• Nuclear Engineering and Technology
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• v.48 no.3
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• pp.727-732
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• 2016

A simple and rapid spectrophotometric method has been developed to enable the determination of plutonium concentration in an irradiated fuel solution in the presence of all fission products. An excess of ceric ammonium nitrate solution was employed to oxidize all the valence states of plutonium to +6 oxidation state. Interference due to the presence of fission products such as ruthenium and zirconium, and corrosion products such as iron in the envisaged concentration range, as in the irradiated fuel solution, was studied in the determination of plutonium concentration by the direct spectrophotometric method. The stability of plutonium in +6 oxidation state was monitored under experimental conditions as a function of time. Results obtained are reproducible, and this method is applicable to radioactive samples resulting before the solvent extraction process during the reprocessing of fast reactor spent fuel. An analysis of the concentration of plutonium shows a relative standard deviation of <1.2% in standard as well as in simulated conditions. This reflects the fast reactor fuel composition with respect to uranium, plutonium, fission products such as ruthenium and zirconium, and corrosion products such as iron.

• Imaging Science in Dentistry
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• v.37 no.1
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• pp.45-51
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• 2007

Purpose : This study aimed to identify the range of normal facial asymmetry using three-dimensional CT and to develop a simple method of diagnosis of facial asymmetry. Materials and Methods : Twenty eight adults with normal occlusion (16 males and 12 females; mean age 24 years and 1 month) were selected whose faces were assessed to be symmetric by an orthodontist. Three-dimensional reconstructions were obtained utilizing spiral CT scans and an oral and maxillofacial radiologist evaluated nineteen anatomic landmarks in three-dimensional coordinates. Facial asymmetry index of each landmark was caluculated. Results : The range of normal facial asymmetry of each landmark was identified using mean and standard deviation of facial asymmetry index. Conclusions : The range of normal facial asymmetry identified in this study may be used as a diagnostic standard for facial asymmetry analysis.

• Archives of Plastic Surgery
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• v.48 no.4
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• pp.395-403
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• 2021

Background Groin wounds occurring after vascular surgical site infection, oncologic resection, or occasionally orthopedic surgery and trauma may represent a surgical challenge. Reconstruction of these defects by the usual workhorse flaps may be contraindicated following previous surgery and in patients with lower limb lymphedema or extreme morbidity. Methods This study included 15 consecutive patients presenting with inguinal wounds after vascular or general surgery that required debridement and soft tissue coverage. All cases had absolute or relative contraindications to conventional reconstructive techniques, including a compromised deep femoral artery network, limb lymphedema, scarring of potential flap harvesting sites, or poor overall condition. Abdominal adipocutaneous excess enabled the performance of adipocutaneous advancement flaps in an abdominoplasty-like fashion. Immediate and long-term outcomes were analyzed. Results Soft tissue coverage was effective in all cases. Two patients required re-intervention due to flap-related complications (venous congestion and partial flap necrosis). All patients fully recovered over a mean±standard deviation follow-up of 2.4±1.5 years. Conclusions Abdominal flaps can be an effective and simple alternative technique for inguinal coverage with reproducible outcomes. In our experience, the main indications are a compromised deep femoral artery network and poor thigh tissue quality. Relative contraindications, such as previous open abdominal surgery, should be considered.

• Journal of Korea Water Resources Association
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• v.33 no.1
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• pp.99-110
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• 2000

In this study we proposed a simple method for generating multi-site daily rainfall based on the 1-order Markov chain and considering the spatial correlation. The occurrence of rainfall is simulated by a simple 1st-order Markov chain and its intensity to be chosen randomly from the observed data. The spatial correlation between sites could be conserved as the rainfall intensity at each site is to be chosen consistently with the target site in time through generation. It is found that the generated daily rainfall data reproduce genera] characteristics of the observed data such as average, standard deviation, average number of wet and dry days, but the clustering level in time is somewhat loosened. Thus, the lag-I correlation coefficient of the generated data gave smaller value than the observed, also the average lengths of wet run and dry run and the wet-to-wet and dry-to-dry probabilities were a bit less than the observed. This drawback seems to be overcome somewhat by choosing a proper site representing overall basin characteristics or by use of more detailed states of rainfall occurrence.

