• The Korean Journal of Nuclear Medicine Technology
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• v.16 no.1
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• pp.86-90
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• 2012

Purpose: Quantification of myocardial blood flow (MBF) using dynamic PET imaging has the potential to assess coronary artery disease. Rb-82 plays a key role in the clinical assessment of myocardial perfusion using PET. However, MBF could be overestimated due to the underestimation of left ventricular input function in the beginning of the acquisition when the scanner has non-linearity between count rate and activity concentration due to the scanner dead-time. Therefore, in this study, we evaluated the count rate linearity as a function of the activity concentration in PET data acquired in list mode. Materials & methods: A cylindrical phantom (diameter, 12 cm length, 10.5 cm) filled with 296 MBq F-18 solution and 800 mL of water was used to estimate the linearity of the Biograph 40 True Point PET/CT scanner. PET data was acquired with 10 min per frame of 1 bed duration in list mode for different activity concentration levels in 7 half-lives. The images were reconstructed by OSEM and FBP algorithms. Prompt, net true and random counts of PET data according to the activity concentration were measured. Total and background counts were measured by drawing ROI on the phantom images and linearity was measured using background correction. Results: The prompt count rates in list mode were linearly increased proportionally to the activity concentration. At a low activity concentration (<30 kBq/mL), the prompt net true and random count rates were increased with the activity concentration. At a high activity concentration (>30 kBq/mL), the increasing rate of the prompt net true rates was slightly decreased while the increasing rate of random counts was increased. There was no difference in the image intensity linearity between OSEM and FBP algorithms. Conclusion: The Biograph 40 True Point PET/CT scanner showed good linearity of count rate even at a high activity concentration (~370 kBq/mL).The result indicates that the scanner is useful for the quantitative analysis of data in heart dynamic studies using Rb-82, N-13, O-15 and F-18.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.4
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• pp.154-160
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• 2018

This thesis aims to develop PBL (Problem-Based-Learning) problems. Its goal is for some groups of students to creative their own problems and to confirm the effectiveness of PBL as they apply it to AI (Artificial Intelligence) in engineering schools. Modern industrial society needs competent people who have abilities in cooperative learning, self-controlled learning, united knowledge application, and creative problem-solving. Universities need to offer their students the opportunity to improve their problem-solving and cooperative learning abilities in order to train the competent people that society demands. PBL activity is an appropriate learning method for the accomplishment of these goals. The study subjects are 37 sophomore students in H University who are studying 'AI'. Five PBL problems were submitted to the class over a period of 15 weeks. The students wrote and submitted a reflective journal after they finished each PBL activity. In addition, they filled out a class evaluation form to assess the performances of each member when the $5^{th}$ PBL problem activity was accomplished. The study shows that the students experienced the effectiveness of PBL in many fields, such as the comprehension of the studied contents (86.48%), comprehension of cooperative learning (94.59%), authentic experience (75.67%), problem-solving skills (89.18%), presentation skills (97.29%), creativity improvement (81.08%), knowledge acquisition ability (86.48%), communication ability (97.29%), united knowledge application (78.37%), self-directed study ability (86.48%) and confidence (97.29%). Through these methods, the students were able to realize that PBL learning activities play an important role in their learning. These methods prepare and enhance their ability to think creatively, work systematically and speak confidently as they learn to become competitive engineers equipped with the knowledge and skills that modern industrial society demands.

• Korean Business Review
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• v.18 no.1
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• pp.59-79
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• 2005

recently, world is progressing large quantity consumption with continuous Innovation and economic growth and pollution is accelerated at these process. Increase of industry activity and service that is point of corporation activity is discharging environmental pollutants at whole process to manufacture of end product and exhaust process from acquisition of raw material for accompanied product production hereupon. At the same time, being promoting resources consumption by that use much raw material, As a result, is becoming obstacle factors in sustainable development. So, corporation's responsibility for environmental protection is emphasized. Corporation which must prepare in green round or environmental problems should consider environmental effects that is happened over whole life of products that include waste treatment after raw material acquisition and use as well as selling end product simply. A Life Cycle Assessment techniques is normalized and standardized in International Standard Organization for technical committee 207(TC 207) world widely, and effort to apply in corporation's activity because mastering LCA techniques in domestic several corporations is undergone actively. Coming into effect of Kyoto's Protocol and International Organization for Standard 14000 series revision are presenting new survival principle in competition between country or corporation. LCA technique may become very useful means to corporation which wish to attempt environment management in real condition that awareness for environment is important. Also, An LCA to each product is going to cause big effects in corporation's whole image as well as competitive power raising for single product. Therefore, this research wishes to examine some instances for the future competitive product development at the estimation of environmental friendliness using LCA techniques and more theoretical considerations of the LCA techniques that can dominate corporation's fate.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2020.08a
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• pp.75-75
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• 2020

