• Journal for History of Mathematics
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• v.24 no.3
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• pp.1-12
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• 2011

It is well known that the sexagesimal cycle(干支) has been playing very important role in ordinary human affairs including astrology and almanacs and the arts of divination(術數). Yin-Yang school related the cycle with the sixty four hexagrams and the system of five notes(五音) and twelve pitch-pipes(十二律), and the processes to relate them are called respectively NaJia(納甲) and NaYin(納音) and quoted in Shen Kuo's Meng qi bi tan(夢溪筆談, 1095). Yang Hui obtained the process NaYin in the context of mathematics. In this paper we show that Yang Hui introduced the concept and notion of functions and then using congruences and the composite of functions, he could succeed to describe perfectly the process in his Xu gu zhai qi suan fa(續古摘奇算法, 1275). We also note that his concept and notion of functions are the earliest ones in the history of mathematics.

• Journal of Korea Game Society
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• v.17 no.2
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• pp.117-122
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• 2017

This study verified the effects of promoting optimism by utilizing communication board games with university students. Since optimism is closely related to grade, self-efficacy, a sense of achievement, the importance of enhancing optimism was emphasized. This study seeks to investigate practical measures that can promote optimism utilizing games in a more casual environment based on the research of Seligman(1990), which claimed that the optimism can be learned regardless of temperaments. In Study1, the level of optimism increased from M=-4.7(t1) to M=12.8 in t2(p<.001). In Study2, a control group(n=22) was added with the experiment group(n=21). The level of optimism increased from M=-2.4(t1) to M=11.5(t2) in the experiment group(p<.001), whereas there was no difference in the control group.

• Korean Journal of Child Studies
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• v.26 no.1
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• pp.329-345
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• 2005

Gender and intelligence of children, parenting practices and socioeconomic status of parents were studied to investigate whether they functioned as protective factors for resilient children. Total of 556 children of 12 years of age were contacted for the study. Teachers were asked to rate the children's interpersonal competence. Children reported their experience of stressful life events on a checklist. Based on the competence scores and the experience of stressful life events, 107 children were classified into adaptive, resilient, and maladaptive group. IQ scores were assessed using an intelligence test for the 107 children. Mothers reported their parenting practices and their socioeconomic status through a questionnaire. Descriptive statistics, chi-squares, t-tests, and one-way ANOVAs were performed to analyze the data. There was no difference in their experience of stressful life events between boys and girls. Girls were rated as being more competent by their teachers. There were more girls in the adaptive and the resilient group and more boys in the maladaptive group. Children in adaptive and the resilient group had higher intelligence scores than the maladaptive group. Mothers of resilient children replied as being warm and acceptive and more refusing and controlling than mothers of the adaptive children Group differences in socioeconomic status of the family were not found. Thus, being a girl and having higher IQ scores were the protective factors for the resilient children.

• The Journal of Society for e-Business Studies
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• v.15 no.4
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• pp.1-19
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• 2010

Recently, it is necessary to process real time sensor data, which is generated from ubiquitous environments. Data, which are written by XML, are small, but, large volumes of data. Therefore, weneed to use an efficient method for processing a large amount of it. An XQuery has two types for sensor data: one is to get sensor identification and value from sensor data; the other is restructuring for user's convenience. Existing XQuery engines don't have efficient method for batch processing of sensor data. This paper proposed the twig query processing over reverse path summary, and we developed and applied restructuring batch processing method for real time processing of a large amount of sensor data. Finally, we do performance evaluation using XMark and RFID EPC data, and comparison analysis with MonetDB/XQuery and Berkeley DB XML.

• Journal of the Korean Geotechnical Society
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• v.20 no.9
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• pp.65-75
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• 2004

In this paper, a mechanism of the soil structure reinforced by geosynthetics is discussed. The reinforcing mechanism is interpreted as an effect arising from the reinforcement works preventing the dilative deformation (negative dilatancy) of soil under shearing. A full-scale in-situ model test was carried out in Kanazawa of Japan (1994), and in the laboratory test the strength and the characteristics of deformation conducting a constant volume shear test are examined. The parameters needed in the FEM are also applied by using the experimental data. The elasto-plastic finite element simulation is carried out, and the results are quantitatively compared with that of experiment. As a results, it is known that the theoretical predictions could explain effectively the experimental results which are obtained by a full-scale in-situ model test.

• Journal of the Korean Geosynthetics Society
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• v.3 no.4
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• pp.3-12
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• 2004

In this paper, a mechanism of the soil structure reinforced by geosynthetics is discussed. The reinforcing mechanism is interpreted an effect arising from the reinforcement works so as to prevent the dilative deformation (negative dilatancy) of soil under shearing. A full-scale in-situ model test was carried out in Kanazawa of Japan(1994) and in the laboratory test the strength and the characteristics of deformation conducting a constant volume shear test are examined. The parameters needed in the FEM are also applied by using the experimental data. The elasto-plastic finite element simulation is carried out, and the results are quantitatively compared with that of experiment. As a results, it is known that the theoretical predictions could be explained effectively the experimental results which are obtained by a full-scale in-situ model test.

