• Title/Summary/Keyword: experimental techniques

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Regeneration of Low Heat - Treated Sciatic Nerve of Rabbit (저온 열처리한 가토 좌골 신경의 재생)

  • Kim, Jae-Do;Kim, Sang-Jin;Jung, Cheoul-Yun;Hong, Young-Gi;Kim, Ghi-Chan
    • The Journal of the Korean bone and joint tumor society
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    • v.3 no.2
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    • pp.80-88
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    • 1997
  • Malignant tumors of extremeties involving major neurovascular structures have been treated by amputation. However recent development of diagnostic tools(CT, MRI etc.), surgical techniques, anticancer chemotherapeutic agents, and radiation techniques allow surgeons to treat malignant tumors in the limb without amputation. It has been reported that a local application of low-heat to the tissue with tumor can kill tumor cells. It is, however, not known if the attendant neural and vascular injuries may be recovered. The present study was, therefore, undertakn to address this question in rabbit sciatic nerves. A low-heat injury to the sciatic nerve was induced by perfusing the nerve with $60^{\circ}C$ saline for 30 minutes and the courses of functional and morphological recovery of the nerve were evaluated for 16 weeks. The results are summerized as follows : 1. In the electromyographic nerve conduction test the average amplitude was markedly attenuated at 4 and 8 weeks after the low-heat treatment, but it progressively increased to the level 89.5% of the control at 16 week post-treatment. The average latency in the control group was 0.62 msec. The latency in the experimental group was much longer than this at 4 and 8 week post-treatment, but it progressively reverted to the control level, showing 0.622 msec at 16 weeks. 2. In the needle EMG, many fibrillation potentials and positive sharp waves were appeared until 8 weeks post-treatment. After 16 weeks, however, no fibrillation potential was observed. 3. In the early phase of post-treatment period, the myelinated nerve fibers contained many vacuoles and the number of myelinated nerve fibers appeared to be considerably reduced. However, as time goes myelinated nerve fibers were regenerated, such that after 16 weeks the histologic appearance of the nerve was similar to that of the control group.

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A Comparative Analysis According to a Presence or Absence of Metal Artifacts when a Dose Change and QAC Technique are Applied in PET/CT Tests (PET/CT 검사에서 선량변화와 QAC기법 적용 시 Metal Artifact 유무에 따른 SUV 비교분석)

  • Yun, Sun-Hee;Kim, Yang-Jung;Kang, Young-Jik;Park, Su-Young;Kim, Ho-Sin;Ryu, Hyoung-Ki
    • The Korean Journal of Nuclear Medicine Technology
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    • v.19 no.1
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    • pp.51-56
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    • 2015
  • Purpose As medical radiation exposures on patients are being social issues an interest in a relief of radiation exposures on patients is increasing. Further, there are many cases where some patients among who are getting PET/CT tests choose to get implanted with metal artifacts in their bodies. This study is to find out effects of presence or absence of metal artifacts when dose change or CT attenuation correction for the relief of radiation exposures are applied using phantoms through changes in standard uptake value (SUV). Materials and Methods GE company's Discovery 710 machine was used for PET/CT test equipments. We used NEMA IEC body phantoms. We also used screw and mesh cage made of titanium which are used in real clinical processes for the metal artifacts. Two experiments were conducted: One is to test and measure repeatedly about SUV about differences in CT attenuation corrections according to dose changes and another is to do the same procedure for SUV about the presence and absence of the metal artifacts. We injected $^{18}F-FDG$ into NEMA IEC body phantoms with a TBR ratio of 4:1 and then put the metal material into the transformation phantoms. Once a scanning for the metal artifacts was done we eliminated the metal artifacts and went on non-metal artifacts. For the each two experiments, we scanned repeatedly with CT kVp (140, 120, 100, 80) and mA (120, 80, 40, 20, 10) for an experimental condition. For PET, we reconstructed each with standard AC (STD) technique and quantitation achieved cnsistently QAC) technique among CT attenuation correction methods. We conducted a comparative analysis on measured average values and variations which were measured through repeated measure of SUV of region 1, 2, 3 spheres for each conditions of non-metal /metal scan. Results For each kVp, 120, 80, 40 (mA) of non/metal (screw, mesh cage) showed low frequency of fluctuation rates of above 2%. In 20, 10 mA above 2% of fluctuation rates appeared in high frequency. Also, when we compared the fluctuation rates of STD and QAC techniques in non/metal (screw, mesh cage) tests QAC technique showed about 1-10% of differences for each conditions compared to STD technique. In addition, metal types did not have significant effects on fluctuation rates. Conclusion We confirmed that SUV fluctuation rates for both STD and QAC techniques increase as dosage is lower. We also found that the SUV of PET data was maintained steadily in a low dosage for QAC technique when compared with STD technique. Hence, when the low dosage is used for the relief of radiation exposures on patients QAC technique may be exploited helpfully and this could be applied in the same way for patients with metal artifacts implanted in their bodies.

