• 한국전자파학회논문지
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• 제21권11호
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• pp.1220-1228
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• 2010

본 논문에서는 비선형 RF 전력 증폭기의 효율적인 다항식 기반의 이산 신호 모델링 방법을 제시하였다. 비선형 RF 증폭기의 입, 출력 신호의 샘플링 과정을 통하여 이산 비선형 모델을 추출하는 과정을 기술하고, 테일러 급수와 메모리 다항식 구조를 이용한 다항식 기반의 비선형 이산 모델에서 모델 인자인 샘플률, 비선형 차수, 최대 메모리 깊이의 변화에 따른 모델의 오차를 분석하였다. 다항식 기반의 비선형 모델에서 오차는 샘플률, 비선형 차수, 최대 메모리 깊이에 대하여 특정 값 이후부터 일반적으로 수렴하는 특성을 보인다. 이에 모델 인자값에 따른 시스템의 복잡성을 고려하는 효율적인 이산 신호 모델링 기법을 제시하였다. 모델링 효율 지수를 정의하고, 이를 활용하여 최적의 모델 인자 값을 추출하는 방법을 제시하였다. 제시한 방법을 WiBro, WCDMA 등의 다양한 신호를 가지는 RF 전력 증폭기의 모델링에 적용하고, 제시한 방법의 효율성을 검증하였다. 제안된 기법은 빠른 속도의 모델링과 저렴한 가격의 디지털부를 사용할 수 있게 하여 차후 광대역 송신기에서의 빠른 속도와 낮은 가격의 디지털 전치 왜곡기 구성 등에 활용될 수 있을 것으로 사료된다.

• 대한가정학회지
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• 제31권3호
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• pp.197-212
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• 1993

The purpose of this study was to find out the physical change of the farm house and its anbang(the main room : master bed room), to identify the behavioral changes : activity and awareness of anbang, and to clarify the relationship between the physical changes of the farm house, and the behavioral changes of housing life-style in the anbang space. Bibliographical studies, cultural approaches and field survey method with questionnaire were used to collect data from 55 residents of Anwhari and Yangkyori in Pyong Teck Koon. Tables and drawings were made to analyze the data. The major findings were 1) the heating system of the ondol anbang. The most popular type is the double heating system(new pipes added to the traditional ondol). This combination ondol system brought some conviniences to the farmers. This change in structure of the ondol were of four types : Complete change in style, enlarged-completely changed style, partially changed style, enlarged-partially changed style. 2) from 1960 through 1970 lighting of the anbang changed room oil lamp to electricity. 3) the finishing material of the anbang floor changed from traditional oil paper and straw mats to vinyl flooring. 4) Traditional furniture and small decor items are gradually disappearing and are being replaced by modern items. 5) The awareness and actual use of the ondol anbang has not much changed from the multi-functional and sacred space of daily living : which are the characteristics of Korean traditional ondol anbang. The biggest consistency in the ondol anbang is the heating system of the floor, which is the characteristic of ondol culture in Korea. This system will continue regardless of time and place in Korea.

• Asian-Australasian Journal of Animal Sciences
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• 제14권2호
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• pp.288-296
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• 2001

The behavior of declawed emus in a farm environment has not been described despite its importance in the husbandry and welfare of the emu. This study examined whether declawing of emus causes chronic pain resulting in permanent changes in the locomotor and general behavior of declawed yearling emus compared to emus not declawed. One group of 40 emus were declawed on the day of hatch by removing the distal phalangeal joint using a Lyon beak-trimming machine. Another group of 40 emus not declawed were the controls. Declawed emus one year of age were allocated to a paddock $250m{\times}125m$, while the control group was placed in an adjoining paddock of the same dimensions. One hour video records of individual emus from each treatment were made from 08:00 and 17:00 h over 2 periods; firstly when food and water was available and secondly during a period when food and water was not available after being withdrawn overnight. Inactive, ingestive, posture change, grooming, aggressive and locomotor behaviors were monitored from the videotape. There was no behavioral evidence to indicate loss of locomotor ability of declawed emus or to suggest declawed emus were suffering from severe chronic pain as indicated by declawed emus engaging in significantly more bouts (p<0.05) and time of searching (p<0.05). Declawed emus also engaged in less stereotype pacing (p<0.05) indicating they were under less stress and not as frustrated as control birds which engaged in more step pushing behavior (p<0.05). Modelling analysis showed that pecking behavior in birds was most closely related to foraging behavior. Birds subject to pecking attacks demonstrated higher levels of stereotype behavior presumably as a method to cope with stress. The behavioral evidence in this study would indicate that declawing does not compromise the locomotor ability of emus and has the benefit of improving the social structure in the groups by reducing stereotype behavior and aggression.

