 잔유응력분포측정을 통하여 피로크랙의 하한계특성에 미치는 여러가지 영향인자에 대하여 검토하였다.