• 산업경영시스템학회지
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• 제25권6호
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• pp.42-47
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• 2002

This paper examines the effects on mental task of changes in the intensity of physical activity. A treadmill-equipped instrument and perception tester were used to attain several levels of physical activity. In this paper, in order to determine the individual levels of physical activity of subjects, Borg-RPE scale, heart rate(HR) and respiratory quotient(RQ) were used. Also, an arithmetic addition test in whole-body activity on treadmill-equipped instrument as an indicator of mental task were performed. In the above experiments, the scores obtained in arithmetic addition test administered before and after physical activity at each intensity level used. Restricted within the limits of this paper, the results of these tests showed that the performance of mental task was Increased after physical activity.

• 정보교육학회논문지
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• 제15권4호
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• pp.635-644
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• 2011

본 연구는 컴퓨터를 통한 덧셈학습을 낮은 숫자(1 - 5)의 조합인 덧셈 학습과 높은 숫자(6 - 9)의 조합인 덧셈학습으로 나누어 문제 난이도에 따른 뇌 반구성을 분석하였다. 뇌 반구성의 특성을 보기 위하여 암묵적 연합검사(IAT, Implicit Association Test)를 통하여 덧셈학습 형태를 뇌의 반구성을 나타내는 감정과 논리와 연합시켜 덧셈 학습의 난이도에 따른 인지적 차이를 좌우뇌와 연결하여 분석하였다. 연구결과 뇌의 전체영역에서는 두정엽쪽의 저알파파(8-10Hz)와 후두엽의 SMR파(12Hz-15Hz), 남녀별로는 남자는 의미 있는 차이가 없고 여자인 경우 전두엽의 알파파(8-12Hz)에서 의미 있는 차이를 보여주었다. 뇌의 반구성은 측두엽을 중심으로 세타파(4-8Hz)와 베타파(12-30Hz)에서 의미 있는 차이를 보여주었다. 본 연구를 통하여 개인별 뇌기능의 특성에 기반한 컴퓨터 수학학습의 구성과 자료 개발을 위한 생리학적 기반 근거를 마련하였다. 본 연구결과는 수학 정보교육에서의 난이도 구성 및 문제해결과정의 학습자 인지과정에 대한 뇌활성도를 제시한 것으로 다양한 정보교육 과목 및 문제유형의 뇌과학적 규명에 대한 가능성을 보여주었다.

• 한국수학교육학회지시리즈A:수학교육
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• 제57권3호
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• pp.311-328
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• 2018

In school mathematics, the concept of an average is not a concept that is limited to a unit of statistics. In particular, high school students will learn about arithmetic mean and geometric mean in the process of learning absolute inequality. In calculus learning, the concept of average is involved when learning the concept of average speed. The arithmetic mean is the same as the procedure used when students mean the test scores. However, the procedure for obtaining the geometric mean differs from the procedure for the arithmetic mean. In addition, if the arithmetic mean and the geometric mean are the discrete quantity, then the mean rate of change or the average speed is different in that it considers continuous quantities. The average concept that students learn in school mathematics differs in the quantitative nature of procedures and objects. Nevertheless, it is not uncommon to find out how students construct various mathematical concepts into mathematical knowledge. This study focuses on this point and conducted the interviews of the students(three) in the second grade of high school. And the expression of students in the process of average concept formation in arithmetic mean, geometric mean, average speed. This study can be meaningful because it suggests practical examples to students about the assertion that various scholars should experience various properties possessed by the average. It is also meaningful that students are able to think about how to construct the mean conceptual properties inherent in terms such as geometric mean and mean speed in arithmetic mean concept through interview data.

• 한국초등수학교육학회지
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• 제19권4호
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• pp.501-525
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• 2015

본 논문은 2009 개정 교육과정 초등학교 3학년 수학 교과서와 익힘책에 제시된 곱셈과 나눗셈 문장제를 유형별로 분석하고, 초등학교 4학년 학생을 대상으로 문장제 유형에 따른 문제해결능력을 살펴봄으로써 곱셈과 나눗셈 문장제의 효율적인 지도 방안을 생각해보기 위한 것이다. 이를 위해 먼저 초등학교 3학년 수학 교과서와 익힘책에 제시된 자연수의 곱셈 문장제를 동수누가, 비율, 비교, 정렬, 조합의 5가지 의미 유형으로, 나눗셈은 등분제와 포함제의 2가지 유형으로 구분하여 살펴보았다. 이와 함께 곱셈과 나눗셈 문장제에서 미지수의 위치에 따라 처음량, 변화량, 결과량을 묻는 문장제의 구문 유형에 대해서도 살펴보았다. 그런 다음 4학년 학생을 대상으로 문장제 문제해결능력 검사 도구를 개발하였는데, 앞서 분석한 곱셈과 나눗셈의 문장제 유형을 의미와 구문으로 나누어 2차례의 검사를 실시하여 정답률과 학생들의 오답 반응 등을 분석하였다. 분석 결과 곱셈은 동수누가에서의 정답률이 높게 나온 반면 나눗셈의 경우 포함제와 등분제에서 차이를 보이지 않았는데, 이는 교과서의 문제 유형 분포와 상관관계를 보임을 알 수 있다. 이러한 논의를 바탕으로 곱셈과 나눗셈 문장제의 효과적인 지도와 학생들의 문장제 문제해결능력을 향상시키기 위해 다양한 유형의 문장제를 제시할 필요가 있음을 제안하고 있다.

