• The KIPS Transactions:PartB
• /
• v.14B no.4
• /
• pp.287-294
• /
• 2007

Many classification algorithms for real world data suffer from a data class imbalance problem. To solve this problem, various methods have been proposed such as altering the training balance and designing better sampling strategies. The previous methods are not satisfy in the distribution of the input data and the constraint. In this paper, we propose a focused sampling method which is more superior than previous methods. To solve the problem, we must select some useful data set from all training sets. To get useful data set, the proposed method devide the region according to scores which are computed based on the distribution of SOM over the input data. The scores are sorted in ascending order. They represent the distribution or the input data, which may in turn represent the characteristics or the whole data. A new training dataset is obtained by eliminating unuseful data which are located in the region between an upper bound and a lower bound. The proposed method gives a better or at least similar performance compare to classification accuracy of previous approaches. Besides, it also gives several benefits : ratio reduction of class imbalance; size reduction of training sets; prevention of over-fitting. The proposed method has been tested with kNN classifier. An experimental result in ecoli data set shows that this method achieves the precision up to 2.27 times than the other methods.

• Smart Structures and Systems
• /
• v.17 no.3
• /
• pp.363-389
• /
• 2016

Deficient modes that cannot be always identified from different sets of measurement data may exist in the application of operational modal analysis such as the stochastic subspace identification techniques in large-scale civil structures. Based on a recent work using the long-term ambient vibration measurements from an instrumented cable-stayed bridge under different wind excitation conditions, a benchmark problem is launched by taking the same bridge as a test bed to further intensify the exploration of mode identifiability. For systematically assessing this benchmark problem, a recently developed SSI algorithm based on an alternative stabilization diagram and a hierarchical sifting process is extended and applied in this research to investigate several sets of known and blind monitoring data. The evaluation of delicately selected cases clearly distinguishes the effect of traffic excitation on the identifiability of the targeted deficient mode from the effect of wind excitation. An additional upper limit for the vertical acceleration amplitude at deck, mainly induced by the passing traffic, is subsequently suggested to supplement the previously determined lower limit for the wind speed. Careful inspection on the shape vector of the deficient mode under different excitation conditions leads to the postulation that this mode is actually induced by the motion of the central tower. The analysis incorporating the tower measurements solidly verifies this postulation by yielding the prevailing components at the tower locations in the extended mode shape vector. Moreover, it is also confirmed that this mode can be stably identified under all the circumstances with the addition of tower measurements. An important lesson learned from this discovery is that the problem of mode identifiability usually comes from the lack of proper measurements at the right locations.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.22 no.2
• /
• pp.45-54
• /
• 2018

The seismically isolated nuclear power plants shall be designed for design basis earthquake (DBE) and considered to ensure safety against beyond design basis earthquake (BDBE). In order to limit the excessive displacement of the seismic isolation system of the seismically isolated structure, the moat is installed at a certain distance from the upper mat supporting the superstructure. This certain distance is called clearance to stop (CS) and is calculated from the 90th percentile displacement of seismic isolation system subjected to BDBE. For design purposes, the CS can be obtained simply by multiplying the median displacement of the seismic isolation system against DBE by scale factor with a value of 3. The DBE and BDBE used in this study were generated by using 30 sets of artificial earthquakes corresponding to the nuclear standard design spectrum. In addition, latin hyper cube sampling was applied to generate 30 sets of artificial earthquakes corresponding to maximum - minimum spectra. For the DBE, the median displacement and the 99th percentile displacement of the seismic isolation system were calculated. For the BDBE, the suitability of the scale factor was assessed after calculating the 90th percentile displacement of the seismic isolation system.

