• Journal of Radiation Protection and Research
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• v.31 no.3
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• pp.155-164
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• 2006

It is judged that there could be certainty in every process of analyzing environmental samples using Liquid Scintillation Counter. Therefore, this study focuses on quantitative evaluation on uncertainty in an effort to analyze comparatively accurately environmental samples. For this, after parameters which can have an effect on uncertainty was derived, the evaluation on each parameter was tamed out. The results of analysis of each parameter showed that the effect according to the weight difference of Teflon vial did not appear, and that standard deviations of SQP(E) averages reached saturation point at $75{\sim}90$ sec at the result of making increases step by step the irradiation time of External standard, and that values measured by repeat method produces good results compared with replicate. Also, conclusion was derived that analysis on sample after it is left in cold and dark room at least above 1,000 minutes have to be carried out, and the result of carrying out verification on results measured as well as equipment itself using radioactivity-error-analysis and chi-square test, resonable result was derived.

• Journal of the Korea Concrete Institute
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• v.17 no.4 s.88
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• pp.581-586
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• 2005

High-performance concrete (HPC), which is particularly sensitive to self-desiccation, is required to be durable even in severe environmental conditions, i.e. costal area, cold district, etc. However, in recent years, some attention was particularly given to cracking sensitivity of high performance concrete at early age. It has been argued and demonstrated experimentally that such concrete undergoes autogenous shrinkage due to self-desiccation at early age under restrained condition, nd, as a result, internal tensile stress may develop, leading to micro cracking and macro cracking. This shrinkage-introduced crack produces a major serviceability problem for concrete structures. One possible method to reduce cracking due to autogenous shrinkage is the addition of expansive additive. Tests conducted by many researches have shown the beneficial effects of addition of expansive additive for reducing the risk of autogenous shrinkage-introduced cracking. However, the research on hydration model of expansion additive has been hardly researched up to now. This paper presents a study of the hydration model of Ettringite-Gypsum type expansive additive. As a result of comparing forecast values with experiment value, proposed model is shown to expressible of hydration of expansive additive.

• Journal of the Korean GEO-environmental Society
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• v.12 no.12
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• pp.79-88
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• 2011

Adfreeze bond strength develops upon freezing of pore water within soil and at foundation surface. It has been reported that various factors like temperature, soil type, and pile surface roughness affect adfreeze bond strength. Especially, pile surface roughness has been considered as a primary factor to design pile foundation in frozen ground. It has usually been estimated with fixed correction factors for pile materials. However, even if the pile foundation material is the same, the surface roughness could vary depending on the production circumstances. In this study, laboratory test was carried out to quantitatively analyze the effects of surface roughness on the adfreeze bond strength, and fractal dimension was used as a measure for surface roughness. Test results showed that adfreeze bond strength increased with decreasing temperature, increasing vertical stress and surface roughness. The adfreeze bond strength varies sensitively with surface roughness in the early freezing section of $-2^{\circ}C$, but its sensitivity decreased in the temperature ranging between $-2^{\circ}C$ to $-5^{\circ}C$. The results conclude that the roughness highly affects the frictional resistance of pile surface in frozen ground; however, the roughness does not affect considerably when the temperature drops below about $-2^{\circ}C$.

• The Journal of Korean Obstetrics and Gynecology
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• v.35 no.4
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• pp.91-104
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• 2022

Objectives: This study was performed to review the impact of Coronavirus disease 2019 (COVID-19) infection during pregnancy and the applicability of traditional Chinese medicine (TCM) on COVID-19 infection during pregnancy. Methods: We searched 6 data bases on August, 2022 and articles about the impact of COVID-19 infection during pregnancy, TCM treatment of COVID-19 infection, TCM treatment of pregnancy common cold (姙娠 感冒) or cough (姙娠 咳嗽) were reviewed. Results: COVID-19 infection can bring out negative effects both on pregnant women and fetus. In the case of COVID-19 infection during pregnancy, the symptoms and treatment are similar to those of general COVID-19 infection, but the safety of drug intervention has not been completely verified. Herbal medicine treatment can be applied according to the severity, stage and TCM syndrome types of COVID-19 infection, but the prohibited herbs list during pregnancy and its dosage should be checked carefully. Also, when it comes to pregnancy disease, the effect of "Stabilizing Fetus" should be considered in the perspective of TCM treatment strategy. Glycyrrhizae Radix et Rhizoma, Rhizoma Atractylodis Macrocephalae, Scutellariae Radix have been widely used on COVID-19 infection and the safety of them during pregnancy have been verified. In the case of acupuncture treatment, acupoints also can be selected according to the severity, symptoms, and TCM syndrome types of COVID-19, but acupoints with strong Qi sensitivity or acupoints located in lower abdomen should be avoided during pregnancy. Conclusions: TCM treatment can be applied to COVID-19 infection during pregnancy. Clinical studies and systematic reviews of the efficacy and safety of TCM treatment on COVID-19 infection during pregnancy are required.

