• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.8
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• pp.83-93
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• 2013

By comparing Wiener's MMSE on stochastic signal transmission with Shannon's mutual information first proved by C.E. Shannon in terms of information theory, connections between two approaches were investigated. What Wiener wanted to see in signal transmission in noisy channel is to try to capture fundamental limits for signal quality in signal estimation. On the other hands, Shannon was interested in finding fundamental limits of signal quantity that maximize the uncertainty in mutual information using the entropy concept in noisy channel. First concern of this paper is to show that in deriving limits of Shannon's point to point fundamental channel capacity, Shannon's mutual information obtained by exploiting MMSE combiner and Wiener filter's MMSE are interelated by integro-differential equantion. Then, At the meeting point of Wiener's MMSE and Shannon's mutual information the upper bound of spectral efficiency and the lower bound of energy efficiency were computed. Choosing a proper lattice-type code of a mod-${\Lambda}$AWGN channel model and MMSE estimation of ${\alpha}$ confirmed to lead to the fundamental Shannon capacity limits.

• Journal of the Institute of Electronics and Information Engineers
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• v.54 no.5
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• pp.65-73
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• 2017

In this paper, we propose a stereo matching method to improve the image quality at the hole and the disparity discontinuity regions. The stereo matching method extracts disparity map finding corresponding points between stereo image pair. However conventional stereo matching methods have a problem about the tradeoff between accuracy and precision with respect to the length of the baseline of the stereo image pair. In addition, there are hole and disparity discontinuity regions which are caused by textureless regions and occlusion regions of the stereo image pair. The proposed method extracts initial disparity map improved at disparity discontinuity and miss-matched regions using modified AD-Census-Gradient method and adaptive weighted cost aggregation. And then we conduct the disparity map refinement to improve at miss-matched regions, while also improving the accuracy of the image. Experimental results demonstrate that the proposed method produces high-quality disparity maps by successfully improving miss-matching regions and accuracy while maintaining matching performance compared to existing methods which produce disparity maps with high matching performance. And the matching performance is increased about 3.22(%) compared to latest stereo matching methods in case of test images which have high error ratio.

• Journal of the Korea Society of Computer and Information
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• v.15 no.11
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• pp.225-231
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• 2010

Transaction value of business-to-business(B2B) is composed of various factors for groups and time series. In this paper, we use the panel data for finding various variables and using this we analyse the factors that is major influence to transaction value of business-to-business. For analysis we looked at transaction value of business-to-business of 7 groups such as manufacturing industry, electric, gas and piped water industry, construction industry, retail & wholesale trade, traffic industry, publish, image; broad-casting & telecommunication and information service industry, etc. In our analysis we looked at the transaction value of business-to-business during the period from 2005.01 to 2009.12. We examined the data in relation to the transaction value of cyber shopping mall, company bond, composite stock price index, transaction value of credit card, loaned rate of interest in deposit bank, rate of exchange looking at the factors which determine the transaction value of business-to-business, evidence was produced supporting the hypothesis that there is a significant positive relationship between the transaction value of cyber shopping mall, composite stock price index and loaned rate of interest in deposit bank, rate of exchange. The company bond is negative relationship, transaction value of credit card is positive relationship and they are not significant variables in terms of the transaction value of business-to-business.

• Journal of radiological science and technology
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• v.25 no.1
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• pp.63-71
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• 2002

The aim of this study Is to develop a simple and fast method which computes in-vivo doses from transmission doses measured doting patient treatment using an ionization chamber. Energy fluence and the dose that reach the chamber positioned behind the patient is modified by three factors: patient attenuation, inverse square attenuation. and scattering. We adopted a straightforward empirical approach using a phantom transmission factor (PTF) which accounts for the contribution from all three factors. It was done as follows. First of all, the phantom transmission factor was measured as a simple ratio of the chamber reading measured with and without a homogeneous phantom in the radiation beam according to various field sizes($r_p$), phantom to chamber distance($d_g$) and phantom thickness($T_p$). Secondly, we used the concept of effective field to the cases with inhomogeneous phantom (patients) and irregular fields. The effective field size is calculated by finding the field size that produces the same value of PTF to that for the irregular field and/or inhomogeneous phantom. The hypothesis is that the presence of inhomogeneity and irregular field can be accommodated to a certain extent by altering the field size. Thirdly, the center dose at the prescription depth can be computed using the new TMR($r_{p,eff}$) and Sp($r_{p,eff}$) from the effective field size. After that, when TMR(d, $r_{p,eff}$) and SP($r_{p,eff}$) are acquired. the tumor dose is as follows. $$D_{center}=D_t/PTF(d_g,\;T_p){\times}(\frac{SCD}{SAD})^2{\times}BSF(r_o){\times}S_p(r_{p,eff}){\times}TMR(d,\;r_{p,eff})$$ To make certain the accuracy of this method, we checked the accuracy for the following four cases; in cases of regular or irregular field size, inhomogeneous material included, any errors made and clinical situation. The errors were within 2.3% for regular field size, 3.0% irregular field size, 2.4% when inhomogeneous material was included in the phantom, 3.8% for 6 MV when the error was made purposely, 4.7% for 10 MV and 1.8% for the measurement of a patient in clinic. It is considered that this methode can make the quality control for dose at the time of radiation therapy because it is non-invasive that makes possible to measure the doses whenever a patient is given a therapy as well as eliminates the problem for entrance or exit dose measurement.

