• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제14권7호
• /
• pp.2879-2890
• /
• 2020

In this paper, we study the estimation of angle, range and polarization parameters of a bistatic polarization sensitive frequency diverse array multiple-input multiple-output (PSFDA-MIMO) radar system. The application of polarization sensitive array in receiver is explored. A signal model of bistatic PSFDA-MIMO radar system is established. In order to utilize the multi-dimensional structure of array signals, the matched filtering radar data can be represented by a third-order tensor model. A joint estimation of the direction-of-departure (DOD), direction-of-arrival (DOA), range and polarization parameters based on parallel factor (PARAFAC) algorithm is proposed. The proposed algorithm does not need to search spectral peaks and singular value decomposition, and can obtain automatic pairing estimation. The method was compared with the existing methods, and the results show that the performance of the method is better. Therefore, the accuracy of the parameter estimation is further improved.

• 한국추진공학회:학술대회논문집
• /
• 한국추진공학회 2004년도 제22회 춘계학술대회논문집
• /
• pp.789-794
• /
• 2004

The pressure sensitive paint (PSP) technique has been well established in external flow field. However, there are still unresolved issues in internal flow field. This work was focused on the application to unsteady pressure measurement of fan flow field. The PSP measurement system was established and the image processing software was developed. First, the performance of PSP was investigated at the static cell. Then the unsteady PSP measurement was carried out at fan test facility. PSP data images were acquired from the suction and pressure surface of stator vanes. Pressure distributions on the surface of the stator vane were detected non-intrusively. The issues of image acquisition and image processing were clarified through the practical PSP application to fan flow field.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2001년도 추계학술대회논문집 II
• /
• pp.1376-1383
• /
• 2001

Modem technology depends on the reliability of extremely high technology equipments. In the production of semiconductor wafer, optical and electron microscopes, ion-beam, laser device must maintain their alignments within a sub-micrometer. This equipment requires a vibration free environment to provide its proper function. Especially, lithography and inspection devices, which have sub-nanometer class high accuracy and resolution, have come to necessity for producing more improved giga and tera class semiconductor wafers. This high technology equipments require very strict environmental vibration standard, vibration criteria, in proportion to the accuracy of the manufacturing, inspecting devices. The vibration criteria of high sensitive equipment should be represented in the form of 'exactness' and 'accuracy', because this is used as basic data for the design of building structure and structural dynamics of equipment. This paper deals with the properties of time and frequency domain in order to obtain more improved vibration criteria for high sensitive equipment.

• 한국미생물·생명공학회지
• /
• 제27권1호
• /
• pp.8-14
• /
• 1999

This study was developed to evaluate the growth inhibition effects of cell wall components of Enterococcus faecalis 2B4-1 obtained from feces of neonates against tumor cell lines. Polysaccharide fraction (PS) shown sensitive growth inhibition effect in the cell wall components was isolated and characterized. In growth inhibition effects, residue fractin of whole cell was shown sensitive level of percent survival about 30% when administrated at ehe concentration of 100${\mu}$g/ml, and that was more effective than that of supernatant fraction against the tumor cell lines, SNU-1, 3LL, FARROW and HEC-1-B. Sensitive growth inhibition effects against SNU-1, FARROW and HEC-1-B were performed by whole cell (WC) fraction from Ent. faecalis 2B4-1. Cytoplasm fractin (CP) of WC was shown non-inhibition effect, however, the other part of WC, precipitate of disrupted cell (PD), was sensitive against the tumor cell line mentioned above. Followed by separation to peptidoglycan fraction (PG) and polysaccharide fraction (PS) were all sensitive which the latter was shown more sensitive percent survival than the former. Composed sugars of polysaccharide fraction were determined to D-glucose, L-rhamnose and D-glucosamine, and the rate fo composition was calculated to about 1:1:1 by the data of elemental analysis, IR, TLC and HPLC.

