• BMB Reports
• /
• 제40권2호
• /
• pp.226-231
• /
• 2007

Housekeeping genes are widely used as internal controls in a variety of study types, including real time RT-PCR, microarrays, Northern analysis and RNase protection assays. However, even commonly used housekeeping genes may vary in stability depending on the cell type or disease being studied. Thus, it is necessary to identify additional housekeeping-type genes that show sample-independent stability. Here, we used statistical analysis to examine a large human microarray database, seeking genes that were stably expressed in various tissues, disease states and cell lines. We further selected genes that were expressed at different levels, because reference and target genes should be present in similar copy numbers to achieve reliable quantitative results. Real time RT-PCR amplification of three newly identified reference genes, CGI-119, CTBP1 and GOLGAl, alongside three well-known housekeeping genes, B2M, GAPD, and TUBB, confirmed that the newly identified genes were more stably expressed in individual samples with similar ranges. These results collectively suggest that statistical analysis of microarray data can be used to identify new candidate housekeeping genes showing consistent expression across tissues and diseases. Our analysis identified three novel candidate housekeeping genes (CGI-119, GOLGA1, and CTBP1) that could prove useful for normalization across a variety of RNA-based techniques.

• 한국문헌정보학회지
• /
• 제47권2호
• /
• pp.143-159
• /
• 2013

본 연구는 국방과학 분야 연구도서관에서 정보자원 수집의 효율성을 기하고, 모기관으로부터의 지속적인 지원을 확보하기 위해, 국방과학 분야 국내 대표 학술지에 게재된 학술지 논문의 참고문헌을 조사 분석하여, 국방과학 연구자들이 인용하는 자료 유형의 선호도를 밝힌 것이다. 조사 대상은 "한국군사과학기술학회지"로 선정하였고, 조사 기간은 1998년-2012년(창간호-통권 59호)으로 하였다. 총 537편의 논문에 이용된 참고문헌 4,563건에 관해서 연도별 자료 유형을 조사하여, 국방과학 분야의 연구자들이 많이 인용하는 자료 유형을 식별하였다.

• 한국의류학회지
• /
• 제37권7호
• /
• pp.972-983
• /
• 2013

This study investigates the effects of fashion innovativeness and utilization on the price perception of formal wear and climbing wear as well as gender differences on price perception and the relationship of the variables. Price perception measurements were based on reference price and reservation price; subsequently, a premium price ratio was calculated based on the measured prices. A survey that involved male and female adult consumers was conducted in Daegu in August 2011. A total of 321 responses were analyzed using descriptive statistics, factor analysis, reliability analysis, correlations and independent sample t-test. Two factors of fashion innovativeness were derived and named as unique-oriented innovativeness and change-oriented innovativeness. The utilization of formal wear and climbing wear was higher in the male group versus the female group. Reference price and reservation price were identified similar to the actual consumer purchasing prices reported in previous studies. Male consumers showed a tendency in price perception in accordance with the utilization. The change-oriented innovativeness of the female group led to a positive relationship with the perceived price of climbing jackets.

• Journal of Pharmaceutical Investigation
• /
• 제35권3호
• /
• pp.157-163
• /
• 2005

The pellets with multiple drug release system (MDRS) of Diltiazem. HCl which consist of immediate drug release layer, drug reservoir layer and controlled release rate membrane, were prepared by using CF-Coater. As main factors for more effective MDRS of Diltiazem. HCl, ethylcellulose was used for the controlling drug release rate, and diethylphthalate was used for plasticizer, respectively. In vitro evaluation study was performed by comparative dissolution test between our test MDRS and reference Diltiazem. HCl preparation. The physical tests were performed using FT-IR and SEM. In vivo evaluation was also performed by observing the behavior of a plasma drug concentration after oral administration. The bioavailability was determined by analyzing the blood sample after oral administration to healthy, male volunteers once a day. As a result, there were no significant differences in bioequivalence parameters $(AUC_{\infty},\;C_{max},\;t_{1/2})$ between two systems. It might be concluded that our MDRS of Diltiazem. HCl could be an alternative delivery system to reference drug preparation.

• 한국전기전자재료학회논문지
• /
• 제19권4호
• /
• pp.398-403
• /
• 2006

This paper describes the evaluation of the long duration current impulse withstand characteristics of ZnO blocks for high voltage surge arresters. Four ZnO varistors were manufactured with the general ceramic production method and the long duration current impulse withstand test, electrical uniformity evaluation test and microstructure observation were performed. All varistors exhibited high density, which was in the range of $5.42{\sim}5.46g/cm^3$. In the electrical properties, the reference voltage of samples was in the range of $5.11{\sim}5.25\;kV$ and the residual voltage was in the range of $8.314{\sim}8.523\;kV$. In the long duration current impulse withstand test, sample No.2 and No.3 failed at the 2nd and 4th shot of series impulse currents, respectively, but the rest survived 18 shots during the test. Before and after this test, the variation ratio of the residual voltage of samples survived was below 0.5 %, which was in the acceptance range of 5 %. According to the results of the test, it is thought that if the soldering method is improved, ZnO varistors would be possible to apply to the high voltage arresters like the station class and transmission line arresters in the near future.