• 전자공학회논문지C
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• 제34C권2호
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• pp.29-37
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• 1997

A new algorithm and parallel architecture for high-speed complex number multiplication is presented, and a prototype chip based on the proposed approach is designed. By employing redundant binary (RB) arithmetic, an N-bit complex number multiplication is simplified to two RB multiplications (i.e., an addition of N RB partial products), which are responsible for real and imaginary parts, respectively. Also, and efficient RB encoding scheme proposed in this paper enables to generate RB partial products without additional hardware and delay overheads compared with binary partial product generation. The proposed approach leads to a highly parallel architecture with regularity and modularity. As a results, it results in much simpler realization and higher performance than the classical method based on real multipliers and adders. As a test vehicle, a prototype 8-b complex number multiplier core has been fabricated using $0.8\mu\textrm{m}$ CMOS technology. It contains 11,500 transistors on the area of about $1.05 \times 1.34 textrm{mm}^2$. The functional and speed test results show that it can safely operate with 200 MHz clock at $V_{DD}=2.5 V$, and consumes about 90mW.

• 한국초등수학교육학회지
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• 제21권1호
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• pp.23-47
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• 2017

본 연구에서 초등학교에서 분수에 대한 사칙연산의 학습을 마친 시점에 있는 6학년 학생들을 대상으로 학업성취수준에 따라 분수의 사칙연산 과정에서 발생하는 오류는 어떤 것들이 있는지 분수의 사칙연산 유형별로 오답률을 분석하였고, 학업성취수준에 따라 각각의 분수의 오류유형에는 어떤 차이가 있는지 알아보았다. 분수의 사칙연산에서 진분수 사이의 계산보다는 대분수가 같이 있는 계산에서 가장 높은 오답률을 보이고 있다. 특히 동분모 분수의 계산보다는 이분모 분수에서의 계산에서 높은 오답률을 보이고 있는데 학생들이 이분모 분수에서 통분을 하는 것을 어려워하는 것으로 나타났다. 분수의 곱셈에서는 상 수준과 중 수준의 학생들은 계산오류에서 가장 높은 오답률을 보이고 있으며, 하수준의 학생들은 역수오류가 가장 높은 오답률을 보이고 있다.

• 대한전기학회논문지:전력기술부문A
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• 제48권5호
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• pp.636-642
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• 1999

The synthesis of the 3D images is the most important part of the virtual reality. The ray tracing is the best method for reality in the 3D graphics. But the ray tracing requires long computation time for the synthesis of the 3D images. So, we implement the ray tracing with software and hardware. Specially we design the hit-test unit with FPGA tool for the ray tracing. Hit-test unit is a very important part of ray tracing to improve the speed. In this paper, we proposed a new hit-test algorithm and apply the parallel architecture for hit-test unit to improve the speed. We optimized the arithmetic unit because the critical path of hit-test unit is in the multiplication part. We used the booth algorithm and the baugh-wooley algorithm to reduce the partial product and adapted the CSA and CLA to improve the efficiency of the partial product addition. Our new Ray tracing processor can produce the image about 512ms/F and can be adapted to real-time application with only 10 parallel processors.

• 한국산업정보학회논문지
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• 제9권1호
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• pp.56-62
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• 2004

산업현장에서는 높은 강도의 육체적 작업에 병행하여 정신적 작업이 요구되는 경우가 있다. 육체적 작업 후에 피로의 회복을 위한 충분한 시간이 주어지지 않는 경우, 이 피로에 수반되는 정신적 피로에 의해 정신적 작업의 정확도는 저하된다는 보고가 있다. 그러나 본 연구에서는 높은 강도의 근육활동에 숙련된 그룹과 숙련되지 못한 그룹 모두에서 본 연구를 위한 실험조건 하에서는 오히려 육체적 활동 후의 정신적 작업의 정확도가 증가한다는 것이 밝혀졌다. 또한 물리적 자극에 대한 이들 그룹의 반응시간을 측정하여 정신작업의 정확도와의 관계를 해석하였다. 그 결과 반응시간은 높은 강도의 근육활동에 숙련된 그룹에서만 운동강도에 따라 안정적으로 점증하였고, 모든 피실험자 그룹에 대해서 정신작업의 정확도와 반응시간은 밀접한 관계에 있지 않음을 알 수 있었다.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2001년도 학술발표회 발표논문집
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• pp.93-98
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• 2001