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.39 no.4
• /
• pp.370-380
• /
• 2002

This paper proposes an ATR (Automatic Target Recognition) algorithm for identifying non-occluded and occluded military vehicles in natural FLIR (Forward Looking InfraRed) images. After segmenting a target, a radial function is defined from the target boundary to extract global shape features. Also, to extract local shape features of upper region of a target, a distance function is defined from boundary points and a line between two extreme points. From two functions and target contour, four global and four local shape features are proposed. They are much more invariant to translation, rotation and scale transform than traditional feature sets. In the experiments, we show that the proposed feature set is superior to the traditional feature sets with respect to the similarity-transform invariance and recognition performance.

• Geophysics and Geophysical Exploration
• /
• v.5 no.3
• /
• pp.169-177
• /
• 2002

We develop the weighted-averaging finite-element method which uses four kinds of element sets. By constructing global stiffness and mass matrices for four kinds of element sets and then averaging them with weighting coefficients, we obtain a new global stiffness and mass matrix. With the optimal weighting coefficients minimizing grid dispersion and grid anisotropy, we can reduce the number of grid points required per wavelength to 4 for a $1\%$ upper limit of error. We confirm the accuracy of our weighted-averaging finite-element method through accuracy analyses for a homogeneous and a horizontal-layer model. By synthetic data example, we reconfirm that our method is more efficient for simulating a geological model than previous finite-element methods.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.12 no.3
• /
• pp.202-209
• /
• 2002

This paper deals with simplification of classification rules for data mining and rule bases for control systems. Datamining that extracts useful information from such a large amount of data is one of important issues. There are various ways in classification methodologies for data mining such as the decision trees and neural networks, but the result should be explicit and understandable and the classification rules be short and clear. The rough sets theory is an effective technique in extracting knowledge from incomplete and inconsistent data and provides a good solution for classification and approximation by using various attributes effectively This paper investigates granularity of knowledge for reasoning of uncertain concopts by using rough set approximations and uses a hierarchical classification structure that is more effective technique for classification by applying core to upper level. The proposed classification methodology makes analysis of an information system eary and generates minimal classification rules.

• 한국해양학회지
• /
• v.22 no.1
• /
• pp.1-8
• /
• 1987

The Sinyangri Formation crops out in the vicinity of the Seongsan Peninsula, Cheju Island. Based on sedimentary structures, texture and composition, the lithologic sequence has been classified, in ascending stratigraphic order, into three lithofacies: parallel laminated sandstone facies (Facies I): conglomerate facies(Facies Il); and cross stratified sandstone facies (F acies Ill). Wedge-to-parallel, seaward-inclined in low angle less than 10$^{\circ}$lamina -sets with alternations of coarseand fine-grained sediments in the Facies I are the characteristic sedimentary structures in the foreshore depositional environment. Grains of this faciesare well sorted with good roundness compared with the other two facies, partly showing inverse graded bedding. Facies II,largely composed of claset-supported,very poorly-sorted conglomerates,does not pinch out but occurs continuously along the Sinyangri beach.Interstitial spaces between the clasts are mostly infilled with volcanic-ash and small amounts of well-rounded shell fragments.Maximum bed thickness as well as the size of imbedded basaltic clasts decreases to the south(toward Sinyangri). Large clasts with parallel lamination originated from the underlying Facies i,are generally elongated parallel to the bedding plane and display no systematic horizontal variations in size indicative of in-situ clasts.In view of the facts above it seems that large gravels from the basaltic rocks are transgressive lag conglomerates which are partly affected by the combination of longshore currents and propagating wave.Local occurrence of cross-strata dipping toward the south in the upper part of Facies IIreinforces the evidence of the action of longshore currents. Facies IIIis characterized by bidirectional trough cross-starifiction and wave ripples associated with the upper shoreface(surfzone) environments.In summary,the Sinyangri Formation represents the depositional environments of foreshore to upper shoreface truncated by disconformity between Facies Iand II.