• 한국정보과학회논문지:데이타베이스
• /
• 제32권1호
• /
• pp.12-23
• /
• 2005

지난 10년간 CPU의 속도는 메모리의 속도에 비해 급속한 속도로 발전하였다 그 결과 데이터 베이스 시스템을 포함한 다른 컴퓨터 응용분야에서 메모리의 접근이 병목현상을 일으키게 되었다. 메모리의 접근 속도를 줄이기 위해 캐시 메모리가 도입되었다 하지만 캐시 메모리는 원하는 데이타가 캐시에 옮겨져 있어야 메모리 접근 속도를 줄일 수 있다. 때문에 응용프로그램에서 데이타를 어떤 순서로 액세스 하느냐에 따라 캐시의 활용도가 달라지고 응용프로그램의 성능이 달라지게 된다. 이 시점에서 현재 컴퓨터에서 B+-트리가 T-트리보다 더 빠르다는 사실이 알려졌다. B+-트리가 T-트리보다 캐시를 더 효율적으로 사용하기 때문이다. 또한 B+-트리를 개선하여 캐시를 더욱 효율적으로 사용하는 CSB+-트리(Cache Sensitive B+-tree)가 제안되기도 하였다 본 논문의 목표는 T-트리가 캐시를 효율적으로 사용하도록 새로운 T-트리 구조를 개발하는 것이다. CSB+-트리와 같이 시스템의 L2 캐시를 최대한 활용하며 기존 T-트리가 가지는 장점을 가지는 새로운 CST-트리(Cache Sensitive T-트리)를 설계 개발하고, 실험을 통해 기타 다른 인덱스 구조에 비교하여 CST-트리의 우수성을 보인다.

• 방송공학회논문지
• /
• 제1권1호
• /
• pp.29-34
• /
• 1996

차등적 오류 방지는 전송되는 정보에 따라 채널에서 오류가 발생했을 때 미치는 영향이 다른 것을 이용하여 채널 오류에 민감한 정보를 다른 정보보다 강력하게 채널 오류로부터 보호하는 방법이다. 그러나 채널에서 오류가 없다는 가정하에 LBG 알고리듬으로 설계한 벡터 양자화 신호에 차등적 오류 방지를 그대로 적용할 수 없다. 따라서 본 논문에서는 이러한 벡터 양자화 신호의 전송에서 차등적 오류 방지를 적용할 수 있도록 부호 벡터에 체계적으로 이진 인덱스를 할당하는 기법을 제안하였다. 또한 제안한 기법을 벡터 양자화 한 1차 Gauss-Marcov 신호의 전송에 중요한 정보의 비율을 50%로 하여 적용하였다.

• 대한기계학회논문집B
• /
• 제30권2호
• /
• pp.153-160
• /
• 2006

A technique for measuring surface temperature field in micro scale is newly proposed, which uses temperature-sensitive fluorescent (TSF) dye coated on the surface and is easily implemented with a fluorescence microscope and a CCD camera. The TSF dye is chosen among mixtures of various chemical compositions including rhodamine B as the fluorescent dye to be most sensitive to temperature change. In order to examine the effectiveness of this temperature measurement technique, numerical analysis and experiment on transient conduction heat transfer for two different substrate materials, i. e., silicon and glass, are performed. In the experiment, to accurately measure the temperature with high resolution temperature calibration curves were obtained with very fine spatial units. The experimental results agree qualitatively well with the numerical data in the silicon and glass substrate cases so that the present temperature measurement method proves to be quite reliable. In addition, it is noteworthy that the glass substrate is more appropriate to be used as thermally-insulating locally-heating heater in micro thermal devices. This fact is identified in the temperature measuring experiment on the locally-heating heaters made on the wafer of silicon and glass substrates. Accordingly, this technique is capable of accurate and non-intrusive high-resolution measurement of temperature field in microscale.

