• 수면정신생리
• /
• 제15권2호
• /
• pp.67-70
• /
• 2008

Overlap syndrome can be defined as a coexistence of chronic obstructive pulmonary disease (COPD) and sleep apnea-hypopnea syndrome (SAHS). The association of COPD and SAHS has been suspected because of the frequency of both diseases. Prevalence of COPD and SAHS is respectively 10 and 5% of the adult population over 40 years of age. However, a recent study has shown that the prevalence of SAHS is not higher in COPD than in the general population. The coexistence of the two diseases is only due to chance. SAHS does not affect the pathophysiology of COPD and vice versa. Prevalence of overlap syndrome is expected to occur in about 0.5% of the adult population over 40 years of age. Patients with overlap syndrome have a more profound hypoxemia, hypercapnia, and pulmonary hypertension when compared with patients with SAHS alone or usual COPD patients without SAHS. To treat the overlap syndrome, nocturnal noninvasive ventilation (NIV) or nasal continuous positive airway pressure (nCPAP) can be applied with or without nocturnal oxygen supplement.

• 한국초등과학교육학회지:초등과학교육
• /
• 제34권1호
• /
• pp.72-85
• /
• 2015

Conception in learner's cognitive structure has a niche as species in ecosystems. The purpose of this study is to analyze the change of niche overlap of photosynthesis concept through instruction. The photosynthesis concepts were selected from literature review. Selected concepts were in 4 areas: Location of photosynthesis, reactants, products, and environmental factors. The subjects consisted 304 elementary students. The respondent marked the relevance between the presented concepts and each area on a scale of 1~30 points. The analysis of niche overlap in concepts was performed by changing in niche overlap graph, niche space size, and overlap index before and after instruction. The results are as follows. First, on the whole understanding level and relevance of the scientific concepts was increased through instruction as a result of learning. Second, elementary school students cognitive concepts in the form of chunking concepts through classification process. Based on the results, this study has the following suggestion. Students' conceptual ecologies and niche analyzed by this study will be used as material for development of instruction strategy.

• 한국정밀공학회지
• /
• 제27권11호
• /
• pp.17-23
• /
• 2010

Titanium alloy is one of the hard processing materials made by the traditional manufacturing method because of the excellent mechanical strength. Ablation of titanium alloy is investigated by using a femtosecond laser which is a regenerative amplified Ti:sapphire laser with 1kHz repetition rate, 184fs pulse duration time and 785nm wavelength. Experiments are carried out under various ablation conditions with different pulse overlap ratios for the rectangular shape and micro hole. Test results show that the ablation characteristic according to pulse overlap ratio of titanium alloy seems to be as non-linear type at the different zone of energy fluence. The optimal condition of rectangular shape processing is obtained at the laser peak power 1.3mW, pulse overlap ratio of 90%, beam gap of $1\;{\mu}m$. The micro hole has a good quality from the pulse overlap ratio of 99% at the same laser peak power. With the optimal processing condition, the fine rectangular shape and micro hole without burr and thermal damage are achieved.

• 한국정보시스템학회지:정보시스템연구
• /
• 제29권1호
• /
• pp.267-287
• /
• 2020

Purpose Online platform companies can increase the spread of content by communicating with users who have diverse preferences through social networks. Previous studies show the mixed effect on the network overlap, and there was a limited examinations for the underlying mechanism. This study expects high academic and practical implications that can be provided by studying on the user's viewership network. The purpose of this research is to examine the effects of network overlap on the users' viewership for creators of user-generated content in YouTube. We explain the direct and in-direct effects through the content sharing and the valence of user ratings. Design/methodology/approach The data contains 45 channels and 4,085 video clips from YouTube. We control the effect of the categories, channel characteristics, and vide clip characteristics on the viewership. PROCESS macro were used to analyze the direct and in-direct effects of network overlap. Findings The analysis results showed that the network overlap directly affect on the users' viewership. The variable decreases the moderators (i.e., content sharing and the valence of user ratings). This result implies that the users can not satisfy their need for uniqueness which is achieved by content sharing and rating in the overlapped network.

• 한국통신학회논문지
• /
• 제36권2C호
• /
• pp.99-104
• /
• 2011

처프 확산 대역 (chirp spread spectrum: CSS) 기술은 데이터 신호를 처프 신호를 통하여 최소 필요 대역보다 더 넓은 주파수 대역으로 확산시켜 전송하는 기술로서 오버랩 기법을 사용하여 데이터 전송률을 늘릴 수 있다. 그러나 데이터의 신뢰성 있는 전송을 위해서는 오버랩으로 인해 발생하는 심볼 간 간섭에 (intersymbol interference: ISI) 대한 분석이 필수적이다. 본 논문에서는 오버랩 기반 direct modulation binary phase shift keying CSS 시스템에서 오버랩 횟수와 ISI의 상관관계를 수학적으로 분석하였다. 구체적으로는 몇몇 특정 오버랩 횟수에 대해서는 오버랩으로 인한 ISI가 나타나지 않으며, 오버랩 횟수의 변화에 따라 오버랩으로 인한 ISI가 진동하거나 단조 증가함을 보였고, 모의실험 결과와 분석한 내용이 일치하는 것을 확인하였다.

