• Journal of Conservation Science
• /
• v.25 no.4
• /
• pp.451-464
• /
• 2009

To do conservation for ceramics, sometimes it needs to clean the ceramics chemically to remove stains on the ceramics, which should be performed with caution. This study will provide quantitative data about the extraction characteristics of major elements from ceramics through the soaking test to evaluate the stability of ceramic cleaning agents. As soft textured pottery(fired at $700^{\circ}C$) had high absorption, it showed higher extraction characteristics in short soaking time. Especially the strong acid among chemical cleaning agents caused the expoliation and the color change on the surface of soft textured pottery. But these color change had no effect on the physical characteristics of soft textured pottery. The hard textured pottery(fired at $1,000^{\circ}C$) is relatively stable in the cleaning agent because it is ascertained the extraction of that was not enough and also it had little chromatic and physical change by strong acid. Porcelains(Celadon, Whiteware and Puncheong ware) was safer than the soft textured pottery due to their low extraction. But it should take precautions to clean the porcelains with lots of cracklewares such like Puncheong ware chemically in connection with the extraction characteristics and their cracklewares.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.1
• /
• pp.439-447
• /
• 2020

Re-coating of the mirror is one of the important things to maintain the performance of a telescope. The metal coated on the mirror reflects light, and if the reflectance decreases, then the telescope's performance decreases, so the mirror must be periodically recoated. It is important to predict re-coating cycles for military telescopes and to develop maintenance plans not only for performance, but also for the telescope's availability for missions and the maintenance costs for long-term use. However, most similar telescopes used for astronomy research determine recoating cycles based on experience and operating conditions, and not for prediction of recoating. Therefore, this study predicts the cleaning cycles and re-coating cycles of a military telescope's mirror by using simulation. First, this study analyzed similar cases of domestic and foreign astronomy research institutes and the study also reviewed the need for re-coating and predicting re-coating cycles. Second, this study developed simulation for predicting cleaning and re-coating cycles according to data analysis and modeling. Finally, the study predicts cleaning cycles and re-coating cycles according to varying reflectance reduction (5%, 10%, 15%, 20%) and cleaning conditions (per 3 months, 6 months, 1 year and 2 years). As a result, this study suggests reference criteria to develop the planning for military telescopes and their maintenance.

• Journal of Information Technology Services
• /
• v.12 no.2
• /
• pp.361-371
• /
• 2013

Public domain defect data sets, such as NASA data sets which are available from the NASA MDP and PROMISE repositories, make it possible to compare the results of different defect prediction models by using the same data sets. This means that repeatable and general prediction models can be built. However, some recent studies have raised questions about the quality of two versions of NASA data set, and made new cleaned data sets by applying their data cleaning processes. We find that there are two ways in the NASA MDP versions to determine the defectiveness of a module, 0 or 1, and the two results are different in some cases. This serious problem, to our knowledge, has not been addressed in previous studies. To handle this ambiguity problem, we define two kinds of module defectiveness and two conditions that can be used to determine the ambiguous cases. We meticulously analyze 5 projects among the 13 NASA projects by using our ambiguity analysis method. The results show that JM1 and PC4 are the best projects with few ambiguous cases.

• Journal of Convergence for Information Technology
• /
• v.10 no.10
• /
• pp.298-307
• /
• 2020

This study conducted MBTI test of freshmen majoring in skin care who studied skin care curriculum to reveal the characteristics of the students, and analyzed their adaptation to university life a year later. It conducted a 4-year follow-up survey of 261 freshmen majoring in skin care from 2016 to 2019, followed by data coding and data cleaning, and analyzed them using the SPSS V. 21.0 statistical package program. As a result, freshmen majoring in skin beauty prefer a wide range of interpersonal relationships and like to understand and learn from experience, and they can see that they have many tendencies to prepare and carry out everything in advance, and to be productive and purposeful.

• Journal of Astronomy and Space Sciences
• /
• v.27 no.4
• /
• pp.309-318
• /
• 2010

We introduce a technical approach for reducing three-dimensional infrared (IR) spectroscopic data generated by integral field spectroscopy or slit-scanning observations. The first part of data reduction using IRAF presents a guideline for processing spectral images from long-slit IR spectroscopy. Multichannel image reconstruction, Image Analysis and Display (MIRIAD) is used in the later part to construct and analyze the data cubes which contain spatial and kinematic information of the objects. This technic has been applied to a sample data set of diffuse 2.1218 ${\mu}m$ $H_2$ 1-0 S(1) emission features observed by slit-scanning around Sgr A East in the Galactic center. Details of image processing for the high-dispersion infrared data are described to suggest a sequence of contamination cleaning and distortion correction. Practical solutions for handling data cubes are presented for survey observations with various configurations of slit positioning.

