• Title/Summary/Keyword: $f_T$

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PROBABILITIES OF ANALOGUE OF WIENER PATHS CROSSING CONTINUOUSLY DIFFERENTIABLE CURVES

  • Ryu, Kun Sik
    • Journal of the Chungcheong Mathematical Society
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    • v.22 no.3
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    • pp.579-586
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    • 2009
  • Let $\varphi$ be a complete probability measure on $\mathbb{R}$, let $m_{\varphi}$ be the analogue of Wiener measure over paths on [0, T] and let f(t) be continuously differentiable on [0, T]. In this note, we give the analogue of Wiener measure $m_{\varphi}$ of {x in C[0, T]$\mid$x(0) < f(0) and $x(s_0){\geq}f(s_{0})$ for some $s_{0}$ in [0, T]} by use of integral equation techniques. This result is a generalization of Park and Paranjape's 1974 result[1].

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OSCILLATION CRITERIA OF DIFFERENTIAL EQUATIONS OF SECOND ORDER

  • Kim, Rae Joong
    • Korean Journal of Mathematics
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    • v.19 no.3
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    • pp.309-319
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    • 2011
  • We give sufficient conditions that the homogeneous differential equations : for $t{\geq}t_0$(> 0), $$x^{{\prime}{\prime}}(t)+q(t)x^{\prime}(t)+p(t)x(t)=0,\\x^{{\prime}{\prime}}(t)+q(t)x^{\prime}(t)+F(t,x({\phi}(t)))=0$$, are oscillatory where $0{\leq}{\phi}(t)$, 0 < ${\phi}^{\prime}(t)$, $\lim_{t\to{\infty}}{\phi}(t)={\infty}$. and $F(t,u){\cdot}sgn$ $u{\leq}p(t)|u|$. We obtain comparison theorems.

A Performance Equation of Bath Tubs (욕조의 보온성능연구)

  • Lee, Byung-Ho;Suh, Jung-Il
    • The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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    • v.10 no.1
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    • pp.1-11
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    • 1981
  • In this paper, a new performance equation of bath tubs has been derived, which is very characteristically illuminating and in good agreement with experiments : $$T=T_{\infty}+(T_0-T_{\infty})e-\frac{k(A'_f+A_0)}{Mc_{P{\Delta}x}t$$, where $T_{\infty}$ is the temperature of the bathroom, $T_0$ that of the bathwater at t=0, k the overall heat conductivity of the tub- wall, $A'_f$ the equivalent surface area to the wall, $A_0$ the submerged area of the tub-wall, M mass of the bath-water, $C_p$ the specific heat of the bathwater and ${\Delta}x$ the thickness of the tub-wall. Here the equivalent-free surface area is written as $$A'_f=mA_f,\;m=const.(1-{\phi})^{0.88}$$ : where m is a numerical factor which is determined by a simple experiment and some calculation, {\phi}$ the relative humidity and $A_f$ the real free-surface area. From this study, it has been clarified that cooling of bath-water is mainly due to mass-transfer through evaporation from the free surface and conductive heat loss through the tub-wall is minor, which rather gaily mock at common sense. The effect of keeping bathwater warn by increase of the tub-wall thickness is also analyzed by a new idea of the thickness gain factor.

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ASYMPTOTIC EQUIVALENCE IN VARIATION BETWEEN NONLINEAR DIFFERENTIAL SYSTEMS

  • Song, Se-Mok
    • Journal of applied mathematics & informatics
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    • v.12 no.1_2
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    • pp.429-436
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    • 2003
  • We study the asymptotic equivalence between the nonlinear differential system $\chi$'(t) = f(t, $\chi$(t)) and its variational system ν'(t) = f$\chi$(t, 0)ν(t) by using the comparison principle and notion of strong stability.