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Comparison of mDixon, T2 TSE, and T2 SPIR Images in Magnetic Resonance Imaging of Lumbar Sagittal Plane (요추 시상면 자기공명 영상검사에서 mDixon과 T2 TSE, T2 SPIR 영상의 비교 연구)

  • Jung, Da-Bin;Lee, Hae-Kag;Heo, Yeong-Cheol
    • Journal of the Korean Society of Radiology
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    • v.15 no.6
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    • pp.927-933
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    • 2021
  • The purpose of this study was to compare and analyze the differences in scan time, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) in the third lumbar vertebral region including the back fat, spinal cord, and cerebrospinal fluid using the mDixon, T2 TSE, and T2 spectral pre-saturation with inversion-recovery (SPIR) techniques. With the factors affecting the SNR fixed, the lumbar sagittal plane images of 30 adults were compared on mDixon, T2 TSE, and T2 SPIR imaging tests. The test times for mDixon, T2 TSE, and T2 SPIR were 115 seconds, 60 seconds, and 60 seconds, respectively. The mDixon T2 images showed higher SNR than the T2 TSE images at the third lumbar vertebral region (p<0.05), lower SNR in the back fat and cerebrospinal fluid (p<0.05) areas, and comparable SNR in the spinal cord (p>0.05). The CNR between the third lumbar vertebral area and back fat was higher in the mDixon T2 images, and the CNR of the cerebrospinal fluid and spinal cord images was higher in the T2 TSE images (p<0.05). The mDixon T2 FS images CNR was lower for the 3rd lumbar vertebral body region and back fat than the T2 SPIR images, and higher for the spinal cord and cerebrospinal fluid images (p<0.05). The CNR between the third lumbar body and back fat areas was higher in the mDixon T2 FS images (p<0.05), and there was no difference in the CNR in the images of the cerebrospinal fluid and the spinal cord (p>0.05). It is difficult to determine whether the mDixon technique is superior to the conventional T2 TSE and T2 SPIR techniques in terms of test time, SNR, and CNR. This study was confined to patients with simple lower back pain and was limited by controlled experimental conditions. Studies using clinically applied protocols are warranted in the future.

A Study on Growth Characteristics of Wild-simulated Ginseng (Panax ginseng C.A. Meyer) by Direct Seeding and Transplanting (직파 및 이식재배 유형에 따른 산양삼의 생육특성 연구)

  • Kim, Kiyoon;Jeong, Daehui;Kim, Hyun-Jun;Jeon, Kwonseok;Kim, Mahnjo;Um, Yurry
    • Korean Journal of Plant Resources
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    • v.32 no.2
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    • pp.160-169
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    • 2019
  • The this study was carried out to investigate the growth characteristics of wild-simulated ginseng by direct seeding and transplanting cultivation for develop standard cultivation techniques of wild-simulated ginseng. Bonghwa experimental field were confirm to be suitable location environment for cultivation of wild-simulated ginseng. As a result of this study, the germination rate of wild-simulated ginseng was significantly highest when seed size was over 6.5 mm in the spot seeding cultivation. In the case of transplanting, survival rate was significantly increased when the diameter of root was over 10 mm, planting distance was 7 cm, and the thickness of soil covering was less then 2 cm. The result of growth characteristics of wild-simulated ginseng by cultivation type, growth of stem in spot seeding cultivation was showed significantly increased when seed size over 6 mm, seeding number was 3 grains, and the seeding distance was less then 5 cm. Strip seeding cultivation was showed significantly increased in stem and root growth when seeding distance was 30 cm grains and quantity of seeding was less then 23 g. In the case of transplanting cultivation, it's was showed significantly increased in stem growth when diameter of root was over then 10 mm and direction of rhizome was top and bottom. The results of this study was that to clearly establish the techniques of cultivation of managements and it's will be suggest contribute to the industrial activation of wild-simulated ginseng.

