• Environmental Analysis Health and Toxicology
• /
• v.30 no.sup
• /
• pp.7.1-7.10
• /
• 2015

Objectives For successful adoption of legislation controlling registration and assessment of chemical substances, it is important to obtain sufficient toxicological experimental evidence and other related information. It is also essential to obtain a sufficient number of predicted risk and toxicity results. Particularly, methods used in predicting toxicities of chemical substances during acquisition of required data, ultimately become an economic method for future dealings with new substances. Although the need for such methods is gradually increasing, the-required information about reliability and applicability range has not been systematically provided. Methods There are various representative environmental and human toxicity models based on quantitative structure-activity relationships (QSAR). Here, we secured the 10 representative QSAR-based prediction models and its information that can make predictions about substances that are expected to be regulated. We used models that predict and confirm usability of the information expected to be collected and submitted according to the legislation. After collecting and evaluating each predictive model and relevant data, we prepared methods quantifying the scientific validity and reliability, which are essential conditions for using predictive models. Results We calculated predicted values for the models. Furthermore, we deduced and compared adequacies of the models using the Alternative non-testing method assessed for Registration, Evaluation, Authorization, and Restriction of Chemicals Substances scoring system, and deduced the applicability domains for each model. Additionally, we calculated and compared inclusion rates of substances expected to be regulated, to confirm the applicability. Conclusions We evaluated and compared the data, adequacy, and applicability of our selected QSAR-based toxicity prediction models, and included them in a database. Based on this data, we aimed to construct a system that can be used with predicted toxicity results. Furthermore, by presenting the suitability of individual predicted results, we aimed to provide a foundation that could be used in actual assessments and regulations.

• Journal of the Korean Geotechnical Society
• /
• v.22 no.12
• /
• pp.15-24
• /
• 2006

The evaluation of shear modulus is very important in various fields of civil engineering. Non-destructive seismic methods can be used to determine shear wave velocity ($V_s$) profile. Non-destructive seismic methods geneally consist of three steps: field testing, evaluation of dispersion curve, and determination of Vs profile by inversion process. Non-destructive seismic methods can be divided into two categories according to the number of receivers used for data reduction: two-channel tests and multi-channel tests. Two channel tests use apparent velocity dispersion curve and multi-channel tests use mode dispersion curves. Multi-channel tests using mode dispersion curve can reduce calculation time to determine soil profile and uncertainties in inversion process. So far, only multi-channel tests can determine mode dispersion curves but multi-channel test needs many receivers to determine reasonable mode dispersion curves. In this paper, HWAW (Harmonic Wavelet Analysis of Wave) method is applied to determine mode dispersion curves. HWAW method uses short test setup which consists of two receivers with a spacing of 1 to 3 m. Through numerical simulations and field application, it is shown that HWAW can determine resonable mode disperson curves.

• Journal of Pharmacopuncture
• /
• v.17 no.2
• /
• pp.57-66
• /
• 2014

Objectives: This study was performed to analyze single dose toxicity and the lethal dose of Scolopendrid Pharmacopuncture in rats. Methods: All experiments were conducted at the Korea Testing & Research Institute (KTR), an institution authorized to perform non-clinical studies, under the regulations of Good Laboratory Practice (GLP). Sprague-Dawley rats were chosen for the pilot study. Doses of Scolopendrid pharmacopuncture, 0.1, 0.5, and 1.0 mL, were administered to the experimental group, and 1.0 mL doses of normal saline solution were administered to the control group. This study was conducted under the approval of the Institutional Animal Ethic Committee. Results: No deaths or abnormalities occurred in any of the groups. No significant changes in the weight, hematological parameters or clinical chemistry were noted between the control group and the experimental group. To check for abnormalities in organs and tissues, we used microscopy to examine representative histological sections of each specified organ; the results showed no significant differences in any of the organs or tissues. Conclusion: The above findings suggest Scolopendrid Pharmacopuncture is a relatively safe to use for treatment. Further studies on the subject should be conducted to yield more concrete evidence.