This study was performed to analyse the rainfall and the rainfall-runoff characteristics of a rural watershed. The Sangwha basin($105.9km^{2}$) in the Geum river system was selected for this study. The arithmetic mean method, the Thiessen's weighing method, and the isohyetal method were used to analyse areal rainfall distribution and the Huff's quartile method was used to analyse temporal rainfall distribution. In addition, daily runoff analyses were peformed using the DAWAST and tank model. In the model calibration, the data from June through November, 1999 were used. In the model calibration, the observed runoff depth was 513.7mm and runoff rate was 45.2%, and the DAWAST model simulated runoff depth was 608.6mm and runoff rate was 53.5%, and the tank model runoff depth was 596.5mm and runoff rate was 52.5%, respectively. In the model test, the data from June through November, 2000 were used. In the model test, the observed runoff depth was 1032.3mm and runoff rate was 72.5%, and the DAWAST model simulated runoff depth was 871.6mm and runoff rate was 61.3%, and the tank model runoff depth was 825.4mm and runoff rate was 58%, respectively. The DAWAST and tank model's $R^{2}$ and RMSE were 0.85, 3.61mm, and 0.85, 2.77mm in 1999, and 0.83, 5.73mm, and 0.87, 5.39mm in 2000, respectively. Both models predicted low flow runoff better than flood runoff.

• Asian Pacific Journal of Cancer Prevention
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• 제14권5호
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• pp.3243-3254
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• 2013

It is well known that increased incidences of lung, skin, and bladder cancers are associated with occupational exposure to PAHs. Animal studies show that certain PAHs also can affect the hematopoietic and immune systems and can produce reproductive, neurologic, and developmental effects. As a consequence, several studies have been attempted to investigate the fate of PAHs in atmospheric environment during the past decades. However, there is still a lack of information in regard to the atmospheric concentration of PAHs during the "Bon Fire Night". In this study, twenty-three polycyclic aromatic hydrocarbons and twenty-eight aliphatics were identified and quantified in the $PM_{10}$ and vapour range in Birmingham ($27^{th}$ November 2001-$19^{th}$ January 2004). The measured concentrations of total particulate and vapour (P+V) PAHs were consistently higher at the BROS in both winter and summer. Arithmetic mean total (P+V) PAH concentrations were $51.04{\pm}47.62$ ng $m^{-3}$ and $22.30{\pm}19.18$ ng $m^{-3}$ at the Bristol Road Observatory Site (BROS) and Elms Road Observatory Site (EROS) respectively. In addition arithmetic mean total (P+V) B[a]P concentrations at the BROS were $0.47{\pm}0.39$ ng $m^{-3}$ which exceeded the EPAQS air quality standard of 0.25 ng $m^{-3}$. On the other hand, the arithmetic mean total (P+V) aliphatics were $81.80{\pm}69.58$ ng $m^{-3}$ and $48.00{\pm}35.38$ ng $m^{-3}$ at the BROS and EROS in that order. The lowest average of CPI and $C_{max}$ measured at the BROS supports the idea of traffic emissions being a principle source of SVOCs in an urban atmosphere. The annual trend of PAHs was investigated by using an independent t-test and oneway independent ANOVA analysis. Generally, there is no evidence of a significant decline of heavier MW PAHs from the two data sets, with only Ac, Fl, Ph, An, 2-MePh, 1+9-MePh, Fluo and B[b+j+k]F showing a statistically significant decline (p<0.05). A further attempt for statistical analysis had been conducted by dividing the data set into three groups (i.e. 2000, 2001-2002 and 2003-2004). For lighter MW compounds a significant level of decline was observed by using one-way independent ANOVA analysis. Since the annual mean of $O_3$ measured in Birmingham City Centre from 2001 to 2004 increased significantly (p<0.05), it may be possible to attribute the annul reduction of more volatile PAHs to the enhanced level of annual average $O_3$. By contrast, the heavier MW PAHs measured at the BROS did not show any significant annual reduction, implying the difficulties of 5- and 6-ring PAHs to be subject to photochemical decomposition. The deviation of SVOCs profile measured at the EROS was visually confirmed during the "Bonfire Night" festival closest to the $6^{th}$ November 2003. In this study, the atmospheric PAH concentrations were generally elevated on this day with concentrations of Fl, Ac, B[a]A, B[b+j+k]F, Ind and B[g,h,i]P being particularly high.