A The Visualization of Semantic Context in the Film (영화 <이다>에 나타난 의미적 맥락의 시각화)

  • Kim, Tae-Kyue;Kim, Kyu-Nam
    • Journal of Korea Entertainment Industry Association
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    • v.15 no.8
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    • pp.145-159
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    • 2021
  • is a contemporary experimental film that forms ambiguity in the narrative and the psychological motivation of the characters, destroys linear temporality, and reminds of manipulation possibilities in digital images through varied techniques, and it carries implication by the fact that the transformation process of human subjects and self-awareness are connected to social trauma and makes way to infer by comparing it to the historical contexts of other nations or societies. centers on the space outside the screen, absent space, and the intrinsic meaning within the space and the frame and shares the information in the visible space and the space outside the screen and arouses an active perceptual process so that the audience can deduce the information that is not presented. The film visualized the historical meaning without describing the background of the times in detail and aimed to express the conflicts and worries between the god, a transcendental existence, with humans, which are marginal beings, within the conflicting structure among humans. Moreover, attempted to resolve the sadness of loss and absence through the spatial aesthetics and the film presented the progression of the situation through the contrast of the characters and also the comparison between light and darkness. This study intends to make an attempt of interpreting the realm involving personal (characters) stories and the social and historical backgrounds together with the religious sphere and discuss the visualization of the semantic context. In addition, this study analyzed the sequence of the scenes in , which reconstructs identity and historical cases and religious values to observe the meaning and characteristics and closely analyze the general meaning pursued by the film. discussed the issues of trauma that individuals, regions, and nations confront as a representation and interpretation of the trauma connoted in the film, and consideration can be provided about the implication concerning the situation and context in South Korea. Furthermore, the film placidly discusses the growth and agony in humans and the society without expressing it excessively, so it will be a valuable research result to inspire the trend of creating films that incorporate new imaging technology and original visualization techniques.

Analysis of Thesis Using Physiological Variables ; -with reference to the thesis published in Korea from 1962 to 1996- (석.박사 학위논문에서 생리적 변수를 다룬 연구에 대한 분석 -1962년부터 1996년까지 발표된 국내 학위논문을 중심으로-)

  • Choe, Myoung-Ae;Kim, Joo-Hyun;Park, Mi-Jung;Choi, S-Mi;Lee, Kyung-Sook
    • Journal of Korean Biological Nursing Science
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    • v.2 no.2
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    • pp.53-66
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    • 2000
  • Objectives: The studies in biological, behavioral and psychosocial perspectives in nursing research are fundamental in the balanced development of nursing knowledge. Many nursing researchers have placed a strong emphasis on developing psychological and behavioral aspects of nursing knowledge as is evidenced by the large body of research in these areas. However, the paucity of nursing research using the principles of biological science for measurements and techniques have often invited open criticism by many nursing researchers. This study attempts to characterize the researches performed in master and doctoral thesis which used physiological variables. Methods: We analyzed masters' thesis from 1962 to 1996 and doctoral thesis from 1982 to 1996 listed in CD from Korean Nurses Association. Results: Out of 3060 masters' thesis from 1962 to 1996, 342 (11.2%) thesis used physiological variables whereas 43 (10.1%) doctoral thesis used physiological ones. Number of thesis with physiological variables was the highest in Seoul National University for masters' thesis whereas for the doctoral thesis the number was the highest in Yonsei University. The research subjects in these thesis with physiological variables were mostly patients (53.5% in masters' and 69.8% in doctoral). Master's thesis often conducted either nonexperimental or survey research (69.9%) whereas experimental research design prevailed vital signs(181 thesis), blood tests(133), body composition(124), microorganisms(74), gastrointestinal functions(36), lab test(33), drug(21), urinary functions(20), movement(17), Apgar Score(15), reproductive functions(9), skin related functions(6), body fluid and electrolytes(4), parasite(4), metabolism(3), and sensory(1), Among the 338 master' thesis which studied the common nursing concepts such as anxiety, pain, stress, and depression, 48(14.2%) thesis utilized physiological variables while 15 out of 35 doctoral thesis addressed these concepts using physiological variables. Conclusion: In summary, our results indicate that despite the large amount of nursing research performed over the last decades, there are a few nursing researches done with physiological variables either in masters' or doctoral thesis. To enrich nursing knowledge with different perspectives of nursing including especially biological ones, the efforts have to be made to conduct bionursing science research.

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Bearing Capacity Analyses of Shallow Foundations in Reinforced Slopes

