• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.6A
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• pp.609-616
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• 2011

The Delay/Disruption Tolerant Network (DTN) is a network designed to operate effectively using the mobility and storage of intermediate nodes under no end-to-end guaranteed network. This new network paradigm is well-suited for networks which have unstable path and long latencies (e.g. interplanetary network, vehicular network). In this paper, we first found that each taxi has its own regularly visiting area and define this property as spatial regularity. We analyze 4000 taxi trace data in Shanghai and show the existence of spatial regularity experimentally. Based on a spatial regularity in urban environment, we present a new DTN routing method. We introduce a Weighted Center (WC) which represents spatial regularity of each node. Through the association with evenly distributed access points (APs) in urban environment, most of vehicles get their grid locations and calculate their WCs. Since our routing method only uses neighbors' WCs for building routing paths, it can be regarded as distributed and practical protocols. Our experiments involving realistic network scenarios created by the traces of about 1500 Shanghai taxies show that our routing method achieves the higher performance compared to ECT, LET by 10%~110%.

• Journal of the Korean Society for Nondestructive Testing
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• v.32 no.1
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• pp.64-70
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• 2012

Two kinds of eddy current probes are mainly used to perform the steam generator tube integrity assesment in NPPs. The first one is the bobbin probe using for inspection of volumetric defect like a fretting wear. The second one is the rotating probe using for inspection of non-volumetric defect like a crack. The eddy current probe is one of the essential components which consist of the whole eddy current examination system, and provides a decisive data for the tube integrity in accordance with acceptance criteria described in specific procedures. The design of ECT probe is especially important to improve examination results because the quality of acquired ECT data is depended on the probe design characteristics, such as coil geometry, electrical properties, operation frequency. In this study, it is analyzed that the coil winding number of differential bobbin probe affects the electrical properties of the probe. Eddy current bobbin probes for the steam generator tubes in NPPs are designed and fabricated according to the results. Experiment shows that the change in coil winding number has much effects on the optimum inspection frequency determined by the tube geometry and material. Therefore, the coil winding number in bobbin probe is very important in the probe design. In this study, a basis of the coil winding number for the eddy current bobbin probe design for steam generator tubes in NPPs is established.

• Journal of the Korean Society for Nondestructive Testing
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• v.21 no.5
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• pp.510-517
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• 2001

This paper describes an initial study for the application of eddy current pattern recognition approaches to more realistic flaw characterization in steam generator tubes. For this purpose, finite-element model-based theoretical eddy current testing (ECT) signals are simulated from 5 types of OD flaws with the variation in flaw size parameters and testing frequency. In addition, three kinds of software are developed for the convenience in the application of steps in pattern recognition approaches such as feature extraction feature selection and classification by probabilistic neural networks (PNNs). The cross point of the ECT signals simulated from flaws with non-symmetric cross-sections shows the deviation from the origin of the impedance plane. New features taking advantages of this phenomenon are added to complete the feature set with a total of 18 features. Then, classification with PNNs are performed based on this feature set. The PNN classifiers show high performance for the identification of symmetry in the cross-section of a flaw. However, they show very limited success in the interrogation of the sharpness of flaw tips.

• Journal of the Korean Society for Nondestructive Testing
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• v.26 no.2
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• pp.90-98
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• 2006

Signals captured from a Combo calibration standard tube paly a crucial role in the evaluation of motorized rotating pancake coil (MRPC) probe signals from steam generator (SG) tubes in nuclear power plants (NPPs). Therefore, the Combo tube signals should be consistent and accurate. However, MRPC probe signals are very easily affected by various factors around the tubes so that they can be distorted in their amplitudes and phase angles which are the values specifically used in the evaluation. To overcome this problem, in this study, we explored possibility of simulation to be used as a practical calibration tool far the evaluation of real field signals. For this purpose, we investigated the characteristics of a MRPC probe and a Combo tube. And then using commercial software (VIC-3D) we simulated a set of calibration signals and compared to the experimental signals. From this comparison, we verified the accuracy of the simulated signals. Finally, we evaluated two defects using the simulated Combo tube signals, and the results were compared with those obtained using the actual field calibration signals.

• Korean Journal of Biological Psychiatry
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• v.13 no.4
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• pp.234-243
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• 2006

Objectives : Several factors, such as biological markers, clinical correlates, and course of the depressive disorders with psychotic symptoms differ from those without psychotic symptoms. Therefore, specification of a treatment algorithm for depressive disorder with psychotic symptoms is legitimated. This article provides a systematic review of somatic treatments for depressive disorder with psychotic symptoms. Methods : According to the search strategy of the Clinical Research Center for Depression of Korean Health 21 R & D Project, first, PubMed and EMBASE were searched using terms with regard to the treatment of depressive disorders with psychotic symptoms(until July 2006). Reference lists of related reviews and studies were searched. In addition, relevant practice guidelines were searched using PubMed. All identified clinical literatures were reviewed and summarized in a narrative manner. Results : Treatment options, such as a combination of an antidepressant and an antipsychotic versus an antidepressant or an antipsychotic alone are summarized. In addition, issues regarding the electroconvulsive therapy( ECT), combination therapy, and maintenance treatment are discussed. Conclusion : In former times, the combination of an antidepressant and an antipsychotic or ECT were recommended as the first line treatment for depressive disorder with psychotic symptoms. Recently, however, there was a suggestion that there was no conclusive evidence that the combination of an antidepressant and an antipsychotic drug is more effective than an antidepressant alone. More evidence regarding the pharmacological treatment for depressive disorder with psychotic symptoms is needed.

