• Journal of the Institute of Electronics Engineers of Korea SC
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• v.38 no.3
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• pp.47-54
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• 2001

This study is to analyze the impedance response in human body by acoustic stimulation on acupoints and contrast parte; for objectification of the meridian substance. It is to verify meridian pathway and channel theory or bio-energy in body. This paper proposes to make an hypothesis about the underground water theory. The meridian has not tube or pipe line type channel but bio-energy flow along the channel similar to flowing pattern of underground water in body. It was analyzed the current characteristic or impedance response after acoustic stimulation by sound wave of 5 specific tones. The response characteristics of current stimulation are measured by the average current magnitude and variation ratio or meridian. The current variation ratio or Live Meridian(gung) 33.2%, Heart Meridian(sang) 30.7% Kidney Meridian (gak) 33.1%, Spleen Meridian(chi) 33.9%, Lung Meridian (wo) 30.7% are to be compared to contrast parts (non-acupoint and meridian). In experimental results, meridian is discrimination to non-meridian, and 5 vital meridians have a reciprocal relationship with sound wave of 5 specific tones.

• Journal of Korean Society of Transportation
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• v.33 no.6
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• pp.520-530
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• 2015

This paper formulates the methodologies to estimate optimal congestion tolls from long-run and short-run perspectives and applies them to the highways of Seoul. An optimal long-run congestion toll is estimated with an optimal volume-capacity-ratio to minimize the total costs which consist of two components: road construction and maintenance costs and traveler costs. By contrast, an optimal short-run congestion toll is estimated with a supply-demand equilibrium which is determined by using a speed-flow function and a disaggregate modal choice model. The results of a long-run analysis for the Seobu urban expressway suggest the optimal volume-capacity-ratio of 1.35 and the optimal congestion toll of 503 Won per automobile kilometer. By contrast, those of a short-run analysis for the Mia-ro urban arterial suggest 1.31 and 420 Won, respectively. Although our results are to some degree dependent on the interest rate and time value assumed, one basic conclusion holds up: the congestions toll tested could generate substantial gains in social welfare if applied to Seoul.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.33 no.6
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• pp.375-382
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• 2020

Owing to the rapid development of infrared guided weapon systems, the threat to aircraft survivability is constantly increasing, and research on infrared stealth technologies are being conducted to ensure aircraft survival. In this study, we analyze the minimum infrared signature of an aircraft according to its flight altitude by considering the characteristics of infrared guided missiles, which detect the contrast signature between the aircraft and background. We conducted computational fluid dynamics simulations for the convective coefficient, and heat transfer simulations were performed considering convection, conduction, and radiation for flight conditions. Thus, we obtained the surface temperature distribution of the aircraft and analyzed the aircraft infrared signature based on the flow characteristics around it. Furthermore, the optimum emissivity for the minimum infrared signature was derived, and the effect of the infrared signature was analyzed when this optimum emissivity was applied to the fuselage surface for each flight condition.

• Korean Journal of Microbiology
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• v.39 no.1
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• pp.27-35
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• 2003

No currently available methods to monitor pathogenic protozoa, Cryptosporidium and Giardia in environmental water come close to acceptable sensitivity, specificity and reproducibility, and so it has to be accompanied by thorough quality control and performance evaluation to credibly predict the distribution of them. We collected surface water samples from the Han River and spiked our prepared (oo)cysts, determined Matrix Spike recoveries using USEPA Method 1623 and considered what factors influence MS recovery and validity. As a result, average 46% of spiked oocysts and 60% of spike cysts were recovered, but repetitive sampling and statistical approach seemed to be necessary to determine the environmental pollution level of two protozoa as their variation coefficients was so much as 35oio and 26%. And MS recoveries with two acid dissociations during immunomagnetic separation were improved more 10% than that with one dissociations and the use of spiked suspension enumerated by flow cytometry instead of manual preparation enhanced the validity and reliability in spiking tests. Because fluorescence characteristics of (oo)cysts stained on well slides with FITC-labeled monoclonal antibodies and DAPI was not always same, well Elides from spiked field samples were helpful to evaluate the performance of staining. We found many (oo)cyst-like objects with typical fluorescence, not (co)cysts, from the Han River water samples, and then it was concluded that nuclei staining by DAPI (4',6-diamidino-2-phenylindole) and examination by Differential Interference Contrast Microscope should be critical for valid identification.

