• The Korean Journal of Emergency Medical Services
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• v.19 no.3
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• pp.139-148
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• 2015

Purpose: This study aimed to compare the chest compression quality between compression-only cardiopulmonary resuscitation (CPR) and conventional CPR. Methods: This study involved 123 participants randomly assigned to either the chest compression-only CPR training and conventional CPR training. After training for 120 min, the participants performed CPR for 4 min and the CPR quality was evaluated. The primary outcome was evaluated as the mean compression depth, and the secondary outcome was calculated as the proportion of chest compressions with an appropriate depth among the total chest compressions. Results: The mean compression depth was more deeper in conventional CPR than in compression-only CPR (57mm vs. 53mm, p <.001). The proportion of appropriate chest compression depth was also more higher in conventional CPR (98.8% vs. 68.6%, p <.001). As compared with every minute over time for a total of 4 min, the mean compression depth and the proportion of appropriate chest compression depth were deeper and higher after 1 min in conventional CPR than in compression-only CPR. Conclusion: The results suggested that conventional CPR is a better method than compression-only CPR in terms of chest compression quality.

• Proceedings of the Korean Geotechical Society Conference
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• 2002.10a
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• pp.577-584
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• 2002

We have employed two methods to remove slime at the end of the sampler in clay layers. The first method is a sampling process that harnesses low pressure to clean up the ground around the sampler tip. The second method, in consideration of a disturbed layer, involves a technique of inserting the sampler 50 cm deep into the ground before cleaning up the verge of the sampler by using high pressure. Physical and mechanical properties of these two methods have been compared and analyzed to investigate how different sampling methods affect degree of disturbance. The first method shows little disturbance since the unconfined compression test results in quite greater E$\_$50//q$\_$u/ in the first method than in the second method. On the other hand, the consolidation test results in a slightly greater compression index in the second method than in the first method, when their indexes are compared in the same depth. This suggests that the second method demonstrates less disturbance than the first method does. It is assumed that the second method may reduce disturbance slightly, However, we suspect that choosing any of the two methods would not obtain a considerable difference in sampling.

• Journal of the Korean Society for Precision Engineering
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• v.25 no.7
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• pp.72-78
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• 2008

The line-of-sight(LOS) stabilization system is a precision electro-mechanical gimbals assembly for suppressing vibration due to its environment and tracking the target in a desired direction. This paper describes the design of gimbals system to reject the disturbance and to improve stabilization. The controller consists of a DSP with transducer and actuator interfaces. Unknown parameters of the gimbals are estimated by the signal compression method. The cross-correlation coefficient between the impulse response from the assumed model and the one from model of the gimbals is used to obtain the better estimation. The quasi-impulse response through linear element included in the gimbals could be obtained by the signal compression method. The unknown parameter of the linear element could be estimated as comparing the bode plots for impulse response from gimbals with them from model's response.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.30 no.9 s.252
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• pp.1049-1061
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• 2006

In the study, the flow stress of material and friction condition were determined by using the cylinder compression test and numerical method. We proposed the flow stress equation including the initial yield strength to predict it from the upper bound method. The upper bound technique uses the velocity field which includes two unknowns to effectively express bulging. Also, inverse engineering technique uses the object function to minimize area enclosed by load-stroke curve. The friction factor is determined from the radius of curvature of the barrel by cylinder compression test. Flow stress and initial yield strength predicted from the above techniques are verified through the finite element simulation.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.1
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• pp.59-64
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• 2012

This paper addresses a blind estimation and classification algorithm of the speech compression methods by using analysis on the structure of compressed bitstreams. Various speech compression methods including vocoders are developed in order to transmit or store the speech signals at very low bitrates. As a key feature, the vocoders contain the block structure inevitably. In classification of each compression method, we use the Measure of Inter-Block Correlation (MIBC) to check whether the bitstream includes the block structure or not, and to estimate the block length. Moreover, for the compression methods with the same block length, the proposed algorithm estimates the corresponding compression method correctly by using that each compression method has different correlation characteristics in each bit location. Experimental results indicate that the proposed algorithm classifies the speech compression methods robustly for various types and lengths of speech signals in noisy environment.

