• Geophysics and Geophysical Exploration
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• v.17 no.2
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• pp.49-57
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• 2014

3D magnetic inversion, based on the assemblage of 2D forward modeling and inversion as a practical technique to reflect the a priori information, was conducted to investigate the spatial distribution features of black-shale related and pyrometamorphic uranium deposit and several lithological units of Ogcheon Super Group in an area of Geumsan. By using the 3D visualization technique with suitable susceptibility interval and horizontal slice map, the spatial distribution of magnetic susceptibility corresponded to the black shale related uranium bearing lithological units, Black Slate member was well coincided with a information of uranium deposit. Also, even though it is indirect indicator for the detetction of uranium deposits interbedded in Gray Hornfels member, spatial susceptibility distribution which shows the south-east magnetic linearment corresponding to the Majeon-ri formation and Dark Gray Slate were matched well. From this investigation, we inferred that maximum depth extension which Black Slate member can be separately recognized with respect to adjacent Dark Gray Slate with strong magnetic susceptibility anomaly is about 150m with reference elevation level of 306m. In addition, Majeon-ri formation located south of Black Slate member revels relatively high magnetic susceptibility range but shows high spatial susceptibility fluctation. And, as an intrusive rocks, Jurassic Biotite Granite shows relatively low magnetic susceptibility characteristics. On the contrary, Cretaceous granite distributed in soutthern part of the study area shows the relatively high susceptibility distribution.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.5C
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• pp.355-364
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• 2012

Target processing mechanisms are necessary to collect target information, real-time data fusion, and tactical environment recognition for cooperative engagement ability. Among these mechanisms, the target tracking starts from predicting state of speed, acceleration, and location by using sensors' measurements. However, it can be a problem to give the reliability because the measurements have a certain uncertainty. Thus, a technique which uses multiple sensors is needed to detect the target and increase the reliability. Also, data fusion technique is necessary to process the data which is provided from heterogeneous sensors for target tracking. In this paper, a target tracking algorithm is proposed based on probabilistic data association(PDA) by fusing radar and ESM sensor measurements. The radar sensor's azimuth and range measurements and the ESM sensor's bearing-only measurement are associated by the measurement fusion method. After gating associated measurements, state estimation of the target is performed by PDA filter. The simulation results show that the proposed algorithm provides improved estimation under linear and circular target motions.

• Food Science and Industry
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• v.51 no.3
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• pp.174-184
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• 2018

The impact of regulations on industrial activities is significant. Because the food industry has to observe given obligations and bear costs and expenses resulted from complying with applicable food safety regulations. Meanwhile, A government drafts the regulatory impact analysis report prior to enactment, amendment or reinforcement of any regulations. The analysis powered by objective and scientific methodologies enable a government to judge whether a particular regulation will be good or bad for the society. An effective policy implementation in practice and cost-bearing is entirely up to industries. Moreover, opportunity cost and actual cost relating to or arising from regulatory compliance will be estimated only by the respective industries. Therefore, the food Industry needs to collect and accumulate the said information and also to disseminate their hardships and financial burdens. Objective and practical information will encourage a government to set out regulatory frameworks that rational policy making.

• Proceedings of the Korea Database Society Conference
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• 1999.06a
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• pp.175-186
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• 1999

Detecting the features of significant patterns from their own historical data is so much crucial to good performance specially in time-series forecasting. Recently, a new data filtering method (or multi-scale decomposition) such as wavelet analysis is considered more useful for handling the time-series that contain strong quasi-cyclical components than other methods. The reason is that wavelet analysis theoretically makes much better local information according to different time intervals from the filtered data. Wavelets can process information effectively at different scales. This implies inherent support fer multiresolution analysis, which correlates with time series that exhibit self-similar behavior across different time scales. The specific local properties of wavelets can for example be particularly useful to describe signals with sharp spiky, discontinuous or fractal structure in financial markets based on chaos theory and also allows the removal of noise-dependent high frequencies, while conserving the signal bearing high frequency terms of the signal. To date, the existing studies related to wavelet analysis are increasingly being applied to many different fields. In this study, we focus on several wavelet thresholding criteria or techniques to support multi-signal decomposition methods for financial time series forecasting and apply to forecast Korean Won / U.S. Dollar currency market as a case study. One of the most important problems that has to be solved with the application of the filtering is the correct choice of the filter types and the filter parameters. If the threshold is too small or too large then the wavelet shrinkage estimator will tend to overfit or underfit the data. It is often selected arbitrarily or by adopting a certain theoretical or statistical criteria. Recently, new and versatile techniques have been introduced related to that problem. Our study is to analyze thresholding or filtering methods based on wavelet analysis that use multi-signal decomposition algorithms within the neural network architectures specially in complex financial markets. Secondly, through the comparison with different filtering techniques' results we introduce the present different filtering criteria of wavelet analysis to support the neural network learning optimization and analyze the critical issues related to the optimal filter design problems in wavelet analysis. That is, those issues include finding the optimal filter parameter to extract significant input features for the forecasting model. Finally, from existing theory or experimental viewpoint concerning the criteria of wavelets thresholding parameters we propose the design of the optimal wavelet for representing a given signal useful in forecasting models, specially a well known neural network models.

