경제적 부가가치(EVA)의 산업별 측정과 유용성 분석

송준기,우태우 세명대학교 2000 世明論叢 Vol.8 No.-

Economic Value Added(EVA) has been used as a new measure of firm's performances. This paper estimates firm's EVA, and then analyses the relationships between EVA and returns of stock through regression methods. Most estimated companies' EVAs show negative values, which implies that most Korean companies have emphasized on the external growth rather than the efficient operations. The regression results show that the relationships between EVA and returns of stock are significant partially.

세라믹 필터의 帶域幅 調整에 관한 硏究

宋埈泰 成均館大學校 1983 論文集 Vol.33 No.-

This paper showed the technique how to change the bandwidth of ceramic filter at will. The resonant mode of trapezoid type ceramic filter is synthesized by the resonant mode of the major side and the minor side independently, so the bandwidth is broadened. In this result if some constants of ceramic filter are known, two port ceramic filter showing a wanted bandwidth can be fabricated easily. In those computer simulations. the bandwidths were changed from 3.2kHz to 6.4 kHz in sample A, and from 5. 1kHz to 10.2 kHz in sample B.

光센서를 利用한 脈波 測定에 관한 硏究

宋埈泰 成均館大學校 科學技術硏究所 1984 論文集 Vol.35 No.2

This paper showed how to observe the blood pressure and to measure the arterial pulses using photo coupler. The photo current detected from the index finger by the photocoupler (EL-1KL_2, HP-3FR2) was amplified by the OP amp., converted to digital data by A/D convertor (ADC 0800) and analized by the microcomputer. This method may be useful in M.E. field because it is the quick and easy way to observe the arterial pulses.

蒼耳子에 대한 면역글로블린E 생성억제 효과

宋昊埈,河顯秀,金台現,辛民敎 대한본초학회 1998 大韓本草學會誌 Vol.13 No.2

We studies inhibitation effect of IgE release in the human B cell line(U266B1) and in the serum and spleen cell of mouse that has been immunized by antigen in order to find antiallergic effect of Fructus Xanthii (FX). We have some findings as below. 1. IgE release in serum was inhibited dose dependently in case of administering FX orally in the mouse immunized. 2. IgE release in serum was inhibited dose dependently in case of injecting FX into abdomen in the mouse immunized. 3. When we take LPS+IL-4 way in the mouse spleen cell, IgE release was less than LPS way. 4. When we take LPS+IL-4 way in the human B cell line (U266B1), IgE release was less than LPS way.

초음파 센서를 이용한 물체 인식에 관한 연구

宋埈泰,辛龍德,張洪寬 成均館大學校 科學技術硏究所 1988 論文集 Vol.39 No.1

The object recognition using the ultrasonic resonator is reconstructed computationally on a CRT. The recognition information is obtained sequentially by the scanning the transmitter-receider unit in twodimension by the fan-beam method. The system consists of the scanning transmitter-receiver unit, step motor for position control, computing part and display unit including a CRT. The distance between sensor and object was measured quickly in each sampling point. The resolution of disk shape of 25cm diameter and the square shape of 25cm x 25cm were 77%, 61% each. The object recognition using the ultrasonic wave was carried out in air.

에너지 트랩 單一 電極 세라믹 필터의 주파수 스펙트럼

宋埈泰,鄭仁永,李鍾德,徐東勳 成均館大學校 科學技術硏究所 1991 論文集 Vol.42 No.1

The thickness -extensional trapped energy mode vibrations are treated analytically. In each program the solution cinsists of a sum the dominant plate eigensolutions for shoted electrodes in the electroded resgion and for zero surface charge in the unelectroded region. The driven thickness solution is also included in the electroded region in the programs of forced vibrations. Combinations of these solutions for the infinite plate, which satisfy the differance equations and boundary conditions on the major surfaces exactry, are then employed in an appropriate variational principle of the linear piezoelectricity in order to satisfy the remaining boundary conditions at the junction between the electroded and unelectroded regions approximately.

초음파 현미경의 음향 렌즈 설계에 관한 연구

宋埈泰,張洪寬 成均館大學校 科學技術硏究所 1992 論文集 Vol.43 No.1

The design of piezoelectric layer and acoustic lens for scanning acoustic microscope is described. Acoustic lens utilizes the principle of optical lens, but it is the concave type in contrast with the optical lens. Mainly, the materials of acoustic lens are composed of ZnO which operates the longitudinal mode and has a large electromechanical coupling constant with the piezoelectric transducer and A1_20_3 which is very hard and whose difference of acoustic velocity is large about the acoustic lens rod. The segment of entire circle(O) must be generally 50˚ which is larger than Rayleigh's critical angle. If θ_max is 50˚ K is 53.33 or 15.74. Thus, according to the frequency of piezoelectric transducer, the radius of top electrode is obtained by formula (4.16). Peizoelectric transducer must be the thickness mode of circular plate, and piezoelectric layer is between λ / 4 and λ/2. And with the frequency of half wavelength of f_o = ω_o/2π = v_o/21_o and the acoustic velocity of v_0, the thickness of 1_0, the thickness of transducer is taken.

9.5/65/35 PLZT를 이용한 Color filtering 특성에 관한 연구

宋埈泰,余東勳,李範熙 成均館大學校 科學技術硏究所 1992 論文集 Vol.43 No.1

In this study 9.5/65/35 PLZT was selected which has the excellent quadratic electro-optic property and slim-loop. It was fabricated by the methods of vacuum hot-pressing and sintering. The electrode of color filter was evaporated using the interdigital type masks. They had the ratio of electrode gaps and the specimen thickness which were 1 : 1, 1.5 : 1, 2 : 1, and 2.5 : 1. Its color filtering characteristics were measured in the range of wavelength 380 to 780[nm] and electric field 0 to 15[kV/cm]. The results shows the relationship between the thickness of specimen, the electrode gap and the maximum RGB transmittance.

에너지 트랩형 압전 세라믹 필터의 분산특성에 관한 연구

宋埈泰,鄭仁永,陳弘範 成均館大學校 科學技術硏究所 1989 論文集 Vol.40 No.1

The energy trapping theories of the ferroelectric ceramic polarized in the thickness direction are analyzed by the same way which was developed by H.F. Tiersten and B.K. Sinha. The dispersion curves of two special cases, one with PZT-7A ceramic and the other with PZT-4 ceramic, are obtained and compared. From the dispersion curves, we can see that the greater piezoelectric coupling coefficient is the wider bandwid bandwidth is. The results of this paper can be used for the selection of materials which have suita-ble bandwidth.

100㎒ 超音波펄스용 ACOUSTIC 사파이어렌즈의 設計

宋埈泰,李鍾德 成均館大學校 科學技術硏究所 1994 論文集 Vol.45 No.1

In this study, the design of Acoustic Sapphire Lens for SAM is described. Also, We are designed directly Acoustic Sapphire Lens for 100MHz acoustic, pulse. The acoustic focus beam can be readily realized by Acoustic Sapphire Lens with a cylindrical concave surface. The design criteria of Acoustic Sapphire Lens include the following three points. (1) effective use of acoustic field distribution in the Fresnel region to determine Acoustic Sapphire Lens' length. (2) suppression of spurious signals caused by the internal reflections in the Sapphire, and Sufficient distance for the Sapphire without overlapping a information signal. (3) spherical aberration and acoustic attenuation of water are considered suitable. Here, Acoustic Sapphire Len's demensions which used in acoustic pulse 100MHz were obtained as following conclusion. Aperture angle θ=45°, Aperture radius R=1.13mm, Focal length f=1.31mm, Sapphire length 1=18mm.