• Journal of Positioning, Navigation, and Timing
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• v.2 no.1
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• pp.33-40
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• 2013

In this paper, GPS signal anomaly generation software is proposed which can be used for the analysis of GPS signal anomaly effect and the design, verification, and operation test of anomalous signal monitoring technique. For the implementation of anomalous signal generation technique, anomalous signals are generated using a commercial signal generation simulator, and their effects and characteristics are analyzed. An error model equation is proposed from the result of analysis, and the anomalous signal generation software is constructed based on this equation. The proposed anomalous signal generation software has high scalability so that users can easily utilize and apply, and is economical as the additional cost for purchasing equipment is not necessary. Also, it is capable of anomalous signal generation based on real-time signal by comparing with the commercial signal generation simulator.

• Journal of Korean Academy of Nursing
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• v.35 no.8
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• pp.1451-1460
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• 2005

Purpose. The purpose of this study was to evaluate the premature infants' responses to infant massage (tactile and kinesthetic stimulation). These responses measured by weight, physiological (vagal tone, heart rate, oxygen saturation) and behavioral responses (behavioral states, motor activities, and behavioral distress). Methods. This study was conducted using an equivalent control pretest-posttest design. The sample was divided into two groups of 13 infants with gestational age less than 36 weeks at birth, birth weight less than 2000g, and no congenital anomalies. The experimental group received the massage intervention twice daily for 10 days. The data were collected for 10 minutes prior to and 10 minutes after the massage. Results. The vagal tone was significantly higher after massage than before massage in the experimental group, while no change in the control group. The experimental group had significantly higher scores for awake state and motor activity than the control group. Significantly greater awake state, more fidgeting or crying, and increased motor activity were reported after massage than before massage. Conclusions. The results of this study showed that massage therapy might enhance optimal physiological responses and behavioral organization of premature infants. Nursing staff in the NICU can use massage to promote the infant's capability to respond positively to his environment and to provide developmental support for healthy premature infants.

• Journal of Mechanical Science and Technology
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• v.16 no.12
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• pp.1652-1663
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• 2002

It is desirable to perform nondestructive evaluation to assess material properties and part homogeneity because manufacturing of carbon/carbon (C/C) composites requires complicated and costly processes. In this work several ultrasonic techniques were applied to carbon/carbon composites for the evaluation of spatial variations in material properties that are attributable to the manufacturing process. In a large carbon/carbon composite manufactured by chemical vapor infiltration (CVI) method, the spatial variation of ultrasonic velocity was measured and found to be consistent with the densification behavior in CVI process in order to increase the density of C/C composites. Ultrasonic velocity and attenuation depend on a density variation of materials. Low frequency through-transmission scans based on both amplitude and time-of-flight of the ultrasonic pulse were used for mapping out the material property inhomogeneity These results were compared with that obtained by dry-coupling ultrasonics. Pulse-echo C-scans was used to image near-surface material property anomalies such as the placement of spacers between disks during CVI. Also, optical micrograph had been examined on the surface of C/C composites using a destructive way.

• Journal of Chest Surgery
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• v.24 no.7
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• pp.693-700
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• 1991

A rare case of the association of distal aortopulmonary septal defect, aortic origin of the right pulmonary artery, intact ventricular septum, patent ductus arteriosus and interrupted aortic isthmus in a 40-day-old infant is reported. The infant was suffered from two operations with an interval of nine days. At the first operation a 10mm polytetrafluoroethylene prosthesis was inserted instead of the interrupted aortic isthmus and ductus was ligated via the left posterolateral thoracotomy. But the patient could not be weaned from the respirator because of large amount of left-to-right shunt. So the total correction was subsequently performed after an interval of nine days. At the second operation, tunneling of the right pulmonary artery to the main pulmonary artery through the aortopulmonary septal defect was performed using the Dacron patch via a longitudinal transaortic approach and a separate autologous pericardial patch was applied to the longitudinally incised margins of the anterior wall of the ascending aorta. The second postoperative course was relatively uneventful except some respiratory distress and nutritional problems. Now he is at 6 months of age and thrives well without any symptom. Because the success of the surgical repair of this complex anomalies depends upon the accurate diagnosis and meticulous design of each step of procedure prior to operation these problems are also discussed.

• Asia-Pacific Journal of Business
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• v.11 no.2
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• pp.15-25
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• 2020

Purpose - The purpose of this study is to examine whether the change of settlement procedures have an impact on the distribution of day of the week effect in the UK and French markets or not. U.K and France changed their systems from fixed settlement date systems to fixed settlement lag systems Design/methodology/approach - This study adopted the data of the specific stock market indices such as FTSE 100 in the U.K market and FRCAC 40 in the French market, This study constructs a test of the differences in mean returns across the days of the week by computing the regression equations for each country index. Findings - First, this study found that the evolving settlement procedures in stock exchanges have an effect on stock return of day of the week. Second, long-run improvements in market efficiency may have diminished the effects of certain anomalies in recent periods. Improvements in market efficiency and evolving settlement systems may cause the disappearance of the weekend effect. Research implications or Originality - The Implication of this study is that recent settlement systems contributed to the disappearance of the weekend effect and explains improvements in market efficiency and diminishments of market anomaly. This study may be the first study which examines whether evolving settlement systems have an effect on the disappearance of the weekend effect in the market or not.

