• 음성과학
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• 제12권1호
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• pp.107-119
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• 2005

The current study considers that the distinctive acoustic properties and variations in the closed plateau are realized by four different pitch accents(/Hi*_ H*/ or /Hi*_$h*_f$ for an emphatic phrase and /hi*_ H*/ for a neutral phrase) in an intermediate phrase in the French intonational structure. Thus, an attempt is made to define the acoustic property of the CP in the ip according to the duration time and pitch range, while different combinations of the four pitch accents of the CP are used to explain the way a speaker will highlight. The duration time of the CP was measured at about 0.67 sec. for males and 0.75 sec. for females. The duration properties of the plateau in the CP were found to control the pitch range based on two different prominent pitch accents, which appeared in more than two APs. Therefore, the ip was identified as having a hierarchical level in the French intonational structure, along with the AP and IP. In addition, the CP in the ip was used as a specific location to explain the pragmatic meaning of the rhythm using the two acoustic factors and different combinations of the four pitch accents.

• 대한전자공학회논문지
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• 제21권6호
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• pp.1-6
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• 1984

본 논문은 주파수에 의존하는 감쇠를 보상하고 해석신호의 크기를 이용하여 충실하게 포락선 검파를 행하므로써 거리분해능의 향상을 가져을 수 있음을 다룬다. 해석신호의 크기를 계산하는 것이 재래적 방식에 비해서 나은 결과를 보이고 있으며 또한 제안된 방식이 A-mode에서 근접한 두 경계면을 전술한 방식들보다 더 잘 구분할 수 있음을 알 수 있다. 실험결과 3.5MHz의 트랜스듀서를 사용하여 0.5mm의 거리분해능을 얻었다. 이 방식은 의료나 비파괴 검사에 응용될 수 있을 것이다.

• 센서학회지
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• 제17권1호
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• pp.41-52
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• 2008

In this paper, a circuit analysis of the complementary CMOS active pixel and readout circuit is carried out. Complementary pixel structure which is different from conventional 3TR APS structure is consist of photo diode, reset PMOS, several NMOSs and PMOSs sets for complementary signals. Photo diode is modelled with Medici device program. HSPICE was used to analyze the variation of the signal feature depending on light intensity using $0.5{\mu}M$ standard CMOS process. Simulation results show that the output signal range is from 0.8 V to 4.5 V. This signal range increased 135 % output dynamic range compared to conventional 3TR pixel in the condition of 5 V power supply.

• 대한기계학회논문집B
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• 제27권6호
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• pp.693-700
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• 2003

The effect of the configuration of the nozzle and the impinging surface on the characteristics of the hole-tones has been experimentally investigated. It is found that the plate-tone is a special case of hole-tones, where the hole diameter is zero. The jet velocity range for hole-tones is divided into the low velocity region associated with laminar jet and the high velocity region with turbulent jet. The frequency of the tone is that for the shear layer instability at the nozzle exit or that attainable by a cascade of vortex pairing process with increase of the impinging distance. When the distance is longer than one diameter the frequency decreases to the terminal value near the preferred frequency of the column mode instability, in the range 0.23< $St_d$<0.53, where $St_d$ is the Strouhal number defined by $fd/U_J$, f the frequency, d the nozzle diameter, and $U_J$ the exit velocity. While the convection speed of the downstream vortex, in the present study, is almost constant at low-speed laminar jet, it increases with distance at high-speed turbulent jet. As the frequency increases, the convection speed decreases in the low frequency range corresponding to the preferred mode, in agreement with the existing experimental data for a free jet.

• 한국안전학회지
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• 제11권3호
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• pp.81-88
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• 1996

In order to investigate the electrical properties of transformer oils for large power, the characteristics of AC and Impulse breakdown in gap length of 1.0~2.5mm and that of volume resistivity were researched in temperature range of 20~$100^{\circ}C$. An geometrical capacitance of electrode with coaxial cylindrical shape for measuring the volume resistivity was 16pF, and highmegohm meter with model no. VMG-1000 was used, and also the applied voltage were DC 100, 250 and 500V. In the dependance of breakdown characteristics due to electrode gap length, it was confirmed that breakdown voltage was nearly uniform by volume effect according to the increase of gap. In the characteristics for AC breakdown, the dielectric strength was increased to $90^{\circ}C$ but decreased over $90^{\circ}C$, and also in case of impulse breakdown, it was increased to 7$0^{\circ}C$ and at dated $70^{\circ}C$ over in temperature range. The calculated mobility of oils in the characteristics for impulse breakdown were about $10^{-5}$~$10^{-4}cm^2/V{\cdot}S$, and the value of volume resistivity was almost invariable in low temperature range, regardless of voltage by the stable thermal properties, and it indicated a peak at $50^{\circ}C$ and had a sudden change to decrease over that temperature, and also the value of volume resistivity in 250V/mm at $80^{\circ}C$ is suitable for the International electrical standards, it was confirmed.