The Effect of Tonsillectomy and Adenoidectomy on Acoustic Factors (구개편도 및 아데노이드 절제술이 음향학적 자질에 미치는 영향)

  • 임성태;손진호;유정운;강지원;이현석;신승헌;박재율
    • Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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    • v.9 no.1
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    • pp.38-42
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    • 1998
  • It has been reported that Tonsillectomy & Adenoidectomy(T & A) resulted in the change of voice by structural changes directly to the vocal track. We studied the effect of T & A on the voice of patients comparing the pre-operative to the post-operative voice. It was performed using a Computerized Speech Lab(CSL50) which is currently used as a method for voice analysis. Forty-five patients who had T&A, aging from 3 to 42 years old, took part in studies and wert evaluated for voice changes and the degree of formant changes of four basic vowels, /a/, /i/, /o/, and /u/. They were evaluated pre-operatively and post-operatively one month later using MDVP, CSL program of CSL50. The results obtained were as follows ; In using MDVP, there were some differences between pre-operative and post-operative shimmer measures within the normal range but other acoustic measures(Fo, jitter, NHR) show no significant differences(p>0.05). F3 of /a/ and /o/ were significantly decreased(p<0.05) and F2, F3 of /i/ were increased(p>0.05) in patients who only had Tonsillectomy in doing CSL spectrogram. For the patients who had T & A, Fl and F3 of /a/, F3 of /i/, Fl, F2 and F3 of /o/ were decreased with significant increase in F1 and F2 of /i/(p<0.05).

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STATISTICAL STUDY ON DENTAL CARIES INCIDENCES OF INLAND SCHOOL CHILDREN IN CHOONG CHUNG BUK DO OF KOREA (한국 내륙지방 충주.중원지역 학동의 치아우식발생빈도에 관한 통계학적 연구)

  • Chung, Tae-Hyoung;Lee, Jong-Gap
    • Journal of the korean academy of Pediatric Dentistry
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    • v.11 no.1
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    • pp.181-189
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    • 1984
  • 1,840 school children aged 6 to 13 years who live in inland area in CHOONG CHUNG BUK DO were surveyed epidemiologically on the dental caries prevalence. The results were as follows; 1. The prevalence of dental carries was 76.35 percentage in male, 76.15 percentage in female, and 76.25 percentage in both sexes. 2. d.m.f rate was 77.72 percentage in male, 80.07 percentage in female, and 78.86 percentage in both sexes. D.M.F rate was 30.73 percentage in male, 38.52 percentage in female, and 34.51 percentage in both sexes. 3. d.m.f.t. rate and index was 27.94 percentage,2.55T, and d.m.f.s. rate & index was 13.62 percentage, 6.22T. 4. D.M.F.T rate & index in permanent teeth was 4.86 percentage,0.72T, and D.M.F.S. rate & index was 1.20 percentage,0.89T. 5. The filling rate was 3.90 percentage in decidious teeth, 2,00 percentage in permanent teeth.

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THE FRACTIONAL WEAK DISCREPANCY OF (M, 2)-FREE POSETS

  • Choi, Jeong-Ok
    • Bulletin of the Korean Mathematical Society
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    • v.56 no.1
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    • pp.1-12
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    • 2019
  • For a finite poset $P=(X,{\preceq})$ the fractional weak discrepancy of P, denoted $wd_F(P)$, is the minimum value t for which there is a function $f:X{\rightarrow}{\mathbb{R}}$ satisfying (1) $f(x)+1{\leq}f(y)$ whenever $x{\prec}y$ and (2) ${\mid}f(x)-f(y){\mid}{\leq}t$ whenever $x{\parallel}y$. In this paper, we determine the range of the fractional weak discrepancy of (M, 2)-free posets for $M{\geq}5$, which is a problem asked in [9]. More precisely, we showed that (1) the range of the fractional weak discrepancy of (M, 2)-free interval orders is $W=\{{\frac{r}{r+1}}:r{\in}{\mathbb{N}}{\cup}\{0\}\}{\cup}\{t{\in}{\mathbb{Q}}:1{\leq}t<M-3\}$ and (2) the range of the fractional weak discrepancy of (M, 2)-free non-interval orders is $\{t{\in}{\mathbb{Q}}:1{\leq}t<M-3\}$. The result is a generalization of a well-known result for semiorders and the main result for split semiorders of [9] since the family of semiorders is the family of (4, 2)-free posets.