• Journal of Korea Water Resources Association
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• v.45 no.10
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• pp.969-981
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• 2012

In this study, we analysed hydrologic variability in quantity and onset of annual maximum flow and low flow by impacts of the different phases of ENSO (El Ni$\tilde{n}$o Southern Oscillation) over the Han River Basin. The results show that annual maximum flow has increased statistically significant about 48.3% of all over the watershed. The onset of annual maximum flow was delayed in the west of the Han River basins and in the east of the basins was likely to be rapid onset. Also, this study shows that 7-day low flow was deceased statistically significant about 26.0% of the total area in the Han River Basin, and onset of 7-day low flow tends to be faster in the upper-middle basins of the Han River. The onset of annual maximum flow shows similar pattern during the CT (Cold tongue)/WP (Warm-pool) El Ni$\tilde{n}$o years, but annual maximum flow appeared less in 89.0% of all basins during the CT El Ni$\tilde{n}$o years. In addition, the onset of 7-day low flow tended to be faster about 17 days on average during the WP El Ni$\tilde{n}$o years, and 72.7% of the basins show significant increase during the CT El Ni$\tilde{n}$o years. Consequently, it was found that the different phases of CT/WP El Ni$\tilde{n}$o have effects on sensitivity to variability in quantity and onset of water resources over the Han River Basin. We expect that the present diagnostic study on hydrological variability during different phases of ENSO will provide useful information for long-term prediction and water resources management.

• Pediatric Infection and Vaccine
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• v.6 no.1
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• pp.86-92
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• 1999

Purpose : The purpose of this study is to know the epidemiology and clinical characteristics in patients with M. pneumoniae pneumonia during study period retrospectively. Methods : We had reviewed 500 patients with Mycoplasma pneumoniae pneumonia who were hospitalized at the pediatric ward of Seoul Adventist Hospital from July 1986 through June 1996. we had analysed clinical and laboratory problems of pulmonary and extrapulmonary manifestations including demographics and epidemiological characteristics. Results : Peak occurrence of the disease was 3 years interval and seasonal occurrence of the disease had no difference. 43.4% of patients was below 4 years old and male to female ratio was nearly 1:1. The most common site of infiltration on chest PA was right lower lobe and the most common type of pneumonia was interstitial pneumonia(43%). Pulmonary complications were atelectasis(11cases), emphysema(5cases), pleural effusion(27cases) and sinusitis(13cases) and extrapulmonary manifestations were hepatitis(109cases), skin rash(29cases), proteinuria(20cases) and hematuria(16cases). cold agglutinin test was carried out in 500cases and mycoplasma antibody test was carried out in 448cases. sensitivity of mycoplasma antibody test was 53.3%. Conclusion : Mycoplasma pneumoniae pneumonia showed epidemics at intervals of 3 year in its major occurrence. it exhibits a tendency that occurs at younger age group not in school age group. diagnosis of the disease need more accurate method due to low sensitivity of mycoplasma antibody test. also we need to carried out other laboratory test(for example, LFT, U/A).

• The Journal of Korean society of community based occupational therapy
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• v.7 no.2
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• pp.9-18
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• 2017

Objective : This study was to find out the level of sensory process type, adult attachment and interpersonal problems on university students and then to investigate the correlation. Methods : For this study, 169 students who don't know about the evaluation tool in university students of K area in Korea were participated. To execute evaluation, Adolescents/Adults Sensory Profile (AASP) was used for the sensory process type, Short Form of the Korean Inventory of Interpersonal Problems Circumplex Scale (KIIP-SC) was used for interpersonal problems, and Experiences in Close Relationships Scale-Revised (ECR-R) was used for the adult attachment. The correlation between sensory process type and interpersonal problems, adult attachment was analyzed by using pearson correlation analysis. Results : Sensory process type of university students appeared that sensory seeking was lower than general people, and the rest of items showed similar results with general people. For interpersonal problems, there was a lot of difficulty in self-sacrificing and overly accommodating, whereas there was a little difficulty in vindictive and domineering / controlling. For adult attachment, attachment avoiding was more stable than attachment anxiety. Also, low registration and sensory sensitivity all showed positive correlation with interpersonal problems and adult attachment. Among interpersonal problems, self-sacrificing and intrusive showed positive correlation with sensory seeking whereas cold, socially inhibited, nonassertive, and overly accommodating showed positive correlation with sensory avoiding. Thus, sensory seeking and sensory avoiding showed different results (p<.05). Conclusion : In occupational therapy clinic, not only the disabled but non-disabled people that experience issue of interpersonal problems and attachment could be helped with managing high quality social activity if they execute intervention according to sensory process type.

