• Bulletin of the Korean Chemical Society
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• v.28 no.12
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• pp.2363-2368
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• 2007

A glassy carbon electrode (GCE) modified with phytic acid (PA) and single-walled carbon nanotubes (SWNTs) were investigated by voltammetric methods in buffer solution. The PA-SWNTs/GCE-modified electrode demonstrated substantial enhancements in electrochemical sensitivity and selectivity towards dopamine (DA) in the presence of L-ascorbic acid (AA). The PA-SWNTs films promoted the electron transfer reaction of DA, while the PA film, acting as a negatively charged linker, combined with the positively charged DA to induced DA accumulation in the film at pH under 7.4. However, the PA film restrained the electrochemical response of the negatively charged AA due to the electrostatic repulsion. The anodic peak potentials of DA and AA could be separated by electrochemical techniques, and the interferences from AA were effectively eliminated in the DA determination. Linear calibration plots were obtained in the DA concentration range of 0.1-10 μM and the detection limit of the DA oxidation current was determined to be 0.06 μM at a signal-to-noise ratio of 3. The results indicated that the modified electrode is used to determine DA without interference from AA.

• Journal of the Korean Vacuum Society
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• v.19 no.5
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• pp.319-325
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• 2010

Pressure vacuum measurement technique using acoustic impedance change of ultrasonic transducers was studied. The sensor has been setup using two air-coupled ultrasonic transducers, one as a transmitter and the other as a receiver, and put it into vacuum chamber and measured pressure versus ultrasonic amplitude. The result confirms that the standard deviations of four repeat measurements were from 0.0093 to 0.3325 at pressure 6.66 kPa to 202.65 kPa(about two atmosphere), and the relative percents were 0.018% and 0.164% at pressure 133.32 kPa and 202.65 kPa, respectively.

• Radiation Oncology Journal
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• v.35 no.1
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• pp.78-89
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• 2017

Purpose: To determine the optimal radiotherapy technique for gastric mucosa-associated lymphoid tissue lymphoma (MALToma), we compared the dosimetric parameters and the risk of solid secondary cancer from scattered doses among anterior-posterior/ posterior-anterior parallel-opposed fields (AP/PA), anterior, posterior, right, and left lateral fields (4_field), 3-dimensional conformal radiotherapy (3D-CRT) using noncoplanar beams, and intensity-modulated radiotherapy composed of 7 coplanar beams (IMRT_co) and 7 coplanar and noncoplanar beams (IMRT_non). Materials and Methods: We retrospectively generated 5 planning techniques for 5 patients with gastric MALToma. Homogeneity index (HI), conformity index (CI), and mean doses of the kidney and liver were calculated from the dose-volume histograms. Applied the Biological Effects of Ionizing Radiation VII report to scattered doses, the lifetime attributable risk (LAR) was calculated to estimate the risk of solid secondary cancer. Results: The best value of CI was obtained with IMRT, although the HI varied among patients. The mean kidney dose was the highest with AP/PA, followed by 4_field, 3D-CRT, IMRT_co, and IMRT_non. On the other hand, the mean liver dose was the highest with 4_field and the lowest with AP/PA. Compared with 4_field, the LAR for 3D-CRT decreased except the lungs, and the LAR for IMRT_co and IMRT_non increased except the lungs. However, the absolute differences were much lower than <1%. Conclusion: Tailored RT techniques seem to be beneficial because it could achieve adjacent organ sparing with very small and clinically irrelevant increase of secondary solid cancer risk compared to the conventional techniques.

• Journal of Communications and Networks
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• v.14 no.3
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• pp.310-318
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• 2012

Detecting intrusion attacks accurately and rapidly in wireless networks is one of the most challenging security problems. Intrusion attacks of various types can be detected by the change in traffic flow that they induce. Wireless industrial networks based on the wireless networks for industrial automation-process automation (WIA-PA) standard use a superframe to schedule network communications. We propose an intrusion detection system for WIA-PA networks. After modeling and analyzing traffic flow data by time-sequence techniques, we propose a data traffic prediction model based on autoregressive moving average (ARMA) using the time series data. The model can quickly and precisely predict network traffic. We initialized the model with data traffic measurements taken by a 16-channel analyzer. Test results show that our scheme can effectively detect intrusion attacks, improve the overall network performance, and prolong the network lifetime.

