• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.499-500
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• 2006

The electrode wear in micro-EDM significantly deteriorates the machining accuracy. In this regard, electrode wear needs to be compensated in-process to improve the product quality. Therefore, there are substantial amount of research about electrode wear. In this study a control method for micro-EDM using discharge pulse counting is proposed. The method is based on the assumption that the removed workpiece volume is proportional to the number of discharge pulses, which is verified from experimental results analyzing geometrically machined volume according to various number of discharges. Especially, the method has an advantage that electrode wear does not need to be concerned. The proposed method is implemented to an actual micro-EDM system using high speed data acquisition board, simple counting algorithm with 3 axis motion system. As a result, it is demonstrated that the volume of hole machined by EDM drilling can be accurately estimated using the number of discharge pulses. In EDM milling process a micro groove without depth variation caused by electrode wear could be machined using the developed control method. Consequently, it is shown that machining accuracy in drilling and milling processes can be improved by using process control based on the number of discharge pulses.

• Spatial Information Research
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• 제14권3호
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• pp.299-319
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• 2006

본 연구는 위성 영상을 이용한 녹지 조사의 결과를 지도화하고 다양한 시기의 녹지변화 실태를 통합한 데이터베이스를 구축하여 그 결과를 토대로 GIS의 공간 객체 재정의 기법을 이용하여 녹지의 총량규제를 위한 기초자료를 확보할 수 있는 지의 가능성을 탐색하고자 출발하였다. 그리하여 사례 연구지역의 녹지 변화 추세에 대한 평가가 이루어졌고 규제 총량을 산정하는 과정에서 활용 방안이 제시되었다. 아울러 공간 객체 재정의를 통한 총량 규제 기초자료를 확보하는 데 있어 고려해야 할 기술적인 문제들과 더불어 실무에 도입시 고려하여야 할 핵심 사안(토지 모자이크의 분류, 녹피을 훼손 추세의 평가 등)에 대한 지침을 제시하였다. 기존에 조사지점에만 국한된 통계 수치정보가 광역적인 녹지 공간 변화 추이를 시각적으로 제시하는 데 많은 한계가 있었으나 공간 객체 재정의 기법의 활용을 통해 녹지의 규제 총량 결정과정의 설득력 확보에 기여할 수 있을 것으로 판단되었다. 본 연구가 녹지 보전에 있어 객관적인 데이터에 의거한 정책결정이 아닌 직관에 의존하여 왔던 관행을 개선될 수 있는 계기가 되어 향후 녹지보전관련 기술적인 측면이나 정책적인 측면에서 중요한 참고 자료가 될 수 있을 것으로 사료된다.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• 제32권4호
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• pp.129-136
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• 2021

Objectives: To investigate the relationship between brain structure and empathy in early adolescents with attention-deficit/hyperactivity disorder (ADHD). Methods: Nineteen early adolescents with ADHD and 20 healthy controls underwent 3T MRI. All the participants were assessed for different aspects of empathy using measures including the Interpersonal Reactivity Index and Empathy Quotient. Cortical thickness and subcortical structural volume based on T1-weighted scans were analyzed using FreeSurfer. Results: Cognitive empathy (t=-2.52, p=0.016) and perspective taking (t=-2.10, p=0.043) were impaired in the ADHD group compared with the control group. The cluster encompassing the left posterior insular, supramarginal, and transverse temporal cortices [cluster-wise p-value (CWP)=0.001], which are associated with emotional empathy, was significantly smaller in the ADHD group, and the volume of the left nucleus accumbens was greater than that of the control group (F=10.12, p=0.003, effect size=0.22). In the control group, the left superior temporal (CWP=0.002) and lingual cortical (CWP=0.035) thicknesses were positively associated with cognitive empathy, while the right amygdala volume was positively associated with empathic concern (Coef=14.26, t=3.92, p=0.001). However, there was no significant correlation between empathy and brain structure in the ADHD group. Conclusion: The ADHD group had a smaller volume of the cortical area associated with emotional empathy than the control group, and there was no brain region showing significant correlation with empathy, unlike in the control group.

• 한국컴퓨터정보학회논문지
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• 제22권10호
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• pp.63-71
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• 2017

In this paper, we develop the system for audio volume equalization of video on demand(VoD) content and propose the solution for it. In recent years, there has been a steady increase in the number of VoD users in addition to linear channels. However, viewers ought to sit in an uncomfortable way, adjusting the volume intermittently while they are broadcasted. Sudden changes of volume occur between the broadcasting channels, the programs from the co-channel, or the linear channels and the VoDs. Especially, upsurged dissatisfaction from the televiewers has been found due to the unequalized volume when shifting between the linear channel and the VoD. In order to solve this problem, multilateral efforts were put forth, such as a system for keeping the volume at a certain level in digital broadcasting program has been legislated domestically. It leads success in equalizing linear channel volume. On contrary, too little notice has been taken for distorted volume problem of video on demand(VoD) content. In this paper, we developed and applied the volume equalization system into VoD content to achieve uniformization, a similar condition with linear channel(-24LKFS). This suggestion helped uneven current of volume which was in the stage -16 ~ -20LKFS to stable condition by lowering into the stage of -24LKFS. It also brought 20% increase in perspective of volume quality satisfaction level.

