• Title/Summary/Keyword: above-threshold

Search Result 521, Processing Time 0.027 seconds

Mentolabial angle and aesthetics: a quantitative investigation of idealized and normative values

  • Naini, Farhad B.;Cobourne, Martyn T.;Garagiola, Umberto;McDonald, Fraser;Wertheim, David
    • Maxillofacial Plastic and Reconstructive Surgery
    • /
    • v.39
    • /
    • pp.4.1-4.7
    • /
    • 2017
  • Background: This study is a quantitative evaluation of the influence of the mentolabial angle on perceived attractiveness and threshold values of desire for surgery. Methods: The mentolabial angle of an idealized silhouette male Caucasian profile image was altered incrementally between $84^{\circ}$ and $162^{\circ}$. Images were rated on a Likert scale by pretreatment orthognathic patients (n = 75), lay people (n = 75) and clinicians (n = 35). Results: A mentolabial angle of approximately $107^{\circ}$ to $118^{\circ}$ was deemed the most attractive, with a range of up to $140^{\circ}$ deemed acceptable. Angles above or below this range were perceived as unattractive, and anything outside the range of below $98^{\circ}$ or above $162^{\circ}$ was deemed very unattractive. A deep mentolabial angle ($84^{\circ}$) or an almost flat angle ($162^{\circ}$) was deemed the least attractive. In terms of threshold values of desire for surgery, for all groups, a threshold value of ${\geq}162^{\circ}$ and ${\leq}84^{\circ}$ indicated a preference for surgery, although clinicians were least likely to suggest surgery. The clinician group was the most consistent, and for many of the images, there was some variation in agreement between clinicians and lay people as to whether surgery is required. There was even more variability in the assessments for the patient group. Conclusions: It is recommended that in orthognathic and genioplasty planning, the range of normal variability of the mentolabial angle, in terms of observer acceptance, is taken into account as well as threshold values of desire for surgery. The importance of using patients as observers in attractiveness research is stressed.

Power extraction efficiency and lasing wavelength distribution of complex-coupled DFB lasers for various facet reflectivity combinations and coupling coefficient ratios (양 단면 반사율 조합과 결합 계수 비에 따른 Complex-Coupled DFB 레이저 다이오드의 파워 추출 효율과 발진 파장 분포)

  • 김상택;김부균
    • Korean Journal of Optics and Photonics
    • /
    • v.15 no.2
    • /
    • pp.149-157
    • /
    • 2004
  • We have calculated the power extraction efficiency and the lasing wavelength distribution of complex-coupled(CC) DFB lasers above threshold for various|$\chi$L| and facet reflectivity combinations, and we have compared the results with those at threshold. Also, we have investigated the effect of coupling coefficient ratio(CR) and the reflectivity of AR facet on the power extraction efficiency and the lasing wavelength distribution. At threshold, the single mode yield as a function of power extraction efficiency of in-phase(IP) CC DFB lasers is the same as that of anti-phase(AP) CC DFB lasers. Above threshold, however, the single mode yield as a function of power extraction efficiency of IP CC DFB lasers is much larger than that of AP CC DFB lasers. For IP CC DFB lasers, AR-HR combination has high single mode yield and large power extraction efficiency compared to other facet combinations. IP CC DFB laser with AR-HR combination for |$\chi$L|of 0.8 has the highest single mode yield and largest power extraction efficiency above threshold among the cases considered. For AR-HR combination, as CR increases and the reflectivity of AR facet decreases, both single mode yield and power extraction efficiency increase due to the reduction of the spatial hole burning effect. For AR-HR combination, the lasing wavelength of CC DFB laser has distributed over the stopband of DFB. As CR increases, the lasing wavelength concentrates on the long wavelength side for IP CC DFB laser, while on the short wavelength side for AP CC DFB laser. As |$\chi$L| increases, the width of the wavelength distribution decreases and the lasing wavelength moves to the long wavelength side.

Single mode yield analysis of complex-coupled DFB lasers above threshold for various coupling coefficient ratios and facet reflectivity combinations (문턱 전류 이상에서 Complex-Coupled DFB 레이저 다이오드의 여러 가지 결합 계수 비와 양 단면 반사율 조합에 따른 단일 모드 수율 해석)

  • 김부균;김상택;전재두
    • Korean Journal of Optics and Photonics
    • /
    • v.14 no.5
    • /
    • pp.521-529
    • /
    • 2003
  • For complex-coupled (CC) DFB lasers, we found that there might be little correlation between the single mode yields at threshold and above threshold. At threshold, the single mode yield considering f number of in-phase (IP) CC DFB lasers is the same as that of anti-phase (AP) CC DFB lasers. However, the single mode yield as a function of injection current above threshold of IP CC DFB lasers is much different from that of AP CC DFB lasers. In the case of IP CC DFB lasers, the single mode yield increases as the coupling coefficient ratio (CR) increases, while, in the case of AP CC DFB lasers, the single mode yield decreases rapidly regardless of CR as the injection current increases. In the case of AR-HR combinations, the effect of AR ref1ectivity on the single mode yield increases as the coupling strength decreases. As the coupling strength decreases, the CR at which the increase rate of the single mode yield starts to decrease, increases, and the maximum single mode yield increases. Single mode yields of AR-HR and AR-AR combinations are larger than those of AR-CL and CL-CL combinations.