• Journal for History of Mathematics
• /
• v.18 no.2
• /
• pp.95-106
• /
• 2005

This paper is investigated conception and methodology of data selection, cleaning, integration, transformation, reduction, selection and application of data mining techniques, and model evaluation during procedure of the knowledge discovery in database (KDD) based on Mathematics. Statistical role and methodology in KDD is studied as branch of Mathematics. Also, we investigate the history, mathematical background, important modeling techniques using statistics and information, practical applied field and entire examples of data mining. Also we study the differences between data mining and statistics.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.18 no.2
• /
• pp.149-160
• /
• 2008

Bag-filter system has been widely used in industrial field to remove the particulate matters from the exhaust gas. The cylindrical type of bag-filter has been generally used. But it has many shortcomings. The reattachment of separated particles on the surface of bags could result in high pressure drop of bag-filter system and subsequent decrease of air flow rate since the cylindrical type bag-filter system should have the upward flow pattern. In addition, the supply of very high pressure pulse air jet to remove particulate matters on the surface of filter could result in a frequent rupture of bags. To overcome these shortcomings of the cylindrical type, the rectangular type was developed in the developed countries and imported to Korea. But, there was not many design data available to understand the mechanisms. Thus, the fundamental experiments were conducted in this study to get some ideas about the pulse jet cleaning of rectangular type bag filter system. The experimental factors are as follows; pulse distance, pulse duration, pulse interval, pulse pressure and pulse nozzle type. Experiments followed the factorial design method. With the shorter pulse distance, the distribution of pressure drops was relatively not uniform while the particulate removal efficiency was higher. With the longer duration of pulsing and the more number of pulse nozzle, the removal efficiency was higher and the pressure drop distribution was more uniform.

• Journal of Korean Society of Water and Wastewater
• /
• v.31 no.6
• /
• pp.539-549
• /
• 2017

In water treatment process using microfiltration membranes, manganese is a substance that causes inorganic membrane fouling. As a result of analysis on the operation data taken from I WTP(Water Treatment Plant), it was confirmed that the increase of TMP was very severe during the period of manganese inflow. The membrane fouling fastened the increase of TMP and shortened the service time of filtration or the cleaning cycle. The TMP of the membrane increased to the maximum of $2.13kgf/cm^2$, but it was recovered to the initial level ($0.17kgf/cm^2$) by the 1st acid cleaning step. It was obvious that the main membrane fouling contaminants are due to inorganic substances. As a result of the analysis on the chemical waste, the concentrations of aluminum(146-164 mg/L) and manganese(110-126 mg/L) were very high. It is considered that aluminum was due to the residual unreacted during coagulation step as a pretreatment process. And manganese is thought to be due to the adsorption on the membrane surface as an adsorbate in feed water component during filtration step. For the efficient maintenance of the membrane filtration facilities, optimization of chemical concentration and CIP conditions is very important when finding the abnormal level of influent including foulants such as manganese.

• Korean Journal of Health Education and Promotion
• /
• v.26 no.2
• /
• pp.25-33
• /
• 2009

Objectives: Smoking is related to periodontal disease and periodontal therapy. So the aim of this study was to investigate the effects of professional tooth cleaning and plaque control instruction (PT & PCI) for smoking behavior. Methods: A total of 151 adults were investigated using the O'Leary Plaque Index (PI), $L\ddot{o}e$ & Silness gingival index (GI) and the number of sextants possessing periodontal pocket (SPP). And adults were given a through dental scaling and Watanabe method for dental plaque control. Follow up examination were conducted after 3 months and compared the pre and post- status. The collected data were analyzed with t-test, paired t-test and one-way analysis of variance. Results: Regardless of smoking behavior, improving effects were identified after PT & PCI on PI, GI and SPP in the whole population. However, the effects of GI improvement were significant in the smoking group alone; those of PI improvement were most significant in the non-smoking group; and those of SPP improvement were more significant in non-smoking and pre-smoking groups than in the smoking group. The shorter period of smoking and the smaller amount of smoking, the greater effects of PT & PCI by smoking-related characteristics. Conclusion: Smoking cessation instruction should necessarily be included in oral health education in that smoking is an important factor to consider in prevention of periodontal diseases and periodontal therapies.

• Restorative Dentistry and Endodontics
• /
• v.42 no.2
• /
• pp.105-110
• /
• 2017

Objectives: This study investigated the cleaning ability of ultrasonically activated irrigation (UAI) and a novel activation system with reciprocating motion (EC, EasyClean, Easy Equipamentos $Odontol\acute{o}gicos$) when used with a relatively new chelating agent (QMix, Dentsply). In addition, the effect of QMix solution when used for a shorter (1 minute) and a longer application time (3 minutes) was investigated. Materials and Methods: Fifty permanent human teeth were prepared with K3 rotary system and 6% sodium hypochlorite. Samples were randomly assigned to five groups (n = 10) according to the final irrigation protocol: G1, negative control (distilled water); G2, positive control (QMix 1 minute); G3, QMix 1 minute/UAI; G4, QMix 1 minute/EC; G5, QMix 3 minutes. Subsequently the teeth were prepared and three photomicrographs were obtained in each root third of root walls, by scanning electron microscopy. Two blinded and pre-calibrated examiners evaluated the images using a four-category scoring system. Data were statistically analyzed using Kruskal-Wallis and Dunn tests (p < 0.05). Results: There were differences among groups (p < 0.05). UAI showed better cleaning ability than EC (p < 0.05). There were improvements when QMix was used with auxiliary devices in comparison with conventional irrigation (p < 0.05). Conventional irrigation for 3 minutes presented significantly better results than its use for 1 minute (p < 0.05). Conclusions: QMix should be used for 1 minute when it is used with UAI, since this final irrigation protocol showed the best performance and also allowed clinical optimization of this procedure.