• 동아시아식생활학회지
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• 제23권3호
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• pp.349-356
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• 2013

When making a yellow layer cake, an existing chemical leavening agent, sourdough starter powder, was used instead of using baking powder in order to produce batter where the acid agent in the baking powder was reduced using baking soda. The control group had the lowest share of the batter and therefore had the highest specific volume. In a test group, the share of SP4 was low and therefore, the specific volume was high. In terms of physiochemical characteristics, the volume, symmetry and uniform index was high in SP4 in the test group. The control group had the highest moisture content followed by SP4. In terms of texture, the control group had the lowest hardness and highest springiness. In the test group, SP4 had the lowest hardness and highest springiness. The result of the sensory evaluation indicates that SP4 had the best taste and flavor. In terms of overall preference, SP4 showed significantly higher preference overall. However, it did not show any significant difference compared to the control group.

• 대한한의학회지
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• 제30권2호
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• pp.117-126
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• 2009

Objectives: This study was performed to investigate the effects of Semen Persicae (SP) on infarct volume, COX-2 protein expression in the middle cerebral artery occlusion (MCAo) rats. Methods: Twenty-eight rats were randomly assigned to four groups (MCAo experimental group, MCAo control group, sham experimental group, control group). The middle cerebral artery (MCA) was occluded in the MCAo group by proximal focal cerebral ischemia rat model, while the MCA was not occluded in the sham group. SP extraction was administrated for 4 days to each experimental group. Neuroprotective effects were investigated by measurement of brain damage using 2, 3, 5-triphenyltetrazolium chloride staining and analysis of COX-2 protein expression by western blotting. Results: The occurrence of infarct volume in the SP oral administration group decreased compared to the control group. COX-2 protein expression in the SP oral administration group decreased compared to the control group. Conclusions: The present study demonstrates the effect of SP in reducing infarct volume and decreasing COX-2 expression.

• 한국산학기술학회논문지
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• 제1권2호
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• pp.9-14
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• 2000

건물의 에너지 효율과 절약을 위해 최근 주목을 많이 받고 있는 가변 풍량 유닛(VAV)에 대해 실제적인 적용을 위한 적분기를 가진 상태 궤환 제어기를 연구한다. 디지털 제어기에 적합하도록 제어기를 개발하게 되며, 디지털 제어기는 결과적으로 대상으로 하는 실내 공간의 온도와 급기 유량으로부터 VAV 유닛 댐퍼의 개도를 조절한다. 설정 온도의 변화와 외부 온도의 변화등의 조건에 대해 모의 실험이 수행되었으며, 단순화된 대상 실내 공간과 댐퍼 구동기의 모델링이 고려되어 제어기의 이득 파라미터와 시스템의 동특성과의 관계를 고찰한다.

• 한국식품조리과학회지
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• 제18권3호
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• pp.280-289
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• 2002

The quality characteristics of breads with different concentrations(2%, 4%) of Paecilomyces japonica (J2, J4) and Cordyceps militaris (M2, M4) powder were compared in terms if sensory and mechanical properties. In the sensory test, J2 and M2 groups gained good scores in taste, texture and odor acceptance as control grourp. Paecilomyces japonica-added group showed higher moisture and bigger volume than that of control group, and Cordyceps militaris group showed lower moisture content and decreasing volume. 'L' values of J and M groups was lower than control, and the longer the storage period, the lower the lightness. The more Paecilomyces japonica was added, the higher the 'a' value was, but Cordyceps militaris showed an opposite trend. The hardness of the bread was the lowest in J2 group and the highest in M4 group, and the longer tile storage period. the higher the hardness was (p＜.001). Overall, the addition of 2% Paecilomyces japonica showed a similar tendency with control group, and showed good scores especially in acceptance, moisture and volume. Paecilomyces japonica appeared to be more desirable than Cordyceps militaris.

• 대한한의학회지
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• 제22권4호
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• pp.142-150
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• 2001

Objectives : The purpose of this investigation is to evaluate and compare the effects of Sunghyangjunggi-san (SH) and Gwackhyangjunggi-san (GH) extracts on reperfusion following the MCA occlusion in rats. Methods : To evaluate the effect of Sunghyangjunggi-san (SH) and Gwackhyangjunggi-san (GH) extracts on reperfusion following the MCA occlusion, the volume of cerebral infarction and edema were measured and the change of the CA1 pyramidal neurons in the hippocampus were investigated by light microscopy. Results : 1. The infarction volume of the control group was 23.6%, that of the GH group was 23.7%, and that of the SH group was 18.5%. 2. The brain edema volume of the control group increased by 16% compared with that of the normal group, that of the GH group increased by 14%, and that of the SH group increased by 9%. 3. The number of surviving pyramidal neurons in the CAI area of the hippocampus was investigated under light microscopy. In the control group, few surviving pyramidal neurons excisted (mean 6.4) and similarly in the GH group (mean 8.5), but in the SH group, the number of surviving pyramidal neurons was significantly higher, to the mean 18.4. Conclusions : According to the above results, in regard to the damage of neurons following cerebral ischemia, the GH group has little effect of the protection of neurons compared to the control group, but the SH group has a remarkable effect.

• 호남수학학술지
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• 제32권2호
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• pp.193-202
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• 2010

We investigate the estimation of the moisture transfer coefficients in porous media by optimization technique which minimizes the functional defined by the squares error of the numerical solution of an inverse diffusion problem from their experimental values of the moisture content at the some time-steps. In this paper, we solve a diffusion equation numerically by the control volume finite element methods.