• 대한족부족관절학회지
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• 제8권2호
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• pp.191-194
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• 2004

Purpose: Anatomic configuration of the ankle joint is useful information during various ankle procedures. This study was prospectively designed to investigate the sagittal inclination pattern of the ankle joint. Materials and Methods: Lateral standing ankle radiographs from one-hundred people (age: $17{\sim}68$, M:F=45:55) and magnetic resonance (MR) sagittal ankle images from twenty-four people (age: $16{\sim}65$, M:F=14:10) were studied. Post-traumatic, arthritic, or grossly deformed ankles at any reason were excluded. The posterior inclination angle (PIA) of the distal tibia was measured and compared between the lateral and the medial segment. Results: On plain radiographic data, the average PIA of the distal tibia was $6.14^{\circ}{\pm}3.56^{\circ}$ (range $0^{\circ}$ to $14^{\circ}$) in the lateral segment and $13.16^{\circ}{\pm}3.05^{\circ}$ (range $6^{\circ}$ to $22^{\circ}$) in the medial segment. On MR imaging data, the average PIA of the distal tibia was $5.08^{\circ}{\pm}4.26^{\circ}$ (range $1^{\circ}$ to $10^{\circ})$ in the lateral segment and $10.16^{\circ}{\pm}4.87^{\circ}$(range $5^{\circ}$ to $17^{\circ}$) in the medial segment. The PIA between two segments was significantly different. Conclusion: The sagittal configuration of the medial area ankle joint and the lateral area ankle joint has difference in the degree of posterior inclination and shape of curvature.

• 대한약리학회지
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• 제11권2호
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• pp.41-46
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• 1975

The isolated strips of tortoise intestine are evaluated as a test organ for bioassay of prostaglandin $E_1$. This preparation responded highly sensitively to $PGE_1$ and $PGE_2$ in picogram concentration range. The mean slope and the value of precision index among the doses of 0.1, 0.3 and 0.5ng/ml in final concentration were 37.7 and 0.143, respectively. And this was relatively insensitive to different prostaglandins; $E_1/E_2{\gtrsim}1$, $E_1/A_2{\sim}50$ and $E_1/F_{2\alpha}{\sim}100$, and showed the dual responses to 5-hydroxytryptamine and histamine; initial contraction followed by relaxation. The dose-ratio inducing the relative equal contraction height for $PGE_1$, acetylcholine, caerulein, angiotensin and barium chloride was 0.4 : 50 : 25 : 10 : 100 in this order. These results suggest that the intestinal strips of the tortoise are suitable for bioassay of prostaglandin $E_1$ and $E_2$ between the doses of 0.1 and 1.0 ng/ml level in the tissue extracts.

• 한국결정성장학회:학술대회논문집
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• 한국결정성장학회 1998년도 PROCEEDINGS OF THE 14TH KACG TECHNICAL MEETING AND THE 5TH KOREA-JAPAN EMGS (ELECTRONIC MATERIALS GROWTH SYMPOSIUM)
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• pp.39-43
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• 1998

