• Current Optics and Photonics
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• v.8 no.3
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• pp.230-238
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• 2024

The refractive index is a key material-design parameter, especially for high-refractive-index glasses, which are used for precision optics and devices. Increased demand for high-precision optical lenses produced by the glass-mold-press (GMP) process has spurred extensive studies of proper glass materials. B₂O₃, SiO₂, and multiple heavy-metal oxides such as Ta₂O₅, Nb₂O₅, La₂O₃, and Gd₂O₃ mostly compose the high-refractive-index glasses for GMP. However, due to many oxides including up to 10 components, it is hard to predict the refractivity solely from the composition of the glass. In this study, the refractive index of optical glasses based on the B₂O₃-La₂O₃-Ta₂O₅-SiO₂ system is predicted using machine learning (ML) and compared to experimental data. A dataset comprising up to 271 glasses with 10 components is collected and used for training. Various ML algorithms (linear-regression, Bayesian-ridge-regression, nearest-neighbor, and random-forest models) are employed to train the data. Along with composition, the polarizability and density of the glasses are also considered independent parameters to predict the refractive index. After obtaining the best-fitting model by R² value, the trained model is examined alongside the experimentally obtained refractive indices of B₂O₃-La₂O₃-Ta₂O₅-SiO₂ quaternary glasses.

• Journal of Korean Medicine Rehabilitation
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• v.19 no.4
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• pp.115-126
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• 2009

Objectives : The aim of this study was to evaluate whether the foot pressure distribution correlates with the lumbo-sacral curvature, and the Oswestry Disability Index in chronic low back pain patients. Methods : We measured the fore foot pressure and the rare foot pressure using the foot analyzer in 28 women subjects with chronic low back pain. The lumbo-sacral curvature and the Oswestry Disability Index(ODI) were also measured. Results : 1. Subjects with higher ODI(%) had significantly lower Fore foot pressure/Rare foot pressure ratio(F/R ratio) (p<0.01). 2. Lumbar lordotic angle and Ferguson angle were inversely related to ODI(%) (p<0.05, p<0.01). 3. Lumbar lordotic angle and Ferguson angle were positively related to F/R ratio (all p<0.05). Conclusions : Using the Foot Analyzer(FA-48S, Tech storm Inc.) we have shown that F/R ratio has significant correlation with the lumbo-sacral curvature and the Oswestry Disability Index. These result suggest that the Foot analyzer may be used in assessing back pain in chronic low back pain patients.

• Economic and Environmental Geology
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• v.30 no.6
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• pp.553-566
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• 1997

Origin, behavior and enrichment of environmental toxic elements from the Deokpyeong area were investigated on the basis of major, trace and rare earth element geochemistry. Coaly metapelites of the Deokpyeong area are subdivided into grey phyllite, dark grey phyllite, coaly slate and black slate, which are interbedded along the Ogcheon Supergroup. The coaly slate had been mined for coal, but mining is closed. The coaly and black slates are lower contents of $SiO_2$ and $Al_2O_3$, and higher contents of LOI, CaO, $Na_2O$ and BaO as compared with the phyllitic rocks. Rare earth elements are highly enriched in the coaly and black slate. Average compositions (ppm) of minor and/or environmental toxic elements in the coaly and black slate are revealed as As=127, Ba=30,163, Cd=18, Cr=740, Cu=84, Mo=378, Pb=43, Sb=12, Se=44, U=144, V=8,147 and Zn=292, which are extremely high concentrations than those in the NASC compositions. Major elements (average enrichment index; 5.34) in the coaly metapelites are mostly depleted, excepting $P_2O_5$ and BaO, normalized by NASC. Rare earth elements (average enrichment index; 1.48) are enriched in the coaly slate. On the basis of NASC, minor and/or environmental toxic elements in the coaly metapelites were strongly enriched of all the elements with the exception of Co, Cs, Ni and Sr. Average enrichment index of trace elements in coaly metapelite is 31.51 (coaly slate; 51.94 and black slate; 15.46). Especially, enrichment index of potentially toxic elements (As, Ba, Cr, Cu, Mo, Ni, Sb, Se, U, V and Zn) of the rock is 46.10 (grey phyllite; 7.15, dark grey phyllite; 4.77, coaly slate; 88.96 and black slate; 22.11). These coal formations were deposited in basin of boundary between terrestrial and marine environments deduced to carbon, sulfur (C/S=2.2 to 275.7), trace and rare earth elements characteristics. Irregular behavior and dispersion between major, minor and rare earth elements of those metapelites indicates a variable source materials, incomplete mixing of differential source and/or reequilibrium of diagenesis and metamorphism.