• 한국광학회지
• /
• 제19권2호
• /
• pp.103-107
• /
• 2008

기존 OCT 시스템의 Michelson 간섭계와 다르게 간섭신호가 프로브 끝단에서 유도되어 기준신호와 샘플신호가 동일한 경로를 통해 진행하는 공통경로 OCT 시스템을 제작하였다. 최적의 기준신호가 생성되도록 하기 위해 부분반사 프로브(Probe)의 굴절률을 최적화하였고 생체 샘플의 이미지 획득이 가능하도록 프로브의 끝단에서 초점이 맺히도록 볼록 렌즈형 프로브를 제작하였다. 이를 통해서 실제 샘플의 2차원 이미지의 획득이 가능하였다.

• 대한화학회지
• /
• 제38권10호
• /
• pp.726-733
• /
• 1994

대기부유분진(air particulate material)중에 존재하는 다환방향족탄화수소(polycyclic aromatic hydrocarbons, PAH)를 신속하고 정확하게 분석하기 위하여 대기부유분진 시료를 10ml의 초임계유체($N_2O$ )로 30분간 추출 후 별도의 전처리와 농축과정 없이 GC/MS에서 분석하여 분석시간과 분석과정을 단축 및 단순화하였다. 시료로서 NBS 대기부유분진 인증표준기준물질(certified particulate reference material, CRM)1649와 서울의 도심에서 채취한 대기부유분진 시료를 이용하여 기존의 추출법 및 분석방법과 비교하였다. 그 결과 본 분석방법은 기존의 분석법에 비해 회수율은 상대적으로 작았으나 재현성이 좋았으며 분석과정이 간단하고 분석시간이 현저히 단축됨을 알 수 있었다.

• 한국해양공학회지
• /
• 제22권4호
• /
• pp.106-113
• /
• 2008

This paper presents an underwater navigation system based on range measurements from a known reference station fixed on the sea bottom or floated at surface with a buoy, for which the system is extended to 3-dimensional coordinates. We formulated a state equation in polar coordinates and constituted an extended Kalman filter for discrete-time implementation of the navigation algorithm. The autonomous underwater vehicle, lSiMl, cruising with a constant speed can estimate its trajectory using just range measurements and additional depth, heading and pitch sensors. Simulation studies were performed to evaluate the underwater navigation of the maneuvering AUV with range measurements. We modulated the sample rate of range measurements to evaluate the effect of the update rate, and changed the initial position error of the AUV to check the robustness to estimation errors. Simulation results illustrates that the extended navigation system provides convergence of the state estimates. The navigation system was conditionally stable when it had initial position errors.

• 아동학회지
• /
• 제38권2호
• /
• pp.93-105
• /
• 2017

Objective: This study aimed to investigate the trajectories of mobile phone use with reference to its purposes, and to examine the effects of gender and interpersonal factors on the same in early adolescents. Methods: Latent growth modeling was used with a sample of 2,378 early adolescents from Grade 4 to 8. Data from the Korean Children and Youth Panel Survey conducted by the National Youth Policy Institute were used. Results: In boys and girls, overtime, the level of mobile phone use for communicating with family decreased, while that for communicating with friends increased. Level of mobile phone use for entertainment increased across time in boys; however, in girls, it increased from Grade 4 to 6 and decreased thereafter, until Grade 8. Gender was associated with the changes of mobile phone use according to the purpose of the same. Positive parenting, negative parenting, relationships with peers, and relationships with teachers predicted changes in mobile phone use for communicating with friends. Conclusion: These findings suggest that the processes involved in the trajectories of mobile phone use in early adolescence operate differently based on the purposes of the same. Additionally, the present results show that interpersonal factors are highly associated with mobile phone use for communicating with friends.

• Journal of Biosystems Engineering
• /
• 제17권4호
• /
• pp.354-362
• /
• 1992

This study was intended to examine feasibility of sizing and color grading of Fuji apple with black/white image processing system, to develop a device with which the whole surface of an apple could be captured by one camera, and to develop an algorithm for a high speed sorting. The results are summarized as follows : 1. The black/white image processing system used in this study showed a maximum error of 1.3% in area measurement with a reference figure while the focusing point of camera and location of the reference figure were changed within a certain range. 2. As the result of evaluating four automatic image segmentation algorithms with apple images, Histogram Clustering Method was the best in terms of computation time and accuracy. 3. The fast algorithm for analyzing size and coloration of apple was developed. 4. The whole surface of an apple could be captured in an image frame with two mirrors installed on the both sides of the sample. The total area of the image representing the whole surface showed a correlation of 0.995 with the weight of apple. 5. The gray level when a particular band pass filter was mounted on the camera showed high correlation with 'L' and 'a' values of Hunt color scale and could represent the coloration of apple.