• Management & Information Systems Review
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• v.29 no.1
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• pp.79-96
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• 2010

The purpose of this study is to investigate factors that affect corporate CEOs' tax avoidance, ultimately helping find how to fundamentally prevent the avoidance, establish a tax system that ensures tax payers' compliance and revise tax laws and regulations in a positive way. For the purpose, this researcher surveyed corporate CEOs with a questionnaire that contained many questions of various types, which was developed based on previous studies. Findings of the study can be summarized as follows. Main factors affecting tax avoidance were the application of tax provisions, the ability to understand tax laws and the expectation of tax avoidance. The more corporate CEOs' were influenced by the first and the third factors, the higher their propensity for tax avoidance was. On the contrast, corporate CEOs were lower in propensity for tax avoidance when they were more able to understand tax laws. Regarding the three factors' relative influences, tax avoidance was most affected by the expectation of tax avoidance, followed by the ability to understand tax laws and the application of tax provisions in order. Meanwhile, a multi-regression analysis using the sequential deletion technique showed that tax avoidance were affected by the application of tax provisions and the expectation of tax avoidance and that tax avoidance was most influenced by the application of tax provisions, followed by the expectation of tax avoidance. These findings indicate that the degree of corporate CEOs' tax avoidance may vary depending on social and environmental changes that their business face. Meanwhile, positive factors such as tax-bearing capacity and the procedure of tax calculation and negative factors such as management ethics and tax authorities' regulation are all thought to be not helping prevent tax avoidance.

• Geophysics and Geophysical Exploration
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• v.10 no.1
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• pp.37-43
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• 2007

The MH21 Research Consortium has conducted a high-resolution 3D seismic survey and a seafloor geochemical survey, to explore methane hydrate reservoirs in the eastern Nankai Trough, offshore Japan. Excellent geological information about shallow formations was obtained from the high-resolution 3D seismic survey, which was designed to image the shallow formations where methane hydrates exist. The information is useful in constructing a geological and geochemical model, and especially to understand the complex geology of seafloor, including geochemical manifestations and the structure of migration conduits for methane gas or methane-bearing fluid. By comparing methane seep sites observed by submersibles with seismic sections, some significant relationships between methane hydrate reservoirs, free gas accumulations below the seafloor, and seafloor manifestations are recognised. Bathymetric charts and seafloor reflection amplitude maps, constructed from seismic reflections from the seafloor, are also useful in understanding the relationships over a vast area. A new geochemical seafloor survey targeted by these maps is required. The relationships between methane hydrate reservoirs and seafloor manifestations are becoming clearer from interpretation of high-resolution 3D seismic data. The MH21 Research Consortium will continue to conduct seafloor geochemical surveys based on the geological and geochemical model constructed from high-resolution 3D seismic data analysis. In this paper, we introduce a basis for exploration of methane hydrate reservoirs in Japan by fusion of 3D seismic exploration and seafloor geochemical surveys.

• Korean Journal of Construction Engineering and Management
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• v.13 no.1
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• pp.118-128
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• 2012

As the bearing wall structure, which has been widely applied to domestic apartment buildings since the 1980s, cause many problems during remodeling of buildings, the government encourages constructors to adopt flat plate or rahmen structure through legal incentives. In line with such a trend, the green frame, an eco-friendly rahmen structure that has removed the shortcomings of previous structures, was developed to enhance structural safety, constructability, and eco-friendliness. The construction of green frame can reduce the labor cost and facilitate the composition of iron bars to reduce rebar loss through calculating the quality and establishing the bar bending schedule automatically on the precast concrete member data collected over the design phase. Therefore, the purpose of this study is to develop the algorithm to automate the calculation of iron bar volume for the green frame designed on composite precast concrete members. Automated algorithm to calculate concrete structural design information and design information. Practices through the application site should prove efficacy. The database established by the developed algorithm will automate the establishment of iron bar processing map and bar cutting list and the calculation of optimal composition and order volume to minimize the rebar loss. This will also reduce the expenses on management staff and overall construction cost through the minimization of rebar loss.