• Journal of Environmental Impact Assessment
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• v.21 no.4
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• pp.509-523
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• 2012

This basic study is to present the methods and raw data for carrying out to objectively assess an ecosystem by developing the plant ecological indices. The results are as follows. The plant ecological indices were 7 units including RI (Rare Index), EI (Endemic Index), SI (Specific Index), NI (Naturalized Index), UI (Urbanized Index), Pte-Q (Pteridophyta Index) and HI (Halophytes Index). The vascular plants in Mt. Waryong, Mt. Bongmyeong and Bito island were summarized as 471 taxa including 104 families, 294 genera, 419 species, 3 subspecies, 41 varieties and 8 forms. We surveyed 5 taxa of rare plants, 7 taxa of endemic plants, 38 taxa of specific plants by floristic region, 40 taxa of naturalized plants, 1 taxa of invasive alien plant, 19 taxa of pteridophyta and 14 taxa of halophytes. Bito island had the highest RI was 1.2%. Mt. Bongmyeong was 1.4% higher than other sites. If the SI of 2.9% was the highest in Bito island. Bito island was the highest NI, and the UI was the hightest in Mt. Waryong. Mt. Bongmyeong was the lowest NI and UI. In Mt. Waryong and Bito island, the highest DI was 9.1%. The Pte-Q of Mt. Waryong was 1.3 higher than the other sites. Bito island, the highest HI was 8.1%. Overall, 1.5% of RI, 1.9% of EI, 2.3% of SI, 8.5% of NI, 14.3% of UI, 9.1% of DI, 1.0 of Pte-Q and 3.0% were analyzed with HI.

• Journal of the Korean Ceramic Society
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• v.37 no.1
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• pp.33-43
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• 2000

Up-conversion of rare-earth element added glass is promising area for short wavelength laser source by utilizing high power semiconductor infra-red laser if the efficiency can be increased by proper method. In this study, relatively low phonon energy fluoride glasses were prepared by co-doping rare-earth elements to realize the high efficiency up-convertor. The physical, chemical, andoptical properties of co-doped fluoride glasses were measured. 10 combinations of 5 different rare-earth fluoride elements doped samples were prepared and their transition temperatures, chemical durability, density, hardness, refractive index, absorption, fluorescence, and fluorescence lifetime were measured. 480nm wavelengths blue up-conversion was found in the Yb3+/Tm3+ co-doped glass sample with 800nm laser source and the optimum composition for the most efficient blue up-conversion was found from the glass sample with 0.3 mol% TmF3 and 1 mol% YbF3.

• Journal of Trauma and Injury
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• v.36 no.4
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• pp.416-420
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• 2023

Blunt intrathoracic tracheal injuries are rare, even among blunt chest trauma patients. An early diagnosis based on a high index of suspicion allows for timely surgical management of potentially fatal airway trauma, thereby improving overall outcomes. Diagnosing these injuries can be difficult due to their nonspecific clinical features and the occasional difficulty in radiologic diagnosis. If a patient exhibits respiratory compromise with difficult ventilation and poor lung expansion, despite the insertion and management of an intercostal drain following high-energy blunt trauma, there should be a heightened suspicion of potential airway trauma. The aim of primary repair is to restore airway integrity and to minimize the loss of pulmonary parenchyma function. This case report discusses the rare clinical presentation of a patient with blunt trauma to the intrathoracic airway, the surgical management thereof, and his overall outcome. Although blunt traumatic injuries of the trachea are extremely rare and often fatal, early surgical intervention can potentially reduce the risk of mortality.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.21 no.2
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• pp.271-281
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• 2023

