• 치과방사선
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• 제21권1호
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• pp.137-143
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• 1991

In the study of the focal trough of panoramic radiograph using Panoura Eight-S (the Yoshida company), a series of 63 X-ray films were taken with the 8-19 metal pins placed in the holes of the plastic model plate and evaluated by 4 observers. The author analized the focal trough defined by the sharpness criteria and calculated dimension of focal trough in the horizontal plane. The results were as follows; 1. Focal trough was not continued in the anterior region within a very high degree of sharpness. 2. With optional sharpness, the width of anterior and posterior focal trough was approximately l3㎜ and 60㎜ respectively. 3. The focal trough was narrow in the anterior region and was flared laterally with symmetry in posterior region. 4. Sharp image began to show at the position of 18㎜ posteriorly from the most anterior position of chin rest.

• 치과방사선
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• 제12권1호
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• pp.115-121
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• 1982

In the study of the focal trough of panoramic radiograph, using the Moritta compony Panex-EC a series of 48 exposures were: taken with the 6-18 brass pins placed in the holes of the plastic model plate, then eveluated by 4 observers. The author analyzed the focal trough defined by the sharpness criteria and calcuated the vertical and horizontal magnification range in the corrected focal trough. The results were as follows; 1. Continuous focal trough was not defined in the anterior region using a very high degree of sharpness. 2. As degree of sharpness used in the analysis became less, focal trough was continuous in the anterior and posterior regions, symmetrized bilaterally, and the widths of the focal trough increased more in the posterior region. e. As sharpness criteria were reduced, the percentage range of image magnification increased on both vertical and horizontal magnification, and especially the percentage range of horizontal magnification was greater than that of vertical magnification.

• Ocean and Polar Research
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• 제24권3호
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• pp.179-187
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• 2002

The Ayu Trough, located in the southern end of the Philippine Sea, represents a divergent boundary between the Philippine Sea and the Caroline Plates. A detailed geophysical survey was carried out in the Ayu Trough by R/V Onnuri. Topographically, the Ayu Trough resembles an slow spreading ridge. The trough can be divided into three sections: the south $(0^{\circ}-1^{\circ}30'N),\;middle\;(1^{\circ}30'-4^{\circ}N)$, and north $(4^{\circ}-6^{\circ}30'N)$. The seafloor in the middle section is characterized by features asymmetric with respect to the axis. These features were probably produced by NW-SE and NNW-SSE extensions and seem to support the argument that the opening of the Ayu Trough occurred in an oblique fashion. Farther south, a long transform fault but with a short offset defines the boundary between middle and southern sections. The axial depth increases a stepwise to the south of $1^{\circ}30'N$. A clear difference can be seen between the southern and middle sections with the latter exhibiting much higher mantle Bouguer anomaly values in the axial region. The anomaly indicates that the axial crust perhaps experienced a much higher degree of extension in the middle than in the southern section. The analyses of magnetic field data reveal that the region beyond 100km exhibits considerable variations, whereas the magnetic anomalies within 100km from the trough axis are very much subdued. This observation suggests that the opening of the Ayu Trough involved an initial stage of rifting of existing volcanic arcs, followed by production of new seafloor.

• 대한화학회지
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• 제29권3호
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• pp.271-276
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• 1985

송아지 胸線 DNA가 單分子的 凝縮된(collapsed) 構造를 이루는 spermine 濃度에서 얻어지는 異例的 吸光度-溫度 樣相(anomalous absorbance-temperature profile)의 trough 領域에 이르는 相變移에 對한 cooperativity, enthalpy, 및 相變移 midpoint를 구하여 그 값들을 Tm 領域의 값들과 比較한 結果 그 두 그룹의 값들은 서로 相異하였으며 前者의 값들이 後者의 값들 보다 ethidium bromide에 對하여 더 銳敏하였다. Ethidium bromide 濃度를 增加시킴에 따라서 그 trough의 깊이가 작아져서 終局的으로 없어졌으나 그와 對照的으로 Tm은 實驗的으로 一定하게 維持되었다. 本 硏究結果를 基礎로 하여 DNA 凝縮 메카니즘을 推理하였다.

• 천문학회보
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• 제37권2호
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• pp.126.1-126.1
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• 2012

The middle-latitude ionization trough, the plasma density depletion in the subauroral region, has been extensively studied since its discovery in the 1960s. Our knowledge of the variability of the trough is mostly based on the observations in the northern hemisphere. Recently, the COSMIC observations enabled the investigation of the trough in both hemispheres at all local time. However, the investigation was limited to the period of the low solar activity. In this study, we investigate the variability of the trough location and morphology with local time, solar cycle, magnetic activity, and interplanetary magnetic field. For this purpose, we analyze the DMSP F15 data acquired during 2000-2010.

