• 대한의용생체공학회:의공학회지
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• 제15권3호
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• pp.347-354
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• 1994

This paper describes a diagnostic protocol of nonlinear dynamic characteristics of biological system using chaos theory. An integrated chaos analysis system for the diagnosis of biological system was designed. We suggest a procedure of attractor reconstruction for reliable qualitative and quantitative analysis. The effect of autonomic nervous system activity on heart rate variability with power spectral analysis and its characteristics of chaotic attractors are investigated. The results show the applicability to evaluate the mental and physical conditions using nonlinear characteristics of biological signal.

• 대한의용생체공학회:의공학회지
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• 제14권3호
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• pp.273-282
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• 1993

This study is concerned with the temperature dependence characteristics of ultrasound parameters in biological tissues, which are basic on the noninvasive deep body temperature estimation. Used parameters are ultrasonic attenuation coefficient and sound velocity In order to accomplishment our purpose, several signal processing methods were used. Attenua4iorl coefficient was estimated by spectral difference method and sound velocity was estimated by P-P method. And we also examined these methods through a series of IN VITRO experi mentis that used tissue-mimicking phantom samples and biological tissue samples. In order to imitate the biological soft tissue two kinds of phantom samples are used, one is agar phantom sample which is composed of agar, graphite, N-propyl alcohol and distilled water, and the other is fat phantom sample which is composed of pure animal fat. And the ultrasound transmission mode and reflection mode experiments are performed on the pig's spleen, kidney and fat. As a result, it is found that the temperature characteristics are uniform in case of phan- tom samples but not in biological tissues because of complicate wave propagation within them. Consequently, the possibility of temperature measurement using ultrasound on biological tissue is confirmed and its results may contribute to the establishment of reference values of internal temperature measurement of biological tissues.

• Applied Science and Convergence Technology
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• 제24권6호
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• pp.232-236
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• 2015

The electro-optical characteristics of several functional layers over the MgO protective layer were studied during the continuous discharge of an AC-PDP. In order to observe the degradation of each functional layer on the MgO protection layer, we measured the surface morphology, cathodoluminescence (CL) spectrum, the secondary electron emission coefficient (${\gamma}$) and the discharge characteristics after 500 hours of discharge during the operation of the AC-PDP.

• Journal of Microbiology and Biotechnology
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• 제14권3호
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• pp.509-514
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• 2004

Six new serovarieties of B. thuringiensis carrying specific H-antigen have minor differences in biochemical characteristics and morphological characteristics of crystals, which are commonly resistant against four antibiotics. The B. thuringiensis serovar. coreanensis is nontoxic to silkworm larvae, but it is moderately toxic against the Culex pipiens larvae. The B. thuringiensis serovar. konkukian and leesis are nontoxic against mosquitos larvae, but are toxic against silkworm larvae. The B. thuringiensis serovar. seoulensis, sooncheon, and yosoo are highly toxic to B. mori larvae and moderately toxic to C. pipiens larvae. The six serovarieties harbor different plasmid DNA patterns. A 102-kDa protein is a major crystal protein in the four serovarieties and a 86-kDa protein is in one serovariety.

• 한국어업기술학회:학술대회논문집
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• 한국어업기술학회 2000년도 춘계수산관련학회 공동학술대회발표요지집
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• pp.463-464
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• 2000

Skates are one of the most favorite food fishes for Korean people. It is, I think, important to know the biological characteristics of skates for protecting the fishes from the extinction caused by overfishing. Femily Rajidae encompasses about 200 species which is one fourth of elasmobranch fishes, and 11 species known from the Korean waters. But, very few biological characteristics of skates have been known Some of them are shown here and discussed comparing with those of other elasmobranch fishes (sharks and rays) and teleost fishes. (omitted)

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1998년도 추계학술대회
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• pp.197-198
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• 1998

We tested the capability of Pointwise Correlation Dimension(PD2), Approximate Entropy (ApEn) and LZ complexity, as alternative measures of a biological signal. For this purpose, we analyzed standard data and a healthy child's 24-hour heart rate variability. Our conclusion is as follows. First, PD2, ApEn and LZ complexity can be used for discerning chaotic attractor, white noise, and periodic signal. Second, these measures show different characteristics on day and night. Third, these measures can be used for detecting time-varying characteristics of biological signals.

