• 한국학교수학회논문집
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• 제23권3호
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• pp.259-276
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• 2020

본 연구는 이전과 현재의 교육과정에 따른 3~4학년군 초등학교 수학 교과서의 그래프 지도에서 교수학적 지도 방법이 어떤 방식으로 발생하고 전개되었는가를 파악하는 것이다. 이에 본 연구에서는 제5차 교육과정부터 2015 개정 교육과정까지의 각 교육과정에 따른 교과서와 지도서를 대상으로 막대그래프와 꺾은선그래프 단원을 분석하였고, 그래프 지도에서 통계 교육적 의의를 탐색하였다. 연구 결과 지속적인 교육과정 변천에도 막대그래프와 꺾은선그래프의 지도 시기는 변화가 거의 없었고, 공학의 활용을 최근의 교육과정이 강조하는 바에 비교해서 교과서는 적극적으로 활용되고 있지 않았다. 또한 통계에서 유의미한 개념인 자료의 변동성, 분포, 표본, 표본추출 등을 실제적으로 다루고 있지 않았다. 본 연구의 결과를 기반으로 통계 그래프 지도 및 통계 영역에서 교과서 개발에의 시사점을 제안하는 바이다.

• 한국수자원학회논문집
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• 제30권3호
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• pp.279-291
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• 1997

본 연구는 중소하천 유역에서 강우-유출과정의 모의절 위한 정도 높은 개념적 모형을 결정하기 위하여 기존의 개념적 선형 모형인 Clark 모형, Nash 모형과 개념적 비선형 모형인 Laurenson 모형과 WBN 모형을 위천 유역을 대상으로 적용 및 비교검토를 하였다. 선형 모형에서 산정된 매개변수들의 변동성은 비선형 모형의 매개변수의 변동성 보다 크게 나타났으며, 계측유역에서 4개 개념적 모형으로부터 합성한 수문곡선을 분석한 결과 첨두유량은 4개 모형간에 큰 차이가 없으나 첨두시간은 비선형 모형인 Laurenson 모형과 WBN 모형이 선형 모형보다 적합도가 높은 것으로 나타났다. 순위검정에 위한 Friedman의 이원분산분석결과 첨두유량을 예측하기 위한 4개 모형의 가능성간에는 모든 유역에서 어떤 유의한 차이도 나타내고 있지 않으나 유출수문곡선 전체의 재현성에서 비선형모형들이 선형 모형들 보다 다소 우월한 것으로 나타났다.

• Structural Engineering and Mechanics
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• 제75권4호
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• pp.425-434
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• 2020

Practical non-synoptic fluctuating wind often exhibits nonstationary features and should be modeled as nonstationary random processes. Generally, the coherence function of the fluctuating wind field has time-varying characteristics. Some studies have shown that there is a big difference between the fluctuating wind field of the coherent function model with and without time variability. Therefore, it is of significance to simulate nonstationary fluctuating wind field with time-varying coherent function. However, current studies on the numerical simulation of nonstationary fluctuating wind field with time-varying coherence are very limited, and the proposed approaches are usually based on the traditional spectral representation method with low simulation efficiency. Especially, for the simulation of multi-variable wind field of large span structures such as transmission tower-line, not only the simulation is inefficient but also the matrix decomposition may have singularity problem. In this paper, it is proposed to conduct the numerical simulation of nonstationary fluctuating wind field in one-spatial dimension with time-varying coherence based on the wavenumber-frequency spectrum. The simulated multivariable nonstationary wind field with time-varying coherence is transformed into one-dimensional nonstationary random waves in the simulated spatial domain, and the simulation by wavenumber frequency spectrum is derived. So, the proposed simulation method can avoid the complicated Cholesky decomposition. Then, the proper orthogonal decomposition is employed to decompose the time-space dependent evolutionary power spectral density and the Fourier transform of time-varying coherent function, simultaneously, so that the two-dimensional Fast Fourier transform can be applied to further improve the simulation efficiency. Finally, the proposed method is applied to simulate the longitudinal nonstationary fluctuating wind velocity field along the transmission line to illustrate its performances.