• Korean Journal of Remote Sensing
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• v.28 no.6
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• pp.635-651
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• 2012

To produce a level-3 monthly composite image from daily level-2 Sea-viewing Wide Field-of-view Sensor (SeaWiFS) chlorophyll-a concentration data set in the East Sea, we applied four average methods such as the simple average method, the geometric mean method, the maximum likelihood average method, and the weighted averaging method. Prior to performing each averaging method, we classified all pixels into normal pixels and abnormal speckles with anomalously high chlorophyll-a concentrations to eliminate speckles from the following procedure for composite methods. As a result, all composite maps did not contain the erratic effect of speckles. The geometric mean method tended to underestimate chlorophyll-a concentration values all the time as compared with other methods. The weighted averaging method was quite similar to the simple average method, however, it had a tendency to be overestimated at high-value range of chlorophyll-a concentration. Maximum likelihood method was almost similar to the simple average method by demonstrating small variance and high correlation (r=0.9962) of the differences between the two. However, it still had the disadvantage that it was very sensitive in the presence of speckles within a bin. The geometric mean was most significantly deviated from the remaining methods regardless of the magnitude of chlorophyll-a concentration values. Its bias error tended to be large when the standard deviation within a bin increased with less uniformity. It was more biased when data uniformity became small. All the methods exhibited large errors as chlorophyll-a concentration values dominantly scatter in terms of time and space. This study emphasizes the importance of the speckle removal process and proper selection of average methods to reduce composite errors for diverse scientific applications of satellite-derived chlorophyll-a concentration data.

• Journal of Chest Surgery
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• v.18 no.4
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• pp.623-634
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• 1985

One of the most widely recognized problems in patients with TGA [transposition of the great arteries] after the Senning operation is the occurrence of arrhythmias. From June 1982 through October 1984, 22 patients, 11 with "simple" and 11 with "complex" TGA, underwent correction of TGA by a modification of the Senning operation designed to avoid dysrhythmias. 16 were males and 6 females, with ages ranging from 3 months to 27 months. [mean age 10.8 months] 7 patients [31.8%], 1 with simple TCA and 6 with complex TGA, died in the early post-operative period. The operative mortality was 9.1% in "simple" TGA, and 54.9% in "complex" TGA. There were 4 late deaths but only one of these patients died of a dysrhythmia as a possible factor. The standard ECG [Electrocardiography] checked preoperatively showed sinus rhythm in 17 [77.3%], 1 AV block in 5 [22.7%]. In 22 patients studied postoperative 1st day, the incidence of arrhythmias was 63.6%, with significant incidence compared with preoperative study. [P<0.05]. But, in 15 patients studied postoperatively at intervals from 1 month to 26 months, the incidence of arrhythmias was 26.7%, with no significant incidence compared with preoperative study [P>0.1]. Our results indicate that a modified Senning operation may reduce the frequency of surgically induced arrhythmias. The mean frontal plane P-wave axis also revealed significant deviation to the right side [P<0.05], compared with preoperative study. These findings raise the possibility that what has been called sinus rhythm postoperatively may have a different origin and conduction sequence from normal. But the rhythm seems to be functionally similar.rhythm seems to be functionally similar.

• Geomechanics and Engineering
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• v.34 no.6
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• pp.697-726
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• 2023