• Journal of the Korean Society of Radiology
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• v.11 no.7
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• pp.571-578
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• 2017

Bubbles are generated by the boiling of the cooling water when an accident occurs in the reactor and then in order to measure the void fraction, the Optical Fiber Probe(OFP) and optical camera are used in thermal hydraulic safety research. However, such an optical method is not suitable for measuring the void fraction in a $17{\times}17$ array of fuel rods due to the geometrical limitations. This study was conducted as a preliminary study using x-ray system and various phantoms before applying to rod bundles. Through radiographic and tomographic experiments, the tube voltage of the x-ray generator was 130 kVp and the tube current was 1 mA. In addition, it is possible to measure the hole of 1mm in size visually through the bubble resolution phantom, and it is confirmed that the contrast is relatively decreased in the inside of the freon in the case of the contrast evaluation using the road phantom. However, we could obtain good image without distortion when reconstructing the image. Bubble generation phantom experiments were used to confirm the flow direction of the bubbles and to acquire tomography images. The image J tool was used to measure the void fraction of 18 % for a single tomography image. This study has carried out previous researches for the measurement of the bubble rate around the nuclear fuel and could be used as a basic research for continuous research.

• Ocean and Polar Research
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• v.25 no.4
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• pp.557-567
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• 2003

High-resolution (3.5 kHz) subbottom profiles were analyzed in order to reveal sedimentation pattern of late Quaternary in the northern South Shetland continental margin and the South Scotia Sea, Antarctica. On the basis of clarity, continuity and geometry of surface and subbottom echoes together with seafloor topography, high-resolution echo characters are classified into eight echo types which represent rock basements (echo type III-1), coarse-grained subglacial till or moraine (echo type I-1), slides/slumps (echo type IV), debris-flow deposits (echo types II-3 and III-2), and bottom-current deposits (echo types I-2, II-1 and II-2). Subglacial till or moraine (echo type I-1) is mostly present in the lower continental shelf and upper continental slope of the northern South Shetland continental margin, which changes downslope to slides/slumps (echo type IV) and debris-flow deposits (echo types II-3 and III-2) in the middle to lower continental slope. This distribution suggests that the continental slopes of the northern South Shetland continental margin were mostly affected by downslope gravitational processes. Further downslope, bottom-current sediments (echo type I-2) deposited by the southwestward flowing Antarctic Deep Water (ADW) occur at the South Shetland Trench, reflecting an Interaction between mass flows and bottom currents in the area. In contrast to the northern South Shetland continental margin, the South Scotia Sea is dominated by bottom-current deposits (echo types II-1 and II-2), indicating that the sedimentation was mostly controlled by the westward flowing ADW. Flow intensity of the ADW has increased in the relative topographic highs, forming thin covers of coarse-grained contourites (echo type II-1), whereas it has decreased in the relative topographic lows, depositing thick, fine-grained contourites (echo type II-2). The poor development of wave geometry in the fine-grained bottom-current deposits (echo type II-2) is suggestive of the unsteady nature of the ADW flow.

• Journal of Korean Medical classics
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• v.23 no.2
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• pp.157-189
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• 2010

Many chapters of the Hwangjenaegyeong[HN] explain the process of transmission and transmutation of disease. The transmission and transmutation process in the HN can be categorized into one between the viscera and bowels, and another of the external pathogenic gi itself. The process between the viscera and bowels indicates the transport of the pathologic burden between each viscera and bowel. This again is categorized into three types. Interpromoting, intercontrolling and that by Saeng-yang(生陽), Sa-eum(死陰). Next, the transport of the pathogenic gi can be categorized into one moving inwards from the exterior according to personal traits, and that according to the three Eum and three Yang. Although there are numerous types of transmission and transmutation, there are two main criteria in understanding the process. First, whether the process is in accordance with the physiological or natural flow of the body. Interpromoting and three Eum three Yang processes are such examples. To follow the physiological flow of the body means to correspond to either the Heaven and Earth or the original physiology of the human body. Therefore, the disease progresses according to a certain date or season. This indicates a partial malfunction in the circulation of the vital energy, which is relatively easy to recover. In contrast, there are processes that go against the physiological flow, for example, intercontrolling transmission and transmutation. This process focuses on the movement of the pathogenic gi rather than the vital gi. The disease progresses regardless of the flow of the vital energy, and sequential functional damage occurs accordingly. Consequently, as the transmission and transmutation continue, formerly passed organs are left damaged, and the whole process is headed towards death. The second criteria for understanding the process is whether it is cyclic or not. To have a cyclic pattern means that the occurrence of a disease and the time of death is not fixed. Transmission and transmutation processes that have a cyclic pattern mostly follow the physiological flow of the body. As a result, they rarely end in deaths, and the process is centered on vital energy. On the other hand, those with acyclic patterns have a fixed occurrence and death point in the course of the disease. They are mostly unnatural processes, found in fatal acute diseases or consumption diseases.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.1
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• pp.633-640
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• 2021

This study analyzes the effects of text and image presenting methods in video lectures on students' learning flow, learning satisfaction and learning outcomes. The text presenting methods include forming short sentences of 2 or 3 words or using key words, while image presenting methods include images featuring both detailed and related information as well as images containing only related information. 167 first year students from Xingtai University were selected as experimental participants. Groups of participants were randomly assigned to engage in four types of video. The research results are as follows. First, it was found that learning flow, learning satisfaction and learning outcomes of group presented with video forms of short sentences had higher statistical significance compared to the group experiencing the key word method. Second, learning flow, learning satisfaction and learning outcomes of group presented with video forms of only related information had higher statistical significance compared to the group experiencing the presenting method of both detailed and related information. That is, the mean values of dependent variables for groups of short form text and only related information were highest. In contrast, the mean values of dependent variables for groups of key words and both detailed and related information were the lowest.