• Journal of the Korean Society of Radiology
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• v.11 no.7
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• pp.679-685
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• 2017

Computed tomography has widely been used to diagnose patient disease, and patient dose also increase rapidly. To reduce the patient dose by CT, various techniques have been applied. The iterative reconstruction is used in view of image reconstruction. Image quality of the reconstructed section image through algebraic reconstruction technique, one of iterative reconstruction methods, was examined by the normalized root mean square error. The computer program was written with the Visual C++ under the parallel beam geometry, Shepp-Logan head phantom of $512{\times}512$ size, projections of 360, and detector-pixels of 1,024. The forward and backward projection was realized by Joseph method. The minimum NRMS of 0.108 was obtained after 10 iterations in the regularization parameter of 0.09-0.12, and the optimum image was obtained after 8 and 6 iterations for 0.1% and 0.2% noise. Variation of optimum value of the regularization parameter was observed according to the phantom used. If the ART was used in the reconstruction, the optimal value of the regularization parameter should be found in the case-by-case. By finding the optimal regularization parameter in the algebraic reconstruction technique, the reconstruction time can be reduced.

• Journal of the Korean School Mathematics Society
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• v.17 no.4
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• pp.771-804
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• 2014

The concept of the center of gravity is presently being introduced in elementary school curriculums and is broadly applied to Mathematics, Physics, and the Engineering field in University education which are mostly theoretical classes much separated from actual life in the practical educational field. In 2013, ${\bigcirc}{\bigcirc}$ University of Science and Gifted Education, had developed the multidisciplinary approach program of verifying the center of gravity for gifted students, but this program was reconstructed and applied to ordinary students and the effectiveness was analyzed to lay the foundation and generalize this convergence education. Including experiments for verifying the center of gravity in an object with a hollow interior and the existence of a center of gravity outside an object, I proposed realizing the calculations by considering the weight of the lever, the Principle of the lever being a core factor when finding the center of gravity. We altered the existing 8 step program to a 4 step program for the told 65 students from elementary, Junior and High School students, letting them freely select the class lecture by themselves. The analysis attained from surveys, debates and interviews showed that by precise error analysis, students achieved a higher success experience, showing us the importance of the development of a new convergence program.

• Korean Journal of Psychosomatic Medicine
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• v.15 no.2
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• pp.73-80
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• 2007

Anumber of prior studies have reported eye movement dysfunction in patients with dementia. The eye movement test which is non-invasive can evaluate the local brain function quantitatively. Therefore, it can be a useful method for characterizing regional brain abnormalities of patients with dementia. The aim of this paper is to review the literatures on eye movement abnormalities in dementia patients. Saccade system dysfunctions in Alzheimer disease include increased latency, reduced accuracy, and increased antisaccade error rates. Patients with frontotemporal dementia showed impaired reflexive saccade inhibition and increased latency and errors of antisaccade task. And delayed initiation of voluntary saccades, slow saccades, and increased errors and latency on antisaccade task were found in Huntington's disease. Patients with Parkinson’s disease dementia and dementia with Lewy bodies have characteristics of impaired in both reflexive saccade execution and complex saccade performance. However, there were few reports of abnormal eye movements in Creutzfeldt-Jakob disease; they could be found at the later stages after symptoms of dementia came to be evident, and secondary to cerebellar and vestibular involvement. Slowing of saccades and hypometric saccades might precede the supranuclear limitation of vertical gaze in PSP. Dysfunction of voluntary eyelid movements was a characteristic finding of PSP as well. In conclusion, patients with dementia can show various abnormal eye movements and they are related with cortial and subcortical brain dysfunctions. The research on localization of brain relevant to each symptom can promise more clinical implications of eye movement of dementia.

