• 천문학논총
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• 제30권2호
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• pp.193-195
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• 2015

The Palomar Transient Factory is a project making use of a Schmidt 48 inch telescope located on the Palomar Mountain, which is surveying the sky with dynamical cadences. It was deployed in 2009 and the observed sky region is over 1200 square degrees. We have studied the long-term periodic variabilities of the known galactic cataclysmic variables (CVs). More than 20 of the sources had been found to have long term periodic signals, ranging from several tens of days to several hundreds of days. Some possible scenarios are proposed to explain the results, such as a magnetic field change of the companion star, precession of the accretion disk, triple systems and superoutburst cycles. Some preliminary discussion will be presented in this article.

• 천문학논총
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• 제30권2호
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• pp.587-589
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• 2015

We present the results from analysis of the Hilbert-Huang transform (HHT) for the 4 Hz quasi-periodic oscillations (QPO) around the black hole X-ray binary XTE J1550-564. The resultant Hilbert spectra demonstrate that the QPO is composed of a series of intermittent signals appearing occasionally. From the analysis of the HHT, we further found the distribution of the lifetimes for the intermittent oscillations and the distribution for the time intervals with no significant signal (the break time). The mean lifetime is 1.45 s and 90% of the oscillation segments have lifetimes less than 3.1 s whereas the mean break time is 0.42 s and 90% of break times are less than 0.73 s. We conclude that the intermittent feature of the QPO could be explained by the Lense-Thirring precession model and rules out interpretations of continual frequency modulation.

• 한국음향학회지
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• 제23권7호
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• pp.514-520
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• 2004

수중에서 음원의 위치 추정을 위해 적용되어지는 기법으로써 시간지연차 (TDOA : Time Difference Of Arrival) 추정, 빔 형성 기법, 고 분해능 기법 등이 있다. 본 논문에서는 상대적으로 적은 수의 센서를 사용하여 주파수 영역에서 시간 지연차 추정에 사용되는 MCPSP (Modified Cross Power Spectrum Phase) 함수를 이용하였다. 그러나 MCPSP 함수에 기반한 방법은 CW (Continuous Wate) 신호를 대상으로 할 경우 추정 성능이 크게 떨어진다. 이에 본 논문에서는 Pulsed CW신호를 사용하는 수중 음원의 위치를 추정하기 위해 단 구간 (short-time) 에너지 검출을 이용하여 핑(ping)의 경계 영역을 포함하는 세그먼트를 구성하고 이로부터 MCPSP 함수를 구하는 방법을 제안하였다. 제안된 방법의 성능에 대한 이론적인 접근과 함께 다양한 환경 하에서 분석이 이루어졌다.

• 한국음향학회지
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• 제15권4호
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• pp.65-69
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• 1996

능동소나운용의 목적은 표적의 탐지 뿐만 아니라, 필요한 경우에는 표적의 분류 및 상태분석을 하는 데에 있다. 본 연구에서는, 3차원 해양환경에서 움직이는 표적의 표적상태를 분석하는 알고리듬에 관하여 2가지 방법을 알고리듬의 적용 가능한 조건의 분석과 시뮬레이션을 통해 장단점을 비교하여 표적상태 분석방법론의 방향을 제시하였다. 표적상태 분석방법은 거리에 따른 표적의 방위에 의한 방법, Range-Doppler Map을 이용하는 방법, 그리고 표적의 궤적을 사용하는 방법으로 구분될 수 있다. R-D Map은 소나 또는 표적이 움직이는 경우에만 적용할 수 있으며, 거리에 대한 표적의 방위각은 정지한 표적 또는 움직이는 표적에 모두 적용할 수 있다. 움직이는 표적의 궤적에 의한 표적상태 추정은 소나의 자체운동에 의한 궤적의 정보가 필수적이다. 시뮬레이션 결과와 장단점의 비교에 의하면 2가지의 방법은 독립적인 것이 아니라 서로 보완적으로 사용되어야 할 것으로 결론지어 진다.

• Journal of Electrical Engineering and Technology
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• 제13권3호
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• pp.1355-1362
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• 2018

In order to obtain a better understanding of the ageing process of the field composite insulators, it is necessary to explore a quantitative-valuation method for the aging state evaluation. And the linear relationship between volume resistivity and temperature is proposed. In this paper, the composite insulators with different lengths of operating lives from two manufacturers were tested. The relationship between trap characteristics and volume resistivity-temperature characteristics were analyzed based on Thermal Stimulated Current (TSC), volume resistivity-temperature test, Scanning Electron Microscope (SEM) and Fourier Transform Infrared Spectroscopy (FTIR). Furthermore, the application of trap characteristics in the quantitative evaluation of aging state of composite insulators was discussed. The results showed that there was a general negative correlation between the relative variation ratio of trap charges and the volume resistivity-temperature characteristics. Meanwhile, the physicochemical properties would change with the aging time, which would result in the increasing of electron traps. Combined with the TSC and volume resistivity test results, the trap characteristic thresholds which indicated the serious age of the composite insulators had been proposed.