• Investigative Magnetic Resonance Imaging
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• v.8 no.1
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• pp.17-23
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• 2004

Purpose : To evaluate changes in total cerebral blood flow (tCBF) with aging, parenchymal volume changes and vascular abnormalities, using 2 dimensional (D) phase-contrast magnetic resonance imaging (PC MRI). Materials and Methods : Routine brain MRI including T2 weighted image, time-of-flight (TOF) MR Angiography (MRA) and 2D PC MRI were performed in 73 individuals, including 12 volunteers. Normal subjects (12 volunteers, and 21 individuals with normal MRI and normal MRA) were classified into groups according to age (18-29, 30-49 and 50-66 years). For the group with abnormalities in brain MRIs, cerebral parenchymal volume changes were scored according to the T2 weighted images, and atherosclerotic changes were scored according to the MRA findings. Abnormal groups were classified into 4 groups: (i) mild reduction in volume, (ii) marked reduction in volume by parenchymal volume and atherosclerotic changes, and (iii) increased volume and (iv) Moya-moya disease. Volumetric flow was measured at the internal carotid artery (ICA) and vertebral artery bilaterally using the velocity-flow diagrams from PC MRI, and combined 4 vessel flows and tCBF were compared among all the groups. Results : The age-specific distribution of tCBFs in normal subjects were as follows: $12.0{\pm}2.1ml/sec$ in 18-29 years group, $11.8{\pm}1.9ml/sec$ in 30-49 years group, $10.9{\pm}2.2ml/sec$ in 50-66 years group. The distribution of tCBFs in the different subsets of the abnormal population were as follows: $9.5{\pm}2.5ml/sec$ in the group with mild reduction in volume, $7.6{\pm}2.0ml/sec$ in the group with marked reduction in volume, and $7.3{\pm}1.2ml/sec$ and $7.0{\pm}1.1ml/sec$ in the increased parenchymal volume and Moya-moya disease groups respectively. Conclusion : Total cerebral blood flow decreases with increasing age with a concomitant reduction in parenchymal volumes and increasing atherosclerotic changes. It is also reduced in the presence of increased parenchymal volume and Moya-moya disease.2D PC MRI can be used as a tool to evaluate tCBF with aging and in the presence of various conditions that can affect parenchymal volume and cerebral vasculature.

• The Korean Journal of Pain
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• v.27 no.4
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• pp.353-359
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• 2014

Background: Epidural steroid injections are an accepted procedure for the conservative management of chronic backache caused by lumbar disc pathology. The purpose of this study was to evaluate the epidurographic findings for the midline, transforaminal and parasagittal approaches in lumbar epidural steroid injections, and correlating them with the clinical improvement. Methods: Sixty chronic lower back pain patients with unilateral radiculitis from a herniated/degenerated disc were enrolled. After screening the patients according to the exclusion criteria and randomly allocating them to 3 groups of 20 patients, fluoroscopic contrast enhanced epidural steroids were injected via midline (group 1), transforaminal (group 2) and parasagittal interlaminar (group 3) approaches at the level of the pathology. The fluoroscopic patterns of the three groups were studied and correlated with the clinical improvement measured by the VAS over the next 3 months; any incidences of complications were recorded. Results: The transforaminal group presented better results in terms of VAS reduction than the midline and parasagittal approach groups (P < 0.05). The epidurography showed a better ventral spread for both the transforaminal (P < 0.001) and the paramedian approaches (P < 0.05), as compared to the midline approach. The nerve root filling was greater in the transforaminal group (P < 0.001) than in the other two groups. The ventral spread of the contrast agent was associated with improvement in the VAS score and this difference was statistically significant in group 1 (P < 0.05), and highly significant in groups 2 and 3 (P < 0.001). In all the groups, any complications observed were transient and minor. Conclusions: The midline and paramedian approaches are technically easier and statistically comparable, but clinically less efficacious than the transforaminal approach. The incidence of ventral spread and nerve root delineation show a definite correlation with clinical improvement. However, an longer follow-up period is advisable for a better evaluation of the actual outcom.