Brittleness as an important property of rock plays a crucial role both in the failure process of intact rock and rock mass response to excavation in engineering geological and geotechnical projects. Generally, rock brittleness indices are calculated from the mechanical properties of rocks such as uniaxial compressive strength, tensile strength and modulus of elasticity. These properties are generally determined from complicated, expensive and time-consuming tests in laboratory. For this reason, in the present research, an attempt has been made to predict the rock brittleness indices from simple, inexpensive, and quick laboratory test results namely dry unit weight, porosity, slake-durability index, P-wave velocity, Schmidt rebound hardness, and point load strength index using multiple linear regression, exponential regression, support vector machine (SVM) with various kernels, generating fuzzy inference system, and regression tree ensemble (RTE) with boosting framework. So, this could be considered as an innovation for the present research. For this purpose, the number of 39 rock samples including five igneous, twenty-six sedimentary, and eight metamorphic were collected from different regions of Iran. Mineralogical, physical and mechanical properties as well as five well known rock brittleness indices (i.e., B₁, B₂, B₃, B₄, and B₅) were measured for the selected rock samples before application of the above-mentioned machine learning techniques. The performance of the developed models was evaluated based on several statistical metrics such as mean square error, relative absolute error, root relative absolute error, determination coefficients, variance account for, mean absolute percentage error and standard deviation of the error. The comparison of the obtained results revealed that among the studied methods, SVM is the most suitable one for predicting B₁, B₂ and B₅, while RTE predicts B₃ and B₄ better than other methods.

• Bulletin of the Korean Chemical Society
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• v.35 no.3
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• pp.821-827
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• 2014

An isotope dilution liquid chromatography tandem mass spectrometry (ID LC-MS/MS) method has been developed and applied to the determination of arsenobetaine (AsB, ${(CH_3)_3}^+AsCH_2COO^-$) from oyster candidate certified reference material (CRM). The exact matching isotope dilution approach was adopted for accurate determination of AsB using $^{13}C_2$-labeled AsB as an internal standard. Efficiencies of different AsB extraction methods were evaluated using a codfish reference material and a simple sonication method was selected as the method of choice for the certification of the oyster candidate CRM. The hydrophilic interaction liquid chromatography (HILIC) combined with electrospray ionization tandem mass spectrometry (ESI/MS/MS) in selected reaction monitoring (SRM) mode was optimized for adequate chromatographic retention and robust quantification of AsB from codfish and oyster samples. By analyzing 12 subsamples taken from each 12 bottles systematically selected from the whole oyster CRM batch, the certified value of AsB was determined as $6.60mg{\cdot}kg^{-1}{\pm}0.31mg{\cdot}kg^{-1}$ and it showed excellent between-bottle homogeneity of less than 0.42%, which is represented by relative standard deviation of 12 bottles from the CRM batch. The major source of uncertainty was the certified value of the AsB standard solution.

• Journal of the Korea Society of Computer and Information
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• v.19 no.2
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• pp.133-142
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• 2014

According to the development of medical information systems, shortened examination time per patient could increase the number of treatments, resulting in the rapid growth of the amount of medical data. Studies on how to efficiently compress and store medical text data of increasing patients are in progress. However, previous methods have the shortcoming of compressing medical text data as it is, resulting in low compression rate. This research tries to overcome the problem by using the gamma coding method which enables compression in bit unit. We propose a new compression scheme which encodes the deviations between measured values and normal range values. Furthermore, we suggest to use the previous value with the least deviation from the measurement as the standard value to encode that deviation. Even though the suggested methods are simple, they have high compression rates. Through performance evaluation, we show that the suggested methods are more efficient than the previous methods.

• Bulletin of the Korean Chemical Society
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• v.31 no.7
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• pp.1976-1980
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• 2010

A simple and reliable method has been developed to selectively separate and concentrate trace amounts of Fe(III) ions from water and food samples by using flame atomic absorption spectrometry. A new reagent, 5-hydroxy-4-ethyl-5,6-di-pyridin-2-yl-4,5-dihydro-2H-[1,2,4] triazine-3-thione, was synthesized and characterized by using FT-IR spectroscopy and elemental analysis. Effects of pH, concentration and volume of elution solution, sample flow rate, sample volume and interfering ions on the recovery of Fe(III) were investigated. The optimum pH was found to be 5. Eluent for quantitative elution was 10 mL of 2 M HCl. The preconcentration factor of the method, detection limit (3s/b, ${\mu}gL^{-1}$) and relative standard deviation values were found to be 25, 4.59 and 1%, respectively. In order to verify the accuracy of the method, two certified reference materials (TMDA 54.4 lake water and SRM 1568a rice flour) were analyzed. The results obtained were in good agreement with the certified values. The method was successfully applied to the determination of Fe(III) ions in water and food samples.