• 한국품질경영학회:학술대회논문집
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• 한국품질경영학회 1998년도 The 12th Asia Quality Management Symposium* Total Quality Management for Restoring Competitiveness
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• pp.361-377
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• 1998

The measurement of welding temperature of connector is usually performed with an infra red temperature gauge. However, the factors, which influence the temperature measurement, are rarely known. This research used the welding temperature measurement of the connector as an example, applying the experimental design, in two-phase experiments, to search the affecting factors. In phase-I experiment, we used a resolution III, seven-factor fractional factorial design with two levels for each factor. The result showed that none of the factor was significant in affecting the welding temperature when the type I error ${\alpha}$ was 0.05. Next, we did the phase-II factorial experiment with three factors and each factor had three levels. The experiment showed the experimental time was significant in affecting the temperature measurement when the type I error ${\alpha}$ was 0.05. Further Duncan's multiple range tests on the second experimental data showed that the later the experimental time, the weaker the light intensity could have on the temperature measurement and the average of the highest temperatures was lower. Moreover, the later the experimental time, the smaller was the variance of the temperature measurement and the difference between the averages of the highest and the lowest temperatures was also lower.

• Animal cells and systems
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• 제14권1호
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• pp.25-30
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• 2010

We employed a new and improved differential display reverse transcription-polymerase chain reaction (DDRT-PCR) method, which involves annealing control primers (ACPs), to identify the genes that are specifically or prominently expressed in olive flounder (Paralichthys olivaceus) juveniles (35 days post-hatch; dph) compared to larval-stage (dph 21) flounder. Using 60 ACPs, we identified eight differentially expressed genes (DEGs) and basic local alignment search tool (BLAST) searches revealed eight known genes. Gene expression levels were confirmed by RT-PCR. Phosphoglucose isomerase (PGI) was highly expressed at 21 dph, while nephrosin, myosin light chain (MLC), myosin heavy chain (MHC), carboxypeptidase A, chymotrypsin B, fish-egg protein, and matrix protein were expressed at 35 dph. PGI, MLC, and MHC expression was further analyzed by RT-PCR. The differentially expressed genes identified in this study may provide insights into the molecular basis of development in olive flounder.

• 천문학회보
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• 제40권1호
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• pp.82.2-82.2
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• 2015

In this talk, we introduce the Lee Sang Gak Telescope (LSGT), a 0.43m telescope that can be operated remotely. This telescope was installed at the Siding Spring Observatory in 2015 October, and since then, it has been operated through a robotic reservation system, remotely from Korea. This telescope is now being used for educational and research activities of SNU Astronomy program. By placing the telescope at a place with an excellent astro-climate in Australia, the observation class activity can include objects in the southern hemisphere to the magnitude limit of V=20 mag at an exposure time of a few minutes. For example, Cepheid stars in Magellanic clouds can be observed during a class activity for constructing the classical Cepheid light curves that has been a key distance measure technique. Research activities such as transient observation and monitoring observation of AGN are possible, and we are currently running a high cadence supernovae search program by monitoring nearby galaxies intensively (see a presentation by C. Choi). The installation of the telescope was made possible from a support from the Seoul.

• 한국수학교육학회지시리즈A:수학교육
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• 제51권2호
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• pp.161-171
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• 2012

Generally mathematics is regarded as a subtle subject to grasp their true meaning. And teacher's personal conceptions of mathematics influence greatly on the teaching and learning of mathematics. More over often teachers confess their difficulties in explaining the true nature of mathematics. In this paper, applying the theory of epistemology, we tried to search factors that must be counted important when trying to understand the true nature of mathematics. As results, we identified five characteristics of mathematical knowledge such as logical reasoning, abstractive concept, mathematical representation, systematical structure, and axiomatic validation. Next, we tried to investigate math education major students' conception of mathematics using these items. To proceed this research we asked 51 students from three Universities to answer their opinion on 'What do you think is mathematics?'. Analysing their answers in the light of the above five items, we got the following facts. 1. Only 38% of the students regarded mathematics as one of the five items, which can be considered to reveal students' low concern about the basic nature of mathematics. 2. The status of students' responses to the question were greatly different among the three Universities. This shows that mathematics professors need to lead students to have concern about the true nature of mathematics.