• 한국생산제조학회지
• /
• 제25권2호
• /
• pp.118-123
• /
• 2016

Overlap cutting is a fundamental method of applying abrasive water jet (AWJ) machining to milling to produce a wider surface because the nozzle outlet is approximately 1.0 mm wide. In this study, the effects of overlap cutting on the depth profile and surface roughness are investigated. The overlapping area depends on the amount of step over, which is controlled in the pick-feed direction. If the step over is equal to or larger than the diameter of the nozzle, no overlap cut occurs but large cusps remain between the cut paths. A step over as small as one-thirds of the nozzle diameter may lead to triple-overlap cutting resulting in an extraordinary depth. By using pocket milling experiments with a step over of 0.46 (or 0.47), it is verified that AWJ can produce a milled surface of titanium, one of the hard-to-cut materials, with $76{\mu}m$ Ra.

• Clinical and Experimental Pediatrics
• /
• 제52권4호
• /
• pp.504-507
• /
• 2009

자가면역성 간염, 원발성 담관성 간경화증, 원발성 경화성 담관염은 대표적인 자가 면역성 간질환이다. 이 각 질환의 임상적, 조직학적, 혈청학적 특징이 혼재되어 어느 한 질환으로 진단하기 어려운 경우를 중복증후군(overlap syndrome)이라 하고, 최근 소아에게서도 드물게 보고되고 있다. 한편 경화성 담관염은, 염증성 장질환에서 가장 흔히 동반되는 간담도계질환으로 알려져 있다. 저자들은 궤양성 대장염으로 진단된 환아에게서 간조직 검사, 혈청 검사, 방사선 검사 등을 통해 자가면역성 간염-원발성 경화성 담관염의 중복증후군을 진단하였기에 보고하는 바이다. 염증성 장질환 환아에게서 자가 면역성 간질환 또는 중복증후군 동반여부를 염두에 두어 임상적, 조직학적, 혈청학적 검사를 통해 적절한 진단과 치료가 필요하겠다.

• 접착 및 계면
• /
• 제7권4호
• /
• pp.1-9
• /
• 2006

The single lap joint is the most studied joint in the literature in terms of both theory and practice. It is easy to manufacture and the lap shear strength is a useful value for strength assessment and quality control. Simple design rules exist such as the one present in standard ASTM 1002 or in a recent paper by Adams and Davies. The main factors that have an influence on the lap shear strength are the type of adhesive, i.e. ductile or brittle, the adherend yield strength and the overlap length. The overlap increases the shear strength almost linearly if the adhesive is sufficiently ductile and the adherend does not yield. For substrates that yield, a plateau is reached for a certain value of overlap corresponding to the yielding of the adherend. For intermediate or brittle adhesives, the analysis is more complex and needs further investigation. In order to quantify the influence of the adhesive, the adherend and the overlap on the lap shear strength, the experimental design technique of Taguchi was used. An experimental matrix of 27 tests was designed and each test was repeated three times. The influence of each variable could be assessed as well as the interactions between them using the statistical software Statview. The results show that the most important variable on the lap shear strength is the overlap length followed by the type of adherend.

• 대한한의학회지
• /
• 제22권2호
• /
• pp.31-40
• /
• 2001

This experimental studies was to investigate location of labeled neurons in CNS following injection of pseudorabies virus(PRV), Bartha strain, into the uterus and Sanyinjiao(Sp6) of rats. After survival times of 4-5 days following the injection of PRV, the rats were perfused, and their brain and spinal cord were frozen sectioned($30\mu\textrm{m}$). These sections were stained by PRV immunohistochemical staining methods, and observed with light microscope. The results were as follows: 1. In the spinal cord, overlap areas of PRV labeled neurons projecting to uterus and Sp6 were observed in lamina VII, IX and X areas of cervical segments. In thoracic segments, overlap areas were observed in lamina IV, VII, X and intermediolateral n.. In lumbar segments, overlap area of PRV labeled neurons were observed in lamina I, V-VII, IX, X and intermediolateral n.. In sacral segments, overlap areas of PRY labeled neurons were observed in lamina N, V, VII, X and sacral parasympathetic n.. 2. In the brain, overlap areas of PR V labeled neurons projecting to the uterus and Sp6 were observed in lateral paragigantocellular n., rostroventrolateral reticular n., raphe obscurus n., raphe pallidus n., raphe magnus n., locus coeruleus n., Barrington's n., A5 cell group, central gray n., paraventricular hypothalamic n. and arcuate n. This results suggest that overlap areas of PRV labeled neurons of the spinal cord projecting to the uterus and Sp6 might be the first-order neurons related to the viscera-somatic sensory and sympathetic preganglionic neurons. PRV labeled neurons of the brain may be the second and third-order neurons response to the movement of smooth muscle of uterus. These PRV labeled neurons may be central autonomic center related to the integration and modulation of reflex control linked to the sensory and motor system monitoring the internal environment. These overlap areas of spinal cord and brainmay be related to autonomic centers related to regulation of uterus.

• 대한기계학회논문집
• /
• 제15권1호
• /
• pp.376-385
• /
• 1991

본 연구에서는 그루브의 각도에 따라 그루브 에징을 한 형상과 상사하게 가상 의 슬라브를 제작하여 오버랩에 영향을 미치는 압연인자들을 분석하고 그 영향을 검토 함으로써 최적 G 롤의 각도를 결정하였고, 최적인 G 롤의 형상으로 에저를 제작하여 G 에징량에 따른 오버랩량의 변화를 고찰하였다.