Potatoes were first introduced outside the Andes region four centuries ago, and have become an integral part of much of the world's food. Potatoes were first introduced into Europe in the 16th century and Korea in the early 19th century. Potatoes have a short growing season, high production per unit area, relatively strong environmental adaptability, and are cultivated in more than 130 countries around the world. It is the world's fourth-largest crop, following rice, wheat, bean and maize. In the nutritional aspects, potatoes contain abundant vitamins and minerals, as well as an assortment of phytochemicals such as carotenoids and natural phenols. Due to the high content of potato functional compounds, it has known that potatoes are effective in the prevention of various human diseases. In particular, the potato contains a large amount of polar compounds, including the saponin in the polar compounds, and the physiological activity of the saponins, such as immunity enhancement, antioxidant and anti-inflammatory is known. In this study, the antioxidative activity of polar compounds from five potatoes was examined by cell based anti-oxidation assay. The smallest amount of ROS(Reactive oxygen species) was generated when the compound was derived from 'Haryung' and 'hongyoung' and strong SOD(Superoxide dismutase) activity was observed in 'Sumi' and 'Jayoung'. The results of this study reveal the antioxidative effect of polar compounds extracted from various kind of potatoes, which will enable the acquisition of new bioactive candidates and the establishment of new profit generation models for farmers

• The Journal of Korean Physical Therapy
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• v.15 no.2
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• pp.75-84
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• 2003

The purpose of this study was to review of mechanism and application methodology about mental practice. The mental practice is symbolic rehearsal of physical activity in the absence of any gross muscular movements. Human have the ability to generate mental correlates of perceptual and motor events without any triggering external stimulus, a function known as imagery, Practice produces both internal and external sensory consequences which are thought to be essential for learning to occur, It is for this reason that mental practice, rehearsal of skill in imagination rather than by overt physical activity, has intrigued theorists, especially those interested in cognitive process. Several studies in sport psychology have shown that mental practice can be effective in optimizing the execution of movements in athletes and help novice learner in the incremental acquisition of new skilled behaviors. There are many theories of mental practice for explaining the positive effect In skill learning and performance. Most tenable theories are symbolic learning theory, psyconeuromuscular theory, Paivio's theory, regional cerebral blood flow theory, motivation theory, modeling theory, mental and muscle movement nodes theory, insight theory, selective attention theory, and attention-arousal set theory etc.. The factors for influencing to effects of mental practice are application form, application period, time for length of the mental practice, number of repetition, existence of physical practice.

• Biomolecules & Therapeutics
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• v.16 no.3
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• pp.249-254
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• 2008

The present study was undertaken to determine whether hypoxia influences on the agonist-induced vascular smooth muscle contraction and, if so, to investigate the related mechanism. The measurement of isometric contractions using a computerized data acquisition system was combined with molecular experiments. Hypoxia significantly inhibited fluoride-induced contraction regardless of endothelial function, but there was no relaxation on thromboxane $A_2$ mimetic U-46619-induced contraction suggesting that other pathway such as $Ca^{2+}$ entry or thin filament regulation was not affected. In addition, hypoxia significantly decreased fluoride-induced increase of phospho-myosin-targeting subunit of myosin light chain phosphatase (pMYPT1). Interestingly, hypoxia didn't inhibit significantly phenylephrine-induced contraction suggesting that myosin light chain kinase (MLCK) activity or thin filament regulation is less important on the hypoxia-induced vasorelaxation in the denuded muscle than Rho-kinase activity. In conclusion, this study provides the evidence and possible related mechanism concerning the vasodilation effect of hypoxia on the agonist-specific contraction in rat aortic rings regardless of endothelial function.

