• Journal of Educational Research in Mathematics
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• 제27권2호
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• pp.171-189
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• 2017

By designing and applying the lesson helping to discover the power laws, we tried to investigate the characteristics on the class. To do this, we designed a discovery lesson on the power laws and applied to 54 8th grade students. As results, we could observe the overproduction of monotonous laws, tendency to vary the type of development and increase error to students without prior learning experience, and various errors. All participants failed to express the generalization of $a^m{\div}a^n$ and some participants expressed an incomplete generalization using variables partially for the base or power. We could also observe an error of limited generality or a representation error which did not use the equal sign or variables. In the survey of students, there were two contradictory positions to appeal to the enjoyment of the creation and to talk about the difficulty of creation. Based on such results, we discussed the pedagogical implications relating to the discovery of power laws.

• Journal of Positioning, Navigation, and Timing
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• 제6권2호
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• pp.79-86
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• 2017

Precise Point Positioning-Real Time Kinematic (PPP-RTK) refers to a technology that combines PPP with network-RTK in which a user does not directly receive observed data from a reference station but receives State-Space Representation (SSR) messages corrected for error components from a central processing station through Networked Transport of RTCM via Internet Protocol (NTRIP) or Digital Multimedia Broadcasting (DMB) for purposes of positioning. SSR messages, which refer to corrections used in PPP-RTK, are generated by a central processing station using real-time observed data collected from reference stations and account for corrections needed due to the ionosphere, troposphere, satellite orbital errors, satellite time offsets, and satellite biases. This study used a type of SSR message provided in South Korea, known as Korea-SSR (K-SSR), to implement a PPP-RTK algorithm based on code-pseudorange measurements and validated its accuracy within the reference station network. In order to validate the accuracy of the implemented algorithm outside of the network, the K-SSR was extrapolated and applied to positioning in reference stations in Changchun, China (CHAN) and Japan (AIRA). This also entailed a quantitative evaluation that measured improvements in accuracy in comparison with point positioning. The results of the study showed that positioning applied with extrapolated K-SSR correction data was more accurate in both AIRA and CHAN than point positioning with improvements of approximately 20~50%.

• The Journal of the Korea institute of electronic communication sciences
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• 제15권5호
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• pp.807-812
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• 2020

This paper proposes a blind speech source separation algorithm using a microphone to separate only the target speech source signal in an environment in which various speech source signals are mixed. The proposed algorithm is a model of frequency domain representation based on independent component analysis method. Accordingly, for the purpose of verifying the validity of independent component analysis in the frequency domain for two speech sources, the proposed algorithm is executed by changing the type of speech sources to perform speech sources separation to verify the improvement effect. It was clarified from the experimental results by the waveform of this experiment that the two-channel speech source signals can be clearly separated compared to the original waveform. In addition, in this experiments, the proposed algorithm improves the speech source separation performance compared to the existing algorithms, from the experimental results using the target signal to interference energy ratio.

• Journal of KIISE:Computing Practices and Letters
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• 제15권8호
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• pp.566-575
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• 2009

Clinical Data Interchange Standards Consortium (CDISC) developed global and platform-independent data standards to improve ineffective processes of clinical trial studies. Regardless of its objective toward global cooperation, the current version of the CDISC standard cannot describe clinical trial data in various languages for multi-national investigators or reviewers. This problem applies not only to tabulated datasets in Study Data Tabulation Model (SDTM) but also to extensible markup language representation of the datasets in Operational Data Model (ODM) instances. In order to address this issue, we propose to extend the current version of SDTM and ODM to collect clinical data for multi-national clinical trials. SDTM needs to have new special-purpose domain for multi-language representation purpose. Additionally, ODM is recommended to extend its XML schema using subtyping or type inheritance mechanism respectively. Our extension of SDTM and ODM enable to represent any granule of study data tabulation model or XML data entities to describe in efficient languages. This result will contribute to collect multi-language data easily for multi-national clinical trials.

• Archives of design research
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• 제13권4호
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• pp.195-201
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• 2000

To find out media's function on the various effects in communication, this paper reviews studies that utilize multimedia as a device for conveying information. We discuss multimedia as an integrated symbol system with advantages and also problems in representing information. The cognitive dissimilarity of media could be explained by various attributes of medium that are about physical characteristics and even cognitive actions. With advantages from integrated media and interactivity, multimedia has negative results such as cognitive overload and in that reason systematic approach is needed. This paper shows the factors on media selection and relationship to interface components. To select appropriate media to the needs and situation, it should be considered the user's ${\circled1}$background ${\circled2}$knowledge / frequency of use / expertise, contents ${\circled1}$task nature ${\circled2}$type of knowledge and media ${\circled1}$representation format ${\circled2}$interaction techniques. Varying the media factors and varying the expression factors offers concrete design features.