• Journal of Astronomy and Space Sciences
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• 제31권4호
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• pp.325-333
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• 2014

We are motivated by both the accumulating evidence for the connection of solar variability to the chemistry of nitrogen oxide in the atmosphere and recent finding that the Galactic cosmic-ray (GCR) influx is associated with the solar north-south asymmetry. We have analyzed the measured pH in precipitation over the 109 stations distributed in the United States. We have found that data of pH in precipitation as a whole appear to be marginally anti-correlated with the solar asymmetry. That is, rain seems to become less acidic when the southern hemisphere of the Sun is more active. The acidity of rain is also found to be correlated with the atmospheric temperature, while not to be correlated with solar activity itself. We have carried on the analysis with two subsamples in which stations located in the east and in the west. We find that the pH data derived from the eastern stations which are possibly polluted by sulfur oxides and nitrogen oxides are not correlated with the solar asymmetry, but with the temperature. On the contrary, the pH data obtained from the western stations are found to be marginally anti-correlated with the solar asymmetry. In addition, the pH data obtained from the western stations are found to be correlated with the solar UV radiation. We conclude by briefly pointing out that a role of the solar asymmetry in the process of acidification of rain is to be further examined particularly when the level of pollution by sulfur oxides and nitrogen oxides is low.

• Asian-Australasian Journal of Animal Sciences
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• 제25권2호
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• pp.286-290
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• 2012

The majority of laboratory animals were transported from commercial breeders to a research facility by ground transportation. During the transportation, many biological functions and systems can be affected by stress. In this experiment, the change of body weight during the transportation was measured and the recovery periods from the transportation stress established based on the body weight changes. Total 676 laboratory animals which were aged between 3 to 9 wk old were studied. The transportation time taken from container packing to unpacking the container was approximately 24 h. The temperature of animal container was constantly maintained by air-conditioning and heating equipment. Rats were found to be more sensitive than mice. The body weight of rats was significantly decreased 3.71% (p<0.05) compared to the body weight of mice which decreased 0.9% There was no significant difference between the strains in the same species. When the changes of body weights were compared between delivery days, C57BL/6 mice showed the most variable changes compared to other species and strains. Consequently, C57BL/6 was more sensitive to stress than the other strains and the transportation process needs to be standardized to reduce between day variability. To establish the recovery periods from transportation stress, the body weight changes were measured during the acclimation period. Although the body weight of animals decreased during transportation, animals recovered their weight loss after the next day.

• 유통과학연구
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• 제18권2호
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• pp.99-108
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• 2020

Purpose: This paper investigated the relationship between market competition and firm valuation error. Furthermore, Additional analyses were made according to the quality of financial reports and the listed market. Through the process we confirm to the impact of competition on the capital market. The purpose of this study is to analyze the impact of competition on valuation errors. The preceding studies did not provide a consistent results of the effects of competing functions on the capital market. One view is that the competition could mitigate the information asymmetry, and the other is that monopolistic lessens the manager's involvement in financial reporting. This study is intended to expand the prior study by analyzing the impact of competition on the capital market and on the valuation of investors. Research design, data, and methodology: The analysis was conducted on 12,031 samples over 11 years from 2008 to 2018 using data from market in Korea. Here the valuation error was measured by the research methodology of Rhodes-Kropf, Robinson and Viswanathan (2005), and competition measured by Herfindahl-Hirschman Index multiplied by (-1), and Concentration Ratio by (-1). Results: We confirm that the positive relationship between competition and the valuation error. In addition, we also found that the positive relation between competition and valuation error was in cases of low discretionary accruals and the KOSDAQ market. This means that the net function of competition does not mitigate valuation errors. Conclusions. This study has the following contributions when compared to prior research. First, the relevance between the level of competition and the valuation of the entity was confirmed. The study by Haw, Hu and Lee (2015) suggested that monopolistic industry of analysts' forecast is more accurate due to lower the variability in earnings. This study magnified it to confirm that monopolistic lessen information uncertainty in valuation. Second, the study on valuation errors was expanded. While the study on the effect of valuation errors on the capital market is generally relatively active, it is different that competition degree has analyzed the effect on valuation errors amid the lack of research on the effect on valuation errors.

