• Proceedings of the Korean Society for Cognitive Science Conference
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• 2005.05a
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• pp.212-215
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• 2005

연령의 증가에 따른 신경원의 활성화도 변화는 기억 및 집행기능 등의 인지기능에 영향을 미치는 것으로 알려져 왔다. 그러나 어떠한 뇌 영역의 기능적 저하가 연령증가에 따라 남자와 여자에서 차별적으로 인지기능의 변화를 가져오는지에 대해서는 거의 알려진 바가 없다. F-18 FDG PET을 이용하여 78명의 정상 성인 남녀를 대상으로 뇌 포도당 대사량을 조사하였다. 남녀가 공통적으로 연령증가에 따라 뇌 포도당 대사량의 저하를 보이는 영역은frontal lobe과 left insula, right anterior cingulate gyrus, bilateral caudate body, thalamus. right corpus callosum 이었다. 여성의 경우 남성과 달리 추가적으로 right caudate와 bilaterial thalamus에서 연령과 뇌 포도당대사량 간에 부적 상관을 보이고 있었다(P < 0.001 uncorrected). 남녀 모두에서 연령이 증가하면서 포도당 대사 저하를 보이는 right inferior frontal gyrus는 여자에게서만 포도당대사 감소비율이 유의하게 컸다. 남녀에서 보이는 이러한 노화 과정 동안의 뇌 포도당 대사의 저하율의 차이가 여성과 남성의 연령증가에 따른 인지적 기능의 차별적 저하에 대한 설명을 제시할 수 있을 것이라 생각한다.

• Journal of the Korean GEO-environmental Society
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• v.8 no.5
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• pp.23-29
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• 2007

The performance of the improved soil against liquefaction depends upon the chemical density, and it has been decided on the basis of the unconfined compressive strength of the improved soil up to date. On the other hand, several authors have proposed that the stiffness degradation could be treated as the clue for the judgment of the possibility of liquefaction. In this study, therefore, the stiffness degradation of the improved soil was estimated as the resistance against liquefaction by using the strain controlled cyclic triaxial test equipment. Based on the test results, it is concluded that the chemically treated sand can resist against the liquefaction in aspect of the reduction in effective stress and in the stiffness. Furthermore, even in the case of low chemical density, such as 2% in this study, has enough liquefaction resistance when compared with the 5~6% which often used in practical design. Considering this fact, the design of chemical density based on the unconfined strength can lead the overestimation in chemical density, and chemical density can be reduced when considering the stiffness reduction shown in this study.

• Journal of Digital Convergence
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• v.13 no.3
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• pp.295-304
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• 2015

We assessed reading-related skills in children with reading comprehension difficulties ("Poor comprehenders"), word decoding difficulties ("Poor decoders") and normal readers, matched for age and nonverbal IQ. The reading-related skill tests used in our study are phonological processing, visual processing test, and receptive vocabulary test. The authors argue that children who had difficulty in reading comprehension had lower scores only on the phonological short-term memory test compared with normal readers, although their performance on receptive vocabulary and visual processing tests are comparable to normal readers. The results of our study revealed that poor decoders had lower scores on the phonological processing, visual processing, and receptive vocabulary tests.

• The Journal of the Korea Contents Association
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• v.13 no.7
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• pp.301-310
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• 2013

The purpose of this study was to investigate and compare the risk factors of cognitive impairment between non-depressive elderly and depressive elderly. Data was obtained from 1,477 elderly not diagnosed to dementia. In result, non-depressive elderly group was found as having risk factors of cognitive function in age and educational level. In non-depressive group, older elderly(OR=1.095) and the elderly with no experience of education(OR=9.129) had more in risk of cognitive impairment. Depressive elderly group was found as having risk in age, educational level, and residence style. In depressive elderly, older elderly (OR=1.101), the person with low education(illiteracy:OR=33.020, elementary:OR=10.176, middle school: OR=9.841), and the elderly living in nursing home(OR=8.490) had more in risk of cognitive impairment. Through this result, it could be suggested that the depressive elderly with low educational level living in nursing home should be intervened to decrease the rate of dementia more effectively.