• Journal of the Korean Society for Nondestructive Testing
• /
• v.36 no.4
• /
• pp.300-307
• /
• 2016

The faults in railway vehicle components may result in either the stoppage of the service and the derailment of the vehicle. Therefore, it is important to diagnose and monitor the main components of a railway vehicle. The use of temperature is one of the basic methods for the diagnosis of abnormal conditions in the rotational components of a railway vehicle, such as bearings, reduction gears, brake discs, wheels and traction motors. In the present study, the diagnose of the rotational components using infrared thermography and a pattern recognition technique was carried out and a field test was performed. The results show that this method of diagnosis using infrared thermography can be used to identify abnormal conditions in rotational components of a railway vehicle.

• The Journal of Advanced Prosthodontics
• /
• v.8 no.2
• /
• pp.101-109
• /
• 2016

PURPOSE. To investigate the void parameters within the resin cements used for fiber post cementation by micro-CT (${\mu}CT$) and regional push-out bonding strength. MATERIALS AND METHODS. Twenty-one, single and round shaped roots were enlarged with a low-speed drill following by endodontic treatment. The roots were divided into three groups (n=7) and fiber posts were cemented with Maxcem Elite, Multilink N and Superbond C&B resin cements. Specimens were scanned using ${\mu}CT$ scanner at resolution of $13.7{\mu}m$. The number, area, and volume of voids between dentin and post were evaluated. A method of analysis based on the post segmentation was used, and coronal, middle and apical thirds considered separately. After the ${\mu}CT$ analysis, roots were embedded in epoxy resin and sectioned into 2 mm thick slices (63 sections in total). Push-out testing was performed with universal testing device at 0.5 mm/min cross-head speed. Data were analyzed with Kruskal-Wallis and Mann-Whitney U tests (${\alpha}=.05$). RESULTS. Overall, significant differences between the resin cements and the post level were observed in the void number, area, and volume (P<.05). Super-Bond C&B showed the most void formation ($44.86{\pm}22.71$). Multilink N showed the least void surface ($3.51{\pm}2.24mm^2$) and volume ($0.01{\pm}0.01mm^3$). Regional push-out bond strength of the cements was not different (P>.05). CONCLUSION. ${\mu}CT$ proved to be a powerful non-destructive 3D analysis tool for visualizing the void parameters. Multilink N had the lowest void parameters. When efficiency of all cements was evaluated, direct relationship between the post region and push-out bonding strength was not observed.

• Progress in Medical Physics
• /
• v.28 no.4
• /
• pp.197-206
• /
• 2017

We develop guidelines for the quality assurance of radiation treatment planning systems (TPS) by comparing and reviewing recommendations from major countries and organizations, as well as by analyzing the AAPM, ESTRO, and IAEA TPS quality assurance guidelines. We establish quality assurance items for acceptance testing, commissioning, periodic testing, system management, and security, and propose methods to perform each item within acceptable standards. Acceptance includes tests of hardware and network environments, data transmission, software, and benchmarking as specified by the system supplier, and apply the IAEA classification criteria. Commissioning includes dosimetric and non-dosimetric items for assessing TPS performance by applying the AAPM classification criteria and the latest technical items from the IAEA. Periodic quality assurance tests include daily, weekly, monthly, yearly, and occasional items by applying the AAPM classification criteria. System management and security items include the state and network connectivity of TPS, periodic data backup, and data access security. The guidelines for TPS quality assurance proposed in this study will help to improve the safety and quality of radiotherapy by preventing incidents related to radiotherapy.

• Journal of the Korean Society for Nondestructive Testing
• /
• v.29 no.2
• /
• pp.108-113
• /
• 2009

MFL(magnetic flux leakage) inspection is a general method of non-destructive evaluation(NDE) of underground gas pipelines. Pipelines are magnetized by permanent magnets when MFL PIG(pipeline inspection gauge) gets through them. If defects or corrosions exist in pipelines, effective thickness is changed and thus variation of leakage flux occurs. The leakage flux signals detected by hall-sensors are analyzed to characterize defect's geometries such as length, width, depth, and so on. This paper presents several methods for estimating defect's length using MFL signals and their performances are compared for real defects carved in KOGAS pipeline simulation facility. It is found that 80% and 90% of minimum values for axial and peak values for radial signals respectively show the best performance in the point of length estimation error.