• Physical Therapy Korea
• /
• v.27 no.1
• /
• pp.1-10
• /
• 2020

Background: Thoracic spine self-mobilization exercise is commonly used to manage patients with neck pain. However, no previous studies have investigated the effects of thoracic spine self-mobilization exercise alone in patients with chronic neck pain. Objects: The purpose of this study was to investigate the effects of thoracic self-mobilization using a tool on cervical range of motion (ROM), disability level, upper body posture, pain and fear-avoidance beliefs questionnaire (FABQ) in patients with chronic neck pain. Methods: The subjects were 49 patients (21 males, 28 females) with chronic neck pain. The subjects were randomly divided into an experimental group (EG, n = 23) and control group (CG, n = 26). For the EG, thoracic self-mobilization was applied. We placed a tool (made with 2 tennis balls) under 3 different vertebral levels (T1-4, T5-8, T9-12) of the thoracic spine and the subjects performed crunches, which included thoracic flexion and extension in supine position. Five times × 3 sets for each levels, twice a week, for 4 weeks. Cervical pain, disability, upper body posture, FABQ results, and ROM were evaluated at baseline, after 4 weeks of intervention, and at 8 weeks of follow-up. Assessments included the quadruple visual analogue scale (QVAS); Northwick Park neck pain questionnaire (NPQ); craniovertebral angles (CVA), forward shoulder angle (FSA) and kyphosis angle (KA) measurements for upper body posture; FABQ and cervical ROM testing. Results: The EG showed a statistically significant improvement after intervention in the QVAS (-51.16%); NPQ (-53.46%); flexion (20.95%), extension (25.32%), left rotation (14.04%), and right rotation (25.32%) in the ROM of the cervical joint; KA (-7.14%); CVA (9.82%); and FSA (-4.12%). Conclusion: These results suggest that, for patients with chronic neck pain, thoracic self-mobilization exercise using a tool (tennis balls) is effective to improve neck pain, disability level, the ROM, and upper body posture.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.15 no.7
• /
• pp.4290-4300
• /
• 2014

The previous HL7 interface should be developed as a separate package or conversion module for each version to process HL7 messages from different versions. This study designed and developed an HL7 parser compatible among different versions based on the requirements of compatibility defined in HL7 V2.5. According to the structure of the parser, the inheritance concept in object-oriented programming was adopted so that the class object of the HL7 message from the lower version could be inherited to the class object of the upper version. Therefore, every version's HL7 messages could be processed using only the upper class' object regardless of the version. To evaluate the compatibility of the developed parser, 700 data sets about inpatients with rheumatoid arthritis were used. The 700 cases underwent the compatibility test successfully. In the near future, further research on the Inter-compatibility HL7 parser is planned.

• The Research Journal of the Costume Culture
• /
• v.19 no.6
• /
• pp.1205-1220
• /
• 2011

The purpose of this study is to verify the change of body posture by putting on the late $19^{th}$ century English women's bodice or waistcoat. This study analyzed the female somatotype which puts on upper garments of Victorian era with using 3D body scan technology. Two sets of $19^{th}$ century women's bodice and waistcoat patterns were developed with the $19^{th}$ century model size and those patterns were used for making the experimental garments. The fit of experimental garments was evaluated by the degree of change with posture and waist measurements. Three women with the same waist girth measurements with the model size were participated to the fitting test. The postural change was measured from cross-sectional body diagrams. The result of this study showed that the waist measurement of the late $19^{th}$ century English women's bodice and waistcoat pattern was smaller than the waist girth measurement. These garments compressed the midriff of the body and it made women's distinct body silhouette. The waist girth measurement of 1876 bodice pattern was 9.2cm smaller than presented model size. The subjects' waist girth measurements were shortened by 5.0~6.1cm after wearing the 1876 bodice garment. The waist girth measurement of 1880 waistcoat pattern was 7.1cm smaller than presented model size. The subjects' waist girth measurements were shortened by 2.7~3.7cm after wearing the 1880 waistcoat garment. The back side parts of their waist were compressed and their postures were changed. The neck and shoulders were moved forward after wearing the experimental garments. These results showed that body posture could be changed to "S" shape silhouette as wearing the late $19^{th}$ century English women's bodice or waistcoat.