• Research in Mathematical Education
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• v.13 no.4
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• pp.297-307
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• 2009

This research examined intuitive knowledge of 6th grade students in Israel prior to the formal learning of percentages in school. In other words. the research investigated knowledge of basic concepts and familiarity with the usage of percentages in daily life. Results have shown that students are familiar with the concept of percentages and thai some students are able to handle simple problems composed of common percentages (50% and 25%). However, it was also found that many students had misconceptions that should be taken into account while the subject has been taught.

• The Korean Journal of Zoology
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• v.18 no.3
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• pp.157-159
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• 1975

本 硏究는 안주애기박쥐에 대한 寒冷$(6 \\pm 2^\\circ C)$의 反應을 調査한 基礎資科로서 寒冷에서 冬眠에 突入時 體溫과 心膊率의 變動樣相은 큰갈색박쥐와 작은 갈색박쥐의 경우와 相異하였다. 體溫曲線에서 흔히 高平部를 볼 수 있었으나, 體溫調節의 特徵인 据置狀變化는 本 硏究에서는 볼 수 없었다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2018.11a
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• pp.114-116
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• 2018

본 논문에서는 빔-호핑 위성 전송 시스템을 위한 카운터를 기반의 연속적인 beam allocation time schedule (BATS) 변경 기법을 제안한다. 제안하는 기법은 BATS 를 처음 변경할 때, 카운터를 기반으로 gateway (GW)와 space craft (SC) 양단에서 BATS 변경 시점을 동기화 시킨다. 이 후, BATS를 계속 변경하더라도 전송 데이터 손실 없이 BATS 를 변경할 수 있다.

• Animal cells and systems
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• v.2 no.1
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• pp.49-53
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• 1998

The winter-resident Korean bats, Murina leucogaster ognevi, show a circadian cycle of thermoregulation and locomotion in summer, as do other bat species in temperate regions. They are most active between dusk and dawn with body temperature (Tb) of 35-4OC, and are usually torpid in their roost sites for the rest of day with their Tb close to ambient temperature (Ta) of around 15C. The present study was conducted to determine thermogenic and thermolabile properties of the heterothermic bats that would influence their daily feeding activities and ultimately, their energy conservation strategy. Testing on active male Murina, resting metabolic rate (RMR, gauged by oxygen consumption rate) at the lower limit of thermoneutral zone (31C) was 2.0 L kq-1 h-1. The regression slope of RMR below the thermoneutral zone (an index of metabolic thermal sensitivity) was -0.38 L $kg^{-l} h^{-1} C^{-1}$. The metabolic rate at the roost Ta (15C) was 4.5 times the lowest RMR in the active state but becomes nearly zero in the torpid state. This implies that by being torpid during daytime (between dawn and dusk), the individual bats would save about 4.7 kcal each day in mid-summer. Interspecific comparisons of thermal metabolic response over a mass scale suggest that the smaller bats show a relatively higher metabolic rate in thermoneutral zone and a greater thermal sensitivity of metabolism, which follows the general principle seen in homeothermic metabolism. Thermolabile features in metabolic responses seem to be fairly common for these bats in conditions other than a fully active state. Types of thermolabile responses and their energetic significance are discussed.

• Animal cells and systems
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• v.5 no.1
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• pp.31-35
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• 2001

Temperate-resident bats exhibit a circadian cycle of torpor and arousal In summer. The physiological role and selective advantage of torpor as an energy saving mechanism have been received much attention by hibernation biologists. However, despite the significance of the recovering euthermic function, the arousal process and mechanism in these animals have been poorly addressed. In this study, we investigated thermogenic and motor activities of a local bat species Murina leucogaster during arousal by simultaneously examining oxygen consumption rate, body temperature ($T_b$) and pectoral electromyography (EMG). We found that Tb of the torpid bats (12-14$^{\circ}C$) was augmented slowly by nonshivering mechanism during the initial awakening phase. The pectoral shivering, gauged by EMG activity, occurred between 17$^{\circ}C$ and 38$^{\circ}C$. Over this Tb range of shivering, heat was produced at a rate of 0.145 kcal $kg^{-1}\;min^{-1}$ to raise 1$^{\circ}C$ $T_b$ per min. Shivering was most intensive at 30-35$^{\circ}C$ where both EMG amplitude and spike frequency were the highest. Activation of the pectoral myofibers seemed to be controlled in a manner that motor units were recruited from smaller to larger sizes, with greater synchronization, as muscle shivering became intensive with increasing $T_b$.

• Applied Microscopy
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• v.16 no.2
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• pp.61-74
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• 1986

The anatomy of the renal papilla and pelvis of the bat(Pipistrellus abramus abramus Temminck) and their ultrastructure of the epithelium has been studied by means of light, scanning and transmission electron microscopy. The bats were captured at Ondal cave located in Yangchun-Myun, Tanyang-Kun, Chungchongpuk-Do, Korea in the active(July) and hibernating(January) phases. A conical renal papilla with several papillary foramina at the apex was curved toward the ureter. At the margin of the funnel-shaped renal pelvis, the fornix extended deeply into the kidney parenchyme was formed between the outer zone of the medulla and the cortex. The epithelium of the papilla covered the inner zone of the medulla. The epithelium of the fornix medially overlayed the outer zone of the medulla, and laterally the cortex. The surface epithelium of the papilla was simple columnar in shape with the scanty organelles and the short microvilli on their luminal surface. The fornix was Jined with $1{\sim}2$ cell layered squamous epithelium. On the medial surface of the fornix, two types of the superficial epithelial cells were identified; one had numerous short microvilli and the other had the microplicae and plaques on their luminal surface. The lateral surface of the fornix lined with the epithelial cells showed microridges and plaques on the luminal surface. The epithelial cells on the medial and lateral surfaces of the fornix were similar to their internal ultrastructures. The pelvic epithelium was a typical transitional type, which was composed of a layer of basal cells, one or two layers of intermediate cells, and a layer of superficial(facet) cells. The fusiform vesicles were observed in the cytoplasm of the intermediate and facet cells. There were no noticeable morphological changes in the epithelium of the papilla, fornix and pelvis except the medial epithelium of the fornix in the hibernating cycle. The microvillar cells were more numerous in the hibernating phase than in the active phase. The morphology, of the renal papilla and fornix of bats, indicates that a functional relationship may exist between the pelvic urine and the renal parenchyme.