A Comparative Study on the Injection Rate Characteristics of Conventional and F-T Synthetic Gasoline Under Various Fuel Temperatures (다양한 연료온도 조건에 있어서의 기존 가솔린과 F-T합성 가솔린의 분사율 특성 비교 연구)

  • Jihyun Son;Gyuhan Bae;Seoksu Moon
    • Journal of ILASS-Korea
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    • v.28 no.3
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    • pp.143-149
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    • 2023
  • Amidst the drive towards carbon neutrality, interest in renewable synthetic e-fuels is rising rapidly. These fuels, generated through the synthesis of atmospheric carbon and green hydrogen, offer a sustainable solution, showing advantages like high energy density and compatibility with existing infrastructure. The physical properties of e-fuels can be different from those of conventional gasoline based on manufacturing methods, which requires investigations into how the physical properties of e-fuels affect the fuel injection characteristics. This study performs a comparative analysis between conventional and Fischer-Tropsch (F-T) synthetic gasoline (e-gasoline) across various fuel temperatures, including the cold start condition. The fuel properties of F-T synthetic and conventional gasoline are analyzed using a gas chromatography-mass spectrometry technique and the injection rates are measured using a Bosch-tube injection rate meter. The F-T synthetic gasoline exhibited higher density and kinematic viscosity, but lower vapor pressure compared to the conventional gasoline. Both fuels showed an increase in injection rate as the fuel temperature decreased. The F-T synthetic gasoline showed higher injection rates compared to conventional gasoline regardless of the fuel temperature.

The Quality of Life Analysis in Patients with Cervical Cancer (자궁경부암 환자의 삶의 질 분석)

  • Kim, Yoon-Sook;Kim, Boon-Han
    • Journal of Hospice and Palliative Care
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    • v.7 no.1
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    • pp.8-16
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    • 2004
  • Purpose: The porpose of this descriptive study was grasp the QOL (Quality of Life) of cervix cancer patient and to analysis QOL (Quality of Life) by stage of disease, type of treatment and de me graphic characteristics Methods: Data were collected from 67 patients with cervical cancer from 3 General Hospitals from March 15 to June 4 using The "QOL (Quality of Life)-Cancer Version" inventory made by Ferrell et al (1995). The data were analysed by using SPSS $PC^+$ program including t-test, ANOVA, and Scheffe test. Results: Progressing stage of disease and QOL, the significant between the progressing stage of disease and QOL was significant (F=5.06, P=.003). The degree of difference between the progresstion of the stage of the disease and each item in the test was physical well-being (F=3.97 P=.012), the items of psychological well-being (F=3.91, P=.013), the items of social well-being (F=4.96, P=.004). It show a significant difference, but the item of spiritual well-being (F=1.36, P=.262) was not significant difference. The significance between the type of treatment and QOL was insignificant. The degree of difference between each area of life was the psychological well-being (t=-2.14, P=.037), the social well-being (t=-2.15, P=.036). But the physical well-being (t=-.93, P=.356), the spiritual well-being (t=.73, P=.469) was insignificant. Conclusion: As a result, The QOL of patients with cervical cancer is differentiated by the stage of disease, the type of treatment, and the demographic data. Therefore, there is a need to apply nursing intervention to patients with cervical cancer by considering the stage of disease, the type of treatment, and the demographic data.

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The ionization energy and lattice parameters of Co- and Ce-doped cubic zirconia (YSZ) single crystal (Co와 Ce를 첨가한 큐빅지르코니아(YSZ) 단결정의 이온화에너지 및 격자상수)

  • Seok, Jeong-Won
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.20 no.4
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    • pp.159-163
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    • 2010
  • Co-(0.5 mol%) and Ce-(0~0.3 mol%) doped cubic zirconia ($ZrO_2:Y_2O_3$=64:36 mol%) single crystals grown by a skull melting method were heat-treated in $N_2$ at $1200^{\circ}C$ for 3 hrs. The brown-colored as-grown single crystals were changed into either green or blue color after the heat treatment. Before and after the heat treatment, the YSZ (yttriastabilized zirconia) single crystals were cut for wafer form (${\phi}7mm{\times}t2mm$) and round brilliant cut ($\phi$ 12 mm). The optical and structural properties were examined by UV-VIS spectrophotometer and X-ray diffraction. Absorption by $Ce^{3+}(^2F_{5/2},\;_{7/2}(4f){\rightarrow}^2T_g(5d^1)),\;Co^{2+}(^4A_2(^4F){\rightarrow}^4T_1(^4F)$ or $^4T_1(^4P))$ and $Co^{3+}$, change of ionization energy and lattice parameter were confirmed.