• 한국농촌건축학회논문집
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• 제14권1호
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• pp.83-90
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• 2012

The purpose of this study was to set and analyze the standard model for prioritizing and deciding to take part in housing environment improvement project in the perspective of the public sector. The results of this study were as follows. The location competitiveness, potential demand, marketability and competitive price, etc were selected by assessment indicators. And Various indicators, including of the size of the area, public transportation, accessibility, convenience of living and the influx of the population, were used by weights indexes. The profit of local residents and the public promoter, variability of earnings, sensitivity analysis and the ratio of money in reserve, etc were also established as detailed indexes for the profitability and business risk analysis. To analyze the cash flow of the project process and review the necessary capital in advance, the payback, total working expenses, gearing ratio and sensitivity of a risk, etc were also set as additional detailed indexes. Lastly, considering it is quasi-public projects, the measure to protect tenants, necessity need of redevelopment and local government's will were additionally used by indexes. And Points were distributed on the importance of each index and scored out of 100. It will allow for the public project promoter to decide rationally whether to come in on the project. The public project promoter like the Korea Land and Housing Corporation will be able to make use of various indexes are based on this study to make decision whether joining the housing environment improvement project in depressed region.

• 복식
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• 제67권4호
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• pp.131-152
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• 2017

The purpose of this study is to analyze modern fashion culture in the 20th century through changes in transmedia in order to better understand characteristics of fashion contents. The study also strived to identify the characteristics of remediation in modern fashion and media by exploring the cultural code, and use it to establish an integrated view. The subjects and the method of the study are as follows. First, the study analyzed the development of transmedia and fashion culture since the 20th century. Second, it identified the transitional characteristics of transmedia. Third, the study analyzed the characteristics of remediation in modern fashion culture by using the characteristics of mediation, which appeared with the transitional characteristics of transmedia. The study results are as follows. First, the types of remediation are 'borrowing,' 'Representation,' 'Expansion,' 'Refashion,' and 'Absorb.' In old and new media, each type can be aesthetically experienced in 'transparency,' opaqueness,' 'Hypermediacy,' and 'Immediacy.' Second, fashion culture can undergo a transformation from its original form to a second and a third iteration, and this process allows for possibility of an expansion of multiple plots and well-rounded character settings. This opens up the possibility for fashion consumer participation, and signifies a transition into an environment where expansion of time and space is possible. The third finding is the non-mediation of fashion objects. The mediating relationship between clothes and media is directly connected to the development of new media. The immersion of new media by fashion consumers has the characteristics of 'transparency'/'Non-mediation,' and the reinterpretation and reproduction of original fashion styles have the characteristics of 'opaqueness'/'Hyper-mediation.' Fourth, fashion culture has data variability. Through 'Borrowing,' 'Representation,' 'Expansion,' 'Remodeling,' and 'Absorption,' the cultural hierarchy of reproduced fashion forms a multi-layered integrated network. Mediation code, which repurposes fashion culture contents, also creates new media fashion through transmedia.

• 품질경영학회지
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• 제39권4호
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• pp.527-542
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• 2011

The importance of service industry in national economy is getting increasing due to current trend of aging society and increasingly desire for better quality of life. However, the level of labor productivity in domestic service industry is lower than Japan and Germany that are typically strong in manufacturing industry. Difficulty of process control and measurement in accordance with variability and intangibility which are features of service industry, is considered as the cause of this poor labor productivity in Korea. This study aims to present managerial implications by calculating sigma levels on branch bank service quality and suggesting the quality dimensions of banks can be checked through a gap comparison between the sigma level on service quality in the whole banks and service quality in each bank. Quality level presented by the KS-SQI is applied to the measurement method that Yoo Han Joo and Song Kwang Seok suggested in 2006. Spss18.0 is used as an analysis tool. As a result of factorial analysis, 7 dimensions of service quality in KS-SQI can be divided into new 3 dimensions of service quality. This study also suggests that width and number of questions in previous questionnaire shall be extended. The whole of the bank service quality level is evaluated 3 sigma. The research help banks to figure out their service quality level through gap comparison objectively.

• 천문학회보
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• 제42권1호
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• pp.34.2-34.2
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• 2017

A small wide-field imaging telescope is a powerful instrument to survey the Universe: wide-field image can monitor the variability of many sources at a time, e.g. young stellar objects and active galactic nuclei, and it can be an effective way to locate transient sources without precise positional information such as gravitational wave sources or some gamma-ray bursts. In February 2017, we installed a 0.25 m f/3.6 telescope on the McDonald 0.8 m telescope as a piggyback system. With a $4k{\times}4k$ CCD camera, the telescope has a $2.35{\times}2.35deg$ field-of-view. Currently, it is equipped with Johnson UBVRI filters and 3 narrow-band filters: $H{\alpha}$, OIII and SII. We will present the installation process, and the telescope performance such as detection limit and image quality based on the data from commissioning observations. We will also discuss possible scientific projects with this system.