• Journal of the Korean Society for Nondestructive Testing
• /
• v.34 no.3
• /
• pp.233-240
• /
• 2014

In this study, we investigated the dispersion characteristics of guided waves in thin films. Dispersion curves are essential for understanding not only the behavior of ultrasonic waves, but also the mechanical properties of thin films. Matrix techniques are presented for modeling ultrasonic waves in multilayered structures before being used to calculate the dispersion curves for Al-steel and Al-composite specimens. When compared with the dispersion curves obtained using the commercial program (Disperse), the dispersion curves generated from the transfer matrix method show its validity. These developed methods are used to obtain dispersion curves for Al thin films deposited on a Si substrate. The resulting dispersion curves enable observation of both dispersive and non-dispersive behavior for the guided waves, depending on the thickness of the thin films.

• Journal of Korean Academy of Nursing
• /
• v.47 no.4
• /
• pp.526-539
• /
• 2017

Purpose: This study was undertaken to develop and test a mastery learning program of nursing skills for undergraduate nursing students. Methods: In this methodological study, first, the preliminary draft of a mastery learning program to provide training for nursing skills was developed based on Bloom's framework for mastery learning. Second, to test the developed program, a single-blinded, nonequivalent control group nonsynchronized study was conducted on 50 senior nursing students in a University selected by convenient sampling. Thirteen students were assigned to a control group; 13, 12, and 13 of them were assigned to intravenous therapy, transfusion, and patient transfer groups, respectively. The achievement levels and performance scores of the selected nursing skills were measured before and after the completion of the program in all the groups. Lastly, the final program was confirmed based on the results of the program testing. Results: Intravenous therapy, transfusion, and patient transfer were selected as essential nursing skills for the program based on the priorities rated by clinical instructors and staff nurses. The achievement levels of selected nursing skills were determined by Angoff scores. After participating in the program, the proportion of passers and performance scores of the nursing skills in the experimental groups were significantly higher than those in the control group. The final program was confirmed which included a diagnostic test, enrichment activities for the passers and three repetitions of corrective activities and formative assessments for non-passers. Conclusion: The results suggest that a mastery learning program for undergraduate students can lead to better improvement and performance of essential nursing skills.

• Asian Pacific Journal of Cancer Prevention
• /
• v.15 no.18
• /
• pp.7885-7889
• /
• 2014

Background: Activating mutations of epidermal growth factor receptor (EGFR) could predict response to tyrosine kinase inhibitor (TKI) treatment in patients with non-small cell lung cancer (NSCLC). However, the detection of EGFR mutation is frequently challenging in clinical practice for the lack of tumor tissue. The aim of this study was to investigate the feasibility of performing EGFR mutation testing on various types of liquid-based cytology (LBC) samples. Materials and Methods: A total of 434 liquid-based cytology samples were collected from March 2010 and November 2013. Among them, 101 with diagnosis of lung adenocarcinoma had paired surgically resected specimens. The ADx Amplification Refractory Mutation System (ADx-ARMS) was used to determine EGFR mutation status both in LBC and resected samples. Results: All liquid-based cytology samples were adequate for EGFR mutation analysis. The mutation rate was 50.5% in the 434 NSCLC patients with LBC samples and the incidence rates of EGFR mutation were consistent among different specimens. We also detected EGFR positives in 52.5% (53/101) patients with paired histologic specimens. The concordance rate of EGFR mutation between LBC samples and paired histologic specimens was 92.1%. Conclusions: Our results suggest that liquid-based cytology samples are highly reliable for EGFR mutation testing in patients with NSCLC.