• Journal of Astronomy and Space Sciences
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• 제36권3호
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• pp.121-131
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• 2019

The ionospheric mid-latitude trough (IMT) is the electron density depletion phenomenon in the F region during nighttime. It has been suggested that the IMT is the result of complex plasma processes coupled to the magnetosphere. In order to statistically investigate the characteristics of the IMT, we analyze topside sounding data from Alouette and ISIS satellites in 1960s and 1970s. The IMT position is almost constant for seasons and solar activities whereas the IMT depth ratio and the IMT feature are stronger and clearer in the winter hemisphere under solar minimum condition. We also calculated transition heights at which the densities of oxygen ions and hydrogen/helium ions are equal. Transition heights are generally higher in daytime and lower in nighttime, but the opposite aspects are seen in the IMT region. Utilizing the Incoherent Scatter Radar (ISR) electron temperature measurements, we find that the electron temperature in the IMT region is enhanced at night during winter. The increase of electron temperature may cause fast transport of the ionospheric plasma to the magnetosphere via ambipolar diffusion, resulting in the IMT depletion. This mechanism of the IMT may work in addition to the simply prolonged recombination of ions proposed by the traditional stagnation model.

• 대한화학회지
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• 제29권5호
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• pp.533-538
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• 1985

Spermine에 의하여 誘發되는 凝縮 DNA 構造의 安定化에 있어서 hydrophobic interaction의 重要性을 試驗하기 위하여 spermine-DNA 複合體의 異例的 吸光度-溫度 樣相에 미치는 urea의 效果를 調査하였다. 그 結果 異例的 吸光度-溫度 樣相의 downward peak(trough) 領域에 이르는 相變移에 對한 cooperativity, enthalpy, midpoint의 값들이 Tm 領域의 값들 보다 urea에 敏感한 影響을 받았으며, urea의 濃度 增加에 따라 downward peak가 점차 사라졌다. 이 data는 異例的 吸光度-溫度 樣相을 構成하는 downward peak가 spermine에 의하여 誘發되는 hydrophobic interaction에 의한 凝縮된 tertiary structure의 形成을 나타내고 있다고 불 수 있다.

• Bulletin of the Korean Chemical Society
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• 제12권3호
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• pp.262-264
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• 1991

An anomalous absorbance-temperature profile of calf thymus DNA, having a hypochromic trough just before the rise the $T_m$-region phase, occurs at the spermine concentration where the DNA collapses into a compact structure. The trough phase can be eliminated by the addition of ethidium bromide and also by a hydrophobic environment.

• Archives of Plastic Surgery
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• 제45권3호
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• pp.214-221
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• 2018

Clarification is needed regarding the definitions and classification of groove and hollowness of the infraorbital region depending on the cause, anatomical characteristics, and appearance. Grooves in the infraorbital region can be classified as nasojugal grooves (or folds), tear trough deformities, and palpebromalar grooves; these can be differentiated based on anatomical characteristics. They are caused by the herniation of intraorbital fat, atrophy of the skin and subcutaneous fat, contraction of the orbital part of the orbicularis oculi muscle or squinting, and malar bone resorption. Safe and successful treatment requires an optimal choice of filler and treatment method. The choice between a cannula and needle depends on various factors; a needle is better for injections into a subdermal area in a relatively safe plane, while a cannula is recommended for avoiding vascular compromise when injecting filler into a deep fat layer and releasing fibrotic ligamentous structures. The injection of a soft-tissue filler into the subcutaneous fat tissue is recommended for treating mild indentations around the orbital rim and nasojugal region. Reducing the tethering effect of ligamentous structures by undermining using a cannula prior to the filler injection is recommended for treating relatively deep and fine indentations. The treatment of mild prolapse of the intraorbital septal fat or broad flattening of the infraorbital region can be improved by restoring the volume deficiency using a relatively firm filler.

• 한국해안·해양공학회논문집
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• 제20권3호
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• pp.268-276
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• 2008

오키나와 트러프에서 발생되는 잠재 지진해일의 한반도 남서외해에서의 전파특성을 규명하기 위한 수치모의를 수행하였다. 동중국해 대륙붕의 얕은 수심과 오키나와 트러프의 깊은 수심은 이 지역에서 발생하는 지진해일의 전파특성에 중요한 역할을 한다. 전파특성은 전파 단계에 따라 두 가지로 분류된다. 첫 단계는 수심이 깊은 트러프를 따라서 북동과 남서방향으로 전파해가는 과정이고, 두 번째 단계는 등수심선과 직각방향으로 동중 국해의 대륙붕으로 진입하는 과정이다. 수치모의 결과 오키나와 트러프에서 발생하는 지진해일파는 남서외해의 특수한 해저지형의 영향으로 우리나라 남해안과 서해안에 미치는 영향이 매우 작은 것으로 나타났다.