• Imaging Science in Dentistry
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• v.48 no.3
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• pp.161-165
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• 2018

Purpose: To evaluate the usefulness of shear wave elastography in the diagnosis of oral and maxillofacial diseases. Materials and Methods: Ten patients with oral and maxillofacial diseases and 28 volunteers drawn from our student doctors were examined by shear wave elastography with a 14-MHz linear transducer using an Aplio 300 apparatus (Canon Medical Systems, Otawara, Japan). A statistical analysis of the shear elastic modulus(kPa) of healthy tissue (the sublingual gland, submandibular gland, anterior belly of the digastric muscle, and geniohyoid muscle) in the 28 volunteers was performed using 1-way repeated measures analysis of variance with the Tukey honest significant difference test. The maximum shear elastic modulus(kPa) of 8 patients with squamous cell carcinoma (SCC) and 2 patients with benign lesions was evaluated with the Mann-Whitney U test. The analysis used a 5% significance level. Results: The mean shear elastic modulus of the sublingual gland ($9.4{\pm}3.7kPa$) was lower than that of the geniohyoid muscle ($19.2{\pm}9.2kPa$, P=.000) and the anterior belly of the digastric muscle ($15.3{\pm}6.1kPa$, P=.004). The maximum shear elastic modulus of the SCCs($109.6{\pm}14.4kPa$) was higher than that of the benign lesions($46.4{\pm}26.8kPa$, P=.044). Conclusion: Our results demonstrated the usefulness of shear wave elastography in the diagnosis of oral and maxillofacial diseases. Shear wave elastography has the potential to be an effective technique for the objective and quantitative diagnosis of oral and maxillofacial diseases.

• International Journal of Computer Science & Network Security
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• v.23 no.1
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• pp.46-52
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• 2023

With billions of IoT (Internet of Things) devices populating various emerging applications across the world, detecting anomalies on these devices has become incredibly important. Advanced Intrusion Detection Systems (IDS) are trained to detect abnormal network traffic, and Machine Learning (ML) algorithms are used to create detection models. In this paper, the NSL-KDD dataset was adopted to comparatively study the performance and efficiency of IoT anomaly detection models. The dataset was developed for various research purposes and is especially useful for anomaly detection. This data was used with typical machine learning algorithms including eXtreme Gradient Boosting (XGBoost), Support Vector Machines (SVM), and Deep Convolutional Neural Networks (DCNN) to identify and classify any anomalies present within the IoT applications. Our research results show that the XGBoost algorithm outperformed both the SVM and DCNN algorithms achieving the highest accuracy. In our research, each algorithm was assessed based on accuracy, precision, recall, and F1 score. Furthermore, we obtained interesting results on the execution time taken for each algorithm when running the anomaly detection. Precisely, the XGBoost algorithm was 425.53% faster when compared to the SVM algorithm and 2,075.49% faster than the DCNN algorithm. According to our experimental testing, XGBoost is the most accurate and efficient method.

• Journal of Yeungnam Medical Science
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• v.1 no.1
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• pp.95-100
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• 1984

In the beginning of anesthetic training, one of the clinical practices that anesthetists have to learn is manually controlled ventilatory techniques. The popularity of manually controlled ventilatory techniques has been gradually decreased with increased use for anesthetic ventilators. However it is important and basic for the anesthetists to master manually controlled ventilatory techniques skillfully. Recently, we analyzed the arterial blood gas in 30 cases before and during general anesthesia, and studied the effects of the manually controlled ventilation on the pulmonary gas exchange. The results were as follow; 1) Mean value of $PaCO_2$ during the manually controlled ventilation, $29.9{\pm}2.9mmHg$ was decreased statistically comparing with that of $PaCO_2$ before the anesthesia, $39.8{\pm}2.8mmHg$. 2) Mean values of pH and ${HCO_3}^-$ during the manually controlled ventilation were $7.48{\pm}0.03$, $22.2{\pm}2.4mEq/l$, respectively and values before the anesthesia were $7.41{\pm}0.02$, $25.2{\pm}1.8mEq/l$, respectively. 3) Mean values of $PaO_2$ and $O_2$ saturation during the manually controlled ventilation were $270.0{\pm}28.8mmHg$, $99.6{\pm}0.2%$, respectively and values before the anesthesia were $92.5{\pm}4.0mmHg$, $96.9{\pm}1.0%$ respectively. These results indicates that manually controlled ventilation at our department of anesthesiology produced mild hyperventilatory state. However these were no significant changes in cerebral blood flow and other biochemical parameters.

