• Journal of the Korea Concrete Institute
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• v.12 no.2
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• pp.21-30
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• 2000

In the Ultimate Strength Design, the design strength of a member is determined by multiplying the strength reduction factor to the nominal strength. This concept may be a reasonable approach, however it can not consider failure modes appropriately. Moreover, column design strength diagram show an abrupt change at a low level of axial load, which does not seem to be reasonable. This research compares the design strength determined by the strength resistance factors. As the material resistance factors for flexure and compression, 0.65 and 0.90 are proposed for concrete and steel, respectively. The design strength calculation process by applying material resistance factors addresses failure modes more effectively than by applying member strength reduction factor, and provides more resnable design strength for reinforced concrete flexural and compression members.

• Journal of the Korean Society for Precision Engineering
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• v.26 no.8
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• pp.142-147
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• 2009

Spinal fixation systems provide surgical versatility, but the complexity of their design reduces their strength and fatigue resistance. There is no published data on the mechanical properties of such screws. Screws were assembled according to a vertebrectomy model for destructive mechanical testing. A group of two assemblies was tested in static compression. One group was applied to surface a grit blasting method and another group was applied to surface a bead blasting method. Modes of failure, yield, and ultimate strength, yield stiffness, and cycles to failure were determined for six assembles. Static compression 2% offset yield load ranges was from 327 to 419N. Fatigue loads were determined two levels, 37.5% and 50% of the average load from static compression ultimate load. An assembly of bead blasting treatment only achieved 5 million cycles at 37.5% level in compression bending.

• 한국가스학회:학술대회논문집
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• 1998.09a
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• pp.255-260
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• 1998

This study describes the results of Coefficient Of Performance(COP) analysis by cycle simulation for two types of absorption-compression hybride cycle using the water/Lithium Bromide solution pair, These types are basic hybride systems introducing a mechanical compression process into the refrigerant vapor phase of the single effect absorption cycle. In absorption-compression hybrid cycles, coefficient of performance is improved compared with absorption cycle. Hybride cycle Type ll is considered as a key technology to support energy utilization system, given its capability of utilizing waste heat to drive system with a high level of efficiency.

• Korean Journal of Computational Design and Engineering
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• v.12 no.2
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• pp.109-117
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• 2007

Three-dimensional mesh models have been widely used in various applications such as simulations, animations, and e-catalogs. In such applications the normal vectors of mesh models are used mainly for shading and take up the major portion of data size and transmission time paper over networks. Therefore a variety of techniques have been developed to compress them efficiently. In this paper, we propose the MOEC (Modified Octree Encoding Compression) algorithm, which allow multi lever compression ratios for 3D mesh models. In the algorithm, a modified octree has nodes representing their own positions and supporting a depth of the tree so that the normal vectors are compressed up to levels where the shading is visually indistinguishable. This approach provides efficient in compressing normals with multi-level ratios, without additional encoding when changing in compression ratio is required.

• Proceedings of the KOSOMBE Conference
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• v.1996 no.11
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• pp.293-296
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• 1996

In this paper, we studied two image characteristics, similarity and smoothness, which give rise to local and global redundancy in image representation. The similarty means that any patterns in the image repeat itself anywhere in the rest of image. The smoothness means that the gray level values within a given block vary gradually rather than abruptly. In this sense, we propose a lossless medical image compression scheme which exploits both types of redundancy. This method segments the image into variable size blocks and encodes them depending on characteristics of the block. The proposed compression schemes works better than other compression schemes such as the huffman, the arithmetic, the Lempel-Ziv and the lossless scheme of JPEG.

• Korean Journal of Agricultural Science
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• v.23 no.2
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• pp.233-241
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• 1996

The mechanical properties of biological materials depend on numerous factors. The majority of these relationships are still unknown today, especially with regard to their quantitative characteristics. The reason is that biological materials constitute biomechanical systems of very complex construction, whose behavior cannot be characterized by simple physical constants, as for example can that of engineering materials. The objectives of this investigation were to determine the compression creep and recovery properties of rice stalks at various levels of applied load The compression creep and recovery behavior of the rice stalk could be predicted precisely by rheological model which approached closely to the measured values. But the coefficients of the Burgers recovery model were different from those of the creep model. The Steady state creep behavior occurred at the higher level of force and the logarithmic creep behavior occurred at the lower level of force. The mechanical model being expected the creep behavior in relation with the level of applied load, which was well explained that the rice stalk might be visco-elastic material.

