• Biotechnology and Bioprocess Engineering:BBE
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• 제9권2호
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• pp.127-131
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• 2004

A low-cost, simple strip reader system using a linear movement mechanism of CD-ROM deck has been developed to characterize a lateral flow membrane-based immunochromatographic assay. The test strip reader was assembled by a CD-ROM deck and home-made optical head especially designed for immunoassays. The optical head for detecting reflected light from the test strip surface consists of green light-emitting diode, large area silicon photodiode, and anodized aluminum mounting block providing a slit structure for cutting light from the LED. The stepping motor of the deck was operated in the full step mode, whose distance of each reading point is about 0.15mm. The performance of the strip reader was tested by analysis of HBV(hepatitis B virus) antigen test kit. This strip reader can be useful for inexpensive, disposable, and membrane-based assays that provide visual evidence of the presence of an analyte in a liquid sample.

• Applied Microscopy
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• 제47권1호
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• pp.3-7
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• 2017

The automatic equipment for three-dimensional electron microscopy (3DEM) can acquire serial sections of a large sample in a relatively short time, and is especially suitable for the connectomics, which is a field related to understanding the brain structure as a whole. As many results obtained through 3DEM using automatic serial sections have been published in the field of brain research, many researchers continue to apply this technique to various samples. We reviewed the equipment for automatic serial sectioning, the block preparation method, the limitations of 3DEM, and future directions.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 2014년도 하계학술대회
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• pp.230-231
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• 2014

Compressive sensing is a new sampling technique, which allows to sample a signal under the Nyquist-Shannon sampling rate. For block-based compressive sensing, a hybrid sensing matrix which contains low-frequency patterns in addition to the random Gaussian numbers is good for exploiting typical property of natural images. By noting that MH-BCS-SPL is well known for its good recovery performance, this paper investigates effect of the hybrid sensing matrix on MH-BCS-SPL in the sense of how large portion of low-frequency patterns can provide performance improvement.

• 전력전자학회논문지
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• 제20권4호
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• pp.297-304
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• 2015

A conventional single-phase high-power system typically generates a large AC line input current at universal 90 VAC condition. Sometimes, this phenomenon can block the Earth Leakage Circuit Breaker (ELCB), which causes problems. Replacing power facilities is essential to ensure smooth operations. Thus, this paper proposes a method that can drive higher power than the limit of conventional power facilities. The proposed method can reduce the large AC line input current by limiting the input power of Power Factor Correction (PFC). An additional battery circuit can supplement the power deficiency. Specifically, a bidirectional converter with charging and discharging functions was adopted for the battery circuit. Finally, the validity of the proposed system could be confirmed by modal analysis and simulation, and an experiment in 2 KW condition was implemented with a prototype sample as well.

• 재무관리연구
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• 제26권1호
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• pp.65-94
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• 2009

본 연구는 KOSPI 200주가지수의 구성종목 변경 사건에 대한 시장반응을 재검증하는 데 초점을 두었다. 국내에서 두 차례 이루어진 과거 실증연구들에서는 KOSPI 200지수종목의 변경이 정보력이 없는 사건으로 분석되었으며, 일부 표본에 대해서만 가격압박가설을 지지하는 것으로 나타났다. 본 연구는 이러한 실증적 결과가 변경기업의 속성과 주식시장의 장세에 따라 다르게 나타날 수 있다고 판단하여 기업규모와 시장상황에 따라서 샘플을 구분하여 분석하였다. 실증분석의 결과 지수종목에 신규로 포함되는 기업의 경우 평균적으로 가격압박가설을 지지하는 것으로 나타났다. 또한 종목들을 기업규모와 시장상황에 따라 나누어서 분석해보면 주가반응이 크게 나타났던 년도의 표본수가 많지 않았기 때문에 시장의 평균적 반응을 살펴보면 정보력이 없거나 가격압박가설을 지지하는 것처럼 나타난 것으로 분석되었다. 이러한 연구결과는 거래량분석을 통해서도 지지되었는데, 시가총액이 큰 기업은 공시일 전에 새로운 지수종목으로 진입될 것을 예상되기 때문에 공시일 이전에 거래량이 크게 증가하는 것으로 나타났다. 그러나 지수종목에서 탈락되는 기업의 경우에서는 장기적인 주가반응이 뚜렷하게 나타났지만 거래량에 의한 추가적 설명은 부족한 것으로 분석되었다.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제54권8호
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• pp.378-383
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• 2005

We report the development of miniature fluorescence detection systems that employ miniature prism, mirrors and low coat CCD camera to detect the fluorescence emitted from 40 fluorescently-labeled protein patterns without scanner. This kind of miniature fluorescence detection system can be used in point of care. We introduce two systems, one uses prism+mirror block and the other uses prism and two mirrors. A large NA microscope eyepiece and low cost CCD camera are used. We fabricated protein chip containing multi-pattern BSA labeled with Cy5, using MEMS technology and modified the surface chemically to clean and to immobilize proteins. The measurements show that the combination of prism and mirrors can homogenize elliptical excitation light over the sample with higher optical efficiency, and increase the separation between excitation and fluorescence light at the CCD to give higher signal intensity and higher signal to noise ratio. The measurements also show that protein concentrations ranging from 10 ng/ml to 1000 ng/ml can be assayed with very small error. We believe that the proposed fluorescence detection system can be refined to build a commercially valuable hand-held or miniature detection device.