• BMB Reports
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• 제44권12호
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• pp.793-798
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• 2011

Recently, pluripotency induction or cellular reprogramming by introducing critical transcription factors has been extensively studied, but has been demonstrated only in vitro. Based on reports that Oct4 is critically involved in transforming neural stem cells into pluripotent cells, we used the lentiviral vector to introduce the Oct4 gene into the hippocampal dentate gyrus (DG) of adult mice. We examined whether this manipulation led to cellular or behavioral changes, possibly through processes involving the transformation of NS cells into pluripotent cells. The Oct4 lentivirus-infused group and the green fluorescent protein lentivirus-infused group showed a similar thickness of the DG and a comparable level of synaptophysin expression in the DG. Furthermore, our behavioral analyses did not show any differences between the groups concerning exploratory activity, anxiety, or memory abilities. This first trial for pluripotency induction in vivo, despite negative results, provides implications and information for future studies on in vivo cellular reprogramming.

• BMB Reports
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• 제54권6호
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• pp.317-322
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• 2021

CCCTC-binding factor (CTCF), a zinc finger protein, is a transcription factor and regulator of chromatin structure. Forebrain excitatory neuron-specific CTCF deficiency contributes to inflammation via enhanced transcription of inflammation-related genes in the cortex and hippocampus. However, little is known about the long-term effect of CTCF deficiency on postnatal neurons, astrocytes, or microglia in the hippocampus of adult mice. To address this, we knocked out the Ctcf gene in forebrain glutamatergic neurons (Ctcf cKO) by crossing Ctcf-floxed mice with Camk2a-Cre mice and examined the hippocampi of 7.5-10-month-old male mice using immunofluorescence microscopy. We found obvious neuronal cell death and reactive gliosis in the hippocampal cornu ammonis (CA)1 in 7.5-10-month-old cKO mice. Prominent rod-shaped microglia that participate in immune surveillance were observed in the stratum pyramidale and radiatum layer, indicating a potential increase in inflammatory mediators released by hippocampal neurons. Although neuronal loss was not observed in CA3, and dentate gyrus (DG) CTCF depletion induced a significant increase in the number of microglia in the stratum oriens of CA3 and reactive microgliosis and astrogliosis in the molecular layer and hilus of the DG in 7.5-10-month-old cKO mice. These results suggest that long-term Ctcf deletion from forebrain excitatory neurons may contribute to reactive gliosis induced by neuronal damage and consequent neuronal loss in the hippocampal CA1, DG, and CA3 in sequence over 7 months of age.

• 한국학교수학회논문집
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• 제26권2호
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• pp.137-158
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• 2023

본 연구는 1993년부터 시행된 대학수학능력시험 수학 영역의 변화를 살펴봄으로써 향후 수학 영역 체제의 개선 방향을 탐색하고 우리나라 고등학교 수학교육에서의 평가 방향 정립을 위한 시사점을 도출하고자 하였다. 이를 위해, 대학수학능력시험 수학 영역을 시험 체제, 내용 영역, 행동 영역을 중심으로 분석하고 다음과 같은 결과를 얻었다. 첫째, 시험 체제는 시험 시간, 문항 수 외에 평가 요소와 문항 유형 등에도 영향을 미쳤음을 확인하였다. 둘째, 내용 영역 분석을 통하여 교육과정과 평가 영역의 관계성을 확인하고, 평가 영역 설정의 중요성을 확인하였다. 셋째, 행동 영역 분석을 통하여 특정 행동 영역에서 문항 유형의 고착화 가능성을 확인하고, 평가 문항의 유형에 대한 지속적 변화의 필요성을 확인하였다. 이를 바탕으로 대학수학능력시험 수학 영역에서의 시대적 요구와 변화를 반영할 수 있는 평가의 방향과 그에 따른 제반 사항에 대하여 논의하였다.