• 대한교통학회지
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• 제14권3호
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• pp.45-59
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• 1996

The shortest path algorithm for route guidance is implicitly required not only to support geometrical variations of transportation network such as U-TURN or P-TURN but to efficiency search reasonable routes in searching mechanism. The purpose of this paper is to integrate such two requirements ; that is, to allow U-TURN and P-TURN possibilities and to cut down searching time in locating routes between two points (origin and destination) in networks. We also propose a new type of link searching algorithm which can solve the limitation of vine building algorithm at consecutively left-turn prohibited intersections. The test site is a block of Gangnam road network that has some left-turn prohibited and allowed U-TURN intersections. Four models have been identified to be comparatively analyzed in terms of searching efficiency. The Models are as follows : (i) Model 1 - Link Searching Dijkstra Algorithm without Searching Area Extraction (SAE) ; (ii) Model 2 - Link Searching Dijkstra Algorithm with SAE ; (iii) Model 3 - Link Searching Bidirectional Dijkstra Algorithm without SAE ; and (iv) Model 4 - Link Searching Bidirectional Dijkstra Algorithm with SAE. The results of comparative evaluation show that Model 4 can effectively find optimum path faster than any other models as expected. Some discussions and future research agenda have been presented in the light of dynamic route guidance application of the urban ATIS.

• Genomics & Informatics
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• 제5권4호
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• pp.179-187
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• 2007

An increasing number of primate genomes are being sequenced. A direct comparison of repeat elements in human genes and their corresponding chimpanzee orthologs will not only give information on their evolution, but also shed light on the major evolutionary events that shaped our species. We have developed REPEATOME to enable visualization and subsequent comparisons of human and chimpanzee repeat elements. REPEATOME (http://www.repeatome.org/) provides easy access to a complete repeat element map of the human genome, as well as repeat element-associated information. It provides a convenient and effective way to access the repeat elements within or spanning the functional regions in human and chimpanzee genome sequences. REPEATOME includes information to compare repeat elements and gene structures of human genes and their counterparts in chimpanzee. This database can be accessed using comparative search options such as intersection, union, and difference to find lineage-specific or common repeat elements. REPEATOME allows researchers to perform visualization and comparative analysis of repeat elements in human and chimpanzee.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.349-353
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• 2007

The main functions of excavator are mainly carried out by excavator attachments such as arm and boom. These components should be designed to be light as well as durable enough because their effects on the whole structure are significant. In this paper, an optimization procedure for lightweight design considering fatigue strength for excavator attachments is presented. The weight of attachments and allowable fatigue stresses at critical areas are used as objective function and constraints, respectively, in which design variables are the thickness of the plates of attachments. The simulated annealing search method is adopted for a global optimization solution. Besides, the response surface method using the artificial neural network is used to simulate constraint function for the sake of practical fast calculation. Some example case of optimization is presented here for a sample excavator. This weight optimization is expected to contribute to a considerable improvement of fuel efficiency of excavator.

• Journal of Astronomy and Space Sciences
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• 제29권1호
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• pp.57-61
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• 2012

Binary companions are often invoked to explain the axial and point symmetry seen in the majority of planetary nebulae and proto-planetary nebulae (PPNs). To explore this hypothesis, we have undertaken a long-term (20 year) study of light and velocity variations in PPNs. From the photometric study of 24 PPNs, we find that all vary in brightness, and from a subset of 12 carbon-rich PPNs of F-G spectral type we find periods of 35-155 days, with the cooler having the longer periods. The variations are seen to be due to pulsation; no photometric evidence for binarity is seen. A radial velocity study of a sub-sample of seven of the brightest of these shows that they all vary with the pulsation periods. Only one shows evidence of a longer-term variation that we tentatively identify as being due to a binary companion. We conclude that the present evidence for the binary nature of these PPNs is meager and that any undetected companions of these PPNs must be of low mass (< 0.25 $M_{\odot}$) or long period (> 30 years).

• Asian Pacific Journal of Cancer Prevention
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• 제15권3호
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• pp.1075-1079
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• 2014

MicroRNA expression is a research focus in studies of tumors. This article concentrates attention on potential links between tumors caused by mouse mammary tumor virus (MMTV) and human breast cancer, in order to provide theoretical basis for using mouse model to search for miRNA effects mediated by Wnt/beta-catenin signaling in human breast cancer. By analyzing interactions between miRNAs and the Wnt/beta-catenin signaling pathway in breast cancer, we hope to casts light on more biological functions of miRNAs in the process of tumor formation and growth and to explore their potential value in cancer diagnosis, prognosis and treatment. Our endeavor aimed at providing theoretical basis for finding safer, more effective methods for treatment of human breast cancer at the miRNA molecular level.

• Journal of Applied Biological Chemistry
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• 제57권1호
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• pp.29-32
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• 2014

This study was initiated to search for the most effective method for extraction of anthocyanins from Morus alba Fruits using organic acids and to evaluate the stability of the pigments at various storage environments. The anthocyanins were effectively extracted by addition of organic acids such as citric acid, malic acid and fumaric acid. The anthocyanins were not degraded at $25^{\circ}C$ and under a fluorescent light with 183 lux, but sharply degraded at $60^{\circ}C$.