• Title/Summary/Keyword: frontal inversion

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CHARACTERISTICS OF LOW LEVEL TEMPERATURE INVERSION IN TAIWAN

  • Liou Yuei-An;Yan Shiang-Kun
    • Proceedings of the KSRS Conference
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    • 2005.10a
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    • pp.38-41
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    • 2005
  • The observation data from MTP-5HE ofEPA are used to study the temperature inversion phenomenon in the lower boundary layer in Taipei, Taichung and Kaohsiung of Taiwan. Characteristics of temperature inversion at three cities are extracted using different classification methods. The characteristics of temperature inversion in Taichung and Kaohsiung show a similar trend but are different from that in Taipei. The numbers of the occurrence of temperature inversion in Taichung and Kaohsiung were much larger than that in Taipei. The main types of temperature inversion in Taiwan are radiation inversion and frontal inversion. Compared to frontal inversion, radiation inversion on average occurs at a lower altitude, lasts a longer period, has a deeper thickness, and reaches a higher temperature difference of inversion. Frontal inversion plays a significant role for the inversion event lasting over 12 hours.

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A STUDY OF LOW-LEVEL BOUNDARY-LAYER TEMPERATURE INVERSION EVENTS IN TAIWAN

  • Liou, Yuei-An;Yan, Shiang-Kun;Wang, Kuo-Chung
    • Proceedings of the KSRS Conference
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    • v.1
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    • pp.320-323
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    • 2006
  • Temperature inversion may cause air pollution problems because air pollutants cannot be dissipated through vertical motion of the atmosphere and are accumulated near the surface. The air quality is worsen gradually if an inversion event lasts for a long time. An inversion event is defined as consecutive temperature profiles with occurrence of the temperature inversion condition. In this paper, temperature inversion events over three major cities on Taiwan are analyzed. They are measured by ground-based microwave radiometers installed in Taipei, Taichung, and Kaohsiung from 2002 to 2004 by the Environment Protection Administration (EPA) of Taiwan. Characteristics of temperature inversion events at the three cities are extracted using different classification methods.

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Distribution of Water Masses and Characteristics of Temperature Inversion in the Western Seas of Jeju Island in Spring (봄철 제주도 서부해역의 수괴 분포와 수온역전 특징)

  • Kang, So-Young;Moon, Jae-Hong
    • Ocean and Polar Research
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    • v.44 no.3
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    • pp.191-207
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    • 2022
  • Using the results of CTD casts made in Spring from 2017 to 2021, in this study we investigated the water mass distribution and occurrence of temperature inversion in the western seas of Jeju Island in spring. The distribution of water masses was characterized by cold and fresh water in the northwest and warm and saline water in the southeast, forming a strong thermohaline front running in the southwest-to-northeast direction. Strong temperature inversion mainly occurred in the frontal boundary when the cold water intrudes beneath the warm water at depths of 30-50 m. Analysis of the mixing ratio demonstrated that Jeju Warm Water is dominantly distributed in the western seas of Jeju Island, but its ratio can be modified depending on the southward extension of Yellow Sea Cold Water (YSCW). Results of in situ measurement showed that in 2020, the YSCW largely expanded to the western seas of Jeju Island, occupying approximately 40 % of the mixing ratio. Due to the expansion of YSCW, a strong thermohaline front was formed in the study area, thereby causing thick and strong temperature inversion. On the other hand, in 2018 the mixing ratio of YSCW was minimum (~18%) during the study period of 2017-2021, and thus a relatively weak frontal boundary was formed, without the occurrence of temperature inversion. The observational results also suggest that the interannual changes of water mass distribution and the associated temperature inversion in the western seas of Jeju Island are closely related with wind-driven Yellow Sea circulation in spring, which is the summer monsoon transition period.

Evaluation and Modification on the New Concept Plow

  • Shoji, Koichi;Namikawa, Kiyosi;Umeda, Mikio
    • Proceedings of the Korean Society for Agricultural Machinery Conference
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    • 1993.10a
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    • pp.1026-1035
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    • 1993
  • Further evaluation and modification were done on the new concepts plow (frontal plow), a plow which inverts the soil furrow without lateral displacement . First, kinematics of soil cutting section was analyzed and an experiment was conducted to report draft and power requirement. Second, function of main moldboards was examined and modification was made. As a result of the modification , force applied to the moldboard was reduced, but the furrow inversion became less stable.