• Nutrition Research and Practice
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• 제18권4호
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• pp.464-478
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• 2024

BACKGROUND/OBJECTIVES: Chronic alcohol consumption causes oxidative stress in the body, which may accumulate excessively and cause a decline in memory; problem-solving, learning, and exercise abilities; and permanent damage to brain structure and function. Consequently, chronic alcohol consumption can cause alcohol-related diseases. MATERIALS/METHODS: In this study, the protective effects of Phyllostachys edulis (Carrière) J. Houz (PE) against alcohol-induced neuroinflammation and cognitive impairment were evaluated using a mouse model. Alcohol (16%, 5 g/kg/day for 6 weeks) and PE (100, 250, and 500 mg/kg/day for 21 days) were administered intragastrically to mice. RESULTS: PE showed a protective effect against memory deficits and cognitive dysfunction caused by alcohol consumption, confirmed through behavioral tests such as the T-maze, object recognition, and Morris water maze tests. Additionally, PE attenuated oxidative stress by reducing lipid oxidation, nitric oxide, and reactive oxygen species levels in the mice's brains, livers, and kidneys. Improvement of neurotrophic factors and downregulation of apoptosis-related proteins were confirmed in the brains of mice fed low and medium concentrations of PE. Additionally, expression of antioxidant enzyme-related proteins GPx-1 and SOD-1 was enhanced in the liver of PE-treated mice, related to their inhibitory effect on oxidative stress. CONCLUSION: This suggests that PE has both neuroregenerative and antioxidant effects. Collectively, these behavioral and histological results confirmed that PE could improve alcohol-induced cognitive deficits through brain neurotrophic and apoptosis protection and modulation of oxidative stress.

• 전자통신동향분석
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• 제35권1호
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• pp.25-33
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• 2020

Just as it is possible to distinguish people by using physical features, such as fingerprints, irises, veins, and faces, and behavioral features, such as voice, gait, keyboard input pattern, and signatures, the an IoT device includes various features that cannot be replicated. For example, there are differences in the physical structure of the chip, differences in computation time of the devices or circuits, differences in residual data when the SDRAM is turned on and off, and minute differences in sensor sensing results. Because of these differences, Sensor data can be collected and analyzed, based on these differences, to identify features that can classify the sensors and define them as sensor-based device DNA technology. As Similar to the biometrics, such as human fingerprints and irises, can be authenticatedused for authentication, sensor-based device DNA can be used to authenticate sensors and generate cryptographic keys that can be used for security.

• 생물정신의학
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• 제2권1호
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• pp.28-37
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• 1995

Clinical neuropsychology which belongs to the necuroscience field is concerned with relationship between human behaviors and the brain structure. Clinical neuropsychology has grown to be a specialized separate field within psychology over the last twenty years. Clinical neuropsychology offers an objective methodology to consider the mind-body interaction and evaluate the behavioral consequences and functional deficits associated with brain lesions. Clinical neuropsychological assessment is composed of cognitive, perceptual, motor and emotional function through various neuropsychological examinations such as Halsted-Reitan and Luria-Nebraska batteries, and computerized neuropsychological test such as PCIS Vienna Test System and Stim. The goals of neuropsychological evaluation are to identify of neuropsychological dysfuncitions, to develop execute and monitor treatment plans, and to make rehabilitation programs. Recently, the neuropsychiatric patients are increasing in number and 15-20% of acute psychiatric patients suffer from organic mental problems. Moreover, clinical neuropsychology has an increasingly important role in both neurobehavioral foundation and clinical application. So, psychiatrists must play a major role in the development of clinical neuropsychology in psychiatry.

• 한국공작기계학회논문집
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• 제16권3호
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• pp.23-30
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• 2007

Nano-stages are used in many ultra-precision systems, such as scanning probe microscope(SPM), optical fiber aligners, ultra-precision cutting, measuring systems, and optical systems. It is difficult to find the solutions because the performances and characteristics of nano-scale motion stage are determined by various factors. To understand effects of nano-scale motion stage, three types of hinge structures were designed and manufactured. Each hinge structures were designed following with the results of simulation. And from the result of experiments, hysteresis, displacement, and accuracy were compared with each hinge structures.