• Journal of Environmental Science International
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• v.26 no.6
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• pp.779-788
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• 2017

In this study, we analyzed the changes in the echolocation and prey-capture behavior of the horseshoe bat Rhinolophus ferrumequinum from search phase to capture time. The experiment was conducted in an indoor free-flight room fitted with an ultra-high-speed camera. We found that the bats searched for food while hanging from a structure, and capturing was carried out using the flight membrane. In addition, it was confirmed that the mouth and uropatagium were continuously used in tandem during the capturing process. Furthermore, using Constant Frequency (CF), we confirmed that the prey catching method reflected the wing morphology and echolocation pattern of R. ferrumequinum. The echolocation analysis revealed that the pulse duration, pulse interval, peak frequency, start-FM-bandwidth, and CF duration decreased as the search phase approached the terminal phase. Detailed analysis of echolocation pulse showed that the end-FM bandwidth, which increases as it gets nearer to the capture time of prey, was closely related to the accurate grasp of the location of an insect. At the final moment of prey capture, the passive listening that stopped the divergence of the echolocation was identified; this was determined to be the process of minimizing the interruption from the echo of the echolocation call emitted from the bat itself and sound waves emitted from the prey.

• Publications of The Korean Astronomical Society
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• v.32 no.1
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• pp.197-199
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• 2017

Using the InfraRed Camera (IRC) on board the infrared astronomical satellite AKARI we study the ${3.3{\mu}m}$ polycyclic aromatic hydrocarbon (PAH) feature and its connection to active galactic nucleus (AGN) properties for a sample of 54 hard X-ray selected bright AGN, including both Seyfert 1 and Seyfert 2 type objects. The sample is selected from the 9-month Swift/BAT survey in the 14-195 keV band and all of the sources have known neutral hydrogen column densities ($N_H$). The ${3.3{\mu}m}$ PAH luminosity ($L_{3.3{\mu}m}$) is used as a proxy for star-formation (SF) activity and hard X-ray luminosity ($L_{14-195keV}$) as an indicator of the AGN power. We explore for possible difference of SF activity between type 1 (un-absorbed) and type 2 (absorbed) AGN. We use several statistical analyses taking the upper-limits of the PAH lines into account utilizing survival analysis methods. The results of our log($L_{14-195keV}$) versus log($L_{3.3{\mu}m}$) regression shows a positive correlation and the slope for the type 1/unobscured AGN is steeper than that of type 2/obscured AGN at a $3{\sigma}$ level. Also our analysis shows that the circum-nuclear SF is more enhanced in type 2/absorbed AGN than type 1/un-absorbed AGN for low $L_{14-195keV}$ luminosity/low Eddington ratio AGN, while there is no significant dependence of SF activity on the AGN type in the high $L_{14-195keV}$ luminosities/Eddington ratios.

• Journal of Conservation Science
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• v.36 no.1
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• pp.15-27
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• 2020

The Main Hall of the Fengguo monastery in Yixian county, Liaoning province, China, is the best preserved and largest wooden Buddhist structure, typical of the Liao dynasty style, in China. However, some degradation to the timber frame of the Main Hall has been noted, and this is causing concern in terms of the long-term preservation of the structure. In this study, wooden pillars showing the degradation phenomena of whitening, for areas in contact with the stone floor, and extensive surface damage at higher locations(mostly above 1 m) have been examined. Samples taken from wooden pillar surfaces were analyzed using X-ray powder diffraction, Fourier-transform infrared spectroscopy(FTIR), ion chromatography, and pH measurements. With respect to the whitening phenomenon, we found inorganic calcium precipitates and oxalate ions, along with higher pH values. These symptoms indicated that chemical changes were taking place in response to alkaline conditions, suggesting that alkaline mixtures with calcium content in the foundations may be responsible. Regarding the upper surface-damaged areas, no valid evidence for chemical degradation was found using FTIR analysis, while damaged areas exhibited the presence of more bat guano-related materials than which were apparent in undamaged areas. The occurrence of this surface-damaged phenomenon has therefore been attributed to physical damage caused by bat activity over long periods of time.

• The Journal of the Korea Contents Association
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• v.17 no.2
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• pp.656-677
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• 2017

This study aims to examine the effects of native advertising on consumer-brand relationship quality (BRQ) formation of the potential consumers in the context of an automotive brand. Specifically, the study verifies (1) whether the respondents cognize the content of native advertisement as an advertisement and (2) how the value dimensions of native advertising impact BRQ through brand attitude (BAT). To fulfill the purposes, the researchers categorized three types of advertisements (product, brand and non-commercial) and then showed three manipulated stimuli to potential consumers in the automotive market before measuring. The findings drawn from the 345 valid cases are as following. First, the rate of respondents' advertising recognition is low in the non-commercial advertisement, while it is high in ones of product and brand. Second, most of the respondents perceive less irritation toward the native ads, especially toward the non-commercial advertisement. Third, the entertainment and informativeness of native advertising positively influence BRQ, while the effect of irritation on BRQ is negative. Also, the effects of advertising value dimensions on BRQ are all mediated by BAT.