• Culinary science and hospitality research
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• v.12 no.4 s.31
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• pp.259-268
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• 2006

It has been recognized that high level of serum cholesterol is a risk factor associated with atherosclerosis and coronary heart disease. Ingestion of probiotic lactic acid bacteria(LAB) in Kimchi would possibly be a method to decrease serum cholesterol in humans, as it was reported. In vitro culture experiment evaluated the effects of LAB(Leu. citreum, Lac. plantarum, Leu. mesenteroides, Weissella kimchii, W. confusa) extracted from Kimchi on cholesterol reduction in the MRS broth containing soluble cholesterol. Experimental strain of Leu. citreum and Leu. mesenteroides dominated in the first phase of Kimchi fermentation reduced the level of cholesterol 55.64% and 56.37%, respectively. Also, cholesterol lowering-effect was observed in over 55% of Lac. plantarum, W. kimchii and W. confusa strains, which were dominated in the end phase of fermentation. Our results suggest that selected probiotic LAB from Kimchi have an excellent cholesterol reducing effect in in vitro culture.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.1
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• pp.151-157
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• 2013

In this paper, a comparative analysis of PBTI induced device degradation in nanowire n-channel junctionless and inversion mode Multiple-Gate MOSFET(MuGFETs) has been performed. It has been observed that the threshold voltage is increased after PBTI stress and the threshold voltage variation of junctionless device is less significant than that of inversion mode device. However the degradation rate of junctionless device is less significant than that of inversion mode device. The activation energy of the device degradation is larger in inversion mode device than junctionless device. In order to analyze the more significant PBTI induced device degradation in inversion mode device than junctionless device, 3-dimensional device simulation has been performed. The electron concentration in inversion mode device is equal to the one in junctionless device but the electric field in inversion mode device is larger than junctionless device.

• Korean Journal of Remote Sensing
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• v.20 no.2
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• pp.117-124
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• 2004

A spherical earth surface is used for realistic analysis of the geometrical performance characteristics generated by 2-dimensional line-of-sight (LOS) tilt of the satellite imager using the Time Delay and Integration(TDI) technique. A 2-dimensional LOS tilt ever the spherical Earth surface is proposed to compensate geometric performance degradation caused by the satellite altitude decrease below the normal operation altitude. The compensation can be achieved by TDI re-match without degradation of modulation transfer function and with ground sample distance slightly increased. Effective methods of LOS tilt for the compensation are investigated. This study can be useful for mission assurance and flexibility in imager operation.

• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.31-31
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• 2020

가뭄 발생 시 국내 농어촌 지자체 대부분은 추가 수원공 확보를 위한 긴급 대책으로 신규 관정을 개발하거나, 저수지와 하천을 준설하여 가뭄 수요에 대응하는 편이다. 이러한 방법은 즉시 대응에는 효과가 있지만, 고가의 비용이 소요되고, 무엇보다도 국지적으로 가뭄이 빈번하게 발생하는 지역에는 적용에 한계가 있다. 이러한 한계를 극복하기 위하여, 최근 기설 관정을 연계 이용하여 지하수 공급 극대화를 도모하는 기술이 제안되었다. 그런데 기설 관정 연계 이용 시 가장 중요한 사항은 모든 관정에서 최대 양수량을 유지하며 지하수를 공급할 수 있도록 관리해야 하는 점이며, 특히 암반관정의 과잉양수로 인한 간섭현상으로 충적관정이 고갈되어 공급가능한 지하수 수량이 오히려 감소되는 것을 사전에 방지하여야 한다. 이 연구에서는 가뭄 발생 시 암반관정(양수정)에서 최대로 양수했을 때에도 주변 충적관정의 양수능이 유지되는 최소 지하수위를 「지하수위 저하 한계치」로 지정하여 관정 연계 이용의 최적화를 도모하였다. 지하수위 저하 한계치 산정을 위하여, Theis의 자유면 대수층 정상류 우물수리 방정식과 지하수영향반겅 설정에 관한 경험식(Schultz, Weber, Kozeny 및 Jacob 경험식)을 이용하였다. 그런데 지정된 지하수위 저하 한계치는 충적관정의 지하수위이므로, 암반관측공만 소재하는 지역에 대해서는 충적층 지하수위 변동과 암반층 지하수위 변동 간의 상관분석을 통해 암반 관측공의 지하수위 저하 한계치를 추정하였다. 이후, 양수시험 자료(양수정과 주변 관측공의 수위변동 자료)를 이용하여 지하수 대수층의 이방성을 확인하였고, 이를 통해 암반관정의 양수에 따른 간섭을 크게 받는 충적관정과 그렇치 않은 충적관정을 구분하여 이방성에 따른 지하수위 저하 한계치를 수정하고, 상습가뭄 발생지역의 암반관정과 충적관정의 최적 지하수 양수를 도모하였다.