• 비파괴검사학회지
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• 제35권4호
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• pp.239-244
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• 2015

생체 조직은 세포 배열이나 조직 형태 등 다양한 차이에 의해 각각 고유의 전기적 특성을 가지며, 생물학적 변화가 일어나면 고유의 전기적 특성이 변한다. 본 연구는 방사선 피폭에 따른 생체 조직의 전기적 특성 변화를 측정하기 위한 선행연구로 측정 과정에서 방사선 피폭 우려가 있으므로, 실험자의 방사선 장애를 방지하기 위해 LabVIEW를 이용하여 자동제어 측정 시스템을 개발한 후 생체 조직의 특성을 평가하고자 하였다. 생체 조직의 전기적 특성 측정전 후 형태학적 변화를 관찰한 결과 조직 변화는 관찰되지 않았으며, 유사한 양상이었다. Impedance/Gain-phase analyzer로 생체 조직의 임피던스를 반복 측정한 결과 변동계수가 10% 미만으로 측정값은 재현성이 있었다. 주파수 변화에 따른 생체 조직의 전기적 특성 중에서 위상차 변화는 거의 없었으며, 조직은 저항성을 나타내었고, 임피던스 크기는 주파수에 비례하여 일정하게 감소하였다. 본 연구를 통해 생체 조직의 전기적 특성 변화를 측정할 수 있는 자동제어 시스템을 개발하였으며, 생체 조직의 전기적 특성을 이해할 수 있었다.

• 한국균학회지
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• 제45권3호
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• pp.167-174
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• 2017

In the ongoing survey of fungal diversity in Korea, two Ascomycetes species, namely Rhinocladiella similis and Toxicocladosporium irritans, were isolated in 2016. These species were identified based on the internal transcribed spacer region and morphological characteristics. This is the first report of these species in Korea, and the morphological characteristics and images of the fungi are presented.

• 한국균학회지
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• 제44권3호
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• pp.145-149
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• 2016

Pseudeurotium bakeri KNU14-21 isolated from crop field soil is a previously unreported fungal species in Korea. This fungal species was identified through morphological and molecular characteristics. Based on the shape and size of conidia and conidiophores as well as the internal transcribed spacer region of rDNA, the isolate was confirmed to be Pseudeurotium bakeri. This species has not been previously reported from Korea, and this is the first report of its incidence in Korea.

• 한국균학회지
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• 제50권1호
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• pp.1-29
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• 2022

Hypocreales is one of the largest orders within the class Sordariomycetes in Ascomycota. Several species of this order are cosmopolitan and have a broad range of habitats. Here, we isolated several fungal strains from environmental samples, including freshwater sediment and plant litter. The strains were identified via molecular and phylogenetic analyses of rDNA and other DNA markers, such as TUB, RPB2, and EF1. The morphological characteristics of the fungi were investigated using microscopy, and culture characteristics were assessed from their growth on several media. We identified 17 species previously unrecorded in Korea: Dactylonectria hordeicola, Flavocillium bifurcatum, Fusarium luffae, Ilyonectria ilicicola, Ilyonectria qitaiheensis, Ilyonectria robusta, Lecanicillium aphanocladii, Nectria ulmicola, Neonectria lugdunensis, Ovicillium oosporum, Pseudonectria foliicola, Sarocladium spinificis, Scolecofusarium ciliatum, Trichoderma appalachiense, Trichoderma subviride, Trichoderma taiwanense, and Trichoderma tsugarense.