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Brain MRI Findings of Nitrogen Gas Inhalation for Suicide Attempt: a Case Report

  • Kim, Young-eun;Lee, Donghoon;Kim, Minji;Hwang, Hokyoung
    • Investigative Magnetic Resonance Imaging
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    • v.21 no.4
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    • pp.264-268
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    • 2017
  • South Korea has the highest reported suicide rate among all countries belonging to the Organization for Economic Cooperation and Development. Nitrogen is a colorless, odorless and nontoxic gas. Nitrogen gas has, however, been recently used as a method of attempted suicide, its nontoxity notwithstanding. We herein report on an unusual case involving a 30-year-old male who presented with symptoms after a suicide attempt by nitrogen inhalation. Diffusion-weighted imaging of his brain was showed curvilinear high signal intensity in the bilateral frontal and right occipital cortices, with subtle low apparent diffusion coefficient value. In addition, T2-weighted images and fluid attenuated inversion recovery images revealed subtle high signal intensity in the bilateral frontal cortices, basal ganglia and occipital cortices with contrast enhancement.

Analysis of the Lower Extremity's Coupling Angles During Forward and Backward Running (앞으로 달리기와 뒤로 달리기 시 하지 커플링각 분석)

  • Ryu, Ji-Seon
    • Korean Journal of Applied Biomechanics
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    • v.16 no.3
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    • pp.149-163
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    • 2006
  • The purpose of this study was to compare the lower extremity's joint and segment coupling patterns between forward and backward running in subjects who were twelve healthy males. Three-dimensional kinematic data were collected with Qualisys system while subjects ran to forward and backward. The thigh internal/external rotation and tibia internal/external rotation, thigh flexion/extension and tibia flexion/extension, tibia internal/external rotation and foot inversion/eversion, knee internal/external rotation and ankle inversion/eversion, knee flexion/extension and ankle inversion/eversion, knee flexion/extension and ankle flexion/extension, and knee flexion/extension and tibia internal/external rotation coupling patterns were determined using a vector coding technique. The comparison for each coupling between forward and backward running were conducted using a dependent, two-tailed t-test at a significant level of .05 for the mean of each of five stride regions, midstance(1l-30%), toe-off(31-50%), swing acceleration(51-70%), swing deceleration(71-90), and heel-strike(91-10%), respectively. 1. The knee flexion/extension and ankle flexion/extension coupling pattern of both foreward and backward running over the stride was converged on a complete coordination. However, the ankle flexion/extension to knee flexion/extension was relatively greater at heel-strike in backward running compared with forward running. At the swing deceleration, backward running was dominantly led by the ankle flexion/extension, but forward running done by the knee flexion/extension. 2. The knee flexion/extension and ankle inversion/eversion coupling pattern for both running was also converged on a complete coordination. At the mid-stance. the ankle movement in the frontal plane was large during forward running, but the knee movement in the sagital plane was large during backward running and vice versa at the swing deceleration. 3. The knee flexion/extension and tibia internal/external rotation coupling while forward and backward run was also centered on the angle of 45 degrees, which indicate a complete coordination. However, tibia internal/external rotation dominated the knee flexion/extension at heel strike phase in forward running and vice versa in backward running. It was diametrically opposed to the swing deceleration for each running. 4. Both running was governed by the ankle movement in the frontal plane across the stride cycle within the knee internal/external rotation and tibia internal/external rotation. The knee internal/external rotation of backward running was greater than that of forward running at the swing deceleration. 5. The tibia internal/external rotation in coupling between the tibia internal/external rotation and foot inversion/eversion was relatively great compared with the foot inversion/eversion over a stride for both running. At heel strike, the tibia internal/external rotation of backward running was shown greater than that of forward(p<.05). 6. The thigh internal/external rotation took the lead for both running in the thigh internal/external rotation and tibia internal/external rotation coupling. In comparison of phase, the thigh internal/external rotation movement at the swing acceleration phase in backward running worked greater in comparison with forward running(p<.05). However, it was greater at the swing deceleration in forward running(p<.05). 7. With the exception of the swing deceleration phase in forward running, the tibia flexion/extension surpassed the thigh flexion/extension across the stride cycle in both running. Analysis of the specific stride phases revealed the forward running had greater tibia flexion/extension movement at the heel strike than backward running(p<.05). In addition, the thigh flexion/extension and tibia flexion/extension coupling displayed almost coordination at the heel strike phase in backward running. On the other hand the thigh flexion/extension of forward running at the swing deceleration phase was greater than the tibia flexion/extension, but it was opposite from backward running. In summary, coupling which were the knee flexion/extension and ankle flexion/extension, the knee flexion/extension and ankle inversion/eversion, the knee internal/external rotation and ankle inversion/eversion, the tibia internal/external rotation and foot inversion/eversion, the thigh internal/external rotation and tibia internal/external rotation, and the thigh flexion/extension and tibia flexion/extension patterns were most similar across the strike cycle in both running, but it showed that coupling patterns in the specific stride phases were different from average point of view between two running types.