• Journal of Korean Neurosurgical Society
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• v.42 no.4
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• pp.271-275
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• 2007

Objective : Although a significant correction of local kyphosis has been reported previously, only a few studies have investigated whether this correction leads to an improved overall sagittal alignment. The study objective was to determine whether an improvement in the local kyphotic angle improves the overall sagittal alignment. We examined and compared the effects of thoracic and lumbar level kyphoplasty procedures on local versus overall sagittal alignment of the spine. Methods : Thirty-eight patients with osteoporotic vertebral compression fractures who showed poor response to conventional, palliative medical therapy underwent single-level kyphoplasty. The pertinent clinical data of these patients, from June 2006 to November 2006, were reviewed retrospectively. We measured preoperative and postoperative vertebral body heights, which were classified as anterior, middle, or posterior fractured vertebral body heights. Furthermore, the local and overall sagittal angles after polymethylmethacrylate deposition were measured. Results : More height was gained at the thoracic level, and the middle vertebral height regained the most. A significant local kyphosis correction was observed at the fractured level, and the correction at larger spanning segments decreased with the distance from the fractured level. Conclusion : The inflatable balloon kyphoplasty procedure was the most effective in regaining the height of the thoracic fractured vertebra in the middle vertebral body. The kyphosis correction by kyphoplasty was mainly achieved in the fractured vertebral body. Sagittal angular correction decreased with an increase in the distance from the fractured vertebra. No significant improvement was observed in the overall sagittal alignment after kyphoplasty. Further studies in a larger population are required to clarify this issue.

• Fashion & Textile Research Journal
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• v.18 no.5
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• pp.716-723
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• 2016

The purpose of this study was to investigate the change in blood velocity(mm/sec) when compression and/or heat were applied to the knee joint for the elderly who has both normal and painful legs with osteoarthritis(OA). Experimental compression knee band was prepared from the 3D knee data of the average women in 60's. 3D replica of knee was reduced by 7, 10, and 13% from the nude pattern in course direction. Clothing pressure was measured at the front and back of each healthy and painful knee of elderly women for one minute while standing and sitting on the chair. Blood velocity was measured at 13 cm upper from the mid-patella for 15 minutes. Results are as follows: first, compression or heating treatment itself did not change blood velocity of both legs; second, combination treatment with heating and compression was effective to increase blood velocity. In details, for healthy legs, combination treatments with compression by 10% reduced pattern(about 1.3kPa) and heating($43^{\circ}C$) induced the maximal blood velocity, however, for knees with OA, 7% reduced pattern(about 1.0kPa) with simultaneous heating($43^{\circ}C$) was more effective than other cases. These results indicated that pain and spasticity of knee joint with OA could be reduced by applying heat and compression therapy, where the compression level of painful knee should be slightly lower than of healthy leg.

• Journal of the Korean Society of Radiology
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• v.2 no.2
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• pp.11-16
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• 2008

The most difficult of implementation PACS is large amount of data. Therefore, PACS needs mass storage, as well as rapid transmission time. Consequently, medical images needs compression when stored in PACS. WT(wavelet transform) was announced by Ingrid Daubechies and Stephane Mallat, WT was methods of signal analysis by a base functions set same as Fourie transform. This paper estimated an efficiency, that experimental medical images compressed by DWT. The result of estimated, we are knows effectiveness that display to remained signal in low frequency region after 4-level DWT form $512{\times}512{\times}2^8$ input images. Compression ratio of images by 4-level DWT was 1:16. It is a high compression ratio, the other side has a problem appears on staircase phenomenon.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.49 no.1
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• pp.23-28
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• 2012

The performance improvement of the secondary storage is very slow compared to the main memory and processor. The data is loaded from secondary storage to memory for the execution of an application. At this time, there is a bottleneck. In this paper, we propose an Executable Compression Method to speed up the initial loading time of application. and we examined the performance. So we implemented the two applications. The one is a compressor for Execution Binary File. and The other is a decoder of Executable Compressed application file on the Embedded System. Using the test binary files, we performed the speed test in the six files. At the result, one result showed that the performance was decreased. but others had a increased performance. the average increasing rate was almost 29% at the initial loading time. The level of compression had different characteristics of the file. And the performance level was dependent on the file compressed size and uncompress time. so the optimized compression algorithm will be needed to apply the execution binary file.