• Korean Journal of Social Welfare Studies
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• v.49 no.1
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• pp.297-334
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• 2018

This study focused on accomplishment of successful life development after discharge a child-care facility even though they had a variety of diversity in hard environment on their own past. Furthermore the research analyzed expression progress and detail information of resilience effect on twenty healthy members of society, who lived theirselves for more than 10 years at out of chid-care centers, based on grounded theory methodology participants. As written in the result section of the study, using the paradigm model analysis showed that it was caused by 'Practical planning for the future', 'Organization of positive meaning' and 'Understanding in another's shoe'. The contextual condition appeared as 'Self examination, 'Seeking anchor as ontology' and 'Natural intimacy among family members'. The centralization phenomenon came in 'Living philosophy of internal stabilities'. The intervention condition appeared as 'Rise up through the world' and 'faith all the world'. The action-interaction showed up as 'Strict self-discipline' and 'Growing up own family'. The consequence appeared as 'Making social family' and 'Being a someone's social mentor'. This research shows discussion in depth based on above analyzed result.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.240-240
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• 2016

인류문명의 발달과 함께 경제력도 크게 개선되었으나 인구가 집중되어 있는 도시지역에서의 침수가 반복되고 있다. 도시침수는 직간접적인 피해규모가 심각하므로 구조적인 대책과 비구조적인 대책을 통하여 홍수방재에 많은 투자가 이루어져 왔다. 또한 계획규모 또한 상향조정되어 있다. 그러나 실제로 향상된 계획규모에 적합하도록 전체 홍수방재시설을 개수하는 데는 많은 기간과 예산으로 인하여 진행이 이루어지고 있지 못하고 있으며 과거의 호우사상에서 살펴볼 수 있는 바와 같이 계획규모를 크게 초과되는 홍수는 자주 발생되어 왔으며 이로 인한 도시침수도 계속되어 왔다. 이러한 현상은 기후변화 및 돌발홍수 등으로 인하여 앞으로도 반복될 가능성이 매우 높아질 것으로 예측된다. 따라서 현재의 홍수방재시설에 대하여 향상된 계획규모의 호우사상 또는 이를 초과하는 극대호우사상에서의 홍수방재를 위한 방안수립이 시급한 상황이라고 판단된다. 본 연구에서는 계획규모를 초과하는 극대호우사상에 대비하여 최소한의 예산으로도 획기적으로 도시침수를 억제할 수 있는 방안을 제시하고자 하였다. 도시지역에서의 홍수방재는 침수억제가 가장 중요하므로 침수모의를 통하여 통수능이 부족한 경우라도 침수가 발생되지 않는 지역은 제외하고 침수에 취약한 지점만을 대상으로 침수원인을 파악하여 역경사 또는 경사부족구간의 개선, 소규모 분산형 저류지를 통한 침수억제 및 빗물저류조와 빗물펌프장에서의 운영강화 등을 통하여 경제적인 침수억제방안의 수립을 전제하여 침수모의를 수행하였다. 연구결과 최소한의 구조적 개선과 기존 방재시설의 운영강화로 기왕의 홍수사상에서 발생된 침수에 대비하여 침수발생을 크게 저감시킬수 있는 것으로 분석되었다. 따라서 전반적인 개수보다는 중요침수지역들을 대상으로 우선순위를 결정하여 침수원인을 해소 하는 방안으로 홍수방재계획을 추진한다면 빠른 기간에 작은 예산으로 도시침수를 크게 저감 시킬 수 있을 것으로 기대된다.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.687-694
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• 2008

Given the daily tactical schedule, the purpose of the traffic management system is to develop operating plan that will achieve the stated schedule as best as possible. The operating plan has to be modified during the day because of occurring disturbance(e.g. delay, infrastructure breakdown, etc.) Conflict detection and resolution(CDRS) are aimed for adjusting the distorted schedule to tactical schedule. Our research separate CDRS into two hierarchy modules, line conflict control module and station conflict control module. We define the role of each modules and design the cooperative architecture. We suggest the conflict detection and resolution approach based on mathematical model. These results can be implemented as prototype modules.

• 한국노년학
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• v.28 no.4
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• pp.1213-1225
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• 2008

The purpose of this study was to determine psychosocial variables of exercise behaviors for old adults. A major research problem identified through theory of planned behavior and it's empirical data: Do cognitive-social variables(health risk perception, self-efficacy, group conformity, exercise attitude) significantly mediate exercise behaviors(intention, action, maintenance)? A total of 453 older adults above 65 years(171 males and 282 females) who were enrolled in various classes were randomly selected at adults centers in Seoul. Participants completed a battery of questionnaires including the psycho-social variables(health risk perception, self-efficacy, group conformity, exercise attitude) and exercise behaviors(intention, action, maintenance). The results of statistical procedures(e.g., hierarchical multiple regression) indicated self-efficacy and exercise attitude significantly predicted exercise intentions of older adults. Exercise intention was a significant predictor of action, and action was a significant predictor of exercise maintenance. In discussion, various psycho-social mechanisms were provided to interpret the results of this study, and future directions were suggested.