• Journal of Information Technology Applications and Management
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• v.19 no.1
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• pp.1-12
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• 2012

Data mining is the process of searching and analyzing large quantities of data for finding out meaningful patterns and rules. Artificial Neural Network (ANN) is one of the tools of data mining which is becoming very popular in forecasting the future values. Some of the areas where it is used are banking, medicine, retailing and fraud detection. In finance, artificial neural network is used in various disciplines including stock market forecasting. In the stock market time series, due to high volatility, it is very important to choose a model which reads volatility and forecasts the future values considering volatility as one of the major attributes for forecasting. In this paper, an attempt is made to develop two models - one using feed forward back propagation Artificial Neural Network and the other using Autoregressive Conditional Heteroskedasticity (ARCH) technique for forecasting stock market returns. Various parameters which are considered for the design of optimal ANN model development are input and output data normalization, transfer function and neuron/s at input, hidden and output layers, number of hidden layers, values with respect to momentum, learning rate and error tolerance. Simulations have been done using prices of daily close of Sensex. Stock market returns are chosen as input data and output is the forecasted return. Simulations of the Model have been done using MATLAB$^{(R)}$ 6.1.0.450 and EViews 4.1. Convergence and performance of models have been evaluated on the basis of the simulation results. Performance evaluation is done on the basis of the errors calculated between the actual and predicted values.

• Journal of the Korean Academy of Esthetic Dentistry
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• v.16 no.2
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• pp.7-18
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• 2007

There is now an increased demand for harmony between the peri-implant gingiva and adjacent dentition. In the event of a pending loss of a single tooth in the aesthetic zone with healthy periodontium, expectation for optimal gingival and prosthodontic aesthetics are often very high. Unfortunately, bone resorption is common following the removal of an anterior tooth, compromising the gingival tissue levels for the eventual implant restoration. Also, improper implant placement and inadequate osseous-gingival support potentially deleterious aesthetic result. The creation of an esthetic implant restoration with gingival architecture that harmonizes with the adjacent dentitionis formidable challenge. The predictability of the peri-implant esthetic outcome may ultimately be determined by the patient's own presenting anatomy rather than the clinician's ability to manage state-of-the-art procedures. To more accurately predict the peri-implant esthetic outcome before removing a failing tooth, a considering of diagnostic keys is essential. This presentation addresses the useful diagnostic keys that affect the predictability of peri-implant gingival aesthetics and the overcoming of the risk factors in anterior single-tooth replacement; it also describes a surgical and prosthodontic technique in achieving a long term successful esthetic outcome. Proper diagnosis and understanding of the biological and periodontal variables of failing dentition and their response to surgical and prosthodontic procedures are the essence of predictability. Using a smart protocol that alters the periodontium toward less risk and more favorable assessment of the diagnostic keys before implant placement will provide the most predictable esthetic outcome. Simple diagnostic keys suggested this presentation are useful method to evaluate the overcoming of the risk factors in anterior single implant restoration.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.23 no.2
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• pp.196-206
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• 2012

AESA radar is able to instantaneously and adaptively position and control the beam, and such adaptive beam pointing of AESA radar enables to remarkably improve the multi-mission capability, compared with mechanically scanned array radar. AESA radar brings a new challenges, radar resource management(RRM), which is a technique efficiently allocating finite resources, such as energy and time to each task in an optimal and intelligent way. Especially radar beam scheduling is the most critical component for the success of RRM. In this paper, we proposed stochastic radar beam scheduling algorithm using simulated annealing(SA), and evaluated the performance on the multi-function radar scenario. As a result, we showed that our proposed algorithm is superior to previous dispatching rule based scheduling algorithm from the viewpoint of beam processing latency and the number of scheduled beams, with real time capability.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.14 no.1
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• pp.151-160
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• 1994

Recently, terrestrial photogrammetry has been applied effectively to data acquisition in GIS and to monitoring precise machinery for simulation test. Because 3-D coordinates of many object points can be quickly measured with constant accuracy and easy modeling by this method. In this study, the composition concerned with multi-camera system which simultaneously analyzes structure from multi-station using various cameras was developed. The errors of results were analyzed to investigate the accuracy of the system, error of unknown points and control points, convergent and strip adjustment for optimal network design also. As results of this study, the efficiency of multi-camera system developed here was proved through application to monitoring the entire area of the precise model ship. We could also acquire 3-dimensional coordinates with good accuracy by arranging pass points. Therefore, possibility of measurement of instantaneous deformation as well as precision analysis of structures can be suggested.

• Korean Journal of Remote Sensing
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• v.28 no.5
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• pp.561-571
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• 2012

The MTF(Modulation Transfer Function) is one of quality assesment factors to evaluate the performance of satellite images. Image restoration is needed for MTF compensation, but it is an ill-posed problem and doesn't have a certain solution. Lots of filters were suggested to solve this problem, such as Inverse Filter(IF), Pseudo Inverse Filter(PIF) and Wiener Filter(WF). The most commonly used filter is a WF, but it has a limitation on distinguishing signal and noise. The L-curve-based Modified Wiener Filter(MWF) is a solution technique using a Tikhonov regularization method. The L-curve is used for estimating an optimal regularization parameter. The image restoration was performed with Dubaisat-1 images for PIF, WF, and MWF. It is found that the image restored with MWF results in more improved MTF by 20.93% and 10.85% than PIF and WF, respectively.