• Journal of Microbiology and Biotechnology
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• 제31권2호
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• pp.233-239
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• 2021

Cyanobacteriochromes (CBCRs) are phytochrome-related photoreceptor proteins in cyanobacteria and cover a wide spectral range from ultraviolet to far-red. A single GAF domain that they contain can bind bilin(s) autocatalytically via heterologous recombination and then fluoresce, with potential applications as biomarkers and biosensors. Here, we report that a novel red/green CBCR GAF domain, SPI1085g2 from Spirulina subsalsa, covalently binds both phycocyanobilin (PCB) and phycoerythrobilin (PEB). The PCB-binding GAF domain exhibited canonical red/green photoconversion with weak fluorescence emission. However, the PEB-binding GAF domain, SPI1085g2-PEB, exhibited an intense orange fluorescence (λabs.max = 520 nm, λfluor.max = 555 nm), with a fluorescence quantum yield close to 1.0. The fluorescence of SPI1085g2-PEB was selectively and instantaneously quenched by copper ions in a concentration-dependent manner and exhibited reversibility upon treatment with the metal chelator EDTA. This study identified a novel PEB-binding cyanobacteriochrome-based fluorescent protein with the highest quantum yield reported to date and suggests its potential as a biosensor for the rapid detection of copper ions.

• Parasites, Hosts and Diseases
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• 제59권6호
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• pp.635-638
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• 2021

In this study, we intended to describe a human case of lumbosacral canal sparganosis in People's Republic of China (China). A 56-year-old man was admitted to Xiangya Hospital Central South University in Changsha, Hunan province, China after having an experience of perianal pain for a week. An enhancing mass, a tumor clinically suggested, was showed at the S1-S2 level of the lumbosacral spine by the examination of magnetic resonance imaging (MRI) with gadolinium contrast. The patient was received the laminectomy from S1 to S2, and an ivory-white living worm was detected in inferior margin of L5. In ELISA-test with cerebrospinal fluid (CSF) and serum samples, anti-sparganum antibodies were detected. He had a ingesting history of undercooked frog meat in his youth. By the present study, a human case of spinal sparganosis invaded in lumbosacral canal at the S1-S2 level was diagnosed in China. Although the surgical removal of larvae is known to be the best way of treatment for sparganosis, we administered the high-dosage of praziquantel, albendazole and dexamethasone to prevent the occurrence of another remain worms in this study.

• Smart Structures and Systems
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• 제33권3호
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• pp.201-215
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• 2024

Spline chirplet transform and local maximum synchrosqueezing are introduced to present a novel structural instantaneous frequency (IF) identification method named local maximum synchrosqueezing spline chirplet transform (LMSSSCT). Namely spline chirplet transform (SCT), a transform is firstly introduced based on classic chirplet transform and spline interpolated kernel function. Applying SCT in association with local maximum synchrosqueezing, the LMSSSCT is then proposed. The index of accuracy and Rényi entropy show that LMSSSCT outperforms the other time-frequency analysis (TFA) methods in processing analytical signals, especially in the presence of noise. Numerical examples of a Duffing nonlinear system with single degree of freedom and a two-layer shear frame structure with time-varying stiffness are used to verify the effectiveness of structural IF identification. Moreover, a nonlinear supported beam structure test is conducted and the LMSSSCT is utilized for structural IF identification. Numerical simulation and experimental results demonstrate that the presented LMSSSCT can effectively identify the IFs of nonlinear structures and time-varying structures with good accuracy and stability.

• 지역과문화
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• 제8권3호
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• pp.27-48
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• 2021

近年来, 中国的旅游演艺进行了一系列新项目的落成, 使旅游演艺产业的票房增加, 经济收入增高, 同时带动了旅游演艺的品牌形成, 而且拥有了一定的良好口碑, 对地域的文化传播, 经济发展都有一定的推动作用, 其中大型情景体验剧就是重点项目之一。大型情景体验剧是一种以模拟真实环境空间设计为空间, 使观众在视觉, 听觉, 嗅觉, 味觉和触觉等多位感官上进行主动式体验, 互动性极强的新戏剧形式。大型情景体验剧根据中国的传统文化, 地域文化, 流传已久的故事进行了改编, 又结合了灯光, 音效, 特效, 3D效果等高科技, 使观众的体验更加真实。《又见平遥》作为中国第一部大型室内情景体验剧, 以新的表现形式和创作手段来体现山西文化的博大精深。以情景体验剧的形式, 使观众更加直观地感受到了"山西人"的"山西情"和"山西德", 推动山西旅游业的发展, 带动山西地区的经济, 逐渐形成了完整的产业链。但也有剧情连接不顺及游客管理不当等局限, 可以通过更多的观众互动及指引完善演出效果。因此可以看出, 大型情景体验剧对地域在传统文化, 价值观的传播上, 旅游产业的发展上, 地域的品牌特色形成以及经济发展上都有很大的推动作用。通过这些, 可以看出大型情景体验剧对实景演出的发展具有创新思维内容, 逐渐形成产业链闭环以及拓宽宣传渠道等启示作用。

• Journal of applied mathematics & informatics
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• 제7권2호
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• pp.467-482
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• 2000

Testing equality of two and k distributions has long been an interesting issue in statistical inference. To overcome the sparseness of data points in high-dimensional space and deal with the general cases, we suggest several projection pursuit type statistics. Some results on the limiting distributions of the statistics are obtained, some properties of Bootstrap approximation are investigated. Furthermore, for computational reasons an approximation for the statistics the based on Number theoretic method is applied. Several simulation experiments are performed.