Single crystals of{{{{ { Zn}_{ 1-x} {Mn }_{x }{Te} }}}} with x=0.3-0.6 were prepared by the standard Bridgeman method. Diffuse neutron diffraction intensities due to the short range magnetic ordering is found in the vicinities of 1 1/2 0 reciprocal point and its equivalent point, indicating that the magnetic correlation of the clusters is the type III antiferromangetic one do the F-type Bravais class crystals, being identical with that of {{{{{ Cd}_{ 1-x} {Mn }_{x }Te }}}}. Neutron inelastic scattering measure-ment has been performed for {{{{{ Zn}_{ 0.6} { Mn}_{ 0.4}Te }}}} sample using the cold neutron spectrometer. AGNES. High resolution measurement with the energy resolution of {{{{ TRIANGLE E= +- .01meV}}}} was carried out in the temperature range from 10K to the ambient. Critical scattering, closely related with the spin glass transition, has been observed for the first time in this semimagnetic semi-conductor. The critical scattering is observed at temperatures in the vicinity of the spin glass transition temperature, 17K. The scattering is observed as a kind of quasielastic scattering in the reciprocal range where the elastic magnetic diffuse scattering has been observed, e.g., 11/20 reciprocal point, indicating the spin fluctuation has dynamic components in this material. Photoconductivity has been discovered below 150K in {{{{{ Zn}_{ 0.4} {Mn }_{0.6 } Te}}}}. The electric AC conductivity has been increased dramatically under the laser light with the wave lengths of {{{{ lambda =6328,5145 and4880 }}}}$\AA$ ,respectively. After the light was darkened, the conductivity was reduced to the original level after about 2000 seconds at 50K, being above the spin glass transition temperature. This phenomenon is the typical persistent photoconductivity; PPC which was similarly found in {{{{ { Zn}_{ 1-x} { Mn}_{x} Te}}}}.

• 한국해양공학회지
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• 제9권1호
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• pp.92-100
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• 1995

The effect of different anisotropy and stress ratio on fatigue crack propagation behavior was investigated under various stress ratio(R=-0.4, -0.2, 0.2, 0.2, 0.4) using pure titanium sheet used in aerospace, chemical and food industry. The rack closure behavior under constant load amplitude fatigue crack propagation test was examined. Fatigue crack propagation rate da/dN was estimated in terms of effective stress intensity factor range, $\Delta$K$_{eff}$, regardless of various stress ratio but was influenced by anisotropy. Also, it was found that the effect of anisotropy was considerably decreased but still not negligible when he da/dN was evaluated by a conventional parameter, $\Delta$$K_{eff}$/E and when the modified da/dN.$\sqrt{\varepsilon}_f$ was evaluated by $\Delta$$K_{eff}$/E. On the other hand, da/dN could be evaluated uniquely by effective new parameter, $\Delta$K$_{eff}$/$sigma_{ys}$, regardless of anisotropy, as int he following equation da/dN=C''[\frac{{\Delta}K_{eff}}{{\sigma}_{ys}}]^{n''}. And effective stress intensity factor range ratio, U was estimated by the following equation with respect to the ratio of reversed plastic zone size, $\Delta r_{p}$ to monotonic plastic zone size, $r_p$ regardless of stress ratio and anisotropy. U=-4.45$(\Delta r_{p}/r_{p})^{2}$+4.1$(\Delta r_{p}/r_{p})$+0.245_{p})$+0.245

• 한국세라믹학회지
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• 제41권11호
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• pp.858-863
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• 2004

본 연구는 입방정 L $a_{2}$ 3/Ti $O_{2.84}$ 세라믹스의 전기전도율, 열기전력 그리고 자기적 특성에 대하여 조사하였다. 350 K 이하의 은도영역에서의 입방정 L $a_{2}$ 3/Ti $O_{2.84}$ 세라믹스의 열기전력은 음으로 나타났다 열기전력은 온도의 증가와 더불어 선형적으로 증가하여 A+BT의 형태로 표현가능 하였으며, Emin과 Wood가 제안한 모델과 잘 일치하였다. 이와 같은 열기전력의 온도의존성은 L $a_{2}$ 3/Ti $O_{2.84}$ 세라믹스의 전도 carrier가 small polaron임을 의미한다. L $a_{2}$ 3/Ti $O_{2.84}$ 세라믹스는 실온 이하의 특정온도에서 variable range hopping에서 small polaron hopping으로 변화하였다. 저온영역에서는 직류전도 기구해석은 Mott의 접근방식을 이용하였다. Mott의 보조변수 해석결과 Fermi면에서의 상태밀도 [N( $E_{F}$)]는 3.18${\times}$$10^{20}$ $cm^{-3}$e $V^{-1}$이었으며, 무질서에너지 $W_{d}$는 0.93로 고온에서의 활성화 에너지 보다 매우 크다. 200K와 300K온도 범위에서 log($\sigma$T)와 1/T의 직선 관계가 존재 하였으며, small polaron의 hopping energy는 0.15 eV였다.