• Archives of Plastic Surgery
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• v.41 no.4
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• pp.403-406
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• 2014

Background Perforations in the nasal septum (NSP) give rise not only to disintegration of the septum anatomy but also impairment in normal nasal physiology. The successes of these surgical techniques are usually equated to anatomical closure of the perforation. The goal of this study is to evaluate the subjective and objective results of our surgical technique for septal perforation surgery. Methods All NSPs in the six patients were closed by inferior turbinate flap. The Nasal Obstruction Symptom Evaluation (NOSE) instrument was used to evaluate the preoperative and postoperative subjective sensation of nasal obstruction. Measurement of preoperative and postoperative nasal airway resistance was performed using active anterior rhinomanometry which is an objective test. Wilcoxson signed rank test and Spearman correlation test were used to analyze correlation between NOSE scores and rhinomanometric measurements. Results The full closure of the septal perforations was noted in 100% of patients. The total NOSE score was 14 preoperatively and one postoperatively. The improvement in NOSE scores was statistically significant ($P{\leq}0.002$). The mean preoperative total resistance (ResT150) value was $0.13Pa/cm^3s^{-1}$, which is below the normal range ($0.16-0.31Pa/cm^3s^{-1}$), while the mean postoperative ResT150 value was $0.27Pa/cm^3s^{-1}$. The correlation between the improvement in NOSE scores and improvements in ResT150 values was statistically significant. Conclusions Surgical approaches should aim to solve both the anatomical and physiological problems of NSP. The application of subjective and objective tests in the postoperative period will help surgeons assess the applied techniques.

• Journal of KIISE:Software and Applications
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• v.26 no.12
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• pp.1418-1427
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• 1999

시간지원 데이타베이스 시스템은 자료의 과거 및 현재, 그리고 미래의 상태까지 관리함으로써, 사용자에게 시간에 따라 변화하는 자료에 대한 저장 및 질의 수단을 제공한다. 시간지원 데이타베이스는 경향 분석, 버전 관리, 의료 기록 관리 및 비디오 데이타 관리 등과 같이 자료의 시간적 특성이 중요시 되는 모든 분야에 폭 넓게 응용될 수 있다. 시간지원 데이타베이스에서의 집계는 시간 애트리뷰트를 고려하지 않은 기존의 집계와는 큰 차이가 있으며, 기존의 집계 처리 기법을 이용하여 효과적으로 처리될 수 없다. 본 논문에서는 시간지원 집계를 효율적으로 처리하기 위한 새로운 자료 구조인 PA-트리를 제안하고, 이를 이용한 시간지원 집계 처리 기법을 제안한다. 또한 본 논문에서는 제안된 PA-트리를 이용한 기법과 기존의 집계 트리를 이용한 기법의 성능을 최악 경우 분석과 실험을 통해 비교한다.Abstract Temporal databases manage time-evolving data. They provide built-in supports for efficient recording and querying of temporal data. Many application area such as trend analysis, version management, and medical record management have temporal aspects, and temporal databases can handle these temporal aspects efficiently. The aggregate in temporal databases, that is, temporal aggregate is an extension of conventional aggregate on the domain and range of aggregation to include time concept. The basic techniques behind computing aggregates in conventional databases are not efficient when applied to temporal databases. In this paper, we propose a new tree structure for temporal aggregation, called PA-tree, and aggregate processing method based on the PA-tree. We compare the PA-tree with the existing aggregation tree which has been proposed for temporal aggregate.

• Geomechanics and Engineering
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• v.35 no.2
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• pp.135-147
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• 2023

Sand columns in clayey soil are considered one of the most economical and environmentally-friendly soil-improving techniques. It improves the shear strength parameters, reduces the settlement, and increases the bearing capacity of clayey soils. The aim of this paper is to study the effect of grain shape in sand columns on their performance in improving the mechanical properties of clayey soils. An intensive series of consolidated-drained triaxial tests were performed on clay specimens only and clay specimens with sand columns. The parameters examined during the experimental work were grain shape in sand columns (angular, rounded, sub-rounded) and effective confining pressure (50 kPa, 100 kPa, 200 kPa). The results indicated that there is a significant improvement in the deviatoric stress and stiffness values of specimens with sand columns. Improving deviatoric stress values in the use of angular sand grains was found to be higher than those in the use of sub-rounded and rounded sand grains. A 187%, 159%, and 153% increment in deviatoric stress values were observed for the sand columns with angular, sub-rounded, and rounded grain shapes, respectively. The specimens were observed to be more contractive as the sand column was installed, and as the angularity of grains in the sand column was increased. Sand column installation improves significantly the angle of internal friction, and the effective angle of internal friction increases as the angularity of the sand grains increases.