• The Journal of Korean Philosophical History
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• no.52
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• pp.341-364
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• 2017

This thesis is to reflect prevalently stereo-typed community ideas and find alternative ones that have interconnected, relational, and autonomous acting system for our lives. Probably community is the collective space in which 'I' as the subject in the world meet others and achieve the desirable objects each other. By the way the community spaces could be nation state, societies, and people of nation or ones that deal local problems, environments, and ecology and clubs ect, which are variable according to our concerns. In a sense community pay attention to not societies such as nations or people but lives of individuals, preparing for the territories where men feel convenient in their bodies and mentalities without artificial manipulation. In such a community the participant's vital energy can be stretched actively and relationally, and even if the leader be, there is the politics of doing nothingness not to be the obstacle in the way mens' will goes. In those communities they can live their lives at their nature and realize their dreams without barriers to their way. If we find these ideas of communities which are alternative for our period, we should gaze at Asiatic ones that may be scattered in classics of Confucianism, Daoim and ect. With these concepts and concerns, this paper was drawn up.

• Journal of the Korea Society of Computer and Information
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• v.27 no.1
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• pp.183-191
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• 2022

The Korea Stewardship Code 'Principles on the Fiduciary Responsibilities of Institutional Investors' was introduced in 2016 and the National Pension Service adopted it in 2018. the National Pension Service casted 'dessent' vote on the agenda which is able to reduce the ownership interest of shareholder in general meeting. This paper examines whether 'dissent' voting affected on the ownership interest of shareholder or not. The 'dissent' vote on the agenda are related to revision artical of corperation, appointment or compensation of director and auditor, approval of financial statements ect. The proxies of earnings management is discretionary accruals calculated by modified Jones model. The control variablies are size of assets, liabilities per assets, returns on assets. The results of this study are as followings. First, the 'dissent' voting on the agenda are related to revision artical of corperation, M&A, approval of financial statements ect. are not significant because their sample size is too small, Second, the 'dissent' voting on appointment of director and auditor affected on reduction of discretionary accruals. So the National Pension Service activism shall affect on increasing the ownership interest of shareholder. Third, the 'dissent' voting on compensation of director and auditor is not affected on reduction of discretionary accruals. This results show that 'unconditional dissent voting' on the agenda in general meeting is not to reduce the ownership interest of shareholder.

• Korean Journal of Cognitive Science
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• v.34 no.2
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• pp.67-84
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• 2023

In this study, Korean older adults (70-75 yrs) were divided into two groups according to the degree of reading exposure, and real-time data were collected through a reading eye movement tracking experiment. Then, overall reading patterns and word frequency ef ects were compared with two groups of older adults and younger adults (20-28 yrs). Furthermore, through the results of the eye movement tracking experiment of older adults with rich reading exposure and older adults with poor reading exposure, we tried to find out whether reading performance af ects not only changes in age but also reading exposure. As a result of the experiment, the older adults with poor reading exposure group generally had a longer fixation time and a shorter saccade than the younger adults group, and the older adults with rich reading exposure group showed the same reading patterns as the younger adults group. The word frequency ef ect was confirmed in all groups, and the fixation time was short in the order of older adults with rich reading exposure group and older adults with poor reading exposure group. In addition, an interaction ef ect was shown in the two elderly groups according to reading exposure, but no interaction could be confirmed in the dif erence between the younger adults group and the older adults with rich reading exposure group. This suggests the possibility that reading performance is not af ected by age itself, but by the reading experience of the elderly.

• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.6
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• pp.620-627
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• 2023

Ship noise is one of the important factors for the living and health of seafarers, and ef orts to reduce ship noise are actively underway. There are two methods of noise reduction: passive noise Control (PNC) and active noise control (ANC). Unlike cars and airplanes, ANC is not widely used for noise reduction on ships. This study aimed to reduce the noise generated in the engine room by using soundproof panels and high-frequency vibration generators, as well as active noise control (ANC). For this purpose, an experimental model was made using an acrylic box, and the noise reduction effect was measured under four conditions. The experimental results are as follows: First, the soundproof panel had a noise reduction effect in all ranges from 55 dB to 85 dB. In the case of using a high-frequency vibration generator, there was no ef ect in the low noise range such as 55 dB(A), but there was a noise reduction effect in the high noise range such as 70.8 dB(A) and 85 dB(A).Second, when the soundproof panel and the high-frequency vibration generator were used simultaneously, the noise reduction ef ect was up to -2.2 dB(A). The results of this experiment were obtained from an experimental model made of acrylic, and they may be different from actual ships made of steel plate. In future studies, we plan to experiment using iron plate (considering the material, thickness, and structure) used in actual ships. We hope that this study will help to improve the living environment and health of seafarers on ships.

• Herbal Formula Science
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• v.15 no.1
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• pp.1-19
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• 2007

This study was investigated to make sure the range of Gypsum treatment, the nature of disease, the pathology and the dosage of it in Dongeuybogam. The following conclusions were reached through investigations on the prescriptions that use Gypsum as a key ingredient. The Gypsum blended prescriptions are utilized in 23 fields of treatment such as cold, head. ect. Prescriptions that use Gypsum as the main ingredient are used commonly in the treatment of cold, head disease, fever, skin disease, diabetes, stroke, ophthalmic disease, jaundice, ENT disease and dental disease. The Gypsum is used for nature of disease which of cold, heat(fever), summer heat, phlegm, malfunction of liver, malfunction of liver and kidney, heat of stomach, malfunction of spleen and fever of stomach. The clinical dosage of Gypsum has ranged at a wide variety of amount from 1.6g to 16g per dose with 4g ${\sim}$ 8g being the typical dose for most treatment. The Gypsum is applied as a fundamental prescription with several herb remedies for the pathology.