• The Korean Journal of Applied Statistics
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• v.36 no.5
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• pp.399-413
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• 2023

Recently, monitoring and detecting anomalies in social networks have become an interesting research topic. In this study, we investigate the detection of abnormal changes in a network modeled by the DCSBM (degree corrected stochastic block model), which reflects the propensity of both individuals and communities. To this end, we propose three methods for anomaly detection in the DCSBM networks: One method for monitoring the entire network, and two methods for dividing and monitoring the network in consideration of communities. To compare these anomaly detection methods, we design and perform simulations. The simulation results show that the method for monitoring networks divided by communities has good performance.

• Asia-Pacific Journal of Business
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• v.14 no.3
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• pp.45-66
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• 2023

Purpose - This paper examines whether overnight returns and idiosyncratic volatility (IVOL) jointly affects the cross-section of expected stock returns in the Korean stock market. Design/methodology/approach - Constructing 5×5 bivariate monthly portfolios independently sorted on overnight returns and IVOL, this paper tests whether overpricing of stocks with high overnight returns is more pronounced for the stocks that also have high IVOL. In addition, we also investigate whether time-variation in the degree of overpricing for those stocks can be explained by market volatility. Findings - Our results show that stocks having both high overnight returns and high IVOL exhibit strong negative returns in the future. In contrast, we are unable to observe such negative returns for the stocks that have high overnight returns and low IVOL. This suggests that overpricing of stocks with high overnight returns is concentrated for the stocks having high IVOL. Moreover, we also find that the degree to which such stocks are overpriced is negatively related to market volatility. Research implications or Originality - his paper is the first attempt to explore whether degree of overpricing of stocks having high overnight returns is related to IVOL. We also discover time-varying property of overpricing is jointly driven by overnight returns and IVOL. Our results indicate that IVOL might help explain other previously documented stock return anomalies, suggesting interesting topics for future research.

• The Journal of Bigdata
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• v.6 no.1
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• pp.23-35
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• 2021

In the era of the 4th industrial revolution, smart factories have received great attention, where production and manufacturing technology and ICT converge. With the development of IoT technology and big data, automation of production systems has become possible. In the advanced manufacturing industry, production systems are subject to unscheduled performance degradation and downtime, and there is a demand to reduce safety risks by detecting and reparing potential errors as soon as possible. This study designs a model based on supervised and unsupervised learning for detecting anomalies. The accuracy of XGBoost, LightGBM, and CNN models was compared as a supervised learning analysis method. Through the evaluation index based on the confusion matrix, it was confirmed that LightGBM is most predictive (97%). In addition, as an unsupervised learning analysis method, MD, AE, and LSTM-AE models were constructed. Comparing three unsupervised learning analysis methods, the LSTM-AE model detected 75% of anomalies and showed the best performance. This study aims to contribute to the advancement of the smart factory by combining supervised and unsupervised learning techniques to accurately diagnose equipment failures and predict when abnormal situations occur, thereby laying the foundation for preemptive responses to abnormal situations. do.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.11 no.2
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• pp.203-212
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• 2004

Purpose: This study was done to determine whether providing auditory and vestibular stimulation to preform infants would have an effect on stress hormones. Methods: The design was a nonequivalent control group protest-posttest design in a quasi-experimental study Seventy-nine preform infants were assigned either one of two experimental groups or to a control group: 27 in the auditory stimulation group, 25 in the vestibular stimulation group and 27 in the control group. The criteria for inclusion in this study were 1) gestational age of less than 37 weeks, 2) birth weight of less than 2,500g, 3) the absence of congenital anomalies or specific diseases, 4) recovering physiological weight loss, and 5) weaned from ventilatory assistance or oxygen. The data were collected from March 2002 to May 2003. The auditory stimulation, a music audiotape, was provided 20 minutes twice a day for 10 days and the vestibular stimulation, an infant waterbed, was provided for 10 days. On day 1 and day 10 of the study, 24 hour urine sample was collected for norepinephrine, epinephrine, and cortisol assays. In the data analysis SPSSWIN 10.0 program was utilized for descriptive statistics, ANOVA and t-test. Results: General characteristics of the three groups showed no significant differences, thus three groups were found to be homogenous. The 24 hour urine cortisol for the auditory (t=3.489, p=.001) and for the vestibular (t=2.638, p=.013) stimulation group were significantly reduced compared to the control group after 10 days. Conclusions: The results suggest that auditory and vestibular stimulation can be used to reduce 24 hour urine cortisol in preform infants. Therefore, music audiotapes and waterbeds provided in incubator are be recommended for reduction of the stress in preform infants who are hospitalized in neonatal intensive care units.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.5
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• pp.9-15
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• 2018

With the advent of the 5G communication era recently, advancement of the convergence technologies related to IoT has been progressed rapidly. IoT convergence technologies using various sensors are actively applied many fields in our lives, and it contributes to the popularization of these convergence technologies among many people successfully. The security problem of the IoT which connects many things on the network is critically vulnerable and is one of the most important challenge to be solved urgently. In this paper, we design an intrusion detection and self-treatment system for IoT, which can detect external attacks and anomalies in order to solve the security problems in IoT, perform self-treatment by operating the vaccine program according to the intrusion type whenever it detects certain intrusion. Furthermore, we consider the broadcasting of intrusion alarm message according to the frequency of similar circumstances in order to block intrusion contagious in IoT.