• Journal of Intelligence and Information Systems
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• v.4 no.1
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• pp.115-131
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• 1998

Customer service process is one of the most important processes in today's competitive business environment. Among the various activities of customer service process, equipment malfunction diagnosis activity should be performed fast and accurately. When a customer calls the service center and reports the observed symptoms, he/she describes them in layman's terms. Therefore, the customer-reported symptoms have not been considered helpful information for service representatives. However, in order to perform diagnosis activity fast and accurately, we need to make use of the customer-reported symptoms actively. In this research, we developed three systems called R-EMD (Rule-based Equipment Malfunction Diagnostic system), C-EMD (Case-based Equipment Malfunction Diagnostic system) and R&C-EMD (Rule & Case-based Equipment Malfunction Diagnostic system), each of which diagnoses equipment malfunctions using the customer-reported symptoms. R&C-EMD is a hybrid system that utilizes both rule-based and case-based technologies. The diagnosis rules used in R&C-EMD and R-EMD were not acquired from service manuals or interviews with service representatives. Rater, we extracted them directly from the past diagnosis cases based on symptoms' frequencies. By this way, we were able to overcome the knowledge acquisition bottleneck. Using the real 100 malfunction diagnosis cases, we evaluated the performances of R&C-EMC, R-EMD and C-EMD in terms of speed and accuracy. In diagnosis time, R&C-EMD took longer than R-EMD and shorter than C-EMD. However, R&C-EMC was the best in accuracy.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.55 no.11
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• pp.495-501
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• 2006

Diagnostics of unborn baby is mainly aimed at prediction and detection of occurrence of intrauterine hypoxia. Consequences resulting from fetal hypoxia appear in its heart activity. In this study, we have developed a new non-invasive system for fetal hypoxia diagnosis which provides systolic time interval(STI) parameters on the basis of analysis of electrical and mechanical heart activity together. For this we have worked on 1) the proper lead system for the acquisition of abdominal ECG, 2) the independent component analysis based signal processing and fetal ECG separation, 3) the development of a hardware which consists of an abdominal ECG amplifying module and an ultrasound module and 4) the detection of characteristic points of FECG and Doppler signal and the extraction of diagnostic parameters. The developed system was evaluated by the clinical experiments in which 33 subjects were participated. The acquired STI by the system were distributed within the ranges from the well-established invasive results of other researchers. From this, we can conclude that the developed non-invasive fetal hypoxia diagnosis system is useful.

• Mycobiology
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• v.51 no.3
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• pp.169-177
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• 2023

To further explore the molecular mechanism of triterpenoid biosynthesis and acquire high-value strain of Sanghuangporus baumii, the Agrobacterium tumefaciens-mediated transformation (ATMT) system was studied. The key triterpenoid biosynthesis-associated gene isopentenyl diphosphate isomerase (IDI) was transformed into S. baumii by ATMT system. Then, the qRT-PCR technique was used to analyze gene transcript level, and the widely targeted metabolomics was used to investigate individual triterpenoid content. Total triterpenoid content and anti-oxidant activity were determined by spectrophotometer. In this study, we for the first time established an efficient ATMT system and transferred the IDI gene into S. baumii. Relative to the wild-type (WT) strain, the IDI-transformant (IT) strain showed significantly higher transcript levels of IDI and total triterpenoid content. We then investigated individual triterpenoids in S. baumii, which led to the identification of 10 distinct triterpenoids. The contents of individual triterpenoids produced by the IT2 strain were 1.76-10.03 times higher than those produced by the WT strain. The triterpenoid production showed a significant positive correlation with the IDI gene expression. Besides, IT2 strain showed better anti-oxidant activity. The findings provide valuable information about the biosynthetic pathway of triterpenoids and provide a strategy for cultivating high-value S. baumii strains.

• Journal of Radiation Industry
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• v.17 no.3
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• pp.219-224
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• 2023

A high-efficiency underwater radiation monitoring system, HydroGamma, has been developed for detecting ¹³⁷Cs and ¹³¹I in the event of waterborne radiation contamination. The system consists of a 3-inch NaI (Tl) detector, solar panels for power supply, data acquisition and transmission modules, and batteries. HydroGamma also includes a ⁴⁰K calibration source for remote performance evaluation and energy calibration. In this study, some simulations and experiments were carried out to evaluate the minimum detectable activities (MDA) of HydroGamma. We installed the HydroGamma at Tapjeongho Lake in Nonsan-si and acquired background data since MDA is calculated based on the experimental background data. The results show that the minimum detectable activities for ¹³⁷Cs and ¹³¹I were 1.78Bq L^-1 and 1.81Bq L^-1, respectively even though the gamma rays emitted from ⁴⁰K(1,460 keV) affect the minimum detectable activities for them.