• Journal of Korean Society of Transportation
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• v.25 no.1 s.94
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• pp.109-119
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• 2007

Increasingly, the emphasis in regional Passenger rail Planning is finding ways to more efficiently use existing facilities, with particular attention being Paid to Policies designed to spread Peak-Period travel demand more evenly throughout the week with consideration of train classification. In this context the individual's choice of time to travel is of crucial significance. This paper investigates the use of multinomial logit analysis to model ridership by rail classification using data collected for travel from Seoul to Busan during the one week in October 2004. The Particular model form that was successfully calibrated was the multinomial logit (MNL) model : it describes the choice mechanism that will Permit rail systems and operations to be planned on a more reliable basis. The assumption of independently and identically distributed(IID) error terms in the MNL model leads to its infamous independence from irrelevant alternatives (IIA) property. Relaxation of the IID assumption has been undertaken along a number or isolated dimensions leading to the development of the MNL model. For business and related rail travel patterns, the most important variables of choice were time and frequency to the chosen destination. The calibrated model showed high agreement between observed and Predicted market shares. The model is expected to be of use to railroad authorities in Planning and determining business strategies in the Increasingly competitive environment or regional rail transport.

• Journal of Fashion Business
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• v.3 no.4
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• pp.139-146
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• 1999

The purpose of this study is to analyze the efficiency and working conditions of the patternwork departments by surveying the apparel manufacturing companies sampled in Seoul for their organization, working enviornment and technology of their patternwork departments, and thereby, find the ways to promote the functions of the patternwork department. The results of this study can be summarized as follows; 1. As a result of analyzing the working environment of patternwork departments, it was found that the problems counted by most of the pattern workers were lack of workforce, unhygienic or unpleasant workplaces. 2. As a consequence of analyzing the sample production in terms of tacking methods and times, They rarely tacked the white cotton. Such an omission of tacking procedure may serve to save time, but if a sewing error occurs, the working time would rather be longer due to the defects of pattern to be remedied. 3. As a result of reviewing the general patternwork conditions, it was found that the patterns were still worked out in two dimensions. On the other hand, more than 60% of the pattern workers were applying to their patternworks the styles which they had learned from their seniors. Few patterns are being developed in conformity to apparel trends or body shape changes. 4. As a consequence of examining the problems involving the production of patternsl, the problems involved primarily the patterns incised off no-dart pattern and body structure, and in light of items, involved mainly the trousers and in light of material, involved much the stretch or velvet. Moreover, it is deemed necessary to establish a special institute devoted to a systematic development of pattern technology. 5. Most of the CAD patternworks are used not for pattern designing but for grading and marking works, which suggests that pattern workers need to be educated on this new technology for more diverse and precise patternworks. 6. Lastly, as a result of examining the conditions of patternwork departments and their relevant works, most of the pattern workers were found to be subject to irregular and excessive workload, having little time to produce good patterns. This finding suggests that it is necessary to mandate the pattern workers to more involve the commodity planning.

• Geophysics and Geophysical Exploration
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• v.21 no.2
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• pp.67-81
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• 2018

We acquired the magnetic and bathymetry data around the TA (Tofua Arc) 22 seamount in the Lau Basin for finding submarine hydrothermal deposits. From the data, we estimated the magnetic characteristics in the study area. The bathymetry shows that TA 22 seamount consists of the western and eastern summits. Each summit exhibits a caldera. The western caldera is smaller, but deeper than the eastern caldera. The slope gradients of the TA 22 are steeper around ~1000 m depth range and relatively gentle at the summit areas with the small difference of two calderas. The magnetic properties of TA 22 seamount present high anomalies at the summit and the vicinity of the caldera. Low magnetization zones appear over the outer flanks and center of the calderas. These magnetic patterns are similar to the previous studies which had represented high anomalies and low magnetization zones inside of the summit area or on the flank of the outside of the summit area. The results of the 2D magnetic forward modeling with seismic profiles show about 20 nT of RMSEs (root mean square error) between the modeled and observed values. The low RMSEs proposes a good correlation between the modeled 2D structure and the geophysical observation in this study area. Based on the modeling and magnetization distribution, hydrothermal deposits are predicted to be located at the inner area of the calderas or at small mounds around caldera rims.