• Journal of Nutrition and Health
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• v.49 no.5
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• pp.313-322
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• 2016

Purpose: This study was conducted to examine the relationship among cognitive function, nutrition screening initiative (NSI) score, and food intake status. Methods: A total of 409 subjects aged over 60 years were recruited from the Yongin dementia prevention and control center. Mini Mental State Examination Dementia Screening (MMSE-DS) method was used to assess the cognitive function of the subjects. Information on health related behaviors and food intake was collected by face to face interview using a structured questionnaire. The questionnaires included the NSI DETERMINE checklist, food intake sheets by 24 hr recall method and by semi-quantified food frequency questionnaire. Results: Subjects were divided into low cognitive or normal groups according to the MMSE-DS result. The prevalence of low cognitive function in the subjects was 25.7%. The low cognitive group exercised less and had higher nutritional health risk than the normal group. The low cognitive group had lower consumption of polyunsaturated fatty acid and higher tendency of thiamin, riboflavin, and iron deficiency. The low cognitive group had less frequency of eating mackerel, pepper, tangerine, and watermelon and higher frequency of eating white rice and cookies than the normal group. Conclusion: The results of this study imply that the cognitive function of elderly is related to exercise behavior, nutritional health risk, and food and nutrient intake status.

• Korean Journal of Psychosomatic Medicine
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• v.25 no.2
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• pp.136-144
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• 2017

Objectives : Cognitive complaints are reported frequently after breast cancer treatments. The causes of cognitive decline are multifactorial, a result of the effect of cancer itself, chemotherapy, and psychological factors such as depression and anxiety. However, cognitive decline does not always correlate with neuropsychological test performance. The purpose of this study was to examine the relationship of subjective cognitive decline with objective measurement and to explore associated factors of cognitive function in breast cancer survivors. Methods : We included 29 breast cancer survivors who complain cognitive decline at least 6 months after treatment and 20 age-matched healthy controls. Neuropsychological tests were performed in all participants. Multivariable regression analysis evaluated associations between neuropsychological test scores and psychological distress including depression and anxiety, also considering age, education, and comorbidity. Results : There were no statistically significant differences in neuropsychological test performances. However, the breast cancer survivors showed a significantly higher depression(p=0.002) and anxiety(p<0.001) than the healthy controls did. Among the cancer survivors, poorer executive function was strongly associated with higher depression(${\beta}=-0.336$, p=0.001) and anxiety(${\beta}=-0.273$, p=0.009), after controlling for age, education, and comorbidity. In addition, poorer attention was also significantly related with depression(${\beta}=-0.375$, p=0.023) and anxiety (${\beta}=-0.404$, p=0.013). Conclusions : The results of this study showed the discrepancies between subjective complaints and objective measures of cognitive function in breast cancer survivors. It suggests that subjective cognitive decline could be indicators of psychological distress such as depression and anxiety.