The Characteristics of Conduction rind Switching Voltage for As-Ge-Te Memory Switching Device (As-Ge-Te 메모리 스위칭 소자의 전도 및 스위칭 전압 특성)

  • 이병석;이현용;이영종;정흥배
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 1995.11a
    • /
    • pp.67-70
    • /
    • 1995
  • Amorpous As$\sub$10/Ge$\sub$15/Te$\sub$75/ device shows the memory switching characterisite under d.c. bias. In bulk material, a-As$\sub$10/Ge/sub15/Te$\sub$75/s switching voltage range is above 100 volts. Our purposes in this gaudy are decreasing a switching threshold voltage, finding the properties of d.c., a.c. conduction, and the characterisitics of switching threshold voltage fur a-As$\sub$10/Ge$\sub$15/Te$\sub$75/. As the results, the d.c.and a.c. conductivities increase with temperature. From the data of conductivity, various electrical and physical properties are obtained experimentally. The switching threshold voltages decrease with increasing annealing temperature and time, but increase with increasing film thickness and distance of electrode for d.c. bias.

  • PDF

Characteristics of N-and P-Channel FETs Fabricated with Twin-Well Structure (Twin-well 구조로 제작된 N채널 및 P채널 FET의 특성)

  • 김동석;이철인;서용진;김태형;김창일;장의구
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 1992.05a
    • /
    • pp.86-90
    • /
    • 1992
  • We have studied the characteristics of n-and p-channel FETs with submicron channel length fabricated by twin-well process. Threshold voltage variation and potential distribution with channel ion implantation conditions and impurity profile of n-and p-channel region wee simulated using SUPREM-II and MINIMOS 4.0 simulater, P-channel FET had buried-channel in the depth of 0.15 $\mu\textrm{m}$ from surface by counter-doped boron ion implantation for threshold voltage adjustment. As a result of device measurement, we have obtained good drain saturation characteristics for 3.3 [V] opreation, minimized short channel effect with threshold voltage shift below 0.2[V], high punchthrough and breakdown voltage above 10[V] and low subthreshold value.

  • PDF

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

  • Keum, C.H.;Kwun, S.I.
    • Journal of the Korean Society for Heat Treatment
    • /
    • v.3 no.2
    • /
    • pp.37-44
    • /
    • 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.

  • PDF

Photodissociation to Several Atomic Terms: Near-threshold Resonance for Production of O($^3$P) and O($^1$D) in OH Photodissociation

  • Lee, Seong Yeol
    • Bulletin of the Korean Chemical Society
    • /
    • v.22 no.12
    • /
    • pp.1333-1336
    • /
    • 2001
  • A theoretical analysis is presented for the multichannel type resonance at energies above the dissociation threshold to O(1D) in the photodissociation of OH. Dissociations to both oxygenic terms O(3P) and O(1D) are treated. Total cross sections for producing these oxygen terms display asymmetric resonance due to the quantum interference resulting from complicated interplay of electronic states correlating to these two oxygenic terms. The branching ratios of O(3Pj, j = 0, 1, 2), and the vector properties of O(3Pj, j =0,1,2) and O(1D) display extensive changes near the threshold resonance as the result of the interactions among the electronic states correlated with O(3P) and O(1D).

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

  • Ke Chen;Jongheuk Kim
    • East Asian Economic Review
    • /
    • v.28 no.2
    • /
    • pp.175-219
    • /
    • 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.

IV ECM Threshold Cointegration Tests and Nonlinear Monetary Policy in Korea (분계점 공적분 검정법을 사용한 한국의 비선형 테일러 통화정책 검증)

  • Enders, Walter;Lee, Junsoo;Strazicich, Mark C.
    • KDI Journal of Economic Policy
    • /
    • v.29 no.2
    • /
    • pp.135-157
    • /
    • 2007
  • The goal of this paper is to examine the validity of nonlinear Taylor rules in Korea. To perform our tests, we utilize new IV ECM threshold cointegration tests that are invariant to nuisance parameters. The new tests have a standard chi-square distribution and the same critical values can be used throughout. This is in contrast to OLS ECM threshold cointegration tests, which depend on nuisance parameters and have nonstandard distributions. After finding significant support for nonlinear cointegration, we find that the Bank of Korea raises the call rate of interest only when inflation is above a threshold rate. We additionally find that the Bank of Korea increases the call rate of interest to possibly counter domestic currency deprecation only when the rate of currency deprecation exceeds a threshold.

  • PDF

Relations between Resonance Structures in Photoionization Spectra in Three-Channel-Systems Studied by Multichannel Quantum Defect Theory

  • Lee, Chun-Woo
    • Bulletin of the Korean Chemical Society
    • /
    • v.33 no.7
    • /
    • pp.2168-2176
    • /
    • 2012
  • Relations between fitted parameters for photoionization spectra both below and above the thresholds in the systems involving 3 channels are obtained using phase-shifted version of the multichannel quantum-defect theory. Analytical continuation of the photoionization cross sections in the form of ${\langle}{\sigma}_{below}{\rangle}_{v_{below}}={\sigma}_{above}$ examined using several representations.