• The Journal of the Acoustical Society of Korea
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• v.20 no.2E
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• pp.30-45
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• 2001

This study considers the environmental factors affecting propagation loss and sonar performance in the continental regions of the East Coast Sea of Korea. Water mass distributions appear to change dramatically in a few weeks. Simple calculation with the case when the NKCW (North Korean Cold Water) develops shows that the difference in propagation loss may reach in the worst up to 10dB over range 5km. Another factor, an eddy, has typical dimensions of 100-200km in diameter and 150-200m in thickness. Employing a typical eddy and assuming frequency to be 100Hz, its effects on propagation loss appear to make lower the normal formation of convergence zones with which sonars are possible to detect long-range targets. The change of convergence zones may result in 10dB difference in received signals in a given depth. Thermal fronts also appear to be critical restrictions to operating sonars in shallow waters. Assuming frequency to be 200Hz, thermal fronts can make 10dB difference in propagation loss between with and without them over range 20km. An observation made in one site in the East Coast Sea of Korea reveals that internal waves may appear in near-inertial period and their spectra may exist in periods 2-17min. A simulation employing simple internal wave packets gives that they break convergence zones on the bottom, causing the performance degradation of FOM as much as 4dB in frequency 1kHz. An acoustic experiment, using fixed source and receiver at the same site, shows that the received signals fluctuate tremendously with time reaching up to 6.5dB in frequencies 1kHz or less. Ambient noises give negative effects directly on sonar performance. Measurements at some sites in the East Coast Sea of Korea suggest that the noise levels greatly fluctuate with time, for example noon and early morning, mainly due to ship traffics. The average difference in a day may reach 10dB in frequency 200Hz. Another experiment using an array of hydrophones gives that the spectrum levels of ambient noises are highly directional, their difference being as large as 10dB with vertical or horizontal angles. This fact strongly implies that we should obtain in-situ information of noise levels to estimate reasonable sonar performance. As one of non-stationary noise sources, an eel may give serious problems to sonar operation on or under the sea bottoms. Observed eel noises in a pier of water depth 14m appear to have duration time of about 0.4 seconds and frequency ranges of 0.2-2.8kHz. The 'song'of an eel increases ambient noise levels to average 2.16dB in the frequencies concerned, being large enough to degrade detection performance of the sonars on or below sediments. An experiment using hydrophones in water and sediment gives that sensitivity drops of 3-4dB are expected for the hydrophones laid in sediment at frequencies of 0.5-1.5kHz. The SNR difference between in water and in sediment, however, shows large fluctuations rather than stable patterns with the source-receiver ranges.

• The Journal of the Korean bone and joint tumor society
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• v.7 no.1
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• pp.28-35
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• 2001

Purpose : Authors investigated the efficiency of preoperative MRI in suspicious glomus tumor and the clinical outcomes after marginal excision. Materials and Methods : In 10 cases of glomus tumors in the fingers, authors retrospectively analyzed the clinical data, including previous trauma, treatment history, preoperative symptoms, physical examination, plain radiography, MRI (9 cases), pathological findings and postoperative complications. Results : The patients had pain in 10 cases, tenderness in 9 cases, cold sensitivity in 3 cases and edema in one case. MRI showed low signal (3 cases) or iso-signal (5) intensity on T1 weighted image, high signal intensity (8) on T2 weighted image, and all the lesions were enhanced in gadolinium enhancement images. The exact locations of glomus tumors were median in 6 cases, lateral in 5, lateral fold in 2 and pulp in 3 in transverse section and nail bed in 5 cases and nail matrix in 5 in sagittal section. Marginal excision was performed by lateral approach in one case and transungual in 9 cases. Histologically, all 10 cases were composed of solid sheets of round cells interrupted by thin-walled blood vessels. Most of clinical symptoms were disappeared in all cases after operation. Nail deformity was found in one case, which was originated from nail matrix, however, there was no recurrence. Summary : Clinical symptom was the most impotant factor in diagnosis of glomus tumor in the fingers. However, preoperative MRIs were helpful in patients, who had obscure pain or prolonged clinical symptoms with suspicious glomus tumors. Preoperative MRI might be one of the most useful tools for establishing the exact diagnosis and detecting the location of glomus tumors, in spite of the relatively high expenses.

• Journal of Sensor Science and Technology
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• v.7 no.3
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• pp.154-162
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• 1998

A planar Bi-Sb multijunction thermal converter with high thermal sensitivity and small ac-dc transfer error has been fabricated by preparing the bifilar thin film Pt-heater and the hot junctions of thin film Bi-Sb thermopile on the $Si_{3}N_{4}/SiO_{2}/Si_{3}N_{4}$-diaphragm, which functions as a thermal isolation layer, and the cold junctions on the dielectric membrane supported with the Si-substrate, which acts as a heat sink, and its ac-dc transfer characteristics were investigated with the fast reversed dc method. The respective thermal sensitivities of the converter with single bifilar heater were about 10.1 mV/mW and 14.8 mV/mW in the air and vacuum, and those of the converter with dual bifilar heater were about 5.1 mV/mW and 7.6 mV/mW, and about 5.3 mV/mW and 7.8 mV/mW in the air and vacuum for the inputs of inside and outside heaters, indicating that the thermal sensitivities in the vacuum, where there is rarely thermal loss caused by gas, are higher than those in the air. The ac-dc voltage and current transfer difference ranges of the converter with single bifilar heater were about ${\pm}1.80\;ppm$ and ${\pm}0.58\;ppm$, and those of the converter with dual bifilar heater were about ${\pm}0.63\;ppm$ and ${\pm}0.25\;ppm$, and about ${\pm}0.53\;ppm$ and ${\pm}0.27\;ppm$, respectively, for the inputs of inside and outside heaters, in the frequency range below 10 kHz and in the air.