A study was conducted on the vitrification of the rare earth oxide waste generated from the PyroGreen process. The target rare earth waste consisted of eight elements: Nd, Ce, La, Pr, Sm, Y, Gd, and Eu. The waste loading of the rare earth waste in the developed borosilicate glass system was 20wt%. The fabricated glass, processed at 1,200℃, exhibited uniform and homogeneous surface without any crystallization and precipitation. The viscosity and electrical conductivity of the melted glass at 1,200℃ were 7.2 poise and 1.1 S·cm^-1, respectively, that were suitable for the operation of the vitrification facility. The calculated leaching index of Cs, Co, and Sr were 10.4, 10.6, and 9.8, respectively. The evaluated Product Consistency Test (PCT) normalized release of the glass indicated that the glass satisfied the requirements for the disposal acceptance criteria. Furthermore, the pristine, 90 days water immersed, 30 thermal cycled, and 10 MGy gamma ray irradiated glasses exhibited good compressive strength. The results indicated that the fabricated glass containing rare earth waste from the PyroGreen process was acceptable for the disposal in the repository, in terms of chemical durability and mechanical strength.

• Korean Journal of Bronchoesophagology
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• v.3 no.1
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• pp.164-168
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• 1997

Multiple primary tumors in the head and neck are not uncommon, however those in the thyroid and the larynx are known to be very rare. In most cases of multiple primary tumors involving the thyroid and the larynx, lesions are observed usually simultaneously and thyroid tumors are found incidentally during the laryngeal tumor surgery. In rare cases, thyroid tumors are found metachronously after radiation therapy of laryngeal cancer. The authors recently experienced a case of multiple primary tumor involving the thyroid and the larynx, in which thyroid papillary carcinoma was the index tumor and the laryngeal squamous carcinoma was the meatachronous second tumor. Both tumors showed aggressive local extension and regional nodal meatastasis with tumor collision in the same node. The patient died of recurrent or of residual squamous carcinoma shortly after main surgical treatment index thyroid cancer.

• Journal of Chest Surgery
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• v.54 no.2
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• pp.143-145
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• 2021

In a newborn in whom cor triatriatum was missed on echocardiography, infracardiac total anomalous pulmonary venous connection was successfully repaired with the aid of cardiac computed tomography (CT). In rare combinations, as in this case, an accurate diagnosis prior to surgery, which is of vital importance for successful repair, can be made through a high index of suspicion and the use of a supplemental imaging modality such as CT.

• Journal of Korean Clinical Nursing Research
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• v.14 no.3
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• pp.153-163
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• 2008

Purpose: The purpose of this research, using descriptive correlation design was to identify the extent to which the mothers having children with rare genetic metabolic diseases(MPS, PWS) have parenting stress and guilt feeling. Method: This study used PSI /SF(Abidin, 1995) and Guilt Index as devised herein. From 156 mothers, data were collected from February to July 2006, using self-administered questionnaires. This study received the approval from IRB at S Hospital (IRB File No: 2006-02-014). Data were analyzed with descriptive statistics, t-test, ANOVA, and correlation. Results: Mothers felt very high level of parenting stress and sense of guilt. Parenting stress was related positively to guilt feeling. Conclusion: These findings could help understand the families of children with rare genetic metabolic diseases and those provide basic information in developing effective counseling and education programs for relief of parenting stress and guilt feeling. This study would be significant in the fact that it is the first research, targeting on the families of children with rare genetic metabolic diseases in Korea.