• The Korean Journal of Physiology and Pharmacology
• /
• 제1권5호
• /
• pp.477-484
• /
• 1997

Intracellular recordings of oscillatory firing (bursting activity) were obtained from Purkinje cells (PCs) in rat cerebellar slices. Apamin inhibited post-burst hyperpolarizations (PBHs) progressively and finally terminated oscillatory firing activity of PCs. Apamin did not affect the amplitude or duration of the after-hyperpolarization (AHP) between spikes within the burst. In the voltage clamp mode, apamin shifted the whole-cell, quasi-steady state I/V relationship in an inward direction and abolished the zero slope resistance (ZSR) region by blocking outward current. Nickel ($Ni^{2+}$) terminated oscillatory activity and also abolished the ZSR region. However, $Ni^{2+}$ did not have progressive blocking action on the post-burst hyperpolarization before it blocked oscillatory activity. $Ni^{2+}$ blocked an inward current at potentials positive to approximately -65 mV, which was responsible for the ZSR region and outward current at more negative potentials. These data indicated that oscillatory activity of PCs is sustained by a balance between a slow $Ni^{2+}$-sensitive inward current and an apamin-sensitive outward current in the region of ZSR of the whole-cell I/V curve.

• 대한전기학회논문지:전력기술부문A
• /
• 제55권1호
• /
• pp.37-44
• /
• 2006

In this paper we explore the susceptibility of common sensitive loads by voltage sags of power distribution systems. The experimental approach was used for obtaining the susceptibility of single-phase loads and the three-phase induction motor. The experimental result of single-phase loads was transformed to the ITIC(Information of Technology Industry Council) format and used for evaluating the adverse impacts of a individual and repetitive sags using the performance contour of the foreign standard data. In order to assess the impact of voltage sags on three-phase induction motor, also, the experiment was peformed. The experiment was focused on the current, torque, and speed loss of the motor during a voltage sag. For comparing the impacts of individual and repetitive voltage sags, the variations of motor torque is focused among the experimental results. The sensitive curves of instantaneous current peak are used to describe the susceptibility of three-phase induction motor and 진so it were used for the quantitative analysis of the impact of three-phase induction motor due to voltage sags. Through the results of experiment, we verified that some types loads have more severe impact at repetitive voltage sags than individual ones and proposed method can be effectively used to evaluate the actual impact of voltage sags.

• Journal of the Korean Data Analysis Society
• /
• 제20권6호
• /
• pp.2883-2893
• /
• 2018

본 논문에서는 모집단이 층으로 구성되어 있고 얻고자 하는 속성이 민감할 때, 덜 민감한 속성 B와 강요응답으로 구성되어 있는 확률장치를 통해 "예"라고 응답한 사람들에게만 민감한 속성 A 와 무관한 속성 Y를 포함하고 있는 Greenberg et al.(1969)의 무관질문모형을 사용하도록 하여 모집단이 층화된 경우 층화추정을 위한 층화 조건부 무관질문모형을 제안하였다. 그리고 제안한 층화 조건부 무관질문모형에서 각 층에 표본을 배분할 때 비례배분과 최적배분 문제를 다루었다. 또한 층화 조건부 무관질문모형을 무관한 속성이 미지인 경우 두 개의 독립표본을 이용하는 층화 이표본 조건부 무관질문모형으로 확장하였으며, 제안한 층화 이표본 조건부 무관질문모형의 두 번째 단계에서 사용되는 h층의 표본의 크기에 대한 최적값을 도출하여 최소분산을 구하였다. 마지막으로 층화 조건부 무관질문모형이 층화 무관질문모형과 층화 Carr et al.(1982)의 모형보다 효율적이 되는 조건을 제시하여 일정한 조건하에서 제안한 모형이 기존 모형들보다 효율적임을 보였으며, 제안한 층화 조건부 무관질문모형이 ${\pi}_{h2}$ 값이 작고 ${\pi}_{hy}$ 값이 작을수록 층화 Carr et al.(1982)의 모형보다 효율적임을 수치적으로 보였다.