• Journal of the Society of Disaster Information
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• v.11 no.4
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• pp.520-526
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• 2015

Reinforcing bar splices are inevitable in reinforced concrete structure. In these days, there are three main types of splices used in reinforced concrete construction site - lapped splice, mechanical splice and welded splice. Low cost, practicality in construction site, less time consuming and high performance make gas pressure welding become a favorable splice method. However, reinforcing bar splice experiences thermal loading history during the welding procedure. This may lead to the presence of residual stress in the vicinity of the splice which affects the fatigue life of the reinforcing bar. Therefore, residual stress analysis and tensile test of the gas pressure welded splice are carried out in order to verify the load bearing capacity of the gas pressure welded splice. The reinforcing bar used in this work is SD400, which is manufactured in accordance with KS D 3504. The results show that the residual stresses in welded splice is relatively small, thus not affecting the performance of the reinforcing bar. Moreover, the strength of the gas pressure welded splice is high enough for the development of yielding in the bar. As such, the reinforcing bar with gas pressure welded splice has enough capacity to behave as continuous bar.

• Journal of Korean Academy of Nursing
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• v.7 no.1
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• pp.30-38
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• 1977

Breast cancer is one of the most feared health problems in women ; Recent studies revealed that it had come up to be the second most in this country and high prevalent disease in the western countries among breast disease in women. However, early detection of the cancer mass is known to be easier than in many other malignancies. This study was performed to investigate the various characteristics of patients of breast cancer ; by the structural variables, menstrual, marital, and child bearing, and also their understandings and attitude towards the disease. A hundred any in- and out- patients of 51. Mary's Hospital and National Atomic Institute, Seoul were sampled. Data were gathered through direct interview by the researcher from February 1976 to January 1977 and the clinical records were used as references. Results are as follows ; 1. Breast cancer revealed to be most prevalent in the forties ; average age of 45.2 years. 2. The average age of menarche revealed to be 15.4 years ; the largest group were the 16-20 years (N=75, 68.2%). In 55 cases (50%) menstruation were normal, 38 (34.5%) postmenopausal and only in 17 (15.5%), menstruation revealed irregularity. 3. The average marital age revealed to be 22.3 years ; the largest group were 21-25 group (N=43, 39.1%). The average duration of marital life revealed to be 24.7 years ; 11-20 years group were the largest (M=34, 30.9%). 4. Most of the patients revealed to have pregnancy experiences(N=100, 90.9%) ; the average rate of experience were 5, 3 times the largest group were 3.4 times group(N= 32, 29.1%). 54 patients (49.1%) revealed to have had abortion experience ; the average were 3.4 times. 5. The largest group(N=77, 70%) had been breast feeding : followed by mixed feeding (N=12, 10.9%) and artificial feeding(N=10, 9.1%). 6. Personal health history revealed that in 20 patients (18.2%) revealed to have the past history of Purulent mastitis, 5 patients(4.5%) of breast cancer and 3 patients(2.7%) of uttering cancer family history. 7. In the one half (N=56, 50.9%, they had some information about breast cancer :27 (24.5%) by mass media, 12 (10.9%) through personal contacts and 17 (15.5%) were not able to classify the source of information. 8. In 55 cases (50%) the canoe, mass were discovered incidentally, in 39 cases (35.5%) by manual detection by self, in 10 cases (9%) by others and in 6 cases(5.5%) by observing subjective symptoms. 9. The average duration lapsed between the discovery of cancer mass and the visit to the hospital revealed to be 9.4 month. Chief reason for the delay revealed to be the non-chaplaincy due to the absence of pain(N=50, 45.5 %) followed by the administration of herb and commercial medication (N=19, 17.3%). 10. The left side breast was more affected than the right side breast, represent by 60 cases in the left and 39 cases in the right. The most frequent site of the breast cancer was the upper- outer quadrant in 53 cases (47.7%), and followed by the center in 20 cases(18 %), and the upper inner quadrant, in 19 cases (17.1%). There was / cases of bilateral carcinoma. The most prominent symptom was painless mass.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.47 no.7
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• pp.489-498
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• 2019

The airloads and structural loads of Light Civil Helicopter (LCH) rotor are investigated using a loose CFD/CSD coupling. The structural dynamics model for LCH 5-bladed rotor cwith elastomeric bearing and inter-bladed damper is constructed using CAMRAD-II. Either isolated rotor or rotor-fuselage model is used to identify the effect of the fuselage on the aeromechanics behavior at a cruise speed of 0.28. The fuselage effect is shown to be marginal on the aeromechanics predictions of LCH rotor, though the effect can be non-negligible for the tail structure due to the prevailing root vortices strengthened by the fuselage upwash. A lifting-line based comprehensive analysis is also conducted to verify the CFD/CSD coupled analysis. The comparison study shows that the comprehensive analysis predictions are generally in good agreements with CFD/CSD coupled results. However, the predicted comprehensive analysis results underestimate peak-to-peak values of blade section airloads and elastic motions due to the limitation of unsteady aerodynamic predictions. Particularly, significant discrepancies appear in the structural loads with apparent phase differences.