• The Journal of the Acoustical Society of Korea
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• v.31 no.7
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• pp.427-434
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• 2012

The overlap-add technique based on waveform similarity (WSOLA) method is known to be an efficient high-quality algorithm for time scaling of speech signal. The computational load of WSOLA is concentrated on the repeated normalized cross-correlation (NCC) calculation to evaluate the similarity between two signal waveforms. To reduce the computational complexity of WSOLA, this paper proposes a fast NCC computation method, in which NCC is obtained through pre-calculated sum tables to eliminate redundancy of repeated NCC calculations in the adjacent regions. While the denominator part of NCC has much redundancy irrespective of the time-scale factor, the numerator part of NCC has less redundancy and the amount of redundancy is dependent on both the time-scale factor and optimal shift value, thereby requiring more sophisticated algorithm for fast computation. The simulation results show that the proposed method reduces about 40%, 47% and 52% of the WSOLA execution time for the time-scale compression, 2 and 3 times time-scale expansions, respectively, while maintaining exactly the same speech quality of the conventional WSOLA.

• Journal of Chest Surgery
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• v.46 no.6
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• pp.433-438
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• 2013

Background: Surgical repair of post-infarct ventricular septal defect (VSD) is considered one of the most challenging procedures having high surgical mortality. This study aimed to evaluate the outcomes of the surgical repair of post-infarct VSD. Methods: From May 1991 to July 2012, 34 patients (mean age, $67.1{\pm}7.9$ years) underwent surgical repair of post-infarct VSD. A retrospective review of clinical and surgical data was performed. Results: VSD repair involved the infarct exclusion technique using a patch in all patients. For coronary revascularization, 12 patients (35.3%) underwent concomitant coronary artery bypass graft, 3 patients (8.8%) underwent preoperative percutaneous coronary intervention, and 9 patients (26.5%) underwent both of these procedures. The early mortality rate was 20.6%. Six patients (17.6%) required reoperation due to residual shunt or newly developed VSD. During follow-up (median, 4.8 years; range, 0 to 18.4 years), late death occurred in nine patients. Overall, the 5-year and 10-year survival rates were $54.4%{\pm}8.8%$ and $44.3%{\pm}8.9%$, respectively. According to a Cox regression analysis, preoperative cardiogenic shock (p=0.069) and prolonged cardiopulmonary bypass time (p=0.008) were independent predictors of mortality. Conclusion: The early surgical outcome of post-infarct VSD was acceptable considering the high-risk nature of the disease. The long-term outcome, however, was still dismal, necessitating comprehensive optimal management through close follow-up.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.2
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• pp.211-216
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• 2003

The objective of this study was to determine the degradability of cassava chip (CC), cassava waste (CW), yellow sweet potato (YP), white sweet potato (WP), purple sweet potato (PP), corn meal (CM), and rice bran (RB) using in situ technique. Two ruminally fistulated steers with an average weight of $303{\pm}10kg$ were used to determine in situ degradabilities of DM and OM. Seven feed sources were weighted in nylon bags ($38{\mu}m$ pore size) and incubated ruminally for 1, 2, 4, 6, 8, 12, 24, and 48 h. The results showed that asymptote (a+b) and effective degradability (ED) of DM of energy sources ranked from the highest to the lowest; CC, YP, WP, PP, RB, CW, and CM (99.3, 92.5; 97.6, 87.9; 97.5, 87.9; 97.2, 87.8; 87.5, 63.6; 78.6, 63.0 and 81.7; 59.3, respectively) and for OM asymptote (a+b) and effective degradability (ED) were similar to those of degradation of DM (99.4, 93.4; 98.8, 89.8; 98.5, 89.4; 98.4, 88.1; 92.4, 65.8; 85.1, 66.9 and 83.6, 63.3, respectively). It was concluded that disappearance characteristic of CC was the highest and it may potentially facilitate the achievement of optimal ruminal availability of energy: protein especially with NPN for microbial protein synthesis.

• Journal of the Korea Society of Computer and Information
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• v.25 no.10
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• pp.59-67
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• 2020

With the development of wearable devices, individuals' health status can be checked in real time and risks can be predicted. For example, an application has been developed to detect an emergency situation of a patient with heart disease and contact a guardian through analysis of health data such as heart rate and electrocardiogram. However, health data is seriously damaging when it is leaked as it relates to life. Therefore, a method to protect personal information is essential in collecting health data, and this study proposes a method of collecting data while protecting the personal information of the data owner through a LDP(Local Differential Privacy). The previous study introduced a technique of transmitting feature point data rather than all data to a data collector as an algorithm for searching for fixed k feature points. Next, this study will explain how to improve the performance by up to 75% using an algorithm that finds the optimal number of feature points k.

• Journal of Yeungnam Medical Science
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• v.37 no.4
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• pp.345-348
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• 2020

Papillary fibroelastomas are the second most common primary cardiac tumor in adults. Over 80% of fibroelastomas occur on the cardiac valves, usually on the left side of the heart, while the remaining lesions are typically scattered throughout the atria and ventricles. Although the optimal timing for surgery is controversial and depends on tumor size and location, prompt surgical resection is warranted in patients at high risk of embolism. A tumor on the cardiac valve can be removed using the slicing excision technique without leaflet injury. Here we present two cases of papillary fibroelastomas occurring on the ventricular surface of the aortic valve and in the right ventricle.