Intracranial Plasma Cell Granuloma

  • Kim, Dae-Jin;Choi, Yu-Seok;Song, Young-Jin;Kim, Ki-Uk
    • Journal of Korean Neurosurgical Society
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    • v.46 no.2
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    • pp.161-164
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    • 2009
  • Plasma cell granuloma is a tumor-like disease characterized by non-neoplastic polyclonal proliferation of plasma cells and other mononuclear cells. This disease occurs most frequently in the lung and upper respiratory tract, while the involvement of the central nervous system is very rare. A 44-year-old female patient presented with nausea and progressive visual disturbance. Brain magnetic resonance imaging (MRI) revealed the mass along the right tentorium with low signal intensity in the T2 weighted image (T2WI) and fluid-attenuated inversion recovery (FLAIR) sequence, and an isosignal intensity in T1 weighted image (T1WI), the latter of which was enhanced after administration of gadolinium-diethylenetriamine penta-acetic acid (Gd-DTPA). The thickest portion of the tentorium was partially excised via the combined suboccipital and infratentorial approach. The histopathological examination indicated a diagnosis of plasma cell granuloma. Postoperative steroid therapy was administered for remnant tumor control. Although a follow up MRI scan taken 20 months after the operation showed a slight decrease in tumor size, the lesion had extended to the falx and left frontal convexity along with parenchymal edema at 32 months after the operation and the clinical status was aggravated. The mass was removed from the left frontal convexity. Radiation therapy was given, together with steroid administration.

The Effect of Total Contact Inserts on the Gait Parameters During High-Heeled Shoes Walking (높은 굽 신발 보행 시 전면 접촉인솔이 보행 변수에 미치는 영향)

  • Moon, Gon-Sung;Kim, Tack-Hoon
    • Physical Therapy Korea
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    • v.18 no.2
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    • pp.1-8
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    • 2011
  • The purpose of this study was to investigate the effect of high heeled shoes with the total contact insert (TCI) on the frontal plane of the joints for the lower extremity during the gait. Ten healthy females voluntarily participated in this study and the height of the high heeled shoes was 7 cm. A three-dimensional motion analysis system (VICON) and force plates were used to analyze the movements of the joints for the lower extremities. The results were as follows: There were no significant differences for the angle value on the event of the gait cycle in the maximum eversion and inversion of the ankle joint, the varus and valgus of the knee joint, and the adduction and abduction of the hip joint (p>.05). But, there was a significant difference or the range of motion in the ankle joint (p<.05). The value of ankle and knee moment with a TCI was less than the value for no TCI. And there were significant differences for the moment value of the maximum inversion and eversion on the ankle joint and for the maximum varus and valgus on the knee joint (p<.05). Therefore, a TCI would be effective in stabilizing the joints of the lower extremities and increasing the balance of a body to reduce the injure from a fall during the gait.

Pose Transformation of a Frontal Face Image by Invertible Meshwarp Algorithm (역전가능 메쉬워프 알고리즘에 의한 정면 얼굴 영상의 포즈 변형)

  • 오승택;전병환
    • Journal of KIISE:Software and Applications
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    • v.30 no.1_2
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    • pp.153-163
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    • 2003
  • In this paper, we propose a new technique of image based rendering(IBR) for the pose transformation of a face by using only a frontal face image and its mesh without a three-dimensional model. To substitute the 3D geometric model, first, we make up a standard mesh set of a certain person for several face sides ; front. left, right, half-left and half-right sides. For the given person, we compose only the frontal mesh of the frontal face image to be transformed. The other mesh is automatically generated based on the standard mesh set. And then, the frontal face image is geometrically transformed to give different view by using Invertible Meshwarp Algorithm, which is improved to tolerate the overlap or inversion of neighbor vertexes in the mesh. The same warping algorithm is used to generate the opening or closing effect of both eyes and a mouth. To evaluate the transformation performance, we capture dynamic images from 10 persons rotating their heads horizontally. And we measure the location error of 14 main features between the corresponding original and transformed facial images. That is, the average difference is calculated between the distances from the center of both eyes to each feature point for the corresponding original and transformed images. As a result, the average error in feature location is about 7.0% of the distance from the center of both eyes to the center of a mouth.

Diurnal Variation of the Surface Wind in the Coastal Boundary Layer (沿岸境界層에서의 表層風의 日變化)

  • Choi, Hyo
    • 한국해양학회지
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    • v.19 no.2
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    • pp.210-216
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    • 1984
  • Diurnal variations of coastal surface wind speed are analyzed with five years of hourly wind from Port Aransas, Texas. These data reveal the highest frequency of occurrence of the nighttime wind maximum near midnight, especially during those seasons when onshore flow prevails. Nighttime wind maxima with a southerly component occurred approximately three times more frequently than with a northerly component on the annual average. The neutral atmospheric stability prevails near the coast. Thus it allows downward transfer of momentum from the nocturnal low level jet under the onshore wind situation and strong wind shear between an elevated frontal and ground-based inversion for offshore wind, resulting in the nocturnal coastal surface wind maximum.

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