• The Journal of the Korea Contents Association
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• v.18 no.3
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• pp.299-308
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• 2018

This study focused on the fact that medical images that are issued at different hospitals may affect image quality on PACS when different software is used. A university hospital image was copied to the DICOM file and registered on the PACS of the university hospital B. The capacity and image quality of the software used in the university hospital were evaluated by SNR, CNR and histogram. As the compression ratio increased, SNR and CNR tended to decrease. Note that Lossless Compression decreased the data size by half compared to No Compression, but SNR and CNR did not change. As a result of the histogram analysis, the information loss due to the underflow phenomenon was conspicuous. When moving to another hospital, No compression or lossless compression method should be used. In conclusion, it is useful to use the lossless compression method, considering waiting time and economic efficiency in uploading.

• Journal of Broadcast Engineering
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• v.13 no.1
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• pp.109-118
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• 2008

In mapping a texture image into a 3D mesh model for photo-realistic graphic applications, the compression of texture image is as important as geometry of 3D mesh. Typically, the size of the (compressed) texture image of 3D model is comparable to that of the (compressed) 3D mesh geometry. Most 3D model compression techniques are to compress the 3D mesh geometry, rather than to compress the texture image. Well-known image compression standards (i.e., JPEG) have been extensively used for texture image compression. However, such techniques are not so efficient when it comes to compress an image with texture patches, since the patches are little correlated. In this paper, we proposed a preprocessing method to substantially improve the compression efficiency of texture compression. From the experimental results, the proposed method was shown to be efficient in compression with a bit-saving from 23% to 45%.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.10C
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• pp.961-967
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• 2009

In this paper, the lossless compression method is proposed for an 8-bit bitplane of the input image. The lower bitplanes are not well compressed because of irregularity of pixels. To overcome these drawbacks, this paper propose a mixed coding method that using the block-based lossless compression and the bit-based losselss compression, introducing the H. 264 and the JBIG. First, to take advantage of the characteristics of the bitplanes, 8-bitplane against the top 4 bits and lower 4 bits were separated. Next, the JBIG compression method was used in separated top 4-bitplane because of a lot of correlation between bits. And a separated lower 4-bitplane was applied the improved method that using the H. 264 lossless prediction. A pre-processing method applied to the lower 4-bitplane then irregular distribution of pixel values are converted to regular. Using the proposed method to test for various test images were performed. Experimental results from a printer using 8-bit image compared to JBIG average 19%, lower 4bit image compression performance with an average of 11% could be obtained.

• Journal of the Korea Society for Simulation
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• v.18 no.2
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• pp.9-17
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• 2009

A face database has contained a large amount of facial information data since face recognition was widely used. With the increase of facial information data, the face recognition based on distributed processing method has been noticed as a major topic. In existing studies, there were lack of discussion about the transferring method for large data. So, we proposed a fuzzy logic-based bit compression rate selection method for distributed face recognition. The proposed method selects an effective bit compression rate by fuzzy inference based on face recognition rate, processing time for recognition, and transferred bit length. And, we compared the facial recognition rate and the recognition time of the proposed method to those of facial information data with no compression and fixed bit compression rates. Experimental results demonstrates that the proposed method can reduce processing time for face recognition with a reasonable recognition rate.

• Journal of the Korean Geotechnical Society
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• v.26 no.9
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• pp.25-35
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• 2010

Settlement at reclamation area caused by secondary compression should be considered using spatial evaluating method because the thickness of consolidation layer varies at every location. Probabilistic method can be implemented to evaluate uncertainty of spatial distribution of secondary compression. This study spatially evaluated mean and standard deviation of secondary compression in the overall analyzing region using spatial distribution of consolidation thickness estimated by ordinary kriging method and statistical values of soil properties. And then, the area where secondary compression exceeds a design criterion at the specific time was evaluated using probabilistic method. It was observed that the area exceeding the design criterion increased as the variability of $C_{\alpha}/(1+e_o)$ increased or the probabilistic design criterion 0: decreased. It is considered that the probabilistic method can be used for the geotechnical design of soft ground when a probabilistic design criterion is established in the specification.