• 응용통계연구
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• 제19권2호
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• pp.231-240
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• 2006

일반적으로 쌍체 비교(paired comparison 또는 paired t test)가 효과적인 쌍으로의 구획을 통하여 소위 독립비교(group comparison)라고 일컫는 독립 이표본 t 검정(two-sample t test)보다 정밀한 결과를 제공하는 것으로 알려져 있다. 본 논문에서는 이와 같은 사실을 통계적으로 됫받침하기 위하여 두 방법의 정밀도를 보다 정량적으로 비교하였다. 독립 비교와 쌍체 비교가 각각 일원배치법과 이원배치법 (특히, 임의화 블록 설계법)의 특수한 경우이므로 각각에 상응하는 신뢰구간의 길이의 비로 정의된 비교 통계량은 분산분석의 통계량으로 표현된다. 다시 말해서, 이 통계량은 t 와 F 분포함수로 표현되므로 쉽게 독립비교와 쌍체비교의 정밀도를 비교할 수 있다. 실제로, 자주 쓰이는 유의수준에서는 쌍체표본 내에 구획 간의 유의한 변동이 있으면 쌍체비교가 독립비교보다 정밀할 가능성이 더 높다.

• 천문학회보
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• 제44권1호
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• pp.33.3-33.3
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• 2019

Automatic, yet reliable methods to find and classify barred galaxies are going to be more important in the era of large galaxy surveys. Here, we introduce a new approach to classify barred galaxies by analyzing the butterfly pattern that Buta & Block (2001) reported as a bar signature on the potential map. We make it easy to find the pattern by moving the ratio map from a Cartesian coordinate to a polar coordinate. Our volume-limited sample consists of 1698 spiral galaxies brighter than Mr = -15.2 with z < 0.01 from the Sloan Digital Sky Survey/DR7 visually classified by Ann et al. (2015). We compared the results of the classification obtained by four different methods: visual inspection, ellipse fitting, Fourier analysis, and our new method. We obtain, for the same sample, different bar fractions of 63%, 48%, 36%, and 56% by visual inspection, ellipse fitting, Fourier analysis, and our new approach, respectively. Although automatic classifications detect visually determined, strongly barred galaxies with the concordance of 74% to 86%, automatically selected barred galaxies contain different amount of weak bars. We find a different dependence of bar fraction on the Hubble type for strong and weak bars: SBs are preponderant in early-type spirals, whereas SABs are in late-type spirals. Moreover, the ellipse fitting method often misses strongly barred galaxies in the bulge-dominated galaxies. These explain why previous works showed the contradictory dependence of the bar fraction on the host galaxy properties. Our new method has the highest agreement with visual inspection in terms of the individual classification and the overall bar fraction. In addition, we find another signature on the ratio map to classify barred galaxies into new two classes that are probably related to the age of the bar.

• 한국경영과학회지
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• 제39권2호
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• pp.67-82
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• 2014

The purpose of this study is two-fold : the one is to examine the causal relationship between domestic large firms' win-win growth effort and their financial performance by fiscal years; and the other is to develop a quantitative win-win growth index to overcome the limitation of the current one mainly using a survey method developed by NCCP (National Commission for Corporate Partnership). To serve the first purpose, we take a sample of 128 large companies whose win-win growth indices as of year 2011 and 2012 were evaluated by NCCP. We use their respective fiscal year's financial data to select 62 candidate financial ratios, which are then used in subsequent empirical tests. For the tests, we employ ordered probit model with stepwise selection method and two-way ANOVA with randomized block design to identify which of the 62 financial ratios are statistically significant ones to affect the firms' win-win growth index as well as to determine if the firms' win-win growth effort would cause their financial performance positively. To serve the second purpose, we devise a model using the 123 firms' 45 financial ratios, which employs ordered probit model with stepwise selection, and the validation of the model follows. We claim that the model suggested in this study serve as an alternative complementing the current one as it can produce the index in a more objective and swift manner using the firms' publicized financial statements.

• 한국가축번식학회지
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• 제16권3호
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• pp.209-215
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• 1992

These studies were carried out to overcome 2-cell block and in vitro development to blastocysts in vitro fertilization of mouse embryos. The unfertilized ova were obtained by superovulation in ICR mice of 4 to 6 weeks old. Tyrode's 280 solution was used as basal media, and the pH range of media examined was designed from 6.5 to 7.5 with 0.2 interval and the range of osmolality from 250 to 370 mOsm with 20 interval, and the period of sperm preincubation examined was 30, 60, 120, and 180 minutes. The ova developed to 2-cell embryos after 26hrs of incubation with preincubated sperm were evaluatated as in vitro fertilized ones. The results obtained were summarized as follows: 1. The optimal ranges of pH and osmolality of culture media and of sperm preincubation time for in vitro development of in vitro fertilized ova to blastocyst were pH 7.1 to 7.3, 250 to 350 mosmol and 60 to 180 min, respectively. 2. With the media of pH 7.1, 310 mOsm and sperm preincubation period of 120min in another experiment of large sample size, the in vitro fertilized ova was found 66.5% and the in vitro development of in vitro fertilized ova to blastocyst was found 35.8%. From the above results it was concluded that the optimal conditions of pH and osmolality of the media for mouse IVF and embryo culture, and the period of sperm preincubation might be 7.1, 310 mOam and 120min, respectively.