• Journal of Advanced Marine Engineering and Technology
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• 제32권7호
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• pp.1051-1060
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• 2008

Now days, various types of ships are operated to transport both cargo and passengers all around the world. Most of the important auxiliary machinery installed in those ships is fluid machinery such as pumps, compressors, and fans. A large percentage of fluid machinery is pumps which are classified as turbo and positive displacement pumps. This paper analyzes only turbo pumps out of the two types. This thesis has two aims: (a) to analyze the present status of pumps installed in merchant and training ships and (b) to find the correlation among sea going pump kW, port pump kW, GE kW, ME MCR, number of pumps, ME kgf, pump kgf. Based on the ship's type, my paper seeks to find special characteristics as a result of analyzing head, flow rate, and kW. Moreover this paper analyzes and compares number of pumps, rpm of pumps, pump kW/ME MCR and pump kW/GE kW under the conditions of seagoing and berthing according to the ship's type. In conclusion, (1) For the exact comparison, information on the head, kW, flow rate, number of pumps by ship's type, the pump installation status of the Merchant Ships and Training Ships were tabulated and compared in this paper. (2) In order to qualify one ship as the delegate ship, several methods were used. The result of the examination indicates that the chosen ships could be justified as a suitable representation of ships of their own type. (3) The correlation of several values(total pump kW, port pump kW, GE kW, seagoing pump kW, pump weight, ME weight, ME MCR, number of pumps and ME kW) could be obtained.

• The KIPS Transactions:PartA
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• 제9A권3호
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• pp.363-370
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• 2002

OPKFDD (Ordered Pseudo-Kronecker Functional Decision Diagram) is one of ordered-DDs (Decision Diagrams) in which each node can take one of three decomposition types : Shannon, positive Davio and negative Davio decompositions. Whereas OBDD (Ordered Binary Decision Diagram) uses only the Shannon decomposition in each node, OPKFDD uses the three decompositions and generates representations of functions with smaller number of nodes than other DDs. However, this leads to the extreme difficulty of getting an optimal solution for the minimization of OPKFDD. Since an appropriate decomposition type has to be chosen for each node, the size of the representation is decided by the selection of the decomposition type. We propose a heuristic method to generate OPKFDD efficiently from the OBDD of the given function and the algorithm of the decision of decomposition type for a given variable ordering. Experimental results demonstrate the performance of the algorithm.

• Asian-Australasian Journal of Animal Sciences
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• 제21권3호
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• pp.331-339
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• 2008

The genetic structure and diversity of 15 Chinese indigenous chicken breeds was investigated using 29 microsatellite markers. The total number of birds examined was 542, on average 36 birds per breed. A total of 277 alleles (mean number 9.55 alleles per locus, ranging from 2 to 25) was observed. All populations showed high levels of heterozygosity with the lowest estimate of 0.440 for the Gushi chickens, and the highest one of 0.644 observed for Wannan Three-yellow chickens. The global heterozygote deficit across all populations (FIT) amounted to 0.180 (p<0.001). About 16% of the total genetic variability originated from differences between breeds, with all loci contributing significantly to this differentiation. An unrooted consensus tree was constructed using the Neighbour-Joining method and pair-wise distances based on marker estimated kinships. Two main groups were found. The heavy-body type populations grouped together in one cluster while the light-body type populations formed the second cluster. The STRUCTURE software was used to assess genetic clustering of these chicken breeds. Similar to the phylogenetic analysis, the heavy-body type and light-body type populations separated first. Clustering analysis provided an accurate representation of the current genetic relations among the breeds. Remarkably similar breed rankings were obtained with all methods.

• Journal of Fashion Business
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• 제10권4호
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• pp.16-28
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• 2006

The purpose of this study is to investigate the content and changes of modern Korean men's wear advertisement from the 1960s to the 1990s by reviewing fashion magazines and pictorials. Research problems were as follows.; First, analyze the types and their units of measurement in men's fashion advertisements from 1962 to 1998. Second, examine the differences of quantitative change in men's fashion advertisements according to each period. The total 857 advertisements were selected from Shin Dong-A, Joongang Magazine, and Bokjangwolbo from 1972 to 1998. For analyze the result, frequency analysis and $x^2$-test were used. Results were as follows. First, through the review of literatures and pre-tests, 6 units of measurement were identified. They were product type(formal wear, casual wear, sports wear, dress shirts, accessory, inner wear, fabric and the others), brand type(national brand, licensed brand, imported brand, others), appeal type(image, product, others), representation type(photograph, illustration, others), medium type(man, product, others), and color type of advertisement(black & white picture, color picture). Second, for the types of advertisements, formal wear, national brand, image appeal, figure medium, photograph for presentation and color picture are the most frequently shown in men's fashion advertisements from 1962 to 1998. Third, for product, more accessory advertisements were found than the clothing in the 60s and the 70s, and casual wear advertisements in the 80s and formal wear advertisements in the 90s were dominated. National brand type was dominant through all four period. Product appeal type in the 60s and the 70s and image appeal type in the 80s and the 90s were prevailed. For medium, product type in the 60s and the 70s and figure type in the 80s and the 90s were dominated. Black & white picture in the 60s and the 70s and color picture in the 80s and the 90s were prevailed. Lastly, photograph was the most frequently used for presentation type through all periods.

• Bulletin of the Korean Mathematical Society
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• 제54권6호
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• pp.1951-1967
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• 2017

We aim to introduce a further extension of a family of the extended Hurwitz-Lerch Zeta functions of two variables. We then systematically investigate several interesting properties of the extended function such as its integral representations which provide extensions of various earlier corresponding results of two and one variables, its summation formula, its Mellin-Barnes type contour integral representations, its computational representation and fractional derivative formulas. A multi-parameter extension of the extended Hurwitz-Lerch Zeta function of two variables is also introduced. Relevant connections of certain special cases of the main results presented here with some known identities are pointed out.