  • Kim, Hong-Taek;Choi, In-Sik;Sim, Young-Jong
    • Geotechnical Engineering
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    • v.12 no.3
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    • pp.127-148
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    • 1996
  • Recently, foundations of heavy structures such as bridge abutments have been built on slopes or near the crest of slopes at an increasing rate. Because the bearing capacity of such foundations is considerably lower than the bearing capacity of the same soil on a level ground, deep footings such as piles and caissons are often used. However, the costs of such methods are generally very high. One of the new techniques to overcome the problem is to place reinforcing members such as geosynthetics or metal strips horizontally at some depths beneath the footings. Rational methods of analysis to predict the bearing capacity of footings in reinforced slopes are therefore needed. This paper proposes an analytical method for estimating the increase in bearing capacity gained from the included horizontal strips or ties of tensile reinforcing in the foundation soil below the footing built near the crest of a slope. A failure mechanism, including the concept of'wide slab effect', adopted in the present study for analyzing the bearing capacity of foundations in reinforced slopes, is established through the observed model test behaviors described by Binquet SE Lee and Huang et al, and the Boussinesq solutions. The analytical results are then compared with the experimental data described in the paper by Huang et al. Also in order to properly evaluate the soil reinforcement interaction, typical pullout test values of the apparent friction coefficient, which usually vary with depths owing to both the increase of the shearing volume and the increase in local stress caused by soil dilatancy, are analyzed and related functionally. Furthermore, analytical parametric studies are carried out to investigate the effect and significance of various pertinent parameters associated with design of reinforced slope foundations. Keywords : Bearing capacity, Reinforced slope, Slab effect, Friction coefficient.

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Baseline-Free Crack Detection in Steel Structures using Lamb Waves and PZT Polarity (램파와 압전소자 극성을 사용한 강구조의 실시간 균열손상 감지기법 개발)

  • Sohn, Hoon;Kim, Seung-Bum
    • Journal of the Earthquake Engineering Society of Korea
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    • v.10 no.6 s.52
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    • pp.79-91
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    • 2006
  • A new methodology of guided wave based nondestructive testing (NDT) is developed to detect crack damage in civil infrastructures such as steel bridges without using prior baseline data. In conventional guided wave based techniques, damage is often identified by comparing the "current" data obtained from a potentially damaged condition of a structure with the "past" baseline data collected at the pristine condition of the structure. However, it has been reported that this type of pattern comparison with the baseline data can lead to increased false alarms due to its susceptibility to varying operational and environmental conditions of the structure. To develop a more robust damage diagnosis technique, a new concept of NDT is conceived so that cracks can be detected without direct comparison with previously obtained baseline data. The proposed NDT technique utilizes the polarization characteristics of the piezoelectric wafers attached on the both sides of the thin metal structure. Crack formation creates Lamb wave mode conversion due to a sudden change in the thickness of the structure. Then, the proposed technique instantly detects the appearance of the crack by extracting this mode conversion from the measured Lamb waves even at the presence of changing operational and environmental conditions. Numerical and experimental results are presented to demonstrate the applicability of the proposed technique to crack detection.

Nonlinear Filter-based Adaptive Shoot Elimination Method (비선형 필터 기반의 적응적 슈트제거 방법)

  • Cho, Jin-Soo;Bae, Jong-Woo
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.45 no.2
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    • pp.18-25
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    • 2008
  • The current display systems including TVs are going digital and large-sized, and high visual quality of those systems becomes a very important selling point in the current display system market. Thus, various researches have been carried out for enhancing the visual quality of digital display systems. One of the important digital image(or video) enhancement techniques is sharpness enhancement, and it is generally based on a transient improvement technique that reduces the edge transition time. However, this technique often generates overshoot and undershoot, which cause undesirable pixel-level changes around the transient improved edge. In this paper, we propose a new nonlinear filter-based adaptive shoot elimination method for effectively suppressing the overshoot and undershoot that occur in the transient improvement, so that we can obtain visually sharper and clearer digital images(or videos). The proposed method uses two orthogonal directional min/max nonlinear filters with an adaptive shoot elimination scheme in order to effectively suppress the visually sensitive overshoot and undershoot. Experimental results show that the proposed method suppresses the overshoot and undershoot almost perfectly while maintaining the effect of the transient improvement. The applications of the proposed method include digital TVs, digital monitors, digital cameras/camcoders, portable media players(PMP), etc.

Efficient Structral Safety Monitoring of Large Structures Using Substructural Identification (부분구조추정법을 이용한 대형구조물의 효율적인 구조안전도 모니터링)

  • 윤정방;이형진
    • Journal of the Earthquake Engineering Society of Korea
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    • v.1 no.2
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    • pp.1-15
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    • 1997
  • This paper presents substructural identification methods for the assessment of local damages in complex and large structural systems. For this purpose, an auto-regressive and moving average with stochastic input (ARMAX) model is derived for a substructure to process the measurement data impaired by noises. Using the substructural methods, the number of unknown parameters for each identification can be significantly reduced, hence the convergence and accuracy of estimation can be improved. Secondly, the damage index is defined as the ratio of the current stiffness to the baseline value at each element for the damage assessment. The indirect estimation method was performed using the estimated results from the identification of the system matrices from the substructural identification. To demonstrate the proposed techniques, several simulation and experimental example analyses are carried out for structural models of a 2-span truss structure, a 3-span continuous beam model and 3-story building model. The results indicate that the present substructural identification method and damage estimation methods are effective and efficient for local damage estimation of complex structures.

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